Flat parallel light source

• US 5,839,812 A
• Filed: 07/18/1995
• Issued: 11/24/1998
• Est. Priority Date: 07/18/1995
• Status: Expired due to Fees

• Current Assignee: Transmarine Enterprises Limited
• Original Assignee: GL Displays Incorporated
• Inventors: Ge, Xiaoqin, Ge, Shichao, Huang, Xi
• Primary Examiner(s): Sember, Thomas M.
• Application Number:
  US08/503,588
• Time in Patent Office: 1,225 Days
• Field of Search: 362/26, 362/27, 362/29, 362/30, 362/31, 362/224, 362/328, 362/330, 349/62, 349/63, 349/64, 349/65
• US Class Current: 362/607
• CPC Class Codes: G02B 6/003 Lens or lenticular sheet or layer
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0071 with elongated shape, e.g. tube

Abstract

The present invention relates to a flat parallel light source using the principle of the mirror reflection and diffuse reflection, which comprises a light source, a diffuse reflective chamber with high reflectance walls, a light coupler, a small hole array at the top surface of said diffuse reflective chamber, a mirror reflective cone array on the small hole array, and a convex lens array on said cone array. The light generated by the light pass through the light coupler into the diffuse reflective chamber, and then pass through the small hole array, mirror reflective cone array, and lens array to form parallel light. The flat parallel light source can generate a high intensity parallel light with excellent parallelism or a given scattering angle parallel light. It can be used for backlighting for all kinds of LCDs, and other equipment where parallel light is needed. It can also be used in LCDs to increase the brightness of the display image and reduce power consumption.

Claims

1. A flat device for supplying parallel light, comprising:

a hot cathode fluorescent lamp;

a diffuse reflective chamber with high reflectance walls receiving light from the light source;

an array of holes at a surface of the diffuse reflective chamber;

an array of light reflective cones adjacent to the surface;

each of said cones having a pointed end and a non-pointed end; and

an array of convex lenses adjacent the non-pointed ends of the cones;

wherein each of the cones is substantially aligned along a common axis with a corresponding lens in the array of lenses and is between the corresponding lens and a corresponding hole in the array of holes;

wherein light from the light source passes into diffuse reflective chamber, and then through said holes into said cones and through said lenses to provide parallel output light wherein said fluorescent lamp is further enclosed within a glass pipe, said pipe defining a vacuum chamber therein for housing said lamp to reduce heat loss from the fluorescent lamp, to increase the efficiency of the fluorescent lamp and to thermally insulate the fluorescent lamp from an environment.

2. The device of claim 1, further comprising a reflector surrounding the light source to collect and convey the light emitted from the light source into the reflective chamber.

3. The device of claim 2, wherein said reflector comprises a Ag, Al or alloy thin film.

4. A flat device for supplying parallel light, comprising:

a light source;

a diffuse reflective chamber with high reflectance walls receiving light from the light source;

an array of holes at a surface of the diffuse reflective chamber;

an array of light reflective cones adjacent to the surface;

each of said cones having a pointed end and a non-pointed end; and

an array of convex lenses adjacent the non-pointed ends of the cones;

wherein each of the cones is substantially aligned along a common axis with a corresponding lens in the array of lenses and is between the corresponding lens and a corresponding hole in the array of holes;

wherein light from the light source passes into diffuse reflective chamber, and then through said holes into said cones and through said lenses to provide parallel output light further comprising high reflectance walls that define therein a diffuse reflective chamber wherein at least one wall is a diffuse reflective wall and wherein said device further comprises a light window connected to the chamber.

5. The device of claim 4, said chamber having four sides, wherein said light source is at one side, two sides or four sides of the reflective chamber.

6. A flat device for supplying parallel light, comprising:

a light source;

a diffuse reflective chamber with high reflectance walls receiving light from the light source;

an array of holes at a surface of the diffuse reflective chamber;

an array of light reflective cones adjacent to the surface;

each of said cones having a pointed end and a non-pointed end; and

an array of convex lenses adjacent the non-pointed ends of the cones;

wherein each of the cones is substantially aligned along a common axis with a corresponding lens in the array of lenses and is between the corresponding lens and a corresponding hole in the array of holes;

wherein light from the light source passes into diffuse reflective chamber, and then through said holes into said cones and through said lenses to provide parallel output light, and wherein the diffuse reflective chamber is shaped as a flat panel with two sides, wherein the light source is closer to one side than the other, and wherein the side near the light source is thicker, and the other side is thinner to make the output light from the holes more uniform.

7. The device of claim 6, further comprising walls that define therein the diffuse reflective chamber, said walls including a high reflectance thin film that comprises Ag, Al or an alloy.

8. A flat device for supplying parallel light, comprising:

a light source;

a diffuse reflective chamber with high reflectance walls receiving light from the light source;

an array of holes at a surface of the diffuse reflective chamber;

an array of light reflective cones adjacent to the surface;

each of said cones having a pointed end and a non-pointed end; and

an array of convex lenses adjacent the non-pointed ends of the cones;

wherein each of the cones is substantially aligned along a common axis with a corresponding lens in the array of lenses and is between the corresponding lens and a corresponding hole in the array of holes;

wherein light from the light source passes into diffuse reflective chamber, and then through said holes into said cones and through said lenses to Provide parallel output light, wherein said cones have different oblique angles between their walls and a line normal to a surface of the diffuse reflective chamber, said oblique angles having a range from 1°

to 60°

.

9. The device of claim 8, wherein said cones comprise high reflectance mirror reflective walls, said walls including a thin film composed of Al, Ag or an alloy.

10. The device of claim 8, wherein said cones have circular, elliptical, square or rectangular shapes.

11. The device of claim 8, wherein said reflective cones contain a medium and said diffuse reflective chamber contains a medium that is the same as that in the cones, said medium including transparent plastic, glass or air.

12. The device of claim 8, wherein the reflective cone and the diffuse reflective chamber are attached to reduce light reflection between said reflective cone and said diffuse reflective chamber.

13. The device of claim 8, wherein said convex lenses have non-spherical surface to provide parallel output light.

14. The device of claim 8, wherein said array of cones and said array of lenses are made into and as one piece.

15. The device of claim 8, wherein said array of cones and said array of lenses are separated and independent of one another.

16. A flat device for supplying parallel light, comprising:

a light source;

a diffuse reflective chamber with high reflectance walls, receiving light from the light source;

an array of holes at a surface of the diffuse reflective, chamber;

an array of light reflective cones adjacent to the surface;

each of said cones having a pointed end and a non-pointed end; and

an array of convex lenses adjacent the non-pointed ends of the cones;

wherein each of the cones is substantially aligned along a common axis with a corresponding lens in the array of lenses and is between the corresponding lens and a corresponding hole in the array of holes;

wherein light from the light source passes into diffuse reflective chamber, and then through said holes into said cones and through said lenses to provide parallel output light, wherein the pointed end of each cone is substantially at the focal point of the corresponding lens.

17. A flat parallel light source, comprising

a light source;

a lens array;

a diffuse reflective chamber with light reflectance walls;

an array of holes at a surface of the diffuse reflective chamber; and

an array of light reflective cones on the surface of the, diffuse reflective chamber, each of said cones having a pointed end, and a non-pointed end, wherein said pointed end of each cone is aligned with a corresponding hole;

wherein light from the light source passes into said diffuse reflective chamber, and then through said holes into said cones and the lens array to provide parallel output light, said device further comprising a reflector collecting light emitted by the light source and light coupler between said light source and said diffuse reflective chamber to guide passage of light from said light source to said diffuse reflective chamber.