JPS5991654A - Near infrared emission low pressure rare gas electric- discharge lamp - Google Patents

Abstract

PURPOSE:To obtain picture without making subjects conscious of being picked up by using as a pickup illumination light source a low pressure rare gas electric-discharge lamp formed by the use of filter glass having practically zero transmissivity of visible light and a high transmissivity of near infrared light. CONSTITUTION:A glass discharge tube 1 is formed by the use of filter glass having practically zero transmissivity of visible light and a high transmissivity of near infrared light. A near infrared emission low pressure rare gas electric- discharge lamp 4 is made by fusing a pair of electrodes 2 inside the tube 1 and charging it with a rare gas 3 such as xenon or argon. Such a lamp 4 is combined with a pickup device such as a video camera having sensitivity to the near infrared region to constitute a crime-prevention monitoring device or a visitor- recognizing device. As a result, use of near infrared light removes inconveniences caused in picking up images by use of visible light, thereby enabling clear pictures to be obtained without making subjects conscious of being illuminated or picked up.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-pressure rare gas discharge lamp that emits near-infrared radiation. In an imaging device such as a camera, images are taken under illumination that radiates into the visible region.

However, in imaging methods that use visible light.

Various inconveniences arise due to the fact that the object or the imaging device is visible during imaging.

For example, in various crime prevention monitoring devices such as stores, shops, factories, houses, etc., and visitor recognition devices in the United States, visible light video from objects (objects to be imaged) illuminated by visible illumination light is used. Capture it on camera and take an image.

The signal was displayed on a TV or cathode ray tube, or input to a videotape and played back.

Therefore, in the security monitoring device, an intruder or the like can easily recognize the presence of the monitoring device, resulting in an S1 error.

Furthermore, visitor recognition devices installed at the entrance or back door of a residence have drawbacks such as the visitor being dazzled by the illumination light and feeling uncomfortable because it becomes clear that the visitor is being photographed by a camera. there were.

In this way, the above-mentioned drawbacks were unavoidable in conventional imaging devices that take images under visible light.

The present invention relates to an imaging device and its light source for making a person to be imaged or an animal to be imaged unaware of being illuminated or being imaged, and relates to a light source that emits near-infrared light and a light source thereof. This is the near-infrared light imaging device used. In other words, it consists of a low-pressure rare gas discharge lamp that emits light in the near-infrared region, and an imaging device sensitive to the near-infrared region that irradiates the object to be imaged using the discharge lamp as an illumination light source and captures the reflected light to take an image. This invention relates to a near-infrared light imaging device.

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

FIG. 1 shows a near-infrared-emitting low-pressure rare gas discharge lamp according to an embodiment of the present invention. A pair of electrodes (2), (21!) are sealed at both ends of the glass discharge tube +13, and are filled with xenon, krypton,
Noble gas (3) such as argon is 0.1 to 10 torr
A low pressure rare gas discharge lamp (4) is manufactured. Here, the glass discharge tube (1) is made of filter glass, which has virtually zero transmittance for visible light and high transmittance for near-infrared light, and is made of filter glass that has substantially zero transmittance for visible light and high transmittance for near-infrared light. It also plays the role of removing Enclosed rare gas (3
), a low-pressure rare gas discharge lamp using a rare gas mainly composed of argon, and a low-pressure rare gas discharge lamp using a filter glass that cuts the visible part of 700 nm or less as the discharge tube glass, 1
It shows radiation concentrated in the near-infrared region between 00 and 1.1100 nm. The visible radiation from a discharge lamp is a discharge, 't! Since it is constructed from solid filter glass, it is an extremely small and highly efficient near-infrared emitting lamp that does not emit radiation into the visible region.

Therefore, by using the near-infrared emitting low-pressure rare gas discharge lamp of the present invention as an illumination light source for imaging, near-infrared light can be imaged by an imaging device such as a video camera that is sensitive to the near-infrared region and is equipped with a solid-state imaging device. By constructing crime prevention monitoring devices and visitor recognition devices using optical imaging devices, clear images can be obtained using synchrotron radiation in the near-infrared region, and since it does not substantially contain radiation in the visible region, it is possible to The above-mentioned drawbacks when using conventional imaging devices using light can be eliminated.

FIG. 2 is an explanatory diagram showing an embodiment in which the near-infrared light imaging device of the present invention is applied to a crime prevention monitoring device.

The security monitoring device (7) is equipped with the above-mentioned near-infrared emitting low-pressure rare gas discharge lamp (5) and a near-infrared camera (6) which is an imaging device equipped with a solid-state image sensor sensitive to near-infrared light. There is.

(8) is a general fluorescent lamp that emits visible light;
) are trespassers.

In such a device, if the fluorescent lamp +8) is turned off at night, it will be dark, and an intruder (9) will be able to see the security monitoring device (7).
Since the existence of the surveillance device (
7). In conventional crime prevention monitoring devices that do not have a light source, the fluorescent lamp (8) remains lit, and in those that do have a light source, the light source remains lit, so the existence of the crime prevention monitoring device is ignored. The intruder may be recognized and try to avoid being caught by the security monitoring device, reducing the effectiveness of the security monitoring device.

In the above example, low pressure rare gas discharge, argon as the lamp? Although I have explained the examples of sealed lamps, low-pressure rare gas discharge lamps using xenon and chlorine gas also contain argon.

It goes without saying that a low-pressure rare gas discharge lamp in which other gases such as neon, lium, etc. are mixed with rare gases such as chlorine and xenon can also be used.

In addition, in this invention, the filter glass is a discharge tube glass, but this filter glass has a filter, tube, etc. tightly integrated on the outside of a transparent glass tube. It goes without saying that structures in which a discharge lamp is inserted into a filter or tube and covered with a transparent tube cover, heat-shrinkable plastic, tube, etc. have similar effects and are included in the present invention. A similar effect can also be obtained by coating the surface of the discharge tube glass with a paint that transmits near-infrared light and cuts visible light. As described above, the present invention also includes a rare gas discharge lamp in which the discharge tube glass is closely and integrally coated with a filter material.

As described above, the present invention provides a low-pressure rare gas discharge lamp that emits radiation in the near-infrared region without substantially including radiation in the visible region, and a near-infrared-emitting low-pressure rare gas discharge lamp of the present invention as an illumination light source for imaging. The present invention provides a near-infrared light imaging device that can be used as an imaging device and is sensitive to near-infrared light. It is useful because it can eliminate various inconveniences that occur when taking images, and it is possible to capture images without making the person being photographed aware of being illuminated or being photographed. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a near-infrared light-emitting low-pressure rare gas discharge lamp, which is an embodiment of the present invention, and FIG. 2 is a block diagram of a near-infrared light imaging device, which is also an embodiment of the present invention. Are the same symbols in the diagram the same or equivalent parts? (1) is a discharge tube, (2) is an electrode, (3) is a rare gas, (41, (5
1 is a near-infrared emitting low-pressure rare gas discharge lamp, (6) t'! Near-infrared camera, (7) is a security monitoring device, (9) is an intruder's agent Shin Kuzuno - Procedural amendment (voluntary) Permit J1 Director 1, Indication of incident Patent application No. 67-202848 2, Invention Name of near-infrared emitting low-pressure rare gas Hokigen 3, Name of person making the amendment (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama Yabukan Column for detailed explanation of the invention in the specification to be amended. Higashi: The detailed description of the amendment is amended as follows.

Claims (1)

[Claims] 1) Argon in a discharge tube having a plurality of electrodes. A near-infrared-emitting low-pressure rare gas discharge lamp filled with a luminescent rare gas of either krypton or xenon, characterized in that the discharge tube is constructed of a filter glass that removes radiation in the visible region. discharge lamp. (2) The filter glass of the discharge tube is constructed by making the glass itself a colored glass or by integrating a filter substance into the glass in close contact with the first claim.
The near-infrared-emitting low-pressure rare gas discharge lamp described in . (3) Argon pressure inside the discharge tube with multiple electrodes. A near-infrared-emitting low-pressure rare gas discharge lamp is constructed of a low-pressure rare gas discharge lamp whose discharge tube is filled with a type of luminescent rare gas such as krypton or xenon, and a filter glass that removes radiation in the visible region. An imaging camera that captures and images the reflected near-infrared light emitted from the discharge lamp to the irradiated object. A near Chinese external light imaging device characterized by comprising: