DISPLAY APPARATUS

• US 20090147191A1
• Filed: 03/14/2008
• Published: 06/11/2009
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakajima, Yoshiharu, Yamanaka, Go
• Granted Patent: US 8,587,755 B2
• Time in Patent Office: Days
• US Class Current: 349/116
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs

Abstract

A liquid crystal display apparatus having little influence of noise and able to improve an SN ratio of a light reception system without requiring a calibration operation when turning on the power, is provided. The apparatus has a plurality of display cells 21 having display circuits 210, light receiving cells 22 each including a light receiving element 221, a reference cell 23 having a configuration equivalent to the configuration of the light receiving cell and blocked from incidence of a light upon the light receiving element 221, and a received light signal processing circuit 6 performing differential signal processing of an output signal of the light receiving cell 22 and an output signal of the reference cell 23 and deleting noise.

Claims

1. A display apparatus comprising:

at least one display cell having a display circuit;

at least one light receiving cell including a light receiving element;

at least one reference cell having a configuration equivalent to the configuration of the light receiving cell and blocked from incidence of light upon the light receiving element; and

a signal processing circuit performing differential signal processing of an output signal of the light receiving cell and an output signal of the reference cell.

2. A display apparatus as set forth in claim 1, wherein:

in an effective pixel area portion of the display apparatus,

a plurality of the display cells are arranged in a matrix, and

the light receiving cell and the reference cell are arranged mixed in the matrix array of the display cells.

3. A display apparatus as set forth in claim 2, wherein,

in the effective pixel area portion,

the light receiving cell is arranged close to at least one first display cell,

at least one second display cell is arranged adjacent to the light receiving cell, and

an arrangement pattern on which the reference cell is arranged close to the arranged second display cell is periodically repeated.

4. A display apparatus as set forth in claim 2, wherein:

the effective pixel area portion comprises;

a first arrangement system in which the light receiving cell is arranged close to at least one first display cell, at least one second display cell is arranged close to the light receiving cell, and the reference cell is arranged close to the arranged second display cell; and

a second arrangement system in which a first dummy cell from which an output cannot be extracted is arranged close to at least one third display cell, at least one fourth display cell is arranged adjacent to the first dummy cell, and a second dummy cell from which an output cannot be extracted is arranged close to the arranged fourth display cell.

5. A display apparatus as set forth in claim 4, wherein:

the first arrangement system and the second arrangement system are adjacent and are arranged so as to be periodically repeated.

6. A display apparatus as set forth in claim 1, wherein:

in the light receiving cell, an opening guiding light to be detected to the light receiving element is formed in a light shield mask, and

the reference cell is blocked from incidence of the light to be detected.

7. A display apparatus as set forth in claim 2, wherein:

the signal processing circuit performs differential signal processing of output signals between the light receiving cell and the reference cell arranged close to each other.

8. A display apparatus comprising:

an effective pixel area portion in which a plurality of display cells are arrayed in a matrix and in which at least one light receiving cell including a first light receiving element and at least one reference cell having a configuration equivalent to the configuration of the light receiving cell and blocked from incidence of light upon a second light receiving element are arranged mixed in the matrix array of the display cells;

a signal processing circuit performing differential signal processing of an output signal of the light receiving cell and an output signal of the reference cell; and

a back light emitting light to the effective pixel area portion.

9. A display apparatus as set forth in claim 8, wherein:

the effective pixel area portion has

a first transparent substrate arranged facing the back light and on which circuits of the display cells, light receiving cells, and reference cells and the first and second light receiving elements are formed,

a second transparent substrate arranged facing the second transparent substrate,

a liquid crystal layer arranged between the first transparent substrate and the second transparent substrate, and

light shield masks formed at the light receiving cell and the reference cell and blocking light to be detected,

an opening for guiding the light to be detected to the first light receiving element being formed in the light shield mask of the light receiving cell.

10. A display apparatus as set forth in claim 9, wherein:

a bottom gate type thin film transistor is formed on the first transparent substrate including the light receiving cell and the reference cell, a gate electrode of the thin film transistor is formed on an optical path of at least light from the back light to the second light receiving elements of the light receiving cell and the reference cell, and the gate electrode has a function of blocking light from the back light.

11. A display apparatus as set forth in claim 8, wherein:

in the effective pixel area portion,

the light receiving cell is arranged close to at least one display cell,

at least one display cell is arranged close to the light receiving cell, and

an arrangement pattern on which the reference cell is arranged close to the arranged display cell is periodically repeated.

12. A display apparatus as set forth in claim 8, wherein:

the effective pixel area portion comprises;

a first arrangement system in which a light receiving cell is arranged close to at least one first display cell, at least one second display cell is arranged close to the light receiving cell, and the reference cell is arranged close to the arranged second display cell and

a second arrangement system in which a first dummy cell from which an output cannot be extracted is arranged close to at least one third display cell, at least one fourth display cell is arranged adjacent to the first dummy cell, and a second dummy cell from which an output cannot be extracted is arranged close to the arranged fourth display cell.

13. A display apparatus as set forth in claim 12, wherein:

the first arrangement system and the second arrangement system are adjacent and are arranged so as to be periodically repeated.

14. A display apparatus as set forth in claim 8, wherein:

the signal processing circuit performs differential signal processing on output signals between the light receiving cell and the reference cell which are arranged close to each other.