Light control module and method thereof

• US 7,355,588 B2
• Filed: 12/06/2004
• Issued: 04/08/2008
• Est. Priority Date: 02/03/2004
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lan, Jeng-Feng, Lin, Chun-Huang
• Primary Examiner(s): Mengistu; Amare
• Assistant Examiner(s): SHEETS, ELIJAH M
• Application Number:
  US11/005,454
• Publication Number:
  US 20050168444A1
• Time in Patent Office: 1,219 Days
• Field of Search: 345/166
• US Class Current: 345/166
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• 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 3/0383 Signal control means within the pointing device
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A light control module appropriate for an optical pointing device. The light control module comprises a processing unit outputting a first signal and a second signal, a photo sensor unit executing a capture operation according to an impulse of the first signal, and a light emitting unit executing a light emitting operation according to an impulse of the second signal, wherein when a frequency value of the first signal is less than a first preset value, at least one impulse is inserted between two successive impulses of the second signal for adjusting a frequency value of the second signal such that an equivalent frequency value corresponding to any two successive impulses of the second signal is greater than a second preset value, thus rendering flickers of the light emitting unit imperceptible.

Claims

1. A light control module, appropriate for an optical pointing device, comprising:

a processing unit outputting a first signal and a second signal;

a photo sensor unit executing a capture operation according to an impulse of the first signal; and

a light emitting unit executing a light emitting operation according to an impulse of the second signal;

wherein when a frequency value of the first signal is less than a first preset value, at least one impulse is inserted between two successive impulses of the second signal for adjusting a frequency value of the second signal such that an equivalent frequency value corresponding to any two successive impulses of the second signal is greater than a second preset value, thus rendering flickers of the light emitting unit imperceptible.

2. The light control module as claimed in claim 1, wherein the optical pointing device is an optical mouse.

3. The light control module as claimed in claim 1, wherein the processing unit comprises:

a counter outputting a counting number; and

a controller outputting the first signal and the second signal according to the counting number.

4. The light control module, as claimed in claim 1, wherein the first preset value is equal to the second preset value.

5. The light control module as claimed in claim 4, wherein the first preset value is 60 Hz and the second preset value is 60 Hz.

6. A light control method, appropriate for an optical pointing device, comprising the steps of:

outputting a first signal and a second signal;

executing a capture operation according to an impulse of the first signal;

executing a light emitting operation according to an impulse of the second signal;

determining whether a frequency value of the first signal is less than a first preset value; and

if so, inserting at least one impulse between two successive impulses of the second signal for adjusting a frequency value of the second signal such that an equivalent frequency value corresponding to any two successive impulses of the second signal is greater than a second preset value, thus rendering flickers of light imperceptible.

7. The light control method as claimed in claim 6, wherein the optical pointing device is an optical mouse.

8. The light control method as claimed in claim 6, wherein the step of outputting a first signal and a second signal comprises the steps of:

outputting a counting number; and

outputting the first signal and the second signal according to the counting number.

9. The light control method as claimed in claim 6, wherein the first preset value is equal to the second preset value.

10. The light control method as claimed in claim 9, wherein the first preset value is 60 Hz and the second preset value is 60 Hz.