OPTICAL TOUCH DISPLAY, A CALIBRATION APPARATUS AND A CALIBRATION METHOD THEREOF

• US 20130127785A1
• Filed: 08/06/2012
• Published: 05/23/2013
• Est. Priority Date: 11/21/2011
• Status: Active Grant

• Current Assignee: Wistron Corporation
• Original Assignee: Chun-Wei Wang
• Inventors: WANG, Chun-Wei
• Granted Patent: US 8,749,530 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

An optical touch display, a calibration apparatus, and a calibration method thereof are disclosed. The calibration method is used for calibrating the optical touch display, and the optical touch display has a plurality of image detecting sensors. The calibration method includes the following steps: generating a plurality of calibration points; generating a plurality of representative calibration points from the plurality of calibration points; obtaining a first image position of each representative calibration point via the plurality of image detecting sensors; constructing a coordinate transformation mechanism for transforming the first image position into a first screen position; calculating a relative position between the representative calibration points and its neighboring calibration points; calculating a second image position of each calibration point based on the relative position; and calculating a second screen position by using the transformation mechanism and the second image position.

Claims

1. A calibration method for calibrating an optical touch display, wherein the optical touch display comprises a plurality of image detecting sensors, the calibration method comprising the following steps:

generating a plurality of calibration points;

generating a plurality of representative calibration points from the plurality of calibration points;

obtaining a first image position of each representative calibration point relative to the plurality of image detecting sensors via the plurality of image detecting sensors;

constructing a coordinate transformation mechanism for transforming the first image position of each representative calibration point relative to the plurality of image detecting sensors to a first screen position of each representative calibration point relative to the optical touch display;

calculating a relative position between each representative calibration point and its neighboring calibration points;

calculating a second image position of each calibration point relative to the plurality of the image detecting sensors based on the relative position and the first image position; and

calculating a second screen position of each calibration point relative to the optical touch display via the coordinate transformation mechanism and the second image position.

2. The calibration method as claimed in claim 1, wherein constructing the coordinate transformation mechanism comprises the following steps:

generating a plurality of standard calibration points on a standard optical touch display and storing a standard screen position of each standard calibration point relative to the standard optical touch display;

obtaining a standard image position of each standard calibration point via the plurality of image detecting sensors of the standard optical touch display; and

constructing the coordinate transformation mechanism based on a coordinate transformation between the standard image position and the standard screen position.

3. The calibration method as claimed in claim 2, wherein the relative position is calculated from the standard image position of each standard calibration point.

4. The calibration method as claimed in claim 3, wherein before the first image position of each representative calibration point relative to the plurality of image detecting sensors is obtained via the plurality of image detecting sensors, the calibration method further comprises the following steps:

placing a calibration template to cover the optical touch display, wherein the calibration template comprises a plurality of opening holes whose positions correspond to the plurality of representative calibration points; and

passing a touching object through the plurality of opening holes to point to the plurality of representative calibration points to obtain the first image position of each representative calibration point relative to the plurality of image detecting sensors via the plurality of image detecting sensors.

5. A calibration apparatus for calibrating an optical touch display, wherein the optical touch display comprises a plurality of image detecting sensors, the calibration apparatus comprising:

a processor electrically connected to the plurality of image detecting sensors;

a memory electrically connected to the processor, a plurality of instructions stored in the memory, and the processor reading the plurality of instructions to perform the following mechanism;

generating a plurality of calibration points via a calibration point generating module;

generating a plurality of representative calibration points from the plurality of calibration points via a representative calibration point generating module;

obtaining a first image position of each representative calibration point relative to the plurality of image detecting sensors via the plurality of image detecting sensors;

transforming the first image position of each representative calibration point relative to the plurality of image detecting sensors to a first screen position of each representative calibration point relative to the optical touch display via a coordinate transformation mechanism;

calculating a relative position between each representative calibration point and its neighboring calibration points via a relative position generating module;

calculating a second image position of each calibration point relative to the plurality of image detecting sensors via an image position calculating module based on the relative position and the first image position; and

calculating a second screen position of each calibration point relative to the optical touch display via the coordinate transformation mechanism and based on the second image position.

6. The calibration apparatus as claimed in claim 5, wherein the processor is a control chip and the control chip is disposed on the optical touch display.

7. The calibration apparatus as claimed in claim 6 comprising:

a calibration template covering the optical touch display comprising a plurality of opening holes whose positions correspond to the plurality of representative calibration points; and

a touching object for passing through the plurality of opening holes to point to the plurality of representative calibration points to obtain the first image position of each representative calibration point relative to the plurality of image detecting sensors via the plurality of image detecting sensors.

8. An optical touch display comprising:

a plurality of image detecting sensors;

a processor electrically connected to the plurality of image detecting sensors;

a memory electrically connected to the processor, a plurality of instructions stored in the memory, and the processor reading the plurality of instructions to perform the following mechanism;

generating a plurality of calibration points via a calibration point generating module;

generating a plurality of representative calibration points from the plurality of calibration points via a representative calibration point generating module;

obtaining a first image position of each representative calibration point relative to the plurality of image detecting sensors via the plurality of image detecting sensors;

transforming the first image position of each representative calibration point relative to the plurality of image detecting sensors to a first screen position of each representative calibration point relative to the optical touch display via a coordinate transformation mechanism;

calculating a relative position between each representative calibration point and its neighboring calibration points via a relative position generating module;

calculating a second image position of each calibration point relative to the plurality of image detecting sensors via an image position calculating module based on the relative position and the first image position; and

calculating a second screen position of each calibration point relative to the optical touch display via the coordinate transformation mechanism and based on the second image position.

9. The optical touch display as claimed in claim 8, wherein the plurality of image detecting sensors is a plurality of photo sensors or a plurality of optical cameras.

10. The optical touch display as claimed in claim 8, wherein the processor is a control chip.