JPH0214837B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color imaging device using a solid-state imaging device such as a CCD.

Conventionally, in a color television camera, an incident light beam is separated into three primary color lights (red, green, and blue), and optical images of these three colors are formed on the photosensitive surfaces of three solid-state imaging devices. A method is used in which a color image is reproduced by obtaining three primary color signals of red, green, and blue, and then superimposing each image based on these three primary color signals.

When a CCD is used as an imaging device in such a method, scanning is performed digitally using drive pulses, so the size of the image,
Distortion and scanning position can be accurately determined without change. Therefore, when a color imaging device is constructed using three CCDs, once they are superimposed, they become stable without any adjustment. However, red, green, and blue 3
Color optical images usually have slightly different sizes because the wavelengths of light are different. In this case, if three identical CCDs are used, color shift will occur in the reproduced three-color image, resulting in a very unsightly image. To improve this, we can make the three-color optical images match each other accurately by making special corrections in the optical system such as the imaging lens and color separation prism, or
It is necessary to manufacture special devices such as CCDs and other imaging devices with different photosensitive surfaces for each color. However, this method has disadvantages, such as the optical system having a complicated and expensive structure, and the need for a large number of devices in small quantities.

This invention was made in view of the above-mentioned drawbacks, and once the images are accurately superimposed, it is possible to easily change the scanning range of the images without adjusting the linear distortion or size of the images. It is an object of the present invention to provide a color imaging device that can be adjusted by means.

A color imaging device using a plurality of CCDs according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic configuration of a color imaging device using three CCDs according to the present invention. 1
The image is formed on photosensitive surfaces 4 and 15. This dichroic prism 12 separates the incident light into the three primary color lights of red, green, and blue and transmits them to different optical paths. On the surface, blue light is blue for CCD
The images are respectively formed on 15 photosensitive surfaces.

Each CCD 13, 14, 15 is driven by a drive pulse generated from a synchronization signal generator 16. That is, the signal from the synchronizing signal generator 16 is applied to three CCD drive circuits 17, 18, and 19 for red, green, and blue, respectively.
18 and 19 generate various pulse waveforms necessary for the operation of the CCD. The signal output from each CCD 13, 14, 15 is applied to amplifiers 20, 21, 22, amplified to a desired level, and then applied to signal processing circuits 23, 24, 25. Here, processing such as gamma correction, white clipping, and clamping necessary for color signals is performed, and each signal is added to a color encoder 26 to become an NTSC signal.

The three drive circuits 17, 18, and 19 generate a horizontal transfer pulse and a vertical transfer pulse in addition to the bias voltage applied to the CCD, and the frequency of the horizontal transfer pulse can be finely adjusted. That is, it is composed of a pulse oscillator that oscillates using a horizontal synchronizing pulse, and is configured to be able to set an arbitrary frequency.

As shown in FIG. 2, for example, when the width of the red optical image is larger than that of green by d ₁ and the width of the blue optical image is smaller than that of green by d ₂ , the horizontal width of the CCD drive circuit 18 for green is Keep the frequency constant and use CCD for red color
Increase the horizontal frequency of the drive circuit 17 to increase the CCD for blue color.
If the horizontal frequency of the drive circuit 19 is lowered, the difference in the horizontal widths of d ₁ and d ₂ can be corrected and the three images can be made to match accurately.

Also, as shown in Figure 2, when the left edges of the optical images are aligned and only the right edges are different, you only need to change the frequency, but if the left edges are not aligned, the pulse generator It is necessary to change not only the oscillation frequency but also the phase at which oscillation starts. In this case, it is necessary to insert a variable pulse delay circuit such as a mono-multi instead of directly controlling the pulse generator using horizontal periodic pulses. This delay circuit allows accurate positioning by setting the delay time to match the left end positions, and then finely adjusting the horizontal frequency.

As explained above, the color imaging device of the present invention has the great advantage that by simply adding a simple fine-adjustment circuit to the electronic circuit, it is possible to accurately align the three-color optical images and obtain clear color images. be.

In other words, it is difficult to accurately match the sizes of color images of three colors with different wavelengths using an optical system, but if the sizes of the optical images can be matched accurately by just correcting the vertical direction, it is easy to match the sizes in the horizontal direction. This will allow adjustments to be made. On the other hand, solid-state imaging devices have the advantage that there is no need to change the pixel size for each wavelength, making it easy to adjust.

In the above description, an optical image is separated into three colors of red, green, and blue and formed. I have explained the so-called 3-plate type, but the so-called 2-plate type, which is divided into two colors, red, blue and green, has been explained.
Of course, it is also applicable to a plate type.

Further, although the solid-state imaging device has been described using a CCD, it is also applicable to other solid-state imaging devices such as MOS and CID.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a color imaging device of the present invention, and FIG. 2 is a schematic diagram illustrating the difference in size of three-color optical images.

Claims (1)

[Claims] 1. An optical system that divides an optical image into a plurality of colored lights, means for providing a photosensitive section of a solid-state imaging device at the imaging position of each of the plurality of colored lights, and a frequency of a driving pulse applied to at least one of the solid-state imaging devices. What is claimed is: 1. A color imaging device comprising means for making the frequency different from that applied to another solid-state imaging device.