JPH0453636Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) The present invention relates to a multi-frame photographic device in an image diagnostic apparatus using ultrasound or X-rays, and more specifically, The present invention relates to a multi-frame photographic apparatus in which the exposure time for each lens is set in advance and the shutter of the selected lens is opened and closed during the exposure time.

(Prior Art) As is well known, an image diagnostic apparatus using X-rays (hereinafter referred to as a CT apparatus) has a computer-centered configuration, and roughly has the following three means. I can say that. That is, a data collection means that collects projection data by irradiating the subject with X-rays and stores it in memory, and performs reconstruction calculation processing using the projection data read from the memory and converts it into a two-dimensional cross-sectional image. Then, an image reconstruction means stores the image data in memory again, and processes the reconstructed image data to display a two-dimensional cross-sectional image (hereinafter referred to as a CT image) on a CRT (black and white television monitor) or the like. It has an image display/processing means.

Conventionally, as shown in Fig. 2, the multi-frame photographing device in such a CT device is driven by a composite video signal from an image display/processing means, and the CT image is a CRT that displays an image in which black and white are inverted. A monitor 1, lenses 2A to 2F supported on a lens support plate 3 and arranged two-dimensionally (the lenses are arranged in two rows at equal intervals in the longitudinal direction of the lens support plate 3), and a cassette. (not shown) and is set at a predetermined position. Lenses 2A to 2F are individually shuttered (not shown).
It is operated by a control signal from a control unit (such as a computer of a CT device). In addition, the CRT monitor 1, lens support plate 3, and film 4 are arranged so that the image center 5X and the lens support plate center 3
While aligning X and film center 4X (align each center on a perpendicular line passing through image center 5X),
The configuration is such that the display surface of the CRT monitor 1, the plate surface of the lens support plate 3, and the surface of the film 4 are kept parallel (hereinafter referred to as parallelism of the image plane, etc.).
Note that the parallelism of the image plane, etc. is adjusted to a predetermined accuracy using an adjustment mechanism.

In the above configuration, the image 5 (black and white gray image) displayed on the CRT monitor 1 is transferred to 6 on the film 4.
When photographing a frame, the shutters of the lenses 2A to 2F are switched at a predetermined shutter time (the shutters are opened and closed by a control signal from the control section).
As a result, the film 4 has lenses 2A to 2F.
Images 7A to 7F are sequentially photographed.

By the way, since each lens is arranged two-dimensionally, the angle of view when looking at the same point in the image 5 from each lens may be different. For example, lens 2
From C and 2D, the angle at which the image center 5X is viewed is smaller than the angle at which the image center 5X is viewed from other lenses. At this time, the density of the portions corresponding to the image center 5X in the images 7C and 7D is higher than that of the other images. Also, such a concentration difference is
This problem also occurs when the optical dimensions of each lens vary or when the parallelism of image planes, etc. is not maintained.

(Problems that the invention attempts to solve) However, in the case of conventional multi-frame photographic devices,
Since the difference in angle of view of the lens is not corrected, there is a problem in that a difference in density occurs between each frame of the film. In addition, the difference in density between each frame due to factors other than differences in angle of view is corrected by adjusting the parallelism of the image plane, etc., but there was also the problem that it took time to bring the parallelism within accuracy. .

(Means for solving the problem) The present invention was made in view of the above,
The purpose is to provide a multi-frame photographic device that can correct density differences between each frame based on differences in angle of view of lenses, variations in optical dimensions of lenses, errors in parallelism of image planes, etc., with simple adjustments. It is in.

The multi-frame photography device of the present invention that achieves the above object has a configuration in which an exposure time is set in advance for each individual lens arranged two-dimensionally, and the shutter of the selected lens is opened and closed at the exposure time. It's summery.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

The present invention is characterized by a shutter control system, and one embodiment thereof has the configuration shown in FIG. 2 with the shutter speed selection circuit shown in FIG. 1.

FIG. 1 is a block diagram showing a main part of a multi-frame photographic apparatus according to an embodiment of the present invention, that is, a shutter speed selection circuit. Shutters 11A to 11
F is arranged in each of the lenses 2A to 2F shown in FIG. The shutter speed selection circuit is
Exposure time setters 12A to 12F are provided corresponding to these shutters 11A to 11F (the exposure time setters have a deep switch for time setting), and the output side of the exposure time setters 12A to 12F is controlled by the shutter selection signal. a timer 14 controlled by a signal from an exposure time setter connected via the changeover switch 13, and a timer 14 controlled by the shutter selection signal and connected to the next stage circuit; The timer 14 is composed of a shutter corresponding to an exposure time setting device connected to the timer 14 and a changeover switch 15 connecting the output side of the timer 14. The exposure time setters 12A to 12F are set in advance so that when the image 5 of the CRT monitor 1 with equal brightness is photographed on each frame of the film 4, the density of the image center 5X is equal in each frame 7A to 7F. This is done by manipulating the .

In the above configuration, the changeover switches 13 and 1
5 is switched in synchronization with a shutter selection signal, and connects a predetermined exposure time setter and shutter to the input and output sides of the timer 14, respectively. timer 14
The shutter is operated by a signal from an exposure time setting device selectively connected by the changeover switch 13, and opens and closes the shutter at a time corresponding to the setting time of the exposure time setting device.
As a result, each frame of the film 4 is photographed by sequentially opening and closing the shutters 11A to 11F at independently set exposure times. Each exposure time at this time is a time determined based on the image center 5X of the CRT monitor 1, that is, the equal brightness part (in the example, the density of the image center 5X) in the CRT monitor image 5 is determined at each frame 7A to 7F. The time is set to be equal. Therefore, the image of each frame of film 4 is
Differences in angle of view of lenses, variations in optical dimensions of lenses,
It is obtained by correcting density differences between each frame due to parallelism errors on the image plane, etc.

(Effects of the invention) As explained above, according to the multi-frame photographing apparatus of the invention, the exposure time for each lens arranged two-dimensionally is set in advance, and the shutter of the selected lens is Since it opens and closes depending on the exposure time, it can be easily adjusted (simply by setting the exposure time setting device) and can be adjusted based on differences in the angle of view of the lens, variations in the optical dimensions of the lens, parallelism errors of the image plane, etc. It is possible to correct the density difference between each frame.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a shutter speed selection circuit according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. 1...CRT monitor, 2A to 2F...lens,
3... Lens support plate, 4... Film, 11A to 11F... Shutter, 12A to 12F... Exposure time setting device.

Claims (1)

[Claim for Utility Model Registration] Lenses of the same number as the number of frames to be photographed are arranged two-dimensionally between the CRT monitor and the film, and the shutter of each lens is controlled by the shutter selection signal from the control section. In the multi-frame photographic device to be operated, the exposure time for each individual lens is set in advance,
1. A multi-frame photographic apparatus comprising means for operating a shutter of a selected lens at the exposure time.