OPTICAL TOUCH DISPLAY

• US 20110316813A1
• Filed: 11/04/2010
• Published: 12/29/2011
• Est. Priority Date: 06/23/2010
• Status: Abandoned Application

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Gu, Ren-Hau, Lin, Chih-Hsin, Chen, Hsin-Chia, Huang, Yu-Hao, Yang, Shu-Sian, Su, Tzung-Min
• Application Number:
  US12/939,173
• Publication Number:
  US 20110316813A1
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

When an object touches a touch panel, a projection light source projects a predetermined image including image information and forms an object image having the image information on a surface of the object. An image sensor captures a reflection image including the object image. Then, an angle is calculated according to an image location of the object in the reflection image and a relative position of predetermined axis, and a distance between the object and the image sensor is calculated by comparing the predetermined image with the location, size and/or phase of the image information of the reflection image so as to determine a coordinate of the object on the touch panel according to the angle and the distance.

Claims

1. An optical touch display comprising:

a touch panel contactable by at least one object, the touch panel having a first predetermined axis;

at least one projection light source for projecting at least one predetermined image comprising at least one predetermined pattern onto the touch panel, and forming at least one similar pattern on a surface of the object;

at least one image sensor for capturing at least one reflection image comprising an image of the object, wherein the at least one reflection image comprises the at least one similar pattern;

an angle calculation module, for finding a line between an image sensor of the at least one image sensor and the object according to an image formation position of the object in the at least one reflection image for calculating a difference angle between the connecting line and the first predetermined axis;

a distance calculation module for comparing positions, dimensions and/or phases of a predetermined pattern of the at least one predetermined pattern and a similar pattern of the at least one similar pattern for calculating straight line distance of an image sensor between the at least one image sensor and the object; and

an object positioning module for locating position coordinates of the object on the touch panel according to the difference angle and the straight line distance.

2. The optical touch display of claim 1, wherein the predetermined pattern is a speckle pattern or a coded pattern.

3. The optical touch display of claim 1, wherein the at least one image sensor comprises a first image sensor and a second image sensor, the first image sensor captures a first reflection image utilized by the angle calculation module in calculating the difference angle, and the second image sensor captures a second reflection image utilized by the distance calculation module in calculating the straight line distance.

4. The optical touch display of claim 3, wherein the first image sensor is an infrared image sensor for capturing infrared light, and a projection light source of the at least one projection light source is an infrared light source for projecting infrared light onto the touch panel for the first image sensor to capture the first reflection image comprising an image of the object.

5. The optical touch display of claim 3, wherein a projection light source of the at least one projection light source is capable of emitting monochromatic narrow-wavelength light, and the second image sensor is utilized for capturing the second reflection image comprising a similar pattern formed on the object surface by the projection light source.

6. An optical touch display comprising:

a touch panel contactable by at least one object;

at least one projection light source for projecting a predetermined image comprising a pattern onto the touch panel, and forming the pattern on a surface of the object;

at least one image sensor for capturing at least one reflection image comprising an image of the object, wherein the at least one reflection image comprises the pattern;

an angle calculation module, for finding a line between the image sensor and the object according to an image formation position of the object in the reflection image for calculating a difference angle between the connecting line and a first predetermined axis;

a distance calculation module for calculating time difference between emitting the predetermined image comprising the pattern and receiving the reflection image comprising the pattern for calculating straight line distance between the image sensor and the object; and

an object positioning module for locating position coordinates of the object on the touch panel according to the difference angle and the straight line distance.

7. The optical touch display of claim 6, wherein the at least one image sensor comprises a first image sensor and a second image sensor, the first image sensor is for capturing a first reflection image for the angle calculation module to calculate the difference angle, and the second image sensor is for capturing a second reflection image for the distance calculation module to calculate the straight line distance.

8. The optical touch display of claim 7, wherein the first image sensor is an infrared image sensor for capturing infrared light, and further providing an infrared light source for projecting infrared light onto the touch panel for the first image sensor to capture the first reflection image comprising image formation information of the object.

9. The optical touch display of claim 7, wherein the projection light source is capable of emitting monochromatic narrow-wavelength light, and the second image sensor is utilized for capturing the second reflection image comprising the pattern formed on the object surface by the projection light source.

10. An optical touch display comprising:

a touch panel contactable by at least one object;

at least one image sensor for capturing at least one reflection image reflected by a surface of the object;

an angle calculation module for finding a connecting line between the image sensor and the object according to an image formation position of the object in the reflection image for calculating a difference angle between the connecting line and a predetermined axis of the touch panel;

a distance calculation module for calculating straight line distance between the image sensor and the object according to image formation size and/or image formation brightness of the object in the reflection image; and

an object positioning module for locating position coordinates of the object on the touch panel according to the difference angle and the straight line distance.

11. The optical touch display of claim 10, wherein the at least one image sensor comprises a first image sensor and a second image sensor, the first image sensor captures a first reflection image utilized by the angle calculation module in calculating the difference angle, and the second image sensor captures a second reflection image utilized by the distance calculation module in calculating the straight line distance.

12. The optical touch display of claim 11, wherein the first image sensor is an infrared image sensor for capturing infrared light, and further provides an infrared light source for projecting infrared light onto the touch panel for the first image sensor to capture the first reflection image comprising image formation information of the object.

13. The optical touch display of claim 11, wherein the second image sensor is an infrared image sensor for capturing infrared light, and further providing an infrared light source for projecting infrared light onto the touch panel for the second image sensor to capture the second reflection image comprising image formation information of the object.

14. An optical touch display comprising:

a touch panel contactable by at least one object;

at least one image sensor for capturing a reflection image reflected from a surface of the object;

an ultrasound transceiver for projecting an ultrasound signal onto the touch panel, and receiving an ultrasound reflection signal reflected from the object;

an angle calculation module for finding a line between the image sensor and the object according to an image formation position of the object in the reflection image for calculating a difference angle between the connecting line and a first predetermined axis;

a distance calculation module for calculating time difference between emitting the ultrasound signal and receiving the reflection image for calculating straight line distance between the ultrasound transceiver and the object; and

an object positioning module for locating position coordinates of the object on the touch panel according to the difference angle and the straight line distance.

15. The optical touch display of claim 14, wherein the image sensor is an infrared image sensor for capturing infrared light, and further provides an infrared light source for projecting infrared light onto the touch panel for the image sensor to capture the reflection image comprising image formation information of the object.

16. An optical touch display comprising:

a touch panel contactable by at least one object;

a first projection light source for projecting a first predetermined image comprising a first predetermined pattern onto the touch panel, and forming a first similar pattern on a surface of the object;

a second projection light source for projecting a second predetermined image comprising a second predetermined pattern onto the touch panel, and forming a second similar pattern on a surface of the object;

a first image sensor for capturing a first reflection image comprising the first similar pattern of the object;

a second image sensor for capturing a second reflection image comprising the second similar pattern of the object;

a distance calculation module for comparing positions, dimensions and/or phases of the first similar pattern of the first reflection image, the second similar pattern of the second reflection image, the first predetermined image, and the second predetermined image for calculating straight line distance between the object and the first image sensor, and straight line distance between the object and the second image sensor; and

an object positioning module for locating position coordinates of the object on the touch panel according to the straight line distance between the object and the first image sensor, and the straight line distance between the object and the second image sensor.

17. The optical touch display of claim 16, wherein the first predetermined patter and the second predetermined pattern are speckle patterns or coded patterns.

18. The optical touch display of claim 16, wherein the first projection light source and the second projection light source are capable of emitting monochromatic narrow-wavelength light.