Distributed lighting system with fiber optic controls

• US 5,311,410 A
• Filed: 10/29/1992
• Issued: 05/10/1994
• Est. Priority Date: 10/29/1992
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Hsu, Tsung-Yuan, Yen, Huan-Wun
• Primary Examiner(s): Dority, Carroll B.
• Application Number:
  US07/968,637
• Time in Patent Office: 558 Days
• Field of Search: 362/32, 362/20, 385/16, 385/19-23
• US Class Current: 362/552
• CPC Class Codes: B60Q 1/0011 with light guides for distributing the light between several lighting or signalling devices
• CPC Class Codes: F21S 41/24 Light guides
• CPC Class Codes: F21S 41/635 by moving refractors, filters or transparent cover plates
• CPC Class Codes: F21S 41/692 Shields, i.e. screens not creating an image meant to be projected
• CPC Class Codes: F21S 43/247 with a single light source being coupled into the light guide
• CPC Class Codes: F21S 43/251 the light guides being used to transmit light from remote light sources
• CPC Class Codes: F21V 14/06 by movement of refractors in vehicle head lamps F21S41/635
• CPC Class Codes: F21V 14/08 by movement of the screens or filters
• CPC Class Codes: F21V 19/04 with provision for changing light source, e.g. turret auxiliary devices for cleaning, placing, or removing incandescent lamps H01K3/32, fluorescent lamps H01J9/006
• CPC Class Codes: F21V 2200/10 of light guides of the optical fibres type
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: G02B 6/0005 the light guides being of the fibre type G02B6/0003 takes precedence
• CPC Class Codes: G02B 6/3504 Rotating, tilting or pivoting the waveguides, or with the waveguides describing a curved path rotary joint G02B6/3628
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/3574 Mechanical force, e.g. pressure variations
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• CPC Class Codes: G02B 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams
• CPC Class Codes: G02B 6/4222 : by observing back-reflected light
• CPC Class Codes: G02B 6/4226 : Positioning means for moving the elements into alignment, e.g. alignment screws, deformation of the mount

Abstract

A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front. The switches include various mechanisms for moving the input and output fibers into and out of alignment with each other, including a shaped resilient sleeve, a hinge pivotally joining the fibers, an opaque shutter with a transmissive section movable between the fibers, and also a liquid-based switch that relies upon total internal reflection. A feedback mechanism for some of the switches dims the source lamp when the switch is OFF to conserve energy. The oscillators operate by normally urging an input fiber towards an OFF position, at which it actuates a mechanism that shifts it to an ON position at which the mechanism is deactivated. A failsafe system employs multiple light sources, with each source sharing its light output with the load for another source that has failed.

Claims

1. A lighting system for a vehicle that includes a plurality of headlight assemblies, comprising:

a light source,

a plurality of optical loads,

an optical fiber network extending from said light source to provide illumination for said optical loads, and

at least one optical switch within said optical fiber network, each of said switches including a respective input fiber from said light source and a respective output fiber to a respective optical load, said switches operating by selectively enabling or disabling an optical connection between their respective input and output fibers,

each of said headlight assemblies including;

at least one headlight lens for transmitting a headlight beam,

a respective optical fiber of said optical fiber network aligned with each lens to illuminate the lens for transmitting a headlight beam, and

means for adjusting the positions of said fibers relative to their respective lenses to adjust the nature of the headlight beam.

2. The vehicle lighting system of claim 1, said fiber adjusting means for each headlight assembly comprising means for moving the fibers in a generally vertical direction to switch between high and low beam positions.

3. The vehicle lighting system of claim 1, said fiber adjusting means for each headlight assembly comprising means for moving the fibers toward and away from their respective lenses to adjust the beam collimation.

4. The vehicle lighting system of claim 1, each headlight assembly including a plurality of lenses and aligned fibers, said aligned fibers being held in a common mounting member, and a motor for adjusting the position of said mounting member.

5. The vehicle lighting system of claim 1, further including means for detecting light within a predetermined wavelength from the opposite side of the lenses from said fibers, said adjusting means adjusting the positions of said headlight fibers in response to such detected light.

6. The vehicle lighting system of claim 5, wherein said light detecting means responds to light at a wavelength of the headlight beam to adjust the positions of said headlight fibers.

7. The vehicle lighting system of claim 6, wherein said headlight fiber position adjusting means moves the fibers with respect to their respective lenses to increase the headlight beam diffusion and/or lower the headlight beam in response to said light detecting means detecting light at said headlight beam wavelength.

8. The vehicle lighting system of claim 5, said light detecting means including at least two light detectors that are laterally spaced from each other, and means for enabling said headlight fiber position adjustment only in response to the ratio of light intensities detected by said detectors corresponding to the reflection of said headlight beam from a vehicle in front in the same traffic lane and/or a distant oncoming vehicle in an adjacent traffic lane, but not to the detection of a headlight beam from a nearby oncoming vehicle in the adjacent traffic lane.

9. The vehicle lighting system of claim 1, wherein the optical fiber for each lens comprises an input fiber, and further comprising a plurality of output fibers for each lens, said output fibers being located at different positions relative to their respective lenses so that the lenses transmit headlight beams in different directions when illuminated by different ones of their respective output fibers, and said means for adjusting the positions of said input fibers operates by moving said input fibers between optical alignments with their respective output fibers.

10. A lighting system comprising:

a light source,

a plurality of optical loads,

an optical fiber network extending from said light source to provide illumination for said optical loads, and

at least one optical switch within said optical fiber network, each of said switches including a respective input fiber from said light source and a respective output fiber to a respective optical load, said switches operating by selectively enabling or disabling an optical connection between their respective input and output fibers, at least one of said optical switches, comprising;

a housing having a pair of intersecting fiber and shutter bores extending through the housing,

a pair of fiber pistons positionable in said fiber bore on opposite sides of said intersection, said fiber pistons including means for holding respective input and output fibers in optical alignment with each other,

an opaque shutter that is positionable within said shutter bore to block the transmission of light between said input and output fibers in a switch OFF position, said shutter including a generally transmissive section that enables the transmission of light between said input and output fibers when the transmissive section is positioned between said fibers in a switch ON position, and

a pair of shutter pistons mounting said shutter between them and movable through said shutter bore as a unit with said shutter between said switch OFF and switch ON positions.

11. The lighting system of claim 10, further comprising a mechanical control means for controlling the position of said shutter pistons within said shutter bore.

12. The lighting system of claim 10, said shutter pistons being formed from a magnetic material, and further comprising a pair of electromagnets on opposite sides of said shutter pistons within said shutter bore, and means for selectively actuating said electromagnets to control the positions of said shutter and shutter pistons within said bore.

13. The lighting system of claim 10, further comprising first and second gradient index rod lenses respectively between said input fiber and bore intersection and between said bore intersection and output fiber within said fiber bore, said lenses expanding a light beam from the input lens and contracting the beam back into said output fiber after transmission through said generally transmissive shutter section with said switch in an ON position, said lenses reducing light losses that would otherwise occur from forming of a light beam emitted from said input fiber.

14. The lighting system of claim 10, said generally transmissive shutter section comprising a color filter.

15. A vehicle headlight assembly, comprising:

at least one optical lens for transmitting a headlight beam,

a respective optical fiber aligned with each lens to illuminate the lens for transmitting a headlight beam, and

means for adjusting the positions of said fibers relative to their respective lenses to adjust the nature of the headlight beam.

16. The headlight assembly of claim 15, said fiber adjusting means comprising means for moving the fibers in a generally vertical direction to switch between high and low beam positions.

17. The headlight assembly of claim 15, said fiber adjusting means comprising means for moving the fibers toward and away from their respective lenses to adjust the beam collimation.

18. The headlight assembly of claim 15, including a plurality of lenses and aligned fibers, wherein said fibers are held in a common mounting member, and a motor is provided for adjusting the position of said mounting member.

19. The headlight assembly of claim 15, further including means for detecting light within a predetermined wavelength from the opposite side of the lenses from said fibers, said adjusting means adjusting the position of said fibers in response to such detected light.

20. The headlight assembly of claim 19, wherein said light detecting means responds to light at a wavelength of the headlight beam to adjust the positions of said fibers.

21. The headlight assembly of claim 20, wherein said fiber position adjusting means moves the fibers closer to their respective lenses to increase the diffusion of the headlight beam in response to said light detecting means detecting light at said headlight beam wavelength.

22. The headlight assembly of claim 19, said light detecting means including at least two light detectors that are laterally spaced from each other, and means for enabling said fiber position adjustment only in response to the ratio of light intensities detected by said detectors corresponding to the reflection of said headlight beam from a vehicle in front in the same traffic lane and/or a distant oncoming vehicle in an adjacent traffic lane, but not to the detection of a headlight beam from a nearby oncoming vehicle in the adjacent traffic lane.

23. The headlight assembly of claim 15, wherein said optical fibers comprises input fibers, and further comprising a plurality of output fibers for each lens, said output fibers being located at different positions relative to their respective lenses so that the lenses transmit headlight beams in different directions when illuminated by different ones of their respective output fibers, and said means for adjusting the positions of said input fibers operates by moving said input fibers between optical alignments with their respective output fibers.

24. An optical switch, comprising:

input and output optical fibers having aligned but mutually spaced ends,

an opaque shutter between said fiber ends, said shutter including a generally transmissive section,

means for moving said shutter between a switch OFF position with the shutter blocking the transmission of light between said fibers, and a switch ON position with the shutter'"'"'s generally transmissive section aligned with said fibers and enabling the transmission of light therebetween, and

first and second gradient index rod lenses respectively between said input fiber and shutter, and between said shutter and output fiber, said lenses expanding a light beam from the input fiber and contracting the beam back into said output fiber after transmission through said generally transmissive shutter section with said switch in an ON position, said lenses reducing light losses that would otherwise occur from fanning of a light beam emitted from said input fiber.

25. The optical switch of claim 24, said generally transmissive section comprising a color filter.

26. The optical switch of claim 25, said shutter moving means including means for moving said shutter to intermediate positions between said OFF and ON switch position, and thereby providing a dimming capability.

27. An optical switch, comprising:

a housing having a pair of intersecting fiber and shutter bores extending through the housing,

a pair of fiber pistons positionable in said fiber bore on opposite sides of said intersection, said fiber pistons including means for holding respective input and output fibers in optical alignment with each other,

an opaque shutter that is positionable within said shutter bore to block the transmission of light between said input and output fibers in a switch OFF position, said shutter including a generally transmissive section that enables the transmission of light between said input and output fibers when the transmissive section is positioned between said fibers in a switch ON position, and

a pair of shutter pistons mounting said shutter between them and movable through said shutter bore as a unit with said shutter between said switch OFF and switch ON positions.

28. The optical switch of claim 27, further comprising a mechanical control means for controlling the position of said shutter pistons within said shutter bore.

29. The optical switch of claim 27, said shutter pistons being formed from a magnetic material, and further comprising a pair of electromagnets on opposite sides of said shutter pistons within said shutter bore, and means for selectively actuating said electromagnets to control the positions of said shutter and shutter pistons within said bore.

30. The optical switch of claim 27, further comprising first and second gradient index rod lenses respectively between said input fiber and bore intersection and between said bore intersection and output fiber within said fiber bore, said lenses expanding a light beam from the input lens and contracting the beam back into said output fiber after transmission through said generally transmissive shutter section with said switch in an ON position, said lenses reducing light losses that would otherwise occur from forming of a light beam emitted from said input fiber.

31. The optical switch of claim 27, said generally transmissive shutter section comprising a color filter.

32. A failsafe lighting system for multiple optical loads, comprising:

at least two light sources connected by optical fibers to respective optical loads,

respective optical beam splitters associated with each of said light sources for diverting a portion of the light from its respective light source to the optical load for another light source while continuing to supply a portion of the light from its respective light source to its own optical loads, so that both sets of loads are supplied by the same light source, and

actuating means responsive to the failure of one light source for actuating the beam splitter for the other light source.

33. The failsafe lighting system of claim 32, wherein the beam splitter for each light source has a first non-actuated position, a second position at which it diverts a portion of the light from its respective light source to the optical load for another light source, and a third position at which it directs light diverted from another light source to its own optical load, said actuating means placing the beam splitter for each of said light sources in its third position when the beam splitter for the other light source is in its second position.

34. The failsafe lighting system of claim 33, wherein said beam splitters are rotatable between said first, second and third positions, with the second position for each beam splitter is optically aligned with the third position for the other beam splitter to which it diverts light when the other beam splitter'"'"'s light source has failed.

35. The failsafe lighting system of claim 32, wherein the beam splitter for each light source is moveable between a first position out of the optical path between its light source and optical load and a second position at which it diverts a portion of the light from its respective light source, and further comprising respective reflectors for each of said light sources that are moveable between first positions out of the optical paths between their light sources optical loads, and second positions that are optically aligned with the second positions for the other light source'"'"'s beam splitter, said reflectors in their second positions reflecting light from the beam splitter for the other light source into the optical load for their own light source.

36. The failsafe lighting system of claim 32, for a vehicle lighting system, wherein one light source normally illuminates the vehicle'"'"'s head and tail lights, and another light source normally illuminates the vehicle'"'"'s other lighting systems.

37. The failsafe lighting system of claim 32, wherein the output intensities from said light sources is adjustable, and further comprising means for increasing the output intensities of said light sources when a portion of their optical outputs is diverted to the optical load for another light source.