JPS593225A - Multispectral scanner - Google Patents

Abstract

PURPOSE:To achieve a higher reliability of an equipment while making it compact and light with a simple construction by arranging a rotary type chopper mirror, having reflectors in the perimeter at varied angles in the same number as that of calibration light sources, at the position of focusing observation light in the main optical system to introduce all calibration lights. CONSTITUTION:An observation light L scanned with a scan mirror SM driven by a motor MT is focused with reflectors M1-M4 and a focusing mirror CM1 and CM2, reflected with a reflector M5 and divided into a visible light VK and an infrared light IR with a spectroscope BS. The visible light VR and the infrared light IR are divided into 5 and 3 wavelength zones with respective groups of a spectroscope and reflectors BSM1 and BSM2 and enter photo detectors D1-D5 and D6-D8 respectively. On the other hand, calibration lights from calibration light sources S11-S15 are introduced sequentially into the main optical system A through mirrors M11-M15 of a chopper mirror CHO driven by a motor MTO. This achieves a higher reliability of the equipment while making it compact and light with a simple construction.

Description

Detailed Description of the Invention (1) Technical Field of the Invention The invention relates to a multispectral scanner (hereinafter abbreviated as IMSMS scanner), and particularly relates to an optical system of an aircraft MS scanner that is mounted on an aircraft and used for observing volcanoes, etc. It is something.

(2) Technology's backbone In recent years, a system has been proposed in which an MS scanner is mounted on an aircraft to observe, for example, a volcano and create an infrared image (temperature, arm turn) of the image, which can then be used to predict volcanic activity.

Generally, aircraft-mounted equipment is required to be lightweight, small, and highly reliable. However, conventional MS
Scanners have problems as described below, and countermeasures are desired.

(3) Prior art and problems FIG. 1 shows the optical system of a first example of a conventional MS scanner for volcano observation. In the figure, the arrows indicate light (infrared, visible light) from the scene (volcano) to be observed.

Symbol SM indicates a scanning mirror of the main optical system, which rotates at a high speed (for example, 240 rpm) in the direction of arrow X (counterclockwise in the figure) and scans the scene from left to right in the figure. It is assumed that the aircraft equipped with the MS scanner is flying in a direction perpendicular to the plane of the drawing, thereby scanning a two-dimensional area. Light L from the scene (hereinafter referred to as "observation light") is reflected by the scanning mirror SM, and then reflected by the reflecting mirrors M1 and M2 and M3 and M.
The light beam is sequentially reflected by the light beam 4, and is further focused at a predetermined position by condenser mirrors CMI and CM2 (Cassegrain). In addition, a spectroscope (glychroic beam sysmeter) is installed between this observation light condensing position and condensing mirror CM2.
A BS is arranged, and the observation light is split into visible light VR and infrared IR by this spectrometer BS, and each is detected by a corresponding photodetector (not shown). Infrared images can then be obtained by processing the output electrical signals of the photodetector. In FIG. 1, reference numeral M5 is a reflecting mirror for simply changing the direction of visible light VR. On the other hand, in order to know the actual temperature of a volcano, we need a calibration light that shows the temperature standard. In the case of the illustrated example, a visible calibration light source S1, an infrared calibration light source (Black Dedy) B2, and reflecting mirrors M6 and M7 are arranged at the left and right positions of the scanning mirror SM, and the scanning mirror SM emits calibration light Ll from these two light sources. ,L2
is introduced into the main optical system. However, in this conventional configuration, the viewing angle θ of the scanning mirror is limited by the calibration light reflecting mirrors M6 and M7 and cannot be increased.

In order to solve the drawbacks of the conventional example, an optical system configuration as shown in FIGS. 2 and 3 has been proposed.

In FIG. 2, reference numeral A indicates the main optical system, which scans the scene with a scanning mirror SM driven by a motor MT and transmits observation light L' (j reflecting mirrors M1 to M4 and The light is focused at a predetermined position by condensing mirrors CMI and CM2.

Note that the arrangement of the condensing mirrors CMI and CM2 is different between FIG. 2 and FIG. 3; in FIG. condenser mirror CMI
The configuration is such that light is reflected to the side by a reflecting mirror M5 disposed between and CM2. The observation light thus collected is divided into visible light VR and infrared IR by a spectroscope BS. And visible light VR has the code BSMI
A group of spectrometers (4 pieces) and reflectors (3 pieces) are summarized in
The light is divided into five different wavelength bands using a photodetector (e.g. 5iPIN diode) in the corresponding visible light (A) range.
Detected by D5. On the other hand, infrared IR has the symbol BSM
Using another group of spectrometers (2 pieces) and a reflector (1 piece), which are generally shown in 2, the infrared light is divided into three different wavelength bands, and the corresponding infrared light detectors (for example, H
gCdTe detector) Detected by D6 to D8. Next, in FIG. 2, reference numeral B1 indicates an optical system for introducing visible calibration light, and there are two visible calibration light sources, that is, a skylight condensing system 8.
11 and calibration lights Lll and L12 from the standard light source 812
is introduced into the main optical system using a scanning mirror SMI and a chopper mirror CHI. On the other hand, symbol B2 indicates an optical system for introducing infrared calibration light, and calibration light L13 from three infrared calibration light light sources (black is D) 813 to 815 is shown.
~ L15 as scanning mirror SM2 and chopper mirror CH2'e
It is configured so that it can be used and introduced into the main optical system. According to such a configuration, since the optical system for introducing the calibration light is arranged on the spectroscopic side of the main optical system rather than on the scanning side, there is an advantage that a wide viewing angle can be obtained. However, the calibration light introduction optical system (4) B1 and B2 as a whole consists of two mirrors CHI, CH2 and two scanning mirrors SMI.

8M2 and 4 motors M to drive them
It requires TI to MT4, has a very complicated structure, and is large and heavy (in Figure 3, the motors MTI to MT4 are shown small for convenience of illustration, but they are actually quite large). . Moreover, these motors MTI to MT4
needs to be synchronized with the motor MT for the main scanning mirror ST, and the electrical control circuit becomes very complex.

(4) Purpose of the Invention Therefore, in view of the above-mentioned prior art, the present invention improves the optical system for introducing calibration light, thereby achieving a simple structure, small size and light weight, and a simple control circuit. The purpose of this invention is to provide a multispectral scanner that is excellent for use.

(5) Structure of the Invention The present invention generally provides a multispectral scanner comprising a main optical system as described above and an optical system for introducing calibration light, in which the same number of light sources as the calibration light sources are arranged at different angles. One rotating mirror with a reflecting mirror around it is arranged at the observation light focusing position of the main optical system, and all the calibration light is introduced by the main mirror. .

(6) Embodiment of the Invention Hereinafter, an embodiment of the invention will be described with reference to FIGS. 4 to 7 of the drawings. In this embodiment, the main optical system A has a substantially similar structure to that shown in FIG. 3 in particular. That is,
The observation light scanned by the scanning mirror SM driven by the motor MT is transmitted through the reflecting mirrors M1 to M4 and the condensing mirrors CMI and CM2.
The light is focused by the mirror M5 and reflected laterally by the reflecting mirror M5. The focused observation light is then split into visible light VR and infrared IR by a spectroscope BS. Visible light VR is divided into five wavelength bands by a group of spectrometers and a reflecting mirror BSMI, as in the past, and detected by photodetectors D1 to D5. Well, the infrared IR is also 1 as before.
It is divided into three wavelength bands by the group spectrometer and reflector BSM 2 and detected by infrared detectors D6 to D8.

The feature of the present invention lies in the optical system B for introducing calibration light.

In this optical system BFi, as particularly shown in FIG. The light sources 811 to 815 are arranged radially. As shown in FIG. 7, the chopper mirror CHO has the same number of calibration light sources 811 to 815, that is, 5, around it.
Mirrors Mll to M15 are provided. These mirrors are formed at different angles, and as shown in Figure 6, when one of the mirrors (Mll in Figure 6) coincides with the optical axis LA of the observation light, the observation is performed by this mirror. The light is chopped (chopped), and the calibration light from any light source corresponding to this mirror (light source 8 in FIG. 6) is
The calibration light L11) from 11 is aligned with the optical axis L by the mirror.
The structure is such that the light overflows A and is reflected to the right in the figure. Therefore, when the chopper mirror CHO is rotated in the direction of arrow Y by the motor MTO, the observation light is chopped every time the mirrors Mll to M15 coincide with the optical axis LA.
Instead, the calibration light Lll from the calibration light sources 811 to 815
.about.I, 15 are sequentially introduced into the main optical system.

Incidentally, the chopper mirror CHOO hole H shown in FIG. 7 is for compensating for the uneven load caused by the mirrors Mll to M15 to obtain dynamic stability.

According to the configuration of the present invention as described above, all the calibration light can be introduced with one chopper mirror CHO and one motor MTO, and the structure is therefore much simpler than the conventional example shown in FIGS. 2 and 3. It is easy to use, and can be dramatically reduced in size to 1 ml. Moreover, since there is only one motor, the control circuit needed to synchronize with the scanning motor MT is simple, and reliability can be improved accordingly.

Although not shown, the chopper mirror CHO is connected to the scanning mirror S.
If it is directly connected to the drive shaft of M and driven by the scanning motor MT, the mirror drive motor MT (1) becomes unnecessary, and the structure can be further simplified and made smaller and lighter. , and no synchronization circuit is required at all.As a specific configuration example of direct drive of the chopper mirror by the main scanning motor MTO, in FIG. The optical axis LA of the observation light beam may be bent downward by interposing some reflecting mirrors between the CHO and the mirror CHO, and the mirror CHO may be placed downward. Needless to say, the arrangement of the optical system after the device BS is also moved.

(7) Effects of the Invention As described above, according to the present invention, by improving the optical system for introducing the calibration light, the structure is simple, small and lightweight, and moreover, it is easy to control, highly reliable, and can be mounted on an aircraft. It is possible to realize a multispectral scanner that is very suitable for use.

[Brief explanation of the drawing]

Figure 1 is a diagram of the optical system configuration of the first row of a conventional MS scanner.
Figure 2 is an optical system configuration diagram of a second example of a conventional MS scanner.
FIG. 3 is a schematic perspective view of the optical system of the conventional example shown in FIG. 2, FIG. 4 is a configuration diagram of the optical system of an embodiment of the MS scanner according to the present invention, and FIG. FIG. 6 is a diagram illustrating the operation of the optical system for introducing calibration light in the same embodiment, and FIG. 7 is a front view of the mirror for introducing calibration light. A... Main optical system, L... Observation light, SM... Scanning mirror, MT... Scanning motor, M1 to M5... Reflecting mirror,
CMI, CM2...Condensing mirror, BS...Spectrometer, vR
...Visible light, Engineering R...Infrared light, BSM 1, 88
M2... Spectrometer and reflecting mirror group, D1-D8... Photodetector, B... Optical system for introducing calibration light, CHO... Choya mirror, M11-M15... Reflecting mirror, MTO・
...Motor, S11-815...Calibration light source, Lll
~L15... Calibration light. Patent Applicant: Fujitsu Limited, Patent Application Agent, Patent Attorney: Akira Ki, Patent Attorney, Kazuyuki Nishidate, Patent Attorney: 1) Yukio, Patent Attorney, Akiyuki Yamaguchi (11) Procedural Amendment (Volunteer) July 1981 JC Patent Director General Wakasugi Kazuo 1, Indication of the case 1982 Patent Application No. 111517 2, Name of the invention Multi-spectral scanner 3, Relationship with the person making the amendment Name of the patent applicant (522) Fujitsu Co., Ltd. Dansha 4. Agent (3 other people) 5. Figure 1fi to be amended (Figures 1 to 7) 6. I am crying out for the official diagram of the contents of the amendment. ('#, da [7 contents have changed '8' zen) Z Attached witty catalog

Claims (1)

[Claims] 1. A main optical system that scans the scene to be observed with a scanning mirror and focuses the observation light on a predetermined position, and then divides the light into a plurality of different wavelength bands and makes them enter a photodetector; In a multispectral scanner comprising a calibration light introducing optical system that introduces a plurality of calibration lights into the optical system, one rotating type scanner having around the same number of reflecting mirrors with different angles as the number of calibration light sources, - A multispectral device characterized in that a mother mirror is arranged at the observation light condensing position of the main optical system, and is configured such that all the calibration light is introduced into the main optical system by the horns and mirrors. scanner.