REDUCTION OF SOLAR INTERFERENCE IN AN INFRARED TOUCH SYSTEM

• US 20080093536A1
• Filed: 10/24/2006
• Published: 04/24/2008
• Est. Priority Date: 10/24/2006
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Brower, David Campbell, Crockett, Timothy Wayne, Talley, William Lewis
• Application Number:
  US11/552,371
• Publication Number:
  US 20080093536A1
• Time in Patent Office: Days
• US Class Current: 250/221
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An apparatus is provided for an infrared touch system that decreases solar interference. The infrared touch system includes a mounting board, which has a number of sides that encompass an area. The infrared touch system includes a number of optical detectors and optical sources mounted along the edges on the mounting board. The optical detectors and optical sources are aligned such that a central portion of a beam pattern of each optical source is directed transversely across the opening toward one of the optical detectors so that solar interference will be decreased.

Claims

1. An infrared touch system comprising:

a mounting board having four sides interconnected in a substantially rectangular configuration, wherein the mounting board has a size and a shape selected to allow the four sides to be positioned along respective edges of an opening positioned between the four sides;

a plurality of optical detectors mounted along a first plurality of the edges, including two opposite edges, on the mounting board adjacent to the opening, wherein the plurality of optical detectors are mounted at one of a first angle or a second angle to reduce interference; and

a plurality of optical sources mounted along a second plurality of the edges, including two opposite edges, on the mounting board adjacent to the opening, wherein the plurality of optical sources are mounted at one of a third angle and a fourth angle, wherein each of the plurality of optical sources has a predetermined beam pattern, wherein each of the plurality of optical sources is aligned with a corresponding optical detector on an adjacent edge of the plurality of edges, and wherein each of the plurality of optical sources is aligned such that a central portion of a beam pattern of each optical source in the plurality of optical sources is directed transversely across the opening toward one of the plurality of optical detectors so that solar interference will be decreased.

2. The infrared touch system of claim 1, wherein the plurality of optical detectors are phototransistors.

3. The infrared touch system of claim 1, wherein the plurality of optical sources are light emitting diodes.

4. The infrared touch system of claim 1, wherein the first angle is an angle of 21 degrees to 89 degrees.

5. The infrared touch system of claim 1, wherein the second angle is an angle of 91 degrees to 159 degrees.

6. The infrared touch system of claim 1, wherein the third angle is an angle of 201 degrees to 269 degrees.

7. The infrared touch system of claim 1, wherein the fourth angle is an angle of 271 degrees to 339 degrees.

8. The infrared touch system of claim 1, wherein the opening is a display opening.

9. An infrared touch system comprising:

a mounting board having a plurality of sides encompassing an area, wherein the mounting board has a size and a shape selected to allow the plurality of sides to be positioned along edges of an opening positioned within the plurality of sides;

a plurality of optical detectors mounted along the edges, including two opposite edges, on the mounting board, wherein the plurality of optical detectors are mounted at one of a first angle or a second angle to reduce interference; and

a plurality of optical sources mounted along the edges, including two opposite edges, on the mounting board, wherein the plurality of optical sources are mounted at one of a third angle and a fourth angle, wherein each of the plurality of optical sources has a predetermined beam pattern, wherein each of the plurality of optical sources is aligned with a corresponding optical detector on an adjacent edge of the edges, and wherein each of the plurality of optical sources is aligned such that a central portion of a beam pattern of each optical source in the plurality of optical sources is directed transversely across the opening toward one of the plurality of optical detectors so that solar interference will be decreased.

10. The infrared touch system of claim 9, wherein the plurality of optical detectors are phototransistors.

11. The infrared touch system of claim 9, wherein the plurality of optical sources are light emitting diodes.

12. The infrared touch system of claim 9, wherein the first angle is an angle of 21 degrees to 89 degrees.

13. The infrared touch system of claim 9, wherein the second angle is an angle of 91 degrees to 159 degrees.

14. The infrared touch system of claim 9, wherein the third angle is an angle of 201 degrees to 269 degrees.

15. The infrared touch system of claim 9, wherein the fourth angle is an angle of 271 degrees to 339 degrees.

16. The infrared touch system of claim 9, wherein the opening is a display opening.