Photoelectric Sensor

Abstract

To provide a photoelectric sensor capable of shielding a light receiving element from noise from the outside with a simple configuration.SOLUTION: A light receiving element 31b is mounted on a first surface 30a of a substrate 30. A light guide block 50 has a light guide part 53 disposed between the front surface of a body case and the first surface 30a. A shield case 70 is disposed on the first surface 30a, has an opening 79 through which incident light can pass, and covers the light receiving element 31b between the first surface 30a and the light guide block 50. A conductive film 90 is disposed between the light guide block 50 and the shield case 70, and covers the opening 79. The substrate 30 has ground wiring to which the shield case 70 is electrically connected. The shield case 70 includes a leaf spring piece 81 which has a contact part 83 contacting a conductive layer of the conductive film 90 and which sandwiches the conductive film 90 between the contact part 83 and the light guide part 53 by a biasing force that biases the contact part 83 toward the light guide part 53.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to photoelectric sensors. [Background technology]

[0002] Conventionally, photoelectric sensors are known that detect the presence or absence of an object by light received by a light receiving element. Some of these photoelectric sensors are equipped with a shield structure that shields the light receiving element from external noise in order to suppress a decrease in the S / N ratio of the light receiving element.

[0003] For example, the photoelectric sensor described in Patent Document 1 has a light receiving lens and a light receiving element that receives light transmitted through the light receiving lens. Between the light receiving lens and the light receiving element, a transparent conductive film and a holding member that engages the light receiving lens are arranged. The surface of the holding member or the entire holding member is conductive. In addition, a flexible substrate is arranged at a position where the light receiving element is sandwiched between the holding member and the flexible substrate. A ground pattern is formed on almost the entire surface of the flexible substrate. This ground pattern is arranged on the back surface of the light receiving element. The holding member is electrically connected to the ground pattern by soldering. In addition, the photoelectric sensor has a fixing member. The fixing member fixes the light receiving lens, the conductive film, the holding member, the light receiving element, and the flexible substrate integrally by sandwiching these components in the arrangement direction of these components. When the light receiving lens, the conductive film, the holding member, the light receiving element, and the flexible substrate are integrally fixed by the fixing member, the conductive film comes into contact with the surface of the holding member. The conductive film comes into contact with the surface of the holding member, thereby being electrically connected to the holding member. Therefore, the conductive film, the holding member, and the ground pattern are electrically connected to each other, and the conductive film, the holding member, and the ground pattern form a shielding structure that shields the light receiving element from external noise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-267594 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the shielding structure described in Patent Document 1 has a complex structure in which a holding member and a conductive film are sandwiched between the light receiving element and the light receiving lens to electrically connect the holding member and the conductive film. In addition, the holding member is not only used to configure the shielding structure but also to position the light receiving element and the light receiving lens. Therefore, the holding member has a complex shape in order to engage the light receiving element and the light receiving lens with the holding member. Thus, there was a problem in that the shielding structure for shielding the light receiving element from external noise was complex. [Means for solving the problem]

[0006] The photoelectric sensor disclosed herein includes a main body case having a light-transmitting window on a front surface, a substrate having a first surface and a second surface facing opposite to each other and accommodated in the main body case with the first surface facing the front surface of the main body case, a light-receiving element mounted on the first surface, a control circuit arranged on at least one of the first surface and the second surface and controlling the light-receiving element, a light-guiding block having a light-guiding section arranged between the front surface and the first surface of the main body case and having a limiting hole that limits the range of light incident on the light-receiving element, and an opening arranged on the first surface through which incident light that has passed through the light-transmitting window from outside the main body case and passed through the limiting hole can pass. and a conductive shielding case covering the light receiving element between the first surface and the light guiding block, and a transparent conductive film arranged between the light guiding block and the shielding case and covering at least the opening, wherein the substrate has a ground wiring to which the shielding case is electrically connected, and the conductive film has a conductive film having conductivity on a surface facing the shielding case, and the shielding case has at least one leaf spring piece having a contact portion in contact with the conductive film and sandwiching the conductive film between the contact portion and the light guiding portion by a biasing force that biases the contact portion toward the light guiding portion. Effect of the Invention

[0007] According to the photoelectric sensor of the present disclosure, the light receiving element can be shielded from external noise with a simple configuration. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a photoelectric sensor according to an embodiment. [Diagram 2] FIG. 2 is a side cross-sectional view of a photoelectric sensor according to an embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of a light guide block, a conductive film, a shield case, and a substrate in the photoelectric sensor according to the embodiment. [Figure 4] FIG. 2 is an exploded perspective view of a light guiding block and a main case in the photoelectric sensor according to the embodiment. [Diagram 5]FIG. 4 is a rear view of a light guide block and a conductive film in the photoelectric sensor according to the embodiment. [Figure 6] FIG. 2 is a perspective view of a substrate and a shield case in the photoelectric sensor according to the embodiment. [Figure 7] FIG. 2 is a side view of a light guide block, a conductive film, a shield case, and a substrate in the photoelectric sensor according to the embodiment. [Figure 8] FIG. 2 is an enlarged side view showing a portion of the light guide block, the conductive film, the shield case, and the substrate in the photoelectric sensor according to the embodiment. [Figure 9] 2 is a cross-sectional view of a light guide block, a conductive film, a shield case, and a substrate in the photoelectric sensor according to the embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the photoelectric sensor will now be described. In addition, the attached drawings may show components enlarged to facilitate understanding. In the attached drawings, the dimensional ratio of the components may differ from the actual one or from that in another drawing. In addition, in the cross-sectional view, hatching of some components may be omitted to facilitate understanding. In this specification, "parallel" and "orthogonal" do not only mean strictly parallel or orthogonal, but also include roughly orthogonal or parallel within the scope of the action and effect of this embodiment. In addition, the term "annular" in this specification may refer to any structure that forms a loop, i.e., a continuous shape without an end, as well as a structure that has a gap such as a C-shape and forms a loop shape as a whole. The shape of the "annular" includes, but is not limited to, a circle, an ellipse, and a polygon with sharp or rounded corners. In addition, the present invention is not limited to these examples, but is intended to include all modifications within the meaning and scope of the claims, which are indicated by the claims.

[0010] The photoelectric sensor 10 of the present embodiment shown in Figs. 1 to 9 is a reflective photoelectric sensor that emits detection light, receives the reflected light of the detection light reflected by the detection object, and detects the presence or absence of the detection object. Here, the direction in which the detection light is emitted is referred to as "forward", and the opposite side of the forward side is referred to as "rearward". The photoelectric sensor 10 has, for example, a cable 22 for outputting the detection result. In the photoelectric sensor 10, the side on which the cable 22 is provided is referred to as "downward", and the opposite side of the downward side is referred to as "upward". In the drawings, the forward side is illustrated by an arrow X, and the upward side is illustrated by an arrow Z. Also, the right direction when viewed from the rear to the front is illustrated by an arrow Y. When arranging the photoelectric sensor 10, the "downward" of the photoelectric sensor 10 does not necessarily have to be vertically downward. The photoelectric sensor 10 can be arranged so that the "forward", "rear", "downward", and "upward" of the photoelectric sensor 10 are oriented in any direction.

[0011] (Overall configuration of photoelectric sensor 10) As shown in FIG. 1 , the photoelectric sensor 10 has a main body case 20 and a light guiding block 50. The light guiding block 50 is held in the main body case 20. For example, a part of the light guiding block 50 is exposed to the outside from the main body case 20. The light guiding block 50 may constitute a part of the main body case 20. Furthermore, the light guiding block 50 does not have to constitute a part of the main body case 20, and the entire light guiding block 50 may be accommodated inside the main body case 20.

[0012] Body case 20 is a generally rectangular box shape that is long in the vertical direction. Body case 20 has a front surface 201, a rear surface 202, side surfaces 203 and 204, a top surface 205, and a bottom surface 206. Note that a part of front surface 201 and a part of side surfaces 203 and 204 are formed by a part of light guiding block 50 exposed from body case 20.

[0013] 1 and 2, a cable holding portion 21 is formed on the lower surface 206. The cable holding portion 21 holds a cable 22 of the photoelectric sensor 10. Note that Fig. 2 shows the main body case 20 and the light guide block 50 in cross section.

[0014] The main body case 20 has, for example, a mounting hole 23a. The light guiding block 50 has, for example, a mounting hole 23b. The mounting hole 23b is provided in a portion of the light guiding block 50 exposed from the main body case 20. The mounting holes 23a and 23b are arranged side by side in the up-down direction on the front surface 201 side of the main body case 20. The mounting hole 23a penetrates the main body case 20 so as to open to both side surfaces 203, 204. The mounting hole 23b penetrates the light guiding block 50 so as to open to both side surfaces 203, 204. A fixing member such as a bolt for fixing the photoelectric sensor 10 is inserted into each of the mounting holes 23a, 23b.

[0015] The main body case 20 has a light-transmitting window 25 on the front surface 201. The main body case 20 has, for example, an opening 24 on the front surface 201. The light-transmitting window 25 is disposed in the opening 24. The light-transmitting window 25 has a light-projecting window portion 25a and a light-receiving window portion 25b. A light-projecting lens 25c may be integrally provided in the light-projecting window portion 25a. Similarly, a light-receiving lens 25d may be integrally provided in the light-receiving window portion 25b. Note that the light-projecting lens 25c may be disposed inside the main body case 20 separately from the light-projecting window portion 25a. Similarly, the light-receiving lens 25d may be disposed inside the main body case 20 separately from the light-receiving window portion 25b. The light-guiding block 50 has a limiting hole 55 through which light that has passed through the light-receiving window portion 25b from outside the main body case 20 can pass.

[0016] The main body case 20 has an opening 26 on the top surface 205. An upper cover 27 is disposed in the opening 26. The upper cover 27 has a display unit 27a and a through hole 27b. The display unit 27a is disposed in approximately the center of the upper cover 27 in the front-to-rear direction. The through hole 27b is disposed behind the display unit 27a. An operation unit 101 of an operation rotor 100 (described later) is disposed in the through hole 27b. The operation rotor 100 is provided, for example, to adjust the sensitivity of the photoelectric sensor 10. The operation unit 101 is disposed so as not to protrude beyond the upper surface of the upper cover 27.

[0017] As shown in FIG. 2, the photoelectric sensor 10 includes a substrate 30, an electronic component 40, a shield case 70, and a conductive film 90. The substrate 30 has a first surface 30a and a second surface 30b. The first surface 30a and the second surface 30b are main surfaces of the substrate 30. For example, the first surface 30a is the front surface of the substrate 30, and the second surface 30b is the back surface of the substrate 30. The substrate 30 is accommodated in the main body case 20 with the first surface 30a facing the front surface 201 of the main body case 20.

[0018] A photoelectric element 31 is mounted on the first surface 30a of the substrate 30. The photoelectric element 31 includes, for example, a light-emitting element 31a and a light-receiving element 31b. The light-emitting element 31a emits detection light and is, for example, a light-emitting diode. The detection light emitted from the light-emitting element 31a passes through the light-emitting window 25a and is emitted to the outside of the photoelectric sensor 10. The light-receiving element 31b receives reflected light that passes through the light-receiving window 25b and enters the photoelectric sensor 10. The light-receiving element 31b is, for example, a line CCD. The photoelectric sensor 10 detects the presence or absence of a detection target based on the light incident on the light-receiving element 31b.

[0019] The shield case 70 is disposed on the first surface 30a. The shield case 70 is conductive. The shield case 70 covers the light receiving element 31b between the first surface 30a and the light guiding block 50. A space exists between the inner surface of the shield case 70 and the light receiving element 31b. That is, the shield case 70 is disposed on the first surface 30a so as not to contact the light receiving element 31b.

[0020] 2 and 3, the shield case 70 has an opening 79 through which incident light can pass that has passed through the light-transmitting window 25 from the outside of the main body case 20 and has passed through the limiting hole 55. The shield case 70 has the opening 79 on, for example, the front surface of the shield case 70.

[0021] The conductive film 90 is disposed between the light guide block 50 and the shield case 70. The conductive film 90 has a transparent sheet shape. The conductive film 90 covers at least the opening 79.

[0022] As shown in FIG. 2, the electronic component 40 is mounted on the second surface 30b of the substrate 30. The electronic component 40 has a rotatable operated portion 42. The rotatable operated portion 42 is rotated around an axis (first rotation axis) parallel to the second surface 30b of the substrate 30. In other words, the electronic component 40 is mounted on the substrate 30 so that the first rotation axis AX1 of the rotatable operated portion 42 is parallel to the second surface 30b of the substrate 30. The electronic component 40 changes its electrical characteristics by rotating the rotatable operated portion 42. The electrical characteristics is, for example, a resistance value, and the electronic component 40 is a single-turn variable resistance element (volume).

[0023] A control circuit 33 is disposed on the substrate 30. The control circuit 33 is composed of a plurality of circuit elements 33a. The circuit elements 33a include elements such as resistors, capacitors, transistors, and ICs. Electronic components 40 constituting the control circuit 33 are disposed on at least one of the first surface 30a and the second surface 30b of the substrate 30. The control circuit 33 controls the light emission of the light-emitting element 31a, and is configured to output a detection signal that detects the presence or absence of a detection target based on the light incident on the light-receiving element 31b. The control circuit 33 drives the light-emitting element 31a, detects the presence or absence of a detection target based on the light incident on the light-receiving element 31b, and outputs a detection signal according to the detection result.

[0024] Furthermore, the control circuit 33 processes a signal based on the operation of the electronic component 40 and adjusts the sensitivity for detecting the detection target. The control circuit 33 adjusts the sensitivity by, for example, adjusting the amount of detection light emitted from the light-emitting element 31a, adjusting the amplification factor for amplifying the signal output from the light-receiving element 31b, etc.

[0025] Display elements 34a and 34b are mounted on the second surface 30b of the substrate 30. The display elements 34a and 34b are disposed on the upper part of the substrate 30. As shown in Figs. 2 and 3, the substrate 30 is fixed to the main body case 20 so that the display elements 34a and 34b are disposed inside the display section 27a of the main body case 20. In Fig. 2, the display elements 34a and 34b are shown overlapping each other. The display elements 34a and 34b are, for example, light-emitting diodes. The display elements 34a and 34b are connected to the control circuit 33. The display elements 34a and 34b are provided to notify the operation state of the photoelectric sensor 10 to the outside. The on / off state of the display elements 34a and 34b is confirmed via the display section 27a of the main body case 20 (for example, the upper cover 27). The operation state is, for example, when the photoelectric sensor 10 is operating, when stable detection is being performed, etc.

[0026] As shown in FIG. 2, the photoelectric sensor 10 may have an operating rotor 100 and an intermediate member 110. The operation rotor 100 is rotatably supported by the main body case 20. More specifically, the main body case 20 rotatably supports the operation rotor 100 by a through hole 27b formed in the upper cover 27 and a support arm 28 formed in the main body case 20. The operation rotor 100 is rotated from the outside around an axis intersecting with the surface of the main body case 20 (for example, the upper surface 205 of the main body case 20). For example, the main body case 20 accommodates the electronic component 40 and supports the operation rotor 100 so that the second rotation axis AX2 of the operation rotor 100 is located at a position different from the first rotation axis AX1 of the rotationally operated portion 42 of the electronic component 40. The distance from the second surface 30b to the second rotation axis AX2 is set to be larger than the distance from the second surface 30b of the substrate 30 to the first rotation axis AX1. That is, the first rotation axis AX1 and the second rotation axis AX2 are not on the same straight line, that is, the axes are misaligned.

[0027] The operation rotor 100 has an operation unit 101. The operation unit 101 is exposed to the outside of the main body case 20 from the through hole 27b. The operation unit 101 has a slit 101a of a predetermined shape. A predetermined tool (e.g., a flathead screwdriver) can be inserted into the slit 101a from the outside of the main body case 20. The operation rotor 100 is rotated forward and backward by the tool inserted into the slit 101a.

[0028] The intermediate member 110 is disposed between the operating rotor 100 and the rotatable operated portion 42 of the electronic component 40. The intermediate member 110 engages with the operating rotor 100 and rotates together with the rotation of the operating rotor 100. The intermediate member 110 engages with the rotatable operated portion 42 and rotates the rotatable operated portion 42.

[0029] For example, the intermediate member 110 is formed to be slidable in a second direction intersecting the second rotation axis AX2 of the operating rotor 100. Furthermore, the intermediate member 110 of this embodiment is configured to be slidable in a first direction intersecting the first rotation axis AX1 of the rotatably operated portion 42. The first direction and the second direction are different from each other. For example, the first direction and the second direction are perpendicular to each other.

[0030] The intermediate member 110 rotates together with the operating rotor 100 by a rotation operation relative to the operating rotor 100. At this time, the intermediate member 110 moves relative to the operating rotor 100 and the rotatably operated part 42 in the second direction and the first direction, and rotates the rotatably operated part 42. In this manner, the axial misalignment between the first rotation axis AX1 of the rotatably operated part 42 of the electronic component 40 and the second rotation axis AX2 of the operating rotor 100 is compensated for.

[0031] Next, light guide block 50, conductive film 90, substrate 30, and shield case 70 will be described in detail. (Light guiding block 50) The light guide block 50 is, for example, a resin molded product. The light guide block 50 has an arrangement surface 51 on the surface of the light guide block 50. The arrangement surface 51 is flat.

[0032] As shown in Figs. 2 and 4, the main case 20 has a main case 29. The main case 29 is generally rectangular and open at the front and top. The rear surface of the main case 29 constitutes a rear surface 202 of the main case 20. Both side surfaces of the main case 29 constitute both side surfaces 203, 204 of the main case 20. The bottom surface of the main case 29 constitutes a bottom surface 206 of the main case 20. The main case 29 has a side wall 29a including the side surface 203 and a side wall 29b including the side surface 204. The side wall 29a and the side wall 29b face each other. The light guiding block 50 is held by the main case 29.

[0033] As shown in Fig. 4, for example, the main case 29 has two retaining protrusions 29c and two positioning protrusions 29d on the inner surface of the main case 29. The two retaining protrusions 29c are located in an upper end region on the inner surface of the main case 29. One of the two retaining protrusions 29c protrudes from the inner surface of the side wall 29a into the main case 29, and the other retaining protrusion 29c protrudes from the inner surface of the side wall 29b into the main case 29. Fig. 4 illustrates only the other retaining protrusion 29c provided on the side wall 29b out of the two retaining protrusions 29c.

[0034] The two positioning protrusions 29d are located in a lower end region on the inner surface of the main case 29. One of the two positioning protrusions 29d protrudes from the side wall 29a into the main case 29, and the other positioning protrusion 29d protrudes from the side wall 29b into the main case 29. Of the two positioning protrusions 29d, only the other positioning protrusion 29d provided on the side wall 29b is shown in Fig. 4.

[0035] The light guiding block 50 has two holding recesses 52 in an upper end region of the light guiding block 50. One of the two holding recesses 52 protrudes from a side surface of the light guiding block 50 facing side wall 29a. The other of the two holding recesses 52 protrudes from a side surface of the light guiding block 50 facing side wall 29b.

[0036] The light guide block 50 is held by the main case 29 with the arrangement surface 51 facing the rear surface 202. The light guide block 50 held by the main case 29 is positioned in the front-rear direction with respect to the main case 29 by the two holding protrusions 29c respectively engaging with the two holding recesses 52 and the arrangement surface 51 abutting against the two positioning protrusions 29d. The arrangement surface 51 is flat and perpendicular to the front-rear direction inside the main body case 20.

[0037] Light guiding block 50 has, for example, a light guiding portion 53 and an attachment portion 54. Light guiding portion 53 and attachment portion 54 are integrally formed. For example, attachment portion 54 is located above light guiding portion 53. Attachment portion 54 is exposed to the outside of main body case 20, for example. Attachment portion 54 has attachment hole 23b. A rear surface of light guiding portion 53 is included in arrangement surface 51. Also, a rear surface of attachment portion 54 is included in arrangement surface 51.

[0038] As shown in FIG. 2, the light guide section 53 is disposed behind the light-transmitting window 25 inside the main body case 20. The light guide section 53 is adjacent to the light-transmitting window 25 in the front-rear direction. The light guide section 53 includes a limiting hole 55 that limits the range of incidence of light to the light receiving element 31b. The light guide section 53 may also include a control hole 56 for guiding the light of the light projecting element 31a forward. In the light guide section 53, the control hole 56 is located below the limiting hole 55. Each of the limiting hole 55 and the control hole 56 penetrates the light guide section 53 in the front-rear direction. Each of the limiting hole 55 and the control hole 56 opens on the arrangement surface 51. The limiting hole 55 is located behind the light receiving window section 25b and is adjacent to the light receiving window section 25b in the front-rear direction. The control hole 56 is located behind the light projecting window section 25a and is adjacent to the light projecting window section 25a in the front-rear direction.

[0039] As shown in FIGS. 3 and 5, the light guide block 50 has a first support portion 57, a second support portion 58, and a third support portion 59 protruding from the arrangement surface 51. The first support portion 57 and the second support portion 58 protrude rearward from an upper end region of the arrangement surface 51. The first support portion 57 and the second support portion 58 are, for example, located above the restricting hole 55. Also, for example, the first support portion 57 and the second support portion 58 protrude rearward from a portion of the arrangement surface 51 that corresponds to the rear surface of the mounting portion 54. Also, for example, the first support portion 57 and the second support portion 58 are located at both ends of the arrangement surface 51 in the left-right direction. Each of the first support portion 57 and the second support portion 58 is in the form of a plate extending perpendicular to the arrangement surface 51. Each of the first support portion 57 and the second support portion 58 is in the form of a plate that is, for example, parallel to the front-rear direction and parallel to the up-down direction.

[0040] The third support portion 59 protrudes rearward from a portion of the arrangement surface 51 near the lower end. The third support portion 59 is located, for example, below the restriction hole 55. For example, the third support portion 59 protrudes rearward from a portion of the arrangement surface 51 that corresponds to the rear surface of the light guiding portion 53. The third support portion 59 has, for example, a ring shape that surrounds the opening of the control hole 56 that opens into the arrangement surface 51. The third support portion 59 extends perpendicular to the arrangement surface 51.

[0041] The first support portion 57 has a first abutment surface 57a on a tip surface of the first support portion 57. The second support portion 58 has a second abutment surface 58a on a tip surface of the second support portion 58. The third support portion 59 has a third abutment surface 59a on a tip surface of the third support portion 59. Each of the first abutment surface 57a, the second abutment surface 58a, and the third abutment surface 59a is flat and parallel to the arrangement surface 51. The first abutment surface 57a, the second abutment surface 58a, and the third abutment surface 59a are located rearward of the arrangement surface 51 and in the same plane.

[0042] In addition, the light guiding block 50 may have a first pin 61 and a second pin 62 . The first pin 61 protrudes backward from the mounting portion 54, for example. As shown in FIG. 2, the "backward" corresponds to the direction from the arrangement surface 51 toward the first surface 30a of the substrate 30. In the figure, the "backward" is the opposite direction to the arrow X. As shown in FIG. 3 and FIG. 5, the light guide block 50 has a recess 63 recessed forward from the arrangement surface 51 between the first support portion 57 and the second support portion 58, for example. The recess 63 is provided on the rear surface of the mounting portion 54, for example. The first pin 61 protrudes backward from the bottom surface of the recess 63 between the first support portion 57 and the second support portion 58. The first pin 61 is columnar. The tip of the first pin 61 is located rearward from the arrangement surface 51. Furthermore, the tip of the first pin 61 is located rearward from the tip of the first support portion 57, i.e., the first abutment surface 57a. That is, the height of the first pin 61 from the arrangement surface 51 is greater than the height of the first support portion 57 from the arrangement surface 51. The light guide block 50 may have a first reinforcing rib 64 connecting the first pin 61 and the first support portion 57. The first reinforcing rib 64 extends on the bottom surface of the recess 63 from the first pin 61 to the first support portion 57.

[0043] The second pin 62 protrudes rearward from the light guiding section 53, for example. The second pin 62 protrudes rearward from the arrangement surface 51 in the light guiding section 53. The second pin 62 is columnar and is provided integrally with the third support section 59, for example. The tip of the second pin 62 is located rearward of the tip of the third support section 59, i.e., the third abutment surface 59a. In other words, the height of the second pin 62 from the arrangement surface 51 is greater than the height of the third support section 59 from the arrangement surface 51.

[0044] The first pin 61 and the second pin 62 are misaligned in the left-right direction. When the light guiding block 50 is viewed from the rear (i.e., the state shown in FIG. 5 ), for example, the first pin 61 is located to the left of the restriction hole 55, and the second pin 62 is located to the right of the restriction hole 55. In addition, the first pin 61 and the second pin 62 are misaligned in the up-down direction. When the light guiding block 50 is viewed from the rear, for example, the first pin 61 is located above the restriction hole 55, and the second pin 62 is located below the restriction hole 55.

[0045] The light guide block 50 may have a positioning pin 65. The positioning pin 65 protrudes backward from the mounting portion 54, for example. The positioning pin 65 protrudes backward from the bottom surface of the recess 63, for example, between the first pin 61 and the second support portion 58. The positioning pin 65 is located, for example, above the limiting hole 55. The positioning pin 65 is columnar. The tip of the positioning pin 65 is located behind the arrangement surface 51. More specifically, the position of the tip of the positioning pin 65 in the front-rear direction is located at the tip of the second support portion 58, that is, between the second abutment surface 58a and the arrangement surface 51. The light guide block 50 may have a second reinforcing rib 66 connecting the positioning pin 65 and the second support portion 58. The second reinforcing rib 66 extends from the positioning pin 65 to the second support portion 58 on the bottom surface of the recess 63.

[0046] (Substrate 30) As shown in Figs. 3 and 6, the substrate 30 is, for example, a flat plate that is long in the vertical direction. The substrate 30 may have a first fixing hole 30c and a second fixing hole 30d. Each of the first fixing hole 30c and the second fixing hole 30d penetrates the substrate 30 from the first surface 30a to the second surface 30b. That is, each of the first fixing hole 30c and the second fixing hole 30d penetrates the substrate 30 in the thickness direction of the substrate 30. The first fixing hole 30c and the second fixing hole 30d are located at positions corresponding to the first pin 61 and the second pin 62, respectively, on the substrate 30 when the substrate 30 is placed on the light guide block 50 with the first surface 30a facing the placement surface 51. The first fixing hole 30c is located, for example, above the light receiving element 31b on the substrate 30. The second fixing hole 30d is located on the substrate 30, for example, below the light receiving element 31b and between the light receiving element 31b and the light emitting element 31a.

[0047] As shown in FIG. 2, FIG. 3, FIG. 6, and FIG. 7, the substrate 30 is arranged with the first surface 30a facing the arrangement surface 51 relative to the light guide block 50 with the first pin 61 inserted in the first fixing hole 30c and the second pin 62 inserted in the second fixing hole 30d. For example, the first pin 61 is press-fitted into the first fixing hole 30c, and the second pin 62 is press-fitted into the second fixing hole 30d. The first pin 61 and the second pin 62 are inserted into the first fixing hole 30c and the second fixing hole 30d, respectively, to position the substrate 30 relative to the light guide block 50 in the left-right direction and the up-down direction. The tip of the first pin 61 and the tip of the second pin 62 are heat-stakingly fixed on the second surface 30b side. This prevents the substrate 30 from coming off the light guide block 50 in a direction away from the arrangement surface 51.

[0048] Moreover, the first surface 30a of the substrate 30 abuts against each of the first abutment surface 57a, the second abutment surface 58a, and the third abutment surface 59a, thereby positioning the substrate 30 with respect to the light guide block 50 in the front-rear direction.

[0049] The substrate 30 is accommodated in the main body case 20 in a state where it is fixed to the light guide block 50, for example. In a state where the substrate 30 is fixed to the light guide block 50, the arrangement surface 51 faces the first surface 30a. The arrangement surface 51 and the first surface 30a are parallel to each other. The arrangement surface 51 and the first surface 30a are perpendicular to the front-rear direction. In the light guide block 50, the light guide unit 53 is disposed between the front surface 201 of the main body case 20 and the first surface 30a of the substrate 30. For example, the entire light guide block 50 is disposed between the front surface 201 and the first surface 30a. Note that even when the front surface of the light guide unit 53 is included in the front surface 201 of the main body case 20, the light guide unit 53 is also disposed between the front surface 201 and the first surface 30a.

[0050] 6, the substrate 30 has a connection cutout 30e. The connection cutout 30e is located on the outer edge of the substrate 30. The connection cutout 30e is located near the light receiving element 31b on the substrate 30. For example, when the substrate 30 is viewed from the first surface 30a side, the connection cutout 30e is located at the upper left of the light receiving element 31b. The connection cutout 30e penetrates the substrate 30 from the first surface 30a to the second surface 30b.

[0051] The substrate 30 has a ground wiring 35. The ground wiring 35 has, for example, a first ground pad 35a exposed from the substrate 30 so as to surround the opening of the connection cutout 30e opened on the first surface 30a. The ground wiring 35 also has a second ground pad 35b exposed on the second surface 30b. The first ground pad 35a and the second ground pad 35b are located near the light receiving element 31b on the substrate 30. For example, when the substrate 30 is viewed from the first surface 30a side, the first ground pad 35a is located at the upper left of the light receiving element 31b, and the second ground pad 35b is located at the lower right of the light receiving element 31b. The ground wiring 35 is connected to the ground via a cable 22 electrically connected to the substrate 30.

[0052] (Shield case 70) As shown in FIG. 3 and FIG. 6 to FIG. 8, the shield case 70 is disposed between the first surface 30a and the arrangement surface 51. The shield case 70 is, for example, made of a single metal plate having a plurality of bent portions 71. For example, when forming the shield case 70, first, a metal plate is punched by press working to form a component in which the shield case 70 is in an unfolded state, that is, before the bent portions 71 are formed. Then, in the component, a surface pressing process is performed on the surface that will become the outer surface of the shield case 70. As a result, burrs generated during the press working are mechanically crushed and removed. After that, the component is bent at a plurality of places to form a plurality of bent portions 71. By forming the bent portions 71, the shield case 70 having a desired shape is formed.

[0053] The material of the shield case 70 may be, for example, any of metal materials such as brass, nickel silver, phosphor bronze, etc. However, the material of the shield case 70 may be a metal material other than brass, nickel silver, and phosphor bronze.

[0054] The shield case 70 has, for example, a covering portion 72 that covers the light receiving element 31b, and a first connecting portion 73a and a second connecting portion 73b for electrically connecting the shield case 70 to the substrate 30.

[0055] The covering portion 72 has, for example, a box shape that is slightly larger than the outer shape of the light receiving element 31b. The covering portion 72 has a first covering portion 74, a second covering portion 75, a third covering portion 76, a fourth covering portion 77, and a fifth covering portion 78. Each of the first covering portion 74, the second covering portion 75, the third covering portion 76, the fourth covering portion 77, and the fifth covering portion 78 has a flat plate shape.

[0056] The first covering portion 74 covers the front of the light receiving element 31b. When the shield case 70 is arranged on the first surface 30a, the outer surface 74a of the first covering portion 74 is parallel to the first surface 30a. The outer surface 74a corresponds to the front surface of the shield case 70. The outer surface 74a is arranged at a position inside the main body case 20 with a small gap between it and the arrangement surface 51. Furthermore, the outer surface 74a is parallel to the arrangement surface 51, for example. The second covering portion 75 covers the upper side of the light receiving element 31b. The third covering portion 76 covers the lower side of the light receiving element 31b. The fourth covering portion 77 and the fifth covering portion 78 each cover the side of the light receiving element 31b. For example, when the substrate 30 is viewed from the side of the first surface 30a, the fourth covering portion 77 covers the left side of the light receiving element 31b, and the fifth covering portion 78 covers the right side of the light receiving element 31b. The second to fifth covering portions 75 to 78 are bent so as to form a right angle with respect to the first covering portion 74. The second to fifth covering portions 75 to 78 as a whole form a frame shape that surrounds the outer periphery of the light receiving element 31b.

[0057] The first connection portion 73a extends from the second covering portion 75. When the substrate 30 is viewed from the first surface 30a side, the first connection portion 73a extends rearward from the left end of the second covering portion 75. The first connection portion 73a is inserted into the connection cutout portion 30e and penetrates the connection cutout portion 30e. The first connection portion 73a is electrically connected to the first ground pad 35a by solder on the second surface 30b of the substrate 30. That is, the shield case 70 is electrically connected to the ground wiring 35 at the first connection portion 73a.

[0058] The second connection portion 73b extends from the third covering portion 76. When the substrate 30 is viewed from the first surface 30a side, the second connection portion 73b extends downward from the right end of the third covering portion 76. The second connection portion 73b is bent so as to be perpendicular to the third covering portion 76. The second connection portion 73b is disposed on the second ground pad 35b. The second connection portion 73b is electrically connected to the second ground pad 35b by solder. That is, the shield case 70 is electrically connected to the ground wiring 35 also at the second connection portion 73b.

[0059] As shown in FIGS. 3, 5, and 8, the first covering portion 74 has an opening 79. The opening 79 penetrates the first covering portion 74 in a direction perpendicular to the first surface 30a. The opening 79 has a portion that overlaps with the light receiving element 31b in the front-rear direction. When viewed from the front, the entire opening of the limiting hole 55 that opens in the arrangement surface 51 overlaps with the opening 79. In other words, when viewed from the front, the opening of the limiting hole 55 that opens in the arrangement surface 51 does not have a portion that overlaps with the first covering portion 74. As shown in FIGS. 2 and 8, in the photoelectric sensor 10, the light receiving window portion 25b, the limiting hole 55, the opening 79, and the light receiving element 31b are arranged in this order from the front.

[0060] 3 and 5, the opening 79 has, for example, a rectangular shape when viewed from a direction perpendicular to the first surface 30a. The direction perpendicular to the first surface 30a is the same as the direction perpendicular to the arrangement surface 51. The shape of the opening 79 is not limited to a rectangular shape, and may be, for example, any of polygonal shapes other than a rectangular shape, a circular shape, an elliptical shape, a rectangular shape with rounded corners, or any other arbitrary shape.

[0061] The shield case 70 has at least one leaf spring piece 81. For example, the shield case 70 has two leaf spring pieces 81, a first leaf spring piece 81a and a second leaf spring piece 81b. The first leaf spring piece 81a and the second leaf spring piece 81b are, for example, integrally provided on the first covering portion 74. The first leaf spring piece 81a and the second leaf spring piece 81b are cut out from the first covering portion 74 and bent. The first leaf spring piece 81a and the second leaf spring piece 81b are, for example, of the same shape.

[0062] When viewed from a direction perpendicular to the first surface 30a, the first leaf spring piece 81a and the second leaf spring piece 81b each extend from the inner periphery of the opening 79 to the inside of the opening 79. That is, the first leaf spring piece 81a and the second leaf spring piece 81b extend from the inner periphery of the first covering portion 74. Each of the first leaf spring piece 81a and the second leaf spring piece 81b is a leaf spring having a cantilever shape. Each of the first leaf spring piece 81a and the second leaf spring piece 81b has an elastic portion 82 that extends from the inner periphery of the opening 79 to the inside of the opening 79, and a contact portion 83 that extends from the tip of the elastic portion 82 in the opposite direction to the base end of the elastic portion 82. Each of the first leaf spring piece 81a and the second leaf spring piece 81b has a contact portion 83 in the tip region of each.

[0063] In each of the first leaf spring piece 81a and the second leaf spring piece 81b, the elastic portion 82 is strip-shaped. The elastic portion 82 has a bent portion 71 in a base end region of the elastic portion 82, and is thereby inclined with respect to the outer surface 74a of the first covering portion 74. The elastic portion 82 is inclined so as to move away from the first surface 30a from the bent portion 71 provided at the base end of the elastic portion 82 toward the tip end of the elastic portion 82. In each of the first leaf spring piece 81a and the second leaf spring piece 81b, the elastic portion 82 is elastically deformed to allow the contact portion 83 to move relative to the base end of the elastic portion 82 in a direction perpendicular to the first surface 30a.

[0064] 3, 5 and 8, the contact portion 83 has, for example, a flat plate shape. Each of the first leaf spring piece 81a and the second leaf spring piece 81b has a bent portion 71 at the boundary between the elastic portion 82 and the contact portion 83. The contact portion 83 is slightly folded back toward the inside of the covering portion 72 with respect to the elastic portion 82.

[0065] When viewed from a direction perpendicular to the first surface 30a, the first leaf spring piece 81a is located above the opening of the limiting hole 55 that opens into the arrangement surface 51. When viewed from the same direction, the second leaf spring piece 81b is located below the opening of the limiting hole 55 that opens into the arrangement surface 51. In the up-down direction, the opening of the limiting hole 55 that opens into the arrangement surface 51 is located between the first leaf spring piece 81a and the second leaf spring piece 81b.

[0066] Here, the center of the opening 79 when the photoelectric sensor 10 is viewed from the front surface 201 of the main body case 20 is defined as the center O1. Incidentally, Fig. 5 is a view of the light guide block 50 viewed from the rear surface 202 of the main body case 20. When viewed from the front surface 201 of the main body case 20, the first leaf spring piece 81a and the second leaf spring piece 81b are, for example, positioned so that the center O1 of the opening 79 is disposed between them. When viewed from the rear surface 202 of the main body case 20, the first leaf spring piece 81a and the second leaf spring piece 81b are, for example, positioned so that the center O1 of the opening 79 is disposed between them.

[0067] When viewed from the front surface 201 of the main body case 20, the direction from the fixed end to the free end of the first leaf spring piece 81a and the direction from the fixed end to the free end of the second leaf spring piece 81b are opposite to each other. In FIG. 5, the direction from the fixed end to the free end of the first leaf spring piece 81a is illustrated by an arrow α1, and the direction from the fixed end to the free end of the second leaf spring piece 81b is illustrated by an arrow α2. The fixed end of the first leaf spring piece 81a corresponds to the base end of the first leaf spring piece 81a, and the free end of the first leaf spring piece 81a corresponds to the tip of the first leaf spring piece 81a. The fixed end of the second leaf spring piece 81b corresponds to the base end of the second leaf spring piece 81b, and the free end of the second leaf spring piece 81b corresponds to the tip of the second leaf spring piece 81b.

[0068] Also, for example, when viewed from the front surface 201 of the main body case 20, the contact portions 83 of the first leaf spring piece 81a and the second leaf spring piece 81b are in a rotationally symmetrical positional relationship with the center O1 of the opening 79 as the center of symmetry. For example, the contact portion 83 of the first leaf spring piece 81a and the contact portion 83 of the second leaf spring piece 81b are in a 180-degree symmetrical positional relationship with the center O1 of the opening 79 as the center of symmetry. In other words, when viewed from the front surface 201 of the main body case 20, the two contact portions 83 are disposed at equal angular intervals in the circumferential direction around the center O1 of the opening 79.

[0069] (Conductive Film 90) As shown in Figs. 7 to 9, the conductive film 90 is disposed between the light guiding block 50 and the shielding case 70 and is in contact with the arrangement surface 51. Fig. 9 is a cross-sectional view taken along line 9-9 in Fig. 7. The conductive film 90 has a conductive film having conductivity on a surface 90a facing the shielding case 70. The conductive film 90 has a conductive film only on one surface 90a in the thickness direction of the conductive film 90, for example. The thickness of the conductive film 90 is slightly smaller than the width of the gap between the arrangement surface 51 and an outer surface 74a of the shielding case 70 in a direction perpendicular to the arrangement surface 51.

[0070] 5, the conductive film 90 is larger than the opening 79 when viewed from a direction perpendicular to the first surface 30a. The conductive film 90 is large enough to cover the opening 79, the first leaf spring piece 81a, and the second leaf spring piece 81b. For example, the size of the portion of the conductive film 90 that overlaps with the first covering portion 74 in the front-rear direction is larger than the opening 79 and slightly smaller than the first covering portion 74.

[0071] As shown in FIG. 3 and FIG. 5, the conductive film 90 has a hole-shaped or notched induction portion 91 penetrating the conductive film 90 in the thickness direction of the conductive film 90. For example, the induction portion 91 is located on the periphery of the conductive film 90 and has a notched shape. The induction portion 91 has a through hole 91a and a through groove 91b. The through hole 91a is a hole penetrating the conductive film 90 in the thickness direction of the conductive film 90. The through groove 91b extends from the through hole 91a to the periphery of the conductive film 90. For example, the through groove 91b extends leftward from the through hole 91a when viewed from the rear surface 202 of the main body case 20, that is, when viewed in the direction of the arrow X. The through groove 91b opens to the through hole 91a and opens to the outer periphery of the conductive film 90. The through groove 91b also penetrates the conductive film 90 in the thickness direction of the conductive film 90. In this specification, as described above, a "cutout shape" refers to a shape having a through hole that penetrates the conductive film in the thickness direction of the conductive film, and a groove that extends from the through hole to the periphery of the conductive film and penetrates the conductive film in the thickness direction of the conductive film.

[0072] By providing the induction portion 91 on the conductive film 90, the conductive film 90 is asymmetric with respect to a straight line that passes through the center of the conductive film 90 in the left-right direction and extends in the up-down direction when viewed in the thickness direction of the conductive film 90. In addition, by providing the induction portion 91 on the conductive film 90, the conductive film 90 is asymmetric with respect to a straight line that passes through the center of the conductive film 90 in the up-down direction and extends in the left-right direction when viewed in the thickness direction of the conductive film 90.

[0073] The conductive film 90 is arranged with the surface 90a having the conductive film facing the first surface 30a in a state where the first pin 61 is inserted into the guiding portion 91. That is, the guiding portion 91 is for guiding the direction in which the surface 90a having the conductive film of the conductive film 90 faces the direction facing the first surface 30a. For example, the guiding portion 91 is located in a position where the first pin 61 is not inserted when the conductive film 90 is arranged so that the surface 90a having the conductive film of the conductive film 90 faces the arrangement surface 51. On the other hand, the guiding portion 91 is located in a position where the first pin 61 is inserted when the front and back of the conductive film 90 are in the correct orientation and the position of the conductive film 90 in the direction parallel to the arrangement surface 51 is correct and the conductive film 90 is arranged relative to the light guide block 50. For this reason, if the conductive film 90 is arranged relative to the light guide block 50 by abutting the first pin 61 against the arrangement surface 51 while inserting the first pin 61 into the guiding portion 91, it is possible to suppress an incorrect assembly of the front and back of the conductive film 90. Furthermore, it is possible to position the conductive film 90 with respect to the light guide block 50 in a direction parallel to the arrangement surface 51. Note that, for example, the first reinforcing rib 64 is also inserted into the guide portion 91. The first reinforcing rib 64 is inserted into the through groove 91b, for example.

[0074] The conductive film 90 may have a positioning hole 92 into which the positioning pin 65 is inserted. The positioning hole 92 is located at a position in the conductive film 90 that is offset from the guiding portion 91. The positioning hole 92 penetrates the conductive film 90 in the thickness direction of the conductive film 90. When the conductive film 90 is positioned relative to the light guiding block 50 with the conductive film 90 positioned correctly in the direction parallel to the arrangement surface 51, the positioning pin 65 is inserted into the positioning hole 92. That is, when the conductive film 90 is positioned relative to the light guiding block 50 by abutting the conductive film 90 against the arrangement surface 51 while inserting the positioning pin 65 into the positioning hole 92, the conductive film 90 can be positioned relative to the light guiding block 50 in the direction parallel to the arrangement surface 51.

[0075] As shown in FIG. 5 and FIGS. 7-8, the conductive film 90 arranged on the light guide block 50 covers the entire opening of the limiting hole 55 opened on the arrangement surface 51. The conductive film 90 is pressed against the arrangement surface 51 by the first leaf spring piece 81a and the second leaf spring piece 81b of the shield case 70. That is, each of the first leaf spring piece 81a and the second leaf spring piece 81b sandwiches the conductive film 90 between the contact portion 83 and the light guide portion 53 by a biasing force that biases the contact portion 83 toward the light guide portion 53. In detail, when the substrate 30 on which the shield case 70 is arranged on the first surface 30a is fixed to the light guide block 50 on which the conductive film 90 is arranged on the arrangement surface 51, each elastic portion 82 is elastically deformed so that the contact portion 83 moves toward the first surface 30a more than in a state before the substrate 30 is fixed to the light guide block 50. Therefore, in each of the first leaf spring piece 81a and the second leaf spring piece 81b, an urging force is generated that presses the contact portion 83 toward the arrangement surface 51. The urging force presses the conductive film 90 against the arrangement surface 51. Therefore, the urging force fixes the conductive film 90 between the light guiding block 50 and the shield case 70. As shown in FIG. 2, in the photoelectric sensor 10, the front surface 201, the light guiding portion 53 of the light guiding block 50, the shield case 70, the light receiving element 31b, and the substrate 30 are arranged in this order from the front surface 201 of the main body case 20 toward the rear.

[0076] 8, the contact portions 83 of the first leaf spring piece 81a and the second leaf spring piece 81b come into contact with the surface 90a of the conductive film 90, and thereby come into contact with the conductive film of the conductive film 90. Therefore, the shield case 70 is electrically connected to the conductive film 90 at the contact portions 83 of the first leaf spring piece 81a and the second leaf spring piece 81b.

[0077] 8 and 9, the contact portion 83 comes into surface contact with the conductive film 90 when the conductive film 90 is sandwiched between the contact portion 83 and the light guiding portion 53. That is, the bending angle of the contact portion 83 with respect to the elastic portion 82 is an angle at which the contact portion 83 comes into surface contact with the surface 90a of the conductive film 90 when the substrate 30 having the shield case 70 arranged on the first surface 30a is fixed to the light guiding block 50. In FIG. 9, the leaf spring piece 81 in a state before the substrate 30 is fixed to the light guiding block 50 is illustrated by a two-dot chain line, and the leaf spring piece 81 in a state in which the substrate 30 is fixed to the light guiding block 50 is illustrated by a solid line.

[0078] (Operation of the embodiment) The operation of this embodiment will be described. The light receiving element 31b is mounted on the first surface 30a of the substrate 30. The shield case 70 covering the light receiving element 31b is disposed on the first surface 30a. The shield case 70 is electrically connected to the ground wiring 35 of the substrate 30. The shield case 70 is disposed between the light guide block 50 and the first surface 30a. A conductive film 90 covering the opening 79 of the shield case 70 is disposed between the shield case 70 and the light guide block 50. The first leaf spring piece 81a and the second leaf spring piece 81b of the shield case 70 sandwich the conductive film 90 between the contact portion 83 and the light guide portion 53 by a biasing force that biases the contact portion 83 toward the light guide portion 53. Each contact portion 83 contacts the conductive film of the conductive film 90, so that the shield case 70 and the conductive film 90 are electrically connected. Therefore, the conductive film 90 and the shield case 70 are connected to the ground via the ground wiring 35 and the cable 22. As a result, a shield structure is formed that covers the front, upper, lower, left, and right sides of the light receiving element 31b.

[0079] (Effects of the embodiment) The effects of this embodiment will be described. (1) The photoelectric sensor 10 includes a main body case 20 having a light-transmitting window 25 on a front surface 201, and a substrate 30 having a first surface 30a and a second surface 30b facing opposite directions and accommodated in the main body case 20 with the first surface 30a facing the front surface 201. The photoelectric sensor 10 also includes a light receiving element 31b mounted on the first surface 30a, and a control circuit 33 arranged on at least one of the first surface 30a and the second surface 30b and controlling the light receiving element 31b. The photoelectric sensor 10 also includes a light guide block 50 having a light guide portion 53 arranged between the front surface 201 and the first surface 30a. The light guide portion 53 includes a limiting hole 55 that limits the range of light incident on the light receiving element 31b. The photoelectric sensor 10 also includes a conductive shield case 70 arranged on the first surface 30a. The shield case 70 has an opening 79 through which incident light that has passed through the light-transmitting window 25 from outside the main body case 20 and the limiting hole 55 can pass, and covers the light-receiving element 31b between the first surface 30a and the light-guiding block 50. The photoelectric sensor 10 also includes a transparent conductive film 90 that is disposed between the light-guiding block 50 and the shield case 70 and covers at least the opening 79. As shown in Fig. 2, the front surface 201, the light-guiding section 53 of the light-guiding block 50, the shield case 70, the light-receiving element 31b, and the substrate 30 are arranged in this order from the front surface 201 of the main body case 20 toward the rear.

[0080] Furthermore, substrate 30 has ground wiring 35 to which shield case 70 is electrically connected. Conductive film 90 has a conductive film having conductivity on surface 90a facing shield case 70. Shield case 70 has at least one leaf spring piece 81 that has contact portion 83 in contact with the conductive film and sandwiches conductive film 90 between contact portion 83 and light guide portion 53 by a biasing force that biases contact portion 83 toward light guide portion 53.

[0081] According to this configuration, the shield case 70 and the conductive film 90 form a shield structure that shields the light receiving element 31b from external noise. The shield case 70 is disposed on the first surface 30a of the substrate 30 on which the light receiving element 31b is disposed, and therefore the shield case 70 can easily cover the light receiving element 31b. Furthermore, the shield case 70 is disposed on the first surface 30a of the substrate 30, and therefore the shield case 70 can easily be electrically connected to the ground wiring 35 of the substrate 30. The shield case 70 also has a leaf spring piece 81 that sandwiches the conductive film 90 between the light guide portion 53. The light guide portion 53 is disposed between the front surface 201 of the main body case 20 and the first surface 30a of the substrate 30, and therefore is located close to the shield case 70. The biasing force of the leaf spring piece 81 presses the contact portion 83 of the leaf spring piece 81 against the conductive film of the conductive film 90. This allows easy electrical connection between the conductive film of the conductive film 90 and the shielding case 70, and also stabilizes the electrical connection between the conductive film of the conductive film 90 and the shielding case 70. As a result, the light receiving element 31b can be shielded from external noise with a simple configuration.

[0082] (2) The shield case 70 has a plurality of leaf spring pieces 81. With this configuration, compared to a case in which the shield case 70 has only one leaf spring piece 81, it is possible to suppress the conductive film 90 from being misaligned in the direction parallel to the first surface 30a of the substrate 30 with respect to the light guide block 50 and the shield case 70.

[0083] (3) Each of the leaf spring pieces 81 has a cantilever shape. With this configuration, the shape of each of the leaf spring pieces 81 can be simplified. This makes it possible to prevent the shape of the shield case 70 from becoming complicated.

[0084] (4) When viewed from the front surface 201 of the main body case 20, the two leaf spring pieces 81 are positioned so that the center O1 of the opening 79 is located between them. This configuration makes it easier to maintain the conductive film 90 covering the opening 79.

[0085] (5) The shield case 70 has two leaf spring pieces 81. When viewed from the front surface 201 of the main case 20, the direction from the fixed end to the free end of the first leaf spring piece 81a of the two leaf spring pieces 81 is opposite to the direction from the fixed end to the free end of the other second leaf spring piece 81b. This configuration makes it easier to maintain the conductive film 90 covering the opening 79.

[0086] (6) The shield case 70 has a plurality of leaf spring pieces 81. When viewed from the front surface 201 of the main body case 20, the contact portions 83 of the plurality of leaf spring pieces 81 are in a rotationally symmetrical positional relationship with the center O1 of the opening 79 as the center of symmetry. This configuration makes it easier to maintain the state in which the conductive film 90 covers the opening 79.

[0087] (7) The leaf spring piece 81 has a shape that is cut out from the shield case 70 and bent. With this configuration, it is possible to prevent an increase in the number of parts that constitute the shield case 70 due to the provision of the leaf spring piece 81 in the shield case 70. Furthermore, the leaf spring piece 81 can be formed by cutting out a portion of the shield case 70 or a portion of a part that will become the shield case 70 into the shape of the leaf spring piece 81 and then bending the cut portion. Therefore, the leaf spring piece 81 can be easily formed.

[0088] (8) The shielding case 70 is made of a single metal plate having multiple bent portions 71. This configuration can reduce the number of parts that make up the shielding case 70. In addition, the shielding case 70 can be easily formed by pressing or the like.

[0089] (9) The contact portion 83 comes into surface contact with the conductive film when the conductive film 90 is sandwiched between the contact portion 83 and the light-guiding portion 53. With this configuration, the conductive film 90 is less likely to shift in position in a direction perpendicular to the thickness direction of the conductive film 90. In addition, the electrical connection between the conductive film of the conductive film 90 and the shielding case 70 becomes more stable.

[0090] (10) The light guide block 50 has an arrangement surface 51 that faces the first surface 30a and is arranged so that the conductive film 90 is in contact with the arrangement surface 51, and a first pin 61 that protrudes from the arrangement surface 51 in a direction toward the first surface 30a. The conductive film 90 has a guide portion 91 that is a hole or a notch shape that penetrates the conductive film 90 in the thickness direction of the conductive film 90. The conductive film 90 has a conductive film only on one surface 90a in the thickness direction of the conductive film 90. The conductive film 90 is arranged with the surface 90a having the conductive film facing the first surface 30a with the first pin 61 inserted into the guide portion 91.

[0091] According to this configuration, when the conductive film 90 is disposed on the light guiding block 50, the conductive film 90 is disposed while the first pin 61 is inserted into the guiding portion 91, so that the surface 90a of the conductive film 90 having the conductive film faces the first surface 30a. Therefore, it is possible to prevent the conductive film 90 from being disposed such that the surface 90a of the conductive film 90 having the conductive film faces the placement surface.

[0092] Furthermore, in this embodiment, inserting the first pin 61 into the guide portion 91 can contribute to the positioning of the conductive film 90 with respect to the light guide block 50 in the direction parallel to the arrangement surface 51.

[0093] (11) The substrate 30 has a first fixing hole 30c that penetrates the substrate 30 from the first surface 30a to the second surface 30b and into which the first pin 61 is inserted. According to this configuration, by inserting the first pin 61 into the first fixing hole 30c, the substrate 30 can be positioned relative to the light guide block 50 in a direction parallel to the arrangement surface 51. The first pin 61 serves both as a pin for determining the direction in which the surface 90a having the conductive film of the conductive film 90 faces (i.e., a guide pin) and as a pin for positioning the substrate 30 relative to the light guide block 50. This makes it possible to reduce the number of pins that the light guide block 50 has. As a result, the shape of the light guide block 50 can be prevented from becoming complicated.

[0094] (12) Light guide block 50 has arrangement surface 51 that faces first surface 30a and is arranged with conductive film 90 in contact therewith, and positioning pins 65 that protrude from arrangement surface 51 in a direction toward first surface 30a. Conductive film 90 has positioning holes 92 into which positioning pins 65 are inserted.

[0095] According to this configuration, by inserting the positioning pin 65 into the positioning hole 92, the conductive film 90 can be positioned relative to the light guiding block 50 in a direction parallel to the arrangement surface 51. In this embodiment, the positioning pin 65 is inserted into the positioning hole 92, and the first pin 61 is inserted into the guide portion 91. Therefore, the conductive film 90 is prevented from rotating relative to the light guiding block 50 around an axis extending in a direction perpendicular to the arrangement surface 51. Then, the substrate 30 can be fixed to the light guiding block 50 in a state in which the conductive film 90 is prevented from rotating relative to the light guiding block 50. Therefore, the process of fixing the substrate 30 having the shield case 70 arranged on the first surface 30a of the light guiding block 50 to the light guiding block 50 having the conductive film 90 arranged thereon can be easily performed.

[0096] (13) The photoelectric sensor 10 further includes a light-projecting element 31a mounted on the first surface 30a. The control circuit 33 controls light projection from the light-projecting element 31a and outputs a detection signal that detects the presence or absence of a detection target based on incident light to the light-receiving element 31b. The light-transmitting window 25 has a light-projecting window portion 25a through which the detection light from the light-projecting element 31a passes and a light-receiving window portion 25b through which the incident light passes.

[0097] According to this configuration, in the photoelectric sensor 10 in which both the photoelectric elements 31, the light emitting element 31a and the light receiving element 31b, are housed inside the main body case 20, the light receiving element 31b can be shielded from external noise with a simple configuration. Also, since both the photoelectric elements 31, the light emitting element 31a and the light receiving element 31b, are housed inside the main body case 20, the internal structure of the main body case 20 is likely to be complicated compared to a case in which only the light receiving element 31b is housed in the main body case 20. In such a photoelectric sensor 10, if the shield structure for the light receiving element 31b can be simplified, the internal structure of the photoelectric sensor 10 can be prevented from becoming complicated.

[0098] (14) In order to electrically connect the shielding case and the conductive film, a conductive double-sided tape may be used. In this case, if a load is not applied to press the double-sided tape and the conductive film against the shielding case, the electrical connection between the shielding case and the conductive film via the double-sided tape becomes unstable. In contrast, in this embodiment, the contact portions 83 of the first leaf spring piece 81a and the second leaf spring piece 81b of the shielding case 70 are pressed against the conductive film of the conductive film 90 by the biasing force of the first leaf spring piece 81a and the second leaf spring piece 81b. Therefore, the electrical connection between the shielding case 70 and the conductive film 90 is more stable than when a conductive double-sided tape is used.

[0099] In addition, in order to electrically connect the shielding case and the conductive film, the arrangement surface of the light guide block and a claw provided at a position on the light guide block away from the arrangement surface toward the rear side may be used. In this case, the shielding case and the conductive film are sandwiched between the arrangement surface and the claw to maintain the shielding case and the conductive film in abutment. However, in this case, due to the dimensional tolerance of the parts, the gap between the arrangement surface and the claw may become wider than the thickness of the shielding case and the conductive film in the front-rear direction. Then, the electrical connection between the shielding case and the conductive film becomes unstable. In contrast, in this embodiment, the elasticity of the first leaf spring piece 81a and the second leaf spring piece 81b can absorb the dimensional tolerance and dimensional error. Then, the biasing force of the first leaf spring piece 81a and the second leaf spring piece 81b presses the contact portion 83 against the conductive film of the conductive film 90, so that the electrical connection between the shielding case 70 and the conductive film 90 is stable.

[0100] (Example of change) This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0101] In the above embodiment, the photoelectric sensor 10 includes the light-projecting element 31a and the light-receiving element 31b. However, the photoelectric sensor 10 does not need to include the light-projecting element 31a. In this case, a photoelectric sensor including the light-projecting element 31a and a photoelectric sensor 10 including the light-receiving element 31b are combined to detect an object to be detected.

[0102] The substrate 30 may have a through hole penetrating the substrate 30 from the first surface 30a to the second surface 30b and into which a positioning pin 65 is inserted. In this way, by inserting the positioning pin 65 into the through hole, the substrate 30 can be positioned relative to the light guide block 50 in a direction parallel to the arrangement surface 51. In this case, the positioning pin 65 serves both as a pin for positioning the conductive film 90 relative to the light guide block 50 in a direction parallel to the arrangement surface 51 and as a pin for positioning the substrate 30 relative to the light guide block 50. Therefore, the number of pins that the light guide block 50 has can be reduced. As a result, the shape of the light guide block 50 can be prevented from becoming complicated.

[0103] The light guiding block 50 may include a plurality of positioning pins 65. In this case, the conductive film 90 has positioning holes 92 in a number corresponding to the number of positioning pins 65. Furthermore, the light guiding block 50 does not need to include the positioning pins 65. In this case, the conductive film 90 does not need to include the positioning holes 92.

[0104] The positions of the first pin 61 and the positioning pin 65 in the light guiding block 50 may be different from those in the above embodiment. The first pin 61 does not have to be inserted into the first fixing hole 30c. For example, the tip of the first pin 61 may be located between the arrangement surface 51 and the first surface 30a. Also, for example, the first pin 61 may be located at a position that does not overlap with the substrate 30 in a direction perpendicular to the first surface 30a. Also, the light guiding block 50 does not have to include the first pin 61 used as a guide pin.

[0105] The induction portion 91 may be a hole penetrating the conductive film 90 in the thickness direction of the conductive film 90. In this case, the induction portion 91 can be used as a positioning hole, and the first pin 61 can be used as a positioning pin. The conductive film 90 does not have to include the induction portion 91.

[0106] The conductive film 90 may have a conductive film on both sides in the thickness direction of the conductive film 90. Light guide block 50 may have three or more fixing pins for fixing substrate 30. Light guide block 50 does not need to have at least one of first pin 61 and second pin 62. In this case, substrate 30 may be fixed to light guide block 50 by screws or the like.

[0107] The contact portion 83 may be configured to make line or point contact with the conductive film when the conductive film 90 is sandwiched between the contact portion 83 and the light guide portion 53 . The shape of the contact portion 83 is not limited to a flat plate. For example, the contact portion 83 may be a hemisphere protruding from the surface of the elastic portion 82 that faces the conductive film 90.

[0108] The shield case 70 may be configured by combining a plurality of metal parts. For example, the shield case 70 may have a plate-shaped metal part that covers the front surface of the light receiving element 31b and a frame-shaped metal part that surrounds the outer periphery of the light receiving element 31b. The plate-shaped metal part and the frame-shaped metal part are assembled together to form a box shape. The leaf spring piece 81 may be cut out from a plate-shaped metal part and bent. In this case, the leaf spring piece 81 can be formed by cutting out a part of the plate-shaped metal part into the shape of the leaf spring piece 81 and then bending the cut out part. The step of cutting out a part of the plate-shaped metal part into the shape of the leaf spring piece 81 and the step of bending the part into the shape of the leaf spring piece 81 may be performed simultaneously. In addition, the method of cutting out a part of the plate-shaped metal part into the shape of the leaf spring piece 81 may be press working, or a method other than press working may be used.

[0109] When viewed from the front surface 201 of the main body case 20, the contact portions 83 of the plurality of leaf spring pieces 81 do not have to be in a rotationally symmetrical positional relationship with the center O1 of the opening 79 as the center of symmetry. The direction from the fixed end to the free end of the first leaf spring piece 81a and the direction from the fixed end to the free end of the second leaf spring piece 81b do not have to be opposite to each other when viewed from the front surface 201 of the main body case 20. For example, the direction from the fixed end to the free end of the first leaf spring piece 81a and the direction from the fixed end to the free end of the second leaf spring piece 81b may be directions that intersect perpendicularly to each other or may be the same direction when viewed from the front surface 201 of the main body case 20.

[0110] When viewed from the front surface 201 of the main body case 20, the center O1 of the opening 79 does not have to be located between the first leaf spring piece 81a and the second leaf spring piece 81b. The leaf spring piece 81 does not have to be in a cantilever shape as long as it functions as a leaf spring. That is, the leaf spring piece 81 may have any shape that allows the conductive film 90 to be sandwiched between a contact portion that contacts the conductive film of the conductive film 90 and the light guide portion 53. The first leaf spring piece 81a and the second leaf spring piece 81b may have different shapes.

[0111] In the above embodiment, the shield case 70 has two leaf spring pieces 81. However, the shield case 70 may have three or more leaf spring pieces 81. In this case, the leaf spring pieces 81 may be positioned such that the center O1 of the opening 79 is located between each of them when viewed from the front surface 201 of the main body case 20. In this way, it is possible to achieve the same effect as that of the above embodiment (4). Also, the shield case 70 may have only one leaf spring piece 81.

[0112] In the above embodiment, the leaf spring piece 81 extends from the inner peripheral edge of the opening 79 toward the inside of the opening 79. However, the leaf spring piece 81 may be cut and raised at a location on the first covering portion 74 separate from the opening 79.

[0113] The substrate 30 may be fixed to the main case 20 instead of to the light guiding block 50. For example, the substrate 30 may be fixed to the main case 29. In the above embodiment, the entire light guiding block 50 is disposed between the front surface 201 of the main body case 20 and the first surface 30a of the substrate 30. However, it is sufficient that at least the light guiding section 53 of the light guiding block 50 is disposed between the front surface 201 and the first surface 30a.

[0114] The shape of light guide block 50 is not limited to that in the above embodiment. Light guide block 50 may have at least light guide portion 53 having limiting hole 55. In the above embodiment, the main body case 20 has the cable holding portion 21 on the bottom surface 206. However, the main body case 20 may have the cable holding portion 21 on any of the front surface 201, the rear surface 202, the side surfaces 203 and 204, and the top surface 205. That is, the cable 22 may be drawn out from the main body case 20 in any of the directions toward the front, rear, side, and above the photoelectric sensor 10.

[0115] The photoelectric sensor 10 may include a light receiving lens 25d separate from the light receiving window 25b. In this case, the photoelectric sensor 10 may include an adjustment unit that moves the light receiving lens 25d up and down. In this way, the detection distance of the photoelectric sensor 10 can be adjusted. (Appendix 1) a main body case having a light-transmitting window on a front surface; a substrate having a first surface and a second surface facing in opposite directions and accommodated in the main body case with the first surface facing the front surface of the main body case; A light receiving element mounted on the first surface; a control circuit disposed on at least one of the first surface and the second surface and controlling the light receiving element; a light guiding block having a light guiding portion disposed between the front surface and the first surface of the main body case and including a limiting hole for limiting a range of light incident on the light receiving element; a conductive shield case disposed on the first surface, the conductive shield case having an opening through which incident light that has passed through the light-transmitting window from the outside of the main body case and the limiting hole can pass, the conductive shield case covering the light-receiving element between the first surface and the light guiding block; a transparent conductive film that is disposed between the light guiding block and the shielding case and covers at least the opening; Equipped with the substrate has a ground wiring to which the shielding case is electrically connected, the conductive film includes a conductive film having conductivity on a surface facing the shield case, The shielding case is a photoelectric sensor having at least one leaf spring piece having a contact portion that contacts the conductive film and that sandwiches the conductive film between the contact portion and the light-guiding portion by a biasing force that biases the contact portion toward the light-guiding portion. (Appendix 2) The photoelectric sensor according to claim 1, wherein the shielding case has a plurality of the leaf spring pieces. (Appendix 3) 3. The photoelectric sensor according to claim 2, wherein each of the leaf spring pieces has a cantilever shape. (Appendix 4) 4. The photoelectric sensor according to claim 2, wherein the leaf spring pieces are positioned such that the center of the opening is disposed between the leaf spring pieces when viewed from the front surface of the main body case. (Appendix 5) The shield case has two of the leaf spring pieces, 5. A photoelectric sensor according to any one of claims 1 to 4, wherein, when viewed from the front surface of the main body case, a direction from the fixed end to the free end of one of the leaf spring pieces and a direction from the fixed end to the free end of the other of the leaf spring pieces are opposite to each other. (Appendix 6) The shield case includes a plurality of the leaf spring pieces, 3. The photoelectric sensor according to claim 2, wherein, when viewed from the front surface of the main body case, the contact portions of the plurality of leaf spring pieces are positioned in a rotationally symmetrical relationship with the center of the opening as the center of symmetry. (Appendix 7) 7. The photoelectric sensor according to claim 1, wherein the leaf spring piece is cut out from the shielding case and bent. (Appendix 8) 8. The photoelectric sensor according to claim 1, wherein the shielding case is made of a single metal plate having a plurality of bent portions. (Appendix 9) 9. The photoelectric sensor according to claim 1, wherein the contact portion is in surface contact with the conductive film when the conductive film is sandwiched between the contact portion and the light-guiding portion. (Appendix 10) the light guiding block has an arrangement surface facing the first surface and arranged so that the conductive film is in contact with the arrangement surface, and a guide pin protruding from the arrangement surface in a direction toward the first surface, The photoelectric sensor of any one of Supplementary Note 1 to Supplementary Note 9, wherein the conductive film has a guide portion having a hole-like or notch-like shape penetrating the conductive film in a thickness direction of the conductive film, and the conductive film is provided only on one surface of the conductive film in the thickness direction, and the surface having the conductive film is disposed facing the first surface with the guide pin inserted into the guide portion. (Appendix 11) 11. The photoelectric sensor of claim 10, wherein the substrate has a fixing hole penetrating the substrate from the first surface to the second surface and into which the guide pin is inserted. (Appendix 12) the light guide block has an arrangement surface facing the first surface and arranged so that the conductive film is in contact with the arrangement surface, and a positioning pin protruding from the arrangement surface in a direction toward the first surface, 12. The photoelectric sensor according to claim 1, wherein the conductive film has a positioning hole into which the positioning pin is inserted. (Appendix 13) Further comprising a light emitting element mounted on the first surface, the control circuit is configured to control light emission from the light-emitting element and to output a detection signal indicating the presence or absence of a detection target based on the light incident on the light-receiving element; 13. The photoelectric sensor according to claim 1, wherein the light-transmitting window has a light-emitter window portion through which the detection light from the light-emitter element passes and a light-receiving window portion through which the incident light passes. [Explanation of symbols]

[0116] O1 center 10 Photoelectric Sensor 20 Main unit case 201 Front 25 Translucent window 25a Light projection window 25b Light receiving window 30 Substrate 30a 1st page 30b 2nd side 30c 1st fixing hole (fixing hole) 31a Light emitting element 31b Photodetector 33 Control circuit 35 Ground wiring 50 Light Guide Block 51 Placement plane 53 Light guide section 55 Restriction hole 61 First pin (guiding pin) 65 Positioning pin 70 Shielding case 71 Bend 79 Aperture 81 Leaf spring piece 81a First leaf spring piece (leaf spring piece) 81b Second leaf spring piece (leaf spring piece) 83 Contact Part 90 Conductive Film 90a side 91 Guidance part 92 Positioning hole

Claims

1. a main body case having a light-transmitting window on a front surface; a substrate having a first surface and a second surface facing in opposite directions and accommodated in the main body case with the first surface facing the front surface of the main body case; A light receiving element mounted on the first surface; a control circuit disposed on at least one of the first surface and the second surface and controlling the light receiving element; a light guiding block including a light guiding portion disposed between the front surface and the first surface of the main body case and including a limiting hole for limiting a range of light incident on the light receiving element; a conductive shield case disposed on the first surface, the conductive shield case having an opening through which incident light that has passed through the light-transmitting window from the outside of the main body case and the limiting hole can pass, the conductive shield case covering the light-receiving element between the first surface and the light guiding block; a transparent conductive film disposed between the light guiding block and the shielding case and covering at least the opening; the substrate has a ground wiring to which the shielding case is electrically connected, the conductive film includes a conductive film having conductivity on a surface facing the shield case, The shielding case is a photoelectric sensor having at least one leaf spring piece having a contact portion that contacts the conductive film and that sandwiches the conductive film between the contact portion and the light-guiding portion by a biasing force that biases the contact portion toward the light-guiding portion.

2. 2. The photoelectric sensor according to claim 1, wherein the shield case has a plurality of the leaf spring pieces.

3. 3. The photoelectric sensor according to claim 2, wherein each of said leaf spring pieces has a cantilever shape.

4. 4. The photoelectric sensor according to claim 2, wherein the leaf spring pieces are positioned such that the center of the opening is located between the leaf spring pieces when viewed from the front surface of the main body case.

5. The shield case has two leaf spring pieces, 2. The photoelectric sensor according to claim 1, wherein, when viewed from the front surface of the main body case, the direction from the fixed end to the free end of one of the leaf spring pieces is opposite to the direction from the fixed end to the free end of the other of the leaf spring pieces.

6. The shield case includes a plurality of the leaf spring pieces, 2. The photoelectric sensor according to claim 1, wherein, when viewed from the front surface of the main body case, the contact portions of the plurality of leaf spring pieces are positioned in a rotationally symmetrical relationship with the center of the opening as a center of symmetry.

7. 2. The photoelectric sensor according to claim 1, wherein the leaf spring piece is cut out from the shield case and bent.

8. 2. The photoelectric sensor according to claim 1, wherein the shield case is made of a single metal plate having a plurality of bent portions.

9. The photoelectric sensor according to claim 1 , wherein the contact portion is in surface contact with the conductive film when the conductive film is sandwiched between the contact portion and the light guiding portion.

10. the light guiding block has an arrangement surface that faces the first surface and is arranged so that the conductive film is in contact with the arrangement surface, and a guide pin that protrudes from the arrangement surface in a direction toward the first surface, 2. The photoelectric sensor according to claim 1, wherein the conductive film has a guide portion having a hole-like or notch-like shape penetrating the conductive film in a thickness direction of the conductive film, and the conductive film is provided on only one surface of the conductive film in the thickness direction, and the surface having the conductive film is arranged facing the first surface with the guide pin inserted into the guide portion.

11. The photoelectric sensor according to claim 10 , wherein the substrate has a fixing hole penetrating the substrate from the first surface to the second surface and into which the guide pin is inserted.

12. the light guide block has a placement surface facing the first surface and in contact with the conductive film, and a positioning pin protruding from the placement surface in a direction toward the first surface, 2. The photoelectric sensor according to claim 1, wherein the conductive film has positioning holes into which the positioning pins are inserted.

13. Further comprising a light emitting element mounted on the first surface, the control circuit is configured to control light emission from the light-emitting element and to output a detection signal indicating the presence or absence of a detection target based on the light incident on the light-receiving element; 2. The photoelectric sensor according to claim 1, wherein the light-transmitting window has a light-emitter window portion through which the detection light from the light-emitter element passes, and a light-receiving window portion through which the incident light passes.

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