JPH0157883B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical signal output ring in an optical signal transmission device such as a vehicle that transmits each operation signal of a plurality of switches provided on a steering wheel to its load control device via an optical signal. Regarding a light source.

Conventionally, this type of ring-shaped light source for outputting optical signals has been made of an optically transparent material with high light transmittance, such as acrylic resin, as shown in Figure 1 A and B, Figure 2 A and B, and Figure 3 A and B. The light guide rings 1 and 2 have a rectangular or trapezoidal vertical cross-sectional shape, or the light guide ring 3 has a taper on the opposite side of the light output surface along the circumference. One light emitting element L provided inside covers the entire circumference of the light output surface. Therefore, as shown in FIG. 4, the lighting circuit for the light emitting element L amplifies the signal from the transmission signal output section 4 using, for example, a transistor 5 to light one light emitting element L.

Such conventional ring-shaped light sources for optical signal output use only one light-emitting element as a light-emitting source, so if the light-emitting circuit or light-emitting element becomes abnormal or damaged, signal transmission becomes impossible and the vehicle, etc. There are drawbacks that can interfere with the operation of vehicles and, depending on the load, can even lead to dangerous situations.

This invention was made in view of the above points,
Multiple light guiding rings each containing a built-in light emitting element are combined in concentric circles or on the same circumference,
By configuring each light emitting element to light up at the same time, even if one light guiding ring and its optical signal transmission path fail, the remaining light guiding rings can continue optical signal transmission, making it extremely reliable. An object of the present invention is to provide a ring-shaped light source with high optical power.

Hereinafter, the present invention will be explained in detail by way of examples with reference to the drawings.

First, a light-emitting element (hereinafter, light-emitting elements with the same function are indicated by the same reference numerals regardless of the drawing)
The lighting circuit will be explained with reference to FIG. In the figure, the electric signal from the transmission signal output section 6 is amplified by one transistor 7, and the output is used to connect the light emitting elements (light emitting diodes in the figure) L ₁ , L ₂ .
The lights are lit in parallel. In FIG. 4B, the output signal of the transmission signal output section 6 is connected to the bases of transistors 8 and 9 whose loads are the light emitting elements L ₁ and L ₂ , respectively.

Next, examples of light guide rings and their combinations will be described. FIG. 6 shows an embodiment of the light guiding ring. In FIG. The respective facing parts 10b and 11b are connected to the light guiding ring 1.
A taper is provided along each circumference of 0 and 11. The inner diameter of the larger light guide ring 10 is dimensioned to match the outer diameter of the smaller light guide ring 11, and these two light guide rings 10 and 11 are arranged concentrically on the same plane and tightly closed as shown in FIG. 6B. They may be combined into one piece by fitting, or may be molded into one piece from the beginning. In the figure, light emitting elements L ₁ , L ₂
are embedded in the thickest parts of the light guiding rings 10 and 11, respectively, with their input terminals protruding, and the light emitted from the light emitting elements L ₁ and L ₂ causes the light output surfaces 10a and 11a of the respective light guiding rings 10 and 11 to be illuminated. It is arranged to cover the entire circumference of the light output.

By stacking and combining the light guide rings 10 and 11 in this way, it is possible to not only light up both the light emitting elements L ₁ and L ₂ at the same time, but also to light up the light output surface 10 a of the outer light guide ring 10 even when only one of them is lit. Optical signals can be transmitted to the outside from.

In the embodiment shown in FIGS. 7 and 8, the light output surface 12a is formed on the side surface of the light guide ring 12 in the light output direction P, and the light emitting element _L1 is the thickest or widest part of the light guide ring 12. Embedded in place,
In the figure, the light emitted from the light emitting element _L1 is guided through the light guide ring 12 by dividing into left and right sides along the circumference by the notched light entrance surface 12b. Light guide ring 12
The inner diameter surface of the light guide ring 12, that is, the facing surface of the light output surface 12a, has a serrated knurling finish for light reflection, and is formed so that light is outputted radially to the outside from the ring side surface 12a of the light guide ring 12. . Note that instead of knurling, a reflective layer may be formed by applying a reflective material to the inner diameter surface.

A light guide ring 13 formed in the same shape and structure as this light guide ring 12 is stacked on the light guide ring 12 so that the light emitting element L ₁ and the light emitting element L ₂ are on opposite sides of each other or at a position forming a desired angle. is the 8th
They are shown in Figures A, B, and C. Although the light emitting elements L ₁ and L ₂ in the above two embodiments can be lit by a lighting circuit as shown in FIG. 5, the circuit configuration is not limited to this.

Further, in the above embodiment, two light guiding rings were described, but the number may be two or more.

As described above, the present invention combines or integrates a plurality of light guide rings each equipped with a light emitting element along the same center line to form a ring-shaped light source for outputting an optical signal having the same shape. Therefore, even if the optical transmission path of any one of the ring-shaped light sources for optical signal output is damaged, or the light emitting element, light emitting circuit, etc. is broken, optical signal transmission can continue through the remaining optical guide ring. It becomes extremely reliable. It can also be applied not only to steering wheels but also to optical signal transmission with rotating devices.

[Brief explanation of drawings]

1, 2, and 3 are a perspective view and a sectional view, respectively, showing a conventional example of a light guide ring of a ring-shaped light source for outputting an optical signal, FIG. 4 is an example of a conventional light emitting element lighting circuit, and FIG. 5 - Figures 8 are for explaining the present invention; Figures 5A and 5B are examples of light emitting circuits of light emitting elements, Figure 6A is an exploded perspective view of a light guide ring of one embodiment, and Figure 6B is the same. A plan view and a front view of the assembled state, FIGS. 7A and 7B are details and exploded perspective views of other embodiments of the light guiding ring, and FIGS. 8A and 8B are exploded perspective views.
C shows the plane, front, and front of the ring-shaped light source for optical signal output after the light guide ring has been assembled in Fig. 7, respectively.
FIG. 10, 11, 12, 13...light guide ring, 10
a, 11a...Light output surface, _L1 , _L2 ...Light emitting element.

Claims (1)

[Scope of Claims] 1. In an optical signal transmission device that transmits the output from the operation of switches provided on a steering wheel as an optical signal to control a load, a plurality of sets of light guide rings each having a light emitting element embedded therein are stacked and integrated. A ring-shaped light source for outputting an optical signal, characterized in that it is configured as follows. 2. The ring-shaped light source for outputting an optical signal according to claim 1, wherein the opposite side of the light output surface of the light guiding ring is a light reflecting surface. 3. Claims 1 or 2, wherein the opposite surface of the light output surface of the light guide ring is formed into a tapered surface such that the thickness in the direction of light output decreases depending on the distance from the light incidence point of the light emitting element. A ring-shaped light source for outputting an optical signal according to any one of paragraphs.