Display apparatus and method of driving the same using photonic and electrophoresis principle

• US 9,336,702 B2
• Filed: 04/06/2012
• Issued: 05/10/2016
• Est. Priority Date: 08/01/2011
• Status: Active Grant

• Current Assignee: Hydis Technologies Co Ltd (E Ink Holdings Incorporated)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Jang-Kyum, Kim, Sangil, Kim, Myung-Eun, Roh, Namseok, Yeo, Gilhwan, Kim, Yeun Tae, Lim, KyoungHo
• Primary Examiner(s): Nguyen, Jimmy H
• Assistant Examiner(s): Lin, Hang
• Application Number:
  US13/441,074
• Publication Number:
  US 20130033531A1
• Time in Patent Office: 1,495 Days
• Field of Search: 345204-215, 345690-695, 359/589
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• 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 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 2340/00 Aspects of display data processing
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• 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

A display apparatus includes an image data comparator which receives first, second and third color image data, extracts first, second and third image data from the first, second and third color image date by comparing gray scale values of the first, second and third color image date such that each of grayscale values of the second and third image data is greater than or equal to a gray scale value of the first image data, and compares the gray scale value of the first image data with a predetermined gray scale value, a driving circuit which generates a gray scale signal based on a result of the comparison and generates first and second color signals based on the first, second or third image data, and a pixel including a first sub-pixel which receives the gray scale signal, second and third sub-pixels which receive the first and second color signals, respectively.

Claims

1. A display apparatus comprising:

an image data comparator which receives a pixel image data including a first color image data, a second color image data and a third color image data, extracts a first image data, a second image data and a third image data from the first color image data, the second color image data and the third color image data by comparing gray scale values of the first color image date, the second color image data and the third color image data with each other such that each of a grayscale value of the second image data and a grayscale value of the third image data is greater than or equal to a gray scale value of the first image data, and compares the gray scale value of the first image data with a predetermined gray scale value;

a driving circuit which generates a gray scale signal based on a compared result of the gray scale value of the first image data and the predetermined gray scale value and generates a first color signal and a second color signal based on at least one of the first image data, the second image data and the third image data, wherein each of the first and second color signals includes at least one color information; and

a pixel including a first sub-pixel which receives a gray voltage corresponding to the gray scale signal to display a gray scale, a second sub-pixel which receives a first driving voltage corresponding to the first color signal to display at least two primary colors, and a third sub-pixel which receives a second driving voltage corresponding to the second color signal to display at least two primary colors,

wherein a wavelength of each color displayed from the second sub-pixel and the third sub-pixel is corresponding to each of the first driving voltage and the second driving voltage,

wherein the predetermined gray scale value is obtained by multiplying a maximum gray scale value of the pixel image data by a ratio of a maximum reflectance of the first sub-pixel to a maximum reflectance of the pixel.

2. The display apparatus of claim 1, wherein

when the gray scale value of the first image data is less than the predetermined gray scale value, the driving circuit generates the gray scale signal based on the first image data, and the first sub-pixel displays a gray scale corresponding to a gray scale level in gray scale levels from a black gray scale to a white gray scale based on a ratio of the gray scale value of the first image data to the predetermined gray scale value.

3. The display apparatus of claim 2, wherein

the driving circuit generates the first color signal based on the second image data,

the first color signal includes at least one of a first color voltage having first color information or a black voltage having black color information, and

the second sub-pixel displays a first color corresponding to the first color information or a black color corresponding to the black color information.

4. The display apparatus of claim 3, wherein

the second sub-pixel successively displays the first color and the black color, and

a time ratio, in which the first color and the black color are displayed, satisfies the following Equation,

C1t:

Bk1t=(G2−

G1);

(Mg−

G2),

wherein C1t denotes a time period during which the first color is displayed in the second sub-pixel, Bk1t denotes a time period during which the black color is displayed in the second sub-pixel, G2 is the gray scale value of the second image data, G1 is the gray scale value of the first image data, and Mg is the maximum gray scale value.

5. The display apparatus of claim 2, wherein

the driving circuit generates the second color signal based on the third image data,

the second color signal includes at least one of a second color voltage having second color information or a black voltage having black color information, and

the third sub-pixel displays a second color corresponding to the second color information or a black color corresponding to the black color information.

6. The display apparatus of claim 5, wherein

the third sub-pixel successively displays the second color and the black color, and

a time ratio, in which the second color and the black color are displayed, satisfies the following Equation,

C2t:

Bk2t=(G3−

G1);

(Mg−

G3),

wherein C2t denotes a time period during which the second color is displayed in the third sub-pixel, Bk2t denotes a time period during which the black color is displayed in the third sub-pixel, G3 is the gray scale value of the third image data, G1 is the gray scale value of the first image data, and Mg is the maximum gray scale value.

7. The display apparatus of claim 1, wherein

the image data comparator extracts a color image data having a highest gray scale value among the first color image data, the second color image data and the third color image data as the second image data.

8. The display apparatus of claim 7, wherein

when the gray scale value of the first image data is greater than or equal to the predetermined gray scale value, the driving circuit generates a gray scale signal, which allows the first sub-pixel to have the maximum reflectance, and the first sub-pixel displays a white gray scale.

9. The display apparatus of claim 8, wherein

the driving circuit generates the first color signal based on the first image data and the second image data,

the fist color signal includes at least one of a first color voltage having first color information or a black voltage having black color information, and

the second sub-pixel displays a first color corresponding to the first color information or a black color corresponding to the black color information.

10. The display apparatus of claim 9, wherein

when the gray scale value of the first image data is greater than the predetermined gray scale value, the first color information corresponds to an intermediate color obtained by mixing a color corresponding to the color information of the first image data with a color corresponding to the color information of the second image data.

11. The display apparatus of claim 10, wherein

the second sub-pixel successively displays the first color and the second color, and

a time ratio, in which the first color and the second color are displayed, satisfies the following Equation,

C3t:

C4t=(G1−

Cg);

(G2−

G1),

wherein C3t denotes a time period during which the first color is displayed in the second sub-pixel, C4t denotes a time period during which the second color is displayed in the second sub-pixel, G1 denotes the gray scale value of the first image data, G2 denotes the gray scale value of the second image data, and Cg denotes the predetermined gray scale value.

12. The display apparatus of claim 9, wherein

the driving circuit generates the second color signal based on the third image data,

the second color signal includes at least one of a third color voltage having third color information or a black voltage having black color information, and

the third sub-pixel displays a third color corresponding to the third color information or a black color corresponding to the black color information.

13. The display apparatus of claim 12, wherein

the third sub-pixel successively displays the third color and the black color, and

a time ratio, in which the third color and the black color are displayed, satisfies the following Equation,

C5t:

C6t=(G3−

Cg);

(G2−

G3),

wherein C5t denotes a time period during which the third color is displayed in the third sub-pixel, C6t denotes a time period during which the black color is displayed in the third sub-pixel, G3 denotes the gray scale value of the third image data, Cg denotes the predetermined gray scale value, G2 denotes the gray scale value of the second image data, and G2 is greater than or equal to G3.

14. The display apparatus of claim 1, further comprising:

a display panel comprising;

a first substrate including a plurality of first lines extending in a first direction, and a plurality of second lines extending in a second direction crossing the first direction and insulated from the first lines, wherein each of the second lines includes a first sub-line, a second sub-line and a third sub-line; and

a second substrate spaced apart from the first substrate and including a common electrode disposed on a surface thereof facing the first substrate.

15. The display apparatus of claim 14, wherein

the first sub-pixel comprises:

a first sub-pixel electrode disposed on the first substrate;

a first thin film transistor connected to the first sub-line, the first sub-pixel electrode and one of the first lines; and

an electrophoretic material interposed between the first sub-pixel electrode and the common electrode.

16. The display apparatus of claim 15, wherein

the second sub-pixel comprises:

a second sub-pixel electrode disposed on the first substrate;

a second thin film transistor connected to the second sub-line, the second sub-pixel electrode and the one of the first lines, to which the first thin film transistor is connected; and

a photonic crystal material interposed between the second sub-pixel electrode and the common electrode, and

the third sub-pixel comprises;

a third sub-pixel electrode disposed on the first substrate;

a third thin film transistor connected to the third sub-line, the third sub-pixel electrode and the one of the first lines, to which the first thin film transistor is connected; and

a photonic crystal material interposed between the third sub-pixel electrode and the common electrode.

17. A method of driving a display apparatus comprising a pixel including a first sub-pixel which displays a gray scale, a second sub-pixel which displays at least two different primary colors of three different primary colors, and a third sub-pixel which displays at least two different primary colors of the three different primary colors, the method comprising:

receiving a pixel image data including a first color image data, a second color image data and a third color image data;

extracting a first image, a second image data and a third image data by comparing gray scale values of the first color image date, the second color image data and the third color image data with each other such that each of a grayscale value of the second image data and a grayscale value of the third image data is greater than or equal to a gray scale value of the first image data;

comparing the gray scale value of the first image data with a predetermined gray scale value;

generating a gray scale signal based on the comparing the gray scale value of the first image data and the predetermined gray scale value;

generating a first color signal and a second color signal based on at least one of the first image data, the second image data and the third image data, wherein each of the first and second color signals includes at least one color information;

applying a gray voltage corresponding to the gray scale signal to the first sub-pixel to display a gray scale corresponding to a gray scale level in gray scale levels from a black gray scale to a white gray scale; and

respectively applying a first driving voltage corresponding to the first color signal and a second driving voltage corresponding to the second color signal to the second sub-pixel and the third sub-pixel to display the at least one color,

wherein a wavelength of each color displayed from the second sub-pixel and the third sub-pixel is corresponding to each of the first driving voltage and the second driving voltage,

wherein the predetermined gray scale value is obtained by multiplying a maximum grayscale value of the pixel image data by a ratio of a maximum reflectance of the first sub-pixel to a maximum reflectance of the pixel.