JPH10144244A - X-ray image intensifier device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently take the output light without giving a bad influence to a TV camera or the like by receiving the light, which is focused by a ring- like focus lens provided between an objective lens and a front surface of an output fluorescent surface, with a ring-like photoelectric transferring element. SOLUTION: An optical image output from an output fluorescent surface 11 enters an objective lens 21 of an optical system 20, and the light is formed into the parallel light, and focused by a camera lens 31 of a TV camera 30 so as to form an image in an image pickup surface 32. A ring-like focus lens 12 formed of a projecting lens and a ring-like photoelectric transferring element 13 for receiving the focused light are fitted between a front surface of the fluorescent surface 11 and the objective lens 21. Since the light, which directs the objective lens 21, passes through the lens 12 and a hollow part of the element 13, influence of the light to the camera 30 and reduction of the light are prevented. Since the light led to the element 13 is is spattered in the periphery and it is not utilized yet, efficiency of the whole is improved, and a large electric signal with a sufficient quantity of light is generated in the element 13. On the basis of this signal, quantity of X-ray is controlled by an X-ray fluoroscopic image pickup device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray image intensifier suitable for use in an X-ray fluoroscopy apparatus as a medical diagnostic apparatus.

[0002]

2. Description of the Related Art In an X-ray fluoroscopic apparatus, an output optical image of an X-ray image intensifier is transmitted through an optical system to T-rays.
The X-ray film is transported to the front of the X-ray image intensifier device while the film is guided to the V camera, and the film is photographed. When taking an image on an X-ray film, a part of the light from the output phosphor screen of the X-ray image intensifier is detected, and the X-ray dose is controlled according to the amount of light. That is, a part of the light emitted from the output phosphor screen is guided to the photoelectric conversion element, the amount of received light is converted into an electric signal, and the electric signal is sent to the X-ray controller, and the X-ray dose is increased or decreased according to the electric signal. , X
The X-ray dose to be exposed to the X-ray film is adjusted.

A so-called phototopic device for collecting a part of light on an output fluorescent screen of the X-ray image intensifier apparatus has conventionally been built into an optical system provided in front of the output fluorescent screen. I have. That is, the light converted into parallel light through the objective lens inside the optical system is
Light is collected by a mirror (or prism), collected by a focusing lens, and guided to a photoelectric conversion element.

[0004]

However, in the conventional X-ray image intensifier, since a mirror for raising the topic and its holder are arranged in the parallel light portion of the optical system, the camera inside the TV camera is not provided. When the aperture of the lens is narrowed down, there is a problem that the shadow of the topical up appears on the TV camera. Therefore, the structure of the topical up is made as small as possible so that the shadow does not appear. As a result, there is a problem that it is easily affected by external noise and it is difficult to handle the signal.

SUMMARY OF THE INVENTION In view of the above, the present invention provides an X-ray image intensifier apparatus improved so that a sufficient amount of output light can be collected without adversely affecting a TV camera or the like. Aim.

[0006]

In order to achieve the above object, in an X-ray image intensifier according to the present invention, a ring-shaped focusing lens provided between an objective lens and a front surface of an output fluorescent screen is provided. And a ring-shaped photoelectric conversion element arranged to receive the light focused by the lens.

The focusing lens has a ring shape, and of the light emitted from the output phosphor screen, the light going to the objective lens is:
Since the light passes through the central hollow portion of the ring-shaped focusing lens, it is incident on the objective lens without any obstacle. The light focused by the ring-shaped focusing lens is not the light directed toward the objective lens, but the unused light that diffuses around the objective lens. Therefore, even if the light is collected and guided to the photoelectric conversion element, the light is focused on the objective lens side. Light to the TV camera or the like does not decrease. Therefore, a sufficient amount of light is collected and guided to the photoelectric conversion element, and a sufficiently large signal can be obtained. In the past, because unused light was effectively used,
Overall efficiency is increased. Further, since the focusing lens and the photoelectric conversion element are ring-shaped and exist only at the outer peripheral portion of the light traveling toward the objective lens, there is no adverse effect such that a shadow thereof appears on a TV camera.

[0008]

Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, an X-ray image intensifier 10 according to the present invention comprises an image intensifier tube and a metal case covering the outside thereof, and the lower side of the figure is an input surface on which X-rays are incident. The output fluorescent screen 11 is formed on the upper side. When an X-ray transmitted through a patient or the like enters the input surface, the X-ray image is formed on the output fluorescent screen 11, and an optical image with enhanced brightness is output from the output fluorescent screen 11.

X-ray image intensifier 10
The TV camera 30 is connected to the output fluorescent screen 11 side via an optical system 20. The optical image output from the output phosphor screen 11 enters the objective lens 21 of the optical system 20, is converted into parallel light by the optical system 20, enters the camera lens 31 of the TV camera 30, and is focused by the camera lens 31. ,
An image is formed on the imaging surface 32 of the TV camera 30. In the vicinity of the front surface of the output fluorescent screen 11, between the objective lens 21 of the optical system 20, a ring-shaped focusing lens 12 and a ring-shaped photoelectric conversion element 13 are mounted.

The focusing lens 12 and the photoelectric conversion element 1
Reference numeral 3 denotes a ring, and the objective lens 2 of the optical system 20
The light going to 1 passes through these hollow portions, so that their shadow does not appear on the TV camera 30 and the light going to the TV camera 30 is not reduced.

The ring-shaped photoelectric conversion element 13 may be, for example, one in which a large number of photoelectric conversion elements such as a photodiode or a photomultiplier are arranged in a ring shape, or may be an integrally formed ring shape. Ring focusing lens 1
2 has a ring shape as a whole, but is formed as a convex lens that focuses the light from the output phosphor screen 11 to the ring-shaped photoelectric conversion element 13.

Therefore, the light focused by the ring-shaped focusing lens 12 and guided to the ring-shaped photoelectric conversion element 13 is not the light directed to the objective lens 21 of the optical system 20, but the light.
It is light that is not normally used, spreading around it. Since such unused light is used, the efficiency is increased as a whole. In addition, since such unused light is collected, even if the amount of collected light is increased, a shadow does not occur, and light directed to the TV camera 30 does not decrease.

Therefore, a sufficient amount of light can be guided to the ring-shaped photoelectric conversion element 13 to generate a large electric signal. In the X-ray fluoroscopic apparatus, the electric signal is
Since the X-ray is sent to the X-ray controller and the X-ray dose is controlled in accordance with the signal, the controllability for automatically adjusting the density of the X-ray film is enhanced, and it is possible to perform film exposure with an appropriate density. .

The above description is based on one example, and it goes without saying that the present invention is not limited to the above description. The specific configuration and the like can be variously changed in addition to the above.

[0015]

As described above, according to the X-ray image intensifier of the present invention, a sufficient amount of light is collected without any adverse effect on an optical image output to a TV camera or the like. An electric signal of a magnitude can be obtained.
Therefore, if applied to an X-ray fluoroscopy apparatus, the function of automatically adjusting the X-ray film density by this electric signal is enhanced,
X-ray film photography at an appropriate density can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic side view, partially in section, showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 X-ray image intensifier apparatus 11 Output fluorescent screen 12 Ring focusing lens 13 Ring photoelectric conversion element 20 Optical system 21 Objective lens 30 TV camera 31 Camera lens 32 Imaging surface

Claims (1)

[Claims] 1. A light-emitting device comprising: a ring-shaped focusing lens provided between an objective lens and a front surface of an output phosphor screen; and a ring-shaped photoelectric conversion element arranged to receive light focused by the lens. Characteristic X-ray image intensifier.