JP6482015B2 - Laser radar device and light receiving device of laser radar device - Google Patents

Description

  The present invention relates to a laser radar device and a light receiving device of the laser radar device.

  Various laser radar devices have been proposed in the past that use a laser beam scanning unit to two-dimensionally scan a laser beam from a laser light source as a deflected laser beam and detect a reflected laser beam from a detection object as a return laser beam. (Patent Document 1 etc.).

  As is well known, laser radar devices are roughly classified into “coaxial system” and “different axis system”.

  The “coaxial system” shares part of the optical system that constitutes the laser beam scanning unit and part of the optical system that constitutes the light receiving unit, and is advantageous for making the laser radar device compact.

  On the other hand, the “different axis system” is an optical separation of the laser beam scanning unit and the light receiving unit and requires separate optical systems for the laser beam scanning unit and the light receiving unit. High degree of design freedom.

  This invention makes it a subject to implement | achieve the novel light-receiving device of a laser radar apparatus of a different axis | shaft system.

In the “light receiving device of a laser radar device” of the present invention, a laser beam from a laser light source is two-dimensionally scanned as a deflected laser beam by a laser beam scanning unit, and a reflected laser beam from a detection object is returned as a laser beam. In the laser radar device for detection, the light receiving device receives the return laser light from the detection object, and receives at least one light receiving element and a wide range of return laser light, and is on a side of the one or more light receiving elements. a condenser lens system for injection into one and more of the light guide member for guiding without any laser light emitted from the condenser lens system, is formed on the light receiving surface of the front SL 1 or more light-receiving element, the a, the focusing lens system is a convex lens surface having a single negative power lens surface closest incident side are continuous, the one or more light receiving elements wherein the said one or more light guide members It is intended for receiving signaling the laser light guided to the light plane by the one or more light receiving elements, for receiving all of the laser light emitted from the converging lens system.

  As described above, according to the present invention, it is possible to realize a novel light receiving device of an off-axis laser radar device having a laser beam scanning unit and a light receiving device separately.

It is a figure which shows one specific example of a condensing lens system. It is a figure which shows another specific example of a condensing lens system. It is a figure which shows six examples of embodiment. It is a figure which shows 6 examples of other forms of implementation. It is a figure for demonstrating the laser radar apparatus of a different axis | shaft system. It is a figure for demonstrating the system structure of a laser radar apparatus.

  The “different-axis laser radar device” will be briefly described with reference to FIG.

  FIG. 5A is a diagram for explaining a “laser beam scanning unit”, and FIG. 5B is a diagram for explaining a “light receiving device”.

  In FIG. 5A, reference numeral 10 indicates a simplified “laser beam scanning unit”.

  The laser beam scanning unit 10 includes a laser light source 11, a collimator lens 13, and a deflecting unit 15.

As the laser light source 11, for example, a semiconductor laser can be used.
The laser beam emitted from the laser light source 11 is converted into a parallel beam by the collimator lens 13 and enters the deflecting unit 15.

  The deflecting means 15 reflects the incident “parallel laser beam” and scans it two-dimensionally as a deflected laser beam SLB.

  Various deflecting means 15 can be considered.

  For example, two rotating polygon mirrors with orthogonal rotation axes reflect laser beams in order and scan two-dimensionally, or two perturbation mirrors with orthogonal rotation axes orthogonal to each other. A two-dimensionally scanned image that is sequentially reflected can be considered.

  Furthermore, what constitutes what is called "MEMS" what performs a two-dimensional scan by two-dimensionally swinging a reflecting surface and deflecting a laser beam two-dimensionally is known.

  The deflecting means 15 in FIG. 5A is a simplified drawing of only the reflecting surface portion that swings two-dimensionally. The deflected laser beam SLB is deflected in a direction parallel to the drawing and in a direction orthogonal to the drawing.

  If there is a “detection target” in the scanning region of the deflection laser beam SLB scanned two-dimensionally, the detection target is scanned by the deflection laser beam SLB.

  At the time of this scanning, the deflected laser beam SLB is reflected by the object to be detected and returns to a laser beam.

The return laser beam is received by the “light receiving device”.
In FIG.5 (b), the code | symbol 20 has shown the light-receiving device simplified.

  The light receiving device 20 includes a condenser lens system 21 and a light receiving element 20.

  A “return laser beam” indicated by reference sign BKL enters the condenser lens system 21 and is condensed toward the light receiving surface of the light receiving element 23.

When the light receiving element 23 receives the return laser beam BKL, it converts it into a light reception signal.
The laser radar device has “control calculation means” for controlling the laser beam scanning unit 10 and the light receiving device 20.

  The control calculation unit controls the laser beam scanning unit 10 to cause the laser light source 11 to “pulse light emission at a predetermined cycle”, for example.

  Based on the light reception signal of the light receiving element 23, the control calculation means starts from the moment when an arbitrary deflected laser beam is pulsed until it is reflected by the detection target and becomes a return laser beam BKL and received by the light receiving element 23. Time: 2T is specified.

  Then, the distance: CT is calculated from the speed of light: C and time: 2T.

  Since the deflected laser beam SLB is pulse-emitted, it is known at each moment which direction (orientation) is directed at each moment.

  Therefore, the distance from the direction of the deflected laser beam SLB at each moment and the distance: CT to the detection target is known at each moment along with the direction of the deflection laser beam SLB. The surface shape and distance will be known.

  The laser radar device is desired to have a “wide detection range (a region in which the deflected laser beam SLB scans)”.

  By increasing the deflection angle of the deflected laser beam SLB, it is possible to widen the “detection region”.

  When the deflection angle of the deflected laser beam SLB is increased in order to widen the detection region, it is necessary to widen the converging lens system 21 accordingly to “widen the entire angle of view”.

  This is because the deflected laser beam SLB emitted from the laser beam scanning unit 10 and the return laser beam BKL are “in the same direction” at each moment.

  The “positional relationship between the condensing lens system 21 and the light receiving element 23” in the light receiving device 20 may be, for example, matching the light receiving surface of the light receiving element 23 and the focal plane of the condensing lens system 21.

  By doing so, the return laser beam BKL by the detection object is substantially collimated at the stage where it enters the condensing lens system 21, and is thus condensed on the light receiving surface.

  In this case, when the condensing lens system 21 is widened in accordance with the increase in the deflection angle of the deflected laser beam SLB, the incident angle of the “return laser beam BKL having a large angle of view” on the light receiving surface increases.

  As a result, the detection output of the light receiving element 23 decreases with respect to the “returning laser beam with a large angle of view”, the detection accuracy decreases, and the light receiving surface of the light receiving element 23 increases.

  This tendency increases as the angle of view of the condensing lens system 21 increases, and becomes prominent particularly when the total angle of view becomes 90 degrees or more.

  Here, two specific examples of the condensing lens system 21 having a wide angle of view are given.

"Example 1"
FIG. 1 shows a lens configuration of the condensing lens system of the first specific example.

  This condensing lens system has a negative first lens group G1, a positive second lens group G2, an aperture stop S, and a positive third lens group G3 in this order from the incident side (left side in the figure).

  The condenser lens system is a wide-angle lens having a half angle of view: 85 degrees (full angle of view: 170 degrees).

  The negative first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3 arranged in order from the incident side as shown in the figure.

  The first lens L1 and the second lens L2 are both “negative meniscus lenses” having a concave surface having a large curvature directed toward the exit side (right side in the figure), and the third lens L3 has a large curvature on the concave surface on the exit side. It is a “biconcave lens”.

  The positive second lens group G2 includes a fourth lens L4 and is a “convex flat lens” having a convex surface directed toward the incident side.

  The third lens group G3 has a positive refractive power, and is configured by arranging a fifth lens L5, a sixth lens L6, and a seventh lens L7 in order from the incident side.

  Both the fifth lens L5 and the sixth lens L6 are “positive meniscus lenses” with convex surfaces having a large curvature directed toward the incident side.

  The seventh lens L7 is a “convex flat lens” with a convex surface facing the incident side.

  The aperture stop S is disposed between the fourth lens L4 and the fifth lens L5.

  Specific data of the condensing lens system of Example 1 is shown in Table 1.

  “No.” in the left column of Table 1 is a surface number counted from the incident side and includes the surface of the aperture stop.

  “R” is the radius of curvature, “D” is the surface separation, “N” is the refractive index of the material, and “glass type” is “name of glass material”.

  In Table 1, “aperture stop: 11.081” is “aperture radius (mm)”, and thus the aperture diameter is 22.162 mm.

  Specific example 1 of the condensing lens system is a “wide-angle lens” having a total field angle of 170 degrees, but the beam diameter φ of the “return laser beam BKL” incident on the incident surface is 6 mm, and the light-receiving surface of the light-receiving element 23. The diameter φ is assumed to be 6 mm.

  “The diameter of the light receiving surface: 6 mm” is a “diameter of a circular region” that is a set of images condensed on the light receiving surface, and the light receiving surface of the light receiving element 23 has a size that can receive the circular region. .

  In FIG. 1, “H5” represents the light beam radius (distance from the optical axis) when the light beam diameter of the light beam exiting from the exit surface of the condenser lens system (the exit side surface of the seventh lens) is minimized. .

  “H5” in the specific example 1 is “5.686 mm”, and thus the light beam diameter φ: 11.372 mm when the light beam emitted from the exit side surface of the seventh lens becomes the minimum diameter.

  The imaging position (geometric optical back focus) of the condensing lens diameter of the first specific example is 9.528 mm from the exit side surface of the seventh lens L7.

  “SF” in FIG. 1 indicates a position 5 mm away from the exit surface of the seventh lens L7 in order to chuck the beam variation.

"Example 2"
FIG. 2 shows the lens configuration of the condensing lens system of the second specific example.

  In order to avoid complications, the same reference numerals as those in FIG.

  This condensing lens system has a negative first lens group G1, a positive second lens group G2, an aperture stop S, and a positive third lens group G3 in this order from the incident side (left side in the figure).

  The condenser lens system is a wide-angle lens having a half angle of view: 85 degrees (full angle of view: 170 degrees).

  The negative first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3 arranged in order from the incident side as shown in the figure.

  The first lens L1 and the second lens L2 are both “negative meniscus lenses” having a concave surface having a large curvature directed toward the exit side (right side in the figure), and the third lens L3 has a large curvature on the concave surface on the exit side. It is a “biconcave lens”.

  The positive second lens group G2 includes a fourth lens L4 and is a “convex flat lens” having a convex surface directed toward the incident side.

  The third lens group G3 has a positive refractive power, and is configured by arranging a fifth lens L5, a sixth lens L6, and a seventh lens L7 in order from the incident side.

  Both the fifth lens L5 and the sixth lens L6 are “positive meniscus lenses” with convex surfaces having a large curvature directed toward the incident side.

  The seventh lens L7 is a “convex flat lens” with a convex surface facing the incident side.

  The aperture stop S is disposed between the fourth lens L4 and the fifth lens L5.

  Table 2 shows specific data of the condensing lens system of Example 2 following Table 1.

  “No.” in the left column of Table 2 is a surface number counted from the incident side and includes the surface of the aperture stop.

  “R” is the radius of curvature, “D” is the surface spacing, “N” is the refractive index of the material, and “glass type” is the name of “glass material”.

  In Table 2, “aperture stop: 11.081” is “aperture radius (mm)”, and thus the aperture diameter is 22.162 mm.

  Specific example 2 of the condensing lens system is also a “wide-angle lens” having a total angle of view: 170 degrees, but as in specific example 1, the beam diameter φ of “return laser beam BKL” incident on the incident surface is 6 mm. The diameter φ of the light receiving surface of the light receiving element 23 is assumed to be 6 mm.

  In FIG. 2, “H5” represents the light beam radius (distance from the optical axis) when the light beam diameter of the light beam exiting from the exit surface of the condenser lens system (the exit side surface of the seventh lens) is minimized. .

  “H5” in the specific example 2 is “4.989 mm”, and accordingly, the luminous flux diameter φ when the luminous flux emitted from the emission side surface of the seventh lens becomes the minimum diameter is 9.978 mm.

  The imaging position (geometric optical back focus) of the condensing lens diameter in specific example 2 is a position of 3.265 mm from the exit side surface of the seventh lens L7.

  “SF” in FIG. 2 also indicates a position 5 mm away from the exit surface of the seventh lens L7 in order to chuck the beam variation.

  As can be seen by comparing the data of specific examples 1 and 2, they differ only in the radius of curvature of the incident side lens surface of the fifth lens L5 and are the same.

  The curvature radius of the incident side surface of the fifth lens L5 is 17 mm in the first specific example and 16 mm in the second specific example, and the second specific example is slightly smaller.

That is, the refractive power of the incident side surface (surface number: 10) of the fifth lens L5 is slightly larger in the specific example 2.
In this way, by making the refractive power of the incident side surface of the fifth lens L5 slightly larger than that of the first specific example, the light beam radius when the light beam diameter of the light beam emitted from the exit surface of the condenser lens system is minimized: H5 is slightly smaller in the specific example 2 than the specific example 1 (≈0.7 mm, the diameter is approximately 1.4 mm).

  However, on the other hand, on the surface SF 5 mm away from the exit side surface of the seventh lens L7, the “range in which the return light beam spreads” is about 1.5 times larger in the second specific example than in the first specific example.

  In any case, in both the first and second examples, the size of the surface SF is large, and the incident angle of the imaging light beam incident on the peripheral portion of the surface SF is also large.

  This tends to lead to an increase in the size of the light receiving element and a deterioration in detection accuracy.

  In the present invention, one or more light guide members and one or more light receiving elements are used to cope with an increase in size of the light receiving elements and a deterioration in detection accuracy.

  Hereinafter, embodiments will be described. As the condensing lens system, those in Specific Example 1 and Specific Example 2 listed above are appropriately used.

  FIG. 3 shows six embodiments using the condensing lens system described above.

  In the embodiment shown in FIG. 3A, the light is guided to the exit side lens surface side of the seventh lens L7 closest to the image side of the “condensing lens system having a three-lens group seven-lens configuration” described above. This is an example in which the member LG1 is arranged.

  The light guide member LG1 is “a frustoconical light guide (also called“ tapered rod ”)”.

  The light guide member LG1 has a reflecting surface as a peripheral surface, a bottom surface portion having a large area is disposed close to or in close contact with the exit side lens surface of the seventh lens L7, and a small surface of the truncated surface is a light receiving surface of the light receiving element PD. Proximity or close.

  The bottom surface portion of the large area that is close to or in close contact with the exit side lens surface of the seventh lens L7 has a size that allows “substantially all” of the light beam emitted from the seventh lens L7 to enter.

  Therefore, the laser light emitted from the condenser lens system to the light receiving element PD side is “substantially all” incident on the light guide member LG1 from the bottom surface portion.

  Then, the light is guided to the light receiving element PD side while being reflected by the “reflecting surface forming the peripheral surface” of the light guide member LG1, and is received by the light receiving element PD.

  The laser radar apparatus according to the present invention includes “one or more light receiving elements, a condensing lens system that receives return laser light and emits the laser light toward the one or more light receiving elements, and a laser light that is emitted from the condensing lens system. And one or more light guide members for guiding light to the one or more light receiving elements.

  Then, the surface shape and the distance of the detection target are known from the direction in which the deflected laser beam SLB toward the detection target is directed and the time for the laser light to reciprocate the distance to the detection target.

  The “significance of the light receiving element” in the detection of such a detection object is to specify the time for the laser beam to reciprocate the distance to the detection object.

  The significance of the condensing lens system is to capture the return laser beam BKL and deliver it as a laser beam to the light receiving element.

  That is, the condensing lens system only needs to be able to “deliver” the return laser beam BKL to the light receiving element, and there is no need to image (condense) the return laser beam BKL on the light receiving surface of the light receiving element.

  As described above, when the returning light beam is condensed on the light receiving surface of the light receiving element by the action of the condensing lens system, the light receiving element having a large area of the light receiving surface is required.

  However, as shown in FIG. 3A, if substantially all of the laser light emitted from the condenser lens system to the light receiving element PD side is guided to the light receiving surface of the light receiving element PD by the light guide member LG1, the light reception is performed. The element PD does not require a large area light receiving surface, and can accurately detect the return laser beam BKL.

FIG. 3B shows five examples of modifications of the embodiment shown in FIG.
In order to avoid complications, the same reference numerals as those in FIG. 3B to 3F, only the seventh lens L7 of the third lens group G3 closest to the image side is shown with respect to the condensing lens system.

  In the example shown in FIG. 3B, a light guide member LG2 having a “aspherical reflection surface” on the circumferential surface with the optical axis of the seventh lens L7 as a rotational symmetry axis is used.

  The incident-side surface of the light guide member LG2 has a size that allows substantially all of the light beam emitted from the seventh lens L7 to enter.

  Therefore, the laser light emitted from the condenser lens system to the light receiving element PD side is “substantially all” incident on the light guide member LG2.

  Then, the light is guided to the light receiving element PD side while being reflected by the aspherical reflecting surface forming the peripheral surface of the light guide member LG2, and is received by the light receiving element PD.

  In the example shown in FIG. 3C, a light guide member LG3 having a “spherical reflection surface” on the circumferential surface with the optical axis of the seventh lens L7 as a rotational symmetry axis is used.

  The incident-side surface of the light guide member LG3 has a size that allows substantially all of the light beam emitted from the seventh lens L7 to enter.

  Accordingly, the laser light emitted from the condenser lens system to the light receiving element PD side is “substantially all” incident on the light guide member LG3.

  Then, the light is guided to the light receiving element PD side while being reflected by the spherical reflecting surface forming the peripheral surface of the light guide member LG3, and is received by the light receiving element PD.

  The example shown in FIG. 3D is an example using the light guide member LG10 and the light receiving element PD.

  The light guide member LG10 is formed by bundling a plurality of light guides LG11, LG12, LG13, and the like. The light guides LG11 to LG13 shown in the figure are bundled as a whole, the incident side is close to or in close contact with the exit side surface of the seventh lens L7, and the exit side is close to or in close contact with the light receiving surface of the light receiving element PD. doing.

  The light guide LG11 or the like is a tapered rod whose peripheral surface is a “tapered reflecting surface”, and the light receiving element PD side is thin as shown in the figure.

  The incident side of the light guide member LG10 is a collective surface of incident surfaces of the plurality of light guides, and has a size that allows substantially all of the light beam emitted from the seventh lens L7 to enter.

  While the laser light emitted from the seventh lens L7 is reflected inside the light guide LG11 and the like, substantially all of it is guided to the light receiving element PD and received by the light receiving element PD.

  The example shown in FIG. 3E is an example using the light guide member LG20 and a plurality of light receiving elements PD1, PD2, PD3, and the like.

  The light guide member LG20 is formed by bundling a plurality of light guides LG21, LG22, LG23 and the like. The light guide LG21 or the like is a taper rod having a “reflecting surface with a tapered peripheral surface”, and is tapered from the incident side to the emission side as shown in the figure.

  The light guides LG21 to LG23 and the like shown in the drawing are bundled with one incident side, and the bundled incident side surface has a size that allows substantially all of the light beam emitted from the seventh lens L7 to enter. , Close to or close to the exit side surface of the seventh lens L7.

  The emission sides of the plurality of light guides LG21 and the like are separated from each other, and the individual emission sides are close to or in close contact with the light receiving surfaces of the plurality of light receiving elements PD1 and PD2 provided for each light guide.

  The practically all of the laser light emitted to the exit side of the condenser lens system is guided to the light receiving element PD1 or the like by the light guide LG21 or the like and received by the light receiving element PD1 or the like.

  By combining output signals from a plurality of light receiving elements PD1, etc., light reception information for the entire laser light emitted from the condenser lens system can be obtained.

  The example shown in FIG. 3F is an example in which a light guide member LG30 and a plurality of light receiving elements PD1, PD2, PD3, and the like are used.

  The light guide member LG30 is formed by bundling a plurality of light guides LG31, LG32, LG33 and the like. The light guide LG31 or the like is a taper rod having a “reflecting surface with a tapered peripheral surface”, and is tapered from the incident side to the emission side as shown in the figure.

  The illustrated light guides LG31 to LG33 and the like are bundled on one incident side, and the bundled incident side surface has a size that allows substantially all of the luminous flux emitted from the seventh lens L7 to enter. It is close to or close to the exit side of the 7 lens L7.

  The exit sides of the plurality of light guides LG31 and the like are separated from each other, and the individual exit sides are close to or in close contact with the light receiving surfaces of the plurality of light receiving elements PD1 and PD2 provided for each light guide.

  All practically the laser light emitted to the exit side of the condenser lens system is guided to the light receiving element PD1 and the like by the light guide LG31 and received by the light receiving element PD1 and the like.

  By combining output signals from the plurality of light receiving elements PD1 and the like, light reception information for the entire laser light emitted from the seventh lens L7 of the condenser lens system can be obtained.

  Comparing the example shown in FIG. 3E and the example shown in FIG. 3F, in the example shown in FIG. 3F, the emission sides of the plurality of light guides LG31 and the like are greatly separated.

  In this way, the degree of freedom of the arrangement position of the light receiving element PD1 and the like increases.

  In each embodiment shown in FIG. 3, the condenser lens system includes, in order from the incident side, a negative first lens group G1, a positive second lens group G2, an aperture stop S, and a positive third lens group G3. A wide-angle lens having a full field angle of 170 degrees or more, and one or more light guide members (LG1 and the like) are arranged so that their incident surfaces are close to or in close contact with the exit lens surface of the third lens group G3. Has been.

  In the embodiment described with reference to FIG. 3, an object having a full angle of view of 170 degrees or more is used as the condensing lens system, but generally the same effect can be obtained below this full angle of view. Is self-explanatory (in the specific example, it covers the entire range from 0 to 170 degrees).

  Therefore, the effect of the present invention can be achieved more easily with a general wide-angle lens (90 ° or more).

  Here, looking at the role of the “condensing lens system” in the light receiving device of the present invention, as described above, the “condensing lens system” has the role of “delivering” the return laser beam BKL as a laser beam to the light receiving element. ing.

  That is, the condensing lens system does not need to image (condense) the return laser beam BKL on the light receiving surface of the light receiving element.

  From this point of view, when the condensing lens systems shown in FIGS. 1 and 2 mentioned above as specific examples are viewed, the condensing lens systems of these specific examples are arranged in order from the incident side to the negative first lens group G1, The wide-angle lens has a positive second lens group G2, an aperture stop S, and a positive third lens group G3, and has an angle of view of 170 degrees or more.

  In the three-lens group condensing lens system, a portion excluding the third lens group G3, that is, “a portion constituted by the first lens group G1, the second lens group G2, and the aperture stop S” will be considered.

  The “portion constituted by the first lens group G1, the second lens group G2, and the aperture stop S” has a total angle of view of 170 degrees, takes in the return laser beam BKL, and emits it from the aperture stop S.

  At this time, the light beam emitted from the aperture stop S is “all emitted from the seventh lens L7” in the above-described condensing lens system.

  That is, the light beam emitted from the aperture stop S includes the “all laser light” of the return laser light beam BKL.

  From this point of view, the “first lens group, second lens group, aperture stop” portion obtained by removing the third lens group from the condensing lens system of the three lens groups is the light receiving device of the laser radar device of the present invention. It fulfills the functions of the necessary “condensing lens system”.

  Therefore, the “first lens group, second lens group, aperture stop” portion obtained by removing the third lens group from the three-lens condensing lens system is newly referred to as a “condensing lens system”. Laser light emitted from the “optical lens system” toward one or more light receiving elements can be guided to one or more light receiving elements using one or more light guide members.

  FIG. 4 shows six examples of embodiments using the new condensing lens system in this case.

  In each figure of FIG. 4, the left side of the figure is the entrance side, and the right side is the exit side.

  In the embodiment shown in FIG. 4A, the “third lens group condensing lens composed of the first lens group G1, the second lens group G2, the aperture stop S, and the third lens group G3” is used. This is an example in which a lens other than the group G3 is used as a “new condenser lens”.

  In this example, the light guide member LG10A is disposed on the exit side of the aperture stop S provided on the exit side of the fourth lens L4 constituting the second lens group G2.

  The light guide member LG10A is “a frustoconical light guide”.

  The light guide member LG10A has a reflective surface, a bottom surface portion having a large area is disposed close to or in close contact with the opening of the aperture stop S, and a truncated surface having a small area serves as a light receiving surface of the light receiving element PD. Proximity or close.

  The bottom surface portion having a large area close to or in close proximity to the exit side of the aperture stop S has a size that allows “substantially all” of the laser light emitted from the aperture stop S to enter.

  Accordingly, the laser light emitted from the condenser lens system to the light receiving element PD side is “substantially all” incident on the light guide member LG10A from the bottom surface portion.

  Then, the light is guided to the light receiving element PD side while being reflected by the reflecting surface forming the peripheral surface of the light guide member LG10A, and is received by the light receiving element PD.

FIG. 4B shows five examples of modifications of the embodiment shown in FIG.
In order to avoid complication of the drawing, in FIG. 4B to FIG. 4F, among the “first lens L1 to fourth lens L4 and aperture stop S constituting a new condenser lens system”, the fourth lens and the aperture. Only the diaphragm S is shown.

  Further, in order to avoid congestion, the same reference numerals as those in FIG.

  In the example shown in FIG. 4B, a light guide member LG20A having a “aspherical reflection surface” on the circumferential surface with the optical axis of the fourth lens L4 as a rotational symmetry axis is used.

  The incident-side surface of the light guide member LG20A has a size that allows all of the light beams emitted from the aperture stop S to enter.

  Therefore, the laser light emitted from the condenser lens system to the light receiving element PD side is “substantially all” incident on the light guide member LG20A.

  Then, the light is guided to the light receiving element PD side while being reflected by the aspherical reflecting surface forming the peripheral surface of the light guide member LG20A, and is received by the light receiving element PD.

  In the example shown in FIG. 4C, a light guide member LG30A having a “spherical reflection surface” on the circumferential surface with the optical axis of the fourth lens L4 as a rotational symmetry axis is used.

  The incident-side surface of the light guide member LG30A has a size that allows substantially all of the laser light emitted from the aperture stop S to be incident thereon.

  Therefore, the laser light emitted from the condenser lens system to the light receiving element PD side is “substantially all” incident on the light guide member LG30A.

  Then, the light is guided to the light receiving element PD side while being reflected by the spherical reflecting surface forming the peripheral surface of the light guide member LG30A, and is received by the light receiving element PD.

  The example shown in FIG. 4D is an example using the light guide member LG40 and the light receiving element PD.

  The light guide member LG40 is formed by bundling a plurality of light guides LG41, LG42, LG43 and the like. The light guides LG41 to LG43 shown in the drawing are bundled as a whole, the incident side is close to or close to the exit side of the aperture stop S, and the exit side is close to or close to the light receiving surface of the light receiving element PD. ing.

  The light guide LG11 and the like have a “tapered reflecting surface” on the peripheral surface, and the light receiving element PD side is thin as shown in the figure.

  The incident side of the light guide member LG10 is a collective surface of incident surfaces of a plurality of light guides, and has a size that allows substantially all of the laser light emitted from the aperture stop S to be incident thereon.

  While the laser beam emitted from the aperture stop S is reflected inside the light guide LG41 and the like, substantially all of it is guided to the light receiving element PD and received by the light receiving element PD.

  The example shown in FIG. 4E is an example using a light guide member LG50 and a plurality of light receiving elements PD1, PD2, PD3, and the like.

  The light guide member LG50 is formed by bundling a plurality of light guides LG51, LG52, LG53, and the like. The light guide LG51 or the like is a “reflecting surface with a tapered peripheral surface”, and is narrowed from the incident side to the emission side as shown in the figure.

  The light guides LG51 to LG53 shown in the drawing are bundled on one incident side, and the bundled incident side surface has a size that allows substantially all of the light beam emitted from the seventh lens L7 to enter. , Close to or close to the exit side surface of the aperture stop S.

  The emission sides of the plurality of light guides LG51 and the like are separated from each other, and the individual emission sides are close to or in close contact with the light receiving surfaces of the plurality of light receiving elements PD1 and PD2 provided for each light guide.

  All practically the laser light emitted to the exit side of the condenser lens system is guided to the light receiving element PD1 and the like by the light guide LG51 and the like, and is received by the light receiving element PD1 and the like.

  By combining output signals from a plurality of light receiving elements PD1, etc., light reception information for the entire laser light emitted from the condenser lens system can be obtained.

  The example shown in FIG. 4F is an example using a light guide member LG60 and a plurality of light receiving elements PD1, PD2, PD3, and the like.

  The light guide member LG60 is formed by bundling a plurality of light guides LG61, LG62, LG63 and the like. The light guide LG61 or the like is a “reflecting surface with a tapered peripheral surface”, and becomes thinner from the incident side to the emission side as shown in the figure.

  The light guides LG61 to LG63 shown in the drawing are bundled on one incident side, and the bundled incident side surface has a size that allows substantially all of the laser light emitted from the aperture stop S to enter. , Close to or close to the exit side surface of the aperture stop S.

  The exit sides of the plurality of light guides LG61 and the like are separated from each other, and the individual exit sides are close to or in close contact with the light receiving surfaces of the plurality of light receiving elements PD1 and PD2 provided for each light guide.

  All practically the laser light emitted to the exit side of the condenser lens system is guided to the light receiving element PD1 and the like by the light guide LG61 and received by the light receiving element PD1 and the like.

  By combining output signals from a plurality of light receiving elements PD1, etc., light reception information for the entire laser light emitted from the condenser lens system can be obtained.

  Comparing the example shown in FIG. 4E and the example shown in FIG. 4F, in the example of FIG. 4F, the emission sides of the plurality of light guides LG31 and the like are greatly separated.

  In this way, the degree of freedom of the arrangement position of the light receiving element PD1 and the like increases.

  In each embodiment shown in FIG. 4, the condensing lens system includes, in order from the incident side, a negative first lens group G1, a positive second lens group G2, an aperture stop S, and a total angle of view: 170. The one or more light guide members (LG10A and the like) are arranged in close proximity to or in close contact with the exit surface of the aperture stop S.

  In each of the embodiments described with reference to FIG. 4, the condensing lens system uses an object having a full angle of view of 170 degrees or more, but generally the same effect is obtained below this full angle of view. This is self-evident (in the specific example, the entire range from 0 to 170 degrees is covered).

  Therefore, the effect of the present invention can be achieved more easily with a general wide-angle lens (full angle of view: 90 ° or more).

In each of the embodiments described above, the light guide member and the light guide have a peripheral surface portion that is a reflective surface.
That is, it can be manufactured by forming the shape of the light guide member or the light guide with a transparent material such as glass or transparent plastic, and forming the reflection surface on the peripheral surface portion by a method such as vapor deposition.

  In the light guide member LG2 or LG20A, the reflection surface has an aspheric shape, and this aspheric shape is designed so that the laser light is efficiently guided to the light receiving element side.

  Further, the light guide members LG3 and LG30A can efficiently guide the laser light to the light receiving element PD with the same effect as a so-called “integrating sphere”.

  Although the specific example of the light guide member was shown above, not only this but various forms are possible.

  That is, in the above example, a transparent material such as glass or transparent plastic is used, and the shape of the light guide member or light guide is formed, and the reflection surface is formed on the peripheral surface portion by a method such as vapor deposition. Of course, this is not a limitation.

  In these examples, the outer peripheral surface portion is a reflecting surface, and the inside of the reflecting surface is a transparent body having an actual state, but instead of doing this, the inside is hollow and the inner surface is a reflecting surface, and the light guide member or A light guide can be constructed.

  Moreover, although the axially symmetric (rotationally symmetric) shape is exemplified above as the shape of the light guide member and the light guide, the shapes of the light guide member and the light guide are not limited to those exemplified above.

  As described above, the function of the light guide member is as follows: “Laser light emitted from the condensing lens system is guided to one or more light receiving elements, and laser light emitted from the condensing lens system by one or more light receiving elements. All light is received.

  Note that “all” here does not have a strict meaning, but may be “substantially all”.

  Accordingly, in this sense, the light guide member only needs to be able to effectively deliver all of the laser light incident on the light guide member from the condensing lens system to the light receiving element side. If so, the shape can be arbitrarily determined.

  The various light guide members shown in FIGS. 3 and 4 have their emission sides close to or in close contact with the light receiving surface of the light receiving element.

  As described above, since the light guide member and the light guide have “degree of freedom of shape”, the shapes of the light guide members and light guides described above on the emission side are the “light receiving surface shape of the light receiving element”. It is reasonable to match.

  Hereinafter, one embodiment of the system structure of the laser radar apparatus will be briefly described with reference to FIG.

  The laser radar device is a laser radar device that two-dimensionally scans a laser beam from a laser light source as a deflected laser beam by a laser beam scanning unit, and detects a reflected laser beam from a detection target as return laser light.

  The laser radar device includes a laser beam scanning unit 100, a light receiving device 200, a control calculation unit 300, and a display 400.

  The laser beam scanning unit 100 has a function of two-dimensionally scanning a laser beam from a laser light source as a deflected laser beam SLB. For example, the laser beam scanning unit 100 has been briefly described above with reference to FIG. It is like this.

  The light receiving device 200 is a part having a function of detecting a reflected laser beam from a detection target as return laser light BKL.

  For example, as described in the embodiment with reference to FIGS. 3 and 4, this portion includes one or more light receiving elements and a condensing light that is incident on a return laser beam and is emitted toward the one or more light receiving elements. A lens system; and one or more light guide members that guide laser light emitted from the condenser lens system to the one or more light receiving elements.

  The control calculation unit 300 shown in FIG. 6 controls the laser beam scanning unit 100 and the light receiving device 200, calculates the “distance to the detection target” based on the light reception information of the light receiving device 200, and the “azimuth” of the detection target unit. And a control calculation means for specifying “and distance”.

  The control calculation unit 300 as “control calculation means” is configured as a microcomputer or a CPU.

  The display 400 is a “display unit that displays the direction and distance of the detection target” specified by the control calculation unit 300, and various types such as a liquid crystal display can be used.

  As described above, according to the present invention, the following “laser radar device and its light receiving device” can be realized.

[1]
In a laser radar apparatus that scans a laser beam from a laser light source two-dimensionally as a deflected laser beam by a laser beam scanning unit and detects a reflected laser beam from a detection object as a return laser beam, the laser object by the detection object A light-receiving device that receives return laser light, and includes one or more light-receiving elements (such as PD) and a condensing lens system that receives a wide range of return laser light BKL and emits the laser light toward the one or more light-receiving elements. One or more light guide members (LD1 or the like) for guiding all of the laser light emitted from the condenser lens system to the one or more light receiving elements without forming an image on the light receiving surface of the one or more light receiving elements If, having, the condensing lens system is a convex lens surface having a single negative power lens surfaces are continuous on the most incident side, the one or more light receiving elements in the one or more light guide members Ri said and the laser light guided to the light receiving surface intended to receive signaling, by said at least one light receiving element, the light receiving device of the laser radar system for receiving all the laser light emitted from the converging lens system.

[2]
[1] The light receiving device of the laser radar device according to [1], wherein the condensing lens system is a wide angle lens having a total angle of view of 90 degrees or more .
[3]
In the light receiving device of the laser radar device according to [1] or [2], the light guide members LG1 and LG10A are single taper rods whose cross-sectional area decreases from the incident surface toward the exit surface, and the exit surface is simply receiving device of the laser radar apparatus that is close to or closely to the light receiving surface of one light receiving element.

[4]
The light receiving device of the laser radar device according to [1] or [2], wherein the light guiding members LG2 and LG20A are single and have a deformed aspheric surface having a concave reflecting surface as an inner surface.

[5]
The light receiving device of the laser radar device according to [1] or [2], wherein the light guiding members LG3 and LG30A are single and have a spherical surface with a concave reflecting surface as an inner surface.

[6]
In the light receiving device of the laser radar device according to [1] or [2], the light guide member (LD10, LD40, etc.) has a plurality of tapered rods whose cross-sectional area decreases from the incident surface toward the exit surface. Light receiving device.

[7]
[6] The light receiving device of the laser radar device according to [6], wherein the exit sides of the plurality of taper rods are close to or in close contact with the light receiving surface of the same light receiving element PD.

[8]
[6] In the light receiving device of the laser radar device according to [6], the exit side of the plurality of taper rods (LD21, etc.) is individually close to or in close contact with the light receiving surface of the light receiving element (PD1, etc.) corresponding to each taper rod. The light receiving device of the device.

[9]
A laser radar device that two-dimensionally scans a laser beam from a laser light source as a deflected laser beam by a laser beam scanning unit and detects a reflected laser beam from an object to be detected as a return laser beam, the laser beam scanning unit 100, the light receiving device 200 that receives the return laser light from the detection target, the laser beam scanning unit and the light receiving device, and calculates the distance to the detection target based on the light reception information of the light receiving device and has a control arithmetic means 300 for specifying the orientation and distance of the detected object, and display means 400 for displaying the azimuth and distance of the detected object specified by control arithmetic unit, wherein the light receiving device A laser radar device using the device according to any one of [1] to [8] as 200.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments described above, and the invention described in the claims unless otherwise specified in the above description. Various modifications and changes are possible within the scope of the above.

  As is clear from the above description, since the condensing lens system used in the present invention does not have “imaging” as a problem, any wide-angle lens can be used.

  Needless to say, if there is a lens group on the incident side of the aperture stop, it can be used as a condensing lens system for guiding laser light emitted from the aperture stop to the light receiving element by the light guide member.

  Although the “angle of view: 90 degrees or more” is mentioned as the wide-angle lens, the angle of view: 90 degrees does not mean strictly 90 degrees, and includes a case where it is substantially 90 degrees.

  Even when the angle of view is smaller than 90 degrees, for example, “85 degrees”, “the incident angle of the return laser beam BKL having a large angle of view on the light receiving surface increases. Needless to say, the present invention can be effectively applied in the case where the light receiving surface is lowered or the light receiving surface of the light receiving element 23 is increased.

  Of course, it goes without saying that the present invention can be effectively applied to a condensing lens system having a larger angle of view than the condensing lens system having a field angle of 170 degrees given as a specific example.

  The effects described in the embodiments of the present invention are merely a list of suitable effects resulting from the invention, and the effects of the present invention are not limited to those described in the embodiments.

100 Laser beam scanning unit
200 Photodetector 300 Control operation unit
400 display
L1 First lens of the condenser lens system
L2 Second lens of the condenser lens system
L3 Third lens of the condenser lens system
L4 4th lens of condenser lens system
L5 Fifth lens of condenser lens system
L6 6th lens of condenser lens system
L7 7th lens of condenser lens system
S Condensing lens system aperture stop
SF Image surface of condenser lens system
LG1 Light guide member
LG2 Light guide member LG3 Light guide member
LG10 Light guide member
LG20 Light guide member
LG30 Light guide member
LG10A Light guide member
LG20A Light guide member
LG30A Light guide member
LG40 Light guide member
LG50 Light guide member
LG60 Light guide member
PD photo detector
PD1 light receiving element
PD2 light receiving element
PD3 light receiving element

JP2013-113684A

Claims (9)

In a laser radar apparatus that scans a laser beam from a laser light source two-dimensionally as a deflected laser beam by a laser beam scanning unit and detects a reflected laser beam from a detection object as a return laser beam, the laser object by the detection object A light receiving device for receiving a return laser beam,
One or more light receiving elements;
A condensing lens system that receives a wide range of return laser light and emits it toward the one or more light receiving elements;
A 1 and more of the light guide member for guiding without any laser light emitted from the condenser lens system, is formed on the light receiving surface of the front SL 1 or more light-receiving element, and
The condensing lens system is a convex lens surface having a single negative power in which the most incident side lens surface is continuous,
The one or more light receiving elements convert the laser light guided to the light receiving surface by the one or more light guide members into a light reception signal,
A light receiving device of a laser radar device that receives all of the laser light emitted from the condenser lens system by the one or more light receiving elements. In the light receiving device of the laser radar device according to claim 1,
The light receiving device of the laser radar device, wherein the condensing lens system is a wide angle lens having a total angle of view of 90 degrees or more. In the light receiving device of the laser radar device according to claim 1 or 2,
The light guide member is a single taper rod whose cross-sectional area decreases from the incident surface to the exit surface, and the light receiving device of the laser radar apparatus has the exit surface close to or in close contact with the light receiving surface of a single light receiving element. . In the light receiving device of the laser radar device according to claim 1 or 2,
A light receiving device of a laser radar device having a single light guiding member and a deformed aspherical surface having a concave reflecting surface as an inner surface. In the light receiving device of the laser radar device according to claim 1 or 2,
A light receiving device of a laser radar device having a single light guide member and a spherical surface having a concave reflecting surface as an inner surface. In the light receiving device of the laser radar device according to claim 1 or 2,
A light receiving device of a laser radar device, wherein the light guide member includes a plurality of tapered rods having a cross-sectional area that decreases from an incident surface toward an emission surface. In the light receiving device of the laser radar device according to claim 6,
A light receiving device of a laser radar device, wherein the exit sides of a plurality of taper rods are close to or in close contact with the light receiving surface of the same light receiving element. In the light receiving device of the laser radar device according to claim 6,
A light receiving device of a laser radar device, wherein the exit sides of the plurality of taper rods are individually close to or in close contact with the light receiving surfaces of the light receiving elements corresponding to the respective taper rods. A laser radar device that two-dimensionally scans a laser beam from a laser light source as a deflected laser beam by a laser beam scanning unit, and detects a reflected laser beam from a detection object as a return laser beam,
A laser beam scanning unit;
A light receiving device for receiving the return laser light by the detection object;
Control operation means for controlling the laser beam scanning unit and the light receiving device, calculating a distance to the detection target based on light reception information of the light receiving device, and specifying an orientation and a distance of the detection target;
Display means for displaying the azimuth and distance of the detection object specified by the control calculation means;
Have
A laser radar device using the light receiving device according to any one of claims 1 to 8.

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