JP3835016B2

JP3835016B2 - Laser radar equipment

Info

Publication number: JP3835016B2
Application number: JP29478998A
Authority: JP
Inventors: 隆一樋口
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1998-10-16
Filing date: 1998-10-16
Publication date: 2006-10-18
Anticipated expiration: 2018-10-16
Also published as: JP2000121724A

Description

【０００１】
【発明の属する技術分野】
この発明はレーザレーダ装置の送信軸と受信軸との軸ずれ検出に関するものである。
【０００２】
【従来の技術】
レーザレーダ装置は、自らレーザを発射して目標物に当て目標物からの反射光を受けて信号の大きさと発射時からの時間を測ることにより、目標物の特性や目標物までの距離を求める装置である。最近は応用分野が拡がり、人工衛星に搭載して大気の散乱特性の高度分布を測定することも可能になった。レーザレーダ装置においてはレーザ反射光を受けるので、レーザで照射された目標物が必ず受信光学系の視野内になければならない。視野内から完全に外れればそもそも信号を掴むことができないし、部分的に外れても目標物の特性を正確に測定できなくなる。したがって、レーザで照射された目標物を受信光学系の視野中心に保つこと、言い替えれば、送信と受信の軸を一致させることはレーザレーダ装置にとって不可欠の条件である。送信と受信の軸を一致させるには軸ずれ検出および軸ずれ補正が必要である。
【０００３】
図５は従来の軸ずれ検出方式を示す図である。図５において、１はレーザ、２はダブルウェッジのような、レーザビームの方向を調節する調節装置、３はカセグレイン光学系のような受信望遠鏡、４はピンホールのような視野絞り、５はリレー光学系、６は狭帯域フィルタ、７は検出器、８は信号処理回路、１０は半透鏡、１６はレンズ、１７は４象限検出器である。
【０００４】
次に動作について説明する。レーザ１から発生されたレーザビームは調節装置２および半透鏡１０を介して目標に向けて送出される。目標からの反射光はカセグレイン主鏡３ａおよびカセグレイン副鏡３ｂからなる受信望遠鏡３により集光されて視野絞り４を通る。視野絞り４を通過した光はレンズ５ａおよびレンズ５ｂからなるリレー光学系５の内部に置かれた狭帯域フィルタ６を通過して検出器７に集められる。光は検出器７で電気信号に変換され、信号処理回路８により増幅、デジタル化され目標情報が抽出される。このようなレーザレーダ装置において軸ずれ検出を次のように行う。半透鏡１０によりレーザビームの一部は反射して、レンズ１６を経て４象限検出器１７に入る。４象限検出器１７はレンズ１６の焦点に置かれているので、４象限検出器１７面上でレーザビームは小さなスポットになる。スポットが４象限検出器１７の中心にあれば４象限検出器１７の出力は０であり、中心からずれていれば、ずれに比例した出力が得られる。このようにスポットの位置を検出することによりレーザビームの方向を知ることができる。ずれが発生すれば、４象限検出器１７の出力を監視しながら調節装置２により修正する。
【０００５】
【発明が解決しようとする課題】
レーザレーダ装置における従来の軸ずれ検出装置は以上のように送信軸ずれを検出するものである。大きな電力を消費し従って発熱量が大きいレーザ装置に起因する送信軸ずれに比べて、発熱量が遥かに小さい受信側の軸ずれは小さいので、地上における通常環境で使う限り、送信軸ずれにより送受信の相対軸ずれを代用しても支障ない。ところが、内部発熱が無くても熱的なアンバランスが生じる人工衛星搭載機器においては受信軸ずれを無視できなくなるので、送信軸ずれの検出のみを行う従来の方法では送受信の相対軸ずれを正当に評価できないという問題点がある。
【０００６】
この発明は上記のような問題点を解消するためになされたもので、送信軸ずれと同時に受信軸ずれも検出することにより送受信の相対軸ずれ検出可能な装置を得ることを目的とする。
【０００７】
【課題を解決するための手段】
第１の発明に係る装置は、受信視野を決める視野絞りを照明することにより光を受信光学系から逆向きに出し、この光軸と送信レーザビームの光軸の相対軸ずれを検出するようにしたものである。軸ずれ検出は次のように行う。受信光学系から出る光の一部を反射鏡により折曲げ、また、送信レーザビームの一部を半透鏡により折曲げ、両方のビームを重ね合わせてイメージセンサに結像させる。軸が合っていれば１点で結像するが、軸ずれが起これば、スポットは分かれる。２つのスポットの距離は２つの軸の方向ずれに対応するので軸ずれが分かる。また、反射鏡と半透鏡を相対変化が起きないように一体化構造にすることにより周囲の変化により反射鏡／半透鏡の向きが変わっても、相対的な軸ずれは正確に測定可能である。
【０００８】
第２の発明に係る装置は、第１の発明における反射鏡を半透鏡に置き換えて適用した場合である。
【０００９】
第３の発明に係る装置は、受信光学系の中心からレーザ光が出射する形式、即ち、同軸型のレーザレーダ装置に適用した場合である。
【００１０】
第４の発明に係る装置は、出射レーザビームの一部を光ファイバにより受信検出器に照射して、軸ずれだけでなく検出器のずれも検出可能にするものである。
【００１１】
第５の発明に係る装置は、照明を視野絞りの裏から行って視野中心を光らすことにより観測を容易にするものである。
【００１２】
【発明の実施の形態】
実施の形態１．
以下、この発明の実施の形態１を図について説明する。図１において、１はレーザ、２はダブルウェッジのような、レーザビームの方向を調節する調節装置、３はカセグレイン光学系のような受信望遠鏡、４はピンホールのような視野絞り、５はリレー光学系、６は狭帯域フィルタ、７は検出器、８は信号処理回路であり、これらは通常のレーザレーダ装置の構成要素である。９は反射鏡、１０は半透鏡、１１は反射鏡９と半透鏡１０を一体化して支持する支持枠、１２はイメージセンサ、１３は照明光源である。
【００１３】
次に動作について説明する。レーザ１から発生されたレーザビームは調節装置２および半透鏡１０を介して目標に向けて送出される。目標からの反射光はカセグレイン主鏡３ａおよびカセグレイン副鏡３ｂからなる受信望遠鏡３により集光されて視野絞り４を通る。視野絞り４を通過した光はレンズ５ａおよびレンズ５ｂからなるリレー光学系５の内部に置かれた狭帯域フィルタ６を通過して検出器７に集められる。光は検出器７で電気信号に変換され、信号処理回路８により増幅、デジタル化され目標情報が抽出される。このようなレーザレーダ装置において軸ずれ検出を次のように行う。照明光源１３は視野絞り４を前方から照明する。視野絞り４は通常ピンホールであり、基板に小穴が開いている。照明すると、基板から光が拡散反射される。小穴からの光は皆無ではないが基板からの拡散反射光に対して遥かに小さいので、小穴は黒く見える。基板からの拡散反射光はレーザレーダ装置の入射光とは反対方向に、カセグレイン副鏡３ｂおよびカセグレイン主鏡３ａを経て外へ向かって出る。カセグレイン主鏡３ａから外へ向かって出る光束の一部を反射鏡９により遮り、折曲げて取り出す。レーザ１からのレーザビームの一部も半透鏡１０により折曲げて取り出す。折曲げて取り出した２つのビームは半透鏡１０で合体し、イメージセンサ１２に入る。この像の観測により、スポットが重なれば光軸は合っており、スポットが分離すれば光軸がずれていることが分かる。光軸がずれていればビーム方向調節装置２により修正することができる。周囲の変形があっても反射鏡９と半透鏡１０がおのおの独立に動かないように一体化されているので、光線の方向に関しては１枚の平面鏡と同じであり、送受信軸ずれを正確に測定することができる。
【００１４】
図１において、反射鏡９の代わりに半透鏡を使ってもよい。
【００１５】
実施の形態２．
他の実施の形態を図２に示す。図２においてレーザ１から発生されたレーザビームは調節装置２を通り、２個の直角プリズム１８ａおよび１８ｂによりカセグレイン副鏡３ｂの裏側に平行移動された後、半透鏡１４を介して目標に向けて送出される。目標からの反射光はカセグレイン主鏡３ａおよびカセグレイン副鏡３ｂからなる受信望遠鏡３により集光されて視野絞り４を通る。視野絞り４を通過した光はレンズ５ａおよびレンズ５ｂからなるリレー光学系５の内部に置かれた狭帯域フィルタ６を通過して検出器７に集められる。光は検出器７で電気信号に変換され、信号処理回路８により増幅、デジタル化され目標情報が抽出される。このような同軸型のレーザレーダ装置において軸じれ検出を次のように行う。レーザビームの一部を半透鏡１４により反射させて取り出す。受信望遠鏡から出る光の一部も半透鏡１０により折曲げて取り出す。折曲げて取り出した２つのビームは半透鏡１０で合体し、イメージセンサ１２に結像される。
【００１６】
実施の形態３．
他の実施の形態を図３に示す。図３において、１５は一端をレーザビームの端に置き、他端を検出器近傍に置く光ファイバである。光ファイバ１５によりレーザビームの一部を取り出し、検出器７に照射する。検出器面で拡散反射された光はリレー光学系５および視野絞り４を通過して受信望遠鏡３から出る。リレー光学系５内にはレーザ波長のみ通過させる狭帯域フィルタ６があるので、リレー光学系５を通すためにレーザ光そのものの一部を使用する。この構成で、視野絞り４から出る光は実施の形態１と同じように使うことができる。また、検出器７がずれれば一様な検出器面から外れた光が視野絞り４を通って受信望遠鏡３から出るのでスポットの形状を観測することにより検出器７のずれが分かる。
【００１７】
実施の形態４．
他の実施の形態を図４に示す。図４において、照明は視野絞り４の裏から行う。このように照明すれば、基板からの拡散反射光でなく、基板に開けた穴を通過する光のみがイメージセンサに入るので像が観測し易い。
【００１８】
【発明の効果】
このように、この発明によれば、レーザレーダ装置の送信軸と受信軸の相対軸ずれを測定可能になるので、送信軸だけでなく、受信軸の変化も無視できない人工衛星軌道上のレーザレーダ装置の測定精度を高める。
【図面の簡単な説明】
【図１】この発明の実施の形態１によるレーザレーダ装置を示す図である。
【図２】この発明の実施の形態２を示す図である。
【図３】この発明の実施の形態３を示す図である。
【図４】この発明の実施の形態４を示す図である。
【図５】従来のレーザレーダ装置を示す図である。
【符号の説明】
１レーザ、２レーザビーム方向調節装置、３受信望遠鏡、３ａカセグレイン主鏡、３ｂカセグレイン副鏡、４視野絞り、５リレー光学系、５ａ，５ｂレンズ、６狭帯域フィルタ、７検出器、８信号処理回路、９反射鏡、１０半透鏡、１１支持枠、１２イメージセンサ、１３照明光源、１４半透鏡、１５光ファイバ、１６レンズ、１７４象限検出器、１８ａ，１８ｂ直角プリズム。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to detection of an axial deviation between a transmission axis and a reception axis of a laser radar device.
[0002]
[Prior art]
The laser radar device emits the laser itself, hits the target, receives the reflected light from the target, measures the signal magnitude and the time from the launch, and determines the characteristics of the target and the distance to the target Device. Recently, the field of application has expanded, and it is now possible to measure the altitude distribution of atmospheric scattering characteristics onboard satellites. Since the laser radar device receives the reflected laser beam, the target irradiated with the laser must be in the field of view of the receiving optical system. If it is completely out of the field of view, the signal cannot be grasped in the first place, and even if it is partially off, the characteristics of the target cannot be measured accurately. Therefore, it is an indispensable condition for the laser radar apparatus to keep the target irradiated with the laser at the center of the field of view of the receiving optical system, in other words, to match the axes of transmission and reception. Axis deviation detection and axis deviation correction are required to match the transmission and reception axes.
[0003]
FIG. 5 is a diagram showing a conventional axis deviation detection method. In FIG. 5, 1 is a laser, 2 is an adjustment device for adjusting the direction of the laser beam, such as a double wedge, 3 is a receiving telescope such as a Cassegrain optical system, 4 is a field stop such as a pinhole, and 5 is a relay An optical system, 6 is a narrow band filter, 7 is a detector, 8 is a signal processing circuit, 10 is a semi-transparent mirror, 16 is a lens, and 17 is a quadrant detector.
[0004]
Next, the operation will be described. The laser beam generated from the laser 1 is transmitted toward the target through the adjusting device 2 and the semi-transparent mirror 10. The reflected light from the target is collected by the receiving telescope 3 including the cassegrain primary mirror 3 a and the cassegrain secondary mirror 3 b and passes through the field stop 4. The light that has passed through the field stop 4 passes through a narrow-band filter 6 placed inside a relay optical system 5 including a lens 5a and a lens 5b, and is collected by a detector 7. The light is converted into an electric signal by the detector 7, amplified and digitized by the signal processing circuit 8, and target information is extracted. In such a laser radar apparatus, the axis deviation is detected as follows. A part of the laser beam is reflected by the semi-transparent mirror 10 and enters the four-quadrant detector 17 through the lens 16. Since the 4-quadrant detector 17 is placed at the focal point of the lens 16, the laser beam becomes a small spot on the surface of the 4-quadrant detector 17. If the spot is at the center of the four-quadrant detector 17, the output of the four-quadrant detector 17 is 0. If the spot is shifted from the center, an output proportional to the shift is obtained. By detecting the spot position in this way, the direction of the laser beam can be known. If a deviation occurs, the adjustment device 2 corrects the output while monitoring the output of the four-quadrant detector 17.
[0005]
[Problems to be solved by the invention]
The conventional axis deviation detection device in the laser radar apparatus detects the transmission axis deviation as described above. Compared to the transmission axis misalignment caused by a laser device that consumes a large amount of power and therefore generates a large amount of heat, the misalignment on the receiving side is much smaller. Substituting the relative axis misalignment of can be used. However, in a satellite-equipped device in which thermal imbalance occurs even if there is no internal heat generation, the reception axis deviation cannot be ignored. Therefore, the conventional method that only detects the transmission axis deviation correctly detects the relative axis deviation of transmission and reception. There is a problem that it cannot be evaluated.
[0006]
The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an apparatus capable of detecting transmission and reception relative axis deviations by detecting reception axis deviations simultaneously with transmission axis deviations.
[0007]
[Means for Solving the Problems]
The apparatus according to the first aspect of the invention emits light from the receiving optical system in the reverse direction by illuminating the field stop that determines the receiving field of view, and detects the relative axis shift between the optical axis and the optical axis of the transmitted laser beam. It is a thing. The axis deviation is detected as follows. A part of the light emitted from the receiving optical system is bent by a reflecting mirror, and a part of the transmission laser beam is bent by a semi-transparent mirror, and both beams are superimposed to form an image on an image sensor. If the axes are aligned, the image is formed at one point, but if the axis shifts, the spots are separated. Since the distance between the two spots corresponds to the misalignment of the two axes, the misalignment is known. In addition, by integrating the reflector and the semi-transparent mirror so that relative changes do not occur, even if the orientation of the reflector / semi-transparent mirror changes due to surrounding changes, the relative axis deviation can be measured accurately. .
[0008]
The apparatus according to the second invention is a case where the reflecting mirror in the first invention is replaced with a semi-transparent mirror.
[0009]
The device according to the third invention is a case where the laser beam is emitted from the center of the receiving optical system, that is, applied to a coaxial laser radar device.
[0010]
The apparatus according to the fourth aspect of the invention irradiates a part of the outgoing laser beam to the receiving detector through an optical fiber so that not only the axis deviation but also the deviation of the detector can be detected.
[0011]
The apparatus according to the fifth aspect of the invention facilitates observation by illuminating from the back of the field stop to illuminate the center of the field of view.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a laser, 2 is an adjustment device for adjusting the direction of a laser beam, such as a double wedge, 3 is a receiving telescope such as a Cassegrain optical system, 4 is a field stop such as a pinhole, and 5 is a relay. An optical system, 6 is a narrow band filter, 7 is a detector, and 8 is a signal processing circuit, which are components of a normal laser radar device. Reference numeral 9 denotes a reflecting mirror, 10 denotes a semi-transparent mirror, 11 denotes a support frame that integrally supports the reflecting mirror 9 and the semi-transparent mirror 10, 12 denotes an image sensor, and 13 denotes an illumination light source.
[0013]
Next, the operation will be described. A laser beam generated from the laser 1 is transmitted toward the target via the adjusting device 2 and the semi-transparent mirror 10. The reflected light from the target is collected by the receiving telescope 3 including the cassegrain primary mirror 3 a and the cassegrain secondary mirror 3 b and passes through the field stop 4. The light that has passed through the field stop 4 passes through a narrowband filter 6 placed inside a relay optical system 5 including a lens 5a and a lens 5b, and is collected by a detector 7. The light is converted into an electric signal by the detector 7, amplified and digitized by the signal processing circuit 8, and target information is extracted. In such a laser radar apparatus, the axis deviation is detected as follows. The illumination light source 13 illuminates the field stop 4 from the front. The field stop 4 is usually a pinhole and has a small hole in the substrate. When illuminated, light is diffusely reflected from the substrate. There is no light from the small holes, but they are much smaller than the diffusely reflected light from the substrate, so the small holes look black. Diffuse reflected light from the substrate exits in the opposite direction to the incident light of the laser radar device through the cassegrain secondary mirror 3b and the cassegrain main mirror 3a. A part of the light beam exiting from the Kasegrain main mirror 3a is blocked by the reflecting mirror 9, bent, and taken out. A part of the laser beam from the laser 1 is also bent by the semi-transparent mirror 10 and taken out. The two beams taken out by bending are merged by the semi-transparent mirror 10 and enter the image sensor 12. From the observation of this image, it can be seen that the optical axes are aligned when the spots overlap, and the optical axes are shifted when the spots are separated. If the optical axis is deviated, it can be corrected by the beam direction adjusting device 2. Since the reflecting mirror 9 and the semi-transparent mirror 10 are integrated so that they do not move independently even if there is deformation in the surroundings, the direction of the light beam is the same as that of one plane mirror, and the transmission / reception axis deviation is accurately measured. can do.
[0014]
In FIG. 1, a semi-transparent mirror may be used instead of the reflecting mirror 9.
[0015]
Embodiment 2. FIG.
Another embodiment is shown in FIG. In FIG. 2, the laser beam generated from the laser 1 passes through the adjusting device 2 and is translated by the two right-angle prisms 18 a and 18 b to the back side of the cassegrain secondary mirror 3 b, and then toward the target through the semi-transparent mirror 14. Sent out. The reflected light from the target is collected by the receiving telescope 3 including the cassegrain primary mirror 3 a and the cassegrain secondary mirror 3 b and passes through the field stop 4. The light that has passed through the field stop 4 passes through a narrowband filter 6 placed inside a relay optical system 5 including a lens 5a and a lens 5b, and is collected by a detector 7. The light is converted into an electric signal by the detector 7, amplified and digitized by the signal processing circuit 8, and target information is extracted. In such a coaxial type laser radar apparatus, the axis shift detection is performed as follows. A part of the laser beam is reflected by the semi-transparent mirror 14 and taken out. Part of the light emitted from the receiving telescope is also bent out by the semi-transparent mirror 10 and extracted. The two beams taken out by bending are merged by the semi-transparent mirror 10 and imaged on the image sensor 12.
[0016]
Embodiment 3 FIG.
Another embodiment is shown in FIG. In FIG. 3, reference numeral 15 denotes an optical fiber having one end placed at the end of the laser beam and the other end placed near the detector. A part of the laser beam is taken out by the optical fiber 15 and irradiated to the detector 7. The light diffusely reflected by the detector surface passes through the relay optical system 5 and the field stop 4 and exits from the receiving telescope 3. Since there is a narrow band filter 6 that allows only the laser wavelength to pass through in the relay optical system 5, a part of the laser light itself is used to pass through the relay optical system 5. With this configuration, the light emitted from the field stop 4 can be used as in the first embodiment. Further, if the detector 7 is displaced, the light deviating from the uniform detector surface passes through the field stop 4 and exits from the receiving telescope 3, so that the displacement of the detector 7 can be found by observing the spot shape.
[0017]
Embodiment 4 FIG.
Another embodiment is shown in FIG. In FIG. 4, illumination is performed from the back of the field stop 4. By illuminating in this way, only the light that passes through the hole formed in the substrate, not the diffusely reflected light from the substrate, enters the image sensor, so that the image can be easily observed.
[0018]
【The invention's effect】
As described above, according to the present invention, since it is possible to measure the relative axis deviation between the transmission axis and the reception axis of the laser radar apparatus, the laser radar on the artificial satellite orbit where not only the transmission axis but also the change of the reception axis cannot be ignored. Increase instrument measurement accuracy.
[Brief description of the drawings]
FIG. 1 is a diagram showing a laser radar apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a diagram showing a second embodiment of the present invention.
FIG. 3 is a diagram showing a third embodiment of the present invention.
FIG. 4 is a diagram showing a fourth embodiment of the present invention.
FIG. 5 is a diagram showing a conventional laser radar device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Laser, 2 Laser beam direction adjustment apparatus, 3 Reception telescope, 3a Cassegrain primary mirror, 3b Cassegrain secondary mirror, 4 Field stop, 5 Relay optical system, 5a, 5b Lens, 6 Narrow-band filter, 7 Detector, 8 Signal processing Circuit, 9 Reflector, 10 Semi-transparent mirror, 11 Support frame, 12 Image sensor, 13 Illumination light source, 14 Semi-transparent mirror, 15 Optical fiber, 16 Lens, 174 Quadrant detector, 18a, 18b Right angle prism.

Claims

Laser that generates a laser beam, a receiving telescope that receives reflected light from a target irradiated with the laser beam, a field stop that adjusts the field of view of the receiving telescope, and a relay optical system that collects light emitted from the field stop on a detector In a laser radar apparatus comprising: a detector that converts light collected by the relay optical system into an electrical signal; and a signal processing circuit that extracts target information from the electrical signal.
A light source for illuminating the field stop,
A reflecting mirror that bends part of illumination light from the light source that is emitted from the field stop through the receiving telescope;
A semi-transparent mirror that overlaps with the illumination light bent by the reflecting mirror and is arranged in parallel with the reflecting mirror and bends a part of the laser beam;
A support frame that integrally supports the reflector and the semi-transparent mirror;
A laser radar device comprising: an image sensor for photographing light emitted from the semi-transparent mirror.

Laser that generates a laser beam, a receiving telescope that receives reflected light from a target irradiated with the laser beam, a field stop that adjusts the field of view of the receiving telescope, and a relay optical system that collects light emitted from the field stop on a detector In a laser radar apparatus comprising: a detector that converts light collected by the relay optical system into an electrical signal; and a signal processing circuit that extracts target information from the electrical signal.
A light source for illuminating the field stop,
A first semi-transparent mirror that bends part of illumination light from the light source that is emitted from the field stop through the reception telescope;
A second semi-transparent mirror that overlaps the illumination light bent by the first semi-transparent mirror and is arranged in parallel with the reflecting mirror and bends a part of the laser beam;
A support frame that integrally supports the two semi-transparent mirrors,
A laser radar device comprising: an image sensor for photographing light emitted from the second semi-transparent mirror.

Laser that generates a laser beam, a receiving telescope that receives reflected light from a target irradiated with the laser beam, a field stop that adjusts the field of view of the receiving telescope, and a relay optical system that collects light emitted from the field stop on a detector In a laser radar apparatus comprising: a detector that converts light collected by the relay optical system into an electrical signal; and a signal processing circuit that extracts target information from the electrical signal.
A light source for extracting a part of the laser beam with an optical fiber and illuminating the detector;
A reflecting mirror that bends part of illumination light from the light source that is emitted from the field stop through the receiving telescope;
A semi-transparent mirror that overlaps with the illumination light bent by the reflecting mirror and is arranged in parallel with the reflecting mirror and bends a part of the laser beam;
A support frame that integrally supports the reflector and the semi-transparent mirror;
A laser radar device comprising: an image sensor for photographing light emitted from the semi-transparent mirror.

Laser that generates a laser beam, a receiving telescope that receives reflected light from a target irradiated with the laser beam, a field stop that adjusts the field of view of the receiving telescope, and a relay optical system that collects light emitted from the field stop on a detector In a laser radar apparatus comprising: a detector that converts light collected by the relay optical system into an electrical signal; and a signal processing circuit that extracts target information from the electrical signal.
A light source for illuminating the field stop from the back side,
A reflecting mirror that bends part of illumination light from the light source that is emitted from the field stop through the receiving telescope;
A semi-transparent mirror that overlaps with the illumination light bent by the reflecting mirror and is arranged in parallel with the reflecting mirror and bends a part of the laser beam;
A support frame that integrally supports the reflector and the semi-transparent mirror;
A laser radar device comprising: an image sensor for photographing light emitted from the semi-transparent mirror.