JP6904290B2 - Distance measuring device - Google Patents

Description

The present invention relates to a distance measuring device, and is a distance measuring device that measures the distance to the measured body by irradiating the object to be measured with light from the irradiated unit and photographing the light reflected by the measured body by the photographing unit. Regarding.

Distance measuring devices that measure the distance to the object to be measured using the optical cutting method are already well known. For example, the three-dimensional shape of the object to be measured can be measured, or the presence or absence of a flaw on the surface of the object to be measured can be determined. It is used for applications such as detection. The distance measuring device may be used in an environment where suspended matter such as dust, dust and water vapor is present, for example. When the distance measuring device is used in such an environment, there is a possibility that suspended matter adheres to the light transmitting portion (the portion through which the irradiation light or the reflected light is transmitted) provided on the wall surface of the device. Since the adhesion of suspended matter in the light transmitting portion affects the accuracy of distance measurement, it is necessary to suppress the adhesion of suspended matter in the light transmitting portion as much as possible.

As an example of the method of suppressing the adhesion of suspended matter in the light transmitting portion, the technique described in Patent Document 1 can be mentioned. In the technique described in Patent Document 1 (see, for example, 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 and a light receiving surface of a camera). As a result, the suspended matter around the light transmitting portion is purged, and the adhesion of dust in the light transmitting portion is suppressed.

JP-A-2009-244162

However, in the technique described in Patent Document 1, since the tip of the nozzle is arranged near the light transmitting portion, dust is caught in the air ejected from the nozzle, and the air containing the dust is directly blown to the light transmitting portion. It may be attached, and as a result, dust may adhere to the light transmitting portion. As a method of avoiding such a situation, as shown in FIG. 13, a flow path forming member 110 is arranged around the housing 101 of the distance measuring device 100, and gas flows along the lower surface 102 of the housing 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 device 100 according to the comparative example.

In the distance measuring device 100 shown in FIG. 13, on the lower surface 102 of the housing 101, a first transmitting unit 103 through which the light irradiated by the irradiation unit 105 in the housing 101 is transmitted and a photographing unit 106 in the housing 101 are formed. A second transmitting portion 104 through which the light to be photographed (in other words, the reflected light reflected by the object to be measured) is transmitted is provided. Further, exhaust holes 112 and 113 are provided in the flow path forming member 110 at locations facing the first transmission portion 103 and the second transmission portion 104, respectively. Here, the exhaust hole 113 provided at a position facing the second transmission portion 104 is provided at a position facing the first transmission portion 103 for the reason of guiding the reflected light to the photographing unit 106 and the like. It is formed so that the opening area is wider than that of the above.

Under such a configuration, when a gas is flowed through the flow path 111 and the gas is discharged from the exhaust holes 112 and 113, the gas is flowed through the flow path 111 in a laminar flow state and is flown from the exhaust holes 112 and 113, respectively. It is necessary to discharge the 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 portion 104), a backflow T of gas is more likely to occur when the gas is discharged. The backflow T of gas may collide with the second permeation portion 104 while entraining suspended matter such as dust, and in that case, the effect of flowing gas through the flow path 111 (suspended matter purging effect) is appropriately obtained. There is a risk that suspended matter will adhere to the second permeation portion 104 without being able to do so.

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 a backflow of the gas when the gas is discharged 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 object to be measured with light from the irradiation unit, photographs the light reflected by the object to be measured by the photographing unit, and photographs the object to be measured. A distance measuring device for measuring a distance to a gas, which is formed on a housing accommodating the irradiation unit and the photographing unit and an outer wall surface of the housing, and transmits light emitted from the irradiation unit. A transmission portion, a second transmission portion formed on the outer wall surface of the housing and transmitting light photographed by the photographing unit, and an outer wall surface of the housing provided around the outer wall surface of the housing. Of these, a flow path forming member that forms a flow path for flowing a gas along the surface on which the first permeation portion and the second permeation portion are formed, and the first permeation portion in the flow path forming member. A first exhaust hole formed at a facing position and a second exhaust hole formed at a position facing the second transmission portion in the flow path forming member and having a wider opening area than the first exhaust hole. The flow path has a first flow path portion adjacent to the first exhaust hole and a gas that deviates from the first exhaust hole and passes through the first flow path portion to flow toward the second exhaust hole. It is characterized by including a second flow path portion of the above.

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 portion in the flow path forming member, and the second exhaust hole is formed at a position facing the second transmission portion. Is formed. Further, 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 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. A flow path portion and is provided. That is, the gas flowing through the first flow path portion is divided into a portion discharged from the first exhaust hole and a portion flowing through the second flow path portion, and the gas flowing through the second flow path portion is separated from the second exhaust hole. It is discharged. In this way, by lengthening the distance (stroke) through which the gas discharged from the second exhaust hole having a larger opening area flows in the flow path, the gas flow is adjusted (rectified) and the second exhaust hole is arranged. It is possible to prevent the gas from being expelled vigorously. As a result, it is possible to suppress the backflow of gas at the second exhaust hole where the backflow of airflow is likely to occur.
For the reasons described above, in the distance measuring device of the present invention, the gas flow in the flow path is adjusted (rectified), and the adhesion of suspended matter in the second permeation portion is effectively suppressed. It becomes possible.

Further, in the distance measuring device, it is preferable that the second flow path portion is located on the downstream side of the first flow path portion in the flow path.
According to the above configuration, since the second flow path portion is located on the downstream side of the first flow path portion, it is possible to appropriately suppress the backflow of the air flow in the second exhaust hole.

Further, in the distance measuring device, the outer wall surface of the housing has 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 a gas into the flow path, and the flow path is continuous with the blowing hole and adjacent to the second surface. It is preferable to include a three flow path portion and a fourth flow path portion for flowing a gas that has passed through the third flow path portion.
In such a configuration, it is even more preferable that the blow hole is provided in the 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, of the outer wall surface of the housing, the surface on which the first permeation portion and the second permeation portion are formed (first surface). It collides with a different surface (second surface). After that, the gas flows through the fourth flow path portion in the flow path. This makes it possible to prevent the gas blown through the blow holes from being directly blown to the first permeation portion and the second permeation portion. As a result, it is possible to prevent the first permeation portion and the second permeation portion from being damaged by the collision with the gas containing fine suspended matter.

Further, in the distance measuring device, the flow path forming member is formed in a space between the first exhaust hole and the bottom wall on which the second exhaust hole is formed, and the first surface and the bottom wall. A partition wall arranged along the first surface, and a portion of the flow path partitioned by the partition wall, which is closer to the first surface, constitutes the fourth flow path portion, and the bottom thereof. A portion closer to the wall constitutes the first flow path portion and the second flow path portion, and the partition wall has a first through hole formed at a position facing the first transmission portion and the first exhaust hole. It is preferable that the second through hole and the second through hole formed at a position facing the second transmission hole and the second exhaust hole are provided.
According to the above configuration, since the flow path has a two-layer structure, it is possible to secure a flow path having a sufficient length for adjusting (rectifying) the gas flow while suppressing an increase in the size of the device. It becomes.

Further, in the distance measuring device, the first surface is a surface extending 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. It is preferable that the first exhaust hole is provided at a position farther from the blow hole than the second exhaust hole in the longitudinal direction.
According to the above configuration, the first exhaust hole is provided at a position farther from the blow hole than the second exhaust hole. With such a positional relationship, the length of the flow path from the blow hole to the second exhaust hole can be secured longer. As a result, it becomes easier to regulate (rectify) the gas flow in the second exhaust hole.

Further, in the distance measuring device, the fourth flow path portion surrounds the second transmission portion and the adjacent region adjacent to the second through hole in the fourth flow path portion, and the adjacent region is the said. It is preferable that a separating member is provided in the fourth flow path portion from a region other than the adjacent portion.
According to the above configuration, in the fourth flow path portion, the second transmission portion and the adjacent region adjacent to the second through hole are separated from the surrounding region. Therefore, it is possible to prevent the gas from being discharged directly from the fourth flow path portion through the second through hole and from the second exhaust hole while the gas is flowing through the fourth flow path portion. ..

Further, in the distance measuring device, the partition wall communicates the fourth flow path portion and the second flow path portion at a position between the first through hole and the second through hole. It is preferable that the communication portion formed for the purpose is provided.
According to the above configuration, a part of the gas flowing through the fourth flow path portion enters the second flow path portion through the communication portion. The gas that has flowed through the second flow path portion through the communication portion flows toward the second exhaust hole or toward the first exhaust hole. As a result, even when the gas is vigorously discharged from the first exhaust hole, it is possible to suppress the backflow of the gas in the first exhaust hole.

Further, 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 the above configuration, a through hole can be formed as a communication portion by utilizing the space between the first through hole and the second through hole, and the communication portion can be easily provided.

Further, in the above distance measuring device, it is preferable that the opening area of the communication portion is smaller than the opening area of the first through hole.
According to the above configuration, the amount of gas passing through the first through hole is smaller than the amount of gas passing through the communication portion. That is, most of the gas flowing in the fourth flow path portion is flowed from the first through hole to the first flow path portion, and only a part of the gas is flowed from the communication portion to the second flow path portion. As a result, it is possible to secure the amount of gas flowing in each of the first flow path portion and the second flow path portion while suppressing the backflow of gas in the first exhaust hole.

Further, in the distance measuring device, the irradiation unit irradiates the object to be measured with slit-shaped light, and the first transmitting portion and the first exhaust hole are directed in the direction in which the slit-shaped light extends. It may be formed long along the line.
In the above configuration, the first transmission portion and the first exhaust hole can be appropriately shaped in accordance with the irradiation portion irradiating the slit-shaped light.

According to the present invention, it is possible to arrange (rectify) the flow of gas in the flow path and effectively suppress the adhesion of suspended matter in the second permeation portion. This makes it possible to accurately measure the distance to the object to be measured even in an environment where suspended matter exists.

It is a perspective view which shows the appearance of the distance measuring apparatus which concerns on one Embodiment of this invention. It is explanatory drawing of the distance measuring method by the distance measuring apparatus which concerns on one Embodiment of this invention. It is a figure which shows the housing which the distance measuring apparatus which concerns on one Embodiment of this invention has, and the irradiation part and the photographing part housed in the housing. It is a figure which shows the lower surface of the housing which the distance measuring apparatus which concerns on one Embodiment of this invention has. It is a schematic cross-sectional view which shows the structure of the distance measuring apparatus which concerns on one Embodiment of this invention. FIG. 5 is a view of the AA cross section of FIG. 5 viewed from the direction of the arrow. It is a figure which looked at the BB cross section of FIG. 5 from the direction of an arrow. FIG. 5 is a view of the CC cross section of FIG. 5 viewed from the direction of the arrow. It is a figure which shows the flow of a gas in a flow path. It is a schematic cross-sectional view which shows the structure of the distance measuring apparatus which concerns on a reference example. It is a figure which shows the lower surface of the housing which the distance measuring apparatus which concerns on the modification of this invention has. It is a schematic cross-sectional view which shows the structure of the distance measuring apparatus which concerns on the modification of this invention. It is a schematic cross-sectional view which shows the structure of the distance measuring apparatus which concerns on a comparative example.

Hereinafter, the configuration of the distance measuring device according to the embodiment of the present invention (the present embodiment) will be described in detail with reference to the attached drawings. Although the embodiments described below are preferred embodiments of the present invention, they are merely examples and do not limit the present invention. That is, the present invention can be modified and improved without deviating from the gist thereof, and it goes without saying that the present invention includes an equivalent thereof.

In the following, unless otherwise specified, it is assumed that the distance measuring device is placed on a horizontal plane, and the positions and postures of each part of the device in such a state will be described.
Further, in the following, the three axes orthogonal to each other will be referred to as the X-axis, the Y-axis and the Z-axis, and the directions in which the respective axes extend will be referred to as the X-axis direction, the Y-axis direction and the Z-axis direction. Further, 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 the distance measuring device according to this embodiment >>
First, an outline of the distance measuring device (hereinafter, distance measuring device 1) according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view showing the appearance of the distance measuring device 1. FIG. 2 is an explanatory diagram of a distance measuring method using the distance measuring device 1. FIG. 3 is a diagram showing a housing 2 included in the distance measuring device 1, an irradiation unit 3 and a photographing unit 4 housed in the housing 2. FIG. 4 is a diagram showing the lower surface of the housing 2. In each of FIGS. 1, 3 and 4, the directions that can be illustrated in each 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 object to be measured W by using the optical cutting method, and has the appearance shown in FIG. The distance measuring device 1 has an irradiation unit 3 and an imaging unit 4 shown in FIGS. 2 and 3, and the irradiation unit 3 irradiates the object to be measured W with light, and the light reflected by the object W to be measured is photographed. The distance to the object to be measured W is measured by taking a picture with the part 4.

Then, by measuring the distance to the object to be measured W using the distance measuring device 1, it is possible to detect a defect on the surface of the object to be measured W. Specifically, the irradiation unit 3 includes a known laser light irradiation device, and as shown in FIG. 2, irradiates the surface of the object to be measured W with slit-shaped light. The slit-shaped light is light extending 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 Sensor) image sensor, and photographs the light reflected on the surface of the object W to be measured. According to the captured image of the photographing unit 4, the difference in the incident angle (reflection angle) of the light corresponding to the unevenness Wk (for example, a flaw or the like) formed on the surface of the object to be measured W is detected, and the principle of triangulation is used. By applying it, it is possible to convert the difference in incident angle into a distance. Then, based on the calculated distance, a flaw on the surface of the object to be measured W is detected.

The distance measuring device 1 adopts a structure that can be used in an environment where suspended matter such as dust and dirt is present. More specifically, the above-mentioned irradiation unit 3 and imaging unit 4 are housed in a box-shaped housing 2 as shown in FIG. The housing 2 has a rectangular lower surface 5 shown in FIG. 4 and a side surface 8 that rises substantially vertically from the edge of the lower surface 5. Here, the lower surface 5 of the housing 2 corresponds to the first surface of the outer wall surface of the housing 2, and is a surface that extends 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 different from the lower surface 5 which is the first surface.

Further, as shown in FIG. 4, two light transmitting portions through which light can be transmitted are formed on the lower surface 5 of the housing 2. One of them is the first transmitting unit 6 through which the slit-shaped light emitted from the irradiation unit 3 is transmitted. The first transmission portion 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). The other light transmitting unit is the second transmitting unit 7 through which the light (reflected light) photographed by the photographing unit 4 is transmitted. The second transmission portion 7 is a rectangular region longer than the first transmission portion 6 in the Y-axis direction. Further, the area of the second transmission portion 7 is larger than the area of the first transmission portion 6. Further, the first transmission portion 6 and the second transmission portion 7 are arranged at intervals in the Y-axis direction, the first transmission portion 6 is formed on the front side, and the second transmission portion 7 is formed on the rear side. Has been done.

As described above, in the present embodiment, by providing the first transmitting portion 6 and the second transmitting portion 7 on the lower surface 5 of the housing 2, light can be allowed to flow between the inside and the outside of the housing 2. At the same time, it prevents floating objects from entering the housing 2. The first transmission portion 6 and the second transmission portion 7 have an opening formed on the lower surface 5 of the housing 2 and a surface of transparent glass that closes the opening (strictly speaking, the surface of the glass faces downward. It consists of the side that was.

However, even if the first transmission portion 6 and the second transmission portion 7 are provided on the lower surface 5 of the housing 2, the first transmission portion 6 and the second transmission portion 6 are provided in an environment where suspended matter such as dust and dirt is present. If the distance measuring device 1 is used with the 7 exposed, suspended matter adheres to the first transmission portion 6 and the second transmission portion 7. Such adhesion of suspended matter affects the accuracy of distance measurement by the distance measuring device 1.

As a measure to suppress the adhesion of suspended matter in the first permeation part 6 and the second permeation part 7, a dust removing gas is flowed around each of the first permeation part 6 and the second permeation part 7 to purge. Can be considered. However, when a gas for dust removal is flowed around each of the first permeation section 6 and the second permeation section 7, if the gas is directly blown onto the first permeation section 6 and the second permeation section 7, the flow velocity of the gas is high. May be relatively large. In such a case, when the gas entrains suspended matter such as dust and dust around the gas and the gas containing the suspended matter collides with the first permeated portion 6 and the second permeated portion 7, the first permeated portion 6 and the second permeated portion 6 and the second (2) There is a possibility of damaging the transmission portion 7. Further, when the first transmission portion 6 and the second transmission portion 7 are scratched, the suspended matter enters the inside of the scratch and adheres to the first transmission portion 6 and the second transmission portion 7, so that the floating matter 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, and a gas is allowed to flow in the flow path formed by the flow path forming member 10, and the gas flow thereof. Is used to clarify the periphery of the first transmission portion 6 and the second transmission portion 7. Further, in the present embodiment, by adjusting (rectifying) the flow of gas around the first permeation portion 6 and the second permeation portion 7, the gas containing suspended matter and the first permeation portion 6 and the second permeation portion 6 and the second permeation The collision with the part 7 and the trouble caused by the collision are solved.
Hereinafter, the flow path forming member 10 and the flow path of the gas 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 an I-I cross section of FIG. FIG. 6 is a view of the cross section taken along the line AA of FIG. 5 as viewed from the direction of the arrow. FIG. 7 is a view of the BB cross section of FIG. 5 as viewed from the direction of the arrow. FIG. 8 is a view of the CC cross section of FIG. 5 as viewed from the direction of the arrow. In each of FIGS. 5 to 8, the directions that can be illustrated among the X-axis direction, the Y-axis direction, and the Z-axis direction are indicated by arrows. Further, in FIGS. 5 and 6, the structure inside the housing 2 is shown in a simplified manner, and the equipment housed in the housing 2 such as the irradiation unit 3 and the photographing unit 4 is not shown.

The flow path forming member 10 forms a flow path R for flowing a gas along the lower surface 5 (the surface on which the first transmission portion 6 and the second transmission portion 7 are formed) of the housing 2, and is made of aluminum. It is composed of a box-shaped body formed by processing a metal plate 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, as shown in FIG. 1, is provided so as to surround the lower half of the housing 2. Has been done.

As shown in FIGS. 1 and 5, the flow path forming member 10 has a bottom wall 11, a side wall 12, and a ceiling wall 13. The bottom wall 11 is along the lower surface 5 of the housing 2 as shown in FIG. 5 in a state where 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 is provided with two exhaust holes. One of the exhaust holes is the 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 portion 6" means a state in which the first transmission portion 6 is located at a position overlapping the first transmission portion 6 in the Z-axis direction and faces the first exhaust hole 16. .. The first exhaust hole 16 is a rectangular hole whose opening has the same area and shape as the first transmission portion 6. Further, the first exhaust hole 16 is not only an exhaust hole for the gas flowing in the flow path R but also a hole for passing the slit-shaped light irradiated by the irradiation unit 3. Therefore, as shown in FIG. 8, the first exhaust hole 16 is formed long along the direction in which the slit-shaped light extends (that is, the X-axis direction).

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 portion 7" means a state in which the second transmission portion 7 is located at a position overlapping the second transmission portion 7 in the Z-axis direction and faces the second exhaust hole 17. .. The second exhaust hole 17 is a rectangular hole, the opening thereof has the same shape as the second transmission portion 7, and the size (opening area) thereof is the same as or one size larger than that of the second transmission portion 7. .. Further, the second exhaust hole 17 is not only an exhaust hole for gas flowing in the flow path R but also a hole for passing light (reflected light) photographed by the photographing unit 4. Therefore, as shown in FIG. 8, the opening area of the second exhaust hole 17 is wider 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.

Further, 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, the first exhaust hole 16 and the second exhaust hole 17 are arranged at intervals in the Y-axis direction as shown in FIG. 8, and the first exhaust hole 16 is formed on the front side, and the first exhaust hole 16 is formed on the front side. (Ii) The exhaust hole 17 is formed on the rear side. The distance between the first exhaust hole 16 and the second exhaust hole 17 corresponds to the distance between the first transmission portion 6 and the second transmission portion 7 (strictly speaking, substantially the same).

The side wall 12 rises substantially vertically from the outer edge of the bottom wall 11, and is arranged in the front-rear and left-right sides of the housing 2 in a state where 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 arranged at a position of the side surface 8 of the housing 2 facing the corresponding surface. 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 located above the lower surface 5 of the housing 2. doing.

Further, of the four side walls 12, the side wall 12 (the side wall 12 shown on the right side of the paper in FIG. 5) located on the rear side in the Y-axis direction is blown to blow gas into the flow path R. A hole 15 is provided. The blow hole 15 is a round hole, and is a side wall 8 of the housing 2 located on the rear side in the Y-axis direction (the side wall 12 shown on the right side in the paper surface in FIG. 5) among the side walls 12 described above. It is formed in the opposite portion. Further, as shown in FIG. 5, the blow hole 15 is formed at a position above the lower surface 5 of the housing 2. Further, the blow hole 15 is farther 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 blow hole 15 than the second exhaust hole 17 in the Y-axis direction.

Further, 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 project to the outside of the side wall 12. A gas supply source (not shown) including a cylinder or a compressor is connected to the nozzle portion 14 via a tube or the like. Then, 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. As the gas to be supplied, it is possible to use a compressed gas such as air, nitrogen and other inert gas.

The ceiling wall 13 rests on the upper end of each of the four side walls 12, and a rectangular fitting hole is formed in the central portion thereof. The housing 2 is fitted into the fitting hole. The outer wall surface (specifically, the side surface 8) of the housing 2 is 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.

Further, the flow path forming member 10 has a partition wall 18 shown 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 material in a plan view arranged along the lower surface 5 of the housing 2 in order to partition the flow path R, and its four sides are respectively on the inner wall surface of the corresponding side wall 12. I'm in contact. By arranging the partition wall 18, the flow path R is divided into two layers in the Z-axis direction. That is, the flow path R according to the present embodiment is a flow path 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 the 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 portion 6. Further, the first through hole 19 is a hole formed for allowing the first transmission portion 6 to face the first exhaust hole 16 and for passing the slit-shaped light emitted by the irradiation portion 3. Therefore, as shown in FIG. 7, the first through hole 19 is formed long along the direction in which the slit-shaped light extends (that is, the X-axis direction).

As shown in FIG. 5, the second through hole is a second through hole 20 formed at a position facing both the second transmission portion 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 equal to or larger than the size of the second transmission portion 7 and smaller than or equal to the size of the second exhaust hole 17. Further, the second through hole 20 is a hole formed so that the second transmission portion 7 faces the second exhaust hole 17 and the light (reflected light) photographed by the photographing unit 4 passes through. Therefore, as shown in FIG. 7, the opening area of the second through hole 20 is wider 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.

Further, 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, the first through hole 19 and the second through hole 20 are arranged at intervals in the Y-axis direction as shown in FIG. 7, and the first through hole 19 is formed on the front side, and the first through hole 19 is formed. The two through holes 20 are formed on the rear side. The distance between the first through hole 19 and the second through hole 20 corresponds to the distance between the first transmission portion 6 and the second transmission portion 7 (strictly speaking, substantially the same).

In the present embodiment, the first transmission portion 6 and the openings of the first exhaust hole 16 and the first through hole 19 have the same shape and size, and are in the X-axis direction and the Y-axis direction. Are provided at the same position as each other. Further, the second transmission portion 7 and the openings of the second exhaust hole 17 and the second through hole 20 have the same shape as each other, and are provided at substantially the same positions in the X-axis direction and the Y-axis direction. ing. By the way, the size (opening area) of the second through hole 20 is larger than the size of the second transmission portion 7, and the size of the second exhaust hole 17 is larger than the size of the second through hole 20. There is.

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 portion 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 inside both ends of the first through hole 19 in the X-axis direction.

Further, in the upper layer of the flow path R, a square tubular sealing material 21 is arranged around the edge of the second through hole 20 as shown in FIGS. 5 and 7. The sealing material 21 corresponds to a separating member, and in the upper layer of the flow path R (in other words, the fourth flow path portion R4 described later), the second transmission portion 7 and the adjacent region Rx adjacent to the second through hole 20 are formed. It is separated from the portion other than the adjacent region Rx. The sealing material 21 is formed by molding a sealing member such as rubber into a square cylinder shape. The sealing material 21 is arranged 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. There is. As a result, 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 to allow light (reflected light) photographed by the photographing unit 4 to pass through, and this cavity is straight along the Z-axis direction as shown in FIG. The opening has the same shape and area as the opening of the second through hole 20.

Although the configuration of the flow path forming member 10 has been described above, 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 portion close to the lower surface 5 of the housing 2) and a lower layer (a portion 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 composed of a space surrounded by a lower surface 5 and a side surface 8 of the housing 2, a side wall 12 of the flow path forming member 10, a ceiling wall 13, and a partition wall 18. The lower layer of the flow path R is composed of a space surrounded by a bottom wall 11, a side wall 12, and a 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 through which the gas that has passed through the first through hole 19 flows immediately after that. The second flow path portion R2 is a flow path portion for allowing the gas that has deviated from the first exhaust hole 16 and passed through the first flow path portion R1 to flow toward the second exhaust hole 17, and is more than the first flow path portion R1. It is located on the downstream side. The gas flowing through the first flow path portion R1 is discharged from the first exhaust hole 16 to the outside of the flow path R, 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 and 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 shown in FIG. Here, the gas introduction space is provided between the side wall 12 provided with the blow hole 15 and the side surface 8 of the housing 2 facing the side wall 12 among the side walls 12 of the flow path forming member 10. It is a space. The third flow path portion R3 is a flow path portion continuous with the blow 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 between the side wall 12 of the flow path forming member 10 and the side surface 8 of the housing 2 (excluding the gas introduction space). The space between the lower surface 5 of the housing 2 and the partition wall 18 constitutes the fourth flow path portion R4 shown in FIG. The fourth flow path portion R4 is a portion in the flow path R through which the gas passing 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 through hole portion R1. On the other hand, the above-mentioned sealing material 21 is arranged in the fourth flow path portion R4 to surround the adjacent region Rx. Therefore, as shown in FIG. 7, the gas in the region other than the adjacent region Rx in the fourth flow path portion R4 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 R4 passes through the communication portion 22 and the second flow path. It comes to enter the part R2. That is, the communication portion 22 communicates the fourth flow path portion R4 and the second flow path portion R2.

<< About gas flow in the flow path >>
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 showing the flow of gas in the flow path. In FIG. 9, the Y-axis direction and the Z-axis direction that can be illustrated in the figure are indicated by arrows. Further, in FIGS. 6 to 9, the gas flow is illustrated by a thick arrow.

The gas supplied from the gas supply source is blown into the flow path R through the nozzle portion 14 and the blowing hole 15. As shown in FIG. 6, the gas blown into the flow path R collides with the side surface 8 of the outer wall surface of the housing 2 at a position facing the blow hole 15. As described above, in the present embodiment, the gas is not directly applied to the lower surface 5 of the housing 2 in which the first permeation portion 6 and the second permeation portion 7 are formed. It suppresses the damage of the first transmission portion 6 and the second transmission portion 7. Further, by colliding the gas with the side surface 8 of the housing 2, the flow of the gas can be slowed down.

The gas that has collided 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. 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 when it reaches the end in the X-axis direction of the third flow path portion R3, the fourth flow path portion R4 Enter into. 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 located at both ends of the housing 2 in the X-axis direction. It flows. That is, the gas that has flowed 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 portion of the fourth flow path portion R4 in the Y-axis direction, and the first through hole 19 (That is, in the direction indicated by the arrow Q1 in FIG. 7), the gas flows 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, enters the space between the lower surface 5 of the housing 2 and the partition wall 18, and enters the space between the lower surface 5 and the partition wall 18 in the Y-axis direction. It flows forward toward the first through hole 19 (that is, in the direction indicated by the arrow Q2 in FIG. 7) in the fourth flow path portion R4.

Immediately after that, the gas that has reached the position in front of the first through hole 19 passes through the position directly below the first transmission portion 6, changes the direction of the flow 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 permeation portion 6 (particularly, the position directly below the first permeation portion 6) to prevent dust and suspended matter such as dust from entering the periphery of the first permeation portion 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, and then a part of the gas flows from the first exhaust hole 16 to the outside of the flow path R. Is discharged to. At this time, the gas has flowed a sufficient distance (stroke) in the meantime, 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 not discharged from the first exhaust hole 16 changes the direction of the flow again by approximately 90 degrees and flows in the second flow path portion R2 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 deviating from the first exhaust hole 16 in the first flow path portion R1 flows through the second flow path portion R2 so as to fold back in the Y-axis direction.

As shown in FIGS. 8 and 9, the gas flowing through the second flow path portion R2 changes the direction of the flow again by approximately 90 degrees at the second exhaust hole 17 located at the end of the second flow path portion R2. (Ii) The gas is discharged from the exhaust hole 17 to the outside of the flow path R. At this time, the gas is discharged from the second exhaust hole 17 while entraining the air around the second permeation portion 7 (strictly speaking, the air in the adjacent region Rx). As a result, the periphery of the second transmission portion 7 (particularly, the position directly below the second transmission portion 7) is purged, and the intrusion of suspended matter such as dust and dirt into the periphery of the second transmission portion 7 is prevented.

As described above, in the present embodiment, the gas that is 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 in the meantime. After flowing a long distance (stroke), it is discharged from the second exhaust hole 17. Therefore, the gas flow at the time of flowing through the second flow path portion R2 is sufficiently regulated (rectified). As a result, the flow of gas in the flow path R can be adjusted (rectified), and the gas can be suppressed from being vigorously discharged from the second exhaust hole 17 having a wider opening area. As a result, it is possible to suppress the backflow of gas at the second exhaust hole 17 where the airflow tends to flow back because the opening area is larger.

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 with suspended matter such as dust comes into contact with the second permeation portion 7. As a result, there is a risk that suspended matter will adhere to the second permeation portion 7. In the present embodiment, it is possible to appropriately flow the gas into the flow path R while avoiding such a problem.

Further, the above effect is more remarkable by providing the blow hole 15 at a suitable position in relation to the first exhaust hole 16 and the second exhaust hole 17. More specifically, in the present embodiment, as described above, the first exhaust hole 16 is provided at a position farther from the blow 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, on the left side wall 12 in FIG. 5). The stroke of gas flowing from the blow hole 15 to the first exhaust hole 16 is longer than that (when the blow hole 15 is formed). Therefore, the stroke of gas flowing from the blow hole 15 to the second exhaust hole 17 is also longer. As a result, it becomes easier to arrange (rectify) the gas flow in the second exhaust hole 17, and it becomes easier to avoid the backflow of the gas in the second exhaust hole 17 and the troubles 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 speaking, 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) of 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. As a result, even when the gas is vigorously discharged from the first exhaust hole 16, it is possible to suppress the backflow of the gas in the first exhaust hole 16.

Specifically, when the gas is vigorously discharged from the first exhaust hole 16, the air around the first exhaust hole 16 is sucked in. At this time, when the air outside the distance measuring device 1 is sucked in, a backflow of gas (air) occurs in the first exhaust hole 16, and a problem similar to the above-mentioned problem, that is, a suspended substance such as dust is involved. However, there is a risk that the gas may come into contact with the first permeation portion 6 and cause a problem of adhering suspended matter to the first permeation portion 6.
On the other hand, in the present embodiment, when the gas is vigorously discharged from the first exhaust hole 16, as shown in FIG. 5, the gas that has passed through the communication portion 22 and entered the second flow path portion R2 ( The detour airflow V) in FIG. 5 is sucked in. As a result, it is possible to avoid the generation of backflow of gas (air) in the first exhaust hole 16 and the above-mentioned trouble caused by this without sucking the air outside the distance measuring device 1. is there.

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

Further, in the present embodiment, the flow path R is divided 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 flow path having a two-layer structure having a folded back, and constitutes a more compact flow path.
More specifically, as a configuration capable of rectifying the flow of gas, as shown in FIG. 10, a flow path R having a single-layer structure without folding back can be considered. FIG. 10 is a schematic cross-sectional view showing the configuration of the distance measuring device 1X according to the reference example.
The distance measuring device 1X shown in FIG. 10 is common to the distance measuring device 1 according to the present embodiment (that is, the distance measuring device 1 shown in FIG. 5) except that the flow path R does not have a two-layer structure. The parts having the same function are designated by the same reference numerals as those shown in FIG.

When the distance measuring device 1X shown in FIG. 10 is used, in order to adjust (rectify) the gas flow in the first exhaust hole 16 and the second exhaust hole 17, the blow holes 15 to the first exhaust hole 16 are used. It is necessary to secure a sufficient distance (distance with 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 folding back.
On the other hand, in the distance measuring device 1 of the present embodiment shown in FIG. 5, since the flow path R is folded back, the flow path R having the same length as the distance measuring device 1X shown in FIG. 10 is provided. 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 having a sufficient length for adjusting (rectifying) the gas flow while suppressing an increase in the size of the device. is there.

<< Other Embodiments >>
The embodiments described above 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 has a rectangular shape as shown in FIG. 4, but the present invention is not limited to this. The outer shape of the lower surface 5 of the housing 2 may change depending on the number, size, arrangement position, etc. of the irradiation unit 3 and the photographing unit 4 housed in the housing 2, and for example, the irradiation unit 3 may change. When a plurality of units are arranged in the X-axis direction, the outer shape of the lower surface 5 may be a T-shape as shown in FIG. FIG. 11 is a diagram showing the lower surface 5 of the housing 2 included in the distance measuring device according to the modified example of the present invention.

Further, in the above-described embodiment, in order to divert the gas flowing through the fourth flow path portion R4 to the second flow path portion R2, the partition wall 18 is provided with a through hole as the communication portion 22. However, the communication portion 22 is not limited to the through hole, and may be, for example, a notch formed by cutting out a part of the outer edge portion of the partition wall 18 in a semicircular shape or a V shape. ..

Further, in the above-described embodiment, the blow hole 15 is provided in the portion of the flow path forming member 10 facing the side surface 8 of the housing 2 (specifically, the side wall 12), and the blow hole 15 is provided. It was decided that gas would be blown from the side through. However, the present invention is not limited to this, and as shown in FIG. 12, a blow hole 15 is formed in a portion of the ceiling wall 13 of the flow path forming member 10 adjacent to the side surface 8 of the housing 2, and the blow hole 15 is formed. Gas may be blown vertically through the holes 15. Note that FIG. 12 is a schematic cross-sectional view showing the configuration of the distance measuring device according to the modified example of the present invention, and is a diagram corresponding to FIG.
Further, although not particularly shown, a blow hole 15 is provided in the side wall 12 located on the front side in the paper surfaces of FIGS. 5 and 12, and the blow hole 15 penetrates the paper surfaces of FIGS. 5 and 12. Gas may be blown in the direction.

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

Further, in the above embodiment, the distance measuring device of the method of measuring the distance to the object to be measured W by using the optical cutting method has been described as an example, but the distance to the object to be measured W is reached by irradiating light and photographing. The present invention can be applied to a device (light wave rangefinder) that employs a measurement method other than the optical cutting method as long as it measures a distance.

1 Distance measuring device 1X Distance measuring device 2 Housing 3 Irradiating unit 4 Imaging unit 5 Bottom surface (first surface)
6 First transmission part 7 Second transmission part 8 Side surface (second surface)
10 Flow path forming member 11 Bottom wall 12 Side wall 13 Ceiling wall 14 Nozzle portion 15 Blow-in hole 16 First exhaust hole 17 Second exhaust hole 18 Partition wall 19 First through hole 20 Second through hole 21 Sealing material (separator member)
22 Communication part 100 Distance measuring device 101 Housing 102 Lower surface 103 First transmission part 104 Second transmission part 105 Irradiation part 106 Imaging part 111 Flow path 112, 113 Exhaust hole R Flow path R1 First flow path part R2 Second flow path part R3 Third flow path part R4 Fourth flow path part Rx Adjacent area T Backflow of airflow V Detour airflow W Measured object Wk Concavo-convexity

Claims (11)

A distance measuring device that irradiates an object to be measured with light from an irradiation unit, photographs the light reflected by the object to be measured by the photographing unit, and measures the distance to the object to be measured.
A housing for accommodating the irradiation unit and the photographing unit,
A first transmitting portion formed on the outer wall surface of the housing and transmitting light emitted from the irradiation portion, and a first transmitting portion.
A second transmitting portion formed on the outer wall surface of the housing and transmitting light photographed by the photographing portion, and a second transmitting portion.
A flow path is provided around the outer wall surface of the housing to allow gas to flow along the surfaces of the outer wall surface of the housing on which the first permeation portion and the second permeation portion are formed. Flow path forming member and
A first exhaust hole formed at a position facing the first transmission portion in the flow path forming member,
The flow path forming member has a second exhaust hole formed at a position facing the second transmission portion and having an opening area wider than that of the first exhaust hole.
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.
A blowing hole for blowing a gas into the flow path is provided so as to face the second surface.
The flow path is a second flow path portion adjacent to the first exhaust hole and a second flow path for allowing gas that has deviated from the first exhaust hole and passed through the first flow path portion to flow toward the second exhaust hole. A distance measuring device including a flow path portion. The distance measuring device according to claim 1, wherein in the flow path, the second flow path portion is located on the downstream side of the first flow path portion. Before Kiryuro forming member is provided with a front Ki吹inclusive hole,
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 or 2, further comprising a fourth flow path portion for flowing a gas that has passed through the third flow path portion. The distance measuring device according to claim 3, wherein the blow hole is provided in a portion of the flow path forming member facing the second surface. The flow path forming member is arranged along the first surface in the 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. With a compartment wall,
Of the flow paths partitioned by the partition wall, the portion closer to the first surface constitutes the fourth flow path portion, and the portion closer to the bottom wall is the first flow path portion and the second flow path portion. Configure and
The partition wall is formed with a first through hole formed at a position facing the first transmission portion and the first exhaust hole, and a position facing the second transmission portion 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 that extends long along the longitudinal direction of the first surface.
The first exhaust hole and the second exhaust hole are provided at different positions in the longitudinal direction.
The distance measuring device according to claim 5, wherein the first exhaust hole is provided at a position farther from the blow hole than the second exhaust hole in the longitudinal direction. The fourth flow path portion surrounds the second transmission portion in the fourth flow path portion and an adjacent region adjacent to the second through hole, and the adjacent region is the adjacent region in the fourth flow path portion. The distance measuring device according to claim 5 or 6, wherein a separating member is provided so as to be separated from an area other than the portion. The partition wall is provided with a communication portion formed to 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. The distance measuring device according to any one of claims 5 to 7. 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 the opening area of the communication portion is smaller than the opening area of the first through hole. The irradiation unit irradiates the object to be measured with slit-shaped light.
The distance measuring device according to any one of claims 1 to 10, wherein the first transmission portion and the first exhaust hole are formed long along the direction in which the slit-shaped light extends.

Images