Processing circuit and electronic system utilizing the same

• US 8,294,698 B2
• Filed: 03/17/2010
• Issued: 10/23/2012
• Est. Priority Date: 04/09/2009
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: Wu, I-Lin
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Lubit, Ryan A
• Application Number:
  US12/725,573
• Publication Number:
  US 20110018907A1
• Time in Patent Office: 951 Days
• Field of Search: 345/102, 345/207, 348/227.1, 250/200, 250214 R-214 SW, 738/623.24, 356213-236
• US Class Current: 345/207
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A processing circuit coupled to a controlling circuit and including a first capacitor module, a second capacitor, a detection module, a first processing module, and a second processing module is disclosed. The first and the second capacitor modules are charged. The detection module generates a detection signal according to intensity of a light to charge the first and the second capacitor modules. The first processing module asserts a first output signal according to the time of charging the first capacitor module. The second processing module asserts a second output signal according to the time of charging the second capacitor module. The controlling circuit controls a backlight according to the asserted output signal.

Claims

1. A processing circuit coupled to a controlling circuit, comprising:

a first capacitor module;

a second capacitor module;

a detection module generating a detection signal according to intensity of an external light, wherein the first capacitor module and the second capacitor module are both charged via the detection signal, and wherein the capacity of the first and second capacitor modules are different;

a first processing module asserting a first output signal according to the time of charging the first capacitor module; and

a second processing module asserting a second output signal according to the time of charging the second capacitor module, wherein;

when the first output signal is asserted, the controlling circuit controls a backlight according to the first output signal for adjusting intensity of light emitted from the backlight;

when the second output signal is asserted, the controlling circuit controls the backlight according to the second output signal for adjusting intensity of the light emitted from the backlight; and

when the first and the second output signals are asserted, the controlling circuit controls the backlight according to the first and the second output signals or the first output signal for adjusting intensity of the light emitted from the backlight.

2. The processing circuit as claimed in claim 1, wherein the capacity of the first capacitor module is larger than the capacity of the second capacitor module.

3. The processing circuit as claimed in claim 2, wherein the capacity of the first capacitor module is 100˜

1000 times as larger than the capacity of the second capacitor module.

4. The processing circuit as claimed in claim 1, wherein the first capacitor module comprises:

a first capacitor coupled between a first node and a second node; and

a second capacitor coupled between the second node and a third node.

5. The processing circuit as claimed in claim 4, wherein the capacity of the first capacitor equals the capacity of the second capacitor.

6. The processing circuit as claimed in claim 4, wherein the first processing module comprises:

a first comparing unit coupled to the second node and receiving a reference signal; and

a first feedback unit coupled to the first and the third nodes and asserting the first output signal according to the output of the first comparing unit.

7. The processing circuit as claimed in claim 6, wherein the second capacitor module comprises:

a third capacitor coupled between a fourth node and a fifth node; and

a fourth capacitor coupled between the fifth node and a sixth node.

8. The processing circuit as claimed in claim 7, wherein the capacity of the third capacitor equals the capacity of the fourth capacitor and the capacity of the fourth capacitor is less than the capacity of the first capacitor.

9. The processing circuit as claimed in claim 7, wherein the second processing module comprises:

a second comparing unit coupled to the fifth node and receiving the reference signal; and

a second feedback unit coupled to the fourth and the sixth nodes and asserting the second output signal according to the output of the second comparing unit.

10. An electronic system, comprising:

a display panel displaying an image;

a backlight emitting a light to serve as a light source for the display panel;

a controlling circuit controlling the backlight for adjusting the intensity of the light emitted from the backlight; and

a processing circuit comprising;

a first capacitor module;

a second capacitor module;

a detection module generating a detection signal according to intensity of an external light, wherein the first capacitor module and the second capacitor module are both charged via the detection signal, and wherein the capacity of the first and second capacitor modules are different;

a first processing module asserting a first output signal according to the time of charging the first capacitor module; and

a second processing module asserting a second output signal according to the time of charging the second capacitor module, wherein;

when the first output signal is asserted, the controlling circuit controls the backlight according to the first output signal,

when the second output signal is asserted, the controlling circuit controls the backlight according to the second output signal; and

when the first and the second output signals are asserted, the controlling circuit controls the backlight according to the first and the second output signals or the first output signal.

11. The processing circuit as claimed in claim 10, wherein the capacity of the first capacitor module is larger than the capacity of the second capacitor module.

12. The processing circuit as claimed in claim 11, wherein the capacity of the first capacitor module is 100˜

1000 times larger than the capacity of the second capacitor module.

13. The electronic system as claimed in claim 10, wherein the first capacitor module comprises:

a first capacitor coupled between a first node and a second node; and

a second capacitor coupled between the second node and a third node.

14. The processing circuit as claimed in claim 13, wherein the capacity of the first capacitor equals the capacity of the second capacitor.

15. The electronic system as claimed in claim 13, wherein the first processing module comprises:

a first comparing unit coupled to the second node and receiving a reference signal; and

a first feedback unit coupled to the first and the third nodes and asserting the first output signal according to the output of the first comparing unit.

16. The electronic system as claimed in claim 15, wherein the second capacitor module comprises:

a third capacitor coupled between a fourth node and a fifth node; and

a fourth capacitor coupled between the fifth node and a sixth node.

17. The processing circuit as claimed in claim 16, wherein the capacity of the third capacitor equals the capacity of the fourth capacitor and the capacity of the fourth capacitor is less than the capacity of the first capacitor.

18. The electronic system as claimed in claim 16, wherein the second processing module comprises:

a second comparing unit coupled to the fifth node and receiving the reference signal; and

a second feedback unit coupled to the fourth and the sixth nodes and asserting the second output signal according to the output of the second comparing unit.

19. The electronic system as claimed in claim 10, wherein the electronic system is a personal digital assistant (PDA), a mobile phone, a digital camera, a television, a global positioning system (GPS), a car display, an avionics display, a digital photo frame, a notebook computer (NB), or a personal computer (PC).

20. The electronic system as claimed in claim 10, wherein the detection module comprises a photo sensor comprising a cathode coupled to the first and the second capacitor modules.