JP2019163974A - Distance measurement device - Google Patents

Abstract

To provide a distance measurement device that properly flows gas in a flow channel, and can suppress a reverse flow of the gas upon emitting the gas from an exhaust hole.SOLUTION: A distance measurement device of the present invention has in an exterior surface of a housing storing an irradiation unit and an imaging unit, a first transmissive part that light to be irradiated from an irradiation unit transmits. and a second transmissive part that light to be photographed by an imaging unit transmits. Further, around the exterior face of the housing, a flow channel formation member is provided that forms a flow channel for flowing gas along the exterior surface of the housing having the first transmissive part and the second transmissive part formed. In the flow channel formation member, a first exhaust hole is formed at a location facing the first transmissive part, and a second exhaust hole broader in an aperture area that the first exhaust hole is formed at a location facing the second transmissive part. The flow channel includes: a first flow channel part that is adjacent to the first exhaust hole; a second flow channel part for making gas detouring the first exhaust hole and passing through the first flow channel flow toward the second exhaust hole.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a distance measuring device, which irradiates light to a measurement object from an irradiation unit, images the light reflected by the measurement object by an imaging unit, and measures the distance to the measurement object. About.

  A distance measuring device that measures the distance to the object to be measured using the light cutting method is already well known. For example, it measures the three-dimensional shape of the object to be measured, or detects the presence or absence of wrinkles on the surface of the object to be measured. It is used for applications such as detection. The distance measuring device may be used in an environment where floating substances such as dust, dust, and water vapor exist. When the distance measuring device is used in such an environment, there is a possibility that floating substances may adhere to a light transmission portion (a portion through which irradiation light and reflected light are transmitted) provided on the device wall surface. Since the attachment of floating substances in the light transmission part affects the accuracy of distance measurement, it is necessary to suppress the attachment of floating substances in the light transmission part as much as possible.

  As an example of a method for suppressing attachment of suspended solids in the light transmission part, a technique described in Patent Document 1 can be cited. In the technique described in Patent Document 1 (for example, see Paragraph 0046 and FIG. 2 of Patent Document 1), air is ejected from a nozzle toward a light transmitting portion (strictly speaking, a light emitting surface of a light beam and a light receiving surface of a camera). In this way, suspended matter around the light transmission part is purged, and dust adhesion at the light transmission part is suppressed.

JP 2009-244162 A

  However, in the technique described in Patent Document 1, since the tip of the nozzle is arranged in the vicinity of the light transmission part, dust is caught in the air ejected from the nozzle, and the air containing the dust is directly jetted to the light transmission part. There is a risk that dust will adhere to the light transmission part due to this. As a method for avoiding such a situation, as shown in FIG. 13, a flow path forming member 110 is disposed around the casing 101 of the distance measuring device 100 and gas is allowed to flow along the lower surface 102 of the casing 101. It is conceivable to form the flow path 111. FIG. 13 is a schematic cross-sectional view showing the configuration of the distance measuring apparatus 100 according to the comparative example.

  In the distance measuring apparatus 100 illustrated in FIG. 13, a first transmission unit 103 that transmits light emitted from the irradiation unit 105 in the housing 101 and a photographing unit 106 in the housing 101 are formed on the lower surface 102 of the housing 101. And a second transmission unit 104 that transmits light to be photographed (in other words, reflected light reflected by the measurement object). Further, exhaust holes 112 and 113 are provided at locations facing the first transmission portion 103 and the second transmission portion 104 in the flow path forming member 110. Here, the exhaust hole 113 provided at a position facing the second transmission part 104 is provided with an exhaust hole 112 provided at a position facing the first transmission part 103 for the purpose of guiding the reflected light to the photographing unit 106. The opening area is larger than that.

  Under such a configuration, when gas is flowed through the flow path 111 and gas is discharged from the exhaust holes 112 and 113, the gas is flowed into the flow path 111 in a laminar flow state, and the gas is discharged from the respective exhaust holes 112 and 113. It is necessary to discharge gas slowly. On the other hand, in the exhaust hole 113 having a larger opening area (that is, the exhaust hole 113 facing the second transmission part 104), the gas backflow T is more likely to occur when the gas is discharged. The gas backflow T may collide with the second transmission part 104 while entraining floating substances such as dust, and in that case, the effect of flowing gas through the flow path 111 (floating substance purging effect) can be appropriately obtained. Otherwise, there is a risk that suspended matter may adhere to the second transmission part 104.

  Therefore, the present invention has been made in view of the above circumstances, and is a distance measuring device capable of appropriately flowing a gas in a flow path and suppressing the backflow of the gas when discharging the gas from the exhaust hole. The purpose is to provide.

  In order to achieve the above object, the distance measuring device of the present invention irradiates the measurement object with light from an irradiation unit, images the light reflected by the measurement object with the imaging unit, and measures the measurement object. A distance measuring device that measures the distance to the housing, the housing that houses the irradiating unit and the imaging unit, and the outer surface of the housing, through which light emitted from the irradiating unit passes. One transmissive portion, a second transmissive portion that is formed on the outer wall surface of the housing and transmits light captured by the photographing unit, and is provided around the outer wall surface of the housing, A flow path forming member that forms a flow path for flowing a gas along the surface on which the first permeable portion and the second permeable portion are formed, and the first permeable portion in the flow path forming member. A first exhaust hole formed at a facing position, and the second passage portion in the flow path forming member. A second exhaust hole having a larger opening area than the first exhaust hole, and the flow path includes a first flow path portion adjacent to the first exhaust hole, and the first exhaust hole. And a second flow path portion for flowing the gas that has passed through the first flow path portion and deviated from the hole toward the second exhaust hole.

In the distance measuring device of the present invention configured as described above, the first exhaust hole is formed at a position facing the first transmission part in the flow path forming member, and the second exhaust hole is formed at a position facing the second transmission part. Is formed. The opening area of the second exhaust hole is larger than the opening area of the first exhaust hole. Further, the gas flow path includes a first flow path portion adjacent to the first exhaust hole, and a second flow for flowing the gas that has deviated from the first exhaust hole and passed through the first flow path portion toward the second exhaust hole. And a flow path portion. That is, the gas flowing through the first flow path portion is divided into an amount discharged from the first exhaust hole and an amount flowing through the second flow path portion, and the gas flowing through the second flow path portion passes through the second exhaust hole. Discharged. Thus, the gas flow is adjusted (rectified) by increasing the distance (stroke) through which the gas discharged from the second exhaust hole having a larger opening area flows in the flow path, and the second exhaust hole The gas can be prevented from being exhausted vigorously. As a result, it is possible to suppress the backflow of the gas at the second exhaust hole where the backflow of the airflow is likely to occur.
For the reasons described above, in the distance measuring device of the present invention, the flow of gas in the flow path is adjusted (rectified), and adhesion of suspended matters in the second permeation portion is effectively suppressed. It becomes possible.

In the distance measuring apparatus, it is preferable that the second flow path portion is located downstream of the first flow path portion in the flow path.
According to said structure, since the 2nd flow-path part is located downstream from a 1st flow-path part, it becomes possible to suppress the backflow of the airflow in a 2nd exhaust hole appropriately.

In the distance measuring device, the outer wall surface of the housing includes a first surface on which the first transmissive portion and the second transmissive portion are formed, and a second surface different from the first surface. The flow path forming member is provided with a blow hole for blowing gas into the flow path, and the flow path is continuous with the blow hole and is adjacent to the second surface. It is preferable to include a three flow path portion and a fourth flow path portion for flowing the gas that has passed through the third flow path portion.
In such a configuration, it is even more preferable that the blowing hole is provided in a portion of the flow path forming member facing the second surface.
According to the above configuration, the gas blown into the flow path through the blow hole is first a surface (first surface) in which the first transmission portion and the second transmission portion are formed in the outer wall surface of the housing. Collides with a different surface (second surface). Thereafter, the gas flows through the fourth flow path portion in the flow path. Thereby, it becomes possible to avoid that the gas blown through the blow hole is directly blown to the first transmission part and the second transmission part. As a result, it is possible to prevent the first transmission part and the second transmission part from being damaged by the collision with the gas containing the fine suspended matter.

In the distance measuring device, the flow path forming member may be formed in a space between the first wall and the bottom wall where the first exhaust hole and the second exhaust hole are formed, and between the first surface and the bottom wall. A partition wall disposed along the first surface, and a portion closer to the first surface among the flow paths partitioned by the partition wall constitutes the fourth flow path portion, and the bottom A portion closer to the wall constitutes the first flow path portion and the second flow path portion, and the first through hole formed in the partition wall at a position facing the first transmission portion and the first exhaust hole And a second through hole formed at a position facing the second transmission portion and the second exhaust hole is preferable.
According to the above configuration, since the flow path has a two-layer structure, it is possible to secure a flow path long enough to regulate (rectify) the gas flow while suppressing an increase in the size of the apparatus. It becomes.

In the distance measuring device, the first surface is a surface that extends long along one direction, and the first exhaust hole and the second exhaust hole are different from each other in the longitudinal direction of the first surface. Preferably, the first exhaust hole is provided at a position farther from the blowing hole than the second exhaust hole in the longitudinal direction.
According to said structure, the 1st exhaust hole is provided in the position away from the blowing hole rather than the 2nd exhaust hole. With such a positional relationship, the length of the flow path from the blowing hole to the second exhaust hole can be secured longer. As a result, it becomes easier to adjust (rectify) the gas flow in the second exhaust hole.

In the distance measuring device, the fourth channel portion surrounds an adjacent region adjacent to the second transmission part and the second through hole in the fourth channel portion, and the adjacent region is It is preferable that a member separated from the region other than the adjacent portion in the fourth flow path portion is provided.
According to said structure, the adjacent area | region adjacent to a 2nd permeation | transmission part and a 2nd through-hole among the 4th flow-path parts is separated from the area | region of the circumference | surroundings. For this reason, it becomes possible to avoid that the gas passes through the second through-hole and is directly discharged from the second flow passage portion through the second flow passage portion while the gas flows through the fourth flow passage portion. .

In the distance measuring device, the partition wall may communicate the fourth flow path portion and the second flow path portion at a position between the first through hole and the second through hole. For this reason, it is preferable that a communication portion formed for this purpose is provided.
According to said structure, some gas which is flowing through the 4th flow-path part approachs into a 2nd flow-path part through a communicating part. The gas that has flowed through the second flow path portion through the communication portion flows toward the second exhaust hole, or flows toward the first exhaust hole. Thereby, even if it is a case where gas is exhausted vigorously from the 1st exhaust hole, it becomes possible to suppress the back flow of the gas in the 1st exhaust hole.

In the distance measuring device, it is preferable that the communication portion is a through hole formed between the first through hole and the second through hole in the partition wall.
According to said structure, a through-hole can be formed as a communicating part using the space between a 1st through-hole and a 2nd through-hole, and it becomes possible to provide a communicating part easily.

In the distance measuring device, it is preferable that an opening area of the communication portion is smaller than an opening area of the first through hole.
According to said structure, the quantity of the gas which passes a 1st through-hole becomes less than the quantity of the gas which passes a communicating part. That is, most of the gas flowing in the fourth flow path portion is caused to flow from the first through hole to the first flow path portion, and only a part of the gas is allowed to flow from the communication portion to the second flow path portion. Accordingly, it is possible to secure the amount of gas flowing through each of the first flow path portion and the second flow path portion while suppressing the back flow of the gas in the first exhaust hole.

In the distance measuring device, the irradiation unit irradiates the measurement target with slit-shaped light, and the first transmission unit and the first exhaust hole extend in a direction in which the slit-shaped light extends. It may be formed long along.
In said structure, according to the irradiation part irradiating slit-shaped light, it becomes possible to make a 1st permeation | transmission part and a 1st exhaust hole into an appropriate shape.

  According to the present invention, the flow of gas in the flow path is adjusted (rectified), and it is possible to effectively suppress the attachment of suspended matter in the second transmission part. This makes it possible to accurately measure the distance to the object to be measured even in an environment where floating substances exist.

It is a perspective view which shows the external appearance of the distance measuring device which concerns on one Embodiment of this invention. It is explanatory drawing about the distance measuring method by the distance measuring device which concerns on one Embodiment of this invention. It is a figure which shows the irradiation part and imaging | photography part which were accommodated in the housing | casing which the distance measuring device which concerns on one Embodiment of this invention has, and the housing | casing. It is a figure which shows the lower surface of the housing | casing which the distance measuring device which concerns on one Embodiment of this invention has. It is a typical sectional view showing the composition of the distance measuring device concerning one embodiment of the present invention. It is the figure which looked at the AA cross section of FIG. 5 from the arrow direction. It is the figure which looked at the BB cross section of FIG. 5 from the arrow direction. It is the figure which looked at CC cross section of FIG. 5 from the arrow direction. It is a figure which shows the flow of the gas in a flow path. It is typical sectional drawing which shows the structure of the distance measuring device which concerns on a reference example. It is a figure which shows the lower surface of the housing | casing which the distance measuring device which concerns on the modification of this invention has. It is typical sectional drawing which shows the structure of the distance measuring device which concerns on the modification of this invention. It is typical sectional drawing which shows the structure of the distance measuring device which concerns on a comparative example.

  Hereinafter, the configuration of a distance measuring device according to an embodiment (this embodiment) of the present invention will be described in detail with reference to the accompanying drawings. In addition, although embodiment described below is one suitable embodiment of this invention, it is only an example to the last and does not limit this invention. That is, the present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

In the following, unless otherwise specified, it is assumed that the distance measuring device is placed on a horizontal plane, and the position and orientation of each part of the device when in this state will be described.
Hereinafter, the three axes orthogonal to each other are referred to as an X axis, a Y axis, and a Z axis, and directions in which the respective axes extend are referred to as an X axis direction, a Y axis direction, and a Z axis direction. For convenience of explanation, one end side in the Y-axis direction is referred to as “front side”, and the other end side in the Y-axis direction is referred to as “rear side”.

<< Outline of Distance Measuring Device According to this Embodiment >>
First, an outline of a distance measuring device (hereinafter, distance measuring device 1) according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing an appearance of the distance measuring device 1. FIG. 2 is an explanatory diagram of a distance measuring method by the distance measuring device 1. FIG. 3 is a diagram illustrating the housing 2 included in the distance measuring device 1, and the irradiation unit 3 and the imaging unit 4 accommodated in the housing 2. FIG. 4 is a diagram illustrating the lower surface of the housing 2. 1, 3, and 4, the directions that can be illustrated in each figure out of the X-axis direction, the Y-axis direction, and the Z-axis direction are indicated by arrows.

  The distance measuring device 1 is a device that measures the distance to the measurement object W using a light cutting method, and has the appearance shown in FIG. The distance measuring device 1 includes an irradiation unit 3 and an imaging unit 4 illustrated in FIGS. 2 and 3, and irradiates light to the measurement object W from the irradiation unit 3 and images light reflected by the measurement object W. The image is taken by the unit 4 and the distance to the measurement object W is measured.

  Then, by measuring the distance to the measurement object W using the distance measurement device 1, it is possible to detect wrinkles on the surface of the measurement object W. More specifically, the irradiation unit 3 includes a known laser light irradiation device, and irradiates slit-shaped light toward the surface of the measurement target W as shown in FIG. The slit-shaped light is light that extends in the X-axis direction.

  The photographing unit 4 is composed of a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and photographs light reflected on the surface of the measurement object W. According to the photographed image of the photographing unit 4, a difference in the incident angle (reflection angle) of light corresponding to the unevenness Wk (for example, ridge) formed on the surface of the measurement object W is detected, and the principle of triangulation is detected. By applying, it is possible to convert the difference in incident angle into a distance. Based on the calculated distance, wrinkles on the surface of the measurement object W are detected.

  The distance measuring device 1 employs a structure that can be used in an environment where there are floating substances such as dust and dust. If demonstrating it concretely, the above-mentioned irradiation part 3 and the imaging | photography part 4 will be accommodated in the box-shaped housing | casing 2, as shown in FIG. The housing 2 includes a rectangular lower surface 5 illustrated in FIG. 4 and a side surface 8 rising substantially vertically from the edge of the lower surface 5. Here, the lower surface 5 of the housing 2 corresponds to a first surface of the outer wall surfaces of the housing 2 and is a surface extending long along the Y-axis direction (corresponding to one direction). Further, the longitudinal direction of the lower surface 5 of the housing 2 coincides with the Y-axis direction. The side surface 8 of the housing 2 corresponds to the second surface of the outer wall surface of the housing 2 and is a surface different from the lower surface 5 that is the first surface.

  Further, as shown in FIG. 4, two light transmitting portions that can transmit light are formed on the lower surface 5 of the housing 2. One of them is a first transmission part 6 through which slit-like light irradiated from the irradiation part 3 is transmitted. The first transmission part 6 is a horizontally long rectangular region formed long along the direction in which the slit-shaped light extends (that is, the X-axis direction). Another light transmission part is a second transmission part 7 through which light (reflected light) photographed by the photographing part 4 is transmitted. The second transmission part 7 is a rectangular area longer than the first transmission part 6 in the Y-axis direction. Further, the area of the second transmission part 7 is larger than the area of the first transmission part 6. Moreover, the 1st transmission part 6 and the 2nd transmission part 7 are located in a line at intervals in the Y-axis direction, the 1st transmission part 6 is formed in the front side, and the 2nd transmission part 7 is formed in the back side. Has been.

  As described above, in the present embodiment, the first transmission portion 6 and the second transmission portion 7 are provided on the lower surface 5 of the housing 2, thereby allowing light to pass between the inside and the outside of the housing 2. However, entry of the floating substance into the housing 2 is prevented. The first transmissive part 6 and the second transmissive part 7 are provided with an opening formed in the lower surface 5 of the housing 2 and a transparent glass surface (strictly speaking, facing down the glass surface). Surface).

  However, even if the first transmission part 6 and the second transmission part 7 are provided on the lower surface 5 of the housing 2, the first transmission part 6 and the second transmission part in an environment in which floating substances such as dust and dust exist. When the distance measuring device 1 is used in a state in which 7 is exposed, floating substances adhere to the first transmission part 6 and the second transmission part 7. Such adhesion of floating substances affects the accuracy of distance measurement by the distance measuring device 1.

  As a measure for suppressing the adhesion of floating substances in the first transmission part 6 and the second transmission part 7, purging by flowing a dust removing gas around each of the first transmission part 6 and the second transmission part 7. Can be considered. However, when a gas for dust removal is caused to flow around each of the first transmission part 6 and the second transmission part 7, if the gas is blown directly on the first transmission part 6 and the second transmission part 7, the flow velocity of the gas May be relatively large. In such a case, when the gas entrains the suspended matter such as dust and dust around it, and the gas containing the suspended matter collides with the first transmission unit 6 and the second transmission unit 7, the first transmission unit 6 and the first transmission unit 6 There is a possibility of damaging the second transmission part 7. In addition, since flaws occur in the first transmission part 6 and the second transmission part 7, the floating substance enters the inside of the damage and adheres to the first transmission part 6 and the second transmission part 7. It will promote the adhesion of.

Therefore, in the distance measuring device 1, as shown in FIG. 1, a flow path forming member 10 is provided around the housing 2, a gas is caused to flow in the flow path formed by the flow path forming member 10, and the gas flow The periphery of the first transmission part 6 and the second transmission part 7 is clarified using Furthermore, in this embodiment, by adjusting (rectifying) the gas flow around the first transmission part 6 and the second transmission part 7, the gas entrained by the suspended matter, the first transmission part 6 and the second transmission part The collision with the part 7 and the trouble resulting from this are eliminated.
Hereinafter, the flow path forming member 10 and the gas flow path formed by the flow path forming member 10 will be described in detail.

<< About the gas flow path >>
Next, the flow path forming member 10 provided in the distance measuring device 1 and the gas flow path formed by the flow path forming member 10 will be described with reference to FIGS. 1 and 5 to 8 described above. FIG. 5 is a schematic cross-sectional view showing the configuration of the flow path forming member 10, and is a view showing a II cross section of FIG. 1. 6 is a view of the AA cross section of FIG. 5 as viewed from the direction of the arrows. FIG. 7 is a view of the BB cross section of FIG. 5 as seen from the direction of the arrow. FIG. 8 is a view of the CC cross section of FIG. 5 as seen from the direction of the arrow. 5-8, the direction which can be shown among the X-axis direction, the Y-axis direction, and the Z-axis direction is illustrated by arrows. 5 and 6 illustrate the internal structure of the housing 2 in a simplified manner, and illustration of devices housed in the housing 2 such as the irradiation unit 3 and the imaging unit 4 is omitted.

  The flow path forming member 10 forms a flow path R for flowing a gas along the lower surface 5 of the housing 2 (the surface on which the first transmission portion 6 and the second transmission portion 7 are formed). It is comprised by the box-shaped body formed by processing metal plates, such as a plate and a steel plate. In the present embodiment, the flow path forming member 10 is provided around the outer wall surface of the housing 2, and specifically, provided so as to surround the lower half of the housing 2 as shown in FIG. It has been.

  As shown in FIGS. 1 and 5, the flow path forming member 10 includes a bottom wall 11, a side wall 12, and a ceiling wall 13. The bottom wall 11 extends along the lower surface 5 of the housing 2 as shown in FIG. 5 when the flow path forming member 10 is attached around the outer wall surface of the housing 2. The bottom wall 11 has a rectangular outer shape that is one size larger than the lower surface 5 of the housing 2.

  Further, as shown in FIG. 5, the bottom wall 11 has two exhaust holes. One exhaust hole is a first exhaust hole 16 formed at a position facing the first transmission portion 6 in the flow path forming member 10. Here, “facing the first transmission part 6” means a state in which the first transmission part 6 faces the first exhaust hole 16 at a position overlapping the first transmission part 6 in the Z-axis direction. . The first exhaust hole 16 is a rectangular hole whose opening has the same area and shape as the first transmission part 6. The first exhaust hole 16 is an exhaust hole for the gas that has flowed through the flow path R, and is also a hole for allowing the slit-shaped light irradiated by the irradiation unit 3 to pass therethrough. For this reason, as shown in FIG. 8, the 1st exhaust hole 16 is long formed along the direction (namely, X-axis direction) where slit-shaped light is extended.

  The other exhaust hole is a second exhaust hole 17 formed at a position facing the second transmission portion 7 in the flow path forming member 10. Here, “facing the second transmission part 7” means a state in which the second transmission part 7 faces the second exhaust hole 17 at a position overlapping the second transmission part 7 in the Z-axis direction. . The second exhaust hole 17 is a rectangular hole, and its opening is the same shape as the second transmission part 7, and its size (opening area) is the same as or larger than the second transmission part 7. . The second exhaust hole 17 is an exhaust hole for the gas that has flowed through the flow path R, and is also a hole through which light (reflected light) photographed by the photographing unit 4 passes. For this reason, as shown in FIG. 8, the opening area of the second exhaust hole 17 is larger than the opening area of the first exhaust hole 16, and the length in the Y-axis direction is also the second exhaust hole. 17 is longer than the first exhaust hole 16.

  The first exhaust hole 16 and the second exhaust hole 17 are provided at different positions in the Y-axis direction (in other words, the longitudinal direction of the lower surface 5 of the housing 2). Specifically, as shown in FIG. 8, the first exhaust hole 16 and the second exhaust hole 17 are arranged at intervals in the Y-axis direction, and the first exhaust hole 16 is formed on the front side, Two exhaust holes 17 are formed on the rear side. Note that the distance between the first exhaust hole 16 and the second exhaust hole 17 corresponds to the distance between the first transmission part 6 and the second transmission part 7 (strictly substantially coincides).

  The side wall 12 rises substantially vertically from the outer edge of the bottom wall 11, and is disposed on the front and rear sides and the left and right sides of the housing 2 when the flow path forming member 10 is attached around the outer wall surface of the housing 2. . That is, each of the four side walls 12 is disposed at a position facing the corresponding surface among the side surfaces 8 of the housing 2. Further, as can be seen from FIGS. 1 and 5, when the flow path forming member 10 is attached around the outer wall surface of the housing 2, the upper end of each side wall 12 is positioned above the lower surface 5 of the housing 2. is doing.

  Of the four side walls 12, the side wall 12 located on the rear side in the Y-axis direction (the side wall 12 illustrated on the right side in FIG. 5) is blown to blow gas into the flow path R. A hole 15 is provided. The blow hole 15 is a round hole, and of the side wall 12, the side surface 8 of the housing 2 located on the rear side in the Y-axis direction (the side wall 12 illustrated on the right side in FIG. 5 on the paper). It is formed in the part which opposes. Moreover, the blow hole 15 is formed in the upper position rather than the lower surface 5 of the housing | casing 2, as shown in FIG. Further, the blow hole 15 is further away from the first exhaust hole 16 than the second exhaust hole 17 in the Y-axis direction. In other words, the first exhaust hole 16 is provided at a position farther from the blowing hole 15 than the second exhaust hole 17 in the Y-axis direction.

  As shown in FIGS. 1 and 5, the side wall 12 is provided with a nozzle portion 14 whose inside communicates with the blowing hole 15 so as to protrude outward from the side wall 12. A gas supply source (not shown) composed of a cylinder or a compressor is connected to the nozzle portion 14 via a tube or the like. When the gas is supplied from the gas supply source, the gas is introduced into the flow path R through the nozzle portion 14 and the blowing hole 15. In addition, as gas to supply, what compressed air, nitrogen, and other inert gas can be utilized.

  The ceiling wall 13 is placed on the upper end of each of the four side walls 12, and a rectangular fitting hole is formed in the center portion thereof. The housing 2 is fitted into this fitting hole. And the outer wall surface (specifically side surface 8) of the housing | casing 2 has joined to the edge surface of the fitting hole. In such a state, the flow path forming member 10 is attached around the outer wall surface of the housing 2.

  The flow path forming member 10 has a partition wall 18 illustrated in FIGS. 5 to 7 between the lower surface 5 of the housing 2 and the bottom wall 11 of the flow path forming member 10. The partition wall 18 is a rectangular wall member in plan view disposed along the lower surface 5 of the housing 2 in order to partition the flow path R, and each of the four sides thereof corresponds to the inner wall surface of the corresponding side wall 12. It touches. By arranging the partition wall 18, the flow path R is divided into two layers in the Z-axis direction. That is, the channel R according to the present embodiment is a channel having a two-layer structure.

  Further, as shown in FIG. 7, three through holes are formed in the partition wall 18. As shown in FIG. 5, the first through hole is a first through hole 19 formed at a position facing both the first transmission portion 6 and the first exhaust hole 16 in the Z-axis direction. The first through hole 19 is a rectangular hole whose opening has the same area and shape as the first transmission part 6. The first through hole 19 is a hole formed to allow the first transmitting portion 6 to face the first exhaust hole 16 and to allow the slit-shaped light irradiated by the irradiation unit 3 to pass therethrough. For this reason, as shown in FIG. 7, the 1st through-hole 19 is formed long along the direction (namely, X-axis direction) where slit-shaped light is extended.

  As shown in FIG. 5, the second through hole is a second through hole 20 formed at a position facing both the second transmission part 7 and the second exhaust hole 17 in the Z-axis direction. The second through hole 20 is a rectangular hole, and the opening thereof has the same shape as the second transmission portion 7 and the second exhaust hole 17. The size (opening area) of the second through hole 20 is not less than the size of the second transmission part 7 and not more than the size of the second exhaust hole 17. The second through hole 20 is a hole formed to allow the light (reflected light) photographed by the photographing unit 4 to pass through while causing the second transmitting portion 7 to face the second exhaust hole 17. For this reason, as shown in FIG. 7, the opening area of the second through hole 20 is larger than the opening area of the first through hole 19, and the length in the Y-axis direction is also the second through hole. 20 is longer than the first through hole 19.

  The first through hole 19 and the second through hole 20 are provided at different positions in the Y-axis direction (in other words, the longitudinal direction of the lower surface 5 of the housing 2). Specifically, as shown in FIG. 7, the first through hole 19 and the second through hole 20 are arranged at intervals in the Y-axis direction, the first through hole 19 is formed on the front side, Two through holes 20 are formed on the rear side. Note that the distance between the first through hole 19 and the second through hole 20 corresponds to the distance between the first transmission part 6 and the second transmission part 7 (strictly, substantially coincides).

  In the present embodiment, the first transmission part 6 and the openings of the first exhaust hole 16 and the first through hole 19 have the same shape and the same size, and the X-axis direction and the Y-axis direction. Are provided at the same position. The second transmission part 7 and the openings of the second exhaust hole 17 and the second through hole 20 have the same shape, and are provided at substantially the same position in the X-axis direction and the Y-axis direction. ing. Incidentally, the size (opening area) of the second through hole 20 is equal to or larger than the size of the second transmission portion 7, and the size of the second exhaust hole 17 is equal to or larger than the size of the second through hole 20. Yes.

  The third through hole is a communication portion 22 formed at a position between the first through hole 19 and the second through hole 20 in the Y-axis direction. As shown in FIG. 7, the communication part 22 is a rectangular through-hole formed to communicate the upper layer and the lower layer of the flow path R having a two-layer structure. Further, the communication portion 22 is formed long in the X-axis direction like the first through hole 19, but the opening area of the communication portion 22 is smaller than the opening area of the first through hole 19. In the present embodiment, as shown in FIG. 7, the communication portion 22 is formed on the inner side than both ends of the first through hole 19 in the X-axis direction.

Further, in the upper layer of the flow path R, around the edge of the second through hole 20, as shown in FIGS. 5 and 7, a rectangular tube-shaped sealing material 21 is disposed. This sealing material 21 corresponds to a separating member, and in the upper layer of the flow path R (in other words, a fourth flow path portion R4 described later), the adjacent region Rx adjacent to the second transmission portion 7 and the second through hole 20 is formed. It is separated from parts other than the adjacent region Rx. The sealing material 21 is configured by molding a sealing member such as rubber into a rectangular tube shape. The sealing material 21 is disposed at a position surrounding the adjacent region Rx, the upper end surface of the sealing material 21 is in contact with the lower surface 5 of the housing 2, and the lower end surface of the sealing material 21 is in contact with the upper surface of the partition wall 18. Yes. Thereby, in the upper layer of the flow path R, the adjacent region Rx is completely separated from the peripheral portion thereof.
A cavity is formed inside the sealing material 21 so as to allow light (reflected light) captured by the imaging unit 4 to pass through. The cavity is straight along the Z-axis direction as shown in FIG. The opening has the same shape and the same area as the opening of the second through hole 20.

The configuration of the flow path forming member 10 has been described above, but the gas flow path R formed by the flow path forming member 10 will be described below.
The flow path R is surrounded by the flow path forming member 10 and the outer wall surface of the housing 2. As shown in FIG. 5, the flow path R is divided into an upper layer (a part close to the lower surface 5 of the housing 2) and a lower layer (a part close to the bottom wall 11 of the flow path forming member 10) by the partition wall 18. The upper layer of the flow path R is configured by a space surrounded by the lower surface 5 and the side surface 8 of the housing 2, the side wall 12, the ceiling wall 13, and the partition wall 18 of the flow path forming member 10. The lower layer of the flow path R is configured by a space surrounded by the bottom wall 11, the side wall 12, and the partition wall 18 of the flow path forming member 10.

  The lower layer of the flow path R constitutes the first flow path portion R1 and the second flow path portion R2 shown in FIG. Here, the first flow path portion R1 is a portion adjacent to the first exhaust hole 16, and is a flow path portion in which the gas that has passed through the first through hole 19 flows immediately after that. The second flow path part R2 is a flow path part for flowing the gas that has escaped the first exhaust hole 16 and passed through the first flow path part R1 toward the second exhaust hole 17, and is more than the first flow path part R1. Located downstream. The gas flowing through the first flow path portion R1 flows to the outside of the flow path R from the first exhaust hole 16, and flows through the second flow path portion R2 and finally from the second exhaust hole 17 to the flow path R. It is divided into the amount discharged to the outside.

  The gas introduction space in the upper layer of the flow path R constitutes the third flow path portion R3 illustrated in FIG. Here, the gas introduction space is provided between the side wall 12 of the flow path forming member 10 where the blow hole 15 is provided and the side surface 8 of the housing 2 facing the side wall 12. Space. The third flow path portion R <b> 3 is a flow path portion that is continuous with the blowing hole 15. The gas introduced into the flow path R from the blow hole 15 first flows through the third flow path portion R3.

  A space other than the gas introduction space in the upper layer of the flow path R, more specifically, a space (excluding the gas introduction space) between the side wall 12 of the flow path forming member 10 and the side surface 8 of the housing 2; A space between the lower surface 5 of the housing 2 and the partition wall 18 constitutes a fourth flow path portion R4 illustrated in FIG. The fourth flow path portion R4 is a portion in the flow path R through which the gas that has passed through the third flow path portion R3 flows. The gas flowing in the fourth flow path portion R4 flows toward the first through hole 19, and eventually passes through the first through hole 19 and enters the first flow path portion R1. On the other hand, the above-described sealing material 21 is disposed in the fourth flow path portion R4 and surrounds the adjacent region Rx. Therefore, as shown in FIG. 7, in the fourth flow path portion R4, the gas in the region other than the adjacent region Rx passes through the second through hole 20 and is directly exhausted from the second exhaust hole 17. There is no.

  Further, a communication portion 22 is provided on the upstream side (front side) of the first through hole 19, and a part of the gas flowing in the fourth flow path portion R <b> 4 passes through the communication section 22 and passes through the second flow path. Part R2 is entered. That is, the communication part 22 communicates the fourth flow path part R4 and the second flow path part R2.

<< About the gas flow in the channel >>
Next, the gas flow in the flow path R described above will be described in detail with reference to FIGS. 6 to 8 and 9 described above. FIG. 9 is a diagram illustrating a gas flow in the flow path. In FIG. 9, the Y-axis direction and the Z-axis direction that can be illustrated in the same figure are indicated by arrows. Moreover, in FIGS. 6-9, the flow of gas is shown by the thick line arrow.

  The gas supplied from the gas supply source is blown into the flow path R through the nozzle portion 14 and the blow hole 15. As shown in FIG. 6, the gas blown into the flow path R collides with the side surface 8 at a position facing the blow hole 15 on the outer wall surface of the housing 2. As described above, in this embodiment, the gas is not directly applied to the lower surface 5 of the housing 2 in which the first transmission part 6 and the second transmission part 7 are formed. The one transmission part 6 and the second transmission part 7 are suppressed from being damaged. Further, by causing the gas to collide with the side surface 8 of the housing 2, the gas flow can be made gentle.

The gas that collides with the side surface 8 of the housing 2 flows through the third flow path portion R3 in a state where the flow velocity is suppressed by the collision. When the gas in the third flow path portion R3 flows in the third flow path portion R3 toward the outside in the X-axis direction and reaches the end portion in the X-axis direction of the third flow path portion R3, the fourth flow path portion R4. Enter. As shown in FIG. 6, the gas that has entered the fourth flow path portion R4 passes through the fourth flow path portion R4 toward the front side in the Y-axis direction along the side surfaces 8 positioned at both ends of the housing 2 in the X-axis direction. Flowing. That is, the gas flowing in the third flow path portion R3 then flows in the fourth flow path portion R4 along the side surface 8 of the housing 2 on the side of the housing 2. The gas flowing through the fourth flow path portion R4 eventually enters the space between the lower surface 5 of the housing 2 and the partition wall 18 at the front end in the Y-axis direction of the fourth flow path portion R4. (Ie, in the direction indicated by the arrow Q1 in FIG. 7) in the fourth flow path portion R4.
A part of the gas flowing through the third flow path portion R3 descends along the side surface 8 of the housing 2 and enters the space between the lower surface 5 of the housing 2 and the partition wall 18, and the Y-axis direction It flows in the fourth flow path portion R4 toward the first through hole 19 toward the front side (that is, in the direction indicated by the arrow Q2 in FIG. 7).

  Then, the gas that has reached the position immediately before the first through hole 19 passes immediately below the first transmission part 6, changes the flow direction by approximately 90 degrees, and descends toward the first through hole 19. To do. At this time, the gas purges the periphery of the first transmission part 6 (especially, the position immediately below the first transmission part 6), and prevents the entry of floating substances such as dust and dust into the periphery of the first transmission part 6. .

  As shown in FIG. 9, the gas that has passed through the first through-hole 19 flows in the first flow path portion R1 in the flow path R. To be discharged. At this time, the gas has flowed a sufficient distance (stroke) until then, and is exhausted from the first exhaust hole 16 in a state where the flow is adjusted (rectified). As shown in FIG. 9, the gas that has not been discharged from the first exhaust hole 16 again changes the flow direction by approximately 90 degrees and flows in the second flow path portion R <b> 2 toward the second exhaust hole 17. . Here, the second flow path portion R2 is along the Y-axis direction, and the gas flows in the second flow path portion R2 toward the rear side in the Y-axis direction. That is, the gas that has escaped from the first exhaust hole 16 in the first flow path portion R1 flows through the second flow path portion R2 so as to be folded back in the Y-axis direction.

  As shown in FIGS. 8 and 9, the gas flowing through the second flow path portion R2 is changed again by approximately 90 degrees in the flow direction at the second exhaust hole 17 located at the end of the second flow path portion R2. It is discharged out of the flow path R from the two exhaust holes 17. At this time, the gas is discharged from the second exhaust hole 17 while entraining the air around the second transmission part 7 (strictly speaking, the air in the adjacent region Rx). As a result, the periphery of the second transmission part 7 (especially, the position immediately below the second transmission part 7) is purged, and intrusion of floating substances such as dust and dust into the periphery of the second transmission part 7 is prevented.

  As described above, in this embodiment, the gas blown into the flow path R from the blow hole 15 and finally discharged from the second exhaust hole 17 to the outside of the flow path R is sufficient until then. After a long distance (stroke), the air is discharged from the second exhaust hole 17. For this reason, the gas flow at the time of flowing through the second flow path portion R2 is sufficiently adjusted (rectified). Thereby, the flow of the gas in the flow path R can be adjusted (rectified), and the exhaust of the gas from the second exhaust hole 17 having a larger opening area can be suppressed. As a result, since the opening area is larger, the backflow of gas can be suppressed at the second exhaust hole 17 where the airflow easily flows back.

  When a backflow of gas occurs in the second exhaust hole 17, as described in the section “Problems to be solved by the invention”, air entrained by floating matter such as dust contacts the second transmission part 7. As a result, there is a risk of floating matter adhering to the second transmission part 7. In the present embodiment, it is possible to appropriately flow gas into the flow path R while avoiding such a problem.

  In addition, the above-described effect is more significantly exhibited by providing the blowing hole 15 at a suitable position in relation to the first exhaust hole 16 and the second exhaust hole 17. Specifically, in the present embodiment, as described above, the first exhaust hole 16 is provided at a position farther from the blowing hole 15 than the second exhaust hole 17 in the Y-axis direction. In such a positional relationship, when the first exhaust hole 16 is provided at a position closer to the blow hole 15 than the second exhaust hole 17 in the Y-axis direction (for example, in the left side wall 12 in FIG. 5). Compared with the case where the blow hole 15 is formed), the stroke in which the gas flows from the blow hole 15 to the first exhaust hole 16 becomes longer. For this reason, the stroke in which the gas flows from the blowing hole 15 to the second exhaust hole 17 becomes longer. As a result, it becomes easier to adjust (rectify) the gas flow in the second exhaust hole 17, and it is easy to avoid the backflow of gas in the second exhaust hole 17 and the problems associated therewith.

  Returning to the description of the gas flow in the flow path R, as shown in FIGS. 7 and 9, the fourth flow path portion R4 (strictly, between the lower surface 5 of the housing 2 and the partition wall 18). A part of the gas in the space) passes through the communication portion 22 provided on the upstream side (rear side in the Y-axis direction) from the first through hole 19. The gas that has passed through the communication portion 22 enters the second flow path portion R2 from the fourth flow path portion R4. Thereby, even when the gas is exhausted vigorously from the first exhaust hole 16, it is possible to suppress the backflow of the gas through the first exhaust hole 16.

Specifically, when the gas is exhausted vigorously from the first exhaust hole 16, the air around the first exhaust hole 16 is sucked. At this time, when the air outside the distance measuring device 1 is sucked in, the backflow of the gas (air) occurs in the first exhaust hole 16, and the same problem as that described above, that is, the suspended matter such as dust is involved. There is a risk that the gas may come into contact with the first transmission part 6 and cause floating matter to adhere to the first transmission part 6.
On the other hand, in this embodiment, when the gas is exhausted vigorously from the first exhaust hole 16, as shown in FIG. 5, the gas that has entered the second flow path portion R2 through the communication portion 22 ( The detour airflow V) in FIG. Thereby, it is possible to avoid the occurrence of the backflow of gas (air) in the first exhaust hole 16 and the above-described problems caused by this without sucking the air outside the distance measuring device 1. is there.

  When the flow rate of the gas flowing through the second flow path portion R2 via the first flow path portion R1 is small by allowing the gas to enter the second flow path portion R2 from the fourth flow path portion R4 by the communication portion 22. Even so, it is possible to ensure the amount (total amount) of the gas flowing through the second flow path portion R2 toward the second exhaust hole 17.

In the present embodiment, the flow path R is partitioned into upper and lower layers by the partition wall 18, and each layer constitutes the flow path R. That is, the flow path R according to the present embodiment is a double-layered flow path having a fold, and constitutes a more compact flow path.
More specifically, as a configuration capable of rectifying the gas flow, a flow path R having a single-layer structure without folding as shown in FIG. 10 is also conceivable. FIG. 10 is a schematic cross-sectional view showing a configuration of a distance measuring device 1X according to the reference example.
The distance measuring device 1X illustrated in FIG. 10 is common to the distance measuring device 1 according to the present embodiment (that is, the distance measuring device 1 illustrated in FIG. 5) except that the flow path R is not a two-layer structure. Components having the same function are denoted by the same reference numerals as those shown in FIG.

When using the distance measuring device 1X illustrated in FIG. 10, in order to adjust (rectify) the gas flow in the first exhaust hole 16 and the second exhaust hole 17, from the blow hole 15 to the first exhaust hole 16. It is necessary to ensure a sufficient distance (the distance indicated by the symbol L in FIG. 10). That is, the length of the flow path forming member 10 is made longer in the Y-axis direction because there is no return.
On the other hand, in the distance measuring device 1 of the present embodiment illustrated in FIG. 5, the flow path R is folded back, so that the flow path R having the same length as the distance measuring device 1 </ b> X illustrated in FIG. While ensuring, the size of the flow path forming member 10 can be shortened in the Y-axis direction. That is, with the distance measuring device 1 shown in FIG. 5, it is possible to secure a flow path R that is long enough to regulate (rectify) the gas flow while suppressing an increase in the size of the device. is there.

<< Other Embodiments >>
The embodiments described so far are merely examples of the configuration of the distance measuring device of the present invention, and other examples are also conceivable. For example, in the above-described embodiment, the lower surface 5 of the housing 2 is rectangular as shown in FIG. 4, but the present invention is not limited to this. The external shape of the lower surface 5 of the housing 2 can be changed according to the number, size, arrangement position, and the like of the irradiation unit 3 and the imaging unit 4 accommodated in the housing 2. When a plurality of units are arranged in the X-axis direction, the outer shape of the lower surface 5 may be T-shaped as shown in FIG. FIG. 11 is a diagram illustrating the lower surface 5 of the housing 2 included in the distance measuring device according to the modification of the present invention.

  Moreover, in the above-mentioned embodiment, in order to make the gas which flows through 4th flow-path part R4 detour to 2nd flow-path part R2, it decided to provide the through-hole as the communication part 22 in the partition wall 18. As shown in FIG. However, the communication part 22 is not limited to the through hole, and may be a notch formed by notching a part of the outer edge part of the partition wall 18 into a semicircular shape or a V shape, for example. .

Further, in the above-described embodiment, the blowing hole 15 is provided in a portion (specifically, the side wall 12) of the flow path forming member 10 that faces the side surface 8 of the housing 2. Gas was blown from the side through. However, the present invention is not limited to this, and as shown in FIG. 12, a blowing hole 15 is formed in a portion adjacent to the side surface 8 of the housing 2 in the ceiling wall 13 of the flow path forming member 10. Gas may be blown vertically through the holes 15. FIG. 12 is a schematic cross-sectional view showing a configuration of a distance measuring device according to a modification of the present invention, and corresponds to FIG.
Although not particularly shown, a blow hole 15 is provided in the side wall 12 located on the front side of the paper surface of FIGS. 5 and 12, and the paper surface of FIGS. 5 and 12 passes through the blow hole 15. Gas may be blown in the direction.

  In the above-described embodiment, the distance measuring device 1 is used for the purpose of measuring the distance in an environment where there is a suspended matter such as dust. However, the present invention is not limited to this. The distance measuring device of the present invention can also be used when measuring the distance in a clean environment where dust or the like does not exist. However, in the case where the distance is measured in an environment in which floating substances such as dust are present, the effect of the distance measuring device 1 is more meaningfully exhibited.

  In the above-described embodiment, the distance measuring device that measures the distance to the measurement target W using the light cutting method has been described as an example. Any device can be used as long as it can measure the distance, and the present invention can also be applied to an apparatus (light wave rangefinder) that employs a measurement method other than the light cutting method.

DESCRIPTION OF SYMBOLS 1 Distance measuring device 1X Distance measuring device 2 Housing | casing 3 Irradiation part 4 Imaging | photography part 5 Lower surface (1st surface)
6 First transmission part 7 Second transmission part 8 Side surface (second surface)
DESCRIPTION OF SYMBOLS 10 Flow path formation member 11 Bottom wall 12 Side wall 13 Ceiling wall 14 Nozzle part 15 Blowing hole 16 1st exhaust hole 17 2nd exhaust hole 18 Partition wall 19 1st through-hole 20 2nd through-hole 21 Sealing material (separation member)
22 Communication unit 100 Distance measuring device 101 Case 102 Lower surface 103 First transmission unit 104 Second transmission unit 105 Irradiation unit 106 Imaging unit 111 Channel 112, 113 Exhaust hole R Channel R1 First channel part R2 Second channel part R3 Third flow path portion R4 Fourth flow path portion Rx Adjacent region T Backflow of airflow V Detour airflow W Object to be measured Wk Unevenness

Claims (11)

A distance measuring device that irradiates a measurement object from an irradiation unit, images light reflected by the measurement object by an imaging unit, and measures a distance to the measurement object,
A housing for housing the irradiation unit and the photographing unit;
A first transmission part that is formed on the outer wall surface of the housing and transmits light emitted from the irradiation part;
A second transmissive part that is formed on the outer wall surface of the housing and transmits light imaged by the imaging unit;
A flow path is provided around the outer wall surface of the casing, and a flow path for flowing gas along the surface of the outer wall surface of the casing where the first transmission portion and the second transmission portion are formed. A flow path forming member;
A first exhaust hole formed at a position facing the first transmission part in the flow path forming member;
A second exhaust hole formed at a position facing the second transmission portion in the flow path forming member, and having a larger opening area than the first exhaust hole;
The flow path includes a first flow path portion adjacent to the first exhaust hole and a second flow path for flowing the gas that has deviated from the first exhaust hole and passed through the first flow path portion toward the second exhaust hole. And a flow path portion.   The distance measuring device according to claim 1, wherein in the flow path, the second flow path portion is positioned downstream of the first flow path portion. The outer wall surface of the housing includes a first surface on which the first transmission portion and the second transmission portion are formed, and a second surface different from the first surface,
The flow path forming member is provided with a blowing hole for blowing gas into the flow path,
The flow path is
A third flow path portion that is continuous with the blow hole and is adjacent to the second surface;
The distance measuring device according to claim 1, further comprising a fourth flow path portion for flowing the gas that has passed through the third flow path portion.   The distance measuring device according to claim 3, wherein the blowing hole is provided in a portion of the flow path forming member facing the second surface. The flow path forming member is disposed along the first surface in a space between the bottom wall in which the first exhaust hole and the second exhaust hole are formed, and the first surface and the bottom wall. A partition wall,
Of the flow path partitioned by the partition wall, a part closer to the first surface constitutes the fourth flow path part, and parts closer to the bottom wall are the first flow path part and the second flow path part. Configure
The partition wall has a first through hole formed at a position facing the first transmission part and the first exhaust hole, and a position facing the second transmission part and the second exhaust hole. The distance measuring device according to claim 3 or 4, wherein a second through hole is provided. The first surface is a surface extending long along one direction,
The first exhaust hole and the second exhaust hole are provided at different positions in the longitudinal direction of the first surface,
The distance measuring device according to claim 5, wherein the first exhaust hole is provided at a position farther from the blowing hole than the second exhaust hole in the longitudinal direction.   The fourth channel portion surrounds an adjacent region adjacent to the second transmission portion and the second through hole in the fourth channel portion, and the adjacent region is adjacent to the fourth channel portion. The distance measuring device according to claim 5 or 6, wherein a member separated from an area other than the part is provided.   The partition wall is provided with a communication portion formed to communicate the fourth channel portion and the second channel portion at a position between the first through hole and the second through hole. The distance measuring device according to claim 5, wherein the distance measuring device is provided.   The distance measuring device according to claim 8, wherein the communication portion is a through hole formed between the first through hole and the second through hole in the partition wall.   The distance measuring device according to claim 9, wherein an opening area of the communication portion is smaller than an opening area of the first through hole. The irradiation unit irradiates slit-shaped light toward the measurement object;
The distance measuring device according to claim 1, wherein the first transmission part and the first exhaust hole are formed long along a direction in which the slit-shaped light extends.