CALIBRATION METHOD OF PROJECTION EFFECT

• US 20100127986A1
• Filed: 11/21/2008
• Published: 05/27/2010
• Est. Priority Date: 11/21/2008
• Status: Active Grant

• Current Assignee: National Chung-Shan Institute of Science and Technology
• Original Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China)
• Inventors: LIAO, CHIH-MING
• Granted Patent: US 8,102,371 B2
• Time in Patent Office: Days
• US Class Current: 345/166
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry

Abstract

The present invention provides a calibration method of projection effect. The calibration method of projection effect according to the invention comprises the following steps. The first, step (a) is performed to make an optical navigation system move along a predetermined trace relative to an object plane. Then, step (b) is performed to sense the predetermined trace by a sensor to obtain a projection trace. The next, step (c) is performed to calculate a projection effect value according to the included angle between a reflected light and the object plane. Finally, step (d) is performed to calibrate the projection trace with the projection effect value to obtain a calibration trace which is in proportion to the predetermined trace.

Claims

1. A calibration method of projection effect for an optical navigation system provided with a light emitting module and a sensor, wherein the light emitted by the light emitting module is reflected to the sensor by an object plane, the calibration method of projection effect comprising:

(a) making the optical navigation system move along a predetermined trace relative to the object plane;

(b) sensing the predetermined trace by the sensor to obtain a projection trace;

(c) calculating a projection effect value according to the included angle between a reflected light and the object plane; and

(d) calibrating the projection trace with the projection effect value, to obtain a calibration trace in proportion to the predetermined trace.

2. The calibration method of projection effect of claim 1, wherein a first direction perpendicular to the reflected light and a second direction perpendicular to the first direction are defined on the object plane, the predetermined trace having a first real displacement along the first direction and a second real displacement along the second direction.

3. The calibration method of projection effect of claim 2, wherein the projection trace has a second projection displacement corresponding to the second real displacement, and step (d) further comprising:

(d1) calibrating the second projection displacement with the projection effect value to obtain the calibration trace in proportion to the predetermined trace.

4. The calibration method of projection effect of claim 1, wherein the optical navigation system is an optical mouse or a finger navigator.

5. The calibration method of projection effect of claim 1, wherein step (b) to step (d) are performed by an image processor.

6. The calibration method of projection effect of claim 5, wherein the image processor is one selected from a group consisting of an integrated circuit (IC), an application-specific integrated circuit (ASIC), a digital signal processing (DSP), and a central processing unit (CPU).

7. A calibration method of projection effect for an optical navigation system is provided with a light emitting module and a sensor, wherein the light emitted by the light emitting module is reflected to the sensor by an object plane, the calibration method of projection effect comprising:

(a) making an optical navigation system move along a predetermined trace relative to the object plane;

(b) sensing the predetermined trace by the sensor to obtain a projection trace;

(c) calculating a projection effect value according to the projection trace; and

(d) calibrating the projection trace according to the predetermined trace and the projection effect value to obtain a calibration trace in proportion to the predetermined trace.

8. The calibration method of projection effect of claim 7, wherein a first direction perpendicular to the reflected light and a second direction perpendicular to the first direction are defined on the object plane, the predetermined trace having a first real displacement along the first direction and a second real displacement along the second direction, and step (a) further comprising:

(a1) calculating the real ratio according to the first real displacement and the second real displacement.

9. The calibration method of projection effect of claim 8, wherein the real ratio is 1.

10. The calibration method of projection effect of claim 9, wherein the pre-determined trace is one selected from a group consisting of an L-shape trace, a circle trace and a square trace.

11. The calibration method of projection effect of claim 8, wherein the projection trace has a first projection displacement corresponding to the first real displacement and a second projection displacement corresponding to the second real displacement, and step (c) further comprising:

(c1) calculating the projection effect value according to the first projection displacement and the second projection displacement.

12. The calibration method of projection effect of claim 11, wherein the step (d) further comprises:

(d1) judging if the projection effect value is equal to the real ratio, if not, then perform step (d2)

(d2) calibrating the second projection displacement according to the real ratio and the projection effect value, so as to obtain a calibration trace in proportion to the predetermined trace.

13. The calibration method of projection effect of claim 7, wherein the optical navigation system is an optical mouse or a finger navigator.

14. The calibration method of projection effect of claim 7, wherein step (a) is performed by an XY-Table or a robot.

15. The calibration method of projection effect of claim 7, wherein step (b) to step (d) are performed by an image processor.

16. The calibration method of projection effect of claim 15, wherein the image processor is one selected from a group consisting of an integrated circuit (IC), an application-specific integrated circuit (ASIC), a digital signal processing (DSP), a central processing unit (CPU).