JP3496374B2 - Optical fiber sensor connector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connector used for an optical fiber sensor which is suitable for detecting the position of a key of a mute piano or an automatically playing piano.

[0002]

2. Description of the Related Art A mute piano capable of mute performance has been known. Such a mute piano is equipped with a mechanism that prevents hammering by the hammer shank even if a key is pressed, and instead of playing by striking a string, it detects the movement of the key or hammer with a sensor and responds to key depression. Electronically generate a musical tone having a specified pitch, sounding timing, and volume. Then, the performer can practice the performance without disturbing the neighbors by listening to the thus-generated musical tones by, for example, headphones.

An optical fiber sensor is used as a sensor for detecting such a key or hammer. The optical fiber sensor includes a light emitting side optical fiber and a light receiving side optical fiber, and has an optical path through which a beam emitted from the tip of the light emitting side optical fiber is received by the tip of the light receiving side optical fiber. A beam is incident on the light emitting side optical fiber by a light emitting element such as a light emitting diode, and the light emitted from the light receiving side optical fiber is received by a light receiving element such as a photodiode. A voltage having a magnitude corresponding to the intensity of light propagating through is output. Thus, when the shutter attached to the key or the like blocks the beam across the optical path, the displacement of the shutter can be detected. In a mute piano, a plurality of optical fibers on the light emitting side and the light receiving side are used in order to detect movements of many keys and hammers.

Conventionally, in order to transmit and receive the beam, the light emitting side optical fiber and the light emitting element are connected by a light emitting side connector, and the light receiving side optical fiber and the light receiving element are connected by a light receiving side connector. Was there. Each connector includes a plug to which an optical fiber is fixed and a socket to which an element is fixed. When the plug is attached to the socket, the end face of the optical fiber faces the corresponding element. Then, a plurality of light emitting elements and a plurality of light receiving elements are provided, a plurality of optical fibers are made to face each element, respectively, and a plurality of light emitting side optical fibers facing one light emitting element are made to face a plurality of different light receiving elements. A matrix is formed by facing the side optical fiber, and the number of parts is reduced.

At this time, the optical fiber is attached to the plug by bundling and inserting several optical fibers into each of the plurality of fiber through holes provided in the plug, and projecting the end of the optical fiber from the fiber through hole. And then fixing with an adhesive.

[0006]

However, as described above, there is a problem in that the number of parts is large when using separate connectors for the light emitting side and the light receiving side.
Further, it takes a long time to attach the plug and the socket and attach the connector to the board. These problems have been factors that increase the manufacturing cost of the optical fiber sensor.

Further, when a plurality of optical fibers are bundled and inserted into one fiber through hole and projected from this, the ends of the bundled optical fibers are easily separated, and it is difficult to align and cut the ends. If this condition is left as it is, the optical axis of the fiber and the element will shift, and the loss of the beam between the fiber and the element will increase. Therefore, once the optical fiber has been bonded, the wall around the end of the optical fiber The optical fiber is recessed together with the optical fiber so that the end of the optical fiber is held inside the plug. However, when such a processing is applied to the optical fiber, the cut surface of the optical fiber is hard to be smooth, and a gap is formed between the cut surface and the light emitting / receiving element. In addition, it is difficult to perform such cutting work with high accuracy. Therefore, if this cut surface is used as the exit surface or the entrance surface of the optical fiber, the light transmittance is reduced and the beam loss is also increased.

The present invention has been made in consideration of the above circumstances, and an object thereof is to provide an optical fiber sensor connector which can reduce the number of parts and the manufacturing cost.

[0009]

In order to solve the above problems, an optical fiber sensor connector according to the present invention comprises a plurality of light emitting side optical fibers and a plurality of light receiving side optical fibers. A connector used in an optical fiber sensor for detecting a moving body when the moving body intercepts the beam received by the receiving side of the optical fiber on the light receiving side. A plug to which the base ends of the light-emitting side and the light-receiving side of the optical fiber are fixed, and which is used to fix the optical fiber.
Light-curing adhesive that cures light
A transparent element , a fitting space in which the plug is fitted, is formed, a light emitting element that emits a beam toward the base end of the light emitting side optical fiber, and a base end of the light receiving side optical fiber A light receiving element for receiving a beam emitted from the socket, and a first fixing portion to which the light emitting side optical fiber is fixed, and the light receiving side optical fiber are fixed to the plug. A second fixing portion, and a groove that divides the first fixing portion and the second fixing portion are provided, and the fitting space is inserted into the groove, and the first fixing portion and the second fixing portion. It is characterized in that a partition plate is provided which optically shuts off between the fixed part and the fixed part.

In this structure, the light emitting element and the light receiving element are fixed to one socket, and the light emitting side optical fiber and the light receiving side optical fiber are fixed to one plug. And
By fitting the plug into the fitting space formed in the socket, the light emitting element faces the end surface of the light emitting side optical fiber and the light receiving element faces the end surface of the light receiving side optical fiber in one connector. Beams can be exchanged between the optical fiber and the element. Therefore, it is possible to reduce the number of parts and the manufacturing cost. Here, a photo-curable adhesive is used for fixing the optical fiber and the plug, and the plug is transparent or semi-transparent in order to perform the bonding work efficiently. In the configuration according to the present invention, by inserting the partition plate provided in the fitting space into the groove that divides the first fixing portion and the second fixing portion of the plug, even if the plug is transparent or translucent, The first fixed part and the second fixed part are optically blocked. That is, even if the light to be given from the light emitting element to the optical fiber on the light emitting side leaks, it is not transmitted to the optical fiber on the light receiving side and is not received by the light receiving element, and it is possible to prevent a decrease in detection accuracy. Becomes

Further, a socket base engageable with a board provided with a circuit to which the light emitting element and the light receiving element are connected and engageable with the socket is provided, and the socket base includes the light emitting element and the light receiving element. It is preferable to form a plurality of terminal through holes through which the terminal penetrates and increase the cross-sectional area of the terminal through holes on the element side. In this configuration, while the socket base is engaged with the substrate, the light emitting element and the light receiving element are fixed to the socket, the terminals of these elements are inserted into the terminal through holes of the socket base, and the socket is engaged with the socket base. To combine. As a result, the terminals of many elements can be smoothly connected to the circuit on the board, and the efficiency of the assembling work can be increased.

[0012]

[0013]

The connector according to the present invention is preferably adhered to a bracket for mounting various parts of the optical fiber sensor. According to this, for example,
It is possible to improve the efficiency of the installation work compared to the case of attaching to the bracket with screws,
It is possible to reduce the cost involved in the mounting work.

[0015]

DETAILED DESCRIPTION OF THE INVENTION

1: Configuration of Embodiments An embodiment of the present invention will be described below with reference to the drawings. The optical fiber sensor of the present embodiment is used to determine the operation timing and speed of the key of a mute piano. However, as will be described later, it may be used to determine the operation timing and speed of the hammer operated by the key.

1-1: Structure of Key First, FIG. 1 is a side view showing the structure of one key of a sound deadening piano having an optical fiber sensor according to the embodiment. As shown in this figure, the key 321 is rotated counterclockwise around the balance pin 29a of the middle reed 29 by pressing the key, using the pin 28a as a guide, to the end position shown by the chain double-dashed line in the figure. It has become. When you release the key, key 3
21 is designed to return to the rest position shown by the solid line. Such a configuration is the same for each of the 88 keys of the piano.

On the other hand, on the lower (back surface) side near the free end between the front reed 28 and the middle reed 29 of the key 321, a rectangular plate shutter 30 is attached in parallel with the longitudinal direction of the key 321. An optical fiber sensor 31 is arranged near the shutter 30. The optical fiber sensor 31 is fixed on a box-shaped bracket 40 attached to the shelf plate 33.

1-2: Structure of Optical Fiber Sensor FIG. 2 is an enlarged side view showing the structure of the optical fiber sensor 31, and FIG. 3 is a bottom view thereof. First, the configuration of the optical fiber sensor 31 will be described with reference to these drawings. FIG. 3 shows three sets of optical fiber sensors 31 that detect the operation of three adjacent keys. Reference numeral 41 is
The shutter 30 is an elongated hole formed in the bracket 40, and the shutter 30 is movable up and down (in the direction perpendicular to the paper surface) in the elongated hole 41. Each optical fiber sensor 31 has an optical path 50 from the optical fiber 42 on the light emitting side to the optical fiber 47 on the light receiving side, passing through the vicinity of the elongated hole 41, that is, the area traversable by the shutter 30.

The light-emitting side optical fiber 42 and the light-receiving side optical fiber 47 are both of the same quality formed by coating acrylic resin with fluororesin. A light emitting diode is connected to an end (not shown) of the optical fiber 42 on the light emitting side, whereby a beam having a constant brightness is propagated in the optical fiber 42. Further, a photodiode is connected to an end portion (not shown) of the optical fiber 47 on the light receiving side, and outputs a voltage having a magnitude corresponding to the intensity of the light emitted from the optical fiber 47. These light emitting diode and photodiode are attached to a connector attached to the outer surface of the bracket 40. Details of the connector will be described later.

Reference numerals 43 and 48 are fiber supports. The fiber supports 43 and 48 attach the light emitting side optical fiber 42 or the light receiving side optical fiber 47 to the bracket 40.
It is fixed on the upper side and is made of the same acrylic material as the optical fibers 42 and 47. Each fiber support 43 or 4
A fitting hole is formed in 8, and the optical fiber 42 or 47 is inserted and adhered therein. In FIG. 3, reference numeral 43 a is a convex portion integrally formed on the bottom surface of the fiber support 43 and fitted into the bracket 40. Similar protrusions are also formed on the fiber support 48 on the light receiving side.

Sensor heads 45 and 46 are arranged between the long holes 41 and 41. Sensor head 45,
Reference numeral 46 is the same shape and the same size, both made of acrylic, and is a prism body in the form of an isosceles right triangular prism having inclined surfaces as reflecting surfaces 45b and 46b.
The lenses 45a and 46 are integrated so that b are at right angles to each other, and convex surfaces are formed on the surfaces where these prism bodies are continuous.
a is formed and configured.

The beam emitted from the optical fiber 42 on the light emitting side and radially emitted from the lens 44 on the light emitting side is reflected sideways by the sensor head 45. In this case, one beam is split into two by the two reflecting surfaces 45b of the sensor head 45,
Is emitted toward both sides of. The sensor head 4
5, a lens 45a for integrally forming a beam emitted from the light emitting side lens 44 into a parallel light and directing it to a reflecting surface 45b is integrally formed. As a result, the beam emitted from the sensor head 45 also becomes parallel light.

As shown in FIGS. 2 and 3, the sensor head 45 is vertically long, and of the beam radially emitted from the light emitting side lens 44, the portion outside the front cross section of the light emitting side sensor head 45 is cut. Thus, the beams that do not reach the reflection surface 45b and are emitted from the emission surfaces 45c on both sides have the same sectional shape and size as those obtained by projecting one reflection surface 45b on the front surface. The dotted area in FIG. 2 corresponds to the area where the beam is emitted.
That is, the cross-sectional shape of the beam emitted from the sensor head 45 is rectangular.

The beam emitted from the sensor head 45 is
It passes beneath the elongated hole 41 and reaches the sensor head 46.
This beam is internally reflected by the reflecting surface 46 b of the sensor head 46 and is emitted toward the light receiving side lens 49. In this case, the sensor head 46 emits two beams from the adjacent sensor heads 45 on both sides toward the light receiving side lens 49 by the two reflecting surfaces 46b.

However, in this embodiment, the optical fiber 42 on the light emitting side is repeatedly caused to emit light in a short cycle, and the adjacent optical fibers 42 on the light emitting side are controlled so as to have different light emission timings. As a result, in the photodiode connected to the optical fiber 47 on the light receiving side, it is possible to clearly distinguish which optical fiber 42 the beam is detected from, depending on the timing at which the light is received. . Therefore, it is not confused as to which displacement of the adjacent shutter 30 is being detected.

It should be noted that the sensor head 46 is integrally formed with a lens 46a for converging a beam from the sensor head 45, which is parallel light, toward the light receiving side lens 49. The light-receiving side fiber support 48 is integrally provided with a light-receiving side lens 49 that converges the beam and makes it incident on the light-receiving side optical fiber 47.

As described above, in the optical fiber sensor 31, the beam emitted from the light emitting side optical fiber 42 is branched by the light emitting side sensor head 45, reflected by the light receiving side sensor head 46, and is reflected by the light receiving side optical fiber 47. Optical path 50 to enter
have. Then, when the shutter 30 crosses the optical path 50 between the light emitting side sensor head 45 and the light receiving side sensor head 46, the amount of light incident on the light receiving side optical fiber 47 changes, and the optical fiber 47 on the light receiving side is connected. It is possible to detect this change by the photodiodes that have been formed.

In FIG. 2, reference numeral 45d is a base integrally formed with the sensor head 45, and this base 45d has a convex portion 45e fitted to the bracket 40. In FIG. 3, the base 45d is omitted for simplification. A similar base is also formed on the light-receiving side sensor head 46.

1-3: Schematic Configuration of Connector FIG. 4 is a plan view showing a bracket 40 provided with an optical fiber sensor 31 and an optical fiber sensor connector (hereinafter referred to as “connector”) 51 according to the present invention. is there. As shown in FIGS. 1 and 4, the bracket 40 has an opening, and the connector 51 is supported by the opening of the bracket 40. In FIG. 4, reference numeral 55 indicates a substrate provided with an electric circuit connected to the light emitting diode (hereinafter referred to as “LED”) and the photodiode (hereinafter referred to as “PDI”). It should be noted that FIG. 4 shows only a part of the many optical fibers 42 and 47, the fiber supports 43 and 48, and the like.

FIG. 5 is a bottom view of the connector 51, and FIG. 6 is a side view. As shown in these figures, the connector 51 includes a plug 52, a socket 53, and a socket base 54. To the plug 52, all of the base ends of the optical fiber 42 on the light emitting side and the optical fiber 47 on the light receiving side, which are provided for detecting the many keys 321 of the sound deadening piano, are fixed. The plug 52 is fixed to the bracket 40.

The socket 53 is provided with an optical fiber 4 on the light emitting side.
All LEDs that emit a beam toward the base end of 2 and a PDI that receives the beam emitted from the base end of the optical fiber 47 on the light receiving side are mounted. In this socket 53,
The plug 52 is fitted, and when these are fitted, the optical fiber 42 and LED, and the optical fiber 47 and PDI are made to oppose. Socket base 54
The substrate 55 is fixed to.

1-4: Structure of Plug Next, FIG. 7 is a bottom view of the plug 52, and FIG. 8 is VIII-V of FIG.
A sectional view taken along the line III-III, and FIG. 9 is a side view of the plug 52.
The configuration of the plug 52 will be described with reference to these drawings.
The plug 52 is a thin long plate member made of transparent resin, and has a first fixing portion 56 to which the light emitting side optical fiber 42 is fixed and a second fixing portion 56 to which the light receiving side optical fiber 47 is fixed. The fixing portion 57 is provided. A groove 58 is formed substantially in the center of the plug 52 along the width direction of the plug 52, and the groove 58 separates the first fixing portion 56 and the second fixing portion 57.

A flange 59 having a U-shaped cross section is formed on one edge of the plug 52. As shown in FIGS. 7 and 9, the groove 59 a of the flange 59 is formed so as to extend around both ends of the plug 52. This groove 5
One side wall of the bracket 40 is fitted into 9a,
The space between the two is fixed by an adhesive. The groove 58 is formed over almost the entire width of the plug 52, and the first fixing portion 56 and the second fixing portion 57 are joined only by the flange 59.

Now, in the plug 52, along the width direction,
A fiber through hole 60 into which the optical fiber 42 or 47 is inserted is formed. Here, 12 fiber through holes 60 are formed in the first fixing portion 56, and eight fiber through holes 60 are formed in the second fixing portion 57.
On the flange 59 side of each fiber through hole 60, a substantially V-shaped guide groove 61 is formed. The guide groove 61 is made wider toward the side edge portion of the plug 52, whereby
It is easy to insert the optical fiber 42 or 47 into the fiber through hole 60.

Further, in the thickness direction of the plug 52, an injection hole 63 reaching the central position of each fiber through hole 60 is formed. After inserting the optical fiber 42 or 47 into the fiber through hole 60, the adhesive is injected through the injection hole 63. When this adhesive cures, the optical fibers 42, 4
7 is fixed to the plug 52. The adhesive used here is a photo-curable adhesive, and the plug 52 is made transparent so that the bonding work can be performed efficiently.

A convex portion 62 is formed on the plug 52 at a side edge portion opposite to the flange 59. The fiber through holes 60 penetrate the convex portions 62, respectively. That is, the convex portion 62 forms the peripheral portion of the fiber through hole 60. In this embodiment, the proximal ends of the plurality of optical fibers 42 or 47 are collectively inserted and fixed in one fiber through hole 60 in a state of being bound. Then, the ends of the optical fibers 42 and 47 are cut together with the tips of the protrusions 62. As a result, the ends of the cut convex portions 62 and the end faces of the optical fibers 42 and 47 are flush with each other. In FIG. 7, reference numeral 64 indicates a through hole for screwing the plug 52 to the socket 53.

1-5: Structure of Socket Next, FIG. 10 is a plan view of the socket 53, FIG. 11 is a bottom view, and FIG. 12 is a view taken along line XII-XII in FIG. The socket 53 is made of black resin and is a thin and long box-shaped member. As a result, the socket 53 has a light blocking effect. As shown in these figures, the socket 53 is composed of a fitting wall portion 65a on which the plug 52 is mounted, an LED mounting portion 70 on which an LED is mounted, and a PDI mounting portion 71 on which a PDI is mounted. There is.

1-5-1: Structure of Fitting Wall Portion The fitting wall portion 65a is formed with a fitting space 65 which is a space having an elongated rectangular cross-section that opens toward one side edge portion.
A black resin partition plate 66 having a light-shielding property is arranged at approximately the center of the fitting space 65, and is integrally formed with the fitting wall portion 65a. As a result, the fitting space 65 becomes the first
It is divided into a fitting part 67 and a second fitting part 68.

As shown in FIG. 5, the first fixing portion 56 of the plug 52 is inserted into the first fitting portion 67 of the socket 53, and the second fixing portion 68 is fitted with the second fixing portion 56. The part 57 is inserted. As a result, the bundle of the optical fibers 42 on the light emitting side (see FIG. 7) inserted and fixed in the first fixing portion 56 is aligned in the first fitting portion 67 and fixed in the second fixing portion 57. The bundle of optical fibers 47 on the light receiving side are aligned in the second fitting portion 68.

When the plug 52 is fitted into the fitting space 65, the partition plate 66 provided in the fitting space 65 is fitted into the groove 58 that divides the first fixing portion 56 and the second fixing portion 57 into two. It is supposed to be plugged in. With this partition plate 66,
The connection between the first fixing portion 56 and the second fixing portion 57 of the plug 52 is blocked, and crosstalk between the two is prevented.

FIG. 13 is a sectional view taken along the line XIII-XIII in FIG. 12, and FIG. 15 is a sectional view taken along the line XV-XV in FIG. As shown in these figures, a counterbore hole 65b is formed in the interior of the fitting space 65. When the plug 52 is attached to the socket 53, the convex portion 62 of the plug 52 is fitted into these counterbore holes 65b. This allows
The end surface of the bundle of the optical fibers 42 on the light emitting side has the first fitting portion 6
7, the end face of the bundle of optical fibers 47 on the light receiving side is located in the counterbore hole 65b in the second fitting portion 68.

A cylindrical portion 79 for mounting on the socket base 54 is provided on the outer surface of the fitting wall portion 65a so as to project therefrom. These cylindrical portions 79 are provided at positions corresponding to the through holes 64 of the plug 52, and the screw holes 6 are provided in the respective cylindrical portions 79.
9 is formed. As shown in FIG. 12, each screw hole 6
9 communicates with the fitting space 65. A screw is inserted through the screw hole 69 and the through hole 64 of the plug 52, whereby the plug 52 and the socket 53 are fixed. Further, a countersink hole 69a into which the head of the screw is fitted is formed on the outer surface on the side opposite to the cylindrical portion 79.

1-5-2: Structure of LED mounting portion As shown in FIG. 12, the LED mounting portion 70 and the PDI mounting portion 71 are formed so as to be continuous with the fitting wall portion 65a. It is made thicker than the whole thickness. Figure 1
As shown in FIGS. 0 and 11, the LED mounting portion 70 is provided in the fitting space 65 at a position corresponding to the first fitting portion 67. Then, in the LED mounting portion 70, a plurality of (12 in the embodiment) LED insertion holes 72 communicating with the first fitting portion 67 are formed from the side surface 70a opposite to the first fitting portion 67. There is. One LED is inserted into each LED insertion hole 72, whereby each LED is fixed to the first fixing portion 56 of the plug 52 and the light on the light emitting side disposed in the first fitting portion 67. The end face of the bundle of fibers 42 can be illuminated.

As shown in FIG. 13 and FIG.
The insertion hole 72 is composed of a body section arranging section 72a having a large cross section in which the body section of the LED is arranged, and a top section arranging section 72b formed in the back thereof and having a small section in which the top section of the LED is arranged.
The top portion arranging portion 72b is formed in a circular cross section, while the body portion arranging portion 72a is substantially circular in cross section, but a part thereof is made flat. A ridge 72c extends along the depth direction of the LED insertion hole 72 on this plane portion. The ridge 72c is formed so as to have a small cross-sectional area, and when the LED is inserted into the LED insertion hole 72, the ridge 72c is crushed so that the LED
Is fixed so that it will not wobble easily.

A communication hole 74 having a diameter substantially the same as or slightly larger than that of the fiber through hole 60 is formed between the top placement portion 72b and the first fitting portion 67. The emitted light reaches only the end face of the bundle of the optical fibers 42 on the light emitting side in the counterbore hole 65b without leaking into the first fixing portion 56 through the convex portion 62 forming the peripheral portion of the fiber through hole 60. It is like this. The first fitting portion 67 is provided with the counterbore hole 65b and the convex portion 62 is arranged here because the distance between the end surface of the optical fiber 42 on the light emitting side and the top portion of the LED is set. Shorten,
This is to reduce the loss until the beam emitted by the LED enters the optical fiber 42 on the light emitting side.

Further, the side surface 70a of the LED mounting portion 70 is formed with a terminal arrangement groove 75 in which the two terminals of each LED are arranged. In this embodiment, an LED whose terminals are bent at a right angle from the body is used, and the LED is
When inserting into the ED insertion hole 72, two terminals are fitted into the terminal arrangement groove 75.

1-5-3: Structure of PDI Mounting Section Further, as shown in FIGS. 10 and 11, the PDI mounting section 71 is provided in the fitting space 65 at a position corresponding to the second fitting section 68. Has been. Then, in the PDI mounting portion 71, a plurality of (8 in the embodiment) PDI insertion holes 73 are formed in a direction orthogonal to the second fitting portion 68. One PDI is inserted into each PDI insertion hole 73.

As shown in FIG. 15, the PDI insertion hole 73
Is formed coaxially with the counterbore hole 65b of the second fitting portion 68 and communicates with the second fitting portion 68 by a communication hole 76 having a diameter that is substantially the same as or slightly larger than the fiber through hole 60. . As a result, each PDI is fixed to the second fixing portion 57 of the plug 52, and the plug 5 is inserted into the second fixing portion 57 through the convex portion 62 that is the peripheral portion of the fiber through hole 60.
Without receiving scattered light etc. that entered from the outside of 2.
Optical fiber 47 on the light receiving side disposed in the second fitting portion 68
It is possible to receive only the beam from the end face of the bundle.
In addition, the counterbore hole 65b is also provided in the second fitting portion 68,
The convex portion 62 is arranged here because the distance between the end surface of the optical fiber 47 on the light receiving side and the light receiving surface of the PDI is shortened so that the beam emitted from the optical fiber 47 on the light receiving side is PDI.
This is to reduce the loss until the light is received by.

FIG. 17 is a sectional view taken along the line XVII-XVII in FIG. As shown in the figure, the PDI insertion hole 73 has a substantially rectangular shape, and a ridge 77 is formed on the bottom surface opposite to the communication hole 76. The ridge 77 is formed with a small cross-sectional area, and when the PDI is inserted into the PDI insertion hole 73, the ridge 77 is crushed so that the PDI is fixed so as not to wobble easily. Has become.

Further, on the side surface of the PDI mounting portion 71, a cylindrical portion 80 for attaching to the substrate 55 together with the socket base 54 is provided in a protruding manner. Furthermore, in the socket 53,
Along the longitudinal direction, the LED mounting portion 70 and the PDI
A ridge 78 is formed over the mounting portion 71. Each PD
The I insertion hole 73 is opened outside within the range of the protrusion 78. Further, as shown in FIG. 11, in the cylindrical portion 80 and the LED mounting portion 70, a screw hole 81 is formed in the protrusion 78.

In this embodiment, 12 LEDs are used to illuminate 12 light emitting side optical fibers 42, and 8 light receiving side optical fibers 47 are used to receive light from 8 PDIs. , The optical fibers 42 on the light emitting side forming each bundle supply a light beam in the direction of the adjacent keys 321 every other octave of the mute piano, and the optical fibers 47 on the light receiving side forming each bundle form one octave of the mute piano. A light beam is supplied from the direction of two adjacent keys 321 inside. And
By shifting the light emission timing of the 12 LEDs, which key 3
It has become possible to know whether or not the action 21 has been detected.

1-6: Structure of Socket Base FIG. 18 is a plan view showing the socket base 54.
9 is a sectional view taken along the line XIX-XIX in FIG. The socket base 54 is a black resin thin plate member and has a light-shielding property. On one surface of the socket base 54, a groove 82 that can be fitted into the protrusion 78 of the socket 53 is formed.

Engaging members 85, 86, 87 are provided on the other surface of the socket base 54 in a protruding manner (see FIGS. 5 and 6).
reference). As shown in FIGS. 6 and 19, each engaging member 8
5,86,87 are composed of a pair of wedge pieces, and are prevented from being extracted when they are inserted into the holes formed in the substrate 55. When assembling the connector 51, the socket base 54 is fixed on the substrate 55 by the engagement tools 85, 86, 87, and the protrusions 78 of the socket 53 are fitted into the grooves 82 of the socket base 54.

A disc-shaped seat portion 83 is formed at the side end of the socket base 54 so as not to tilt when the socket 53 is fixed to the substrate 55. An annular portion 84 having a through hole 88 is formed at the opposite side end of the socket base 54. Further, a through hole 88 is also formed on the inner bottom surface of the groove 82. When the ridge 78 of the socket 53 is fitted in the groove 82 of the socket base 54, the cylindrical portion 80 of the socket 53 is brought into contact with the annular portion 84 (see FIGS. 5 and 11), and the cylindrical portion 7 of the socket 53.
9 is in contact with the seat portion 83, and the screw hole 81 of the socket 53
Corresponds to the through hole 88. In this state, socket 53
The board 55 can be screwed with the socket base 54 sandwiched in the middle. The screw screwed into the screw hole 69 also penetrates the through hole 64 and also serves to fix the plug 52 and the socket 53.

The socket base 54 has a wide L
It has an ED base portion 90 and a narrow PDI base portion 91. The LED base 90 is L of the socket 53.
The PDI base 91 is engaged with the ED mounting part 70,
This is a portion that is engaged with the DI mounting portion 71. The LED base portion 90 is provided with a plurality of terminal through holes 90 a through which the terminals of the LEDs fixed to the socket 53 are inserted (8 in the embodiment.
Pair) is formed. In addition, the groove 8 of the PDI base portion 91
Within the range of 2, a plurality of terminal through holes 91a (12 pairs in the embodiment) through which the terminals of the PDI fixed to the socket 53 are inserted are formed.

Each of the terminal through holes 90a and 91a is tapered so as to become narrower toward the inner side from the surface facing the socket 53, so that when the socket 53 is engaged with the socket base 54, Fixed LE
The D and PDI terminals are easily inserted into the terminal through holes 90a and 91a. Further, the PDI base portion 91 of the socket base 54 functions as a lid that closes all the PDI insertion holes 73 when the socket base 54 is engaged with the socket 53.

2: Connector Assembly Procedure Next, the connector assembly procedure will be described. First, the groove 59a formed in the flange 59 of the plug 52
The fiber supports 43, 47, the sensor head 45,
One side wall of the bracket 40 to which 46 and the like are attached is fitted, and the both are fixed with an adhesive. Next, one optical fiber bundle obtained by bundling a plurality of light emitting side optical fibers 42
Two optical fibers 47 on the light receiving side are prepared while two are prepared.
Eight optical fiber bundles obtained by bundling are prepared. Then, the bundle of the optical fibers 42 on the light emitting side is attached to the first fixing portion 5 of the plug 52.
The optical fiber 47 on the light receiving side is inserted into the fiber through hole 60 on the sixth side, and is inserted into the fiber through hole 60 on the second fixing portion 57 side of the plug 52. At this time, the fiber bundle is inserted from the guide groove 61 side, and the tip thereof is slightly projected from the convex portion 62.

Next, a photo-curable adhesive is injected through the injection hole 63 and cured to cure the optical fiber bundle and the plug 5.
Fix 2 and. Then, the end of the optical fiber bundle is slightly cut, leaving the length of each of the protrusions 62 fitted in the counterbore hole 65b of the plug 52, and the end face of the optical fiber bundle is smoothed.

Further, 12 Ls are formed in the socket 53.
LEDs are inserted into the ED insertion holes 72, respectively.
The terminal of is inserted into the terminal arrangement groove 75. At this time, LED
The protrusion 72c formed in the insertion hole 72 is crushed and the LED is fixed in the LED insertion hole 72. The PDI is inserted into each of the PDI insertion holes 73 formed in the socket 53. At this time, the ridge 77 formed in the PDI insertion hole 73 is crushed and the PDI is fixed in the PDI insertion hole 73.

On the other hand, the engagement tool 85 of the socket base 54,
The socket base 54 is fixed to the substrate 55 by inserting 86 and 87 into the holes formed in the substrate 55. Then, the terminal of the LED fixed to the socket 53 and the PD
The terminals I are connected to the terminal through holes 90a, 9 of the socket base 54.
By inserting the protrusion 78 of the socket 53 into the groove 82 of the socket base 54 while inserting it into the socket 1a and screwing the screw into the screw hole 81 of the socket 53 from the back side of the substrate 55, the socket 53 and the socket base 54 are attached to the substrate 55. Fix it. In this way, each terminal is connected to the terminal through holes 90a, 91.
When it is inserted into a, the terminal is connected to the electric circuit formed on the substrate 55, and the light emission by the LED and the voltage conversion of the light by the PDI are enabled. Then, the ridges 78 are formed in the grooves 82.
By fitting in, the PDI insertion hole 73 is closed and light from the outside is prevented from entering.

Next, the plug 52 is fitted in the fitting space 65 formed in the socket 53, and the countersink hole 6 of the socket 53 is inserted.
9a through the through hole 64, and the screw hole 69 of the socket 53
The plug 52 and the socket 53 are fixed by screwing a screw into the. As a result, the connector 51 is completed.

3: Operation and effect of the embodiment In the above embodiment, the optical fiber 4 on the light emitting side is placed in one socket 53 to which a plurality of LEDs and PDIs are fixed.
2 and the optical fiber 47 on the light receiving side are fixed to the plug 52
LED connector with one connector 51
Faces the end face of the optical fiber 42 on the light emitting side, and the PDI faces the end face of the optical fiber 47 on the light receiving side, so that the beam can be transmitted and received between the optical fiber and the element. Therefore, it is possible to reduce the number of parts, and to significantly reduce the manufacturing cost accordingly.

When the plug 52 is fitted into the socket 53, the fitting space 6 of the socket 53 is fitted into the groove 58 that divides the first fixing portion 56 and the second fixing portion 57 of the plug 52.
5 by inserting the partition plate 66 provided in
Even if 2 is transparent or translucent, crosstalk between the first fixing portion 56 and the second fixing portion 57 is prevented.
That is, even if the light to be given from the LED to the light emitting side optical fiber 42 leaks, it is not transmitted to the light receiving side optical fiber 47 and is not received by the light receiving element, and it is possible to prevent a decrease in detection accuracy. It will be possible.

Further, since the partition plate 66 is inserted between the first fixing portion 56 and the second fixing portion 57 when the plug 52 is fitted in the socket 53, no special work is required. It is not necessary to complicate the assembly work of the connector 51.

Further, by forming the convex portion 62 on the plug 52, as described above, by simply cutting the end of the bundle of optical fibers 42 or 47 together with the tip of the convex portion 62, the bundle of optical fibers The cut surface can be made smooth and the transmittance at the cut surface can be improved. In this case, the cut portion of the plug is reduced, and the fluctuation of the force applied to the optical fiber 42 or 47 during the cutting can be reduced. Therefore, the beam loss at the end face of the optical fiber is reduced,
The beam can be used with high efficiency. In addition, cutting work becomes easy. Furthermore, a convex portion 62 is provided,
By fitting these convex portions 62 into the counterbore holes 65b formed in the socket 53, the end face of the bundle of optical fibers is brought closer to the LED or PDI than the other portion of the plug 52, and the two are transmitted. The loss of the generated beam can be reduced.

Further, communication holes 74 and 76 are formed in the socket 53 so as to communicate with the counterbore hole 65b. The beam is transmitted from the LED through the communication hole 74 only to the light emitting side optical fiber 42, and the light receiving side optical fiber 47. From only communication hole 76
The beam is transmitted to the PDI through.
Then, the PDI base portion 91 of the socket base 54 is
When the socket base 54 engages with the socket 53, it functions as a lid for closing all the PDI insertion holes 73. Therefore, for example, even if the beam emitted from the optical fiber 47 on the light receiving side reaches the PDI and is diffusely reflected in the PDI insertion hole 73, the light does not leak to the adjacent PDI. further,
Since the communication holes 74 and 76 have substantially the same size as the fiber through hole 60, the beam emitted from the LED does not enter the plug 52 through the convex portion 62 of the transparent plug 52, and the light receiving side The beam emitted from the optical fiber 47 is reflected on the surface of the PDI, passes through the convex portion 62,
The amount of light returning to the optical fiber 47 side on the light receiving side is almost eliminated. Therefore, the returned light is not diffusely reflected in the transparent plug 52 and does not affect the other optical fiber 47 on the light receiving side.

Further, in this embodiment, during assembly,
Fixing the socket base 54 to the substrate, LED and PD
With I fixed to the socket 53, the socket 53 is engaged with the socket base 54 while penetrating the terminals of these elements into the terminal through holes 90 a and 91 a of the socket base 54. As described above, the terminal through holes 90a and 91a
Has a tapered shape that narrows inward from the surface facing the socket 53. Further, the socket 53 is provided with a terminal arrangement groove 75, and the terminal is positioned. As a result, it is possible to easily connect the terminals of many LEDs and PDIs to the electric circuit on the substrate 55 without taking time and effort.

Further, since the side wall of the bracket 40 is adhered to the groove 59a of the plug 52 and the connector 51 is fixed to the bracket 40, the efficiency of the mounting work can be improved as compared with the case where the connector 51 is mounted to the bracket 40 with a screw, for example. The manufacturing cost can be reduced at the same time.

3: Modification Example In the above embodiment, the plug 52 is transparent, but it may be semitransparent. In addition, the above embodiment,
The shutter 30 attached to the key 321 of the sound deadening piano is detected to grasp the behavior of the key 321. However, the present invention is not limited to this, and can be used to detect other moving objects regardless of whether they are musical instruments or not. , This fiber optic sensor is applicable, and the connector is also applicable. For example, in a mute piano, a hammer shank driven by a key 321 is prevented from striking a string. However, by allowing the hammer shank to move halfway and understanding its behavior, In addition to the behavioral data of the key 321, a more faithful musical tone may be generated, and the optical fiber sensor and the connector may be used for detecting the operation of the hammer shank. Further, the present invention can be applied to an automatic performance piano in which performance information at the time of performance is collected and stored and an automatic performance is performed based on the stored performance information.

[0070]

As described above, according to the present invention, the number of parts of the connector for the optical fiber sensor is reduced,
It is possible to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a side view showing the configuration of one key of a sound deadening piano provided with an optical fiber sensor according to an embodiment of the present invention.

FIG. 2 is a side view showing a configuration of the optical fiber sensor.

FIG. 3 is a bottom view showing the configuration of the optical fiber sensor.

FIG. 4 is a plan view showing a bracket provided with the optical fiber sensor and a connector for an optical fiber sensor according to an embodiment of the present invention.

FIG. 5 is a bottom view of the optical fiber sensor connector.

FIG. 6 is a side view of the optical fiber sensor connector.

FIG. 7 is a bottom view of a plug forming the optical fiber sensor connector.

8 is a sectional view taken along the line VIII-VIII of FIG.

FIG. 9 is a side view of the plug.

FIG. 10 is a plan view of a socket constituting the optical fiber sensor connector.

FIG. 11 is a bottom view of the socket.

12 is a view taken along arrow XII-XII in FIG.

13 is a sectional view taken along the line XIII-XIII in FIG.

14 is a cross-sectional view taken along the line XIV-XIV of FIG.

15 is a sectional view taken along the line XV-XV in FIG.

16 is a sectional view taken along the line XVI-XVI of FIG.

17 is a sectional view taken along the line XVII-XVII of FIG.

FIG. 18 is a plan view of a socket base that constitutes the optical fiber sensor connector.

19 is a cross-sectional view taken along the line XIX-XIX in FIG.

[Explanation of symbols]

30 shutter (moving body), 31 optical fiber sensor,
40 bracket, 42 light emitting side optical fiber, 43
Fiber support, 45 Light emitting side sensor head, 46
Light receiving side sensor head, 47 Light receiving side optical fiber, 48
Fiber support on the light receiving side, 50 optical paths, 51 optical fiber sensor connector (connector), 52 plug,
53 sockets, 54 socket bases, 55 substrates,
56 first fixing portion, 57 second fixing portion, 58 groove,
60 fiber through hole, 62 convex portion, 65 fitting space,
65a Fitting wall portion, 65b Counterbore hole (recess), 66
Partition plate, 67 First fitting portion, 68 Second fitting portion, 7
0 LED mounting part, 71 PDI mounting part, 72 LED insertion hole, 74, 76 communication hole, 75 terminal arrangement groove, 73
PDI insertion hole, 85, 86, 87 engagement tool, 90 LE
D base portion, 90a terminal through hole, 91 PDI base portion, 91a terminal through hole

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 5-40214 (JP, A) JP-A 6-202620 (JP, A) JP-A 8-171030 (JP, A) JP-A 61- 102694 (JP, A) Actually open 61-10590 (JP, U) Actually open 61-162813 (JP, U) Actually open 63-188611 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/42 G02B 6/36

Claims (3)

(57) [Claims] 1. A plurality of light emitting side optical fibers and a plurality of light receiving side optical fibers are provided, and a beam emitted from the tip of the light emitting side optical fiber is received by the tip of the light receiving side optical fiber, and the moving body is A connector used for an optical fiber sensor for detecting the moving body when blocking the beam, which is a plug to which base ends of the plurality of light emitting side and light receiving side optical fibers are fixed , To fix
The light-curing adhesive used for
A light or translucent material , a fitting space in which the plug is fitted is formed, a light emitting element that emits a beam toward the base end of the light emitting side optical fiber, and the light receiving side optical fiber A light receiving element for receiving a beam emitted from the base end of the light emitting element, and a first fixing portion to which the light emitting side optical fiber is fixed to the plug, and the light receiving side optical fiber. Is provided with a second fixing portion and a groove that divides the first fixing portion and the second fixing portion. The fitting space is inserted into the groove, and the first fixing portion is provided. A connector for an optical fiber sensor, characterized in that a partition plate is provided to optically block between the second fixing portion and the second fixing portion. 2. A socket base engageable with a substrate provided with a circuit to which the light emitting element and the light receiving element are connected and engageable with the socket, wherein the socket base includes the light emitting element and the light receiving element. The connector for an optical fiber sensor according to claim 1, wherein a plurality of terminal through holes through which the terminals penetrate are formed, and a cross-sectional area of the terminal through holes on the element side is increased. 3. A process according to claim 1, characterized in that it is bonded to the bracket for attaching the various components of the optical fiber sensor or
The connector for optical fiber sensor according to item 2 or 3 .