JPH0626821Y2 - Infrared camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an infrared camera used in a thermography device.

[Prior Art] An infrared camera of a thermography device that detects infrared rays radiated from the surface of a subject and displays the temperature distribution as a visible image (thermal image) is generally configured as shown in FIGS. 4 and 5. What has been done is known. That is,
Reference numeral 1 is a subject, 2 is an infrared camera, and the light emitted from the surface of the subject 1 is blocked by visible light 5 by a silicon window 4 provided in a front opening of a housing 3 constituting a camera housing, and only infrared rays 6 are emitted. Enters the infrared camera 2.

Reference numeral 7 denotes a rotating polyhedral mirror which is disposed in the housing 3 and is rotated at a constant speed in the arrow direction by a drive motor (not shown).
The rotating polyhedron mirror 7 is composed of, for example, a dodecahedron, and each of the mirrors 7a to 7j is arranged in a polygonal pyramid shape with an inclination slightly different from the rotation center O of the rotating polyhedron mirror 7 in the vertical direction. . When the infrared ray 6 transmitted through the silicon window 4 is incident on the rotating polyhedron mirror 7, it is reflected by each of the mirrors 7a to 7j, further hits the folding mirror 8 and reflected, and the infrared ray transmitting filter 9
Then, the light enters the infrared detector 11 through the condenser lens 10. Therefore, each of the mirrors 7a-
7j horizontally scans a portion of the subject 1 that is slightly shifted in the vertical direction, and one rotation of the rotating polyhedral mirror 7 scans a range of, for example, 10 ° in the vertical direction.

The infrared detector 11 is composed of 10 detecting elements arranged in parallel in the central axis O direction of the rotating polyhedral mirror 7, and the distance between them is 1 ° for each mirror 7a to 7j with respect to a vertical viewing angle of 10 °. The intervals are equivalent. For this reason, the infrared detector 11 of 10 elements simultaneously receives the thermal image signal of the vertical viewing angle of 1.0 ° of the subject 1 by the first mirror 7a of the rotating polyhedral mirror 7 and the ten infrared detectors 11 are arranged at intervals of 0.1 °. It is output as a scanning line signal. When the next mirror 7b reflects infrared rays 6 from the subject 1 as the rotating polyhedron mirror 7 rotates, the infrared detector 11 of 10 elements is generated due to the difference in inclination of the mirror 7b.
Simultaneously receives a thermal image signal at a position deviated by 1 ° from the previous position, and outputs it as 10 scanning line signals also having an interval of 0.1 °.

When the rotating polygon mirror 7 makes one rotation in this way, the object 1 is scanned over a vertical viewing angle of 10 °, and ten detection objects 1 different from each other by 0.1 ° are arranged on one detection element. Infrared rays 6 will be incident, and the detector 11 as a whole will output 100 infrared scanning signals. The infrared scanning signal output from the infrared detector 11 is amplified by the amplifier circuit 12, and then image-processed by the processor 13.
A color image is displayed on the monitor 14 as a thermal image.

In this case, although the infrared image displayed on the monitor 14 can know the relative temperature of the subject 1,
It is not possible to know the actual temperature of. Therefore, since the temperature and the infrared radiation amount have a fixed relationship according to Planck's radiation formula, the room temperature detection sensor 15 detects the environmental temperature inside the camera and supplies the signal to the processor 13 for processing. I try to know the actual temperature.

Regarding the horizontal scanning angle, each of the mirrors 7a to 7a
The maximum horizontal viewing angle of j is 36 °, but in actuality, scanning is performed within a range of about 15 ° in order to prevent the blurring phenomenon of the optical system.

[Problems to be Solved by the Invention] In such a conventional infrared camera 2, although the temperature of the inner wall surface of the front surface of the housing 3 is detected by the sensor 15 and input to the processor 13 as a room temperature calibration signal, The inner wall surface of the housing has a problem that the temperature of the housing itself fluctuates only when it is exposed to direct sunlight of the sun when it is used outdoors or the like, so that highly accurate temperature calibration cannot be performed.

Therefore, the present invention has been made in view of the conventional problems as described above, and the purpose thereof is to make it possible to perform high-accuracy temperature calibration while being relatively unaffected by external light or the like with a relatively simple structure. It is to provide an infrared camera that can be performed.

[Means for Solving the Problems] In order to achieve the above object, the present invention reflects infrared rays emitted from a subject and entering a housing by a rotating polyhedral mirror, and receives the reflected light by an infrared detector, In an infrared camera configured to output as a thermal image signal, a rotation rear end portion of one mirror surface of the rotating polyhedral mirror is radiated from an object while being separated from an inner surface of the housing and closely facing a part of a peripheral surface of the rotating polyhedral mirror. A room temperature calibration wall that shields light from light is provided in the housing, and a room temperature detection sensor is disposed close to the mirror facing surface of the room temperature calibration wall.

[Operation] In the present invention, the room temperature calibration wall is separated from the inner wall surface of the housing, and is unlikely to be affected by the temperature change of the inner wall surface of the housing due to external light or the like. The space between the inner wall surface of the housing and the room temperature calibration wall forms a heat insulating space.

[Embodiment] Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

FIG. 1 is a partially cutaway front view showing the inside of a housing of an infrared camera according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. Is. In addition,
The same components as those in FIGS. 4 and 5 are designated by the same reference numerals, and the description thereof will be omitted. In these figures, 20 is an opening formed in the center of the front surface of the housing 3, 21 is a window fixing member that holds one end of the silicon window 4 together with the inner surface of the housing, 22
Is a shielding plate, and 24 is a room temperature calibration wall provided in the housing 3 so as to closely face a part of the outer peripheral edge of the rotating mirror 7.

The room temperature calibration wall 24 is provided behind the silicon window 4 and corresponding to the lower part on the front surface side of the rotating polyhedral mirror 7, so that the room inner wall surface of the front surface of the housing 3, which has been used as a calibration reference surface in the conventional camera, is below the wall surface. It is sufficiently separated from the portion 25. In addition, the room temperature calibration wall 24 is the first
As is clear from the figure, the rotating rear end of one mirror surface of the rotating polyhedral mirror 7 is shielded from the light emitted from the subject. That is, the room temperature calibration wall 24 is the same as the rotating polyhedral mirror 7.
The rear end of the rotation of one mirror surface is covered so that the radiated light from the subject does not hit the rear end of the rotation. Then, the room temperature detecting sensor 15 is arranged close to the room temperature calibration wall 24.

Thus, in the infrared camera 2 having such a configuration, since the room temperature calibration wall 24 is provided inside the housing with being sufficiently separated from the front inner wall surface lower portion 25 of the housing 3, the room temperature calibration wall 24 is not heated by the subject. Outside light,
Less affected by fluctuations in external temperature,
Even if the temperature of the housing 3 fluctuates due to outside light or the like, the space up to the lower portion 25 of the inner wall surface of the front face forms a heat insulating space, so that the influence thereof is small and the temperature is maintained substantially constant. Further, since the room temperature detection sensor 15 is arranged at a position where the incident light and the scattered light are blocked by the room temperature calibration wall 24, unnecessary light such as scattered light in the housing does not hit the sensor 15, and the room temperature calibration is performed. Since the wall 24 and the room temperature detecting sensor 15 are arranged in close proximity to each other,
Since there is no error between the reference temperature signal in the thermal image signal obtained by the scanning of the rotating polyhedral mirror 7 and the temperature detected by the room temperature detecting sensor 15, highly accurate room temperature calibration can be performed, and more accurate object It is possible to measure various temperatures.

[Effects of the Invention] As described above, according to the infrared camera of the present invention, after the rotation of one mirror surface of the rotating polyhedral mirror, the infrared camera is spaced apart from the inner surface of the housing and closely faces a part of the peripheral surface of the rotating polyhedral mirror. Since a room temperature calibration wall that shields the end portion from the radiated light of the subject is provided in the housing, and the room temperature detection sensor is arranged close to the mirror facing surface of the room temperature calibration wall, the scattered light in the housing, etc. Since unnecessary light does not hit the room temperature detection sensor and the room temperature calibration wall and the room temperature detection sensor are in close proximity to each other, the reference temperature signal and the room temperature detection sensor in the thermal image signal obtained by scanning the rotating polyhedral mirror. There is no error with the temperature detected in step 1, high-accuracy room temperature calibration can be performed, and accurate temperature measurement can be performed. In addition, the space between the inner wall surface of the housing and the room temperature calibration wall forms a heat insulating space, which is less likely to be affected by external temperature, direct light, etc. Therefore, more accurate room temperature calibration can be performed, and the camera It has an advantage that the performance can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of the inside of a housing showing an embodiment of an infrared camera according to the present invention, and FIG. 2 is a II- of FIG.
II sectional view, FIG. 3 is a III-III sectional view of FIG. 1, 4
FIG. 1 is a front view showing a conventional example of an infrared camera, and FIG. 5 is a schematic configuration diagram of the same camera. 1 ... Subject, 2 ... Infrared camera, 3 ... Housing, 4 ... Silicon window, 6 ... Infrared, 7 ... Rotating polyhedral mirror, 8 ... Folding mirror, 9 ... Infrared transmission filter, 10 ... Condensing lens, 11 ... Infrared detector, 15 ... Room temperature detection sensor, 24 ... Room temperature calibration wall.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-62-144034 (JP, A) Jpn. App. 58-66549 (Jpn. Pat. Appl. Sho 59-172343) A microfilm (JP, U) of which the contents were photographed. A microfilm (JP, U, U) of the specification and drawings attached to the application of the actual application Sho 62-140072 (Actual 64-64726). )

Claims (1)

[Scope of utility model registration request] 1. An infrared camera in which infrared rays radiated from a subject and incident on a housing are reflected by a rotating polyhedral mirror, and the reflected light is received by an infrared detector and output as a thermal image signal. A room temperature calibration wall that is spaced apart from the inner surface of the rotary polyhedron mirror and partially faces the peripheral surface of the rotary polyhedron mirror and shields the rotation rear end of one mirror surface of the rotary polyhedron mirror from the radiated light of the subject is provided in the housing, An infrared camera characterized in that a room temperature detecting sensor is arranged in proximity to the mirror facing surface of the room temperature calibration wall.