JPH08193889A - Detector of thermal image - Google Patents

Abstract

PURPOSE: To execute detection of a wide angle area at a comparatively low cost in a small space and to detect with high accuracy a thermal image having little aberration in a detector of a thermal image utilizing a pyroelectric thermal detector element enclosed in a hermetically sealed metallic package. CONSTITUTION: A metallic package 5 wherein a group 1 of pyroelectric thermal detector elements and electrodes 4 by which an electric output is taken out are enclosed and an infrared transparent wide angle lens 6 are united with each other to form the title device. It comprises a cover section 7 having a function of an infrared transparent fresnel lens that covers the metallic package 5 and infrared transparent wide angle lens 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to radiation temperature detection and human body behavior detection by a thermal image such as temperature distribution in a living room at home and human body behavior detection.

[0002]

2. Description of the Related Art Conventionally, a pyroelectric heat detecting element has a structure of being sealed in a metal package for the purpose of security and noise resistance.

A window for transmitting infrared rays is provided in a portion of the metal package facing the pyroelectric heat detecting element, and the window material has a red wavelength of a wavelength to be detected by blocking a wavelength of a certain value or more. Some have a filter characteristic that allows only external light to pass through.

Further, as a method of enlarging the detection area by the pyroelectric heat detecting element, a concave mirror is used to collect light in front of a window of a metal package enclosing the pyroelectric heat detecting element to obtain a view angle. There was a way to expand.

Further, for safety and reliability, the metal package enclosing the pyroelectric heat detecting element and the condenser mirror are covered with a cover that transmits infrared rays.

Further, as a product mounted on general household electric appliances, a metal package enclosing the pyroelectric heat detecting element and a filter film is vapor-deposited on a window portion of the metal package to detect the pyroelectric heat detecting element. There is also a thermal image detection device in which a wide-angle lens having a single element, in which an antireflection film is vapor-deposited, is arranged on the linear axis of the element and the window, and a cover is provided to cover the whole for reliability and safety.

[0007]

In order to detect a wide area by the pyroelectric type heat detecting element, a concave mirror is fixed in front of a metal package enclosing the pyroelectric type heat detecting element. A mechanism was required and it was not suitable for miniaturization.

When a wide-angle lens is used to detect a wide area, it is difficult to adjust the focal length.
Further, since the distance of the image forming point is short, there is a problem that the image forming performance as a lens is inferior even if the image forming point is arranged outside the metal package.

Further, it is necessary to deposit a filter film on the window portion of the metallic package in order to prevent erroneous detection.
When a wide-angle lens is arranged in front of it, an antireflection film must be vapor-deposited also on the lens, which causes a problem that work efficiency is poor.

Further, there is a problem that a wide-angle lens having a single lens has large aberrations and it is difficult to accurately detect a thermal image.

The present invention solves the above-mentioned problems of the conventional example. By providing an infrared transmitting lens having a filter film deposited on the window portion of a metal package, downsizing of the entire apparatus and improvement of working efficiency are achieved. The purpose is to improve the imaging performance.

Further, the present invention is intended to improve the accuracy of a detected thermal image by using a lens as the cover portion and a double-lens lens having a small aberration with the infrared transmitting lens at the window portion of the metal package. is there.

[0013]

In order to solve the above problems, the present invention provides a metal for hermetically sealing a pyroelectric heat detecting element group and an electrode for taking out an electrical output from the pyroelectric heat detecting element group. A package made of metal, and an infrared transmitting lens provided on the window of the metal package.

Further, according to the present invention, the infrared transmitting lens is provided with a filter characteristic for cutting off a wavelength of a specific frequency.

The present invention also provides a metal package for hermetically sealing a pyroelectric heat detecting element group and an electrode for extracting an electrical output from the pyroelectric heat detecting element group, the infrared transmissive wide-angle lens. And a cover portion that covers the metal package and the infrared transmissive wide-angle lens is a lens.

[0016]

The present invention provides a metal package for hermetically sealing a pyroelectric heat detecting element group and an electrode for taking out an electrical output from the pyroelectric heat detecting element group, and an infrared ray in the window portion of the metal package. By providing the transmission lens, the detection area of the thermal image detection device can be expanded.

In addition, the temperature range to be detected is limited by providing the infrared transmission lens provided in the window portion of the metal package with a filter characteristic for blocking a wavelength of a specific frequency and an antireflection film function. It is possible to reduce the effects of direct sunlight.

Further, since the window portion of the metal package is an infrared transmissive lens, the window portion of the metal package and the filter film of the window portion are not necessary.

Further, a cover for covering the infrared transmission wide-angle lens and a metal package for hermetically sealing the pyroelectric heat detecting element group, an electrode for taking out an electric output from the pyroelectric heat detecting element group. Aberration is reduced by forming a wide-angle lens with two lenses as a part.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal image detecting device according to an embodiment will be described below with reference to FIGS. In FIG. 1, reference numeral 1 is a pyroelectric heat detecting element, which is fixed by a paste of 3 and electrically connected to a substrate of 2, and outputs an electrical output to the outside by an electrode of 4. 1 to 4 are hermetically sealed by a metal package 5 In the portion of the metal package 5 facing the pyroelectric heat detecting element 1, the infrared transmissive wide-angle lens 6 is provided. On the surface of the infrared transmissive wide-angle lens 6 is formed an antireflection film having a filter characteristic for blocking wavelengths of 10 μm or less. By providing the infrared transmissive wide-angle lens 6 having the filter characteristic, it is possible to reduce the influence of the input of energy such as sunlight having a short wavelength and having an extremely large energy as compared with the human body. Further, in the conventional pyroelectric heat detecting element having the structure as shown in FIG. 2 and the package structure, when the infrared transmissive wide-angle lens is used, the image forming point of the wide-angle lens is close to the outside of the infrared transmissive window 9 Therefore, the thermal image cannot be detected with high accuracy and out of focus. Further, as shown in FIG. 2, a component for pressing the lens 8 is required.

FIG. 3 shows the structure when the cover is attached to FIG. The cover 7 is arranged so as to cover the periphery of 1 to 6, and has a structure that prevents the entry of dust and the like and cannot see the inside from the outside. Further, the cover 7 is provided with an infrared transmission type wide-angle Fresnel lens, and the infrared transmission type wide-angle lens 6 is used to form a wide-angle lens composed of two lenses. By using two wide-angle lenses, a wide-angle lens with relatively less aberration can be configured as compared with a single-lens wide-angle lens, and it is possible to detect a thermal image with higher accuracy.

[0022]

According to the present invention, a metal package for hermetically sealing a pyroelectric heat detecting element group and an electrode for extracting an electrical output from the pyroelectric heat detecting element group, and a metal package By providing the infrared transmissive wide-angle lens in the window portion, it is possible to expand the detection area of the thermal image detection device and reduce the size of the entire device.

Further, the infrared transmissive lens provided in the window portion of the metal package is provided with a filter characteristic for cutting off a wavelength of a specific frequency to limit the temperature range to be detected and influence of direct sunlight. Can be reduced, and a more accurate thermal image can be detected.

Further, by forming the window portion of the metal package as an infrared transmissive lens, the window portion of the metal package and the antireflection film on the window portion are not required, and the cost can be reduced. it can.

In addition, a metal package for hermetically sealing the pyroelectric heat detecting element group, an electrode for taking out an electrical output from the pyroelectric heat detecting element group, and an infrared transmissive wide-angle lens are integrated, By using a cover portion that covers the metal package and the infrared transmissive wide-angle lens as a lens and configuring the wide-angle lens with two lenses, aberration is reduced and a more accurate thermal image can be detected. It will be possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram in which a wide-angle infrared transmission lens is provided in a metal package that covers a pyroelectric heat detection element.

FIG. 2 is a schematic configuration diagram when a wide-angle lens is arranged in front of a metal package containing a pyroelectric heat detecting element.

FIG. 3 is a schematic configuration diagram in which a metal package that covers the pyroelectric heat detection element is provided with an infrared-transmissive wide-angle lens, and the periphery thereof is covered with a cover having a Fresnel lens configuration.

[Explanation of symbols]

 1 Pyroelectric heat detection element 2 Substrate 3 Paste 4 Electrode 5 Metal package 6 Infrared transmission type wide-angle lens 7 Fresnel lens structure cover 8 Lens holder 9 Infrared transmission window with filter characteristics

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G01V 8/14 8/10

Claims (3)

[Claims] 1. A metal package for hermetically sealing a pyroelectric heat detecting element group, an electrode for extracting an electrical output from the pyroelectric heat detecting element group, and an infrared transmissive wide-angle lens. A thermal image detection device characterized by the above. 2. The thermal image detecting device according to claim 1, wherein the infrared transmissive wide-angle lens has a filter characteristic for cutting off a wavelength of a specific frequency. 3. A metal package for hermetically sealing a pyroelectric heat detecting element group, an electrode for taking out an electrical output from the pyroelectric heat detecting element group, and an infrared transmissive wide-angle lens, A thermal image detecting device, wherein a cover portion that covers the metal package and the infrared transmissive wide-angle lens is a lens.