Optical detector

Abstract

To provide an optical detector capable of inhibiting a light reception state of a light receiving element from being influenced even when undesired light passes through a light receiving port.SOLUTION: A sensor unit 7 comprises: a light-emitting element 74; a first light receiving element 75; a substrate 70 on which the light-emitting element 74 and the first light receiving element 75 are mounted; a light-emitting opening 7201a for transmitting light from the light-emitting element 74; a first light receiving opening 7202a for transmitting light reflected on the surface of a transfer belt 41; a housing 72 covering the light-emitting element 74 and the first light receiving element 75; and a translucent cover 73 including lenses 731, 732. The translucent cover 73 is attached to the housing 72 with a gap. The housing 72 includes a first isolation wall 725 separating the light-emitting element 74 from the first light receiving element 75, and a cylindrical wall 723a positioned opposite to the first isolation wall 725 from the light receiving element 74. A circle center 723C is away from a straight line L1 passing through the light-emitting element 74 and the first light receiving element 75.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to an optical detection device.

Background Art

[0002] Conventionally, in an image forming apparatus, there is one configured to form a toner image on a photosensitive drum and transfer the formed toner image to a sheet conveyed by a belt mechanism.

[0003] In such an image forming apparatus, due to temperature changes and deterioration of each component and developer, etc., the density of the toner image and the transfer position of the toner image of each color fluctuate. Therefore, it is necessary to perform control to keep the density and transfer position of the toner image in an optimal state. Accordingly, a test pattern formed by the toner image is transferred to the belt, the transferred test pattern is detected by an optical sensor as a toner detection device, and the detection result is fed back.

[0004] In this case, the optical sensor includes a light emitting element that irradiates light toward the belt, a light receiving element that receives the reflected light reflected by the belt, and a housing for blocking unnecessary external light. Further, as disclosed in Patent Document 1, there is an optical sensor provided with a translucent cover located between the housing and the belt and having a lens that condenses the irradiation light from the light emitting element and the reflected light reflected by the belt.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the optical sensor provided with the above-described light-transmitting cover, the housing is provided with an irradiation port through which the irradiation light from the light-emitting element passes and a light-receiving port through which the reflected light reflected by the belt passes, and lenses are arranged in accordance with the respective positions of the irradiation port and the light-receiving port.

[0007] However, if there is a gap between the light-transmitting cover and the housing, a part of the irradiation light from the light-emitting element may be reflected at the edge of the irradiation port, and further reflected between the light-transmitting cover and the housing, and then received by the light-receiving element. Also, the light incident on the light-transmitting cover may be reflected inside the light-transmitting cover and then exit and be received by the light-receiving element.

[0008] The positions and shapes of the irradiation port and the light-receiving port of the housing are set so as not to receive the reflected light from outside the detection region where the test pattern is formed on the belt surface. However, stray light such as the light reflected between the light-transmitting cover and the housing and the light reflected inside the light-transmitting cover reaches the light-receiving element through a different path from the reflected light from outside the detection region on the belt surface, so there is a possibility that appropriate feedback cannot be obtained. In particular, when the wall surface of the housing that reflects light and causes the reflected light to enter the light-receiving element is located near the light-receiving element, the influence of the stray light becomes greater.

[0009] Therefore, in the present invention, there is provided an optical detection device capable of suppressing the influence on the light-receiving state of the light-receiving element even when unintended light passes through the light-receiving port.

Means for Solving the Problems

[0010] The optical detection device for solving the above problems has the following features.

[0011] That is, the optical detection device includes a light-emitting element that irradiates light toward a measurement object, a light-receiving element that receives the light reflected by the measurement object, a substrate having a first surface on which the light-emitting element and the light-receiving element are mounted along a first direction, a first opening through which the light irradiated from the light-emitting element passes, and a second opening through which the light reflected by the measurement object passes. The optical detection device further includes a housing that covers the light-emitting element and the light-receiving element from the first surface side of the substrate, and a translucent cover having a lens through which light can pass and being located between the housing and the measurement object. The translucent cover is attached to the housing with a gap therebetween. The housing has a partition wall that isolates the light-emitting element and the light-receiving element when the housing is assembled to the substrate from the first surface side, and a cylindrical wall located on the side opposite to the partition wall with respect to the light-receiving element. When the center of the circle of the cylindrical wall is projected onto the first surface of the substrate, the center of the circle is separated from the straight line passing through the light-emitting element and the light-receiving element.

[0012] Thereby, when unintended stray light enters the housing from the second opening, the influence on the light-receiving state of the light-receiving element can be suppressed.

[0013] Further, in a second direction orthogonal to the first direction and parallel to the first surface, there is a light-shielding wall located away from the straight line passing through the light-emitting element and the light-receiving element. The partition wall, the cylindrical wall, and the light-shielding wall surround the periphery of the light-receiving element. The light-shielding wall has an inclined portion that inclines toward the side closer to the straight line passing through the light-emitting element and the light-receiving element as it moves away from the partition wall in the first direction.

[0014] Thereby, the direction of the light that enters the housing from the second opening and is reflected by the inclined portion can be deflected away from the direction toward the light-receiving element, so that the influence of the stray light on the light-receiving state of the light-receiving element can be suppressed.

[0015] Further, the inclined portion extends toward the center of the circle of the cylindrical wall.

[0016] As a result, since the inclined portion is connected to the cylindrical wall in a direction perpendicular to the cylindrical wall, when forming the housing, it becomes difficult for sink marks to occur on the cylindrical wall, and the shape of the cylindrical wall can be stabilized.

[0017] Further, the substrate is fixed to the housing by a fastener, the housing has a boss into which the fastener is inserted, and the cylindrical wall is formed by an outer peripheral wall of the boss.

[0018] In this way, since the cylindrical wall is formed by utilizing the outer peripheral wall of the boss that is originally necessary for fixing the substrate to the housing, there is no need to separately provide the cylindrical wall, and an increase in the size of the optical detection device can be suppressed.

[0019] Further, the light-transmitting cover is attached to the housing, and the lens of the light-transmitting cover has a first lens located at a position corresponding to the first opening and a second lens located at a position corresponding to the second opening. The first lens has a first notch in which an end portion on the second lens side in the first direction is cut out, the second lens has a second notch in which an end portion on the first lens side in the first direction is cut out, and the first notch and the second notch are joined.

[0020] As a result, the distance between the first lens and the second lens arranged along the first direction can be reduced, and the size of the optical detection device can be reduced.

[0021] Further, the light-receiving element has a first light-receiving element that receives regular reflected light from the measurement object and a second light-receiving element that receives diffused reflected light from the measurement object. The first light-receiving element is located between the light-emitting element and the cylindrical wall, and the second light-receiving element is located on the opposite side of the first light-receiving element with the light-emitting element interposed therebetween.

[0022] As a result, the influence of stray light of regular reflected light that has entered the space surrounded by the cylindrical wall on the light-receiving state of the first light-receiving element can be suppressed.

[0023] Further, the substrate is fixed to the housing by a fastener. The housing has a boss into which the fastener is inserted. The cylindrical wall is formed by a part of the outer peripheral wall of the boss. The boss is a protruding portion located on the opposite side of the light-receiving element across the cylindrical wall in the first direction, and has the protruding portion protruding toward the substrate side from the cylindrical wall in a third direction orthogonal to the first direction and a second direction orthogonal to the first direction and parallel to the first surface.

[0024] Therefore, when the substrate is fixed to the housing by the fastener, the substrate can be pressed against the housing side, and it is possible to suppress the substrate fixed to the housing from floating from the housing. Thereby, stray light generated by the substrate floating from the housing can be prevented, and the influence of the stray light on the light-receiving state of the light-receiving element can be suppressed.

[0025] Also, a rib located on the opposite side of the boss across the light-emitting element and the light-receiving element in the first direction, and a light-shielding wall located between the rib and the protruding portion of the boss in the first direction and away from a straight line passing through the light-emitting element and the light-receiving element in the second direction are provided. The rib protrudes toward the substrate side from the light-shielding wall in the third direction and is located on the light-shielding wall side from the protruding portion of the boss.

[0026] Therefore, when the substrate is fixed to the housing by the fastener, the substrate can be stably pressed against the housing side. Thereby, even when the substrate is warped or there are variations in the protruding amounts of the boss and the rib, the generation of stray light can be prevented, and the influence of the stray light on the light-receiving state of the light-receiving element can be suppressed.

Advantages of the Invention

[0027] According to the present invention, when unintended stray light enters the housing from the second opening, the influence on the light-receiving state of the light-receiving element can be suppressed.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

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Figure 9

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Figure 15

Embodiments for Carrying Out the Invention

[0029] Next, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

[0030] [Image Forming Apparatus] The image forming apparatus 1 shown in FIGS. 1 and 2 is an embodiment of an image forming apparatus provided with an optical detection apparatus according to the present invention, and is a color laser printer that forms images of a plurality of colors on a sheet S by an electrophotographic method.

[0031] In the following description, the left side in FIG. 1 is defined as the front side of the image forming apparatus 1, the right side in FIG. 1 is defined as the rear side of the image forming apparatus 1, the front side of the paper surface in FIG. 1 is defined as the right side of the image forming apparatus 1, and the back side of the paper surface in FIG. 1 is defined as the left side of the image forming apparatus 1. Also, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

[0032] The image forming apparatus 1 includes a housing 2, a paper feeding unit 3 having a paper feeding tray 10 that supports a sheet S and a sheet conveying unit 30 that conveys the sheet S, and an image forming unit 5 that forms an image on the sheet S conveyed by the paper feeding unit 3.

[0033] The housing 2 is formed in a substantially rectangular parallelepiped shape and houses the paper feeding unit 3 and the image forming unit 5. A front opening 2A is opened on the front surface of the housing 2, and the housing 2 has a front cover 21 that can open and close the front opening 2A.

[0034] The front cover 21 is configured to be rotatable about a rotation axis 21a at the lower end, and by rotating about the rotation axis 21a, it can move between a closed position that closes the front opening 2A and an open position that opens the front opening 2A. A paper discharge tray 22 that slopes downward from the front side to the rear side is formed on the upper surface of the housing 2.

[0035] The paper feeding unit 3 is disposed at the lower part of the housing 2 and conveys the sheet S supported by the paper feeding tray 10 to the image forming unit 5 by the sheet conveying unit 30. The paper feeding tray 10 is configured to be slidable in the front-rear direction and is configured to be movable between a storage position housed in the housing 2 and a separation position pulled forward from the storage position.

[0036] The sheet conveyance unit 30 includes a paper feed roller 32, a separation roller 33, a separation pad 33a, a pair of conveyance rollers 34, and a pair of registration rollers 35. Inside the housing 2, a conveyance path P for the sheet S extending from the paper feed tray 10 through the image forming unit 5 to the paper discharge tray 22 is configured.

[0037] The sheet S supported on the paper feed tray 10 is separated one by one by the paper feed roller 32, the separation roller 33, and the separation pad 33a and sent out onto the conveyance path P. The paper feed roller 32 is a roller that conveys the sheet S from the paper feed tray 10 toward the image forming unit 5. The separation roller 33 and the separation pad 33a constitute a separation means for separating the sheets S supported on the paper feed tray 10 one by one.

[0038] The sheet S sent out onto the conveyance path P is conveyed toward the image forming unit 5 by the pair of conveyance rollers 34 and the pair of registration rollers 35. The pair of registration rollers 35 restricts the movement of the leading edge of the conveyed sheet S and temporarily stops it, and then conveys the sheet S toward the image forming unit 5 at a predetermined timing.

[0039] The image forming unit 5 is disposed above the paper feed unit 3 and includes four toner cartridges 50 arranged side by side in the front-rear direction and photosensitive drums 51 corresponding to the respective toner cartridges 50. Each toner cartridge 50 is provided corresponding to each color of black, yellow, magenta, and cyan. The toner cartridge 50 includes a developing roller 52.

[0040] The toner cartridge 50 is detachably supported by the drawer 59. The drawer 59 is movable between a first position disposed inside the housing 2 through the front opening 2A of the housing 2 by opening the front cover 21 and a second position where at least a part thereof is disposed outside the housing 2.

[0041] The photosensitive drum 51 is formed in a substantially cylindrical shape with the left - right direction as the axial direction and is rotatably supported by the drawer 59. The developing roller 52 extends in the left - right direction and is rotatably supported by the toner cartridge 50. Toner is an example of a developer. The developing roller 52 supplies toner to the photosensitive drum 51.

[0042] The housing 2 has an exposure device 56 that exposes the surface of the photosensitive drum 51. The exposure device 56 includes a laser diode, a polarizer, a lens, and a mirror (not shown). The exposure device 56 is configured to emit a light beam to each photosensitive drum 51 to expose the surface of each photosensitive drum 51.

[0043] Below the conveyance path P of the photosensitive drum 51, the transfer belt 41 is disposed opposite. The transfer belt 41 is in contact with the photosensitive drum 51. The transfer belt 41 is stretched between the drive roller 42 and the driven roller 43 disposed in front of the drive roller 42 and extends in the front - rear direction. Transfer rollers 44 are respectively disposed at positions opposite to each photosensitive drum 51 across the transfer belt 41. In the image forming unit 5, the transfer unit 40 is constituted by the transfer belt 41, the drive roller 42, the driven roller 43, the transfer roller 44, etc.

[0044] The image forming unit 5 includes a charger 54 for charging each photosensitive drum 51. The charger 54 is supported by the drawer 59. The photosensitive drum 51 uniformly charged by the charger 54 is selectively exposed by the exposure device 56. By this exposure, charges are selectively removed from the surface of the photosensitive drum 51, and an electrostatic latent image is formed on the surface of the photosensitive drum 51.

[0045] The toner accommodated in the toner cartridge 50 is charged to a positive polarity and carried on the surface of the developing roller 52. A developing bias is applied to the developing roller 52. When the electrostatic latent image formed on the photosensitive drum 51 faces the developing roller 52, toner is supplied from the developing roller 52 to the electrostatic latent image due to the potential difference between the electrostatic latent image and the developing roller 52. Thereby, a toner image is formed on the surface of the photosensitive drum 51.

[0046] When the sheet S conveyed toward the image forming unit 5 reaches the transfer belt 41, it is conveyed by the transfer belt 41 and sequentially passes between the transfer belt 41 and each photosensitive drum 51. Then, when the toner image carried on the surface of the photosensitive drum 51 faces the sheet S, it is transferred to the sheet S by the transfer bias applied to the transfer roller 44. The transfer belt 41 is an example of a belt that conveys the sheet on which the toner image is formed.

[0047] Note that the transfer belt 41 in the present embodiment is configured as a conveyance belt that conveys the sheet S onto which the toner image is transferred. However, it can also be configured as an intermediate transfer belt on which the toner image is transferred to the belt itself and the toner image transferred to the belt is further transferred to the sheet S.

[0048] The sheet S onto which the toner image is transferred is conveyed to the fixing device 60. The fixing device 60 is an example of a fixing unit. The fixing device 60 is located on the rear end side of the transfer belt 41 in the front-rear direction. The fixing device 60 includes a heating roller 61 and a pressure roller 62 that is pressed against the heating roller 61. The sheet S conveyed to the fixing device 60 has the toner image thermally fixed while passing between the heating roller 61 and the pressure roller 62. That is, the fixing device 60 fixes the toner image formed on the sheet S.

[0049] The sheet S on which the toner image is thermally fixed is conveyed from the fixing device 60 to the downstream side in the conveyance direction, and is further conveyed by the intermediate paper discharge roller pair 63 and the paper discharge roller pair 64 disposed on the downstream side in the conveyance direction of the intermediate paper discharge roller pair 63, and is discharged to the paper discharge tray 22.

[0050] In the image forming apparatus 1, a process unit PU for forming a toner image on a sheet S is constituted by a drawer 59, a toner cartridge 50 supported by the drawer 59, a photosensitive drum 51, a charger 54, and the like. In the process unit PU, the drawer 59 may support the photosensitive drum 51 as in the present embodiment, or the toner cartridge 50 may support the photosensitive drum 51. Further, the process unit PU may include a fixing device 60.

[0051] The image forming apparatus 1 includes a power supply board 11 on which a power supply circuit is formed, and a board cover 12 that covers the power supply board 11. The board cover 12 is formed of a sheet metal member having conductivity and is grounded. The board cover 12 is a grounding member. The board cover 12 is disposed between a paper feed tray 10 and a transfer unit 40 at the rear part inside the housing 2. The housing 2 houses the process unit PU and the board cover 12.

[0052] As shown in FIGS. 1, 3, and 4, in the image forming apparatus 1, when performing density correction, color shift correction, etc. of the toner image formed on the sheet S, the toner image is transferred from the photosensitive drum 51 to the surface of the transfer belt 41 to form a patch P which is a test pattern formed by the toner image.

[0053] The image forming apparatus 1 includes a sensor unit 7 for detecting the patch P formed on the surface of the transfer belt 41. By reading the patch P on the surface of the transfer belt 41 by the sensor unit 7, density correction, color shift correction, etc. of the toner image formed on the sheet S are performed. Thereby, it is possible to keep the density and transfer position of the toner image in an optimal state. The fixing device 60 is located rearward and upward of the sensor unit 7.

[0054] The sensor unit 7 is an optical detection device that irradiates the surface of the transfer belt 41 with light emitted from a light emitting element and receives the reflected light from the transfer belt 41 by a light receiving element to detect the patch P.

[0055] The sensor unit 7 is disposed below and rearward of the driving roller 42 in the transfer unit 40. That is, the sensor unit 7 is located below and on the rear end side of the transfer belt 41. Further, the sensor unit 7 is disposed at a position facing the transfer belt 41. Therefore, the sensor unit 7 can easily irradiate light onto the surface of the transfer belt 41 and receive the reflected light from the transfer belt 41, and can easily read the patch P formed on the transfer belt 41.

[0056] In the transfer unit 40, a plurality of patches P are formed along the front-rear direction at two locations, namely, the left end portion and the right end portion in the left-right direction of the transfer belt 41, on the surface of the transfer belt 41. The sensor unit 7 is provided at two locations on the left and right in accordance with the position of the patch P formed on the transfer belt 41.

[0057] The patch P is detected by the sensor unit 7 in a state where the transfer unit 40 is attached to the housing 2. In this case, since two patches P are provided at intervals in the left-right direction, it is possible to improve the correction accuracy when performing density correction and color shift correction of the image formed on the sheet S.

[0058] As shown in FIG. 2, the housing 2 includes a first main body frame 23 and a second main body frame 24 that is located away from the first main body frame 23 in the left-right direction. The first main body frame 23 and the second main body frame 24 are examples of the main body frame. The first main body frame 23 is located at the left end portion of the housing 2 and extends in the front-rear direction and the up-down direction. The second main body frame 24 is located at the right end portion of the housing 2 and extends in the front-rear direction and the up-down direction. A control board 25 into which a detection signal from the sensor unit 7 is input is supported on the left side surface of the first main body frame 23.

[0059] As shown in FIGS. 3 and 4, the sensor unit 7 is attached to the fixed sheet metal 13. The fixed sheet metal 13 extends in the left - right direction and is disposed between the first main body frame 23 and the second main body frame 24 in the left - right direction. The fixed sheet metal 13 is supported by the first main body frame 23 and the second main body frame 24.

[0060] The fixed sheet metal 13 is fixed to the first main body frame 23 and the second main body frame 24 so as to connect the first main body frame 23 and the second main body frame 24. Therefore, it is possible to stably support the fixed sheet metal 13 by the first main body frame 23 and the second main body frame 24.

[0061] The fixed sheet metal 13 holds one sensor unit 7 at a position closer to the first main body frame 23 than the second main body frame 24 in the left - right direction, and holds the other sensor unit 7 at a position on the second main body frame 24 side rather than one sensor unit 7 in the left - right direction.

[0062] The fixed sheet metal 13 is formed of a sheet metal member whose longitudinal direction is the left - right direction, and has a flat plate portion 131, a first bent portion 132, and a second bent portion 133. The flat plate portion 131 extends in the left - right direction and in a first inclined direction orthogonal to the left - right direction. The first inclined direction is an inclined direction that inclines upward from the front to the rear.

[0063] The first bent portion 132 is connected to the upper end of the flat plate portion 131 in the first inclined direction and extends rearward from the upper end of the flat plate portion 131. The first bent portion 132 extends in the front - rear direction and the left - right direction. The second bent portion 133 is connected to the lower end of the flat plate portion 131 in the first inclined direction and extends in a second inclined direction from the lower end of the flat plate portion 131. The second bent portion 133 extends in the second inclined direction and the left - right direction. The second inclined direction is an inclined direction that inclines downward from the front to the rear and is orthogonal to the left - right direction and the first inclined direction.

[0064] [Sensor Unit] As shown in FIGS. 5 and 6, the sensor unit 7 has a substrate 70, a housing 72, and a translucent cover 73. The sensor unit 7 is configured by attaching the substrate 70 and the translucent cover 73 to the housing 72.

[0065] (Substrate) As shown in FIGS. 5 to 7, the substrate 70 is formed in a substantially rectangular shape with the left - right direction being the longitudinal direction. The substrate 70 is, for example, a double - sided substrate formed of glass epoxy resin, and has a first surface 70A and a second surface 70B on the side opposite to the first surface 70A. The first surface 70A and the second surface 70B are surfaces extending in the left - right direction and the first inclined direction.

[0066] The left - right direction is an example of the first direction. The first inclined direction is an example of a second direction that is orthogonal to the first direction and parallel to the first surface. The second inclined direction is an example of a third direction that is orthogonal to both the first direction and the second direction that is orthogonal to the first direction and parallel to the first surface.

[0067] When the sensor unit 7 is attached to the fixing sheet metal 13, the substrate 70 has a lower end 70C located on the side of the second bent portion 133 in the first inclined direction and an upper end 70D located on the side of the first bent portion 132 in the first inclined direction.

[0068] On the substrate 70, a first positioning hole 701, a second positioning hole 702, an insertion hole 703, and slit holes 704 and 705 are formed. The first positioning hole 701, the second positioning hole 702, the insertion hole 703, the slit hole 704, and the slit hole 705 are formed along the left - right direction. On the substrate 70, from right to left, the first positioning hole 701, the slit hole 704, the slit hole 705, the insertion hole 703, and the second positioning hole 702 are arranged in this order.

[0069] On the first surface 70A of the substrate 70, a light-emitting element 74, a first light-receiving element 75, a second light-receiving element 76, and a first mounted component 706 such as an LSI are mounted. The light-emitting element 74, the first light-receiving element 75, the second light-receiving element 76, and the first mounted component 706 are mounted along the left-right direction. That is, the substrate 70 has a first surface 70A on which the light-emitting element 74, the first light-receiving element 75, and the second light-receiving element 76 are mounted along the left-right direction.

[0070] On the first surface 70A, in the order from right to left, the second light-receiving element 76, the light-emitting element 74, the first light-receiving element 75, and the first mounted component 706 are arranged. In the left-right direction, the second light-receiving element 76 is located on the opposite side of the first light-receiving element 75 with the light-emitting element 74 interposed therebetween. In the left-right direction, the second light-receiving element 76 is located between the first positioning hole 701 and the slit hole 704, the light-emitting element 74 is located between the slit hole 704 and the slit hole 705, the first light-receiving element 75 is located between the slit hole 705 and the insertion hole 703, and the first mounted component 706 is located between the insertion hole 703 and the second positioning hole 702.

[0071] The light-emitting element 74 is an element for irradiating light toward the surface of the transfer belt 41, and the first light-receiving element 75 and the second light-receiving element 76 are elements for receiving the light reflected by the surface of the transfer belt 41. The surface of the transfer belt 41 is an example of the object to be measured.

[0072] The first light-receiving element 75 mainly receives the specularly reflected light from the surface of the transfer belt 41, and the second light-receiving element 76 mainly receives the diffusely reflected light from the surface of the transfer belt 41. However, it is also possible to configure such that the first light-receiving element 75 receives mainly the light diffusely reflected on the surface of the transfer belt 41, and the second light-receiving element 76 receives mainly the light specularly reflected on the surface of the transfer belt 41.

[0073] On the substrate 70, since the first light receiving element 75 and the second light receiving element 76 are mounted, the first light receiving element 75 receives the specularly reflected light, and the second light receiving element 76 receives the diffusely reflected light, so that the detection accuracy by the sensor unit 7 can be improved.

[0074] On the second surface 70B of the substrate 70, a female connector 707 and second mounted components 708 and 709 such as variable resistors are mounted. The female connector 707, the second mounted component 708, and the second mounted component 709 are mounted along the left - right direction.

[0075] On the second surface 70B, in the direction from right to left, the second mounted component 709, the second mounted component 708, and the female connector 707 are arranged in this order. In the left - right direction, the second mounted component 709 is located between the first positioning hole 701 and the slit hole 704, the second mounted component 708 is located between the slit hole 705 and the insertion hole 703, and the female connector 707 is located between the insertion hole 703 and the second positioning hole 702.

[0076] The straight line extending along the left - right direction and passing through the light emitting element 74, the first light receiving element 75, and the second light receiving element 76 is L1. The straight line L1 passes through the centers of the first light receiving element 75 and the second light receiving element 76 in the first inclination direction. The straight line extending along the left - right direction and passing through the center 701C of the first positioning hole 701, the center 702C of the second positioning hole 702 in the first inclination direction, and the center 703C of the insertion hole 703 is L2. The positions of the straight line L1 and the straight line L2 in the first inclination direction are different, and the straight line L1 is located on the upper end 70D side of the straight line L2.

[0077] (Housing) As shown in FIGS. 5, 6, 8 to 10, the housing 72 has a housing body 720 in a substantially rectangular parallelepiped shape with the longitudinal direction being the left-right direction. The housing body 720 has a fixing surface 720A which is the surface on the side where the first surface 70A of the substrate 70 is fixed in the second inclination direction, and a mounting surface 720B on the side opposite to the fixing surface 720A. The fixing surface 720A and the mounting surface 720B are surfaces parallel to the left-right direction and the first inclination direction.

[0078] In a state where the substrate 70 is fixed to the housing 72, the light-emitting element 74, the first light-receiving element 75, and the second light-receiving element 76 are covered from the side of the first surface 70A of the substrate 70 by the housing 72.

[0079] In the housing body 720, there are formed a light-emitting light guide path 7201 that penetrates between the fixing surface 720A and the mounting surface 720B and through which the light irradiated by the light-emitting element 74 passes, a first light-receiving light guide path 7202 that penetrates between the fixing surface 720A and the mounting surface 720B and through which the light received by the first light-receiving element 75 passes, and a second light-receiving light guide path 7203 that penetrates between the fixing surface 720A and the mounting surface 720B and through which the light received by the second light-receiving element 76 passes. The light-emitting light guide path 7201, the first light-receiving light guide path 7202, and the second light-receiving light guide path 7203 penetrate through the inside of the housing body 720 along the second inclination direction.

[0080] In a state where the substrate 70 is fixed to the fixing surface 720A side of the housing body 720, the light-emitting element 74 faces the inside of the light-emitting light guide path 7201, the first light-receiving element 75 faces the inside of the first light-receiving light guide path 7202, and the second light-receiving element 76 faces the inside of the second light-receiving light guide path 7203.

[0081] The mounting surface 720B of the housing body 720 has a light-emitting opening 7201a through which the light-emitting light guide path 7201 opens, a first light-receiving opening 7202a through which the first light-receiving light guide path 7202 opens, and a second light-receiving opening 7203a through which the second light-receiving light guide path 7203 opens. The light-emitting opening 7201a is an example of the first opening through which the light irradiated from the light-emitting element passes. The first light-receiving opening 7202a is an example of the second opening through which the light reflected by the measurement object passes.

[0082] The light emitted from the light-emitting element 74 travels through the light guide path 7201 for light emission, and then exits to the outside of the housing main body 720 through the light-emitting opening 7201a and reaches the surface of the transfer belt 41.

[0083] The light reflected from the surface of the transfer belt 41 enters the first light-receiving guide path 7202 of the housing main body 720 through the first light-receiving opening 7202a and is received by the first light-receiving element 75. Also, the light reflected from the surface of the transfer belt 41 enters the second light-receiving guide path 7203 of the housing main body 720 through the second light-receiving opening 7203a and is received by the second light-receiving element 76.

[0084] The housing main body 720 has a first protrusion 721, a second protrusion 722, and a boss 723 for positioning the substrate 70. The first protrusion 721 and the second protrusion 722 protrude toward the substrate 70 side from the fixed surface 720A, and the boss 723 is formed from the fixed surface 720A side toward the mounting surface 720B side. Also, the boss 723 protrudes toward the substrate 70 side from the fixed surface 720A.

[0085] When fixing the substrate 70 to the housing 72, the first protrusion 721 is fitted into the first positioning hole 701, the second protrusion 722 is fitted into the second positioning hole 702, and a screw 91, which is a connecting member, is inserted into the boss 723 and the insertion hole 703. By screwing the screw 91 into the boss 723 of the housing 72 with the screw 91 inserted into the insertion hole 703 of the substrate 70, the substrate 70 is fastened and fixed to the housing 72. That is, the substrate 70 is fixed to the housing 72 by the screw 91, which is a fastener.

[0086] The housing body 720 has a first partition wall 725 that partitions the light-emitting light path 7201 and the first light-receiving light path 7202, and a second partition wall 724 that partitions the light-emitting light path 7201 and the second light-receiving light path 7203. The first partition wall 725 is located between the light-emitting element 74 and the first light-receiving element 75 in the left-right direction. The second partition wall 724 is located between the light-emitting element 74 and the second light-receiving element 76 in the left-right direction.

[0087] When the housing 72 is assembled to the substrate 70 from the first surface 70A side, the light-emitting element 74 facing the light-emitting light path 7201 and the first light-receiving element 75 facing the first light-receiving light path 7202 are isolated by the first partition wall 725. Also, when the housing 72 is assembled to the substrate 70 from the first surface 70A side, the light-emitting element 74 facing the light-emitting light path 7201 and the second light-receiving element 76 facing the second light-receiving light path 7203 are isolated by the second partition wall 724.

[0088] The first partition wall 725 has a first shielding protrusion 725a that protrudes toward the substrate 70 side from the fixed surface 720A, and the second partition wall 724 has a second shielding protrusion 724a that protrudes toward the substrate 70 side from the fixed surface 720A.

[0089] When fixing the substrate 70 to the housing 72, the first shielding protrusion 725a is fitted into the slit hole 705 of the substrate 70, and the second shielding protrusion 724a is fitted into the slit hole 704 of the substrate 70. By fitting the first shielding protrusion 725a and the second shielding protrusion 724a into the slit holes 705 and 704 respectively, it is possible to suppress the light irradiated from the light-emitting element 74 from leaking out from the light-emitting light path 7201 to the first light-receiving light path 7202, the second light-receiving light path 7203, and the second surface 70B side of the substrate 70.

[0090] The housing body 720 has a cylindrical wall 723a that is located on the opposite side of the first light-receiving element 75 of the substrate 70 fixed to the housing 72 in the left-right direction with respect to the first partition wall 725. The cylindrical wall 723a is located to the left of the first light-receiving element 75. The cylindrical wall 723a is formed in an arc shape that protrudes to the right when viewed from the second inclination direction. In the left-right direction, the first light-receiving element 75 is located between the cylindrical wall 723a and the light-emitting element 74.

[0091] The cylindrical wall 723a is formed by the outer peripheral wall of the boss 723. Specifically, the cylindrical wall 723a is formed by a portion of the outer peripheral wall of the boss 723 that is located to the right of the center of the circle 723C of the outer peripheral wall of the boss 723. That is, the cylindrical wall 723a is formed by a part of the outer peripheral wall of the boss 723. In this way, since the cylindrical wall 723a is formed using the outer peripheral wall of the boss 723 that is originally necessary for fixing the substrate 70 to the housing 72, it is not necessary to separately provide the cylindrical wall 723a, and it is possible to suppress the enlargement of the sensor unit 7.

[0092] The housing body 720 has a rib 727 that is located on the opposite side of the second light-receiving element 76 of the substrate 70 fixed to the housing 72 in the left-right direction with respect to the second partition wall 724. The rib 727 is located to the right of the second light-receiving element 76. The first surface 70A of the substrate 70 fixed to the housing 72 abuts against the rib 727.

[0093] The housing body 720 has a light-shielding wall 726 that extends along the left-right direction. The light-shielding wall 726 is located away from the straight line L1 of the substrate 70 fixed to the housing 72 in the first inclination direction. The light-shielding wall 726 has a pair of light-shielding walls 726A and 726B that are spaced apart in the first inclination direction. The light-shielding wall 726A is located on the upper end 70D side of the substrate 70 with respect to the straight line L1, and the light-shielding wall 726B is located on the lower end 70C side of the substrate 70 with respect to the straight line L1. The light-shielding wall 726A and the light-shielding wall 726B are formed between the boss 723 and the rib 727 in the left-right direction.

[0094] In the housing body 720, a light-emitting light guide path 7201 surrounding the light-emitting element 74 is formed by the first partition wall 725, the second partition wall 724, the light-shielding wall 726A, and the light-shielding wall 726B. Also, a first light-receiving light guide path 7202 surrounding the first light-receiving element 75 is formed by the first partition wall 725, the cylindrical wall 723a, the light-shielding wall 726A, and the light-shielding wall 726B. Further, a second light-receiving light guide path 7203 surrounding the second light-receiving element 76 is formed by the second partition wall 724, the rib 727, the light-shielding wall 726A, and the light-shielding wall 726B.

[0095] The light-shielding wall 726A has an inclined portion 7261A that inclines toward the side approaching the straight line L1 as it moves away from the first partition wall 725 in the left-right direction. The inclined portion 7261A inclines downward in the first inclination direction as it moves away from the first partition wall 725.

[0096] The light-shielding wall 726B has an inclined portion 7261B that inclines toward the side approaching the straight line L1 as it moves away from the first partition wall 725 in the left-right direction. The inclined portion 7261B inclines upward in the first inclination direction as it moves away from the first partition wall 725.

[0097] The inclined portion 7261A and the inclined portion 7261B are respectively located at the left end portions of the light-shielding wall 726A and the light-shielding wall 726B. The left ends of the inclined portion 7261A and the inclined portion 7261B are connected to the cylindrical wall 723a of the boss 723.

[0098] The inclined portion 7261A and the inclined portion 7261B extend toward the center 723C of the circle of the boss 723 where the cylindrical wall 723a is formed. That is, the inclined portion 7261A is formed such that an extension line L3A extending the inclined portion 7261A passes through the center 723C of the circle. The inclined portion 7261B is formed such that an extension line L3B extending the inclined portion 7261B passes through the center 723C of the circle.

[0099] Since the inclined portions 7261A and 7261B extend toward the circular center 723C of the boss 723, the connection direction of the inclined portions 7261A and 7261B to the cylindrical wall 723a is perpendicular to the tangent on the outer peripheral surface of the boss 723. Thus, since the inclined portions 7261A and 7261B are connected to the cylindrical wall 723a in the vertical direction, when molding the housing 72, it is less likely for sink marks to occur on the boss 723 having the cylindrical wall 723a, and the shape of the cylindrical wall 723a can be stabilized.

[0100] When the circular center 723C of the boss 723 is projected onto the first surface 70A of the substrate 70, it is located away from the straight line L1 of the substrate 70. The circular center 723C is located on the lower end 70C side of the substrate 70 by a length D from the straight line L1 in the first inclination direction.

[0101] The boss 723 has a protruding portion 723b that protrudes toward the substrate 70 side more than the cylindrical wall 723a in the second inclination direction. The protruding portion 723b is located on the opposite side of the first light receiving element 75 with the cylindrical wall 723a interposed therebetween in the left - right direction. The protruding portion 723b is located to the left of the circular center 723C of the boss 723. The light - shielding walls 726A and 726B are located between the protruding portion 723b of the boss 723 and the rib 727 in the left - right direction. The first surface 70A of the substrate 70 fixed to the housing 72 abuts against the protruding portion 723b.

[0102] As shown in FIG. 11, the rib 727 protrudes toward the substrate 70 side more than the light - shielding wall 726 in the second inclination direction, and the protruding length of the rib 727 from the light - shielding wall 726 is H1. The cylindrical wall 723a of the boss 723 protrudes toward the substrate 70 side more than the light - shielding wall 726 in the second inclination direction, and the protruding length of the cylindrical wall 723a from the light - shielding wall 726 is H2. The protruding portion 723b of the boss 723 protrudes toward the substrate 70 side more than the light - shielding wall 726 in the second inclination direction, and the protruding length of the protruding portion 723b from the light - shielding wall 726 is H3.

[0103] The protruding length H2 of the cylindrical wall 723a is greater than the protruding length H1 of the rib 727, and the protruding length H3 of the protruding portion 723b is greater than the protruding length H2 of the cylindrical wall 723a (H3 > H2 > H1). That is, the protruding portion 723b protrudes toward the substrate 70 side more than the cylindrical wall 723a in the second inclination direction. Further, the rib 727 is located on the light shielding wall 726 side more than the protruding portion 723b in the second inclination direction.

[0104] As described above, the boss 723 has a protruding portion 723b that protrudes toward the substrate 70 side more than the cylindrical wall 723a. Therefore, as shown in FIG. 10, when the substrate 70 is fastened to the housing 72 by the screw 91, the portion of the substrate 70 on the cylindrical wall 723a side more than the protruding portion 723b can be pressed against the housing 72 side, and it is possible to suppress the substrate 70 fixed to the housing 72 from floating from the housing 72. By suppressing the substrate 70 from floating from the housing 72, it is possible to suppress light from leaking between the substrate 70 and the housing 72 and causing stray light.

[0105] Further, the housing 72 has a rib 727 that protrudes toward the substrate 70 side more than the light shielding wall 726 and is located on the light shielding wall 726 side more than the protruding portion 723b in the second inclination direction. Therefore, even if the substrate 70 is warped or the protruding amounts of the boss 723 and the rib 727 from the light shielding wall 726 vary, it is possible to stably press the substrate 70 against the housing 72 side.

[0106] (Translucent cover) As shown in FIGS. 5, 6, 12, and 13, the translucent cover 73 is formed of a resin member through which light can pass. The translucent cover 73 has a plate shape with the longitudinal direction in the left - right direction and is attached to the mounting surface 720B side of the housing 72. The resin member forming the translucent cover 73 may be transparent or translucent as long as light can pass through it, but it is preferably a resin member with a high light transmittance.

[0107] In the second inclination direction, there is a gap between the translucent cover 73 attached to the housing 72 and the housing 72. That is, the translucent cover 73 is attached to the housing 72 with a gap. The translucent cover 73 attached to the housing 72 is positioned between the housing 72 and the surface of the transfer belt 41 in the second inclination direction.

[0108] The translucent cover 73 has a light-emitting lens 731, a first light-receiving lens 732, and a second light-receiving lens 733. The light-emitting lens 731 is a lens for condensing the light irradiated by the light-emitting element 74. The first light-receiving lens 732 is a lens for condensing the light received by the first light-receiving element 75, and the second light-receiving lens 733 is a lens for condensing the light received by the second light-receiving element 76. The light-emitting lens 731 is an example of the first lens, and the first light-receiving lens 732 is an example of the second lens.

[0109] The translucent cover 73 has a first positioning hole 734, a second positioning hole 735, a locking piece 736, and a locking groove 737. The housing body 720 of the housing 72 has, on the mounting surface 720B side, a first positioning projection 7204a to be inserted into the first positioning hole 734, a second positioning projection 7204b to be inserted into the second positioning hole 735, a locking hole 7205 into which the locking piece 736 is inserted, and a locking projection 7206 to be locked with the locking groove 737.

[0110] When attaching the translucent cover 73 to the mounting surface 720B side of the housing 72, first insert the locking piece 736 into the locking hole 7205 to lock it to the housing body 720. Next, insert the first positioning hole 734 and the second positioning hole 735 into the first positioning projection 7204a and the second positioning projection 7204b, respectively. Further, by locking the locking groove 737 to the locking projection 7206, the translucent cover 73 is fixed to the mounting surface 720B side of the housing 72.

[0111] In a state where the light-transmitting cover 73 is fixed to the housing 72, the light-transmitting cover 73 is disposed at positions corresponding to the light-emitting opening 7201a, the first light-receiving opening 7202a, and the second light-receiving opening 7203a on the mounting surface 720B.

[0112] Specifically, the light-emitting lens 731 of the light-transmitting cover 73 is located at a position corresponding to the light-emitting opening 7201a, the first light-receiving lens 732 of the light-transmitting cover 73 is located at a position corresponding to the first light-receiving opening 7202a, and the second light-receiving lens 733 of the light-transmitting cover 73 is located at a position corresponding to the second light-receiving opening 7203a.

[0113] That is, when viewed from the second inclination direction, the light-emitting lens 731 of the light-transmitting cover 73 is disposed at a position overlapping the light-emitting opening 7201a, the first light-receiving lens 732 of the light-transmitting cover 73 is disposed at a position overlapping the first light-receiving opening 7202a, and the second light-receiving lens 733 of the light-transmitting cover 73 is disposed at a position overlapping the second light-receiving opening 7203a.

[0114] Thereby, the light irradiated by the light-emitting element 74 and the light received by the first light-receiving element 75 and the second light-receiving element 76 can be condensed. Specifically, the light emitted by the light-emitting element 74 is condensed by the light-emitting lens 731 and irradiated onto the surface of the transfer belt 41. Further, the light reflected on the surface of the transfer belt 41 is condensed by the first light-receiving lens 732 and received by the first light-receiving element 75, and is condensed by the second light-receiving lens 733 and received by the second light-receiving element 76.

[0115] The light-emitting lens 731 has a first notch portion 731a in which the left end, which is the end portion on the side of the first light-receiving lens 732 in the left-right direction, is notched. The first light-receiving lens 732 has a second notch portion 732a in which the right end, which is the end portion on the side of the light-emitting lens 731 in the left-right direction, is notched. The first notch portion 731a of the light-emitting lens 731 and the second notch portion 732a of the first light-receiving lens 732 are joined in the left-right direction.

[0116] In this way, by joining the first notch 731a and the second notch 732a, the distance between the light-emitting lens 731 and the first light-receiving lens 732 arranged along the left-right direction can be reduced, and it becomes possible to miniaturize the sensor unit.

[0117] [Optical path of light emitted from the light-emitting element] As shown in FIG. 14, the light emitted from the light-emitting element 74 through the light-emitting aperture 7201a is mainly reflected on the surface of the transfer belt 41. The light that is specularly reflected on the surface of the transfer belt 41 enters the first light-receiving light guide path 7202 through the first light-receiving aperture 7202a and is received by the first light-receiving element 75.

[0118] On the other hand, among the light emitted from the light-emitting element 74, there is stray light that enters the gap between the light-transmitting cover 73 and the housing 72 from the light-emitting aperture 7201a, is reflected between the light-transmitting cover 73 and the housing 72, and then enters the first light-receiving light guide path 7202 through the first light-receiving aperture 7202a. There is also stray light that enters the inside of the light-transmitting cover 73 from the light-emitting aperture 7201a, is reflected inside the light-transmitting cover 73, and then enters the first light-receiving light guide path 7202 through the first light-receiving aperture 7202a.

[0119] When such stray light is received by the first light-receiving element 75, it affects the light-receiving state of the first light-receiving element 75, such as increasing the light-receiving potential of the first light-receiving element 75 due to the stray light, and there is a risk of deterioration in the measurement accuracy and lifespan of the first light-receiving element 75.

[0120] The stray light that enters the first light-receiving light guide path 7202 from the first light-receiving aperture 7202a is reflected by the first partition wall 725, the cylindrical wall 723a, the light-shielding wall 726A, and the light-shielding wall 726B.

[0121] As shown in FIG. 15, the inclined portions 7261A and 7261B of the light-shielding walls 726A and 726B formed in the first light-receiving optical path 7202 are formed on inclined surfaces inclined with respect to the left-right direction. Therefore, the light that enters the first light-receiving optical path 7202 and is reflected by the inclined portions 7261A and 7261B will travel in a direction deviating from the direction toward the first light-receiving element 75.

[0122] Thus, in the sensor unit 7, since the direction of the light that enters the first light-receiving optical path 7202 from the first light-receiving opening 7202a and is reflected by the inclined portions 7261A and 7261B can be deviated from the direction toward the first light-receiving element 75, it is possible to suppress the influence of stray light on the light-receiving state of the first light-receiving element 75.

[0123] Further, since the cylindrical wall 723a is formed in an arc-shaped curved surface, the specularly reflected light that enters the first light-receiving optical path 7202, which is the space surrounded by the cylindrical wall 723a, and is reflected by the cylindrical wall 723a will be reflected in a direction deviated from the direction toward the first light-receiving element 75.

[0124] In particular, since the center 723C of the circle of the cylindrical wall 723a is located away from the straight line L1 passing through the first light-receiving element 75 in the first inclination direction, the direction of the specularly reflected light reflected by the cylindrical wall 723a can be more easily deviated from the direction toward the first light-receiving element 75. Thereby, when unintended specularly reflected stray light enters the first light-receiving optical path 7202 from the first light-receiving opening 7202a, it is possible to suppress the influence on the light-receiving state of the first light-receiving element 75.

[0125] Also, the boss 723 of the housing 72 has a protruding portion 723b that protrudes toward the substrate 70 side more than the cylindrical wall 723a, and it is possible to suppress the substrate 70 fixed to the housing 72 from floating from the housing. Thereby, it is possible to prevent the stray light generated by the substrate 70 floating from the housing, and it is possible to suppress the influence of the stray light on the light-receiving state of the first light-receiving element 75.

[0126] Further, the housing 72 has a rib 727 that protrudes toward the substrate 70 side from the light shielding wall 726 and is located on the light shielding wall 726 side from the protruding portion 723b. Even if the substrate 70 is warped or the protruding amounts of the bosses 723 and the rib 727 vary, it is possible to stably press the substrate 70 against the housing 72 side. Thereby, even when warping of the substrate 70 or variations in the protruding amounts of the bosses 723 and the rib 727 occur, generation of stray light can be prevented and the influence of the stray light on the light receiving state of the first light receiving element 75 can be suppressed.

[0127] In the present embodiment, the light emitting element 74, the first light receiving element 75, and the second light receiving element 76 are mounted on both substrates 70 in the left and right sensor units 7. However, the light emitting element 74, the first light receiving element 75, and the second light receiving element 76 may be mounted on the substrate 70 of one sensor unit 7, and the light emitting element 74 and the first light receiving element 75 may be mounted on the substrate 70 of the other sensor unit 7, but the second light receiving element 76 may not be mounted.

Explanation of Reference Numerals

[0128] 7 Sensor unit 41 Transfer belt 70 Substrate 70A First surface 72 Housing 73 Translucent cover 74 Light emitting element 75 First light receiving element 76 Second light receiving element 91 Screw 723 Boss 723a Cylindrical wall 723b Protruding portion 723C Center of circle 725 First partition wall 726, 726A, 726B Light shielding wall 727 Rib 731 Light emitting lens 731a First notch 732 First light receiving lens 732a Second notch 733 Second light-receiving lens 7201 Light-emitting optical path 7201a Light-emitting aperture 7202 First light-receiving optical path 7202a First light-receiving aperture 7261, 7261A, 7261B Inclined portion H1 Protrusion length (of rib) H2 Protrusion length (of cylindrical wall) H3 Protrusion length (of protrusion) L1 Straight line passing through light-emitting element and first light-receiving element

Claims

1. A light-emitting element that irradiates light toward an object to be measured, a light-receiving element that receives the light reflected by the object to be measured, a substrate having a first surface on which the light-emitting element and the light-receiving element are mounted along a first direction, a housing that has a first opening through which the light emitted from the light-emitting element passes and a second opening through which the light reflected by the object to be measured passes, and covers the light-emitting element and the light-receiving element from the first surface side of the substrate, a light-transmitting cover that has a lens through which light can pass and is located between the housing and the object to be measured, the light-transmitting cover is attached to the housing with a gap, the housing has a partition wall that isolates the light-emitting element and the light-receiving element when assembled to the substrate from the first surface side, and a cylindrical wall located on the side opposite to the partition wall with respect to the light-receiving element, an optical detection device in which when the center of the circle of the cylindrical wall is projected onto the first surface of the substrate, the center of the circle is separated from the straight line passing through the light-emitting element and the light-receiving element.

2. In a second direction orthogonal to the first direction and parallel to the first surface, there is a light-shielding wall located away from the straight line passing through the light-emitting element and the light-receiving element, the periphery of the light-receiving element is surrounded by the partition wall, the cylindrical wall, and the light-shielding wall, The optical detection device according to claim 1, wherein the light-shielding wall has an inclined portion that inclines toward the side closer to the straight line passing through the light-emitting element and the light-receiving element as it moves away from the partition wall in the first direction.

3. The optical detection device according to claim 2, wherein the inclined portion extends toward the center of the circle of the cylindrical wall.

4. The substrate is fixed to the housing by a fastener, the housing has a boss into which the fastener is inserted, The optical detection device according to claim 1 or claim 2, wherein the cylindrical wall is formed by the outer peripheral wall of the boss.

5. The light-transmitting cover is attached to the housing, the lens of the light-transmitting cover has a first lens located at a position corresponding to the first opening and a second lens located at a position corresponding to the second opening, the first lens has a first notch in which an end portion on the second lens side in the first direction is cut out, the second lens has a second notch in which an end portion on the first lens side in the first direction is cut out, The optical detection device according to claim 1 or claim 2, wherein the first notch and the second notch are joined.

6. The light receiving element includes a first light receiving element that receives specularly reflected light from the object to be measured, and a second light receiving element that receives diffusely reflected light from the object to be measured. The first light receiving element is located between the light emitting element and the cylindrical wall. The optical detection device according to claim 1 or claim 2, wherein the second light receiving element is located on the opposite side of the first light receiving element with the light emitting element interposed therebetween.

7. The substrate is fixed to the housing by a fastener. The housing has a boss into which the fastener is inserted. The cylindrical wall is formed by a part of the outer peripheral wall of the boss. The optical detection device according to claim 1, wherein the boss is a protruding portion located on the opposite side of the light receiving element across the cylindrical wall in the first direction, and has a protruding portion protruding toward the substrate side more than the cylindrical wall in a third direction orthogonal to the first direction and a second direction orthogonal to the first direction and parallel to the first plane.

8. A rib located on the opposite side of the boss across the light emitting element and the light receiving element in the first direction. A light shielding wall located between the rib and the protruding portion of the boss in the first direction and away from a straight line passing through the light emitting element and the light receiving element in the second direction. The optical detection device according to claim 7, wherein the rib protrudes toward the substrate side more than the light shielding wall in the third direction and is located on the light shielding wall side more than the protruding portion of the boss.

Images