JPS5927135B2 - Optical signal transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical signal transmission device with improved reliability of a signal transmission path.

As an optical signal transmission device, for example, an optical signal (PCM) obtained by converting a switch signal output by a switch provided on a steering wheel is transmitted to a control circuit provided on the steering post side, and is output from the control circuit. Some control signals actuate corresponding actuators of vehicle electrical components and the like.

According to this steering wheel optical signal transmission device,
An optical fiber transmission line is used to transmit the PCM optical signal corresponding to the signal output from the switch provided on the steering wheel to the control circuit. In this case, since the steering wheel rotates with respect to the steering post as disclosed in JP-A-53-71425, the optical fiber transmission line is wound spirally with an extra length corresponding to the rotation of the steering wheel. This prevents the wire from breaking even when the steering wheel rotates. However, with conventional optical signal transmission devices, the optical fibers are stressed by the rotation of the steering wheel, so there is a risk of the fibers breaking after years of use. It could not be used for an optical transmission line connecting two members having a rotational speed higher than the rotational speed.

Furthermore, the signal transmission device described in JP-A-54-43053 is an optical signal generating device in which a plurality of hollow cylindrical sheets having different diameters are arranged concentrically, and an optical signal receiving device having a similar configuration. , an optical transmission line formed in a space between each cylindrical cylinder and original plate forming the generating device, and a light receiving element placed in the inner part of the space, and each cylinder forming the receiving device. By transmitting an optical signal from the light emitting element at the tip of the free end toward the light receiving element with the free end of the part inserted into the optical transmission path of the generator, the light signal is transmitted by reflection from the inner wall of the transmission path. The light is configured to reach the light receiving element.

However, according to this invention, since the transmission path from the light emitting element to the light receiving element is constituted by a space surrounded by an inner wall made of a mirror surface, transmission loss is large and the amount of received light is reduced. There is a possibility that it may become serious. The present invention has been made in view of the above, and aims to improve reliability by reducing attenuation, etc. in an optical transmission path without using any optical plates, dark rooms, etc., and to improve durability. An optical transmission line connecting two members that rotate relative to each other is an optical signal output ring, and a light receiving element (having a uniform light emitting surface) disposed in the immediate vicinity of the ring and facing a ring-shaped light emitting surface (having a uniform light emitting surface) of the ring. The present invention provides an optical signal transmission device for use in a steering wheel section of an automobile, which is configured to be capable of uniformly receiving light.

That is, the optical signal transmission device according to the present invention includes a first member and a second member arranged so as to be able to rotate relative to each other, and an optical signal transmission device that is provided on the first member side and generates a signal to be transmitted according to an input signal. an optical signal output ring that is fixed to the first member and has a ring-shaped light emitting surface that inputs and converts the transmission signal and outputs an optical signal; and the ring-shaped light emission of the optical signal output ring. The device includes a light receiving element fixed to the second member facing the surface, and a circuit that inputs and processes a signal that the light receiving element converts and outputs the optical signal.

The optical signal transmission device according to the present invention will be explained in detail below.

The attached drawing shows one embodiment of the present invention, and shows a steering wheel 1, a steering shaft 2 that supports the steering wheel 1 and transmits its rotation, and a switch circuit provided on the steering wheel pad 1a and having a plurality of switches 3a. 3, a transmitting circuit 4 which inputs the signal of each switch 3a and outputs a corresponding pulse code signal, and an optical signal which is driven by the pulse code signal of the transmitting circuit 4 and outputs an optical signal equal to the signal. output ring 5;
a steering post 6; a light receiving element 7, such as a phototransistor, which is fixed to the steering post 6 and faces the ring-shaped light emitting surface on the lower surface of the output ring 5 in the immediate vicinity of the optical signal output ring 5; and a signal outputted by the light receiving element 7. control circuit (not shown, which switch 3a of the switch circuit 3)
A lead wire 8 is connected to the steering wheel 1, and slip rings 9 and 10 are provided on the steering wheel 1 and supply power to the horn and the transmission circuit 4, respectively. , 10, and lead wires 13, 14 for connecting the slip contacts 11, 12 to a power source.

The optical signal output ring 5 is composed of a surface emitting diode whose lower end is a ring-shaped light emitting surface, and the transmitting circuit 4
It is also fixed to the steering wheel side.

In the above configuration, any switch 3a of the switch circuit 3 provided on the pad 1a of the steering wheel 1
When the switch 3a is operated, a switch signal is sent from the switch circuit 3 to the transmission circuit 4, and a pulse signal corresponding to the switch 3a is outputted from the transmission circuit 4.

When this pulse signal (for example, a 4-bit pulse code signal such as 1010 or 1001, which controls the corresponding vehicle electrical equipment by the code string) is input to the optical signal output ring 5, the pulse signal corresponds to the pulse signal. ring 5
The ring-shaped light-emitting surface on the bottom end of the device emits light uniformly. Since the light receiving element 7 faces the light emitting lower surface of the optical signal output ring 5, the light signal output from the ring 5 is uniformly received by the light receiving element 7 regardless of the steering angle of the steering wheel 1, and the light is not received. A pulse signal equal to the optical signal from the element 7 is inputted via a lead wire 8 to a control circuit (not shown) to perform the aforementioned control action. By performing the above operations, the driver can press the steering wheel pad 1 without changing his driving position.
Various controls can be performed by operating the switch 3a provided at the switch 3a. In the above embodiments, the light receiving element is arranged opposite to the lower surface of the optical signal output ring, but the invention is not limited thereto. The light receiving element may be arranged to face the surface. As explained above, according to the optical signal transmission device according to the present invention, an optical transmission path connecting two members having relative rotation is connected to an optical signal output ring and a light receiving element disposed opposite to the ring. With this configuration, it is possible to improve the reliability of the optical transmission line and eliminate restrictions on usage.

[Brief explanation of drawings]

The accompanying drawings are explanatory diagrams showing one embodiment of the present invention.

Claims (1)

[Claims] 1 A first member consisting of a steering wheel and a steering pad; a second member consisting of a steering post that supports the first member in a relatively rotatable manner; a transmitting circuit that generates a signal to be transmitted in response to a signal output by operating a switch provided on a first member; and a transmitting circuit fixed to the first member;
an optical signal output ring having a ring-shaped light-emitting surface that inputs and converts the transmission symbol and outputs an optical signal; and a ring-shaped light-emitting surface fixed to the second member in the immediate vicinity of the optical signal output ring, facing the ring-shaped light-emitting surface. What is claimed is: 1. An optical signal transmission device comprising: a light-receiving element, and a circuit for input processing a signal that the light-receiving element input-converts and outputs the optical signal.