Optical pointing system and method for controlling power and/or clock signal thereof

• US 20050194521A1
• Filed: 02/04/2005
• Published: 09/08/2005
• Est. Priority Date: 02/04/2004
• Status: Active Grant

• Current Assignee: Intellectual Discovery Co., Ltd.
• Original Assignee: ATLab, Inc.
• Inventors: Shin, Young-Ho
• Granted Patent: US 7,511,699 B2
• Time in Patent Office: Days
• US Class Current: 250/221
• 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 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry

Abstract

Disclosed are an optical pointing system and method for controlling power and/or clock signal thereof. The optical pointing system includes a movement speed sensing unit for calculating a movement speed using a movement value, a variable power unit for varying a magnitude of power supply voltage according to the calculated movement speed, and a variable clock signal generating unit for adaptively varying an operating speed of a circuit by varying a frequency of a supplied clock signal according to the calculated movement speed. Thus, it is possible to reduce power consumption by adaptively varying the operating speed of the circuit based on the magnitude of the supplied power and/or the frequency of the clock signal according to the movement speed.

Claims

1. An optical pointing system comprising:

a movement speed sensing unit for calculating a movement speed using a movement value; and

a variable power unit for varying a magnitude of power supply voltage according to the movement speed.

2. The optical pointing system as set forth in claim 1, further comprising a variable clock signal generating unit for varying a frequency of a clock signal according to the movement speed.

3. The optical pointing system as set forth in claim 1, wherein the variable power unit includes:

a power setting part for outputting a power setting value which is set in correspondence to the movement speed; and

a power converting part for converting the power setting value into power supply voltage.

4. The optical pointing system as set forth in claim 3, wherein the power converting part includes a D/A converter for converting the power setting value into analog power.

5. The optical pointing system as set forth in claim 3, wherein the power converting part includes a DC-DC converter capable of converting the magnitude of the outputted power supply voltage by use of the power setting value.

6. The optical pointing system as set forth in claim 2, wherein the variable clock signal generating unit includes:

a counter setting part for outputting at least one counter setting value which is set in correspondence to the movement speed; and

a frequency converting part for converting the frequency of the clock signal using the counter setting value.

7. The optical pointing system as set forth in claim 6, wherein the frequency converting part includes a phase locked loop having:

a reference frequency variable counter for varying a reference frequency using any one of the counter setting values; and

a voltage control oscillator frequency variable counter for varying a voltage control oscillator frequency using any one of the counter setting values.

8. The optical pointing system as set forth in claim 6, wherein the frequency converting part includes a frequency locked loop having:

a reference frequency variable counter for varying a reference frequency using any one of the counter setting values; and

a voltage control oscillator frequency variable counter for varying a voltage control oscillator frequency using any one of the counter setting values.

9. A method for controlling power and/or clock signal of an optical pointing system, the method comprising:

a calculating step of calculating a movement speed using a movement value; and

a power and/or frequency varying step of changing a magnitude of the power supply voltage and/or a frequency of the clock signal according to the movement speed.

10. The method as set forth in claim 9, wherein the power and/or frequency varying step includes:

a setting step of setting a power setting value and/or a counter setting value corresponding to the movement speed; and

an outputting step of outputting the power of a magnitude corresponding to the power setting value and/or the clock signal of a frequency corresponding to the counter setting value.

11. An optical pointing system comprising:

an image sensor for sensing light reflected from an object to generate an analog image signal;

an A/D converter for receiving the analog image signal outputted from the image sensor and converting the received analog image signal into a digital signal;

a movement value calculator for calculating a movement value from the digital signal outputted from the A/D converter;

a movement speed sensing unit for calculating a movement speed using the movement value;

a variable power unit for varying a magnitude of power supply voltage according to the movement speed;

a variable clock signal generating unit for varying a frequency of a clock signal according to the movement speed; and

a microcontroller for processing the movement value and input information.

12. The optical pointing system as set forth in claim 11, wherein the image sensor, the A/D converter, the movement value calculator, the movement speed sensing unit, the variable power unit, the variable clock signal generating unit and the microcontroller are implemented in a single semiconductor device.