Optical sensor

Abstract

The present invention discloses an optical sensor. An optical sensor includes a substrate, a light-emitting element, a light-receiving element, and an electronic circuit element. Light from the light-emitting element is blocked by a detection object to detect the detection object. The light-emitting element, the electronic circuit element, and the light-receiving element are mounted on the same surface of the substrate. On the mounting surface of the substrate, the electronic circuit element is disposed between the light-emitting element and the light-receiving element.

Description

Technical Field

[0001] The present invention relates to an optical sensor for detecting a detection object (object to be detected) by using a light-emitting element and a light-receiving element. Background Art

[0002] As a conventional optical sensor, a transmissive photoelectric interrupter uses a light-emitting element such as an LED and a light-receiving element such as a phototransistor, and detects that light is blocked when a detection object passes between the light-emitting element and the light-receiving element, so that detection of the detection object is performed.

[0003] For example, in a transmissive photoelectric interrupter, a surface-mounted light-emitting element and a surface-mounted light-receiving element are mounted on the same surface of a substrate, and a case including an internal reflection surface is assembled with the substrate on which these elements are mounted (Japanese Patent Application Laid-Open (JP-A) No. 11-274550). Further, the following structure is adopted, in which light emitted from the light-emitting element in the vertical direction is reflected twice by the reflection surface of the case and enters the light-receiving element in the vertical direction.

[0004] In such an optical sensor, the following structure can also be realized, in which the case that is subsequently assembled with the substrate on which the light-emitting element and the light-receiving element are mounted is replaced with an optical waveguide made of a transparent resin material. In this case, the light emitted from the light-emitting element is guided by the optical waveguide and then enters the light-receiving element in the vertical direction by internal surface reflection.

[0005] However, in the case where the case provided with the internal reflection surface is subsequently assembled with the substrate on which the light-emitting element and the light-receiving element are mounted, in order to guide light from the light-emitting element to the light-receiving element, it is necessary to achieve proper positioning of the reflection surface. For this reason, a gap is formed between the substrate and the case between the light-emitting element and the light-receiving element. In this case, the light from the light-emitting element enters the light-receiving element indirectly through reflection by the reflection surface, and in addition, directly enters the light-receiving element through the above gap. That is, the light-receiving element is affected by the light that directly enters the light-receiving element through the gap, so that there is a problem that a part of the detection object cannot be correctly detected.

[0006] Further, in the case where the subsequently assembled case is replaced with an optical waveguide made of a transparent resin material, since the optical waveguide is made of a transparent resin, the light from the light-emitting element directly enters the light-receiving element, so that there is a problem that the presence or absence of the detection object cannot be correctly detected. Summary of the Invention

[0007] The main object of the present invention is to provide an optical sensor that can correctly detect a detection object without being affected by light directly entering a light receiving element from a light emitting element, and that employs an inexpensive and simple configuration.

[0008] According to an aspect of the present invention, there is provided an optical sensor including: a substrate; a light emitting element configured to emit light; a light receiving element configured to receive light from the light emitting element through a space where a detection object passes; and an electronic circuit element, wherein the light from the light emitting element is blocked by the detection object to detect the detection object, wherein the light emitting element, the electronic circuit element, and the light receiving element are mounted on the same surface of the substrate, and wherein, on the mounting surface of the substrate, the electronic circuit element is disposed between the light emitting element and the light receiving element.

[0009] More features of the present invention will become clear from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Part (a) of is a perspective view of the optical sensor in Embodiment 1, and Figure 1 Part (b) of is a top view of the optical sensor in Embodiment 1.

[0011] Figure 2 is a perspective view of the optical sensor in Embodiment 1.

[0012] Figure 3 Part (a) of is a cross-sectional view of the optical sensor in the comparative example, and Figure 3 Part (b) of is a cross-sectional view of the optical sensor in Embodiment 1.

[0013] Figure 4 is a circuit diagram showing the equivalent circuit of the optical sensor in Embodiment 1.

[0014] Figure 5 is a graph showing the output characteristics of the optical sensor in Embodiment 1.

[0015] Figure 6 Part (a) of is a perspective view of the optical sensor in Embodiment 2, and Figure 6 Part (b) of is a top view of the optical sensor in Embodiment 2.

[0016] Figure 7 is a schematic diagram showing the layout of the components of the optical sensor in Embodiment 2.

[0017] Figure 8 is a cross-sectional view of the optical sensor in Embodiment 3. DETAILED DESCRIPTION

[0018] Embodiments of the present invention will be specifically described with reference to the accompanying drawings. The dimensions, materials, shapes, and relative arrangements of the constituent elements described in the following embodiments should be appropriately changed depending on the structure and various conditions of the optical sensor to which the present invention is applied, and the scope of the present invention is not intended to be limited thereto.

[0019] [Embodiment 1]

[0020] An Figure 1 optical sensor according to Embodiment 1 of the present invention will be described. Figure 1 Part (a) of Figure 1 is a perspective view of the optical sensor in Embodiment 1, and

[0021] The optical sensor 100 according to Embodiment 1 includes a light-emitting element 101, a light-receiving element 103, and an electronic circuit element 102. The light-emitting element 101 is for emitting light, and the light-receiving element 103 is for receiving the light from the light-emitting element 101 through a space 110 where an object (object to be detected) 106 ( Figure 2 ) passes. The optical sensor 100 detects the object 106 in such a manner that the light from the light-emitting element 101 is blocked by the object 106 in the space 110 and thus the amount of light received by the light-receiving element 103 changes.

[0022] The light-emitting element 101 includes a light-emitting source 101a. In this embodiment, a surface-mounted LED is used as the light-emitting element 101. The light-emitting element 101 is a vertical optical axis type LED that emits light in the vertical direction toward the substrate 104. The light-receiving element 103 includes a light-receiving region 103a. In this embodiment, a phototransistor (Ptr) is used as the light-receiving element 103. The light-receiving element 103 is a vertical optical axis type phototransistor that receives the light traveling toward the substrate 104.

[0023] On the substrate 104, in addition to the light-emitting element 101 and the light-receiving element 103 that constitute the transmissive (light-transmitting) type photoelectric interrupter, the electronic circuit element 102, the CPU 121, and the memory 122 are also mounted on the same surface (plane). On the mounting surface of the substrate 104, the electronic circuit element 102 is disposed between the light-emitting element 101 and the light-receiving element 103. The light-emitting element 101 and the light-receiving element 103 that constitute the photoelectric interrupter serving as an optical sensor, together with other components such as the above-mentioned electronic circuit element 102, are mounted on the substrate 104 by reflow soldering (relow). That is, the electronic circuit element 102 is a reflow-solderable element (component), and is mounted on the same surface of the substrate 104 together with the light-emitting element 101 and the light-receiving element 103 by an automatic mounting device (not shown) for mounting the elements at predetermined positions on the substrate 104.

[0024] On the mounting surface of the substrate 104, the electronic circuit element 102 is deployed between the light-emitting element 101 and the light-receiving element 103. The electronic circuit element 102 is deployed on the line DL that connects the center of the light-emitting source 101a of the light-emitting element 101 and the center of the light-receiving region 103a of the light-receiving element 103. In this embodiment, as the electronic circuit element 102, a chip resistor that is not electrically connected to the light-emitting element 101 and the light-receiving element 103 mounted on the substrate 104 is used. In addition, the chip resistor used as the electronic circuit element 102 has the same size as the LED used as the light-emitting element 101.

[0025] The optical sensor 100 includes an optical waveguide 105 as a light guiding member. The optical waveguide 105 is then mounted on the substrate 104 on which the light-emitting element 101, the electronic circuit element 102, and the light-receiving element 103 have been mounted by reflow soldering. The optical waveguide 105 is made of an acrylic resin material, and guides the light emitted from the light-emitting element 101 in the vertical direction toward the light-receiving element 103 in the vertical direction by reflection on the inner surface of the inclined surface portion. Specifically, the optical waveguide 105 is prepared by integrally forming a first light guiding portion 105a, a second light guiding portion 105b, and a connecting portion 105c that connects the first light guiding portion 105a and the second light guiding portion 105b. The first light guiding portion 105a guides the light emitted from the light-emitting element 101 in the direction of the light passage space 110. The second light guiding portion 105b is disposed opposite to the first light guiding portion 105a through the light passage space 110, and guides the light passing through the light passage space 110 to the light-receiving element 103. The connecting portion 105c is hollow on the mounting surface side of the substrate 104. On the mounting surface of the substrate 104, the electronic circuit element 102 is deployed at a position corresponding to the connecting portion 105c of the optical waveguide 105 on the substrate 104 between the light-emitting element 101 and the light-receiving element 103.

[0026] A space 110 is formed between a first light guide portion 105a and a second light guide portion 105b that are arranged to face each other, and is positioned on an optical path along which light emitted from the light emitting element 101 in the vertical direction is guided to the light receiving element 103. When the detection object 106 is in this space 110, the optical path is blocked, and thus, the light emitted from the light emitting element 101 does not reach the light receiving element 103( Figure 2 ). Accordingly, the amount of light received by the light receiving element 103 changes, such that the detection object 106 is detected.

[0027] Figure 3 Parts (a) and (b) show cross-sectional views of the optical sensor. Figure 3 Part (a) shows a cross-sectional view of the optical sensor in the comparative example, and shows a configuration in which there are no electronic circuit elements between the light emitting element and the light receiving element. Figure 3 Part (b) shows a cross-sectional view of the optical sensor in this embodiment (Embodiment 1), and shows a configuration in which electronic circuit elements are deployed between the light emitting element and the light receiving element. In these figures, the arrows indicated by solid lines represent the optical path along which the light emitted from the light emitting element in the vertical direction is guided to the light receiving element 103. The arrows indicated by dashed lines represent the optical path along which the light emitted from the light emitting element 101 in the horizontal direction travels toward the light receiving element 103.

[0028] In the case where the light emitting element 101 is a vertical optical axis type LED, although most of the emitted light travels in the vertical direction, the light also travels in directions other than the vertical direction. Further, although the vertical optical axis type phototransistor serving as the light receiving element 103 has high sensitivity to light incident thereon from the vertical direction, the phototransistor also has high sensitivity to light incident thereon from directions other than the vertical direction.

[0029] As Figure 3 shown by the dashed arrow in part (a), on the mounting surface of the substrate 104, in the case where the electronic circuit elements are not deployed between the light emitting element 101 and the light receiving element 103, the light emitted from the light emitting element 101 in the horizontal direction enters the light receiving element 103 regardless of the presence or absence of the detection object 106 in the space 110.

[0030] As Figure 3 shown by the dashed arrow in part (b), on the mounting surface of the substrate 104, in the case where the electronic circuit elements 102 are deployed between the light emitting element 101 and the light receiving element 103, the light emitted from the light emitting element 101 in the horizontal direction is blocked by the electronic circuit elements 102, and thus does not enter the light receiving element 103.

[0031] will be used separately Figure 4 and Figure 5 to describe the equivalent circuit and output characteristics of the optical sensor in this embodiment. Figure 4 is a circuit diagram showing the equivalent circuit of the optical sensor in this embodiment. Figure 5 is a graph showing the output characteristics of the optical sensor in this embodiment.

[0032] As Figure 4 shown, the light-emitting element 101 is an LED, whose anode is connected to a DC voltage source through a current-limiting resistor 111, and whose cathode is connected to ground (GND). The light-receiving element 103 is a phototransistor (Ptr), and its collector is connected to a voltage source through a pull-up resistor 112, and its emitter is connected to ground.

[0033] The voltage output unit 113 is connected to the collector of the phototransistor that is the light-receiving element 103, and shows the voltage between the collector terminal and ground. In the state where the phototransistor is turned on, that is, in the state where light enters the phototransistor, the voltage output unit 113 becomes output L. On the other hand, in the state where the phototransistor is turned off, that is, in the state where light does not enter the phototransistor, the voltage output unit 113 becomes output H.

[0034] In Figure 5 , the abscissa represents the current (mA) flowing through the light-emitting element 101. The light emission amount of the light-emitting element 101 is proportional to the current (amount) flowing through the light-emitting element 101. In Figure 5 , the ordinate represents the voltage (V) of the voltage output unit 113. In this embodiment, during the experiment, the DC input voltage is 3.3V, and an LED with a rated current of 50mA is used. During the experiment, an LED with a current of 40mA is used.

[0035] In Figure 5 , the data indicated by the solid line shows the state where the detection object 106 "does not exist (no)" in the space 110 of the optical sensor and the electronic circuit element 102 "exists (yes)" between the light-emitting element 101 and the light-receiving element 103. The data indicated by the dashed line shows the state where the detection object 106 "exists (yes)" in the space 110 of the optical sensor and the electronic circuit element 102 "does not exist (no)" between the light-emitting element 101 and the light-receiving element 103. The data indicated by the dotted line shows the state where the detection object 106 "exists (yes)" in the space 110 of the optical sensor and the electronic circuit element 102 "exists (yes)" between the light-emitting element 101 and the light-receiving element 103.

[0036] When detecting the presence of the object 106 in the space 110 of the optical sensor, the light from the light-emitting element 101 is blocked by the object 106. Therefore, the light-receiving element 103 is in a state where light does not enter the light-receiving element 103, causing the voltage output unit 113 to output H. On the other hand, when the object 106 is not present in the space 110 of the optical sensor, the light from the light-emitting element 101 is not blocked by the object 106. Therefore, the light-receiving element 103 is in a state where light enters the light-receiving element 103, causing the voltage output unit 113 to output L. The optical sensor is required to generate an output depending on the presence or absence of the object 106, regardless of the light emission amount of the light-emitting element 101.

[0037] Regarding the data indicated by the solid line, among the light from the light-emitting element 101, the light emitted horizontally from the light-emitting element 101 is blocked by the electronic circuit element 102 between the light-emitting element 101 and the light-receiving element 103 ( Figure 3 part (b)). For this reason, the amount of light received by the light-receiving element 103 does not depend on the current flowing through the LED serving as the light-emitting element 101, that is, does not depend on the light emission amount of the light-emitting element 101, causing an output L to be generated. For this reason, the optical sensor can distinguish the absence of the object 106 ("no").

[0038] Regarding the data indicated by the dashed line, not only does the light from the light-emitting element 101 enter the light-receiving element 103 indirectly through the reflection of the inner surface of the light guide 105, but also the light emitted horizontally from the light-emitting element 101 directly enters the light-receiving element 103. For this reason, the amount of light received by the light-receiving element 103 depends on the current flowing through the light-emitting element 101, that is, the light emission amount of the light-emitting element 101, causing the output H and the output L to change. For this reason, the optical sensor is affected by the light directly entering the light-receiving element 103 from the light-emitting element 101, making it impossible for the optical sensor to distinguish the presence or absence of the object 106.

[0039] Regarding the data indicated by the dotted line, among the light from the light-emitting element 101, the light emitted horizontally from the light-emitting element 101 is blocked by the electronic circuit element 102 between the light-emitting element 101 and the light-receiving element 103 ( Figure 3 part (b)). For this reason, the amount of light received by the light-receiving element 103 does not depend on the current flowing through the LED serving as the light-emitting element 101, that is, does not depend on the light emission amount of the light-emitting element 101, causing an output H to be generated. For this reason, the optical sensor can distinguish the presence of the object 106 ("yes").

[0040] The voltage output unit 113 is connected to the logic IC, and its voltage is compared with a reference voltage in the logic IC so that the voltage is discriminated into two values of output H and output L. For example, a logic IC operating with an input of 3.3 V recognizes 2.6 V or greater as output H and 0.6 V or less as output L, such that the logic IC cannot correctly recognize 0.6 V to 2.6 V as output H or output L.

[0041] The light emission amount of the light emitting element 101 changes depending on the ambient temperature conditions and the cumulative on-time. In addition, the light emission amount of the light emitting element 101 changes depending on changes such as the luminous efficiency of the light emitting element 101, the optical axis, the sensitivity of the light receiving element 103, and the internal surface reflection of the light guide 105. For this reason, it is necessary to generate an output depending on the presence or absence of the detection object 106 without depending on the light emission amount of the light emitting element 101.

[0042] However, as described above, in the optical sensor, when there is light directly entering the light receiving element 103 from the light emitting element 101, the presence or absence of the detection object 106 in the space 110 cannot be correctly discriminated ( Figure 5 the data indicated by the dashed line in

[0043] Therefore, it is understood that the electronic circuit element 102 is disposed between the light emitting element 101 and the light receiving element 103, and thus, it is effective to block the light directly entering the light receiving element 103 from the light emitting element 102.

[0044] As in this embodiment, when the electronic circuit element 102 is constituted by a chip register, during the installation of the light emitting element 101 and the light receiving element 103 on the substrate 104 by an automatic mounting device as an automatic machine, the electronic circuit element 102 is installed simultaneously and then can pass through a reflow soldering furnace. In addition, general chip registers are inexpensive, such that there are advantages of various sizes being available. For this reason, by disposing the electronic circuit element between the light emitting element and the light receiving element on the mounting surface (the same surface) of the substrate, the detection of the detection object 106 can be correctly performed without being affected by the light directly entering the light receiving element from the light emitting element, such that an optical sensor having an inexpensive and simple structure can be provided.

[0045] In addition, in a structure where the light guide is subsequently assembled with the substrate, there is no need to provide a mechanism for preventing the light directly entering the light receiving element from the light emitting element in the horizontal direction, and thus, the light guide can be configured to be inexpensive and simple.

[0046] Incidentally, in this embodiment, as the electronic circuit element 102, a chip register mounted on the same surface of the substrate is described as an example, but the present invention is not limited thereto. The electronic circuit element may only be required to be mountable by an automatic mounting device and may be a light-shielding component of a reflow soldering furnace, including electronic circuit elements such as chip ceramic capacitors, chip beads, connectors, coils, chip jumpers, etc. that are electrically connected to the light-emitting element and the light-receiving element, and heat-resistant components other than the electronic circuit elements, etc.

[0047] In addition, when the electronic circuit element 102 disposed between the light-emitting element 101 and the light-receiving element 103 has a structure that blocks a part between the light-emitting element and the light-receiving element on the mounting surface of the substrate, an effect can be obtained. However, as the electronic circuit element 102, a member that is thicker (higher) than the height of the light-emitting element 101 or the light-receiving element 103 is preferred.

[0048] In addition, similarly, in the case where an optical guide made of a transparent resin material is used as the light guiding member, there is no need to provide a mechanism for preventing light from directly entering the light-receiving element in the horizontal direction from the light-emitting element. For this reason, an optical sensor can be provided with a cheap and simple structure.

[0049] [Embodiment 2]

[0050] Reference will be made to Figure 6 and Figure 7 to describe the optical sensor according to Embodiment 2 of the present invention. In Embodiment 2, members (parts) similar to those in Embodiment 1 will be omitted from the description. Figure 6 Part (a) of is a perspective view of the optical sensor in this embodiment, and Figure 6 Part (b) of is a top view of the optical sensor in this embodiment. Figure 7 is a schematic diagram showing the component layout and wiring pattern of the optical sensor in this embodiment.

[0051] The equivalent circuit of the optical sensor in this embodiment is the same in content as the equivalent circuit described with reference to Figure 4 in Embodiment 1, and therefore, will be omitted from the description.

[0052] In Embodiment 2, the electronic circuit element disposed between the light-emitting element 101 and the light-receiving element 103 is a part of the components constituting the drive circuit for driving the light-emitting element 101 or the light-receiving element 103. Specifically, the current-limiting resistor 111 for the light-emitting element 101 and the pull-up resistor 112 for the light-receiving element 103 also serve as the electronic circuit elements disposed between the light-emitting element 101 and the light-receiving element 103. As Figure 6 and Figure 7As shown, on the substrate 104, in addition to the light-emitting element 101, the current-limiting resistor 111, the pull-up resistor 112, and the light-receiving element 103, the CPU 121 and the memory 122 are mounted on the same surface. The current-limiting resistor 111 and the pull-up resistor 112, which are electronic circuit elements, are deployed on the mounting surface (the same surface) of the substrate 104 between the light-emitting element 101 and the light-receiving element 103. In this embodiment, the current-limiting resistor 111 and the pull-up resistor 112 serve as electronic circuit elements that block the light directly entering the light-receiving element 103 from the light-emitting element 101.

[0053] In addition, in this embodiment, a plurality of electronic circuit elements are provided that are deployed between the light-emitting element 101 and the light-receiving element 103. The current-limiting resistor 111 and the pull-up resistor 112, which are the plurality of electronic circuit elements, are deployed at different positions between the light-emitting element 101 and the light-receiving element 103. Specifically, the current-limiting resistor 111 and the pull-up resistor 112 are mounted while being positionally offset in the vertical direction of part (b) of Figure 6 . The current-limiting resistor 111 and the pull-up resistor 112 are deployed at different positions with respect to the direction crossing the line DL that connects the center of the light-emitting source 101a of the light-emitting element 101 and the center of the light-receiving area 103a of the light-receiving element 103. In this embodiment, the configuration in which the current-limiting resistor 111 and the pull-up resistor 112 are deployed at different positions with respect to the direction crossing the line DL is described as an example, but the present invention is not limited thereto. In the case where the plurality of electronic circuit elements are deployed at different positions with respect to the direction crossing the line DL that connects the center of the light-emitting source 101a of the light-emitting element 101 and the center of the light-receiving area 103a of the light-receiving element 103, at least one electronic circuit element may be deployed only on the line DL between the light-emitting element 101 and the light-receiving element 103. In addition, the current-limiting resistor 111 and the pull-up resistor 112 used in this embodiment are components that are smaller in size than the light-emitting element 101 and the light-receiving element 103. By mounting the current-limiting resistor 111 and the pull-up resistor 112 on the same surface of the substrate 104 while offsetting the positions of these registers, the light emitted from the light-emitting element 101 in the horizontal direction is blocked along the optical path by which it enters the light-receiving element 103 in the horizontal direction.

[0054] As described above, a configuration is adopted in which the current-limiting resistor 111 and the pull-up resistor 112, which are components constituting the drive circuit for driving the light-emitting element 101 and the light-receiving element 103, serve as electronic circuit elements deployed between the light-emitting element 101 and the light-receiving element 103. Thereby, an increase in cost due to the addition of electronic circuit elements can be eliminated.

[0055] In addition, the current-limiting resistor 111 and the pull-up resistor 112, which are multiple electronic circuit components, are mounted on the same surface of the substrate 104 while offsetting their positions. Thus, even when components smaller in size than the light-emitting element 101 and the light-receiving element 103 are used as the current-limiting resistor 111 and the pull-up resistor 112, the current-limiting resistor 111 and the pull-up resistor 112 can be used as electronic circuit components deployed between the light-emitting element 101 and the light-receiving element 103.

[0056] [Embodiment 3]

[0057] Reference will be Figure 8 made to describe the optical sensor according to Embodiment 3 of the present invention. In Embodiment 3, components (parts) similar to those in Embodiment 1 and Embodiment 2 will be omitted from the description. Figure 8 is a cross-sectional view of the optical sensor in this embodiment.

[0058] The optical sensor in Embodiment 3 is provided with a black housing 108 including reflecting surfaces 109a and 109b, instead of an optical waveguide as a light guiding member that is subsequently assembled with the substrate. Below, this will be specifically described.

[0059] In this embodiment, on the same surface of the substrate 104, the light-emitting element 101, the electronic circuit element 102, and the light-receiving element 103 are mounted in advance, and then the housing 108 is mounted on the substrate 104. The black housing 108 is a member prepared by integrally forming a first hollow portion 108a including a first reflecting surface 109a, a second hollow portion 108b including a second reflecting surface 109b, and a connecting portion 108c connecting the first hollow portion 108a and the second hollow portion 108b. The first hollow portion 108a includes a first reflecting surface 109a and a first slit 108d. The first reflecting surface 109a is for reflecting light emitted from the light-emitting element 101, and the first slit 108d is for allowing the light reflected by the first reflecting surface 109a to pass through toward the space 110. The second hollow portion 108b is provided to face the first hollow portion 108a through the space 110. The second hollow portion 108b includes a second slit 108e and a second reflecting surface 109b. The second slit 108e is for receiving the light passing through the space 110, and the second reflecting surface 109b is for reflecting the light passing through the second slit 108e toward the light-receiving element 103.

[0060] In the case where the housing 108 including the reflecting surfaces 109a and 109b is subsequently assembled with the substrate 104, in order to guide the light from the light-emitting element 101 to the light-receiving element 103, proper positioning of the reflecting surfaces 109a and 109b needs to be performed. For this reason, in the case where the housing 108 is subsequently assembled with the substrate 104, as Figure 8As shown, a gap is generated between the connecting portion 108c of the housing 108 and the substrate 104. In order to assemble the housing 108 and the substrate without generating a gap, it is necessary to design the shape of the housing 108, but this is not easy. When a gap is generated between the connecting portion 108c of the housing 108 and the substrate 104, as Figure 8 indicated by the dashed arrow in, a path is formed along which the light emitted horizontally from the light-emitting element 101 passes through the gap and then directly enters the light-receiving element 103.

[0061] As described above, in the optical sensor, when there is light directly entering the light-receiving element 103 from the light-emitting element 101, the presence or absence of the detection object 106 in the space 110 cannot be correctly discriminated.

[0062] Therefore, in the optical sensor in this embodiment, on the mounting surface (the same surface) of the substrate 104, the electronic circuit element 102 is disposed between the light-emitting element 101 and the light-receiving element 103. Thus, the path of the light directly entering the light-receiving element 103 from the light-emitting element 101 can be blocked by disposing the electronic circuit element 102.

[0063] As described above, in the structure where the light-emitting element and the light-receiving element are mounted on the same surface of the substrate and the housing is then assembled with the substrate, the electronic circuit element is mounted between the light-emitting element and the light-receiving element. Thus, even when a gap is generated between the substrate and the housing, an optical sensor without the influence of stray light can be realized with a cheap and simple structure.

[0064] In addition, there is no need to provide the housing with a mechanism for preventing light from directly entering the light-receiving element from the light-emitting element, and thus, the housing can be constructed cheaply and simply.

[0065] Although the present invention has been described with reference to the exemplary embodiments, it is to be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be given the broadest interpretation so as to encompass all such modifications as well as equivalent structures and functions.

Claims

1. An optical sensor, characterized in that, Comprising: A substrate; A light-emitting element including a light-emitting source configured to emit light; A light-receiving element having a light-receiving area and configured to receive light from the light-emitting element through a space where an object passes; And An electronic circuit element, wherein light from the light-emitting element is blocked by the detected object to detect the detected object, wherein the light-emitting element, the electronic circuit element, and the light-receiving element are mounted on the same surface of the substrate, wherein when observed in a direction perpendicular to the mounting surface of the substrate, the electronic circuit element is deployed on a line connecting the center of the light-emitting source and the center of the light-receiving area and is deployed on the mounting surface of the substrate, and wherein the thickness of the electronic circuit element in a thickness direction perpendicular to the mounting surface of the substrate is greater than the thickness of the light-emitting element or the light-receiving element in the thickness direction, such that light emitted from the light-emitting source in a direction parallel to the mounting surface of the substrate is directly blocked by the electronic circuit element and does not enter the light-receiving element, and wherein the electronic circuit element forms part of a drive circuit for driving the light-emitting element or the light-receiving element.

2. The optical sensor according to claim 1, wherein, The electronic circuit element includes a plurality of electronic circuit element portions, and the plurality of electronic circuit element portions are disposed at different positions on the mounting surface of the substrate in a direction crossing a line connecting the center of the light-emitting source of the light-emitting element and the center of the light-receiving area.

3. The optical sensor according to claim 1, further comprising: A first light guide portion configured to guide light emitted from the light-emitting element in a direction in which light passes through the space; A second light guide portion disposed opposite the first light guide portion through the space, and the second light guide portion is configured to guide light passing through the space to the light-receiving element; And A light guide member, the light guide member being integrally formed with a connecting portion configured to connect the first light guide portion and the second light guide portion, wherein the electronic circuit element is deployed at a position corresponding to the connecting portion between the light-emitting element and the light-receiving element.

4. The optical sensor according to claim 1, further comprising: A first hollow portion including a first reflecting surface and a first slit, the first reflecting surface being configured to reflect light emitted from the light-emitting element, and the first slit being configured to allow the light reflected by the first reflecting surface to pass toward the space; A second hollow portion disposed opposite the first hollow portion through the space, and the second hollow portion includes a second slit and a second reflecting surface, the second slit being configured to receive light passing through the space, and the second reflecting surface being configured to reflect the light passing through the second slit toward the light-receiving element; And A black housing, the black housing being integrally formed with a connecting portion configured to connect the first hollow portion and the second hollow portion, Among them, the electronic circuit element is disposed between the light-emitting element and the light-receiving element and between the substrate and the connection portion of the housing.

5. The optical sensor according to claim 1, wherein, The electronic circuit element is a reflow solder mountable element and is part of a component that constitutes a drive circuit for driving the light-emitting element or the light-receiving element.

6. The optical sensor according to claim 1, wherein, The light-emitting element is a surface-mount type LED, and the light-receiving element is a surface-mount type phototransistor.

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