Display device with feedback brightness sensing

• US 6,713,745 B2
• Filed: 06/28/2002
• Issued: 03/30/2004
• Est. Priority Date: 06/28/2002
• Status: Expired due to Fees

• Current Assignee: Kinpo Electronics Incorporated (Cal-Comp Electronics Public Company Limited)
• Original Assignee: Kinpo Electronics Incorporated (Cal-Comp Electronics Public Company Limited)
• Inventors: Lin, Chiang Hung
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US10/184,123
• Publication Number:
  US 20040000629A1
• Time in Patent Office: 641 Days
• Field of Search: 250/205, 250/214.R, 250/208.1, 250/214.D, 250/214.AL, 250/214.B, 250/214.DC, 345/7-12, 345/48, 345/50, 345/84, 345/87
• US Class Current: 250/205
• CPC Class Codes: G01J 1/32 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02

Abstract

The present invention provides a display device with feedback brightness sensing, suitable for using in a PDA, that comprises a LCD panel at an outside of which is installed a first photo-sensor for sensing a light brightness variation of its environment. A corresponding sensing signal is delivered to a first converter to be converted to a first digital reference signal that is delivered to a microprocessor for determining a brightness increase or decrease of the display panel. Via a light-guiding element and a second photo-sensor installed within the display panel, the light brightness from the display panel is sensed and converted to a second digital reference signal that is compared with the first digital reference signal to determine whether the display brightness is at an optimal value. An automatic brightness adjustment of the display device is thereby achieved to reduce power consumption and protect the user'"'"'s eyes.

Claims

1. A display device with feedback brightness sensing, comprising:

a display device, having a display panel;

a first photo-sensor, sensing a light brightness variation of an external environment of the display panel and outputting a corresponding sensing signal;

a first converter, connected to the first photo-sensor and converting the sensing signal to a corresponding first digital reference signal;

a light-guiding element, receiving and transmitting a light brightness emitted from the display panel;

a feedback sensing unit, comprised of a second photo-sensor and a second converter, the second photo-sensor sensing a light variation from the light-guiding element that is converted through the second converter to a second digital reference signal; and

a microprocessor, controlling the light brightness emitted from the display panel according to a variation of the first and second digital reference signals.

2. The device of claim 1, wherein the display device is installed in a personal digital assistant (PDA).

3. The device of claim 1, wherein the display panel is a liquid crystal display (LCD) panel.

4. The device of claim 1, wherein the first photo-sensor is a photo-sensitive resistor.

5. The device of claim 1, wherein the first photo-sensor is installed on a front face of the display panel.

6. The device of claim 1, wherein the first converter is an analog/digital (A/D) converter.

7. The device of claim 1, wherein the light-guiding element is installed at a side of a light-emitting source of the display panel, a side of the light-guiding element being mounted in the display panel to directly receive and transmit a light brightness emitted from the display panel.

8. The device of claim 7, wherein the light-guiding element is a light-guiding column.

9. The device of claim 1, wherein the second photo-sensor is a photo-sensitive resistor.

10. The device of claim 1, wherein the second photo-sensor is installed within the display panel proximate to the light-guiding element.

11. The device of claim 1, wherein the second converter is a A/D converter.