Lamp masking method and apparatus

• US 6,550,943 B2
• Filed: 03/27/2002
• Issued: 04/22/2003
• Est. Priority Date: 05/25/2001
• Status: Expired due to Term

• Current Assignee: Illume LLC
• Original Assignee: Illume LLC
• Inventors: Strazzanti, Michael
• Primary Examiner(s): Cariaso, Alan
• Assistant Examiner(s): Alavi, Ali
• Application Number:
  US10/108,827
• Publication Number:
  US 20030002291A1
• Time in Patent Office: 391 Days
• Field of Search: 362/464, 362/465, 362/466, 362/513, 362/512, 362/318, 362/319, 362/267, 315/82, 315/83, 427/106, 427/165
• US Class Current: 362/464
• CPC Class Codes: B60Q 1/00 Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor for lighting vehicle interior B60Q3/00
• CPC Class Codes: B60Q 1/0041 of several lamps in relation to each other
• CPC Class Codes: B60Q 1/26 the devices being primarily intended to indicate the vehicle, or parts thereof, or to give signals, to other traffic
• CPC Class Codes: F21S 41/645 by electro-optic means, e.g. liquid crystal or electrochromic devices
• CPC Class Codes: F21V 3/04 characterised by materials, surface treatments or coatings
• CPC Class Codes: G02F 1/13347 working in reverse mode, i.e. clear in the off-state and scattering in the on-state

Abstract

A motor vehicle lamp assembly having a lamp bulb for emitting light and a bulb housing having a light transmissive portion for transmitting light from the lamp bulb to an illumination zone. The housing is coated with a coating material which covers a selected region of the light transmissive portion of the housing. The coating material is electrically energized to alter an amount of light transmitted from the bulb to the illumination zone. A drive circuit electrically coupled to the coating material energizes the coating material to control a light output from the lamp assembly. Alternate materials are disclosed. One of the materials renders the material more light transmissive when activated with a current and a second of the materials renders the material less light transmissive when activated with a current.

Claims

1. A headlamp assembly comprising:

a headlamp bulb for emitting light from the headlamp assembly;

a bulb housing having a light transmissive portion for transmitting light from the headlamp bulb to an illumination zone, a portion of said housing coated with a coating material which covers a selected region of the light transmissive portion of the housing, wherein the coating material is comprised of a material that is more light transmissive when not energized and more opaque when energized to alter an amount of light transmitted from the bulb to the illumination zone; and

a drive circuit electrically coupled to the coating material for selectively energizing the coating material and thereby controlling a light output from the headlamp assembly.

2. The headlamp assembly of claim 1 wherein the coating comprises a sheet of pliable PDLC material that is affixed to the light transmissive portion of the housing.

3. The headlamp assembly of claim 1 wherein the light transmissive portion of the housing includes multiple bands of the coating material which can be independently energized to adjust the light output from the headlamp assembly.

4. The headlamp assembly of claim 3 wherein the driver circuit includes a programmable controller coupled to an output circuit that causes the bands to exhibit one of two light transmissive states, a relatively high light transmissive state and a relatively low light transmissive state.

5. The head lamp assembly of claim 1 wherein the drive circuit comprises:

a) a user interface including a switch selector;

b) a programmable controller for responding to the setting of the switch selector to produce a set of driver outputs; and

c) a driver circuit coupled to the coating material to apply an alternating signal to the coating material to alter the light transmissive characteristics of said coating material.

6. The head lamp assembly of claim 1 wherein the drive circuit includes a control output for adjusting a level of light transmission from the bulb through a region of said coating material at a high level of light transmission, a low level of light transmission, and at least one intermediate level of light transmission.

7. The head lamp assembly of claim 6 wherein the drive circuit includes a programmable controller that selectively controls a pulse width modulating signal output from the controller for adjusting the light transmission level of an associated region of said coating material.

8. A process for constructing a headlamp assembly comprising:

positioning a headlamp bulb that emits light within a headlamp housing having a light transmissive portion for transmitting light from the headlamp bulb to an illumination zone;

applying a coating material to the housing to cover selected regions of the light transmissive portion; and

coupling the coating material to a drive circuit for selectively energizing the coating material, which when electrically energized, renders a region of the light transmissive portion having the coating material less light transmissive to alter light transmitted from the bulb to the illumination zone.

9. The process of claim 8 wherein the coating material is comprised of a reverse mode PDLC material, said material coupled to the drive circuit for selectively energizing the coating material when energized renders a region of the light transmissive portion having the coating material less light transmissive to alter the light transmitted from the bulb to the illumination zone.

10. The process of claim 8 wherein the coating material is organized in multiple bands across a surface of said light transmissive portion of the headlamp assembly which are coupled to the drive circuit independently to allow independent control over the light transmitting characteristics of said bands during operation of the headlamp assembly.

11. The method of claim 8 additionally comprising providing an user interface for monitoring multiple inputs that control the light transmissive state of the multiple bands.

12. The method of claim 8 wherein the energizing of the coating material adjusts a level of light transmission from the bulb through a region of said coating material to a high light transmission state, a low light transmission state, or one or more intermediate light transmission states.

13. The method of claim 12 wherein energizing of the coating material is performed by providing a pulse width modulating signal for adjusting a light transmission state of an associated region of said coating material.

14. A motor vehicle lamp assembly comprising:

a lamp bulb for emitting light from the lamp assembly;

a bulb housing having a light transmissive portion for transmitting light from the lamp bulb to an illumination zone, a portion of said bulb housing including a coating material which covers a selected region of the light transmissive portion of the housing and wherein the coating material is comprised of a PDLC material said which is more light transmissive when not energized and more opaque when energized to alter an amount of light transmitted from the bulb to the illumination zone; and

a drive circuit electrically coupled to the coating material for selectively energizing the coating material and thereby controlling a light output from the lamp assembly.

15. The apparatus of claim 14 wherein the coating comprises a sheet of pliable PDLC material that is supported by the light transmissive portion of the housing.

16. The apparatus of claim 14 wherein the light transmissive portion of the housing includes multiple regions of the coating material that are independently energized to adjust the light output from the lamp assembly.

17. The apparatus of claim 16 wherein the multiple regions of the coating material form a matrix array of rows and columns that are independently energized by the drive circuit to adjust the light output from the lamp assembly.

18. The apparatus of claim 16 wherein the coating material comprises distinct regions that are individually energized by conductors that are routed between the inner and the outer layers of the light transmitting portion of the bulb housing.

19. The apparatus of claim 16 wherein the driver circuit includes a user interface for setting multiple inputs that control the light transmissive state of the multiple regions.

21. The apparatus of claim 16 wherein the drive circuit comprises:

a) a user interface including a switch selector;

b) a programmable controller for responding to the setting of the switch selector to produce a set of driver outputs; and

c) a driver circuit coupled to the coating material to apply an alternating signal to the coating material to alter the light transmissive characteristics of said coating material.

22. The apparatus of claim 16 wherein the drive circuit includes a control output for adjusting a level of light transmission through a region of said coating material and an input for monitoring whether a motor vehicle engine is running and further wherein the drive circuit controls the level of light transmission based on an operating state of said motor vehicle engine.

20. The apparatus of 16 wherein the driver circuit includes a programmable controller coupled to an output circuit that causes the multiple regions to exhibit one of two light transmissive states, a relatively high light transmissive state and a relatively low light transmissive state.

23. A motor vehicle lamp assembly comprising:

a lamp bulb for emitting light from the lamp assembly;

a bulb housing having a light transmissive portion for transmitting light from the lamp bulb to an illumination zone;

a cap attached to the bulb housing that includes a light transmitting cap portion between the lamp bulb and the illumination zone which supports a coating material which when electrically energized alters an amount of light transmitted from the bulb to the illumination zone, said material comprising a PDLC material that is more light transmissive when not energized and is more opaque when energized;

said cap spacing the coating material a distance from the bulb to control heat transfer from the bulb to the coating material; and

a drive circuit electrically coupled to the coating material for selectively energizing the coating material and thereby controlling a light output from the lamp assembly.

24. A process for constructing a motor vehicle lamp assembly comprising:

positioning a lamp bulb that emits light within a lamp housing having a light transmissive portion for transmitting light from the lamp bulb to an illumination zone;

mounting a coating material in relation to the lamp housing to cover selected regions of the light transmissive portion wherein the coating material is comprised of a PDLC material which when energized renders a region of the light transmissive portion having the coating material less light transmissive to alter the light transmitted from the bulb to the illumination zone; and

coupling the coating material to a drive circuit for selectively energizing the coating material which when electrically energized renders a region of the light transmissive portion having the coating material less light transmissive to control light intensity transmitted from the bulb to the illumination zone.

25. The process of claim 24 wherein the coating material is fixed in spaced relation to the light transmissive portion of the lamp housing to avoid heat from the lamp bulb degrading the coating material.

26. The process of claim 24 wherein the coating material forms multiple regions in a matrix of rows and columns across a surface of said light transmissive portion of the lamp assembly which are coupled to the drive circuit independently to allow independent control over the light transmitting characteristics of said regions during operation of the headlamp assembly.

27. The method of claim 24 additionally comprising providing an interface for monitoring multiple inputs to control the light transmissive state of the multiple bands.

28. A process for operating a motor vehicle lamp comprising:

positioning a lamp bulb that emits light within a lamp housing having a light transmissive portion for transmitting light from the lamp bulb to an illumination zone;

mounting a coating material in relation to the lamp housing to cover selected regions of the light transmissive portion wherein the coating material is comprised of a PDLC material which when selectively energized renders a region of the light transmissive portion having the coating material less light transmissive;

coupling the coating material to a drive circuit for controlling a light transmissive state of the coating material; and

selectively activating the drive circuit to energize the coating material and thereby render a region of the light transmissive portion having the coating material less light transmissive.

29. The method of claim 28 wherein the step of selectively activating is based on whether the lamp bulb has been turned on.

30. The method of claim 28 wherein the step of selectively activating is based on whether a motor vehicle engine is running.