JPH0568209A - Ccd digital camera - Google Patents

Abstract

PURPOSE:To obtain a CCD digital camera free from the omission of a picture element like a spot flaw by storing the address of the picture element flaw of a CCD chip, and executing correction at the time of photographing. CONSTITUTION:This camera is provided with a defective picture element detecting part 4 to detect the picture element flaw of the CCD chip 2 in use for each picture element unit, a defective picture element address storage part 5 for storing the address of the picture element flaw for each picture element unit, and a picture element processing part 6 which can correct the picture element flaw of the CCD chip 2 by referring to the address at the time of the actual photographing. Then, a processed picture after the correction of the defective picture element obtained by the picture element processing part 6 is presented for display. Accordingly, even if the CCD chip 2 with the defective picture element is used, photographed contents can be displayed as the picture by detecting the defective picture element for each picture element unit, and executing the defective picture element correction for eliminating the defective picture element according to the address of the detected defective picture element. Thus, the CCD digital camera capable of preventing the omission of the picture element through the use of the CCD chip 2 manufactured inexpensively can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CCD digital camera applied to, for example, an endoscope or an X-ray diagnostic apparatus.

[0002]

2. Description of the Related Art Generally, a CCD image pickup device (hereinafter referred to as "CCD chip") used in this type of CCD digital camera has defective pixels that do not respond to light at all. Nevertheless, conventionally, the image signal obtained by the CCD chip has been digitally processed without being individually corrected for defective pixels and then provided for image display.

[0003]

Therefore, in the case of the conventional CCD digital camera of this type, when a defective pixel exists in the CCD chip, that portion on the display image corresponding to the defective pixel of the CCD chip is detected. There was a problem that it came off like a dot. Therefore, it is considered that a CCD chip having no defective pixels should be used, but in this case, since the yield at the time of manufacturing the CCD chip is greatly reduced, an expensive CCD chip is used, which is economically economical. It will be a disadvantage.

The present invention has been made in view of the above circumstances, and its purpose is to provide a CCD having a defective pixel.
An object of the present invention is to provide a CCD digital camera capable of displaying an image without missing pixels such as dots even if a chip is used.

[0005]

In order to achieve the above-mentioned object, the present invention eliminates the pixel defect of the CCD chip used.
A defective pixel detection unit that detects the pixel unit, a defective pixel address storage unit that stores the address of the detected pixel defect for each pixel unit, and a pixel defect of the CDD chip by referring to the address when actually photographing. An image processing unit capable of performing correction for the image processing unit is provided, and the processed image after the defective pixel correction obtained by the image processing unit is displayed.

[0006]

With the structure of the CCD camera according to the present invention, the defective pixel of the CCD chip to be used is detected by the defective pixel detection unit on a pixel-by-pixel basis, and the address thereof is stored in the defective pixel address storage unit, and when the actual photographing is performed In the image processing unit, the defective pixel is corrected by referring to the address, and the processed image after the defective pixel correction is used for display. Allows you to display images without omissions.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a CC according to an embodiment to which the present invention is applied.
It is a block diagram which shows the circuit structure of a D digital camera.

In the CCD digital camera of the first embodiment, the sync signal generated by the sync signal generator 1 is sent to the CCD.
In addition to the operation of each part of the chip 2, the A / D converter 3, the defective pixel detection unit 4, the defective pixel address storage unit 5, the image processing unit 6, and the D / A converter 7, while actually The switch 9 is turned on to the contact 9a before photographing, and the switch 9 is turned on to the contact 9b at the time of actual photographing so that the contents photographed by the CCD chip 2 are displayed on the CRT 8.

Then, the defective pixel detecting section 4 uses the C to be used.
The pixel defect of the CD chip 2 is detected pixel by pixel. The defective pixel address storage unit 5 stores the address of the pixel defect for each pixel detected by the defective pixel detection unit 4. The image processing section 6 refers to the above-mentioned address when actually taking an image, and performs correction for a pixel defect of the CCD chip 2, for example, correction for replacing a defective pixel with the content of an adjacent pixel. . Since the respective units operated in this way are provided, the overall system operation before and during actual photographing is as described below.

Before the actual photographing, the switch 9 is in a state of being turned on to the contact 9a. When the contact point 9a is closed, the image signal of the CCD chip 2 is applied to the defective pixel detecting section 4 digitized by the A / D converter 3, and the defective pixel detecting section 4 detects the pixel defect of the CCD chip 2 as 1. The detection is performed for each pixel, and the detected pixel defect address for each pixel is stored in the defective pixel address storage unit 5.

Next, at the time of actually photographing, the switch 9 is in a state of being closed. When the contact point 9b is closed, an image signal indicating the content photographed by the CCD chip 2 is digitized by the A / D converter 3 and added to the image processing section 6, where predetermined signal processing is performed. The D / A converter 7 produces an analog image signal, which is sent to the CRT 8 for image display. At this time, since the image processing unit 6 corrects the pixel defect of the CCD chip 2 according to the address of the defective pixel address storage unit 5, it is necessary to display a clean image on the CRT 8 without missing pixels such as dots. You can

As described above, since the defective pixel correction can be performed by the image processing unit 6, even if a CCD chip having defective pixels is used as the CCD chip 2, image display without pixel omission can be performed. Further, the defective pixel detection unit 4 may have a system configuration separately provided from the camera body, but when the system configuration is built in the camera body as in this embodiment, the CCD chip 2 is used. This is convenient because the defective pixel correction can be performed as it is even if is replaced with a new CCD chip. In addition, because of these advantages, C with no defective pixels
Since it is not necessary to use a CD chip, the production yield of CCD chips is improved, and it is possible to provide a CCD digital camera that is inexpensive and has no missing pixels.

[0013]

As described above, according to the present invention, even if a CCD chip having a defective pixel is used, the defective pixel is detected on a pixel-by-pixel basis, and the defective pixel is substantially detected according to the address of the detected defective pixel. Since it is possible to display the captured content as an image by correcting the defective pixels to be eliminated,
It is possible to manufacture a CCD digital camera in which pixel omission is prevented by using an inexpensively manufactured CCD chip. Further, even if only some CCD chip needs to be replaced, the adjustment accompanying the replacement can be easily performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a CCD digital camera of an embodiment to which the present invention is applied.

[Explanation of symbols]

 1 sync signal generator 2 CCD chip 3 A / D converter 4 defective pixel detector 5 defective pixel address storage 6 image processor 7 D / A converter 8 CRT 9 switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H04N 9/04 Z 8943-5C

Claims (1)

[Claims] 1. A pixel defect of a CCD image sensor used is
A defective pixel detection unit for detecting in pixel units, a defective pixel address storage unit for storing the address of the detected pixel defect for each pixel unit, and a pixel defect of the CCD image pickup device by referring to the address when actually taking an image. A CCD digital camera, comprising: an image processing unit capable of performing correction for the above, and displaying the processed image after the defective pixel correction obtained by the image processing unit.