JPH052253B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an infrared camera, and more particularly to an apparatus equipped with a mechanism capable of detecting infrared rays emitted by a subject in different frequency bands.

[Prior Art] In general, an infrared camera having an optical mechanism that scans infrared rays emitted from a subject and guides the infrared rays to an infrared detector is known, for example, a mechanism as shown in FIG. 4 is known. In Fig. 4, 1 is an object, 2 is a scanning mirror, 3 is a concave mirror that further reflects and condenses the infrared rays reflected by the scanning mirror 2, 6 is an infrared detector, 8 is a lens, 10 is a reflecting mirror, and 11 is a reference black. The body furnace 12 is a rotating chopper with a plane mirror on one side. In the figure, the optical path of infrared rays is indicated by a solid arrow. The rotary chopper 12 disposed in the infrared light path has an aperture, and its rotation alternately passes and blocks the infrared light from the subject 1. When the aperture is in a rotational position that does not obstruct the optical path, the infrared rays from the subject 1 are guided to the infrared detector 6, and the rotating chopper 12
When the rotary chopper is at a rotational position that blocks the optical path from the object 1, the mirror on the side of the detector of the rotating chopper reflects the infrared rays from the reference blackbody furnace 11, and the mirror 10
The light then passes through a lens 8 and is focused onto an infrared detector 6 . The above operation is repeated by rotating the chopper 12, and the accurate temperature of the object 1 is measured in a non-contact manner by comparative observation of the object 1 and the reference blackbody furnace 11.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, due to the infrared wavelength sensitivity characteristics of the infrared detector itself, an infrared detection mechanism using one infrared detector can only detect infrared rays in a certain specific wavelength range. First, it is not possible to detect infrared rays in different wavelength ranges for the same subject. In the past, when such a request existed, measurements were taken for one subject using the required number of infrared cameras equipped with detectors with different infrared wavelength sensitivity characteristics, which caused parallax to occur due to shifts in observation positions. was considered a problem. In addition, there are problems in terms of space occupied by the device and cost since it is necessary to prepare multiple expensive devices.

The present invention solves the above-mentioned problems, and aims to provide an infrared detection mechanism that can detect infrared light over a wide area using one infrared camera.

[Means for Solving the Problems] To this end, the present invention provides an infrared detector, a condensing means for condensing infrared rays emitted from a subject onto the infrared detector, and a combination of the condensing means and infrared detection. an optical scanning means disposed between the detector or in the optical path between the condensing means and the subject; a rotating chopper mirror for cutting off infrared rays from the subject incident on the infrared detector; and the rotating chopper mirror. In an infrared camera equipped with a blackbody furnace that generates reference infrared rays that are incident on the detector via the chopper mirror during a period of time when the rotary chopper mirror is inserted into an optical path, the rotary chopper mirror is a double-sided mirror, and the rotating chopper mirror is a double-sided mirror. A second infrared detector is provided for detecting infrared rays from the subject reflected by the rotating tipper mirror during a period when the mirror is inserted into the optical path, and a second infrared detector is provided to detect infrared rays from the subject reflected by the rotating tipper mirror, and the black body is detected while the rotating tipper mirror is out of the optical path. This is characterized in that the reference infrared rays from the furnace are configured to enter the second infrared detector.

[Function] In the present invention, by disposing the first and second infrared detectors and the rotary chopper 4 having an opening with plane mirrors on both sides, the period when the chopper is inserted into the optical path is longer than the conventional one. Infrared rays from the subject that have been blocked and not used are reflected by the plane mirror portion of the chopper 4 and introduced into the second infrared detector 7. At this time, the first infrared detector 6 observes the infrared rays emitted by the reference blackbody furnace 11 and reflected by the plane mirror on one side of the chopper 4 as in the conventional manner. Further, when the aperture of the chopper 4 is on the optical path, infrared rays from the subject 1 pass through the aperture of the chopper 4 and are focused on the first infrared detector 6. At this time, the second infrared detector 7 observes the infrared rays emitted by the reference blackbody furnace 11 through the opening of the chopper 4.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. Figure 1 shows one of the infrared detection cameras according to the present invention.
FIG. 2 is an operational diagram, and FIG. 3 is a timing chart of scanning signals, opening/closing of the chopper 4, and detection signals of the infrared detector.

In FIG. 1, infrared rays emitted from a subject 1 are directed by a scanning mirror 2 to a concave mirror 3, and further reflected and condensed by the concave mirror 3. At the focal point formed by the reflected light from the concave mirror 3 on the optical path of the infrared rays, a rotary chopper 4 whose both sides are plane mirrors and a motor 5 for driving the rotary chopper 4 are disposed. An infrared detector 6 and a lens 8 for focusing the light beam on the infrared detector 6 are disposed on the optical path behind the focal point,
This is the first detection system. The second detection system includes a fixed reflecting mirror 10 for guiding the light beam reflected by the mirror surface on the subject side of the rotating chopper 4 to a second infrared detector 7, a lens 9, and detecting the reflected light beam. The infrared detector 6 has different infrared detection wavelength characteristics, and the infrared detector 7 has different infrared detection wavelength characteristics. 11
is a reference blackbody furnace shared by the first and second detection systems. The infrared detector measures the accurate temperature of the object without contact by alternately comparing and observing the infrared rays emitted by the object 1 and the infrared rays emitted by the reference blackbody furnace 11.

The operation of the optical mechanism of the infrared camera equipped with the first and second detection systems as described above will be explained with reference to FIG. The chopper 4 is inserted on the optical path as shown in FIG.
, the first detection system observes the reference infrared rays from the reference blackbody furnace 11 that are reflected by the plane mirror on one side of the chopper 4, and at the same time the reference infrared rays are reflected by the plane mirror portion on the back of the chopper 4. Infrared rays from the subject are introduced to the second infrared detector 7 through the second optical mechanism.

On the other hand, when the aperture of the chopper 4 is on the optical path as shown in FIG. At this time, the second infrared detector 7 simultaneously observes the reference infrared rays from the reference blackbody furnace 11 passing through the opening of the chopper 4. These operations are repeated by rotating the chopper 4 in synchronization with the horizontal scanning of the object by the scanning mirror 2, and the infrared rays emitted by the object 1 and the infrared rays emitted by the reference blackbody furnace 11 are alternately compared and observed. The accurate temperature of the subject is measured without contact.

In the optical mechanism as described above, in order to uniformly introduce infrared rays from the subject 1 to the two infrared detectors, the scanning mirror 2 and the rotary chopper 4 are driven at the timing shown in FIG. 3. In FIG. 3, a indicates a scanning signal for driving the scanning mirror 2, and b indicates a drive signal for the rotary chopper 4, which simultaneously indicates the positions of the aperture and mirror surface of the chopper. c,
d is a detection signal from the infrared detectors 6 and 7.
The scanning mirror 2 is driven by a scanning signal a, and the driving signals of the chopper 4 are synchronized so that the aperture and mirror surface of the chopper 4 cross the optical path every 1/2 cycle of the scanning signal a. When observing the infrared rays from the subject 1 at this timing, the first infrared detector 6 and the second infrared detector 7 detect the infrared rays emitted by the subject 1 and the reference blackbody furnace 11 as shown in c and d, respectively. It alternately detects the emitted infrared rays. Here, the first
By using second infrared detectors having different wavelength sensitivity characteristics, each detector detects infrared rays so as to compensate for each other's undetectable areas.

In addition, when measuring a wide range of temperature changes in a subject, for example, use detectors with the same characteristics as the first and second detectors, and insert an aperture just before the second detector. If the high temperature region is covered by attenuating the amount of light, the first detector can cover the low temperature region, and the second detector can cover the low temperature region.
These detectors can measure each high temperature region, and a single infrared camera can measure a wide temperature range at once.

[Effects of the Invention] As is clear from the above description, according to the present invention, the first infrared detection mechanism of an infrared camera
By disposing a second infrared detector and a rotating chopper 4 having an aperture with plane mirrors on both sides, it becomes possible to simultaneously detect infrared rays emitted by one subject with two infrared detectors. . Therefore, the parallax that occurs when observing one object with multiple infrared cameras does not occur, and the forward and backward scanning of the scanning mirror 2, which is driven by the scanning signal a and scans the object 1 back and forth, is fully utilized. This improves scanning efficiency.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing one embodiment of the infrared detection mechanism according to the present invention, Fig. 2 is an operation diagram, Fig. 3 is a timing chart of scanning signals, opening/closing of the chopper 4, and detection signals of the infrared detector, and Fig. 4 is a timing diagram of the detection signal of the infrared detector. The figure is a diagram for explaining a conventional example. 1... Subject, 2... Scanning mirror, 3... Concave mirror, 4... Rotating chopper, 5... Motor, 6, 7... Infrared detector,
8, 9... Lens, 10... Reflector, 11... Reference blackbody furnace.

Claims (1)

[Claims] 1. An infrared detector, a condensing means for condensing infrared rays emitted from a subject onto the infrared detector, and an infrared condensing means and an infrared detector, or between the condensing means and the infrared detector. an optical scanning means disposed in the optical path between the objects; a rotating chopper mirror for cutting off the infrared rays from the subject entering the infrared detector; In an infrared camera equipped with a blackbody furnace that generates a reference infrared ray that is incident on the detector through a tipper mirror, the rotating tipper mirror is a double-sided mirror, and the rotating tipper mirror is inserted into the optical path. A second infrared detector is provided to detect the infrared rays from the object reflected by the tipper mirror, and the reference infrared rays from the blackbody furnace are detected by the second infrared rays while the rotating tipper mirror is out of the optical path. An infrared camera characterized in that the infrared camera is configured to be incident on an infrared detector. 2. The infrared camera according to claim 1, wherein the first and second infrared detectors have different detection wavelength regions.