Display device and method of driving the same

• US 10,269,285 B2
• Filed: 02/26/2016
• Issued: 04/23/2019
• Est. Priority Date: 09/09/2015
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Changhoon, Won, Byeonghee, Kim, Ilnam, Park, Wonsang, Baek, Jongin
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): Mathews, Crystal
• Application Number:
  US15/054,661
• Publication Number:
  US 20170069290A1
• Time in Patent Office: 1,152 Days
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2044 using dithering

Abstract

A display device includes: a display unit; a plurality of pixels disposed in the display unit, each pixel including first and second blue sub-pixels; and a driving mode controller configured to set a driving mode to one of a first driving mode in which both of the first and second blue sub-pixels emit light, and a second driving mode in which one of the first and second blue sub-pixels emits light, wherein the first blue sub-pixel emits light of a first frequency, and the second blue sub-pixel emits light of a second frequency different from the first frequency.

Claims

1. A display device, comprising:

a display unit;

a plurality of pixels disposed in the display unit, each of the pixels comprising a red sub-pixel, a green sub-pixel, a first blue sub-pixel and a second blue sub-pixel;

a driving mode controller configured to set a driving mode to one of a first driving mode in which both of the first and second blue sub-pixels emit light, and a second driving mode in which one of the first and second blue sub-pixels emits light;

an output signal generator configured to receive two successive input image signals including first and second input image signals, and generate an output signal based on the two successive input image signals,

wherein the first blue sub-pixel emits light of a first frequency, and the second blue sub-pixel emits light of a second frequency different from the first frequency,

wherein the first input image signal includes a first red image signal, a first green image signal and a first blue image signal, and the second input image signal includes a second red image signal, a second green image signal and a second blue image signal, and

wherein the output signal includes an output red image signal corresponding to the red sub-pixel, an output green image signal corresponding to the green sub-pixel, a first output blue image signal corresponding to the first blue sub-pixel, and a second output blue image signal corresponding to the second blue sub-pixel,

wherein the second driving mode includes a (2-1)-th driving mode in which the first blue sub-pixel emits light, and when the driving mode is the (2-1)-th driving mode, the output signal generator generates the first output blue image signal based on the first and second blue image signals according to the following equation;

2. The device of claim 1, wherein a central wavelength of the light emitted from the first blue sub-pixel is longer than a central wavelength of the light emitted from the second blue sub-pixel.

3. The device of claim 1, wherein a central wavelength of the light emitted from the first blue sub-pixel is in a range from about 464 nm to about 470 nm, and a central wavelength of the light emitted from the second blue sub-pixel is in a range from about 440 nm to about 464 nm.

4. The device of claim 1, wherein the second driving mode includes a (2-2)-th driving mode in which the second blue sub-pixel emits light.

5. The device of claim 4, wherein the driving mode controller is configured to determine a current time as day or night, set the driving mode to one of the first driving mode and the (2-1)-th driving mode when the current time is day, and set the driving mode to the (2-2)-th driving mode when the current time is night.

6. The device of claim 4, wherein the driving mode controller is configured to determine a current location as an outdoor space or an indoor space, set the driving mode to the first driving mode when the current location is the outdoor space, and set the driving mode to one of the (2-1)-th driving mode and the (2-2)-th driving mode when the current location is the indoor space.

7. The device of claim 4, wherein the output signal generator:

generates the first and second output blue image signals to allow the first and second blue sub-pixels to emit light when the driving mode is the first driving mode, and

generates the second output blue image signal based on the first and second blue image signals to allow the second blue sub-pixel to emit light when the driving mode is the (2-2)-th driving mode.

8. The device of claim 7, wherein the output signal generator:

generates the output red image signal based on the first and second red image signals,

generates the output green image signal based on the first and second green image signals,

when the driving mode is the first driving mode, generates the first output blue image signal same as the first blue image signal and the second output blue image signal same as the second blue image signal, and

when the driving mode is the (2-2)-th driving mode, generates the second output blue image signal based on the first and second blue image signals according to the following equation;

9. The device of claim 8, further comprising:

a source driver configured to receive the output red image signal, the output green image signal, and the first and second output blue image signals, and apply data signals to the plurality of pixels,

wherein the source driver;

applies a data signal generated based on the output red image signal to the red sub-pixel,

applies a data signal generated based on the output green image signal to the green sub-pixel,

applies a data signal generated based on the first output blue image signal to the first blue sub-pixel, and

applies a data signal generated based on the second output blue image signal to the second blue sub-pixel.

10. The device of claim 7, wherein the output signal generator is configured to perform gamma correction by using a first gamma value when the driving mode is the first driving mode, by using a second gamma value when the driving mode is the (2-1)-th driving mode, and by using a third gamma value when the driving mode is the (2-2)-th driving mode.

11. The device of claim 1, wherein each of the plurality of pixels comprises a first sub-pixel group comprising the red sub-pixel and the green sub-pixel arranged in a first direction, and a second sub-pixel group comprising the first and second blue sub-pixels arranged in the first direction, and

the display unit comprises a first sub-pixel row in which the first sub-pixel group is arranged in the first direction, and a second sub-pixel row in which the second sub-pixel group is arranged in the first direction.

12. The device of claim 11, wherein the display unit comprises the first and second sub-pixel rows arranged in a second direction substantially perpendicular to the first direction,

the first sub-pixel row comprises:

a (1-1)-th sub-pixel row in which the red sub-pixel and the green sub-pixel are repeatedly arranged in sequence, and a (1-2)-th sub-pixel row in which the green sub-pixel and the red sub-pixel are repeatedly arranged in sequence, and

the second sub-pixel row comprises;

a (2-1)-th sub-pixel row in which the first blue sub-pixel and the second blue sub-pixel are repeatedly arranged in sequence, and a (2-2)-th sub-pixel row in which the second blue sub-pixel and the first blue sub-pixel are repeatedly arranged in sequence.

13. A method of driving a display device comprising a display unit, a plurality of pixels disposed in the display unit, each pixel comprising a red sub-pixel, a green sub-pixel, a first blue sub-pixel and a second blue sub-pixels, a driving mode controller configured to set a driving mode to one of a first driving mode in which both of the first and second blue sub-pixels emit light, a (2-1)-th driving mode in which the first blue sub-pixel emits light, and a (2-2)-th driving mode in which the second blue sub-pixel emits light, wherein the first blue sub-pixel emits light of a first frequency, and the second blue sub-pixel emits light of a second frequency different from the first frequency, the method comprising:

receiving two successive input image signals including first and second input image signals, the first input image signal including a first red image signal, a first green image signal and a first blue image signal, and the second input image signal including a second red image signal, a second green image signal and a second blue image signal;

generating an output signal based on the two successive input image signals, the output signal including an output red image signal corresponding to the red sub-pixel, an output green image signal corresponding to the green sub-pixel, a first output blue image signal corresponding to the first blue sub-pixel, and a second output blue image signal corresponding to the second blue sub-pixel;

determining a current time as day or night;

determining a current position as an outdoor space or an indoor space; and

setting the driving mode to the first driving mode when the current time is day and the current position is the outdoor space, setting the driving mode to the (2-1)-th driving mode when the current time is day and the current position is the indoor space, and setting the driving mode to the (2-2)-th driving mode when the current time is night,

wherein the generating of the output signal comprises;

generating the first output blue image signal based on the first and second blue image signals to allow the first blue sub-pixel to emit light when the driving mode is the (2-1)-th driving mode, and

generating the second output blue image signal based on the first and second blue image signals to allow the second blue sub-pixel to emit light when the driving mode is the (2-2)-th driving mode,

when the driving mode is the (2-1)-th driving mode, the first output blue image signal based on the first and second blue image signals is generated according to the following equation;

14. The method of claim 13, wherein the generating of the output signal comprises:

generating the first and second output blue image signals to allow the first and second blue sub-pixels to emit light when the driving mode is the first driving mode.

15. The method of claim 14, wherein the generating of the output signal comprises:

generating the output red image signal based on the first and second red image signals; and

generating the output green image signal based on the first and second green image signals,

when the driving mode is the first driving mode, generating the first output blue image signal same as the first blue image signal and the second output blue image signal same as the second blue image signal.

16. The method of claim 15, further comprising:

after the generating of the output signal, applying a data signal generated based on the output red image signal to the red sub-pixel, applying a data signal generated based on the output green image signal to the green sub-pixel, applying a data signal generated based on the first output blue image signal to the first blue sub-pixel, and applying a data signal generated based on the second output blue image signal to the second blue sub-pixel.

17. The method of claim 14, wherein the generating of the output signal comprises:

performing gamma correction by using a first gamma value when the driving mode is the first driving mode, by using a second gamma value when the driving mode is the (2-1)-th driving mode, and by using a third gamma value when the driving mode is the (2-2)-th driving mode.

18. A display device, comprising:

a display unit;

a plurality of pixels disposed in the display unit, each of the pixels comprising a red sub-pixel, a green sub-pixel, a first blue sub-pixel and a second blue sub-pixel;

a driving mode controller configured to set a driving mode to one of a first driving mode in which both of the first and second blue sub-pixels emit light, and a second driving mode in which one of the first and second blue sub-pixels emits light;

an output signal generator configured to receive two successive input image signals including first and second input image signals, and generate an output signal based on the two successive input image signals,

wherein the first blue sub-pixel emits light of a first frequency, and the second blue sub-pixel emits light of a second frequency different from the first frequency,

wherein the first input image signal includes a first red image signal, a first green image signal and a first blue image signal, and the second input image signal includes a second red image signal, a second green image signal and a second blue image signal, and

wherein the output signal includes an output red image signal corresponding to the red sub-pixel, an output green image signal corresponding to the green sub-pixel, a first output blue image signal corresponding to the first blue sub-pixel, and a second output blue image signal corresponding to the second blue sub-pixel,

wherein the second driving mode includes a (2-1)-th driving mode in which the first blue sub-pixel emits light and a (2-2)-th driving mode in which the second blue sub-pixel emits light, and

when the driving mode is the (2-2)-th driving mode, the output signal generator generates the second output blue image signal based on the first and second blue image signals according to the following equation;