JPH0543268A - Visible light and ir transparent material - Google Patents

Abstract

PURPOSE:To provide the visible light or IR transmissive filter or lens material which is nontoxic, has environmental reliability and can be easily built into an optical system. CONSTITUTION:This glass material consists essentially of germanium, ion and halogen. The optical filter and lens which allow the transmission of both of the visible light and the IR light, is nontoxic and is safe are formed by this constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a filter or lens that transmits visible light and infrared light, a human body detection sensor including the filter or lens and a pyroelectric infrared sensor, and various devices to which the sensor is applied. It relates to visible light and infrared light transmissive materials.

[0002]

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

[0003]

However, there are problems that silicon and germanium have a low transmittance of infrared light having a wavelength of 8 to 12 μm and a high cost. For example, the transmittance of infrared light with a wavelength of 10 μm for 2 mm-thick silicon is as low as about half that of silver chloride, which is one of the metal halides, and this was one of the factors that caused the sensor to malfunction. In addition, the cost of germanium is about three times that of high-purity silicon (about 250,000 yen / Kg),
There were obstacles to the widespread application development. Further, germanium is easily oxidized by water vapor, and there is a reliability problem that the transmittance of infrared light is reduced.

On the other hand, although metal halides have high infrared light 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 light from visible light to infrared light, but when exposed to ultraviolet light of 0.4 μm or less, it causes a photoreaction, and metallic silver precipitates and becomes black. Discolors and the infrared light transmittance decreases. In order to prevent this, a protective film such as antimony sulfide must be provided on the surface, which causes a problem of high cost.

The well-known KRS-5 (a mixture of thallium bromide and thallium iodide) transmits a wide range of light from visible light to infrared light, but there is a problem that thallium is extremely toxic.

Further, since germanium and silicon do not transmit visible light, when they are incorporated in an optical system, it is necessary to carry out operations such as optical axis alignment using infrared rays, which requires expensive equipment and very troublesome work. However, there is a problem that it takes a long time to assemble and adjust.

The present invention solves such a problem. It transmits visible light and infrared light with high transmittance, does not cause a photoreaction even when exposed to ultraviolet rays, is stable, has no toxicity, and is a consumer product. It is an object of the present invention to provide a visible light and infrared light transmissive material that can be safely used for applications.

[0008]

In order to solve this problem, the present invention comprises an infrared and visible light transmitting material mainly composed of germanium, sulfur and halogen.

Further, germanium is 5 to 50 in atomic%.
%, Sulfur 5 to 95%, and halogen 0 to 70%.

The atomic ratio of germanium to sulfur is 1.5 to 3.0.

[0011]

[Advantage] According to this structure, a glass that transmits visible light and infrared light of 8 to 12 μm and is non-toxic is obtained, and a filter or lens that transmits visible light and infrared light is used using this glass. It will be possible to create.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

(Example 1) Germanium 30% in atomic%,
Weigh each element so that it has a composition of 60% sulfur and 10% iodine, mix them, and seal them in a quartz ampoule.
Vacuum sealed. After melting this ampoule in an electric furnace at 700 ° C for 8 hours, remove the ampoule from the electric furnace and keep it at 20 ° C.
It was soaked in water and cooled to obtain glass. The infrared light transmission characteristics of this glass are shown in FIG. 1, and the visible light transmission characteristics are shown in FIG.

Example 2 Germanium 31.7 in atomic%
%, Sulfur 63.3%, and iodine 5.0%, each element was weighed, enclosed in a quartz ampoule, and vacuum-sealed. After melting this ampoule in an electric furnace at 700 ° C. for 8 hours, the ampoule was taken out of the electric furnace, immersed in water at 20 ° C. and cooled to obtain glass.

(Comparative Example 1) 45% germanium in atomic%,
Each element was weighed so as to have a composition of 45% sulfur and 10% iodine, sealed in a quartz ampoule, and vacuum-sealed. This was melted in an electric furnace at 700 ° C. for 8 hours, then the ampoule was taken out of the electric furnace, immersed in water at 20 ° C. and cooled, but it could not be crystallized to obtain glass. This glass did not transmit visible light at all, and hardly transmitted infrared light.

(Comparative Example 2) 50% germanium in atomic%,
Each element was weighed so as to have a composition of 50% selenium, sealed in a quartz ampoule, and vacuum-sealed. 700 in an electric furnace
After melting at 0 ° C for 5 hours, the ampoule was taken out of the electric furnace, immersed in water at 20 ° C and cooled to obtain glass. The glass did not transmit any visible light.

Various characteristics of the above-mentioned Examples 1 and 2 and Comparative Examples 1 and 2 and the conventional arsenic-based chalcogenide glass are shown in Table 1.

As can be seen from the table, the glass having the composition of this embodiment efficiently transmits both visible light and infrared light.

Although the case where iodine is used as the halogen has been described in this embodiment, the same effect can be obtained by using other halogen such as bromine.

[0020]

[Table 1]

[0021]

As is apparent from the above description of the embodiments, according to the present invention, infrared rays of 8 to 12 μm are efficiently transmitted, so that the sensitivity of the pyroelectric human body detection sensor is improved. In addition, since it is non-toxic and transmits visible light, the optical axis can be adjusted directly by hand, and the work when incorporating it into the sensor becomes easy.

[Brief description of drawings]

FIG. 1 is an infrared light transmission characteristic diagram of glass of Example 1 of the present invention.

[Figure 2] Visible light transmission characteristic diagram

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Yoshida 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. An infrared and visible light transmitting material mainly composed of germanium, sulfur and halogen. 2. The visible light and infrared light transmissive material according to claim 1, which is mainly composed of a range of 5% to 50% germanium, 5% to 95% sulfur, and 70% halogen, in atomic%. 3. The visible light and infrared light transmitting material according to claim 2, wherein sulfur is 1.5 to 3.0 with respect to germanium 1 in atomic ratio.