Touch panel with light-sensitive and pressure-sensitive pixels

• US 7,999,796 B2
• Filed: 11/05/2007
• Issued: 08/16/2011
• Est. Priority Date: 07/26/2007
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Liu, Chun-Hsin, Chiang, Min-Feng, Liu, Po-Yuan, Lee, Hsin-Hung, Chen, Chi-Wen
• Primary Examiner(s): Nguyen; Chanh
• Assistant Examiner(s): Yang; Kwang-Su
• Application Number:
  US11/934,784
• Publication Number:
  US 20090027350A1
• Time in Patent Office: 1,380 Days
• Field of Search: 345173-176
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A touch panel includes a plurality of pixels. Each pixel includes a light sensing component, a pressure sensing component, and a switch. The light sensing component generates a first sensing signal when sensing light. The pressure sensing component generates a second sensing signal when sensing pressure. The switch transmits the first and the second sensing signals when receiving a gate driving signal.

Claims

1. A touch panel comprising:

a plurality of pixels, each pixel comprising;

a light sensing component for sensing light and then generating a first sensing signal;

a pressure sensing component for sensing pressure and then generating a second sensing signal, the pressure sensing component comprising a variable capacitor including;

a first end; and

a second end for receiving a second voltage,

wherein capacitance of the variable capacitor changes when the variable capacitor is pressed; and

a switch, comprising;

a first end coupled to the light sensing component and directly connected to the first end of the variable capacitor;

a control end for receiving a gate driving signal; and

a second end for transmitting the first sensing signal and the second sensing signal according to the gate driving signal.

2. The touch panel of claim 1, further comprising a plurality of gate lines for transmitting a plurality of gate driving signals to the switches of the plurality of pixels.

3. The touch panel of claim 1, further comprising a plurality of data reading lines, each of the data reading lines coupled to the second ends of the switches of corresponding pixels for transmitting the first sensing signals and the second sensing signals.

4. The touch panel of claim 1, wherein the light sensing component comprises:

a photo transistor including;

a first end for receiving a first voltage;

a control end coupled to the first end of the photo transistor; and

a second end coupled to the first end of the corresponding switch.

5. The touch panel of claim 1, further comprising a plurality of detecting circuits for receiving the first sensing signals and the second sensing signals transmitted from the plurality of data reading lines.

6. The touch panel of claim 5, wherein each of the detecting circuits comprises:

an amplifier, comprising;

a positive input end for receiving a reference voltage;

a negative input end coupled to one of the plurality of data reading lines; and

an output end for outputting an output voltage according to a corresponding first sensing signal and a corresponding second sensing signal;

a capacitor coupled between the output end of the amplifier and the negative input end of the amplifier; and

a switch coupled between the output end of the amplifier and the negative input end of the amplifier for coupling the output end of the amplifier to the negative input end of the amplifier when a corresponding pixel does not receive the gate driving signal.

7. The touch panel of claim 4, wherein the first end of the variable capacitor is directly connected to the second end of the photo transistor and is not directly connected to the control end of the photo transistor.