Photoelectric sensor and photoelectric touch panel

• US 9,261,726 B2
• Filed: 12/30/2013
• Issued: 02/16/2016
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Shi, Shiming, Li, Yunfei, Wang, Lu
• Primary Examiner(s): HALEY, JOSEPH R
• Application Number:
  US14/143,484
• Publication Number:
  US 20140211106A1
• Time in Patent Office: 778 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 31/00 Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof H10K30/00 takes precedence; devices consisting of a plurality of solid state components formed in, or on, a common substrate, other than combinations of radiation-sensitive components with one or more electric light sources, H01L27/00

Abstract

A photoelectric sensor, comprising: a first thin film transistor (T1) for converting a photo signal into an electrical signal; a second thin film transistor (T2) for performing an integration operation on the electrical signal; a third thin film transistor (T3) for reading the electrical signal; and a first capacitor (C1) for storing an energy of the electrical signal, wherein a drain electrode of the first thin film transistor (T1) is connected to one end of the first capacitor (C1) and a source electrode of the third thin film transistor (T3); a source electrode of the first thin film transistor (T1) is connected to a drain electrode of the second thin film transistor (T2); a gate electrode of the first thin film transistor (T1) is supplied with a bias signal; wherein a gate electrode of the second thin film transistor (T2) is supplied with an integration signal; a source electrode of the second thin film transistor (T2) is connected to a high level end of a power source; the other end of the first capacitor (C1) is connected to a low level end of the power source; and wherein a gate electrode of the third thin film transistor (T3) is supplied with a scan signal; a drain electrode of the third thin film transistor (T3) is configured to output the read electrical signal.

Claims

1. A photoelectric sensor, comprising:

a first thin film transistor (T1) for converting a photo signal into an electrical signal;

a second thin film transistor (T2) for performing an integration operation on the electrical signal;

a third thin film transistor (T3) for reading the electrical signal; and

a first capacitor (C1) for storing an energy of the electrical signal,

wherein a drain electrode of the first thin film transistor (T1) is directly connected to one end of the first capacitor (C1) and a source electrode of the third thin film transistor (T3);

a source electrode of the first thin film transistor (T1) is directly connected to a drain electrode of the second thin film transistor (T2);

a gate electrode of the first thin film transistor (T1) is supplied with a bias signal;

wherein a gate electrode of the second thin film transistor (T2) is supplied with an integration signal;

a source electrode of the second thin film transistor (T2) is directly connected to a high level end of a power source;

the other end of the first capacitor (C1) is directly connected to a low level end of the power source; and

wherein a gate electrode of the third thin film transistor (T3) is supplied with a scan signal;

a drain electrode of the third thin film transistor (T3) is configured to output the read electrical signal.

2. The photoelectric sensor according to claim 1, further comprising:

a fourth thin film transistor (T4) for loading a voltage to a pixel; and

a second capacitor (C2) for maintaining the voltage stable,

wherein a gate electrode of the fourth thin film transistor (T4) is directly connected to the gate electrode of the third thin film transistor (T3); and

wherein one end of the second capacitor (C2) is directly connected to the one end of the first capacitor (C1) and the low level end of the power source, and the other end of the second capacitor (C2) is directly connected to a drain electrode of the fourth thin film transistor (T4).

3. A photoelectric touch panel, comprising:

a plurality of photoelectric sensors according to claim 1;

a substrate for carrying the photoelectric sensor thereon;

an integration control circuit for providing the integration signal;

a gate scan drive circuit for providing the scan signal;

a charge readout circuit for reading electrical charges;

a common voltage circuit for providing the low level of the power source;

a direct current voltage circuit for providing the high level of the power source; and

a bias voltage circuit for proving the bias signal,

wherein the plurality of photoelectric sensors are arranged on the substrate in rows and columns;

wherein the gate electrode of the first thin film transistor (T1) of each of the photoelectric sensors is directly connected to the bias voltage circuit;

wherein the first capacitor (C1) of the photoelectric sensor is directly connected to the common voltage circuit;

wherein the source electrode of the second thin film transistor (T2) of the photoelectric sensor is directly connected to the direct current voltage circuit, and the gate electrode of the second thin film transistor (T2) of the photoelectric sensor is connected to the integration control circuit; and

wherein the gate electrode of the third thin film transistor (T3) of the photoelectric sensor is directly connected to the gate scan drive circuit, and the drain electrode of the third thin film transistor (T3) of the photoelectric sensor is directly connected to the charge readout circuit.

4. The photoelectric touch panel according to claim 3, further comprising:

an analog to digital conversion circuit directly connected to an output end of the charge readout circuit.

5. The photoelectric touch panel according to claim 3,

wherein the charge readout circuit comprises a plurality of integral amplifiers;

wherein the positive electrode of the integral amplifier is directly connected to a reference voltage, the negative electrode of the integral amplifier is used as an input end of the charge readout circuit, and the output end of the integral amplifier is used as the output end of the charge readout circuit and directly connected to the negative electrode of the integral amplifier through a third capacitor.

6. A photoelectric touch panel, comprising:

a plurality of photoelectric sensors according to claim 2;

a substrate for carrying the photoelectric sensor thereon;

an integration control circuit for providing the integration signal;

a gate scan drive circuit for providing the scan signal;

a charge readout circuit for reading electrical charges;

a common voltage circuit for providing the low level of the power source;

a direct current voltage circuit for providing the high level of the power source; and

a bias voltage circuit for proving the bias signal,

wherein the plurality of photoelectric sensors are arranged on the substrate in rows and columns;

wherein the gate electrode of the first thin film transistor (T1) of the photoelectric sensor is directly connected to the bias voltage circuit;

wherein the first capacitor (C1) of the photoelectric sensor is directly connected to the common voltage circuit;

wherein the source electrode of the second thin film transistor (T2) of the photoelectric sensor is directly connected to the direct current voltage circuit, and the gate electrode of the second thin film transistor (T2) of the photoelectric sensor is directly connected to the integration control circuit; and

wherein the gate electrode of the third thin film transistor (T3) of the photoelectric sensor is directly connected to the gate scan drive circuit, and the drain electrode of the third thin film transistor (T3) of the photoelectric sensor is directly connected to the charge readout circuit.

7. The photoelectric touch panel according to claim 6, further comprising:

a source electrode drive circuit directly connected to the source electrode of the fourth thin film transistor (T4).