JP2011133422A - Thermopile type infrared detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein cost is increased by using an optical lens comprising a silicon material or the like in a conventional procedure, due to the necessity of arrangement of the optical lens comprising the silicon material or the like for condensing radiated infrared rays to an infrared receiving element arranged inside a thermopile type infrared detector from inside a detection object domain, onto a position of an optical design in consideration of the size of the infrared receiving element arranged inside the thermopile type infrared detector and a focal distance comprising the detection object domain. <P>SOLUTION: Instead of the optical lens comprising the silicon material or the like, a condensing lens having a convex and Fresnel-shaped body comprising high-density polyethylene is used and stored in a TO-5 package. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermopile type infrared detection apparatus using a convex lens made of high-density polyethylene in a metal can as an optical system and a Fresnel-shaped condenser lens.

A conventional thermopile type infrared detector used in the past is a thermopile type infrared detector including an optical lens for condensing radiant infrared rays from within a detection target area to an infrared light receiving element disposed inside the thermopile type infrared detector. It is arranged and used at the position of the optical design in consideration of the focal length composed of the size of the infrared light receiving element arranged inside and the detection target region.
An optical lens that condenses the infrared radiation from the detection target area to the infrared light receiving element placed inside the thermopile infrared detector generally uses an infrared transmitting material such as silicon, for example, a plano-convex lens is often used. The thermopile type infrared detector is constructed by bonding and fixing to a metal can case with a transmission window that transmits infrared rays, and resistance welding to a header with lead terminals electrically connected to the thermopile chip. ing.

Japanese Patent Application No. 2002-943

In the conventional method, the infrared radiation from the detection target area is sent to the infrared light receiving element arranged inside the thermopile infrared detector, and the focal length consisting of the size and the detection area of the infrared light receiving element arranged inside the thermopile infrared detector. Therefore, it is necessary to dispose an optical lens made of a silicon material or the like at a position of an optical design in consideration of the above, and using an optical lens made of a silicon material or the like causes a cost increase.
In addition, since the optical lens made of silicon or the like needs to change the height of the metal can by changing the focal length, the initial cost for a new metal can corresponding to the focal length of the optical lens increases the cost. It is a factor.
FIG. 3 shows a thermopile type infrared detecting device using a conventional optical lens made of a silicon material or the like.

In addition, in the method of using a plane filter made of silicon material, etc., without using an optical lens made of silicon material, etc., and narrowing the aperture size by optical design, it makes the detection target area equivalent to the optical lens. If the aperture size is reduced, the sensitivity is reduced, and the gain amplification factor is increased, that is, the noise is increased.
FIG. 4 shows a thermopile type infrared detecting device using a conventional planar filter made of a silicon material or the like and using a technique of reducing the opening size by optical design.

  In the present invention, instead of an optical lens made of a silicon material or the like, a convex filter made of high-density polyethylene and a condensing lens of a Fresnel-shaped body, each having a flat filter, are stored in a TO-5 package. It is characterized by things.

According to the present invention, instead of an optical lens made of a silicon material or the like, a flat filter is provided, and a convex lens made of high-density polyethylene and a condensing lens made of a Fresnel-shaped body enable cost reduction. Become.
In addition, the optical lens made of silicon or the like needs to change the height of the metal can by changing the focal length. Since the distance is changed inside the metal can, there is no need to change the height of the metal can, that is, the initial cost for the new metal can is unnecessary.
In addition, it is possible to obtain sensitivity by eliminating the need to reduce the aperture size by optical design, compared to a method that uses only a plane filter made of silicon material, etc., and obtains an equivalent detection target area, and gain amplification factor Can be suppressed and noise can be reduced.
In addition, instead of the anti-reflection cylinder inside the metal can, a Fresnel-shaped condensing lens-integrated metal can internal anti-reflection cylinder with almost the same unit price is used. Therefore, it becomes possible to cope with almost the same cost.

1 is a schematic side view of a thermopile type infrared detection device including a convex lens made of high-density polyethylene and a Fresnel-shaped condenser lens, which is the most basic embodiment of the present invention. FIG. 2 is a schematic diagram of an object projection area shape in FIG. 1. It is a side surface schematic block diagram of the thermopile type infrared detection apparatus using the optical lens which consists of the conventional silicon | silicone materials. It is a side surface schematic block diagram of the thermopile type infrared detector using the conventional plane filter which consists of silicon materials etc. FIG. 5 is a graph of gain amplification factor and noise output of the thermopile type infrared detection apparatus configured as shown in FIGS. FIG. 6 is a schematic side view of a configuration without a reflection preventing cylinder inside a metal can in a thermopile type infrared detecting device using a conventional optical lens made of a silicon material or the like. It is the target object projection area shape schematic of FIG. In the thermopile type infrared detecting device provided with a convex lens made of high-density polyethylene according to the present invention and a Fresnel-shaped condensing lens, the anti-reflective tube of the anti-reflective tube inside the condensing lens-integrated metal can of the Fresnel-shaped body It is the side surface schematic block diagram which deleted the part.

Hereinafter, the present invention will be described in detail by way of examples. FIG. 1 is the most basic embodiment of the present invention, and is a thermopile type having a convex shape made of high-density polyethylene, and a Fresnel-shaped body-collecting lens integrated anti-reflection tube inside a metal can. An infrared detector is shown.
FIG. 1 shows a schematic side view of the configuration.

In this embodiment, an infrared detection region in which the amount of infrared incident on the thermopile chip is determined from the object projection area, which can detect the temperature of the object by measuring the amount of infrared radiation emitted from the object by receiving infrared rays. With a convex can made of high-density polyethylene that guides the optical design and a condenser lens with a Fresnel-shaped body, a metal can case with an infrared transmission window, and a header with lead terminals electrically connected to a thermopile chip A vapor-deposited flat filter with selectivity in the infrared transmission region is applied to the infrared transmission window portion of the thermopile sensor, which is a general structure with a hermetic seal to prevent environmental changes and electromagnetic interference from outside. It is structured to be bonded and fixed to a metal can case.
In this embodiment, the infrared transmission region is selected as a 5 μm cut-on deposition coating flat filter having selectivity of the infrared transmission region. For example, an uncoated planar filter, a 5.5 μm cut-on deposition coating flat filter, 6 .5 μm cut-on vapor deposition coating flat filter, 8-14 μm band pass vapor deposition coating flat filter, AR vapor deposition coating flat filter may be used.
Further, in this embodiment, the shape of the 5 μm cut-on vapor deposition coating flat filter having selectivity of the infrared transmission region is a square shape. This is because the infrared detection region defined by the object projection area is optically defined. As long as it is a flat filter that does not hinder the optical design of the convex lens made of high-density polyethylene guided by design and the condenser lens of the Fresnel shape body, it may be circular, rectangular, or hexagonal.

FIG. 2 shows a schematic diagram of an object projection area shape.
As a result, the thermopile type infrared detecting device having a convex lens made of high-density polyethylene according to the present invention and a condensing lens of a Fresnel-shaped body is a thermopile using an optical lens using a conventional infrared transmitting material such as silicon. It was confirmed that the object projection area of the mold detection apparatus and the object projection area of the thermopile infrared detection apparatus using a method of reducing the aperture size by optical design using a planar filter were confirmed.

FIG. 5 shows a graph of gain amplification factor and noise output.
As a result, it was confirmed that the gain amplification factor was suppressed and the noise was reduced as compared with a thermopile infrared detector using a conventional flat filter and a method of reducing the aperture size by optical design.

FIG. 6 shows a schematic side view of a conventional thermopile type infrared detector using an optical lens using an infrared transmitting material such as silicon without an antireflection cylinder inside a metal can.
FIG. 7 shows an object projection area diagram to be projected.
Compared with the projected object projection area diagram shown in FIG. 2 in the prior art, it was confirmed that an expanded area was detected in the projected object projection area diagram shown in FIG.
This is because there is no anti-reflection cylinder inside the metal can, and in the infrared optical path to the thermopile chip, infrared rays from a wide range of objects are received by infrared reflection inside the metal can with high reflectivity. It was confirmed that the anti-reflection effect of the anti-reflection cylinder inside the metal can was confirmed.

FIG. 8 shows a thermopile type infrared detector having a convex lens made of high-density polyethylene according to the present invention and a condenser lens having a Fresnel-shaped body. The side surface schematic block diagram which deleted the cylinder part of is shown.
Since the projected object projection area diagram is the same as FIG. 7, it is omitted.
Similarly, by eliminating the tube part of the anti-reflection cylinder inside the metal can with a condenser lens integrated into the Fresnel-shaped body inside the metal can, the infrared light path to the thermopile tip can be used from a wide range of objects. Anti-reflection by the cylindrical part of the anti-reflective cylinder with the built-in condenser lens of the Fresnel-shaped body inside the metal can confirmed that the infrared light is received by the infrared reflection inside the metal can with high reflectivity The effect of was confirmed.
As a result, the condensing lens-integrated metal can internal antireflection cylinder of the Fresnel-shaped body in the thermopile-type infrared detecting device provided with the convex lens made of high-density polyethylene according to the present invention and the condensing lens of the Fresnel-shaped body. Thus, it was confirmed that the same effect as the antireflection tube inside the metal can of the thermopile type infrared detecting device using the optical lens using the infrared transmitting material such as silicon can be obtained.

DESCRIPTION OF SYMBOLS 1 Metal can case 2 Header 3 Thermopile chip | tip 4 5 micrometer cut-on vapor deposition coating flat filter 5 Lead 6 Liquid adhesive 7 Condensation lens integrated can internal antireflection cylinder of Fresnel-shaped body made of high-density polyethylene 8 Thermopile type infrared of Example 1 Detection Device 9 Detection Area 10 Projected by Example 1 Antireflection Tube 11 Uncoated Silicon Plano-Convex Lens 12 Noise Output Value 13 of Example 1 Noise Output Value 14 of Conventional Silicon Lens Type Noise Output Value of Conventional Plane Filter Type 15 Thermopile type infrared detector 16 in FIG. 6 Detection region 17 projected by FIG. 6 High-density polyethylene Fresnel shaped condenser lens

Claims (2)

  In the thermopile type infrared detection device, a convex shape made of high-density polyethylene and a condensing lens of a Fresnel shape body are stored in a TO-5 package.   2. The thermopile infrared detector according to claim 1, wherein the convex lens made of high-density polyethylene and the condensing lens of the Fresnel-shaped body are integrally formed with an anti-reflection cylinder stored inside the can and stored in a TO-5 package. A thermopile type infrared detecting device.

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