JPS62144034A - Infrared camera - Google Patents

Abstract

PURPOSE:To enable high speed scanning and to simplify a structure, by constituting a scanning polygon of an infrared transmitting window and a reflective mirror and at least performing chopping for changing over the horizontal scanning of an object and infrared rays from a reference heat source by the same polygon. CONSTITUTION:A scanning polygon is constituted by alternately arranging an infrared transmitting window 3 and a reflective mirror 4 and the infrared transmitting window 3 is constituted so that the cross-section thereof comes to a prism and the scanning length thereof in a horizontal direction becomes long. Infrared rays incident from an incident window 10 and scanned in a vertical direction by a scanning mirror 1 are condensed by a condensing lens 2 and, when incident to the infrared transmitting window 3, introduced in the horizontal direction by the transmitting window 3 to be incident to a detector 6. Infrared rays from a reference heat source 9 transmit through the transmitting window 3 to scatter when external light is transmitted through the reflective mirror 4 to be incident to the detector 6 and reflected by the reflective mirror 4 at a position where external light is blocked by the reflective mirror 4 to be incident to the detector 6. As mentioned above, scanning and chopping can be performed only by the rotation of the polygon.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (INDUSTRIAL APPLICATIONS) The present invention relates to an infrared camera, and more particularly to an infrared camera having an object plane scanning device ef.

(Prior Art) An infrared camera with a single-objective scanning direction is used for purposes such as diagnosing the walls of collapsed buildings, and its configuration is shown in FIG. That is, infrared rays entering the camera through the entrance window 10 are deflected by the scanning mirror 1, and focused onto the detector 6 by the condensing lens 2 and the 1-lens 5. On the other hand, a reference heat source 9 is disposed inside the camera, and infrared rays from the nuclear heat source are condensed by a lens 8 to a condensing position of the condensing lens 2. A chopper reflector 11 is inserted into and removed from this light collection position, and the infrared light incident on the detector is switched between that from the object and that from the reference heat source. 7 is a preamplifier.

The scanning mirror 1 is supported by a gimbal mechanism, and rotates around Ii1+l' to perform horizontal scanning, and rotates around Ii1' to perform vertical sub-scanning.

Such a rocky structure is complex, and it is difficult to increase the scanning distance.

Fig. 5 shows a conventional example of Ike, which uses an infrared lens 2 made of a material such as Ge%Si to collect infrared light incident from the entrance window.
The light is focused on a scanning polygon made of a similar material. Two polygons are used, one for vertical scanning 12 and one for horizontal scanning 13 having a rotation axis perpendicular to this polygon, and the scanning light is focused on a detector 6 via a relay lens system 5. As in the previous example, the VC in the relay lens 5 includes a chopper 11 which sends a reference heat source to the detector 6 for temperature comparison. Although this camera is suitable for high-speed scanning, it uses two polygons and has a complicated structure, making it difficult to obtain a high-resolution, compact optical scanning system.

(Problems to be Solved by the Invention) This invention performs at least horizontal scanning using polygons, and performs high-speed scanning f0Tf.
A, and by forming the chopper into one body, the aim is to obtain an all-in-one infrared camera with a simple structure.

(Structure of the Invention) In this invention, the two-dimensional distribution of temperature is detected by focusing the infrared rays from the dangerous object, scanning them in the horizontal and vertical directions, and detecting them alternately with the infrared rays from the reference source using a detector. In the infrared camera for detection, the scanning polygon is composed of an infrared transmitting window and a reflecting mirror, and at least horizontal scanning of the object and switching of infrared rays from a reference heat source are performed using the same polygon.

Preferably, the infrared transmitting window has a prismatic cross section perpendicular to its rotation axis, and is further configured to have slightly different inclination angles with respect to the rotation axis pressure. It is possible to perform horizontal and vertical scanning.

In addition, there is a reference heat source in the space surrounded by each face of the polygon.
An infrared detector may also be provided.

(Function) A polygon with a window made of an infrared transmitting material such as Ge is inserted into the infrared beam that enters the camera from the infrared incident window and is focused on the detector by the condensing lens and relay lens. Scanning can be performed by arranging and rotating the device, as in the conventional example shown in FIG. If this window is a prism, the length of the scanning line can be adjusted by utilizing the phenomenon that the deflection angle changes depending on the angle of incidence on the prism.

Furthermore, if the infrared rays from the reference heat source are arranged so as to enter from the opposite side of the transmission window, the infrared rays from the reference heat source that have passed through the transmission window will be dissipated outside the polygon and will be incident on the 13'] vessel. There isn't. If the polygon faces are made up of reflective mirrors,
Since external infrared light is blocked here and infrared light from the reference heat source is reflected and incident on the detector, it can be used both as an external light scanning device and a chopper simply by rotating the polygon.

Furthermore, if the prism is tilted at a slightly different angle with respect to the total rotation axis, the incident light will be shifted in the vertical direction according to the tilt, so vertical scanning can also be performed by rotating the polygon. .

(Example) Examples of the present invention will be described below with reference to plane 1g.

Components in the figures that are the same as those in FIGS. 5 and 6 are designated by the same reference numerals.

In the embodiment shown in FIG. 1, the scanning mirror l does not perform horizontal scanning, but only vertical scanning along its axis.

The scanning polyhedron is formed by alternately arranging infrared transmitting windows 3 and reflecting mirrors 4. Therefore, the incidence is from the input nitrogen 10,
The infrared rays scanned in the vertical direction by the scanning mirror are condensed by the condensing lens 2, and when they enter the infrared transmission window 3, they are deflected horizontally by the transmission window 3 and are incident on the detector 6. As shown in the figure, the infrared transmitting window 3 has a prism cross section to increase the scanning length in the horizontal direction.

As in the conventional example, the infrared rays from the reference heat source 9 are focused by the lens 8 onto the external light condensing section, but if the external light is completely transmitted through the transmission window 3 and enters the detector 6, On the contrary, the infrared rays from the reference heat source 9 pass through the transmission window 3 and are dissipated.

When the polygon rotates and comes to a position where external light is blocked by the reflector 4, the infrared rays from the reference light source 9 will be blocked by the reflector 4.
The light is then reflected and enters the detector 6.

FIG. 2 shows another embodiment in which not only horizontal scanning but also vertical scanning is performed using polygons. The polygonal mirror is composed of an infrared transmitting prism 3, of which only one surface is a reflecting mirror 4. And transparent prism 3
Infrared light from the outside enters the detector 6 while passing through the original axis of the optical system consisting of the condenser lens 2, relay lens 5, and detector 6, while reflected light 4 passes through the original axis. is arranged so that infrared rays from the reference heat source 9 are incident on the detector 6.

In this embodiment, the transmission prism 3 is tilted by an angle α with respect to its axis of rotation, as shown in FIG. 2(b), thereby deflecting incoming infrared rays from the outside in the vertical direction.

This deflection angle α varies for each transmission prism and corresponds to a specific horizontal scan line for each transmission prism. Vertical solution [If the number of elephants is the same as the conventional one, and the detector structure is the same as the conventional one, 3f of transmission prisms will be required, which is the same number as the number of scanning lines, but if the detector is If you make it a play and can detect multiple scanning lines at the same time, how many transparent prisms will make up a polygon? You can get M.

In the illustrated polygon, infrared rays from the reference heat source enter the detector 6 every time one screen is scanned.

FIG. 3 shows an example of the structure of Fumiyoshi's polygons.

Each surface of the polygon is composed of an infrared transmitting prism 3, and t
A portion 4 of the prism 3 is used as a reflecting surface 4.

Structure of the Invention According to the present invention, by configuring a polygon polarizer with an infrared transmitting window and a reflecting mirror, scanning and chopping can be performed only by rotating the polygon.

Furthermore, by arranging a base IIA heat source, a detector, etc. within this polygon, the entire camera can be made compact.

(In addition, by using a prism as the transmission window, the horizontal scanning length is increased, and by changing the angle little by little with respect to the rotation axis, vertical scanning is also possible, making the configuration extremely simple. I can do it.

[Brief explanation of drawings]

1 and 2 are optical layout diagrams of Embodiment 1 and Embodiment 2 of the infrared camera of the present invention, respectively, FIG. FIG. 5 is an optical layout diagram of a conventional infrared camera.

Claims (1)

[Claims] 1) Detecting the two-dimensional distribution of temperature by focusing the infrared rays from the test object and scanning them in the horizontal and vertical directions, and alternately detecting them with the infrared rays from the reference heat source using a detector. An infrared cotton camera characterized in that a scanning polygon is composed of an infrared transmitting window and a reflecting mirror, and at least horizontal scanning of an object and a chopper for switching infrared rays from a reference heat source are performed using the same polygon. 2) An infrared camera according to claim 1, characterized in that the infrared transmitting window is used as a prism to enlarge the horizontal scanning line length. 3) By tilting the infrared transmitting window with respect to its axis of rotation, An infrared camera according to claim 1 or 2, characterized in that the camera performs scanning of