JPS5848178B2 - X-ray movable aperture device - Google Patents

Description

[Detailed Description of the Invention] The X-ray movable diaphragm device narrows down the X-ray irradiation range to the required size using heavy metal plate blades during X-ray photography of the human body, X-ray therapy irradiation, etc., and receives the irradiation. This prevents people from being exposed to unnecessary X-rays, and in order to accurately illuminate the entire X-ray irradiation area with a floodlight, a heavy metal blade is installed between the X-ray tube and the heavy metal blade that narrows down the X-ray flux. A reflector that transmits X-rays and reflects visible light is placed, and the distance from the position of the aperture blades to the focal point of the X-ray tube and the optical distance from the aperture blades to the light source of the floodlight sight through the reflector are determined. At the same time, the irradiation range of the X-ray narrowed down by the same aperture blade and the illumination range of the light source for the floodlight sight (hereinafter referred to as the light irradiation field) are made to be exactly the same, and the X-ray irradiation range is It accurately indicates the entire irradiation range of the line.

However, since the room where X-ray photography is performed is brightly lit to prepare for X-ray photography and perform various other tasks, it is necessary to brighten the light source of the floodlight to make it easier to distinguish the light field.

Therefore, high-performance lamps such as halogen lamps are used, but increasing the illuminance increases the heat output and increases the size of the device and light emitting point, making it difficult to simultaneously obtain a sufficiently high illuminance and accuracy.

Naturally, a convergence (collimator) method using a lens can be considered, but if the light source of the floodlight sight is focused with a lens, the illuminance will increase, but since the beam will be close to parallel, the distance between the aperture blades and the light source of the floodlight sight will increase. For example, the optical distance is long and the distance to the X-ray tube focal point cannot be made the same.

Therefore, with one type of collimator, it is not possible to match the X-ray irradiation field with the light irradiation field at the aperture blades.

The present invention relates to an X-ray movable diaphragm device that illuminates the entire surface of the X-ray irradiation field with a flood sight, and relates to a device that makes it easier to distinguish the light irradiation field. A lens such as a cylindrical lens that converges the light beam into a line is installed between the blade and the floodlight sight, and the light from the floodlight sight is converged into a linear light flux that passes through the center of the light field, giving partial illumination. , which rotates a cylindrical lens using the optical axis of the floodlight as the rotation axis. This mechanism rotates the bright linear light of the floodlight within the light field, making it easy to distinguish the entire range of the light field. You can.

In the linear convergence method using the cylindrical lens of the present invention, the light incident in the long axis direction of the cylindrical lens is not converged at all. The geometric optical light source position of the light that passes through a cylindrical lens, etc. that creates a shadow in the long axis direction can be matched with the distance from the aperture blades to the X-ray focal point, and therefore the aperture blades This allows the X-ray irradiation field to match the light irradiation field narrowed down by the same aperture blade.

A general method of implementing the present invention is to arrange a cylindrical lens or the like between a floodlight sight and a reflector, and make the light from the floodlight a linear beam passing through the center of the light field. It rotates continuously at a speed of one to several times per second, and the rotary power transmission method includes general coupling methods such as a belt drive, as well as a structure in which a cylindrical lens etc. is rotated by wind power and is rotated by the wind from a blower. It can also transmit power.

The lens is a cylindrical lens.
lens) semi-cylindrical lens (anamorphic
To make the lens thinner, if you use a cylindrical lens shaped like a Fresnel lens with small wavy lenses, it will be small and lightweight.
It is easy to arrange the line inside the movable diaphragm.

As described above, the present invention has the effect of making it easier to distinguish the light irradiation field without increasing the capacity of the light source of the floodlight sight of the X-ray movable diaphragm device.

[Brief explanation of drawings]

FIG. 1 shows an example of an X-ray movable diaphragm device of the present invention attached to an X-ray tube in a central sectional view in the front direction. FIG. 2 is a side view of the same, showing the position and rotation mechanism of the semi-cylindrical lens. 1...Aperture blade, 2...Light source for floodlight sight, 3...Semi-cylindrical lens, 4...Optical axis of floodlight sight, 5・・・・・・X-ray movable aperture device, 6
...Electric motor, 7...X-ray tube focal point, 8.
...Reflector, 9...X-ray tube, 10...
...Pulley for lens rotation, 11...Belt.

Claims (1)

[Claims] 1 Between the irradiation field aperture blade 1 and the floodlight sight light source 2,
A lens such as a cylindrical lens or a semi-cylindrical lens 3 that converges a light beam into a linear shape is arranged so as to enter the optical path of the floodlight, and the lens is rotated about the optical axis 4 of the floodlight. Structured X-ray movable aperture device.