JPS6322631B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a cooling type photoelectric conversion device, and in particular to a metal double tube structure (dewar structure) that accommodates a liquid coolant and cools a photoelectric conversion element to a low temperature. The present invention relates to a new structure for a thermally insulated container.

(b) Prior art and problems In general, photoelectric conversion elements such as infrared sensing elements or laser elements that utilize the photoelectric effect of binary compound semiconductors such as InSn or ternary compound semiconductors such as HgCdTe operate at temperatures far below room temperature. It is necessary to cool the device to a certain temperature to eliminate the generation of thermal noise and ensure good operation. Therefore, in a cooled photoelectric conversion device using such a photoelectric conversion element, a transparent window 4 is provided at the bottom using a metal material such as stainless steel, as shown in FIG.
A metal heat insulating container 1 having a double pipe structure (double structure) is constituted by an outer cylinder 2 provided with an outer cylinder 2 and an inner cylinder 3 having a cooling base 5 mounted so as to face the transparent window 4. A photoelectric conversion element 6 is placed on the cooling base 5 of the inner cylinder 3.
At the same time, the space 7 between the inner and outer cylinders 2 and 3 is kept in a vacuum, and a coolant 8 such as liquid nitrogen is stored in the inner cylinder 3 of the metal heat insulating container 1 to cool the photoelectric conversion element 6. A configuration is already well known in which the device is operated while being cooled to approximately the temperature of liquid nitrogen (77〓).

By the way, the heat insulating container 1 with a dewar structure made of metal material such as stainless steel as described above is less susceptible to damage due to shocks, vibrations, etc. and is easier to manufacture than the insulating container with a dewar structure made of glass which has been commonly used. Although it has favorable advantages such as being easy to use and less gas is released from the container members, on the other hand, it has higher thermal conductivity than glass, so if the structure is the same as that of a glass container, there will be no heat leakage from the inside of the container 1. There is a disadvantage that the heat loss increases and the amount of evaporation of the refrigerant 8 such as liquid nitrogen stored in the inner cylinder 3 increases. Therefore, attempts have been made to reduce the thickness of the metal inner cylinder 3 of the heat insulating container 1 to, for example, about 100 to 150 μm, so that the thermal conductivity is as low as that of glass. 3 and the contained refrigerant 8 are all applied to the fixed part 9 of the inner cylinder 3 and the outer cylinder, and the inner cylinder 3 is also damaged due to vibrations etc. during use.
However, if the fixed portion 9 is deformed or damaged, the structure becomes weak and impractical.

(c) Purpose of the Invention The present invention has been made in order to solve the above-mentioned conventional drawbacks, and its purpose is to provide reinforcement within the thin metal inner cylinder constituting the heat insulating container with the metal dewar structure that forms the main body of the device. It is an object of the present invention to provide a novel cooling type photoelectric conversion device which has a good refrigerant retention effect and can be used in practical use by attaching members to reinforce weak structural defects.

(d) Structure of the Invention According to the present invention, an outer cylinder partially provided with a transparent window and formed of a metal material of sufficient thickness, and a position opposite to the transparent window are provided. This is a double-layer structure that is equipped with a cooling base that supports a photoelectric conversion element, and an inner cylinder made of a metal material thinner than the outer cylinder, which is airtightly attached to the base of both, creating a vacuum between the inner and outer cylinders. In the device configuration consisting of a heat insulating container having a tubular structure, a cooling base provided in the inner cylinder and a refrigerant inlet/outlet facing the base interposed to airtightly seal the bases of both the inner and outer cylinders are provided. This is achieved by providing a cooling type photoelectric conversion device characterized in that a plurality of reinforcing pillars for preventing inner cylinder deformation are interposed between the face plate and the face plate.

(e) Embodiments of the invention Preferred embodiments of the invention will be described in detail below with reference to the drawings.

FIG. 2 is a longitudinal sectional view showing an embodiment of a heat insulating container of a cooling type photoelectric conversion device to which the present invention is applied.

As shown in the figure, an outer cylinder 2 constituting a heat insulating container 21
2 and the inner cylinder 23 are both made of metal plates made of stainless steel, and the outer cylinder 22 has a thickness of about 500 to 750 μm, which is sufficient to maintain mechanical strength against external forces, since the intrusion of heat from the outside is not a problem. It has a thickness. In addition, in order to make the inner cylinder 23 have a thermal conductivity as low as at least as low as that of the glass member, a thick cooling base 25 serving as a bottom plate and a thick cooling base 25 are provided.
5 and a refrigerant inlet/outlet 30 facing directly above.
The cylinder wall between the top plate 29 and the top plate 29 having a thickness of 500 μm is made of a thin stainless steel plate of about 100 to 150 μm. In order to reinforce the strength, the cooling base 25 and the top plate 29 are connected as shown in the figure.
In between, there are a plurality of reinforcing pillars 31, two in this embodiment.
A pipe-shaped stainless steel reinforcing column 31 is interposed and fixed and strengthened by brazing or the like. Thus, the inner cylinder 23 is welded into the outer cylinder 22 through a sealing body 32 with a refrigerant inlet/outlet pipe formed of a stainless steel plate with a thickness of about 500 μm and fixed to the refrigerant inlet/outlet 30 of the top plate 29. The space 27 between the inner and outer cylinders 23 and 22 is kept at a high vacuum to form a heat-insulating container 21 having a dewar structure. Hereinafter, a refrigerant 28 such as liquid nitrogen is housed in the inner cylinder 23, and is disposed at the bottom of the inner cylinder 23 at a position facing the transparent window 24 of the outer cylinder 22 via a refrigerant base 25. Photoelectric conversion element 26
The point is that it is operated by cooling it to a low temperature as before. Further, the signal output from the photoelectric conversion element 26 is taken out via a lead wire 32 from a lead-out terminal 34 disposed on a part of the outer tube 22 by glass sealing or the like.

As described above, a plurality of reinforcing columns 31 are interposed within the inner cylinder 23 to strengthen the mechanical strength of the inner cylinder 23, and the refrigerant inlet/outlet 30 is made smaller, thereby reducing heat loss. Structural defects caused by damage caused by vibration, impact, etc. are eliminated.
As shown in the figure, the photoelectric conversion device mainly includes the heat insulating container 21 having such a structure.
For example, the signal output cord 36 connected to the connector 3 is led out from a part of the stainless steel cover 35.
7 has been added to complete it.

(f) Effect of the Invention As is clear from the above explanation, according to the structure of the cooled photoelectric conversion device according to the present invention, the weak structure of the inner cylinder constituting the heat insulating container can be replaced by a plurality of reinforcing pillars. Since the structure is strengthened by heat exchangers, it not only sufficiently suppresses heat input and output loss, but also reduces vibration and vibration.
It has the advantage of eliminating structural defects that make it easily damaged by impacts, etc., and improving the durability of the insulated container, which allows it to retain refrigerants such as liquid nitrogen for a long time. This is extremely advantageous when applied to various cooling type photoelectric conversion devices, such as improved cooling and cold preservation effects for photoelectric conversion elements.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main parts of a cooling type photoelectric conversion device mainly consisting of a conventional heat insulating container made of metal material, and Fig. 2 is a main part illustrating a heat insulating container made of metal to which the present invention is applied. FIG. 1 is a sectional view of a main part of an embodiment of a cooling type photoelectric conversion device. In the figure, 21 is a heat insulating container, 22 is an outer cylinder, 2
3 is an inner cylinder, 24 is a transparent window, 25 is a cooling base, 26
2 is a photoelectric conversion element, 27 is a space, 28 is a coolant, and 2
9 is a top plate, 30 is a refrigerant inlet/outlet, 31 is a plurality of reinforcing pillars, 32 is a sealed body with a refrigerant inlet/outlet pipe, 33 is a lead wire, and 34 is a lead-out terminal.

Claims (1)

[Claims] 1. An outer cylinder 22 partially provided with a transparent window 24 and formed of a sufficiently thick metal material, and the transparent window 2
A cooling base 25 supporting a photoelectric conversion element 26 is provided at a position facing 4, and an inner cylinder 23 formed of a metal material thinner than the thickness of the outer cylinder 22 is hermetically sealed at the bases of both. , in an apparatus configuration consisting of a heat insulating container 21 with a double pipe structure in which a vacuum is created between the inner and outer cylinders 22, 23, the cooling base 25 provided in the inner cylinder 23 and the bases of the inner and outer cylinders 22, 23 are airtight. A refrigerant inlet/outlet 3 facing the base 25 interposed between the
1. A cooling type photoelectric conversion device characterized in that a plurality of reinforcing pillars 31 for preventing inner cylinder deformation are interposed between an upper surface plate 29 having a diameter of 0.