JP2018115943A - Laser radar device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of dew condensation on the outside of a light-transmissive cover of a laser radar device.SOLUTION: A stationary laser radar device comprises: a laser radar optical system for emitting a laser beam to outside and receiving reflections of the laser beam reflected by external objects; an optical system housing configured to accommodates the laser radar optical system and provided with a light-transmissive cover for allowing the emitted laser beam and the reflections to pass; and an air curtain unit configured to form a first air curtain on the outside of the light-transmissive cover to prevent occurrence of dew condensation on the outside of the light-transmissive cover.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a stationary laser radar apparatus.

  Patent Document 1 discloses a stationary laser radar device. This laser radar device includes a laser diode that generates laser light, a mirror that emits laser light to the outside, a rotating deflection mechanism, a photodiode that receives reflected light of the laser light, and a case that houses these members. . Further, the case is provided with a laser light transmission plate (translucent cover) that allows the laser light and the reflected light to pass therethrough.

JP 2010-151788 A

  The stationary laser radar device has a problem that the detection accuracy decreases when dirt or condensation from the outside adheres to the translucent cover. Dirt such as mud splash can be prevented to some extent by providing a dirt prevention member, but it may be difficult to prevent condensation. In particular, stationary laser radar devices used for railroad crossings and the like are installed in a distributed manner, and the number of installations is large. is there. For this reason, it is desired to prevent condensation of the light-transmitting cover. However, in the past, the actual situation is that sufficient measures have not been taken to prevent condensation.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one aspect of the present invention, a laser radar device is provided. The stationary laser radar device includes a laser radar optical system that emits laser light to the outside and receives reflected light of the laser light reflected by an external object, and the laser radar optical system, By forming an optical system case having a translucent cover that allows the emitted laser light and the reflected light to pass therethrough, and forming a first air curtain on the outer side of the translucent cover, condensation occurs on the outer side of the translucent cover. An air curtain device for preventing the above.
According to the laser radar device of this aspect, since the first air curtain is formed outside the light-transmitting cover, dew condensation is caused by replacing the outside air before the outside air contacting the outside of the light-transmitting cover cools down. Can be prevented.

(2) In the laser radar device of the above aspect, the air curtain device includes an air fan that sends out air, and a housing that houses the air fan and the optical system case. An opening for allowing the emitted laser light and the reflected light to pass therethrough is provided at a position corresponding to the translucent cover, and the housing further uses the air sent from the air fan as the first air curtain as the first air curtain. You may have the air curtain formation flow path supplied to the outer side of a translucent cover.
According to the laser radar device of this aspect, since the first air curtain can be formed outside the translucent cover using the air fan and the air curtain forming flow path, the outside air that contacts the outside of the translucent cover is It is possible to prevent condensation from occurring by replacing the outside air before it cools down.

(3) In the laser radar device of the above aspect, the air curtain device may further form a second air curtain at a position outside the first air curtain.
According to the laser radar device of this embodiment, the second air curtain is formed at a position outside the first air curtain. Therefore, dew condensation occurs by replacing the outside air before the outside air contacting the outside of the translucent cover cools down. In addition, the second air curtain can prevent dust and snow from adhering to the translucent cover.

(4) In the laser radar device of the above aspect, the air flow directions of the first air curtain and the second air curtain may be opposite to each other.
According to the laser radar apparatus of this embodiment, even if dust or snow breaks through the second air curtain along the air flow direction of the second air curtain, the air flow direction of the first air curtain is Since it is opposite to the traveling direction of snow or the like, the first air curtain can prevent dust, snow or the like from adhering to the translucent cover.

(5) In the laser radar device of the above aspect, the air flow direction of the first air curtain is directed from the lower side to the upper side, and the air flow direction of the second air curtain is directed from the upper side to the lower side. You may do it.
There is a high possibility that dust, snow, etc. will fall from above to below. According to the laser radar device of this aspect, since the air flow direction of the first air curtain is directed from the lower side to the upper side, the dust, snow, etc. that falls from the upper side to the lower side breaks through the second air curtain. However, the first air curtain can suppress the progression of dust, snow, etc., and can reliably prevent the light curtain from adhering to the light-transmitting cover.

(6) In the laser radar device according to the aspect described above, the air curtain device includes an air fan that sends out air, and a housing that houses the air fan and the optical system case, and the housing includes the optical system case. An opening for allowing the emitted laser light and the reflected light to pass therethrough is provided at a position corresponding to the translucent cover, and the housing further uses the air sent from the air fan as the first air curtain as the first air curtain. The second air curtain is formed by folding an air flow after the air in the first air curtain has passed through the outer side of the translucent cover and having an air curtain forming flow path to be supplied to the outer side of the translucent cover. You may have the 1st guide flow path to do.
According to the laser radar device of this aspect, since the first air curtain and the second air curtain are formed, it is possible to prevent condensation from occurring by replacing the outside air before the outside air that contacts the outside of the translucent cover is completely cooled. In addition, it is possible to prevent dust and snow from adhering to the light-transmitting cover.

(7) In the laser radar device of the above aspect, the air curtain forming flow path is provided at a lower position outside the translucent cover, and the air fan is located above the air curtain forming flow path from above. The first guide flow path is provided above the opening of the housing, and the air of the first air curtain passes from the lower side to the upper side of the translucent cover. After that, the second air curtain may be formed by folding the air flow from above to below.
According to the laser radar device of this aspect, since the air of the first air curtain passes from the lower side to the upper side of the translucent cover, dust, snow, or the like that falls from the upper side to the lower side is temporarily collected from the second air curtain. Even if it breaks through, the 1st air curtain can suppress progress of dust, snow, etc., and can prevent adhesion to a translucent cover.

(8) In the laser radar device according to the above aspect, the housing further includes a second guide channel that folds air flowing from the outside toward the laser radar device and merges the air in the middle of the first guide channel. May be.
When the air in the first air curtain is taken into the first guide channel, a part of the air may be dispersed to reduce the amount of air. According to the laser radar device of this aspect, the second guide flow path joins the outside air in the middle of the first guide flow path, so that the second air curtain can be reinforced.

(9) In the laser radar device according to the above aspect, the housing further includes a lower end plate-like member protruding outward at a lower end portion of the opening, and a part of the air sent from the air fan. And a branch channel that guides to the outside along the shaped member.
According to the laser radar device of this aspect, part of the air sent out from the air fan flows to the outside along the lower end plate member, so that it is possible to prevent snow from accumulating on the lower end plate member in winter.

(10) In the laser radar device according to the above aspect, the air curtain device may include a heating device that heats air serving as the first air curtain.
According to the laser radar device of this aspect, the temperature of the first air curtain rises, so that it is possible to further prevent dew condensation from occurring on the outside of the translucent cover, particularly in winter.

  The present invention can be implemented in various forms other than the above. For example, it can be realized in the form of a condensation prevention device for laser radar.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic explanatory drawing of the laser radar apparatus in 1st Embodiment of this invention. The figure explaining an example of the internal structure of a laser radar main body. The side view of a laser radar apparatus. The top view of a laser radar apparatus. The side view of the laser radar apparatus in 2nd Embodiment. The side view of the laser radar apparatus in 3rd Embodiment. The side view of the laser radar apparatus in 4th Embodiment. The side view of the laser radar apparatus in 5th Embodiment. The side view of the laser radar apparatus in 6th Embodiment. The top view of the laser radar apparatus in 6th Embodiment.

First embodiment:
FIG. 1 is a schematic explanatory diagram of a stationary laser radar apparatus 900 according to the first embodiment of the present invention. The laser radar device 900 includes a laser radar main body 100, an air fan 300, and a housing 200 that houses the laser radar main body 100 and the air fan 300. The air fan 300 and the housing 200 constitute an air curtain device. In FIG. 1, when the laser radar device 900 is viewed from the front, the vertical vertical direction of the laser radar device 900 is the X direction, the horizontal direction is the Y direction, and the front-back direction is the Z direction.

  The laser radar main body 100 includes a laser radar optical system (described later), and an optical system case 110 that houses the laser radar optical system and includes a translucent cover 140. The optical system case 110 is a hollow container that extends in the X direction. In the example of FIG. 1, the optical system case 110 has a shape in which an elongated ridge is divided in half along the central axis in the longitudinal direction. An opening 130 in which a part of the optical system case 110 is cut out is provided at substantially the center of the optical system case 110. A translucent cover 140 is fitted into the opening 130. The translucent cover 140 allows the laser light emitted from the laser radar optical system to pass outside, and allows the reflected light reflected by an external object to pass through the optical system case 110. The air fan 300 is installed on the mounting table 400 below the laser radar main body 100, and sends out air upward. A first air curtain is formed outside the translucent cover 140 by the air sent from the air fan 300. The first air curtain will be described later.

  The housing 200 includes a first housing part 210 that accommodates the upper part of the laser radar main body 100 and a second housing part 220 that accommodates the lower part of the laser radar main body 100. The second housing portion 220 also houses the air fan 300 and its mounting table 400. The first housing part 210 and the second housing part 220 are connected or coupled to each other on the rear side of the laser radar device 900. An opening 230 is formed between the first housing part 210 and the second housing part 220. The opening 230 is formed at a position corresponding to the translucent cover 140 and the opening 130 of the optical system case 110. The opening 230 is formed in a shape that does not obstruct the passage of laser light that passes through the translucent cover 140 or reflected light from the outside.

  An upper end plate-like member 240 and a lower end plate-like member 250 are provided at the upper end portion and the lower end portion of the opening 230 of the housing 200, respectively. These plate-like members 240 and 250 are provided along the periphery of the opening 230 and have a function as a protective member that shields the light-transmitting cover 140 of the optical system case 110 by blocking dirt flying from the outside. . Specifically, the upper end plate member 240 mainly prevents rain and snow from adhering to the translucent cover 140, and the lower end plate member 250 mainly prevents mud and the like from jumping to the translucent cover 140. Is. Further, the lower end plate member 250 is provided with a notch 255 for forming a gap G <b> 1 between the opening 230 and the optical system case 110. The gap G1 is used as an outlet of an air curtain forming channel to be described later. One or both of these plate-like members 240 and 250 may be omitted.

  FIG. 2 is a diagram for explaining an example of the internal configuration of the laser radar main body 100. The laser radar main body 100 includes a laser light generation device 10, a light receiving device 20, a mirror 30, a rotation deflection device 40, and a control device 70. The laser beam generator 10, the light receiver 20, the mirror 30, and the rotation deflector 40 constitute a laser radar optical system. The laser radar optical system is an optical device that performs scanning by receiving reflected light of a laser beam reflected by an external object while emitting the laser beam to the outside.

  The laser light generator 10 includes a laser diode 11 that generates laser light and a collimating lens 12. The laser diode 11 is supplied with a pulse current from a drive circuit (not shown) under the control of the control device 70, and emits a pulse laser beam (laser beam L1). The collimating lens 12 is installed on the optical axis of the laser light L1 emitted from the laser diode 11, and converts the laser light L1 into parallel light.

  The mirror 30 is installed on the optical axis of the laser beam L1 emitted from the laser beam generator 10, and reflects the laser beam L1 to the rotation deflector 40 by the reflection surface 30a. The rotation deflection device 40 includes a mirror 41 having a flat reflecting surface 41a, a support base 43 that supports the mirror 41, a rotation shaft 42 connected to the support base 43, and a drive that rotates the rotation shaft 42. Device 44. The rotation shaft 42 can rotate around the central shaft 42a. The mirror 41 reflects the laser beam L1 again after the laser beam L1 reflected by the reflecting surface 30a of the mirror 30 is incident on the reflecting surface 41a of the mirror 41, and emits the laser beam L1 to the outside through the translucent cover 140. Further, the mirror 41 rotates around the central axis 42a together with the rotation axis 42, thereby scanning the laser light L1 emitted to the outside. The scan angle of the laser beam L1 is preferably 180 ° to 190 °.

  The light receiving device 20 includes a photodiode 21, a condenser lens 22, and an optical filter 23. The photodiode 21 receives the reflected light L2 that is reflected by an external object when the laser light L1 from the laser light generating device 10 is emitted to the outside through the translucent cover 140. The condensing lens 22 is installed below the photodiode 21, collects the reflected light L <b> 2, and guides it to the photodiode 21. The optical filter 23 is installed between the photodiode 21 and the condenser lens 22, and transmits the reflected light L2 and removes light having a wavelength other than the reflected light L2. In addition, after receiving the reflected light L2, the photodiode 21 converts the reflected light L2 into an electric signal and supplies it to the control device 70. The control device 70 uses this electric signal to determine the size, position, and speed of an external object, for example. The above-described internal configuration of the laser radar main body 100 is an example, and various other configurations can be employed.

  FIG. 3 is a side view of the laser radar device 900. For convenience of illustration, the housing 200 is shown in a sectional view. A first air curtain A <b> 1 is formed on the outer side of the translucent cover 140 of the optical system case 110. The housing 200 has an air curtain forming flow path AP that supplies the air sent from the air fan 300 to the outside of the translucent cover 140 as a first air curtain A1. In the present embodiment, the air curtain forming channel AP is provided at a position below the outer side of the translucent cover 140, and is defined by the inner surface S1 of the first channel forming member 270 and the outer surface S2 of the lower part of the optical system case 110. Composed. The first flow path forming member 270 is a plate-like member that surrounds the lower part of the optical system case 110, and has one end connected to the edge of the notch 255 of the lower end plate-like member 250 of the housing 200 and the other end of the housing 200. It is continuous with the inner surface of the second housing part 220. The air fan 300 sends out air upward from below the air curtain forming channel AP.

  The air sent out from the air fan 300 passes through the gap G1 while being pressed by the surfaces S1, S2 on both sides of the air curtain forming channel AP, and passes through the first air curtain A1 along the X direction outside the translucent cover 140. Form. After reaching the upper end plate member 240 of the housing 200, the air flow of the first air curtain A1 turns in the Z direction (forward) and flows out. The first air curtain A1 has a function of preventing dew condensation by replacing the outside air before the outside air that contacts the outside of the translucent cover 140 cools down. The width of the gap G1, that is, the distance between the edge of the notch 255 of the lower end plate member 250 and the optical system case 110 is preferably 1 cm or less. If it carries out like this, the wind speed of 1st air curtain A1 can be raised, and it can further prevent that dew condensation arises by replacing | exchanging outside air which contacts the outer side of the translucent cover 140 early.

  It is preferable that the air fan 300 is always operated to form the first air curtain A1 at all times. In this way, it is possible to reliably prevent dew condensation from occurring on the outside of the translucent cover 140. Further, in this embodiment, since the air sent from the air fan 300 finally flows to the outside along the upper end plate member 240, it is possible to prevent the formation of icicles on the outer edge of the upper plate member 240 in winter. . Note that the air curtain forming flow path AP may be configured only by the second housing portion 220 without using the outer surface S2 of the lower part of the optical system case 110.

  FIG. 4 is a schematic view of the laser radar device 900 of FIG. 3 as viewed from above. For convenience of illustration, the upper end plate member 240 of the housing 200 is omitted, and the lower end plate member 250 is indicated by hatching. The first air curtain A1 is formed by the air sent from the air fan 300 (FIG. 3) flowing through the air curtain forming flow path AP and flowing outside the translucent cover 140 along the X direction.

  As described above, in the first embodiment, since the first air curtain A1 is formed outside the light transmitting cover 140 of the optical system case 110, before the outside air contacting the outside of the light transmitting cover 140 cools down. It is possible to prevent condensation from occurring by replacing the outside air.

Second embodiment:
FIG. 5 is a side view of a laser radar device 900a according to the second embodiment and corresponds to FIG. The difference from the first embodiment shown in FIG. 3 is the configuration of the first housing portion 210a of the housing 200a, and other configurations are substantially the same as those of the first embodiment.

  In FIG. 5, the first housing part 210 a includes a first guide channel GP <b> 1 and a second guide channel GP <b> 2 provided above the opening 230. The first guide flow path GP1 is configured by the upper surface S4 of the upper end plate member 240a of the housing 200a, the lower surface S8 of the second flow path forming member 241, and a part of the lower surface S5 of the third flow path forming member 242. . The second flow path forming member 241 is a plate-like member that is attached to the inside of the first housing portion 210a and has a shape that extends outward along the Z direction. The third flow path forming member 242 is a plate-like member that is integrated with the second flow path forming member 241 and the upper end plate-like member 240a and has a substantially S-shaped cross section. The second guide flow path GP2 is configured by the upper surface S7 of the second flow path forming member 241 and the lower surface S5 of the third flow path forming member 242. In addition, the upper end plate-like member 240a has a substantially L-shaped shape whose front end is bent downward. In addition, an auxiliary protective member 243 that protrudes outward along the horizontal direction is attached to the first housing portion 210a above the inlet of the second guide flow path GP2. The auxiliary protective member 243 prevents snow, dead leaves, and the like from blocking the entrance of the second guide flow path GP2.

  After the air of the first air curtain A1 passes through the outer side of the translucent cover 140 from the lower side to the upper side, the first guide channel GP1 moves the air flow upward at a position outside the first air curtain A1. The second air curtain A2 is formed by folding back from the bottom. Specifically, after the air sent out from the air fan 300 forms the first air curtain A1, it flows in the Z direction along the surfaces S4 and S8 of the first guide flow path GP1, and the third flow path forming member After reaching the lower surface S5 of 242, it turns in the X direction and flows downward to form the second air curtain A2. In addition, the upper part of the 1st housing part 210a is sealed. If it carries out like this, the air sent out from the air fan 300 can flow smoothly into 1st guide flow path GP1.

  The second guide flow path GP2 takes in the wind flowing from the outside toward the laser radar device 900a into the housing 200a, turns it back and joins it in the middle of the first guide flow path GP1. Specifically, the air flowing from the outside toward the laser radar device 900a flows into the second guide flow path GP2 along the upper surface S6 of the third flow path forming member 242 and the lower surface S11 of the auxiliary protection member 243, and turns back. After flowing in the Z direction along the surfaces S5 and S7 of the second guide channel GP2, the air flows through the first guide channel GP1 before the outlet of the first guide channel GP1. Here, in the process of forming the second air curtain A2, when the air of the first air curtain A1 is taken into the first guide flow path GP1, a part of the air is dispersed and the amount of air is reduced. Therefore, if the external wind is merged in the middle of the first guide flow path GP1, the second air curtain A2 can be reinforced using the external wind.

  In the example of FIG. 5, after a part of the air forming the first air curtain A1 reaches the lower surface S3 of the upper end plate member 240a and flows along the Z direction, the upper end plate member 240a. Is folded back by the lower surface S3 and flows downward to join the second air curtain A2. In this way, the second air curtain A2 can be further reinforced. The first guide channel GP1 or the second guide channel GP2 may be omitted.

  Also in the second embodiment of FIG. 5, the first air curtain A1 is formed on the outer side of the translucent cover 140 of the optical system case 110, so that the outside air that contacts the outer side of the translucent cover 140 is cooled before it cools down. It is possible to prevent condensation from occurring by switching. In addition, since the second air curtain A2 is formed at a position outside the first air curtain A1, it is possible to prevent dust, snow, and the like from adhering to the outside of the translucent cover 140. If dust, snow, or the like falls down from above and breaks through the second air curtain A2, the air flow direction of the second air curtain A2 is directed from above to below. And the like reach the first air curtain A1 obliquely downward. However, since the air flow direction of the first air curtain A1 is directed from the lower side to the upper side, the direction of the movement of dust, snow, etc. is hindered, and it is ensured that the dust, snow, etc. adheres to the outer side of the translucent cover 140. Can be prevented.

Third embodiment:
FIG. 6 is a side view of a laser radar device 900b according to the third embodiment, and corresponds to FIG. The difference from the second embodiment shown in FIG. 5 is that the upper plate member 240b of the first housing part 210b of the housing 200b, the second flow path forming member 241b, the third flow path forming member 242b, and the auxiliary protective member. The other configuration is substantially the same as that of the second embodiment.

  In FIG. 6, the lower surface S3 and the upper surface S4 of the upper end plate member 240b are curved surfaces. If it carries out like this, the pressure loss when a part of air which forms 1st air curtain A1 flows along the lower surface S3 of the upper end plate-shaped member 240b can be reduced, and the speed of air can be raised. As a result, the second air curtain A2 can be further reinforced.

  The second flow path forming member 241b is provided with a surface S9 that is in close contact with the optical system case 110. In this way, even if the upper part of the first housing part 210b is not sealed, the air sent from the air fan 300 can smoothly flow into the first guide flow path GP1.

  The third flow path forming member 242b is provided with a flange portion 244 that protrudes outward along the Z direction at the position of the outlet of the second guide flow path GP2. In this way, it is possible to more reliably prevent snow and dead leaves from entering the opening 230. Further, the auxiliary protection member 243b is configured to extend obliquely upward rather than in the horizontal direction. By so doing, it is possible to further reinforce the second air curtain A2 by introducing more air flowing from the outside toward the laser radar device 900b into the housing 200b as compared with the second embodiment.

  Also in the third embodiment of FIG. 6, the first air curtain A1 is formed on the outer side of the translucent cover 140 of the optical system case 110, so that the outside air that comes into contact with the outer side of the translucent cover 140 is cooled before it cools down. It is possible to prevent condensation from occurring by switching.

-Fourth embodiment:
FIG. 7 is a side view of a laser radar device 900c according to the fourth embodiment, and corresponds to FIG. The difference from the first embodiment shown in FIG. 3 is the configuration of the second housing portion 220c of the housing 200c, and other configurations are substantially the same as those of the first embodiment.

  In FIG. 7, in addition to the air curtain forming flow path AP described above, the second housing part 220c is a branched flow path that guides a part of the air sent from the air fan 300 to the outside along the lower end plate member 250c. Has BP. The branch flow path BP is configured by the inner surface S12 of the second housing part 220c and the surface S11 of the fourth flow path forming member 280. The inner surface S12 of the second housing part 220c is a curved surface, and is continuous with the upper surface S13 of the lower end plate member 250c. The fourth flow path forming member 280 is attached to the inside of the second housing part 220c, and is a member having a substantially triangular cross section surrounding the lower part of the optical system case 110. The surface S11 of the fourth flow path forming member 280 is a curved surface and has substantially the same shape as the inner surface S12 of the second housing portion 220c. A surface S10 adjacent to the surface S11 of the fourth flow path forming member 280 forms an air curtain forming flow path AP with the outer surface S2 of the lower part of the optical system case 110.

  In FIG. 7, a part of the air sent out from the air fan 300 flows into the branch flow path BP, and flows to the outside along the inner surface S12 of the second housing part 220c and the upper surface S13 of the lower end plate member 250c. In this way, it is possible to prevent snow from accumulating on the upper surface S13 of the lower plate member 250c in winter. The branch channel BP may be omitted. Also in the fourth embodiment of FIG. 7, the first air curtain A1 is formed on the outer side of the translucent cover 140 of the optical system case 110. Therefore, before the outside air that contacts the outer side of the translucent cover 140 cools down. It is possible to prevent condensation from occurring by replacing the outside air.

-Fifth embodiment:
FIG. 8 is a side view of a laser radar device 900d according to the fifth embodiment, corresponding to FIG. The difference from the first embodiment shown in FIG. 3 is that a heater 600 is installed on the air fan 300, and other configurations are substantially the same as those of the first embodiment. An electric heater is used as the heater 600. In FIG. 8, the air sent from the air fan 300 is heated by the heater 600. By so doing, the temperature of the first air curtain A1 rises, so that it is possible to further prevent condensation from forming on the outer side of the translucent cover 140 of the optical system case 110, particularly in winter. Instead of the heater 600, other types of heating devices may be used. As such a heating device, for example, a heating device that heats the air sent from the air fan 300 using hot water can be used.

-Sixth embodiment:
FIG. 9 is a side view of a laser radar device 900e according to the sixth embodiment and corresponds to FIG. The main difference from the first embodiment shown in FIG. 3 is that an auxiliary fan 500 is installed on the side surface of the translucent cover 140 of the optical system case 110, and other configurations are almost the same as those of the first embodiment. It is. The auxiliary fan 500 sends air in the horizontal direction to the outer side surface of the translucent cover 140.

  FIG. 10 is a schematic view of the laser radar device 900e of FIG. 9 as viewed from above, and corresponds to FIG. Auxiliary fans 500 are respectively installed on both side surfaces of the optical system case 110 outside the translucent cover 140, and send air in the horizontal direction to the outside of the translucent cover 140. The cutout portion 255e of the lower end plate-like member 250 is set to be shorter than the cutout portion 255 of FIG. 4 so that the first air curtain A1 does not collide with the air sent from the auxiliary fan 500. In FIG. 10, the air sent from the air fan 300 and the auxiliary fan 500 can prevent the occurrence of condensation by replacing the outside air before the outside air coming into contact with the outside of the transparent cover 140 cools down. Thus, it is possible to prevent dust, snow, and the like from adhering to the outside of the translucent cover 140.

・ Modification:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

・ Modification 1:
In the first embodiment described above, the air curtain forming flow path AP is provided below the translucent cover 140 of the optical system case 110, but the air curtain forming flow path AP may be provided above the translucent cover 140. Good. In this case, it is preferable that the air fan 300 sends out air from the upper side to the lower side of the air curtain forming channel AP.

Modification 2
In all the embodiments described above, the air fan 300 and the housing 200 are used as the air curtain device, but other air curtain devices capable of forming the first air curtain A1 on the outside of the translucent cover 140 are used. Also good.

・ Modification 3:
In the second and third embodiments described above, the air flow of the first air curtain A1 and the second air curtain A2 is opposite, but the first air curtain and the second air in the same direction of the air flow. A curtain may be formed. However, if the air flow of the first air curtain A1 and the second air curtain A2 is reversed, dust, snow, etc. will break through the second air curtain A2 along the air flow direction of the second air curtain A2. Even so, since the air flow direction of the first air curtain A1 is opposite to the traveling direction of dust, snow, etc., the first air curtain A1 can prevent dust, snow, etc. from adhering to the translucent cover 140. . Further, the air flow direction of the first air curtain A1 may be directed downward from above, and the air flow direction of the second air curtain A2 may be directed upward from below.

  Instead of forming the second air curtain A2 by turning the air flow of the first air curtain A1, the second air curtain is formed using another flow path that does not use the air of the first air curtain A1. May be. Even in this case, since the first air curtain A1 and the second air curtain are formed, it is possible to prevent condensation from occurring by replacing the outside air before the outside air contacting the outside of the transparent cover 140 has cooled. Thus, dust and snow can be prevented from adhering to the translucent cover 140.

-Modification 4:
The above embodiments may be arbitrarily combined. For example, the fourth embodiment (FIG. 7) and the fifth embodiment (FIG. 8) may be applied to other embodiments.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Laser beam generator 11 ... Laser diode 12 ... Collimating lens 20 ... Light receiving device 21 ... Photo diode 22 ... Condensing lens 23 ... Optical filter 30 ... Mirror 30a ... Reflecting surface 40 ... Rotating deflection device 41 ... Mirror 41a ... Reflection Surface 42 ... Rotating shaft 42a ... Center shaft 43 ... Support base 44 ... Drive device 70 ... Control device 100 ... Laser radar main body 110 ... Optical system case 130 ... Opening 140 ... Translucent cover 200, 200a, 200b, 200c ... Housing 210 210a, 210b ... first housing part 220,220c ... second housing part 230 ... opening 240,240a, 240b ... upper plate member 241,241b ... second flow path forming member 242,242b ... third flow path forming member 243, 243b ... auxiliary protection member 244 ... buttock 250, 25 c ... Lower end plate member 255, 255e ... Notch 270 ... First flow path forming member 280 ... Fourth flow path forming member 300 ... Air fan 400 ... Mounting table 500 ... Auxiliary fan 600 ... Heater 900, 900a-900e ... Laser Radar device A1 ... 1st air curtain A2 ... 2nd air curtain AP ... Air curtain formation flow path BP ... Branch flow path G1 ... Gap GP1 ... 1st guide flow path GP2 ... 2nd guide flow path L1 ... Laser beam L2 ... Reflection light

Claims (10)

A stationary laser radar device,
A laser radar optical system for emitting laser light to the outside and receiving reflected light of the laser light reflected by an external object;
An optical system case containing the laser radar optical system and having a translucent cover for allowing the emitted laser light and the reflected light to pass through;
An air curtain device for preventing dew condensation on the outer side of the translucent cover by forming a first air curtain on the outer side of the translucent cover;
A laser radar device comprising: The laser radar device according to claim 1, wherein
The air curtain device includes an air fan that sends out air, and a housing that houses the air fan and the optical system case,
The housing has an opening that allows the emitted laser light and the reflected light to pass therethrough at a position corresponding to the translucent cover of the optical system case,
The housing further includes an air curtain forming flow path for supplying the air sent from the air fan to the outside of the translucent cover as the first air curtain.
Laser radar device. The laser radar device according to claim 1, wherein
The air curtain device further forms a second air curtain at a position outside the first air curtain.
Laser radar device. The laser radar device according to claim 3, wherein
The air flow directions of the first air curtain and the second air curtain are opposite directions,
Laser radar device. The laser radar device according to claim 4, wherein
The air flow direction of the first air curtain is directed from the bottom to the top,
The air flow direction of the second air curtain is directed from above to below,
Laser radar device. In the laser radar device according to any one of claims 3 to 5,
The air curtain device includes an air fan that sends out air, and a housing that houses the air fan and the optical system case,
The housing has an opening that allows the emitted laser light and the reflected light to pass therethrough at a position corresponding to the translucent cover of the optical system case,
The housing further has an air curtain forming flow path for supplying the air sent from the air fan as the first air curtain to the outside of the translucent cover, and the air of the first air curtain is transmitted through the translucent light. Having a first guide flow path that forms the second air curtain by folding the air flow after passing outside the cover;
Laser radar device. The laser radar device according to claim 6, wherein
The air curtain forming flow path is provided at a lower position outside the translucent cover,
The air fan sends out air from below to above the air curtain forming channel,
The first guide channel is provided above the opening of the housing, and the air flow of the first air curtain passes through the outside of the translucent cover from the lower side to the upper side. Forming the second air curtain by folding back from above to below;
Laser radar device. The laser radar device according to claim 7, wherein
The housing further includes a second guide channel that folds air flowing from the outside toward the laser radar device and joins the air in the middle of the first guide channel.
Laser radar device. In the laser radar device according to claim 7 or 8,
The housing further includes a lower end plate-like member protruding outward at the lower end portion of the opening, and a branch flow for guiding a part of the air sent out from the air fan to the outside along the lower end plate-like member. Having a road,
Laser radar device. In the laser radar device according to any one of claims 1 to 9,
The air curtain device includes a heating device that heats air to be the first air curtain.
Laser radar device.

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