JP2006147944A - Photo interrupter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve product accuracy as a photo interrupter and increase a light emission quantity and a light reception quantity by efficiently utilizing light emitted from a light emitting device to improve the reliability of position detection. <P>SOLUTION: The interrupter comprises an insulating board 22; a light emitting element 28 comprising a light emitter 23 and a light receiver 24 disposed right and left opposite to each other on the upside 26 of the insulating board 22 with the emitting surface 29 of the emitter 23 disposed upward on the upside 26 of the insulating board 22; a light receiving element 40 having a light emitting reflection surface 32 located around the light emitting element 28, for reflecting light emitted from the light emitting electric 28 to the light receiver 24 with a light receiving surface 41 upward disposed on the upside 27 of the insulating board 22; and a light receiving reflective surface 44 located around the light receiving element 40 for reflecting light incident on the light receiver 24 to the light receiver element 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmissive photointerrupter that detects a presence or a position of an object by providing a light-emitting element and a light-receiving element facing each other and blocking the light through the space between the objects.

  Conventionally, as this type of photo-interrupter, for example, the one described in Patent Document 1 is known. As shown in FIG. 10, the photo interrupt 1 includes a light emitting element 2, a light receiving element 3, a lens unit 4, and the light emitting element 2, the light receiving element 3 and the lens unit 4 housed therein. And a light-shielding case 5 to be formed. The case 5 has a substantially three-dimensional shape having a groove portion 6 having a concave cross section, and a hollow portion for accommodating the light emitting element 2, the light receiving element 3 and the lens portion 4 is formed therein. Further, an exit slit 7 and an entrance slit 8 are formed at opposite positions on both side surfaces of the groove 6.

  On the other hand, the light-emitting element 2 and the light-receiving element 3 housed in the hollow portion of the case 5 are each composed of lead frames 9 and 10, light-emitting chips 11 or light-receiving chips 12 mounted on the lead frames 9 and 10, respectively. The light-emitting surface 15 of the light-emitting element 2 and the light-receiving surface 16 of the light-receiving element 3 are disposed so as to face each other. The lens unit 4 is disposed on the light emitting surface 15 of the light emitting element 2 in order to bring the light emitted from the light emitting element 2 close to parallel light, and includes a lens 17 and a support base 18.

In the conventional photo interrupter 1 having such a configuration, the light emitted from the light emitting surface 15 of the light emitting element 2 is made close to parallel light by the lens unit 4 and passes through the exit slit 7 and the entrance slit 8. Is incident on the light receiving element 3 through the light receiving surface 16. At this time, if the object passes through the groove 6 of the case 5 and blocks the light, the amount of light received by the light receiving element 3 changes, whereby position detection can be performed.
JP 2001-135852 A

  However, in the conventional photo interrupter 1, the light emitting element 2 and the light receiving element 3 are formed separately from the case 5, and the light emitting element 2 and the light receiving element 3 are inserted into the hollow portion of the case 5 and fixed. Therefore, in addition to the time required for assembling, there is a risk that the product accuracy may decrease due to errors during assembling. Further, in the conventional photo interrupter 1, the light emitting surface 15 of the light emitting element 2 and the light receiving surface 16 of the light receiving element 3 are arranged to face each other, and only a part of the light emitted from the front of the light emitting element 2 is directly applied. Since the structure allows the light to pass through the exit slit 7, even if the light is emitted from the front of the light emitting element 2, the light diffused to the left and right of the exit slit 7 and the light emitted from other than the front of the light emitting element 2 are effectively used. In addition, since the amount of received light is small, the reliability of position detection may be affected.

  Accordingly, an object of the present invention is to eliminate the conventional process of incorporating a light emitting element and a light receiving element into a case, to improve the product accuracy as a photo interrupter, and to efficiently use light emitted from the light emitting element. It is to provide a photo interrupter that increases the light emission amount and the light reception amount and improves the reliability of position detection.

  In order to solve the above-described problems, a photo interrupter of the present invention includes a substrate, and a light emitting unit and a light receiving unit provided on the upper side of the substrate so as to face left and right, and the light emitting unit has a light emitting surface on an upper surface of the substrate. A light emitting element disposed facing upward, and a light emitting side reflecting surface that is located around the light emitting element and reflects light emitted from the light emitting element toward the light receiving part, while the light receiving part is an upper surface of the substrate The light receiving element is arranged with the light receiving surface facing upward, and a light receiving side reflecting surface that is located around the light receiving element and reflects light incident on the light receiving unit to the light receiving element side.

  According to the photo interrupter of the present invention, the light emitting element and the light receiving element are arranged on the same substrate, and the light emitted from the light emitting element having the light emitting surface arranged upward is reflected once inside the light emitting unit, and this reflected light is reflected. Since the light is guided to the light receiving unit, the amount of light incident on the light receiving unit can be increased as compared with the conventional case where the light emitted from the light emitting element is directly guided to the light receiving unit.

  Further, according to the photointerrupter according to the present invention, an ultra-small surface-mount type photointerrupter can be formed by arranging a light emitting element and a light receiving element on the same substrate and sealing the resin above. In addition, by providing the light emitting unit and the light receiving unit integrally on the same substrate, a high-precision and high-quality photo interrupter can be obtained.

  Embodiments of a photo interrupter according to the present invention will be described below in detail with reference to the drawings. 1 to 5 show an embodiment of a photo interrupter according to the present invention. FIG. 1 is a perspective view showing the overall shape of the photo interrupter, and FIG. 2 is an easy-to-understand reflection structure of the photo interrupter shown in FIG. FIG. 3 is a plan view of the photo interrupter shown in FIG. 1, FIG. 4 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 5 is a bottom view of the photo interrupter shown in FIG. It is.

  As shown in FIGS. 1 to 5, the photointerrupter 21 according to this embodiment includes a block-shaped insulating substrate 22, and a light emitting unit 23 and a light receiving unit 24 disposed on the upper surface of the insulating substrate 22. . The insulating substrate 22 has a substantially three-dimensional shape having a groove 25 having a concave cross section at the center, and the light emitting part 23 and the light receiving part 24 are provided on the upper surfaces 26 and 27 on both the left and right sides of the groove 25. The upper surfaces 26 and 27 have the same height.

  The light emitting portion 23 is formed on the upper surface 26 of the insulating substrate 22 to seal the light emitting device 28 and the light emitting device 28 disposed on one upper surface 26 of the insulating substrate 22 with the light emitting surface 29 facing upward. A translucent resin body 30 and a light-shielding resin body 31 covering the outer peripheral surface of the translucent resin body 30. The light emitting element 28 is, for example, a chip-shaped square light emitting diode having a strong light emitting surface on the upper surface, and is disposed on an electrode plate (not shown) printed on the upper surface 26 of the insulating substrate 22. The shape of the translucent resin body 30 is not particularly limited. For example, as shown in FIG. 2, the translucent resin body 30 has a trapezoidal shape having an inclined surface 32 toward the light receiving unit 24 at a position above the light emitting element 28. be able to. The light-shielding resin body 31 has a substantially rectangular parallelepiped shape, and has a bottom surface having substantially the same shape as the top surface 26 of the insulating substrate 22. In addition, a reflection surface that efficiently reflects the light emitted from the light emitting element 28 is formed on the boundary surface between the light shielding resin body 31 and the translucent resin body 30. It is important that the reflecting surface is formed at least on the inclined surface 32, and the light emitted from the light emitting element 28 is reflected by the inclined surface 32 and guided to the light receiving unit 24 side. Therefore, the inclination angle of the inclined surface 32 is also important. Further, since the light emitting element 28 emits not only from the light emitting surface 29 but also from the side surface, not only the inclined surface 32 but also the surrounding surface of the light emitting element 28 in order to reflect the light effectively. That is, it is preferable to form reflective surfaces on the rear surface 33 and the left and right side surfaces 34 and 35 of the translucent resin body 30. As a means for forming the reflective surface, for example, after forming the translucent resin body 30, and before forming the light-shielding resin body 31, a coating film or vapor deposition with high reflectivity is formed on the outer peripheral surface of the translucent resin body 30. A film is formed, or the light-shielding resin body 31 is formed of a resin material having a high infrared reflectance. The resin material of the translucent resin body 30 and the light-shielding resin body 31 is not particularly restricted. For example, as the resin material of the translucent resin body 30, transparent epoxy, transparent silicon, or the like can be used, and as the light-shielding resin body 31, epoxy containing titanium oxide or the like can be used.

  In this embodiment, for example, an exit slit 37 is formed on the front surface 36 of the light shielding resin body 31 on the groove portion 25 side as an exit portion for emitting the light reflected by the inclined surface 32 or the like to the light receiving portion 24 side. ing. The exit slit 37 is formed in a vertical direction at a substantially central portion of the front surface 36, and a part of the translucent resin body 30 is exposed on the slit surface.

  On the other hand, the light receiving unit 24 is provided at a position facing the light emitting unit 23 with the groove 25 of the insulating substrate 22 interposed therebetween, and the light receiving element 40 is disposed on the other upper surface 27 of the insulating substrate 22 with the light receiving surface 41 facing upward. A light-transmitting resin body 42 formed on the upper surface 27 of the insulating substrate 22 for sealing the light-receiving element 40, and a light-blocking resin body 43 covering the outer peripheral surface of the light-transmitting resin body 42. Have. The light receiving element 40 is, for example, a chip-like phototransistor having a light receiving surface 41 on the upper surface, and is disposed on an electrode plate (not shown) printed on the upper surface of the insulating substrate 22 like the light emitting diode. Yes. The shape of the translucent resin body 42 is such that an inclined surface 44 provided above the light receiving element 40 is inclined toward the light emitting element 28, and the inclined surface 44, the rear surface 45, and the left and right side surfaces 46 and 47 are formed as reflecting surfaces. Since it consists of the same structure as the translucent resin body 30 by the side of the said light emission part 23 except being, detailed description is abbreviate | omitted here. In addition, since the light-shielding resin body 43 and the incident slit 49 as the light incident part formed on the front surface 48 on the groove part 25 side of the light-shielding resin body 43 have the same configuration as that of the light emitting part 23 side, the details here. The detailed explanation is omitted.

  In this embodiment, as shown in FIG. 3, the light emitting element 28 and the exit slit 37 of the light emitting section 23, and the light receiving element 40 and the entrance slit 49 of the light receiving section 24 are on a single straight line 50. Is located. Further, as shown in FIG. 5, connection electrodes 52a to 52d for surface mounting on the upper surface printed wiring (not shown) of the mother board 51 shown in FIG. The connection electrodes 52 a to 52 d are electrically connected to an electrode plate (not shown) on which the light emitting element 28 and the light receiving element 40 are disposed via the side electrodes 53 a to 53 d of the insulating substrate 22.

  Next, the operation of the photo interrupter 21 having the above configuration will be described. As shown in FIG. 4, the light emitted from the light emitting surface 29 of the light emitting element 28 is reflected to the light receiving unit 24 side by the inclined surface 32 of the translucent resin body 30, and the reflected light is emitted from the exit slit 37 and the entrance slit. The light passes through 49 and enters the light receiving unit 24. The light incident in the light receiving unit 24 is reflected downward by the inclined surface 44 of the translucent resin body 42 and is directly incident on the light receiving surface 41 of the light receiving element 40. At this time, if an object passes through the groove portion 25 of the photo interrupter 21 and blocks light, the amount of light received by the light receiving element 40 changes, so that position detection can be performed.

  As shown in FIG. 2, the inclined surface 32 of the light emitting portion 23 is not only a narrow portion corresponding to the exit slit 37 but also the entire inclined surface 32 is formed as a reflective surface, Since the rear surface 33 and the left and right side surfaces 34 and 35 are also formed as reflecting surfaces, the light emitted from the side surfaces as well as the upper surface of the light emitting element 28 is reflected by the surrounding reflecting surfaces. And these become strong light and pass through the exit slit 37. On the other hand, not only the inclined surface 44 of the translucent resin body 42 but also the entire outer peripheral surface of the light guided to the incident slit 49 and incident into the light receiving unit 24 is formed as a reflecting surface, as in the light emitting unit 23. Therefore, strong light is incident on the light receiving surface 41 of the light receiving element 40, and not only the light emitting unit 23 but also the light receiving unit 24 can efficiently use the reflection of light to increase the amount of received light. Detection accuracy can be improved.

  According to the photo interrupter 21 according to the present embodiment, the light emitting surface 29 of the light emitting element 28 and the light receiving surface 41 of the light receiving element 40 are both arranged upward without facing each other. By doing so, in addition to the efficient use of reflected light as described above, both elements are arranged on the same substrate, and the upper part is made of resin-sealed structure, so that it can be mounted on the surface of a microminiature photo. The interrupter 21 can be formed.

  6 and 7 show a second embodiment of the photo-interrupter according to the present invention. In the photo interrupter 61 according to this embodiment, the light emitting side reflecting surface formed on the light emitting unit 63 and the light receiving side reflecting surface formed on the light receiving unit 64 are both formed on the outer peripheral surface of the translucent resin bodies 30 and 42. The curved surfaces 65 and 66 are formed. In this embodiment, the curved surfaces 65 and 66 have a quarter shape of a cylindrical body that curves from above to the rear of the light emitting element 28 and the light receiving element 40 respectively. There may be. In this manner, by forming the reflecting surfaces as the curved surfaces 65 and 66, the light reflected by the curved surface 65 can be easily collected in the vicinity of the emission slit 37 in the light emitting portion 63, and the incident slit in the one light receiving portion 64. The light incident from 49 is easily condensed on the light receiving element 40 by the curved surface 66. In addition, if the right and left side surfaces of the translucent resin bodies 30 and 42 are formed as reflection surfaces, the reflection efficiency is further improved. The photo interrupter 61 according to this embodiment has the same configuration as that of the first embodiment except for the above-described curved reflecting surface. Is omitted.

  8 and 9 show a third embodiment of the photo-interrupter according to the present invention. In the photo interrupter 71 according to this embodiment, the light emitting side reflecting surface formed on the light emitting unit 73 and the light receiving side reflecting surface formed on the light receiving unit 74 are both formed on the outer peripheral surface of the translucent resin bodies 30 and 42. The flat upper surfaces 75 and 76 and the rear surfaces 77 and 78 are formed. That is, as in the above-described embodiment, it is a reflection surface in which the outer peripheral surfaces of the translucent resin bodies 30 and 42 are formed in a flat shape without forming an inclined surface or a curved surface. However, even with such a planar reflecting surface, the light emitted from the light emitting element 28 is once reflected by the upper surface 75 and the rear surface 77 and then passes through the exit slit 37, so that the same as in the above embodiment. A reflection effect is obtained. Needless to say, if the left and right side surfaces of the translucent resin bodies 30 and 42 are formed as reflection surfaces, the reflection efficiency is further improved. Since the configuration of the photo interrupter 71 according to this embodiment is substantially the same as that of the first embodiment except for the above-described planar reflection surface, the same configurations are denoted by the same reference numerals and detailed description will be given. Is omitted.

It is a perspective view showing the whole photo interrupter shape concerning a 1st embodiment of the present invention. It is explanatory drawing which represented the reflection structure of the photo interrupter shown in the said FIG. 1 intelligibly. FIG. 2 is a plan view of the photo interrupter shown in FIG. 1. It is sectional drawing cut | disconnected along the AA line in the said FIG. FIG. 2 is a bottom view of the photo interrupter shown in FIG. 1. It is explanatory drawing showing the reflection structure of the photo interrupter which concerns on 2nd Embodiment of this invention clearly. It is sectional drawing cut | disconnected along the BB line in the said FIG. It is explanatory drawing showing the reflection structure of the photo interrupter which concerns on 3rd Embodiment of this invention clearly. It is sectional drawing cut | disconnected along CC line in the said FIG. It is sectional drawing which shows an example of the conventional photo interrupter.

Explanation of symbols

21 Photo interrupter 22 Insulating substrate 23 Light emitting portion 24 Light receiving portion 25 Groove portion 26, 27 Upper surface of insulating substrate 28 Light emitting element 29 Light emitting surface 30 Translucent resin body of light emitting portion 31 Light blocking resin body of light emitting portion 32 Inclined surface (light emitting side) Reflective surface)
37 Outgoing slit (outgoing part)
40 Light-receiving element 41 Light-receiving surface 42 Translucent resin body of light-receiving portion 43 Light-shielding resin body of light-receiving portion 44 Inclined surface (light-receiving side reflecting surface)
49 Incident slit (incident part)
51 Motherboards 52a to 52d Connection electrodes on the lower surface of the substrate 53a to 53d Side electrodes of the substrate

Claims (11)

A substrate,
A light emitting portion and a light receiving portion provided on the upper part of the substrate so as to face left and right,
A light emitting device in which the light emitting unit is disposed on the upper surface of the substrate with the light emitting surface facing upward;
While having a light emitting side reflecting surface that is located around the light emitting element and reflects light emitted from the light emitting element to the light receiving unit side,
A light receiving element in which the light receiving portion is disposed on the upper surface of the substrate with the light receiving surface facing upward;
A photointerrupter having a light-receiving-side reflecting surface positioned around the light-receiving element and reflecting light incident on the light-receiving portion toward the light-receiving element.   The light-emitting unit includes a light-transmitting resin body that seals the light-emitting element, and a light-blocking resin body that covers an outer peripheral surface of the light-transmitting resin body, and includes the light-transmitting resin body and the light-blocking resin body. 2. The photo interrupter according to claim 1, wherein the light emitting side reflecting surface is formed on the boundary surface, and a light emitting portion is formed on a surface of the light shielding resin body facing the light receiving portion.   The light-receiving unit includes a light-transmitting resin body that seals the light-receiving element, and a light-blocking resin body that covers an outer peripheral surface of the light-transmitting resin body, and includes the light-transmitting resin body and the light-blocking resin body. 2. The photointerrupter according to claim 1, wherein the light-receiving side reflection surface is formed on a boundary surface, and a light incident portion is formed on a surface of the light-shielding resin body facing the light-emitting portion.   The photointerrupter according to claim 2 or 3, wherein the emitting part and the incident part are arranged on the same line including the light emitting element and the light receiving element. The photointerrupter according to claim 2 or 3, wherein each of the emitting part and the incident part is a slit.   2. The photo interrupter according to claim 1, wherein the light emitting side reflecting surface is an inclined surface that is inclined above the light emitting element toward the light receiving unit.   2. The photointerrupter according to claim 1, wherein the light receiving side reflecting surface is an inclined surface that is inclined above the light receiving element toward the light emitting unit.   2. The photointerrupter according to claim 1, wherein the light emitting side reflecting surface is a curved surface that curves toward the light receiving part side from above to behind the light emitting element.   2. The photointerrupter according to claim 1, wherein the light-receiving-side reflecting surface is an inclined surface that curves toward the light-emitting portion side from above to behind the light-receiving element.   The substrate is formed in a block shape, the upper surface of the central portion is recessed with respect to the upper surfaces of the left and right sides where the light emitting unit and the light receiving unit are provided, and a groove is formed between the light emitting unit and the light receiving unit. Item 1. A photo interrupter according to item 1.   A connection electrode is formed on each of an upper surface of a substrate on which the light emitting unit and the light receiving unit are disposed and a lower surface of a substrate surface-mounted on a mother board, and the upper and lower connection electrodes are electrically connected by side electrodes of the substrate. The photo interrupter according to 1.

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