Light detection unit

Abstract

A light detection unit is provided. A light waveguide of the light detection unit is allowed to pass through or be installed in a thin space. The light detection unit includes a light waveguide formed in a sheet shape wide in a horizontal direction and respectively having a core and a clad layer, the core and the clad layer being layeredly disposed in a vertical direction, and a sheet-shaped cover member covering the clad layer of the light waveguide and formed in a unit with the light waveguide.

Description

Technical Field

[0001] The present invention relates to a light detection unit connected to an optical sensor having a light-emitting element and a light-receiving element. Background Technology

[0002] Traditionally, light detection units are known to include: a light-emitting element that generates detection light for illuminating a detection area; and a light-receiving element that receives the detection light from the detection area and is configured to compare the light-receiving signal generated by the light-receiving element with a threshold, so as to output a signal about the presence or absence of an article as a comparison result (see, for example, Japanese Patent No. 4177178).

[0003] When using this type of optical detection unit for optical detection, an optical detection unit with an optical fiber on the light-emitting side connected to the light-emitting element and an optical fiber on the light-receiving side connected to the light-receiving element is typically used.

[0004] The optical fiber constituting the optical detection unit of Japanese Patent No. 4177178 is composed of bundled optical fibers formed by bundling multiple optical fibers together.

[0005] At the same time, in the case of bundled optical fibers, such as those described in Japanese Patent No. 4177178, where multiple optical fibers are bundled together, the outer diameter of the optical fiber is inevitably several times larger than the diameter of the optical fibers that make up the fiber due to its structure.

[0006] However, the optical fiber of the optical detection unit may pass through narrow spaces, such as between components, where only thin spaces can be secured, or in some cases, it may be desirable to mount it in such thin spaces. For the bundled optical fiber disclosed in Japanese Patent No. 4177178, these situations are difficult to handle due to its large outer diameter. Summary of the Invention

[0007] The present invention was made in view of this, and the object of the present invention is to enable the optical waveguide of the optical detection unit to pass through a thin space or be installed in such a thin space.

[0008] To achieve the above objectives, according to one embodiment of the present invention, a light detection unit is provided that is connected to an optical sensor, the optical sensor comprising: a light-emitting element that projects detection light toward a detection area; a light-receiving element that receives detection light from the detection area; and a signal generation unit that compares the light-receiving signal generated by the light-receiving element with a threshold and generates a detection signal indicating the comparison result.

[0009] The optical detection unit includes an optical waveguide and a cover member. The optical waveguide is a member that guides light between a first end and a second end, has a horizontally wide sheet-like structure, a core, and a cladding surrounding the core, and projects light into or receives light from the detection area. The core and the cladding are arranged in layers in the vertical direction. The first end is connected to a light-projecting connection or a light-receiving connection for optical coupling with a light-emitting element or a light-receiving element of the optical sensor. The second end serves as a light-projecting end or a light-receiving end. The cover member is a sheet-like member that covers the cladding located near the second end of the optical waveguide or between the first and second ends, and is integrally formed with the optical waveguide.

[0010] According to this structure, since the optical waveguide is formed as a wide sheet in the horizontal direction and has a core and cladding layered in the vertical direction, the light output of the optical waveguide can be ensured while making it thin. Because the cladding near the light-emitting or light-receiving end of the optical waveguide, or between the light-emitting and light-receiving ends, is covered by a sheet-like covering member, the covering member can be used as a mounting surface for the object being mounted. For example, the area near the light-emitting or light-receiving end of the optical waveguide can be fixed to the object, or the portion between the light-emitting and light-receiving ends can be fixed to the object. Therefore, a thin optical waveguide can be easily mounted to an object. The covering member can also be used as a mounting surface for the object being mounted.

[0011] According to another embodiment of the present invention, the covering member can be configured as follows: the covering member has light-blocking properties that block light emitted from the light-emitting element, and blocks the light waveguide near the second end of the light waveguide, in a portion other than the light-emitting end or the light-receiving end.

[0012] According to another embodiment of the present invention, the covering member can be constructed as a member that covers the two main surfaces of the optical waveguide and the two side surfaces of the optical waveguide.

[0013] According to another embodiment of the present invention, the covering member can be configured to cover two main surfaces and two side surfaces of the intermediate portion of the optical waveguide located between the first end and the second end. The covering member may also be a member that covers only the two main surfaces of the optical waveguide.

[0014] That is, the core and cladding that make up an optical waveguide have different refractive indices. Light passing through the core usually travels with total internal reflection at the interface between the core and the cladding, but if the optical waveguide is bent, for example, light may sometimes leak to the outside. This leakage can be suppressed by the covering structure.

[0015] For example, the covering member can be made of a material that blocks light of a certain wavelength emitted from the light-emitting element. Since the portion of the optical waveguide other than the light-emitting or light-receiving end is blocked by the covering member, light leakage from the optical waveguide can be suppressed, thereby improving detection accuracy.

[0016] The covering member can also be configured to cover the portion of the optical waveguide located between the first and second ends, i.e., the middle portion of the optical waveguide. As a result, when, for example, the optical waveguide is configured in a bent manner, light leakage from the cladding can be suppressed by the covering member.

[0017] The covering member can also be configured to block light from the optical waveguide near its first end, except for the portion connected to the light-emitting or light-receiving connection. Alternatively, the covering member can also be configured to cover the end portion of the optical waveguide facing the light-traveling direction.

[0018] According to another embodiment of the invention, the covering member is formed as a strip or sheet having an adhesive layer.

[0019] According to this construction, by attaching the adhesive layer of the cover member to the outer surface of the cladding of the optical waveguide, the cover member can be easily integrated with the optical waveguide. The cover member can be, for example, an adhesive tape or adhesive sheet. The material of the cover member is not particularly limited; examples may include polyimide, and black-printed polyimide can be used. Furthermore, when the cover member is integrated with the optical waveguide, rigidity is improved compared to a separate optical waveguide, and handleability is improved compared to handling the optical waveguide separately.

[0020] According to another embodiment of the present invention, the optical waveguide includes: a light-projecting optical waveguide connected to a light-projecting connection portion of the optical sensor, which projects light onto the detection area with its second end as the light-projecting end; and a light-receiving optical waveguide connected to a light-receiving connection portion of the optical sensor, which receives light from the detection area with its second end as the light-receiving end. In this case, the covering member can be integrally formed with the light-projecting optical waveguide and the light-receiving optical waveguide.

[0021] According to this structure, the optical waveguide for projection and the optical waveguide for receiving can be integrated through a covering component. As a result, operability is improved when the optical waveguide for projection and the optical waveguide for receiving travel along the same path or are installed in the same mounting object.

[0022] According to another embodiment of the present invention, the covering member is a member capable of integrating the light-emitting optical waveguide and the light-receiving optical waveguide while they are separated from each other in the width direction. In this case, the portion between the light-emitting optical waveguide and the light-receiving optical waveguide can be fixed to the mounting object by means of a member such as a screw.

[0023] According to another embodiment of the present invention, a socket for inserting a fixing member for use when installing an object may be formed in the portion of the covering member corresponding to the portion located between the light-emitting optical waveguide and the light-receiving optical waveguide.

[0024] According to this configuration, since the light-emitting waveguide and the light-receiving waveguide are integrated through the covering member, and are separated in the width direction, a socket can be formed to pass between the light-emitting and light-receiving waveguides. A fixing member can be inserted through this socket for fixing to the mounting object. The fixing member can be a fastening member such as a screw or bolt, or a member such as a clip or snap fastener.

[0025] According to another embodiment of the present invention, a light extraction member may be provided, which is configured to extend from the second end of the light-emitting optical waveguide to the second end of the light-receiving optical waveguide, and the light extraction member includes: a light emitting portion that is optically coupled to the second end of the light-emitting optical waveguide and emits light from the main surface side of the light-emitting optical waveguide toward the detection region; and a light incident portion that is optically coupled to the second end of the light-receiving optical waveguide and receives light from the main surface side of the light-receiving optical waveguide. The light extraction member can be constructed using components similar to those in an optical guide path.

[0026] According to this configuration, the light extraction member is positioned to extend from the second end of the light-projecting optical waveguide to the second end of the light-receiving optical waveguide. Light from the light-projecting optical waveguide exits from the light-exiting portion of the light extraction member and enters the detection area. Light from the detection area enters from the light-incident portion of the light extraction member and travels parallel to the light-receiving optical waveguide. Therefore, the light extraction member changes the direction of light travel, allowing light to exit from and be received from the main surface. That is, it is possible to project light along the thickness direction of the optical waveguide and receive light along that thickness direction.

[0027] According to another embodiment of the invention, the optical waveguide has a plurality of cores arranged along the horizontal direction, and the optical extraction member can be configured to have a single core optically coupled to the plurality of cores.

[0028] According to this structure, the amount of light can be increased due to the presence of multiple cores in the optical waveguide, and furthermore, the optical waveguide can be made thinner because the cores are arranged in a horizontal direction. Additionally, since the light extraction component is constructed with a single core, it can be easily manufactured. Note that a cladding layer covering the core of the light extraction component can be provided.

[0029] According to another embodiment of the present invention, the covering member may be provided with through holes for fixing to the installation object.

[0030] According to this structure, the optical waveguide can be positioned in a predetermined location by fixing the through-hole of the cover member to the mounting object. The through-hole can be fixed to the mounting object by fastening members, clips, snaps, straps, etc.

[0031] The covering component can be a component having a stacked structure, the stacked structure having a first covering component covering the cladding and a second covering component covering the first covering component, the first covering component covering the main surface of the cladding, and the second covering component covering the main surface of the first covering component and the two side surfaces of the optical waveguide.

[0032] A reinforcing plate with higher rigidity than the optical waveguide can also be provided on the main surface near the second end of the optical waveguide.

[0033] A sheet-like covering member can be disposed on the main surface near the second end of the optical waveguide, and a reinforcing plate with higher rigidity than the optical waveguide can also be disposed on the main surface of the sheet-like covering member.

[0034] The sheet-like covering member can be black in appearance, and the optical detection unit with the optical waveguide covered by the sheet-like covering member can be sheet-like.

[0035] The end from which light is projected from or received from the detection area can be any one of the main surface of the waveguide, the side surface near the second end, and the side surface in the horizontal direction.

[0036] The connection part of the optical detection unit relative to the optical sensor for light projection or light receiving can be an optical waveguide or an optical fiber optically coupled to the optical waveguide.

[0037] The optical detection unit can be a limited reflective optical detection unit.

[0038] The enhanced version may have through holes, which can communicate with the through holes of the sheet-like cover member.

[0039] An indicator light can be installed between the first and second ends of the optical waveguide, on the projection side or the receiving side. The indicator light extracts the light passing through the core of the optical waveguide to the outside.

[0040] As described above, since the optical waveguide, which has a core and cladding layered in the vertical direction, is a sheet-like structure that is wide in the horizontal direction, it is possible to allow the optical waveguide to pass through or be installed in a thin space while ensuring the amount of light emitted. Because a covering member that covers the cladding near the light-emitting or light-receiving end of the optical waveguide can be used as a mounting surface, the thin optical waveguide can be easily installed onto the mounting object. Attached Figure Description

[0041] Figure 1 This is a perspective view showing the usage state of an optical sensor connected to a light detection unit according to an embodiment of the present invention;

[0042] Figure 2 This is a block diagram of an optical sensor;

[0043] Figure 3 It is a vertical cross-sectional perspective view used to illustrate the component retainer and the component held by the component retainer;

[0044] Figure 4 This is a plan view showing the state in which the light guide and connector of the light detection unit are separated;

[0045] Figure 5 This is a perspective view of the upper cover component omitting the light guide section of the light detection unit;

[0046] Figure 6 It is along Figure 4 A cross-sectional view taken from line VI-VI in the diagram;

[0047] Figure 7 This is a magnified planar view showing the vicinity of the end of the optical waveguide;

[0048] Figure 8A It is an enlarged cross-sectional view of an optical waveguide with multiple cores;

[0049] Figure 8B It is an enlarged cross-sectional view of an optical waveguide with a single core;

[0050] Figure 9 yes Figure 5 An enlarged view of the end side of the light guide section of the light detection unit shown;

[0051] Figure 10 It shows the detection status of the workpiece along... Figure 4 A cross-sectional view of line XX;

[0052] Figure 11 This is a plan view showing an example of a light detection unit being fixed to a mounting component by a fixing component;

[0053] Figure 12 This is a vertical cross-sectional view showing an example of a light detection unit being fixed to a mounting component by a fixing component;

[0054] Figure 13 This is a plan view showing an example of a light detection unit being fixed to a mounting component by a fixing plate;

[0055] Figure 14 This is a vertical cross-sectional view showing an example of a light detection unit being fixed to a mounting component by a fixing plate;

[0056] Figure 15 This is a diagram showing an example of a light detection unit being fixed to a mounting component by a hook-shaped member;

[0057] Figure 16 This is a plan view showing an example of a light detection unit being directly fixed to a mounting component by screws;

[0058] Figure 17 This is a vertical cross-sectional view showing an example of a light detection unit being directly fixed to a mounting component by screws;

[0059] Figure 18 This is a perspective view showing an example of a covering member being provided at a fixed part of the light detection unit;

[0060] Figure 19 This is a perspective view showing an example in which a covering member is provided at the fixed part of the light detection unit to fix both sides of the covering member in the width direction;

[0061] Figure 20 This is a perspective view showing an example in which a covering member is provided at the fixed part of the light detection unit to fix the end side of the covering member.

[0062] Figure 21 This is a perspective view showing an example in which a covering member is provided at the fixed part of the optical detection unit to fix the end side of the covering member and the part located between the light-emitting optical waveguide and the light-receiving optical waveguide;

[0063] Figure 22 This is a vertical cross-sectional view showing an example of using a gasket to fix the light detection unit;

[0064] Figure 23A It is a vertical cross-sectional view of the part where the optical waveguides are connected to each other;

[0065] Figure 23B It is a plan view of the interconnected parts of the optical waveguides;

[0066] Figure 24 This is a perspective view showing a construction example in which a light-emitting waveguide and a light-receiving waveguide are formed in a single component to achieve a defined reflection;

[0067] Figure 25This is a perspective view showing a construction example in which reflectors made of separate components are provided at the ends of the optical waveguide for projection and the optical waveguide for receiving to achieve limited reflection.

[0068] Figure 26 This is a plan view of an example optical detection unit showing a pattern of an optical waveguide that takes into account the reduction of optical loss;

[0069] Figure 27A This is a diagram showing an example of setting a light-emitting mirror on the end face of a light-emitting waveguide;

[0070] Figure 27B This is a diagram illustrating an example of setting the direction of the end face of a light-emitting optical waveguide using a direction-setting component;

[0071] Figure 28 This is a plan view of an example optical detection unit showing a pattern of optical waveguides with priority given to external dimensions;

[0072] Figure 29 This is a three-dimensional diagram showing an example of a waveguide for transmitting light and a waveguide for receiving light constructed by arranging multiple optical fibers in a horizontal direction.

[0073] Figure 30 This is a plan view illustrating an example of defined reflection, where light exits from the end of an optical waveguide;

[0074] Figure 31 This is a plan view showing another example of defined reflection, where light exits from the end of an optical waveguide;

[0075] Figure 32 This is a plan view showing an example of defined reflection of light emitted from the side surface of an optical waveguide;

[0076] Figure 33 This is a plan view showing another example of defined reflection of light emitted from the side surface of an optical waveguide;

[0077] Figure 34 This is a plan view showing an example used as a multi-point reflective optical detection unit;

[0078] Figure 35 This is a diagram showing an example of an optical waveguide with a bent end;

[0079] Figure 36A This is a diagram illustrating an example of combining an optical waveguide and a mirror component;

[0080] Figure 36B This is a diagram illustrating another example of combining optical waveguides and mirror components;

[0081] Figure 37 This is a diagram showing an example of installing a retroreflector;

[0082] Figure 38A This is a diagram showing an example of a transmittance type light detection unit in which the light-emitting optical waveguide and the light-receiving optical waveguide extend in the same direction;

[0083] Figure 38B This is a diagram showing an example of a transmittance type light detection unit in which the light-emitting waveguide and the light-receiving waveguide extend in opposite directions;

[0084] Figure 39 This is a diagram showing an example of a transmittance type light detection unit in which the ends of the light-emitting optical waveguide and the ends of the light-receiving optical waveguide face each other.

[0085] Figure 40 This is a diagram illustrating an example of a transmittance type optical detection unit when a workpiece is detected in the optical detection unit;

[0086] Figure 41 This is a diagram illustrating an example of a transmissive light detection unit with numerous optical paths;

[0087] Figure 42 It is based on the plan view of the connector section of the first example;

[0088] Figure 43 This is a side view of the connector section based on the first example;

[0089] Figure 44 It is along Figure 43 A cross-sectional view taken from line AA in the diagram;

[0090] Figure 45 It is along Figure 42 A cross-sectional view taken from line BB in the middle;

[0091] Figure 46 It is along Figure 42 A cross-sectional view taken from line CC in the diagram;

[0092] Figure 47 This is a diagram of the connector portion of the first example, viewed from the end side;

[0093] Figure 48 This is a perspective view of the connector section of the first example, viewed from the side where the pressure member is located;

[0094] Figure 49 This is a perspective view of the connector section based on the second example;

[0095] Figure 50 It is based on the plan view of the connector section of the third example;

[0096] Figure 51 This is a diagram of the connector portion of the third example, viewed from the end side;

[0097] Figure 52 This is a diagram showing an example with a pre-installed adapter;

[0098] Figure 53 This is a diagram illustrating an example where the light-emitting aperture and the light-receiving aperture of an optical sensor are slit-shaped;

[0099] Figure 54 This is a perspective view showing the connector portion according to the fourth example;

[0100] Figure 55A This is a perspective view of the structure of a first example of a relay section, viewed from the front side.

[0101] Figure 55B This is a perspective view of the structure of a first example of a relay section, viewed from the rear side;

[0102] Figure 55C This is a perspective view showing the structure of a first example of a relay section;

[0103] Figure 56A This is a cross-sectional view showing a first example of a relay section;

[0104] Figure 56B This is a plan view showing a first example of a relay section;

[0105] Figure 57 This is a plan view showing a second example of a relay section;

[0106] Figure 58 This is a cross-sectional view showing a second example of the relay section;

[0107] Figure 59 This is a plan view showing a third example of a relay section;

[0108] Figure 60 It is used to explain the principle of stray light generation. Figure 10 Corresponding diagram;

[0109] Figure 61 This diagram illustrates the process of forming a light-emitting mirror using a cutting tool;

[0110] Figure 62 This illustrates an example of applying the first stray light countermeasure. Figure 10 Corresponding diagram;

[0111] Figure 63 This illustrates an example of applying the second stray light countermeasure. Figure 10 Corresponding diagram;

[0112] Figure 64 This illustrates an example of applying a third stray light countermeasure. Figure 10 Corresponding diagram;

[0113] Figure 65 This illustrates an example of applying the fourth stray light countermeasure. Figure 10 The corresponding diagram; and

[0114] Figure 66 This illustrates an example of applying the fifth stray light countermeasure. Figure 10 The corresponding diagram. Detailed Implementation

[0115] In the following, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following preferred embodiments are merely illustrative in nature and are not intended to limit the invention, its application, or its uses.

[0116] Figure 1 This is a perspective view showing the optical sensor 1 connected to the light detection unit 400 according to an embodiment of the present invention in its usage state. The optical detection device 300 consists of the light detection unit 400 and the optical sensor 1. Figure 1 This is a perspective view of the optical inspection device 300 from an oblique top, showing an example of four optical inspection devices 300 mounted adjacent to each other on the DIN rail 2, with one of the four optical inspection devices 300 shown with the cover 4 open.

[0117] Among the multiple optical inspection devices 300 mounted adjacent to each other on the DIN rail 2, one optical inspection device 300 is the master device, and the other optical inspection devices 300 are slave devices. For example, when the master device completes light projection, a signal to start light projection is supplied from the master device to the first slave device, and light projection is performed by the first slave device. When the first slave device completes light projection, a signal to start light projection is supplied from the first slave device to the second slave device, and light projection is performed by the second slave device. Thereafter, light projection by the third and fourth slave devices begins sequentially.

[0118] Notice, Figure 1 The usage example shown is exemplary, and only a single optical inspection device 300 can be used. The optical inspection device 300 can also be fixed to a component other than the DIN rail 2 and used.

[0119] (Construction of optical sensor 1)

[0120] like Figure 2As shown in the block diagram of the optical detection device 300, the optical sensor 1 constituting the optical detection device 300 includes a light-emitting unit 102 and a light-receiving unit 202. The light-emitting unit 102 outputs a predetermined pulsed light to the light detection unit 400. The light-emitting element 104 of the light-emitting unit 102 is driven by an oscillating pulse supplied from the light-emitting power supply control circuit 302 to emit pulsed light. At the same time, the light received by the light-receiving unit 202 undergoes photoelectric conversion through the light-receiving element 204, and is transmitted to the control unit 308 via the light-receiving element amplification circuit 206, the control amplification circuit 304, and the A / D converter 306. As a result, detection synchronized with the pulsed light is performed, and the detection signal is further converted into a DC signal, etc., and then an ON / OFF signal indicating the detection result is output from the I / O circuit 360 constituting the interface unit.

[0121] The optical sensor 1 includes a light projection circuit 106 configured to drive a light-emitting element 104. The light-emitting element 104 is a component configured to project detection light onto a detection area. A typical example of the light-emitting element 104 is a light-emitting diode (LED), but it is not limited thereto.

[0122] The projection circuit 106 includes a projection APC circuit 108 and a monitoring light-receiving element 110, such as a monitoring PD. The projection APC circuit 108 is controlled so that the output (i.e., the amount of light emitted by the light-emitting element 104) is a predetermined value. The monitoring light-receiving element 110 of the projection unit 102 is connected to a monitoring signal amplification circuit 114 and transmits the amount of light received to the LED luminance monitoring circuit 312 via a monitoring line. The LED luminance monitoring circuit 312 supplies the light received signal, which is converted into a digital signal, to the control unit 308 via an A / D converter 314. The control unit 308 controls the projection power control circuit 302 based on the amount of light received by the monitoring light-receiving element 110, so that the amount of light received becomes a predetermined value, and performs feedback control to adjust the amount of current in the projection APC circuit 108 and drive the light-emitting element 104.

[0123] The optical sensor 1 includes a light-receiving circuit 208 configured to drive a light-receiving element 204. The light-receiving element 204 is a component that receives detection light from a detection area and is connected to a light-receiving element amplification circuit 206. The amount of light received by the light-receiving element 204 is amplified by the light-receiving element amplification circuit 206 and sent to a control amplification circuit 304, where it is further amplified. The analog signal amplified by the control amplification circuit 304 is converted into a digital signal via an A / D converter 306 and input to a signal generation unit 308a of the control unit 308. The signal generation unit 308a detects the amount of light received by the light-receiving element (photodiode PD) 204 and compares the light-receiving signal generated by the light-receiving element 204 with a predetermined threshold to generate a detection signal indicating the comparison result. Finally, the detection signal generated by the signal generation unit 308a is output from the I / O circuit 360.

[0124] The control unit 308, the storage unit 326 configured to store various settings, the display circuit 328 configured to display information on the side of the optical sensor 1, and the operation buttons 6 and 8 configured to receive settings adjustments as a user interface are connected. Figure 1 The switch input circuit 330 (shown) and the I / O circuit 360 for input / output to the outside are connected, and these circuits are driven by the control power supply circuit 332.

[0125] Note that the control unit 308 can be constructed using, for example, ICs (such as central processing units, FPGAs, and ASICs). Each of the various loops (reference numerals 108, 114, 206, 214, 302, 304, 306, 312, 314, 320, 328, 330, 332, and 360) can be constructed using a single IC. Alternatively, a single IC can be used to construct both the control unit 308 and each of the various loops.

[0126] like Figure 1 As shown, a display unit 334 is provided on the upper surface of the housing 10 of the optical sensor 1. Although in this specification, it will be... Figure 1 The side that is located at the top in the usage state shown is called "top", but this is only defined for ease of explanation, and the optical sensor 1 can be installed with any surface facing up.

[0127] The display unit 334 is constructed using, for example, an organic EL display or a flat panel display, and the display unit 334 is composed of... Figure 2 The display circuit 328 shown is controlled by [the circuit]. The display unit 334 can be as follows: Figure 1 The segmented display shown is used to display detected values ​​(light intensity), threshold values, etc., using display unit 334. Display unit 334 can be constructed using seven segmented displays arranged side-by-side.

[0128] like Figure 1 As shown, operation buttons such as the up / down button 6, the mode button 8, and the setting button 9 are arranged adjacent to the display unit 334 on the upper surface of the housing 10 of the optical sensor 1. The optical sensor 1 has two channels for output, but is not limited thereto. Reference numeral 16 indicates an operation indicator configured to display current output or detection status, reference numeral 16a indicates the operation indicator of the first channel, and reference numeral 16b indicates the operation indicator of the second channel.

[0129] When operating buttons 6, 8, and 9, etc., switching between non-conversion display mode and conversion display mode, sensitivity setting, threshold setting, etc., can be performed. The non-conversion display mode directly displays the detected value (light received) and threshold, while the conversion display mode displays the detected value (light received) and threshold after conversion using a display conversion rate or a display conversion method. Note that the display object, display mode, display switching operation, and display mode switching of the optical sensor 1 are described in detail in JP2006-351380A and JP2019-61885A; therefore, their descriptions will be omitted by referencing JP2006-351380A and JP2019-61885A.

[0130] The interior of the housing 10 of the optical sensor 1 is provided with, as follows Figure 3 The component holder 368 is shown. The component holder 368 is a member that holds the light-emitting element 104 and the light-receiving element 204. The component holder 368 houses a light-projecting member 370 and a light-receiving member 372. The light-projecting member 370 is a member that substantially constitutes the aforementioned light-projecting unit 102, and includes the light-emitting element 104, a monitoring light-receiving element 110, and a reflector 380. The light-receiving member 372 is a member that substantially constitutes the aforementioned light-receiving unit 202, and includes the light-receiving element 204 and an LED 212 as an optical display light-emitting element. In this configuration, the light-emitting element 104 and the light-receiving element 204 are arranged vertically, specifically, the light-emitting element 104 is located above the light-receiving element 204. However, the light-receiving element 204 may be located above the light-emitting element 104, or the light-emitting element 104 and the light-receiving element 204 may be arranged horizontally.

[0131] The component holder 368 has a light-emitting aperture 376 and a light-receiving aperture 378 connected to the light detection unit 400. Both the light-emitting aperture 376 and the light-receiving aperture 378 are constructed as through holes with circular cross-sections and are formed to penetrate the component holder 368. The light-emitting aperture 376 forms a light-emitting connection portion, which is configured for transmission through a light-emitting optical waveguide 410 disposed in the light detection unit 400. Figure 4(As shown) It is directly or indirectly connected to the light-emitting element 104 for optical coupling. Additionally, the light-receiving aperture 378 forms a light-receiving connection portion, which is configured to be optically coupled to the light-receiving element 204 through a direct or indirect connection with the light-receiving optical waveguide 420 provided in the light detection unit 400. The specific structures of the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420 will be described later.

[0132] That is, the ends of the light-emitting hole 376 and the light-receiving hole 378 respectively have a first socket 376a and a second socket 378a that open toward the outer surface of the element holder 368. The light-emitting element 104 is disposed on the back side of the light-emitting hole 376. The light-emitting element 104 is mounted on the light-emitting mounting substrate 382. The position of the light-emitting element 104 is set such that the center of the light-emitting surface of the light-emitting element 104 is located on the extension line of the center line of the light-emitting hole 376.

[0133] A light-receiving element 204 is disposed on the back side of the light-receiving aperture 378. The light-receiving element 204 is mounted on a light-receiving mounting substrate 384. The position of the light-receiving element 204 is set such that the center of the light-receiving surface of the light-receiving element 204 is located on the extension line of the center line of the light-receiving aperture 378. The space where the light-emitting element 104 is disposed and the space where the light-receiving element 204 is disposed are optically isolated. A glass plate 374 serving as a light-transmitting member is inserted between the end of the light-receiving element 204 and the back side of the light-receiving aperture 378.

[0134] (Clamping mechanism)

[0135] The optical sensor 1 has a clamping mechanism configured to hold the light detection unit 400 in the connected state. The clamping mechanism is located inside the housing 10 and is configured to clamp the portion of the light detection unit 400 inserted into the light emission hole 376 and the light receiving hole 378 radially (details will be described later). When the portion of the light detection unit 400 inserted into the light emission hole 376 and the light receiving hole 378 is clamped by the clamping mechanism, it prevents the inserted portion from disengaging from the light emission hole 376 and the light receiving hole 378.

[0136] At the same time, such as Figure 1 As shown, an operating lever 7 configured to operate the clamping mechanism from the outside is provided on the exterior of the housing 10. When the operating lever 7 is moved in a predetermined direction, the clamping mechanism can be set to a clamping state. When the operating lever 7 is moved in the opposite direction to the predetermined direction, the clamping mechanism can be set to a non-clamping state.

[0137] The clamping mechanism and the operating lever 7 are not limited to the above-described structure, but can be any structure capable of clamping the portion of the light detection unit 400 inserted in the light projection hole 376 and the light receiving hole 378.

[0138] (Overall structure of the optical detection unit 400)

[0139] As Figure 4 The example shown illustrates that the light detection unit 400 includes a light guide portion 401 and a connector portion 500, and is capable of detecting the workpiece WK by defining a reflection. Figure 10 The unit shown is the connector section 500. The connector section 500 will be described later.

[0140] Here, the sensor for detecting workpiece WK by limiting reflection is as follows: light for detection is emitted by defining a detection area of ​​the object, and the reflected light reflected by workpiece WK in the detection area is received by a light receiving unit to detect whether workpiece WK exists at a predetermined position.

[0141] Although details will be provided later, the light detection unit 400 is provided with a first socket 402 to a fourth socket 405 for inserting a fixing member such as a screw.

[0142] like Figure 5 and Figure 6 As shown, the light guide section 401 includes a light-projecting waveguide 410, a light-receiving waveguide 420, a light-extraction component 430, an upper cover component 440, and a lower cover component 450. Note that, as Figure 4 and Figure 5 The image defines the end side and the base side of the light detection unit 400. The base side of the light detection unit 400 is the side connected to the optical sensor 1, and is the side where the connector portion 500 is provided. The end side of the light detection unit 400 is the side where the workpiece WK ( Figure 9 The side to be tested (as shown in the image).

[0143] like Figure 5 As shown, the light-emitting waveguide 410 is formed as an elongated strip to guide light between the base (first end) and the end (second end) of the light detection unit 400. The base end is the sensor side, and the end end is the detection end. The light-emitting waveguide 410 has a sheet-like shape that is wide in the horizontal direction, wherein, as shown... Figure 8A As shown, the horizontal dimension (width W) is set to be longer than the vertical dimension (thickness t). The main surfaces of the projection waveguide 410 are the upper and lower surfaces. The side surfaces of the projection waveguide 410 are the surfaces located on both sides in the width direction. Note that the projection waveguide 410 can be configured... Figure 6 The horizontal orientation shown is used in a vertical orientation, or in... Figure 6 Use the horizontally tilted posture shown.

[0144] like Figure 8AAs shown, the optical waveguide 410 for projection has a plurality of cores 411 arranged horizontally spaced apart from each other and a cladding 412 surrounding the cores 411. Due to the change in refractive index between the cores 411 and the cladding 412, light incident on the cores 411 will travel simultaneously due to total internal reflection at the interface between the cores 411 and the cladding 412. At this time, there is almost no light loss.

[0145] The number of cores 411 can be set to any number, not limited to the number shown in the figure. It is preferable to provide multiple cores 411 because the light intensity can be increased without increasing the thickness of the optical waveguide 410 for projection. The cross-sectional shape of the cores 411 is not particularly limited and can be, for example, rectangular. The cladding 412 has an upper side portion 412a that covers the cores 411 from above, a lower side portion 412b that covers the cores 411 from below, and an intermediate portion 412c that is between the cores 411 arranged in the horizontal direction. The upper side portion 412a of the cladding 412, the cores 411, and the lower side portion 412b of the cladding 412 are arranged in layers in the vertical direction and integrated.

[0146] The middle portion 412c of the cladding 412 extends from the upper portion 412a to the lower portion 412b. The structure is formed such that the upper portion 412a and the lower portion 412b are connected by the middle portion 412c. Although in Figure 8A In the example shown, the core 411 at both ends of the optical waveguide 410 in the width direction is exposed and not covered by the cladding 412, but the core 411 at both ends of the optical waveguide 410 in the width direction can be covered by the cladding 412.

[0147] For example, a magnified planar view near the end of the optical waveguide 410 used for projection. Figure 7 As shown, the end of the middle portion 412c of the cladding 412 does not necessarily have to reach the end of the optical waveguide 410 for projection.

[0148] like Figure 8B As shown, the number of cores 411 can be one. When there is one core 411, the core 411 can be formed to have a cross-section that is long in the width direction of the optical waveguide 410 for projection. In this case, the middle portion 412c of the cladding 412 is omitted, and the cladding 412 is composed of an upper portion 412a and a lower portion 412b. The two side surfaces of the core 411 in the width direction can be exposed or covered by the cladding 412.

[0149] The light-emitting waveguide 410 is a so-called polymer optical waveguide path. Examples of materials for the light-emitting waveguide 410 may include resins such as acrylic acid, epoxy resin, siloxane, silicone, polyimide, polysilane, polynorbornene, and fluoropolymers, but the material is not limited to these; rather, materials that meet the desired optical and physical properties can be used appropriately. Only one material may be used, or any combination of materials may be used. Additionally, additives may be added to the material to improve the optical and physical properties. Because the light-emitting waveguide 410 is made of the aforementioned resins, it possesses flexibility and plasticity, and also has predetermined heat resistance.

[0150] The method for forming the core 411 of the optical waveguide 410 for projection can be selected based on the material. For example, methods can be selected from physical etching (RIE), imprinting (forming), photoluminescence (UV conversion), direct exposure (UV curing), etc., but are not limited to these.

[0151] like Figure 6 As shown, the light-receiving waveguide 420 can be constructed in the same manner as the light-emitting waveguide 410, and includes a core 421 and a cladding 422. The light-receiving waveguide 420 and the light-emitting waveguide 410 can be identical, or they can have different dimensions, etc. The light-emitting waveguide 410 and the light-receiving waveguide 420 are arranged with a distance between them in the width direction. The distance between the light-emitting waveguide 410 and the light-receiving waveguide 420 is not particularly limited, but it can be set to 5 mm or more, for example, taking into account the screwing, which will be described later.

[0152] The light-emitting waveguide 410 and the light-receiving waveguide 420 are covered by upper cover members 413 and lower cover members 414, which are reinforcing materials on the outside of the light-emitting waveguide 410; by upper cover members 423 and lower cover members 424, which are reinforcing materials on the outside of the light-receiving waveguide 420; and by opaque upper cover members 440 and lower cover members 450. Upper cover members 413, lower cover members 414, upper cover members 423, and lower cover members 424 serve as first cover members. Upper cover members 440 and lower cover members 450 serve as second cover members. Therefore, the light detection unit 400 includes cover members with a stacked structure.

[0153] That is, the lower surface of the cladding 412 of the light-emitting waveguide 410 is covered by the lower covering member 414, the lower surface of the cladding 422 of the light-receiving waveguide 420 is covered by the lower covering member 424, and the lower covering members 414 and 424 are covered by the lower covering member 450. Furthermore, the upper surface of the cladding 412 of the light-emitting waveguide 410 is covered by the upper covering member 413, the upper surface of the cladding 422 of the light-receiving waveguide 420 is covered by the upper covering member 423, and the upper covering members 413 and 423 are covered by the upper covering member 440. Figure 4 and Figure 5 As shown, the upper cover member 440 and the lower cover member 450 are formed as sheets extending from the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 toward the base end side. The base ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 protrude from the base ends of the upper cover member 440 and the lower cover member 450, and are not covered by the upper cover member 440 and the lower cover member 450. The portions of the light-emitting waveguide 410 and the light-receiving waveguide 420 that are not covered by the cover members 440 and 450 are the portions that can be inserted or removed relative to the optical sensor 1.

[0154] In the following text, the upper cover member 413, the lower cover member 414, the upper cover member 423, and the lower cover member 424 are disposed on the upper and lower surfaces of the optical waveguide 410 or the optical waveguide 420, and their description will be omitted. That is, the upper cover member 413 and the lower cover member 414 can be used as members forming part of the optical waveguide 410. In this case, the upper cover member 413 and the lower cover member 414 can be collectively referred to as the optical waveguide 410. For example, when it is described that "a hole is formed in the optical waveguide 410", the upper cover member 413 and the lower cover member 414 located on the upper and lower surfaces of the optical waveguide 410 may also have holes formed, but their description will be omitted for the sake of redundancy. Similarly, the upper cover member 423 and the lower cover member 424 can be used as members forming part of the optical waveguide 420. In this case, the upper cover member 423 and the lower cover member 424 can be collectively referred to as the optical waveguide 420. Note that, without further explanation, upper cover component 413, lower cover component 414, upper cover component 423, and lower cover component 424 can be configured; some of them can be configured, or none of them can be configured. Furthermore, upper cover component 413 and lower cover component 414 can be considered as components different from optical waveguide 410, and upper cover component 423 and lower cover component 424 can be considered as components different from optical waveguide 420.

[0155] The upper cover member 440 and the lower cover member 450 have light-blocking properties that block light emitted from the light-emitting element 104. The upper cover member 440 and the lower cover member 450 do not necessarily need to block 100% of the light emitted from the light-emitting element 104; preferably, they have light-blocking properties of, for example, 90% or more. The upper cover member 440 and the lower cover member 450 preferably have light-blocking properties corresponding to the wavelength of the light emitted from the light-emitting element 104 and attenuation effects that reduce the wavelength of the light. In terms of appearance, the upper cover member 440 and the lower cover member 450 can be, for example, dark blue, in addition to black. The resin material forming the upper cover member 440 and the lower cover member 450 can be colored by printing.

[0156] The light-emitting waveguide 410 and the light-receiving waveguide 420 are made of a material that is transparent to light traveling therein. The upper cover member 413, lower cover member 414, upper cover member 423, and lower cover member 424 are made of an opaque material to enhance the light-emitting waveguide 410 and the light-receiving waveguide 420, and to induce reflection at the interface between the light-emitting waveguide 410 and the light-receiving waveguide 420. Examples of materials may include polyimide. As described above, the upper cover member 440 and lower cover member 450 disposed on the outer side are light-shielding and are treated, such as by coloring, to have a higher light-shielding property than the upper cover member 413, lower cover member 414, upper cover member 423, and lower cover member 424. The upper cover member 440, lower cover member 450, upper cover member 413, lower cover member 414, upper cover member 423, and lower cover member 424 can be made of polyimide as the same material, and differences in light-blocking properties can be provided by printing black on the upper cover member 440 and the lower cover member 450. Note that in Figure 6 The portions located at two horizontal positions between the light-receiving waveguide 420 and the upper cover member 440, and between the light-receiving waveguide 420 and the lower cover member 450, as well as the portions located at two horizontal positions between the light-projecting waveguide 410 and the upper cover member 440, and between the light-projecting waveguide 410 and the lower cover member 450, are air-filled portions. Air may enter when the upper cover member 440 and the lower cover member 450 cover the laminate formed by the light-projecting waveguide 410, the upper cover member 413, and the lower cover member 414, and the laminate formed by the light-receiving waveguide 420, the upper cover member 423, and the lower cover member 424. As a result, light leakage can be reduced due to the difference in refractive index between each of the light-projecting waveguide 410 and the light-receiving waveguide 420 and air.

[0157] An adhesive layer and a bonding layer are provided on the back side of the upper cover member 440. The upper cover member 440 is attached or bonded to the upper surface of the cladding 412 of the light-emitting optical waveguide 410 and the upper surface of the cladding 422 of the light-receiving optical waveguide 420. As a result, the upper cover member 440 is integrally constructed with the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420.

[0158] An adhesive layer and a bonding layer are also provided on the back side of the lower cover member 450. The lower cover member 450 is attached or bonded to the lower surface of the cladding 412 of the light-emitting optical waveguide 410 and the lower surface of the cladding 422 of the light-receiving optical waveguide 420. As a result, the lower cover member 450 is integrally constructed with the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420.

[0159] The upper cover member 440 and the lower cover member 450 are attached or bonded to each other on both sides in the width direction. As a result, light leakage from both sides in the width direction can be suppressed. Furthermore, the upper cover member 440 and the lower cover member 450 are also attached or bonded to each other between the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420. As a result, the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420 can be optically isolated.

[0160] The upper cover member 440 and the lower cover member 450 can be made of, for example, a flexible resin strip, resin sheet, resin film, etc. Examples of resin materials that can be used include polyimide, etc., but the resin material is not limited to this; any resin material that has flexibility, plasticity, and the strength to prevent breakage during fixing, as will be described later, can be used. When coloring the upper cover member 440 and the lower cover member 450, pigments or dyes can be used.

[0161] Furthermore, the light-emitting waveguide 410 and the light-receiving waveguide 420 can be covered by a single covering member that is not separated into an upper covering member 440 and a lower covering member 450. Additionally, the covering member can be bag-shaped, and its shape is not particularly limited. The upper covering member 440 and the lower covering member 450 are formed so as not to cover the light-emitting end of the light-emitting waveguide 410 and the light-receiving end of the light-receiving waveguide 420, and are capable of optically coupling the light-extracting member 430 to the light-emitting end of the light-emitting waveguide 410 and the light-receiving end of the light-receiving waveguide 420.

[0162] On the upper cover member 440 and the lower cover member 450, text, symbols, markings, etc., indicating the manufacturer's name, product number, model number, etc., of the light detection unit 400 can be written. When the upper cover member 440 and the lower cover member 450 are formed of a dark color such as black, and the text, symbols, markings, etc. are formed of a light color such as white, the text, symbols, markings, etc., will become more conspicuous. When, for example, only the upper surface is written with text, symbols, markings, etc., the user can easily determine which is the upper surface. For example, text, symbols, markings, etc., can be written on the upper cover member 440 or the lower cover member 450 as a direction display unit indicating directions such as up, down, forward, and backward.

[0163] Because of the upper cover member 440 and the lower cover member 450, light leakage from the light-emitting waveguide 410 and the light-receiving waveguide 420 can be suppressed when the light detection unit 400 is bent during installation. Furthermore, by integrating the upper cover member 440 and the lower cover member 450 with the light-emitting waveguide 410 and the light-receiving waveguide 420, the strength of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be enhanced. For example, when the light detection unit 400 is bent during installation, breakage of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be suppressed by the upper cover member 440 and the lower cover member 450. Meanwhile, since the upper cover member 440, the lower cover member 450, the light-emitting waveguide 410, and the light-receiving waveguide 420 are flexible, the light detection unit 400 can be bent, twisted, and wrapped, for example, when it is being moved around an obstacle, thereby improving the degree of freedom of operation. Since light leakage from the light-emitting waveguide 410 and the light-receiving waveguide 420 can be suppressed even in this manner, there is no adverse effect on the detection performance.

[0164] Furthermore, the light-emitting waveguide 410 and the light-receiving waveguide 420 are characterized by being sheet-like and thin in this configuration, thus allowing the light detection unit 400 to be disposed within a thin space. On the other hand, it is also considered that if the light-emitting waveguide 410 and the light-receiving waveguide 420 are thin, they are prone to bending and twisting during operation, which degrades operability. However, due to the provision of the upper cover member 440 and the lower cover member 450, bending of the light-emitting waveguide 410 and the light-receiving waveguide 420 is appropriately suppressed, and twisting is almost non-existent, resulting in good operability.

[0165] The rigidity of the resin material forming the upper cover member 440 and the lower cover member 450 can be set to be higher than that of the resin material forming the light-emitting waveguide 410 and the light-receiving waveguide 420. As a result, the enhancement effect of the upper cover member 440 and the lower cover member 450 is further improved. In addition, the resin material forming the upper cover member 440 and the lower cover member 450 can be made to have weaker slippage properties than the resin material forming the light-emitting waveguide 410 and the light-receiving waveguide 420. As a result, the light detection unit 400 becomes less prone to slippage when it is installed.

[0166] In addition, such as Figure 8A and Figure 6 As shown, core 411 is partially exposed on the horizontal end face of the optical waveguide 410 for projection. This is intended to strengthen the end face. For example, when the cladding constituting the optical waveguide 410 for projection is manufactured by changing the core, core 411 becomes stronger than cladding 412. Therefore, by exposing core 411, the strength of the end face side can be improved.

[0167] In addition, such as Figure 7 As shown, the end face of the optical waveguide 410 for projection is core 411. Additionally, the horizontal end face (in...) Figure 7 The core 411 is located at the left and right ends of the paper. Since the core 411 is stronger than the cladding 412, the exposed portion is formed by the core 411 rather than the cladding 412.

[0168] like Figure 9 As shown, the light extraction member 430 is disposed at the end of the light detection unit 400 and is formed as a plate extending from the end of the light-emitting waveguide 410 to the end of the light-receiving waveguide 420. The thickness of the light extraction member 430 is set to be approximately the same as the thickness of either the light-emitting waveguide 410 or the light-receiving waveguide 420. Note that, as Figure 9 The light detection unit 400 is defined as shown, but this is only for illustrative purposes and does not limit the actual usage.

[0169] The light extraction component 430 can be made of a material with the same light-guiding properties as the core 411 of the light-emitting waveguide 410. For example... Figure 10 As shown, a single core 430a is used to construct the light extraction component 430. The light extraction component 430 may have a cladding similar to the cladding 412 of the projection waveguide 410. The lower surface of the light extraction component 430 is attached or bonded to the lower cover component 450, and the upper surface of the light extraction component 430 is attached or bonded to the upper cover component 440. As a result, it is possible to prevent the relative positional misalignment of the light extraction component 430 with the projection waveguide 410 and the receiving waveguide 420, and the light extraction component 430 can be covered by the upper cover component 440 and the lower cover component 450.

[0170] like Figure 9 As shown, the right side of the light extraction member 430 abuts against the end of the projection waveguide 410. As a result, the light extraction member 430 is optically coupled to the plurality of cores 411 of the projection waveguide 410, so that light traveling through the cores 411 of the projection waveguide 410 will be incident on the right side of the light extraction member 430. A transparent elastic material or a transparent adhesive material can be inserted between the light extraction member 430 and the end of the projection waveguide 410.

[0171] A right-angled surface 431 is formed at the right end of the light extraction member 430. The right-angled surface 431 is a reflective surface, and the direction of light incident on the right side of the light extraction member 430 is converted to the left by the right-angled surface 431. The tilt angle of the right-angled surface 431 relative to the length direction of the light-emitting waveguide 410 is set such that the direction of light incident on the right side of the light extraction member 430 is converted to the left.

[0172] A light-emitting mirror 432, serving as a light-emitting section, is provided on the right side of the upper surface of the light extraction member 430. The light-emitting mirror 432 is configured to be inclined at a predetermined angle relative to the upper surface of the light extraction member 430, so that light incident on the right side of the light extraction member 430 and converted to light directed to the left by the right-inclined surface 431 passes through the light-emitting mirror 432 from the main surface side (upper surface side) of the light-emitting waveguide 410 and points towards the detection region R. Figure 10 (As shown) and emitted toward the detection area R. The end of the projection waveguide 410 serves as the projection end, and the light passes through the light extraction member 430 and is projected onto the detection area R. The light-emitting mirror 432 can be obtained, for example, by laser processing. A vapor-deposited film on which metal has been vapor-deposited to improve reflectivity can be formed on the light-emitting mirror 432.

[0173] The incident and exit aperture angles of the light can be set to approximately NA = 0.2, which allows for a small projection point and a small field of view without adding lenses or the like. Note that the optical paths shown in each figure can be reversed. That is, the projection side in each figure can be set as the receiving side, and the receiving side can be set as the projection side. Furthermore, the distance between the light detection unit 400 and the workpiece WK is not particularly limited, but can be set to, for example, approximately 0 mm to 3 mm.

[0174] The detection area R is the region where the workpiece WK to be detected is positioned, and it is the planned placement area for the workpiece WK. In this configuration, the detection area R is located above the light extraction member 430. The light emission angle can be changed with the angle of the light emission mirror 432.

[0175] Furthermore, the left side of the light extraction member 430 abuts against the end of the light-receiving optical waveguide 420. As a result, the light extraction member 430 is optically coupled to the light-receiving optical waveguide 420, so that light traveling through the left side of the light extraction member 430 will be incident on the core 421 of the light-receiving optical waveguide 420. A transparent elastic material or a transparent adhesive material can be inserted between the light extraction member 430 and the end of the light-receiving optical waveguide 420.

[0176] like Figure 10 As shown, when a workpiece WK is disposed in the detection area R, the light emitted to the workpiece WK is reflected and travels downwards. Furthermore, a light incident mirror 433, serving as a light incident portion, is provided on the upper surface of the light extraction member 430 in a manner corresponding to the portion of the light that is reached. The light incident mirror 433 is constructed as a surface inclined at a predetermined angle relative to the upper surface of the light extraction member 430, and the tilt angle of the light incident mirror 433 is set such that the incident light travels towards the left.

[0177] like Figure 9 As shown, a left-sloping surface 434 is formed at the left end of the light extraction member 430. The left-sloping surface 434 is a reflective surface, which causes the direction of light incident from the light incident mirror 433 onto the light extraction member 430 and traveling towards the left to be converted by the left-sloping surface 434 and incident onto the light receiving waveguide 420. The tilt angle of the left-sloping surface 434 relative to the length direction of the light receiving waveguide 420 is set such that the direction of light incident on the left side of the light extraction member 430 is converted towards the base end side of the light detection unit 400. The end of the light receiving waveguide 420 serves as a light receiving end for receiving light from the detection region R passing through the light extraction member 430. The light exit mirror 432 and the light incident mirror 433 are not covered by the upper cover member 440 and are exposed.

[0178] The optical waveguide 410 for projection and the optical waveguide 420 for receiving light are configured with multiple cores 411 and 421, respectively, but the light extraction component 430 has a single core. When multiple cores are provided, it is difficult to align the cores during optical coupling, but it is easy to optically couple multiple cores to form a core with a large cross-sectional area. Therefore, since the optical waveguide 410 for projection and the optical waveguide 420 for receiving light abut against the light extraction component 430, optical coupling can be performed while suppressing light loss, resulting in good assemblability.

[0179] (Fixing structure of optical detection unit 400)

[0180] When Figure 11 and Figure 12 When installed as shown, the light detection unit 400 can be fixed to, for example, a mounting member 600. The mounting member 600 can be, for example, a member forming part of various devices, and can be a surface plate, etc. Figure 11 and Figure 12 In the example shown, the light detection unit 400 is fixed to the surface of the mounting member 600 by a fixing member 601 made of adhesive material, bonding material, double-sided tape, etc. At this time, the lower surface of the lower cover member 450 is the mounting surface and is fixed to the surface of the mounting member 600. When the mounting surface is horizontal, the light-emitting waveguide 410 and the light-receiving waveguide 420 are horizontally arranged, but due to... Figure 3 As shown, the light-emitting aperture 376 and the light-receiving aperture 378 of the optical sensor 1 are arranged in the vertical direction, so the light-emitting waveguide 410 and the light-receiving waveguide 420 must be twisted in the middle. Even in this case, since the light-emitting waveguide 410 and the light-receiving waveguide 420 covered by the upper cover member 440 and the lower cover member 450 are sheet-like and have predetermined flexibility and plasticity, this process can be easily performed.

[0181] The optical detection unit 400 has a wide portion 400a at its end, which is wider than the base end. Since the wide portion 400a is fixed to the mounting member 600 by the fixing member 601, the area of ​​the fixing portion can be widened.

[0182] Figure 13 and Figure 14 An example is shown of using a fixing plate 602 to screw a light detection unit 400 to a mounting member 600. The fixing plate 602 is made of, for example, a rigid resin or metal material and is formed to extend along the upper surface of the mounting member 600. The fixing plate 602 is formed to be wider than the width of the end side of the light detection unit 400. Insertion holes (not shown) for screws 603 are formed on both sides of the fixing plate 602 in the width direction. These insertion holes are located on the outer side of the end side of the light detection unit 400. When the fixing plate 602 is placed on the upper surface of the light detection unit 400 at its end side, and the screws 603 are inserted through the insertion holes and screwed into the mounting member 600, the end side of the light detection unit 400 can be fixed by clamping it between the fixing plate 602 and the mounting member 600 in the thickness direction. The fixing plate 602 is configured not to cover the light emitting mirror 432 and the light incident mirror 433. Instead of screws 603, nails, staples, etc., can be used.

[0183] Figure 15 An example is shown of using a hook-shaped member 604 to secure the light detection unit 400 to the mounting member 600. Figure 15It is a vertical cross-section orthogonal to the length direction of the light detection unit 400. The hook-shaped member 604 is formed to surround the mounting member 600 and is made of, for example, a rigid resin or metal material. The hook-shaped member 604 has a pair of legs 604a. Since the hook-shaped member 604 engages with the mounting member 600 from above on the end side of the light detection unit 400, it is possible to fix the end side of the light detection unit 400 between the hook-shaped member 604 and the mounting member 600 in the thickness direction. The hook-shaped member 604 is configured not to cover the light emitting mirror 432 and the light incident mirror 433.

[0184] Figure 16 and Figure 17 An example of fixation achieved by directly screwing the light detection unit 400 to the mounting member 600 is shown. The light detection unit 400 is provided with a first socket 402 to a fourth socket 405. Figure 4 As shown, screws 605, used as fixing members, are inserted into these sockets when installing the mounting member 600. The first socket 402 to the fourth socket 405 extend through the upper cover member 440 and the lower cover member 450 in the vertical direction. That is, the upper cover member 440 and the lower cover member 450 each have portions covering cladding layers 412 and 422 located between the light-emitting end and the light-receiving end of the light-emitting waveguide 410 and the light-receiving waveguide 420, respectively, and these portions covering the cladding layers 412 and 422 located between the light-emitting end and the light-receiving end are fixed to the mounting member 600.

[0185] The first socket 402 is located at the base end, and the fourth socket 405 is located at the end end. The second socket 403 and the third socket 404 are located between the first socket 402 and the fourth socket 405, with the second socket 403 closer to the base end than the third socket 404. The third socket 404 is closer to the fourth socket 405. Alternatively, elongated holes can be used to form the first socket 402 to the fourth socket 405. The first socket 402 to the fourth socket 405 are located at corresponding portions of the covering members 440 and 450 between the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420, so as not to affect the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420.

[0186] like Figure 16 and Figure 17As shown, when the screw 605 is inserted through the first to fourth sockets 402 and screwed into the mounting member 600, it can be secured by clamping the periphery of the first to fourth sockets 402 between the head of the screw 605 and the mounting member 600. The number of sockets and the number of screws 605 are not limited to four; for example, there can be one. The periphery of the first to fourth sockets 402 serves as a fixing portion for securing to the mounting member 600. A washer (not shown) can be inserted between the head of the screw 605 and the periphery of the first to fourth sockets 402.

[0187] like Figure 18 As shown, the cover member 450 can be disposed at the portion fixed to the mounting member 600. In this case, the screw 605 is preferably configured to pass through the cover member 450 and be screwed into the mounting member 600. As a result, the cover member 450 can be fixed by clamping it between the head of the screw 605 and the mounting member 600.

[0188] like Figure 19 As shown, when the cover member 450 is provided on the portion fixed to the mounting member 600, mounting areas 602, obtained by expanding the light-emitting waveguide 410, the light-receiving waveguide 420, and / or the cover member 450, can be provided on both sides of the cover member 450 in the width direction, and holes provided in the mounting areas 602 can be fixed with screws 605 respectively. In this case, it can be fixed by clamping both sides of the cover member 450 in the width direction between the head of the screw 605 and the mounting member 600.

[0189] like Figure 20 As shown, when the cover member 450 is provided in the portion fixed to the mounting member 600, a mounting area 602 can be provided at the end side of the cover member 450, which is obtained by expanding the light-emitting waveguide 410, the light-receiving waveguide 420, and / or the cover member 450. The holes provided in the mounting area 602 can be fixed with screws 605. In this case, it can be fixed by clamping the end side of the cover member 450 between the head of the screw 605 and the mounting member 600.

[0190] like Figure 21As shown, when the cover member 450 is provided in the portion fixed to the mounting member 600, a mounting area 602, obtained by expanding the light-emitting waveguide 410, the light-receiving waveguide 420, and / or the cover member 450, can be provided on the end side of the cover member 450 and in the portion located between the light-emitting waveguide 410 and the light-receiving waveguide 420. Holes provided in the mounting area 602 can be used for fixing. The end side of the cover member 450 can be fixed by clamping it between the head of the screw 605 and the mounting member 600, and this portion of the cover member 450 can be fixed by allowing the screw 605 to penetrate the portion of the cover member 450 located between the light-emitting waveguide 410 and the light-receiving waveguide 420 in order to be screwed into the mounting member 600.

[0191] like Figure 22 As shown, screws 606 and washers 607 can also be used to fix the light detection unit 400. Figure 22 This is a vertical cross-section orthogonal to the length direction of the light detection unit 400, showing the portion where the fourth socket 405 is formed. A washer 607 is positioned below the light detection unit 400. The washer 607 has an annular portion 607a for insertion into the fourth socket 405. A screw 606 is inserted through the annular portion 607a of the washer 607 and screwed into the mounting member 600. At this time, the head of the screw 606 can be received by the upper end of the annular portion 607a of the washer 607, thus making it difficult for a strong force to act on the light detection unit 400 in the vertical direction, thereby suppressing damage to the light-emitting waveguide 410, the light-receiving waveguide 420, and the light-extraction member 430. The fixing location is not limited to the fourth socket 405, but can be any of the first sockets 402 to the third socket 404, and a similar fixing method can be used for any number of sockets 402 to 405.

[0192] The above-described fixing method is exemplary, and various methods can be used as long as the light detection unit 400 is fixed to the mounting member 600 using this method. For example, fixing methods using straps, wires, etc., can also be used. In addition, the light detection unit 400 can be fixed to the mounting member 600 by combining any two or more of the above-described fixing methods.

[0193] Alternatively, the connector section 500 can be omitted, and the base end of the light-emitting waveguide 410 and the base end of the light-receiving waveguide 420 can be fixed to the optical sensor 1 so that they cannot be removed.

[0194] (Connection structure of optical waveguide)

[0195] Figure 23AThis is a vertical cross-sectional view of the connection between two projection waveguides 410A and 410B, which can be connected and used as shown in the figure. The connection can be achieved by directly abutting the end faces of projection waveguides 410A and 410B against each other, or by inserting a transparent elastic material 460 or a transparent adhesive material between the end faces of projection waveguides 410A and 410B without leaving any air gap.

[0196] A continuous reinforcing material 461 can also be provided from the projection waveguide 410A to the projection waveguide 410B. The reinforcing material 461 is a strip-shaped member attached to the lower surfaces of the projection waveguide 410A and the projection waveguide 410B and is flexible. The reinforcing material 461 preferably has the property of not stretching or contracting along the length of the projection waveguide 410A. Therefore, it is possible to prevent gaps from forming between the two projection waveguides 410A and 410B, for example, when they are pulled apart, thereby suppressing a decrease in efficiency. The reinforcing material 461 can be provided on the upper surfaces of the projection waveguide 410A and the projection waveguide 410B.

[0197] Figure 23B This is a plan view of the connection between two projection waveguides 410A and 410B. The two projection waveguides 410A and 410B can be connected and used as shown in this figure. Figure 23B As shown in the connecting portion located at the center in the left-right direction, the cladding 412 does not necessarily need to extend to the vicinity of the interface. Because the cores 411 abut against each other, sufficient optical coupling to allow light propagation is achieved. Note that the cores 411 can abut against each other.

[0198] (Example of optical waveguide formation)

[0199] Figure 24 An example of a structure is shown in which a light-emitting waveguide 410 and a light-receiving waveguide 420 are formed on a single optical waveguide forming member 470 to achieve a defined reflection. The light-emitting waveguide 410 and the light-receiving waveguide 420 are respectively disposed on both sides of the optical waveguide forming member 470 in the width direction.

[0200] Although not shown in the figure, both the optical waveguide 410 for transmitting light and the optical waveguide 420 for receiving light are made of, for example, Figure 8A The core and cladding are shown in the figure.

[0201] The end of the projection waveguide 410 is bent at the end of the waveguide forming member 470 in a direction close to that of the receiving waveguide 420. A light-emitting mirror 432 is formed on the waveguide forming member 470 in a manner corresponding to the end of the projection waveguide 410. As a result, the end of the projection waveguide 410 serves as the projection end, and light is projected onto the detection area R via the light-emitting mirror 432.

[0202] Furthermore, the end of the light-receiving waveguide 420 is bent in a direction close to the light-emitting waveguide 410 at the end of the waveguide forming member 470. The light-incident mirror 433 is formed on the waveguide forming member 470 in a manner corresponding to the end of the light-receiving waveguide 420. As a result, the end of the light-receiving waveguide 420 serves as the light-receiving end, and light from the detection region R is received via the light-incident mirror 433. In this example, the light-emitting mirror 432 and the light-incident mirror 433 can be provided on the waveguide forming member 470, which includes the light-emitting waveguide 410 and the light-receiving waveguide 420, without providing the light extraction member 430 as a separate entity. Therefore, no relative positional shift occurs between the components, thereby suppressing a decrease in detection accuracy. This can also be described as a configuration in which the light extraction member is incorporated into and integrated with the light-emitting waveguide 410 and the light-receiving waveguide 420.

[0203] Figure 25 A construction example is shown in which reflectors 471, made of separate components, are provided at the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 to achieve defined reflection. The reflectors 471 are made of a resin material with high reflectivity, such as white, and allow the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 to be inserted and held therein. The end of the light-emitting waveguide 410 is cut along a direction inclined relative to the length direction of the light-emitting waveguide 410 and abuts against the first inner surface 471a of the reflector 471. Light traveling through the light-emitting waveguide 410 is reflected by the first inner surface 471a of the reflector 471, and its direction of travel is changed towards the light-receiving waveguide 420. The reflector 471 is provided with a light-emitting mirror surface 432. When the light that has traveled through the projection waveguide 410 is reflected by the first inner surface 471a of the reflector 471, the light reaches the light exiting mirror 432 and travels through the light exiting mirror 432 toward the detection area R.

[0204] Furthermore, the end of the light-receiving waveguide 420 is also cut along a direction inclined relative to the length direction of the light-receiving waveguide 420, and abuts against the second inner surface 471b of the reflector 471. The reflector 471 is provided with a light-incident mirror 433 adjacent to the light-emitting mirror 432. Light from the detection region R is incident on the second inner surface 471b of the reflector 471 via the light-incident mirror 433, reflected by the second inner surface 471b, and incident on the light-receiving waveguide 420. Since the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be held by the reflector 471 in this example, the relative positional shift between the components can be suppressed.

[0205] Figure 26 This is a plan view of an optical detection unit 400, illustrating an example pattern of optical waveguides that takes into account the reduction of light loss. The light-emitting waveguide 410 extends near its end in a curved manner while maintaining a large curvature, and the light-receiving waveguide 420 also extends near its end in a curved manner while maintaining a large curvature. Although increasing the curvature of the light-emitting waveguide 410 and the light-receiving waveguide 420 makes the width of the optical detection unit 400 wider, when the layout of the optical detection unit 400 allows for a wide optical detection unit 400, using a pattern with large curvature as in this example can reduce light loss.

[0206] like Figure 27A As shown, the light-emitting mirror 432 can be disposed at the end of the light-emitting waveguide 410. Similarly, the light-incident mirror 433 can be disposed at the end of the light-receiving waveguide 420 (see...). Figure 26 ).

[0207] When passing through, as Figure 27B When the direction setting member 472 is used to set the direction of the end face 410a of the light-emitting waveguide 410, the light emission direction can be set to a direction that allows for limited reflection. Similarly, the light-emitting side can be set by the direction setting member (not shown).

[0208] Figure 28 This is a plan view of a light detection unit 400, illustrating an example of a pattern for an optical waveguide with preferred dimensions. The light-emitting waveguide 410 extends near its end in a direction away from the light-receiving waveguide 420, and the light-receiving waveguide 420 extends near its end in a direction away from the light-emitting waveguide 410. However, the distance between the near ends of the light-emitting waveguide 410 and the near ends of the light-receiving waveguide 420 is set to be greater than... Figure 26The distance in the example shown is short. As a result, the width of the light detection unit 400 can be narrowed, which can support installation sites with narrow widths. The light emitting mirror 432 can be disposed at the end of the light-emitting waveguide 410, and the light-incident mirror 433 can be disposed at the end of the light-receiving waveguide 420. Figure 27A and Figure 27B The structure shown can also be applied to Figure 28 The example shown.

[0209] Figure 29 An example is shown where both the light-emitting waveguide 410 and the light-receiving waveguide 420 are constructed by arranging multiple optical fibers in a horizontal direction. Specifically, the light-emitting waveguide 410 is constructed using bundled optical fibers 413, which are formed by bundling multiple optical fibers together, and the light-emitting waveguide 410 is formed by arranging the fiber lines of the bundled optical fibers 413 in a horizontal direction. Similarly, the light-receiving waveguide 420 is constructed using bundled optical fibers 423, and the light-receiving waveguide 420 is formed by arranging the fiber lines of the bundled optical fibers 423 in a horizontal direction. The fiber lines of the light-emitting waveguide 410 and the light-receiving waveguide 420 are covered by an upper cover member 440 and a lower cover member 450. Although not shown, the upper cover member 440 and the lower cover member 450 are... Figure 29 The upper cover member 440 and the lower cover member 450 can be attached and fixed at the horizontal end, which sandwiches the light-emitting waveguide 410 and the light-receiving waveguide 420 from above and below.

[0210] Figure 30 An example of defined reflection is shown, where light exits from the end of an optical waveguide. In this example, the core 411 of the projection waveguide 410 reaches the end of the projection waveguide 410, and the core 421 of the receiving waveguide 420 reaches the end of the receiving waveguide 420. Therefore, light can exit from the end of the projection waveguide 410 along its length to illuminate the workpiece WK. Light from the detection region R can be incident on the end of the receiving waveguide 420.

[0211] exist Figure 5 In the example shown, light is emitted from the main surface of the projection waveguide 410 into the detection area, and the light reflected by the workpiece WK is received by the main surface of the receiving waveguide 420. However, in Figure 30 In the example shown, the end face (side surface) of the light-emitting waveguide 410 located at the end side is used as the light-emitting surface, and the end face (side surface) of the light-receiving waveguide 420 located at the end side is used as the light-receiving surface. In this way, portions other than the main surfaces of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be used as the light-emitting and light-receiving surfaces, respectively.

[0212] In addition, such as Figure 24 , Figure 26 , Figure 28 and Figure 30 As shown, in addition to the linear patterns in waveguides 410 and 420, core patterns can be freely drawn in the plane, thus providing a high degree of design freedom for the optical paths in waveguides 410 and 420.

[0213] Figure 31 Another example of defined reflection is shown, where light exits from the end of an optical waveguide. In this example, light traveling through the core 411 of the projection waveguide 410 can exit from the end of the projection waveguide 410 along the length of the projection waveguide 410 to illuminate the workpiece WK. Light from the detection region R can be incident on the end of the receiving waveguide 420. Figure 31 The example shown has the same Figure 30 It uses the same optical path, but instead of utilizing the pattern in the optical waveguide, it can change the optical path by utilizing the difference in refractive index between the optical waveguide and the outside obtained by obliquely cutting the side surface of the optical waveguide.

[0214] like Figure 32 As shown, light can exit from and be incident on the side surface of the optical waveguide. In this example, light traveling through the core 411 of the projection waveguide 410 can illuminate the workpiece WK from the side surface of the projection waveguide 410. Similarly, light from the detection region R can be incident on the receiving waveguide 420 from the side surface. This can be achieved by forming patterns on the cores 411 and 412.

[0215] Figure 33 Another example of defined reflection is shown, where light exits from the side surface of the optical waveguide. Since a light-emitting mirror 432 is provided at the end of the light-emitting waveguide 410, the workpiece WK can be illuminated using light from the side surface of the light-emitting waveguide 410. Since a light-receiving waveguide 420 is provided at the end of the light-receiving waveguide 420, light from the detection region R can enter the light-receiving waveguide 420 from the side surface. In this example, the formation patterns of cores 411 and 412 can remain linear.

[0216] Figure 34 An example of using the light detection unit 400 as a multi-point reflection type light detection unit is shown. The light detection unit 400 has a core 411 (421) formed therein, capable of projecting light in multiple directions and receiving light from multiple directions. As a result, light is emitted from the end of the light detection unit 400 in multiple directions, and light from multiple directions can be received at the end of the light detection unit 400. Therefore, even if the surface of the workpiece WK has unevenness, the detection accuracy can be improved by reducing the influence of unevenness.

[0217] like Figure 35As shown, the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 of the light detection unit 400 can be bent. As a result, light from the light-emitting waveguide 410 can be emitted along the bending direction, and light from the detection region R can be received from the bending direction of the light-receiving waveguide 420. Alternatively, a core pattern in a plane can be used to achieve bending without bending the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420.

[0218] Figure 36A An example of combining an optical waveguide and a mirror component is shown. A projection mirror component 480 is configured facing the end of the projection waveguide 410. A light-emitting mirror surface 480a is formed on the projection mirror component 480, through which light can be emitted above the projection waveguide 410. Additionally, a light-receiving mirror component 481 is configured facing the end of the light-receiving waveguide 420. A light-incident mirror surface 481a is formed on the light-receiving mirror component 481, through which light can be incident from above the light-receiving waveguide 420.

[0219] Figure 36B Another example of combining an optical waveguide and a mirror component is shown. The end of the light-emitting optical waveguide 410 and the light-emitting mirror component 480 are configured to abut against each other. Even with this configuration, light can be emitted above the light-emitting optical waveguide 410 via the light-emitting mirror surface 480a. Additionally, the end of the light-receiving optical waveguide 420 and the light-receiving mirror component 481 are configured to abut against each other. Even with this configuration, light can be incident from above the light-receiving optical waveguide 420.

[0220] Figure 37 An example is shown where light emitted from the projection waveguide 410 illuminates the retroreflector 485. In this example, the light reflected from the retroreflector 485 can be received at the end of the receiving waveguide 420. When the workpiece WK is present between the retroreflector 485 and the projection and receiving waveguides 410 and 420, the light is blocked by the workpiece WK, making it difficult for the receiving waveguide 420 to receive the light. This example is applicable to detection methods that utilize this example.

[0221] (Transmittance-type light detection unit)

[0222] Although the above examples mainly illustrate the application of the invention to detection methods using limited reflection, the invention can also be used as a transmissive light detection unit 400.

[0223] Figure 38AAn example of a transmissive light detection unit 400 is shown where the projection waveguide 410 and the receiving waveguide 420 extend in the same direction. The direction of light traveling through the projection waveguide 410 is converted towards the receiving waveguide 420 by a light-exiting mirror 432 located at the end of the projection waveguide 410. Light emitted from the projection waveguide 410 is received by the receiving waveguide 420, and its direction is converted by a light-incident mirror 433 to travel through the receiving waveguide 420.

[0224] Figure 38B An example of a transmissive light detection unit 400 is shown where the light-emitting waveguide 410 and the light-receiving waveguide 420 extend in opposite directions. As in this example, the reflection angle of light traveling through the light-emitting waveguide 410 can be set by the light-emitting mirror 432. As a result, even if the light-emitting waveguide 410 and the light-receiving waveguide 420 are configured to extend in opposite directions, the workpiece WK can still be detected.

[0225] Figure 39 An example is shown where the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 face each other. As in this example, the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be configured to have a predetermined distance between them, and light emitted from the end of the light-emitting waveguide 410 can be received by the end of the light-receiving waveguide 420. In this case, the workpiece WK located between the ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be detected.

[0226] Figure 40 An example of a workpiece WK in a detection light unit 400 is shown. The detection light unit 400 is provided with an insertion portion 459 for the workpiece WK, formed by a recess or a hole. Light that has traveled through the projection waveguide 410 can be projected into the insertion portion 459 and received at the end of the receiving waveguide 420. When the workpiece WK is inserted into the insertion portion 459, the light projected from the projection waveguide 410 is blocked.

[0227] Figure 41 An example of a transmissive light detection unit 400 with a large number of optical paths is shown. Light is projected from the end of a light-emitting waveguide 410 to form a large number of optical paths. Correspondingly, the end of a light-receiving waveguide 420 is capable of receiving light from the large number of optical paths. In this example, the detection range can be expanded.

[0228] (Connector Section 500)

[0229] Figure 4The configuration shown includes the connector portion 500, and illustrates the state before the connector portion 500 is connected to the light-emitting waveguide 410 and the light-receiving waveguide 420. The connector portion 500 is a component that connects to the base terminals of the light-emitting waveguide 410 and the light-receiving waveguide 420. The connector portion 500 is a component that optically connects the base terminals of the light-emitting waveguide 410 and the light-receiving waveguide 420 to the light-emitting aperture 376 and the light-receiving aperture 378 of the optical sensor 1, respectively, directly or indirectly, and is detachably mounted to the light-emitting aperture 376 and the light-receiving aperture 378. The material forming the connector portion 500 can be, for example, a resin material, and the color of the resin material is preferably an opaque or nearly opaque color.

[0230] Figures 42 to 46 The connector portion 500 shown in the first example according to this embodiment has a main body 501 and a light-emitting side protrusion 502 and a light-receiving side protrusion 503 protruding from the main body 501. The light-emitting waveguide 410 and the light-receiving waveguide 420 can be integrated through the connector portion 500. The light-emitting side protrusion 502 and the light-receiving side protrusion 503 are respectively inserted into the light-emitting hole 376 and the light-receiving hole 378 of the optical sensor 1. Figure 3 (as shown). Therefore, the interval between the light-emitting side protrusion 502 and the light-receiving side protrusion 503 is approximately the same as the interval between the light-emitting aperture 376 and the light-receiving aperture 378 of the optical sensor 1.

[0231] The cross-section of the projection-side protrusion 502 is approximately circular around the projection waveguide 410 and roughly coincides with the cross-section of the projection aperture 376 of the optical sensor 1. The outer diameter of the projection-side protrusion 502 is set to be larger than the thickness of the projection waveguide 410. Alternatively, the outer diameter of the projection-side protrusion 502 can be set to be slightly smaller than the outer diameter of the projection aperture 376 of the optical sensor 1, but when the projection-side protrusion 502 is inserted into the projection aperture 376, the gap between the projection-side protrusion 502 and the projection aperture 376 is small. As a result, the projection-side protrusion 502 is positioned radially. Furthermore, the length of the projection-side protrusion 502 corresponds to the depth of the projection aperture 376, such that when the projection-side protrusion 502 is inserted into the projection aperture 376, the end face of the projection-side protrusion 502 contacts or approaches... Figure 3 The end face of the reflector 380 shown. The insertion depth of the light-projecting protrusion 502 can be defined by bringing the end face of the light-projecting protrusion 502 into contact with the end face of the reflector 380. The insertion depth of the light-projecting protrusion 502 can also be defined by pressing the main body 501 against a portion of the optical sensor 1.

[0232] The light-receiving protrusion 503 is constructed in the same manner as the light-projecting protrusion 502, and has a generally circular shape surrounding the light-receiving waveguide 420. The light-receiving protrusion 503 is positioned radially and in the insertion direction when inserted into the light-receiving aperture 378 of the optical sensor 1.

[0233] like Figure 44 As shown, the main body 501 has a light guide insertion hole 501a for inserting the base end of the light guide 401. An elastic material 504, made of rubber or an elastomer, is disposed between the base end of the light guide 401 and the inner surface of the light guide insertion hole 501a. The elastic material 504 is formed to cover the outer peripheral surface of the base end of the light guide 401. Multiple engagement protrusions 504a are formed on the elastic material 504. The main body 501 has engagement holes 501b that engage with the engagement protrusions 504a of the elastic material 504. With the engagement protrusions 504a of the elastic material 504 engaged with the engagement holes 501b of the main body 501, the elastic material 504 is prevented from detaching from the main body 501. Note that the elastic material 504 can be omitted.

[0234] The light-projecting waveguide 410 of the light guide section 401 passes through the interior of the light-projecting side protrusion 502. For example, in... Figure 47 As shown in the first example, the end of the projection waveguide 410 reaches and is exposed to the end face of the projection-side protrusion 502. The end of the projection waveguide 410 and the end face of the projection-side protrusion 502 can be flush with each other, or the end of the projection waveguide 410 can be recessed from the end face of the projection-side protrusion 502. In the recessed case, damage to the end of the projection waveguide 410 can be prevented. Furthermore, in the recessed case, the distance between the end of the projection waveguide 410 and the end face of the projection-side protrusion 502 is preferably set to 0.5 mm or less. This aims to suppress the reduction of light intensity.

[0235] like Figure 48 As shown, the projection-side protrusion 502 has a concave projection-side receiving portion 502a for receiving the projection waveguide 410. The projection-side receiving portion 502a has an opening on the outer peripheral surface of the projection-side protrusion 502. The projection-side receiving portion 502a is provided with a pressure member 505 configured to press down on and hold the projection waveguide 410. The pressure member 505 engages with the inner surface of the projection-side receiving portion 502a and is held in a predetermined position. As a result, the relative position of the projection waveguide 410 with respect to the projection-side protrusion 502 is determined. Therefore, when the projection-side protrusion 502 is inserted into the projection hole 376 of the optical sensor 1, the end of the projection waveguide 410 is located at... Figure 3 The center position of the light-emitting surface of the light-emitting element 104 shown. The pressure member 505 can be omitted, and the light-emitting waveguide 410 can be attached to the inner surface of the light-emitting side receiving part 502a.

[0236] Furthermore, the light-receiving protrusion 503 has a concave light-receiving receiving portion 503a for receiving the light-receiving optical waveguide 420. The light-receiving receiving portion 503a has an opening on the outer peripheral surface of the light-receiving protrusion 503. The light-receiving receiving portion 503a is provided with a pressure member 506 configured to press down on and hold the light-receiving optical waveguide 420. The pressure member 506 engages with the inner surface of the light-receiving receiving portion 503a and is held in a predetermined position. As a result, the relative position of the light-receiving optical waveguide 420 with respect to the light-receiving protrusion 503 is determined. Therefore, when the light-receiving protrusion 503 is inserted into the light-receiving aperture 378 of the optical sensor 1, the end of the light-receiving optical waveguide 420 is located at... Figure 3 The center position of the light-receiving surface of the light-receiving element 204 shown.

[0237] Figure 49 A connector portion 500 according to a second example of this embodiment is shown. The main body portion 510 of the connector portion 500 in the second example is composed of an upper member 511 and a lower member 512. The upper member 511 and the lower member 512 can be integrated using screws or the like, or they can be integrated using adhesives or the like.

[0238] The lower member 512 has a first groove 512a and a second groove 512b. The first groove 512a holds a light-emitting waveguide 410 protected by a protective elastic material 513, and the second groove 512b holds a light-receiving waveguide 420 protected by a protective elastic material 514. The upper member 511 has a first fitting portion 511a embedded in the first groove 512a and a second fitting portion 511b embedded in the second groove 512b. By embedding the first fitting portion 511a into the first groove 512a, the light-emitting waveguide 410 can be clamped and held between the end face of the first fitting portion 511a and the bottom surface of the first groove 512a. By embedding the second fitting portion 511b into the second groove 512b, the light-receiving waveguide 420 can be clamped and held between the end face of the second fitting portion 511b and the bottom surface of the second groove 512b.

[0239] Furthermore, the upper member 511 has a third fitting portion 511c embedded in the light-emitting side receiving portion 502a and a fourth fitting portion 511d embedded in the light-receiving side receiving portion 503a. The third fitting portion 511c and the fourth fitting portion 511d replace the pressure members 505 and 506 in the first example, and the third fitting portion 511c and the fourth fitting portion 511d can apply downward pressure to the light-emitting waveguide 410 and the light-receiving waveguide 420.

[0240] Figure 50A connector portion 500 according to a third example of this embodiment is shown. In the connector portion 500 of the third example, a main body portion 520, a light-emitting side protrusion 522, and a light-receiving side protrusion 523 are constructed using separate components. Each of the light-emitting side protrusion 522 and the light-receiving side protrusion 523 is constructed using a rod-shaped component. The light-emitting side protrusion 522 is constructed from a base member 522a having a partially notched shape and a fitting member 522b that is inserted into the notched portion. Since the light-emitting waveguide 410 is disposed in the notched portion of the base member 522a, the light-emitting waveguide 410 can be positioned relative to the base member 522a. Since the fitting member 522b is inserted into the notched portion of the base member 522a when the light-emitting waveguide 410 is positioned, the light-emitting waveguide 410 can be held in a position where it cannot move. The light-receiving side protrusion 523 is also constructed in the same manner and has a base member 523a and a fitting member 523b.

[0241] like Figure 51 As shown, the main body 520 has a light-emitting side retaining hole 520a and a light-receiving side retaining hole 520b. The light-emitting side retaining hole 520a retains the light-emitting side protrusion 522 when inserted, and the light-receiving side retaining hole 520b retains the light-receiving side protrusion 523 when inserted. When the light-emitting side protrusion 522 is inserted into the light-emitting side retaining hole 520a, the light-emitting side protrusion 522 can rotate around its center line. Similarly, the light-receiving side protrusion 523 can rotate in the same manner. The main body 520 can be made of rubber or the like. The main body 520 can be omitted.

[0242] like Figure 52 As shown, the optical sensor 1 may be equipped with a pre-installed adapter 540. In this example, the light detection unit 400 may be connected to the optical sensor 1 via the pre-installed adapter 540.

[0243] like Figure 53 As shown, the sockets 376a of the light-emitting aperture 376 and 378a of the light-receiving aperture 378 of the optical sensor 1 can be slit-shaped. Since the slit-shaped sockets 376a and 378a are approximately the same as the cross-sectional shape of the light-emitting waveguide 410 and the light-receiving waveguide 420, the base ends of the light-emitting waveguide 410 and the light-receiving waveguide 420 can be directly connected to the light-emitting aperture 376 and the light-receiving aperture 378 without the connector section 500.

[0244] Figure 54The projection-side connector portion 550 and the light-receiving side connector portion 551 according to a fourth example of the embodiment are shown. The projection-side connector portion 550 is formed as a column that can be positioned by being inserted into the projection hole 376 of the optical sensor 1. The projection-side connector portion 550 has a slit-shaped hole portion 550a for insertion of the projection waveguide 410. The light-receiving side connector portion 551 is also constructed in the same manner and is formed as a column that can be positioned by being inserted into the light-receiving hole 378 of the optical sensor 1 and has a slit-shaped hole portion 551a.

[0245] The optical sensor 1 can be connected by deeply inserting the light-emitting connector 550 and the light-receiving connector 551 into the light-emitting hole 376 and the light-receiving hole 378 of the optical sensor 1, and by deeply inserting the light-emitting waveguide 410 and the light-receiving waveguide 420 into the holes 550a and 551a.

[0246] (Construction of the relay section)

[0247] like Figure 55A , Figure 55B , Figure 55C , Figure 56A and Figure 56B As shown in the first example of the relay section, the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420 can be connected to the bundled optical fibers via the relay connector section 580. The relay connector section 580 is a component that bundles the light-emitting optical fiber 560 and the light-receiving optical fiber 561 together. The light-emitting optical fiber 560 is connected to the base end of the light-emitting optical waveguide 410 and optically coupled to the light-emitting aperture 376 of the optical sensor 1 in a pluggable manner. The light-receiving optical fiber 561 is connected to the base end of the light-receiving optical waveguide 420 and optically coupled to the light-receiving aperture 378 of the optical sensor 1 in a pluggable manner. The light-emitting optical fiber 560 and the light-receiving optical fiber 561 are constructed using bundled optical fibers formed by bundling multiple optical fibers.

[0248] The repeater connector section 580 can be used to extend the optical detection unit 400. The repeater connector section 580 includes a connector housing 581 made of an opaque or nearly opaque resin material. With the optical fibers 560a and 561a arranged horizontally (in the width direction of the optical waveguides 410 and 420), the light-emitting fiber 560 and the light-receiving fiber 561 are held by fiber optic adapters 560b and 561b, respectively. The fiber optic adapters 560b and 561b are fixed in a state where they are housed within the connector housing 581. Within the connector housing 581, the light-emitting and light-receiving sides are optically isolated.

[0249] The light-emitting adapter 490 and the light-receiving adapter 491 are respectively attached to the base terminals of the light-emitting waveguide 410 and the light-receiving waveguide 420. The light-emitting adapter 490 and the light-receiving adapter 491 are fixed in a state where they are housed in the connector housing 581.

[0250] The fiber optic lines 560a constituting the projection-side fiber optic 560 are arranged in the same direction as the width of the projection waveguide 410, and the fiber optic lines 560a are configured from one end corresponding to the width of the projection waveguide 410 to the other end. Similarly, on the light-receiving side, the fiber optic lines 561a are arranged in the same direction as the width of the light-receiving waveguide 420, and the fiber optic lines 561a are configured from one end corresponding to the width of the light-receiving waveguide 420 to the other end.

[0251] A long-length rod-shaped lens 582, extending along the width of the optical waveguide 410, is disposed between the end of the optical fiber 560 on the projection side and the base end of the optical waveguide 410 on the projection side. Similarly, a long-length rod-shaped lens 583, extending along the width of the optical waveguide 420 on the receiving side, is disposed between the end of the optical fiber 561 on the receiving side and the base end of the optical waveguide 420 on the receiving side. Instead of the rod-shaped lenses 582 and 583, transparent elastic materials or adhesives can be used. Alternatively, the rod-shaped lenses 582 and 583 can be omitted, and the ends of the optical fiber 560 and the optical waveguide 410, and the ends of the optical fiber 561 and the optical waveguide 420 can be abutted together. Note that a single core can be used instead of multiple optical fibers.

[0252] Alternatively, instead of integrating the light-emitting waveguide 410 and the light-receiving waveguide 420 into a single housing 581, the light-emitting waveguide 410 and the light-receiving waveguide 420 can be separated.

[0253] Alternatively, the light leaking out due to the coupling between the end of the projection fiber 560 and the base end of the projection waveguide 410 can be used as an operation indicator light, and the light leaking out due to the coupling between the end of the receiving fiber 561 and the base end of the receiving waveguide 420 can be used as an output indicator light 585. Figure 55A (As shown).

[0254] Note that, although in Figure 55A The indicator light 585 is positioned on the receiving side, but it can also be positioned on the projecting side. Furthermore, the light source for the indicator light can be... Figure 3The LED 212 shown can be light emitted from the light-emitting element 104 used for detection or light obtained when reflected by the workpiece WK. Alternatively, the indicator light can be implemented by partially cutting the surface of the optical waveguide. When the leakage light generated at the coupling end faces of the optical waveguides 410 and 420 and the optical fibers 560 and 561 is successfully used as an indicator light, the loss of detection light can be reduced.

[0255] like Figure 55A and Figure 55B As shown, the repeater connector section 580 may also be provided with a through hole 588. In the through hole 588 of the repeater connector section 580, the through hole located at the end side communicates with the through hole provided between optical waveguides or in the optical waveguide path.

[0256] Additionally, a reinforcing plate 461 is provided at the ends of the optical waveguides 410 and 420. The reinforcing plate 461 is preferably made of metal or resin and is thin and high-strength. Furthermore, by attaching the reinforcing plate 461 to the lower cover member 450 using adhesive or double-sided tape, bending or deformation of the end detection unit can be suppressed.

[0257] The reinforcement plate 461 can be disposed only on the back of the optical waveguides 410 and 420, only on the front, or on both surfaces. Figure 56A and Figure 56B In this configuration, the reinforcing plate 461 is only disposed on the back side of the optical waveguides 410 and 420. Furthermore, the surface on which the reinforcing plate 461 is disposed is not limited to the main surfaces of the optical waveguides 410 and 420, and the end faces of the detection unit located on three sides can be surrounded by the reinforcing plate 461. Additionally, the reinforcing plate 461 is wider than the optical waveguides 410 and 420 or the sheet-like covering member.

[0258] The reinforcing plate 461 may also be provided with holes communicating with the third jack 404 and the fourth jack 405 of the optical waveguides 410 and 420. These holes can be used as fixing holes for screwing.

[0259] Methods for fixing the reinforcing plate 461 are not limited to screwing; methods such as bonding, double-sided tape, and clamping can also be used to set the reinforcing plate 461 to the fixing surface.

[0260] Note that, although not shown, text can be written on the front and back of the repeater connector housing 581 or on the strips of the optical waveguides 410 and 420 using adhesive labels, screen printing, engraving, etc., for identification purposes.

[0261] Although it has been referenced Figures 55A to 55C The outline of the relay connector section 581 is described, but reference will be made to... Figure 56B This section briefly describes the assembly method for optical coupling between optical waveguides 410 and 420 and optical fibers 560 and 561 via repeater connector section 581. When using... Figure 56B The configuration shown allows for effective connection between the end of the light-receiving optical fiber 561 and the base end of the light-receiving optical waveguide 420.

[0262] ( Figure 56B (Explanation of the structure of the relay connector section)

[0263] 1. Remove the end coating from optical fibers 560 and 561 (bundled optical fibers) to arrange the bundled optical fibers in rows on optical fiber adapters 560b and 561b.

[0264] 2. Use tape to attach optical waveguides 410 and 420 to each other to determine the pitch in the width direction, and make the coupling portions with optical fibers 560 and 561 protrude slightly.

[0265] 3. Embed fiber optic adapters 560b and 561b into connector housing 581 and position them in the width direction using positioning bosses (on the ellipse).

[0266] 4. Embed the optical waveguides 410 and 420 into the connector housing 581 and position them in the width direction using the positioning boss (on the ellipse).

[0267] 5. Move the fiber optic adapters 560b and 561b and the optical waveguides 410 and 420 embedded in the connector housing 581 along the length direction. With the optical coupling end faces abutting each other or having a small gap, fix the roots of the fiber optic adapters 560b and 561b and the optical waveguides 410 and 420 with a strong adhesive. Fix the optical coupling part by filling the coupling gap with a transparent elastic material or adhesive.

[0268] 6. Finally, close the cover of connector housing 581. At this point, use adhesive, double-sided tape, or solder to prevent the cover from opening.

[0269] As in Figure 57 and Figure 58 As shown in the second example of the relay section structure, the relay connector section 590 can be composed of three components. The relay connector section 590 includes: a first retaining member 591, which retains the light-emitting optical fiber 560 and the light-receiving optical fiber 561; a second retaining member 592, which retains the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420; and an intermediate member 593, which is disposed between the first retaining member 591 and the second retaining member 592.

[0270] like Figure 58As shown, the first holding member 591 has holding holes 591a and 591b, in which the ends of the light-emitting optical fiber 560 and the light-receiving optical fiber 561 are held in an inserted state. The second holding member 592 has holding holes 592a and 592b, in which the base ends of the light-emitting optical waveguide 410 and the light-receiving optical waveguide 420 are held in an inserted state.

[0271] The first retaining member 591, the intermediate member 593, and the second retaining member 592 are integrated by a screw 594. That is, the screw 594 passes through the first retaining member 591 and the intermediate member 593 from the side of the first retaining member 591, and then is screwed into the second retaining member 592. The position of the screw 594 is not limited to... Figure 58 The position shown is not, for example, in such a location. Figure 59 As shown in the third example of the relay section, if the spacing between the light-emitting fiber 560 and the light-receiving fiber 561 is wide, the screw 594 can be placed between the light-emitting fiber 560 and the light-receiving fiber 561.

[0272] Furthermore, optical fibers 560 and 561 extending from the repeater connector section 580 can be configured as free-cutting optical fibers. For free-cutting optical fibers, the length of the optical fiber can be adjusted by using a free-cutting fixture.

[0273] In addition, in the first to third examples of the relay section, when small-diameter optical fibers are used as optical fibers 560 and 561 extending from the relay connector section 580 to the optical sensor 1 side, an adapter configured to connect the optical fiber to the optical sensor 1 can be used to facilitate optical coupling.

[0274] Optical fibers 560 and 561, with arbitrary diameters, can be used. Similar to the ends of the optical waveguide, a reduction in thickness is desired for the repeater connector section 580 to increase flexibility in the installation space. As the diameter of the optical fiber increases, the thickness of the repeater connector section 580 also increases. Therefore, it is preferable to have the fiber diameter as small as possible, but considering the coupling efficiency with the optical waveguide, there is a degree of design freedom that allows for flexible design.

[0275] Note that, although Figure 6 As shown in Figure 8, this embodiment has given an explanation of setting the core 411 as a single layer, but it is not limited thereto, and the core 411 can be set as two or more layers.

[0276] Additionally, when the optical sensor 1 is mounted upright, it makes such a... Figure 1As shown, when the display unit 334 is located on the upper surface, the light-emitting aperture 376 and the light-receiving aperture 378 are arranged side-by-side vertically relative to the housing 10, while the light-emitting and light-receiving paths of the optical waveguide are arranged in a sheet-like manner horizontally. Therefore, since the two vertically arranged portions are aligned horizontally, a twisting unit is needed between the optical sensor 1 and the end of the optical waveguide to align the already vertically arranged portions horizontally. Twisting a thin, linear optical fiber is easier than twisting a sheet-like optical waveguide, thereby reducing breaks, light leakage, and losses.

[0277] (Strray light countermeasure structure)

[0278] The light detection unit 400 according to this embodiment provides countermeasures against stray light. That is, as a prerequisite, for example, Figure 10 As shown, the optical detection unit 400 is a unit capable of detecting whether a workpiece WK exists in a detection area R set at a predetermined distance from the optical detection unit 400. For example, as Figure 60 As shown, it is assumed that workpiece WK is not present in the detection area R, but workpiece WKA is present closer to the optical detection unit 400 than the detection area R. When workpiece WKA is present, light emitted from the light emitting mirror 432 will be emitted to workpiece WKA, reflected, and then incident on surface 435. The light incident on surface 435 will travel towards the light-receiving side in the core 430a of the light extraction member 430 and be incident on the surface 436 formed on the light-receiving side. The light incident on surface 436 will be reflected upward and emitted to workpiece WKA, and sometimes, after being reflected by workpiece WKA, it will be incident on the light incident mirror 433. The light incident on the light incident mirror 433 will reach the optical sensor 1. As a result, although workpiece WK is not actually present, the optical sensor 1 will determine that workpiece WK is present in the detection area R. This is the principle behind the erroneous determination caused by stray light.

[0279] Here, when Figure 61 When forming a light-emitting mirror 432 on a light-exiting member 430, for example, a rotating circular cutting tool 700 is applied to the light-exiting member 430 to remove a portion of the light-exiting member 430 through the cutting edge 700a of the cutting tool 700. As a result, although a light-emitting mirror 432 can be obtained, a surface 435 is also formed simultaneously. Although the angle of this surface 435 can be set by the cutting edge 700a of the cutting tool 700, if... Figure 60 Setting the angle as shown would likely result in the aforementioned incorrect judgment caused by stray light.

[0280] Figure 62An example of applying a first stray light countermeasure to prevent erroneous judgments caused by stray light is shown. The first stray light countermeasure is characterized by the angle of the surface 435 formed when the light emitting mirror 432 is obtained. Specifically, a surface 435 extending downward from the upper edge 432a of the light emitting mirror 432 is formed on the light extraction member 430, and the angle of the surface 435 is set to prevent the reception of light reflected from the workpiece WKA, which is located in a region closer to the detection region R. Specifically, the surface 435 is formed as a steep surface such that light reflected from the workpiece WKA is incident on the side of the light incident mirror 433 (left side in the figure), rather than on the surface 435. As a result, even if light reflected from the workpiece WKA is incident on the light extraction member 430, the light travels only along the incident direction, thereby suppressing the light from reaching the light incident mirror 433. The light reflected from the workpiece WKA enters the light extraction member 430 and then reaches the lower cover member 450, where it is absorbed. That is, the angle of surface 435 is set such that light reflected from workpiece WKA can reach the lower cover member 450. Surface 435 with this angle is a stray light suppression unit that prevents light reflected from workpiece WKA from reaching the light incident mirror surface 433. It can be said that the light extraction member 430 is provided with a stray light suppression unit. In addition, surface 435 can also be referred to as a stray light removal unit that removes stray light entering the light incident mirror surface 433. Note that, in addition to the cutting tool 700, the light incident mirror surface 433 and surface 435 can also be formed by, for example, laser processing.

[0281] In addition, in the formation Figure 62 When light is incident on mirror 433, surface 436 is formed similarly to the light emitting side, and similarly to surface 435, surface 436 can also be formed as a steep surface.

[0282] Figure 63 An example of applying a second stray light countermeasure is shown. In the second stray light countermeasure, a stray light suppression groove 437 is formed in the light extraction member 430 to prevent light reflected from the workpiece WKA from reaching the light incident mirror 433. The stray light suppression groove 437 is located between the light emitting mirror 432 and the light incident mirror 433 of the light extraction member 430. The stray light suppression groove 437 opens on the upper side of the light extraction member 430, i.e., on the side where the detection area R of the workpiece WK is located. The inner surface of the stray light suppression groove 437 includes a side surface 437a on the light emitting side and a side surface 437b on the light incident side. The side surfaces 437a and 437b approach each other away from the opening of the stray light suppression groove 437 and connect to each other on the opposite side (lower side) of the opening, thereby forming a V-shaped cross-section.

[0283] exist Figure 63In the example, light reflected from the workpiece WKA, located in a region closer to the detection region R, is incident on surface 435 and travels towards the light-receiving side within the core 430a of the light extraction member 430. The light traveling towards the light-receiving side within the core 430a is incident on the side surface 437a of the stray light suppression groove 437, reflected downwards by the side surface 437a, and reaches the lower cover member 450. The light reaching the lower cover member 450 is absorbed by the lower cover member 450. As a result, even if light reflected from the workpiece WKA is incident on the light extraction member 430, the light will not reach the light incident mirror 433. That is, the side surface 437a of the stray light suppression groove 437 can be referred to as a stray light suppression unit that prevents light reflected from the workpiece WKA from reaching the light incident mirror 433, or as a stray light removal unit that removes stray light entering the light incident mirror 433.

[0284] Furthermore, the side surfaces 437a and 437b of the stray light suppression groove 437 can be smooth mirror surfaces, or they can be surfaces with numerous unevenness or roughness. By forming uneven or rough surfaces, light can be diffusely reflected and attenuated. Surfaces with numerous unevenness or roughness attenuate light and can therefore be called light attenuation surfaces. In this case, the light attenuation surface is disposed between the light exit mirror 432 and the light incident mirror 433 of the light extraction member 430.

[0285] Figure 64 An example of applying a third stray light countermeasure is shown. In the third stray light countermeasure, a stray light suppression groove 438, which prevents light reflected from the workpiece WKA from reaching the light incident mirror 433, is formed on the side opposite to the second stray light countermeasure. The stray light suppression groove 438 opens on the opposite side of the light extraction member 430, i.e., on the side where the detection area R of the workpiece WK is located. The inner surface of the stray light suppression groove 438 includes a side surface 438a on the light emitting side and a side surface 438b on the light incident side. The side surfaces 438a and 438b approach each other away from the opening of the stray light suppression groove 438 and connect to each other on the opposite side (upper side) of the opening, thereby forming a V-shaped cross-section. The side surfaces 438a and 438b of the stray light suppression groove 438 are constructed using the aforementioned light attenuation surfaces.

[0286] exist Figure 64 In the example, light reflected from the workpiece WKA, located in a region closer to the detection region R, is incident on surface 435 and travels towards the light-receiving side within the core 430a of the light extraction member 430. The light traveling towards the light-receiving side within the core 430a is then incident on the side surface 438a of the stray light suppression groove 438. Since the side surface 438a is constructed using a light-attenuating surface, the light is attenuated.

[0287] The light incident on the side surface 438a may be attenuated, resulting in no component of light emanating from the side surface 438a to the workpiece WKA, or there may be a component emanating from the side surface 438a to the workpiece WKA. The component emanating from the side surface 438a to the workpiece WKA will be reduced due to the light attenuation surface. Figure 64 The light emitted from the side surface 438a to the workpiece WKA is reflected by the workpiece WKA and incident on the side surface 438b of the stray light suppression groove 438. Since this side surface 438b is also a light attenuation surface, the light incident on the side surface 438b is also attenuated and further weakened. If there is a component reflected by the side surface 438b, the light is incident on the surface 436 and emitted to the workpiece WKA. Subsequently, although the light reflected from the workpiece WKA sometimes incident on the light incident mirror 433, this light has been significantly attenuated, thus becoming light weaker than the decision threshold of the optical sensor 1, thereby suppressing false decisions. In this way, multiple light attenuation surfaces can be provided between the light exit mirror 432 and the light incident mirror 433 of the light extraction member 430.

[0288] Notice, Figure 63 and Figure 64 The stray light suppression grooves 437 and 438 shown are grooves with depth, wherein the bottom surface is located near the surface on the opposite side of the opening side, but the depth of the groove is not particularly limited. The deeper the groove, the easier it is to suppress or remove stray light.

[0289] Figure 65 An example of applying a fourth stray light countermeasure is shown. In this fourth stray light countermeasure, a stray light suppression member 800 is provided to prevent light reflected from the workpiece WKA from reaching the light incident mirror 433. The stray light suppression member 800 can be disposed between the light exiting mirror 432 and the light extraction member 430. That is, a receiving groove 439 for receiving the stray light suppression member 800 is formed between the light exiting mirror 432 and the light incident mirror 433 of the light extraction member 430. The receiving groove 439 can be open on the upper side or the lower side of the light extraction member 430. The receiving groove 439 is preferably deep.

[0290] The stray light suppression member 800 is, for example, a light-absorbing member, a light-shielding member, etc., and can be made of, for example, the same material as the covering members 440 and 450. The stray light suppression member 800 is a member capable of removing stray light, and therefore can be called a stray light removal member. These stray light suppression members can be used as a stray light suppression unit. Alternatively, a stray light removal member can be used as a stray light suppression unit.

[0291] exist Figure 65In the example shown, light reflected from the workpiece WKA, located in a region closer to the detection region R, is incident on surface 435 and travels towards the light-receiving side within the core 430a of the light extraction member 430. The light traveling towards the light-receiving side within core 430a is incident on the stray light suppression member 800 and absorbed or blocked by it, thus eliminating any component traveling towards the light-incident mirror 433. It is not necessary to absorb all the light incident on the stray light suppression member 800. In this case, although weak light is incident on the light-incident mirror 433, this light is weaker than the decision threshold of the optical sensor 1, thereby suppressing false decisions.

[0292] In this way, in the example of applying the first to the fourth stray light countermeasures, the stray light is weakened by repeated reflection from the upper cover member 440 and the lower cover member 450 of the light extraction member 430, thereby applying a countermeasure against stray light.

[0293] Figure 66 An example of applying a fifth stray light countermeasure is shown. In this fifth stray light countermeasure, cores 430a are formed on the light extraction member 430 to draw a stray light suppression pattern or a stray light removal pattern. That is, a plurality of cores 430a are formed in the light extraction member 430, and a cladding layer 430b is provided between adjacent cores 430a. The cores 430a all extend obliquely toward the end of the light detection unit 400. As a result, when light reflected from a workpiece in a region closer to the detection area is incident on the surface 435 and reaches the cores 430a of the light extraction member 430, the light passes through the cores 430a, travels toward the end of the light detection unit 400, and exits to the outside. In this case, a covering member can be provided to cover the end of the light extraction member 430. An opaque member, such as an upper covering member 440, can be used to construct the covering member. A stray light removal pattern is an example of providing stray light removal units on the light extraction member 430. In addition, the stray light suppression pattern is an example of setting stray light suppression units on the light extraction member 430.

[0294] In this way, in the example of applying the fifth stray light countermeasure, the stray light generated in the light extraction member 430 is released to the end side or the base side to apply the stray light countermeasure.

[0295] (Effects of the implementation method)

[0296] According to this embodiment, optical waveguides 410 and 420 are formed into wide sheets in the horizontal direction and have cores 411 and 421 and cladding layers 412 and 422 arranged in layers in the vertical direction, so that the light intensity of optical waveguides 410 and 420 can be ensured while making them thinner. The cladding layers 412 and 422 of optical waveguides 410 and 420 are covered by sheet-shaped covering members 440 and 450, which form mounting surfaces for mounting objects, thus enabling the thin optical waveguides 410 and 420 to be easily mounted to mounting objects.

[0297] Additionally, optical waveguides 410 and 420 can be connected to the optical sensor 1 via connector 500. Since connector 500 is detachably mounted to the optical sensor 1, it is easy to connect the light detection unit 400 to the optical sensor 1 and replace the light detection unit 400 as needed.

[0298] Furthermore, since the light-emitting side and the light-receiving side are integrated through the covering component, connector section, relay connector section, etc., the light detection unit 400 can be easily processed as a single unit.

[0299] The above embodiments are merely exemplary in all respects and should not be construed as limiting. Furthermore, all modifications and alterations falling within the equivalent scope of the claims are included within the scope of this invention.

[0300] As described above, the present invention can be used, for example, in detecting the presence of an item.

Claims

1. A light detection unit connected to an optical sensor, the optical sensor comprising: A light-emitting element that projects detection light toward the detection area; A light-receiving element that receives detection light from the detection area; and The signal generation unit compares the light-receiving signal generated by the light-receiving element with a threshold and generates a detection signal indicating the comparison result. The optical detection unit includes: An optical waveguide guides light between a first end and a second end, has a horizontally wide sheet shape, a core and a cladding surrounding the core, and projects light onto or receives light from a detection region. The core and the cladding are arranged in layers in a vertical direction. The first end is connected to a light-projecting connection or a light-receiving connection for optical coupling with a light-emitting element or a light-receiving element of the optical sensor. The second end serves as a light-projecting end or a light-receiving end. A sheet-like covering member covers the cladding located near the second end of the optical waveguide or between the first and second ends, and is integrally formed with the optical waveguide. The optical waveguide includes: a light-projecting waveguide connected to the light-projecting connection portion of the optical sensor, which projects light onto the detection area with its second end as the light-projecting end; and a light-receiving waveguide connected to the light-receiving connection portion of the optical sensor, which receives light from the detection area with its second end as the light-receiving end. The covering component is integrated with the light-projecting optical waveguide and the light-receiving optical waveguide.

2. The optical detection unit according to claim 1, characterized in that, The covering member has a light-blocking property that blocks light emitted from the light-emitting element, and blocks the light waveguide near the second end of the light waveguide, in a portion other than the light-emitting end or the light-receiving end.

3. The optical detection unit according to claim 1, characterized in that, The covering member covers the two main surfaces and the two side surfaces of the optical waveguide.

4. The optical detection unit according to claim 3, characterized in that, The covering member covers the two main surfaces and two side surfaces of the middle portion of the optical waveguide located between the first end and the second end.

5. The optical detection unit according to claim 1, characterized in that, The covering member is formed as a strip or sheet with an adhesive layer.

6. The optical detection unit according to claim 1, characterized in that, With the light-emitting waveguide and the light-receiving waveguide separated from each other in the width direction, the covering member integrates the light-emitting waveguide and the light-receiving waveguide.

7. The optical detection unit according to claim 6, characterized in that, In the portion of the covering member corresponding to the portion located between the light-emitting waveguide and the light-receiving waveguide, a socket is formed for inserting a fixing member used when installing the object.

8. The optical detection unit according to claim 1, further comprising: A light extraction component is configured to extend from the second end of the light-emitting optical waveguide to the second end of the light-receiving optical waveguide, and the light extraction component includes: The light emitting section is optically coupled to the second end of the light-emitting waveguide and emits light from the main surface side of the light-emitting waveguide toward the detection area; The light incident section is optically coupled to the second end of the light receiving waveguide and receives light from the main surface side of the light receiving waveguide.

9. The optical detection unit according to claim 8, characterized in that, The optical waveguide has a plurality of cores arranged along the horizontal direction, and The light extraction component has a single core that is optically coupled to the plurality of cores.

10. The optical detection unit according to claim 1, characterized in that, The covering component includes a through hole for fixing to the object to be installed.

11. The optical detection unit according to claim 1, characterized in that, The covering member has a layered structure, the layered structure having a first covering member covering the cladding layer and a second covering member covering the first covering member. The first covering member covers the main surface of the cladding, and The second covering member covers the main surface of the first covering member and the two side surfaces of the optical waveguide.

12. The light detection unit according to claim 1, further comprising: A reinforcing plate having higher rigidity than the optical waveguide and disposed on the main surface of the optical waveguide near the second end.

13. The light detection unit according to claim 1, further comprising: A reinforcing plate, having higher rigidity than the optical waveguide, is disposed on the main surface of the sheet-like covering member. in, The sheet-like covering member is disposed on the main surface of the optical waveguide near the second end.

14. The optical detection unit according to claim 1, characterized in that, The sheet-like covering member is black in appearance, and The optical detection unit, which has an optical waveguide covered by the sheet-like covering member, is sheet-like.

15. The optical detection unit according to claim 1, characterized in that, The end from which light is projected into or received from the detection area by the optical waveguide is any one of the main surface of the optical waveguide, the side surface near the second end, and the side surface in the horizontal direction.

16. The optical detection unit according to claim 1, characterized in that, The connection part of the optical detection unit relative to the light-emitting connection part or the light-receiving connection part of the optical sensor is an optical fiber or the optical waveguide that is optically coupled to the optical waveguide.

17. The optical detection unit according to claim 1, characterized in that, The light detection unit is a limited reflective light detection unit.

18. The optical detection unit according to claim 12, characterized in that, The reinforcing plate has through holes, and The through-hole of the reinforcing plate communicates with the through-hole of the sheet-like covering member.

19. The light detection unit according to claim 1, further comprising: An indicator light is provided that extracts light passing through the core of the optical waveguide to the outside and is disposed on the optical waveguide between the first and second ends, on the light-emitting side or the light-receiving side.

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