Optical touch control apparatus and method thereof

• US 8,325,154 B2
• Filed: 02/13/2008
• Issued: 12/04/2012
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lin, Cho-Yi, Hsu, Yao-Ching, Chen, Hui-Hsuan, Lee, Chin-Chou, Li, Kuo-Hsiung, Chen, Hsin-Chia
• Primary Examiner(s): OSORIO, RICARDO
• Application Number:
  US12/069,965
• Publication Number:
  US 20080259052A1
• Time in Patent Office: 1,756 Days
• Field of Search: 345173-178, 345/207, 178 1801- 1807, 178 1901- 1905
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

The present invention discloses an optical touch control apparatus, comprising: a light guide module having an optical information capturing position, the light guide module guiding light to the optical information capturing position, and generating optical information according to light input through or reflected from the optical information capturing position; and an image sensor module for sensing the optical information, and generating an electronic signal according to the optical information.

Claims

1. An optical touch control apparatus, comprising:

a light source projecting light;

a light guide module having an optical information capturing position on a working surface, the light guide module guiding the light projected from the light source to the optical information capturing position, and generating optical information according to light input through or reflected from the optical information capturing position, wherein the optical information relates to movement of an input device;

an image sensor module for sensing the optical information, and generating an electronic signal according to the optical information, wherein the image sensor module is located at a lateral side of the light guide module; and

a lens module including a first lens interposed between the optical information capturing position and the light guide module, and a second lens interposed between and the light guide module and the image sensor module, wherein the lens module and the light guide module are integrated as one piece, and the lens module focuses light passing through the lens module;

wherein the light guide module includes a bevel at a side opposing to the optical information capturing position, the bevel having a relative angle with respect to the working surface such that at least part of the light projected from the light source is transmitted through the bevel to reach the optical information capturing position and reflected from the optical information capturing position to reach the bevel, and at least part of the light reflected from the optical information capturing position to reach the bevel is reflected by the bevel to the image sensor module.

2. The apparatus as claimed in claim 1, wherein the light source is an infrared light source and projects linear light.

3. The apparatus as claimed in claim 2, wherein the light guide module has a trapezoidal cross section and transforms the light projected from the light source into planar light.

4. The apparatus as claimed in claim 1, wherein said electronic signal is sent to a processor circuit to generate three-dimensional information.

5. The apparatus as claimed in claim 4, wherein the image sensor module includes at least two image sensors having a relative distance T therebetween, each image sensor having a focal distance f, and wherein said three-dimensional information (X, Y, Z) is obtained by

X=(T×

x_l)/(x₁−

x_r);

Y=(T×

y_l)/(x₁−

x_r); and

Z=f×

[T/(x_l−

x_r)],

wherein x_l and y_l are two-dimensional coordinates obtained by one image sensor, and x_r and y_r are two-dimensional coordinates obtained by the other image sensor.

6. The apparatus as claimed in claim 1, wherein the input device includes a portion made of a reflective material.

7. The apparatus as claimed in claim 1, further comprising a feedback control circuit which controls illumination of the light source according to the optical information generated by the light guide module.

8. The apparatus as claimed in claim 7, wherein said feedback control circuit receives signals from the image sensor module or from the processor circuit.

9. The apparatus as claimed in claim 1, wherein the optical information capturing position is an opening.

10. The apparatus as claimed in claim 1, wherein the optical information capturing position is a surface, and the surface is a part of a physical contact button.

11. The apparatus as claimed in claim 1, wherein the optical information capturing position has an area most of which is coverable by a finger or an input device.

12. A method for controlling an optical touch control apparatus, comprising:

projecting light;

providing a light guide module having a working surface on which is provided an optical information capturing position, the light guide module guiding the projected light to the optical information capturing position, wherein the light guide module includes a bevel at a side opposing to the optical information capturing position, the bevel having a relative angle with respect to the working surface such that at least part of the projected light is transmitted through the bevel to reach the optical information capturing position and reflected from the optical information capturing position to reach the bevel, and at least part of the light reflected from the optical information capturing position to reach the bevel is reflected by the bevel to a lateral side of the light guide module, wherein the optical information relates to movement of an input device;

causing the light guide module to generate optical information according to light input through or reflected from the optical information capturing position; and

sensing the optical information by an image sensor from the lateral side of the light guide module, and generating an electronic signal according to the optical information,

wherein the light guide module is integrated with a lens module as one piece, the lens module including a first lens interposed between the optical information capturing position and the light guide module, and a second lens interposed between the light guide module and where the optical information is sensed, and the lens module focusing light passing through the lens module.

13. The method as claimed in claim 12, wherein the projected light is linear infrared light, and the light guide module has a trapezoidal cross section, the light guide module transforming the linear infrared light into planar infrared light.

14. The method as claimed in claim 13, further comprising:

generating a feedback signal according to the optical information, to control the illumination of the infrared light.

15. The method as claimed in claim 12, further comprising:

controlling a cursor on a display according to the electronic signal.

16. The method as claimed in claim 12, further comprising:

controlling three-dimensional information according to the electronic signal.

17. The method as claimed in claim 12, further comprising:

moving the input device on or above the optical information capturing position of the light guide module, the input device being at least partially made of a reflective material.

18. The method as claimed in claim 12, wherein the optical information capturing position has an area most of which is coverable by a finger or an input device.