METHOD FOR DRIVING DISPLAY DEVICE

• US 20080084403A1
• Filed: 05/01/2006
• Published: 04/10/2008
• Est. Priority Date: 05/02/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime, Yamazaki, Shunpei
• Granted Patent: US 8,994,756 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G09G 2300/0439 Pixel structures
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• 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 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/3241 the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
• CPC Class Codes: G09G 3/325 the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements

Abstract

There is no method combining advantages of both an analog gray scale method and a digital gray scale method. An object is to provide a means that can perform display in a plurality of display modes. In a display mode-specific video signal generation circuit, an input video signal is output as an analog value without any change, as a binary digital value, and as a multi-valued digital value. As a result, a display gray scale of a pixel changes in a timely manner. Accordingly, a clear image can be displayed. In other words, an analog signal and a digital signal are switched and input to a source driver. In addition, the display device also includes a means that switches and outputs an analog signal and a digital signal. By using such means, the display device can have the advantages of both the analog gray scale method and the digital gray scale method, thereby achieving the above object.

Claims

1. A display device comprising:

pixels arranged in matrix; and

a source driver and a gate driver,

wherein an analog signal is supplied to the source driver in a first display mode, and a digital signal is supplied to the source driver in a second display mode.

2. The display device according to claim 1,

wherein the first mode and the second display mode are controlled by a controller.

3. The display device according to claim 1,

wherein the display device further comprises a display mode-specific video signal generation circuit, from which the analog signal and the digital signal supplied to the source driver are output.

4. The display device according to claim 1,

wherein the display device further comprises a display mode-specific video signal generation circuit including a binarization circuit, and

wherein an analog video signal is input to the display mode-specific video signal generation circuit, and the analog video signal is converted into an analog signal and a digital signal using the binarization circuit.

5. The display device according to claim 1,

wherein the display device further comprises a display mode-specific video signal generation circuit including a DA converter circuit, and

wherein a digital video signal is input to the display mode-specific video signal generation circuit, and the digital video signal is converted into an analog signal and a digital signal using the DA converter circuit.

6. The display device according to claim 1,

wherein the display device further comprises a light emitting element.

7. An electronic device comprising the display device according to claim 1.

8. A display device comprising:

pixels arranged in matrix; and

a source driver and a gate driver,

wherein a first analog signal is supplied to the source driver and a second analog signal is supplied to the pixel from the source driver in a first display mode, and a first digital signal is supplied to the source driver and a second digital signal is supplied to the pixel from the source driver in the second display mode.

9. The display device according to claim 8,

wherein the first mode and the second display mode are controlled by a controller.

10. The display device according to claim 8,

wherein the display device further comprises a display mode-specific video signal generation circuit, from which the first analog signal and the first digital signal supplied to the source driver are output.

11. The display device according to claim 8,

wherein the display device further comprises a display mode-specific video signal generation circuit including a binarization circuit, and

wherein an analog video signal is input to the display mode-specific video signal generation circuit, and the analog video signal is converted into an analog signal and a digital signal using the binarization circuit.

12. The display device according to claim 8,

wherein the display device further comprises a display mode-specific video signal generation circuit including a DA converter circuit, and

wherein a digital video signal is input to the display mode-specific video signal generation circuit, and the digital video signal is converted into an analog signal and a digital signal using the DA converter circuit.

13. The display device according to claim 8,

wherein the display device further comprises a light emitting element.

14. An electronic device comprising the display device according to claim 8.

15. A method of driving a display device comprising:

supplying an analog signal to a source driver in a first display mode, and

supplying a digital signal to a source driver in a second display mode.