Reflective optical sensor and detection device

Abstract

To provide a reflective optical sensor and a detection device that can prevent dust adhering to the lens surface from causing false detection.SOLUTION: A reflective optical sensor includes a light-emitting element that emits first light, a first lens having a first lens surface that transmits the first light, and causes the first light to exit from the first lens surface and to direct the first light toward a detection position, a second lens having a second lens surface that transmits second light that comes from the detection position and is incident on the second lens surface, a light-receiving element that receives the second light, and a light-shielding wall that blocks light from reaching any position on the first lens surface to any position on the second lens surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to reflective optical sensors and sensing devices. [Background technology]

[0002] Patent Document 1 discloses a reflective optical sensor. In this reflective optical sensor, the upper surface of a convex lens portion of a lens emits irradiated light, and reflected light is incident on the upper surface of the convex lens portion. A light-shielding portion blocks the irradiated light propagating within the lens. This prevents internally reflected light from entering a light-receiving element when it is caused by dirt or the like adhering to the upper surface of the lens (see paragraphs 0016, 0028-0031, 0042, and Figure 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6817479 Summary of the Invention [Problem to be solved by the invention]

[0004] In the reflective optical sensor disclosed in Patent Document 1, when paper dust or the like attached to the light-emitting surface from which the irradiated light is emitted and the light-incident surface to which the reflected light is incident scatters the light and generates diffusely reflected light, the diffusely reflected light may enter the light-receiving element, and therefore the paper dust or the like may cause false detection.

[0005] In view of this problem, an aspect of the present disclosure provides a reflective optical sensor and a detection device that can prevent, for example, dust adhering to a lens surface from causing false detection. [Means for solving the problem]

[0006] A reflective optical sensor according to one embodiment of the present disclosure includes a light-emitting element that emits first light, a first lens having a first lens surface that transmits the first light, causing the first light to exit the first lens surface and direct the first light toward a detection position, a second lens having a second lens surface that transmits second light that comes from the detection position and is incident on the second lens surface, a light-receiving element that receives the second light, and a light-shielding wall that blocks light from reaching any position on the first lens surface to any position on the second lens surface.

[0007] Another aspect of the detection device of the present disclosure includes a reflective optical sensor and a structure that defines a path along which an object to be detected by the reflective optical sensor passes, wherein the reflective optical sensor includes a light-emitting element that emits first light, a first lens having a first lens surface that transmits the first light, causing the first light to exit from the first lens surface and direct the first light toward a detection position, a second lens having a second lens surface that transmits second light that comes from the detection position and enters the second lens surface, and a light-receiving element that receives the second light, and the structure includes a light-shielding wall that blocks light from any position on the first lens surface to any position on the second lens surface. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view schematically illustrating a detection device according to a first embodiment. [Figure 2] FIG. 2 is a top view schematically illustrating a reflective optical sensor provided in the detection device of the first embodiment. [Figure 3] FIG. 1 is an enlarged cross-sectional view schematically illustrating a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in the detection device of the first embodiment, as well as first paper powder adhering to the first lens and second paper powder adhering to the second lens. [Figure 4] 10 is an enlarged cross-sectional view schematically illustrating a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in a detection device of a second embodiment. FIG. [Figure 5]10 is an enlarged cross-sectional view schematically illustrating a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in a detection device of a third embodiment. FIG. [Figure 6] FIG. 10 is an enlarged cross-sectional view schematically illustrating a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in a detection device of a fourth embodiment, and a light-shielding wall of a structure provided in the detection device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0010] 1. First embodiment 1.1 Detection Device FIG. 1 is a cross-sectional view that schematically illustrates a detection device according to a first embodiment.

[0011] The detection device 1 of the first embodiment shown in FIG. 1 is incorporated into a multifunction peripheral, copier, or printer. The detection device 1 detects paper P present at a detection position DP within a path PT along which transported paper P passes. The detection device 1 is provided with measures to prevent paper dust that falls off the detected paper P from causing false detection. The detection device 1 may be incorporated into devices other than multifunction peripherals, copiers, and printers. The detection device 1 may also detect objects other than paper P. The measures provided to the detection device 1 also prevent dust other than paper dust from causing false detection.

[0012] As shown in FIG. 1, the detection device 1 includes a reflective optical sensor 11 and a structure 12 .

[0013] The reflective optical sensor 11 detects the paper P. In doing so, the reflective optical sensor 11 emits a first light L1 and directs the emitted first light L1 toward a detection position DP. The detection position DP is located above the reflective optical sensor 11. When the paper P is present at the detection position DP, the paper P reflects the first light L1, generating a second light L2. When the paper P is not present at the detection position DP, the second light L2 is not generated. The reflective optical sensor 11 receives the second light L2 coming from the detection position DP. When the reflective optical sensor 11 receives the second light L2, it detects the paper P, and when it does not receive the second light L2, it does not detect the paper P. The reflective optical sensor 11 is also called a reflective photointerrupter. The reflective optical sensor 11 is a light modulation photointerrupter. The reflective optical sensor 11 may be a photointerrupter other than a light modulation photointerrupter. The reflective optical sensor 11 is installed so that the detection position DP is located vertically above the reflective optical sensor 11.

[0014] The structure 12 defines a path PT along which the paper P passes. The path PT is located above the reflective optical sensor 11. The structure 12 is made of metal. The structure 12 is fabricated by sheet metal processing. The structure 12 may be made of a material other than metal. The structure 12 may be fabricated by a fabrication method other than sheet metal processing.

[0015] 1.2 Reflective optical sensor FIG. 2 is a top view schematically illustrating a reflective optical sensor provided in the detection device of the first embodiment.

[0016] As shown in Figures 1 and 2, the reflective optical sensor 11 includes a light-emitting element 21, a first primary molded lens 22, a first lens 23, a second lens 24, a second primary molded lens 25, a light-receiving element 26, a frame 27, a housing 28, a connector 29, and a light-shielding wall 30.

[0017] The light emitting element 21 emits a first light L1. The light emitting element 21 emits the first light L1 in accordance with an input signal. The light emitting element 21 is a light emitting diode (LED). The light emitting element 21 may be a light emitting element other than an LED. The emitted first light L1 is infrared light. The first light L1 may be light other than infrared light.

[0018] The first primary molded lens 22 transmits the first light L1 emitted by the light emitting element 21 and directs the first light L1 toward the detection position DP via the first lens 23. The first primary molded lens 22 is a plano-convex lens. The first primary molded lens 22 condenses the first light L1 that is transmitted through it.

[0019] The first lens 23 has a first lens surface 23a. The first lens surface 23a is an emission surface facing the direction of the detection position DP. The first lens 23 transmits the first light L1 that has passed through the first primary molded lens 22, causing the first light L1 to exit from the first lens surface 23a and direct the first light L1 toward the detection position DP. The first lens surface 23a is a convex lens surface. The first lens 23 focuses the first light L1 that is transmitted through it.

[0020] When the paper P is present at the detection position DP, the first light L1 traveling toward the detection position DP is reflected by the paper P, generating reflected light. The generated reflected light becomes the second light L2.

[0021] The second lens 24 has a second lens surface 24a. The second lens surface 24a is an incident surface facing the direction of the detection position DP. The second lens 24 transmits the second light L2 that comes from the detection position DP and is incident on the second lens surface 24a, and directs the second light L2 toward the light receiving element 26 via the second primary molded lens 25.

[0022] The second primary molded lens 25 transmits the second light L2 that has transmitted through the second lens 24, and directs the second light L2 toward the light receiving element 26. The second primary molded lens 25 is a plano-convex lens. The second primary molded lens 25 condenses the second light L2 that is transmitted through it.

[0023] The light receiving element 26 receives the second light L2. The light emitting element 21 outputs a signal according to the received second light L2. The light receiving element 26 is a photodiode. The light receiving element 26 may be a light receiving element other than a photodiode.

[0024] The frame 27 supports the light emitting element 21 and the light receiving element 26 .

[0025] The housing 28 is formed with a first internal space 28a, a second internal space 28b, a third internal space 28c, a fourth internal space 28d, and a fifth internal space 28e. The first internal space 28a is exposed on the top surface of the housing 28. The second internal space 28b and the fourth internal space 28d are continuous with the first internal space 28a and are located below the first internal space 28a. The third internal space 28c and the fifth internal space 28e are continuous with the second internal space 28b and the fourth internal space 28d, respectively, and are located below the second internal space 28b and the third internal space 28c, respectively. The first internal space 28a houses the first lens 23, the second lens 24, and the light-shielding wall 30. The second internal space 28b and the fourth internal space 28d house the first primary molded lens 22 and the second primary molded lens 25, respectively. The third internal space 28c and the fifth internal space 28e respectively accommodate the light emitting element 21 and the light receiving element 26. The housing 28 holds the first primary molded lens 22, the first lens 23, the second lens 24, the second primary molded lens 25, the frame 27, and the light-shielding wall 30. The housing 28 is made of an opaque material that does not transmit the first light L1 and the second light L2.

[0026] The connector 29 is coupled to the housing 28. Signals, power required to operate the reflective optical sensor 11, and the like are input to the connector 29. The connector 29 outputs signals.

[0027] 1.3 Shading walls 1 and 2, the first lens 23 and the second lens 24 are arranged in a direction D and are spaced apart from each other in the direction D. The first lens surface 23a and the second lens surface 24a are also arranged in a direction D and are spaced apart from each other in the direction D. The reflective optical sensor 11 is installed so that the direction D is horizontal.

[0028] The light-shielding wall 30 is disposed between the first lens 23 and the second lens 24, and between the first lens surface 23a and the second lens surface 24a. As a result, the light-shielding wall 30 separates the first lens 23 and the second lens 24 from each other, and separates the first lens surface 23a and the second lens surface 24a from each other.

[0029] The thickness direction of the light-shielding wall 30 is parallel to the direction D.

[0030] The light-shielding wall 30 is made of an opaque material that does not transmit the first light L1 and the second light L2.

[0031] 1 and 2, the light-shielding wall 30 has a first end 41 and a second end 42. The first end 41 is on the side opposite to the side where the detection position DP is located. The second end 42 is on the side where the detection position DP is located. The detection position DP is above the reflective optical sensor 11. Therefore, the first end 41 is the lower end, and the second end 42 is the upper end.

[0032] The first end 41 is at the same height as or lower than the lowest parts of the first lens 23 and the second lens 24, and is in contact with the housing 28. As a result, the light-shielding wall 30 separates the optical path of the first light L1 from the optical path of the second light L2 below the first lens 23 and the second lens 24. As a result, it is possible to prevent the first light L1 from entering the light-receiving element 26 via the second primary molded lens 25 below the first lens 23 and the second lens 24.

[0033] The second end 42 is at the same height as or higher than the top of the first lens 23 and the second lens 24, and reaches the same height as the top surface of the housing 28. This prevents one of the first and second lenses 23 and 24 from being seen through to the other of the first and second lenses 23 and 24, and prevents one of the first and second lens surfaces 23a and 24a from being seen through to the other of the first and second lens surfaces 23a and 24a. This causes the light shielding wall 30 to interfere with the path of light from any position on the first lens surface 23a to any position on the second lens surface 24a. This prevents light from reaching any position on the first lens surface 23a to any position on the second lens surface 24a.

[0034] Light-shielding wall 30 does not obstruct the view of detection position DP from first lens surface 23a and second lens surface 24a. As a result, light-shielding wall 30 does not interfere with the optical path of first light L1 traveling from an arbitrary position on first lens surface 23a to detection position DP, and does not interfere with the optical path of second light L2 traveling from detection position DP to an arbitrary position on second lens surface 24a. As a result, light-shielding wall 30 does not block first light L1 traveling from an arbitrary position on first lens surface 23a to detection position DP, and does not block second light L2 traveling from detection position DP to an arbitrary position on second lens surface 24a.

[0035] 1.4 Suppression of false detection by light-shielding walls FIG. 3 is an enlarged cross-sectional view that schematically illustrates the first lens, the second lens, and the light-shielding wall of the reflective optical sensor provided in the detection device of the first embodiment, as well as the first paper powder adhering to the first lens and the second paper powder adhering to the second lens.

[0036] As shown in FIG. 3, when first paper dust particles PP1 and second paper dust particles PP2 adhere to first lens surface 23a and second lens surface 24a, respectively, first light L1 strikes first paper dust particles PP1. As a result, a portion of first light L1 is diffusely reflected by first paper dust particles PP1, generating first diffusely reflected light DRL1. As a result, only a portion of first light L1 becomes transmitted light TL toward detection position DP. Therefore, the transmitted light TL toward detection position DP is weakened. Without light-shielding wall 30, the generated first diffusely reflected light DRL1 is further diffusely reflected by second paper dust particles PP2, generating second diffusely reflected light DRL2. The generated second diffusely reflected light DRL2 is incident on second lens surface 24a, sequentially passes through second lens 24 and second primary mold lens 25, and is received by light-receiving element 26. This results in false detection, in which paper P is detected even when paper P is not present at detection position DP. However, when the light-shielding wall 30 is provided, the generated first diffused reflection light DRL1 is blocked by the light-shielding wall 30, and the second diffused reflection light DRL2 is not generated. Therefore, false detection does not occur. Therefore, it is possible to prevent the first paper dust PP1 and the second paper dust PP2 from becoming a cause of false detection.

[0037] 1.5 Tilt of the first and second lenses As shown in Figures 2 and 3, the first lens 23 and the second lens 24 have a plate-like shape. Therefore, the first lens 23 has a first main surface 23m. The second lens 24 has a second main surface 24m. The first main surface 23m is on the side where the detection position DP is located. The second main surface 24m is on the side where the detection position DP is located. The first main surface 23m includes a first lens surface 23a and a first flat surface 23b. The second main surface 24m includes a second lens surface 24a and a second flat surface 24b. The first lens surface 23a protrudes from the first flat surface 23b. The second lens surface 24a protrudes from the second flat surface 24b.

[0038] The baffle wall 30 has a plate-like shape. Therefore, the baffle wall 30 has a first wall surface 30a and a second wall surface 30b. The first wall surface 30a is on the side where the first lens 23 is disposed. The second wall surface 30b is on the side where the second lens 24 is disposed.

[0039] The first lens 23 and the second lens 24 are inclined from a state parallel to direction D to a state facing each other, and from a state parallel to direction D to a state toward the side where the baffle wall 30 is disposed. Therefore, the first main surface 23m has a first inclined region 23n that slopes down toward the baffle wall 30. The second main surface 24m has a second inclined region 24n that slopes down toward the baffle wall 30. The first inclined region 23n consists of a portion of the first lens surface 23a closer to the baffle wall 30 and the entire first flat surface 23b. The second inclined region 24n consists of a portion of the second lens surface 24a closer to the baffle wall 30 and the entire second flat surface 24b. The first inclined region 23n guides paper dust adhering to the first main surface 23m toward the side where the baffle wall 30 is disposed. The second inclined region 24n guides paper dust adhering to the second main surface 24m to the side where the light-shielding wall 30 is disposed.

[0040] The first inclined region 23n and the first wall surface 30a form an acute angle. The second inclined region 24n and the second wall surface 30b form an acute angle. A space G1 along the intersection line between the first inclined region 23n and the first wall surface 30a serves as a collection area for collecting the first paper dust PP1 that has been introduced. A space G2 along the intersection line between the second inclined region 24n and the second wall surface 30b serves as a collection area for collecting the second paper dust PP2 that has been introduced. This makes it possible to prevent the first paper dust PP1 and the second paper dust PP2 from diffusely reflecting light and causing scattered light.

[0041] 2. Second embodiment The following describes the differences between the second embodiment and the first embodiment. For points that are not described, the second embodiment also employs the same configuration as that employed in the first embodiment.

[0042] FIG. 4 is an enlarged cross-sectional view that schematically illustrates a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in a detection device of the second embodiment.

[0043] In the second embodiment, as shown in FIG. 4, the second end 42 has a convex cross-sectional shape.

[0044] The second end 42 includes a protruding portion 51 , a first non-protruding portion 52 and a second non-protruding portion 53 .

[0045] The protruding portion 51 is formed between the first non-protruding portion 52 and the second non-protruding portion 53 in the direction D. The first non-protruding portion 52 is on the side where the first lens 23 is disposed relative to the protruding portion 51. The second non-protruding portion 53 is on the side where the second lens 24 is disposed relative to the protruding portion 51. The protruding portion 51 protrudes further from the first non-protruding portion 52 and the second non-protruding portion 53 toward the side where the detection position DP is located.

[0046] The protrusion 51 has a tip surface 51a, a first side surface 51b, and a second side surface 51c. The tip surface 51a is closest to the detection position DP. The tip surface 51a is parallel to the direction D and faces upward. Therefore, paper dust accumulates on the tip surface 51a. The first side surface 51b is located on the opposite side of the tip surface 51a from the detection position DP and on the side where the first lens 23 is located from the tip surface 51a. The second side surface 51c is located on the opposite side of the tip surface 51a from the detection position DP and on the side where the second lens 24 is located from the tip surface 51a. The first side surface 51b is perpendicular to the direction D. The second side surface 51c is perpendicular to the direction D. Therefore, paper dust does not accumulate on the first side surface 51b, and the first side surface 51b directs the paper dust into the space G1 below. Paper dust does not accumulate on the second side surface 51c, and the second side surface 51c guides the paper dust to the space G2 below.

[0047] The first non-protruding portion 52 has a first surface 52a. The second non-protruding portion 53 has a second surface 53a. The first surface 52a is parallel to direction D and faces upward. The second surface 53a is parallel to direction D and faces upward. Therefore, paper dust guided downward by the first side surface 51b accumulates on the first surface 52a. Paper dust guided downward by the second side surface 51c accumulates on the second surface 53a.

[0048] The space S1 along the tip end surface 51a serves as a collection area for collecting paper dust, thereby preventing the paper dust from diffusely reflecting light and causing scattered light.

[0049] The first side surface 51b and the first surface 52a are perpendicular to each other. The second side surface 51c and the second surface 53a are perpendicular to each other. A space G3 along the intersection line between the first side surface 51b and the first surface 52a serves as a collection area for collecting paper dust. A space G4 along the intersection line between the second side surface 51c and the second surface 53a serves as a collection area for collecting paper dust. This makes it possible to prevent the paper dust from diffusely reflecting light and causing scattered light.

[0050] 3 Third embodiment The following describes the differences between the third embodiment and the first embodiment. For points that are not described, the third embodiment also employs the same configuration as that employed in the first embodiment.

[0051] FIG. 5 is an enlarged cross-sectional view that schematically illustrates a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in a detection device of the third embodiment.

[0052] In the third embodiment, the second end 42 has a trapezoidal cross-sectional shape, as shown in Figure 5. This makes it possible to reduce the number of sharp edges on the second end 42.

[0053] The second end 42 tapers continuously in the direction D towards the side where the sensing position DP is located.

[0054] The second end 42 has a tip surface 42p, a first side surface 42q, and a second side surface 42r. The tip surface 42p is closest to the detection position DP. The tip surface 42p is parallel to direction D and faces upward. Therefore, paper dust accumulates on the tip surface 42p. The first side surface 42q is located on the opposite side of the tip surface 42p from the detection position DP and on the side where the first lens 23 is located from the tip surface 42p. The second side surface 42r is located on the opposite side of the tip surface 42p from the detection position DP and on the side where the second lens 24 is located from the tip surface 42p. The first side surface 42q is perpendicular to a direction that slopes upward from one direction parallel to direction D. The second side surface 42r is perpendicular to a direction that slopes upward from another direction parallel to direction D. Paper dust is less likely to accumulate on the first side surface 42q, and the first side surface 42q guides the paper dust into the space G1. Paper dust is less likely to accumulate on the second side surface 42r, and the second side surface 42r guides the paper dust into the space G2.

[0055] The space S2 along the tip end surface 51a serves as a collection area for collecting paper dust, thereby preventing the paper dust from diffusely reflecting light and causing scattered light.

[0056] Paper dust guided downward by the first side surface 51b accumulates on the first inclined region 23n, and paper dust guided downward by the second side surface 51c accumulates on the second inclined region 24n.

[0057] 4 Fourth embodiment The following describes the differences between the fourth embodiment and the first embodiment. For points that are not described, the fourth embodiment also employs the same configuration as that employed in the first embodiment.

[0058] FIG. 6 is an enlarged cross-sectional view schematically illustrating a first lens, a second lens, and a light-shielding wall of a reflective optical sensor provided in a detection device of a fourth embodiment, as well as the light-shielding wall of a structure provided in the detection device.

[0059] 6, in the fourth embodiment, the second end 42 of the light-shielding wall 30 provided in the reflective optical sensor 11 is located below the uppermost parts of the first lens 23 and the second lens 24. Therefore, the light-shielding wall 30 cannot block light reaching from any position on the first lens surface 23a to any position on the second lens surface 24a.

[0060] In the fourth embodiment, the structure 12 includes a light-shielding wall 61. The light-shielding wall 61 protrudes downward. The light-shielding wall 61 included in the structure 12 blocks light from any position on the first lens surface 23a to any position on the second lens surface 24a, in place of the light-shielding wall 30 included in the reflective optical sensor 11. This makes it possible to prevent the first paper dust PP1 and the second paper dust PP2 from causing false detection, as in the first embodiment.

[0061] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0062] 1 Detection device, 11 Reflective optical sensor, 12 Structure, 21 Light-emitting element, 22 First primary molded lens, 23 First lens, 23a First lens surface, 23b First flat surface, 23m First main surface, 23n First inclined region, 24 Second lens, 24a Second lens surface, 24b Second flat surface, 24m Second main surface, 24n Second inclined region, 25 Second primary molded lens, 26 Light-receiving element, 27 Frame, 28 Housing, 28a First internal space, 28b Second internal space, 28c Third internal space, 28d Fourth internal space, 28e Fifth internal space, 29 Connector, 30 Light-shielding wall, 30a First wall surface, 30b Second wall surface, 41 First end, 42 Second end, 42p Tip surface, 42q First side surface, 42r: Second side surface, 51: Protruding portion, 51a: Tip surface, 51b: First side surface, 51c: Second side surface, 52: First non-protruding portion, 52a: First surface, 53: Second non-protruding portion, 53a: Second surface, 61: Light-shielding wall, P: Paper, PT: Path, DP: Detection position, L1: First light, L2: Second light, D: Direction, PP1: First paper dust, PP2: Second paper dust, DRL1: First diffusely reflected light, DRL2: Second diffusely reflected light, TL: Transmitted light, G1, G2, G3, G4, S1, S2: Space.

Claims

1. a light-emitting element that emits a first light; a first lens having a first lens surface, transmitting the first light, causing the first light to exit from the first lens surface, and directing the first light toward a detection position; a second lens having a second lens surface and transmitting second light coming from the detection position and incident on the second lens surface; a light receiving element that receives the second light; a light-shielding wall that blocks light from reaching an arbitrary position on the first lens surface to an arbitrary position on the second lens surface; A reflective optical sensor comprising:

2. the first lens has a first major surface that includes the first lens surface; the second lens has a second principal surface that includes the second lens surface; the first main surface has a first inclined region that slopes down toward the light-shielding wall, The second main surface has a second inclined region that slopes downward toward the light-shielding wall. The reflective optical sensor according to claim 1 .

3. the light-shielding wall has a first wall surface on a side where the first lens is disposed and a second wall surface on a side where the second lens is disposed, the first inclined region and the first wall surface form an acute angle; The second inclined region and the second wall surface form an acute angle. The reflective optical sensor according to claim 2 .

4. the light-shielding wall has a first wall surface on a side where the first lens is disposed and a second wall surface on a side where the second lens is disposed, The space along the intersection line of the first inclined area and the first wall surface and the space along the intersection line of the second inclined area and the second wall surface collect dust that has fallen off an object to be detected by the reflective optical sensor. The reflective optical sensor according to claim 2 .

5. the light-shielding wall has an end portion on the side where the detection position is located, the end portion includes a protruding portion, a first non-protruding portion located on a side of the protruding portion where the first lens is to be disposed, and a second non-protruding portion located on a side of the protruding portion where the second lens is to be disposed, The protruding portion protrudes toward the detection position from the first non-protruding portion and the second non-protruding portion.

5. The reflective optical sensor according to claim 1.

6. the protrusion has a tip surface, a first side surface on a side where the first lens is disposed relative to the tip surface, and a second side surface on a side where the second lens is disposed relative to the tip surface, the first non-protruding portion has a first surface; the second non-protruding portion has a second surface; The space along the tip surface, the space along the intersection line between the first side surface and the first surface, and the space along the intersection line between the second side surface and the second surface collect dust that has fallen off an object to be detected by the reflective optical sensor.

6. The reflective optical sensor according to claim 5.

7. the light-shielding wall has an end portion on the side where the detection position is located, The end portion is continuously tapered toward the side where the detection position is located in the direction in which the first lens and the second lens are arranged.

5. The reflective optical sensor according to claim 1.

8. The end portion has a tip surface, The space along the tip surface collects dust that falls off from the object to be detected by the reflective optical sensor. The reflective optical sensor according to claim 7 .

9. a reflective optical sensor; a structure that defines a path along which an object to be detected by the reflective optical sensor passes; Equipped with The reflective optical sensor includes: a light-emitting element that emits a first light; a first lens having a first lens surface, transmitting the first light, causing the first light to exit from the first lens surface, and directing the first light toward a detection position; a second lens having a second lens surface and transmitting second light coming from the detection position and incident on the second lens surface; a light receiving element that receives the second light; Equipped with The structure is a light-shielding wall that blocks light from reaching any position on the first lens surface to any position on the second lens surface; Equipped with Detection device.

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