Optical overlay for an electronic display

• US 8,330,736 B2
• Filed: 11/19/2009
• Issued: 12/11/2012
• Est. Priority Date: 11/19/2009
• Status: Active Grant

• Current Assignee: Garmin International, Inc. (Garmin Limited)
• Original Assignee: Garmin International, Inc. (Garmin Limited)
• Inventors: Klein, Jared S., Rudebusch, Andrew C., Rippel, Laura A.
• Primary Examiner(s): Haley, Joseph
• Assistant Examiner(s): LEE, NICHOLAS J
• Application Number:
  US12/621,627
• Publication Number:
  US 20110115720A1
• Time in Patent Office: 1,118 Days
• Field of Search: None
• US Class Current: 345/173
• CPC Class Codes: G02B 27/0938 Using specific optical elements
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G06F 1/1609 to support filters or lenses
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An optical overlay filters radiation striking the overlays at a non-planar incidence angle while passing and focusing in-plane signals. In embodiments, an optical overlay comprises an inner wall, an outer wall, an upper wall, and a lower wall. The inner wall may be formed to include a planar surface. The outer wall may be spaced apart from the inner wall and may be formed to include a convex surface. The combination of the planar surface of the inner wall and the convex surface of the outer wall may form a plano-convex lens. The upper wall may include a first plurality of ridges that are generally parallel to the inner wall. The lower wall may include a second plurality of ridges that are generally parallel to the inner wall. The combination of the first plurality of ridges and the second plurality of ridges may form an optical filter.

Claims

1. An optical module comprising:

a lens including a planar surface and a convex surface configured to collimate and focus an optical signal; and

a filter coupled to the lens, including an upper wall and an opposing lower wall, each wall including a plurality of reflective elements that are angled with respect to the vertical and configured to pass the optical signal and to reflect at least some radiation traveling on a path that is not parallel to the upper wall and the lower wall;

wherein each reflective element includes a first reflective surface coupled along a top edge to an opposing second surface, such that the first surface is configured to reflect at least some radiation toward the planar surface of the lens and the second surface is configured to reflect at least some radiation from the upper wall to the lower wall and from the lower wall to the upper wall.

2. The module of claim 1, wherein the filter further includes a coating configured to scatter and/or absorb radiation that strikes the filter.

3. The module of claim 1, wherein the filter is positioned between the planar surface and the convex surface of the lens.

4. The module of claim 1, wherein the first reflective surface is positioned at an angle of approximately twenty degrees with respect to the vertical.

5. The module of claim 1, wherein the second reflective surface is positioned at an angle of approximately seventy degrees with respect to the vertical.

6. An optical overlay comprising:

an inner wall that extends along a four-sided perimeter;

an outer wall spaced apart from the inner wall and extending along the four-sided perimeter;

a lens including a planar surface formed along the inner wall and a convex surface formed along the outer wall configured to collimate and to focus an optical signal;

an upper wall coupled to the top of the inner wall and the outer wall;

a lower wall coupled to the bottom of the inner wall and the outer wall; and

a filter formed along the upper wall and the lower wall and including a plurality of reflective ridges that are angled with respect to the vertical, the ridges being configured to reflect at least some radiation traveling on a path that is not parallel to the upper wall and the lower wall;

wherein each ridge includes a first reflective surface coupled along a top edge to an opposing second surface, such that the first surface is configured to reflect at least some radiation toward the planar surface of the lens and the second surface is configured to reflect at least some radiation from the upper wall to the lower wall and from the lower wall to the upper wall.

7. The optical overlay of claim 6, further including a coating applied to the upper wall and the lower wall configured to scatter and/or absorb radiation that strikes the filter.

8. The optical overlay of claim 6, wherein the first reflective surface is positioned at an angle of approximately twenty degrees with respect to the vertical.

9. The optical overlay of claim 6, wherein the second reflective surface is positioned at an angle of approximately seventy degrees with respect to the vertical.

10. An electronic display system comprising:

a display configured to display information;

a plurality of transmitters positioned along at least one side of the display and configured to transmit a plurality of optical signals;

a plurality of receivers positioned along at least one side of the display opposing the transmitters and configured to receive the optical signals; and

an optical overlay positioned around the perimeter of the display between the transmitters and the receivers and configured to collimate and focus the optical signals and to reflect at least some radiation traveling on a path that is not parallel to the optical signal, the optical overlay including;

an inner wall and a spaced apart outer wall that both extend along a four-sided perimeter,

a lens with a planar surface formed along the inner wall and a convex surface formed along the outer wall,

an upper wall coupled to the top of the inner wall and the outer wall and a lower wall coupled to the bottom of the inner wall and the outer wall, and

a filter formed along the upper wall and the lower wall and including a plurality of reflective ridges that are angled with respect to the vertical;

wherein each reflective ridge includes a first reflective surface coupled along a top edge to an opposing second surface, such that the first surface is configured to reflect at least some radiation toward the planar surface of the lens and the second surface is configured to reflect at least some radiation from the upper wall to the lower wall and from the lower wall to the upper wall.

11. The electronic display system of claim 10, wherein the optical overlay further includes a coating applied to the upper wall and the lower wall configured to scatter and/or absorb radiation that strikes the filter.

12. The electronic display system of claim 10, wherein the first reflective surface is positioned at an angle of approximately twenty degrees with respect to the vertical.

13. The electronic display system of claim 10, wherein the second reflective surface is positioned at an angle of approximately seventy degrees with respect to the vertical.

14. A method of creating an optical overlay, the method comprising the steps of:

a) forming a four-sided ring of a material wherein each side includes an inner wall, an outer wall, an upper wall, and a lower wall;

b) forming the inner wall to have a generally planar surface;

c) forming the outer wall to have a generally convex surface, such that the outer wall in combination with the inner wall form a plano-convex lens;

d) forming a first plurality of ridges on the upper wall that are generally parallel to the inner wall; and

e) forming a second plurality of ridges on the lower wall that are generally parallel to the inner wall, such that the second plurality of ridges in combination with the first plurality of ridges form an optical filter;

wherein each ridge includes an angled forward surface facing the inner wall and an angled rear surface facing the outer wall; and

wherein the ridges are formed such that radiation that enters the optical overlay through the inner wall with a non-zero angle of incidence is reflected off of the forward surface and the rear surface.

15. The method of claim 14, further including the step of applying a coating to the upper wall and the lower wall to scatter and/or absorb radiation that contacts the optical filter.

16. The method of claim 14, wherein the material is transmissive to radiation with wavelengths ranging from approximately 870 nanometers to approximately 1050 nanometers.