Electrooptical device and electronic apparatus

• US 10,074,335 B2
• Filed: 08/20/2016
• Issued: 09/11/2018
• 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): Jansen, II, Michael J
• Assistant Examiner(s): Karki, Paras D
• Application Number:
  US15/242,498
• Publication Number:
  US 20160358578A1
• Time in Patent Office: 752 Days
• 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 plurality of pixels that are arranged so as to correspond to a plurality of intersections of a plurality of scanning lines and a plurality of signal lines;

a scanning line driving circuit that selects one of the plurality of scanning lines in each of a plurality of horizontal scanning periods; and

a signal supply circuit that supplies a designated gradation potential to each of the plurality of pixels in a first write period of each of the plurality of horizontal scanning periods;

a plurality of switches that are each disposed between the signal supply circuit and the plurality of signal lines to electrically connect the signal supply circuit and a corresponding signal line in each of the plurality of horizontal scanning periods; and

a control circuit that controls each of the plurality of switches, wherein the signal supply circuit supplies a predetermined pre-charge potential simultaneously to the plurality of signal lines in a first horizontal scanning period during a precharge period prior to the write period, and does not supply the predetermined pre-charge potential to the plurality of signal lines in a second horizontal scanning period, wherein the second horizontal scanning period is different from the first horizontal scanning period,

wherein the control circuit controls each of the plurality of switches so as to simultaneously electrically connect the signal supply circuit and the plurality of signal lines in the pre-charge period of the first horizontal scanning, and electrically connects the signal supply circuit and the plurality of signal lines in a sequential manner during each of the write periods of the first horizontal period and the second horizontal scanning period to supply the designated gradation potential, and does not electrically connect the signal supply circuit and the plurality of signal lines to supply the predetermined pre-charge potential to the signal lines prior to the write period of 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 a plurality of scanning lines in each of the plurality of horizontal scanning periods in a plurality of vertical scanning periods.

6. The electro-optical device according to claim 1, wherein each of the plurality of horizontal scanning periods corresponding to the odd number lines is set to one of the first horizontal scanning period and the second horizontal scanning period.

7. The electro-optical device according to claim 6, wherein each of the plurality of horizontal scanning periods corresponding to the even number lines is set to the other of the first horizontal scanning period and the second horizontal scanning period.

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

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

9. An electronic apparatus including the electro-optical device of claim 1.

10. A control method for an electro-optic device provided with a plurality of scanning lines, a plurality of signal lines and a plurality of pixels each provided so as to correspond to one of intersections of the plurality of scanning lines and the plurality of signal lines, a signal supply circuit supplying a designated gradation potential to each of the plurality of pixels in a first write period of each of the plurality of horizontal scanning periods, a plurality of switches which are each disposed between the signal supply circuit and the plurality of signal lines to electrically connect the signal supply circuit and a corresponding signal line in each of the plurality of horizontal scanning period and a control circuit controlling each of the plurality of switches, the control method comprising;

controlling the plurality of switches via the control circuit so as to simultaneously electrically connect the signal supply circuit and the plurality of signal lines in a pre-charge period of the first horizontal scanning period which is prior to the write period;

supplying a predetermined pre-charge potential simultaneously to the plurality of signal lines in a first horizontal scanning period during the pre-charge period and not supplying the predetermined pre-charge potential to the plurality of signal lines in a second horizontal scanning period, wherein the second horizontal scanning period is different from the first horizontal scanning period;

electrically connecting the signal supply circuit and the plurality of signal lines via the plurality of switches in a sequential manner during each of the write periods of the first horizontal period and the second horizontal scanning period; and

supplying the designated gradation potential to the corresponding signal line during each of the write period of the first horizontal period and the second horizontal scanning period;

wherein the control circuit does not electrically connect the signal supply circuit and the plurality of signal lines to supply the predetermined pre-charge potential to the signal lines prior to the write period of the second horizontal scanning period.

11. The control method for the electro-optical device according to claim 10, 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.

12. The control method for the electro-optical device according to claim 10, 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.

13. The control method for the electro-optical device according to claim 10, 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.

14. The control method for the electro-optical device according to claim 10, comprising:

selecting a plurality of scanning lines in each of the plurality of horizontal scanning periods in a plurality of vertical scanning periods.

15. The control method for the electro-optical device according to claim 10, wherein each of the plurality of horizontal scanning periods corresponding to the odd number lines is set to one of the first horizontal scanning period and the second horizontal scanning period, and each of the plurality of horizontal scanning periods corresponding to the even number lines is set to the other of the first horizontal scanning period and the second horizontal scanning period.