DISPLAY DEVICE DRIVE CIRCUIT AND DISPLAY DEVICE

• US 20100295832A1
• Filed: 01/19/2009
• Published: 11/25/2010
• Est. Priority Date: 04/11/2008
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kumada, Kouji, Nishio, Masaaki
• Application Number:
  US12/864,088
• Publication Number:
  US 20100295832A1
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 2360/141 the light conveying information used for selecting or modulating the light emitting or modulating element
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/2096 Details of the interface to the display terminal specific for a flat panel suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A display device drive circuit (4) includes an AD conversion circuit (45) which carries out AD conversion of an analog signal (Vs), which is inputted via a first terminal (P) connected with data signal lines (SLR, SLG, and SLB). The first terminal (P) is time-divisionally used for (i) a period during which a data signal (Vd) is sent out and for (ii) a period during which the analog signal (Vs) is inputted. The first terminal (P) is (a) connected with the AD conversion circuit (45) via only a switching circuit (47b) and a sample hold circuit, and (b) directly connected with an output circuit (47a), During the period during which the data signal (Vd) is sent out, the switching circuit (47b) disconnects the first terminal (P) from the AD conversion circuit, whereas, during the period during which the analog signal (Vs) is inputted, the switching circuit (47b) electrically connects the first terminal (P) to the AD conversion circuit and an output of the output circuit (47a) becomes high impedance. Accordingly, it is possible to provide a display device drive circuit employing a COG technique capable of carrying out appropriate AD conversion of an analog signal processed in a display panel.

Claims

1. A display device drive circuit, comprising:

an analog-to-digital conversion circuit for converting analog signals inputted therein via respective first terminals,

the first terminals serving also as output terminals via which data signals are sent out to data signal lines, the first terminals being time-divisionally used for (i) a period during which the data signals are sent out and for (ii) a period during which the analog signals are inputted,

each of the first terminals being (a) connected with an input of the analog-to-digital conversion circuit via only a switching circuit and a sample hold circuit and (b) directly connected with an output terminal of a corresponding one of output circuits from which the data signals are sent out to the first terminals, and

the switching circuit disconnecting the first terminal from the input of the analog-to-digital conversion circuit during the period during which the data signals are sent out, whereas, the switching circuit electrically connecting the first terminal to the inputs of the analog-to-digital conversion circuit and an output of the output circuit becoming high impedance during the period during which the analog signals are inputted.

2. The display device drive circuit according to claim 1, wherein the first terminals are terminals into which the analog signals are inputted, which analog signals are sensor outputs indicative of light intensity detected by photosensors included in respective display regions of a display panel.

3. The display device drive circuit according to claim 1, wherein the analog-to-digital conversion circuit includes an analog-to-digital conversion section for each first terminal.

4. The display device drive circuit according to claim 1, wherein:

the analog-to-digital conversion circuit includes a plurality of analog-to-digital conversion sections so that each of the plurality of analog-to-digital conversion sections is shared by corresponding ones of the first terminals, and

the switching circuit selectively connects (i) corresponding ones of the first terminals to (ii) an input of corresponding one of the plurality of analog-to-digital conversion sections.

5. The display device drive circuit according to claim 3, further comprising second terminals which are not for receiving the analog signals but for sending out the data signals to the respective data signal lines.

6. A display device, comprising a display device drive circuit as set forth in claim 1.

7. The display device according to claim 6, wherein the display device drive circuit is mounted on a display panel by a COG method.

8. The display device according to claim 6, wherein:

the photosensors are included in the respective display regions of the display panel, and

the sensor outputs indicative of the light intensity detected by the photosensors, which sensor outputs are the analog signals, are inputted into the first terminals.

9. The display device according to claim 8, wherein:

the data signal lines are divided into a plurality of groups, each of which includes a plurality of the data signal lines,

the data signal lines in one group are time-divisionally and individually connected to corresponding one of the first terminals, and

any one of the data signal lines in one group is used for transmitting the sensor outputs to the corresponding one of the first terminals.

10. The display device according to claim 8, wherein:

each of the first terminals is connected to corresponding one of the data signal lines, and

the corresponding one of the data signal lines is used for transmitting the sensor outputs to corresponding one of the first terminals.