JPH0560876A - Photosensor - Google Patents

Abstract

PURPOSE:To obtain a photosensor having a plurality of detection directions. CONSTITUTION:A rotary body 14 having first and second engaging parts 12,13 respectively freely engageable with the intermediate part 1a of an optical fiber 1 at two points is provided. The rotating shaft 15 supported with respect to a main body 11 in a freely rotatable manner is provided to a roughly central part of the rotary body 14. When the external force in the two-dimensional direction crossing the rotating shaft at right angles is applied to the rotating shaft, the rotating shaft and the rotary body are integrally rotated around a rotation direction along with the first and second engaging parts and the optical fiber is deformed and, as a result, a change in the quantity of light is generated to make it possible to perform detection in the two-dimensional direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical sensor which utilizes the optical characteristics of an optical fiber such that when the optical fiber is deformed, optical loss occurs at the deformed portion.

[0002]

2. Description of the Related Art Optical sensors of this type are disclosed, for example, in JP-A-61-34493 and JP-A-58-125835. The optical sensors disclosed therein connect a light emitter to one end of a flexible optical fiber and a light receiver to the other end thereof, and
An object that is movable in a certain direction is engaged with an intermediate portion of an optical fiber. Therefore, when the object does not deform the optical fiber, the light from the light emitter propagates to the light receiver at a relatively high rate, but when the object moves and deforms the optical fiber, optical loss occurs at the deformed portion, The amount of light propagating to the light receiver is reduced as compared with the case where there is no deformation. As described above, in this type of optical sensor, the movement of an object or the like is detected by the change in the amount of light accompanying the deformation of the optical fiber.

[0003]

Since the conventional optical sensor is configured as described above, it is possible to detect the movement of the object or the like only when the object moves in a certain direction, and in other directions, for example, When the object moves in a direction substantially perpendicular to the above direction, the deformation of the optical fiber by the object is zero, and as a result, the change in the light amount is also zero. That is, there was only one direction that can be detected by the optical sensor (hereinafter referred to as "detection direction"). Therefore, when it is necessary to detect in two or more directions, a plurality of optical sensors are required.

The present invention has been made to solve the above problems, and an object thereof is to provide an optical sensor having a plurality of detection directions.

[0005]

An optical sensor according to the present invention comprises a flexible optical fiber, a light projector connected to one end of the optical fiber, and a light receiver connected to the other end of the optical fiber. And engaged with the middle part of the optical fiber,
In order to achieve the above object, the deformation applying mechanism section is provided at two points of an intermediate section of the optical fiber, wherein the deformation applying mechanism section applies a deformation to the intermediate section according to an external force. First and second engaging respective optical fibers
A rotating body having an engaging portion, and a rotating shaft projectingly provided on the rotating body so as to extend in a direction substantially orthogonal to a longitudinal direction of the optical fiber engaged by the first and second engaging portions,
The main body is configured to rotatably support the rotary shaft around the shaft according to the external force.

[0006]

In the optical sensor according to the present invention, when an external force from a two-dimensional direction orthogonal to the rotating shaft is applied to the rotating shaft, the rotating body having the rotating shaft and the first and second engaging portions is integrated around the rotating shaft. The optical fiber is rotated, and the intermediate portion of the optical fiber is deformed. As a result, the amount of light received by the light receiver changes according to the amount of deformation, and the external force from the two-dimensional direction is detected.

[0007]

1 is a perspective view of an essential part of an optical sensor according to the present invention. 2 and 3 are a side view and a plan view of a main part, respectively. This optical sensor includes a light projecting device, a light receiving device, a highly flexible optical fiber 1, and a deformation applying mechanism part 1 for deforming the intermediate part 1a of the optical fiber 1 in response to an external force.
It is composed of 0 and. Although not shown in FIGS. 1 to 3, the light emitter and the light receiver are respectively connected to one end and the other end of the optical fiber 1, and the light from the light emitter is guided to the light receiver through the optical fiber 1. Get burned.

Next, the structure of the deformation applying mechanism 10 will be described. The deformation applying mechanism portion 10 has a main body 11, and a through hole 11 provided in a side surface portion of the main body 11.
The optical fiber 1 is inserted through a and 11b. In addition, the deformation applying mechanism 10 includes the intermediate portion 1 a of the optical fiber 1.
Is sandwiched between two cylindrical members 12a, 12a (FIGS. 2 and 3), and a first engaging portion 12 that engages with the optical fiber 1 at one point of the intermediate portion 1a, and a first engaging portion. The optical fiber 1 is composed of two cylindrical members 13a and 13a as in the optical fiber 1
The second engaging with the optical fiber 1 at another point of the intermediate portion 1a of the
A rotating body 14 having an engaging portion 13 is provided. A rotating shaft 15 is provided at the center of the upper surface of the rotating body 14 so as to extend in a direction orthogonal to the longitudinal direction of the optical fiber 1 engaged by the first and second engaging portions 12 and 13. .. The rotating shaft 15 is rotatably supported with respect to the main body 11, and when an external force from a two-dimensional direction orthogonal to the rotating shaft 15 is applied to the rotating shaft 15, the rotating direction α (rotation direction α) with the shaft as the center of rotation. Alternatively, the rotating body 14 having the rotating shaft 15 and the first and second engaging portions 12 and 13 at −α) is configured to integrally rotate.

Therefore, when the external force from the two-dimensional direction acts on the deformation applying mechanism portion 10 as described above, the intermediate portion 1a of the optical fiber 1 is deformed, and as a result, a light receiver (not shown) is formed according to the deformation amount. ) Changes the amount of light received,
External force from the two-dimensional direction can be detected. For example, consider a case where bars 16 and 17 extending in the longitudinal direction X of the optical fiber 1 and the direction Y substantially orthogonal to the direction X are provided at the tip of the rotary shaft 15 as shown in FIG. In this case, when the external force F1 is applied to the bar 16 (or the external force F2 is applied to the bar 17), the rotating shaft 15 and the rotating body 14 move the first and second engaging portions 1 as described above.
Together with 2 and 13, they rotate in the direction (-α) by an angle θ (FIG. 5), and the intermediate portion 1a of the optical fiber 1 is deformed.
Therefore, the propagation mode of the light is changed in a part of the light propagating to the intermediate portion 1 a of the optical fiber 1, and the light leaks from the optical fiber 1. As a result, the amount of light propagated to the light receiver side decreases.

FIG. 6 is a graph showing the relationship between the rotation angle θ and the light amount change ΔPf. In the figure, the circles indicate the following conditions: Optical fiber 1 ..... phi.1 mm plastic fiber spacing between engaging parts 12 and 13 ... 20 mm Cylindrical member spacing .... 8 mm When the diameter of the cylindrical member is 6 mm and the optical fiber 1 is not deformed (angle θ = 0 °), the amount of light received by the light receiver and the angle θ are 10 ° and 20 °, respectively. , 30 ° and 40 ° are plots of changes in light amount obtained from the light amounts.

As can be seen from the figure, since a predetermined relationship is recognized between the rotation angle θ and the light amount change ΔPf, it can be seen that a two-dimensional external force is simply applied to the rotating shaft 15 from the light amount change ΔPf. Not only can it be detected, but the angle of rotation of the rotary shaft 15 and the magnitude of the external force can be determined from that angle.

As an example of the use of the above-mentioned optical sensor, as shown in FIG.
19 can be attached to each to function as an impact sensor. In this case, when a shock is applied in the X direction, the weights 18 and 19 rotate around the rotating shaft 15 due to the inertial force, and the shock can be detected in the same manner as described above. As another usage mode, the bars 16 and 1 are further provided.
By attaching springs 20 and 21 to 7 respectively (FIG. 8), it is possible to function as an acceleration sensor. That is, for example, when acceleration occurs in the X direction, the rotating shaft 15 rotates against the spring force, while when the acceleration disappears, it returns to the original state (FIG. 8) against the spring force.

In the above embodiment, the rotating shaft 15 is provided with the bars 16 and 17 orthogonal to each other, but the means for rotating the rotating shaft 15 in the direction α is not limited to this.

Further, the engaging portions 12 and 13 are each constituted by two cylindrical members 12a, 12a, 13a and 13a, but other means, for example, the same size as the outer diameter of the optical fiber 1 is used. A plate having a through hole may be prepared, and the optical fiber 1 may be inserted into the through hole to engage with the intermediate portion 1a of the optical fiber 1.

[0015]

As described above, according to the optical sensor of the present invention, the rotating body having the first and second engaging portions which can respectively engage the two points of the intermediate portion of the optical fiber is provided.
Since the deformation applying mechanism is formed by rotatably supporting the rotating shaft projecting on the rotating body on the main body, when an external force from a two-dimensional direction orthogonal to the rotating shaft is applied to the rotating shaft, the rotation of the rotating shaft is caused. In addition, the rotating shaft and the rotating body are integrally rotated together with the first and second engaging portions to deform the intermediate portion of the optical fiber, which changes the light quantity at the light receiver. Can be detected.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an optical sensor according to the present invention.

FIG. 2 is a side view of a main part of the optical sensor of FIG.

FIG. 3 is a plan view of a main part of the optical sensor of FIG.

FIG. 4 is a main part plan view showing an embodiment of an optical sensor.

5 is a main-portion plan view showing an operation of the optical sensor of FIG. 4. FIG.

FIG. 6 is a graph showing a relationship between a rotation angle and a change in light amount.

FIG. 7 is a plan view of relevant parts showing an example of how the optical sensor of FIG. 1 is used.

FIG. 8 is a plan view of a main portion showing another example of a usage mode of the optical sensor of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 1a Intermediate part 10 Deformation applying mechanism part 11 Main body 12 First engaging part 13 Second engaging part 14 Rotating body 15 Rotating shaft

Claims (1)

[Claims] 1. A flexible optical fiber, a light transmitter connected to one end of the optical fiber, a light receiver connected to the other end of the optical fiber, and an intermediate portion of the optical fiber. An optical sensor including a deformation applying mechanism that applies a deformation to an intermediate portion of the optical fiber according to an external force, wherein the deformation applying mechanism engages the optical fiber at two points of the intermediate portion of the optical fiber. A rotating body having a first and a second engaging portion and a protruding body provided on the rotating body so as to extend in a direction substantially orthogonal to a longitudinal direction of the optical fiber engaged by the first and the second engaging portions. An optical sensor comprising a rotating shaft and a main body that supports the rotating shaft rotatably around the rotating shaft according to the external force.