Reflective mirror member, photoelectric sensor, and optical ranging device

Abstract

To provide a reflective mirror member which can be efficiently manufactured and is capable of appropriately reflecting light, and to provide a photoelectric sensor equipped with the same, and an optical ranging device.SOLUTION: A reflective mirror member provided herein comprises a resin layer and a reflective surface. The reflective surface is formed of a plating film on at least one surface of the resin layer. The one surface of the resin layer has a groove serving as a boundary definer, a first area provided inside the boundary definer, and a second area provided outside the boundary definer. The reflective surface includes a first reflective area formed on the first area and a second reflective area formed on the second area. Such an arrangement allows the flatness of the first reflective area to be smaller than that of the second reflective area.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a reflection mirror member, a photoelectric sensor including the same, and a light distance measuring device.

Background Art

[0002] In recent years, devices for detecting an object using laser light have been used in various fields. For example, the light distance measuring device disclosed in Patent Document 1 includes a photoelectric sensor and a light scanning unit. The light scanning unit includes a deflection mirror that deflects the measurement light output from the photoelectric sensor toward the monitoring area and guides the reflected light from the object to the photoelectric sensor, and a motor that rotationally drives the deflection mirror.

[0003] In the above light distance measuring device, the propagation time of light between the photoelectric sensor and the object is calculated from the output timing of the measurement light and the detection timing of the reflected light. Further, based on the propagation time and the speed of light, the distance from the photoelectric sensor to the object is calculated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventionally, when manufacturing a deflection mirror as described above, generally, a reflective surface for reflecting light is formed by depositing a metal thin film on the surface of a substrate by vapor deposition. By forming the reflective surface by vapor deposition, the flatness of the reflective surface can be increased. On the other hand, when forming the reflective surface by vapor deposition, there is a problem that it is difficult to improve the manufacturing efficiency.

[0006] Therefore, an example of the object of the present invention is to provide a reflection mirror member that can be efficiently manufactured and can appropriately reflect light, as well as a photoelectric sensor and a light distance measuring device including the same.

Means for Solving the Problems

[0007] (1) To achieve the above object, a reflection mirror member according to one aspect of the present invention includes a resin layer portion and a reflection surface formed by a plating film on at least one surface side of the resin layer portion. One surface of the resin layer portion has a boundary defining portion, a first region provided inside the boundary defining portion, and a second region provided outside the boundary defining portion. The boundary defining portion is a groove provided between the first region and the second region, or a wall surface that forms a step between the edge of the first region and the edge of the second region so that the edge of the first region is located outside the edge of the second region in the thickness direction of the resin layer portion.

[0008] In this reflection mirror member, the reflection surface is formed by a plating film. In this case, the reflection mirror member can be manufactured more efficiently than when the reflection surface is formed by vapor deposition. Further, when forming the plating film on one surface of the resin layer portion, it is possible to suppress the influence of the thickness of the plating film formed on the second region (the region outside the groove or the wall surface) on the thickness of the plating film formed on the first region (the region inside the groove or the wall surface). Thereby, the flatness of the surface (the first reflection region) of the plating film formed on the first region can be reduced, so that light can be appropriately reflected. Therefore, for example, in a photoelectric sensor, the detection accuracy of the photoelectric sensor can be improved by reflecting the measurement light by the first reflection region with a small flatness.

[0009] (2) In the reflecting mirror member of (1) above, the first region may be formed in a planar shape, and the second region may be formed to include a curved surface. In this case, while reducing the flatness of the surface (first reflection region) of the plating film formed on the first region, the surface (second reflection region) of the plating film formed on the second region can be surely formed in a curved surface shape. Thereby, while increasing the density of the measurement light irradiated to the object to be detected by reflecting the measurement light by the first reflection region, the reflected light from the object can be efficiently condensed by the second reflection region. As a result, the detection accuracy of the photoelectric sensor can be improved.

[0010] (3) In the reflecting mirror member of (1) or (2) above, the reflecting surface includes a first reflection region formed on the first region and a second reflection region formed on the second region, and the flatness of the first reflection region may be smaller than the flatness of the second reflection region.

[0011] In this case, while increasing the density of the measurement light irradiated to the object to be detected by reflecting the measurement light by the first reflection region, the reflected light from the object can be efficiently condensed by the second reflection region. As a result, the detection accuracy of the photoelectric sensor can be improved.

[0012] (4) In any of the reflecting mirror members of (1) to (3) above, the reflecting surface includes a first reflection region formed on the first region and a second reflection region formed on the second region, and the maximum value of the thickness of the plating film in the first reflection region may be smaller than the maximum value of the thickness of the plating film in the second reflection region.

[0013] In this reflecting mirror member, when forming the plating film, it is prevented that the thickness of the plating film formed on the first region is affected by the thickness of the plating film formed on the second region. In this case, since the flatness of the first reflection region of the plating film formed on the first region can be reduced, light can be appropriately reflected.

[0014] (5) Any of the reflecting mirror members (1) to (4) above is used in a photoelectric sensor that emits measurement light and receives reflected light from an object. The reflecting surface includes a first reflecting region formed on the first region and a second reflecting region formed on the second region. A support portion for supporting a guide member that guides the measurement light to the first reflecting region is formed in the resin layer portion. The support portion may support the guide member such that the guide member covers the boundary defining portion.

[0015] In this case, even if a groove or a wall surface is formed on the surface of the plating film by the boundary defining portion (groove or wall surface), the groove or the wall surface is covered by the guide member, so that it does not reflect the measurement light and the reflected light from the object. Therefore, it does not affect the detection accuracy of the photoelectric sensor.

[0016] (6) In any of the reflecting mirror members (1) to (5) above, the resin layer portion may have a first resin layer portion on which a plating film is formed, and a second resin layer portion that is made of a material different from that of the first resin layer portion and is integrally formed with the first resin layer portion by two-color molding on the other surface side where the plating film is not formed.

[0017] In this reflecting mirror member, for example, the first resin layer portion can be formed of a material having high affinity with the material of the plating film, and the second resin layer portion can be formed of a material having low affinity with the material of the plating film. Thereby, when the first resin layer portion and the second resin layer portion are immersed in the plating solution, it is possible to prevent a plating film from being formed on the surface of the second resin layer portion. In this case, masking can be omitted or simplified, so that the manufacturing efficiency of the reflecting mirror member is improved.

[0018] (7) The reflecting mirror member (6) above may further include a connecting portion that is integrally formed with the second resin layer portion and is connected to a driving portion that swings or rotates the reflecting mirror member. In this case, the reflecting mirror member can be swung or rotated by the driving portion via the connecting portion.

[0019] (8) The photoelectric sensor according to one aspect of the present invention includes a light projecting unit that emits measurement light, a light receiving unit that receives reflected light reaching from the measurement target space, a light deflecting unit that deflects the measurement light in a predetermined direction, and / or a light scanning unit that scans the measurement light in a predetermined direction, and the light deflecting unit or the light scanning unit includes any one of the reflecting mirror members of the above (1) to (7).

[0020] In this photoelectric sensor, the detection accuracy can be improved by reflecting the measurement light by a region with a small flatness (the plating film on the first region) on the reflecting surface of the reflecting mirror member.

[0021] (9) In the photoelectric sensor of the above (8), the reflecting surface includes a first reflecting region formed on the first region and a second reflecting region formed on the second region, and the measurement light is reflected by the first reflecting region of the reflecting surface of the reflecting mirror member and emitted into the measurement target space, and the reflected light from the measurement target space is reflected by the reflecting surface and received by the light receiving unit. It may be configured as such. In this case, an object in the measurement target space can be detected accurately.

[0022] (10) In the photoelectric sensor of the above (9), the reflecting surface of the reflecting mirror member may be formed such that the reflected light from the measurement target space reflected by the second reflecting region is received by the light receiving unit. In this case, an object in the measurement target space can be detected accurately.

[0023] (11) The optical distance measuring device according to one aspect of the present invention includes any one of the photoelectric sensors of the above (8) to (10), and a control unit that controls the light projecting unit and the light receiving unit, and the control unit calculates the distance to an object in the measurement target space based on the measurement light and the reflected light.

[0024] In this optical distance measuring device, an object in the measurement target space can be detected accurately by reflecting the measurement light by a region with a small flatness (the plating film on the first region) on the reflecting surface of the reflecting mirror member.

Effects of the Invention

[0025] According to the present invention, a reflection mirror member can be efficiently manufactured, and light can be appropriately reflected using the reflection mirror member.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0027] (First Embodiment) Hereinafter, a reflection mirror member according to the first embodiment of the present invention, a photoelectric sensor, and a distance measuring device including the same will be described with reference to the drawings.

[0028] (Configuration of the Distance Measuring Device) FIG. 1 is a schematic diagram showing the configuration of a distance measuring device 100 according to an embodiment of the present invention. As shown in FIG. 1, in this embodiment, the distance measuring device 100 is housed in a casing 102 including an optical window (not shown) through which light passes. The distance measuring device 100 includes a photoelectric sensor 10 and a control unit 12. The distance measuring device 100 is a device that detects an object in a predetermined monitoring area (measurement target space) and measures the distance to the object.

[0029]

[0030] The photoelectric sensor 10 includes a light projecting unit 14, a light projecting lens 16, a light scanning unit 18, a condenser lens 20, and a light receiving unit 22. Note that, since various known configurations of distance measuring devices can be used for the light projecting unit 14, the light projecting lens 16, the condenser lens 20, and the light receiving unit 22, they will be briefly described below. The light projecting unit 14 includes a light emitting element such as a laser diode and emits measurement light (laser light). The light projecting lens 16 shapes the measurement light emitted from the light projecting unit 14 into parallel light. Although details will be described later, the light scanning unit 18 deflects the measurement light shaped into parallel light by the light projecting lens 16 toward the monitoring area. Further, the light scanning unit 18 deflects the measurement light (reflected light) reflected by an object in the monitoring area toward the condenser lens 20. The condenser lens 20 condenses the reflected light deflected by the light scanning unit 18. The light receiving unit 22 includes a light receiving element such as an avalanche photodiode, receives the reflected light condensed by the condenser lens 20, and converts the light intensity of the received reflected light into an electrical signal.

[0031] The control unit 12 controls the light projecting unit 14 and the light receiving unit 22. In the present embodiment, the control unit 12, for example, pulse-drives the light emitting element of the light projecting unit 14 and controls the drive voltage of the light receiving element of the light receiving unit 22. Further, the control unit 12 has a distance measuring unit that calculates the distance between the optical distance measuring device 100 and an object in the monitoring area based on the time difference between the light projection time of the measurement light in the light projecting unit 14 and the light reception time of the reflected light in the light receiving unit 22. In the present embodiment, the distance measuring unit of the control unit 12 includes, for example, a TDC (time to digital converter) circuit, detects the flight time of light (the above time difference), and calculates the distance between the optical distance measuring device 100 and the object based on the detected flight time of light and the speed of light. Note that since the control unit 12 can utilize the configuration of a known optical distance measuring device using the TOF (Time of Flight) method, a detailed description thereof is omitted.

[0032] The light scanning unit 18 includes a reflection mirror member 30, a guide member 32, and a drive unit 34. FIG. 2 is a cross-sectional view showing the schematic structure of the reflection mirror member 30 and the guide member 32, and FIG. 3 is a schematic perspective view showing the reflection mirror member 30 (a view of the reflection mirror member 30 of FIG. 1 placed with the top and bottom reversed as seen obliquely from above). Further, FIG. 4 is a view of the reflection mirror member 30 placed with the top and bottom reversed as seen from the direction indicated by arrow A in FIG. 2, FIG. 5(a) is a schematic cross-sectional view showing the a-a portion of FIG. 4, and FIG. 5(b) is a schematic cross-sectional view showing the b-b portion of FIG. 4.

[0033] As shown in FIGS. 1 to 4, the reflection mirror member 30 includes a resin layer portion 36 and a connection portion 38. In the present embodiment, the resin layer portion 36 includes a first resin layer portion 40 and a second resin layer portion 42. In the present embodiment, the connection portion 38 is integrally formed with the resin layer portion 36 (more specifically, the second resin layer portion 42).

[0034] As shown in FIG. 5, a plating film 46 is formed on one surface 36a side in the thickness direction of the resin layer portion 36. In the present embodiment, one surface 36a is one surface on one side in the thickness direction of the first resin layer portion 40. That is, the plating film 46 is formed on the first resin layer portion 40. The plating film 46 is formed, for example, by electroplating. The second resin layer portion 42 is provided on the other surface 36b side in the thickness direction of the resin layer portion 36.

[0035] Note that FIG. 5 is a schematic diagram for explaining the positional relationship among the first resin layer portion 40, the second resin layer portion 42, and the plating film 46, and does not accurately represent the first resin layer portion 40, the second resin layer portion 42, and the plating film 46 according to actual dimensions. In FIG. 5, the plating film 46 is formed only on one surface on one side in the thickness direction of the first resin layer portion 40, but the plating film 46 may also be formed on the side surface of the first resin layer portion 40.

[0036] As shown in FIGS. 1 and 2, in the present embodiment, the surface 60 of the plating film 46 functions as a reflecting surface that reflects the measurement light emitted from the light projecting portion 14 and its reflected light. Hereinafter, the surface 60 of the plating film 46 will be referred to as the reflecting surface 60. As the material of the plating film 46, for example, copper, gold, nickel, or chromium is used. From the viewpoint of suppressing the manufacturing cost of the reflection mirror member 30, the plating film 46 is formed, for example, using copper.

[0037] The first resin layer portion 40 and the second resin layer portion 42 are made of different materials from each other. Also, the first resin layer portion 40 and the second resin layer portion 42 are integrally formed by two-color molding. In the present embodiment, the first resin layer portion 40 is made of a material having high affinity with the material of the plating film 46. Also, the second resin layer portion 42 is made of a material having lower affinity with the material of the plating film 46 than the first resin layer portion 40. Thereby, when the first resin layer portion 40 and the second resin layer portion 42 are immersed in the plating solution, it is possible to prevent a plating film from being formed on the surface of the second resin layer portion 42. In this case, masking can be omitted or simplified, so that the manufacturing efficiency of the reflective mirror member 30 is improved. In the present embodiment, for example, the first resin layer portion 40 is formed using an ABS (acrylonitrile butadiene styrene) resin, and the second resin layer portion 42 is formed using a PC (polycarbonate) resin.

[0038] FIG. 6 is a schematic view showing the second resin layer portion 42 and the connecting portion 38. As shown in FIG. 6, a plurality of recesses 42a and a plurality of support portions 42b are formed in the second resin layer portion 42. In the present embodiment, the recesses 42a and the support portions 42b are through-holes, respectively. As shown in FIG. 5, a plurality of convex portions 40a that fit into the plurality of recesses 42a are formed in the first resin layer portion 40. As shown in FIG. 4, in the present embodiment, the first resin layer portion 40 is formed on the second resin layer portion 42 so that the plurality of support portions 42b formed in the second resin layer portion 42 are exposed.

[0039] As shown in FIGS. 4 and 5(b), a groove 44 is formed in one surface 36a of the resin layer portion 36. As shown in FIG. 4, in the present embodiment, the groove 44 is formed in a frame shape (square annular shape) at the central portion of the resin layer portion 36. As shown in FIG. 5, one surface 36a of the resin layer portion 36 is partitioned by the groove 44 into a first region 48a inside the groove 44 and a second region 48b outside the groove 44. In the present embodiment, the groove 44 corresponds to the boundary defining portion.

[0040] In the present embodiment, when viewed from the thickness direction of the plating film 46, the region formed on the first region 48a among the reflecting surfaces 60 is defined as the first reflecting region 60a, and the region formed on the second region 48b is defined as the second reflecting region 60b. In the present embodiment, the second reflecting region 60b is arranged so as to surround the first reflecting region 60a.

[0041] Note that due to the characteristics of plating, when forming a plating film on the surface of a member, the thickness of the plating film on the central portion of the member becomes smaller, and the thickness of the plating film near the outer edge of the member becomes larger. Also in the present embodiment, the thickness of the plating film 46 on the central portion of the resin layer portion 36 is smaller than the thickness of the plating film 46 near the outer edge of the resin layer portion 36. Therefore, when the entire one surface 36a of the resin layer portion 36 is flat, as shown in Fig. 5(a), the plating film 46 is formed in a curved surface shape (concave surface shape) such that the thickness at the central portion is the smallest. Further, as shown in Fig. 11 to be described later, even when the entire resin layer portion 36 is thicker at its periphery than at its center (that is, even when one surface 36a of the resin layer portion 36 is concave as a whole with its central portion being recessed), the plating film 46 is formed in a curved surface shape such that the thickness at the central portion is the smallest.

[0042] However, in the present embodiment, a groove 44 is formed in the central portion of one surface 36a of the resin layer portion 36. In this case, when forming the plating film 46 on one surface 36a of the resin layer portion 36, it is possible to suppress the influence of the thickness of the plating film 46 formed on the second region 48b (the region outside the groove 44) on the thickness of the plating film 46 formed on the first region 48a (the region inside the groove 44). Thereby, the thickness of the plating film 46 formed on the first region 48a can be made substantially uniform. In the present embodiment, since the first region 48a is formed in a planar shape, the first reflecting region 60a on the first region 48a can also be formed in a planar shape. For this reason, in the present embodiment, the flatness of the first reflecting region 60a can be made smaller than the flatness of the second reflecting region 60b. Also, in the present embodiment, the maximum value of the thickness of the plating film 46 in the first reflecting region 60a can be made smaller than the maximum value of the thickness of the plating film 46 in the second reflecting region 60b.

[0043] In the thickness direction of the resin layer portion 36, the depth of the groove 44 is set to be, for example, 10 to 30 times the thickness of the plating film 46 (the thickness of the plating film 46 on the first region 48a). In the present embodiment, the thickness of the plating film 46 is, for example, 20 to 30 μm.

[0044] As shown in FIGS. 1 and 2, the guide member 32 is formed in a cylindrical shape so that measurement light can pass through the inside. In the present embodiment, the guide member 32 has a cylindrical portion 32a bent at a substantially right angle and a plurality of hook portions 32b for attaching the cylindrical portion 32a to the reflection mirror member 30. In the present embodiment, a plurality of hook portions 32b are provided on the guide member 32 so as to correspond to the plurality of support portions 42b (see FIG. 3) of the second resin layer portion 42. In the present embodiment, by hooking the plurality of hook portions 32b on the plurality of support portions 42b, the guide member 32 is supported by the second resin layer portion 42 of the reflection mirror member 30.

[0045] As shown in FIG. 2, an opening 32c is formed in a portion of the guide member 32 (cylindrical portion 32a) bent at a substantially right angle. In the present embodiment, the guide member 32 is supported by the second resin layer portion 42 so that the reflection surface 60 is exposed in the guide member 32 at the opening 32c. In FIG. 4, the position of the opening 32c on the reflection surface 60 is indicated by a dashed-dotted line. As shown in FIG. 4, in the present embodiment, the opening 32c is provided so as to be located inside the groove 44. That is, the first reflection region 60a is exposed in the guide member 32 at the opening 32c. In FIG. 2, the illustration of the groove 44 is omitted.

[0046] In the present embodiment, the guide member 32 is provided so as to cover the groove 44. Therefore, in the present embodiment, the portion of the plating film 46 above the groove 44 does not reflect the measurement light and the reflected light from the object. Therefore, even if grooves are formed on the surface of the plating film 46 by the grooves 44, it does not affect the detection accuracy of the photoelectric sensor 10.

[0047] As shown in FIG. 2, the measurement light that has passed through the projection lens 16 (see FIG. 1) and entered the guide member 32 from one end of the guide member 32 (cylindrical portion 32a) is guided to the first reflection region 60a by the guide member 32 (cylindrical portion 32a). The measurement light guided to the first reflection region 60a is deflected in the first reflection region 60a and then emitted from the other end of the guide member 32 (cylindrical portion 32a).

[0048] As shown in FIG. 1, the drive unit 34 is attached to the connection portion 38 of the reflection mirror member 30 and rotates the connection portion 38 around the rotation axis R. As a result, the reflection mirror member 30 rotates around the rotation axis R. In the present embodiment, the first reflection region 60a (see FIG. 2) is positioned on the rotation axis center of the reflection mirror member 30 (on the extension line of the rotation axis R). Note that the reflection surface 60 of the reflection mirror member 30 is provided so as to be inclined at 45° with respect to the rotation axis R. In the present embodiment, an electromagnetic motor is used as the drive unit 34, and the connection portion 38 is fixed to the rotor of the electromagnetic motor.

[0049] In the optical distance measuring device 100 according to the present embodiment, by rotating the reflection mirror member 30 by the drive unit 34 and emitting the measurement light from the light projection unit 14, the measurement light can be scanned in a predetermined monitoring region around the optical distance measuring device 100.

[0050] (Function and effect) In the reflection mirror member 30 according to the present embodiment, the reflection surface 60 is formed by the plating film 46. In this case, the reflection mirror member 30 can be manufactured more efficiently than in the case where the reflection surface is formed by vapor deposition.

[0051] Also, in the reflection mirror member 30 according to the present embodiment, one surface 36a of the resin layer portion 36 has a groove 44, a first region 48a provided inside the groove 44, and a second region 48b provided outside the groove 44. Thus, as described above, the flatness of the first reflection region 60a on the first region 48a can be made smaller than the flatness of the second reflection region 60b on the second region 48b. In the present embodiment, the measurement light is deflected by the first reflection region 60a with a small flatness, and the reflected light is deflected by the second reflection region 60b with a larger flatness than the first reflection region 60a.

[0052] Here, the flatness of the reflection surface 60 affects the parallelism of the light reflected by the reflection surface 60. In this regard, the distance between the first reflection region 60a and the object to be detected is long, for example, several meters to several tens of meters. Therefore, if the parallelism of the measurement light deflected by the first reflection region 60a is low, the density of the measurement light irradiated on the object to be detected becomes low. As a result, the measurement accuracy decreases.

[0053] On the other hand, since the reflected light reflected by the object to be detected is diffused light, the light density is low in the first place. Therefore, even when the flatness of the second reflection region 60b is relatively large, it does not significantly affect the light condensing amount of the condenser lens 20. In other words, even when the flatness of the second reflection region 60b is relatively large, a decrease in measurement accuracy is suppressed.

[0054] Therefore, in this embodiment, the measurement light is deflected by the first reflection region 60a with a small flatness, and the reflected light is deflected by the second reflection region 60b with a larger flatness than the first reflection region 60a. In this way, the measurement light and the reflected light can be appropriately reflected by the reflection mirror member 30. Of course, the reflected light may be deflected by the first reflection region 60a with a small flatness toward the condenser lens 20. It is only necessary to mainly deflect the reflected light by the second reflection region 60b so that it is received by the light receiving unit 22. In other words, the reflection surface 60 of the reflection mirror member 30 may be formed such that more of the reflected light from the measurement target space reflected by the second reflection region 60b is received by the light receiving unit 22 than the reflected light from the measurement target space reflected by the first reflection region 60a. In this embodiment, the reflection surface 60 is formed such that the measurement light emitted from the light projecting unit 14 is not reflected by the second reflection region 60b but only reflected by the first reflection region 60a.

[0055] Incidentally, the shorter the wavelength of the measurement light, the greater the influence of the flatness of the reflection surface 60 on the measurement accuracy. In other words, the shorter the wavelength of the measurement light (λ = 600 to 1550 nm. For example, in the case of this embodiment, it is 905 nm.), the more remarkable the above-described effect according to the present invention appears.

[0056] The flatness (PV: Peak to Valley) of the first reflection region 60a is preferably, for example, λ / 4 to λ / 2, and the flatness (PV: Peak to Valley) of the second reflection region 60b is preferably, for example, 2λ to 4λ (where λ represents the wavelength of the measurement light). The flatness can be measured using a three-dimensional optical profiler system (NewView6300) manufactured by Zygo Corporation and the attached analysis software (MetroPro) using the scanning white light interference method. The measurement conditions are LED wavelength: 380 to 780 μm (white), measurement area: 30 mm × 30 mm.

[0057] In this embodiment, the second reflection region 60b is provided so as to surround the first reflection region 60a. In this case, since it is easy to increase the area of the second reflection region 60b, the light collection amount of the condenser lens 20 can be improved.

[0058] In this embodiment, a support portion 42b for supporting the guide member 32 is formed in the second resin layer portion 42. In this case, it is not necessary to form a support portion (through hole) for supporting the guide member 32 in the first resin layer portion 40. Thereby, it is possible to prevent a weld line from being formed in the first resin layer portion 40 during the molding of the first resin layer portion 40. As a result, it is possible to prevent the flatness of the reflecting surface 60 formed on the first resin layer portion 40 from deteriorating due to the weld line.

[0059] Note that the shape of the groove 44 is not particularly limited. However, in order to make the shape of the reflecting surface 60 around the groove 44 a smooth shape, as shown in FIG. 7(a), a C surface 44a may be provided at the upper end portion of the groove 44, or as shown in FIG. 7(b), an R surface 44b may be provided at the upper end portion of the groove 44.

[0060] (Modification example) In the above-described embodiment, as shown in FIG. 4, the case where the rectangular groove 44 is formed so as to surround the opening 32c in the guide member 32 when viewed from the thickness direction of the plating film 46 has been described. However, the shape of the groove 44 is not limited to the above example. For example, as shown in FIG. 8, an elliptical or circular groove 44 may be formed when viewed from the thickness direction of the plating film 46.

[0061] Also, other grooves may be formed on one surface 36a of the resin layer portion 36 so as to be continuous with the groove 44. For example, as shown in FIGS. 9 and 10, a plurality of grooves 45 may be formed so as to be continuous with the groove 44. In the reflection mirror member 30 shown in FIGS. 9 and 10, a plurality of grooves 45 are formed as plating solution escape grooves in consideration of the flow of the plating solution when the plating film 46 is formed.

[0062] In the above-described embodiment, the case where both the first region 48a and the second region 48b on one surface 36a of the resin layer portion 36 are formed in a planar shape has been described. However, as shown in FIG. 11, the second region 48b may include a curved surface portion. Specifically, in the example shown in FIG. 11, the thickness around the resin layer portion 36 is larger than the thickness of the central portion, and one surface 36a of the resin layer portion 36 is formed in a concave shape as a whole. In this case, the second reflection region 60b on the second region 48b can be surely formed in a curved surface shape. That is, the second reflection region 60b for reflecting the reflected light from the measurement target space can be formed in a curved surface shape. Thereby, the light reception efficiency of the reflection mirror member 30 can be improved.

[0063] In addition, when the second region 48b is formed in a curved surface shape as described above, the reflection surface 60 also tends to be in a curved surface shape. However, also in this embodiment, since the groove 44 is formed, the thickness of the plating film 46 formed on the first region 48a can be made substantially uniform in the same manner as in the above-described embodiment. Thereby, the flatness of the first reflection region 60a can be made sufficiently small.

[0064] Further, when the outer edge side is formed in a curved surface shape on one surface 36a of the resin layer portion 36, due to the curing shrinkage that occurs during cooling after molding of the resin layer portion 36, the central portion of one surface 36a is pulled toward the outer edge side. As a result, the central portion side of one surface 36a also easily deforms into a curved surface shape. However, in this embodiment, since the groove 44 is formed, even when the second region 48b is formed in a curved surface shape, it is possible to suppress the first region 48a from being pulled toward the second region 48b side. Thereby, it is possible to prevent the flatness of the first region 48a from increasing. As a result, it is possible to sufficiently prevent the flatness of the first reflection region 60a from increasing.

[0065] In the above-described embodiment, the case where the boundary defining portion (groove 44) is formed in an annular shape (for example, a square annular shape or a circular annular shape) when viewed from the thickness direction of the plating film 46 has been described. However, the shape of the boundary defining portion is not limited to the above example. Specifically, the boundary defining portion may be formed so as to be able to partition one surface 36a of the resin layer portion 36 into an inner first region and an outer second region in an arbitrary direction when viewed from the thickness direction of the plating film 46. For example, as shown in FIG. 12, a pair of grooves 44 may be formed so as to extend in one direction (Y direction in FIG. 12) when viewed from the thickness direction of the plating film 46. In this case, among one surface of the resin layer portion 36, the portion inside the pair of grooves 44 in the X direction (a direction orthogonal to the Y direction) becomes the first region, and the portion outside the pair of grooves 44 becomes the second region. Although not shown, on one surface 36a of the resin layer portion 36, a pair of grooves may be formed so as to extend in a direction different from the pair of grooves 44 in FIG. 12 (for example, the X direction).

[0066] (Second Embodiment) FIG. 13 is a cross-sectional view showing a reflection mirror member according to the second embodiment of the present invention. The cross-section shown in FIG. 13 is a cross-section of a portion corresponding to the b-b portion of the reflection mirror member 30 shown in FIG. 4.

[0067] The reflection mirror member 30a according to the present embodiment is different from the reflection mirror member 30 shown in FIG. 5(b) in that a wall surface 50 is formed between the edge of the first region 48a and the edge of the second region 48b so that the edge of the first region 48a is located outside the edge of the second region 48b in the thickness direction of the resin layer portion 36. In the thickness direction of the resin layer portion 36, the height of the wall surface 50 is set in the same manner as the depth of the above-described groove 44. In the present embodiment, the wall surface 50 corresponds to the boundary defining portion.

[0068] In this embodiment, the wall surface 50 serves the same role as the groove 44 in the above-described embodiment. Specifically, when forming the plating film 46 on one surface 36a of the resin layer portion 36, it is possible to suppress the thickness of the plating film 46 formed on the first region 48a (the region inside the wall surface 50) from being affected by the thickness of the plating film 46 formed on the second region 48b (the region outside the wall surface 50). Thereby, the thickness of the plating film 46 formed on the first region 48a can be made substantially uniform. Also in this embodiment, since the first region 48a is formed in a planar shape, the first reflection region 60a on the first region 48a can also be formed in a planar shape. For this reason, in this embodiment, the flatness of the first reflection region 60a can be made smaller than the flatness of the second reflection region 60b. Also, the maximum value of the thickness of the plating film 46 in the first reflection region 60a can be made smaller than the maximum value of the thickness of the plating film 46 in the second reflection region 60b. Therefore, also in this embodiment, the same operational effects as those of the above-described embodiment can be obtained.

[0069] Note that, similar to the groove 44 shown in FIG. 4 or FIG. 8, the wall surface 50 may be formed in an annular shape (for example, a square annular shape or a circular annular shape), or similar to the pair of grooves 44 shown in FIG. 12, a pair of wall surfaces 50 may be formed so as to extend in one direction when viewed from the thickness direction of the plating film 46.

[0070] Also, similar to the groove 44 shown in FIGS. 7(a) and 7(b), a C surface or an R surface may be formed at the upper end portion of the wall surface 50. Also in this embodiment, similar to the above-described embodiment (see FIG. 11), the second region 48b of one surface 36a of the resin layer portion 36 may be formed in a curved surface shape.

[0071] (Other Embodiments) In the above-described embodiment, the case where the resin layer portion 36 includes the first resin layer portion 40 and the second resin layer portion 42 has been described, but the resin layer portion 36 may be formed of a single resin material.

[0072] The shape of the reflection mirror member to which the present invention is applied is not limited to the above example. For example, the present invention can also be applied to a polygon-type reflection mirror member as shown in FIGS. 14 and 15. Hereinafter, the polygon-type reflection mirror member will be briefly described.

[0073] The reflection mirror member 70 shown in FIG. 14 includes a resin layer portion 72. The resin layer portion 72 has a substantially triangular prism shape, and a pair of plating films 78a and 78b that form reflection surfaces are formed on each of the three side surfaces that constitute the outer peripheral surface. The plating films 78a and 78b are formed so as to be separated from each other and have a rectangular shape. In the present embodiment, a part of the surface of the plating film 78a (the region surrounded by the dashed line) is set as the first reflection region that deflects the measurement light, and the entire surface of the plating film 78b is set as the second reflection region that deflects the reflected light. Although detailed description is omitted, also in the present embodiment, on the surface of the resin layer portion 72, a boundary defining portion (groove or wall surface) is formed at a portion corresponding to the portion indicated by the dashed line.

[0074] The reflection mirror member 80 shown in FIG. 15 includes a resin layer portion 82. The resin layer portion 82 has a substantially quadrangular prism shape, and a plating film 88 that forms a reflection surface is formed on each of the four side surfaces that constitute the outer peripheral surface. Although detailed description is omitted, also in the present embodiment, a groove or a wall surface as a boundary defining portion (not shown) is formed on the surface of the resin layer portion 82, and a portion of the surface of the plating film 88 that is inside the boundary defining portion is the first reflection region, and a portion that is outside the boundary defining portion is the second reflection region.

[0075] Although detailed description is omitted, the present invention may also be applied to various other mirror members such as a right-angle prism mirror.

[0076] In the above-described embodiment, the case where the driving unit 34 rotationally drives the reflection mirror member 30 has been described. However, the present invention may also be applied to a photoelectric sensor (optical distance measuring device) in which the reflection mirror member is swing-driven by a driving unit. Further, in the above-described embodiment, the photoelectric sensor 10 (optical distance measuring device 100) including the optical scanning unit 18 that deflects and scans the measurement light in a predetermined direction has been described. However, the present invention may also be applied to a photoelectric sensor (optical distance measuring device) including an optical deflection unit that deflects the measurement light in a predetermined single direction. For example, in the above-described photoelectric sensor 10, the reflection mirror member 30 may be fixed to the casing 102 without providing the driving unit 34, and the reflection mirror member 30 may be used as the optical deflection unit. Further, the present invention may also be applied to a photoelectric sensor (optical distance measuring device) including both an optical scanning unit and an optical deflection unit. For example, the photoelectric sensor may be configured such that the optical deflection unit deflects the measurement light emitted from the light projecting unit 14, and the optical scanning unit scans the monitored area with the deflected measurement light. In this case, the optical scanning unit can be configured in the same manner as the above-described optical scanning unit 18, for example. Further, for example, a reflection mirror member 30 different from the reflection mirror member 30 of the optical scanning unit may be fixed to the casing 102, and the fixed reflection mirror member 30 can be used as the optical deflection unit.

[0077] (Reference Example) FIG. 16 is a diagram showing a reflection mirror member 30b according to a reference example, and FIG. 17 is a schematic cross-sectional view showing a c-c portion of FIG. 16. The reflection mirror member 30b shown in FIGS. 16 and 17 is different from the reflection mirror member 30 shown in FIGS. 4 and 5 in that a pair of through holes 40b are formed in the first resin layer portion 40 instead of the groove 44, and a pair of convex portions 42c that fit into the pair of through holes 40b are formed in the second resin layer portion 42. As shown in FIG. 16, the pair of through holes 40b and the pair of convex portions 42c are formed so as to be located on both sides of the opening 32c (both sides in the X direction in FIG. 16) and to be curved in an arc shape.

[0078] As described above, the second resin layer portion 42 is formed of a material having low affinity with the plating film 46. Therefore, as shown in FIGS. 16 and 17, the plating film 46 is not formed on the convex portion 42c of the second resin layer portion 42. In this case, when the plating film 46 is formed on one surface 36a of the resin layer portion 36, the thickness of the plating film 46 formed on the first region 48a (the region inside the pair of convex portions 42c in the X direction) can be suppressed from being affected by the thickness of the plating film 46 formed on the second region 48b (the region outside the pair of convex portions 42c in the X direction). Thereby, the thickness of the plating film 46 formed on the first region 48a can be made substantially uniform. In this reference example, since the first region 48a is formed in a planar shape, the first reflection region 60a on the first region 48a can also be formed in a planar shape.

Industrial Applicability

[0079] According to the present invention, since the reflection mirror member can be efficiently manufactured, the manufacturing cost of the optical sensor and the optical distance measuring device can be reduced.

Explanation of Signs

[0080] 10 Optical sensor 12 Control unit 14 Light projecting unit 16 Light projecting lens 18 Light scanning unit 20 Condensing lens 22 Light receiving unit 30, 30a, 70, 80 Reflection mirror member 32 Guide member 34 Driving unit 36 Resin layer portion 38 Connection portion 40 First resin layer portion 42 Second resin layer portion 42b Support portion 44 Groove 46 Plating film 60 Reflecting surface 60a First reflection region 60b Second reflection region

Claims

1. A resin layer portion, a reflective surface formed by a plating film on at least one surface of the resin layer portion, the one surface of the resin layer portion has a boundary defining portion, a first region provided inside the boundary defining portion, and a second region provided outside the boundary defining portion, the boundary defining portion is a groove provided between the first region and the second region, or a wall surface that forms a step between an edge of the first region and an edge of the second region such that an edge of the first region is positioned outside an edge of the second region in a thickness direction of the resin layer portion. Reflective mirror component.

2. The first region is formed in a planar shape, The second region is formed to include a curved surface. The reflective mirror member according to claim 1 .

3. the reflective surface includes a first reflective area formed on the first area and a second reflective area formed on the second area, The flatness of the first reflection area is smaller than the flatness of the second reflection area. The reflective mirror member according to claim 1 .

4. the reflective surface includes a first reflective area formed on the first area and a second reflective area formed on the second area, a maximum value of the thickness of the plated coating in the first reflective area is smaller than a maximum value of the thickness of the plated coating in the second reflective area; The reflective mirror member according to claim 1 .

5. The present invention is used in a photoelectric sensor that emits measurement light and receives reflected light from an object, the reflective surface includes a first reflective area formed on the first area and a second reflective area formed on the second area, a support portion for supporting a guide member that guides the measurement light to the first reflection region is formed in the resin layer portion; The support portion supports the guide member such that the guide member covers the boundary defining portion. The reflective mirror member according to claim 1 .

6. The resin layer portion includes a first resin layer portion on which the plated coating is formed, and a second resin layer portion on the other surface side on which the plated coating is not formed, the second resin layer portion being made of a material different from the first resin layer portion and being integrally molded with the first resin layer portion by two-color molding. The reflective mirror member according to claim 1 .

7. a connecting portion formed integrally with the second resin layer portion and connected to a driving portion that swings or rotates the reflection mirror member; The reflective mirror member according to claim 6.

8. a light projection unit that emits measurement light; A light receiving unit that receives reflected light arriving from the measurement target space; an optical deflection unit that deflects the measurement light in a predetermined direction, and / or an optical scanning unit that scans the measurement light in a predetermined direction; A photoelectric sensor, wherein the optical deflection section or the optical scanning section includes the reflective mirror member according to claim 1 .

9. the reflective surface includes a first reflective area formed on the first area and a second reflective area formed on the second area, The measurement light is reflected by the first reflection area of ​​the reflection surface of the reflection mirror member and emitted into the measurement target space, and the reflected light from the measurement target space is reflected by the reflection surface and received by the light receiving unit. The photoelectric sensor according to claim 8.

10. The reflection surface of the reflection mirror member is formed so that the reflected light from the measurement target space reflected by the second reflection area is received by the light receiving unit. The photoelectric sensor according to claim 9.

11. The photoelectric sensor according to claim 8 ; a control unit that controls the light projecting unit and the light receiving unit, the control unit calculates a distance to an object in the measurement target space based on the measurement light and the reflected light. Optical ranging device.

Images