Electrooptical device and electronic apparatus

• US 9,460,680 B2
• Filed: 08/26/2011
• Issued: 10/04/2016
• Est. Priority Date: 09/03/2010
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Ito, Akihiko
• Primary Examiner(s): Ghebretinsae, Temesgh
• Assistant Examiner(s): Karki, Paras D
• Application Number:
  US13/219,154
• Publication Number:
  US 20120056917A1
• Time in Patent Office: 1,866 Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2310/0218 with collection of electrodes in groups for n-dimensional addressing
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A scanning line driving circuit sequentially selects each of a plurality of scanning lines for each unit period. A signal supply circuit supplies, to a signal line, a gradation potential in accordance with a designated gradation of a pixel in a write period within the unit period. The signal supply circuit supplies a pre-charge potential to the signal line in a pre-charge period before the start of the write period in a first unit period of the plurality of unit periods, and the supply of the pre-charge potential to the signal line stops in a second unit period.

Claims

1. An electro-optical device, comprising:

a first pixel that is arranged so as to correspond to each intersection of a first scanning line and a plurality of signal line, and displays a first gradation corresponding to a potential of the signal line at the time of selection of the first scanning line;

a second pixel that is arranged so as to correspond to each intersection of a second scanning line and the signal line, and displays a second gradation corresponding to a potential of the signal line at the time of selection of the second scanning line;

a scanning line driving circuit that selects the first scanning line in a first horizontal scanning period and the second scanning line in a second horizontal scanning period; and

a signal supply circuit which supplies a first gradation potential corresponding to a first designated gradation of the first pixel in a write period to the signal line and a second gradation potential corresponding to a second designated gradation of the second pixel in the write period to the signal line,

wherein the signal supply circuit supplies a pre-charge potential to the first pixel before supplying the first gradation potential in the first horizontal scanning period, and

wherein the signal supply circuit supplies no pre-charge potential to the second pixel before supplying the second gradation potential in the second horizontal scanning period.

2. The electro-optical device according to claim 1, wherein the first horizontal scanning period and the second horizontal scanning period are set to the same time length, and the write period of the first horizontal scanning period and the write period of the second horizontal scanning period are set to the same time length.

3. The electro-optical device according to claim 1, wherein the first horizontal scanning period and the second horizontal scanning period are set to the same time length, and a time length of the write period of the second horizontal scanning period is longer than a time length of the write period of the first horizontal scanning period.

4. The electro-optical device according to claim 1, wherein the write period of the first horizontal scanning period and the write period of the second horizontal scanning period are set to the same time length, and a time length of the second horizontal scanning period is shorter than a time length of the first horizontal scanning period.

5. The electro-optical device according to claim 1, wherein the scanning line driving circuit sequentially selects the first scanning line and the second scanning line.

6. The electro-optical device according to claim 5, wherein each of the odd number lines is set to one of the first scanning line and the second scanning line, and each of the even number lines is set to the other of the first scanning line and the second scanning line.

7. The electro-optical device according to claim 1, wherein the signal supply circuit includes:

a signal generation circuit that supplies, to a control line, a control signal which is set to a pre-charge potential in a pre-charge period before the start of the write period of first horizontal scanning period while being set to the first gradation potential in a time division manner in the write period the first horizontal scanning period and the second horizontal scanning period,

a plurality of switches that control the connection between each of the polarity of signal lines and the control line, and

a control circuit that controls all of the plurality of switches in an on state in the pre-charge period of the first horizontal scanning period, and sequentially controls each of the plurality of switches in an on state in the write period of the first horizontal scanning period and the second horizontal scanning period.