Display device and imaging method

• US 7,545,371 B2
• Filed: 11/16/2004
• Issued: 06/09/2009
• Est. Priority Date: 11/17/2003
• Status: Active Grant

• Current Assignee: Japan Display Central Incorporated (Japan Display Incorporated)
• Original Assignee: Toshiba Matsushita Display Technology (Japan Display Incorporated)
• Inventors: Nakamura, Takashi, Yoshida, Masahiro, Ishikawa, Miyuki
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Sheng; Tom V
• Application Number:
  US10/988,599
• Publication Number:
  US 20050104877A1
• Time in Patent Office: 1,666 Days
• Field of Search: 345 81-100, 345/204, 345/690, 345/207
• US Class Current: 345/207
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A display device has a pixel array part having display elements provided inside of pixels formed in vicinity of cross points of signal lines and scanning lines aligned in matrix form; image capture circuits provided corresponding to the display elements, each including an optical sensor which picks up image at prescribed range of an imaging subject; and an image capture processing unit which generates ultimate image capture data based on result of having picked up images a plurality of times while changing image capture condition except for display color, with respect to each of M kinds of display colors.

Claims

1. A display device, comprising:

a pixel array part having display elements provided inside of pixels formed in vicinity of cross points of signal lines and scanning lines aligned in matrix form;

image capture circuits provided corresponding to said display elements, each including an optical sensor which picks up image at prescribed range of an imaging subject;

an image capture processing unit which generates ultimate image capture data based on result of having picked up images a plurality of times while changing image capture condition except for display color, with respect to each of M kinds of display colors, and

a color correction linear converter which performs matrix operation by using 3×

3 matrix in which positive and negative signs of diagonal component and non-diagonal component are different from each other, with respect to a first color gradation signal, a second color gradation signal and a third color gradation signal outputted from said image capture circuit,

wherein said image capture processing unit generates ultimate image capture data based on result of matrix operation by said color correction linear converter.

2. The display device according to claim 1, wherein said M kinds of display colors include red, green and blue.

3. The display device according to claim 1, wherein said M kinds of display colors include cyan, magenta and yellow.

4. A display device, comprising:

a pixel array part having display elements provided inside of pixels formed in vicinity of cross points of signal lines and scanning lines aligned in matrix form;

image capture circuits provided corresponding to said display elements, each including an optical sensor which picks up image at prescribed range of an imaging subject; and

an image capture processing unit which generates ultimate image capture data based on result of having picked up images a plurality of times while changing image capture condition except for display color, with respect to each of M kinds of display colors,

wherein display color at a first image capture time is a first color, display color at a second image capture time is a second color, and display color at a third image capture time is a third color;

said first color, said second color and said third color are selected in the order of color having lower S/N ratio of said optical censor.

5. The display device according to claim 4, further comprising a gradation correction unit which performs gradation correction in accordance with gradation value of a specialized color with respect to a first color gradation signal, a second color gradation signal and a third color gradation signal outputted from said image capture circuit.

6. The display device according to claim 5, further comprising an irregularity subtraction unit which subtracts display irregularity of a first color gradation signal, a second color gradation signal and a third color gradation signal outputted from said image capture circuit,

wherein the gradation value of the specialized color is a gradation value of the specialized color after performing subtraction processing of display irregularity.

7. The display device according to claim 6, wherein said irregularity subtraction unit performs subtraction processing of display irregularity by calculating difference from uniform image picked up by said image capture circuit at state of setting the whole pixel array part to halftone.

8. The display device according to claim 5, wherein said specialized color is blue.

9. The display device according to claim 5, wherein said specialized color is a color having a highest S/N ratio of said optical sensor.

10. The display device according to claim 5, wherein gradation correction by said gradation correction unit is performed when the imaging subject is composed of line drawing data.

11. A display device, comprising:

an image array part which has display elements provided inside of pixels formed in vicinity of cross points of signal lines and scanning lines aligned in matrix form;

image capture circuits provided corresponding to said display elements, each picking up image at prescribed range of an image capture subject;

an image capture condition switching unit which switches in stages a exposure time in said image capture circuit; and

an irregularity processing unit which performs irregularity processing of a picked-up image, taking into consideration polarity of display data written into the pixel at image capture time.

12. The display device according to claim 11, wherein said irregularity processing unit has a unit of forming one piece of picked-up image by combining display data having a certain polarity of two picked-up images having polarities opposite to each other written into pixels at image capture time.

13. A display device, comprising:

a pixel array part having display elements provided inside of pixels formed in vicinity of cross points of signal lines and scanning lines aligned in matrix form;

image capture circuits provided corresponding to said display elements, each including an optical sensor which picks up image at prescribed range of an imaging subject;

an image capture condition switching unit which switches in stages exposure time in said image capture circuits,

wherein said image capture condition switch unit sets exposure time T in said image capture circuits so that (1/T−

1/T₀)^1/γ

changes at substantially a constant interval, where T is an exposure time of said image capture circuits, T0 is an exposure time for reading out ideal black and γ

is a gamma value of said pixel array part.

14. The display device according to claim 13, further comprising an exposure time storage which stores in advance a plurality of exposure times which change a value (1/T−

1/T₀)^1/γ

of at constant interval,

wherein said image capture condition switching unit selects the exposure times stored in said exposure time storage in order, to decide the exposure time of said image capture circuit.

15. The display device according to claim 13, wherein said T0 is time when a white color face material is arranged closely on display face side of said pixel array part, images are picked up repeatedly while changing the imaging time of said image capture circuit at state of turning off a backlight, and a ratio between white and black of image capture data outputted from said image capture circuit becomes 1:

1.

16. The display device according to claim 13, wherein a minimum value of said T is time when a white color face material is arranged closely on display face side of said pixel array part, image are picked up repeatedly while changing the imaging time of said image capture circuit at state of turning on a backlight, and a ratio between white and black of image capture data outputted from said image capture circuit becomes 1:

1.

17. The display device according to claim 13, further comprising a lid openable and closable which arranges the white color face closely to display face.