JPH02205999A - Bidirectional optical signal transmitter for rotary body - Google Patents

Abstract

PURPOSE:To execute the exact transmission and bidirectional communication of a signal by making light beam, which is projected respectively from two projectors in a fixed direction, always made incident to a light receiver regardless of the rotary angle position of a rotary body and keeping an incident angle constant as well. CONSTITUTION:On the end face of a rotary body on the axial line of the rotary body 1 and the surface of a still stand facing to the rotary body, light receivers 23 and 26 are respectively fitted so that a light receiving surface can be orthogonal to the axial line. Then, in the side parts of the light receivers 23 and 26, projectors 22 and 27 are respectively fitted toward the direction of the light receivers 23 and 26 in the still stand 25 and the rotary body 1. Accordingly, regardless of the rotary angle position of the rotary body 1, the light beam projected in the fixed direction is always made incident to the light receivers 23 and 26. Since the incident angle always holds a fixed value, there is no danger that fluctuation is generated in the outputs of the light receivers 23 and 26 by the change of the rotary angle position. Thus, the bidirectional optical communication can be executed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for transmitting an optical signal between a rotating body and a stationary part, from the rotating body to the stationary part, and conversely from the stationary part to the rotating body.

In order to transmit optical signals bidirectionally between a rotating body and a stationary part facing it, an emitter and a receiver must be attached to each of them, so that the emitter of the rotating body always faces the receiver of the stationary stand. Also, it must be constructed so that the light projector on the stationary stand always faces the light receiver on the rotating body. However, for this purpose, it is necessary to form at least one of the two sets of light emitters and receivers into an annular shape, and it is generally extremely difficult to obtain such a light emitter and receiver. Furthermore, if only one of the emitter or receiver is formed in an annular shape, and the opposite receiver or emitter is formed in a dot shape, fluctuations in the light amount or sensitivity due to changes in the rotation angle will become a large noise component. Accurate signal transmission cannot be performed. Accordingly, the present invention provides a device capable of bidirectionally transmitting optical signals without such drawbacks.

In the present invention, light receivers are mounted to face each other on the axis of the end face of the rotating body and at opposing positions on the surface of the stationary table, and projectors are attached to the sides of these, and the light receivers are attached to the sides of these, and the light receivers are attached to the sides of the stationary table. The light receiver is configured to project signal light from a light projector on a stationary stand toward a light receiver on a rotating body. That is, the light beams projected in a fixed direction from each of the two light projectors always enter the light receiver regardless of the rotational angular position of the rotating body, and the angle of incidence is also kept constant. Therefore, there is no fluctuation in the output of the receiver due to changes in the rotational angular position, and signals can be transmitted accurately. At the same time, signals can be transmitted from the stationary table to the rotating body and from the rotating body to the stationary table. Two-way communication is possible.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIGS. 2, 3, 4, and 5 are A-A in FIG.
They are BB, CC, and DD cross-sectional views. That is, in this embodiment, the present invention is applied to a sample thermogravimetric analysis apparatus, in which a hollow cylindrical rotating body 1 is rotatably supported by a bearing 2.3, and a gear 4 attached to the lower end is connected to a motor 5. It is designed to mesh with gear 6 and rotate at high speed. A vertical shaft 8 is swingably supported at the upper end of this rotating body l by a radial shaft 7, and a horizontal rod 9 fixed to the upper end of the shaft 8 has a sample 10 for thermogravimetric analysis at both ends and a standard sample for this sample. II and housed in a disc-shaped heating furnace 12. Also, at the lower end of the shaft 8 is a light shielding rod 13.
, and projector 14 of parallel light beam p is attached to both sides of this rod.
and a photoreceiver 15 are arranged, and a bar magnet 16 whose both ends are N and S poles as shown in the figure is fixed in the center, and the magnetic poles are inserted into wire rings 17 and I8. . Note that the light receiver 15 has two light receiving elements 1 as shown in FIG.
9 and 20 are provided.

In such an apparatus, when the rotating body 1 is rotated at a high speed by the motor 5 and the temperature of the furnace 12 is changed, if the mass of the sample 10 changes due to this temperature change, the axis 8 will tilt. This causes fluctuations in the light incident on the light receiving elements 19 and 20. Therefore, this fluctuation and the output of the temperature detector of the sample IO (not shown) are added to the processing circuit 21 and input to the projector 22 in a time-sharing manner, for example. The light emitter 22 is mounted diagonally on the side of the bottom surface of the rotating body l, and the light receiver 23 is mounted on the central axis so that its light receiving surface is orthogonal to the axis, and its output is amplifier 24
It is amplified and added to the coil I7. Further, a light receiver 26 is attached to the stationary stand 25 so as to face the light receiver 23, and a light projector 27 is installed on the side thereof facing toward the light receiver 23. That is, the light receivers 23 and 26 are mounted on the axis of the rotating body 1 on the end face of the rotating body 1 and the upper surface of the stationary table 25 facing the end face so that their light-receiving surfaces are perpendicular to the axis of rotation. Further, signal light projectors 22 and 27 are attached to the sides of the light receiver on a stationary table 25, respectively, facing toward the light receiver 26 or 23.

A signal separation circuit 30 is provided on the stationary table 25 to add the time-division output of the light receiver 26 to the recorder 28 for recording, and to add the output signal of the light receiver 26 to the control circuit 29. Furthermore, the output of the control circuit 29 is recorded by the recorder 28 and at the same time sent to the projector 27 via the amplifier 31.
In addition to.

Therefore, by further amplifying the output of the light receiver 23 into which the light beam from the projector enters and applying it to the wire ring 17, the inclination of the shaft 8 can be corrected. A battery power source is provided inside the device, or the required power is supplied via a slip ring or the like.

As described in the embodiments above, the present invention provides a method of attaching a light receiver to the end face of the rotary body on the axis of the rotary body and a stationary table face opposite thereto, so that the light receiving surfaces are perpendicular to the axis. A light projector is attached to the side of the light receiver so as to face the light receiver on the stationary stand and the rotating body, respectively. Therefore, two-way optical communication can be performed using the two sets of light projector and light receiver. In addition, the light beam from the projector is always projected in a fixed direction and enters the light receiver, regardless of the rotational angular position of the rotating body. In addition, since the incident angle always maintains a constant value, there is no risk of fluctuations in the receiver's output due to changes in rotational angle position. Therefore, extremely high precision can be achieved simply by using a receiver with constant sensitivity characteristics in the circumferential direction. Two-way optical communication can be performed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, and FIGS. 2, 3, 4, and 5 are A-A and B-B in FIG. 1, respectively.
-B, CC, and DD portions are cross-sectional views. In the figure, l is a rotating body, 2゜3 is a bearing, 5 is a motor, and 7 is a rotating body.
is the axis, 10.11 is the sample and standard sample, 22.27 is the emitter, and 23°26 is the light receiver.

Claims (1)

[Claims] A light receiver is disposed on the axis of the rotating body on an end face of the rotating body and a stationary table facing the end face so that the light receiving surfaces thereof are perpendicular to the axis, and A two-way optical signal transmission device for a rotating body, characterized in that signal light projectors are attached to the sides of the stationary table and the rotating body, respectively, so as to face each of the light receivers.