JPH05167926A - Video camera system - Google Patents

Abstract

PURPOSE:To obtain a video camera system capable of obtaining high vertical resolution and reducing influence due to generation of an unnecessary frequency component. CONSTITUTION:Plural CCD image pickup elements 2, 3 for reading out mutual picture elements between two lines in the scanning direction are prepared. Image pickup signals outputted from the elements 2, 3 are synthesized to form a picture with high resolution. In this case, a component due to an output level difference between the two solid state image pickup elements 2, 3 is inclined and becomes visually inconspicous, and even at the time of removing the component through a filter, deterioration of picture quality is not almost generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera system suitable for use in, for example, a high resolution still image recording / reproducing system.

[0002]

2. Description of the Related Art Still image recording / reproducing systems are desired to be capable of reproducing higher resolution screens. A conventional video camera performs interlaced scanning in which odd lines and even lines are alternately scanned for each field. Therefore, when a still image is formed from a 1-field screen,
About 250 lines (262.5 in NTSC system)
Book). However, the vertical resolution cannot be satisfied with a still image having 250 lines. On the other hand, if a still image is formed from a one-frame screen, blurring occurs in the case of a subject that moves rapidly, and the dynamic resolution deteriorates.

Therefore, it is conceivable to prepare two image pickup devices and control the two image pickup devices so that they are spatially displaced from each other or the read lines are displaced from each other to form a single screen still image. That is, as shown in FIGS. 8 and 9, pixels of even lines are read by one of the image pickup devices, and image pickup signals of odd lines are read by the other image pickup device. In this way, since information about the number of lines for one frame is obtained at the same time, the vertical resolution is improved and the dynamic resolution is not deteriorated.

[0004]

However, as described above, simply arranging the two image pickup devices and spatially shifting the image pickup devices from each other or shifting the read line,
When the signals of these two image pickup devices are used, there arises a problem that an unnecessary frequency component appears on the screen due to variations in the characteristics of the two image pickup devices. In other words, in this case, the image sensor that reads the even lines is different from the image sensor that reads the odd lines, so that the pixel pitch frequency fv in the vertical direction is (1) due to the variation in the output levels of the two image sensors. (1 /) of the frequency of / 2)
2) The frequency component of fv occurs in the vertical direction. This (1 /
2) The frequency component of fv appears as horizontal stripes for each line on the screen and deteriorates the image quality. Since the frequency component of (1/2) fv is within the band of the required frequency component in the vertical direction of the video signal, if this frequency component is removed by the filter in the vertical direction, the image quality deteriorates.

Therefore, an object of the present invention is to provide a video camera system which can obtain a high vertical resolution and can reduce the influence of the generation of unnecessary frequency components.

[0006]

SUMMARY OF THE INVENTION The present invention has two or more solid-state image pickup devices each having a number of pixels corresponding to one frame, and these solid-state image pickup devices alternate between two lines in the scanning direction. Is a video camera system configured to read out pixels, and to form a high-resolution screen by synthesizing image pickup signals from two or more solid-state image pickup elements.

[0007]

With the provision of two solid-state image pickup devices, these solid-state image pickup devices are made to read out alternate pixels between two lines in the scanning direction, and image pickup signals from these solid-state image pickup devices are combined to obtain high resolution. If you try to form the screen of 2
The component resulting from the output level difference between the two solid-state image pickup devices is in an oblique direction, which makes it visually inconspicuous, and even if it is removed by using a filter, the image quality is hardly deteriorated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In FIG. 1, the subject image light that has passed through the lens 1 is decomposed into two paths P1 and P2 by the half mirror 2. The light passing through one path P1 is supplied to the light receiving surface of the CCD image sensor 2, and the light passing through the other path P2 is supplied to the light receiving surface of the CCD image sensor 3.

The CCD image pickup devices 2 and 3 are read out by 2
The lines are alternately switched to perform zigzag reading. Then, in the CCD image pickup devices 2 and 3,
Timing signals are supplied from the timing signal input terminals 4 and 5. This timing signal makes the read positions of the CCD image pickup device 2 and the CCD image pickup device 3 different.

That is, as shown in FIGS. 2 and 3, the CCD image pickup devices 2 and 3 have pixels P (l,
m) (1 is a line number, m is a pixel number in the horizontal direction), and these pixels are read out in a zigzag manner. In the CCD image pickup device 2 or 3 on the one hand, for example, in an odd field, as shown in FIG. 2, first, pixels P (1, 1), P
(2,2), P (1,3), P (2,4), P (1,
5) ... are read out, and then pixels P (3,1), P (4,4)
2), P (3,3), P (4,4), P (3,5) ... Are read in a zigzag manner line by line. At this time, in the other CCD image pickup device 3 or 2,
As shown in FIG. 3, first, pixels P (2,1), P (1,
2), P (2,3), P (1,4), P (2,5) ... Are read out, and then pixels P (4,1), P (3,2), P
(4,3), P (3,4), P (4,5) ... Are read out in a zigzag manner line by line.

In FIG. 1, the output of the CCD image pickup device 3 is supplied to the sample hold circuit 6. The output of the CCD image pickup device 3 is supplied to the sample hold circuit 7. The output of the sample hold circuit 6 is the terminal 8A of the switch circuit 8.
And to the terminal 9A of the switch circuit 9. The output of the sample hold circuit 7 is supplied to the terminal 8B of the switch circuit 8 and the terminal 9B of the switch circuit 9. Timing signals are supplied to the switch circuits 8 and 9 from terminals 10 and 11. The switch circuits 8 and 9 are switched by this timing signal,
For example, the switch circuit 8 outputs an image pickup signal of pixels of odd line numbers, and the switch circuit 9 outputs an image pickup signal of pixels of even line numbers.

That is, for example, from the CCD image pickup device 2, as shown in FIG. 2, the pixels P (1,1), P (2,2), P
(1,3), P (2,4), P (1,5) ..., Pixel P
(3,1), P (4,2), P (3,3), P (4,
4), P (3,5), ... Are read out, and the pixels P (2,1), P from the CCD image pickup device 3 are read out as shown in FIG.
(1,2), P (2,3), P (1,4), P (2,
5) ... Pixels P (4,1), P (3,2), P (4,4
3), P (3,4), P (4,5) ... In this case, the switch circuit 8 is sequentially switched to the 8A side and the 8B side for each pixel. As a result, the output of the CCD image pickup device 2 and the CCD are output from the switch circuit 8.
The output of the image sensor 3 is alternately output, and the pixels P (1,1), P (1,2), P (1,3), P of odd line numbers are output.
(1, 4) ..., P (3, 1), P (3, 2), P (3,
3), P (3,4) ... Are output. The switch circuit 9 is sequentially switched to the 9B side and the 9A side for each pixel. As a result, the output of the CCD image sensor 3 and the output of the CCD image sensor 2 are alternately output from the switch circuit 9, and the pixels P (2,1), P (2,2), P of even line numbers are output.
(2,3), P (2,4) ..., P (4,1), P (4
2), P (4,3), P (4,4) ... Are output.

In FIG. 1, the image pickup output of the pixel of the odd line number from the switch circuit 8 is supplied to the AGC circuit 12. The image pickup output of the even-numbered pixels from the switch circuit 9 is supplied to the AGC circuit 13. AGC circuit 12
Is output to the memory 16 and the synthesis circuit 17 via the gamma correction circuit 14. The output of the AGC circuit 13 or the memory 16 via the gamma correction circuit 15
And to the synthesizing circuit 17.

The image pickup signal of each pixel of the odd line and the image pickup signal of each pixel of the even line are simultaneously input to the memory 16 via the gamma correction circuits 14 and 15. Therefore, information for one frame can be obtained at the same time, and a signal with high vertical resolution can be obtained. Such a high vertical resolution signal can be used, for example, for recording a still image.
The output of the memory 16 is supplied to a two-dimensional filter 18 that removes unnecessary signal components as needed. The output of the two-dimensional filter 18 is output from the output terminal 19. In addition, the synthesis circuit 17 obtains an interlaced image pickup signal corresponding to the normal NTSC system. This image pickup signal is output from the output terminal 19.

The characteristics of the CCD image pickup device 2 and the CCD image pickup device 3 vary. For this reason, frequency components due to variations in the CCD image pickup device 2 and the CCD image pickup device 3 appear. In the conventional CCD image pickup device, this frequency component appears as a component of (1/2) fv on the vertical axis, whereas in the embodiment of the present invention, the CCD image pickup device 2 and the CCD image pickup device 3 define each pixel. Since the reading is performed in a zigzag manner, it appears as components A ₁ and A ₂ on the diagonally upper side, as shown in FIGS. As shown in FIGS. 4 and 5, in the one CCD image pickup device 2 and the other CCD image pickup device 3, the phases of the components A ₁ and A ₂ on the diagonal line are inverted. The arrows of the components A ₁ and A ₂ are
The phase direction is shown. Therefore, if the characteristics of the CCD image sensor 2 on the one hand and the CCD image sensor 3 on the other hand are completely the same, the components A ₁ and A ₂ on the diagonal lines cancel each other out.

However, since the CCD image pickup device 2 and the CCD image pickup device 3 have different characteristics, the diagonal line component A ₃ remains, as shown in FIG. The component A of this diagonal line
_{Since 3} does not have a band in the necessary video signal in the vicinity of this frequency component, ₃ can be removed by using the two-dimensional filter 18. Even if such a filter is not used, the component of the diagonal line is visually less noticeable than the component in the vertical direction.

FIG. 7 shows another embodiment of the present invention. Although a monochrome image was obtained in the above-described embodiment, a color image is obtained in this embodiment.
In FIG. 7, the subject image light that has passed through the lens 21 is split into three paths P11, P12, and P13 by the prism 22 and supplied to the three CCD image pickup devices 23, 24, and 25, respectively. Of these CCD image pickup devices 23, 24, 25, the CCD image pickup devices 23, 24 are provided with a filter for outputting a green signal component. Then, the CCD image pickup devices 23 and 24 are configured to read each pixel in a zigzag manner as described above. The CCD image pickup devices 23 and 24 have different read positions.

Of the CCD image pickup devices 23, 24, 25,
The CCD image pickup device 25 is a CCD image pickup device that is normally read (directly reads each line). The CCD image pickup device 25 is provided with filters for outputting red and blue color signal components.

The output of the CCD image pickup device 23 is supplied to the terminal 26A of the switch circuit 26 and the switch circuit 2
No. 7 terminal 27A. The output of the CCD image pickup device 24 is supplied to the terminal 26B of the switch circuit 26 and the terminal 27B of the switch circuit 27. A timing signal (not shown) is supplied to the switch circuits 27 and 28, and the timing signal is supplied to the switch circuits 2 and 28.
7 and 28 are switched. For example, the switch circuit 26 outputs an image pickup signal of pixels of odd line numbers, and the switch circuit 27 outputs an image pickup signal of pixels of even line numbers.

The outputs of the switch circuits 26 and 27 are AGC.
It is supplied to the circuits 28 and 29. AGC circuits 28 and 2
The output of 9 is supplied to the gamma correction circuits 31 and 33, and is also supplied to the synthesis circuit 32.

The combining circuit 32 combines the green signals. The outputs of the gamma correction circuits 31 and 33 are supplied to the memory 34. The output of the memory 34 is output from the output terminal 36 via the two-dimensional filter 35. This output terminal 36
A high-vertical resolution luminance signal is obtained from the output of. This high vertical resolution luminance signal can be used for still picture recording.

The output of the AGC circuit 30 is supplied to the sample hold circuits 37 and 38. The sample and hold circuit 37 separates the green color signal. The sample-hold circuit 38 separates the red signal. The red and blue outputs from the sample hold circuit 37 and the sample hold circuit 38 are supplied to the white balance circuit 39. Further, the green signal from the combining circuit 32 is supplied to the white balance circuit 39. With the white balance circuit 39,
The gain of each of these color signals is adjusted, and the white balance is adjusted.

The output of the white balance circuit 39 is supplied to the matrix circuit 41 via the gamma correction circuit 40. In the matrix circuit 41, the luminance signal Y and the color difference signal R
-Y and BY are formed. The luminance signal Y and the color difference signals RY and BY are output terminals 41A, 41B, 41.
It is output from C.

The luminance signal Y and the color difference signals RY and BY obtained from the output terminals 41A, 41B and 41C are
It can be used as a normal NTSC video signal. In addition, the luminance signal from the output terminal 36 and the output terminal 4
Using the color difference signals RY and BY from 1B and 41C, a color video signal with high vertical resolution can be obtained. This signal can be used for high-resolution still image recording, for example.

The present invention can be applied not only to a still image recording system but also to a system requiring high vertical resolution.

[0026]

According to the present invention, two solid-state image pickup devices are prepared, and these solid-state image pickup devices are arranged in the scanning direction.
By alternately reading out pixels between lines, the image pickup signals from these solid-state image pickup devices are combined to form a high-resolution screen. As a result, the component resulting from the output level difference between the two solid-state image pickup devices is in an oblique direction, which makes it visually inconspicuous, and even if it is removed by using a filter, image quality deterioration hardly occurs. Therefore, it is possible to realize a video camera system that can obtain a high vertical resolution and reduce the influence of the generation of unnecessary frequency components.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram used for explaining a CCD image pickup device in one embodiment of the present invention.

FIG. 3 is a schematic diagram used for explaining a CCD image pickup device in one embodiment of the present invention.

FIG. 4 is a diagram used for explaining generation of a frequency component in the embodiment of the present invention.

FIG. 5 is a diagram used for explaining generation of frequency components in the embodiment of the present invention.

FIG. 6 is a diagram used for explaining generation of a frequency component in the embodiment of the present invention.

FIG. 7 is a block diagram of another embodiment of the present invention.

FIG. 8 is a schematic diagram used to describe a conventional CCD image sensor.

FIG. 9 is a schematic diagram used to describe a conventional CCD image sensor.

[Explanation of symbols]

 2, 3 CCD image sensor 16 memory

Claims (1)

[Claims] 1. A solid-state imaging device having two or more pixels having the number of pixels corresponding to one frame, wherein the solid-state imaging device is configured to read out alternate pixels between two lines in a scanning direction, A video camera system for forming a high-resolution screen by synthesizing image pickup signals from two or more solid-state image pickup devices.