JP2516224B2 - Automatic final image recorder for X-ray television - Google Patents

Description

The present invention relates to an automatic final image recording apparatus suitable for recording a final image obtained by an X-ray television apparatus.

[Conventional technology]

A conventional device of this type receives a recording command signal from an X-ray device and then A / D-converts a video signal for one screen and records it in a memory. In such a conventional apparatus, the recording command signal must be sent before stopping the X-ray emission, and the X-ray emission should be stopped after the recording is completed. Therefore, conventionally, in general, a signal is generated when the X-ray fluoroscopic switch is opened to record the final image, and this is used as the recording command signal, while the X-ray fluoroscopic switch is opened. From a certain time (1
The X-ray emission is stopped after a delay such that a video signal for the screen is obtained).

[Problems to be solved by the invention]

However, such a conventional device has the following problems.

(1) Since the recording command signal from the X-ray apparatus is indispensable and the X-ray apparatus itself needs a delay circuit, it is not applicable or difficult to the existing X-ray television apparatus.

(2) Television camera (hereinafter referred to as TV camera)
Generally requires a predetermined rise time to output a good image. Therefore, for example, when the X-ray fluoroscopic switch is closed for a short period of time and opened immediately after that, the final image obtained is dark or flicker even if X-rays are emitted for a certain period after the opening. "Is occurring. Further, even when the X-ray fluoroscopic switch was opened after the fluoroscopy was performed for a time sufficiently exceeding the rise time, "flickering" occurred in the image due to the chatter of the switch. Moreover, in this case, since the image before the defective image has been erased (since the conventional device is a type in which the image is constantly updated for each screen), no good image remains.

The present invention has been made in order to solve the above-mentioned problems, and therefore can be easily attached to any X-ray television apparatus without having any relation with the X-ray apparatus, and is also transparent. Bright and long,
An object of the present invention is to provide an automatic final image recording device for an X-ray television device, which can record a stable final image.

[Means for solving problems]

The above object is achieved by a memory having a storage capacity for two screens, a circuit for averaging video signals, and means for controlling the memory by comparing an output value of this circuit with a set value. That is, a memory having a storage capacity for two screens is divided into a main memory and a sub memory, and an input video signal (for one screen) is first recorded in the sub memory. At this time, the video signals are averaged and compared to determine if they have a sufficient value, and if sufficient, the contents of the sub memory are transferred to the main memory. If not enough, the transfer is not performed, and the main memory retains the latest contents that have been transferred so far.

[Action]

According to such means, the contents of the sub-memory are sequentially transferred to the main memory during the normal perspective, and X
If the line emission stops in the middle of one screen configuration, the image signal average value of the image at that time does not reach the set value, so the contents of the sub memory are not transferred to the main memory and the image before the X-ray stops It is stored in the main memory as it is. In any case, the main memory holds the latest contents based on a sufficient value, so if the contents of the main memory are displayed on the TV monitor, A bright and stable final image will be displayed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an example of the overall configuration of an X-ray television apparatus equipped with the apparatus of the present invention, in which 1 is an X-ray tube. When X-rays are radiated from the X-ray tube I, the X-rays transmitted through the subject II are incident on the image intensif eye (II) III and X
A line transmission image is formed. Through the optical lens IV
The image is taken by the TV camera V and displayed on the TV monitor VIII through the camera controller (CCU) VI and the automatic final image recording device VII which is the device of the present invention. At this time, the automatic final image recording device VII records the image (final image) when the fluoroscopy is finished.

FIG. 1 is a block diagram showing an embodiment of such an automatic final image recording apparatus for an X-ray television apparatus according to the present invention.
In the figure, 1 is a sync separation circuit. This sync separation circuit 1
The television (TV) signal from the camera controller VI is separated into a video signal and a sync signal and output. Of these, the synchronizing signal is given to the A / D converter 2, the main and sub memories 4, 3, the D / A converter 8, the synthesizing circuit 9 and the video signal averaging circuit 5, and is used for their synchronizing control. On the other hand, the video signal is given to the A / D converter 2 and the video signal averaging circuit 5 as an input signal. The video signal input to the A / D converter 2 is converted from an analog signal to a digital signal and recorded in the sub memory 3 having a storage capacity for one screen. Further, the video signals input to the video signal averaging circuit 5 are averaged and output as an average voltage V _A. This average voltage V _A is compared with a preset voltage V _S corresponding to the average voltage of an image having a predetermined brightness and stability. If the result is V _A > V _S , a transfer signal is sent from the transfer signal generator 7 to the main and sub memories 4 and 3, and the memory contents of the sub memory 3 are transferred to the main memory 4. When X-rays are continuously emitted, that is, during fluoroscopy, the average voltage V _A is higher than the set voltage V _S (V _A > V _S ) except at the rising edge of the operation start of the TV camera V. Therefore, the memory contents of the sub memory 3 are sequentially transferred to the main memory 4. As a result, the memory contents of the main memory 4 are rewritten to the latest contents.
Further, if the X-ray stops (end of fluoroscopy), the average voltage V _A
As V becomes smaller than V _A <V _S , no transfer signal is generated. Therefore, the main memory 4 of the memory contents of the sub memory 3
To the main memory 4, the rewriting of the memory contents of the main memory 4 is stopped, and the main memory 4 retains the immediately preceding memory contents. The same is true at the start of the operation of the TV camera V.

The memory content of the main memory 4 is sent to the D / A converter 8 and converted into an analog signal (video signal).
Given to. The synthesizing circuit 9 synthesizes the video signal from the D / A converter 8 and the sync signal from the sync separation circuit 1 into a composite video signal, which is supplied to the television monitor VIII.

Therefore, when X-rays are continuously emitted, a continuous perspective image is displayed on the television monitor VIII during that period, and when X-ray emission is stopped, one screen at that time is displayed.
If the relationship of V _A > V _S is satisfied, the image is displayed on the television monitor VIII as the final image (still image). In addition, when the X-ray emission stops in the middle of one screen configuration, or the image when the X-ray emission is stopped is dark and unstable like the image at the start of the operation of the TV camera V, V _A When <V _S , the bright and stable image immediately before that is displayed on the television monitor VIII as the final image (still image) based on the memory contents of the main memory 4.

〔The invention's effect〕

According to the present invention, the final image can be recorded by simply introducing a television signal without transmitting / receiving any signal to / from the X-ray apparatus, so that it can be easily attached to any X-ray television apparatus. You can Further, when the X-ray fluoroscopic switch is closed for a short period of time and then opened immediately after that, in other words, when an image having a low average video signal value is captured, the conventional device erases the previous image. Was recorded. Therefore, the recorded final image was dark or unstable and "flickering" occurred. However, in the present invention, in the same case, the previous image (image having a sufficient video signal average value) is erased. It is held without doing so, and there is an effect that a bright and stable final image can always be recorded.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the device of the present invention.
FIG. 1 is a diagram showing an example of the overall configuration of an X-ray television device equipped with the device of the present invention. 1 ... Sync separation circuit, 2 ... A / D converter, 3 ... Sub memory, 4 ... Main memory, 5 ... Video signal averaging circuit,
6 ... Comparator, 7 ... Transfer signal generator, 8 ... D / A converter, 9 ... Combining circuit, VIII ... TV monitor.

Claims (1)

(57) [Claims] 1. A sub-memory for storing one screen of a digital signal obtained by A / D converting a video signal in a TV signal from a camera controller of an X-ray television device, and a memory content of this sub-memory is transferred. A main memory for storing the video signal, and a video signal averaging circuit for averaging the video signal,
This was compared with an output value V _A of the image signal averaging circuit and a preset V _S, the memory contents of the main memory by transferring the memory contents of the auxiliary memory into said main memory when the V _A> V _S The transferred memory contents are rewritten and recorded, and V _A
When <V _S , the memory content of the sub memory is not transferred to the main memory and rewritable recording is not performed, and the memory content previously recorded in the main memory is retained as a final image in the main memory. An automatic final image recording device for an X-ray television device, characterized in that