WO2015098130A1 - Two-dimensional scanning laser beam projection device and laser radar device - Google Patents

Abstract

Provided is a two-dimensional scanning type novel laser beam projection device which, in at least one of two perpendicular directions, is capable of variable magnification of the angle of deflection of a laser beam scanned by deflection in two dimensions by a deflection device. This two-dimensional scanning type laser beam projection device projects a two-dimensionally deflected laser beam (SRL), and comprises a laser source (10, 13) which emits the laser beam, a deflection device (14) which deflects in two dimensions the laser beam (LF) emitted from the laser source, and a deflection angle variable magnification element (16) which obtains the deflected laser beam by variably magnifying, in at least one of two perpendicular directions, the deflection angle of the laser beam (LF1) deflection-scanned in two dimensions by the deflection device.

Description

Two-dimensional scanning laser beam projection apparatus and laser radar apparatus

The present invention relates to a two-dimensional scanning laser beam projection apparatus and a laser radar apparatus.

Various types of laser radar devices have been proposed and known (Patent Document 1 and the like).
The laser radar device scans a beam of laser light two-dimensionally and irradiates the object to be detected, and the laser light reflected by the object to be detected is received by the light receiving element for detection and detected.
Then, the distance to the object to be detected is measured by "the time required for the laser beam to travel the distance to the object to be detected". As described above, since the distance to the detection target is measured, the laser radar device may be called "two-dimensional distance measuring device".
In the following, a beam-like laser beam which is two-dimensionally scanned and irradiated to a detection target is referred to as a “deflection laser beam”.

Although laser radar apparatuses for vehicles, robots, product inspections, and the like have been put to practical use, there is a demand for optimizing the field of view.
The term "field of view" as used herein means "two-dimensional deflection angle (deflection angle in each of two directions forming two dimensions and orthogonal to each other)" when a polarized laser beam applied to an object is two-dimensionally scanned. It is.

Heretofore, as a deflecting device for deflecting a laser beam, "polygon mirror or MEMS" is known (Patent Document 2 etc.).
The "deflection device" conventionally known often has a fixed deflection angle.
For example, “two-axis MEMS (Micro Electro Mechanical Systems)” is compact and capable of high-speed deflection, and is excellent as a deflection device that deflects a laser beam two-dimensionally.
There are various types of “laser beam deflection angles” of the biaxial MEMS, such as 20 degrees, 30 degrees, and 40 degrees, and the deflection angles can be changed within a “certain range”.

In these MEMS, it is general that the design of the best reflecting surface shape and the like for realizing the deflection angle is determined by using the deflection angle as a design condition.
Therefore, it is preferable that the MEMS perform deflection at the “design deflection angle”, and the range in which the deflection angle can be changed is naturally limited, and a large change in the deflection angle is difficult.
Hereinafter, the change of the deflection angle is referred to as "variation of deflection angle".

The magnification change of the deflection angle is considered to be an increase or decrease of the deflection angle.

With regard to the expansion of the deflection angle, conventionally, it has been proposed to optically expand the deflection angle of the laser beam which is two-dimensionally deflected by the deflection device (Patent Document 2).
On the other hand, reducing the deflection angle has not been known as far as the inventors know.

By reducing the deflection angle, the two-dimensional scanning range of the laser beam can be narrowed, the scanning can be densified, and the shape of the object can be detected with high precision.

The present invention realizes a novel two-dimensional projection type laser beam projection apparatus capable of changing the deflection angle of a laser beam two-dimensionally deflected and scanned by a deflection device in at least one of two directions orthogonal to each other. As an issue.

The two-dimensional scanning laser beam projection apparatus according to the present invention is a two-dimensional scanning laser beam projection apparatus that emits a two-dimensionally deflected polarized laser beam, which comprises: a laser light source that emits a laser beam; A deflector for two-dimensionally deflecting a laser beam emitted from a light source, and changing a deflection angle of a laser beam two-dimensionally scanned by the deflector in at least one of two directions orthogonal to each other And a deflection angle variable magnification element to be a deflection laser beam.

According to the present invention, it is possible to realize a novel two-dimensional projection type laser beam projection apparatus capable of varying the deflection angle.

It is a figure for demonstrating one Embodiment of the two-dimensional scanning-type laser beam projection apparatus which can carry out magnification change of deflection angle. It is a figure for demonstrating another embodiment of the two-dimensional scanning-type laser beam projection apparatus which can carry out magnification change of deflection angle. It is a figure for demonstrating one example of the whole structure of one Embodiment of a two-dimensional scanning-type laser beam projection apparatus. An embodiment of a laser radar device is illustrated in an explanatory view only for the main part. It is a figure for demonstrating an expansion concentric coefficient. It is a figure for demonstrating another form of implementation of a laser radar apparatus. It is a figure for demonstrating the other form of implementation of a laser radar apparatus. It is a figure which shows the part of the laser beam projection apparatus of the laser radar apparatus shown in FIG. It is a figure which shows the part of the laser beam projection apparatus of the laser radar apparatus shown in FIG. It is a figure for demonstrating conversion of a light beam form. It is a figure for demonstrating the other form of implementation of a laser radar apparatus. It is a figure for demonstrating the part of the laser beam projection apparatus of the laser radar apparatus of FIG. It is a figure for demonstrating the further another form of implementation of a laser radar apparatus. It is a figure for demonstrating another two forms of implementation of a laser radar apparatus. It is a figure for demonstrating another form of implementation of a laser radar apparatus. It is a figure for demonstrating another form of implementation of a laser radar apparatus. It is a figure for demonstrating another form of implementation of a laser radar apparatus. It is a figure for demonstrating one Embodiment of the two-dimensional scanning-type laser beam projection apparatus which can carry out magnification reduction of deflection angle.

Hereinafter, embodiments will be described.

FIG. 1 is a view for explaining one embodiment of a two-dimensional scanning laser beam projection apparatus. The figure (a) has shown the principal part of embodiment in figure in illustration.
In this figure, reference numeral 10 denotes a "light source", reference numeral 12 denotes a "coupling lens", reference numeral 14 denotes a "deflection device", and reference numeral 16 denotes a "reflecting surface member as a deflection angle magnifying element which is a deflection angle varying element Each one is shown.
As the light source 10, a "semiconductor laser" is used in this embodiment.
It is abbreviated as 10.
The divergent laser beam emitted from the LD 10 is incident on the coupling lens 12.

The coupling lens 12 has positive refractive power and suppresses the divergence of the incident laser beam. In this example, the coupling lens 12 has a "collimation function".
Therefore, a collimated laser beam LF is emitted from the coupling lens 12. The emitted laser beam LF is incident on the deflection device 14.
That is, the LD 10 and the coupling lens 12 constitute a “laser light source for emitting the laser beam LF”.

The deflection device 14 “two-dimensionally deflects and scans” the incident laser beam LF.
In this embodiment, the deflecting device 14 has reflecting surfaces which can be swung in two directions orthogonal to each other, reflects the laser beam LF by the reflecting surfaces, and performs deflection scanning by swinging the reflecting surface.
Such deflection devices are well known, but in the embodiment being described, one as shown in FIG. 1 (b) is used.

That is, the deflecting device 14 has the reflecting mirror 140, the first frame 142 and the second frame 144.
The reflecting mirror 140 is a plane mirror, has a reflecting surface slightly larger than the diameter of the light beam of the laser beam LF, and can receive and reflect the entire laser beam LF.
The first frame 142 and the second frame 144 are both rectangular frames, and the reflecting mirror 140 is fixed to the first frame 142 by axes j1 and j2 sharing a swing axis.
The axes j1 and j2 have torsional elasticity, and the restoring force of the torsional deformation enables the reflecting mirror 140 to swing about the swing axis shared by the axes j1 and j2.

The first frame 142 is fixed to the second frame 144 by axes j3 and j4.
The axes J3 and j4 also share the swing axis.
The axes j3 and j4 also have torsional elasticity, and the first frame 142 can be swung around the swing axis shared by the axes j3 and j4 by the restoring force of the torsional deformation.
The second frame 144 is fixedly provided in the device space of the two-dimensional scanning laser beam emission device and immobile.
The swing axis shared by the axes j1 and j2 and the swing axis shared by the axes j3 and j4 are orthogonal to each other.
Therefore, the reflecting mirror 140 can be "swayed independently in two directions orthogonal to each other (ie, in the horizontal direction and the vertical direction)".

The rocking is performed by a driving unit (not shown).
For example, a "piezoelectric element" can be used as the driving means.
The piezoelectric element fixed to the first frame 142 can be connected to the reflecting mirror 140 to drive the reflecting mirror 140 to swing.
Similarly, the piezoelectric element fixed to the second frame 144 can be connected to the first frame 142 to drive the first frame 142 having the reflecting mirror 140 to swing.
The deflection device 14 is configured as a “two-axis MEMS”.

The deflection device 14 may be any appropriate known device other than those configured as such “two-axis MEMS”.
For example, two “one-axis MEMS in combination for deflection in the vertical and horizontal directions” and a combination of one-axis MEMS and one-axis galvano mirror or one-axis polygon mirror can be mentioned. Alternatively, it can be implemented as “combination of a uniaxial galvano mirror and a uniaxial polygon mirror”.
Since these “two-dimensional deflection devices” are well known as described in Patent Document 2 and the like, the description will be omitted.

The laser beam LF is reflected by the reflecting mirror 140 of the deflecting device 14, and when the reflecting mirror 140 swings in a two-dimensional manner, it becomes a two-dimensionally deflected laser beam LF1.
The reflecting surface member 16 has a reflecting surface on which the laser beam LF <b> 1 deflected and scanned two-dimensionally by the deflecting device 14 is incident.
In the embodiment of FIG. 1, the reflecting surface member 16 has a “conical convex reflecting surface”.
The two-dimensionally deflected and scanned laser beam LF1 is incident on the reflecting surface of the reflecting surface member 16 so as to “scan the reflecting surface two-dimensionally”.
FIG. 1C shows a reflective surface portion 160 of the reflective surface member 16 that is “two-dimensionally scanned with the laser beam LF1”. The horizontal direction in the figure is the horizontal direction, and the vertical direction is the vertical direction.

When the laser beam LF1 scans the “vertical top” of the reflecting surface member 16, the laser beam LF1 scans the arc portion AB of FIG. 1 (c).
When scanning "in the middle of the vertical direction", the arc-shaped portion CD is scanned. Further, when scanning the “lowermost part in the vertical direction”, the arc-shaped portion EF is scanned.
FIG. 1D shows a state in which the arc-shaped portion CD is scanned as viewed from the symmetry axis direction of the reflective surface portion 160. As shown in FIG.
As shown in this figure, the “horizontal deflection angle is θ1” when the laser beam LF1 scans the arc-shaped portion CD.
Since the reflecting surface portion 160 is a conical "convex reflecting surface", it is reflected by the reflecting surface portion 160 to be reflected as a polarized laser beam LF2.

Therefore, the deflection angle in the horizontal direction of the deflected laser beam LF2 is “θ2”.
As apparent from FIG. 1D, “deflection angle: θ2> deflection angle: θ1”.
That is, the deflection angle θ 2 in the horizontal direction of the deflection laser beam LF 2 is obtained by “magnifying and scaling” the deflection angle θ 1 of the laser beam LF 1 by the deflection device 14.
That is, as described above, the reflecting surface member 16 is a "deflection angle enlarging element".

FIG. 1E shows the “state in which the laser beam LF1 is reflected in the vertical direction” when the reflective surface portion 160 is viewed from the horizontal direction.
In the drawing, the portion indicated by the symbol a is the incident position on the arc portion AB of the laser beam LF1, and the portion indicated by the symbol f is the “incident position on the arc portion EF”.
The reflection surface portion 160 has no curvature in the vertical direction, so the deflection angle in the vertical direction of the polarized laser beam LF2 does not enlarge the deflection angle in the vertical direction by the deflection device.

That is, the “two-dimensional scanning laser beam projection apparatus” whose embodiment is shown in FIG. 1 is an apparatus that emits a two-dimensionally deflected polarized laser beam LF2.
The laser light source 10, 12 emits a laser beam LF, and a deflector 14 two-dimensionally deflects and scans the laser beam LF emitted from the laser light source.
Further, it has a reflecting surface member (deflection angle enlarging element) 16 for reflecting the laser beam LF1 which has been two-dimensionally deflected and scanned by the deflecting device.

The reflecting surface member 16 has a reflecting surface portion 160 having a curved surface shape for enlarging and changing the deflection angle of the polarized laser beam LF2 in the horizontal direction.
If the curvature in the horizontal cross section of the reflecting surface portion 160 of the reflecting surface member 16 is "strong (weak)", the magnification of the horizontal magnification change can be "high (low)".
Therefore, by appropriately setting the shape of the reflective surface portion 160, "the magnification change of the deflection angle of the deflection laser beam LF2 in the horizontal direction to the desired deflection angle range" can be performed.
In the example of FIG. 1, the reflecting surface portion 160 of the reflecting surface member 16 is formed as a convex conical surface so as to "magnify and change the deflection angle of the deflected laser beam LF2 in the horizontal direction to a desired deflection angle range".

However, the shape of the reflecting surface of the reflecting surface member is not limited to this, and various shapes can be considered. For example, it can be a "convex cylinder surface".
Moreover, the curved surface shape of the reflective surface part of a reflective surface member is not restricted to a convex.

For example, if the cross-sectional shape in the horizontal direction of the reflective surface portion is "concave", it is possible to scale the deflection angle in the horizontal direction at a reduction ratio to "narrow down" the horizontal field of view.
Also, assuming that the shape of the reflecting surface member in the vertical direction is “concave shape (convex shape)”, the deflection angle in the vertical direction may be scaled with a reduction (magnification) magnification to narrow (expand) the visual field in the vertical direction. it can.
The reflective surface member may also have a "recessed cylindrical surface or a concave conical surface" in the shape of the reflective surface. When the shape of the reflecting surface is "concave", the curvature of the concave surface is increased to narrow the deflection angle in the horizontal or vertical direction, and the deflection laser beam once intersects in space and then becomes the expansion deflection angle. You can also do so.
Depending on the shape of the reflective surface portion, the magnification (magnification) of the magnification change with respect to the “at least one of horizontal direction and vertical direction” deflection angle of the laser beam LF1 deflected by the deflection apparatus can be set appropriately.

Accordingly, at least one of the horizontal and vertical deflection angles of the deflection laser beam LF2 can be set to a desired deflection angle range.
That is, the reflecting surface member, which is a deflection angle variable magnification element, has a curved reflecting surface portion that changes the deflection angle of the reflected laser beam into a desired deflection angle range in at least one of the horizontal direction and the vertical direction. There can be.
The deflecting device 14 described above is one which "swings" the reflecting mirrors 140 around one another.
However, the present invention is not limited to this, and it is also possible to combine two one-dimensional reflection / deflecting devices which vibrate or rotate the reflecting surface about an axis, with the axes orthogonal.

FIG. 2 is a view for explaining another embodiment of the two-dimensional scanning laser beam projection apparatus. FIG. 2 (a) shows the entire apparatus in a simplified illustration.
As in FIG. 1, in FIG. 2A, reference numeral 10 denotes a semiconductor laser (LD), and reference numeral 12 denotes a coupling lens.
When the LD 10 emits light, the emitted laser beam is collimated by the coupling lens 12 and converted into a “parallel” laser beam LF.
The laser beam LF is incident on the adjustment lens 13 and is converted into a laser beam LA which converges in one direction.

In this embodiment, the LD 10, the coupling lens 12 and the adjusting lens 13 constitute a "laser light source". The laser beam LA which converges in one direction is incident on the mirror 40 and reflected in a predetermined direction.
The mirror 40 is a plane mirror and is provided to "bent the light path of the laser beam LA", but may be omitted depending on the layout of the apparatus.
The laser beam LA reflected by the mirror 40 enters the deflection device 14 while converging in one direction.
The deflection device 14 is configured as a “two-axis MEMS”, and swings the reflection surface two-dimensionally to deflect the reflected light two-dimensionally.
The description of the deflecting device 14 incorporates the previous description with respect to FIG.

The two-dimensionally deflected laser beam is periodically scanned in two directions orthogonal to each other with a substantial center of "point of origin of deflection" by the deflection device 14 as indicated by a symbol LD in Fig. 1A. Be done.
The two-dimensionally deflected and scanned laser beam LD is incident on a deflection angle variable magnification element 18. The deflection angle variable magnification element 18 is a “deflection angle magnification element as a deflection angle magnification element”.
The deflection angle variable magnification element 18 is a concave cylinder lens in the example shown in FIG. 2, the incident side surface 18A forms a "concave cylinder surface", and the emission side surface 18B is a "plane".
The axial direction (the direction having no power) of the concave cylinder surface 18A is referred to as "longitudinal direction" for convenience, and the direction orthogonal to the longitudinal direction in a plane perpendicular thereto is referred to as "lateral direction" for convenience.
The above-mentioned "horizontal direction / vertical direction" is an example of these "longitudinal direction / horizontal direction".

In addition, below, as a shape of a cylinder surface, a "concave cylinder surface" is also called "a concave cylinder surface", and a "convex cylinder surface" is also called a "convex cylinder surface."

The deflected and scanned laser beam LD two-dimensionally scans the incident side surface 18A of the deflection angle variable magnification element 18 in the longitudinal direction and the transverse direction.
As described above, the laser beam LD which is two-dimensionally deflected and scanned and incident on the incident side surface 18A is given a converging tendency in one direction by the adjusting lens 13.
The convergence tendency of the laser beam LD is given in the "lateral direction".
The laser beam LD deflects and scans the deflection angle variable magnification element 18 in the longitudinal and lateral directions, and emits from the emission side surface of the deflection angle magnification element 18 as a deflected laser beam LB whose deflection angle is expanded.

FIG. 2B shows the state of deflection of the laser beam LD as seen from the vertical direction. That is, the state of this figure shows the state of the lateral deflection of the laser beam LD.
In FIG. 2B, reference numeral 10A indicates a light emitting portion of the LD 10.
As described above, the laser beam emitted from the LD 10 is converted by the coupling lens 12 into a parallel laser beam LF.
Then, the laser beam LA is given a “trapping tendency in the lateral direction” by the adjusting lens 13, and enters the deflecting device 16A in a converged state to be two-dimensionally deflected.

As shown in FIG. 2B, the deflected laser beam LD is incident on the incident side surface 18A of the deflection angle variable magnification element 18 while being converged as viewed from the vertical direction.
In the embodiment shown in FIG. 2, the "point of origin of deflection" by the deflecting device 16A is substantially located on the cylinder axis of the "concave cylinder surface" forming the incident side surface 18A.
That is, when viewed from the longitudinal direction, the incident side surface 18A has a “arc shape centered on the origin of deflection”.
For this reason, the laser beam LD is incident so as to be “perpendicular to the incident side surface 18A” when viewed from the longitudinal direction, and is not refracted in the lateral direction.

When the laser beam LD passes through the deflection angle variable magnification element 18, it emerges from the exit side surface 18B.

The emission side surface 18B is a plane, and the polarized laser beam LB is refracted and emitted.
That is, in the lateral direction, the deflection laser beam LB is enlarged in deflection angle by the refracting action of the emission side surface 18B.
The deflection angle variable magnification element 18 is connected to the cylinder lens 13 in the following positional relationship.

That is, the position of the object-side focal point of the deflection angle variable magnification element 18 (“imaginary focal point” on the exit side of the deflection angle magnification element 18) substantially coincides with the “position of image side focus” of the adjustment lens 13.
The position of the image-side focal point of the adjusting lens 13 is such that the laser beam LD from the adjusting lens 13 travels toward the center of the deflection angle variable magnification element 18 and “does not receive the action of the deflection angle magnification element 18”. It is a "focusing position in one direction (lateral direction)" when
Due to such positional relationship, when the laser beam LD is deflected and scanned on a plane orthogonal to the cylinder axis of the incident side surface 18A, the deflected laser beam LB becomes a parallel luminous flux.
Then, as shown in FIG. 2B, the beam diameter of the deflected laser beam LB becomes thinner than the parallel laser beam LF.
Therefore, it is possible to illuminate the object of ranging detection which projects the polarized laser beam LB with high resolution.
FIG. 2C shows the state of deflection of the laser beam LD as viewed from the lateral direction.

In the deflection angle variable magnification element 18, the incident side surface 18A is "a cylinder surface whose axis is in the vertical direction", and the emission side surface 18B is a plane.
Therefore, neither the incident side 18A nor the exit side 18B has refractive power in the vertical direction.
That is, the deflection angle does not increase in the vertical direction. The deflected and incident laser beam LD is emitted in the longitudinal direction as “a deflected laser beam LB maintaining a deflection angle”.
Thus, the two-dimensional scanning laser beam projection apparatus described with reference to FIG. 2 can expand and project the deflection angle of the laser beam LD in the lateral direction out of the two vertical and horizontal directions.

That is, the two-dimensional scanning laser beam projection apparatus described with reference to FIG. 2 is a “laser beam projection apparatus that emits a two-dimensionally deflected laser beam LB”.
The apparatus comprises a laser light source 10 for emitting a laser beam LA, a coupling lens 12, a adjusting lens 13, and a deflector 14 for two-dimensionally deflecting and scanning a laser beam LA emitted from the laser light source.
In addition, a deflection angle expanding element is a deflection angle magnification element that expands a deflection angle of the laser beam LD two-dimensionally deflected and scanned by the deflection device 14 in at least one of two directions orthogonal to each other. An angular magnification element 18 is provided.

The two directions orthogonal to each other are the vertical and horizontal two directions in the example of FIG. 2, and the expansion of the deflection angle is performed in the horizontal direction.
The deflection angle enlargement element is a deflection angle variable magnification element 18 which has a concave incident side surface 18A, transmits the two-dimensionally deflected scanning laser beam LD, and expands the deflection angle by refraction.
The deflection angle variable magnification element 18 is also flat on the exit side of the laser beam LD.
The incident side surface 18A of the laser beam LD is a "concave cylinder surface".

The two-dimensional scanning type laser beam projection apparatus shown in FIG. 2 has a focusing optical system 13 which causes the laser beam LD incident on the deflection angle variable magnification element 18 to be incident on the deflection angle magnification element in a converged state.
Further, in the deflection angle variable magnification element 18, the incident side surface 18A of the laser beam LD is a concave cylinder surface, and the emission side surface 18B is a flat surface.
Then, the deflection center of the two-dimensionally deflected laser beam LD is located on the substantially cylinder axis of the concave cylinder surface 18A.

Further, the two-dimensionally deflected laser beam LD is brought into the “one-directionally convergent state”, and enters the deflection angle variable magnification element 18.
The virtual condensing position at which the laser beam LD incident on the deflection angle variable magnification element 18 at a deflection angle of 0 converges in one direction is the “object-side focal position in the lateral direction” of the deflection angle magnification element. .
Since the deflection angle variable magnification element 18 is a negative lens in the lateral direction, the “object side focal point in the lateral direction” exists on the exit side of the deflection angle magnification element 18 and is a “virtual focus”.
Therefore, the deflected laser beam LB emitted from the deflection angle variable magnification element 18 becomes a "parallel beam".

More specifically, the “laser light source” includes the coupling lens 12 as a “collimator” that collimates the laser beam emitted from the LD 10.
In addition, the adjustment lens 13 is provided as a “condensing lens” that condenses the laser beam LF collimated by the collimating element in one direction.
The laser beam LA condensed in one direction by the adjusting lens 13 is two-dimensionally deflected by the deflection device 16A, and is incident on the concave cylinder surface 18A of the deflection angle variable magnification element 18.

In the embodiment described with reference to FIG. 2, the expansion of the deflection angle is performed not by the concave cylinder surface of the deflection angle variable magnification element but by refraction by the plane forming the emission surface 18B.
However, it is needless to say that the function of “deflection angle expansion due to refraction” may be provided not only to this but also to the incident side surface of the deflection angle variable magnification element.
For example, in the embodiment shown in FIG. 2, the incident side of the deflection angle variable magnification element 18 may be a "two-dimensional concave surface", and the concave surface may be provided with a "refractive function in both longitudinal and lateral directions".
In this way, the deflection angle of the deflected laser beam LD can be expanded not only in the lateral direction but also in the longitudinal direction.

Further, when the power of the two-dimensional concave surface is "different in the longitudinal direction and the lateral direction", the deflection angle enlargement magnification can be made different in the longitudinal direction and the lateral direction.
By using “aspheric or free-form surface” at least one of the lens surfaces of the deflection angle variable magnification element 18, the deflection direction of the deflection laser beam LB can be adjusted with high accuracy.
FIG. 3 is a view for explaining an example of the entire configuration of an embodiment of a two-dimensional scanning laser beam projection apparatus.
The configuration of an optical system from the laser light source to the deflection angle variable magnification element is the same as that shown in FIG.
An optical system from the laser light source 10, the coupling lens 12, and the adjustment lens 13 to the deflection angle variable magnification element 18 is housed inside the envelope housing CS.

A feature of this embodiment is that the deflection angle variable magnification element 18 doubles as a beam emitting portion of the envelope housing CS of the apparatus.
In this way, the deflection angle variable magnification element 18 can also function as the "dust-proof glass of the envelope housing CS", and the number of parts can be reduced to reduce the apparatus cost.

FIG. 4 is an explanatory view schematically showing only the main part of an embodiment of the laser radar device.
The "portion drawn below" in the figure is the two-dimensional scanning laser beam projection apparatus described with reference to FIG. 2, and the upper part in the figure indicates "light receiving means".
The two-dimensional scanning type laser beam projection apparatus two-dimensionally deflects and scans the polarized laser beam LB and projects it onto a detection target (an object to be subjected to distance measurement).

The “light receiving means” is a means for receiving the reflected laser light LO diffused and reflected by the detection target onto which the two-dimensionally scanned deflected laser beam LB is projected.
The light receiving means has a light receiving element 20 and a focusing optical system 22 for focusing the reflected laser light LO onto the light receiving element 20.
The laser radar device also has control calculation means for controlling the blinking of the laser light source of the laser beam projection device and performing necessary calculations on the output of the light receiving element 20.

The laser light source is turned on, and the polarized laser beam LB is scanned two-dimensionally to be projected on the detection target, and the reflected laser light LO is received by the light receiving element 20.
In this way, "time for laser light to travel to the object: T" is detected, and using the speed of light c, the distance: DS is detected as cT / 2.
According to the two-dimensional scanning of the polarized laser beam LB, the “distance to the detection target” to be measured can be two-dimensionally measured.
Alternatively, the distance can be determined by emitting a phase-modulated laser beam from the laser light source and detecting a phase difference from the reflected laser beam LO received by the light receiving element 20.
Since these ranging methods are already known, detailed description will be omitted.

Various types of "two-dimensional distance measuring devices" are known.
In the example shown in FIG. 4, it is a so-called “biaxial type” in which the reflected laser light LO is condensed on the light receiving element 20 by the condensing optical system 22 separate from the deflection angle variable magnification element 18.
However, it is also possible to make the deflection angle variable magnification element 18 itself a "coaxial type" laser radar device that uses it as a focusing optical system.
The two-dimensional scanning laser beam projection apparatus of the present invention can be suitably used as a laser beam projection unit in these various laser radar apparatuses.

In the laser beam projection apparatus of the embodiment described above with reference to FIG. 2, the expansion of the deflection angle by the deflection angle variable magnification element 18 is performed in the “lateral direction”.
However, the present invention is not limited to this, and the expansion of the deflection angle can be performed in "both the longitudinal and lateral directions".
That is, in the example described above, instead of the deflection angle variable magnification element 18, at least one of the incident side surface and the emission side surface is made a two-dimensional curved surface, and using two dimensional curved surface refraction, they are orthogonal to each other. It is possible to carry out "expansion of deflection angle" in two directions.

For example, in the example described above, the surface on the incident side of the deflection angle variable magnification element 18 is a concave cylinder surface, but it may be replaced by a “two-dimensional concave surface”.
The two-dimensional concave surface may be a "concave spherical surface" or an "anamorphic concave surface" having different curvatures in directions orthogonal to each other.
If an anamorphic concave surface is used, it is possible to set the enlargement factors of deflection angle enlargement differently in two directions orthogonal to each other.

In the example described above, the surface on the exit side of the deflection angle variable magnification element 18 is a plane, but the surface shape on the exit side is not limited to this, and may be a convex surface or a concave surface.
The “convex surface or concave surface” may also be a convex or concave cylinder surface, a convex spherical surface or a concave spherical surface with rotational symmetry of the optical axis, or an anamorphic convex surface or concave surface.
In the laser beam projection apparatus described with reference to FIG. 2, “the laser light source is a laser that is collimated by the collimator element 12 as the coupling lens 12 that collimates the laser beam from the LD 10 together with the LD 10. And a condenser lens 13 as an adjustment lens for condensing the beam in at least one direction.
The laser beam LA focused by the focusing lens 13 is two-dimensionally deflected by the deflecting device 14 to be incident on the deflection angle variable magnification element 18.
The laser beam LD incident on the deflection angle varying element 18 at a deflection angle of 0 converges in one direction at a position where the “object side focal point in the lateral direction” of the deflection angle changing element 18 should be occupied.

Here, "the expansion concentric coefficient: CE" is defined as follows.
As shown in FIG. 5, the distance between the “point of origin of deflection” by the deflecting device 16A and the incident surface 18A of the deflection angle variable element 18 is “L”.
Further, the curvature radius of the incident surface side 18A of the deflection angle variable magnification element 18 is set to "R (<0)".

At this time, the expansion concentric coefficient: CE is defined as follows.
CE = L / (-R).

When the incident surface 18A of the deflection angle variable magnification element 18 is a concave cylinder surface, the radius of curvature R is a radius of curvature in a direction orthogonal to the direction without curvature (the axial direction of the cylinder surface).
If the incident surface is a two-dimensional concave surface, the radii of curvature are in two directions (two vertical and two directions in the above example) orthogonal to each other, and these are referred to as RA and RB. In the case of a concave spherical surface, RA = RB = R.
Expanded concentric coefficient: CE, condition:
(1) 0.8 <CE <1.5
It is preferable to satisfy
In the case of a two-dimensional concave surface, it is preferable that the above conditions are satisfied with respect to the radiuses of curvature: RA and RB in the orthogonal two directions.

If the concentric coefficient: CE is outside the range of the condition (1), the beam diameter of the laser beam whose deflection angle is expanded is likely to increase twice or more, and the resolution tends to be lowered when projected onto the detection target.
Also, “angular distortion”, which indicates the degree of expansion of the laser beam whose deflection angle is expanded, tends to decrease at 0.8 or less, and the “degree of expansion” of the deflection angle decreases.

Hereinafter, specific numerical values of the optical system portion related to the two-dimensional scanning laser beam projection apparatus described with reference to FIG. 2 will be described as an example.
In the following, “distance: L” is “the distance between the origin of deflection by the deflection device and the incident surface of the deflection angle variable magnification element” described with reference to FIG.
“Distance: SL” is the distance between the condensing lens (adjustment lens) 13 and the incident surface (the distance when the incident angle is 0).

"Example 1"
The deflection angle variable magnification element, the adjusting lens, their layout, and the enlargement concentric coefficient according to Example 1 are shown in Table 1.

"Deflecting angle"
The data of the deflection angle in Example 1 is shown below.
Let α and β be directions orthogonal to each other, where α is the “horizontal direction” and β is the “vertical direction”.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 2.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 3.

"Data of expansion of deflection angle of laser beam in β direction"
The data of expansion of the deflection angle of the laser beam in the β direction is shown in Table 4 as angular distortion.

The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 5 with respect to the α direction.

"Example 2"
The deflection angle variable magnification element, the adjusting lens, their layout, and the enlargement concentric coefficient according to Example 2 are shown in Table 6.

"Deflecting angle"
The data of the deflection angle in the second embodiment will be shown below in accordance with the first embodiment.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 7.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 8.

"Data of expansion of deflection angle of laser beam in β direction"
The data of expansion of the deflection angle of the laser beam in the β direction is shown in Table 9 as angular distortion.

The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 10 with respect to the α direction.

"Example 3"
The deflection angle variable magnification element, the adjusting lens, their layout, and the enlargement concentric coefficient according to Example 3 are shown in Table 11.

"Deflecting angle"
The data of the deflection angle in Example 3 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 12.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 13.

"Data of expansion of deflection angle of laser beam in β direction"
The data of expansion of the deflection angle of the laser beam in the β direction is shown in Table 14 as angular distortion.

The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 15 with respect to the α direction.

"Example 4"
The deflection angle variable magnification element, the adjusting lens, their layout, and the enlargement concentric coefficient according to Example 4 are shown in Table 16.

"Deflecting angle"
The data of the deflection angle in Example 4 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 17.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 18.

"Data of expansion of deflection angle of laser beam in β direction"
The data of the expansion of the deflection angle of the laser beam in the β direction is shown in Table 19 as angular distortion.

The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 20 with respect to the α direction.

"Example 5"
Deflection angle variable magnification elements, adjustment lenses, layouts thereof, and enlargement concentric coefficients according to Example 5 are shown in Table 21.

"Deflecting angle"
The data of the deflection angle in Example 5 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 22.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 23.

Since the deflection angle variable magnification element has no power in the β direction, the angular distortion in the β direction is zero.
The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 24 with respect to the α direction.

"Example 6"
Deflection angle variable magnification elements, adjustment lenses, layouts thereof, and enlargement concentric coefficients according to Example 6 are shown in Table 25.

"Deflecting angle"
The data of the deflection angle in Example 6 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 26.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 27.

Since the deflection angle variable magnification element has no power in the β direction, the angular distortion in the β direction is zero.
The beam diameters of the laser beams whose deflection angles are expanded are shown in Table 28 with respect to the α direction.

"Example 7"
Deflection angle variable magnification elements, adjustment lenses, layouts thereof, and enlargement concentric coefficients according to Example 7 are shown in Table 29.

"Deflecting angle"
The data of the deflection angle in Example 7 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 30.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 31.

Since the deflection angle variable magnification element has no power in the β direction, the angular distortion in the β direction is zero.
The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 32 with respect to the α direction.

"Example 8"
Deflection angle variable magnification elements, adjustment lenses, layouts thereof, and enlargement concentric coefficients according to Example 8 are shown in Table 33.

"Deflecting angle"
The data of the deflection angle in Example 8 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 34.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 35.

Since the deflection angle variable magnification element has no power in the β direction, the angular distortion in the β direction is zero.
The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 36 with respect to the α direction.

"Example 9"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the enlargement concentric coefficient according to Example 9 are shown in Table 37.

"Deflecting angle"
The data of the deflection angle in Example 9 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 38.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 39.

Since the deflection angle variable magnification element has no power in the β direction, the angular distortion in the β direction is zero.
The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 40 with respect to the α direction.

"Example 10"
The deflection angle variable magnification element, the adjusting lens, their layout, and the enlargement concentric coefficient according to Example 10 are shown in Table 41.

"Deflecting angle"
The data of the deflection angle in Example 10 is shown below.
“Data of expansion of deflection angle of laser beam in α direction” is shown in Table 42.

"Angular distortion in the α direction"
The angular distortion in the α direction is shown in Table 43.

Since the deflection angle variable magnification element has no power in the β direction, the angular distortion in the β direction is zero.
The beam diameter of the laser beam whose deflection angle has been expanded is shown in Table 44 with respect to the α direction.

As shown in Examples 1 to 10, the deflection angle by the deflection device: ± 30 degrees could be “expanded to ± 60 degrees or more”.
Also, the variation of the beam diameter of the laser beam whose deflection angle is expanded does not exceed twice.

The “angular distortion” is defined as follows.
Assuming that the scanning deflection angle by the deflection angle variable magnification element 18 is “θ 0” when the reflecting surface of the deflecting device 16A is inclined 0.5 degrees, the scanning deflection angle when the reflecting surface is inclined by an angle “θ” is “ It is assumed that θ1.
At this time, the “angular distortion” is calculated as follows.
[{Θ1 / (θ0 × 2θ)} × 100]-100 (%)
For example, taking the case of the first embodiment described above as an example, the angular distortion at θ = 15 degrees by the deflecting device in the α direction will be calculated.

When the reflecting surface of the deflecting device is inclined by 0.5 degrees, the reflected laser beam enters a deflection angle variable magnification element, and the deflection angle θ0 is 1.78 degrees.
Therefore, 30θ0 = 30 × 1.78 = 53.4 degrees. On the other hand, the enlarged deflection angle when θ = 15 degrees (the deflection angle of the deflection device is 30 °): θ1 is 62.92 degrees from Table 1.
Therefore, the angular distortion in the α direction is
(62.92 / 53.4) x 100-100 = 17.827
It becomes. Therefore, the "angular distortion at an enlarged deflection angle of 60 degrees" is 17.83 as shown in Table 2.

Embodiment 5 In each of the following embodiments, since the deflection angle variable magnification element 18 has no power in the β direction, the numerator and denominator of the fraction in the right side parenthesis in the definition equation of the above angle distortion become equal. Is zero.
Incidentally, the deflection angle: θ 0 is as follows in Examples 1 to 10.
Example 1 (1.78), Example 2 (1.71), Example 3 (1.94), Example 4 (1.82), Example 5 (1.78), Example 6 (1. 71), Example 7 (1.94), Example 8 (1.82), Example 9 (1.67), Example 10 (1.97).

Further, the enlarged deflection angle: θ 1 is as follows in Examples 1 to 10.
Example 1 (62.92), Example 2 (62.86), Example 3 (62.88), Example 4 (62.92), Example 5 (62.92), Example 6 (62) 86), Example 7 (62.88), Example 8 (62.92), Example 9 (62.89), Example 10 (62.91).
By using these values, the angular distortion in the α direction shown in each embodiment can be obtained according to the above definition formula.

It goes without saying that the present invention is not limited to the embodiments and examples described above. The present invention is not limited to the embodiments and examples described above, and various embodiments and the like are possible.

FIG. 6 is a diagram for explaining another embodiment of the laser radar device, and illustrates the main parts in an explanatory manner.
The laser radar device of this embodiment is a "coaxial type" (hereinafter also referred to as "coaxial system").
In FIG. 6, reference numeral 10 denotes the "semiconductor laser (" LD 10 ")" as before.
The reference numeral 12 denotes a "collimator lens", the reference numeral 13B denotes a "adjustment lens", and the reference numeral 40 denotes a "mirror for turning back the light path for illumination".
The collimator lens 12 is called “coupling lens 12” in the description of the embodiment of FIGS. 1 and 2 to 5.

The reference numeral 14 denotes a "deflection device", and the reference numeral 18 denotes a deflection angle scaling element as a "deflection angle reduction element which is a deflection angle scaling element".

Reference numeral 30 is a "light receiving element", reference numeral 32 is a "condenser lens", reference numeral 34 is a "light receiving lens", reference numeral 40A is a "mirror for returning the light path for receiving light", and reference numeral 400 is a "control operation unit". Show.
When the laser light source 10 emits light, the emitted laser light is collimated by the collimator lens 12 and enters the adjustment lens 13B.

The adjustment lens 13B has a positive refractive power and gives a “converging tendency” to the laser beam incident from the collimator lens 12 side.
The laser beam which is given the tendency to converge is bent in its optical path by the mirror 40 and is incident on the deflecting device 14.
The deflection device 14 is a known deflector configured as a two-axis MEMS, and "performs two-dimensional motion of the mirror portion" to deflect the reflected light two-dimensionally.
That is, the two-dimensional peristalsis of the mirror unit is a peristalsis with a direction perpendicular to the drawing as a peristalsis axis and a peristalsis with a direction parallel to the drawing as a peristalsis axis, and these peristalsis is superimposed.
The deflecting device 14 is similar to the deflecting device in the embodiment described above with reference to FIG. Therefore, the description uses the previous explanation regarding FIG. 1 (b).

The laser beam two-dimensionally deflected by the deflecting device 14 oscillates in the “in a plane parallel to the drawing” of FIG. 6 and also oscillates in the “direction orthogonal to the drawing”.
As described above, the laser beam from the LD 10 is two-dimensionally deflected by the deflection device 14 and enters the deflection angle variable magnification element 18 and is emitted as the deflection laser beam SRL.
The deflection angle variable magnification element 18 has “positive refractive power”, and reduces the deflection angle of the deflection laser beam SRL in at least one direction with respect to the deflection angle by the deflection device 14 as described later.

The polarized laser beam SRL is irradiated on the object to be detected while being deflected two-dimensionally, and scans the object to be detected two-dimensionally.
That is, in the embodiment shown in FIG. 6, the “two-dimensional scanning type laser beam projection apparatus” has the LD 10, the collimator lens 12, the adjusting lens 13B, the mirror 40, the deflecting device 14 and the deflection angle variable magnification element 18.
The laser beam reflected by the object to be detected becomes a returning laser beam BKL, and is incident on the deflection angle variable magnification element 18.

Generally, the distance between the object to be detected and the deflection angle varying element 18 is larger than the effective diameter of the deflection angle varying element 18. Therefore, the return laser beam BKL reflected by the object to be detected and incident on the deflection angle variable magnification element 18 is "parallel in the same direction" as the deflection laser beam SRL in a substantially parallel beam state.
The return laser beam BKL incident on the deflection angle variable magnification element 18 is given a convergence tendency by the positive refractive power of the deflection angle magnification element 18, and is incident on the deflection device 14 and reflected.
The return laser beam BKL reflected by the deflecting device 14 is bent in the optical path by the mirror 40A and is incident on the light receiving lens 34.
When the return laser beam BKL is converged by the deflection angle variable magnification element 18, it converges in front of the light receiving lens 34 on the light path and then diverges and enters the light receiving lens 34.

The return laser beam BKL transmitted through the light receiving lens 34 is condensed toward the light receiving element 30 via the condensing lens 32 and received by the light receiving element 30.
That is, the deflection angle variable magnification element 18, the deflecting device 14, the mirror 40A, the light receiving lens 34, the condensing lens 32, and the light receiving element 30 constitute "a detection means for detecting the return laser beam BKL reflected by the object to be detected". Do.
That is, of the optical system for projecting the deflection laser beam SRL, the deflection angle variable magnification element 18 and the part of the deflecting device 14 are shared as a part of the optical system for detection.

When receiving the return laser beam BKL, the light receiving element 30 sends a light reception signal (amplified by an appropriate amplification factor) to the control operation unit 400.
The main part of the control calculation unit 400 is constituted by a CPU, a microcomputer and the like, and controls each unit of the “laser radar device” shown in FIG. 6 to calculate the distance to the detection target.
That is, the control operation unit 40 causes the LD 10 to emit light in pulses, determines the time: 2T from the moment of pulse light emission to the moment of receiving the light reception signal, and calculates the distance: cT using the light speed: c.

Acquisition of time: 2T and calculation of distance: cT are repeated according to the deflection of the polarized laser beam SRL to obtain a two-dimensional distance to the object to be detected, that is, a "three-dimensional shape of the object to be detected".
That is, the control calculation unit 40 constitutes "control calculation means".

As described above, the laser radar device shown in FIG. 6 has the above-mentioned "two-dimensional scanning laser beam projection device", "detection means" and "control operation means".
The light flux form of the deflection laser beam SRL emitted from the deflection angle variable magnification element 18 can be “parallel light flux”, “convergent light flux”, or “divergent light flux”.
Assuming that the beam form of the polarized laser beam SRL is “parallel beam”, the beam diameter can be regarded as substantially unchanged on the way to the detection target, and the light intensity can also be regarded as substantially unchanged.

Therefore, regardless of the distance to the object to be detected, the object to be detected can always be two-dimensionally scanned with the “polarized laser beam of the same intensity”, and stable distance measurement can be performed.
It should be noted that the term "parallel light flux" does not mean that this is "strict parallel light flux". In the implementation state of the laser beam projection apparatus or the laser radar apparatus, it is sufficient to have the degree of parallelism to be recognized as substantially parallel light flux. Such a luminous flux form is called "parallel luminous flux".

In fact, even if the deflected laser beam SRL projected from the laser beam projection apparatus is a "perfect parallel beam", when the deflected laser beam SRL travels, "deviation from the collimated beam" due to the influence of the atmosphere and diffraction. Will occur.

However, such "displacement" does not affect the identity of the intensity of the polarized laser beam SRL, and can be ignored.
Assuming that the deflected laser beam SRL is a “converged beam”, for example, the deflected laser beam SRL can be condensed as a small diameter spot on a detection target at a specific position from the laser radar device, and the three-dimensional surface shape of the detection target Can be measured with high accuracy.
Conversely, if the deflection laser beam SRL is a "divergent beam", the beam diameter of the deflection laser beam SRL irradiated to the object to be detected can be enlarged, and the measurement accuracy can be stabilized.

In the embodiment described above with reference to FIG. 6, "a case of realizing a collimated luminous flux deflection laser beam SRL" will be described.
As described above, the adjusting lens 13B has a positive refractive power, and the laser beam collimated by the collimator lens 12 is given a "focusing tendency" by the adjusting lens 13B.
Then, the laser beam is bent in the optical path by the irradiation optical path bending mirror 16B and is incident on the deflecting device 14, and is two-dimensionally deflected by the deflecting device 14, and the deflected laser beam is converted into a collimated beam It is converted into a beam SRL and emitted.
That is, the convergence tendency given to the laser beam by the adjusting lens 13B is canceled by the deflection angle variable magnification element 18 to be collimated.

For the following description, X, Y, and Z directions orthogonal to one another are determined as shown in the figure.
The X direction is "a direction orthogonal to the drawing" and corresponds to what is called "lateral direction or horizontal direction" in the above description. The Y direction corresponds to the "vertical direction in the drawing", which is called the "vertical direction or the vertical direction" in the above description. The Z direction is a direction parallel to the optical axis AX of the deflection angle variable magnification element 18. The optical axis of the adjustment lens 13B is also parallel to the Z direction.
The convergence tendency given to the laser beam by the adjustment lens 13B and the recovery to a parallel beam by the deflection angle variable magnification element 18 can be various combinations.

For example, in FIG. 6, the adjusting lens 13B is a positive lens rotationally symmetric (hereinafter referred to as “axially symmetric”) around the optical axis, and gives the laser beam a convergence tendency in the X direction and the Y direction.
On the other hand, the deflection angle variable magnification element 18 is also an “axisymmetric positive lens”, and the arrangement is determined such that the focal position on the object side is the point PF in FIG.
When the adjusting lens 13B is displaced in the Z direction, the "focusing position at which the laser beam having a converging tendency is focused" moves in the optical axis direction.

Therefore, the adjusting lens 13B is positionally adjusted in the optical axis direction so that the light collecting position "matches with the point PF". In the example being described, the laser beam incident on the adjustment lens 13B from the side of the collimator lens 12 is a "parallel beam", so the "focus position" is the image-side focal position of the adjustment lens 13B.
Accordingly, the optical conditions for emitting “a collimated laser beam that has been converted to a collimated light beam” from the deflection angle variable magnification element 18 are the image side focal position of the adjustment lens 13 B and the deflection angle magnification element 18 in the example being described. The object-side focal position (the point "PF") of
In this way, the deflection angle variable magnification element 18 emits the collimated laser beam SRL.
The method of realizing the collimated deflected laser beam is not limited to the method described above.

For example, the following method is also possible.
The adjusting lens 13B is set as "a lens having a positive refractive power only in the X (or Y) direction".

In this case, the collimated laser beam from the side of the collimating lens 12 is given a convergence tendency in the X (or Y) direction by the adjusting lens 13B.
At this time, the laser beam is not given a tendency to converge in the Y (or X) direction, and maintains a parallel light flux state.

By adjusting the position of the adjusting lens 13B in the optical axis direction, the focusing position (image-side focal position) in the X (or Y) direction is made to coincide with the point PF.
On the other hand, the focal angle position in the X (or Y) direction on the object side is positioned at the point PF as "a lens having positive refractive power only in the X (or Y) direction" as well as the deflection angle variable magnification element 18.
In this way, the convergence tendency in the X (or Y) direction given by the adjusting lens 13B is recovered by the deflection angle variable magnification element 18, and a collimated laser beam SRL is obtained.
That is, by adjusting the displacement of the adjusting lens 13B in the optical axis direction to adjust the incident state to the deflection angle variable magnification element 18, it is possible to make the deflection laser beam SRL in a parallel light flux shape.

Another embodiment of the laser radar device will be described with reference to FIG. In order to avoid complexity, those which are considered to have no risk of confusion are given the same reference numerals as in FIG.
A difference from the embodiment shown in FIG. 6 is that both the adjusting lens 14C and the light receiving lens 34A are "negative lenses".
The laser beam collimated by the collimating lens 12 is given a "divergent tendency" by the adjusting lens 14C.
The laser beam is bent in its optical path by the mirror 40 and enters the deflecting device 14, is two-dimensionally deflected by the deflecting device 14, and is converted into “collimated laser beam SRL converted by the deflection angle variable element 18. Converted and injected.
That is, the diverging tendency given to the laser beam by the adjusting lens 14C is canceled by the deflection angle varying element 18 to be collimated.

In FIG. 7, the adjusting lens 13 </ b> C is an “axisymmetric negative lens” and gives the laser beam “a divergence tendency” in the X direction and the Y direction.
The deflection angle variable magnification element 18 is an “axisymmetric positive lens”, and the arrangement is determined such that the focal position on the object side thereof is the point PF1 in FIG.
When the adjusting lens 14C is displaced in the Z direction, the “origin of the diverging laser beam divergent” moves in the optical axis direction.
Therefore, by adjusting the position of the adjusting lens 14C in the optical axis direction, the point of origin of the divergence "is made to coincide with the point PF1".
That is, in the example of FIG. 7, the object-side focal position of the adjusting lens 14C and the object-side focal position of the deflection angle variable magnification element 200 are made to coincide at the point “PF1” in FIG.
In this way, the deflection angle variable magnification element 18 emits the collimated laser beam SRL.

According to the fact that the adjusting lens 14C is made “axisymmetric negative lens”, the light receiving lens 34A is also made axisymmetric negative lens.
When the return laser beam BKL is incident on the deflection angle variable magnification element 18, it is given a convergence tendency by the action of the deflection angle magnification change element 18, and is incident on the deflection device 14 and reflected.
The return laser beam BKL reflected by the deflecting device 14 is bent in the optical path by the light receiving path bending mirror 36 and is incident on the light receiving lens 34A.

The return laser beam BKL given a convergence tendency by the deflection angle variable magnification element 200 is incident on the light receiving lens 34A (with the image side focal point thereof as a focusing point) in the converged state.
Accordingly, the return laser beam BKL incident on the light receiving lens 34A is collimated by the negative refractive power of the light receiving lens 34A, condensed toward the light receiving element 30 by the condensing lens 32, and received by the light receiving element 30. Be done.
The “positive refractive power combination” of the adjusting lens 13B and the deflection angle variable magnification element 18 used in the embodiment of FIG. 6 has been described above.
That is, it is only necessary to "adjust the displacement of the adjusting lens 13B in the direction of the optical axis to adjust the incident state to the deflection angle variable magnification element 18 so that the polarized laser beam SRL has a parallel beam shape".

Above, the case where the lens (positive cylinder lens) having a positive refractive power only in the X (or Y) direction was mentioned as the adjusting lens 13B was mentioned.
However, the present invention is not limited to this, and the adjusting lens 13B can be a "positive anamorphic lens" having "positive refractive powers different from each other" in the X direction and the Y direction.
In this case, the deflection angle variable magnification element 18 is also a “positive anamorphic lens” having “different positive refractive powers” in the X direction and the Y direction.
In any of the above cases, the shape of the adjustment lens 13B is appropriately set according to the shape of the deflection angle variable magnification element 200, and the displacement of the adjustment lens 13B in the optical axis direction is adjusted to obtain a deflection angle magnification element 18, a collimated beam of deflected laser beam SRL can be emitted.

The same applies to the relationship between the adjusting lens 13C and the deflection angle variable magnification element 18 shown in FIG.
That is, the adjustment lens 13C is not limited to the above-described axially symmetric negative lens, but may be a "negative cylinder lens" having negative refractive power only in the X direction or only in the Y direction. It can also be a "negative anamorphic lens" having "different negative refractive powers" in the direction and the Y direction.
In any of these cases, the form of the adjusting lens 13C is set to "negative cylinder lens or negative anamorphic lens" according to the shape of the deflection angle variable magnification element 18, and the adjusting lens 13C is directed in the optical axis direction. The displacement adjustment is performed so that the object-side focal position of the adjustment lens 13C and the object-side focal position of the deflection angle variable magnification element 18 coincide with each other, and the deflection angle magnification change element 20 emits the parallel laser beam SRL. It can be done.

Above, in the embodiment shown in FIG. 6 and FIG. 7, the case of emitting the “parallel beam shape” polarized laser beam SRL from the deflection angle variable magnification element 18 has been described.

However, as described above, the deflection laser beam emitted from the deflection angle variable magnification element 18 is not limited to the parallel light flux, and may be a convergent light flux or a diverging light flux.

These cases will be briefly described.
FIG. 8 shows a portion of the laser beam projection system in FIG.
In order to simplify the description, an optical axis ray (a ray coincident with the optical axis of the collimator lens 12) from the collimator lens 12 to the deflection angle variable magnification element 18 is shown in a linearly expanded state.

For the sake of concreteness of description, it is assumed that both the adjustment lens 13B and the deflection angle variable magnification element 18 are axially symmetric positive lenses.
The adjustment lens 13B is displaceable in the optical axis direction (the Z direction in the drawing).
In FIGS. 8A and 8B, the case where the position of the adjusting lens 13B is at the “position indicated by a broken line” is referred to as a “reference position” of the adjusting lens 13B.

When the adjustment lens 13 B is at the reference position, the image-side focal position thereof coincides with the object-side focal position PF of the deflection angle variable magnification element 18. Therefore, in this case, as described above, the deflected laser beam SRL emitted from the deflection angle variable magnification element 18 is in the form of a parallel light flux as indicated by the "broken line".
When the adjustment lens 13B is shifted to the side of the collimator lens 12 with respect to the reference position as shown by the solid line in FIG. 8A, the position PFC of the image-side focal point of the adjustment lens 13B is obtained by The object side focal position PF is shifted to the object side.
The laser beam from the collimating lens 12 is condensed at the position PFC of the image side focal point of the adjusting lens 13 B and then diverges and enters the deflection angle variable magnification element 18.
At this time, the position PFC of the image side focal point is located on the object side with respect to the position PF of the object side focal point of the deflection angle variable magnification element 200, and the deflection laser beam SRLC is emitted from the deflection angle magnification element 18 as a "converging light beam". Do.

When the adjusting lens 13B is shifted toward the deflection angle changing element 18 with respect to the reference position as shown by the solid line in FIG. 8B, the position PFD of the image side focus of the adjusting lens 13B is changed to the deflection angle changing magnification. It is shifted to the image side from the position PF of the object side focal point of the element 18.
In this case, since the position PFD of the image side focal point is on the image side of the focal position PF, the deflected laser beam SRLD emitted from the deflection angle variable magnification element 18 becomes a “divergent light beam”.

FIG. 9 shows a portion of the laser beam projection apparatus in FIG.
In order to simplify the description, optical axis rays from the collimator lens 12 to the deflection angle variable magnification element 18 are shown in a linearly expanded state.

For the sake of concreteness of description, it is assumed that both the adjustment lens 13C and the deflection angle variable magnification element 18 are axially symmetric lenses. The adjustment lens 13C is an “axisymmetric negative lens”.

The adjustment lens 13C is displaceable in the optical axis direction (the Z direction in the drawing).
In FIGS. 9A and 9B, the case where the position of the adjusting lens 13C is at the “position indicated by a broken line” is referred to as a “reference position” of the adjusting lens 13C.
When the adjustment lens 13C is at the reference position, the position of the object-side focal point thereof coincides with the position PF1 of the object-side focal point of the deflection angle variable magnification element 18. Therefore, in this case, as described above, the deflected laser beam SRL emitted from the deflection angle variable magnification element 18 is in the form of a parallel luminous flux as indicated by the “broken line”.

When the adjustment lens 13C is shifted toward the collimating lens 12 with respect to the reference position as shown by the solid line in FIG. 9A, the position PFC of the object-side focal point of the adjustment lens 14C is determined by The object side focal point PF1 is shifted to the object side.
Therefore, in this case, the laser beam from the collimator lens 12 becomes a "divergent luminous flux" starting from the position PFC of the object-side focal point of the adjustment lens 13C and enters the deflection angle variable magnification element 18.
At this time, since the diverging start point PFC is closer to the object side than the focal point position PF, the deflected laser beam SRLC emitted from the deflection angle variable magnification element 18 has “convergence”.

When the adjustment lens 13C is shifted toward the deflection angle variable element 18 with respect to the reference position as shown by the solid line in FIG. 9B, the position PFD of the object-side focal point of the adjustment lens 13C is a deflection angle magnification It is shifted to the image side of the position PF1 of the object-side focal point of the element 18.
Thus, the laser beam from the collimating lens 12 enters the deflection angle variable magnification element 18 as a divergent light beam originating from the position PFD of the object side focal point of the adjustment lens 13C.
At this time, since the diverging start point PFD is on the image side of the focal point position PF1, the deflected laser beam SRLD emitted from the deflection angle variable magnification element 20 becomes “divergent”.
The return laser beam BKL is in the parallel beam state when it is incident on the deflection angle variable magnification element 18 as described above. Therefore, as the "detection means" also in the cases of FIG. 8 and FIG. The same ones can be used.

The beam form of the deflected laser beam emitted from the deflection angle variable magnification element is a collimated beam or a convergent beam depending on the situation to be used when the laser radar apparatus is implemented. It can be determined as a design condition whether it is a divergent beam.
In such a case, the "optical relationship" between the adjustment lenses 13B and 13C and the deflection angle variable magnification element 18 can be set in accordance with the light beam form of the deflection laser beam.
By setting and fixing the optical arrangement of the laser beam projection apparatus so as to realize the optical relationship set in this way, it is possible to realize a collimated light beam or a desired "convergent light beam or divergent light beam" polarized laser beam. .

Here, “displacement in the optical axis direction” of the adjustment lenses 13B and 13C will be described.
In each of the embodiments described above, the control calculation unit 400, which is a control calculation unit, performs displacement of the adjusting lenses 13B and 13C in the optical axis direction.
That is, the control calculation unit 400 has a "parallel movement mechanism" for displacing the adjustment lenses 13B and 13C in the optical axis direction, and has a function to "control the direction or movement amount" of the parallel movement.
In the embodiment described above with reference to FIGS. 6 and 7, the position of the image-side focal point of the adjustment lens 13B and the position of the object-side focal point of the adjustment lens 13C The adjustment lenses 13B and 13C are displaced in order to match the position of the side focus.
As described above with reference to FIGS. 8 and 9, the displacement of the adjusting lenses 13 B and 13 C on the optical axis allows the light beam form of the deflection laser beam emitted from the deflection angle variable magnification element 18 to be It can be changed into parallel light flux (SRL), convergent light flux (SRLC), and divergent light flux (SRLD).

Not only that, in the case where the deflection laser beam is a convergent beam or in the case of a divergent beam, the “degree of convergence or divergence” can also be changed.
That is, by adjusting the displacement of the adjustment lens in the optical axis direction, it is possible to change the form of the laser beam emitted from the deflection angle variable magnification element.
Therefore, the control calculation unit 40 can have a function of adjusting the displacement of the adjustment lens so as to set the light beam form of the deflection laser beam emitted from the deflection angle variable magnification element to a desired form.

The adjustment may be performed by controlling the parallel movement mechanism by programming control by control means such as a CPU provided in the control calculation unit 40, or the parallel movement mechanism may be manually adjusted.
Above, the adjustment lenses 13B and 13C and the deflection angle variable magnification element 200 are all described as “axisymmetric lenses rotationally symmetric around the optical axis”.
However, these lenses can also be used as "anamorphic lenses" such as cylinder lenses.

As an example of such a case, the case where both of the adjustment lens and the deflection angle variable magnification element are “cylinder lenses” will be described with reference to FIG.
FIG. 10 shows, for example, a state in which the state of “change of the diameter of the luminous flux of the laser luminous flux” in the XZ plane in the above description is virtually linearly expanded in the optical path from the laser light source 10 to the deflection angle variable magnification element 18C. As shown.
The adjusting lens 13B and the deflection angle variable magnification element 18C are both "cylinder lenses having no refractive power in the XZ plane".

Therefore, the beam diameter of the laser beam emitted from the laser light source 10 and collimated by the collimator lens 12 does not change in the "XZ plane" as shown in FIG. The light enters the magnification changing element 18C.
Since the deflection angle variable magnification element 18C also "does not have refractive power in the XZ plane", the polarized laser beam SRL emitted from the deflection angle magnification element 18C is in a parallel state in which a collimated state is maintained by the collimator lens 12 It is.

The sectional shape of the adjusting lens 13B in the direction (in the YZ plane) orthogonal to the drawing of FIG. 10 is also shown in FIG. 7 as being the “cross sectional shape of a positive lens” like the adjusting lens 13B of FIG. It can also be a "cross-sectional shape of a negative lens" such as the adjustment lens 13C.
Therefore, in the YZ plane, the displacement start point (the above-described positions PFC and PFD) in the YZ plane of the “laser beam toward the deflection angle variable magnification element 18C” can be displaced by the displacement of the adjustment lens 13B. At this time, the beam diameter of the laser beam “in the XZ plane” does not change.
Therefore, by adjusting the displacement of the adjustment lens 13B, it is possible to adjust only the "form of light in the YZ plane" of the deflected laser beam emitted from the deflection angle variable magnification element 20C.

In the following, the characterizing portion of the “two-dimensional scanning laser beam projection apparatus” shown in FIG. 6 and the following will be described in line with the embodiment of FIG.
As described above, the “two-dimensional scanning laser beam projection apparatus” in FIG. 6 includes the “laser light source” including the LD 10, the collimate lens 12, and the adjusting lens 13B, the irradiation path bending mirror 16B, and the deflecting device 14 And a deflection angle variable magnification element 18.
The mirror 40 can be omitted depending on the layout of the optical system.

The mirror 40A can also be omitted depending on the layout of the optical system.
The deflection angle variable magnification element 18 may be an axially symmetric positive lens or an anamorphic positive lens having different refractive powers in the X and Y directions.
The deflection angle variable magnification element 18 has a function of “reducing the deflection angle in at least one of the X direction and the Y direction”.
In FIG. 6, a plane including the optical axis AX of the deflection angle variable magnification element 18 and parallel to the Y direction (called the “YZ plane” in the above description) is called the “α plane”.
The angle in the figure: θα is the maximum deflection angle (hereinafter referred to as the “maximum deflection angle” in the α plane) at which the deflecting device 14 deflects the “laser beam directed to the deflection angle variable element 18” in the α plane. Represents

Of the laser light emitted from the LD 10, a light beam that coincides with the optical axis of the collimator lens 12 is called a "central light beam".
The "deflection angle" is the angle between the deflected central ray and the optical axis of the deflection angle variable magnification element.
On the other hand, when the laser beam having the maximum deflection angle: θα is incident on the deflection angle variable magnification element 200 in the α plane, the central ray of the deflection laser beam SRL emitted from the deflection angle magnification element 200 is the optical axis AX. The angle made with respect to: θ _Dα is called “the maximum scanning deflection angle in the Y direction”.

The fact that the deflection angle variable magnification element 18 has "a function to reduce the deflection angle in the Y direction" means that the maximum scanning deflection angle: _θDα is smaller than the maximum deflection angle: θα in the α plane (θ _Dα <θα Means that).
Angle: θ _Dα When considering θ _α as positive or negative, it is “0 ≦ | θ _{D α} | <| θ α |”.
Generally, “the deflection angle in the positive direction of Y in the α plane” by the deflection device 14 is “θY (0 ≦ θY ≦ θα)”.
In addition, the scanning deflection angle with respect to the deflection angle: θY (the positive angle that the deflection laser beam emitted from the deflection angle variable magnification element 200 makes with the optical axis AX in the α plane) is “θy (0 ≦ θy ≦ θ _Dα ) "

At this time, in the case where “reduction of the deflection angle” is performed in the α plane, that is, in the Y direction, “θY> θy” is generally satisfied.
As described above, when the deflection angle is reduced in the Y direction, “the reduction ratio (%) of the deflection angle in the Y direction” is defined by the following equation.
Reduction ratio of deflection angle in Y direction = "{1- (θy / θY)} × 100"
The deflection of the laser beam by the deflection device 14 and the deflection angle variable element 18 is symmetrical with respect to the optical axis AX in the α plane.
That is, the deflection angle: θY described above changes in the range of ± θα, and the scanning deflection angle: θy changes in the range of ± _θDα .

FIG. 6 shows the state of deflection in the “α plane” as described above, but the “reduced concentric coefficient in the α plane” is defined as follows.
As shown in FIG. 6, the "incident side" of the deflection angle variable magnification element 18 is referred to as an entrance surface 18A, and the exit side is referred to as an exit surface 18B.
A deflection angle variation element 18 of the central ray of the laser beam deflected by the deflection device 14 at the maximum deflection angle: θα with respect to the optical axis AX in the α plane and refracted at the incident surface 18A of the deflection angle variation element 18 The portion of the lens in the lens is called "central ray in the lens in the .alpha.

As shown in the figure, an extension line ETL extending toward the deflecting device 14 in the α plane is “intersecting with the optical axis AX of the deflection angle variable magnification element 18 at the intersection position Qα”.
Further, the in-lens central ray PL intersects the exit surface 18B of the deflection angle variable magnification element 18 at the intersection position qα.
A component in the direction of the optical axis AX of "the distance between the intersection points Qα and qα" in the α plane is "Aα" as shown in the figure.
On the other hand, it is assumed that the exit surface 18B of the deflection angle variable magnification element 18 has a radius of curvature: Rα in the α plane. According to the definition of the radius of curvature in a normal lens surface, the radius of curvature is considered to be positive or negative.

The laser beam transmits the deflection angle variable magnification element 18 from the left side to the right side of the figure, so the right side of the figure is taken as the “positive direction”. The center of curvature of the exit surface 18B is located to the left or "negative side" of the exit surface in the figure. Therefore, the radius of curvature: Rα has "negative magnitude".
At this time, the reduced concentric coefficient Cα in the α plane is defined as follows.

Cα≡ | Aα / Rα |
Next, considering the direction orthogonal to the drawing in FIG. 6, that is, the X direction, a plane including the optical axis AX of the deflection angle variable magnification element 18 and parallel to the X direction is called a “β plane”.
The maximum deflection angle by the deflecting device 14: _θβ and the maximum scanning deflection angle in the X direction: _θDβ can be defined for the “β plane” just as described above.
Further, the deflection angle of X in the positive direction in the β plane: θX (0 ≦ θX ≦ θβ), the deflection angle: the scanning deflection angle with respect to θX (the deflection laser beam emitted from the deflection angle variable element 18 is light in the β plane A positive angle with respect to the axis AX): θx (0 ≦ θx ≦ θ _Dβ ) can be defined.
In this case, in the case where reduction of the deflection angle is performed in the β plane, that is, in the X direction, generally, “θX> θx”.

As described above, when the deflection angle is reduced in the X direction, “the reduction ratio (%) of the deflection angle in the X direction” is defined by the following equation.
“Reduction ratio of deflection angle in X direction (%)” = “{1− (θx / θX)} × 100”
The deflection of the laser beam by the deflection device 14 and the deflection angle varying element 18 is symmetrical with respect to the optical axis AX also in the β plane.
That is, the deflection angle: θX described above changes in the range of ± _θβ , and the scanning deflection angle: θx changes in the range of ± _θDβ .

The fact that the deflection angle variable magnification element 18 "has the function of reducing the deflection angle in the X direction" means that the maximum scanning deflection angle: _θDβ is smaller than the maximum deflection angle: _θβ in the β plane (θ _Dβ < _θβ Means that).
In the β plane, the deflection device 14 deflects the light beam at a maximum deflection angle θβ with respect to the optical axis AX, and refracts the central ray of the laser beam refracted by the incident surface 18A of the deflection angle variable magnification element 20 The optical axis AX of the distance between the position where the extension line linearly extended to the 14 side intersects the optical axis AX, and the intersection position of the central ray in the lens and the exit surface 18B of the deflection angle variable magnification element 18 Let the distance component in the direction be Aβ.
Further, the reduction concentric radius Cβ is given by “the radius of curvature in the β plane: Rβ” of the exit surface 18 B of the deflection angle variable magnification element 18 and the above distance component: Aβ
Cβ≡ | Aβ / Rβ |
Define by

As is apparent from the above description, if the deflection angle variable magnification element 18 is axisymmetric and the maximum angle of two-dimensional deflection by the deflection device 14 is the same in the X direction and Y direction, then the reduced concentric coefficient: Cα and Cβ are equal to each other (Cα = Cβ).
The two-dimensional scanning laser projector according to the present invention satisfies the following conditions with respect to the “direction in which the deflection angle is reduced” among the reduction concentric coefficients: Cα and Cβ.
(2α) 0.5 ≦ Cα ≦ 1.8
(2β) 0.5 ≦ Cβ ≦ 1.8

The meaning of the reduced concentric coefficient is explained taking Cα as an example.

Reduced concentric coefficient: As is apparent from the definition of Cα, Cα is larger as “Aα is larger” and is larger as “the absolute value of Rα is smaller”.

The larger the angle at which the laser beam having the maximum deflection angle θα is refracted by the incident surface 18A of the deflection angle variable element 18 in the α plane, the closer the central ray PL in the lens becomes to be parallel to the optical axis AX , Distance component: A α becomes large.
Also, as the absolute value of the radius of curvature Rα in the α plane of the exit surface (convex surface) 18B of the deflection angle variable magnification element 18 decreases, the maximum scanning deflection angle _θDα also becomes closer to parallel to the optical axis AX.
As can be understood from this, the reduction concentric coefficient: Cα is related to the reduction ratio by the deflection angle variable magnification element 20 in the α plane, and the reduction concentricity coefficient: the reduction ratio of the deflection angle in the Y direction (% ) Is large.
Just as well, the "reduction rate of deflection angle in X direction (%)" is larger as the reduction concentric coefficient: Cβ is larger.

When viewing a two-dimensional scan of an object to be detected by the deflected laser beam SRL from the “quality surface”, the following two points become important.

That is, the “beam diameter” and the “angular distortion” of the two-dimensionally scanned deflected laser beam SRL.
The “beam diameter” is the size of the irradiation portion (hereinafter also referred to as “irradiation spot”) when the deflection laser beam SRL is irradiated in a spot shape on the ranging detection target.
In order to achieve good distance measurement, it is important that the beam diameter of the deflected laser beam is stable regardless of the deflection angle, and the angle distortion is also small.
Deterioration of the beam diameter is caused by “coma aberration” which is an off-axis aberration of the deflection angle variable magnification element according to the deflection angle.
For example, when the coma of the deflection angle variable magnification element increases in accordance with the deflection angle, the “beam diameter” collapses where the deflection angle is large, and the measurement accuracy is degraded in the portion where the deflection angle is large.

As the angular distortion increases, the scanning locus is likely to be distorted, and distortion is likely to occur in the acquired “three-dimensional shape of the detection object”.
The upper limit of the reduced concentric coefficient: Cα, Cβ relates to the angular distortion, and the lower limit relates to the beam diameter of the polarized laser beam, ie to the off-axis aberration.
If the reduction concentric coefficients: Cα and Cβ exceed the upper limits of the above conditions (2α) and (2β), the maximum value of the angular distortion tends to exceed “−20%”, and the distortion of the scanning locus becomes noticeable.
Reduced concentric coefficient: When Cα and Cβ exceed the lower limits of the above conditions (2α) and (2β),
The off-axis aberration becomes large, and it becomes easy to bring about "deterioration of the beam diameter" off-axis.

The above conditions (2α) and (2β) are general conditions, and the appropriate ranges of the upper and lower limit values of the conditions (2α) and (2β) are also the above depending on the “material and lens shape” of the deflection angle variable magnification element. Varies within the range.
For example, in the case of a deflection angle variable magnification element made of a material of the deflection angle variable magnification element 18, particularly a material having a high refractive index (for example, SF6) in terms of refractive index, the lower limit value of the reduction concentric coefficient is the condition (2α) It is preferable that the value is larger than the lower limit value of (2β) (for example, about 0.6).
Conversely, in the case of a deflection angle variable magnification element made of a material having a low refractive index (for example, BK7), the upper limit value of the reduction concentric coefficient is smaller than the upper limit values of the conditions (2α) and (2β) (for example, 1. 5) is good.

The reduced concentric coefficients described above: Cα and Cβ are defined in exactly the same manner as described above in the various lens configurations permitted for the adjustment lenses 13B and 13A and the deflection angle variable magnification elements 18 and 18C described above. Also in the case of these lens forms, the above conditions (2α) and (2β) are satisfied in the direction in which the deflection angle is reduced.
The combination of the adjustment lens and the form (axisymmetric shape, cylinder shape, anamorphic lens, etc.) of the deflection angle variable magnification element has been described above.
That is, “the shape of the deflection angle variable magnification element is adjusted according to the form of the adjustment lens, the displacement of the adjustment lens is adjusted in the direction of the optical axis, and the deflection angle magnification change element A combination is allowed that allows "injection".

As described above, by imposing the conditions (2α) and (2β) on the reduction concentric coefficients: Cα and Cβ, off-axis aberration and angular distortion can be within the allowable range.
Therefore, the beam shape of the deflected laser beam varies according to the deflection angle, but the variation of the beam diameter accompanying this variation is within the allowable range.
The reduced concentric coefficients described above: Cα and Cβ are collectively referred to as a reduced concentric coefficient: CR, and Cα and Cβ in the direction in which the deflection angle is reduced.
When the reduced concentric coefficient: CR is used, the conditions (2α) and (2β) described above are the conditions for the direction in which the deflection angle is reduced:
(2) 0.5 ≦ CR ≦ 1.8
It can be done.

Hereinafter, nine specific examples of the two-dimensional scanning laser beam projection apparatus described in FIG.
The following Examples 11 to 19 are specific examples in which both the adjusting lens and the deflection angle variable magnification element are positive lenses to obtain a parallel beam-like polarized laser beam.
The laser light source used as a laser light source has an operating wavelength of 870 nm.
In each embodiment, data on the adjustment lens and the deflection angle variable magnification element and the reduction concentric coefficient are listed.
In each embodiment, the distance L represents "the distance between the deflecting device and the incident side surface of the deflection angle variable element" along the optical axis of the deflection angle variable element, and the distance SL represents "the emission of the adjusting lens The distance from the side surface to the incident surface of the deflection angle variable magnification element when the deflection angle is 0 is represented.
The refractive index is for the used wavelength, and all the lenses are made (by SCHOTT).

Further, the maximum deflection angle by the deflection device is ± 30 degrees in the α plane and the β plane.

"Example 11"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 11 are shown in Table 45.

In Example 11, the deflection angle variable magnification elements are axisymmetric, and the reduction concentric coefficients: Cα and Cβ are equal to one another.
The deflection angles by the deflection apparatus in Example 11 and the scanning deflection angles by the deflection angle variable magnification element are shown in Table 46. These are in the above-mentioned α plane and β plane, and the unit is “degree”.

Since the deflection angle variable magnification element is axisymmetric, these angles in the α plane and β plane are substantially equal, and the “reduction rate of deflection angle” is “the maximum deflection angle ± 30 degrees in the α plane” 51.2% "and substantially equal in the beta plane.
The angular distortion (abbreviated as "ANDT" in the following table. The unit is "%") is shown in Table 47. The values in the α plane and in the β plane are equal.

Table 48 shows the relationship between the “deflection angle” and the beam diameter of the deflected laser beam SRL.
The values in the α plane and in the β plane are equal.
In Examples 11 to 19, "beam diameter" is a value obtained from a spot diagram at "a position of 3 m" from the exit surface of the deflection angle variable magnification element.

As shown in Tables 47 and 48, the maximum value of the angular distortion is also as small as -11.1, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
In addition, the maximum value of the beam diameter is also as small as 8.8 mm, and the resolving power is good.

"Example 12"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 12 are shown in Table 49.

Also in the twelfth embodiment, the deflection angle variable magnification elements are axisymmetric, and the reduction concentric coefficients: Cα and Cβ are equal to one another.
The deflection angles by the deflection apparatus in Example 12 and the scanning deflection angles by the deflection angle variable magnification element are shown in Table 50 according to Table 46.
Since the deflection angle variable magnification element is axisymmetric, these angles in the α plane and β plane are substantially equal, and the “reduction rate of deflection angle” is “the maximum deflection angle ± 30 degrees in the α plane” 30.3% 'and substantially equal in the beta plane.

The angular distortion is shown in Table 51. The values in the α plane and in the β plane are equal.

Table 52 shows the relationship between the “deflection angle” and the beam diameter of the deflected laser beam SRL. The values in the α plane and in the β plane are equal.

As shown in Tables 51 and 52, the maximum value of the angular distortion is also as small as -6.6%, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
Also, the maximum value of the beam diameter is as small as 17.2 mm, and the resolving power is good.

"Example 13"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 13 are shown in Table 53.

Also in the thirteenth embodiment, the deflection angle variable magnification element is axisymmetric, and the reduction concentric coefficients: Cα and Cβ are equal to one another.
The deflection angles by the deflection apparatus in Example 13 and the scanning deflection angles by the deflection angle variable magnification element are shown in Table 54 according to Table 46.
Since the deflection angle variable magnification element is axisymmetric, these angles in the α plane and β plane are substantially equal, and the “reduction rate of deflection angle” is “the maximum deflection angle ± 30 degrees in the α plane” 69.6% ”and substantially equal in the β plane.

The angular distortion is shown in Table 55. The values in the α plane and in the β plane are equal.

Table 56 shows the relationship between the “deflection angle” and the beam diameter of the deflected laser beam SRL. The values in the α plane and in the β plane are equal.

As shown in Tables 55 and 56, the maximum value of the angular distortion is −20% or less, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
In addition, the maximum value of the beam diameter is also as small as 9.7 mm, and the resolving power is good.

"Example 14"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 14 are shown in Table 57.

In the fourteenth embodiment, the incident surface of the deflection angle variable magnification element is a flat surface, and the exit surface is a cylinder surface having an axis in the X direction. Therefore, the deflection angle is not reduced in the X direction.
Therefore, among the reduced concentric coefficients, the one that should satisfy the condition is “Cα”.

The deflection angles by the deflection apparatus in Example 14 and the scanning deflection angles by the deflection angle variable magnification element are shown in Table 58.
The deflection angle variable magnification element 18 does not reduce the deflection angle in the X direction, and the reduction ratio of the deflection angle in the Y direction is 54.6% with respect to the maximum deflection angle: ± 30 degrees.

The angular distortion in the α plane is shown in Table 59.

The relationship between the “deflection angle” in the α plane and the beam diameter of the deflected laser beam SRL is shown in Table 60.

As shown in Tables 59 and 60, the maximum value of the angular distortion in the Y direction is as small as −12.2%. Therefore, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
Also, the maximum value of the beam diameter is as small as 7.6 mm, and the resolving power is good.

"Example 15"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 15 are shown in Table 61.

Also in the fifteenth embodiment, the incident surface of the deflection angle variable magnification element is a flat surface, and the exit surface is a cylinder surface having an axis in the X direction. Therefore, the deflection angle is not reduced in the X direction.
Therefore, among the reduced concentric coefficients, the one that should satisfy the condition is “Cα”.

The incident surface of the adjustment lens 13B is also a cylinder surface having an axis in the X direction.
The deflection angles of the deflection apparatus in Example 15 and the scanning deflection angles of the deflection angle variable element are shown in Table 62.
The deflection angle variable magnification element 20 does not reduce the deflection angle in the X direction, and the reduction ratio of the deflection angle in the Y direction is 46.4% with respect to the maximum deflection angle: ± 30 degrees.

The angular distortion in the α plane is shown in Table 63.

The relationship between the “deflection angle” and the beam diameter of the deflected laser beam SRL in the α plane is shown in Table 64.

As shown in the above embodiment, the maximum value of the angular distortion in the Y direction is as small as -9.9%. Therefore, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
In addition, the maximum value of the beam diameter is also as small as 7.9 mm, and the resolving power is good.

"Example 16"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 16 are shown in Table 65.

In the sixteenth embodiment, the incident surface of the deflection angle variable magnification element is a flat surface, and the exit surface is a cylinder surface having an axis in the Y direction. Therefore, the deflection angle is not reduced in the Y direction.
Therefore, among the reduced concentric coefficients, the one that should satisfy the condition is “Cβ”.

The incident surface of the adjustment lens 13B is also a cylinder surface having an axis in the Y direction.
The deflection angles by the deflection apparatus in Example 16 and the scanning deflection angles by the deflection angle variable magnification element are shown in Table 66.
The deflection angle variable magnification element 20 does not reduce the deflection angle in the Y direction, and the reduction ratio of the deflection angle in the X direction is 52.9% with respect to the maximum deflection angle ± 25.7 degrees.

The angular distortion in the β plane is shown in Table 67.

Table 68 shows the relationship between the “deflection angle” in the β plane and the beam diameter of the deflected laser beam SRL.

As shown in Tables 67 and 68, the maximum value of the angular distortion in the X direction is as small as -9.9%. Therefore, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
Also, the maximum value of the beam diameter is as small as 61.9 mm, and the resolving power is good.

"Example 17"
Deflection angle variable magnification elements, adjustment lenses, layouts thereof, and reduction concentric coefficients according to Example 17 are shown in Table 69.

Also in the seventeenth embodiment, the incident surface of the deflection angle variable magnification element is a flat surface, and the exit surface is a cylinder surface having an axis in the Y direction. Therefore, the deflection angle is not reduced in the Y direction.
Therefore, among the reduced concentric coefficients, the one that should satisfy the condition is “Cβ”.

The incident surface of the adjustment lens 13B is also a cylinder surface having an axis in the X direction.
The deflection angles of the deflection apparatus in Example 17 and the scanning deflection angles of the deflection angle variable element 18 are shown in Table 70.
The deflection angle variable magnification element 18 does not reduce the deflection angle in the Y direction, and the reduction ratio of the deflection angle in the X direction is 37.9% with respect to the maximum deflection angle ± 25.7 degrees.

The angular distortion in the β plane is shown in Table 71.

The relationship between the “deflection angle” in the β plane and the beam diameter of the deflected laser beam SRL is shown in Table 72.

As shown in Tables 71 and 72, the maximum value of the angular distortion in the X direction is as small as -7.1%. Therefore, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
In addition, the maximum value of the beam diameter is as small as 35.9 mm, and the resolving power is good.
In Example 16 and Example 17, as shown in Table 68 and Table 72, the "variation in beam diameter" is suppressed to be extremely small with respect to the change in deflection angle.

"Example 18"
Deflection angle variable magnification elements, adjustment lenses, layouts thereof, and reduction concentric coefficients according to Example 18 are shown in Table 73.

In Example 18, the deflection angle variable magnification elements are axisymmetric, and the reduction concentric coefficients: Cα and Cβ are equal to one another. The adjustment lens 13B is also axially symmetric.
The deflection angles by the deflection apparatus in Example 18 and the scanning deflection angles by the deflection angle variable magnification element are shown in Table 74.
Since the deflection angle variable magnification element is axisymmetric, these angles in the α plane and β plane are substantially equal, and the “reduction rate of deflection angle” is “the maximum deflection angle ± 30 degrees in the α plane” 51.2% "and substantially equal in the beta plane.

The angular distortion is shown in Table 75. The angular distortion has the same value in the α plane and β plane.

The relationship between the “deflection angle” and the beam diameter of the deflected laser beam SRL is shown in Table 76.

As shown in Example 18 above, the maximum value of the angular distortion is as small as -9.6%. Therefore, the distortion of the scanning locus is small, and the distortion of the acquired three-dimensional image of the detection object is less noticeable.
Further, the maximum value of the beam diameter is also as small as 9.0 mm, and the "variation of the beam diameter" is suppressed to be small with respect to the change of the deflection angle, and the resolving power is good.

"Example 19"
The deflection angle variable magnification element, the adjusting lens, their layouts, and the reduction concentric coefficient according to Example 19 are shown in Table 77.

Also in the nineteenth embodiment, the deflection angle variable magnification element is axisymmetric, and the reduction concentric coefficients: Cα and Cβ are equal to each other. The adjustment lens 13B is also axially symmetric.
The deflection angles of the deflection apparatus in Example 19 and the scanning deflection angles of the deflection angle variable element are shown in Table 78.
Since the deflection angle variable magnification element is axisymmetric, these angles in the α plane and β plane are substantially equal, and the “reduction rate of deflection angle” is “the maximum deflection angle ± 30 degrees in the α plane” 51.2% "and substantially equal in the beta plane.

The angular distortion is shown in Table 79. The angular distortion has the same value in the α plane and β plane.

The relationship between the “deflection angle” and the beam diameter of the deflected laser beam SRL is shown in Table 80.

As shown in Tables 79 and 80, the maximum value of the angular distortion is extremely small at -1.9%. Therefore, distortion of the scanning locus is also extremely small, and distortion of the acquired three-dimensional image of the detection object is less noticeable.
Further, the maximum value of the beam diameter is also as small as 5.1 mm, and the "variation of the beam diameter" is suppressed to be small with respect to the change of the deflection angle, and the resolving power is good.
.

Supplementary a little.
In Examples 11 to 19, as for the positional relationship between the adjustment lens and the deflection angle variable magnification element, the convergence position of the laser beam converged by the adjustment lens is the position of the focal point on the object side of the deflection angle magnification element (FIG. 6). It is adjusted to coincide with the point PF), and in this state, the deflected laser beam SRL emitted from the deflection angle variable magnification element becomes a "parallel beam". The positional relationship in this case is referred to as "reference positional relationship".

In each of the above embodiments, the position of the adjusting lens in the optical axis direction is finely adjusted after “the positional relationship between the adjusting lens and the deflection angle variable magnification element” is determined so as to satisfy the reference positional relationship.
That is, in this fine adjustment, the “beam diameter of the deflected laser beam” at a position 3 m from the exit surface of the deflection angle variable magnification element is made substantially equal at deflection angle: 0 degrees and the maximum deflection angle.
Due to this fine adjustment, in Examples 11 to 13 and Examples 18 and 19 in which axially symmetrical lenses are used as deflection angle variable magnification elements, a slight difference in “reduction rate of deflection angle” in the α plane and in the β plane is obtained. It occurs.

The minute difference is as follows.
Example 11
Reduction rate in α plane: 51.2%, reduction rate in β plane: 49.6%
Example 12
Reduction rate in α plane: 30.3%, reduction rate in β plane: 29.0%
Example 13
Reduction rate in α plane: 69.6%, reduction rate in β plane: 67.5%
Example 18
Reduction rate in α plane: 51.2%, reduction rate in β plane: 49.8%
Example 19
Reduction rate in α plane: 51.2%, reduction rate in β plane: 49.8%
The “fine difference in the reduction ratio in the α and β planes” in these embodiments does not substantially affect the reduction concentric coefficient and the angular distortion shown above.

In addition, in the nineteenth embodiment mentioned above, both the entrance surface and the exit surface of the deflection angle variable magnification element are spherical. The incident surface is a concave spherical surface, the exit surface is a convex spherical surface, and the radius of curvature is both negative.
In such a case, assuming that the radius of curvature of the entrance surface is RA and the radius of curvature of the exit surface is RB, it is important that the ratio RA / RB is large to some extent.
For example, in the case where the deflection angle variable magnification element is formed of a glass material having a large refractive index as in Example 9, RA / RB is preferably 1.6 or more.
In this case, if RA / RB is less than 1.6, the angular distortion tends to increase as the deflection angle increases.

When the deflection angle variable magnification element is formed of a glass material having a low refractive index such as BK7, RA / RB is preferably 1.8 or more.
In this case, if RA / RB is less than 1.8, the angular distortion tends to increase as the deflection angle increases.
In Example 19, RA / RB = 1.87, which is a sufficiently large value, and the angular distortion is also good.
From the viewpoint of alleviation of the off-axis aberration, it is preferable that the value of the reduction concentric coefficient: CR (Cα, Cβ) be “close to 1”.

The two-dimensional scanning type laser beam projectors of the above-described embodiments 11 to 19 basically obtain a collimated luminous flux polarized laser beam.
However, as described above, the light flux of the deflection laser beam emitted from the deflection angle variable magnification element can be in the form of a convergent light flux or in the form of a divergent light flux.
As one example, in Example 1 above, when the data other than the adjusting lens is left as it is and only the curvature radius of the inclining surface of the adjusting lens is changed from 48.9 mm to 19.6 mm, the positive refraction of the adjusting lens Force increases.
For this reason, assuming that the focal length of the deflection angle variable magnification element is “f”, the parallel light flux laser beam incident on the adjustment lens from the collimator lens is collected at a distance of 2 f on the object side of the deflection angle magnification element. Light up.

Therefore, an image by the deflection angle variable magnification element having this point as an object point is formed as an equal magnification image at a distance of 2 f on the image side of the deflection angle magnification element. Therefore, the deflection laser beam emitted from the deflection angle variable magnification element is in the form of a convergent beam.
The two-dimensional scanning type laser beam projection apparatus according to the eleventh to nineteenth embodiments can be combined with the detecting means and the control calculating means as shown in FIG. 6 to constitute a laser radar apparatus.

Hereinafter, still another embodiment of the present invention will be described.
FIG. 11 illustrates the main part of still another embodiment of the present invention in an explanatory diagram.
In order to avoid complexity, the symbols shown in FIG. That is, in FIG. 11, reference numeral 10 denotes "LD", reference numeral 12 denotes a "coupling lens", reference numeral 13B denotes a "adjustment lens", and reference numeral 40 denotes a "mirror for returning the light path for irradiation".
Reference numeral 14 is a "deflection device", reference numeral 181 is a deflection angle variable magnification element as a deflection angle change element, reference numeral 30 is a "light receiving element", reference numeral 32 is a "condenser lens", and reference numeral 34 is a light receiving lens. ".
Further, reference numeral 40A on the light receiving side indicates "a mirror for turning back the light path for light reception", and reference numeral 400 indicates a "control operation unit as control operation means". The “light receiving element 30” is also referred to as “detection light receiving element 30”.

In order to simplify the description, the X, Y, and Z directions are defined as shown in FIG.
The X direction is the direction orthogonal to the drawing (corresponding to the above-mentioned "horizontal direction""lateraldirection"), the Y direction is "parallel to the drawing and the vertical direction of the figure (the above" vertical direction "" horizontal direction " Corresponding to The Z direction is "parallel to the drawing in the lateral direction of the drawing (direction parallel to the optical axes of the coupling lens 12 and the deflection angle variable element 181)".

The LD 10 emits high-power laser light.
The laser beam emitted from the LD 10 passes through the coupling lens 12 and the adjusting lens 13B, and is converted into a “convergent laser beam” under the optical action of these components.
That is, the coupling lens 12 and the adjustment lens 13B constitute “a coupling optical system for converting the laser beam emitted from the LD 10 into a convergent laser beam”.
The LD 10, the coupling optical system 12, and the adjustment lens 13B constitute a "laser light source".

The laser light flux which has been given a convergence tendency by the light flux conversion by the coupling optical system is incident on the mirror 40 and is reflected toward the deflecting device 14.

The deflection device 14 is configured as the “two-axis MEMS” described above, and two-dimensionally deflects the direction of the reflected light.
The deflected laser beam oscillates in the “Y direction” of FIG. 11 and also oscillates in the “X direction”. That is, two-dimensional deflection by the deflection device 14 is performed by peristalsis in the X direction and the Y direction.
The laser beam is incident on the deflection angle variable magnification element 201 while being two-dimensionally deflected by the deflection device 14 as described above.
The coupling lens 12 and the adjusting lens 13B, the deflecting device 14 and the deflection angle variable magnification element 181 shown in FIG. 11 constitute an “irradiation optical system”.

The laser beam two-dimensionally deflected by the deflecting device 14 is incident on the deflection angle variable magnification element 181 and becomes a deflected laser beam SRL by the optical action of the deflection angle magnification element 181.
The deflected laser beam SRL is a “laser beam for irradiating a detection target”.
In response to the two-dimensional deflection of the laser beam by the deflection device 14, the deflection laser beam SRL is also deflected in two directions of X and Y, and is irradiated on the “detection object”, and the detection object is two-dimensionally Scan to
The deflected laser beam SRL irradiated with the object to be detected is reflected by the object to be detected and becomes “return laser beam BKL”.
The laser radar device is used, for example, for “vehicle-mounted or monitoring camera”, but in a general use situation, “distance to a detection target” is larger than the size of the irradiation optical system.
Therefore, the return laser beam BKL reflected by the object to be detected and incident on the deflection angle variable magnification element 201 is substantially parallel and in the same direction as the deflection laser beam SRL in the opposite direction.

When the return laser beam BKL passes through the deflection angle variable magnification element 181, it enters the deflection device 14 and is reflected.
The return laser beam BKL reflected by the deflecting device 14 is then reflected by the mirror 40A and is incident on the light receiving lens 34.
The return laser beam BKL transmitted through the light receiving lens 34 is incident on the condensing lens 32, condensed toward the detection light receiving element 30, and received by the detection light receiving element 30.
The light receiving lens 34 and the condenser lens 32 constitute a "condenser lens system".

When receiving the return laser beam BKL, the detection light receiving element 30 sends a light reception signal (amplified by an appropriate amplification factor) to the control calculation unit 40.
The control calculation unit 400 is configured by a CPU or a microcomputer.
The control calculation unit 400 causes the LD 10 to emit light in pulses, determines the time: 2T from the moment of light emission to the moment of receiving the light reception signal, and calculates the distance: cT using the speed of light c.
The acquisition of the time: 2T and the calculation of cT are repeated together with the deflection of the deflected laser beam SRL. In this way, the distance to the object to be detected and the three-dimensional shape of the object to be detected can be obtained.

That is, the laser radar device of FIG. 11 includes the LD 10 and an “irradiation optical system” which two-dimensionally deflects the laser beam from the LD 10 to form a deflected laser beam SRL that scans a detection target.
The detection light receiving element 30 receives the return laser beam BKL reflected by the detection target, and the “light receiving optical system” guides the return laser light BKL to the detection light element 30.
A control operation means 40 is provided for determining the distance cT to the object to be detected by 2T from the time the laser beam is emitted until the light receiving element for detection 30 returns and the laser beam BKL is received.

The “optical system for irradiation” includes coupling optical systems 12 and 13B for converting the laser beam emitted from the LD 10 into a convergent laser beam, and a deflector 14 for two-dimensionally deflecting the laser beam subjected to the beam conversion. Have.
Furthermore, it has a deflection angle variable magnification element 181 for emitting a two-dimensionally deflected laser beam as the deflected laser beam SRL.
The "light receiving optical system" uses the deflection angle variable magnification element 181 and the deflecting device 14 in the irradiating optical system as "shared with the irradiating optical system".
Then, focusing lens systems 34 and 32 are provided which transmit the deflection angle variable magnification element 181 and condense the return laser beam BKL deflected by the deflection device 14 toward the light receiving element 30 for detection.

Further, in the embodiment shown in FIG. 11, the irradiation optical system bends the light path of the convergent laser light flux which has been converted by the coupling optical system 12 and the adjusting lens 13B toward the deflecting device 14. The optical path bending mirror 40 is provided.
The light receiving optical system also has a mirror 40A that bends the optical path of the return laser beam BKL through the deflection device 14 toward the condensing lens system 34, 32.
The mirror 40A is added. As described above, the return laser beam BKL is incident on the deflection angle variable magnification element 181 in the “parallel beam state in the opposite direction in the same direction” as that of the deflection laser beam SRL. Then, when the light is transmitted through the deflection angle variable magnification element 181, the light is reflected by the deflection device.
Therefore, the optical path of the return laser beam BKL reflected by the deflecting device 14 is parallel to the optical path of the laser beam directed from the mirror 40 A to the deflecting device 14.

In the embodiment shown in FIG. 11, the optical axis of the coupling optical system and the optical axis of the condensing lens system are laid out parallel to each other.
Therefore, in this case, the mirror surface of the mirror 40A is parallel to the mirror surface of the mirror 40 as shown.
In the embodiment shown in FIG. 11, the “coupling optical system” includes the coupling lens 12 disposed on the LD 10 side, and the adjustment lens 13 B for imparting convergence to the laser beam transmitted through the coupling lens 12. .

Above, the case where the pulse light emission of the laser light source 10 is used to determine 2T from when the laser light is emitted from the LD 10 to when the light receiving element 30 for detection returns and receives the laser beam BKL is described. did.
As a method of determining the time: 2T, a method of using “frequency modulation of laser light emitted from a laser light source” and the like are known.
In the laser radar device of the present invention, the determination of the time: 2T is not limited to the above-described method using pulsed light emission, but may be other known methods such as a method using frequency modulation.

Hereinafter, the laser radar device shown in FIG. 11 will be described more specifically.
In the present invention, the laser beam emitted from the LD 10 is converted into a light flux by the coupling optical system, and the laser light flux converted into the light flux is two-dimensionally deflected by the deflection device 14.
Then, the two-dimensionally deflected laser beam is converted into a deflected laser beam SRL by the deflection angle variable magnification element 181.

The combination of the function of “converting the laser beam emitted from the LD 10 by the coupling optical system” and the optical function of the deflection angle variable magnification element 181 enables deflection laser beams SRL of various light flux forms.
Various combinations of the coupling optical system and the deflection angle variable magnification element are possible.

In the embodiment shown in FIG. 11, the coupling lens 12 has a collimating action, and converts the laser beam from the LD 10 into a “parallel beam” parallel to the Z direction.
That is, in this case, the coupling lens 12 is a "collimate lens".
The adjustment lens 13B is a "cylinder lens" and has "positive refractive power in the Y direction" in a plane parallel to the YZ plane, and does not have refractive power in the X direction.
Therefore, the laser beam in the parallel beam state entering the adjustment lens 13B from the coupling lens 12 side converges in the Y direction, but maintains the parallel beam state in the X direction.
The deflection angle variable magnification element 181 is also a cylinder lens having “negative refractive power” only in the Y direction, and does not have refractive power in the X direction orthogonal to the drawing.

A laser beam incident on the deflection angle variable magnification element 181 “parallel to the Z direction” is considered. The traveling direction of the light beam coincides with the “optical axis of the coupling optical system extended through the reflecting surface of the irradiation optical path bending mirror 16B or the deflecting device 14”. Such a laser beam incident on the light source will be referred to as "optical axis beam".
Then, in the example described with reference to FIG. 11, the optical axis luminous flux is “converging property in the Y direction and parallel luminous flux state in the X direction”.

When the laser beam incident on the deflection angle variable magnification element 181 is deflected by the deflecting device 14, the deflected laser beam is in a "convergent beam state" as viewed from the X direction and as a parallel beam state as viewed from the Y direction. It is.
The convergence of the laser beam incident on the deflection angle variable magnification element 181 is reduced by the negative refractive power of the deflection angle magnification element 181.
The deflection angle variable magnification element 181 does not have refracting power in the X direction, so the deflection laser beam SRL emitted from the deflection angle magnification element 181 is in a “parallel light flux state” when viewed from the Y direction.

FIG. 12 shows a state in which the laser beam LF emitted from the LD 10 enters the deflection angle variable magnification element 201 as an optical axis beam and emits from the deflection angle magnification element 181 as the polarized laser beam SRL. In order to simplify the drawing, parts relating to the light receiving optical system are not shown.
As described above, the adjusting lens 13 B tends to converge the laser light LF collimated by the coupling lens 12 in the Y direction.
The convergent laser beam LF is converged in the Y direction and enters the deflection angle variable magnification element 181 through the irradiation optical path bending mirror 16 and the deflecting device 14.
The deflection angle variable magnification element 181 has negative refracting power in the Y direction, and a focal point (imaginary focal point) FP by the negative refracting power is on the "detection object side (right side in the figure)" of the deflection angle magnification element 181. To position.
If the “optical axis light flux” incident on the deflection angle variable magnification element 181 converges on the virtual focal point FP, the deflection laser beam SRL emitted from the deflection angle magnification power element 181 becomes a parallel light flux.

In order to actually realize this, the adjustment lens 13B is adjusted in displacement in the optical axis direction (Z direction), and "the convergence point of the optical axis luminous flux converged in the Y direction" with respect to the deflection angle variable magnification element 201. The position of the convergence point may be adjusted to match the position of the virtual focal point FP of the deflection angle variable magnification element 181.
In the example being described, the optical axis light beam incident on the deflection angle variable magnification element 201 is convergent in the Y direction, is in the “parallel light flux state” in the X direction, and the deflection angle magnification element 181 is in the X direction. Have no refractive power.
Therefore, as described above, when the optical axis light flux is made to "conform to the position of the focal point FP" and is made incident on the deflection angle variable magnification element 18, the deflected laser beam emitted from the deflection angle variable magnification element 181 The SRL is in a parallel light flux state, that is, a "parallel light flux" in both the X direction and the Y direction.

Here, in general, with regard to the “beam form” of the deflection laser beam SRL, various combinations of beam forms of deflection laser can be obtained by combining the beam conversion action of the coupling optical system and the optical action of the deflection angle variable magnification element. Beam SRL is possible.
As a typical light flux form of a deflected laser beam, consider "divergent light flux", "convergent light flux", and "parallel light flux".
When the distance from the laser radar device to the object to be detected is "large to some extent", the divergent light beam-like polarized laser beam has a large irradiation area (hereinafter referred to as "irradiation spot area") for irradiating the object to be detected. The accuracy of In addition, since the light intensity in the irradiation section is reduced, a laser light source with a large output and a detection light receiving element with a large detection capability are required.
However, if it is desired to increase the “irradiation spot area” to some extent for a relatively short detection object and shorten the measurement measurement time even at the expense of resolution, the use of a divergent luminous flux-like deflection laser beam is effective It is.

Even in the case of a convergent luminous flux-like polarized laser beam, the polarized laser beam becomes a divergent luminous flux after being condensed by the convergence, so that it is divergent when the distance from the laser radar device to the object to be detected is somewhat large. There is the same problem as in the case of a deflected laser beam.
However, when measuring the shape of a "not large detection target" at a relatively short fixed position, detection is performed with a polarized laser beam of "small irradiation spot area" according to the size of the detection target By scanning the object two-dimensionally, accurate shape measurement is possible.
In such a case, the use of a convergent beam-like polarized laser beam is effective.

If the deflection laser beam is a parallel light beam, the beam diameter of the deflection laser beam is in principle “constant regardless of the distance from the laser radar device”, and the “beam diameter change” is It is negligible.
Therefore, if the polarized laser beam can be collimated, the irradiation spot area "does not substantially change even in consideration of the diffraction effect" regardless of the distance to the object to be detected, regardless of the distance to the object to be detected As a result, good detection is stably possible.
In the laser radar device under discussion, “the divergence or convergence position of the divergent or convergent laser beam in at least one direction converted by the coupling optical system and the focal position of the deflection angle variable magnification element are And the positional relationship according to the form of the light beam.

The “beam form” is the “parallel beam shape or convergent beam shape or divergent beam shape” mentioned above.

The phrase "a deflection laser beam is in the form of a parallel beam" literally means that the deflection laser beam is a parallel beam regardless of the deflection angle by the deflection device, and also includes the following cases.
That is, the case where the deflected laser beam "can be convergent or divergent depending on the deflection angle by the deflector" is in a state close to a collimated beam whether it is convergent or divergent. .
For example, the “maximum distance detectable by the laser radar device” is temporarily set to 100 m.
In this case, the beam spot diameter of the deflected laser beam emitted from the laser radar device may be a size that can realize an irradiation spot area of a size capable of effectively detecting “a detection target at a position of 100 m”.
A "divergent or convergent polarized laser beam" satisfying such conditions is also referred to as "parallel light flux".
That is, as described above, the luminous flux form is such that “the irradiation spot area at the maximum distance detectable by the laser radar device” can be made effective detection of the detection object in consideration of the diffraction effect. It is said that "parallel light flux".

As in the case described above with reference to FIG. 12, the convergence position of the convergent optical axis light beam incident on the deflection angle variable magnification element 181 is made to coincide with the position of the virtual focal point FP of the deflection angle magnification element 181 In this case, the optical axis light beam becomes “a deflection laser beam collimated by the deflection angle variable magnification element 181”.
In this case, since the convergence point of the laser beam two-dimensionally deflected by the deflection device 14 moves on the spherical surface centering on the origin of deflection by the deflection device 14, the convergence point position becomes The deflection angle changing element 181 is displaced more than the focal plane of the deflection angle changing element 181.
For this reason, the light flux form of the polarized laser beam SRL is a parallel light flux state when viewed from the Y direction in FIG. 1A, but “convergence” is accompanied by an increase in the deflection angle when viewed from the X direction. It becomes stronger and deviates from the parallel luminous flux state.
In this case, the “degree of deviation from the parallel light flux” of the polarized laser beam in the state viewed from the X direction is in a range in which effective detection of the farthest object to be detected is possible. This can be realized by "design of the optical system for irradiation".

In FIG. 12, when the convergence position of the optical axis light beam is positioned slightly away from the deflection angle variable magnification element 181 than the position of the virtual focal point FP of the deflection angle variable magnification element 181, the deflection laser beam SRL becomes an optical axis light flux. Is somewhat divergent, but as the deflection angle increases, the divergence diminishes.
Then, it becomes a parallel light flux at a certain deflection angle, and then turns into convergence.
In this case, by shifting the convergence position of the optical axis light flux from the position of the virtual focal point FP of the deflection angle variable magnification element 181, the "displacement from parallel light flux" of the deflected laser beam within the deflection range is diverged. And convergence can be distributed.
This also makes it possible to easily realize the above-mentioned "collimated beam-like deflection laser beam".

In FIG. 12, “converging position of optical axis luminous flux” is shifted to the left (deflection device 14 side) in FIG. 12 with respect to the position of the virtual focal point FP of the deflection angle variable magnification element 181. A polarized laser beam SRL is obtained.
In order to realize this, the adjustment lens 13B may be shifted to the coupling lens 12 side. Conversely, if the “converging position of the optical axis light flux” in FIG. 12 is shifted to the right in the figure with respect to the position of the virtual focal point FP of the deflection angle variable magnification element 181, a deflection laser having a divergent flux shape A beam SRL is obtained.
In order to realize this, the adjustment lens 13B may be shifted to the mirror 40 side.

As described above, the polarization laser beam SRL is adjusted by adjusting the positional relationship between the convergent position of the convergent laser beam in at least one direction, which is converted by the coupling optical system, and the focal position FP of the deflection angle variable magnification element. Can change the form of light flux.
Also in the case of “convergent beam shape” or “divergent beam shape”, the convergence angle or the divergence angle may be changed along with the two-dimensional deflection of the polarized laser beam.
That is, for example, even when the optical axis light beam is a convergent light beam (or a divergent light beam) due to the deflection angle variable magnification element 181, the convergence angle (or the divergence angle) along with the deflection of the polarized laser beam ) May change to become divergent luminous flux (or condensed luminous flux).
Including such a case, it is called "convergent luminous flux (or divergent luminous flux)".

In the example described with reference to FIGS. 11 and 12, the coupling optical system is configured of the coupling lens 12 and the adjusting lens 13B, and “the direction (Y direction) to which convergence is provided by the coupling optical system” A deflection angle variable power element 181 having a negative refractive power is combined.
The combination of the coupling optical system and the deflection angle variable magnification element is not limited to the above.
For example, the deflection angle variable magnification element 181 is set as “a negative lens rotationally symmetrical with respect to the optical axis”, and the adjustment lens 13B is also set as a “positive lens rotationally symmetrical with respect to the optical axis”.
Then, the positional relationship between the position of the image-side focal point of the adjustment lens 13B, which is a positive lens, and the position of the imaginary focal point of the deflection angle variable magnification element 181 with respect to the optical axis light beam is set as described above.
Also in this case, it is possible to obtain a deflected laser beam SRL in the form of parallel light flux (or in the form of convergent light flux, divergent light flux).
In this case, the adjusting lens 13B may be omitted, and the coupling lens 12 alone may obtain a convergent laser beam, which may be made incident on the deflection angle variable magnification element 181.
Even in this case, by adjusting the positional relationship between the focusing position of the convergent laser beam and the focal position of the deflection angle variable magnification element 201, deflection of a parallel beam shape (or convergent beam shape, divergent beam shape) is performed. The laser beam SRL can be realized.

FIG. 13 shows another embodiment. In order to avoid complexity, those which are considered to have no risk of confusion are given the same reference numerals as in FIG.
In the embodiment shown in FIG. 13, instead of “the deflection angle variable power element 201 of negative refractive power” in FIG. 11, “the deflection angle power element 202 having positive refractive power in one direction (Y direction)” Is used.
In this case, the “optical axis luminous flux convergent in the Y direction” toward the deflection angle variable magnification element 182 is made to converge at or near the “incident side focal point FPA” position of the deflection angle magnification element 182.
Then, the light beam converges to the position of the focal point FPA and then diverges and enters the deflection angle variable magnification element 202, and the positive refracting power of the deflection angle magnification change element 182 reduces the divergence and parallel as shown by a broken line. The light beam is emitted as a deflected laser beam SRL.
The laser light two-dimensionally deflected by the deflecting device 14 also converges in front of the deflection angle variable magnification element 182 and then becomes divergent and enters the deflection angle magnification element 182.
Then, a “collimated beam-like polarized laser beam SRL” which is two-dimensionally deflected is obtained.

That is, in the embodiment shown in FIG. 13, the deflection angle variable magnification element 182 has “positive refractive power” in one direction (Y direction) of two-dimensional deflection by the deflection device 14.
The coupling optical system includes the coupling lens 12 disposed on the LD 10 side, and the adjustment lens 13B that imparts “the convergence in the Y direction” to the laser beam transmitted through the coupling lens.
The “optical axis luminous flux convergent only in the Y direction” converted to luminous flux converges on the position of the focal point FPA or in the vicinity thereof, then changes to diverging state and enters the deflection angle variable magnification element 182 in the diverging state.
As a result, a two-dimensionally deflected collimated laser beam SRL is obtained.

The return laser beam BKL incident on the deflection angle variable magnification element 182 as "substantially parallel light flux" is diverged after being "converged in the Y direction" on the deflection device 14 side of the deflection angle magnification element 182 It enters the device 14.
Also in the case shown in FIG. 13, if the optical axis luminous flux convergent in the Y direction is condensed on the near side (or the side of the deflection angle variable magnification element 20) of the focal point FPA of the deflection angle variable magnification element 182, It is possible to obtain a deflected laser beam SRL which converges (or diverges) in the Y direction.

Here, the “light receiving optical system” will be described by taking the cases shown in FIGS. 11 and 13 as an example.
In the example shown in FIGS. 11 and 13, of the condenser lens 32 and the light reception lens 34 that constitute the "condenser lens system of the light reception optical system", the light reception lens 34 is a "convex cylinder lens" and is in the Y direction. Only with positive refractive power.
The light receiving lens 34 returns the divergent return laser beam BKL to a parallel beam and makes it enter the condenser lens 32.
The light receiving element 30 for detection has its light receiving part positioned at the focal position of the condenser lens 32, and receives the return laser beam BKL condensed by the condenser lens 32.
When the adjusting lens 13B is a "rotationally symmetric positive lens with respect to the optical axis", the light receiving lens 34 may be a rotationally symmetric positive lens, and the return beam BKL may be collimated.
In addition, since the diameter of the return laser beam BKL is larger than the diameter of the laser beam passing through the adjustment lens 13B at the stage of entering the condensing lens system, the lens diameter of the lens constituting the condensing lens system is also correspondingly You need to make it bigger.
For this reason, the lens size of the light receiving lens 34 and the condenser lens 32 is increased.

In the case of the example described above with reference to FIGS. 11 and 13, the light reception lens 34 may be omitted, and the return light beam BKL may be condensed directly on the detection light receiving element 30 by the condenser lens 32.
In this case, in order to make the condensed state of the return laser beam BKL favorable in the Y direction and the X direction, the condenser lens 32 may be an "anamorphic positive lens".
In a laser radar system, in general, the distance to the object to be detected is "sufficiently large compared to the size of the laser radar system". Therefore, the return laser beam returning to the deflection angle variable element is parallel as described above. It is in a luminous state.
Therefore, in the light receiving optical system, the composite imaging system including the condensing lens system constituting the light receiving optical system and the deflection angle variable magnification element is an infinite distance on the detection object side in the X direction and the Y direction, The light receiving optical system may be configured such that the light receiving surface position of the element is in a conjugate relationship.

As described above, although the coupling optical system can be configured with a coupling lens alone, by configuring the coupling optical system with “a coupling lens having a collimating function and an adjusting lens”, the layout of the optical system can be realized. The degree of freedom is increased.
Similarly, although the "condenser lens system" can be configured by a single condenser lens, as described above, if a condenser lens system is configured by combining the condenser lens 32 and the light receiving lens 34, the optical system Freedom of layout is increased.
In a specific implementation situation, of course, the positional relationship between the condensing lens systems 32 and 34 and the light receiving element 30 for detection is adjusted to realize “appropriate detection of the return laser beam BKL”.

Hereinafter, other embodiments of the present invention will be described.
In the example described based on FIGS. 11 to 13, the coupling optical system converts the laser beam emitted from the LD 10 into “a laser beam convergent in the Y direction”.
However, “light flux conversion” by the coupling optical system is not limited to such conversion.
That is, the coupling optical system can also have a light flux conversion function of converting the laser light from the LD 10 into a diverging laser light flux.

FIG. 14 illustrates two embodiments of such a case. In order to avoid complexity, the symbols shown in FIG. 11 to FIG.
In FIG. 14A, the coupling optical system is constituted by the coupling lens 12 and the adjusting lens 14D.
The coupling lens 12 is a collimating lens, and collimates the laser light from the LD 10.

The adjustment lens 13D is a "negative cylinder lens" having refractive power only in the Y direction, and converts the laser beam collimated by the coupling lens 12 into "a laser beam divergent only in the Y direction". Do.

The “laser beam diverging in the Y direction”, which has been converted, passes through the mirror 40 and the deflecting device 14 and enters the deflection angle magnification element 183 while maintaining the diverging state.

The deflection angle variable magnification element 183 is a “positive cylinder lens” having “refractive power only in the Y direction”, and emits a divergingly incident laser beam as a deflected laser beam bundle SRL.
The symbol FPB in FIG. 14A is the "focus on the incident side" of the deflection angle variable magnification element 183, and the adjustment lens 13D of the coupling optical system is the "start point of divergence" of the diverging laser beam by the beam conversion. Is positioned at or near the focal point FPB.
By doing this, the deflection angle variable magnification element 183 emits the divergingly incident laser beam as a collimated luminous flux deflection laser beam SRL.

Among the condenser lens 32 and the light receiving lens 34A that form the "condensing lens system of the light receiving optical system", the light receiving lens 34A is a "cylinder lens having negative refractive power only in the Y direction".
The light receiving lens 34 </ b> A returns the return laser beam BKL, which is incident while converging in the Y direction, to a parallel beam and makes it enter the condensing lens 32. The reference numeral Q1 in the figure is the convergence position of the return laser beam BKL incident on the light receiving lens 34A, and this point is the position of the exit-side focal point (virtual focal point) of the light receiving lens 34A.
The light receiving element 30 for detection has its light receiving part positioned at the focal position of the condenser lens 32, and receives the return laser beam BKL condensed by the condenser lens 32.

In the embodiment shown in FIG. 14 (b), the coupling optical system is constituted by the coupling lens 12 and the adjusting lens 13E.
The coupling lens 12 has a collimating function, and collimates the laser beam from the LD 10.

The adjustment lens 13E is a cylinder lens having negative refractive power only in the Y direction, and converts the laser beam collimated by the coupling lens 12 into a divergent laser beam only in the Y direction.
The “laser beam diverging in the Y direction”, which has been converted into a beam, diverges and enters the deflection angle magnification element 183 in a diverging state via the mirror 40 and the deflecting device 14.

The deflection angle variable magnification element 183 is a cylinder lens having “a positive refracting power only in the Y direction”, and emits the diverging laser beam flux incident thereon as a deflection laser beam flux SRL.
The laser beam diverging in the Y direction by the beam conversion has its “point of divergence” positioned at the focal point FPC on the incident side of the deflection angle variable magnification element 183 or in the vicinity thereof.
By doing this, a deflection laser beam SRL in the form of a parallel luminous flux is emitted from the deflection angle variable magnification element 183.

In the embodiment of FIG. 14 (b), the “negative refractive power” of the adjusting lens 13E is stronger than the “negative refractive power” of the adjusting lens 13D of FIG. 14 (a).
Thus, the divergence of the converted laser beam is stronger than that in the case of FIG. 14A, and the focal point FPC on the incident side of the deflection angle variable magnification element 183 is more than the position FPB in the case of FIG. Is also close to the deflection angle variable magnification element 183.
That is, the deflection angle variable magnification elements 183 in FIGS. 14A and 14B are given the same reference numerals to avoid complexity, but the lens characteristics are different from each other.

In the example of FIG. 14B, since the negative power of the adjusting lens 13E is strong, the position Q2 at which the return laser beam BKL converges is located closer to the mirror 40A than the incident side lens surface of the light receiving lens 34B. .
Therefore, the light receiving lens 34B is a "cylinder lens" having positive refractive power only in the Y direction, and the focal point on the incident side is made to coincide with the position Q2.
By doing this, the return light beam BKL can be collimated by the light receiving lens 34B and can be made incident on the condenser lens 32.
Also in the embodiment of FIG. 14 (b), the deflection angle variable magnification element 183 is a "positive lens rotationally symmetric about the optical axis", and accordingly, the adjusting lens 13E and the light receiving lens 34B are also " It is needless to say that the lens can be made rotationally symmetric.

In FIG. 14, the beam diameter of the deflection laser beam SRL is drawn larger than that of the deflection angle variable magnification element 183, but this is for convenience of illustration and is different from the actual magnitude relationship.
Also in the case of the embodiment described above with reference to FIG. 14, the origin of the divergence of the diverging laser light beam incident on the deflection angle variable magnification element 183 and the focal point FPB or FPC of the deflection angle magnification element 183 By adjusting the positional relationship in the above, it is possible to obtain a convergent beam-like or divergent beam-like polarized laser beam SRL.

Hereinafter, a modification of the embodiment shown in FIG. 11 will be described.
Also in the respective drawings described below, in order to avoid complication, the same reference numerals as in FIG. 11 are used for those which are considered to have no possibility of confusion.

The embodiment shown in FIG. 15 is an example of a laser radar device in which the mirror 40B doubles as a "mirror for turning back the light path for light reception".
In this embodiment, the mirror 40B, which doubles as a mirror that folds the light path for light reception, reflects the divergent return laser beam BKL from the deflecting device 14 toward the LD 10.
The return laser beam BKL reflected to the laser light source 10 side is incident on the adjustment lens 13B1 to be converted into a parallel beam, and is incident on the optical path separation means 38A.
The optical path separation means 38A is a "semi-transparent mirror" and reflects the returning laser beam BKL downward (-Y direction) in the figure.

The reflected return laser beam BKL is incident on the condenser lens 32A, condensed toward the detection light receiving element 30, and received by the detection light reception element 30.
That is, in this example, the adjustment lens 13B1 and the condenser lens 32A constitute a "condenser lens system".
On the other hand, the laser beam emitted from the LD 10 is collimated by the coupling lens 12, transmitted through the semitransparent mirror 38A, converted to a convergent laser beam by the adjusting lens 13B1, and converted to the deflecting device 14 by the mirror 40B. It is reflected towards.
The function of the adjustment lens 13B1 is the same as that of the adjustment lens 13B shown in FIG. 11 with respect to the laser beam emitted from the LD 10.
However, the adjusting lens 13B1 also performs the function of the light receiving lens 34 shown in FIG. 11 for the return laser beam BKL, in order to efficiently take in the return laser beam BKL whose beam diameter is enlarged. The lens size is about the same as the "light receiving lens 34".

FIG. 16 is a view showing another embodiment of the laser radar device.
This embodiment is a modification of the embodiment shown in FIG. 15. In order to avoid complexity, the symbols common to those in FIG. 15 are used for those considered to have no possibility of confusion.
The apparatus configuration shown in FIG. 16A differs from the embodiment of FIG. 15 in the optical path separation means 38B.

The optical path separating means 38B is an optical element having a transmitting portion for transmitting the laser light from the LD 10 side, and a "reflecting portion for reflecting the returning laser beam" around the transmitting portion.

FIG. 16 (b) shows an explanatory view of the optical path separating means 38 B.
In this figure, the optical path separation means 38B is divided into two parts.
That is, the “transmission part” indicated by reference numeral 38 a is a part that transmits the laser light from the LD 10 side (which is collimated by the coupling lens 12).

The portion indicated by reference numeral 38b is a "reflecting portion", which reflects the returning laser beam BKL.
The transmitting portion 38 a is formed to have a minimum size necessary to transmit the laser light from the laser light source side without excess or deficiency.
The reflecting portion 38 b is the “whole surface excluding the transmitting portion 38 a” of the optical path separating means 38 B.
Therefore, as shown in FIG. 16B, the return laser beam BKL incident on the optical path separation means 38B reflects the luminous flux portion incident on the portion (reflection portion 38b) other than the transmission portion 38a.

The optical path separation means 38B has, for example, formed a “reflection film made of a metal thin film etc.” on one side of the parallel flat transparent glass (the side on which the return laser beam BKL is incident) excluding the transmission part 38a. It can be configured as a thing.
Alternatively, a hole may be bored in a flat metal plate to form the transmitting portion 38a, and one side of the flat metal plate (the side on which the return laser beam BKL is incident) may be mirror-finished.
In the latter case, the transmission part 38b is a "hole", but in this case it is also referred to as a "transmission part".

That is, in the laser radar device of which the embodiment is shown in FIGS. 15 and 16, the mirror 40B for turning back the light path for irradiation also serves as a "mirror for turning back the light path for receiving light".
Then, the mirror 40 B reflects the divergent return laser beam BKL from the deflecting device 14 toward the LD 10.
Furthermore, it has optical path separation means 38A, 38B for separating the return laser beam BKL reflected toward the LD 10 from the optical path of the irradiation optical system.
The return laser beam BKL separated by the optical path separation means 38A, 38B is condensed toward the detection light receiving element 30 via the condensing lens system 14C, 32A.

In addition, the “coupling optical system” includes the coupling lens 12 and the adjustment lens 13B1 disposed on the laser light source 10 side.
The adjustment lens 13B1 imparts “the convergence in the Y direction to the laser beam transmitted through the coupling lens 12”, and the positional relationship between the convergence position in the Y direction and the position of the virtual focal point of the deflection angle variable magnification element 181 is deflected. The position in the Z direction is adjusted so that the laser beam SRL has a parallel beam shape.

The adjustment lens 13B1 also serves as "a part of the focusing lens system", and the optical path separation means 38A and 38B are disposed between the adjustment lens 13B1 and the coupling lens 12 and the return laser separated by the optical path separation means The luminous flux is condensed toward the light receiving element 30 for detection via the condensing lens 32A which constitutes a "condensing lens system" together with the adjustment lens 13B1.
The "optical path separation means" may be a semitransparent mirror 38A, and an optical element having a transmitting portion 38a for transmitting laser light from the LD 10 side, and a reflecting portion 38b for returning around the transmitting portion and reflecting the laser beam BKL. It can also be 38B.
It goes without saying that the modification shown in FIGS. 15 and 16 can also be applied to the embodiments shown in FIGS. 14 (a) and 14 (b).

The laser radar device whose embodiment is shown in FIG. 17 is another modification of the embodiment shown in FIG. 11, and the same reference numerals as in FIG. 11 are used for those which are considered to have no possibility of confusion.
In the laser radar device of the embodiment shown in FIG. 17, the mirror 40B1 for turning back the light path for irradiation included in the optical system for irradiation also serves as a "mirror for turning back the light path for light reception included in the light receiving optical system".
The mirror 40B1 bends the optical path of the convergent laser beam in the Y direction, which has been converted by the coupling optical system (12, 13B), toward the deflecting device 14.
The mirror 40B1 also serves as "a light receiving path bending mirror for bending the light path of the diverging return laser beam BKL through the deflecting device 14 toward the focusing lens systems 32 and 34".

A portion from the LD 10 through the coupling lens 12 and the adjusting lens 13B to the mirror 40B1 and a portion from the mirror 40B1 to the light receiving lens 34 and the condensing lens 32 to the detecting light receiving element 30 are shown in FIG. Are arranged so as to "overlap in the direction orthogonal to the drawing".

FIG. 17B shows the state of FIG. 17A as viewed in the X direction of FIG. As shown in FIGS. 17 (a) and 17 (b), a mirror that folds the light path for illumination and a mirror that folds the light path for light reception are made common as one mirror 40B1.
The adjustment lens 13B and the light reception lens 34 are assumed to be “cylindrical lenses” as in the case of FIG.
As described above, by sharing the light paths for irradiation and light reception as one mirror 40 B 1, the number of parts can be reduced to reduce the cost of the laser radar device, and the laser radar device can be configured. Space of the arrangement of each part can be reduced.
Of course, if desired, the mirror 40B1 can be cut with dashed lines in the figure to be separate mirrors.
Note that a cylinder lens having the same function as the adjustment lens 13B and the light reception lens 34 can be used.

In such a case, in the case of the arrangement as shown in FIG. 17, the adjusting lens 13B and the light receiving lens 34 should be configured as "one cylinder lens" and be shared by the irradiating optical system and the light receiving optical system. Can.
In addition to the embodiment shown in FIG. 17, as described above, when the return laser beam BKL is incident on the mirror 40B1, the beam diameter is greatly expanded.
Accordingly, the beam diameter of the return laser beam BKL is larger than that of the reflection surface of the mirror 40B1 in FIG. 17 (b).
In the embodiment of FIG. 17, of the return laser beam BKL, only the “portion incident on the light receiving lens 34” indicated by the broken line is received by the light receiving element 30 for detection.

It goes without saying that the modification shown in FIG. 17 can also be applied to the embodiments shown in FIGS. 14 (a) and 14 (b).
Also in the embodiment described above and shown in FIGS. 15, 16 and 17, as the deflection angle variable power element, the deflection angle variable power elements 182 and 183 having positive refractive power shown in FIG. 13 and FIG. It will be readily understood that the laser radar apparatus can be configured using

All of the above-described laser radar devices change the deflection angle (deflection angle) of the deflected laser beam SRL.
The "deflection angle changing function" for changing the deflection angle is included in the deflection angle variable magnification element.
For example, the deflection angle variable magnification element 181 used in the embodiments shown in FIG. 11, FIG. 15, FIG. 16 and FIG. 17 is a "negative cylinder lens" having refractive power in only one direction. Is a concave cylinder surface, and the surface on the injection side is a flat surface.
The deflection angle variable magnification element 181 has a deflection angle enlargement function.

The deflection angle variable magnification elements 182 and 183 used in the embodiments shown in FIGS. 13 and 14 are “cylinder lenses” having positive refractive power in the Y direction.
The shape of the positive cylinder lens may be, for example, "a plane of incidence surface, a convex cylinder surface". The deflection angle variable magnification element 182 has a deflection angle enlargement function.
However, it is of course possible to make the deflection laser beam in the form of a parallel luminous flux other than the optical axis luminous flux.
In order to realize this, if the focal plane of the deflection angle variable magnification element is two-dimensionally curved, and the plane described by the convergence point of the laser beam deflected by the deflecting device is located at the focal plane. Good.
This can be achieved by "free-form forming" at least one of the inclining surface and the exit surface of the deflection angle variable magnification element.

Also in the embodiment described with reference to FIGS. 15 to 17, it is possible to obtain a deflected laser beam SRL in the form of convergent light flux or divergent light flux.
That is, the divergence start point or convergence position of the divergent or convergent laser beam in at least one direction converted by the coupling optical system (12, 13B1) and the focal position of the deflection angle variable magnification element 181 By adjusting the positional relationship, it is possible to make the light flux form of the polarized laser beam SRL into a convergent light flux or a divergent light flux.
In these cases, in the X direction and the Y direction, the composite imaging system including the condensing lens system (13B1 and 32A, or 32 and 34) constituting the light receiving optical system and the deflection angle variable magnification element 181 is The light receiving optical system may be configured such that an infinite distance on the detection target side and a light receiving surface position of the light receiving element 30 for detection have a conjugate relationship.

In the following, seven specific examples of each embodiment shown in FIG.

Examples 20 to 26 are all examples for realizing "a collimated luminous flux deflection laser beam".
"Example 20"
Example 20 is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 181"
The deflection angle variable magnification element 181 is as follows.
"shape"
A concave cylinder lens having no refractive power in the direction (X direction) orthogonal to the drawing in FIG.
Incident side concave cylinder surface radius of curvature: -24.3 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjustment lens 13B"
The adjustment lens 13B is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing of FIG. 11
Incident side convex cylinder surface radius of curvature: 47.4 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm

"Receiver lens 34"
The light receiving lens 34 is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing of FIG. 11
Incident side: plane Curvature radius: ∞
Injection side: convex cylinder surface radius of curvature: 59.7 mm
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

Distance from the exit side of the adjustment lens 13B to the entry side of the deflection angle variable element 181: 59.9 mm
The distance from the incident side of the light receiving lens 34 to the exit side of the deflection angle variable magnification element 181 (the plane from which the return laser beam is emitted, which is a concave cylinder surface): 84.1 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the light receiving lens 34.
The deflection angle variable magnification element 181 in the twentieth embodiment has a deflection angle enlargement function of enlarging the deflection angle of the deflection laser beam.

"Example 21"
Example 21 is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 182"
The deflection angle variable magnification element 182 is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG.
Incident side Plane curvature radius: ∞
Injection side convex cylinder surface radius of curvature: -45 mm
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjustment lens 13B"
The adjustment lens 13B is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing of FIG. 13
Incident side convex cylinder surface radius of curvature: 48.9 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

"Receiver lens 34"
The light receiving lens 34 is as follows.
"shape"
A convex cylinder lens that does not have refractive power in the direction orthogonal to the drawing in FIG. 13 Incident side surface: plane curvature radius: ∞
Injection side: convex cylinder surface radius of curvature: 74.4 mm
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

Distance from the exit side of the adjustment lens 13B to the entrance side of the deflection angle variable element 182: 150 mm
Distance from the incident side of the light receiving lens 34 to the exit side of the deflection angle variable magnification element 182 (the plane from which the return laser beam is emitted, which is a concave cylinder plane): 200 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the light receiving lens 34.
The deflection angle variable element 182 in the twenty-first embodiment has a deflection angle reduction function of reducing the deflection angle of the deflection laser beam.

"Example 22"
Example 22 is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 183"
The deflection angle variable magnification element 183 is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG.
Incident side Plane curvature radius: ∞
Injection side convex cylinder surface radius of curvature: -300 mm
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjustment lens 13D"
The adjustment lens 13D is as follows.
"shape"
Concave cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG. 14 (a) Incident side Concave cylinder surface Curvature radius: -117.5 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

"Light receiving lens 34A"
The light receiving lens 34A is as follows.
"shape"
A concave cylinder lens having no refractive power in the direction orthogonal to the drawing of FIG. 14
Incident side: plane Curvature radius: ∞
Injection side: concave cylinder surface radius of curvature: -92.0 mm
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

Distance from the exit side of the adjustment lens 13D to the entry side of the deflection angle variable element 182: 150 mm
The distance from the incident side of the light receiving lens 34A to the exit side of the deflection angle variable magnification element 183 (the plane from which the return laser beam is emitted, which is a concave cylinder plane): 200 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the light receiving lens 34.
The deflection angle variable magnification element 183 in Embodiment 22 has a deflection angle reduction function of reducing the deflection angle of the deflection laser beam.

"Example 23"
Example 23 is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 183"
The deflection angle variable magnification element 183 is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG.
Incident side Plane curvature radius: ∞
Injection side convex cylinder surface radius of curvature: -300 mm
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjusting lens 13E"
The adjustment lens 13E is as follows.
"shape"
Concave cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG. 14 (b) Incident side Concave cylinder surface Curvature radius: -117.5 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

"Receiver lens 34B"
The light receiving lens 34B is as follows.
"shape"
Concave cylinder lens that does not have refractive power in the direction orthogonal to the drawing in FIG.
Injection side: convex cylinder surface radius of curvature: 35.4 mm
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

Distance from the exit side of the adjustment lens 13E to the entrance side of the deflection angle variable element 183: 150 mm
Distance between the incident side of the light receiving lens 34B and the exit side of the deflection angle variable magnification element 183 (the plane from which the return laser beam is emitted and a convex cylinder surface): 450 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the light receiving lens 34B.
The deflection angle variable element 183 in the twenty-third embodiment has a deflection angle reduction function of reducing the deflection angle of the deflection laser beam.

"Example 24"
Example 24 is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 181"
The deflection angle variable magnification element 181 is as follows.
"shape"
In Fig. 15, a concave cylinder lens having no refractive power in the direction orthogonal to the drawing.
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjustment lens 13B1 (= lens for light reception)"
The adjustment lens 13B1 which doubles as a light receiving lens is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing of FIG. 4
Incident side convex cylinder surface radius of curvature: 47.4 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

Distance from the exit side of the adjustment lens 13B1 to the entry side of the deflection angle variable element 181: 59.9 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the adjusting lens 13B1 which also serves as a light receiving lens.
The deflection angle variable magnification element 181 in the twenty-fourth embodiment has a deflection angle enlargement function of enlarging the deflection angle of the deflection laser beam.

"Example 25"
The twenty-fifth embodiment is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 181"
The deflection angle variable magnification element 181 is as follows.
"shape"
A concave cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG.
Incident side Cylinder surface radius of curvature: -24.3 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjustment lens 13B1 (= lens for light reception)"
The adjustment lens 13B1 which doubles as a light receiving lens is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG. 16 (a) Incident side convex cylinder surface radius of curvature: 47.4 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm

Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)
Distance from the exit side of the adjustment lens 13B1 to the entry side of the deflection angle variable element 181: 59.9 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the adjusting lens 13B1 which also serves as a light receiving lens.

The deflection angle variable magnification element 181 in the twenty-fifth embodiment has a deflection angle enlargement function of enlarging the deflection angle of the deflection laser beam.

"Example 26"
Example 26 is a specific example of the embodiment shown in FIG.
"Deflecting angle variable element 181"
The deflection angle variable magnification element 181 is as follows.
"shape"
A concave cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG.
Incident side Cylinder surface radius of curvature: -24.3 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: SF6 (refractive index: wavelength: 1.780698 for light of 870 nm)

"Adjustment lens 13B"
The adjustment lens 13B is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG. 17A.
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

"Receiver lens 34"
The light receiving lens 34 is as follows.
"shape"
A convex cylinder lens having no refractive power in the direction orthogonal to the drawing in FIG.
Injection side: convex cylinder surface radius of curvature: 59.7 mm
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)

Distance from the exit side of the adjustment lens 13B to the entry side of the deflection angle variable element 181: 59.9 mm
The distance from the incident side of the light receiving lens 34 to the exit side of the deflection angle variable magnification element 181 (the plane from which the return laser beam is emitted, which is a concave cylinder surface): 59.9 mm

By the optical system specified by the above data, a parallel beam-like polarized laser beam SRL is obtained, and the return laser beam BKL is collimated by the light receiving lens 34.
The deflection angle variable magnification element 181 in the twenty-sixth embodiment has a deflection angle enlargement function of enlarging the deflection angle of the deflection laser beam.

In Examples 20 to 26 mentioned above, each of the adjusting lens and the deflection angle variable magnification element is a cylinder lens having refractive power only in the Y direction, and the luminous flux is converted into convergent or divergent luminous flux by the adjusting lens. The convergent point or "origin of divergence" of the light flux is matched with the focal position of the deflection angle variable magnification element.
Therefore, the beam form of the deflection laser beam emitted from the deflection angle variable magnification element becomes a parallel beam with respect to the optical axis beam in the Y direction, but deviates from the parallel beam when the deflection angle is large.

The “divergence angle or convergence angle of the deflected laser beam” at the maximum deflection angle in the Y direction is as follows.
Example 20 Y direction (maximum deflection angle: 62.9 degrees) Divergence angle: 0.001 degree Example 21 Y direction (maximum deflection angle: 14.6 degrees) convergence angle: 0.29 degrees Example 22 Y direction ( Maximum deflection angle: 27.4 degrees Convergence angle: 0.18 degrees Example 23 Y direction (maximum deflection angle: 27.4 degrees) Convergence angle: 0.18 degrees Example 24 Y direction (maximum deflection angle: 62. 9 degree) Divergence angle: 0.001 degree Example 25 Y direction (maximum deflection angle: 62.9 degrees) Divergence angle: 0.001 degree Example 26 Y direction (maximum deflection angle: 62.9 degrees) divergence angle: 0.001 degree

The luminous flux form at the maximum deflection angle in the Y direction is "substantially parallel luminous flux state" in Examples 20 and 24 to 26, and "substantially parallel luminous flux state" in Examples 2 to 4.
Each of the deflection angle variable magnification elements of Examples 20 to 26 is a cylinder lens and has no refractive power in the X direction. Therefore, the beam form of the deflected laser beam in the X direction is "parallel beam state".
Further, the deflection angle variable magnification elements of Examples 20 to 26 do not have the function of changing the deflection angle in the X direction. The deflection angle in the X direction is equal to the deflection angle in the X direction of the deflection device.

The maximum deflection angle in the X direction is as follows for each example.

Example 20 Maximum deflection angle in the X direction: 25.831 degrees
Example 21 Maximum deflection angle in the X direction: 25.669 degrees
Example 22 Maximum deflection angle in the X direction: 25.698 degrees
Example 23 Maximum deflection angle in the X direction: 25.698 degrees
Example 24 Maximum deflection angle in the X direction: 25.831 degrees
Example 25 Maximum deflection angle in the X direction: 25.831 degrees
Example 26 Maximum deflection angle in the X direction: 25.831 degrees
In either case, the deviation from the parallel beam with respect to the maximum deflection angle is small, and a “parallel beam-like polarized laser beam” can be realized.

It is easy to modify these embodiments to obtain a convergent beam-like or divergent beam-like deflected laser beam, as described above.

Further, the adjustment lenses 13B, 13B1, 13D, and 13E of the coupling optical system can be displaced in the optical axis direction, and the displacement of the adjustment lens makes the light flux form of the polarized laser beam be parallel light flux, convergent light flux, It is also clear that it can be changed in the form of a divergent beam.

Although the example of expanding and changing the deflection angle using the deflection angle variable magnification element having the convex reflecting surface according to FIG. 1 has been described above, the reflecting surface is also used for reduction and magnification of the deflection angle. It can also be done.

FIG. 18 is a diagram for describing an embodiment of a two-dimensional scanning laser radar projection apparatus that performs reduction magnification of deflection angle using a reflection surface.

In FIG. 18, the X, Y, and Z directions are the directions described above.
FIG. 18A shows the state in the direction parallel to the YZ plane. (B) shows the state in the direction parallel to the XZ plane.

The laser beam from the LD 10 is collimated by the coupling lens 12 and incident on the deflecting device 14 through the adjustment lens 13A to be two-dimensionally deflected in the XY2 direction.

A two-dimensionally deflected laser beam is made incident on a deflection angle variable magnification element CM to be a two-dimensionally deflected polarized laser beam SRL.

The deflection angle variation element CM reflects the laser beam by the “concave reflection surface” and reduces the variation angle of the deflection angle.

As shown in FIG. 18, a concrete example of a two-dimensional scanning laser beam projection apparatus using a deflection angle variable magnification element CM having a concave reflection surface will be described below as a twenty-seventh embodiment.

"Example 27"
"Deflecting angle scaling element CM"
The deflection angle variable magnification element CM is as follows.
"shape"
Radius of curvature: 100 mm concave sphere
"Adjusting lens 13A"
The adjustment lens 13A is as follows.
"shape"
Axisymmetric convex lens
Incident side convex lens surface radius of curvature: 39.58 mm
Exit side plane radius of curvature: ∞
Thickness: 3 mm
Material: BK7 (refractive index: wavelength: 1.509493 for light of 870 nm)
Focal length: 49.4 mm
Distance from the exit side of the adjustment lens 13A to the deflection device 14: 99 mm
Distance on the optical axis from the deflecting device 14 to the concave reflecting surface of the deflection angle changing element CM: 26.7 mm
The deflection angle variable magnification element CM has a deflection angle reduction function of reducing the deflection angle of the deflection laser beam.

The relationship between the deflection angle (XZ plane) of the laser beam by the deflection device 14 and the reduced deflection angle of the deflection laser beam SRL is as follows. The unit of angle is "degree".
Deflection angle 25.7 17.24 8.65 8.65 17.24 25.7
Reduced deflection angle 13.0 9.0 4.6 4.6 9.0 13.0
The relationship between deflection angle and angular distortion (ANDT) is as follows.
Deflection angle 25.7 17.24 8.65 8.65 17.24 25.7
ANDT -6.7 -2.8 -0.6 -0.6 -2.8 -6.7
The relationship between the deflection angle and the beam diameter (the value obtained from the spot diagram at the “3 m position from the reflecting surface of the deflection angle changing element CM”) is as follows.
Deflection angle 25.7 17.24 8.65 0 8.65 17.24 25.7
Beam diameter (mm) 23.5 23.06 23.52 23.5 23.52 23.06 23.5
The angular distortion is also small and stable, and the variation in beam diameter is also small.

It goes without saying that the laser radar device can be configured by combining the two-dimensional scanning laser beam projection device of the twenty-seventh embodiment with the various light receiving means described above.

As described above, according to the present invention, it is possible to realize the following two-dimensional scanning laser beam projection apparatus and laser radar apparatus.

[1]
A two-dimensional scanning laser beam projector which emits two-dimensionally deflected polarized laser beams LF2 and SRL, which comprises a laser light source (10, 12, etc.) for emitting a laser beam, and the laser light source A deflection device (14) for deflecting a laser beam two-dimensionally and a deflection angle of the laser beam deflected and scanned two-dimensionally by the deflection device are changed in at least one of two directions orthogonal to each other A two-dimensional scanning laser beam projector comprising: deflection angle magnification elements (16, 18, 180, 181, 182, 183) which are deflection laser beams.

[2]
[1] The two-dimensional scanning type laser beam projection device according to [1], wherein the deflection angle variable magnification element is configured to set a deflection angle of the two-dimensionally deflected scanning laser beam in at least one of two directions orthogonal to each other. A two-dimensional scanning laser beam projector which is a deflection angle expanding element (16, 18, 181, etc.) which magnifies in to a deflection laser beam.

[3]
[1] The two-dimensional scanning type laser beam projection device according to [1], wherein the deflection angle variable magnification element is configured to set a deflection angle of the two-dimensionally deflected scanning laser beam in at least one of two directions orthogonal to each other. A two-dimensional scanning laser beam projection apparatus, which is a deflection angle reduction element (180, 20C, CM, etc.) for reducing in size to a deflection laser beam.

[4]
[2] The two-dimensional scanning laser beam projection apparatus according to [2], wherein the deflection angle enlarging element is composed of lenses (18, 181, etc.).

[5]
[4] The two-dimensional scanning laser beam projection apparatus according to [4], wherein the deflection angle magnifying element (18) configured by the lens has an expanding concentric coefficient: CE for the direction in which the deflection angle is magnified. :
(1) 0.8 ≦ CE ≦ 1.5
A two-dimensional scanning laser beam projector that satisfies

[6]
[2] The two-dimensional scanning laser beam projector according to [2], wherein the deflection angle enlarging element (16) is a mirror.

[7]
[3] The two-dimensional scanning laser beam projection apparatus according to [3], wherein the deflection angle reduction element is constituted by lenses (180, 18C) and the like.

[8]
[7] The two-dimensional scanning laser beam projection apparatus according to [7], wherein the deflection angle reduction element configured by the lens (180 or the like) has a reduction concentric coefficient: CR in the direction in which the deflection angle is reduced. conditions:
(2) 0.5 ≦ CR ≦ 1.8
A two-dimensional scanning laser beam projector that satisfies

[9]
[3] The two-dimensional scanning laser beam projection apparatus according to [3], wherein the deflection angle reduction element (CM) is a mirror.

[10]
A laser beam emitted from a laser light source is two-dimensionally scanned as a polarized laser beam (SRL) and irradiated onto a detection target, and light reflected by the detection target is returned as a laser beam (BKL) as a light receiving element (30 A laser radar device for measuring the distance to the object to be detected, wherein the laser beam from the laser light source (10) is two-dimensionally scanned as a polarized laser beam (SRL) to detect the object A two-dimensional scanning type laser beam projection device for irradiating the light, detection means (30, 32, 34) for detecting a return laser beam reflected by the detection object, and controlling the laser beam projection device and the detection means Control calculation means (400) for measuring the time for which the laser light reciprocates the distance to the object to be detected and calculating the distance to the object to be detected; As beam projection device, a laser radar apparatus using a laser beam projection system of the two-dimensional scanning type according to any one of [1] to [9].

[11]
[10] The laser radar device according to [10], wherein the detection means shares the deflection angle magnification element (18, 180, etc.) and the deflection device (14) with the laser beam projection device.

In addition, the following two-dimensional scanning laser beam projection apparatus and laser radar apparatus can be realized.

(A-1)
A laser beam projector for emitting a two-dimensionally deflected laser beam, comprising: a laser light source (10, 12) for emitting a laser beam (LF); and a two-dimensionally laser beam emitted from the laser light source A deflecting device (14) for deflecting and scanning, and a reflecting surface member (16) for reflecting a laser beam (LF1) two-dimensionally deflected and scanned by the deflecting device (14) as a reflected laser beam (LF2) The reflecting surface member (16) is a curved reflecting surface portion that changes the deflection angle of the reflected laser beam (LF2) into a desired deflection angle range in at least one of the horizontal direction and the vertical direction. A two-dimensional scanning laser beam projection device comprising (160).

(A-2)
In the two-dimensional scanning laser beam projection apparatus according to (A-1), the reflecting surface member (16) desirably has a deflection angle of the reflected laser beam (LF2) at least in the horizontal direction and the vertical direction. What is claimed is: 1. A two-dimensional scanning laser beam projector comprising: a curved reflective surface portion (160) that changes magnification within the deflection angle range of (1).

(A-3)
In the two-dimensional scanning laser beam projector according to (A-1), the reflecting surface member (16) changes the deflection angle of the reflected laser beam (LF2) into a desired deflection angle range in the horizontal direction and the vertical direction. A two-dimensional scanning laser beam emitting device having a reflecting surface portion of a curved surface to be doubled.

(A-4)
In the two-dimensional scanning laser beam emission device according to any one of (A-1) to (A-3), the laser beam LF emitted from the laser light source (10, 12) is two-dimensionally deflected and scanned. The deflection device (14) is a two-dimensional scanning laser beam emitting device for swinging the reflecting mirrors about mutually orthogonal axes.

(A-5)
In the two-dimensional scanning laser beam projector according to any one of (A-1) to (A-4), the reflecting surface member is a cylindrical surface having a convex surface or a conical surface having a convex surface. A two-dimensional scanning laser beam projector characterized in that

(A-6)
In the two-dimensional scanning laser beam projection apparatus according to any one of (A-1) to (A-4), the reflective surface member has a concave surface, a concave cylinder surface or a concave conical surface (160 A two-dimensional scanning laser beam projector.

(B-1)
A two-dimensional scanning laser beam projection apparatus that emits a two-dimensionally deflected laser beam, comprising: a laser light source (10, 12, 13) that emits a laser beam; and a laser beam (a laser beam emitted from the laser light source A deflection device (14) for two-dimensionally deflecting and scanning LA), and a deflection angle of a laser beam (LD) two-dimensionally deflected and scanned by the deflection device in at least one of two directions orthogonal to each other The deflection angle magnification element (18) is concave in at least one of the two directions, and the deflection angle magnification element (18) is two-dimensionally deflected A two-dimensional scanning laser beam projector which is a negative power deflection angle variable magnification element that transmits a scanned laser beam (LD) and expands a deflection angle by refraction.

(B-2)
(B-1) The two-dimensional scanning type laser beam projection apparatus according to (B-1), wherein a deflection angle of the laser beam which is two-dimensionally deflected and scanned by the deflection device (14) is determined by a deflection angle variable magnification element (18). A two-dimensional scanning laser beam projection apparatus which magnifies and expands in two directions orthogonal to each other.

(B-3)
A two-dimensional scanning laser beam projector as described in (B-1) or (B-2), wherein
The deflection angle variable magnification element is a two-dimensional scanning laser beam projection apparatus in which the incident side surface is a concave cylinder surface or a two-dimensional concave surface.

(B-4)
In the two-dimensional scanning laser beam projection apparatus according to any one of (B-1) to (B-3), the deflection angle variable magnification element (18) has a concave exit side (18B), A two-dimensional scanning laser beam projector which is either a convex surface or a flat surface.

(B-5)
The laser beam projector according to any one of (B-1) to (B-4), wherein the laser light source comprises an LD (10) and a laser emitted from the LD (10). A condenser element (12) for collimating the luminous flux, and a condenser lens (13) for condensing the laser beam collimated by the collimator element in at least one direction; 13) The laser beam (LA) collected by the laser beam is two-dimensionally deflected by the deflecting device (14) to be incident on the deflection angle variable magnification element (18), and the emission side of the deflection angle variable magnification element A two-dimensional scanning laser beam projection apparatus in which the focal position of the lens and the focal position on the exit side of the condenser lens (13) are substantially matched.

(B-6)
The laser beam projection apparatus of two-dimensional scanning type according to any one of (B-1) to (B-5), which comprises: a starting point of deflection by the deflection device (14); Magnified concentric coefficient defined as L / (-R) by the distance L to the incident surface (18A) and the radius of curvature R: <(0) of the incident surface side 18A of the deflection angle variable magnification element (18) : CE, condition:
(1) 0.8 <CE <1.5
Two-dimensional scanning laser beam projection device that satisfies

(B-7)
In the two-dimensional scanning laser beam projection apparatus according to any one of (B-1) to (B-6), the deflection angle variable magnification element (18) is a beam of an envelope housing (CS) of the apparatus. A two-dimensional scanning laser beam projector that doubles as an emitting part.

(B-8)
The laser beam projection apparatus of two-dimensional scanning type according to any one of (B-1) to (B-7), wherein the deflection angle enlarged by the deflection angle variable magnification element (18) is 60 in one direction. Two-dimensional scanning laser beam projection device that is more than

(B-9)
The laser beam projection apparatus of two-dimensional scanning type according to any one of (B-1) to (B-8), wherein the deflector (14) deflects and scans the laser beam (LA) in two dimensions. , A combination of two-axis MEMS or one-axis MEMS, or a combination of one-axis MEMS and one-axis galvano mirror or one-axis polygon mirror, or a combination of one-axis galvano mirror and one-axis polygon mirror A two-dimensional scanning laser beam projection apparatus.

(B-10)
Laser radar that projects a two-dimensionally scanned laser beam (LD) onto a detection target, detects laser light diffused and reflected by the detection target, and measures the distance to the detection target two-dimensionally A two-dimensional scanning laser beam projection apparatus that scans a laser beam (LB) in a two-dimensional manner and projects the laser beam (LB) onto a detection target, and reflection from the detection target onto which the laser beam (LB) is projected A light receiving means for receiving a laser beam (LO), the light receiving means comprising a light receiving element (20), and a light receiving condenser lens (22) for collecting the reflected laser beam (LO) on the light receiving element And a laser radar apparatus using the two-dimensional scanning laser beam projector according to any one of (B-1) to (B-9) as the laser beam projector.

(C-1)
The LD (10), a collimating lens (12) for collimating a laser beam emitted from the LD (10), and a laser beam collimated by the collimating lens in X and Y directions orthogonal to each other A laser light source having an adjusting lens (13B, 13C) for giving a converging tendency or a diverging tendency in at least one of the two directions, and a laser beam transmitted through the adjusting lens (13B etc.); And a deflecting device (14) for deflecting two-dimensionally in the direction and the Y direction, a laser beam having positive refractive power and being deflected two-dimensionally by the deflecting device is incident, and the X direction and the Y direction A deflection angle variable magnification element (180, 18C) for emitting a deflection laser beam (SRL) with a reduced deflection angle at at least one of the deflection angle magnification element; When an optical axis (AX) of the optical axis is a Z direction orthogonal to the X and Y directions, and a plane parallel to the Y direction is an α plane and a plane parallel to the X direction is a β plane, A laser beam deflected by the deflection device (14) at a maximum deflection angle: θα with respect to the optical axis (AX) in the α plane and refracted at the incident surface (180A) of the deflection angle variable magnification element A position Qα where an extension line (ETL) obtained by linearly extending the in-lens central ray (PL) toward the deflecting device intersects the optical axis (AX), the in-lens central ray, and the deflection angle variation The distance component in the optical axis direction of the distance between the doublet element with the exit surface (180B) and the intersection position qα is Aα, and the inside of the α plane of the exit surface (180B) of the deflection angle variable element (180) Radius of curvature at the center of the circle: reduced concentric coefficient by Rα: Cα (≡ | Aα Of the laser beam which is deflected at the maximum deflection angle: θβ with respect to the optical axis in the β plane by the deflection device (14) and refracted at the incident surface of the deflection angle variable magnification element An extension line obtained by linearly extending an in-lens central ray toward the deflecting device intersects the optical axis, and a position of an intersection between the in-lens central ray and the exit surface of the deflection angle variable magnification element The radius component of the exit surface of the deflection angle variable magnification element in the β plane: the reduction concentric radius by Rβ: Cβ (≡ | Aβ / Rβ |) Among them, conditions for the reduction of the deflection angle:
(2α) 0.5 ≦ Cα ≦ 1.8
(2β) 0.5 ≦ Cβ ≦ 1.8
A two-dimensional scanning laser beam projector that satisfies

(C-2)
(C-1) The laser beam projection apparatus according to (C-1), wherein the adjustment lens (13B) and the deflection lens are deflected so that the deflection laser beam (SRL) emitted from the deflection angle variable magnification element (180, 18C) becomes a parallel beam. A two-dimensional scanning laser beam projection apparatus in which an optical relationship between angular magnification elements (180, 18C) is set.

(C-3)
(C-1) The laser beam projection apparatus according to (C-1), wherein the adjusting lens is configured such that the deflected laser beam (SRL) emitted from the deflection angle variable magnification element (180, 18C) becomes a convergent or divergent beam. A two-dimensional scanning laser beam projection apparatus in which an optical relationship between (13B) and a deflection angle variable magnification element (180, 18C) is set.

(C-4)
(C-1) The laser beam projection apparatus according to (C-1), wherein the deflection laser beam (SRL) emitted from the deflection angle variable magnification element (180, 18C) by adjusting the displacement of the adjusting lens (13B) in the optical axis direction. A two-dimensional scanning laser beam projection apparatus in which the form of light flux of the light source can be changed.

(C-5)
The laser beam projection apparatus according to any one of (C-1) to (C-4), wherein both of the adjustment lens and the deflection angle variable magnification element are axially symmetric lenses that are rotationally symmetric around the optical axis. A two-dimensional scanning laser beam projection apparatus.

(C-6)
The laser beam projection apparatus according to any one of (C-1) to (C-4), wherein both of the adjustment lens (13B) and the deflection angle variable magnification element (180) are in the α plane or β plane A two-dimensional scanning laser beam projector which is a cylindrical lens having no refractive power inside.

(C-7)
The laser beam projection apparatus according to any one of (C-1) to (C-4), wherein the adjusting lens (13B) and the deflection angle variable magnification elements (180, 18C) are both in the α plane. A two-dimensional scanning laser beam projection apparatus which is an anamorphic lens which has different refractive power in the β plane.

(C-8)
A laser beam emitted from a laser light source is two-dimensionally scanned as a polarized laser beam (SRL) and irradiated onto a detection target, and light reflected by the detection target is returned as a laser beam (BKL) as a light receiving element (30 A laser radar device that receives light and measures the distance to the detection target, and two-dimensionally scans a laser beam from a laser light source as a polarized laser beam (SRL) to irradiate the detection target A two-dimensional laser beam projection apparatus, detection means for detecting a return laser beam (BKL) reflected by the detection object, and the laser beam projection apparatus and detection means are controlled, and the laser light reaches the detection object Control calculation means (400) for calculating the distance to the object to be detected by measuring the time for reciprocation of the distance -1) through a laser radar apparatus using a two-dimensional laser beam projection apparatus according to any one of (C-7).

(C-9)
(C-8) The laser radar device according to (C-8), wherein the control calculation means (400) in the two-dimensional laser beam projection device can adjust the position of the adjusting lens (13B) in the optical axis direction.

(D-1)
A laser radar device for two-dimensionally scanning an object to be detected with a polarized laser beam having a parallel luminous flux shape or a convergent luminous flux shape or a divergent luminous flux shape, and a laser light source and a laser luminous flux from the laser light source An illumination optical system that deflects two-dimensionally to form a deflection laser beam (SRL) that two-dimensionally scans a detection target, and detection that receives a return laser beam (BKL) reflected by the detection target Light receiving element (30), a light receiving optical system (32, 34) for guiding the return laser beam to the light receiving element for detection, and the light receiving element for detection after the laser light is emitted Control computing means (400) for determining the distance to the object to be detected according to the time taken to receive the light flux, and the optical system for illumination is emitted from the LD (10) and the LD (10) A laser light source having a coupling optical system (12, 13A) for converting the laser beam into a luminous flux, and a deflection device (14) for two-dimensionally deflecting the laser luminous flux converted by the coupling optical system And a deflection angle variable magnification element (181 or the like) for receiving a two-dimensionally deflected laser beam and emitting it as a deflected laser beam, and the beam conversion of the coupling optical system is performed from the LD (10) Irradiated laser light is converted into a divergent or convergent laser beam in at least one direction of two-dimensional deflection by the deflection device (14), and the deflection angle variable magnification element (181, etc.) Has a scanning angle changing function of enlarging or reducing a scanning angle of the deflection laser beam (SRL) in at least one direction of two-dimensional deflection by the deflection device. The light receiving optical system shares at least the deflection angle variable magnification element (181) and the deflection device (14) with the irradiation optical system, and diverges according to the refractive power of the deflection angle magnification element. A condensing lens system (32, 34) for condensing the return laser beam which has been deflected by the deflecting device into a flexible or convergent beam toward the detection light receiving element (30); A divergence start point or a convergence position of the divergent or convergent laser beam in the at least one direction, which is converted by the coupling optical system, and a focal position of the deflection angle variable magnification element (181) A laser radar device having a positional relationship according to a light beam form of a laser beam (SRL).

(D-2)
(D-1) The laser radar device according to (D-1), which is a divergence origin or convergence position of a divergent or convergent laser beam in at least one direction, converted by the coupling optical system, and deflection angle magnification A laser radar device having a positional relationship such that the light beam form of a polarized laser beam (SRL) is in the form of a parallel light beam with a focal position of an element (181 or the like).

(D-3)
(D-1) The laser radar device according to (D-1), which is a divergence origin or convergence position of a divergent or convergent laser beam in at least one direction, converted by the coupling optical system, and deflection angle magnification A laser radar device having a positional relationship such that a light flux form of a polarized laser beam (SRL) has a convergent light flux shape with a focal position of an element.

(D-4)
(D-1) The laser radar device according to (D-1), which is a divergence origin or convergence position of a divergent or convergent laser beam in at least one direction, converted by the coupling optical system, and deflection angle magnification A laser radar device having a positional relationship such that a light flux form of a polarized laser beam is in the form of a diverging light flux with a focal position of an element.

(D-5)
The laser radar device according to any one of (D-1) to (D-4), wherein the coupling optical system collimates the laser beam emitted from the LD (10) into a collimated lens (12 And an adjusting lens (13B or the like) for converting a laser beam collimated by the collimating lens into a diverging or converging laser beam in at least one direction of two-dimensional deflection by the deflection device. Laser radar device.

(D-6)
(D-5) The laser radar device according to (D-5), wherein the adjustment lens (13B etc.) of the coupling optical system is displaceable in the optical axis direction, and the displacement of the adjustment lens causes the deflection laser beam (SRL) to Laser radar device that changes luminous flux form.

(D-7)
The laser radar device according to any one of (D-1) to (D-6), wherein the deflection angle variable magnification element (201) is a deflection laser in at least one direction of two-dimensional deflection by the deflection device. Laser radar system with scan angle enlargement function to expand the beam scan angle.

(D-8)
In the laser radar device according to any one of (D-1) to (D-6), the deflection angle variable magnification element (183) deflects in at least one direction of two-dimensional deflection by the deflection device (14). A laser radar device having a scan angle reduction function for reducing the scan angle of a laser beam (SRL).

(D-9)
In the laser radar device according to any one of (D-1) to (D-8), the coupling optical system is configured to perform one of two-dimensional deflection of the laser beam directed to the deflection device (14) by the deflection device. A laser radar device having a light flux conversion function parallel to one direction and divergent or convergent in another direction, and the deflection angle variable magnification element has no refractive power in one direction.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above, and the invention described in the appended claims unless otherwise limited in the above description. Various modifications and changes are possible within the scope of the present invention.
The effects described in the embodiments of the present invention merely list the preferable effects resulting from the invention, and the effects of the invention are not limited to those described in the embodiments.

10 LD (semiconductor laser)
12 coupling lens
13, 13A, 13B, 13C, 13D, 13E Adjustment lens 14 Deflecting device
16 Reflecting surface member (deflection angle magnification element)
LF laser beam
18, 18C, 181, 182, 183 deflection angle variable magnification element
30 light receiving element
32 Focusing Lens
34, 34A, 34B Lenses for Receiving Light
40, 40A mirror

JP, 2013-113684, A JP 2012-58178 A

Claims (10)

1. What is claimed is: 1. A two-dimensional scanning laser beam projection apparatus that emits a two-dimensionally deflected polarized laser beam, comprising:
   A laser light source emitting a laser beam;
   A deflector for two-dimensionally deflecting a laser beam emitted from the laser light source;
   A deflection angle variable magnification element for changing a deflection angle of a laser beam which is two-dimensionally deflected and scanned by the deflection apparatus in at least one of two directions orthogonal to each other to form a deflection laser beam; Scanning laser beam projector.
2. The two-dimensional scanning laser beam projection apparatus according to claim 1, wherein
   Two-dimensional scanning in which a deflection angle variable magnification element is a deflection angle expanding element which expands a deflection angle of a two-dimensionally deflected and scanned laser beam in at least one of two directions orthogonal to each other to form a deflected laser beam. Type laser beam projector.
3. The two-dimensional scanning laser beam projection apparatus according to claim 1, wherein
   Two-dimensional scanning which is a deflection angle reducing element which reduces a deflection angle of a two-dimensionally deflected scanning laser beam in at least one of two directions orthogonal to each other to form a deflected laser beam. Type laser beam projector.
4. The two-dimensional scanning laser beam projection apparatus according to claim 2, wherein
   The deflection angle expansion element is a two-dimensional scanning laser beam projection apparatus composed of a lens.
5. 5. The two-dimensional scanning laser beam projection apparatus according to claim 4, wherein
   The deflection angle magnifying element constituted by the lens has a magnifying concentric coefficient: CE in the direction in which the deflection angle is broadened:
   (1) 0.8 ≦ CE ≦ 1.5
   A two-dimensional scanning laser beam projector that satisfies
6. The two-dimensional scanning laser beam projection apparatus according to claim 2, wherein
   A two-dimensional scanning laser beam projection apparatus in which the deflection angle expanding element is composed of a mirror.
7. 4. The two-dimensional scanning laser beam projection apparatus according to claim 3, wherein
   The deflection angle reduction element is a two-dimensional scanning laser beam projection apparatus composed of a lens.
8. 8. The two-dimensional scanning laser beam projection apparatus according to claim 7, wherein
   The deflection angle reduction element configured by the lens has a reduction concentricity coefficient: CR in the direction in which the reduction of the deflection angle is performed.
   (1) 0.5 ≦ CR ≦ 1.8
   A two-dimensional scanning laser beam projector that satisfies
9. 4. The two-dimensional scanning laser beam projection apparatus according to claim 3, wherein
   The deflection angle reduction element is a two-dimensional scanning laser beam projection apparatus composed of a mirror.
10. A laser beam emitted from a laser light source is two-dimensionally scanned as a deflection laser beam to irradiate an object to be detected, light reflected by the object to be detected is received by a light receiving element as a laser beam, and the object to be detected is A laser radar device for measuring the distance to
    A two-dimensional scanning laser beam projection apparatus for two-dimensionally scanning a laser beam from a laser light source as a deflection laser beam to irradiate the object to be detected;
    Detection means for detecting a return laser beam reflected by the detection object;
    Control computing means for controlling the laser beam projection device and the detection means, measuring the time for which the laser light reciprocates the distance to the detection object, and calculating the distance to the detection object;
    A laser radar device using the two-dimensional scanning laser beam projection device according to any one of claims 1 to 9 as the laser beam projection device.

Images