JPH08184667A - Laser radar and i/o window therefor - Google Patents

Abstract

PURPOSE: To obtain a laser radar and an I/O window therefor in which the number of components, weight and cost can be reduced while making compact the optical system thereof. CONSTITUTION: The I/O window for laser radar comprises a sheet of transmission-type hologram 1, 20, 30 for receiving an oscillating laser light L1 from a light emitting element 3 to direct a reproduction light L6 toward an obstacle and receiving a scattering reflection light L7 from the obstacle to direct a converging light LS toward a light receiving element 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser radar input / output window and a laser radar device applicable to, for example, vehicle obstacle detection.

[0002]

2. Description of the Related Art As shown in FIG. 8, an optical system of a conventional laser radar device 100 includes a partition 102 for a light emitting chamber 10.
3, a casing 101 divided into a light receiving chamber 104,
The emitting lens 105 attached to the window 103a of the light emitting chamber 103, the incident lens 106 attached to the window 104a of the light receiving chamber 104, the light emitting element 107 provided in the interior of the light emitting chamber 103, and the light receiving chamber 104. It is generally composed of a light receiving element 108 provided in the inner part.

The optical system of the laser radar device 100 is
The laser divergent light L ₁ oscillated from the light emitting element 107 is converted into a parallel light L ₂ by the emission lens 105 and applied to an obstacle (not shown) in front of the window 103a, and diffuse reflected light L ₃ from the obstacle is incident. The lens 106 converts the converged light L ₄ to be converged on the light receiving element 108, and the converged light L ₄ is detected by the light receiving element 108.

That is, the optical system of the laser radar device 100 emits laser light oscillated from the light emitting element 107 toward an obstacle, and the diffused reflection light of the laser light from the obstacle is detected by the light receiving element 108. , Obstacle detection or /
It is also possible to measure the distance of obstacles.

[0005]

As described above, since the conventional laser radar input / output window is composed of the lens system composed of the exit lens 105 and the entrance lens 106, the laser divergent light on the surface of the exit lens 105 is obtained. Reflected light of L ₁ L ₅
May reach the light receiving element 108 and may be erroneously detected. Therefore, in order to prevent this erroneous detection, it is necessary to partition the casing 101 to separate the light emitting chamber 103 and the light receiving chamber 104. There is a problem in that the size of the optical system for the laser radar is inevitably increased and the device 100 as a whole becomes large because it is necessary to secure an appropriate space.

The conventional laser radar input / output window is
The emitting lens 1 is provided in each of the light emitting chamber 103 and the light receiving chamber 104.
No. 05 and the entrance lens 106 are required, and there is also a problem that the number of parts and the weight are increased, and eventually the cost is increased.

The present invention has been made to solve the above problems, and an object thereof is to make the optical system for a laser radar compact and to reduce the number of parts, weight and cost. An object is to provide an input / output window for a laser radar and a laser radar device.

[0008]

In order to achieve the above-mentioned object, the input / output window for a laser radar according to the first aspect of the invention is a reproduction which is emitted toward an obstacle by the incidence of laser light oscillated from a light emitting element. It is characterized by a single transmission hologram that reproduces light and reproduces converged light that converges toward a light receiving element when diffused reflected light from an obstacle of the reproduced light is incident.

According to a second aspect of the present invention, there is provided the laser radar input / output window according to the first aspect, wherein the one transmission hologram reproduces reproduction light emitted toward an obstacle. An incident section for reproducing convergent light that converges diffusely reflected light from an obstacle toward the light receiving element 4, and outputs and records the interference fringes for incidence and the interference fringes for incidence respectively on the emission section and the incidence section. It is characterized by being formed.

The invention according to claim 3 is the input / output window for a laser radar according to claim 1, wherein the one transmission hologram reproduces reproduction light emitted toward an obstacle. And an incident unit for reproducing convergent light that converges diffusely reflected light from an obstacle toward a light receiving element, and multiple recording of an emission interference fringe and an incidence interference fringe in the emission unit, and It is characterized in that interference fringes for incidence are recorded on the incidence part.

Furthermore, the invention of claim 4 is the same as claim 1.
The input / output window for laser radar according to any one of claims 1 to 3, wherein the one transmission hologram corresponds to the light emitting element and the light receiving element mounted on a dashboard of a vehicle, and is an inner surface of a windshield. It is characterized in that it is formed by recording interference fringes conforming to the positional relationship attached to.

According to the fifth aspect of the invention, the laser radar device reproduces the reproduction light emitted toward the obstacle by the incidence of the laser light oscillated from the light emitting element, and diffuses the reproduction light from the obstacle. A single transmission hologram that reproduces convergent light that converges toward the light-receiving element when light is incident is provided so as to close the opening of the casing.
The light receiving element is located at the convergent position of the convergent light and is displaced from the light emitting element so as to be located outside the light flux of the regular reflection light of the transmission hologram of the laser light, and the opening is formed. It is characterized in that it is provided in the same space portion that it has.

The invention according to claim 6 is the laser radar device according to claim 5, wherein the inner wall of the space in which the light emitting element and the light receiving element are provided absorbs the specularly reflected light. It is characterized by.

[0014]

Since the invention according to claims 1 to 6 has the above-mentioned structure, it has the following effect.

That is, since the input / output window for the laser radar according to the first aspect of the present invention is composed of a single transmission hologram, the laser oscillated from the light emitting element by utilizing the diffraction phenomenon which is the basic function of the hologram. The reflected light of the light on the hologram surface can be easily deflected from the light receiving element to prevent erroneous detection of the light receiving element, and the light weight and thin shape can be achieved.

According to the second aspect of the present invention, since the input / output window for the laser radar is composed of a single transmission hologram in which interference fringes are separately recorded on the emission part and the incidence part, respectively, the emission part and the incidence part are respectively formed. By providing a light emitting element and a light receiving element in correspondence with each other, when the laser beam is diffracted by the emitting section, the profile can be reproduced without distorting except for contracting in the vertical direction, and at the hologram surface of the laser beam. The reflected light can be easily deflected from the light receiving element. This one piece of transmissive hologram which is divided and recorded can be easily formed by masking the one which is not recorded at the time of recording of each of the emission part and the incidence part.

According to the third aspect of the present invention, since the laser radar input / output window is composed of a single transmission hologram having a multiple-recorded emitting portion and a single-recording incident portion, the emitting portion and the incident portion are incident. By providing a light emitting element and a light receiving element corresponding to each section, laser light can be reproduced by the emitting section without distorting the profile, and reflected light on the hologram surface of laser light can be easily emitted from the light receiving element. You can distract. This transmissive hologram having the multiple-recorded exit portion can be easily formed by masking the entrance portion when recording the exit portion and recording the entire portion including the exit portion when recording the entrance portion. You can

Further, the invention according to claim 4 is an interference fringe adapted to a positional relationship in which a single transmission hologram is attached to an inner surface of a windshield in correspondence with a light emitting element and a light receiving element attached to a vehicle dashboard. It is suitable for a laser radar input / output window of a vehicle obstacle detection device.

According to a fifth aspect of the laser radar device of the present invention, the laser light oscillated from the light emitting element is reproduced into reproduction light which is incident on the transmission hologram and is emitted toward the obstacle, and the reproduction light is obstructed. Diffuse reflected light from an object is reproduced as convergent light that is incident on the transmission hologram and converges toward the light receiving element, and the light receiving element can detect this convergent light to detect an obstacle.

In this laser radar device, since the light receiving element is provided so as to be located outside the light flux of the regular reflection light of the transmission hologram of the laser light oscillated from the light emitting element,
Erroneous detection due to the specularly reflected light can be prevented, and the light emitting element and the light receiving element are provided in the same space, so that the optical system can be made compact.

According to the sixth aspect of the invention, since the inner wall of the space where the light emitting element and the light receiving element are provided has a light absorbing structure for absorbing the specularly reflected light, erroneous detection due to the reflected light can be further prevented. You can

[0022]

The present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 shows an optical system of a laser radar device 10 as one embodiment.

The optical system of the laser radar device 10 includes a transmission hologram 1 as an input / output window for the laser radar,
The light-emitting element 3 oscillates a laser beam and the light-receiving element 4 for detecting diffused reflected light from an obstacle.

The transmission hologram 1 is provided so as to close the opening 2a of the casing 2, and the light emitting element 3 and the light receiving element 4 are provided in the same space 2b having the opening 2a.

The transmission hologram 1, by the incidence of the infrared laser beam L ₁ oscillated from the light emitting element 3 reproduces the reproduction light L ₆ emitted toward the obstacle from the obstacle of the reproducing light L ₆ It is formed as a single hologram that reproduces the convergent light L ₈ that converges toward the light receiving element when the diffuse reflected light L ₇ is incident.

The light emitting element 3 and the light receiving element 4 are arranged such that the light receiving element 4 is at the convergent position of the converged light L ₈ and the laser light L ₁
Is provided in the space 2b having the opening 2a by being displaced relative to the light emitting element 3 so as to be located outside the light flux of the regular reflection light L ₉ by the transmission hologram 1.

The transmission hologram 1 is formed as follows.

FIG. 4A shows an example of recording by a combination of an infrared sensitive emulsion and infrared laser light. In this recording example, the direction is 30 mm downward from the center of the hologram and 200 mm
It is assumed that a diverging light from a distance of is converted into a parallel light and is emitted in a direction normal to the hologram surface to obtain an emitting hologram.

That is, infrared laser light (908 nm) L
_The object light L _{11 obtained} by processing ₁₀ by the collimator lens 5 and the objective lens 6 into parallel light, and the objective lens 7 provided at the divergence point P ₁ at a distance of 200 mm from the center of the hologram original plate 1a in the downward 30 ° direction. Infrared laser light (908 nm)
By using the reference light L ₁₃ that has been processed as a divergent light by processing L ₁₂ , interference fringes can be recorded on the hologram master plate 1 a holding an emulsion having sensitivity to infrared light to obtain an outgoing hologram.

In practice, however, it is difficult to obtain and handle a hologram emulsion that is sensitive to infrared light. Therefore, a hologram 1A for emission is obtained by combining an emulsion sensitive to visible light and visible laser light.

FIG. 4B shows a visible laser beam (633n).
m) is an example of recording for obtaining interference fringes substantially equal to the infrared laser light (908 nm) described above.

That is, the visible laser light (633 nm) L ₁₅ is processed by the objective lens 8 provided at the divergence point P ₂ at a distance of approximately 1600 mm in the downward 4 ° direction (θ = 4 °) from the center of the hologram original plate 1b. Object light L ₁₆
25 ° below the center of the hologram master plate 1b, 250 m
By the reference light L ₁₈ that processes the visible laser beam L ₁₇ is divergent light by the objective lens 9 provided on the divergence point P ₃ located a distance of m, hologram original plate 1b which holds the emulsions sensitive to visible light It is possible to obtain an output hologram by recording interference fringes on the.

The outgoing hologram 1A formed by the visible laser light (633 nm) is the infrared light (908) described above.
The same function as that of the exit hologram 1A formed with a wavelength of 1 nm is achieved.

That is, as shown in FIG. 5A, the outgoing hologram 1A formed by the visible laser beam (633 nm) is an infrared laser beam (908 nm) from the divergence point P ₁ shown in FIG. 4A. It is possible to emit substantially parallel light in the normal line direction of the hologram surface by irradiating the divergent light.

On the other hand, the converging hologram 1B for converging the diffused and reflected light that the emitted light impinges on the object, reflects, and returns can be recorded and formed as shown in FIG.

FIGS. 6A and 6B are respectively shown in FIG.
It corresponds to (a) and (b), and is an example of recording formation by infrared light and visible light, and the converging hologram 1B can be obtained by irradiating the object light and the reference light from the opposite direction to FIG.

That is, in FIG. 6A, the diffuse reflection light is regarded as parallel light, and this is made to be the reference light (908 nm) L ₂₀ and is made incident on the hologram original plate 1c from the opposite direction to that of FIG. Object light (908 for converging parallel light)
(nm) L ₂₁ is made to enter the convergent light that converges at the position of the divergence point P ₁ in FIG. 4A into the hologram original plate 1c to obtain the converging hologram 1B.
In FIG. 4B, from the opposite direction to FIG.
Convergence hologram 1B by making reference light (633 nm) L ₂₂ and convergent light (633 nm) L ₂₃ as convergent lights that converge respectively at divergence points P ₂ and P ₃ in (b) enter hologram original plate 1c. Can be obtained.
In this way, the converging hologram 1B obtained with infrared light and visible light both have the same function, and the infrared light (908 nm)
The diffuse reflection light as can be converged to the P ₁ point,
By arranging the light receiving element near the point P _1, it becomes possible to measure the distance by detecting the diffusely reflected light from the obstacle.

The reason why the diffuse reflection light is regarded as parallel light in FIG. 6A is that the reflection position is judged to be sufficiently far from the arrangement position of the optical system.

By the way, the object light L ₁₁ of FIG.
The reference light L ₂₀ of FIG. 4A and the reference light L ₁₃ of FIG. 4A and the object light L ₂₁ of FIG. The exit holograms 1A and the convergence holograms 1B obtained respectively in ()) have exactly the same interference fringes recorded therein and have the same functions.

That is, the outgoing hologram 1A is shown in FIG.
As shown in (b), the diffuse reflection light as infrared light (908 nm) can be converged on the divergence point P ₁ as in the case of the converging hologram 1B.
As shown in (a), the convergence point P
By irradiation with infrared laser light (908 nm) from _1, it is possible to emit substantially parallel light in the direction normal to the hologram surface.

Therefore, both the outgoing hologram 1A and the converging hologram 1B can be used as the transmissive hologram 1 of this embodiment, but in reality, it is difficult to produce a convergent light. 4 (a),
The exit hologram 1A recorded and formed in (b) is used. The exit hologram 1A is formed as a single hologram having exit interference fringes recorded on the entire surface.

When this outgoing hologram 1A is used as the transmission hologram 1, the light receiving element 4 diverges from the divergence point P ₁ (of the reference light L ₁₃ when recording the outgoing hologram 1A as shown in FIG. 1). 4A), and the light emitting element 3 is displaced in the horizontal direction so that the distance from the transmission hologram 1 is the same as the light receiving element 4 in the same horizontal plane as the light receiving element 4. The optical system of the laser radar device 10 can be formed by arranging the above.

Laser radar device 1 formed in this way
The optical system of 0 is the infrared laser light L oscillated from the light emitting element 3.
_{Although 1} is reflected on the surface of the transmission hologram 1, this reflection is specular reflection on the hologram dry plate surface as shown in FIG. 1B, and the lower end of the light flux of specular reflection light L ₉ is above the light emitting element 3. By passing the light receiving element 4 in the same horizontal plane as the light emitting element 3, it is possible to prevent the specular reflection light L _{9 from} reaching the light receiving element 4 and prevent erroneous detection.

Further, in the optical system of the laser radar device 10, the outgoing hologram 1A having outgoing interference fringes recorded and formed on the entire surface is used as the transmission hologram 1, and reference is made when the outgoing hologram 1A is recorded. Since the light emitting element 3 is provided so as to be displaced from the divergence point P ₁ of the light L ₁₃ , the profile of the reproduction light L ₆ is slightly distorted, but it functions sufficiently.

In addition, in the optical system of the laser radar apparatus 10, it is desirable that the inner wall 2c of the space portion 2b of the casing 2 in which the light emitting element 3 and the light receiving element 4 are provided is reflected by the regular reflection light L.
_It has a light absorption structure that absorbs ₉ . This light absorbing structure is formed by painting the inner wall 2c with black, or by sticking a black cloth such as velvet to the inner wall 2c, or by performing flocking printing on the inner wall 2c.

Since the optical system of the laser radar device 10 having such a light absorbing structure can absorb the regular reflection light L ₉ by the light absorbing structure, the light receiving element 4 is detected by detecting the regular reflection light L ₉ . False detection can be prevented more reliably.

2 and 3 show transmission holograms 20 and 30 as another embodiment.

As shown in FIG. 2, the transmission hologram 20 directs the emitting portion 21 for reproducing the reproduction light L ₆ emitted toward the obstacle and the diffuse reflection light L ₇ from the obstacle toward the light receiving element 4. The incident part 22 for reproducing the convergent light L ₈ that converges is formed by separately recording the outgoing interference fringes and the incoming interference fringes on the outgoing part 21 and the incoming part 22 (FIG. 1).
reference). In this case, the emitting portion 21 is formed on a circular portion of a part of the hologram, and the incident portion 22 is formed on the entire hologram excluding the circular portion.

The transmission hologram 20 has an emitting portion 21.
When recording either one of the incident part 22 and the incident part 22, the other part is masked while the other is masked on the exit part 21 and the incident part 22 according to the recording example shown in FIG. It is formed by recording the interference fringes for emission and the interference fringes for incidence. At this time, the emitting portion 21
The central axis of the hologram is the center point P of the circular portion of the emitting portion 21.
_The center axis of the hologram of the incident portion 22 passes through the center point P _{22 of the} entire transmission hologram 20.

The transmissive hologram 20 is provided so as to close the opening 2a of the casing 2 as in the transmissive hologram 1 described above, and the light emitting element 3 and the light receiving element 4 are provided with an emitting portion 21 and an incident portion 22, respectively. The optical system of the laser radar device 10 shown in FIG. 1 is provided near the divergence point of the reference light at the time of recording.

The transmission hologram 2 formed in this way
As shown in FIG. 1, the optical system having 0 reproduces the reproduction light L ₆ emitted toward the obstacle by the incidence of the infrared laser light L ₁ oscillated from the light emitting element 3 on the emission portion 21, and When the diffused reflected light L ₇ from the obstacle of the reproduction light L ₆ is incident on the incident portion 22, the converged light L ₈ that converges toward the light receiving element 4 is reproduced, and the converged light L ₈ is detected by the light receiving element 4. It is possible to measure the distance of obstacles.

Moreover, in the optical system having the transmission hologram 20, the specular reflection light L ₉ on the surface of the transmission hologram 20 of the infrared laser light L ₁ reaches the light receiving element 4 similarly to the transmission hologram 1. It is possible to prevent erroneous detection by avoiding the above, and it is possible to obtain the reproduction light L ₆ with no profile distortion, which improves the measurement accuracy.

As shown in FIG. 3, the transmissive hologram 30 is formed to have an emitting portion 31 and an incident portion 32, like the transmissive hologram 20 described above. First, the incident portion 32 is masked. The interference fringes for emission are recorded with the hologram central axis passing through the circular central portion P ₃₁ as a reference to form the emitting portion 31, and then the hologram central axis passing through the central portion P ₃₂ of the entire transmission hologram 30 is used as a reference. Then, the interference fringes for incidence are recorded on the whole to form the incident portion 31, and the emission portion 31 is multi-recorded to form the whole.

This transmission hologram 30 is composed of the light emitting element 3
The optical system of the laser radar device 10 shown in FIG. 1 is formed by maintaining the positional relationship between the light receiving element 4 and the light receiving element 4 in the same manner as the transmission hologram 20 and closing the opening 2a of the casing 2.

The transmission hologram 3 formed in this way
As shown in FIG. 1, the optical system having 0 regenerates the reproduction light L ₆ emitted toward the obstacle by the incidence of the infrared laser light L ₁ oscillated from the light emitting element 3 on the emission portion 31, and
When the diffused reflected light L ₇ from the obstacle of the reproduced light L ₆ is incident on the incident portion 32, the converged light L ₈ that converges toward the light receiving element 4 is reproduced, and the converged light L ₈ is detected by the light receiving element 4. Then, the distance of the obstacle can be measured.

At this time, the optical system having the transmission hologram 30 can prevent erroneous detection of the light receiving element 4 in the same manner as the transmission hologram 20 described above, and obtain the reproduction light L ₆ without profile distortion. The measurement accuracy is improved.

FIG. 7 shows a transmission hologram 40 as still another embodiment.

This transmission hologram 40 corresponds to a light emitting element (not shown) mounted on a dashboard 52 of a vehicle 50 and a light receiving element 4, and a windshield 51.
It is formed by recording interference fringes on the assumption of a positional relationship to be attached to the inner surface of the.

That is, the transmission hologram 40 is shown in FIG.
The divergence point P ₁ of the reference light L _{13 in} (a) or FIG. 4 (b)
It is formed by recording the interference fringes by setting the positional relationship between the divergent points P ₃ and P ₂ of the reference light L ₁₈ and the object light L ₁₆ and the original hologram plate in accordance with the above-mentioned positional relationship. The interference fringes formed at this time may be of any of the transmission holograms 1, 20, and 30 described above.

The optical system having the transmission hologram 40 emits infrared laser light oscillated from the light emitting element to the front of the vehicle 50 by utilizing the windshield 51 for diffraction in addition to the diffraction phenomenon of the transmission hologram 40. An optical path that can be reproduced as reproduction light and that is diffused and reflected L ₂₀ from an obstacle in front of the vehicle 50 to converged light L ₂₁ that converges on the light receiving element 4 provided on the dashboard 52 is easily designed. can do.

The optical system having the transmission hologram 40 is similar to the above-mentioned optical system in the transmission hologram 4.
Since the erroneous detection of the light receiving element 4 can be prevented by the diffraction phenomenon which is the basic function of 0, the light emitting element and the light receiving element 4 can be installed in the same space, and the optical system can be made compact. Is suitable as an obstacle detection device for the vehicle 50.

As described above, the transmission holograms 1, 20, 30, and 40 as the input / output windows for the laser radar and the laser radar device 10 using these transmission holograms 1, 20, and 30 have basic hologram functions. Due to the diffraction phenomenon of the light-emitting element 3
Since the light receiving element 4 and the light receiving element 4 can be installed in the same space, the optical system can be made compact and
Compared to the conventional exit and entrance lens systems, one transmissive hologram constitutes the input / output window,
The number of parts, weight and cost can be reduced.

[0064]

As described in detail above, the present invention has the following effects.

That is, according to the invention of claim 1,
Since the input / output window for the laser radar is composed of a single transmission hologram, it is possible to easily divert the reflected light on the hologram surface of the laser oscillation light from the light receiving element by using the diffraction function which is the basic function of the hologram. As a result, the light emitting element and the light receiving element can be set in the same room without the need to enclose the light emitting element and the light receiving element in the same room, and the laser radar input / output window can be made compact by that amount. can do.

In addition, according to the first aspect of the present invention, as compared with the conventional one that requires a lens system for each of emission and incidence, the transmission / reception window for the laser radar is formed by a single transmission hologram. Since it is configured, it is possible to provide an input / output window for a laser radar that can reduce the number of parts, weight, and cost.

According to the second aspect of the present invention, since the laser radar input / output window is composed of a single transmission hologram in which interference fringes are separately recorded on the emission part and the incidence part, respectively. By providing the light-emitting element and the light-receiving element corresponding to the above, it is possible to reproduce the reproduction light of the laser oscillation light by the emitting portion without distorting the profile, and to reflect the reflection light of the laser oscillation light on the hologram surface. It can be easily dislocated from the light receiving element, and can be easily formed by masking the unrecorded side of each of the emission part and the incidence part. As a result, in addition to the effect of claim 1. It is possible to provide an input / output window for a laser radar that can further improve the detection accuracy and can be easily formed.

According to the third aspect of the present invention, since the laser radar input / output window is composed of a single transmission hologram having an emission section for multiple recording and an incidence section for single recording, the emission section is composed. By providing a light emitting element and a light receiving element respectively corresponding to the incident part and the incident part, the reproduction light of the laser oscillation light can be reproduced by the emission part without distorting the profile and the laser oscillation light is reflected on the hologram surface. Light can be easily deflected from the light receiving element, and it can be easily formed by masking the incident part and recording the incident part when recording the emitting part and recording the entire part including the emitting part. As a result, in addition to the effect of claim 1, the detection accuracy can be further improved, and an input / output window for a laser radar that is easy to form can be provided. Kill.

Further, according to the invention described in claim 4, one transmission hologram is adapted to the positional relationship of being mounted on the inner surface of the windshield in correspondence with the light emitting element and the light receiving element mounted on the dashboard of the vehicle. Since the interference fringes are recorded and formed, it is possible to provide the laser radar input / output window suitable for the vehicle obstacle detection device.

According to the fifth aspect of the invention, since the transmission hologram is used as the input / output window for the laser radar, the number of parts, weight, and
Also, it is possible to reduce the cost, and to provide a laser radar device in which the optical system can be made compact because the light emitting element and the light receiving element are provided in the same space while preventing the false detection of the light receiving element. be able to.

Further, according to the invention of claim 6, the inner wall of the space where the light emitting element and the light receiving element are provided has a light absorbing structure for absorbing the specularly reflected light on the hologram surface.
It is possible to provide a laser radar device that can more surely prevent erroneous detection due to the specularly reflected light.

[Brief description of drawings]

FIG. 1 is a schematic view of an optical system of a laser radar device as one embodiment, (a) is a plan view thereof, and (b) is a side view thereof.

FIG. 2 is a plan view of a transmission hologram as another example.

FIG. 3 is a plan view of a transmission hologram according to still another embodiment.

FIG. 4 shows a recording system arrangement of a transmission type hologram for emission,
(A) is an infrared light recording system layout and (b) is a visible light recording system layout.

FIG. 5 is an explanatory diagram of reproduced light of a transmission hologram,
(A) is explanatory drawing which reproduce | regenerates a parallel light, (b) is explanatory drawing which reproduces a converging light.

FIG. 6 shows a recording system arrangement of a converging transmission hologram,
(A) is an infrared light recording system layout and (b) is a visible light recording system layout.

FIG. 7 is a schematic explanatory diagram in which an optical system having a transmission hologram is applied to a vehicle.

FIG. 8 is a schematic view of an optical system of a conventional laser radar device, (a) is a plan view thereof, and (b) is a side view thereof.

[Explanation of symbols]

1,20,30,40 Transmissive hologram 2 Casing 2a Opening (of casing) 2b Space (of casing) 2c Inner wall (of space) 3 Light emitting element 4 Light receiving element 21,31 Light emitting portion 22,32 Light incident portion 50 Vehicle 51 Windshield 52 Dashboard L ₁ laser light (infrared laser light) L ₆ reproduction light L ₇ diffuse reflection light L ₈ convergent light L ₉ specular reflection light

Claims (6)

[Claims] 1. Reproduction of reproduction light emitted toward an obstacle by incidence of laser light oscillated from a light emitting element, and
An input / output window for a laser radar, comprising a single transmission hologram that reproduces converged light that converges toward a light receiving element when diffused reflected light from an obstacle of the reproduced light is incident. 2. The input / output window for a laser radar according to claim 1, wherein the one transmission hologram reproduces reproduction light emitted toward an obstacle by laser light oscillated from a light emitting element. Section and an incident section that reproduces convergent light that converges diffusely reflected light from an obstacle toward a light receiving element, and the emission interference fringes and the incidence interference fringes are separately recorded in the emission section and the incidence section, respectively. An input / output window for a laser radar, which is formed by 3. The input / output window for a laser radar according to claim 1, wherein the one transmission hologram reproduces reproduction light emitted toward an obstacle by laser light oscillated from a light emitting element. And an incident unit for reproducing convergent light that converges diffusely reflected light from an obstacle toward a light receiving element, and multiple recording of an emission interference fringe and an incidence interference fringe in the emission unit, and An input / output window for a laser radar, which is formed by recording an interference fringe for incidence on an incident part. 4. The laser radar input / output window according to claim 1, wherein the one transmission hologram is used in the light emitting element and the light receiving element mounted on a dashboard of a vehicle. An input / output window for a laser radar, characterized in that it is formed by recording interference fringes corresponding to the positional relationship attached to the inner surface of the windshield. 5. Reproduction of reproduction light emitted toward an obstacle by incidence of laser light oscillated from a light emitting element, and
A single transmission hologram that reproduces the convergent light that converges toward the light-receiving element when the diffused reflected light from the obstacle of the reproduction light is incident is provided so as to close the opening of the casing. Is a converging position of the converging light and is displaced relative to the light emitting element so as to be located outside the light flux of the regular reflection light by the transmission hologram of the laser light, and the same space having the opening. A laser radar device provided in a section. 6. The laser radar device according to claim 5, wherein an inner wall of a space provided with the light emitting element and the light receiving element has a light absorbing structure that absorbs the specularly reflected light. Laser radar device.