Display system having a light source separate from a display device

• US 6,428,198 B1
• Filed: 07/01/1999
• Issued: 08/06/2002
• Est. Priority Date: 07/07/1998
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc.
• Original Assignee: Alliedsignal Inc.
• Inventors: Biemer, Michael G., Steiner, Ivan B., Saccomanno, Robert J.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Neils, Peggy A
• Application Number:
  US09/346,253
• Time in Patent Office: 1,132 Days
• Field of Search: 362/26, 362/559, 362/561, 362/558, 362/554, 362/552, 362/583, 362/560
• US Class Current: 362/559
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide

Abstract

High luminance display devices, typically utilized in applications requiring sunlight readability, require unique design methodologies as the thickness approaches a maximum of one-inch. The present invention relates to a high intensity light generation engine and associated light transmission apparatus for transmitting the light generated by the engine to a remote location. The invention is especially applicable for use in constructing a back lighted display, such as a liquid crystal display (LCD), of minimal thickness, i.e., one-inch or less. A display of minimal thickness is achieved by separating a light source and other peripherals from the display device, using a remote enclosure. Such a display is most suited for use in high ambient lighting conditions where space is at a premium, such as in the cockpit of an aircraft.

Claims

1. A system for illuminating a display, comprising:

a light source for generating light with emitting portions;

a light collecting assembly for collecting the light from the light source and for providing a light output,

wherein said light collecting assembly comprises a plurality of mirrors that surround the emitting portions of said light source wherein each of said mirrors comprises two off-axis ellipsoidal mirror segment surfaces and two side edges, each side edge including a half hole such that two of said plurality of mirrors form a mirror edge slot with an exit port hole located therethrough;

wherein each off-axis ellipsoidal mirror segment surface reflects the light generated from said light source to a corresponding exit port hole, each exit port hole receiving light reflected from two of said off-axis ellipsoidal mirror segment surfaces;

wherein each of said off-axis ellipsoidal mirror segment surfaces has a first focus and a second focus with the first focus of each of said off-axis ellipsoidal mirror segment surfaces coincident with at least one of the emitting portions of said light source and with the second focus of each of said off-axis ellipsoidal mirror segment surfaces located in such a manner that light rays reflected from each of said off-axis ellipsoidal mirror segment surfaces are directed to substantially avoid intercepting said light source; and

a waveguide, responsive to the light output received from said plurality of exit port holes, for transmitting said light output to said display.

2. The system according to claim 1, further comprising:

a plurality of optical light pipes, wherein each of said optical light pipes is coupled to one of said exit port holes, each exit port hole including a plurality of optical light pipes, each of said optical light pipes receiving light reflected from a corresponding off-axis ellipsoidal mirror segment surface, and blocking heat and removing ultraviolet radiation generated by said light collecting assembly.

3. The system of claim 2, wherein each of said optical light pipes being formed of one of glass, fused silica and sapphire.

4. The system according to claim 2, wherein each of said optical light pipes is coated with at least one of a dielectric infrared reflecting coating, an ultraviolet reflecting coating and a transmitting dichromic film.

5. The system according to claim 1, wherein said waveguide has a truncated sawtooth surface.

6. The system according to claim 1, further comprising a collimator, wherein said waveguide is placed between the collimator and the display and said collimator comprises an array of tapered cavities.

7. The system according to claim 6, where each of said array of tapered cavities has one of a square and triangular cross-section.

8. The system according to claim 1, wherein said display is a flat panel display.

9. The system according to claim 1, wherein said off-axis ellipsoidal mirror segment surfaces comprise a set of surfaces of four molded parts.

10. The system according to claim 1, wherein said light collecting assembly further comprises:

an alignment means to control the translational and rotational position of each of said mirrors relative to each other of said mirrors and said light source; and

a thermal management system including cooling and spring-like elements to compensate for expansion and contraction of said mirrors over a temperature range.

11. The system of claim 1, further comprising a homogenizer, responsive to the light collected by said collecting system, for homogenizing the collected light.

12. A system for illuminating a display, comprising:

a light source for generating light with emitting portions;

a light collecting assembly for collecting the light from the light source and for providing a light output;

a multi-stage dimmer, responsive to the light collected by said light collecting assembly, for dimming the collected light and for providing a light output;

said multi-stage dimmer providing a wide dimming range and comprising a first dimming stage including a first set of opposing apertures that can be closed to a minimum aperture size determined by diffraction effects and a second dimming stage including a neutral density filter and a second set of opposing apertures that can be closed to a minimum aperture size determined by diffraction effects;

a homogenizer, responsive to the light dimmed by said multi-stage dimmer, for homogenizing the dimmed light and for providing a light output; and

a waveguide, responsive to the homogenized light received from said homogenizer, for transmitting said homogenized light to said display wherein the homogenized light entering said waveguide is collimated.

13. The system according to claim 12, wherein said dimmer is configured to have a dimming ratio of up to 88,500:

1.

14. The system according to claim 12, wherein said first set of opposing apertures comprises a pair of aperture plates, each plate having a diamond-shaped aperture.

15. The system according to claim 12, wherein one of said first or second dimming stages includes a spectral filter.

16. The system according to claim 12, wherein said homogenizer has an input at one end and an output at the opposite end, and wherein the opening of the input is larger than the opening of the output.

17. The system according to claim 12, wherein said light source, said light collecting assembly, and said homogenizer is included in a remote enclosure, such that said light source, said light collection assembly, and said homogenizer are located separate and apart from said display.

18. A high intensity illumination system comprising:

a high intensity light source for generating light with emitting portions;

a light collecting assembly for collecting the light from the light source and for providing a light output;

a multi-stage dimmer, responsive to the light collected by said light collecting assembly, for dimming the collected light;

wherein said multi-stage dimmer providing a wide dimming range and comprising a first dimming stage including a first set of opposing apertures that can be closed to a minimum aperture size determined by diffraction effects and a second dimming stage including a neutral density filter and a second set of opposing apertures that can be closed to a minimum aperture size determined by diffraction effect;

a homogenizer, responsive to the light dimmed by said multi-stage dimmer, for homogenizing the dimmed light; and

a waveguide, responsive to the homogenized light received from said homogenizer, for transmitting said homogenized light to said display wherein the homogenized light enter said waveguide is collimated.

19. The illumination system according to claim 18, wherein said waveguide transmits said homogenized light to provide said remote illumination to a flat panel display.

20. The illumination system according to claim 18, wherein said waveguide has a truncated sawtooth surface.

21. The illumination system according to claim 18, wherein said dimmer is configured to have a dimming ration of up to 88,500:

1.

22. The illumination system according to claim 18, wherein said set of opposing apertures comprises a pair of aperture plates, each plate having a diamond-shaped aperture.

23. The illumination system according to claim 18, wherein one of said first or second dimming stages includes a spectral filter.

24. The illumination system according to claim 18, further comprising a collimator for collimating said homogenized light, wherein said collimator comprises an array of tapered cavities.

25. The illumination system according to claim 24, where each of said array of tapered cavities has one of a square and triangular cross-section.

26. The illumination system according to claim 18, wherein said homogenizer has an input at one end and an output at the opposite end, and wherein the opening of the input is larger than the opening of the output.

27. The illumination system according to claim 18, wherein said light source, said light collecting assembly, and said homogenizer is included in a remote enclosure, such that said light source, said light collecting assembly, and said homogenizer are located separate and apart from said display.

28. A radiation collecting assembly, comprising:

a radiative source selected from the group consisting of radio frequency (RF), visible light, ultraviolet (UV) light, infra-red (IR) light, microwaves, and X-rays and having emitting portions;

a plurality of mirrors that surround the emitting portions of said radiative source wherein each of said mirrors comprising one or more off-axis ellipsoidal mirror segment surfaces and one or more exit port holes located therethrough;

wherein each off-axis ellipsoidal mirror segment surface reflects radiation, generated from said radiative source, to one of said exit port holes, each exit port hole receiving radiation reflected from one or more of said off-axis ellipsoidal mirror segment surfaces; and

wherein each of said off-axis ellipsoidal mirror segment surfaces has a first focus and a second focus with the first focus of each of said off-axis ellipsoidal mirrors coincident with at least one of the emitting portions of said radiative source and with the second focus of each of said off-axis ellipsoidal mirrors located in such a manner that light rays reflected from each of said off-axis ellipsoidal mirrors are directed to substantially avoid intercepting said radiative source.

29. The radiation collecting assembly according to claim 28, wherein said off-axis ellipsoidal mirror segment surfaces comprise a set of inner surfaces of four molded parts, each molded part containing two ellipsoidal surfaces with a common first focus and distinct second focus.

30. The radiation collecting assembly according to claim 28, wherein said assembly is extremely compact and further comprises:

an alignment means to control the translational and rotational position of each of said mirrors relative to each other said mirrors and said radiative source; and

a thermal management system including cooling and spring-like elements to compensate for expansion and contraction of said mirrors over a temperature range.

31. A high intensity illumination system comprising:

a high intensity light source for generating light with emitting portions;

a light collecting assembly for collecting the light from the light source, wherein said light collecting assembly comprises,

a plurality of optical light pipes,

a plurality of mirrors that surround the emitting portions of said light source, each of said mirrors comprising two off-axis ellipsoidal mirror segment surfaces, each off-axis ellipsoidal mirror segment surface reflecting the light generated from said light source to a corresponding optical light pipe, each optical light pipe receiving radiation reflected from one of said off-axis ellipsoidal mirror segment surfaces; and

wherein each of said off-axis ellipsoidal mirror segment surfaces has a first focus and a second focus with the first focus of each of said off-axis ellipsoidal mirrors coincident with at least one of the emitting portions of said light source and with the second focus of each of said off-axis ellipsoidal mirror segment substantially coincident with a corresponding optical light pipe located in such a manner that light rays reflected from each of said off-axis ellipsoidal mirror segments are directed to substantially avoid intercepting said light source; and

a waveguide, responsive to the light output received from said plurality of optical light pipes, for transmitting said light output to provide remote illumination.

32. The illumination system of claim 31, wherein each of said optical light pipes being formed of one of said glass, fused silica and sapphire.

33. The illumination system according to claim 31, wherein each of said optical light pipes is coated with at least one of a dielectric infrared reflecting coating, an ultraviolet reflecting coating and a transmitting dichromic film.

34. The illumination system according to claim 31, wherein said off-axis ellipsoidal mirror segments comprise a set of inner surfaces of four molded parts, each molded part containing two ellipsoidal surfaces with a common first focus and distinct second focus.

35. The illumination system according to claim 31, wherein said light collecting assembly further comprises:

an alignment means to control the translational and rotational position of each of said mirrors relative to each other said and said light source; and

a thermal management system including cooling and spring-like elements to compensate for expansion and contraction of said mirrors over a temperature range.

36. A method of retrofitting an aircraft display system with a plurality of remote illumination units, a plurality of mechanical dimmers, and a plurality of new display heads with a thickness no greater than one inch comprising:

packaging each of said new display heads to preclude shadowing of instruments adjacent to a set of predetermined display installation areas on an aircraft instrument panel, to preclude interfering with a predetermined pilot ejection envelope, and to preclude interfering with a set of aircraft controls;

removing existing instruments and displays from the set of predetermined display installation areas on the aircraft instrument panel;

installing said new display heads in said predetermined display installation areas, wherein said new display heads overlay the instrument panel where the existing instruments had been previously located;

installing said mechanical dimmers in the mounting provisions of an existing instrument; and

installing said remote illumination system in the mounting provisions of an existing instrument.