METHOD OF DRIVING ELECTROPHORETIC DISPLAY DEVICE, ELECTROPHOTETIC DISPLAY DEVICE, AND ELECTRONIC APPARATUS

• US 20090189848A1
• Filed: 11/24/2008
• Published: 07/30/2009
• Est. Priority Date: 01/24/2008
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: MAEDA, Hiroshi
• Application Number:
  US12/276,597
• Publication Number:
  US 20090189848A1
• Time in Patent Office: Days
• US Class Current: 345/107
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

There is provided a method of driving an electrophoretic display device including electrophoretic elements including electrophoretic particles that is arranged between one pair of substrates, a display unit formed of a plurality of pixels each including a pixel electrode, a pixel switching element, a memory circuit that is connected between the pixel electrode and the pixel switching element, and a switching circuit that is connected between the pixel electrode and the memory circuit, and first and second control lines that are connected to the switching circuit. The method includes extracting a length of the boundary between pixel data of a first gray scale level and pixel data of a second gray scale level from image data transmitted to the display unit as a characteristic amount, determining whether an operation mode of an image displaying operation is to be switched based on the characteristic amount, and switching the operation mode based on the result of the determination acquired in the determining on whether an operation mode is to be switched.

Claims

1. A method of driving an electrophoretic display device, the electrophoretic display device comprising:

electrophoretic elements including electrophoretic particles that is arranged between one pair of substrates;

a display unit formed of a plurality of pixels each including a pixel electrode, a pixel switching element, a memory circuit that is connected between the pixel electrode and the pixel switching element, and a switching circuit that is connected between the pixel electrode and the memory circuit; and

first and second control lines that are connected to the switching circuit, and

the method comprising;

extracting a length of the boundary between pixel data of a first gray scale level and pixel data of a second gray scale level from image data transmitted to the display unit as a characteristic amount;

determining whether an operation mode of an image displaying operation is to be switched based on the characteristic amount; and

switching the operation mode based on the result of the determination acquired in the determining on whether an operation mode is to be switched.

2. The method according to claim 1, wherein the switching of the operation mode is switching between a first operation mode and a second operation mode, the first operation mode being for displaying an image in the display unit by supplying image displaying electric potentials to both the first and second control lines, the second operation mode being for displaying an image of the first gray scale level in the display unit by inputting an image displaying electric potential to either the first control line or the second control line in a state that the other control line is electrically cut off and displaying an image of the second gray scale level in the display unit by interchanging the control line to which the electric potential is supplied and the control line that is electrically cut off.

3. The method according to claim 1, wherein the switching of the operation mode is switching between an operation mode in which a first electric potential is input as the high-level electric potential of the first and second control lines and an operation mode in which a second electric potential lower than the first electric potential is input as the high-level electric potential.

4. The method according to claim 1, wherein the extracting of a length of the boundary is counting the number of boundaries between the pixel data of the first gray scale level and the pixel data of the second gray scale level of the image data which corresponds to the adjacent pixels of the display unit.

5. The method according to claim 1, wherein the extracting of a length of the boundary is extracting the characteristic amount that is embedded in the image data in advance from the image data.

6. The method according to claim 1, wherein the determining on whether an operation mode is to be switched is comparing a reference value set in advance and the characteristic amount and determining whether the operation mode is needed to be switched based on the result of the comparison.

7. An electrophoretic display device comprising:

electrophoretic elements including electrophoretic particles between one pair of substrates;

a display unit formed of a plurality of pixels each including a pixel electrode, a pixel switching element, a memory circuit that is connected between the pixel electrode and the pixel switching element, and a switching circuit that is connected between the pixel electrode and the memory circuit; and

first and second control lines that are connected to the switching circuit,

wherein a characteristic amount acquiring section that extracts a length of the boundary between pixel data of a first gray scale level and pixel data of a second gray scale level from image data transmitted to the display unit as a characteristic amount is disposed in a control unit that controls the display unit, and

wherein the control unit determines whether an operation mode of an image displaying operation is to be switched based on the characteristic amount and switches the operation mode based on the result of the determination.

8. The electrophoretic display device according to claim 7, wherein the control unit has a first operation mode and a second operation mode, the first operation mode being for displaying an image in the display unit by supplying image displaying electric potentials to both the first and second control lines, the second operation mode including an operation for displaying an image of the first gray scale level in the display unit by supplying an image displaying electric potential to one control line between the first and second control lines in a state that the other control line is electrically cut off and an operation for displaying an image of the second gray scale level in the display unit by interchanging the control line to which the electric potential is supplied and the control line that is electrically cut off which are switchable therebetween.

9. The electrophoretic display device according to claim 7, wherein the control unit has an operation mode in which a first electric potential is input as the high-level electric potential of the first and second control lines and an operation mode in which a second electric potential lower than the first electric potential is input as the high-level electric potential which can be switchable therebetween.

10. The electrophoretic display device according to claim 7, wherein the control unit compares a reference value set in advance and the input characteristic amount and determines whether the operation mode is needed to be switched based on the result of the comparison.

11. The electrophoretic display device according to claim 7, wherein the characteristic amount acquiring section acquires the characteristic amount by counting the number of boundaries between the pixel data of the first gray scale level and the pixel data of the second gray scale level of the input image data which corresponds to the adjacent pixels of the display unit.

12. The electrophoretic display device according to claim 7, wherein the characteristic amount acquiring section extracts the characteristic amount that is embedded in the image data in advance from the input image data.

13. An electronic apparatus comprising the electrophoretic display device according to claim 7.