Calibration method of projection effect

• US 8,102,371 B2
• Filed: 11/21/2008
• Issued: 01/24/2012
• 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
• Primary Examiner(s): Pardo, Thuy
• Application Number:
  US12/276,249
• Publication Number:
  US 20100127986A1
• Time in Patent Office: 1,159 Days
• Field of Search: 345/156, 345/163, 345/179, 345/424, 345/166, 345/175, 345/178, 345/589, 356/394
• 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 between an object plane O upon which an optical navigation system is disposed, and an image plane M of a sensor of the optical navigation system comprising a light emitting module and the sensor,

wherein an incident light is emitted by the light emitting module and reflected by the object plane O as an reflected light on the image plane M,

an included angle θ

_i is an angle of non-zero value between the reflected light and O,

a directional A1 on the object plane is perpendicular to the reflected light, and

a directional A2 on the object plane is perpendicular to A1;

the calibration method of projection effect comprising steps;

(a) moving the optical navigation system with a first and a second real displacement of X_0d, and Y_0d along A1 and A2, respectively, along a predetermined trace relative to the object plane, and a ratio of Y_0d;

X_0d being R;

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

(c) calculating a projection effect value PF according to θ

_s;

if R=1, PF=sin θ

_s; and

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

2. The calibration method of projection effect of claim 1, 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.

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

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

5. The calibration method of projection effect of claim 4, 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).

6. A calibration method of projection effect between an object plane O upon which an optical navigation system is disposed, and an image plane M of a sensor of the optical navigation system comprising a light emitting module and the sensor,

wherein an incident light is emitted by the light emitting module and reflected by the object plane O as an reflected light on the image plane M,

an included angle θ

_i is an angle of non-zero value between the reflected light and O,

a directional A1 on the object plane is perpendicular to the reflected light, and

a directional A2 on the object plane is perpendicular to A1;

the calibration method of projection effect comprising steps;

(a) moving an optical navigation system with a first and a second real displacement of X_0d, and Y_0d along A1 and A2, respectively, along a predetermined trace relative to the object plane O;

(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.

7. The calibration method of projection effect of claim 6, wherein step (a) further comprising:

step (a1) calculating la real ratio being the ratio of the second real displacement to the first real displacement.

8. The calibration method of projection effect of claim 7, wherein the real ratio is 1.

9. The calibration method of projection effect of claim 8, wherein the predetermined trace is one selected from a group consisting of an L-shape trace, a circle trace and a square trace.

10. The calibration method of projection effect of claim 7, 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:

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

11. The calibration method of projection effect of claim 10, wherein the step (d) further comprises:

step (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.

12. The calibration method of projection effect of claim 6, wherein the optical navigation system is an optical mouse or a finger navigator.

13. The calibration method of projection effect of claim 6, wherein step (a) is performed by an XY-Table or a robot.

14. The calibration method of projection effect of claim 6, wherein step (b) to step (d) are performed by an image processor.

15. The calibration method of projection effect of claim 14, 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).