OPTICAL DISPLACEMENT DETECTING DEVICE AND OPERATING METHOD THEREOF

• US 20100207872A1
• Filed: 11/04/2009
• Published: 08/19/2010
• Est. Priority Date: 02/17/2009
• Status: Abandoned Application

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: Pixar Imgagin Incorporated
• Inventors: Chao, Tzu Yi, Su, Tzung Min, CHEN, Hsin Chia
• Application Number:
  US12/612,491
• Publication Number:
  US 20100207872A1
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

An operating method of an optical displacement detecting device includes the steps of: capturing a plurality of images; obtaining a displacement according to the images; obtaining a characteristic variation of the images; and suppressing the output of the displacement when the characteristic variation matches a predetermined rule. The present invention further provides an optical displacement detecting device.

Claims

1. An optical displacement detecting device, comprising:

an image sensor, for capturing a plurality of images;

a light source, providing light to the image sensor during image capturing;

a processing unit, coupled to the image sensor, obtaining a displacement and a characteristic variation according to the images and determining whether to output the displacement according to the characteristic variation.

2. The optical displacement detecting device as claimed in claim 1, wherein the characteristic is an average brightness of each image.

3. The optical displacement detecting device as claimed in claim 1, wherein when the characteristic variation matches a predetermined rule, the processing unit suppresses the output of the displacement.

4. The optical displacement detecting device as claimed in claim 3, wherein the predetermined rule is that an average brightness of the images has a fixed change frequency.

5. The optical displacement detecting device as claimed in claim 4, wherein the change frequency is 100 Hz or 120 Hz.

6. The optical displacement detecting device as claimed in claim 4, wherein the change frequency is fixed when the number of the images captured by the image sensor is within a predetermined range in a predetermined number of successive decision periods.

7. The optical displacement detecting device as claimed in claim 6, wherein the decision period is a period in which the average brightness of successive images is monotonically increasing or monotonically decreasing.

8. The optical displacement detecting device as claimed in claim 4, wherein the change frequency is fixed when the number of the images captured by the image sensor is within a predetermined range in each decision period of a predetermined number of successive decision periods.

9. The optical displacement detecting device as claimed in claim 8, wherein the decision period is a period in which the average brightness of successive images is monotonically increasing or monotonically decreasing.

10. The optical displacement detecting device as claimed in claim 1, further comprising a transmission interface unit for transmitting the displacement to an image display.

11. The optical displacement detecting device as claimed in claim 1, wherein the light source is an infrared light source.

12. An operating method of an optical displacement detecting device, comprising the steps of:

capturing a plurality of images;

obtaining a displacement according to the images;

obtaining a characteristic variation of the images; and

suppressing the output of the displacement when the characteristic variation matches a predetermined rule.

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

outputting the displacement when the characteristic variation does not match the predetermined rule.

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

transmitting the displacement to an image display.

15. The operating method as claimed in claim 12, wherein the characteristic is an average brightness of each image.

16. The operating method as claimed in claim 15, wherein the predetermined rule is that the average brightness has a fixed change frequency.

17. The operating method as claimed in claim 16, wherein the change frequency is 100 Hz or 120 Hz.

18. The operating method as claimed in claim 16, wherein the change frequency is fixed when the number of the images is within a predetermined range in a predetermined number of successive decision periods.

19. The operating method as claimed in claim 18, wherein the decision period is a period in which the average brightness of successive images is monotonically increasing or monotonically decreasing.

20. The operating method as claimed in claim 16, wherein the change frequency is fixed when the number of the images is within a predetermined range in each decision period of a predetermined number of successive decision periods.

21. The operating method as claimed in claim 20, wherein the decision period is a period in which the average brightness of successive images is monotonically increasing or monotonically decreasing.

22. An operating method of an optical displacement detecting device, comprising the steps of:

capturing a plurality of images;

obtaining a displacement according to the images;

obtaining an average brightness of each image;

defining decision periods in which the average brightness of successive images is monotonically increasing or monotonically decreasing; and

suppressing the output of the displacement when the number of the images is within a predetermined range in a predetermined number of successive decision periods.

23. The operating method as claimed in claim 22, further comprising:

outputting the displacement when the number of the images is not within the predetermined range in a predetermined number of successive decision periods.

24. The operating method as claimed in claim 23, further comprising:

transmitting the displacement to an image display.

25. The operating method as claimed in claim 22, wherein in the step of suppressing the output of the displacement, the output of the displacement is suppressed when the number of the images is within a predetermined range or the number of the images in each decision period is within a predetermined range in a predetermined number of successive decision periods.