Device having reflective and transmissive properties

• US 6,819,465 B2
• Filed: 10/29/2002
• Issued: 11/16/2004
• Est. Priority Date: 01/22/1998
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Trinium Technologies
• Inventors: Lubart, Neil D., Clikeman, Richard W., Mayfield, Charles Ronald
• Primary Examiner(s): Dang, Hung Xuan
• Application Number:
  US10/282,702
• Publication Number:
  US 20030117682A1
• Time in Patent Office: 749 Days
• Field of Search: 359/247, 359/245, 359/252, 359/253, 359/237
• US Class Current: 359/247
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• 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
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02F 1/133555 Transflectors

Abstract

A device which simultaneously maximizes light reflectivity from one side of the device while maximizing light transmissivity from the opposite side of the device. The device is configured with distinct regions of transparency and reflectivity including a plurality of reflective structures. The structures are generally smaller towards a light transmitting side of the device and larger towards a light reflective side of the device.

Claims

1. A device having reflective and transmissive properties, comprising:

a transparent material having a first surface, and an opposed second surface, the transparent material permitting light arriving from a first direction to enter the first surface, transmit through the transparent material, and exit the second surface; and

a plurality of reflecting structures, disposed within or upon the transparent material, the reflecting structures being configured to reflect light arriving from a second direction, that is opposite the first direction, wherein the sum of the percentage of light being transmitted, relative to the amount of light arriving from the first direction, and the percentage of light being reflected, relative to the amount of light coming from the second direction, is greater than 100 percent.

2. The device of claim 1, wherein the reflective structures are comprised of a material having an index of refraction that is not equal to the index of refraction of the transparent material.

3. The device of claim 1, wherein the reflective structures are comprised of a base, the base being parallel to the second surface, and a plurality of sidewalls, extending at an angle from the base, and joining towards the first surface.

4. The device of claim 3, wherein the base of the reflective structures may be either square or rectangular.

5. The device of claim 3, wherein the shape of the sidewalls is selected from the group consisting of linear, concave, convex, and any combination thereof.

6. The device of claim 3, wherein the reflecting structures have a height, and the ratio of the height to the width of the base is between about 4 and 22.

7. A device having transmissive and reflective properties, comprising:

a transparent material having a first surface and an opposing second surface;

a plurality of spaced-apart reflecting structures, provided within the transparent material, the reflecting structures configured to provide a base surface that presents an area of reflective material on the second surface, wherein the base surface is configured to reflect light from a second direction, and sidewalls that join toward the first surface, and present a smaller area of reflective material on the first surface relative to the amount of reflective material presented by the base surface; and

wherein the sum of the percentage of light being transmitted through the transparent material from the first direction, and the percentage of light being reflected from a second direction, opposite the first direction, said light being reflected off the base surface, is greater than 100 percent.

8. The device of claim 7, wherein the reflecting structures have a shape that includes a base and a plurality of sidewalls.

9. The device of claim 7, wherein the base is parallel to the second surface of the transparent material.

10. The device of claim 7, wherein the reflecting structures have a height, and the ratio of the height to the width of the base is between about 4 and 22.

11. The device of claim 7, wherein the plurality of sidewalls extend out at an angle from the base, and converge toward the first surface of the transparent material.

12. The device of claim 7, wherein the contour of the sidewalls is selected from the group consisting of linear, concave, convex, and any combination thereof.

13. The device of claim 7, wherein regions of transparent material between the reflecting structures act as wave guide structures, guiding light impingent on the first surface through the transparent material and allowing it to exit from the second surface.

14. The device of claim 13, wherein the transparent material and the reflecting structures have unequal indexes of refraction.

15. A collimating device comprising:

a transparent substrate having a first surface and a second surface, the transparent substrate having an index of refraction;

a plurality of spaced-apart wave guide structures provided in the transparent substrate, the plurality of wave guide structures having an index of refraction different than the index of refraction of the transparent substrate, each wave guide structure having a reflective base surface associated with the second surface of the transparent substrate; and

wherein the sum of the percentage of light being transmitted through the transparent substrate from the first direction, and the percentage of light being reflected from a second direction, opposite the first direction, said light being reflected off the base surface, is greater than 100 percent.