JPH0564089A - Image pickup device - Google Patents

Abstract

PURPOSE:To make the section of an image where plural partial images overlap to be inconspicuous with a simple configuration by providing plural imaging means which so pick up an as to obtain plural partial pictures accompanied by an optical image overlaping area. CONSTITUTION:A means to obtain the optical image of an object and plural imaging means (CCD) 1 and 2 which pick up an optical image so as to obtain plural partial images accompanied by overlaped parts are provided. When plural partial images which were picked up by plural imaging means 1 and 2 and accompanied by overlaped parts are joined together to obtain a piece of picture, the image picked up by one imaging means of plural imaging means 1 and 2 is used for a part of overlaping parts and the image picked up by the other imaging means of plural imaging means 1 and 2 is used for the other part. As a result, S/N at an overlaping part is not permitted to improve more than that of other parts, and so, the image at overlaping part in plural partial images is forced to be inconspicuous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus which divides an optical image and picks it up.

[0002]

2. Description of the Related Art An X-ray diagnostic apparatus is an example of an image pickup apparatus for picking up an optical image. The X-ray diagnostic apparatus bombards an object with X-rays from an X-ray source, converts the X-rays transmitted through the object into an optical image by an image intensifier,
By converting this optical image into a TV image signal by a TV camera, an X-ray transmission image based on the difference in X-ray absorption coefficient of each tissue of the subject is displayed on the monitor.

Recently, a TV camera using a solid-state image pickup device such as a charge coupled device (hereinafter referred to as "CCD") instead of the image pickup tube has been put into practical use. A TV camera provided with this CCD is generally called a CCD camera, and the resolution of a display image is determined by the number of pixels of the CCD.

However, it is impossible to increase the number of pixels of one CCD to a certain number or more due to the space problem. Therefore, in order to further improve the resolution of the displayed image, a multi-plate CCD camera has been devised. Multi-plate type C
The CD camera is equipped with a half mirror arranged with an inclination of 45 degrees with respect to the optical axis of the optical image converted by the image intensifier, and the first optical image transmitted through the half mirror and the half mirror. To obtain a second optical image reflected by. And the first optical image and the second
A first CCD for capturing each optical image of the
It has a CD. Here, the first CCD images, for example, the upper half of the optical image converted by the image intensifier to obtain the first image of the upper half, and the second CCD images the lower half and the second image of the lower half. Get the image. Then, when displaying on the monitor, the first image and the second image are combined.

Here, an overlapping portion is set near the boundary between the first image and the second image. This is the first C
It is structurally very difficult to arrange each CCD so that the CD accurately captures the upper half of the optical image and the second CCD accurately captures the lower half of the optical image. Each CCD is arranged to exist. The value (luminance) of each pixel of the plurality of pixels forming the image of the superposed portion is obtained by performing a weighted average process on the pixel value of the first image and the pixel value of the second image which are the same in display position.

However, the circuit configuration for the weighted average processing is very complicated, and the S / N ratio of the image of the superposed portion is high.
Will improve the S / N ratio of the image of the portion other than the superposed portion, and as a result, the image of the superposed portion will be conspicuous in a band shape, which will affect image diagnosis.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image pickup apparatus having a very simple structure and making an image of a superposed portion of a plurality of partial images inconspicuous.

[0008]

An image pickup apparatus according to the present invention comprises means for obtaining an optical image of a subject, and a plurality of image pickup means for picking up the optical image to obtain a plurality of partial images having overlapping portions.

An image picked up by one of the plurality of image pickup means is used for a part of the superposed portion, and one of the plurality of image pickup means is used for a portion other than the part of the superposed portion. Means for obtaining one image by using an image captured by an image capturing means other than the image capturing means.

[0010]

According to the present invention, when obtaining a single image by combining a plurality of partial images having overlapping portions obtained by a plurality of image pickup means, a part of the overlapping portion is provided with the plurality of image pickup means. By using an image captured by one of the image capturing means, by using an image captured by an image capturing means other than the one image capturing means in the plurality of image capturing means in a portion other than the portion of the overlapping portion, It is possible to make the image of the overlapping portion of the plurality of partial images inconspicuous.

[0011]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the arrangement of an image pickup apparatus according to the first embodiment of the present invention, and FIG. 2 is a schematic diagram of an optical system when the first embodiment is applied to an X-ray diagnostic apparatus. 3 is the output image of the image intensifier and the two Cs.
It is a figure which shows the relationship with the partial optical image image-formed on CD.

Before explaining the structure of the image pickup apparatus according to the first embodiment, the image pickup principle of the X-ray diagnostic apparatus using two CCDs will be briefly described with reference to FIGS. 2 and 3. The image intensifier 10 inputs an X-ray image that has been bombarded from an X-ray source (not shown) and transmitted through a subject from an input phosphor screen 10a of the image intensifier 10, and the X-ray image is an optical image on the input phosphor screen. And the optical image is changed to an electronic image on the photocathode provided in contact with the input fluorescent screen 10a, and the output fluorescent screen 1 is output again after being focused and accelerated.
At 0b, it is changed to an optical image and is output as an image intensifier output image to the outside. The output image of the image intensifier is transmitted through the optical system to the first CCD1 and the second CCD2.
An image is formed on each imaging surface on which a large number of light receiving elements are arranged. The optical system includes a primary lens 11a, a half mirror 12, a first secondary lens 11b, and a second secondary lens 11c. Here, the image intensifier output image is divided by the half mirror 12 into a first optical image supplied to the first CCD 1 and a second optical image supplied to the second CCD 2. The imaging surface of each CCD 1, 2 has a field of view for imaging half of the optical system, and the first CCD 1 is arranged at a position for imaging, for example, only the upper half of the first optical image.
The CD 2 is arranged so as to capture only the lower half of the second optical image, for example. As shown in FIG. 3, the upper half of the output image of the image intensifier forms an image on the first CCD 1 and the lower half forms an image on the second CCD 2. However, the first CC
The upper half partial optical image formed on D1 and the lower half partial optical image formed on the second CCD 2 have overlapping portions indicated by diagonal lines. As described above, the half mirror 12 can obtain two optical images. Next, the configuration of the image pickup apparatus according to the first embodiment shown in FIG. 1 will be described.

The CCD 1 has a large number of light receiving elements arranged on the surface on the side receiving the optical image, and picks up and photoelectrically converts the upper half of the optical image having the overlapping portion of the image intensifier output image. Similarly, the CCD 2 has a large number of light receiving elements arrayed on the surface on the side receiving the optical image, and captures the lower half optical image having the overlapping portion of the image intensifier output image, and performs photoelectric conversion for each light receiving element. .. Where 1
It is assumed that the electric signal obtained by photoelectrically converting one light receiving element corresponds to one pixel of the display monitor, and the pixel included in the overlapping portion is known in advance.

Analog / digital converter (A / D) 3
a converts an analog signal for each pixel input from the CCD 1 into a digital signal and outputs the digital signal to the first memory 4a. Similarly, the A / D 3b also inputs an analog signal from the CCD 2 and outputs a digital signal to the second memory 4b.

The first memory 4a stores the digital signal input from the A / D 3a in a predetermined memory position for each pixel. For the sake of easy understanding, the first memory 4a shown in FIG. 1 shows that pixels are arranged and stored in accordance with the arrangement at the time of display, and the pixels in which the shaded portion is included in the overlapping portion are stored. It is indicated that the area is being processed. Similarly, the second memory 4b also stores the digital signal input from the A / D 3b pixel by pixel in a predetermined memory position. Similarly to the case of the first memory 4a, the hatched portion of the second memory 4b shown in FIG. 1 also indicates the area in which the pixels included in the overlapping portion are stored.

The read control circuit 5 includes a first memory 4a and a second memory 4a.
The memory 4b is instructed to control the reading order of pixel data from each memory. The reading order is as follows. First, the pixel data on the right of the same column is read in order from the upper left pixel data on the paper of the first memory 4a, and after reading the rightmost image data, the pixel data immediately below the upper left pixel data is read. Similarly, the pixel data on the right of the same column is sequentially read. Then, in synchronization with the reading of the pixel data to be read out at the beginning of the shaded overlapped portion of the first memory 4a, that is, the reading of the upper left pixel data on the paper surface of the overlapped portion, in the shaded portion of the overlapped paper surface of the second memory 4b. Read the upper left pixel data. The timing of reading the pixel data of the overlapping portion of the first memory 4a and the timing of reading the pixel data of the overlapping portion of the second memory 4b at the same display position as the pixel data are always matched. When reading the pixel data in the overlapping portion of the first memory 4a and the second memory 4b, the pixel data on the right side of the same column is sequentially read out as described above. When the reading of the pixel data of the overlapping portion of the first memory 4a and the second memory 4b is completed, the pixel data on the right side of the same column is read from the upper left pixel data on the paper other than the overlapping portion from the second memory 4b. Read sequentially. In this way, the first memory 4a
Of the pixel data of the first memory 4a and the reading of the pixel data of the second memory 4b is started in synchronization with the start of the reading of the pixel data of the overlapping portion in the first memory 4a. The data is read from the one memory 4a and the second memory 4b at the same time.

The selector 6 selectively outputs the pixel data input from the first memory 4a and the pixel data input from the second memory 4b to the monitor 7 according to a selection signal supplied from the read control circuit 5. .. That is, when either the first memory 4a or the second memory 4b outputs pixel data according to the read control signal input from the read control circuit 5, the selector 6 outputs the first memory 4a or the second memory 4b. Pixel data input from the read control circuit 5 by inputting a selection signal indicating that pixel data is being output from one of the second memories 4b (hereinafter referred to as "first pixel data"). , Or pixel data input from the second memory 4b (hereinafter referred to as “second pixel data”).
(Referred to as “” is output to the monitor 7 as it is. But first
Both the memory 4a and the second memory 4b are read control circuits 5
When the pixel data is simultaneously output according to the read control signal input from the read control circuit 5, the read control circuit 5 outputs a selection signal indicating that the pixel data is being output from both the first memory 4a and the second memory 4b. Input from the monitor 7 and only one of the first pixel data and the second pixel data is monitored.
Output to. The selection method of the first pixel data and the second pixel data is as follows.

Generally, pixel data is represented by a plurality of bits. For example, pixel data capable of expressing 256 gradations is expressed by 8 bits. The first pixel data or the second pixel data depends on a value indicated by a predetermined bit of a plurality of bits expressing this pixel data, usually the least significant bit (hereinafter referred to as "LSB"), that is, "1" or "0". Select. Here, the LSB of the first pixel data of the first pixel data and the second pixel data that are input at the same time is read by the selector 6, the first pixel data is output when it is "1", and the first pixel data is output when it is "0". It is assumed that the second pixel data is output. Of course, the selection may be made according to the LSB of the second pixel data instead of the LSB of the first pixel data, or may be made based on the value of another bit instead of the LSB. The monitor 7 displays one image based on the pixel data output from the selector 6 in a predetermined order. The shaded area is the display area of the overlapping portion. Next, the operation of the image pickup apparatus configured as described above will be described.

The upper half optical image having a superposed portion formed on the light receiving element surface of the CCD 1 is photoelectrically converted by the light receiving element according to its brightness, and further A / D converted,
It is stored in the first memory 4a. At this time, the lower half optical image having a superposed portion formed on the light receiving element surface of the CCD 2 is also photoelectrically converted, further A / D converted, and then stored in the second memory 4b.

The plurality of pixel data stored in the first memory 4a and the second memory 4b are output in a predetermined order under the control of the read control circuit 5. First, pixel data other than the superposed portion of the first memory 4a is read out and supplied to the monitor 7 via the selector 6. Then, at the same time when the reading of the pixel data of the overlapping portion of the first memory 4a is started, the reading of the pixel data of the overlapping portion of the second memory 4b is started. However, the pixel data of the same display position as the display position on the monitor 7 of the pixel data of the superimposed portion read from the first memory 4a is read from the second memory 4b. Then, only one of the pixel data at the same display position, which is simultaneously output from the first memory 4a and the second memory 4b, is selectively supplied to the monitor 7 by the selector 6 according to the LSB value of the first pixel data. .. Here, the LSB of the first pixel data
Since there is no regularity in the appearance of the value of, the first pixel data and the second pixel data are randomly selected in the overlapping portion. When the reading of the pixel data of the superimposed portion is completed, the pixel data of the portion other than the superimposed portion is read from only the second memory 4b and supplied to the monitor 7 via the selector 6. FIG. 4 shows an array of pixel data forming one image displayed on the monitor 7. Circle 1 shown in FIG. 4 indicates pixel data read from the first memory 4a, and circle 2 indicates pixel data read from the second memory 4b. As described above, the first pixel data and the second pixel data randomly appear in the overlapping portion. As described above, by randomly displaying the first pixel data and the second pixel data in the overlapping portion, the overlapping portion does not stand out in a band shape. Next, a second embodiment will be described.

FIG. 5 is a block diagram showing the arrangement of an image pickup apparatus according to the second embodiment of the present invention. 5, the same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In the first embodiment, the pixel data read from the first memory 4a or the pixel data read from the second memory 4b is selected according to the LSB value of the pixel data read from the first memory 4a. However, in this embodiment, the pixel data is selected under the control of the selection signal from the random selection signal generation circuit.

The random selection signal generation circuit 8a inputs the read control signal of the read control circuit 5 and supplies the first select signal or the second select signal to the selector 9 according to the read control signal. Here, when the selector 9 inputs the first selection signal, the pixel data input from the first memory 4a is supplied to the monitor 7, and the pixel data input from the second memory 4b is not supplied to the monitor 7. Further, when the selector 9 inputs the second selection signal, the pixel data input from the second memory 4b is supplied to the monitor 7, and the pixel data input from the first memory 4a is not supplied to the monitor 7. The random selection signal generation circuit 8a outputs the first selection signal while the read control circuit 5 inputs the read control signal for instructing the reading of the pixel data other than the overlapping portion from the first memory 4a, and outputs the first select signal.
While the read control signal for instructing the read of the pixel data of the overlapping portion from the memory 4a and the second memory 4b is input from the read control circuit 5, the first selection signal and the second selection signal are output at random. The second selection signal is output while the read control signal for instructing the read of the pixel data other than the overlapping portion from the second memory 4b is input from the read control circuit 5.

The selector 9 receives the pixel data input from the first memory 4a and the pixel data input from the second memory 4b according to the first selection signal or the second selection signal supplied from the read control circuit 5. And selectively output to the monitor 7. That is, the selector 6 outputs the first selection signal when one of the first memory 4 a and the second memory 4 b outputs pixel data according to the read control signal input from the read control circuit 5. Alternatively, the second selection signal is input from the random selection signal generation circuit 8a, and the first pixel data input from the first memory 4a or the second pixel data input from the second memory 4b is directly output to the monitor 7. However, when both the first memory 4a and the second memory 4b simultaneously output pixel data according to the read control signal input from the read control circuit 5, the random select signal generation circuit 8a randomly supplies the pixel data. First
Input signal or the second selection signal, and outputs only either the first pixel data or the second pixel data to the monitor 7. Next, the operation of the image pickup apparatus according to this embodiment configured as described above will be described.

First, similarly to the first embodiment, the optical images formed on the light receiving element surfaces of the CCDs 1 and 2 are transferred to the first memory 4a and the second memory 4a.
It is stored in the memory 4b. The plurality of pixel data stored in the first memory 4a and the second memory 4b are output in a predetermined order under the control of the read control circuit 5. First, while the pixel data other than the overlapping portion of the first memory 4a is being read, the selector 9 responds to the first selection signal supplied from the random selection signal generating circuit 8a to monitor the pixel data 7 Supply to. Then, while the pixel data of the overlapping portion of the first memory 4a and the pixel data of the overlapping portion of the second memory 4b are simultaneously read, the selector 9 is randomly supplied from the random selection signal generating circuit 8a. First
Pixel signal of the superposed portion of the first memory 4a, or the second memory 4 according to the second selection signal.
The pixel data of the overlapping portion of b is selectively supplied to the monitor 7. While the pixel data other than the superposed portion of the second memory 4b is being read, the selector 9 responds to the second selection signal supplied from the random selection signal generation circuit 8a and sends the pixel data to the monitor 7. Supply. Also in this embodiment,
In the pixel data of the overlapping portion as shown in FIG. 4, the first pixel data and the second pixel data appear randomly.

As described above, also in the present embodiment, the first pixel data and the second pixel data are randomly displayed in the overlapping portion, so that the overlapping portion is not conspicuous in a band shape, and the circuit of the selector 9 is further provided. The configuration can be simplified. Next, a third embodiment will be described.

FIG. 6 is a block diagram showing the arrangement of an image pickup apparatus according to the third embodiment of the present invention. 6, parts that are the same as those shown in FIG. 5 are given the same reference numerals, and detailed description thereof will be omitted. In the second embodiment, the random selection signal generation circuit 8
The first selection signal and the second selection signal are randomly supplied to the selector 9 from a. However, in the present embodiment, the first selection signal and the second selection signal regarding the selection of the pixel data of the overlapping portion are selected. And are alternately supplied to the selector 9.

The alternate selection signal generating circuit 8b inputs the read control signal of the read control circuit 5 as in the case of the second embodiment, and depending on the read control signal, the first select signal or the second select signal. Is supplied to the selector 9.

The alternate selection signal generating circuit 8b is provided in the first memory 4
While a read control signal for instructing reading of pixel data other than the superposed portion from a is input from the read control circuit 5,
While the first control signal is output to the selector 9 and the readout control signal for instructing the readout of the pixel data of the overlapping portion from the first memory 4a and the second memory 4b is simultaneously input from the readout control circuit 5, While alternately outputting the selection signal and the second selection signal to the selector 9 and inputting the read control signal from the read control circuit 5 for instructing the read of the pixel data other than the superposed portion from the second memory 4b. The second selection signal is output to the selector 9.

The selector 9 is the same as in the second embodiment,
When the first selection signal is input, the pixel data input from the first memory 4a is output to the monitor 7, and when the second selection signal is input, the pixel data input from the second memory 4b is output to the monitor 7. Output to. Next, the operation of the image pickup apparatus according to this embodiment configured as described above will be described.

First, similarly to the first and second embodiments, the CCD
The upper half and lower half optical images formed on the respective imaging surfaces of 1 and 2 are stored in the first memory 4a and the second memory 4b. The selector 9 supplies the pixel data to the monitor 7 in response to the first selection signal as in the second embodiment while the pixel data other than the superposed portion of the first memory 4a is being read. , The pixel data of the overlapping portion of the first memory 4a,
While the pixel data of the overlapping portion of the memory 4b is being read at the same time, the selector 9 responds to the first selection signal or the second selection signal alternately supplied from the alternate selection signal generation circuit 8a. While the pixel data of the overlapping portion of the first memory 4a or the pixel data of the overlapping portion of the second memory 4b is selectively supplied to the monitor 7, while the pixel data other than the overlapping portion of the second memory 4b is being read out. Supplies the pixel data to the monitor 7 in response to the second selection signal.

Similar to FIG. 4, FIG. 7 shows an array of pixel data forming one image displayed on the monitor 7.
In the present embodiment, as shown in FIG. 7, the pixel data of the overlapping portion has the first pixel data and the second pixel data alternately appearing.

As described above, according to the present embodiment, by alternately displaying the first pixel data and the second pixel data for the superposed portion, the superposed portion is not conspicuous in a band shape, and the first selection signal, Alternatively, it is possible to eliminate the local conspicuousness in the overlapping portion due to the bias of the second selection signal.

The present invention is not limited to the above embodiment. For example, in the above embodiment, one optical image has two
Although it is divided into two parts, it may be divided into two parts on the left and right sides, or may be divided into a plurality of parts, for example, four parts on the upper, lower, left and right sides. When one optical image is divided into a plurality of pieces, the number of CCDs corresponding to the number of divisions may be used. However, in this case, there are two types of pixel data representing the same display position on the monitor. Of course, there will be multiple overlapping portions. In the first embodiment, the combination of the LSB value and the value of another predetermined bit may be used so that only one of the plurality of pixel data can be selected, and the second and third embodiments are also possible. In the example, the number of types of selection signals supplied to the selector may be increased to cope with this. Further, although the solid-state image pickup device is used as the image pickup means in the above embodiment, this may be an image pickup tube.

[0035]

As described above, according to the present invention, since the S / N of the superposed portion is improved by the conventional weighted averaging process as compared with other portions, the portion is conspicuous in a band shape. With regard to the above, by arranging the pixel data obtained by one CCD and the pixel data obtained by the other CCDs at random as they are, the S / N of the superposed portion is not improved as compared with other portions, and a plurality of partial images It is possible to provide an image pickup apparatus capable of making the image of the overlapping portion of (3) inconspicuous.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing an optical system when the present embodiment is applied to an X-ray diagnostic apparatus.

FIG. 3 is a diagram showing a relationship between an output image of an image intensifier and a partial optical image formed on two CCDs.

FIG. 4 is a diagram showing an array of pixels of one image obtained by the image pickup apparatus according to the first embodiment.

FIG. 5 is a block diagram showing a configuration of an image pickup apparatus according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an image pickup apparatus according to a third embodiment of the present invention.

FIG. 7 is a diagram showing an array of pixels of one image obtained by the image pickup apparatus according to the third embodiment.

[Explanation of symbols]

1 ... 1st CCD, 2 ... 2nd CCD, 3a, 3b ... A / D
Converter, 4a ... First memory, 4b ... Second memory, 5 ... Read control circuit, 6 ... Selector, 7 ... Monitor.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Seiichiro Nagai 1385-1 Shimoishigami, Otawara, Tochigi Prefecture Toshiba Medical Engineering Co., Ltd.

Claims (1)

[Claims] 1. A means for obtaining an optical image of a subject, a plurality of image capturing means for capturing the optical image to obtain a plurality of partial images having a superposed portion, and a portion of the superposed portion of the plurality of image capturing means. An image captured by one of the image capturing means is used, and one image is captured by the image capturing means other than the one image capturing means of the plurality of image capturing means in a portion other than the part of the overlapping portion. An image pickup device comprising: