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 first resin layer and a reflective surface. The reflective surface is formed of a plating film on at least one surface of the first resin layer. The one surface of the first resin layer has a first area curved in an arc to be convex outward in a thickness direction of the first resin layer, and a second area provided outside the first area. 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 reflective mirror member, a photoelectric sensor including the same, and a light distance measuring device.

Background Art

[0002] In recent years, in various fields, devices that detect objects using laser light have been used. 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 light propagation time 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 that reflects 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 part having a first resin layer part, and a reflection surface formed by a plating film on at least one surface side of the first resin layer part. One surface of the first resin layer part has a first region that is arcuately curved so as to be convex toward the outside in the thickness direction of the first resin layer part, and a second region provided outside the first region.

[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 in the case of forming the reflection surface by vapor deposition. Further, the first region of one surface of the first resin layer part is arcuately curved so as to be convex toward the outside in the thickness direction of the first resin layer part. Therefore, when forming the plating film on one surface of the first resin layer part, even if the thickness of the plating film formed on the outer edge portion of the first region is smaller than the thickness of the plating film formed on the central portion of the first region, it is possible to suppress the surface of the plating film on the first region from being recessed. That is, the flatness of the surface (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 having a small flatness.

[0009] (2) In the reflection mirror member of (1) above, the thickness of the first resin layer portion in the first region may be made thicker at the periphery than at the center thereof. If the thickness of the first resin layer portion in the first region is thicker at the periphery than at the center thereof, the surface of the first resin layer portion will be recessed due to sink marks at the periphery. As a result, the first region is curved in an arc shape so as to protrude outward in the thickness direction of the first resin layer portion. For this reason, when forming a plating film on one surface of the first resin layer portion, even if the thickness of the plating film formed on the outer edge portion of the first region is smaller than the thickness of the plating film formed on the central portion of the first region, it is possible to suppress the surface of the plating film from being recessed on the first region.

[0010] (3) In the reflection mirror member of (1) or (2) above, 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.

[0011] (4) In the reflection mirror member of any one of (1) to (3) above, the reflection 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.

[0012] 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.

[0013] (5) In any of the reflecting mirror members of (1) to (4) above, 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 maximum value of the thickness of the plating film in the first reflecting region may be smaller than the maximum value of the thickness of the plating film in the second reflecting region. In this case, it is possible to sufficiently suppress the occurrence of unevenness on the surface of the plating film formed on the first region. As a result, the flatness of the first reflecting region can be made sufficiently small, so that light can be appropriately reflected.

[0014] (6) Any of the reflecting mirror members of (1) to (5) 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 portion, and the support portion may support the guide member so that the guide member covers the outer edge of the first region.

[0015] In this case, the portion on the outer edge of the first region covered by the guide member in the plating film does not reflect the measurement light and the reflected light from the object. Therefore, even if gentle unevenness is formed on the surface of the plating film at the portion on the outer edge of the first region, it does not affect the detection accuracy of the photoelectric sensor.

[0016] (7) In any of the reflecting mirror members of (1) to (6) above, the resin portion may further have a second resin layer portion made of a material different from that of the first resin layer portion and integrally formed with the first resin layer portion by two-color molding on the other surface side of the first resin layer portion where the plating film is not formed.

[0017] In this reflective mirror member, for example, the first resin layer portion can be formed of a material having a high affinity with the material of the plating film, and the second resin layer portion can be formed of a material having a 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 the 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 reflective mirror member is improved.

[0018] (8) In the reflective mirror member of (7) above, a connection portion integrally formed with the second resin layer portion and connected to a driving portion that swings or rotates the reflective mirror member may be further provided. In this case, the reflective mirror member can be swung or rotated by the driving portion via the connection portion.

[0019] (9) The photoelectric sensor according to one aspect of the present invention includes a light projecting portion that emits measurement light, a light receiving portion that receives reflected light reaching from the measurement target space, a light deflecting portion that deflects the measurement light in a predetermined direction, and / or a light scanning portion that scans the measurement light in a predetermined direction, and the light deflecting portion or the light scanning portion includes any one of the reflective mirror members of (1) to (7) above.

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

[0021] (10) In the photoelectric sensor of (9) above, 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 reflective 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 portion. In this case, an object in the measurement target space can be detected accurately.

[0022] (11) In the photoelectric sensor of the above (10), the reflecting surface of the reflecting mirror member may be formed such that the reflected light from the measurement target space reflected in the second reflection region is received by the light receiving unit. In this case, an object in the measurement target space can be detected with high accuracy.

[0023] (12) The optical distance measuring device according to one aspect of the present invention includes any one of the photoelectric sensors of the above (9) to (11), 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 with high accuracy by reflecting the measurement light by a region with low flatness (the plating film on the first region) on the reflecting surface of the reflecting mirror member.

Effect of the Invention

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

Embodiments for Carrying Out the Invention

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

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

[0029] The photoelectric sensor 10 includes a light projecting unit 14, a light projecting lens 16, a light scanning unit 18, a condensing lens 20, and a light receiving unit 22. Since various known configurations of light distance measuring devices can be used for the light projecting unit 14, the light projecting lens 16, the condensing lens 20, and the light receiving unit 22, they will be briefly described below.

[0030] 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 use 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). In the present embodiment, the resin layer portion 36 corresponds to the resin portion.

[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 one surface of 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. In the present embodiment, the second resin layer portion 42 is provided on the other surface side of the first resin layer portion 40 where the plating film 46 is not formed.

[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 using, for example, 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 the 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. Also, as shown in FIGS. 5 and 6, a convex portion 43 protruding toward the first resin layer portion 40 side is formed on the surface of the second resin layer portion 42 (the surface on the first resin layer portion 40 side). In the present embodiment, the convex portion 43 has a cylindrical shape.

[0039] As shown in FIG. 5, a plurality of convex portions 40a that fit into the plurality of recesses 42a and a recess 41 into which the convex portion 43 fits 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.

[0040] Note that, as described above, in the present embodiment, the first resin layer portion 40 and the second resin layer portion 42 are formed by two-color molding. Here, in the present embodiment, columnar convex portions 43 are formed on the surface on the side of the first resin layer portion 40 in the second resin layer portion 42 as described above. In this case, when the first resin layer portion 40 is formed on the second resin layer portion 42, "sink marks" in which the surface is recessed due to the shrinkage of the resin material occur around the convex portions 43. The thickness of the first resin layer portion 40 becomes thicker at the center compared to the periphery around the convex portions 43 of the second resin layer portion 42, and the surface (one surface 36a) of the first resin layer portion 40 is recessed due to sink marks around the convex portions 43. As a result, the surface of the portion formed on the convex portions 43 in the first resin layer portion 40 is curved in an arc shape so as to protrude toward the outside in the thickness direction of the first resin layer portion 40. That is, among the one surface 36a of the resin layer portion 36, the portion located outside the convex portions 43 in the thickness direction of the resin layer portion 36 is curved in an arc shape so as to protrude toward the outside in the thickness direction. Hereinafter, the curved portion among the one surface 36a of the resin layer portion 36 is referred to as a first region 48a. Further, among the one surface 36a of the resin layer portion 36, the region outside the first region 48a as viewed from the thickness direction of the resin layer portion 36 is referred to as a second region 48b. In the present embodiment, the thickness of the portion corresponding to the first region 48a in the first resin layer portion 40 is thicker at the center compared to the periphery.

[0041] 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 a first reflecting region 60a, and the region formed on the second region 48b is defined as a second reflecting region 60b. In the present embodiment, the second reflecting region 60b is arranged so as to surround the first reflecting region 60a.

[0042] 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 this 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. 7 to be described later, even when the entire resin layer portion 36 is thicker at the periphery than at the center thereof (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.

[0043] However, in this embodiment, a first region 48a that is arcuately curved so as to protrude outward in the thickness direction of the resin layer portion 36 is formed at 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, even if the thickness of the plating film 46 formed on the outer edge portion of the first region 48a is smaller than the thickness of the plating film 46 formed on the central portion of the first region 48a, it is possible to suppress the surface of the plating film 46 from being recessed on the first region 48a. That is, the first reflection region 60a on the first region 48a can be formed in a planar shape. Therefore, 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 in this embodiment, 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.

[0044] In the thickness direction of the resin layer portion 36, the height of the first region 48a with respect to the second region 48b is set to be smaller than, for example, the thickness of the plating film 46 (the thickness of the plating film 46 on the first region 48a). Specifically, the height of the first region 48a with respect to the second region 48b is set to, for example, 0.5 to 2 μm. In the present embodiment, the thickness of the plating film 46 is, for example, 20 to 30 μm.

[0045] 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 thereof. 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, the guide member 32 is supported by the second resin layer portion 42 of the reflection mirror member 30 by hooking the plurality of hook portions 32b on the plurality of support portions 42b.

[0046] 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 into 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 into the guide member 32 at the opening 32c. In FIG. 2, the illustration of the concave portion 41, the convex portion 43, and the first region 48a is omitted.

[0047] In this embodiment, a guide member 32 is provided so as to cover the outer edge of the first region 48a. Therefore, in this embodiment, the portion of the plating film 46 on the outer edge of the first region 48a does not reflect the measurement light and the reflected light from the object. In this case, even if gentle unevenness is formed on the surface of the plating film 46 in the portion on the outer edge of the first region 48a, it does not affect the detection accuracy of the photoelectric sensor 10.

[0048] As shown in FIG. 2, the measurement light that has passed through the light projecting 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).

[0049] 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 this 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 this 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.

[0050] In the optical distance measuring device 100 according to this embodiment, while rotating the reflection mirror member 30 by the drive unit 34, by emitting measurement light from the light projecting unit 14, the measurement light can be scanned in a predetermined monitoring region around the optical distance measuring device 100.

[0051] (Function and Effect) In the reflection mirror member 30 according to this 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.

[0052] Also, in the reflection mirror member 30 according to the present embodiment, one surface 36a of the resin layer portion 36 has a first region 48a that is arcuately curved so as to be convex toward the outside in the thickness direction of the resin layer portion 36, and a second region 48b provided outside the first region 48a when viewed from the thickness direction of the resin layer portion 36. Thereby, 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.

[0053] 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, when 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.

[0054] 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 collection 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.

[0055] 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. The reflected light may be mainly deflected by the second reflection region 60b so as to be received by the light receiving portion 22. In other words, the reflection surface 60 of the reflection mirror member 30 may be formed such that more reflected light from the measurement target space reflected by the second reflection region 60b is received by the light receiving portion 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 portion 14 is not reflected by the second reflection region 60b but only reflected by the first reflection region 60a.

[0056] Note that 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] (Modification example) In the above-described embodiment, the case where the second region 48b on one surface 36a of the resin layer portion 36 is formed in a planar shape has been described. However, as shown in FIG. 7, the second region 48b may include a curved surface portion. Specifically, in the example shown in FIG. 7, the thickness around the resin layer portion 36 is larger than the thickness at the center 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.

[0061] In the above-described embodiment, the case where the first region 48a is formed in a circular shape (elliptical shape in this embodiment) when viewed from the thickness direction of the plating film 46 has been described. However, the shape of the first region 48a is not limited to the above example. As long as one surface 36a of the resin layer portion 36 can be partitioned 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. 8, the first region 48a may be formed so as to extend in one direction (Y direction in FIG. 8) 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 outside the first region 48a in the X direction (a direction orthogonal to the Y direction) becomes the second region. Although not shown, in one surface 36a of the resin layer portion 36, the first region 48a may be formed so as to extend in a direction different from the first region 48a in FIG. 8 (for example, the X direction).

[0062] (Other embodiments) In the above-described embodiment, the first region 48a is formed by utilizing the sink marks generated when molding the resin layer portion 36. However, as long as the method can arc-curve one surface 36a of the resin layer portion 36, the method for forming the first region 48a is not limited to the above-described method.

[0063] 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. However, the resin layer portion may be formed of a single resin material. That is, the resin layer portion may be constituted by a single resin layer portion (the first resin layer portion). In this case, for example, the thickness of the central portion of the single resin layer portion (the first resin layer portion) is made smaller than other portions, similar to the central portion of the first resin layer portion 40 described above. Thereby, similar to the first resin layer portion 40 described above, by utilizing the "sink marks", the central portion (the first region) of the surface of the resin layer portion can be arc-curved so as to protrude outward in the thickness direction of the resin layer portion. In the present embodiment, the support portion that supports the guide member 32 is provided, for example, on the single resin layer portion.

[0064] 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. 9 and 10. Hereinafter, the polygon-type reflection mirror member will be briefly described.

[0065] The reflection mirror member 70 shown in Fig. 9 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 to 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 first region similar to the above-described first region 48a is formed in a portion corresponding to the portion indicated by the dashed line.

[0066] The reflection mirror member 80 shown in Fig. 10 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 first region similar to the above-described first region 48a is formed on the surface of the resin layer portion 82. Among the surface of the plating film 88, the portion on the first region is the first reflection region, and the portion outside the first region is the second reflection region.

[0067] Although detailed description is omitted, the present invention may be applied to various other mirror members such as a right-angled prism mirror.

[0068] In the above-described embodiment, the case where the drive 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 drive 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 drive 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 deflected measurement light over the monitoring region. In this case, the optical scanning unit can be configured in the same manner as, for example, the above-described optical scanning unit 18. 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.

Industrial Applicability

[0069] According to the present invention, since the reflection mirror member can be efficiently manufactured, the manufacturing cost of the photoelectric sensor and the optical distance measuring device can be reduced.

Explanation of Signs

[0070] 10 Photoelectric sensor 12 Control unit 14 Light projecting unit 16 Light projecting lens 18 Optical scanning unit 20 Condensing lens 22 Light receiving unit 30, 70, 80 Reflection mirror member 32 Guide member 34 Drive unit 36 Resin layer portion 38 Connection portion 40 First resin layer portion 42 Second resin layer part 42b Support part 46 Plating film 48a First region 48b Second region 60 Reflecting surface 60a First reflection region 60b Second reflection region

Claims

1. a resin portion having a first resin layer portion; a reflective surface formed by a plating film on at least one surface side of the first resin layer portion, The one surface of the first resin layer portion has a first region that is curved in an arc shape so as to be convex toward an outside in a thickness direction of the first resin layer portion, and a second region that is provided outside the first region. Reflective mirror component.

2. The thickness of the first resin layer portion in the first region is formed to be thicker at the periphery than at the center. The reflective mirror member according to claim 1 .

3. The second region is formed to include a curved surface. 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, 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 .

5. 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 .

6. 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 area is formed in the resin portion; The support portion supports the guide member such that the guide member covers an outer edge of the first region. The reflective mirror member according to claim 1 .

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

8. 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 7.

9. 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 .

10. 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 9.

11. 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 10.

12. The photoelectric sensor according to claim 9 ; 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.

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