JPH05241260A - Infrared camera - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a thermal image without spatial displacement and scanning distortion. [Structure] A first turn-back mirror movably provided in the vertical direction, and a first support column provided with a vertical fine adjustment mechanism for supporting the turn-back mirror and finely adjusting the tilt angle in the vertical direction. , A vibration mirror that vibrates at a predetermined angle in the vertical direction, a rotary mirror that horizontally scans the infrared light scanned in the vertical direction by the vibration mirror, and the infrared light that is horizontally and vertically scanned in the infrared detector direction. An optical system scanning mechanism including a second supporting column that supports a second folding mirror that reflects light and that also has a vertical fine adjustment mechanism that finely adjusts the tilt angle in the supine direction. An infrared camera comprising an infrared detector that receives scanning light and outputs it as a thermal image signal. [Effect] Since a horizontal and vertical fine adjustment mechanism is provided, it is easy to finely adjust the optical axis of the light flux in the vertical and horizontal directions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared camera used in an infrared thermal imager.

[0002]

2. Description of the Related Art Generally, an infrared camera used in an infrared thermal imager for detecting infrared rays radiated from the surface of an object and displaying the temperature distribution as a visible image (thermal image) is shown in FIG. There is one configured as. First, the optical system scanning mechanism of this infrared camera will be described. The light emitted from the surface of the subject 50 is blocked from visible light 52 by the silicon window 51 provided in the front opening (not shown) of the housing (not shown), and only the infrared ray 53 enters the infrared camera 54. It is incident. A decahedron rotating mirror 55, which is rotated at a constant speed by a drive motor (not shown), is disposed in the housing on substantially the same plane as the silicon window 51, and is incident on the housing. The infrared ray 53 enters the rotating mirror 55.

The rotating mirror 55 is composed of decahedral mirrors 55a to 55j, which are arranged in a polygonal pyramid shape with slightly different inclinations in the vertical direction with respect to the rotation center O of the rotating mirror. Therefore, when the infrared ray 53 enters the rotating mirror 55, it is reflected by each of the mirrors 55a to 55j. At this time, each of the mirrors 55a to 55j horizontally scans a portion of the subject 50 which is slightly displaced in the vertical direction, and one rotation of the rotary mirror 55 scans a range of 1 ° in the vertical direction. It The infrared ray 53 thus scanned in the horizontal and vertical directions is reflected by the folding mirror 56 arranged on the same plane as the rotating mirror 55, passes through the infrared transmitting filter 57, and passes through the condenser lens. 58
Thus, the beam is converged and is incident on the infrared detector 59.

The infrared detector 59 is composed of 10 detecting elements arranged in parallel in the direction of the rotation center O of the rotating mirror 55, and the element interval is 1 for each element for a vertical viewing angle of 10 °. The intervals correspond to angles in degrees.
Therefore, in the first mirror 55a of the rotating mirror 55, the infrared detector 59 of 10 elements simultaneously receives the thermal image signals at intervals of 1 ° with respect to the vertical direction of the subject 50, and the infrared image signal of each one is 0.1.
It is output as 10 scanning line signals having an interval of °. Next, as the rotating mirror 55 rotates, the next mirror 55
When b reflects infrared rays 53 from the subject 50,
Infrared detector 59 with 10 elements depending on the inclination of 55b
However, a thermal image signal at a position deviated by 0.1 ° from the previous position is simultaneously received, and similarly, it is output as 10 scanning line signals having an interval of 0.1 ° for each line.

In this way, when the rotating mirror 55 makes one rotation, it means that the object 50 has been scanned over a vertical viewing angle of 10 °, and ten 0.
Infrared rays 53 from the subject 50 which are different by 1 ° are incident, and the infrared ray detector 59 as a whole is output as 100 infrared ray scanning signals. Then, the infrared scanning signal output from the infrared detector 59 is amplified by the amplifier circuit 60, subjected to image processing by the processor 61, and color-displayed as a thermal image on the monitor 62.

On the other hand, since the infrared detector 59 detects the infrared light 53 and converts it into an electric signal, the infrared image of the subject 50 whose temperature is changing is limited to 2 with a limited number of elements.
In order to form a three-dimensional image and obtain high sensitivity, an infrared detector 59 having high sensitivity and fast response speed is required. Therefore, conventionally, a quantum type infrared detector 59 such as indium antimony (InSb) or mercury cadmium tellurium (HgCdTe) has been used. However, these In
Since the Sb element and the HgCdTe element need to be cooled at an extremely low temperature of about -200 ° C in order to obtain the highest sensitivity, the JT cooler method and the liquid nitrogen cooling method using argon gas as a cooling medium. Has been cooled to a cryogenic temperature.

[0007]

As described above, in contrast to the structure in which the infrared ray 53 is optically scanned in the horizontal direction and the vertical direction by one rotating mirror 55, the scanned infrared ray 53 is collected by the condenser lens 58. Infrared detector 5 that collects light by
The number of elements of 9 is plural, and 1 ° with respect to the vertical direction.
Since they are arranged at an interval corresponding to, a plurality of condensing positions are spread over a wide range, and as a result, positional deviation, that is, scanning distortion occurs. In the design, the subject 50
When the distance between and the infrared camera is a certain distance,
The design is designed to eliminate this scanning distortion, but there is a problem that the scanning distortion becomes large if the distance deviates significantly from that. Besides, one folded mirror-5
It is time-consuming and very difficult to correct the deviation of the optical axis of the infrared ray 53 in the vertical direction and the horizontal direction in 6, and
This adjustment requires skill and takes a lot of time.

[0008]

The present invention relates to a window that transmits only infrared rays emitted from the surface of a subject,
The reflecting surface is provided so as to be tilted in the vertical direction, receives the infrared rays transmitted through the window, and supports the first folding mirror that reflects in the vertical direction and the first folding mirror, and the vertical surface of the reflecting surface. The first support pillar that sets the tilt angle of the direction, the vertical adjustment mechanism that is provided on the back surface of the first turn mirror and that finely adjusts the tilt angle of the vertical direction, and the infrared ray from the first turn mirror. A vibration mirror that receives light and scans it at a predetermined angle in the vertical direction, a rotating mirror that receives infrared rays scanned in the vertical direction by this vibration mirror, and scans this in the horizontal direction, and the reflection surface is tilted in the horizontal direction. And a second folding mirror for receiving the horizontally and vertically scanned infrared rays from the rotating mirror and reflecting in the horizontal direction, and supporting the second folding mirror and reflecting the horizontal direction of the reflecting surface. The tilt angle of Scanning from an optical scanning mechanism consisting of a second supporting column which is fixed, and a horizontal adjusting mechanism which is provided on the back surface of the second folding mirror and which finely adjusts the tilt angle of the folding mirror in the horizontal direction. By providing an infrared detector that receives infrared light and outputs it as a thermal image signal, a thermal image with high sensitivity can be obtained in real time without spatial displacement and scanning distortion.

[0009]

The infrared light emitted from the subject and passing through the window is received by the first folding mirror and reflected in the vibration mirror direction. The deviation of the optical path of the infrared light flux in the vertical direction at this time is finely adjusted in the vertical direction of the reflecting surface by the vertical adjustment mechanism. The infrared light received by the vibration mirror is scanned by a predetermined angle in the vertical direction and reflected in the rotating mirror direction.
The infrared rays incident on the rotating mirror are scanned horizontally by each plane mirror. The infrared rays scanned in the horizontal and vertical directions are received by the second folding mirror. Here, the horizontal adjustment mechanism finely adjusts the infrared light flux on the reflecting surface in the horizontal direction with respect to the optical path, enters the infrared detector, photoelectrically converts the infrared detector, and outputs a thermal image signal.

[0010]

Embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2 are a plan view and a vertical sectional view of an optical scanning mechanism of an infrared camera, respectively.
Is a perspective view of an essential part showing an optical system scanning mechanism of an electronic cooling type infrared camera, FIG. 4 is a sectional view of an essential part of a horizontal and vertical adjusting mechanism, and FIG. 6 is an explanatory view of a sprite element inside the infrared detector 10. Is. 1 to 3, 1 is a subject, 2
Is a visible light, 3 is an infrared ray (infrared image) emitted from the subject 1, 4 is a window which blocks the visible light 2 and transmits only the infrared ray 3 and is made of silicon, and the housing 11
The window fixing member 1 is provided in the opening 12 that is open to the front of the vehicle.
It is fixed by 3.

Reference numeral 5 is a first folding mirror which receives the infrared rays 3 of the subject 1 which have passed through a window (hereinafter referred to as a silicon window) 4 and reflects them to a vibration mirror 6 located vertically below. Then, the mirror that covers the rotating mirror-7
It is fixed to the upper surface of the cover portion 14 by a screw 16 via a support column 15, and is arranged so as to be located substantially on the same plane as the silicon window 4. The tilt angle of the first folding mirror 5 in the vertical direction is set by the support column 15, and the reflecting surface 5a is accurately oscillated by the vibration mirror 6.
A vertical adjusting mechanism 17 for finely adjusting the tilt angle of the reflecting surface 5a is provided on the back surface of the first folding mirror 5 so as to face the direction.

The vertical adjustment mechanism 17 includes a fixing screw 18 and three adjusting screws 19, 20, 2 which are provided at respective apexes of a substantially equilateral triangle with the fixing screw 18 as a center.
And 0 '. The fixing screw 18 is for fixing the folding mirror 5 to the support column 15, and the adjusting screws 19, 20, 20 'are mainly for finely adjusting the tilt angle of the folding mirror 5 in the vertical direction. As shown in FIG. 4, the support column 15 is formed with a hole 15a through which the fixing screw 18 penetrates, and screw holes 15b, 15c and 15d through which the adjusting screws 19, 20, 20 'penetrate. An aluminum plate 17a is arranged between the support column 15 and the first folding mirror 5, and the aluminum plate 17a is provided.
a is a hole 15a in the support column 15 and screw holes 15b, 15
Screw holes 17b for fixing screws 18 facing c and 15d
And the adjusting screws 19, 20, 2
There are recessed grooves 17c, 17d, 17e into which the tip of 0'is inserted, and by adjusting the adjusting screws 19, 20, 20 ', the tilt angle of the folding mirror 5 mainly in the vertical direction is finely adjusted. It is configured to be able to.

Reference numeral 6 is a vibration mirror for vertically scanning the reflected light (infrared ray) 3 from the folding mirror 5, which is a rotating mirror.
7 is on the same plane, and when viewed from the vertical direction, it is located on the same vertical plane as the silicon window 4, and the galvanometer 21
Is configured to vibrate in the vertical direction by a predetermined angle (which is the vertical viewing angle), and in this embodiment, it is set to vibrate in the effective range of 10 ° in the vertical direction. The rotary mirror 7 is formed in an annular shape by eight plane mirrors 7a to 7h, and each plane mirror 7a ... Has a plane angle parallel to the center of rotation O and is attached to the rotary shaft of the motor 22. Has been. The rotating mirror 7 is surrounded by plane mirrors 7a and 7b.
... A mirror provided on the upper surface of the motor case 23 to prevent dust from adhering to the motor and to prevent noise generated by rotation of the rotary mirror 7.
It is covered with the cover portion 14. The rotating mirror 7 is rotated at a high speed by the motor 22 at a constant speed, and in this embodiment, the rotating speed is set to 14,400 rpm.

Reference numeral 8 is a second folding mirror, which is a rotating mirror.
Infrared detector 1 which receives the infrared rays 3 scanned in the horizontal direction by the plane mirrors 7a ...
It is reflected in the 0 direction, is located on the substantially same vertical plane as the silicon window 4, is also located on the substantially same plane as the rotary mirror 7, and is fixed to the housing 11 via the support column 24 by the screw 25. .. First folding mirror
The tilt angle of the folding mirror 8 in the horizontal direction is set by the support column 24 as in the case of No. 5, and the horizontal fine adjustment mechanism 26 for finely adjusting the tilt angle is provided with the second folding mirror.
It is placed on the back of 8. The horizontal adjusting mechanism 26 includes a fixing screw 27 and an adjusting screw 2 provided at each vertex of a substantially equilateral triangle with the fixing screw 27 as a center.
8, 29, 29 ', and has the same configuration and operation as the vertical adjustment mechanism 17, detailed description thereof will be omitted. Reference numeral 9 denotes a condenser lens, which reflects the reflected light (infrared ray) 3 from the second folding mirror 8 into the infrared detector 1
It is a lens for forming an image at 0, and is fixed to the housing 11 with a screw 30 via a support column 31.

The infrared detector 10 is an electronic cooling type single element sprite element (Singnal Procesing In The Elemen).
t) is used, and as shown in FIG.
By connecting an amplifier 37 to 6, photoelectric conversion is performed. The infrared detector (sprite element) 10 is an electronic cooling type and is cooled to about -70 ° C. The infrared detector 10 is separated from the silicon window 4 in the vertical direction by vibrating the mirror 6, the rotating mirror 7, and the second folding mirror.
It is arranged on substantially the same plane as 8, and as close as possible to the vertical plane where the silicon window 4 is located. Reference numeral 34 denotes a processor, which is arranged outside the infrared camera and performs various kinds of signal processing. 35 is the subject 1
Is a bias electrode of the sprite element 32.

Next, the operation will be described. First,
In the optical system scanning mechanism, infrared rays 3 from the subject 1
However, in order to completely separate the portion spatially transmitting the line scanning horizontally from the infrared detector 10 and the portion spatially transmitting the line scanning vertically,
A rotating mirror-7 and a vibrating mirror-6 are used, and in order to make the vertical optical axis fine adjustment and the horizontal optical axis fine adjustment independent, a vertical folding mirror-5 and a horizontal folding mirror-8 are used. Is used. The folding mirror 5 must be positioned so as to receive the infrared rays 3 incident from the silicon window 4 and accurately totally reflect the infrared rays 3 to the vibration mirror 6. Also, the folding mirror-8 is a rotating mirror-7.
It must be positioned so as to receive the scanned infrared image 3 from and accurately reflect it to the condenser lens 9. However, both of them are machined, and the parts such as the support columns 15 and 24 that support them are also machined, so that a slight deviation occurs in the vertical and horizontal directions in terms of design.

It is very important to correct this shift in the optical system. Therefore, the deviation in the vertical direction is corrected mainly by the vertical adjustment mechanism 17 provided on the back surface of the first folding mirror-5. That is, since the mirror portion of the folding mirror 5 has a free circumferential end with the fixing screw 18 as the center, adjustment is required when the reflecting surface 5a of the folding mirror 5 is changed upward. Adjusting screw 20 'as well as screwing in screws 19 and 20
If it is pulled out in the opposite direction, the reflecting surface 5a tilts vertically upward with the fixing screw 18 as the center. On the other hand, when tilting downward, fine adjustment in the vertical direction is performed in the reverse order of the above procedure. With respect to the horizontal displacement, the horizontal adjustment mechanism 26 provided on the back surface of the second folding mirror 8 is provided.
It is corrected by. That is, like the vertical adjustment mechanism 17,
Since the mirror portion of the folding mirror 8 has a free end at the circumference centering on the fixing screw 27, the inclination angle of the reflecting surface 8a in the horizontal direction is finely adjusted in the same manner as described above.

Next, the infrared detector 10 is separated from the silicon window 4 in the vertical direction and is arranged as close as possible to the vertical plane where the silicon window 4 is located. This is the infrared detector 5 in the past.
Since 9 is located on substantially the same plane as the silicon window 51, the optical path length of the scanning system becomes long, and the infrared detector 59 is located behind the silicon window 51. Depending on the orientation, infrared rays directly enter the infrared detector 59 from the silicon window 51 without passing through the optical system scanning mechanism, and an accurate thermal image cannot be obtained. In addition, since the optical system becomes long, if the portion of this optical system is housed in the housing 11, the horizontal length of the infrared camera 54 itself becomes long, and it is impossible to reduce the size. As described above, in this embodiment, the infrared detector 10 is separated from the silicon window 4 in the vertical direction and is arranged as close to the vertical surface direction where the silicon window 4 is located as possible, so that the optical scanning is performed. Infrared rays passing through the system (rotating mirror
An infrared ray other than 3 does not directly enter, so that an accurate thermal image can be obtained.

Next, the optical system scanning mechanism will be described with reference to FIG. With respect to the light from the surface of the subject 1, the visible light 2 is blocked by the silicon window 4 provided in the opening 12 of the housing 11, and only the infrared ray 3 enters the infrared camera. The infrared ray (infrared image) 3 incident inside is reflected by the first folding mirror 5 located on the same plane as the silicon window 4 in the direction of the vibration mirror 6 located substantially on the same plane as the rotating mirror 7. To be done.
This reflected light (infrared ray 3) is oscillated about 10 degrees in the vertical direction by the oscillating mirror 6, and the plane mirrors 7a ...
・ Injects into. Therefore, each of the plane mirrors 7a ... Scans the surface of the subject 1 in the horizontal direction by slightly shifting the surface of the subject 1 in the vertical direction by vibrating the vibration mirror 6 in the vertical direction. Normally, the number of horizontal scanning lines of this kind of device is 10
It is about 0. In this embodiment, an octahedral rotating mirror is used.
Since 7 is used, the rotation mirror 7 must rotate at least 12.5 rotations while the vibration mirror 6 shakes 10 °. Actually, considering the time required for the return path of the vibration mirror 6, 16 It's spinning. That is, a range of 10 [deg.] In the vertical direction is scanned by 16 rotations of the rotary mirror 7, reflected in the direction of the second folding mirror 8 and reflected in the direction of the condenser lens 9 there. The light flux is narrowed and incident on the infrared detector 10, and is optically scanned on the surface of the infrared detector 10 in the direction indicated by the arrow B, whereby the infrared detector 10
The excess carrier signal generated at 1 is also transmitted in the scanning direction indicated by the arrow B, the electric signal of the thermal image is amplified by the amplifier 33, various signal processing is performed by the processor 34, and displayed on the display device 35.

On the other hand, the infrared ray 3 corresponding to 0.1 ° is incident on the infrared detector 10 by the flat mirror 7a having one surface.
Then, when the next plane mirror 7b scans, the vibration mirror
Since the plane 6 is displaced by 0.1 ° in the vertical direction, the plane mirror 7
The position that is deviated by 0.1 ° in the vertical direction is similarly scanned with respect to the portion horizontally scanned by a. Therefore, one rotation of the rotating mirror 7 scans the subject 1 in the vertical direction of 10 °, and in the horizontal direction, the plane mirrors 7a of the rotating mirror 7 ... Are scanned. Therefore, in order to obtain a thermal image of 100 horizontal scans in real time, the rotation speed of the rotating mirror 7 is set to 14400 rpm.
The infrared detector 10 can obtain a real-time thermal image signal of 15 screens per second.

[0021]

According to the present invention, a window for transmitting only infrared rays radiated from the surface of a subject and a reflecting surface are provided so as to be inclined in the vertical direction, and the infrared rays transmitted through the window are received and reflected in the vertical direction. The first folding mirror, the first supporting pillar that supports the first folding mirror, sets the vertical inclination angle of the reflecting surface, and is provided on the back surface of the first folding mirror. A vertical adjustment mechanism that finely adjusts the tilt angle in the vertical direction, and a vibration mirror that receives infrared rays from the first folding mirror and scans at a predetermined angle in the vertical direction.
And a rotating mirror that receives infrared rays scanned in the vertical direction by the vibration mirror and scans the infrared rays in the horizontal direction, and a reflecting surface is provided so as to be inclined in the horizontal direction, and the horizontal and vertical scanning from the rotating mirror is performed. A second turn mirror that receives the reflected infrared rays and reflects in the horizontal direction; and a second support column that supports the second turn mirror and sets the horizontal tilt angle of the reflecting surface, A horizontal adjusting mechanism, which is provided on the back surface of the second folding mirror and finely adjusts the horizontal tilt angle of the folding mirror, and the infrared rays scanned from the optical scanning mechanism are received to generate a thermal image signal. Since the infrared detector for outputting is provided, a portion for spatially transmitting the line scanned in the horizontal direction and a portion for spatially transmitting the line scanned in the vertical direction as viewed from the infrared detector are provided. Completely independent In both cases, there is nothing on the infrared light path from the window to the first folding mirror, and there is nothing on the infrared light path from the rotating mirror to the second folding mirror. Therefore, the fine adjustment of the optical axis of the light flux in the vertical direction and the horizontal direction can be performed by adjusting the tilt angles of the reflecting surfaces independently by the vertical and horizontal adjusting mechanisms provided on the back surfaces of the first and second folding mirrors, respectively. Since the adjustment can be performed, the adjustment is easier than the conventional one, the adjustment is easy, and the adjustment can be performed in a short time.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing an embodiment of the present invention.

FIG. 3 is a perspective view of an essential part showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view of essential parts of the horizontal and vertical adjustment mechanisms in the embodiment of the present invention.

FIG. 5 is a perspective view of a main part showing a conventional example.

FIG. 6 is a diagram illustrating a sprite element according to an embodiment of the present invention.

[Explanation of symbols]

 1 Subject 3 Infrared 4 Window 5 First Folding Mirror 6 Vibration Mirror 7 Rotating Mirror 8 Second Folding Mirror 10 Infrared Detector (Sprite Element) 15 First Support Pillar 17 Vertical Adjustment Mechanism 24 Second Support pillar 26 Leveling mechanism

Claims (1)

[Claims] 1. A first window that is provided with a window that transmits only infrared rays radiated from the surface of a subject and a reflecting surface that is inclined in the vertical direction, receives the infrared rays that have passed through the window, and reflects the infrared rays in the vertical direction. A folding mirror and a first supporting column that supports the first folding mirror and sets the vertical tilt angle of the reflecting surface, and is provided on the back surface of the first folding mirror in the vertical direction. A vertical adjustment mechanism for finely adjusting the tilt angle of the, a vibration mirror for receiving the infrared rays from the first folding mirror and scanning it at a predetermined angle in the vertical direction, and a vertical direction for scanning by the vibration mirror. A rotary mirror that receives the infrared rays and scans the infrared rays in the horizontal direction and a reflecting surface are provided so as to be inclined in the horizontal direction, and receives the infrared rays that are horizontally and vertically scanned from the rotary mirror and receives the infrared rays in the horizontal direction. Reflection And a second support pillar that supports the second folding mirror and sets the horizontal inclination angle of the reflecting surface, and is provided on the back surface of the second folding mirror. This folding mirror
Infrared, which comprises: a horizontal adjusting mechanism for finely adjusting the horizontal tilt angle of the infrared ray; and an infrared detector that receives the scanned infrared ray from the optical scanning mechanism and outputs it as a thermal image signal. camera.