Optical navigation device and method of operating the same

• US 20070132734A1
• Filed: 09/13/2006
• Published: 06/14/2007
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: ATLab, Inc.
• Original Assignee: ATLab, Inc.
• Inventors: Lee, Bang-Won, Shin, Young-Ho, Kwak, Jong-Taek, Lee, Woo-Seok
• Granted Patent: US 8,044,936 B2
• Time in Patent Office: Days
• US Class Current: 345/166
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Provided is an optical navigation device and a method of operating the same. The optical navigation device includes: a light source for irradiating light; an image sensor for collecting incident light to obtain an image; and a controller for performing a calculation mode that obtains an image when the light source is ON to calculate a movement value and determines whether the optical navigation device is moved on the basis of the movement value, a sleeping mode that turns OFF the light source and stops an operation of the image sensor, and a detection mode that obtains the image when the light source is ON and an image when the light source is OFF and then compares characteristics of the images to determine whether the optical navigation device is separated from the work surface, wherein the controller performs the calculation mode when the optical navigation device is moved and not separated from the work surface, performs the sleeping mode when not moved and separated from the work surface, and periodically performs the detection mode. Therefore, it is possible to precisely detect whether the optical navigation device is spaced apart from a work surface to prevent malfunction and unnecessary power consumption of the optical navigation device due to separation from the work surface.

Claims

1. An optical navigation device comprising:

a light source for irradiating light;

an image sensor for collecting incident light to obtain an image; and

a controller for performing a calculation mode that obtains an image when the light source is ON to calculate a movement value and determines whether the optical navigation device is moved on the basis of the movement value, a sleeping mode that turns OFF the light source and stops an operation of the image sensor, and a detection mode that obtains the image when the light source is ON and an image when the light source is OFF and then compares characteristics of the images to determine whether the optical navigation device is separated from a work surface,

wherein the controller performs the calculation mode when the optical navigation device is moved and not separated from the work surface, performs the sleeping mode when not moved and separated from the work surface, and periodically performs the detection mode.

2. The optical navigation device according to claim 1, wherein the controller divides the detection mode into a first detection mode periodically performed during the calculation mode and a second detection mode periodically performed during the sleeping mode;

compares characteristics of the image when the light source is ON and the image when the light source is OFF to determine whether the optical navigation device is separated from the work surface during the first detection mode; and

compares characteristics of the image when the light source is ON and the image when the light source is OFF to determine whether the optical navigation device is separated from the work surface, and determines whether the optical navigation device is moved on the basis of the image when the light source is ON, during the second detection mode.

3. The optical navigation device according to claim 2, wherein the controller turns OFF the light source, when the optical navigation device is separated from the work surface during the second detection mode, and then periodically determines only whether the optical navigation device is separated from the work surface.

4. The optical navigation device according to claim 2, wherein the controller stops output of the movement value, when the optical navigation device is separated from the work surface during the second detection mode, and then periodically determines only whether the optical navigation device is separated from the work surface.

5. The optical navigation device according to claim 1, wherein the controller obtains a plurality of images when the light source is OFF, and obtains a minimum luminous intensity on the basis of statistics.

6. The optical navigation device according to claim 5, wherein the statistics include an average value of luminous intensities of each of the images when the light source is OFF.

7. The optical navigation device according to claim 5, wherein the controller obtains the image when the light source is ON and the image when the light source is OFF during the first and second detection modes, compensates the images when the light source is OFF and ON using the minimum luminous intensity, and then compares image characteristics of the compensated images when the light source is OFF and ON to determine whether the optical navigation device is separated from the work surface.

8. The optical navigation device according to claim 1, wherein the controller determines that the optical navigation device is separated from the work surface when image characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state, starts the sleeping operation during the calculation mode, and maintains the sleeping operation during the sleeping mode.

9. The optical navigation device according to claim 1, wherein the controller determines that the optical navigation device is separated from the work surface not to output the movement value when image characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

10. The optical navigation device according to claim 1, wherein the controller determines that the optical navigation device is separated from the work surface to turn OFF the light source when image characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

11. The optical navigation device according to claim 7, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

45. The optical navigation device according to claim 8, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

46. The optical navigation device according to claim 9, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

12. An optical navigation device comprising:

a light source for irradiating light;

an image sensor for collecting incident light to obtain an image; and

a controller for performing a compensation mode that obtains the minimum luminous intensity from each luminous intensity of a plurality of images when the light source is OFF, a calculation mode that obtains an image when the light source is ON to calculate a movement value and determines whether the optical navigation device is moved on the basis of the movement value, a sleeping mode that turns OFF the light source and stops an operation of the image sensor, and a detection mode that obtains the image when the light source is OFF, compares the luminous intensity of the image when the light source is OFF with the minimum luminous intensity to determine whether the optical navigation device is separated from a work surface,

wherein the controller performs the calculation mode when the optical navigation device is moved and not separated from the work surface, performs the sleeping mode when not moved and separated from the work surface, and periodically performs the detection mode.

13. The optical navigation device according to claim 12, wherein the controller obtains a plurality of images when the light source is OFF in the compensation mode, and obtains a minimum luminous intensity on the basis of statistics.

14. The optical navigation device according to claim 13, wherein the statistics include an average value of luminous intensities of each of the images when the light source is OFF.

15. The optical navigation device according to claim 12, wherein the controller performs the compensation mode in response to a user'"'"'s request.

16. The optical navigation device according to claim 12, wherein the controller periodically performs the compensation mode.

17. The optical navigation device according to claim 12, wherein the controller divides the detection mode into a first detection mode periodically performed during the calculation mode and a second detection mode periodically performed during the sleeping mode;

obtains the image when the light source is OFF to calculate luminous intensity, and then compares the calculated luminous intensity with the minimum luminous intensity to determine whether the optical navigation device is separated from the work surface, during the first detection mode; and

obtains the image when the light source is OFF to calculate luminous intensity, compares the calculated luminous intensity with the minimum luminous intensity to determine the optical navigation device is separated from the work surface, and at the same time, obtains the image when the light source is ON to calculate a movement value to determine whether the optical navigation device is moved.

18. The optical navigation device according to claim 17, wherein the controller turns OFF the light source when the optical navigation device is separated from the work surface during the second detection mode, and then periodically determines only whether the optical navigation device is separated from the work surface.

19. The optical navigation device according to claim 17, wherein the controller stops output of the movement value when the optical navigation device is separated from the work surface during the second detection mode, and then periodically determines only whether the optical navigation device is separated from the work surface.

20. The optical navigation device according to claim 12, wherein the controller determines that the optical navigation device is separated from the work surface when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state, starts the sleeping operation during the calculation mode, and maintains the sleeping operation during the sleeping mode.

21. The optical navigation device according to claim 12, wherein the controller determines that the optical navigation device is separated from the work surface not to output the movement value when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

22. The optical navigation device according to claim 12, wherein the controller determines that the optical navigation device is separated from the work surface to turn OFF the light source when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

23. The optical navigation device according to claim 20, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

47. The optical navigation device according to claim 21, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

48. The optical navigation device according to claim 22, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

24. A method of operating an optical navigation device, comprising:

a calculation step of obtaining an image when a light source is ON to calculate a movement value, and determining whether the optical navigation device is moved, on the basis of the calculated movement value;

a sleeping step of turning OFF the light source and stopping the image obtaining;

a first detection step of periodically enabling the optical navigation device during the calculation step, obtaining the image when the light source is OFF and the image when the light source is ON, comparing characteristics of each image to determine whether the optical navigation device is separated from a work surface, and starting the sleeping step when the optical navigation device is separated from the work surface; and

a second detection step of periodically enabling the optical navigation device during the sleeping step, obtaining the image when the light source is OFF and the image when the light source is ON, comparing characteristics of each image to determine whether the optical navigation device is separated from the work surface, and at the same time, determining whether the optical navigation device is moved on the basis of the image when the light source is ON, so that the calculation step starts again when the optical navigation device is moved and not separated from the work surface.

25. The method according to claim 24, wherein the first detection step comprises the steps of:

obtaining the image when the light source is OFF and the image when the light source is ON; and

determining that the optical navigation device is separated from the work surface when the image characteristics when the light source is OFF is similar to the image characteristics when the light source is ON.

26. The method according to claim 24, wherein the second detection step comprises the steps of:

obtaining the image when the light source is OFF and the image when the light source is ON;

determining that the optical navigation device is separated from the work surface when the image characteristics when the light source is OFF is similar to the image characteristics when the light source is ON; and

determining that the optical navigation device is not separated from the work surface when the image characteristics when the light source is OFF is different from the image characteristics when the light source is ON, and then calculating a movement value on the basis of the image when the light source is ON to determine whether the optical navigation device is moved on the basis of the calculated movement value.

27. The method according to claim 24, further comprising:

a compensation step of obtaining a plurality of images when the light source is OFF, and obtaining a minimum luminous intensity on the basis of statistics.

28. The method according to claim 27, wherein the statistics include an average value of luminous intensities of each of the images when the light source is OFF.

29. The method according to claim 27, wherein the first detection step further comprises the step of compensating the image when the light source is OFF using the minimum luminous intensity.

30. The method according to claim 28, wherein the second detection step further comprises the step of compensating the image when the light source is OFF using the minimum luminous intensity.

31. The method according to claim 24, wherein the calculation step comprises the steps of:

continuously obtaining the image when the light source is ON, and calculating and outputting a movement value; and

determining whether the optical navigation device is moved on the basis of the calculated movement value.

32. The method according to claim 24, further comprising the step of:

determining that the optical navigation device is separated from the work surface when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state, starting the sleeping operation during the calculation mode, and maintaining the sleeping operation during the sleeping mode.

33. The method according to claim 24, further comprising the step of:

determining that the optical navigation device is separated from the work surface not to output the movement value when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

34. The method according to claim 24, further comprising the step of:

determining that the optical navigation device is separated from the work surface to turn OFF the light source when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

35. The method according to claim 32, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

49. The method according to claim 33, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

50. The method according to claim 34, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

36. A method of operating an optical navigation device, comprising:

a compensation step of obtaining a plurality of images when a light source is OFF, and obtaining a minimum luminous intensity on the basis of statistics;

a calculation step of obtaining an image when the light source is ON to calculate a movement value, and determining whether the optical navigation device is moved on the basis of the calculated movement value;

a sleeping step of turning OFF the light source and stopping the image obtaining;

a first detection step of periodically enabling the optical navigation device during the calculation step, obtaining the image when the light source is OFF, comparing the luminous intensity of the image when the light source is OFF with the minimum luminous intensity to determine whether the optical navigation device is separated from a work surface, and starting the sleeping step when the optical navigation device is separated from the work surface; and

a second detection step of periodically enabling the optical navigation device during the sleeping step, obtaining the image when the light source is OFF, comparing the luminous intensity of the image when the light source is OFF with the minimum luminous intensity to determine whether the optical navigation device is separated from the work surface, and at the same time, determining whether the optical navigation device is moved on the basis of the image when the light source is ON, so that the calculation step starts again when the optical navigation device is moved and not separated from the work surface.

37. The method according to claim 36, wherein the statistics include an average value of luminous intensities of each of the images when the light source is OFF.

38. The method according to claim 36, wherein the first detection step comprises the steps of:

obtaining the image when the light source is OFF and the image when the light source is ON;

calculating luminous intensity of the image when the light source is OFF; and

determining that the optical navigation device is separated from the work surface when the calculated luminous intensity of the image when the light source is OFF is similar to the minimum luminous intensity.

39. The method according to claim 36, wherein the second detection step comprises the steps of:

obtaining the image when the light source is OFF and the image when the light source is ON;

calculating luminous intensity of the image when the light source is OFF;

determining that the optical navigation device is separated from the work surface when the calculated luminous intensity of the image when the light source is OFF is similar to the minimum luminous intensity; and

determining that the optical navigation device is not separated from the work surface when the calculated luminous intensity of the image when the light source is OFF is different from the minimum luminous intensity, and then calculating a movement value on the basis of the image when the light source is ON to determine whether the optical navigation device is moved on the basis of the calculated movement value.

40. The method according to claim 36, wherein the calculation step comprises the steps of:

continuously obtaining the image when the light source is ON, and calculating and outputting a movement value; and

determining whether the optical navigation device is moved on the basis of the calculated movement value.

41. The method according to claim 36, further comprising the step of:

determining that the optical navigation device is separated from the work surface when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state, starting the sleeping operation during the calculation mode, and maintaining the sleeping operation during the sleeping mode.

42. The method according to claim 36, further comprising the step of:

determining that the optical navigation device is separated from the work surface not to output the movement value when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

43. The method according to claim 36, further comprising the step of:

determining that the optical navigation device is separated from the work surface to turn OFF the light source when characteristics of the image when the light source is ON or OFF are changed depending on a peripheral illumination state.

44. The method according to any claim 41, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

51. The method according to claim 42, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.

52. The method according to claim 43, wherein the peripheral illumination state is a state that luminous intensity of the image when the light source is ON is periodically equal to the minimum luminous intensity, when luminous intensity of the peripheral illumination is changed according to frequency of power supplied from the exterior.