DEFECTIVE PIXEL SPECIFYING METHOD, DEFECTIVE PIXEL SPECIFYING SYSTEM, IMAGE CORRECTING METHOD, AND IMAGE CORRECTING SYSTEM

• US 20110058074A1
• Filed: 11/12/2010
• Published: 03/10/2011
• Est. Priority Date: 03/01/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KIMURA, Hajime
• Granted Patent: US 7,969,489 B2
• Time in Patent Office: Days
• US Class Current: 348/243
• CPC Class Codes: H04N 9/30 using solid-state colour display devices

Abstract

A defective pixel specifying method and a defective pixel specifying system for a semiconductor device having a defective pixel are provided. Also provided are an image correcting method and an image correcting system for making a defective pixel inconspicuous on the screen when a read image is displayed. The present invention determines whether or not there is a defective pixel for each pixel and specifies the coordinate of the defective pixel using image signals obtained by reading a plurality of images. The image signal of the defective pixel is set based on the image signals of the pixels adjacent to the defective pixel to correct the image of the subject read.

Claims

1. A driving method of a device comprising a pixel comprising a transistor and a photoelectric conversion element, the driving method comprising:

resetting the photoelectric conversion element by applying a first potential to an n-channel terminal of the photoelectric conversion element;

flowing a first current corresponding to the first potential in the transistor;

resetting the photoelectric conversion element by applying the first potential to the n-channel terminal of the photoelectric conversion element;

flowing a second current corresponding to a second potential in the transistor when the n-channel terminal of the photoelectric conversion element has the second potential after an accumulation time T of the photoelectric conversion element;

wherein the accumulation time T satisfies an expression T>

(C×

Vp)/Id, where C is a capacitance of the photoelectric conversion element, Vp is a voltage applied to both terminals of the photoelectric conversion element when the photoelectric conversion element is reset, and Id is a dark current flowing in the photoelectric conversion element, and

wherein the first potential is almost the same as a potential obtained by reading a black calibration sheet, and the second potential is almost the same as a potential obtained by reading a white calibration sheet.

4. The driving method according to claim 1, further comprising determining whether the pixel is a defective pixel.

7. The driving method according to claim 4, wherein the driving method is used when the device is used for the first time.

10. The driving method according to claim 1, wherein the device is applied to an electronic equipment selected from the group consisting of a video camera, a digital still camera, a notebook computer, a mobile computer, a cellular phone, a portable game machine, and an electronic book.

2. A driving method of a device comprising a pixel comprising a transistor and a photoelectric conversion element, the driving method comprising:

resetting the photoelectric conversion element by applying a first potential to an n-channel terminal of the photoelectric conversion element;

flowing a first current corresponding to the first potential in the transistor;

obtaining a first signal from the pixel when flowing the first current;

resetting the photoelectric conversion element by applying the first potential to the n-channel terminal of the photoelectric conversion element;

flowing a second current corresponding to a second potential in the transistor when the n-channel terminal of the photoelectric conversion element has the second potential after an accumulation time T of the photoelectric conversion element;

obtaining a second signal from the pixel when flowing the second current; and

calculating a difference between the first signal and the second signal,

wherein the accumulation time T satisfies an expression T>

(C×

Vp)/Id, where C is a capacitance of the photoelectric conversion element, Vp is a voltage applied to both terminals of the photoelectric conversion element when the photoelectric conversion element is reset, and Id is a dark current flowing in the photoelectric conversion element, and

wherein the first potential is almost the same as a potential obtained by reading a black calibration sheet, and the second potential is almost the same as a potential obtained by reading a white calibration sheet.

5. The driving method according to claim 2, further comprising determining whether the pixel is a defective pixel.

8. The driving method according to claim 5, wherein the driving method is used when the device is used for the first time.

11. The driving method according to claim 2, wherein the device is applied to an electronic equipment selected from the group consisting of a video camera, a digital still camera, a notebook computer, a mobile computer, a cellular phone, a portable game machine, and an electronic book.

3. A driving method of a device comprising a pixel comprising a transistor and a photoelectric conversion element, the driving method comprising:

resetting the photoelectric conversion element by applying a first potential to an n-channel terminal of the photoelectric conversion element;

flowing a first current corresponding to the first potential in the transistor;

resetting the photoelectric conversion element by applying the first potential to the n-channel terminal of the photoelectric conversion element;

flowing a second current corresponding to a second potential in the transistor when the n-channel terminal of the photoelectric conversion element has the second potential;

wherein a time between resetting the photoelectric conversion element and beginning of flowing the second current is longer than a time between resetting the photoelectric conversion element and beginning of flowing the first current, and

wherein the first potential is almost the same as a potential obtained by reading a black calibration sheet, and the second potential is almost the same as a potential obtained by reading a white calibration sheet.

6. The driving method according to claim 3, further comprising determining whether the pixel is a defective pixel.

9. The driving method according to claim 6, wherein the driving method is used when the device is used for the first time.

12. The driving method according to claim 3, wherein the device is applied to an electronic equipment selected from the group consisting of a video camera, a digital still camera, a notebook computer, a mobile computer, a cellular phone, a portable game machine, and an electronic book.