JPS5841374A - Honeycomb construction with unidirectional focus - Google Patents

Abstract

PURPOSE:To eliminate deviation and distortion of image by arranging hoenycomb hole trains to be straight in the direction of making honeycomb holes parallel. CONSTITUTION:Honeycomb holes are preferably hexagonal to circular and square in the cross-section. This honeycomb construction 1 has numerous honey comb holes 4 hexagonal in the cross-section. The direction of each honey combhole 4 is such that the apex of one hexagon joins the corresponding apex of another hexagon parallel with the plane with a focus. The side of the hexagon containing the first direction contacts the adjacent one in the second direction perpendicular to the first direction. This ensures the linearity in the second direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a fine honeycomb structure of a collimator used, for example, with a scintillation camera, and in particular to a honeycomb structure having a unidirectional focus.

A collimator for a scintillation camera is used to pass only the radiation emitted from spatially distributed radioactive isotopes in a desired direction, and is generally made of a collimator that is opaque to the radiation and has a specific gravity. It is formed by using a block of material with a high atomic number, especially lead or lead alloy from the viewpoint of ease of processing and economy, and providing fine straight holes in it. It is extremely difficult to create fine holes uniformly and densely by machining, so they are formed by metallurgically joining corrugated lead or lead alloy plates of appropriate shapes, or Alternatively, wire rods with a thin outer sheath made of lead alloy and a core material made of a material that is more easily soluble in certain chemicals, etc. are cut into appropriate lengths, bundled and aligned, and appropriately connected to adjacent wire rods. It is becoming common practice to properly melt and remove only the core material after joining the two.

In any case, the pores of the honeycomb structure formed in this way are generally parallel and do not have focal points. On the other hand, there has recently been a demand for a collimator made of a so-called unidirectional compassing or dipersing honeycomb structure, which has a focal point in only one direction, for forming partial enlargement, reduction, and/or tomographic images.

When using a unidirectional focusing honeycomb structure in a scintillation camera, scanning is performed in a direction that does not have a focus, so the linearity of the honeycomb structure in this direction is extremely important, and the honeycomb pores in that direction are extremely important. need to be in close contact with each other, but this is difficult to achieve with conventional honeycomb structures.

An object of the present invention is to provide a honeycomb structure for a collimator that has a unidirectional focus with excellent linearity in the non-focus direction.

The present invention will be described in detail below based on the drawings.

Note that, in general, a hexagonal cross-sectional shape of the honeycomb hole is more advantageous than a circular cross-sectional shape than a square cross-section for sensitivity and other reasons. Therefore, in this embodiment, a wire material disclosed in the above-mentioned Japanese Patent Application Laid-open No. 52-133872 will be described using lead or a lead alloy as the external wave, aluminum as the core material, and a wire rod having a regular hexagonal cross section.

FIG. 1 is a perspective view of a honeycomb structure according to an embodiment of the present invention, and FIGS. 2 and 6 are sectional views taken along lines 1--2 and I--2 in FIG. 1.

FIG. 4 is a top view of the structure shown in FIG. 1, and FIG. 5 is a bottom view thereof.

As shown in FIGS. 2-5, the honeycomb structure 1 in this embodiment has a large number of honeycomb holes 4 having a hexagonal cross section, and the directions of each honeycomb hole 4 are opposite to each other among its six vertices. The direction connecting the two vertices is parallel to the focal plane, and the side of the hexagon that includes this first direction is in contact with the adjacent hexagon in the second direction that is perpendicular to that direction. , thereby obtaining linearity in the second direction.

The honeycomb holes 4 on one surface of this structure 1 are arranged in close contact with each other as shown in FIG. 4, and the honeycomb holes 4 on the other surface are arranged in close contact with each other as shown in FIG.
They are spaced apart in the first direction and closely spaced in the second direction, so as to have a unidirectional focal point.

Such a structure 1 can be formed by bundling a large number of cylindrical bodies 5 each having a cylindrical hole 4 having a uniform hexagonal cross section in the longitudinal direction. For example, as shown in FIG. 6, cylindrical bodies 6 having different wall thicknesses in the second direction are prepared, for example, by precision casting, and after converging the cylindrical bodies in a predetermined direction, they are fixed appropriately. It can also be formed by
Alternatively, a cylinder 7 having a uniform wall thickness as shown in FIG.
is focused, and with one end fixed, the other end is connected to the second
It is also possible to form the spacer 8 by moving it in this direction and then fixing it appropriately.

In any case, the unidirectional focusing honeycomb structure according to the present invention is constructed so that the honeycomb hole rows are in a straight line in the direction in which the honeycomb holes are parallel to each other, so when used as a collimator for a scintillation camera, it can be used as a collimator for a scintillation camera. The linearity is extremely good and the resulting image shift.

Distortion etc. will no longer occur.

The structure prepared in this way is lye.

Of course, aluminum, which is the core material of the material, can be dissolved by immersing it in a caustic soda aqueous solution, for example.

In the above embodiments, a composite wire has been described, but as mentioned above, the present invention is not limited to this, and similar results can be obtained even if a thin tube is used.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the first step in an embodiment of the present invention,
Figure 2 is a diagram showing an example of the process after Figure 1, Figure 6 is a diagram showing the aligned materials in Figure 1, and Figure 4 is a diagram showing the materials in the aligned state in Figure 1.
Figure 5 is a diagram showing the positional relationship when the materials shown in the figure are expanded in one direction, Figure 5 is a diagram showing the positional relationship when the material is expanded in the other direction, and Figure 6 is a partial top view of the completed honeycomb structure. . 4...Material 5...Taper mold 6...Base material 1
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Claims (1)

[Claims] The structure is made by bundling a large number of cylinders having honeycomb holes with a hexagonal cross section, and the honeycomb holes are closely aligned on one side of the structure, and the six vertices of the hexagonal cross section are formed on the other side. One direction that has a focal point in the plane that includes the above-mentioned direction, with an interval only in the direction connecting two opposing vertices, and the surfaces of the hexagonal cross section in the above-mentioned direction are aligned so that they are kept in close contact. Focused...Nicum structure.