JPH0787370A - Image pickup device - Google Patents

Abstract

PURPOSE:To fetch a highly precise picture with simple constitution in an image pickup device. CONSTITUTION:The picture obtained through an image pickup optical system 6 is devided into plural areas by a division optical system 8, and the plural divided pictures are fetched into plural image pickup elements 3 and 4. A picture correction means 5 corrects the reduction of light quantity generated in the connection part of the plural divided pictures and a gain difference between the plural image pickup elements 3 and 4 by using output data S5 and S6 of plural image elements 3 and 4. A picture connection means 5 weights the overlapped part of the plural divided pictures in accordance with a distance from the connection part and synthesizes one picture. Thus, the image pickup device 1 which can obtain the video signal S7 of the picture which is further highly precise with simple constitution can be realized compared with a conventional case.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action (FIG. 1) Example (FIGS. 1 to 9) Effect of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device, and is suitable for application to, for example, a high definition television camera.

[0003]

2. Description of the Related Art Conventionally, for example, in a television camera, a CCD (Charge Coupled Device) is used as an image pickup device.
) Is used. As a result, the television camera of this type can be remarkably simplified in structure and reduced in size and weight as compared with the case where an image pickup tube is used.

[0004]

When a CCD is used to obtain a higher-definition color image, it is conceivable to capture an image using a plurality of CCDs. For example, a method of capturing an optical image divided into three colors by a color separation optical system such as a dichroic prism by three CCDs can be considered. The dichroic prism separates incident light into two colors for each block. Therefore, two blocks are required to obtain three colors of light, and it is difficult to avoid an increase in the size of the optical system.

Another possible method is to shift the pixels and take them in. In this method, it is necessary to accurately align the resist ratio, and it is difficult to accurately align the resist ratio in proportion to the number of CCDs.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose an image pickup apparatus capable of capturing a high-definition image with a simple structure.

[0007]

In order to solve such a problem, according to the present invention, an image obtained through the image pickup optical system 6 is divided into a plurality of regions by a dividing optical system 8 and a plurality of divided images are picked up respectively. In the image pickup device 1 which takes in the elements 3 and 4 and combines the outputs S1 and S2 of the plurality of image pickup elements 3 and 4 and sends out a video signal S7 corresponding to an image,
The division optical system 8 reduces the amount of light generated in the joint portion of the plurality of divided images, and the plurality of image pickup devices 3 and 4 in the joint portion.
The image correction unit 5 that corrects the gain difference and the image connection unit 5 that weights the plurality of divided images according to the distance from the connection unit and combines the divided images into one image are provided.

[0008]

The image obtained through the image pickup optical system 6 is divided into optical systems for dividing the optical system 8.
Are divided into a plurality of regions by, and the plurality of divided images are taken into the plurality of image pickup devices 3 and 4, respectively, and the image correction means 5 uses the output data S5 and S6 of the plurality of image pickup devices 3 and 4 to obtain the plurality of divided images. The decrease in the amount of light generated at the connecting portion of the image and the gain difference between the plurality of image pickup devices 3 and 4 are corrected, and the overlapping portion of the plurality of divided images is weighted by the image connecting means 5 according to the distance from the connecting portion. Combine into one image. As a result, it is possible to realize the image pickup apparatus 1 that can obtain the video signal S7 of a much higher-definition image with a simpler structure than the conventional one.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a television camera as a whole, which captures an image of an object to be imaged which has passed through an optical system 2 and has been divided into upper and lower regions by CCDs 3 and 4, respectively, and then divided into two. The image data is connected by the connection processing unit 5 to be converted into one image, and the image is output to, for example, a video tape recorder (not shown).

2 in which parts corresponding to those in FIG. 1 are designated by the same reference numerals.
As shown in FIG. 2, the optical system 2 divides the light flux imaged on the focal plane 7 by the lens 6 into two areas by the right-angle prism type high reflection mirror 8, and the respective focal planes 7A and 7B after the division are divided. CCDs 3 and 4 are provided in the CCD.

As the CCDs 3 and 4, those having a color filter are used. The color filter has four complementary colors, namely, magenta and cyan, green and yellow, green and cyan, magenta and yellow, and these four complementary colors are arranged in a checkered pattern on the pixels of the CCDs 3 and 4. . Since the optical system 2 is optically symmetrical, the color of the divided image does not differ as in the half mirror method. As a result, color filters having the same characteristics can be used for the CCDs 3 and 4.

In the optical system 2, the resolution of one CCD in the horizontal direction is set to about 70% of the number of pixels in the horizontal direction, so that the resolution of the images connected by the CCDs 3 and 4 is remarkably higher than that of one CCD. Will increase. Registration of the optical system 2 does not require high precision as compared with the pixel shift method.

FIG. 3 in which parts corresponding to those in FIG.
As indicated by the shaded area, vignetting of the light flux occurs at the tip of the mirror 8, so that on the CCDs 3 and 4, the shading occurs at the connecting portion between the lower half and the upper half of the imaging target. Although the shading is corrected in the concatenation processing unit 5, since the S / N is lowered, the area where the shading occurs is set to be as small as possible.

The position Xs where the shading starts on the CCDs 3 and 4 is as shown in FIG. 4 in which the same reference numerals as those in FIG. 2 are attached to the diaphragm diameter D of the lens 6 and the CCD 3 from the optical axis.
Distance L ₁ to the surface or focal surface 7A of the following equation using the distance L ₂ to the tip of the mirror 8 from the exit pupil

[Equation 1] Can be expressed as The shading curve at this time is as shown in FIG. 5 (however, the connecting position is X = 0).
From equation (1), the region where shading occurs can be calculated by the following equation using the distance X from the connection position.

[Equation 2] It is represented by.

Here, in order to narrow the region where shading occurs, it is preferable to first increase the F value of the lens 6 and decrease the diaphragm diameter D, but the F value changes depending on the photographing conditions. If the lens 6 is a telecentric lens, the distance L
₂ becomes larger, but there are lens design limitations. Further, when the CCDs 3 and 4 are brought closer to the mirror 8, the distance L ₁ becomes smaller, but there is a physical limit.

The four types of complementary color data S1 and S2 output from the CCDs 3 and 4 are converted into complementary color data S3 and S4 in the analog digital conversion circuits 9 and 10, respectively, and stored in the frame memories 11 and 12, respectively. The frame memories 11 and 12 exchange complementary color data S5 and S6 with the connection processing unit 5.

The concatenation processing unit 5 uses CC as shown in FIG. 6, for example.
D3 and 4, complementary color data S5 and S of the CCDs 3 and 4 based on the shaded data obtained by actually measuring the relationship between the image forming position and the light amount for each pixel with a filter of each color.
6 is used to perform the shading correction.

The gains of the CCDs 3 and 4 are, for example, as shown in FIG.
In the above, there is an individual difference as shown by the solid lines of the CCDs 3 and 4 in the relationship between the imaging position and the gain, and the gain adjustment is necessary. Therefore, the connection processing unit 5 is the CCD 3
The gain difference is obtained in the overlapping portions of the images of 4 and 4, and the gain is adjusted by correcting the gain difference so that the brightness becomes the same. Gain adjustment CCD3 and 4
Is performed using the complementary color data S5 and S6.

The connection processing unit 5 converts the luminance and color difference of Y, CR and CB based on the complementary color data S5 and S6, and then converts them into color, that is, RGB data.

Further, the concatenation processing unit 5 concatenates the images captured by the CCDs 3 and 4, respectively, by weighting the RGB data as shown in FIG. Image data S
7 is output. The data Dw of the overlapping portion is the data Da of the CCD3, the data Db of the CCD4, and the weight w of the CCD3.
a, using the weight wb of the CCD 4,

[Equation 3] It is expressed by.

In the above configuration, the television camera 1 outputs the image of the object to be imaged by executing the connection processing control procedure RT1 shown in FIG.

That is, in step SP1, the television camera 1 obtains images centering on the lower half and the upper half of the object to be imaged from the CCDs 3 and 4, respectively, as four types of complementary color data of a complementary color system arranged in a checkered pattern, The complementary color data S1 and S2 are digitalized to create a frame memory 11
And 12 are stored. Subsequently, the television camera 1 moves to step SP2, and the complementary color data S5 and S6 of the CCDs 3 and 4 are subjected to the siding correction based on the actually measured siding data.

Next, the television camera 1 is connected to the step S.
At P3, the difference in gain between the CCDs 3 and 4 is detected in the overlapping area while the complementary color data remains unchanged, and at step SP4 C
Adjust the gain of CD3 and CD4. Furthermore, the television camera 1 uses the complementary color data S5 and S6 of the CCDs 3 and 4 in step SP5 to read the R of the CCDs 3 and 4, respectively.
Convert to GB data.

Next, the television camera 1 is connected to the step S.
In P6, the RGB data is used to weight and connect the overlapping portions of the CCDs 3 and 4 according to the equation (3), and the smoothing processing is performed. The television camera 1 has one frame of image data S7 that has been smoothed.
Is output, the process moves to step SP7 to end the connection process. In this way, the television camera 1 processes the images for one frame, and then repeats the processing of each step described above for the subsequent frames.

According to the above construction, the image obtained through the lens 6 is divided into two areas by the mirror 8, the divided images are taken into the CCDs 3 and 4, respectively, and the connection processing section 5 makes the complementary color data S5 of the CCDs 3 and 4. And S6 are used to correct the shading and the gain difference between the CCDs 3 and 4, and the overlapping portions of the two divided images are weighted according to the distance from the connecting portion to be combined into one image, which is compared to the conventional method. Thus, it is possible to obtain the image data S7 of a higher definition image with a simple structure.

Further, the connection processing unit 5 uses four kinds of complementary color data S5 and S6 at the time of performing shading correction and gain adjustment, that is, by having four adjustable variables,
Finer adjustment can be performed as compared with the case of converting into RGB data and processing with three variables.

In the above embodiment, the case of picking up a color image has been described, but the present invention is not limited to this, and can be applied to the case of picking up a monochrome image.

In the above embodiment, the case where the shading correction and the gain adjustment are performed based on the output data of the CCDs 3 and 4 has been described, but the present invention is not limited to this, and the CCD 3 and It may be processed based on the output data of No. 4.

Further, in the above-mentioned embodiment, the case where the CCD provided with the filters in which four kinds of complementary colors are arranged in a checkered pattern on the pixels is used, but the present invention is not limited to this. The same effect as described above can be obtained also when a CCD provided with a filter of RGB three colors is used.

[0031]

As described above, according to the present invention, the image obtained through the image pickup optical system is divided into a plurality of regions by the dividing optical system, and the plurality of divided images are respectively taken into a plurality of image pickup elements to perform image correction. Means for correcting the decrease in the amount of light generated at the joint portion of the plurality of divided images by using the output data of the plurality of image sensors and the gain difference of the plurality of image sensors, and the overlapping portion of the plurality of divided images by the image joint means. Is weighted according to the distance from the connecting portion and is combined into one image, so that an image pickup apparatus capable of obtaining a video signal of a higher definition image with a simpler structure than the conventional one can be realized.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an image pickup apparatus according to the present invention.

FIG. 2 is a schematic diagram for explaining an image forming relationship of an optical system.

FIG. 3 is a schematic diagram used for explaining the shading of an optical system.

FIG. 4 is a schematic diagram used for explaining variables of a relational expression of the shading.

FIG. 5 is a schematic diagram showing a relationship between an image formation position and a change in the amount of light due to shadeine.

FIG. 6 is a curve diagram showing an example of actually measured values of the shielding.

FIG. 7 is a curve diagram used to explain a gain adjustment of a CCD.

FIG. 8 is a curve diagram used for explaining weighting at a connecting portion of two CCDs.

FIG. 9 is a flow chart showing a concatenation processing control procedure of region-divided images.

[Explanation of symbols]

1 ... Television camera, 2 ... Optical system, 3, 4 ...
CCD, 5 ... Connection processing unit, 6 ... Lens, 7, 7A,
7B: focal plane, 8: right-angle prism type high-reflection mirror,
9, 10 ... Analog digital conversion circuit, 11, 12
...... Frame memory.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuichi Machida 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] 1. An image obtained through an image pickup optical system is divided into a plurality of regions by a division optical system, each of the plurality of divided images is taken into a plurality of image pickup elements, and outputs of the plurality of image pickup elements are combined to obtain the above-mentioned image. In an image pickup apparatus which sends out a video signal according to an image, a reduction in the amount of light generated in a connecting portion of the plurality of divided images by the dividing optical system and a gain difference between the plurality of image pickup elements in the connecting portion are corrected. An image pickup apparatus comprising: an image correction unit that performs the above-described image division; and an image connection unit that weights the plurality of divided images according to the distance from the connection unit and combines the images into one image. 2. The image pickup apparatus according to claim 1, wherein the split optical system is a prism type high reflection mirror. 3. The image correction means uses output data of the plurality of image pickup devices to correct a decrease in the light amount occurring in the connection part and / or a gain difference between the plurality of image pickup devices in the connection part. The image pickup device according to claim 1, wherein the image pickup device is corrected.