权利要求：
1. A light comprising:
a housing;
a rotatable selector disposed in an opening in said housing and both rotatably and axially movable in the opening in said housing, said rotatable selector including a member rotatable therewith for providing an indication of the rotational position of said rotatable selector;
wherein one of said housing and said rotatable selector has a projection that engages one or more recesses in the other of said housing and said rotatable selector when said rotatable selector is in an axial position proximate said housing, and wherein the projection does not engage the one or more recesses when said rotatable selector is in an axial position distal said housing; and
a spring biasing said rotatable selector axially towards said housing,
wherein said rotatable selector must be pulled away from said housing against the bias of said spring to disengage the projection from the one or more recesses and to rotate said rotatable selector.
2. The light of claim 1 further comprising:
a light source disposed in said housing; and
an electrical circuit responsive to the indication of the rotational position of said rotatable selector for selecting an operating condition for said light source.
3. The light of claim 2:
wherein the member of said rotatable selector includes an opaque baffle and wherein said electrical circuit is responsive to optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the opaque baffle for selecting the operating condition for said light source; or
wherein the member of said rotatable selector includes an optically reflective member and wherein said electrical circuit is responsive to reflected optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the optically reflective member for selecting the operating condition for said light source; or
wherein the member of said rotatable selector includes a switch actuator and wherein said electrical circuit includes a switch responsive to said switch actuator for selecting the operating condition for said light source; or
wherein the member of said rotatable selector includes a magnet and wherein said electrical circuit is responsive to said magnet for selecting the operating condition for said light source.
4. A light comprising:
a housing;
a rotatable selector disposed in an opening in said housing and both rotatably and axially movable therein, said rotatable selector including a member rotatable therewith for providing an indication of the rotational position of said rotatable selector;
wherein one of said housing and said rotatable selector has a projection that engages one or more recesses in the other of said housing and said rotatable selector when said rotatable selector is in an axial position proximate said housing, and wherein the projection does not engage the one or more recesses when said rotatable selector is in an axial position distal said housing;
a spring biasing said rotatable selector axially towards said housing,
wherein said rotatable selector must be pulled away from said housing against the bias of said spring to disengage the projection from the one or more recesses and to rotate said rotatable selector;
a light source disposed in said housing; and
an electrical circuit responsive to the indication of the rotational position of said rotatable selector for selecting an operating condition for said light source; and
wherein:
the member of said rotatable selector includes an opaque baffle and said electrical circuit is responsive to optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the opaque baffle for selecting the operating condition for said light source, wherein the opaque baffle includes a projection defining a portion of an axial cylinder that rotates with said rotatable selector to interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member of said rotatable selector includes an optically reflective member and said electrical circuit is responsive to reflected optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the optically reflective member for selecting the operating condition for said light source, wherein the optically reflective member includes a pattern defining areas of different reflectivity that rotates with said rotatable selector to interrupt and/or to partially interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member of said rotatable selector includes a switch actuator and said electrical circuit includes a switch responsive to said switch actuator for selecting the operating condition for said light source; or
the member of said rotatable selector includes a magnet and said electrical circuit is responsive to said magnet for selecting the operating condition for said light source, wherein said electrical circuit includes a switch, a reed switch and/or a Hall-effect device that is responsive to said magnet.
5. The light of claim 2 wherein said electrical circuit is responsive to an electrical switch for selectively applying electrical power to energize said light source in the operating condition selected by said rotatable selector, and wherein the electrical switch comprises a pushbutton movable in the axial direction of said rotatable selector.
6. The light of claim 2 further comprising an electrical switch coaxial with said rotatable selector and having a pushbutton movable in the axial direction of said rotatable selector, wherein said electrical switch selectively energizes said light source in the operating condition selected by said rotatable selector.
7. The light of claim 1 wherein the projection and the one or more recesses are separated by a clearance sufficient not to bind in the presence of sand.
8. The light of claim 1 further comprising an electrical switch substantially coaxial with said rotatable selector and having a pushbutton movable in the axial direction of said rotatable selector.
9. A selector comprising:
a housing;
a rotatable selector disposed in an opening in said housing and both rotatable and axially movable, in the opening in said housing, said rotatable selector including a member rotatable therewith for providing an indication of the rotational position of said rotatable selector;
wherein one of said housing and said rotatable selector has a projection that engages one or more recesses in the other of said housing and said rotatable selector when said rotatable selector is in an axial position proximate said housing, and wherein the projection does not engage the one or more recesses when said rotatable selector is in an axial position distal said housing; and
a spring biasing said rotatable selector axially towards said housing,
wherein said rotatable selector must be pulled away from said housing against the bias of said spring to disengage the projection from the one or more recesses and to rotate said rotatable selector.
10. The selector of claim 9 further comprising:
an operatable device;
an electrical circuit responsive to the indication of the rotational position of said rotatable selector for selecting an operating condition for said operatable device.
11. The selector of claim 10:
wherein the member of said rotatable selector includes an opaque baffle and wherein said electrical circuit is responsive to optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the opaque baffle for selecting the operating condition for said operatable device; or
wherein the member of said rotatable selector includes an optically reflective member and wherein said electrical circuit is responsive to reflected optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the optically reflective member for selecting the operating condition for said operatable device; or
wherein the member of said rotatable selector includes a switch actuator and wherein said electrical circuit includes a switch responsive to said switch actuator for selecting the operating condition for said operatable device; or
wherein the member of said rotatable selector includes a magnet and wherein said electrical circuit is responsive to said magnet for selecting the operating condition for said operatable device.
12. A selector comprising:
a housing;
a rotatable selector disposed in an opening in said housing and both rotatable and axially movable therein, said rotatable selector including a member rotatable therewith for providing an indication of the rotational position of said rotatable selector;
wherein one of said housing and said rotatable selector has a projection that engages one or more recesses in the other of said housing and said rotatable selector when said rotatable selector is in an axial position proximate said housing, and wherein the projection does not engage the one or more recesses when said rotatable selector is in an axial position distal said housing;
a spring biasing said rotatable selector axially towards said housing,
wherein said rotatable selector must be pulled away from said housing against the bias of said spring to disengage the projection from the one or more recesses and to rotate said rotatable selector;
an operatable device; and
an electrical circuit responsive to the indication of the rotational position of said rotatable selector for selecting an operating condition for said operatable device; and wherein;
the member of said rotatable selector includes an opaque baffle and said electrical circuit is responsive to optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the opaque baffle for selecting the operating condition for said operatable device, wherein the opaque baffle includes a projection defining a portion of an axial cylinder that rotates with said rotatable selector to interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member of said rotatable selector includes an optically reflective member and said electrical circuit is responsive to reflected optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the optically reflective member for selecting the operating condition for said operatable device, wherein the optically reflective member includes a pattern defining areas of different reflectivity that rotates with said rotatable selector to interrupt and/or to partially interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member of said rotatable selector includes a switch actuator and said electrical circuit includes a switch responsive to said switch actuator for selecting the operating condition for said operatable device; or
the member of said rotatable selector includes a magnet and said electrical circuit is responsive to said magnet for selecting the operating condition for said operatable device, wherein said electrical circuit includes a switch, a reed switch and/or a Hall-effect device that is responsive to said magnet.
13. The selector of claim 10 wherein said electrical circuit is responsive to an electrical switch for selectively applying electrical power to energize said operatable device in the operating condition selected by said rotatable selector, and wherein the electrical switch comprises a pushbutton movable in the axial direction of said rotatable selector.
14. The selector of claim 10 further comprising an electrical switch coaxial with said rotatable selector and having a pushbutton movable in the axial direction of said rotatable selector, wherein said electrical switch selectively energizes said operatable device in the operating condition selected by said rotatable selector.
15. The selector of claim 9 wherein the projection and the one or more recesses are separated by a clearance sufficient not to bind in the presence of sand.
16. The selector of claim 9 further comprising an electrical switch substantially coaxial with said rotatable selector and having a pushbutton movable in the axial direction of said rotatable selector.
17. A light comprising:
a plurality of light sources;
a photo-transmitter and a photo-receiver positioned for optical communication therebetween;
a selector having a member movable for interrupting optical communication between the photo-transmitter and the photo-receiver;
a circuit responsive to optical communication between the photo-transmitter and the photo-receiver and to interruption thereof by the member for selecting one or ones of said plurality of light sources and responsive for selectively applying electrical power to the selected one or ones of said plurality of light sources.
18. The light of claim 17 wherein said selector is rotatable about an axis and wherein:
the member includes a projection defining a portion of an axial cylinder that rotates with said selector to interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member includes a pattern defining areas of different reflectivity that rotates with said selector to interrupt and/or to partially interrupt optical communication between the photo-transmitter and the photo-receiver.
19. The light of claim 17 wherein said selector is rotatable about an axis and has at least two detent positions, and wherein the member interrupts optical communication between the photo-transmitter and the photo-receiver in one detent position and allows optical communication between the photo-transmitter and the photo-receiver in another detent position.
20. The light of claim 17 wherein said circuit is responsive to an electrical switch for selectively applying electrical power to the selected one or ones of said plurality of light sources.
21. The light of claim 20 wherein said selector is rotatable about an axis and wherein the electrical switch comprises a pushbutton movable axially along the axis.
22. The light of claim 17 wherein said circuit includes a processor responsive to optical communication between the photo-transmitter and the photo-receiver and interruption thereof and to an electrical switch for selecting and applying electrical power to one or ones of said plurality of light sources.
23. The light of claim 22 wherein said processor is responsive to said electrical switch for applying electrical power to operate a selected one or ones of said light sources in a momentary ON condition, a continuous ON condition, an OFF condition, a blinking condition, a flashing condition, a dimming condition, a dimmed condition, or any combination of the foregoing conditions.
24. The light of claim 17 wherein said photo-transmitter and said photo-receiver positioned for optical communication therebetween comprises:
first and second pairs of a photo-transmitter and a photo-receiver, wherein the photo-transmitter and the photo-receiver of the first pair are positioned for optical communication with each other independently of the photo-transmitter and the photo-receiver of the second pair, and wherein the photo-transmitter and the photo-receiver of the second pair are positioned for optical communication with each other independently of the photo-transmitter and the photo-receiver of the first pair.
25. The light of claim 24 wherein said member baffles about 180° of rotation of said selector and wherein said first and second pairs are disposed about 90° of rotation apart, thereby defining conditions wherein:
(1) optical communication of said first pair and of said second pair are both not interrupted,
(2) optical communication of said first pair is interrupted and optical communication of said second pair is not interrupted,
(3) optical communication of said first pair and of said second pair are both interrupted, and
(4) optical communication of said first pair is not interrupted and optical communication of said second pair is interrupted.
26. The light of claim 17 wherein said member comprises a pattern of areas having different optical reflectivity in positions corresponding to different positions of rotation of said selector, thereby defining conditions wherein:
(1) optical communication between said photo-transmitter and said photo-receiver is interrupted,
(2) optical communication between said photo-transmitter and said photo-receiver is not interrupted,
(3) optical communication between said photo-transmitter and said photo-receiver is interrupted to a relatively greater degree, and
(4) optical communication between said photo-transmitter and said photo-receiver is interrupted to a relatively lesser degree.
27. A selector comprising:
a selector housing having an opening therein;
a rotatable selector disposed in the opening in said selector housing, wherein said rotatable selector is rotatable in the opening relative to the selector housing and is movable axially in the opening relative to the selector housing, said rotatable selector including a member rotatable therewith for providing an indication of the rotational position of said rotatable selector in the opening of said selector housing;
wherein one of said selector housing and said rotatable selector has one or more projections that engage one or more recesses in the other of said selector housing and said rotatable selector when said rotatable selector is in an axial position proximate said selector housing, and wherein the one or more projections do not engage the one or more recesses when said rotatable selector is in an axial position distal said selector housing; and
a spring bearing on said selector housing and said rotatable selector for biasing said rotatable selector axially towards said selector housing,
an electrical switch that is coaxial with said rotatable selector and having a pushbutton and actuator movable in said rotatable selector in the axial direction thereof;
wherein said rotatable selector must be pulled away from said selector housing against the bias of said spring to disengage the one or more projections from the one or more recesses and to rotate said rotatable selector relative to said selector housing.
28. The selector of claim 27 further comprising:
an operatable device;
an electrical circuit responsive to the indication of the rotational position of said rotatable selector for selecting an operating condition for said operatable device.
29. The selector of claim 28:
wherein the member of said rotatable selector includes an opaque baffle and wherein said electrical circuit is responsive to optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the opaque baffle for selecting the operating condition for said operatable device; or
wherein the member of said rotatable selector includes an optically reflective member and wherein said electrical circuit is responsive to reflected optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the optically reflective member for selecting the operating condition for said operatable device; or
wherein the member of said rotatable selector includes a switch actuator and wherein said electrical circuit includes a switch responsive to said switch actuator for selecting the operating condition for said operatable device; or
wherein the member of said rotatable selector includes a magnet and wherein said electrical circuit is responsive to said magnet for selecting the operating condition for said operatable device.
30. A selector comprising:
a selector housing having an opening therein;
a rotatable selector disposed in the opening in said selector housing, wherein said rotatable selector is rotatable in the opening relative to the selector housing and is movable axially in the opening relative to the selector housing, said rotatable selector including a member rotatable therewith for providing an indication of the rotational position of said rotatable selector in the opening of said selector housing;
wherein one of said selector housing and said rotatable selector has one or more projections that engage one or more recesses in the other of said selector housing and said rotatable selector when said rotatable selector is in an axial position proximate said selector housing, and wherein the one or more projections do not engage the one or more recesses when said rotatable selector is in an axial position distal said selector housing;
a spring bearing on said selector housing and said rotatable selector for biasing said rotatable selector axially towards said selector housing,
an electrical switch that is coaxial with said rotatable selector and having a pushbutton and actuator movable in said rotatable selector in the axial direction thereof;
wherein said rotatable selector must be pulled away from said selector housing against the bias of said spring to disengage the one or more projections from the one or more recesses and to rotate said rotatable selector relative to said selector housing;
an operatable device; and
an electrical circuit responsive to the indication of the rotational position of said rotatable selector for selecting an operating condition for said operatable device; and wherein;
the member of said rotatable selector includes an opaque baffle and said electrical circuit is responsive to optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the opaque baffle for selecting the operating condition for said operatable device, wherein the opaque baffle includes a projection defining a portion of an axial cylinder that rotates with said rotatable selector to interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member of said rotatable selector includes an optically reflective member and said electrical circuit is responsive to reflected optical communication between a photo-transmitter and a photo-receiver and to interruption thereof by the optically reflective member for selecting the operating condition for said operatable device, wherein the optically reflective member includes a pattern defining areas of different reflectivity that rotates with said rotatable selector to interrupt and/or to partially interrupt optical communication between the photo-transmitter and the photo-receiver; or
the member of said rotatable selector includes a switch actuator and said electrical circuit includes a switch responsive to said switch actuator for selecting the operating condition for said operatable device; or
the member of said rotatable selector includes a magnet and said electrical circuit is responsive to said magnet for selecting the operating condition for said operatable device, wherein said electrical circuit includes a switch, a reed switch and/or a Hall-effect device that is responsive to said magnet.
31. The selector of claim 28 wherein said electrical circuit is responsive to an electrical switch for selectively applying electrical power to energize said operatable device in the operating condition selected by said rotatable selector, and wherein the electrical switch comprises a pushbutton movable in the axial direction of said rotatable selector.
32. The selector of claim 28 further comprising an electrical switch coaxial with said rotatable selector and having a pushbutton movable in the axial direction of said rotatable selector, wherein said electrical switch selectively energizes said operatable device in the operating condition selected by said rotatable selector.
33. The selector of claim 27 wherein the projection and the one or more recesses are separated by a clearance sufficient not to bind in the presence of sand.
34. A light comprising:
a plurality of light sources;
at least one photo-transmitter and at least one photo-receiver positioned for optical communication therebetween;
a selector having a selector ring rotatable about an axis and having a member rotatable therewith for interrupting optical communication between the at least one photo-transmitter and the at least one photo-receiver, said rotatable selector ring having at least two detent positions;
an electrical switch actuatable by a pushbutton disposed in said selector ring and movable axially therein; and
a circuit responsive to optical communication between the photo-transmitter and the photo-receiver and to interruption thereof by the member for selecting one or ones of said plurality of light sources and responsive for selectively applying electrical power to the selected one or ones of said plurality of light sources.
35. The light of claim 34 wherein:
the member includes a projection defining a portion of an axial cylinder that rotates with said selector ring to interrupt optical communication between the at least one photo-transmitter and at least one photo-receiver; or
the member includes a pattern defining areas of different reflectivity that rotates with said selector ring to interrupt and/or to partially interrupt optical communication between the at least one photo-transmitter and the at least one photo-receiver.
36. The light of claim 34 wherein the member interrupts optical communication between the at least one photo-transmitter and the at least one photo-receiver in one detent position and allows optical communication between the at least one photo-transmitter and the at least one photo-receiver in another detent position.
37. The light of claim 34 wherein said circuit is responsive to an electrical switch for selectively applying electrical power to the selected one or ones of said plurality of light sources.
38. The light of claim 37 wherein said electrical switch is located proximate the axis of said selector, and wherein said pushbutton comprises an actuator pin movable axially along the axis and an actuator button adjacent said actuator pin.
39. The light of claim 34 wherein said circuit includes a processor responsive to optical communication between the photo-transmitter and the photo-receiver and interruption thereof and to an electrical switch for selecting and applying electrical power to one or ones of said plurality of light sources.
40. The light of claim 39 wherein said processor is responsive to said electrical switch for applying electrical power to operate a selected one or ones of said light sources in a momentary ON condition, a continuous ON condition, an OFF condition, a blinking condition, a flashing condition, a dimming condition, a dimmed condition, or any combination of the foregoing conditions.
41. The light of claim 37 wherein said at least one photo-transmitter and at least one photo-receiver positioned for optical communication therebetween comprises:
first and second pairs of a photo-transmitter and a photo-receiver, wherein the photo-transmitter and the photo-receiver of the first pair are positioned for optical communication with each other independently of the photo-transmitter and the photo-receiver of the second pair, and wherein the photo-transmitter and the photo-receiver of the second pair are positioned for optical communication with each other independently of the photo-transmitter and the photo-receiver of the first pair.
42. The light of claim 41 wherein said member baffles about 180° of rotation of said selector and wherein said first and second pairs are disposed about 90° of rotation apart, thereby defining four conditions wherein:
(1) optical communication of said first pair and of said second pair are both not interrupted,
(2) optical communication of said first pair is interrupted and optical communication of said second pair is not interrupted,
(3) optical communication of said first pair and of said second pair are both interrupted, and
(4) optical communication of said first pair is not interrupted and optical communication of said second pair is interrupted.
43. The light of claim 34 wherein said member comprises a pattern of areas having different optical reflectivity in positions corresponding to different positions of rotation of said selector ring, thereby defining conditions wherein:
(1) optical communication between said at least one photo-transmitter and said at least one photo-receiver is not interrupted,
(2) optical communication between said at least one photo-transmitter and said at least one photo-receiver is substantially fully interrupted,
(3) optical communication between said at least one photo-transmitter and said at least one photo-receiver is interrupted to a relatively greater degree, and
(4) optical communication between said at least one photo-transmitter and said at least one photo-receiver is interrupted to a relatively lesser degree.
44. A light comprising:
a plurality of light emitting diode light sources;
first and second pairs each including a respective photo-transmitter and a photo-receiver positioned for optical communication therebetween;
a selector having a selector ring rotatable about an axis and having a baffle rotatable therewith to interrupt optical communication between the respective photo-transmitter and photo-receiver of each of said first and second pairs of a photo-transmitter and a photo-receiver, said rotatable selector ring having at least two detent positions;
an electrical switch actuatable by a pushbutton disposed in said selector ring and movable axially therein; and
a circuit responsive to optical communication between the respective photo-transmitter and photo-receiver of each of said first and second pairs and to interruption thereof by the baffle for selecting one or ones of said plurality of light emitting diode light sources and responsive to said electrical switch for selectively applying electrical power to the selected one or ones of said plurality of light emitting diode light sources.
45. The light of claim 44 wherein the baffle includes a projection defining a portion of an axial cylinder that rotates with said selector ring to interrupt optical communication between the photo-transmitter and the photo-receiver of each of said first and second pairs.
46. The light of claim 44 wherein the baffle interrupts optical communication between the photo-transmitter and the photo-receiver of said first pair in a first detent position and allows optical communication between the photo-transmitter and the photo-receiver of said first pair in a second detent position.
47. The light of claim 46 wherein the baffle interrupts optical communication between the photo-transmitter and the photo-receiver of said second pair in a third detent position and allows optical communication between the photo-transmitter and the photo-receiver of said second pair in the second detent position.
48. The light of claim 44 wherein said electrical switch is located proximate the axis of said selector, and wherein said pushbutton comprises an actuator pin movable axially along the axis and an actuator button adjacent said actuator pin.
49. The light of claim 44 wherein said circuit includes a processor responsive to optical communication between the photo-transmitter and the photo-receiver of each of said first and second pairs and to interruption thereof and to the electrical switch for selecting and applying electrical power to one or ones of said plurality of light emitting diode light sources.
50. The light of claim 49 wherein said processor is responsive to said electrical switch for applying electrical power to operate a selected one or ones of said light emitting diode light sources in a momentary ON condition, a continuous ON condition, an OFF condition, a blinking condition, a flashing condition, a dimming condition, a dimmed condition, or any combination of the foregoing conditions.
51. A light comprising:
a plurality of light emitting diode light sources;
at least one pair including a photo-transmitter and a photo-receiver positioned for optical communication therebetween;
a selector having a selector ring rotatable about an axis and having a reflective pattern rotatable therewith to interrupt and/or partially interrupt optical communication between the photo-transmitter and photo-receiver of said at least one pair including a photo-transmitter and a photo-receiver, said rotatable selector ring having at least two detent positions;
an electrical switch actuatable by a pushbutton disposed in said selector ring and movable axially therein; and
a circuit responsive to optical communication between the photo-transmitter and photo-receiver of said at least
具体实施方式：
[0019]In the Drawing, where an element or feature is shown in more than one drawing figure, the same alphanumeric designation may be used to designate such element or feature in each figure, and where a closely related or modified element is shown in a figure, the same alphanumerical designation primed to designate the modified element or feature. It is noted that, according to common practice, the various features of the drawing are not to scale, and the dimensions of the various features are arbitrarily expanded or reduced for clarity, and any value stated in any Figure is given by way of example only.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0020]FIGS. 1A and 1B are different isometric views of an example embodiment of a light 10 including a rotatable selector 300, and FIGS. 1C and 1D illustrate example optional accessories that may be attached to light 10. Light 10 comprises a housing 20 which contains a source of electrical power and a light source 200. Housing 20 may have, e.g., a battery housing 30 joined to a light source housing 120 at a rotatable joint or rotatable connection 40, but may also be in a housing not having a rotatable joint 40. Battery housing 30 typically has an internal cavity for receiving one or more electrical power sources, such as one or more batteries which may each be of a single cell or of a plural cell type, or may be packaged together. Battery housing 30 has a removable cover 32 to allow for replacement of the battery or batteries therein and may have tactile features, such as raised “+” symbols 31 that provide a tactile indication of the proper polarity of the batteries so as to permit changing of batteries under low light or darkened conditions. Cover 32 may be removed by disengaging fastener 34, which may be a thumb screw 34 disposed in a recess 33 of cover 32, that threadingly engages battery housing 30, as illustrated.
[0021]Light source assembly 100 is illustrated in a generally straight ahead position wherein light produced by light source 200 of light source assembly 100 projects in a direction indicated by dashed arrow 12 that is generally aligned with the longitudinal direction of housing 20. Light source assembly 100 may be rotated over about ±90° of rotation (or more, as illustrated by dashed lines 13) about axis 41 of rotatable joint or connection 40 so as to be positionable in various positions as may be convenient to a particular user and/or the particular task for which light 10 is being used, as is indicated by the dashed double ended arrow 14. Cover 110 encloses light source 200 in light source housing 120.
[0022]Light 10 includes a selector 300 for controlling the operation and energization of light source 200 as described below. Selector 300 includes a selector ring assembly 310 that is rotatable to different positions for selecting an operating condition for light source 200 and a pushbutton 340 that is pressed for selecting an energization condition for light source 200, as is described below.
[0023]Desirably, selector ring assembly 310 is movable axially away from housing 20 and is biased towards housing 20, and has one or more relatively large projections that extend toward housing 20. Such projections of selector ring 310 extend into one or more relatively large recesses in housing 20, e.g., in housing 120, so that selector ring 310 must be pulled a substantial distance away from housing 20, 120 in order to disengage such projections and recesses so that selector ring 310 can be rotated. By relatively large is meant that the size of the projections and recesses is sufficiently large that clearance therebetween can be large enough that debris, such as sand and dirt, will not be trapped so as to bind selector ring 310 or make operation of selector ring 310 difficult or impossible.
[0024]Operating conditions or modes for light source 200 that are selectable by rotating selector 300 to different rotational positions may include, for a light source 200 including plural light emitting diode (LED) light sources, for example, the selection of one or more of the LED light sources. Light source 200 may include selectable LEDs emitting different colors of light, such as some or all of a white emitting LED, a red emitting LED, a green LED, an infrared (IR) emitting LED, a blue emitting LED, and an amber emitting LED. For example, a white emitting LED may be used for general illumination, a red emitting LED may be used for aviation and/or low light situations, a green LED may be used for low-level illumination not interfering with night vision, an infrared (IR) emitting LED may be used for signaling, siting or aiming, or providing illumination for night vision equipment, an a blue emitting LED may be used for identifying certain materials and/or gases. The selectable LEDs may be selected and/or energized individually (i.e. one at a time) and/or in one or more groups (i.e. two or more at a time). Alternatively and optionally, rotatable selector 300 may have a rotational position that selects a “safe OFF condition in which no light is produced irrespective of actuation of pushbutton 340.
[0025]Energization conditions or modes for light source 200 that are selectable by pressing pushbutton 340 may include, for example, some or all of momentary ON, continuous ON, OFF, dimmed, cyclical dimming, flashing, blinking, timed ON, and other conditions. Such energization conditions may be selected by some or all of momentarily pressing pushbutton switch 340, by pressing and holding switch 340 for a given time, by pressing switch 340 two or more times within a given time or times, or any combination of the foregoing, or any other desired switch sequence.
[0026]Housing 20 preferably may include an attachment arrangement 37, also sometimes referred to as an attachment point or as a hard attachment point, for attaching various accessories to light 10 and/or for attaching light 10 to another object. For example, a pocket or belt clip 37 may be attached to an attachment point 37 of battery housing 30 by a fastener, such as a screw, as illustrated in FIGS. 1B and 1C. Other accessories that may be attached at attachment arrangement 37 include, but are not limited to, a clip, a helmet clip, a head strap, a “dove tail” for engaging a corresponding “dove tail” receptacle on another object, a loop, a lanyard, a magnet, and the like. Alternatively, light 10 may be attached to another object using a fastener that engages light 10 at attachment point 37.
[0027]A “dove tail” may be provided by a rectangular member 38 that is attached to light 10 at attachment point 37, e.g., by a screw or other fastener, and whose edges are chamfered or beveled so that the surface of the dove tail that is proximate to light 10 is smaller than the surface that is distal light 10, as illustrated in FIG. 1D. Dove tail member 38 is typically beveled or chamfered on all four edges, but need be beveled or chamfered only on two opposing edges for engaging a corresponding mounting fixture that can be attached to an object to which light 10 may thus be mounted.
[0028]Preferably, and optionally, attachment 37 may be a hole passing through housing 20 at any convenient location, such as through battery housing 30, and may be threaded for receiving a fastener such as screw, from either side and/or from both sides of housing 30. Preferably, and optionally, attachment 37 may be provided by a threaded insert, e.g., a threaded insert of brass or another metal, that is molded into the housing 20, 30, which is typically a molded polymer housing. Plural objects may be attached to light 10 using attachment arrangement 37, e.g., by separate fasteners that engage opposite ends of attachment point 37.
[0029]FIG. 2 is an exploded view of an example embodiment of a selector 300 and housing 120 useful with the example light 10 of FIG. 1, and FIG. 3 is an isometric view of an example embodiment of the assembled selector 300 of FIG. 2, however, light source 200 is not shown in FIGS. 2 and 3. Light source housing 120 includes a generally rectangular body 122 defining an internal cavity 124 into which light source 200 and selector 300 are placed. Light source housing 120 also includes a generally cylindrical portion extending from body 122 for housing rotatable joint 40 connecting to battery housing 30.
[0030]Housing 120 has a generally rectangular opening for receiving a light source assembly 100 into cavity 124 and the opening defines shoulders 127 and 129 for receiving a cover 110 and a light shield 112 (not shown). Housing 120 also has a number of holes 125 for receiving screws or other fasteners for attaching cover 110 and light shield 112 thereto to enclose light source assembly 100 comprising light source 200 and selector 300 therein. Housing 120 has an opening 128 in one end thereof for receiving selector 300 therethrough.
[0031]Selector 300 comprises a selector ring 310 assembly and a pushbutton 340 assembly. Selector ring 310 assembly comprises selector ring 312 which is an annular member into which insert 330 is placed so that flange 335 engages a shoulder or inward flange of selector ring 312. Insert 330 is disposed in the opening 128 at the end of light source housing 120. Rotatable interrupter 320 slips over the body of insert 330 (e.g., from inside cavity 124 of housing 120) and is fastened thereto by clip 336 which engages groove 332 of insert 330 to prevent it from separating from interrupter 320. As a result, shoulder 333 of insert 330 and end 323 of interrupter330 define a groove in which O-ring 302 is disposed for providing a seal of opening 128, and spring 304 is disposed between flange 324 of interrupter 320 and the interior wall of cavity 124 of housing 120.
[0032]As a result, selector ring assembly 310 is captured on housing 120 and selector ring 312 is biased by spring 304 towards housing 120. Spring 304 maybe any suitable spring, such as a helical or coil spring, or a wavy spring having one or more elements. It is noted that optional O-ring 302 provides a seal between selector ring assembly 310 and housing 120 that resists the passage of moisture, water, dirt, debris and other unwanted materials therebetween, and that flexible boot 342 and retainer ring 344 provide a seal at the end of selector ring assembly 310 that resists the passage of moisture, water, dirt, debris and other unwanted materials into the interior of selector ring assembly 310. Thus, example light 10 is suitable for use in harsh environments, including field conditions such as wind, rain, mud, sand and the like.
[0033]Rotatable interrupter 320 is thus attached to selector ring 312 and is rotatable therewith. Interrupter 320 includes a semi-cylindrical baffle member 322 extending in an axial direction and rotatable with selector ring 312. Baffle member 322 in the example embodiment illustrated, which is also referred to as baffle 322, may be a projection comprising about 180° of a circular cylinder having its axis generally coaxial with the rotation axis of selector ring 312, although baffle 322 could be substantially greater or less than 180° (hence, “about” 180°) in view of the typical four detents 314 of selector ring 312 that are about 90° apart in rotation in the illustrated example embodiment.
[0034]Selector ring 312, interrupter 320 and insert 330 may have respective corresponding recesses and projections, e.g., tabs and axial grooves, for defining their relative rotational positions when assembled, i.e. for constraining selector ring 312, interrupter 320 and insert 330 to rotate as a unit, or may have a sufficiently tight fit as to so constrain selector ring 312, interrupter 320 and insert 330.
[0035]Selector 300 is freely rotatable in both directions with respect to housing 120, without limitation. However, selector ring 312 is preferably provided with optional detents for defining a predetermined number of predefined rotational positions, e.g., corresponding to operating conditions of light 10. In the illustrated example, four detent positions about 90° apart in rotation are provided. To this end, selector ring 312 may be considered to have four projections 314 positioned about 90° apart in rotation that engage recesses 126 and sides 123 surrounding opening 126 of light source housing 120, wherein the projections and recesses engage to provide the detents. Selector ring 312 could also be considered to have four recesses about 90° apart in rotation defined by the spaces between projections 314 and housing 120 could be considered to have projections defined between adjacent ones of recesses 126 and sides 123, wherein the projections and recesses engage to provide the detents.
[0036]To rotate selector 300 to a desired position, selector ring 312 is pulled away from housing 120 overcoming the bias towards housing 120 of spring 304 and to release detents 314, selector ring 312 is then rotated in either direction to the desired position while pulled away from housing 120, and selector ring 312 is then released to be pulled against housing 120 by the bias of spring 304 and to engage detents 314 in the desired position. This rotation of selector 300 correspondingly rotates baffle 322 to the desired position, thereby to select an operating condition of light 10 as is described below. Where selector ring assembly 310 has four detent positions, light 10 typically has four selectable operating conditions corresponding to the four detent positions. Where selector ring assembly 310 has a different number of detent positions, light 10 will typically have that number of selectable operating conditions.
[0037]Preferably, releasing the detents 314 from housing 120 requires pulling selector 300 away from housing 120 by a substantial distance, so that rotation of selector 300 requires intentional action on the part of a user. In addition, this pulling renders it very difficult, if not nearly impossible, for the user to actuate pushbutton 340 which is in the center of selector ring 312 while rotating selector 300, thereby to reduce the likelihood of energization of light source 200 without intentional action by the user. Also preferably, the axial length of baffle 322 allows baffle 322 to continue to interrupt the optical communication path between a photo-transmitter 252 and a photo-receiver 254 even when selector 300 is fully pulled away from housing 120. Additionally, and optionally, spring 304 is sufficiently stiff, i.e. has a relatively high spring constant, so that the force required to move selector ring 312 away from housing 120 is substantial, so that rotation of selector 300 requires intentional action on the part of a user.
[0038]Preferably, projections 314 of selector ring 312 are relatively large projections that extend toward housing 20 and extend into relatively large recesses 126 in housing 120 so that selector ring 310 must be pulled a substantial distance away from housing 120 in order to disengage projections 314 and recesses 126 so that selector ring 312 can be rotated. Desirably, projections 314 and recesses 126 are sized to have sufficient clearance therebetween so that sand, dirt, and other debris will not be trapped so as to bind selector ring 312 or make operation of selector ring 312 difficult or impossible.
[0039]Also preferably, one of detents 314 is provided with a unique feature such as a raised ridge 315 that distinguishes that detent from the other detents 314. Raised ridge 315 can provide a tactile indication to a user of the rotational position of selector 300 which facilitates use of light 10 in low light, darkened and blackout conditions, and can provide a visual indication to a user of the rotational position of selector 300 under normal lighting. Optionally, various detents may be provided with distinct features that identify those detents which would provide tactile and visual indications of the rotational position of selector 300 and could further facilitate use of light 10. Examples of such distinctive features 315 may include, e.g., axial ridges, circumferential ridges, round bumps, square bumps and the like.
[0040]Pushbutton 340 is disposed in the end of selector ring 312 as follows actuator pin 346 passes through and is movable axially within bore 334 of insert 330 to engage an electrical switch (not visible in FIG. 2; described below) that is disposed in internal cavity 124 of light source housing 120. Spring 348 is retained between an enlarged end of actuator pin 346 and the end of bore 334 of insert 330, thereby to bias actuator pin outwardly away from housing 120. Flexible boot 342 is disposed in the end of selector ring 312 and covers the enlarged end of actuator pin 346 providing a flexible actuation surface for a user. Flexible boot 342, and actuator pin 346, are retained in selector ring 310 assembly by retainer ring 344 which engages the inner surface of the opening of selector ring 312. Retainer ring 344 may be retained by an interference fit, by a snap ring, by an adhesive, by chemical or ultrasonic welding, or by any other convenient manner.
[0041]In certain uses of light 10, it may be desired that selector 300 not be too easily rotatable, e.g., so that it cannot be rotated unintentionally or inadvertently or accidentally. In such case, detents 314 have substantial length engaging housing 120 so that selector ring 312 must be pulled a substantial distance away from housing 120 in order to rotate selector 300, and spring 304 may provide substantial bias that a user must overcome.
[0042]In certain uses of light 10, which may be the same or different uses than in the preceding paragraph, it may be desired that pushbutton 340 not be too easily actuatable, e.g., so that it cannot be actuated unintentionally or inadvertently or accidentally. In such case, insert 330 is positioned within selector ring 312 so that flange 335 is recessed, whereby flexible boot 342 is recessed and so is “protected” by selector ring 312 against unintentional, inadvertent or accidental actuation. In addition, actuator pin 346 may be slightly shorter in length and/or spring 348 may have a higher spring rate so that a more definite and deliberate pressing of flexible boot 342 is required for actuation.
[0043]FIGS. 4 and 5 are isometric views of a selector 300 and light source 200 of light source assembly 100, and of the light source 200, respectively, both of which are shown removed from light source housing 120 and are useful with the example light 10 of FIGS. 1-3. Light source 200 and selector 300 are illustrated in the same relative positions that they are in when they are in internal cavity 124 and opening 126 of light source housing 120.
[0044]Light source 200 includes circuit board structure 230 which comprises, e.g., an LED circuit board 232 and a sensor circuit board 234 that are joined together approximately perpendicularly. LED circuit board 232 may carry one or more light-emitting diodes (LEDs) and/or circuitry for energizing the LEDs thereon. Sensor circuit board 234 may carry “photonic” or electro-optical elements that can communicate optically.
[0045]Sensor circuit board 234 in the illustrated example has an electrical switch 260 generally centrally located thereon so that actuator pin 346 actuates switch actuator button 262 when flexible boot 342 is pressed. Switch 260 may have one set of contacts, e.g., normally open contacts, for controlling the energization condition of light 10, either directly or via a processor. Alternatively, switch 260 may have more than one set of contacts, e.g., typically normally open contacts, for controlling the energization condition of light 10, either directly or via a processor.
[0046]Disposed around electrical switch 260 are one or more pairs 250a, 250b of a photo-transmitter 252 and a photo-receiver 254. Photo-transmitter 252 receives electrical power and produces a light output, generally in a direction defined by a cone that is substantially perpendicular to one of its broad faces. Photo-receiver 254 receives light, e.g., from photo-transmitter 252, and produces an electrical output responsive thereto, and may also be referred to as a photo-detector. Photo-receiver 254 is responsive to light received generally in a direction defined by a cone that is substantially perpendicular to one of its broad faces. Each pair 250a, 250b of a photo-transmitter 252 and a photo-receiver 254 are disposed so that the light produced by photo-transmitter 252 will illuminate and be detected by photo-receiver 254.
[0047]Each pair 250a, 250b of a photo-transmitter 252 and a photo-receiver 254 may be energized continuously or may be energized periodically so as to be in optical communication. Photo-transmitter 252 and photo-receiver 254 of each of pairs 250a, 250b are spaced apart so that a physical member may be placed therebetween to interrupt optical communication between the photo-transmitter 252 and photo-receiver 254 of each pair 250a, 250b.
[0048]Selector 300 and sensor circuit board 234 are positioned by housing 120 so that semi-cylindrical baffle 322 of interrupter 320 is in the space between photo-transmitter 252 and photo-receiver 254 of pairs 250a, 250b when selector 300 is rotated to certain rotational positions, and so that actuator pin 346 aligns with actuator button 262 of electrical switch 260. Thus, pressing flexible boot 342 will actuate electrical switch 260. Further, rotating selector ring 310 will result in baffle 322 rotating in a circular path 236 that passes between the photo-transmitter 252 and photo-receiver 254 of each of pairs 250a, 250b. Baffle 322 is preferably of sufficient length that it can interrupt optical communication between photo-transmitter 252 and photo-receiver 254 of pairs 250a, 250b according to its rotational position even when selector ring 312 is fully pulled away from housing so as to clear detents 314 to allow selector assembly 300 to be rotated.
[0049]In the example of a four position selector 310, in a first position optical communication of pair 250a will be interrupted and optical communication of pair 250b will not be interrupted, in a second position optical communication of both pair 250a and pair 250b will be interrupted, in a third position optical communication of pair 250a will not be interrupted and optical communication of pair 250b will be interrupted, and in a fourth position optical communication of neither pair 250a nor pair 250b will be interrupted.
[0050]As a result the electrical outputs of the photo-receivers 254 of pairs 250a and 250b will indicate and correspond to the rotational position of selector 310, and can be employed to control operation of light 10 responsive to the rotational position of selector 300. Such control may be implemented by logic circuits or by a processor, as may be desired, and such logic circuits and processor may be disposed on either or both of sensor circuit board 232 and LED circuit board 234.
[0051]LED circuit board 234 carries one of more light-emitting diodes (LEDs) that may be energized in response to the position of selector ring 310 and pushbutton 340. The one or more LEDs may be of the same type or of different types, as may be desired. In one example light source 200, four different LEDs are provided. One LED 212 of the four LEDs is disposed on circuit board 234 and a lens 220 is disposed thereover, while the other three of these LEDs 214, 216,218 are disposed on LED circuit board 234, e.g., in an arc around the first LED 212 and lens 220. In one example light 10 and light source 200, LEDs 212-218 are white, blue, red, and green emitting LEDs and, in another example, one of LEDs 214-218 is an infrared-emitting LED.
[0052]Typically, blue, red, green and infrared LEDs 214-218 are embedded in a shaped clear plastic package as illustrated, and the clear plastic may or may not be tinted to correspond with the color of the light produced thereby. Also typically, white emitting LEDs operate at higher power levels to produce greater brightness and are packaged in low-profile packages that often include a thermally conductive back to facilitate removal of heat therefrom. Thus, LED 212 which is typically a white-emitting LED is mounted to circuit board 232 and a plastic lens 220 is employed to shape the beam of light produced thereby and/or to fill the space between LED 212 and cover 110.
[0053]Plastic lens 220 may be of a clear plastic and may be generally parabolic in exterior shape, with a generally planar outward face. Lens 220 may have a bore 224 in the LED-facing end thereof adjacent LED 212, and/or may have a bore 222 in the outward facing end thereof adjacent cover 110. The bottom of bore 222 or the bottom of bore 224, or both, may be shaped so as to define a lens 226, in the illustrated example, a double convex lens 226.
[0054]LED circuit board 232 may be attached to sensor circuit board 234 to form circuit board structure 230 in any suitable manner. In one example, tabs extending from an end of LED circuit board 232 have conductors thereon that are soldered to conductors adjacent corresponding slots in sensor circuit board 234. The attachment could be provided by a mechanical connector, an electrical connector, jumper wires, or any other suitable means providing mechanical and electrical connection.
[0055]FIG. 6 is a cross-sectional view of an example embodiment of a light source assembly 100 useful with the example light 10 of FIGS. 1-5, and illustrating the relative positions of the various elements and components thereof within housing 120, most of which is described above.
[0056]Selector 300 is seen disposed in opening 128 of light source housing 120 with selector ring 312 outside of housing 120 with its detents 314 in recesses 126 of housing 120. Interrupter 320 is disposed on insert 330 wherein flange 335 engages selector ring 312 and clip 336 in groove 332 prevents selector ring 312, interrupter 320 and insert 330 from coming apart, thereby keeping selector 300 in opening 128 of housing 120. Spring 304 is seen between housing 120 and interrupter 320 for biasing selector 300 inward in housing 120 so that detents 314 of selector ring 312 engage recesses 126. O-ring 302 is disposed in a groove formed by the mating of interrupter 320 and insert 330.
[0057]Actuator 346 is seen as movable axially (double-ended arrow) in the central bore of insert 330 of selector 300 and is biased away from actuator button 262 of electrical switch 260 by spring 348 to be proximate the rear surface of flexible boot 342 which is retained in selector ring 312 by retainer ring 344. Flexible boot 342 is seen as having room to flex when pressed so that actuator pin 346 moves against the bias of spring 348 to actuate button 262 of electrical switch 260 on sensor board 234. Baffle 322 of interrupter 320 is seen as extending sufficiently to be rotated to come between a photo-transmitter 252 and a photo-receiver 254 to interrupt optical communication therebetween.
[0058]Circuit board structure 230 is seen to be in internal cavity 124 of light source housing 120 with sensor circuit board 234 about perpendicular to LED circuit board 232 which is supported by a shoulder of housing 120. LEDs 216 and 212 are visible mounted to LED circuit board 232 with plastic lens 220 adjacent LED 212. Plastic lens 220 is seen to have two opposing coaxial bores 222, 224, the bottoms of which are convex to define double convex lens 226 in plastic lens 220 adjacent LED 212, typical a white LED useful for general illumination.
[0059]Light shield 112 is opaque and is supported by shoulder 127 of housing 120 so as to cover the space containing photo-transmitters 252 and photo-receivers 254 so that light cannot enter therein and interfere with the operation of photo-receivers 254 and baffle 322. In particular, light shield 112 has a thin cover portion 113 covering the space containing photo-receivers 254, thereby to block external light from entering therein, and has a thick portion 114 defining bores into which LEDs 214-218 fit and a wall adjacent LED 212, thereby to baffle light produced by LEDs 212-218 from entering the space containing photo-receivers 254. LEDs 214-218 are maintained in their respective positions by light shield112 which also is curved at one end so as to fit adjacent to and help position plastic lens 220 in housing 120.
[0060]The outward surface of light shield 112 and the outward end of plastic lens 220 are adjacent cover 110 which is supported on shoulder 129 of housing 120 and is attached by screws 115 or another suitable fastener or fastening means.
[0061]Because rotation of light source assembly 100 about axis 41 with respect to battery housing is limited in the example embodiment as a practical matter by the configuration of housing 20 to about ±90° (or slightly more or less), rotatable connection 40 may be provided by wires passing between battery housing 30 and light source housing 120 via rotatable connection 40, by one or more rotating electrical joints, by slip rings, or by any other convenient means. An example of a suitable rotatable joint and connection arrangement is described in U.S. Pat. No. 5,871,272 entitled “Flashlight With Rotatable Lamp Head,” which is hereby incorporated herein by reference in its entirety, wherein a rotatable joint and connection arrangement is illustrated inter alia in FIGS. 2, 9, 10, 11, 12, 15, 16 and 17 thereof. It is noted that light source assembly 100 may be offset from the remainder of housing 20 so that light source 100 is fully rotatable over 360° with respect to battery housing 30 without restriction to a range of angular rotation.
[0062]In one example embodiment of light 10, housing 20, 30, 120 and light shield 112 are of an opaque plastic, such as an ST-801 nylon available from Clariant Corporation located in Charlotte, N.C., and selector ring 312, interrupter 320 and insert 330 are typically molded plastic parts of a rigid plastic, such as DELRIN® plastic available from General Electric Company, GE Plastics, located in New York, which is made opaque for interrupter 320. Examples of other suitable materials include acetals or polyoxymethylenes (e.g., POM, Delrin® plastic), nylon, polycarbonate and the like. Flexible boot 242 may be molded of rubber, synthetic rubber, silicone rubber or elastomer, neoprene, Santoprene® elastomer, Kraton® polymer, Alcryn® synthetic rubber, or of an elastomer or polymer, or of another suitable flexible and resilient material. Lens 220 and cover 110 may be of polycarbonate or an acrylic plastic. Circuit boards 220, 300, may be of any suitable material, e.g., fiberglass epoxy and FR4. Battery housing 30 may contain two AA size alkaline cells or may contain one or more lithium cells, or other suitable cells or battery, or packaged batteries or cells.
[0063]FIGS. 7A and 7B are schematic diagrams of an example electrical circuits 400, 400′ useful with the light 10 of FIGS. 1-6.
[0064]FIG. 7A illustrates a relatively simple circuit 400 for responding to the position of selector 300 for energizing light source LEDs 212-218. Therein photo-transmitters 252 are represented by photo diodes D7 and D8 and photo-receivers by photo-transistors Q7 and Q8, respectively, which may be disposed on circuit board 234. Resistor R8 sets the current flowing through diodes D7, D8 and capacitor C4 provides filtering.
[0065]Combinatorial logic circuit 410 receives signals LEFT SENSOR IN, RIGHT SENSOR IN, from photo-transistors Q7, Q8 and employs combinatorial logical elements, such as AND gates, OR gates, NAND gates and exclusive OR gates, to decode the signals LEFT SENSOR IN and RIGHT SENSOR IN to produce drive signals WHITE LED ENABLE, BLUE LED ENABLE, RED LED ENABLE, IR LED ENABLE, which enable one or ones of selection transistors Q2, Q3, Q4, Q5 one or more at a time responsive to the particular combination of inputs from photo-transistors Q7, Q8. In one preferred embodiment, selection transistors Q2, Q3, Q4, Q5 and LEDs D1, D2, D3, D4, (LEDs 212-218) are enabled one at a time.
[0066]Selection transistors Q2, Q3, Q4, Q5 when enabled apply supply voltage +V to the selected one of LEDs D1, D2, D3, D4 for energizing the selected LED to produce light. The value of current flowing in each of LEDs D1, D2, D3, D4 may be set by control transistor Q1 acting as a current source, by an individual resistor in series with each of LEDs D1, D2, D3, D4, or by a resistor in series with all of LEDs D1, D2, D3, D4, e.g., a resistor in the position of resistor R1 with transistor Q1 replaced by a short circuit, as may be desired.
[0067]Optionally, but preferably, a controllable current source 420 may be provided to contro