Photosensor including sensor circuit assembly with light emitter and receiver that face each other

A photosensor is provided with a sensor circuit assembly. The sensor circuit assembly includes a light emitter, a light receiver, a light-emitter support, a light-receiver support, and a connecting part. The light emitter and the light receiver face each other. The light-emitter support extends from and supports the light emitter. The light-receiver support extends from and supports the light receiver. The connecting part connects one end of the light-emitter support with one end of the light-receiver support. The connecting part includes a seal and a connection terminal that protrudes from the seal. The connection terminal includes a first press-contact part, and a first pressure part that presses the first press-contact part in a press-contact direction.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority based on 35 USC 119 from prior Japanese Patent Application No. P2013-091481 filed on Apr. 24, 2013, entitled “PHOTOSENSOR”, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The invention relates to photosensors.

2. Description of the Related Art

A photosensor is provided with a light emitting element, a light receiving element, and a seal part. For example, in the photosensor described in Japanese Unexamined Patent Publication No. 11-145505, the light emitting element and the light receiving element are connected via a lead frame, and one part of the lead frame is encapsulated in a seal part. Additionally, a connection terminal, which protrudes from the seal part, is also provided. A borehole through which the wire of a cable may be inserted is formed in the connection terminal; and the wire is secured to the connection terminal via soldering.

In the above described photosensor, a wire passes through the borehole of the connection terminal, and thereafter the connection terminal and the wire need to be soldered together. Therefore, there is the issue that there is an increase in the number of manufacturing workload.

Moreover, given that the connection terminal is integrated with the seal part, it is likely that heat will affect the seal part during soldering.

SUMMARY OF THE INVENTION

One aspect of the invention provides a highly reliable photosensor that may be manufactured using a reduced number of manufacturing man-hours.

A photosensor according to an embodiment comprises a sensor circuit assembly. The sensor circuit assembly includes a light emitter (light emitting element), a light receiver (light receiving element), a light-emitter support, a light-receiver support, and a connector (connecting part). The light emitting element and the light receiving element face each other. The light-emitter support extends from the light emitting element and supports the light emitting element. The light-receiver support extends from the light receiving element and supports the light receiving element. The connecting part connects one end of the light-emitter support with one end of the light-receiver support. The connecting part includes a seal (seal part) and a first terminal (first connection terminal) that protrudes from the seal part. The first connection terminal includes a first press-contact part, and a first pressure part configured to press the first press-contact part in a press-contact direction.

In the photosensor, the light-emitter support and the light-receiver support respectively support the light emitting element and the light receiving element, and are connected by the connecting part, which includes the seal part. Accordingly, the light emitting element, the light receiving element, and the seal part may be integrated within the sensor circuit assembly. Therefore, it is possible to install the light emitting element, the light receiving element, and the seal part, in a unified manner in another component. Additionally, the first connection terminal includes the first press-contact part, and therefore pressing the first connection terminal into contact with the wire connects the first connection terminal with the wire. Accordingly, there is no need for soldering when connecting the first connection terminal and the wire. Thus, the number of manufacturing man-hours decreases. Furthermore, given that soldering is no longer necessary, this curbs the effects of heat on the seal part. Thus, the reliability of the device improves. In this manner, a photosensor according to this aspect has increased reliability and uses a reduced number of manufacturing man-hours.

Moreover, the first connection terminal includes the first pressure part, and therefore the first connection terminal may be pressed into contact by pushing on the first pressure part. Accordingly, it is possible to reduce the load on the seal part compared to a case where the seal part needs to be pushed to make the press contact. Thus, the reliability of the device improves.

The first pressure part of the first connection terminal may be arranged outside a region on which the seal part projects in the press-contact direction. The seal part will not obstruct the first pressure part when the first pressure part is pressed. This facilitates press contact.

The first connection terminal may further include a joint (joining part). The joining part joins the first press-contact part and the seal part. The width of the joining part is smaller than the width of the first press-contact part. The first connection terminal is shaped curving downward from the joining part. In this instance, the first connection terminal may be bent with little force compared to the case where the width of the joining part and the width of the first press-contact part are the same. Therefore it is possible to reduce the amount of force applied to the seal part when bending the first connection terminal. This prevents the seal part from breaking during the bending process. Additionally, given that the first connection terminal may be bent with a small amount of force, this improves the precision of the bending angle for the first connection terminal.

The first pressure part of the first connection terminal may be one portion of an edge face of the first connection terminal as a sheet thickness of the first connection terminal. This facilitates formation of the first pressure part.

The photosensor may further include a first wire configured to connect to the sensor circuit assembly. The first press-contact part of the first connection terminal is pressed into contact with the first wire in the press-contact direction.

The first wire may include a core, and an inner coating that covers the core. The first press-contact part of the first connection terminal passes through the inner coating and cuts into the first wire to come in contact with the core. In this case, pushing the connection terminals onto the wire facilitates pressing the terminals into contact with the wire without first having to remove the inner coating of the wire before press contact.

The photosensor may further include a holder that supports the first wire. The holder includes a first wire housing, and a first terminal housing. The first wire housing houses the first wire. The first terminal housing houses the first connection terminal. The first wire is pressed into contact with the first connection terminal within the first wire housing. When the photosensor includes the holder, pushing the first connection terminal relative to the first wire housing, thereby facilitates pressing the first connection terminal into contact with the first wire.

The first press-contact part of the first connection terminal may include a slit. When the first press-contact part includes a slit, during press contact, the core of the first wire enters the slit, and the first connection terminal and the wire are electrically connected.

The first terminal housing may include a protrusion. The protrusion protrudes from a bottom of the first wire housing toward the slit. The bottom of the first terminal housing faces a tip end of the first connection terminal when the first terminal housing houses the first connection terminal. When the first terminal housing includes the protrusion, during press contact, the protrusion pushes the core of the first wire into the slit of the first connection terminal. Therefore, this prevents the core from escaping from the slit during press contact. Hereby, an accurate connection between the core and the first connection terminal may be established.

The holder may further include a catch that locks onto the sensor circuit assembly. The catch locks onto the sensor circuit assembly when the first connection terminal is pressed into contact with the first wire. When the holder further includes a catch, and the catch of the holder locks onto the sensor circuit assembly to maintain firm press contact between the first connection terminal and the first wire. Furthermore, during press contact, the catch is in the locked position with the sensor circuit assembly when the first connection terminal is arranged in the press-contact position with the first wire. Therefore, a worker may use the catch locking onto the sensor circuit assembly as a means of easily determining whether press contact of the first connection terminal is complete.

A second wire may be further provided to connect to the sensor circuit assembly. The connecting part further includes a second connection terminal that protrudes from the seal part. The second connection terminal is pressed into contact with the second wire in the press-contact direction. When the second wire and second connection terminal is further provided, the plurality of connection terminals may be pressed into contact simultaneously. Thus, the number of manufacturing man-hours decreases.

The second connection terminal may include a second press-contact part, and a second pressure part configured to be used to press the second press-contact part in a press-contact direction. The second connection terminal may be pressed into contact by pushing on the second pressure part in this case. Accordingly, each of the connection terminals may be accurately pressed into contact, compared to providing a common pressure part configured to be used to press the first connection terminal into contact, and to press the second connection terminal into contact.

The seal part may include a first side, and a second side. The first side is located on the opposite side of the second side. The first connection terminal and the second connection terminal may be provided on the first side. That is, no connection terminals are provided on the second side. Providing the first and second connection terminals on the first side and no connection terminals on the second side facilitates uniformly pressing the plurality of connection terminals into contact, compared to a case where the connection terminals are provided on both the first side, and the second side.

A holder that supports the first wire and the second wire may be further provided. The holder includes a first wire housing, a second wire housing, a first terminal housing, and a second terminal housing. The first wire housing houses the first wire. The second wire housing houses the second wire. The first terminal housing houses the first connection terminal. The second terminal housing houses the second connection terminal. The first wire housing and the second wire housing are mutually partitioned. The first wire is pressed into contact with the first connection terminal within the first wire housing. The second wire is pressed into contact with the second connection terminal within the second wire housing. Therefore in this case, the first wire and the second wire may be prevented from coming into contact with each other because the first wire housing, and the second wire housing are mutually partitioned.

The photosensor may further include a cable and a holder that supports the cable. The cable includes a first wire, a second wire, and an outer coating. The outer coating covers the first wire and the second wire. The holder includes a borehole that passes through the holder. An inner surface of the borehole is provided with at least three protrusions. The cable is arranged to pass through the borehole. An adhesive fills between the inner surface of the borehole and the cable. The protrusions establish a uniform gap between the inner surface of the borehole and the outer surface of the cable. Therefore, a uniform amount of adhesive may be poured in between the borehole and the cable when bonding the cable to the borehole. This improves the strength of the adhesive bonding of the cable.

The protrusions may be arranged at equal intervals in the circumferential direction of the borehole. This further establishes a more precisely uniform gap between the inner surface of the borehole and the outer surface of the cable.

The borehole may include a first bore section and a second bore section. The first bore section and the second bore section are arranged side by side along the axial direction of the borehole. The second bore section includes an end section of the borehole. The inner diameter of the second bore section is larger than the inner diameter of the first bore section. Given that the second bore section including the end section of the borehole has a large inner diameter, this facilitates pouring the adhesive between the borehole and the cable.

The holder may include a positioning section. The positioning section is arranged to overlap with one portion of the borehole in the direction the borehole passes through the holder. Including a positioning section in the holder facilitates positioning the end section of the cable when the cable is inserted into the borehole.

The holder may include a wall. The wall is arranged to overlap with one portion of the borehole. The wall includes a first wire housing, and the second wire housing. The first wire housing houses the first wire. The second wire housing houses the second wire. The positioning section is a portion of the wall. The wall, provided with wire housings, may also serve as the positioning section in this case.

The sensor circuit assembly may include a light-emitter lens part and a light-receiver lens part. The light-emitter lens part covers the light emitting element. The light-receiver lens part covers the light receiving element. The light-receiver lens part and the light-emitter lens part have mutually different shapes. When the sensor circuit assembly includes a light-emitter lens part and a light-receiver lens part, the shape of the light-emitter lens part and the shape of the light-receiver lens part may be a shape that is appropriate for the light emitting element and the light receiving element respectively.

The photosensor may further include a cable, a holder, and a main case. The cable includes a first wire. The holder supports the sensor circuit assembly and the cable. The main case includes an internal space that houses the sensor circuit assembly and the holder. With the press-contact direction being downward, and the opposite being upward, the holder includes a borehole that passes vertically through the holder. The cable is arranged to pass through the borehole. The holder includes a first wire housing, and a first terminal housing. The first wire housing houses the first wire. The first terminal housing houses the first connection terminal. The first wire housing extends in a direction intersecting with the vertical direction and opens upward. The first terminal housing is arranged intersecting with the first wire housing, and opens upward. The sensor circuit assembly is mounted onto the holder from above. A tip end of the first connection terminal is arranged facing downward. The first press-contact part of the first connection terminal pierces the first wire from above in the first wire housing and is thereby pressed into contact with the first wire. The internal space of the main case is opens downward. The main case is mounted onto the holder from above.

When assembling the photosensor, in this instance, the cable is inserted vertically into the borehole. Additionally, the sensor circuit assembly is mounted onto the holder from above, and thereby the first connection terminal is inserted into the first terminal housing. Hereby the first connection terminal is pressed into contact with the first wire inside the first wire housing. The main case is then mounted onto the holder from above, and thereby the sensor circuit assembly and the holder are housed in the internal space of the main case. Thus, the sensor circuit assembly and the main case may be assembled onto the holder in this manner in order from the top. This facilitates the assembling of the photosensor.

The photosensor may further include a holder and a main case. The holder supports the sensor circuit assembly. The main case houses the sensor circuit assembly and the holder. A light-emitter case, a light-receiver case, and a detection groove are included in the main case. The light-emitter case houses the light emitting element. The light-receiver case houses the light receiving element. The detection groove is located between the light-emitter case and the light-receiver case. The main case includes a mark. The mark indicates the detection depth required for an object to be detected in the detection groove. When there is a mark indicating the required detection depth, an operator may use the mark to easily determine the detection depth. Moreover, the detection depth signifies that stable detection will take place when an object to be detected is inserted at that depth or deeper than that depth.

The photosensor may further include a cable, a holder, and a main case. The cable includes a first wire and a second wire. The holder supports the sensor circuit assembly and the cable. The main case includes an internal space that houses the sensor circuit assembly and the holder. With the press-contact direction being downward, and the opposite being upward, the holder includes a borehole that passes vertically through the holder. The cable is arranged to pass through the borehole. The holder includes a first wire housing, a second wire housing, a first terminal housing, and a second terminal housing. The first wire housing houses the first wire. The second wire housing houses the second wire. The first terminal housing houses the first connection terminal. The second terminal housing houses the second connection terminal. The first wire housing and the second wire housing extend in a direction intersecting the vertical direction and open upward. The first terminal housing is arranged intersecting with the first wire housing, and opens upward. The second terminal housing is arranged intersecting with the second wire housing, and opens upward. A tip end of the first connection terminal and the tip end of the second connection terminal are arranged facing downward. The first connection terminal is pressed into contact with the first wire within the first wire housing. The second connection terminal is pressed into contact with the second wire within the second wire housing.

In this case the sensor circuit assembly is mounted onto the holder from above, and thereby the first connection terminal is inserted into the first terminal housing, and the second connection terminal is inserted into the second terminal housing. Hereby the first connection terminal is pressed into contact with the first wire inside the first wire housing, and the second connection terminal is pressed into contact with the second wire inside the second wire housing. When the sensor circuit assembly is mounted onto the holder in this manner, the first connection terminal is pressed into contact at the same time the second connection terminal is pressed into contact. This facilitates the assembling of the photosensor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of photosensors are described below with reference to the drawings.FIG. 1is a perspective view of photosensor1.FIG. 2is an exploded perspective view of photosensor1. As illustrated inFIG. 2, photosensor1includes sensor circuit assembly2, holder3, sub case4, main case5, and cable6.

FIG. 3is a perspective view of sensor circuit assembly2.FIG. 4is a front view of sensor circuit assembly2.FIG. 5is a side view of sensor circuit assembly2.

As illustrated inFIG. 3toFIG. 5sensor circuit assembly2includes light emitter part21, light receiver part22, and connecting part20. Light emitter part21, light receiver part22, and connecting part20are all integrated.

In the present embodiment, a press-contact direction (later described) is referred to as “downward”. The direction opposite the press-contact direction is referred to as “upward”. The direction intersecting the press-contact direction, which is the direction along which light emitter part21and light receiver part22are lined up, is referred to as the “left and right direction”. The direction in which light emitter part21and light receiver part22are lined up, and which intersects with the press-contact direction is referred to as “front and rear direction”.

As illustrated inFIG. 4, light emitter part21includes light emitting element211, light-emitter lens part212, and light-emitter support210. Light emitting element211may be, for example, a light emitting diode. However, a different element besides a light emitting diode may be used as light emitting element211. Light emitting element211is mounted on lead frame24(later described). Light-emitter lens part212covers light emitting element211. Light-emitter lens part212is circular when viewed from the light emission direction. Light-emitter lens part212may be formed from a translucent material. Light-emitter lens part212may be made from resin, for example. Light-emitter support210supports light emitting element211. Light-emitter support210extends upward from connecting part20. Light-emitter support210includes light-emitter leads242.

Light receiver part22is arranged separate from light emitter part21in the left and right direction. Light receiver part22includes light receiving element221, light-receiver lens part222, and light-receiver support220. Light receiving element221may be, for example, a phototransistor. However, a different element besides a phototransistor may be used as light receiving element221. Light receiving element221is mounted on lead frame24. Light receiving element221, and light emitting element211are arranged facing each other. In other words, photosensor1according to the present embodiment is a so-called transmissive photosensor. Light-receiver support220supports light receiving element221. Light-receiver support220extends upward from connecting part20. Light-receiver support220includes light-receiver leads243.

Light-receiver lens part222covers light receiving element221. Light-receiver lens part222is circular when viewed from the light receiving direction. Light-receiver lens part222and light-emitter lens part212are arranged facing each other. The shape of light-receiver lens part222differs from the shape of light-emitter lens part212. More specifically, the area of light-receiver lens part222differs from the area of light-emitter lens part212. In other words, the diameter of light-receiver lens part222differs from the diameter of light-emitter lens part212. The diameter of light-receiver lens part222is larger than the diameter of light-emitter lens part212. Light-receiver lens part222may be formed from a translucent material. Light-receiver lens part222may be made from resin, for example. Light-receiver lens part222may be made from the same material as light-emitter lens part212.

Connecting part20connects one end of light-emitter support210with one end of light-receiver support220. Connecting part20includes circuit23, seal part25, main leads241, and a plurality of connection terminals26-29.

Circuit23is electrically connected to light emitting element211, and light receiving element221via lead frame24. Circuit23is an electronic circuit that controls light receiving element221and light emitting element211. Circuit23is mounted on lead frame24. For example, circuit23may be mounted to lead frame24via a mounting method such as wire bonding. Circuit23includes, for example, an IC chip. Circuit23controls the emission of light from light emitting element211. Circuit23also determines whether or not light is received at light receiving element221, and controls the output signal on the basis of the determined result. Sensor circuit assembly2includes an operation indicator231. Circuit23controls operation indicator231on the basis of the result of determining whether or not light was received. Operation indicator231is, for example, a light emitting element such as a light emitting diode, and is mounted on lead frame24.

Lead frame24includes the above described main leads241, light-emitter leads242, and light-receiver leads243. Main leads241are flat in directions extending parallel to the left and right direction and the front and rear direction. Main leads241are located between light-emitter leads242and light-receiver leads243in the left and right direction. Above described circuit23is mounted on main leads241. Above described operation indicator231is also mounted on main leads241.

Light-receiver leads243connect light receiving element221and main leads241. Light receiving element221is mounted on light-receiver leads243. Light-receiver leads243mirrors the shape of light-emitter leads242with respect to a plane that is perpendicular to the left and right direction. Light-receiver leads243protrude leftward out from main leads241. Light-receiver leads243are shaped curving upward. Light-receiver leads243include first light-receiver lead246, and second light-receiver lead247. First light-receiver lead246and second light-receiver lead247are arranged separated from each other in the front and rear direction. First light-receiver lead246and second light-receiver lead247have mutually different shapes. First light-emitter lead244and first light-receiver lead246mirror each other with respect to a plane perpendicular to the left and right direction. Second light-emitter lead245and second light-receiver lead247mirror each other with respect to a plane perpendicular to the left and right direction.

Seal part25seals circuit23on lead frame24. Seal part25seals circuit23and one portion of lead frame24. More specifically, seal part25seals circuit23on main leads241. Seal part25also seals operation indicator231on main leads241. Seal part25may be formed from a translucent material. Seal part25may be made from resin, for example. Seal part25has projection251that protrudes upward. Projection251is arranged facing operation indicator231. Seal part25may be made from the same material as light-emitter lens part212and light-receiver lens part222.

The plurality of connection terminals26-29, protruding from seal part25, is arranged horizontally side by side. Seal part25includes first side252and second side253. First side252is the front surface of seal part25. Second side253is located on the opposite side of first side252. In other words, second side253is the rear surface of seal part25. Of first side252and second side253, the plurality of connection terminals26-29is provided on only first side252. That is, no connection terminals are provided on second side253. The tip ends of the plurality of connection terminals26-29are arranged facing downward. As will be later described, the plurality of connection terminals26-29is respectively pressed into contact with a plurality of wires61-64.

The plurality of connection terminals26-29includes first connection terminal26, second connection terminal27, third connection terminal28, and fourth connection terminal29. First connection terminal26and fourth connection terminal29are arranged separated from each other in the left and right direction. Second connection terminal27and third connection terminal28are arranged between first connection terminal26and fourth connection terminal29. First connection terminal26and fourth connection terminal29are power supply terminals for supplying circuit23with power. Second connection terminal27and third connection terminal28are output terminals for outputting the output signal from circuit23.

First connection terminal26includes first press-contact part261and first joining part262. First joining part262joins first press-contact part261and seal part25. First joining part262is integrally connected with lead frame24. The width of first joining part262is smaller than the width of first press-contact part261. First connection terminal26is shaped bending downward from first joining part262.

As illustrated inFIG. 3andFIG. 4, first connection terminal26includes first pressure part260. First pressure part260is a portion for pressing first press-contact part261in the press-contact direction. That is, first pressure part260is for pressing first press-contact part261downward. First pressure part260is one portion of the edge face (the face formed from the thickness of a sheet like member) of the first connection terminal as a sheet thickness of first connection terminal26. First pressure part260is arranged outside a region on which seal part25projects in the press-contact direction. In other words, first pressure part260does not overlap seal part25when viewed from the press-contact direction. First pressure part260includes first tiered-part263and second tiered-part264. First tiered-part263and second tiered-part264are arranged contiguously with first joining part262. First joining part262is connected with first press-contact part261between first tiered-part263and second tiered-part264. First tiered-part263and second tiered-part264are flat shapes that extend in the left and right direction.

FIG. 6is an enlarged view of first press-contact part261. First press-contact part261tapers downward. More specifically, first press-contact part261includes first-side end part265and second-side end part266. First-side end part265is the right-side end of first press-contact part261. Second-side end part266is located on the opposite side of first-side end part265. In other words, second-side end part266is the left-side end of first press-contact part261. The distance between first-side end part265and second-side end part266decreases toward the lower portion of first-side end part265and second-side end part266.

The tip end of first connection terminal26includes slit267. That is, first press-contact part261includes slit267. Slit267extends from the tip end toward the upper portion of first connection terminal26. Slit267includes linear part268and expanded part269. Expanded part269is located below linear part268. Expanded part269is provided at the entrance to slit267. The width of slit267widens toward the lower portion of expanded part269. Linear part268has a linear shape and extends upward from expanded part269.

Second connection terminal27, third connection terminal28, and fourth connection terminal29are all structured in the same manner as first connection terminal26. More specifically, second connection terminal27includes second press-contact part271and second joining part272. Third connection terminal28includes third press-contact part281and third joining part282. Fourth connection terminal29includes fourth press-contact part291and fourth joining part292. Second press-contact part271, third press-contact part281, and fourth press-contact part291are all structured in the same manner as first press-contact part261, therefore a description thereof will be omitted. Second joining part272, third joining part282, and fourth joining part292are all structured in the same manner as first joining part262, therefore a description thereof will be omitted. Additionally, as illustrated inFIG. 3, second connection terminal27includes second pressure part270. Third connection terminal28includes third pressure part280. Fourth connection terminal29includes fourth pressure part290. Second pressure part270, third pressure part280, and fourth pressure part290are all structured in the same manner as first pressure part260, therefore a description thereof will be omitted.

FIG. 7is a perspective view of holder3.FIG. 8is a perspective view illustrating holder3, sensor circuit assembly2, and cable6. As illustrated inFIG. 8, cable6includes a plurality of wires61-64. More specifically, cable6includes first wire61, second wire62, third wire63, and fourth wire64. Holder3supports sensor circuit assembly2and the plurality of wires61-64.

Holder3includes first wall31. As illustrated inFIG. 7first wall31includes a plurality of wire housings311-314. The plurality of wire housings311-314respectively houses the plurality of wires61-64. The plurality of wire housings311-314passes through first wall31in the front and rear direction. The plurality of wire housings311-314opens upward.

As illustrated inFIG. 2, cable6includes outer coating60. Outer coating60covers the plurality of wires61-64. Outer coating60is removed from the end part of cable6, exposing the plurality of wires61-64. The plurality of wire housings311-314supports the plurality of wires61-64exposed from outer coating60.

As illustrated inFIG. 7, first wall31includes first wire housing311, second wire housing312, third wire housing313, and fourth wire housing314. First to fourth wire housings311-314are mutually partitioned and arranged in the left and right direction side by side. First wire housing311houses first wire61. Second wire housing312houses second wire62. Third wire housing313houses third wire63. Fourth wire housing314houses fourth wire64.

FIG. 9is a top view of holder3. As illustrated inFIG. 9, first wire housing311extends longitudinally. First wire housing311reaches front end surface315of first wall31.FIG. 10is a front view of holder3. As illustrated inFIG. 7andFIG. 10, first wire housing311opens upward.

As illustrated inFIG. 7andFIG. 9, first wall31includes a plurality of terminal housings316-319. The plurality of terminal housings316-319respectively houses the plurality of connection terminals26-29. More specifically, first wall31includes first terminal housing316, second terminal housing317, third terminal housing318, and fourth terminal housing319. First to fourth terminal housings316-319are mutually partitioned and arranged horizontally side by side. First terminal housing316is arranged intersecting with first wire housing311. First terminal housing316houses first connection terminal26. Second terminal housing317is arranged intersecting with second wire housing312. Second terminal housing317houses second connection terminal27. Third terminal housing318is arranged intersecting with third wire housing313. Third terminal housing318houses third connection terminal28. Fourth terminal housing319is arranged intersecting with fourth wire housing314. Fourth terminal housing319houses fourth connection terminal29.

First wire housing311includes first wire holder311aand first wire guide part311b. First wire holder311ais located in front of first terminal housing316. First wire guide part311bis located behind first terminal housing316.

FIG. 11is an enlarged view of first wire holder311a. Additionally,FIG. 11shows a cross-section of first wire holder311aand wire61. As illustrated inFIG. 11, diameter d1of first wire holder311ais the same as, or smaller than diameter d2of wire61. Wire61is thereby supported inside first wire holder311aand does not move.

Further, as illustrated inFIG. 11, first wire housing311includes first slot311c. first slot311cis located in first wire holder311afor inserting wire61. Width w1of first slot311cis smaller than diameter d2of wire61. Additionally, width w1of first slot311cis smaller than diameter d1of first wire holder311a.

First wire housing311includes expanded slot311d. Expanded slot311dis located above first slot311c. The width of expanded slot311dincreases toward the upper portion thereof. Width w2of the upper end part of expanded slot311dis larger than diameter d2of wire61. This facilitates insertion of wire61into first slot311c. second to fourth wire housings312-314are configured in the same manner as first wire housing311, therefore the description thereof will be omitted.

FIG. 12is a side view of holder3.FIG. 13is a cross-sectional view along XIII-XIII inFIG. 12. As illustrated inFIG. 7andFIG. 13, first terminal housing316opens upward. As illustrated inFIG. 13, first terminal housing316includes a pair of first wall surfaces316a,316b. The pair of first wall surfaces316a,316bare arranged horizontally side by side. First connection terminal26is arranged between the pair of first wall surfaces316a,316b. Second terminal housing317includes a pair of second wall surfaces317a,317b. The pair of second wall surfaces317a,317bare arranged horizontally side by side. Second connection terminal27is arranged between the pair of second wall surfaces317a,317b. Third terminal housing318includes a pair of third wall surfaces318a,318b. The pair of third wall surfaces318a,318bare arranged horizontally side by side. Third connection terminal28is arranged between the pair of third wall surfaces318a,318b. Fourth terminal housing319includes a pair of fourth wall surfaces319a,319b. The pair of fourth wall surfaces319a,319bare arranged horizontally side by side. Fourth connection terminal29is arranged between the pair of fourth wall surfaces319a,319b.

As illustrated inFIG. 13, first wall31includes a plurality of protrusions316c,317c,318c, and319c. protrusions316c,317c,318c,319care provided at the respective bottoms of the plurality of terminal housings316-319. The bottom of each of terminal housings316-319faces the tip end of each of connection terminals26-29when terminal housings316-319house connection terminals26-29. More specifically, first wall31includes first protrusion316c, second protrusion317c, third protrusion318c, and fourth protrusion319c. First protrusion316cprotrudes from the bottom of first terminal housing316toward slit267(refer toFIG. 4) in first connection terminal26. Second protrusion317cprotrudes from the bottom of second terminal housing317toward slit277(refer toFIG. 4) in second connection terminal27. Third protrusion318cprotrudes from the bottom of third terminal housing318toward slit287(refer toFIG. 4) in third connection terminal28. fourth protrusion319cprotrudes from the bottom of fourth terminal housing319toward slit297(refer toFIG. 4) in fourth connection terminal29.

FIG. 14is an enlarged view of first connection terminal26and first terminal housing316.FIG. 14illustrates first connection terminal26and first terminal housing316when first to fourth connection terminals26-29are arranged in a press-contact position with wires61-64. As illustrated inFIG. 6, first connection terminal26, oriented downward, pierces wire61and is thereby pressed into contact with wire61. First connection terminal26pierces wire61such that first connection terminal26passes through inner coating611of wire61and comes in contact with core612. Hereby, as illustrated inFIG. 14, core612is sandwiched in first connection terminal26inside slit267, and first connection terminal26is thus connected to wire61.

As illustrated inFIG. 6, width w3of slit267in first connection terminal26is larger than diameter d3of core612. Additionally, width w3of slit267in first connection terminal26is smaller than width w7of a bundle of a plurality of cores612that are not in press contact. Accordingly, during press contact, as illustrated inFIG. 14, the deformation of a bundle of cores612thereby allows the bundle of cores612to be inserted into slit267in first connection terminal26. Finally, inFIG. 6andFIG. 14only one portion of the plurality of cores612is given the reference sign612.

When first to fourth connection terminals26-29are arranged in the press-contact position with wires61-64, a gap is created between first protrusion316cand first connection terminal26without first protrusion316ccoming into contact with first connection terminal26. Hereby, it is possible for inner coating611of wire61to pass through the gap and escape from slit267when first connection terminal26is pressed into contact with wire61. Distance w4between first protrusion316cand first connection terminal26is smaller than diameter d3of core612in wire61. Furthermore, first tiered-part263and second tiered-part264of first connection terminal26protrude upward from first terminal housing316when first to fourth connection terminals26-29are arranged in press-contact position with wires61-64.

As illustrated inFIG. 7andFIG. 9, holder3includes second wall32and third wall33. Second wall32and third wall33are arranged separated from each other in the left and right direction. second wall32connects to the right end part of first wall31. Third wall33connects to the left end part of first wall31. The upper surfaces of first wall31, second wall32, and third wall33are all positioned at the same height. The upper surfaces of first wall31, second wall32, and third wall33are in contact with the bottom surface of sensor circuit assembly2, and support sensor circuit assembly2.

As illustrated inFIG. 7andFIG. 8, holder3includes first catch37and second catch38, which lock onto sensor circuit assembly2. First catch37and second catch38are arranged separated from each other in the left and right direction. First catch37and second catch38extend to a position above the above described first wall31, second wall32, and third wall33. The tip end parts of first catch37and second catch38are shaped to protrude toward each other. More specifically, the tip end part of first catch37protrudes leftward. The tip end part of second catch38protrudes rightward. Furthermore, the tip end part of first catch37and the tip end part of second catch38will be caught on the upper surface of seal part25when sensor circuit assembly2is placed between first catch37and second catch38. Sensor circuit assembly2may thus be secured to holder3.

As illustrated inFIG. 10, the tip end part of first catch37includes first inclined surface371. The tip end part of second catch38includes second inclined surface381. First inclined surface371and second inclined surface381are inclined so that the mutual distance therebetween widens toward the respective upper portions. Accordingly, pushing sensor circuit assembly2downward toward first catch37and second catch38thus widens the gap between first catch37and second catch38, and thereby facilitates arranging sensor circuit assembly2between first catch37and second catch38. Furthermore, first catch37and second catch38arrive at the locked position with sensor circuit assembly2when the above described first to fourth connection terminals26-29are arranged in the press-contact position with wires61-64. Finally, as illustrated inFIG. 8, the bottom of sensor circuit assembly2is supported by the upper surfaces of first wall31, second wall32, and third wall33when first to fourth connection terminals26-29are arranged in the press-contact position with wires61-64.

As illustrated inFIG. 7andFIG. 9, holder3includes recess34. The recess34is located between second wall32and third wall33in the left and right direction. The recess34is located behind first wall31.

As illustrated inFIG. 9andFIG. 13, holder3includes borehole35. Borehole35passes vertically through holder3. Borehole35is provided in the recess34. As illustrated inFIG. 13, borehole35includes first bore section351, second bore section352, and third bore section353. First bore section351, second bore section352, and third bore section353are arranged side by side along the axial direction of borehole35. In other words, first bore section351, second bore section352, and third bore section353are arranged vertically side by side.

First bore section351is linear and extends vertically. The inner diameter of first bore section351is larger than the outer diameter of cable6. Second bore section352includes the upper end section of borehole35. In other words, second bore section352connects to the bottom of the recess34. The inner diameter of second bore section352is larger than the inner diameter of first bore section351. More specifically, the inner diameter of second bore section352is larger toward the upper portion thereof. Third bore section353is located between first bore section351and second bore section352. The inner diameter of third bore section353is larger toward the upper portion thereof. The inner diameter of third bore section353is larger than the inner diameter of first bore section351and smaller than the inner diameter of second bore section352.

FIG. 15is a cross-sectional view along XV-XV inFIG. 9.FIG. 16is a bottom view of holder3.FIG. 15schematically illustrates cable6inserted into borehole35. As illustrated inFIG. 15andFIG. 16, holder3includes positioning section36. The positioning section36is arranged to overlap with one portion of borehole35at the upper portion of borehole35. The positioning section36is the bottom surface of first wall31.

As illustrated inFIG. 9andFIG. 13, the inner surface of borehole35includes a plurality of protrusions354-357. The plurality of protrusions354-357protrudes from the inner surface of borehole35toward the central axis of borehole35. The plurality of protrusions354-357is arranged at equal intervals in the inner circumferential direction of borehole35. The diameter of a circle passing through the tip ends of the plurality of protrusions354-357is smaller than the outer diameter of cable6. Additionally, the protrusions354-357taper toward the central axis of borehole35. Therefore, as illustrated inFIG. 15, when cable6is inserted into borehole35, the tip ends of the protrusions354-357eat into the outer surface of cable6. This prevents cable6from slipping out. More specifically, the inner surface of borehole35includes first protrusion354, second protrusion355, third protrusion355, and fourth protrusion357. As illustrated inFIG. 15, first protrusion354includes inclined surface354aand catch surface354b. The inclined surface354ais inclined in relation to the axial direction of borehole35. The inclined surface354ais inclined so that the upper portion of the inclined surface approaches the central axis of borehole35. The catch surface354bprotrudes from the inner surface of borehole35toward the central axis of borehole35, and catches the outer surface of cable6. Second to fourth protrusions355-357are configured in the same manner as first protrusion354; therefore the description thereof will be omitted. The above-mentioned kind of shape of the plurality of protrusions354-357facilitates the insertion of cable6upward into borehole35while restricting the downward movement of cable6in borehole35.

As above described, the inner diameter of borehole35is larger than the outer diameter of cable6. Additionally the plurality of protrusions354-357supports cable6, resulting in a gap between cable6and borehole35. An adhesive may be poured into this gap, and cable6may be bonded to the inner surface of borehole35with the adhesive.

FIG. 17is a perspective view of main case5. Main case5includes an internal space for housing sensor circuit assembly2and holder3. The bottom surface of main case5is provided with opening51. Thus the internal space in main case5opens downward. Sensor circuit assembly2and holder3pass through the opening51to be arranged in the internal space of main case5.

As illustrated inFIG. 17, main case5includes first mounting hole521and second mounting hole522for mounting main case5to various kinds of machinery. First mounting hole521and second mounting hole522pass longitudinally through main case5. Front surface52of main case5includes first fastening hole523and second fastening hole524. As illustrated inFIG. 7, the front surface of holder3includes first fastening protrusion391and second fastening protrusion392. First fastening protrusion391locks together with first fastening hole523. Second fastening protrusion392locks together with second fastening hole524. Hereby main case5may be secured to holder3. Moreover, as illustrated inFIG. 9, the rear surface of holder3includes third fastening protrusion393and fourth fastening protrusion394. Although not illustrated, the rear surface of main case5includes third fastening hole and fourth fastening hole. Third fastening protrusion393on holder3locks together with the third fastening hole. Fourth fastening protrusion394on holder3locks together with the fourth fastening hole.

As illustrated inFIG. 7andFIG. 9, holder3includes first end surface321and second end surface322. First end surface321and second end surface322are one portion of the front surface of holder3. The above described first fastening protrusion391protrudes frontward from first end surface321. Second fastening protrusion392protrudes frontward from second end surface322. Front end surface315of first wall31is located between first end surface321and second end surface322in the left and right direction. Front end surface315of first wall31is recessed further behind first end surface321and second end surface322.

Light-emitter case53includes light-emitter slit531. Light-emitter slit531extends vertically. Light-emitter slit531extends from at least location facing light emitting element211up to the bottom of detection groove55. More specifically, light-emitter slit531extends from location facing light-emitter lens part212up to the bottom of detection groove55. Light-receiver case54includes light-receiver slit541. Light-receiver slit541is arranged facing light-emitter slit531. Light-receiver slit541extends vertically. Light-receiver slit541extends from at least location facing light receiving element221up to the bottom of detection groove55. Light-receiver slit541extends from location facing light-receiver lens part222up to the bottom of detection groove55.

Main case5includes element position marks532,542and detection depth marks533,543. Element position marks532,542are arranged at positions corresponding to light receiving element221and light emitting element211. More specifically, element position marks532,542are arranged at positions corresponding to the center position of light-emitter lens part212and the center position of light-receiver lens part222. Detection depth marks533,543indicate the detection depth required for detecting an object to be detected in detection groove55. That is, light receiving element221, and light emitting element211will stably detect an object when the object arrives at a location in detection groove55exceeding the detection depth.

Element position marks532,542, and detection depth marks533,543are symbols that are added to main case5. Element position marks532,542may be respectively added to the front surfaces of light-emitter case53and light-receiver case54. Detection depth marks533,543may be respectively added to the front surfaces of light-emitter case53and light-receiver case54. In the present embodiment, element position marks532,542are triangular symbols. Detection depth marks533,543are bar symbols. Recesses and projections in main case5form element position marks532,542, and detection depth marks533,543. More specifically, element position marks532,542are hollowed out of the surface of main case5. Additionally, detection depth marks533,543are hollowed out of the surface of main case5. Although not illustrated, element position marks532,542may also be respectively placed on the rear surface of light-emitter case53and the rear surface of light-receiver case54. Additionally detection depth marks533,543may be respectively placed on the rear surfaces of light-emitter case53and light-receiver case54.

Main case5includes at least one indicator window525,551. More specifically, main case5includes first indicator window525, second indicator window551, and third indicator window (not shown). First indicator window525is provided on the front surface52of main case5. Second indicator window551is provided on the bottom of detection groove55. The third indicator window is provided on the rear surface of main case5. First indicator window525, second indicator window551, and the third indicator window are arranged to face projection251in sensor circuit assembly2.

FIG. 18is a perspective view of sub case4. Sub case4is arranged between main case5and sensor circuit assembly2. Sub case4prevents the transmission of disturbance light, while allowing efficient transmission of infrared light. Sub case4may be made from resin, for example.

Sub case4includes light-emitter cover41, light-receiver cover42, and connecting case43. Connecting case43connects light-emitter cover41and light-receiver cover42. Light-emitter cover41includes first housing space411into which light emitting element211is disposed. Light-emitter cover41covers light emitting element211from the light emission direction of light emitting element211. Opposite the light emission direction, first housing space411is open across the entire light-emitter cover41in the vertical direction. That is, the right portion of first housing space411is entirely open in the vertical direction. First housing space411passes vertically through light-emitter cover41.

Light-receiver cover42includes second housing space421into which light receiving element221is disposed. Light-receiver cover42covers light receiving element221from the light receiving direction of light receiving element221. Opposite the light receiving direction, second housing space421is open across the entire light-receiver cover42in the vertical direction. That is, the left portion of second housing space421is entirely open in the vertical direction. Second housing space421passes vertically through light-receiver cover42.

An inner surface412near first housing space411of light-emitter cover41tapers toward the light emission direction. In other words, the inner surface412of light-emitter cover41tapers towards light receiving element221. Therefore, when sub case4is mounted to sensor circuit assembly2, light-emitter lens part212comes into contact with the inner surface412of light-emitter cover41to thereby position light-emitter cover41. Inner surface422near second housing space421of light-receiver cover42tapers toward the light receiving direction. In other words, the inner surface422of light-receiver cover42tapers toward light emitting element211. Therefore, when sub case4is mounted to sensor circuit assembly2, light-receiver lens part222comes into contact with the inner surface422of light-receiver cover42to thereby position light-receiver cover42.

A protrusion413is provided on the inner surface412of light-emitter cover41. The upper end part of the protrusion413comes into contact with the bottom surface of light-emitter lens part212when light-emitter lens part212is arranged in first housing space411. Protrusion423is provided on the inner surface422of light-receiver cover42. The upper end part of the protrusion423comes into contact with the bottom surface of light-receiver lens part222when light-receiver lens part222is arranged in second housing space421. Hereby, sensor circuit assembly2is prevented from slipping downward in relation to sub case4.

Sub case4includes first indicator opening431and second indicator opening432. First indicator opening431and second indicator opening432are provided in connecting case43. First indicator opening431is arranged facing projection251on sensor circuit assembly2. Projection251is arranged inside first indicator opening431when sub case4is mounted on sensor circuit assembly2. Second indicator opening432mirrors the shape of first indicator opening431about a symmetry axis extending in the vertical direction. Additionally, sub case4is symmetrical about the symmetry axis extending in the vertical direction. Accordingly, it is possible to mount sub case4on sensor circuit assembly2in the reverse of the above described orientation. That is, along with mounting light-emitter cover41on light-receiver lens part222, light-receiver cover42may be mounted on light-emitter lens part212. If mounted in this manner, projection251on sensor circuit assembly2will be arranged inside second indicator opening432.

Next, the process of manufacturing photosensor1will be described.FIGS. 19A and 19Billustrate a process for manufacturing sensor circuit assembly2. In the process illustrated inFIG. 19Aa sheet like frame is punched via stamping to thereby form lead frame240of a prescribed shape. Further, IC chip230of circuit23, operation indicator231, light emitting element211, and light receiving element221are mounted to lead frame240.

Next, in the process illustrated inFIG. 19B, seal part25, light-emitter lens part212, and light-receiver lens part222are cast on lead frame240. Seal part25, light-emitter lens part212, and light-receiver lens part222are all formed from the same of casting material; therefore seal part25, light-emitter lens part212, and light-receiver lens part222may all be cast at one time from a shared die.

Next, in the process illustrated inFIG. 19C, the unneeded portions of lead frame240are removed to form the above described lead frame24for sensor circuit assembly2. Thereafter, light-receiver leads243, and light-emitter leads242are bent upward. Further, the first to fourth connection terminals26-29are bent downward.

FIG. 20toFIG. 22illustrate the assembling of photosensor1. First, in the process illustrated inFIG. 20, cable6is installed in holder3. To install the cable, a plurality of wires61-64are exposed by preliminarily cutting outer coating60at the tip end part of cable6. Next, exposed wires61-64and outer coating60of cable6are moved upward toward holder3and inserted into borehole35in holder3. Thereafter, wires61-64are pulled toward the front and inserted into the first to fourth wire housings311-314.

Next, in the process illustrated inFIG. 21, sensor circuit assembly2is mounted on holder3. To mount the assembly, sensor circuit assembly2is moved downward toward holder3. First to fourth connection terminals26-29are thereby each inserted into first to fourth terminal housings316-319. At this point, first to fourth connection terminals26-29pierce wires61-64inside first to fourth wire housings311-314, and press into contact with wires61-64. When sensor circuit assembly2is pressed downward towards holder3until sensor circuit assembly2is caught on first catch37and second catch38of holder3, first to fourth connection terminals26-29arrive at the press-contact position to complete press-contact between first to fourth connection terminals26-29and wires61-64. Finally, any excess wires protruding from front end surface315of first wall31are cut.

Next, in the process illustrated inFIG. 22, sub case4is mounted on sensor circuit assembly2. Sub case4is moved downward toward sensor circuit assembly2to cover sensor circuit assembly2with sub case4. Hereby, light-emitter lens part212is arranged inside first housing space411. Further, light-receiver lens part222is arranged inside second housing space421.

Main case5is then mounted on holder3. Main case5is moved downward toward sensor circuit assembly2and holder3to cover sensor circuit assembly2, holder3, and sub case4with main case5. Hereby, sensor circuit assembly2, holder3, and sub case4are arranged in the internal space in main case5. Furthermore, light-emitter window44of sub case4is inserted into light-emitter slit531, and light-receiver window45is inserted in light-receiver slit541.

The effects of photosensor1according to the present embodiment are as follows. Light emitting element211, light receiving element221, and seal part25are integrated with photosensor1. Therefore, it is possible to install sensor circuit assembly2, which includes light emitting element211, light receiving element221, and seal part25, in a unified manner in holder3. Further, first to fourth connection terminals26-29are pressed into contact with each of wires61-64and soldering is therefore unnecessary. Thus, the number of manufacturing man-hours decreases.

Further, soldering is no longer necessary, therefore even if there is small distance between seal part25and first to fourth connection terminals26-29, it is possible to prevent the effects of heat on circuit23and seal part25. Thus, the reliability of the device improves. Moreover, given that the tips of first to fourth connection terminals26-29are arranged oriented downward, moving sensor circuit assembly2downward facilitates pressing first to fourth connection terminals26-29into contact with wires61-64. In this manner, photosensor1according to the present embodiment has increased reliability and a reduced number of manufacturing man-hours.

In particular, if the plurality of connection terminals is arranged side by side as in the present embodiment, for a small-sized photosensor the distance between the connection terminals may be extremely small. In this case, it would not be prudent to solder a wire to each of the connection terminals as that would lead to a short circuit between adjacent connection terminals. However, in photosensor1according to the present embodiment, the plurality of connection terminals26-29is connected to wires61-64by being pressed into contact therewith, thereby addressing the above-mentioned types of problems.

Moreover, first connection terminal26includes first pressure part260, and therefore first connection terminal26may be pressed into contact by pressing down first pressure part260. Accordingly, it is possible to reduce load on seal part25compared to case where seal part25needs to be pressed to make the press contact. Thus, the reliability of the device improves.

Each of connection terminals26-29protrudes longitudinally from seal part25and curves downward. Therefore, pressure parts260,270,280,290of connection terminals26-29are arranged outside the region on which seal part25projects in the press-contact direction. Accordingly, when pressure parts260,270,280,290of each of connection terminals26-29are pushed from above, seal part25will not obstruct the pressure parts. This facilitates press contact. Additionally pressure parts260,270,280,290are one portion of the edge face of connection terminals26-29as a sheet thickness of connection terminals26-29. This thus facilitates the forming of pressure parts260,270,280, and290. Moreover, pressure parts260,270,280,290are provided on each of connection terminals26-29. Therefore, each of connection terminals26-29may be uniformly pressed, compared to providing the pressure part on only one portion of connection terminals26-29. Each of connection terminals26-29may thereby be accurately pressed into contact.

Pressing into contact may be achieved by pushing first to fourth connection terminals26-29onto wires61-64, so that first to fourth connection terminals26-29cut through the inner coating of wires61-64to come into contact with the cores. Therefore, the terminals may be easily pressed into contact without first cutting the inner coating of wires61-64in advance. Thus, the number of manufacturing steps decreases.

Wire housings311-314are mutually partitioned. Therefore, wires61-64may be prevented from coming into contact with each other.

The plurality of wire housings311-314extends longitudinally. Accordingly, when manufacturing photosensor1, wires61-64may be arranged along the front and rear direction in wire housings311-314. Further, moving connection terminals26-29downward and pushing the terminals onto wires61-64thereby facilitates pressing terminals26-29into contact.

Cable6is arranged to pass through borehole35. Borehole35passes vertically through holder3. Accordingly, direction cable6is inserted through borehole35, and direction wires61-64are arranged in wire housings311-314are orthogonal. Therefore, wires61-64will be prevented from pushing up sensor circuit assembly2when cable6is inserted, compared to having the same direction for inserting cable6into borehole35, and for arranging wires61-64.

The width of first slot311cin first wire housing311is smaller than diameter d2of wire61. Therefore, it is possible to improve the retention force of first wire housing311on wire61. In other words, wire61will tend not to slip out from first wire housing311. Further, it is possible to have some sense of inserting wire61when wire61passes through first slot311cand is inserted into first wire housing311. Hereby, when manufacturing photosensor1, a worker can easily determine whether installation of wire61into first wire housing311is complete. The second to fourth wire housings312-314provide the same effects as first wire housing311.

First to fourth terminal housings316-319are mutually partitioned. Therefore, the adjacent connection terminals may be prevented from coming into contact with each other.

First terminal housing316is arranged intersecting with first wire housing311. With this arrangement, inserting first connection terminal26into first terminal housing316facilitates first connection terminal26in piercing wire61, which is arranged inside first wire housing311. The second to fourth connection terminals provide the same effects as first connection terminal26.

First connection terminal26is arranged between the pair of first wall surfaces316a,316b. Therefore, the amount of deformation of first connection terminal26while first connection terminal26is being pressed into contact is restricted by the pair of first wall surfaces316a,316b. Hereby, it is possible to secure a stronger press contact between first connection terminal26and the wire. Second to fourth connection terminals27-29provide the same effects as first connection terminal26.

First protrusion316cprotrudes toward slit267in first connection terminal26, within first connection terminal housing316. Therefore, during press contact, first protrusion316cpushes core612of wire61into slit267of first connection terminal26. Therefore during press contact, this prevents core612from escaping from slit267in first connection terminal26. Hereby, an accurate connection between first connection terminal26and core612may be established. Second to fourth connection terminals27-29provide the same effects as first connection terminal26.

First catch37and second catch38arrive at the locked position with sensor circuit assembly2while the above described first to fourth connection terminals26-29are being arranged in the press-contact position with wires61-64. As a result, the locking of first catch37and second catch38onto sensor circuit assembly2, maintains a firm initial press contact between first to fourth connection terminals26-29and wires61-64. Furthermore, during press contact, when first to fourth connection terminals26-29are arranged in the press-contact position with wires61-64, first catch37and second catch38arrive at the locked position with sensor circuit assembly2. Therefore, a worker easily determine that press contact of first to fourth connection terminals26-29is complete when first catch37and second catch38lock onto sensor circuit assembly2.

Light-emitter leads242and light-receiver leads243bend upward. First to fourth connection terminals26-29curve downward. Therefore, when first to fourth connection terminals26-29are pressed downward and pressed into contact with wires61-64, light-emitter leads242and light-receiver leads243will tend not to obstruct the pressing into contact.

First to fourth connection terminals26-29are provided on only first side252of first side252and second side253. If connection terminals are provided on both first side252and second side253, a force must be evenly applied to the connection terminals on first side252and the connection terminals on second side253, however this is hard to achieve. Additionally, to apply a force to the connection terminals on first side252and the connection terminals on second side253evenly, the most effective means would be to press down on seal part25which is between first side252and second side253, making it likely that seal part25will break. Whereas, in the present embodiment, first to fourth terminals26-29are provided on only first side252, and thereby this facilitates evenly pressing the plurality of connection terminals26-29into contact.

The width of first joining part262of first connection terminal26is smaller than the width of first press-contact part261. Therefore, first connection terminal26may be bent with little force compared to the case where the width of first joining part262and the width of first press-contact part261are the same. In the same manner, second to fourth connection terminals27-29may be bent with little force. Thus, it is possible to reduce the amount of force applied to seal part25of sensor circuit assembly2when bending first to fourth connection terminals26-29. This prevents seal part25from breaking during the bending process. Additionally, first to fourth connection terminals26-29may be bent with a small amount of force, and therefore it is possible to improve the precision of the bending angle for first to fourth connection terminals26-29.

First pressure part260protrudes outside of first terminal housing316. This therefore facilitates pressing first pressure part260when pressing first connection terminal26into contact. This further facilitates pressing first connection terminal26into contact with wire61. Second to fourth connection terminals27-29provide the same effects as first connection terminal26.

Width w3of slit267in first connection terminal26is smaller than width w7of a bundle of a plurality of cores612that are not in press contact. In this case, the bundle of cores612are sandwiched by slit267in first connection terminal26to firmly connect cores612and first connection terminal26. Second to fourth connection terminals27-29provide the same effects as first connection terminal26.

The inner surface of borehole35in holder3includes first to fourth protrusions354-357. Accordingly, first to fourth protrusions354-357establish a uniform gap between the inner surface of borehole35and the outer surface of cable6. Therefore, a uniform amount of adhesive may be poured in between borehole35and cable6when bonding cable6to borehole35. This improves the strength of the adhesive bonding of cable6.

The inner diameter of second bore section352is larger than the inner diameter of first bore section351in borehole35in holder3. Additionally the inner diameter of second bore section352is larger towards the end section of borehole35. Therefore, this facilitates pouring an adhesive between borehole35and cable6. This reduces the occurrence of defective bonding.

The positioning section36in holder3is arranged to overlap with one portion of borehole35at the upper portion of borehole35. Therefore, this facilitates positioning of the upper end section of outer coating60of cable6. Additionally, the positioning section36is portion of first wall31. Accordingly, first wall31may also serve as positioning section36.

The area of light-receiver lens part222differs from the area of light-emitter lens part212. Therefore, the area of light-emitter lens part212and the area of light-receiver lens part222may be a size that is appropriate for light emitting element211and light receiving element221respectively. Additionally, light emitting element211and light receiving element221are integrally installed on lead frame24, and therefore light-emitter lens part212and light-receiver lens part222may be cast at the same time when manufacturing sensor circuit assembly2. Therefore, even if the area of light-emitter lens part212and the area of light-receiver lens part222are different, it is possible to cast light-emitter lens part212and light-receiver lens part222with a shared mold without having to use individual molds. Hereby, the number of manufacturing man-hours and the cost decrease.

While cable6is installed in holder3by moving cable6upward towards holder3, sensor circuit assembly2is installed on holder3by moving sensor circuit assembly2downward toward holder3. Additionally, sub case4and main case5are moved downward toward holder3to be mounted on holder3. Accordingly, after installing cable6in holder3, sensor circuit assembly2, sub case4, and main case5may be assembled onto holder3in order in the same direction. This facilitates the assembling of photosensor1.

Main case5includes detection depth marks533,543. Detection depth marks533,543indicate the detection depth for light emitting element211and light receiving element221in detection groove55. Accordingly, an operator may use detection depth marks533,543to easily determine the detection depth. Additionally, detection depth marks533,543made up of recesses, and therefore detection depth marks533,543may also function to prevent photosensor1from slipping.

The claims are not limited to the above-mentioned embodiments, and may be modified in various ways insofar as the modifications do not depart from the spirit and scope of the invention.

The present invention is not limited to a transmissive photosensor, and may be applied to a reflective photosensor.

The shape of the connection terminals is not limited to the shape of the connection terminals in the above-mentioned embodiment. For example, the connection terminals may be pointed similarly to connection terminal71illustrated inFIG. 23. Connection terminal71pierces wire61to connect with wire61. In this case, connection terminal71pierces wire61and comes into contact with core612to thereby electrically connect connection terminal71and wire61. Alternatively, connection terminal may be arranged to pass through the seal part. In this case, pressing the end part of the connection terminal from above the seal part thereby presses the connection terminal into contact with the wire.

The material used for light-emitter lens part212, light-receiver lens part222, and seal part25is not limited to the above described material. For example, light-emitter lens part212, light-receiver lens part222, and seal part25may be formed from a material other than resin. Additionally, light-emitter lens part212, light-receiver lens part222, and seal part25may be made from different materials. However, to integrally cast light-emitter lens part212, light-receiver lens part222, and seal part25, it is preferable for light-emitter lens part212, light-receiver lens part222, and seal part25to be formed of the same material. Seal part25is not limited to sealing only one portion of lead frame24, and may seal the entire lead frame24.

Light-emitter lens part212and light-receiver lens part222are not limited to the shape of a circle. For example, as illustrated inFIG. 24A, light-emitter lens part212and light-receiver lens part222may be the shape of an ellipse. Alternatively, as illustrated inFIG. 24B, one of light-emitter lens part212and light-receiver lens part222may be a circle, while the other is an ellipse. Moreover, inFIG. 24Blight-emitter lens part212is an ellipse and light-receiver lens part222is a circle; however light-emitter lens part212may be a circle, while light-receiver lens part222is an ellipse.

The number of connection terminals is not limited to four. Sensor circuit assembly2may have less than four, or more than four connection terminals. Sensor circuit assembly2may have less than four, or more than four wire housings to match the number of connection terminals. Additionally sensor circuit assembly2may have less than four, or more than four terminal housings to match the number of connection terminals. The number of protrusions on the inner surface of borehole35is not limited to four, and may be no less than three. Furthermore, operation indicator231may be omitted from sensor circuit assembly2.

The arrangement of the plurality of connection terminals is not limited to the above-mentioned arrangements in the embodiment. For example, the plurality of connection terminals may be provided on both first side252and second side253of seal part25. However, if the plurality of connection terminals is provided on both first side252and second side253of seal part25, it will be necessary to provide a uniform force to press down on the connection terminals on first side252, and the connection terminals on second side253during press contact. Accordingly, in an effort to simplify production of the photosensor, the plurality of connection terminals may be preferably provided on only one side of either first side252or second side253of seal part25.

Additionally, in the above-mentioned embodiment the shape of seal part25is a square in a plan view, in other words when viewed from above, however the seal part may have another shape. For example, the seal part may be a triangle in a plan view. Even in this case, providing the connection terminals on only one of a pair of mutually opposite sides thereby allows the connection terminals to be pressed with an even amount of force in the same manner as in the above-mentioned embodiment.

The width of the slit in the connection terminal may be smaller than the diameter of the core. In this case, when the core is deformed and pushed into the slit, the core and the connection terminal are firmly connected.

In the above-mentioned embodiment, the excess wire is cut after first to fourth connection terminals26-29are pressed into contact with wires61-64. However, the excess wire may be cut before first to fourth connection terminals26-29are pressed into contact with wires61-64.

Detection depth marks533,543are not limited to being recessed from the surface of main case5, and may be projections protruding from the surface of main case5. Alternatively, detection depth marks533,543may have some kind of surface roughness that is rougher than the other segments of main case5.

Element position marks532,542are not limited to the above described triangles, but may be another shape. Detection depth marks533,543are not limited to the above described bars, but may be another shape. For example, as illustrated inFIGS. 25A-25H, main case5may be given a pattern or a color different from other segments, where the boundary of the pattern or color represent detection depth marks533,543.

InFIG. 25A, patterns A1, A2constituted by a plurality of straight lines are added to main case5. Each straight-line extends vertically, and is arranged horizontally side by side. The lower boundaries of patterns A1, A2, in other words the lower end sections of each of the straight lines correspond to detection depth marks533,543. InFIG. 25B, patterns B1, B2constituted by a plurality of straight lines are added to main case5. Each straight-line extends vertically, and is arranged horizontally side by side. The upper boundaries of patterns B1, B2, in other words the lower end sections of each of the straight lines correspond to detection depth marks533,543. Additionally, patterns A1, A2, B1, B2may be constituted by recesses and projections. Alternatively, patterns A1, A2, B1, B2may have a rougher surface roughness than the other segments of main case5.

InFIG. 25C, patterns C1, C2constituted by a plurality of straight lines are added to main case5. Each straight-line extends horizontally, and are arranged vertically in a row. The lower boundaries of patterns C1, C2, in other words the straight line at the lowest position corresponds to detection depth marks533,543. InFIG. 25D, patterns D1, D2constituted by a plurality of straight lines are added to main case5. Each straight-line extends horizontally, and are arranged vertically in a row. The upper boundaries of patterns D1, D2, in other words the straight line at the highest position, correspond to detection depth marks533,543. Additionally, patterns C1, C2, D1, D2may be constituted by recesses and projections. Alternatively, patterns C1, C2, D1, D2may have a coarser surface roughness than the other segments of main case5.

InFIG. 25E, meshed patterns E1, E2are added to main case5. The lower boundaries of patterns E1, E2correspond to detection depth marks533,543. InFIG. 25F, meshed patterns F1, F2are added to main case5. The upper boundaries of patterns F1, F2correspond to detection depth marks533,543. Additionally, patterns E1, E2, F1, F2may be constituted by recesses and projections. Alternatively, patterns E1, E2, F1, F2may have a coarser surface roughness than the other segments of main case5.

InFIG. 25G, one portion of main case5has a different color from the other segments of the case. The lower boundaries of different-colored segments G1, G2, correspond to detection depth marks533,543. InFIG. 25H, one portion of main case5has a different color from the other segments of the case. The upper boundaries of different-colored segments H1, H2, correspond to detection depth marks533,543. Additionally segments G1, G2, H1, H2may be constituted by recesses and projections. Alternatively, segments G1, G2, H1, H2may have a coarser surface roughness than the other segments of main case5.

As long as the light-emitter support supports the light emitting element, the shape and structure thereof is not limited to the above described embodiment. For example, the light-emitter support may be a lead as in the above-mentioned embodiment, or maybe another structure configuration such as a pattern formed over a resin material. The light-emitter support is not limited to extending in the vertical direction as in the above-mentioned embodiment, and may extend in another direction. For example, the light-emitter support may extend in a direction inclined in relation to the vertical direction. The light-emitter support is not limited to being linear, and may be another shape. For example, the light-emitter support may be curved. As long as the light-receiver support supports the light receiving element, the shape and structure thereof is not limited to the above described embodiment. For example, the light-receiver support may be a lead as in the above-mentioned embodiment, or maybe another structure configuration such as a pattern formed over a resin material. The light-receiver support is not limited to extending in the vertical direction as in the above-mentioned embodiment, and may extend in another direction. For example, the light-receiver support may extend in a direction inclined in relation to the vertical direction. The light-receiver support is not limited to being linear, and may be another shape. For example, the light-receiver support may be curved.