JPS5923257A - Optical fiber type sensor - Google Patents

Abstract

PURPOSE:To connect directly and electrically a projecting and photodetecting part and a control part, and to eliminate an electric noise picked up by an electric wire, by bundling three optical fibers to one piece, using it as a projecting and photodetecting use detecting cable, and detaching the projecting and photodetecting part from a code plate, and placing it at the control part side. CONSTITUTION:Light is irradiated to a code plate 6 from a projecting part 10 by a projecting fiber 9 in a detecting cable so as to be opposed to a prescribed position of the code plate 6. As the code plate 6 rotates, a reflection face 7 and a non-reflection face 8 make irradiated light pass through alternately, pulse-like reflected light is detected, and it is converted to an electric signal by photodetecting parts 11, 12. In case when a rotary shaft 1 rotates in the right direction, a reflected beam from the reflection face 7 is detected by the photodetecting part 11 first, and thereafter, is detected by the photodetecting part 12. This discrimination is executed by a direction discriminating circuit 13 in a control part 15. The number of pulses obtained by the photodetecting parts 11, 12 corresponds to the number of the reflection faces 7 of the code plate 6, and by counting it, a rotating quantity of the rotary shaft 1, namely, a rotating speed can be known, and also an electric noise picked up by an electric wire can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber sensor, for example, for determining the opening/closing direction of the drive shaft of an automatic door and detecting the moving distance and speed.

2. Description of the Related Art Conventionally, there is a device using a light emitter/receiver as shown in FIG. 1 as a device for detecting the moving distance and speed when an automatic door is opened and closed. This is automatic B no Jll<ir+IJIl
lllf++ Ni solid a sales IJ) Disc f2) No x Intermittent light rays caused by the rotation of the slit disc (2) are caused by the emitter (3) and receiver (4) placed across the slit part. A device that detects this as a pulse train. The number of pulses of light detected determines the moving distance of the automatic door, and the number of pulses of light within a certain period of time determines the moving distance of the automatic door.
The orientation speed of III is known. In the case of such a light beam sensor, a phototransistor, for example, is used as the light receiver (4), and a light signal is converted into a pulsed electric signal. Therefore, the signal from the sensor is transmitted by the electric wire (5), but this electric wire (5) tends to pick up noise due to electromagnetic n1 conduction, and also has the drawback that the signal is attenuated if it is extended for a long time. Furthermore, as a light emitter (3), for example, a light emitting diode is used, but such a light emitter/receiver i3) +41 is connected to the IQ probe with a slit disk (2) in between. I have to be angry. The installation requires a place to install the part side, and the installation is complicated, so the outer shape of the bag layer becomes large.'):If point also occurs.

In addition to the above sensor, a rotary encoder can be used to measure the rotational speed of the automatic door's drive shaft, but since this is a mechanical device, it has a short lifespan when used for a long time.

In view of the above-mentioned drawbacks of the conventional technology, the present invention is an improved version that eliminates the electrical noise, can be stored in a small space, and also determines the rotational direction of the drive shaft of the self-Ils. The aim is to provide sensors that can.

That is, a detection cable in which eight light emitting/receiving light beams are bundled into one is placed opposite to a code plate in which reflective surfaces and non-reflective surfaces are alternately formed at predetermined intervals, and is led out from the other end of the detection cable. A light emitting/receiving element is optically coupled to the eight optical fibers, forming a light emitting/receiving section, where photoelectric conversion is performed. Also, if the light receiving light 7 eyebar is made into two, K υ
To provide a stone sensor that can also determine the direction of rotation of a rotating shaft.

Hereinafter, the configuration of the present invention will be explained according to examples. In Figure 2(a), (6) is the reflective surface (7) and the non-reflective surface (8).
) are formed alternately at predetermined intervals, and are fixed to the rotating shaft fil, PIJ 1: automatic door drive 1q11. The code plate (0) with the slit disk (2
), but the slit part is a reflective surface (7)
This becomes a non-reflective surface (8). and eight optical fibers (
9) F is a detection cable (bundled into one as shown in Fig. 8) with one end facing a predetermined position of the code plate (6).
+1;). Of the eight optical fibers (9) led out from the other end of this detection cable (1φ), one reaches the light projecting section (10) and is optically coupled to a light projecting element, for example, a light emitting diode, The remaining two reach the light receiving section (11) θ→ and are similarly optically coupled to a light receiving element, for example, a 7-ototransistor.

The light signal converted into an electric signal by the light receiving element reaches the control unit 00, where the rotation, position, rotation speed, and rotation direction of the rotation shaft (1) are detected. In addition, θno in FIG. 8 is the attachment part for making the detection cable (16 face the predetermined position of the code plate (6)), and O→ is the 8-piece tree led out from the other end of the detection cable (16). The optical fiber (9) is connected to the light emitting part (1o) and the light receiving part (11) (+2
) The installation of the dam to be connected to is part.

Next, the operation of the present invention will be explained with reference to the drawings. #g2 As shown in FIG. Light is irradiated on. Then, as the code plate (6) rotates, the irradiated light passes through the reflective surface (7) and the non-reflective surface (8) alternately, so that a pulsed reflected light is detected at the light receiving section (11) (+2). . This pulsed light signal is transmitted to the light receiving section C.
11) (converted to electrical signal at 1→, 71')
The result is a pulse train as shown in Figure 4 (a) <b). Here, (M) is the pulse train of the output signal of the light receiving section (11), (B
) indicates the pulse train of the output Ig from the light receiving section 0→. this(
A) The correspondence relationship in (B) differs depending on the rotation direction of the rotating shaft (1), p! Figure c4 (a) shows the right direction (R direction) of the rotation axis +I), and Figure 4 (b) shows the left direction (left direction) of the rotation axis (1). That is, when the rotation axis (1) rotates to the right as shown in Figure 8g2 (b), the reflective surface (7)
The reflected light beam is first detected by the light receiving part (ll), then by the light receiving part (12), and
, which rotates to the left, is detected in the opposite order.

Therefore, the rotation direction is determined based on the order in which the light is detected by the light receiving sections (+1) (1z). This determination is made by the control unit (16)
This is performed by a direction determination circuit (In) within the circuit, for example, a D flip-flop circuit. That is, in the case of lfE 4 to the right in Figure (a), the D flip-flop circuit (13) K
When a clock pulse is input from (^), the information input from (n) to the input terminal (T) is always 150'', so the output 0 is always ・(1''). In the case of the left direction in Figure 4 (b), the D flip-flop circuit 03) (^)
When more clock pulses are input, input from (B) ◇
:The information that enters the cloth (D) is always '1'', so the output (
2) Q is always "0#". However, such a direction can be determined by (A-) (I
There is an overlapping time (1) in the name pulse of υ (easily possible, and if there is no overlapping time (1) f4, when a clock pulse is input from (mu) to the D flip Flora 1 circuit θQ, The information input from the input terminal (D) from the input terminal (D) is always "0" regardless of the direction of rotation of the rotating shaft (1), making it impossible to determine the direction. Therefore, in order to create the time (t) according to the above pattern, the width (N) of the two light-receiving optical fibers (-(9) The output signal from the direction determining circuit 03) must be narrower than or equal to the direction determining circuit 03).
4)', and in particular, the direction of rotation of the rotation axis (+) is determined.

Next, the number of pulses obtained at the light receiving section (11) (+2) corresponds to the KQ of the reflective surface (7) of the code plate (6), so by counting this, the amount of rotation of the rotation axis (1) can be calculated. You can know. The rotational speed of the rotation axis tl+ can be determined from the Kurus interval (4) and the rotational speed shown in FIG.
An output signal from the country enters the 0PU04), where the rotation amount and the oral transmission speed are calculated.

As explained above, the present invention can connect eight optical fibers to one
The light emitting/receiving detection cable is bundled in a book, and this transmits the irradiated light from the light emitting part to the code board, and the reflected light from the code board to the light receiving part. Placed on the control section side? I can do 7 things. Therefore, unlike the conventional method, the light emitting and receiving parts are directly connected to the slit disk.
It is not necessary to connect the light emitting/receiving section and the control section directly to the control section without having to face each other and route the electrical wires from there to connect the control section. The electric current picked up by the wire (target noise I-1) is removed.Also, since only one end of the detection cable bundled into one is placed facing the code board, the installation space can be reduced. , J.I.
Q-shiri is easy to make yourself. Moreover, unlike before, the direction of rotation 111+ can also be determined.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a sensor for detecting the rotation amount and speed of a rotating shaft since Eif.
M (f, opening of the park, Fig. 2 (b) eye: I
Fig. 8 is a perspective view of the detection cable and the light emitting/receiving part according to the present invention, and Fig. 4 (a) and (b) are diagrams showing the pulse of the output signal from the light receiving part according to the present invention. FIG. (I'i)...Code plate, (7)...Reflective surface on the code plate, (8)...Non-reflective surface on the code plate, (9).
...Optical phino (-1 (In) ... light emitting part, (11
) (12)... Light receiving section, θ0... Detection cable.・(hl ■ No. 91/l (weak)

Claims (1)

[Claims] +1) A code plate in which reflective surfaces and non-reflective surfaces are alternately formed at predetermined intervals, and eight optical fibers are bundled into one,
a detection cable with one end facing a predetermined position of the code plate; one throwing C element and two projection C elements optically coupled to each of the eight optical fibers led out from the other end of the detection cable; An optical fiber set sensor comprising a light receiving element and a light receiving element.