Electro-optical device, semiconductor device, display device, and electronic apparatus having the display device

• US 7,619,194 B2
• Filed: 01/30/2008
• Issued: 11/17/2009
• Est. Priority Date: 02/26/2007
• Status: Expired due to Fees

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Epson Imaging Devices Corporation (Seiko Group)
• Inventors: Kobashi, Yutaka
• Primary Examiner(s): Lee; John R
• Application Number:
  US12/010,844
• Publication Number:
  US 20080203279A1
• Time in Patent Office: 657 Days
• Field of Search: 250/205, 250/214.AL, 250/214.B, 345/207, 345/690, 345/63, 345/102, 349/61
• US Class Current: 250/205
• CPC Class Codes: G01J 1/1626 Arrangements with two photodetectors, the signals of which are compared
• 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 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• 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: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: H01J 2329/96 Circuit elements structurally associated with the display panels H01J2329/0494 takes precedence
• CPC Class Codes: H01J 29/96 One or more circuit elements structurally associated with the tube

Abstract

An electro-optical device includes a panel formed so that an electro-optical material is held between a first substrate and a second substrate, a lighting unit that irradiates light to a surface of the first substrate or the second substrate of the panel, a light detecting portion that detects an illuminance of ambient light, and a light control portion that controls the lighting unit on the basis of result detected by the light detecting portion. The light detecting portion is provided on the first substrate or on the second substrate and includes a first optical sensor, a second optical sensor, a first electrode, a second electrode, and an electric potential applying portion. The first optical sensor is irradiated with ambient light. The second optical sensor is shielded against irradiation of ambient light. The electrodes are configured to overlap the respective optical sensors through an insulating layer.

Claims

1. An electro-optical device comprising:

a panel that is formed so that an electro-optical material is held between a first substrate and a second substrate;

a lighting unit that irradiates light to a surface of the first substrate or the second substrate of the panel;

a light detecting portion that detects an illuminance of ambient light; and

a light control portion that controls the lighting unit on the basis of result detected by the light detecting portion, wherein

the light detecting portion is provided on the first substrate or on the second substrate, wherein the light detecting portion includes;

a first optical sensor that is irradiated with ambient light;

a second optical sensor that is shielded against irradiation of ambient light;

a first electrode that is configured to overlap the first optical sensor through an insulating layer in plan view;

a second electrode that is configured to overlap the second optical sensor through an insulating layer in plan view; and

an electric potential applying portion that controls an electric potential of the first electrode and an electric potential of the second electrode, wherein

the first and second optical sensors are photodiodes, and

where a difference in electric potential between a cathode electrode of the first optical sensor and the first electrode is V1, a difference in electric potential between the cathode electrode of the first optical sensor and an anode electrode of the first optical sensor is VD1, a difference in electric potential between a cathode electrode of the second optical sensor and the second electrode is V2, and a difference in electric potential between the cathode electrode of the second optical sensor and an anode electrode of the second optical sensor is VD2, |V1−

V2|<

|VD1| and |V1−

V2|<

|VD2| is established and/or |V1−

V2|<

1 V is established.

2. The electro-optical device according to claim 1, wherein the electric potential applying portion controls the electric potential of the first electrode and/or the electric potential of the second electrode so that the amount of photoelectric current of the first optical sensor and/or the amount of photoelectric current of the second optical sensor becomes substantially a maximum value.

3. The electro-optical device according to claim 2, wherein

one of the first substrate and the second substrate includes a transistor formed thereon, and wherein

the electric potential applying portion controls the electric potential applied to the first electrode and/or the electric potential applied to the second electrode on the basis of a threshold voltage of the transistor.

13. The electro-optical device according to claim 1, wherein

a display area is formed in the panel,

the light detecting portion is provided at a peripheral portion of the display area and

the light detecting portion includes:

a plurality of first optical sensors and a plurality of second optical sensors arranged at the peripheral portion of the display area.

14. The electro-optical device according to claim 13, further comprising:

a light source that irradiates light to the display area of the panel, wherein

the light source is arranged at a side of the peripheral portion of the display area, at which the first optical sensors and the second optical sensors are not arranged.

15. The electro-optical device according to claim 13, wherein the first optical sensors and the second optical sensors are alternately arranged with each other.

16. The electro-optical device according to claim 13, wherein the first optical sensors and the second optical sensors that are arranged adjacent to the first optical sensors are located substantially the same distance from the boundary side of the display area.

17. The electro-optical device according to claim 13, wherein the size of a plurality of opening portions, which are provided in the first substrate or in the second substrate to irradiate ambient light around the panel to the first optical sensors is set to a range of 0.5 mm to 20 mm in a direction parallel to the boundary side of the peripheral portion of the display area, at which the opening portions are arranged, and to a range of 0.05 mm to a thickness of the substrate, which is provided with the opening portions, in a direction perpendicular to the boundary side of the peripheral portion of the display area, at which the opening portions are arranged.

18. The electro-optical device according to claim 17, wherein

the plurality of opening portions include, at the peripheral portion of the display area, at least one first opening portion that is arranged at a side opposite an arranged side at which the light source is arranged and at least one second opening portion that is arranged at a side that is substantially perpendicular to the arranged side, and wherein

an area of opening of the at least one first opening portion is greater than an area of opening of the at least one second opening portion.

19. An electronic apparatus comprising the electro-optical device according to claim 13.

4. A semiconductor device formed on a substrate, comprising:

a first optical sensor that is irradiated with ambient light;

a second optical sensor that is shielded against irradiation of ambient light;

a first electrode that is configured to overlap the first optical sensor in plan view;

a second electrode that is configured to overlap the second optical sensor in plan view; and

an electric potential applying portion that controls an electric potential of the first electrode and an electric potential of the second electrode, wherein

the first optical sensor is a photodiode and the second optical sensor is a photodiode, and

where a difference in electric potential between a cathode electrode of the first optical sensor and the first electrode is V1, a difference in electric potential between the cathode electrode of the first optical sensor and an anode electrode of the first optical sensor is VD1, a difference in electric potential between a cathode electrode of the second optical sensor and the second electrode is V2, and a difference in electric potential between the cathode electrode of the second optical sensor and an anode electrode of the second optical sensor is VD2, |V1−

V2|<

|VD1| and |V1−

V2|<

|VD2| is established and/or |V1−

V2|<

1 V is established.

5. The semiconductor device according to claim 4, wherein the difference in electric potential V1 is set to V1=0 V, and/or the difference in electric potential V2 is set to V2=0 V, and/or the difference in electric potential V1 and the difference in electric potential VD1 are set to V1=VD1, and/or the difference in electric potential V2 and the difference in electric potential VD2 are set to V2=VD2.

6. The semiconductor device according to claim 4, wherein

the first electrode is a first light shielding electrode that shields light and the second electrode is a second light shielding electrode that shields light, or

the first electrode is a first transparent electrode that does not shield light and the second electrode is a second transparent electrode that does not shield light, or

the first electrode is a first light shielding electrode that shields light and a first transparent electrode that does not shield light and the second electrode is a second light shielding electrode that shields light and a second transparent electrode that does not shield light.

7. The semiconductor device according to claim 6, wherein

the first light shielding electrode and the second light shielding electrode form a light shielding electrode gap region in between, in which no light shielding electrode is formed in the light shielding electrode gap region, and wherein

an opaque gap light shielding body is formed in a region that overlaps the light shielding electrode gap region.

8. The semiconductor device according to claim 6, wherein

the first light shielding electrode and the second light shielding electrode form a light shielding electrode gap region in between, in which no light shielding electrode is formed in the light shielding electrode gap region, wherein

the first transparent electrode and the second transparent electrode form a transparent electrode gap region in between, in which no transparent electrode is formed in the transparent electrode gap region, and wherein

the light shielding electrode gap region and the transparent electrode gap region are formed so as not to overlap each other in a vertical direction of the substrate.

9. The semiconductor device according to claim 6, wherein

the first light shielding electrode and the first transparent electrode are applied with the same electric potential, and

the second light shielding electrode and the second transparent electrode are applied with the same electric potential.

10. The semiconductor device according to claim 4, wherein

the electric potential applying portion is provided with a self-correction voltage circuit formed of a transistor, wherein

the self-correction voltage circuit is configured to output a voltage, which varies in response to a threshold value of the transistor, to the first electrode and/or the second electrode.

11. The semiconductor device according to claim 4, wherein the first optical sensor and the second optical sensor each are a PIN junction diode or PN junction diode that uses thin-film polysilicon.

12. A display device comprising the semiconductor device according to claim 4.