JPS6326083A - X-ray television device - Google Patents

Abstract

PURPOSE:To prevent the generation of a halation or a sticking by an excessive X ray by disposing a liquid crystal shutter at the incident side of an image pickup means on which a fluorescence is made incident. CONSTITUTION:When the X ray is radiated, a light signal (fluorescence) corresponding to the quantity of the transmitted X ray is made incident on a TV camera 18. A picture signal corresponding to the light signal is respectively inputted to a television monitor 26 and a liquid crystal shutter controller 28 from the TV camera 18. When liquid crystal shutter controller 28, when said picture signal reaches a level for generating the halation, makes corresponding parts in the liquid crystal shutter 24 opaque. Thereby, the incidence of the light of the excessive quantity to the TV camera 18 is prevented.

Description

[Detailed Description of the Invention] [1 Field of Application] The present invention relates to
The present invention relates to X-ray television equipment, and particularly relates to fluorescent plate-type X-ray television equipment that uses a fluorescent screen to display X-ray images.

[Prior Art] As a fluorescent plate type X-ray television device, for example, the fourth (
2I or: Stopper There is something like the one shown in Figure 5. Among these, the one shown in FIG. 754 is a direct photographing method, and the one shown in FIG. 5 is an optical II method.

In these figures, the entrance plane 10 on which the X-rays are incident,
A fluorescent screen 12 has been delivered. This fluorescent screen 12 has a function of converting incident X-rays into fluorescent light.

Next, the fluorescent light output from the fluorescent screen 12 is reflected by the mirror 14 and passes through the lens 16.

In the example of FIG. 4, this i-light is incident on the TV camera 18, and in the example of FIG. 5, it is incident on the TV camera 22 via an optical image intensifier (hereinafter referred to as "light 11J") 20. Note that the light II 20 amplifies incident light and outputs the amplified light.

As described above, the incident X-ray image is converted into a fluorescent image by the action of the fluorescent screen 12, and this is converted into an image No. 3 that can be visually displayed by the TV camera 18 or 22.

In addition, after performing fluorescent conversion, Xt! In addition to the methods described above, there are other methods for visualizing images, such as using a fluorescence multiplier tube. The difference between these methods is the means for converting X-rays into light (fluorescence), a fluorescent screen, or a fluorescent multiplier. Compared to the fluorescent multiplier tube method, the fluorescent plate method allows for a more flexible field of view.

[Problems to be solved by the invention] However, regardless of the above-mentioned direct imaging method or optical 11 method, when an excessive amount of X-rays enters the fluorescent screen, a large amount of light is generated, causing halation and Inconveniences such as burn-in may occur.

The present invention has been made in view of the above points, and is an X! The purpose of this invention is to provide a jA television device.

Means for Solving Problems U The present invention is characterized in that a liquid crystal shutter is disposed on the incident side of the imaging means into which fluorescent light is incident.

[Operation] According to the present invention, when halation occurs, incident fluorescent light is blocked by opening and closing the liquid crystal shutter.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals are used for the same parts as in the prior art described above.

FIG. 1 shows a first embodiment in which the present invention is applied to an X-ray television apparatus of direct (direct) maximum shadow type. In this figure, a liquid crystal shutter 24 is arranged between the lens 16 and the TV left camera 8. This liquid crystal shutter 24 is
It is possible to drive each area corresponding to one pixel at the most image position (in the TV left camera 8).

Next, the basic operation of the liquid crystal shutter 24 will be explained with reference to FIG. In the same figure (A), a TN type liquid crystal 50 is held between glass substrates 54 having a diameter of 4'152, and furthermore, polarizing plates 56 are provided above and below. These polarizing plates 56 are in a crossed Nicols relationship.

・To briefly explain the principle of optical shutter D with reference to the same figure (B), 1. When the shoulder direction of the light incident on the liquid crystal 50 changes, +-, J lightning is generated by the action of the anti-light 11n. In other words, when the voltage is applied, the light is transmitted to X3. It functions as a light ivy. Such liquid crystal shutters are used as display devices for small televisions.

Next, the overall operation of the above embodiment will be explained. First, the liquid crystal shutter 24 is brought into a transparent initial state. In this state, a predetermined inspection object is placed in front of the apparatus and irradiated with X-rays.

When X-ray irradiation is performed, a transparent iQX is displayed on the TV left camera 8.
A light (fluorescence) signal corresponding to the amount of light is incident. Then, an image signal corresponding to this optical signal is manually inputted from the TV left camera 8 to the TV monitor 26 and the liquid crystal shifter controller 28, respectively.

When the image signal reaches a level that causes halation, the liquid crystal shank controller 28 makes the corresponding portion of the liquid crystal shutter 24 darken by +3. This prevents excessive amounts of light from entering the TV camera 18. It becomes two.

FIG. 6 shows a second embodiment in which two L inventions are used for the optical 110,000 system. In this example (J, lens 16
A liquid crystal screen 24 is disposed between the light source and the light source 20.

It should be noted that the present invention is not limited to the above-mentioned embodiment in any way, and for example, the liquid crystal shutter 24 may be arranged at another position.

[Effects of the Invention] As explained above, the present invention has the effect of effectively preventing the occurrence of halation and burning due to excessive X-rays.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the first embodiment of the present invention, FIG. 2 is an explanatory diagram showing the principle of a liquid crystal shutter, FIG. 3 is a block diagram showing an example of a driving device, and FIGS. 4 and 5 are FIG. 6 is a block diagram showing an example of a conventional device, and FIG. 6 is a block diagram showing a second embodiment of the present invention. 12... Fluorescent screen, 18.22... TV camera, 20... Optical TI, 24... Liquid crystal shutter.

Claims (1)

[Scope of Claims] An X-ray television device that uses a phosphor that outputs fluorescent light when X-rays are incident thereon to visualize and display an X-ray image of the inspection object formed on the input side using an imaging means. An X-ray television apparatus, characterized in that a liquid crystal shutter is provided on the fluorescence incidence side of the imaging means.