JPH0524880A - Infrared ray transmitting lens and human body detecting sensor using the same lens - Google Patents

Abstract

PURPOSE:To prepare lenses by using an infrared ray transmitting material passing infrared rays having 8-12mum emitted from human body, having no toxicity, slightly crystallizing and readily being press molded to form lenses. CONSTITUTION:An infrared ray transmitting lens is produced by using glass consisting essentially of germanium and selenium and a human body detecting sensor device is constituted from the lens and a pyroelectric infrared sensor. Glass having excellent transmittance of infrared rays and no toxicity and slightly being crystallized is obtained by the constitution and the glass is thermally pressed to manufacture a lens. The lens is combined with a pyroelectric infrared detecting sensor to give a scanning human body detecting sensor. Use of the scanning human body sensor device simultaneously detects plural human bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared ray transmissive lens made of chalcogenide glass and a human body detecting sensor device equipped with this lens and a pyroelectric infrared sensor.

[0002]

2. Description of the Related Art A human body detection sensor device using a pyroelectric infrared sensor is widely used in the fields of home electric appliances and industrial equipment. For example, it is used as a sensor for opening and closing a door, a faucet of a toilet bowl, an operation of an air conditioner, and the like. In general, a filter that transmits only infrared light is provided in front of the infrared sensor in order to efficiently collect infrared rays of 8 to 12 μm emitted from the human body. Conventionally, silicon, germanium, metal halides, etc. have been used as the filter material.

FIG. 1 shows an example of the configuration of a conventional human body detection sensor device. As shown in the figure, a lens 2 is provided in front of a plurality of pyroelectric infrared sensors 1 (horizontally represented by one sensor here for simplification) arranged side by side. To send an image to the pyroelectric infrared sensor.
The lens driver for moving the lens is not shown because it is in the direction perpendicular to the lens. Electrodes 3 for taking out the generated voltage are provided on both sides of the pyroelectric infrared sensor 1, and a chopper 4 for intensity-modulating infrared rays is provided in front of the infrared sensor 1. The chopper 4 is a chopper driver. 5
Is rotating at a constant speed. The infrared sensor 1 is supported by a support rod 6, and its output is led out by a lead wire 7.

[0004]

However, silicon and germanium have problems that the transmittance of infrared rays having a wavelength of 8 to 12 μm is low and the cost is high. For example, the transmittance of 2 mm thick silicon at a wavelength of 10 μm is 45%, which is considerably lower than the transmittance of 75% of silver chloride which is one of metal halides, which is one of the causes of malfunction of the sensor. Moreover, the cost of germanium is about three times as high as that of high-purity silicon (about 250,000 yen per kilometer), which hinders widespread application development. Further, there is a problem that germanium is easily oxidized by water vapor and the infrared transmittance is lowered.

On the other hand, although metal halides have high infrared transmittance, they have problems in light resistance and toxicity. For example, silver chloride has a transparent region of 0.4 to 28 μm, which transmits almost all visible light to infrared light, but is exposed to ultraviolet light of 0.4 μm or less, metallic silver is deposited and blackened quickly, and infrared transmittance is also descend. In order to prevent this, a shielding film such as antimony sulfide must be provided on the surface, which is expensive. In addition, the well-known KRS-5 (a mixture of thallium bromide and thallium iodide) has a transparent region of 0.5 to 40 μm and transmits almost all visible light to infrared light, but thallium is extremely toxic. was there.

Further, in recent years, it has been attempted to form a lens in front of a pyroelectric infrared sensor by using a material that transmits only infrared light and measure not only the presence or absence of a human body but also the number of people and body temperature. It was difficult to form a lens with the above glass materials.

Therefore, chalcogenide glass is drawing attention as an infrared-transparent glass that can be easily formed into a lens. Chalcogenide glass is a glass whose main component is a chalcogen element (sulfur, selenium, tellurium), and practically, arsenic-sulfur, germanium-arsenic-selenium, germanium-selenium-tellurium, germanium-selenium-antimony and the like are mainly used. Research and development (eg 31st
Proceedings of the annual glass discussion meeting, p.71-74 (1990)). However, the former two glasses contained arsenic and had a problem of toxicity. Further, since the latter two are likely to be crystallized at the time of reheating, it was difficult to manufacture a lens by press molding.

The present invention solves such a problem. It is an infrared-transparent material in which lenses can be easily manufactured. It transmits infrared rays of 8 to 12 μm emitted from the human body, is not toxic, is hard to crystallize, and is press-molded. It is an object of the present invention to provide a human body detection sensor device using a glass and a pyroelectric sensor, in which an infrared transmissive lens is formed by using glass having good chemical durability, which is easy to manufacture a lens by is there.

[0009]

In order to solve this problem, the present invention is to form an infrared transmissive lens from a non-oxide glass whose starting material is non-oxide and which is mainly composed of germanium and selenium. .

Further, the infrared transmissive lens is formed from glass mainly containing 5 to 22.5 atomic% germanium and 77.5 to 95 atomic% selenium.

Further, the lens is formed from glass mainly containing 5 to 22.5 atomic% germanium, 35 to 95 atomic% selenium, and 0 to 45 atomic% iodine.

A human body detection sensor device is constructed by using the infrared transmissive lens and the pyroelectric infrared sensor.

[0013]

[Function] The main elements of chalcogenide glass are sulfur, selenium, tellurium, germanium, arsenic and antimony. Of these, arsenic and selenium are designated as poisons, but arsenic is particularly toxic. Since selenium is abundant in tomato juice and is an essential nutrient for livestock, it has little toxicity. If it is composed of elements excluding arsenic and that infrared rays of 8 to 12 μm can be transmitted, germanium and selenium will be the main components. When germanium or sulfur is the main component, it is not desirable because it penetrates only up to 11 μm.

Further, a human body detection sensor device is constructed by using a pyroelectric infrared sensor which uses a lens formed of glass mainly containing germanium and selenium.

In addition to germanium and selenium, the glass may contain iodine in order to improve the stability of the glass. Furthermore, antimony is used to expand the infrared transmission range.
A small amount of lithium, sodium, copper, silver, boron, gallium, indium, silicon, tin, lead, bismuth, phosphorus, or bromine, such as tellurium or selenium, may be contained in order to optimize the thermal expansion coefficient.

The reason for limiting the composition is as follows.
In the germanium-selenium system (Ge-Se system, the following system is represented by the element symbol), germanium is 5 to 22.5%, and selenium is 7%.
It does not vitrify except 7.5-95%. Ge-Se-I system does not vitrify except germanium 5 to 22.5%, selenium 35 to 95%, and iodine 0 to 45%. 12 μm when iodine exceeds 45%
Does not penetrate.

This glass transmits infrared rays of 8 to 12 μm,
Since it has no toxicity and is hard to crystallize, it can be easily formed into a lens by press molding.

[0018]

EXAMPLES Examples of the present invention will be described below.

(Example 1) With the composition shown in (Table 1), germanium and selenium were weighed and mixed at a ratio of 5 to 22.5% germanium and 77.5 to 95% selenium in atomic%, put in a quartz ampoule, and vacuum sealed. I stopped. This was melted in an electric furnace at 900 ° C. for 12 hours to obtain glass. The glass obtained is gray to the naked eye and 50 mm for light up to 12.5 μm when it is 2 mm thick (the same applies below).
It had a transmittance of at least%. 5% germanium
Less than or more than 22.5% did not vitrify.

[0020]

[Table 1]

(Example 2) As an example of a Ge-Se-I system glass, as shown in (Table 2), Ge: Se: I = 20: 35 to 7 in atomic%.
Germanium, sulfur and iodine were weighed and mixed in a ratio of 5: 5 to 45, put in a quartz ampoule and vacuum-sealed. This was melted in an electric furnace at 900 ° C. for 12 hours to obtain glass. The obtained glass was gray and had a transmittance of 50% or more for light of up to 12 μm.

[0022]

[Table 2]

(Example 3) As a result of immersing the glass of Samples 1 to 5 in (Table 1) in hot water at 70 ° C for 1 hour, no deterioration of the surface was observed and it was confirmed that the glass had excellent chemical durability. did it.

(Example 4) The glass of Sample 6 in Table 1 was used.
The lens was press molded at 255 ° C. Lens thickness is about 2 mm
The F number was 1.0 and the focal length was 8 mm. Lead fluoride was vapor-deposited on both surfaces of the lens by 1.4 μm to form an antireflection film. This lens was installed in front of a pyroelectric infrared sensor array in which 10 lenses were arranged side by side to form the human body detection sensor device shown in FIG. The lens is movable horizontally 120 °. Stand two men 50 cm apart in front of the sensor,
When the sensor output voltage was examined while moving the lens, a voltage of the pyroelectric infrared sensor of about 350 mV was generated when the human body was detected, confirming the performance as a sensor.

Samples 2 to 7 of (Table 1) and (Table 2)
A lens was molded in the same manner with the above glass, and the performance test of the sensor was performed, and similar results were obtained.

The glass of the present invention contains germanium,
In addition to selenium, iodine may be contained in order to improve stability as glass. In addition, antimony, tellurium, selenium, etc. are used to expand the infrared transmission range, and a small amount of lithium, sodium, copper, and
Silver, boron, gallium, indium, silicon, tin,
It may contain lead, bismuth, phosphorus and bromine.

[0027]

Since the human body detection sensor device of the present invention uses the non-toxic chalcogenide glass, which transmits infrared rays of 8 to 12 μm emitted from the human body, the lens can be easily manufactured by press molding, and it is commercially available. Can be safely incorporated into equipment and industrial equipment.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a conventional human body detection sensor device.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akihiko Yoshida             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (4)

[Claims] 1. An infrared transmissive lens whose starting material is a non-oxide and which is formed from a non-oxide glass mainly containing germanium and selenium. 2. Germanium 5 to 22.5 atomic% and selenium 77.
A glass formed mainly of 5 to 95 atomic%.
The infrared transmissive lens described. 3. Germanium 5 to 22.5 atomic%, selenium 35
The infrared-transmissive lens according to claim 1, which is formed of a glass mainly containing ˜95 atomic% and 0-45 atomic% iodine. 4. A human body detection sensor device comprising the infrared transmissive lens according to claim 1 and a pyroelectric infrared sensor.