Detection device

Abstract

To detect a small object.SOLUTION: A detection device includes: a light-emitting unit which has a light-emitting part including a first light-emitting element and a second light-emitting element and a first lens part on which light emitted from the light-emitting part is incident; and a light-receiving unit which has a light-receiving part including a first light-receiving element and a second light-receiving element and a second lens part that concentrates light toward the light-receiving part. The first light-emitting element and the second light-emitting element are arranged along the second direction which is roughly perpendicular to the first direction along the optical axis. The first lens part includes a first lens on which the light emitted from the first light-emitting element is incident, and a second lens on which the light emitted from the second light-emitting element is incident. The first lens and the second lens are arranged along the second direction. When viewed along the first direction, the first end being the end on the second lens side of the first lens overlaps the second end being the end on the first lens side of the second lens.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sensing device. [Background technology]

[0002] Patent Document 1 discloses an luminescence detection device that is compact and simultaneously achieves high sensitivity and low crosstalk by satisfying specified relationships among the diameter of each light-emitting point in a light-emitting point array, the focal length and spacing of each focusing lens in a focusing lens array, and the optical path length between each focusing lens and an optical element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-97758 Summary of the Invention [Problem to be solved by the invention]

[0004] The invention described in Patent Document 1 describes that crosstalk, which is caused by overlapping light-emitting point images of adjacent light-emitting points, can be adjusted by selecting the focal length f of the condenser lens and the optical path length g between the condenser lens and the sensor, and that crosstalk should be set to 50% or less, preferably 0%, in order to detect light emitted from each light-emitting point independently. However, the invention described in Patent Document 1 places too much emphasis on detecting light emitted from each light-emitting point independently, and may not be able to detect an object between the light-emitting areas from each light-emitting point. In particular, when the object to be detected is small (for example, about 0.01 mm to 0.03 mm in diameter), the invention described in Patent Document 1 cannot detect the object with a high probability.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a detection device capable of detecting small objects. [Means for solving the problem]

[0006] In order to solve the above problem, a detection device according to the present invention includes, for example, a light-emitting unit having a light-emitting section including a first light-emitting element and a second light-emitting element, and a first lens section into which light irradiated from the light-emitting section is incident, and a light-receiving unit having a light-receiving section including a first light-receiving element and a second light-receiving element, and a second lens section that condenses light toward the light-receiving section, wherein the first light-emitting element and the second light-emitting element are arranged along a second direction that is approximately perpendicular to a first direction along an optical axis, and the first lens section includes a first lens into which light irradiated from the first light-emitting element is incident, and a second lens into which light irradiated from the second light-emitting element is incident, and the first lens and the second lens are aligned along the second direction. The first light receiving element and the second light receiving element are arranged in a direction such that, when viewed along the first direction, a first end of the first lens that is an end of the first lens side and a second end of the second lens that is an end of the second lens side of the first lens overlap, the first light receiving element and the second light receiving element are arranged in a direction such that, when viewed along the first direction, a first end of the first lens that is an end of the second lens side and a second end of the second lens that is an end of the first lens side of the second lens overlap, the first light receiving element and the second light receiving element are arranged in a direction such that, when viewed along the first direction, a first end of the first lens that is an end of the second lens side and a fourth end of the fourth lens that is an end of the fourth lens side of the third lens overlap. This makes it possible to detect a small object.

[0007] The first light emitting element and the second light emitting element each may have a light emitting lens, and the light emitting lens may have a roughened surface, thereby reducing unevenness in light intensity and making it easier to detect small objects.

[0008] The light receiving unit may have a plate-like member having a thickness of about 0.05 mm or more and about 0.4 mm or less, provided between the light receiving portion and the second lens portion, the plate-like member being provided adjacent to the light receiving portion, and the plate-like member may have slits at positions overlapping the first light receiving element and the second light receiving element when viewed along the first direction, thereby cutting out ambient light and making it easier to detect small objects.

[0009] The light-emitting unit may have a third lens portion provided between the light-emitting portion and the first lens portion, the third lens portion having a convex lens portion into which the light irradiated from the light-emitting portion is incident when viewed along the first direction, the convex lens portion having a shape that is convex on at least one of two end faces in the first direction when viewed along the second direction, and the first lens, the second lens, the third lens and the fourth lens may have a shape that is convex on at least one of two end faces in the first direction when cut along a surface along the first direction and the second direction. This makes it possible to effectively utilize the light irradiated from the light-emitting portion and increase the amount of parallel light, making it easier to detect small objects.

[0010] The light emitting unit may include a light emitting side case in which the light emitting portion and the first lens portion are provided, and the light receiving unit may include a light receiving side case in which the light receiving portion, the second lens portion and the plate-like member are provided, the light emitting side case may have a first outer slit whose longitudinal direction is along the second direction on a surface adjacent to the first lens portion, and the light receiving side case may have a second outer slit whose longitudinal direction is along the second direction on a surface adjacent to the second lens portion, and the size of the second outer slit may be smaller than the size of the first outer slit. This prevents light not emitted from the light emitting unit from being received by the light receiving portion, making it easier to detect small objects.

[0011] The first end may have a first inclined surface that is inclined so that the width of the first lens in the second direction becomes narrower toward the first light-emitting element, and the second end may have a second inclined surface that is inclined so that the width of the second lens in the second direction becomes narrower toward the second light-emitting element, and a tip end portion of the first end that is farthest from the first light-emitting element may abut on the second inclined surface, or a tip end portion of the second end that is farthest from the second light-emitting element may abut on the first inclined surface. This makes the positional deviation of the first lens and the second lens in the first direction very small, and the first lens portion can be made smaller while maintaining performance. Effect of the Invention

[0012] According to the present invention, small objects can be detected. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing an outline of a detection device 1. FIG. [Diagram 2] 1 is a diagram showing an outline of a detection device 1. FIG. [Diagram 3] 2A and 2B are partial enlarged views of the light-emitting unit 10, in which (A) is an enlarged view of a portion of FIG. 1, and (B) is an enlarged view of a portion of (A) (the portion surrounded by a two-dot chain line). [Figure 4] FIG. 2 is a partial enlarged view of the light-emitting unit 10. [Diagram 5] FIG. 2 is a diagram showing an outline of a light emitting element 111. [Figure 6] 2 is a perspective view showing an outline of an inner lens portion 13. FIG. [Figure 7] FIG. 2 is a perspective view showing an outline of an outer lens 121. [Figure 8] 2A and 2B are partial enlarged views of the light receiving unit 20, in which (A) is an enlarged view of a portion of FIG. 1, and (B) is an enlarged view of a portion of (A) (a portion surrounded by a two-dot chain line). [Figure 9] 13 is a diagram showing an outline of a lens 221, where (A) and (C) are side views, (B) is a rear view (as viewed from the +x direction), and (D) is a perspective view. [Figure 10] 13(A) to 13(D) are diagrams showing schematic diagrams of modified examples of the slit shape. [Figure 11] FIG. 1 is a diagram showing an outline of a detection device 1A in which a light-emitting unit 10 and a light-receiving unit 20 are integrated together. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Hereinafter, a detection device of the present invention will be described taking as an example a light emitting device, a light receiving device, and a sensor having the light emitting device and the light receiving device.

[0015] <First embodiment> 1 and 2 are diagrams showing an outline of a detection device 1 according to an embodiment of the present invention. The detection device 1 mainly includes a light emitting unit 10 and a light receiving unit 20.

[0016] The light-emitting unit 10 mainly has a light-emitting section 11, an outer lens section 12 (corresponding to the first lens section of the present invention), an inner lens section 13 (corresponding to the third lens section of the present invention), and a case 14 (corresponding to the light-emitting side case of the present invention).

[0017] The light-emitting unit 11 has light-emitting elements 111, 112, 113, 114, and 115, and a substrate 116 on which the light-emitting elements 111, 112, 113, 114, and 115 are provided. The light-emitting elements 111, 112, 113, 114, and 115 are, for example, light sources that irradiate infrared light, and are LEDs. A control circuit is provided on the substrate 116, and a power source (not shown) is connected to the substrate 116. The light-emitting elements 111 to 115 are turned on and off by the control circuit.

[0018] Light irradiated from the light emitting unit 11 and passing through the inner lens unit 13 is incident on the outer lens unit 12. The outer lens unit 12 has an outer lens 121 onto which the light irradiated from the light emitting element 111 is incident, an outer lens 122 onto which the light irradiated from the light emitting element 112 is incident, an outer lens 123 onto which the light irradiated from the light emitting element 113 is incident, an outer lens 124 onto which the light irradiated from the light emitting element 114 is incident, and an outer lens 125 onto which the light irradiated from the light emitting element 115 is incident.

[0019] The number of light-emitting elements in the light-emitting unit 11 and the number of outer lenses in the outer lens unit 12 are not limited to these. The light-emitting unit 11 only needs to have at least two light-emitting elements 111, 112, and the outer lens unit 12 only needs to have at least two outer lenses 121, 122.

[0020] The light emitting elements 111-115 are aligned along the optical axis in a y direction (corresponding to a second direction in the present invention) that is substantially perpendicular to the x direction (corresponding to a first direction in the present invention). Similarly, the outer lenses 121-125 are aligned along the y direction.

[0021] Note that the x and y directions are given for convenience, and are not necessarily parallel to the horizontal direction. Also, the direction perpendicular to the x and y directions is the z direction (corresponding to the third direction of the present invention), but the z direction is not necessarily parallel to the vertical direction.

[0022] Light emitted from the light emitting unit 11 is incident on the inner lens unit 13. The inner lens unit 13 is provided between the light emitting unit 11 and the outer lens unit 12. In the present embodiment, one rod-shaped inner lens unit 13 is provided, but the form of the inner lens is not limited to this. The inner lens unit 13 may have multiple inner lenses, and the multiple inner lenses may be arranged along the y direction. Moreover, the inner lens unit 13 is not essential.

[0023] Case 14 is hollow, and light emitting unit 11, outer lens unit 12, and inner lens unit 13 are provided inside case 14. Case 14 is provided with opening 14a (corresponding to a first outer slit of the present invention) through which light that has passed through outer lens unit 12 passes.

[0024] The light receiving unit 20 has a light receiving section 21, a lens section 22 (corresponding to the second lens section of the present invention), a plate-like member 23, and a case 24 (corresponding to the light receiving side case of the present invention).

[0025] The light receiving section 21 has light receiving elements 211, 212, 213, 214, and 215, and a substrate 216 on which the light receiving elements 211, 212, 213, 214, and 215 are provided.

[0026] The lens unit 22 is a member that collects light toward the light receiving unit 21. The lens unit 22 has a lens 221 that collects light toward the light receiving element 211, a lens 222 that collects light toward the light receiving element 212, a lens 223 that collects light toward the light receiving element 213, a lens 224 that collects light toward the light receiving element 214, and a lens 225 that collects light toward the light receiving element 215.

[0027] The number of light receiving elements included in the light receiving unit 21 and the number of lenses included in the lens unit 22 are not limited to these. The lens unit 22 only needs to have at least two light receiving elements 211, 212, and the lens unit 22 only needs to have at least the lenses 221, 222.

[0028] The light receiving elements 211 to 215 are aligned along the y direction. Similarly, the lenses 221 to 225 are aligned along the y direction.

[0029] The plate-like member 23 is provided between the light receiving unit 21 and the lens unit 22 and adjacent to the light receiving unit 21. The plate-like member 23 is a thin plate with a thickness of about 0.05 mm to 0.4 mm. The plate-like member 23 is provided with slits 23a at positions overlapping with the light receiving elements 211, 212, 213, 214, and 215 when viewed along the x direction. The slits 23a are apertures that narrow the light incident on the light receiving unit 21.

[0030] In this embodiment, the light receiving section 21 and the plate-like member 23 are adjacent to each other, but the light receiving section 21 and the plate-like member 23 may be spaced apart from each other. However, in order to limit the light incident on the light receiving section 21, it is desirable that the light receiving section 21 and the plate-like member 23 be adjacent to each other.

[0031] The case 24 is hollow, and the light receiving unit 21, the lens unit 22, and the plate-like member 23 are provided inside the case 24. The case 24 is provided with an opening 24a (corresponding to the second outer slit of the present invention) through which light passes.

[0032] The size of the opening 24a is smaller than the size of the opening 14a. Therefore, the opening 24a can prevent light not emitted from the light-emitting unit 10 (see the dotted line in FIG. 2) from being received by the light-receiving elements 211-215. In particular, it is desirable to narrow the width of the opening 24a in the z direction to about 1 mm to 1.5 mm, thereby making it difficult for unnecessary light to enter the lens portion 22.

[0033] Figures 3 and 4 are partial enlarged views of the light-emitting unit 10. Figure 3(A) is an enlarged view of a portion of Figure 1, and Figure 4 is an enlarged view of a portion of Figure 2. Figure 3(B) is an enlarged view of a portion of Figure 3(A) (the portion surrounded by a two-dot chain line).

[0034] The light emitted from the light emitting elements 111 to 115 is emitted mainly in the +x direction along the central axis (optical axis) of the lens 111g. The light emitting elements 111 to 115 emit diffused light, and the directivity angle is about 30° to 60°.

[0035] 5 is a diagram showing an outline of the light emitting element 111. Since the light emitting elements 111 to 115 have the same configuration, the light emitting elements 111 to 115 will be described below using the light emitting element 111.

[0036] The light emitting element 111 mainly includes an LED element 111a, electrodes 111b and 111c, a lens 111g, and a printed circuit board 111h on which electrodes 111b and 111c are provided. The electrode 111b is an anode, and the electrode 111c is a cathode. The LED element 111a is electrically connected to the electrode 111c by silver paste 111e, and is electrically connected to the electrode 111b by a bonding wire 111d. This forms an electrode assembly.

[0037] The lens 111g is formed by pouring resin into a metal mold. The resin of the lens 111g is mainly epoxy resin. The resin is poured into the metal mold, and the resin is cured with the printed circuit board 111h in contact with the metal mold. In this way, the light emitting element 111 is formed.

[0038] The lens 111g has a rounded tip, i.e., is bullet-shaped. Since the lens 111g is molded in a bullet shape, the lens 111g has a strong directivity and mainly irradiates light forward.

[0039] The light emitting element 111 has a roughened lens 111g. In other words, the outer surface 111f of the lens 111g has a large surface roughness. By finely roughening the surface 111f, the light emitting element 111 becomes a light source that emits a dim diffuse light, such as light shining through frosted glass.

[0040] In this embodiment, the surface roughness of surface 111f has a maximum height Ry of about 30 μm. The maximum height Ry is calculated by extracting a reference length from the roughness curve in the direction of the average line, measuring the distance between the peak line and the valley line of the extracted portion in the direction of the longitudinal magnification of the roughness curve, and expressing this value in micrometers.

[0041] There are various methods for roughening the lens 111g. For example, the surface roughness of the mold used for molding the lens 111g is about 30 μm in maximum height by not polishing or finishing the surface of the mold. This allows the roughness of the mold to be reflected on the surface 111f when molding the lens 111g. Normally, the lens part of an LED light source that emits diffused light is manufactured by applying a mirror finish to the mold and mixing a diffusing material into the molding resin and molding it, but in this embodiment, the mirror finish and the diffusing material are not necessary, reducing the manufacturing process and reducing the manufacturing cost. In addition, for example, the surface roughness of the lens surface of a normal LED light source manufactured using a mold with a mirror finish can be roughened by blasting or the like.

[0042] Returning to the explanation of Figures 3 and 4, since the lens 111g is roughened in this manner, the light emitting elements 111 to 115 emit dimly diffused light (see the dashed dotted lines in Figures 3 and 4).

[0043] The light emitted from the light emitting elements 111 to 115 is incident on the inner lens portion 13. The inner lens portion 13 is rod-shaped and extends longitudinally along the y direction.

[0044] 6 is a perspective view showing an outline of the inner lens portion 13. The inner lens portion 13 has a convex lens portion 13a extending along the longitudinal direction (y direction). Light emitted from the light emitting portion 11 is incident on the inner lens portion 13.

[0045] Convex lens portion 13a has a shape that is convex on at least one of two end faces in the x direction (end faces in the +x direction and the -x direction) when cut along a plane along the x direction and the z direction. In this embodiment, convex lens portion 13a is a biconvex lens that is convex in the +x direction and the -x direction, but the shape of convex lens portion 13a is not limited to this. In addition, convex lens portion 13a has a rectangular shape (here, a rectangular shape) when cut along a plane along the x direction and the y direction.

[0046] Returning to the description of Figs. 3 and 4, the light beams emitted from the light emitting elements 111-115 enter the inner lens unit 13 and are condensed at the convex lens unit 13a. The convex lens unit 13a has a rectangular shape (rectangular shape in this case) when cut along a plane along the x and y directions, so only the width of the light beam in the z direction is narrowed (see Fig. 4). In addition, since the convex lens unit 13a does not condense the light beam in the z direction, the light beams emitted from the light emitting elements 111-115 pass through the convex lens unit 13a as diffused light. Since the convex lens unit 13a extends along the y direction, the light beams emitted from the light emitting elements 111-115 and passed through the inner lens unit 13 have a flat shape with the upper and lower ends in the z direction crushed when viewed along the x direction.

[0047] The light beam that has passed through the inner lens portion 13 enters the outer lens portion 12. Fig. 7 is a perspective view showing an outline of the outer lens 121. Since the outer lenses 121 to 125 have the same configuration, the outer lenses 121 to 125 will be described below using the outer lens 121.

[0048] The outer lens 121 has a shape that is convex on at least one of the end faces in the +x direction and the -x direction when cut along a plane along the x direction and the y direction. In this embodiment, the outer lens 121 is a biconvex lens that is convex in the +x direction and the -x direction, but the shape of the outer lens 121 is not limited to this. The outer lens 121 has a recess 12a on the surface from which light is emitted (the surface on the +x side).

[0049] Furthermore, excluding the recess 12a, the outer lens 121 has a rectangular shape (here, a rectangular shape) when cut along a plane along the x direction and the z direction.

[0050] Returning to the explanation of Figs. 3 and 4, the outer lens unit 12 is arranged such that the ends of the outer lenses 121 to 125 slightly overlap each other. That is, when viewed along the x direction, an end 121b (corresponding to a first end of the present invention) of the outer lens 121 on the outer lens 122 side and an end 122a (corresponding to a second end of the present invention) of the outer lens 122 on the outer lens 121 side overlap each other (see Fig. 3(B)). If there is a gap between the outer lens 121 and the outer lens 122, a gap also occurs in the light beam, and there is a risk that small objects cannot be detected. However, by overlapping the ends of the outer lens 121 and the outer lens 122, the occurrence of a gap in light can be prevented.

[0051] Although not shown in Figure 3, similarly to the outer lenses 121 and 122, when viewed along the x direction, the end 122b of the outer lens 122 on the outer lens 123 side overlaps with the end 123a of the outer lens 123 on the outer lens 122 side, the end 123b of the outer lens 123 on the outer lens 124 side overlaps with the end 124a of the outer lens 124 on the outer lens 123 side, and the end 124b of the outer lens 124 on the outer lens 125 side overlaps with the end 124a of the outer lens 125 on the outer lens 124 side (see Figure 1).

[0052] The ends 121b, 122b, 123b, and 124b (corresponding to the first ends of the present invention) are inclined so that the width along the y direction becomes narrower toward the light emitting elements 111 to 114. The ends 122a, 123a, 124a, and 125a (corresponding to the second ends of the present invention) are inclined so that the width along the y direction becomes narrower toward the light emitting elements 112 to 115. The ends 122a, 123a, 124a, and 125a, which are the furthest from the light emitting elements 112 to 115, abut against the ends 121b, 122b, 123b, and 124b, respectively. In this way, the ends 121a to 125a and 121b to 125b of the outer lenses 121 to 125 are inclined to slightly shift the positions of the outer lenses 121 to 125 in the x direction, so that the ends of the outer lenses 121 to 125 can be slightly overlapped.

[0053] The shape of the outer lenses 121 to 125 is not limited to this. For example, in this embodiment, the ends 121a to 125a and 121b to 125b are inclined so that the width along the y direction becomes narrower toward the light emitting elements 111 to 115, but the inclination of the ends 121a to 125a and 121b to 125b may be reversed. Furthermore, the tip portions of the ends 121b, 122b, 123b, and 124b that are farthest from the light emitting elements 111 to 114 may abut against 122a, 123a, 124a, and 125a.

[0054] Since the outer lenses 121 to 125 have a rectangular shape when cut along a plane along the x direction and z direction, excluding the recess 12a, when viewed along the z direction, the light beams that expand in the +x direction are focused to form parallel light along the x direction (see FIG. 3).

[0055] Furthermore, when viewed along the y direction, the recess 12a spreads the light beam that has passed through the convex lens portion 13a to make it a parallel light beam along the x direction (see FIG. 4). Because the light from the light-emitting element 111 is condensed by the convex lens portion 13a, if the condensed light is output as is from the opening 14a, some of the light beams will cross each other when they leave the opening 14a, causing the light beams to spread and reducing the output. Therefore, the recess 12a collimates the light beams to prevent a reduction in output.

[0056] 1 and 2. With this configuration, the light emitting unit 10 can generate a dim, uniform, and consistent light without gaps.

[0057] The light that has passed through the outer lens portion 12 passes through the opening 14a and is emitted from the case 14, i.e., the light-emitting unit 10. The light-receiving unit 20 detects an object by receiving the light emitted from the light-emitting unit 10 through the opening 24a.

[0058] Fig. 8 is a partial enlarged view of the light receiving unit 20. Fig. 8(A) is an enlarged view of a part of Fig. 1, and Fig. 8(B) is an enlarged view of a part (a part surrounded by a two-dot chain line) of Fig. 8(A).

[0059] A light beam entering the inside of the case 24 through the opening 24 a enters the lens portion 22 . Fig. 9 is a diagram showing an outline of lens 221, where (A) and (C) are side views, (B) is a rear view (as viewed from the +x direction), and (D) is a perspective view. Fig. 9(B) shows Fig. 9(A) as viewed from the right side of the paper, and Fig. 9(C) shows Fig. 9(A) rotated 90 degrees. Lenses 221 to 225 have the same configuration, so hereinafter lenses 221 to 225 will be described using lens 221.

[0060] The lens 221 has a shape in which at least one of the end faces in the +x direction and the -x direction is convex. In this embodiment, the lens 221 is a biconvex lens in which the end faces in the +x direction and the -x direction, i.e., the faces 221c and 221d on both sides (front side and back side) are convex. The faces 221c and 221d are cone-shaped and can collect light in both the up-down direction (z direction) and the left-right direction (y direction). The faces 221c and 221d are connected by four side faces 221e and 221g and four curved faces 221f. Two of the four side faces 221e are inclined. The side faces 221e correspond to the ends 221a to 225a and 221b to 225b (described in detail later).

[0061] The shape of the lenses 221 to 225 is not limited to the form shown in Fig. 9. For example, the protruding height of the faces 221c and 221d is not limited to this, and the side face 221g may be inclined in the same manner as the side face 221e.

[0062] Returning to the explanation of FIG. 8, the lens unit 22 is arranged such that the ends of the lenses 221 to 225 slightly overlap. That is, when viewed along the x direction, an end 221b (corresponding to the third end of the present invention) of the lens 221 on the lens 222 side overlaps with an end 222a (corresponding to the fourth end of the present invention) of the lens 222 on the lens 221 side. If there is a gap between the lenses 221 and 222, a light beam that cannot be detected is generated, and there is a risk that small objects cannot be detected; however, by overlapping the ends of the lenses 221 and 222, it is possible to prevent the occurrence of a gap in the light.

[0063] Although not shown in Figure 3, similarly to lenses 221 and 222, when viewed along the x direction, end 222b of lens 222 on the lens 223 side overlaps with end 223a of lens 223 on the lens 222 side, end 223b of lens 223 on the lens 224 side overlaps with end 224a of lens 224 on the lens 223 side, and end 224b of lens 224 on the lens 225 side overlaps with end 224a of lens 225 on the lens 224 side (see Figure 1).

[0064] The ends 221b, 222b, 223b, and 224b (corresponding to the third end of the present invention) are inclined so that the width along the y direction narrows toward the light receiving elements 211 to 214. The ends 222a, 223a, 224a, and 225a (corresponding to the fourth end of the present invention) are inclined so that the width along the y direction narrows toward the light receiving elements 212 to 215. The ends 222a, 223a, 224a, and 225a, which are the furthest from the light receiving elements 212 to 215, abut against the ends 221b, 222b, 223b, and 224b, respectively. In this way, the ends 221a to 225a and 221b to 225b of the lenses 221 to 225 are inclined to slightly shift the positions of the lenses 221 to 225 in the x direction, so that the ends of the lenses 221 to 225 can be slightly overlapped.

[0065] The shape of the lenses 221 to 225 is not limited to this. For example, in this embodiment, the ends 221a to 225a and 221b to 225b are inclined so that the width along the y direction becomes narrower toward the light receiving elements 211 to 215, but the inclination of the ends 221a to 225a and 221b to 225b may be reversed. Furthermore, the tip portions of the ends 221b, 222b, 223b, and 224b that are farthest from the light receiving elements 211 to 214 may abut against 222a, 223a, 224a, and 225a.

[0066] The lenses 221 to 225 focus only the parallel light incident from the opening 24a onto the slit 23a of the plate-like member 23.

[0067] The light that has passed through the lenses 221-225 passes through the slits 23a of the plate-like member 23 and enters the light receiving elements 211-215, respectively. The plate-like member 23 has a thickness of about 0.05 mm to 0.4 mm, but since if the plate-like member 23 is thick, the inner surface (surface in the thickness direction) of the slits 23a becomes a light reflecting surface, it is desirable to set the thickness to 0.1 mm or less. Also, in order to form the slits 23a with high precision by etching, it is desirable to set the thickness of the plate-like member 23 to 0.1 mm or less.

[0068] The slit 23a is a round hole with a diameter of 0.3 mm or less. Since the light is condensed by the lenses 221 to 225, the diameter of the slit 23a is 0.25 mm in this embodiment.

[0069] It should be noted that the slit 23a is not limited to a round hole. Fig. 10 is a diagram showing an outline of modified shapes of the slit 23a. The slit 23a may be an elongated hole as shown in Fig. 10(A), an elliptical hole as shown in Fig. 10(B), or a rectangular shape as shown in Figs. 10(C) and (D) ((C) is a rectangular shape, and (D) is a square shape). The shape of the slit 23a can be appropriately selected depending on the shape of the light beam and the light receiving elements 211 to 215.

[0070] Returning to the explanation of Fig. 8, the slit 23a blocks all light that has passed through the lenses 221-225 except for parallel light. As a result, only parallel light, which is light from the opposing light-emitting units 10, enters the light-receiving elements 211-215. Light that is not parallel (light with an angle) is disturbance light, and the slit 23a blocks the disturbance light.

[0071] The area through which the parallel light emitted from the light-emitting unit 10 passes becomes the detection area of ​​the detection device 1. When a small object passes through the detection area, the change in output is also small, but because disturbance light also changes the output, it is desirable to cut off disturbance light using the opening 24a and the slit 23a in order to reliably detect small objects.

[0072] According to this embodiment, an outer lens section 12 is used in which the ends of the outer lenses 121-125 slightly overlap, thereby preventing gaps from occurring in the light beam irradiated from the light-emitting unit 10, and a lens section 22 is used in which the ends of the lenses 221-225 slightly overlap, so that all of the parallel light that passes through the opening 24a is incident on the light-receiving section 21, making it possible to detect small objects with a diameter of approximately 0.02 mm.

[0073] Furthermore, according to this embodiment, the lens of light-emitting unit 11 is roughened so that light-emitting unit 11 emits dim diffuse light, thereby reducing unevenness in the intensity of light incident on inner lens unit 13. As a result, even small objects can be detected reliably.

[0074] Furthermore, according to this embodiment, by providing the plate-like member 23 with the slit 23a between the light receiving portion 21 and the lens portion 22, it is possible to cut out disturbance light and make it easier to detect small objects. Furthermore, by providing the opening 24a in the case 24, it is possible to prevent the light not emitted from the light emitting unit 10 from being received by the light receiving elements 211 to 215, making it easier to detect small objects.

[0075] Furthermore, according to this embodiment, the outer lens portion 12 collects the light beam spreading in the y direction to form parallel light along the x direction, and the convex lens portion 13a of the inner lens portion 13 narrows the width of the light beam in the z direction, thereby making effective use of the light emitted from the light-emitting portion 11. Therefore, the amount of parallel light emitted from the light-emitting unit 10 can be increased, making it easier to detect small objects.

[0076] Furthermore, according to this embodiment, the outer lens section 12 can be made smaller by tilting the ends 121a-125a and 121b-125b to slightly shift the positions of the outer lenses 121-125 in the x direction. Similarly, the lens section 22 can be made smaller by tilting the ends 221a-225a and 221b-225b to slightly shift the positions of the lenses 221-225 in the x direction.

[0077] In this embodiment, the lenses of the light-emitting elements 111-115 are roughened, but roughening is not essential. However, if the lenses of the light-emitting elements 111-115 are not roughened, shadows of wires or the like may be generated, which may reduce detection accuracy. Therefore, it is desirable to roughen the lenses of the light-emitting elements 111-115.

[0078] In addition, in this embodiment, the inner lens unit 13 is provided between the light-emitting unit 11 and the outer lens unit 12, but the inner lens unit 13 is not essential. In particular, when the distance between the light-emitting unit 10 and the light-receiving unit 20 is short, it is possible to detect small objects with a diameter of about 0.02 mm without the inner lens unit 13. Furthermore, the recess 12a is not essential. For example, when the distance between the light-emitting unit 10 and the light-receiving unit 20 is short, only the inner lens unit 13 is required and the recess 12a is not necessary, and even if the inner lens unit 13 is not used, the recess 12a is not necessary.

[0079] In the present embodiment, the plate-like member 23 is provided between the light receiving unit 21 and the lens unit 22, but the plate-like member 23 and the slit 23a are not essential. However, in order to stabilize the signal and increase the detection accuracy, it is desirable to provide the plate-like member 23 and the slit 23a.

[0080] In the present embodiment, the size of the opening 24a is smaller than the size of the opening 14a, but the size of the opening 24a is not limited to this. However, in order to make it easier to detect small objects by preventing the light receiving elements 211-215 from receiving light that is not emitted from the light emitting unit 10, it is desirable to make the size of the opening 24a smaller than the size of the opening 14a.

[0081] In addition, in this embodiment, the ends 121a to 125a, 121b to 125b of the outer lenses 121 to 125 are inclined, and the tip ends 122a, 123a, 124a, and 125a of the outer lenses 121 to 125 that are farthest from the light-emitting elements 112 to 115 are abutted against the ends 121b, 122b, 123b, and 124b, respectively, and the outer lenses 121 to 125 are arranged so that the ends of the outer lenses 121 to 125 slightly overlap while slightly shifting the positions of the outer lenses 121 to 125 in the x direction. However, the form in which the outer lenses 121 to 125 are arranged so that the ends of the outer lenses 121 to 125 slightly overlap, i.e., the form of the outer lenses 121 to 125, is not limited to this. For example, the outer lenses 121-125 may be arranged so that the ends of the outer lenses 121-125 are slightly overlapped by shifting the outer lenses 121-125 in the x direction by the thickness of the outer lenses 121-125 without inclining the ends of the outer lenses 121-125. Similarly, the form in which the lenses 221-225 are arranged so that the ends of the lenses 221-225 are slightly overlapped, that is, the form of the lenses 221-225 is not limited to this. However, in order to maintain optical performance, the closer the positions of the outer lenses 121-125 and the lenses 221-225 in the x direction are, the better, so it is desirable to incline the ends 121a-125a, 121b-125b of the outer lenses 121-125 and the ends 221a-225a, 221b-225b of the lenses 221-225.

[0082] In addition, in the present embodiment, the light emitting unit 10 and the light receiving unit 20 are separate, but the light emitting unit 10 and the light receiving unit 20 may be integrated. Fig. 11 is a diagram showing an outline of a detection device 1A in which the light emitting unit 10 and the light receiving unit 20 are integrated. In the detection device 1A, the light emitting unit 10 and the light receiving unit 20 are integrated by a case 30.

[0083] A separate type detection device 1 in which the light emitting unit 10 and the light receiving unit 20 are separate has the advantage that the distance between the light emitting unit 10 and the light receiving unit 20 can be freely changed, but it may be vulnerable to vibration. Therefore, when installing in a place subject to vibration, it is preferable to use an integrated detection device 1A in which the positional relationship between the light emitting unit 10 and the light receiving unit 20 is not distorted. For example, when installing in the vicinity of an actuator, the detection device 1A is advantageous.

[0084] Also, in the case of the detection device 1, it is necessary to prepare a harness (a component in which multiple cables used for power supply and signal communication are bundled together and have connectors attached to the ends) for each of the light-emitting unit 10 and the light-receiving unit 20, but the detection device 1A requires only one harness. Therefore, wiring is easy when attaching the detection device 1A to another device.

[0085] Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes within the scope of the gist of the present invention are also included. For example, the above example has been described in detail to clearly explain the present invention, and is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of the embodiment with the configuration of another embodiment, and it is also possible to add, delete, or replace other configurations to the configuration of the embodiment.

[0086] In the present invention, "approximately" is a concept that includes not only the case of being strictly identical, but also an error or deformation to the extent that the identity is not lost. For example, "approximately orthogonal" is a concept that includes an error of, for example, about several degrees, not limited to the case of being strictly orthogonal. In addition, for example, when expressing orthogonal, parallel, coincidence, etc., it includes not only the case of being strictly orthogonal, parallel, coincidence, etc., but also the cases of being approximately parallel, approximately orthogonal, approximately coincident, etc. In addition, in the present invention, "nearby" means a region in a certain range (which can be determined arbitrarily) near a reference position. [Explanation of symbols]

[0087] 1: Detection device 10: Light emitting unit 11: Light emitting part 12: Outer lens part 12a: Recess 13: Inner lens part 13a: Convex lens part 14: Case 14a: Opening 20: Light receiving unit 21: Light receiving part 22: Lens section 23: Plate-shaped member 23a: Slit 24: Case 24a: Opening 30: Case 101:Detection device 111, 112, 113, 114, 115: Light-emitting element 111a: LED element 111b, 111c: Electrode 111d: Bonding wire 111e: Sealing resin 111f: Surface 111g : Lens 116: Substrate 121, 122, 123, 124, 125: Outer lens 121a, 121b, 122a, 122b, 123a, 123b, 124a, 124b, 125a, 125b: Edge 211, 212, 213, 214, 215: Light receiving elements 216: Substrate 221, 222, 223, 224, 225: Lenses 221a, 221b, 222a, 222b, 223a, 223b, 224a, 224b, 225a, 225b: Edge 221c, 221d: Surface 221e, 221g: Side 221f: Curved surface

Claims

1. a light-emitting unit including a light-emitting section including a first light-emitting element and a second light-emitting element, and a first lens section into which light irradiated from the light-emitting section is incident; a light receiving unit including a light receiving section including a first light receiving element and a second light receiving element, and a second lens section that focuses light toward the light receiving section; Equipped with the first light-emitting element and the second light-emitting element are arranged along a second direction that is substantially perpendicular to a first direction along an optical axis, the first lens portion includes a first lens onto which light emitted from the first light-emitting element is incident and a second lens onto which light emitted from the second light-emitting element is incident, the first lens and the second lens are arranged along the second direction, When viewed along the first direction, a first end of the first lens that is an end of the second lens side and a second end of the second lens that is an end of the first lens side overlap each other, the first light receiving element and the second light receiving element are arranged along the second direction, the second lens portion includes a third lens that focuses light onto the first light receiving element and a fourth lens that focuses light onto the second light receiving element, the third lens and the fourth lens are arranged along the second direction, When viewed along the first direction, a third end of the third lens, which is an end of the third lens on the fourth lens side, and a fourth end of the fourth lens, which is an end of the fourth lens on the third lens side, overlap with each other. A detection device characterized by:

2. the first light-emitting element and the second light-emitting element each have a light-emitting lens, The light-emitting lens has a roughened surface.

2. The detection device according to claim 1.

3. the light receiving unit includes a plate-like member having a thickness of approximately 0.05 mm or more and approximately 0.4 mm or less, the plate-like member being provided between the light receiving portion and the second lens portion; the plate-like member is provided adjacent to the light receiving portion, The plate-like member has slits at positions overlapping the first light receiving element and the second light receiving element when viewed along the first direction.

3. The detection device according to claim 1 or 2.

4. the light-emitting unit has a third lens portion provided between the light-emitting portion and the first lens portion, the third lens portion has a convex lens portion onto which light emitted from the light emitting portion is incident when viewed along the first direction, the convex lens portion has a shape that is convex on at least one of two end faces in the first direction when viewed in the second direction, The first lens, the second lens, the third lens, and the fourth lens have a shape that is convex on at least one of two end faces in the first direction when cut along a plane along the first direction and the second direction.

3. The detection device according to claim 1 or 2.

5. the light emitting unit includes a light emitting side case in which the light emitting portion and the first lens portion are provided, the light-receiving unit includes a light-receiving-side case in which the light-receiving portion, the second lens portion, and the plate-like member are provided, the light-emitting side case has a first outer slit, the first outer slit having a longitudinal direction along the second direction, on a surface adjacent to the first lens portion; The light receiving side case has a surface adjacent to the second lens portion, and a longitudinal direction of the light receiving side case is aligned with the second direction. A second outer slit is provided, The size of the second outer slit is smaller than the size of the first outer slit.

4. The detection device according to claim 3.

6. the first end has a first inclined surface that is inclined so that a width of the first lens along the second direction becomes narrower toward the first light-emitting element, the second end has a second inclined surface that is inclined so that the width of the second lens along the second direction becomes narrower toward the second light-emitting element, A tip end portion of the first end farthest from the first light emitting element abuts against the second inclined surface, or a tip end portion of the second end farthest from the second light emitting element abuts against the first inclined surface.

3. The detection device according to claim 1 or 2.

Images