JPH08241658A - Photo-sensing type switch - Google Patents

Abstract

PURPOSE: To turn on and off a plurality of circuits using one LED by furnishing a resilient piece or light shielding plates to shift in association with swinging of a key top and open or cut the optical path leading to a photo-sensor. CONSTITUTION: When a key top 5 is not pushed, none of the key top 5 and a supporting shaft 3A is swinging, and the light-beam emitted from an LED 9 is reflected by a light-guide 2 and put incident to all sensors such as photo- sensors 4A, 4C. At this time, light shielding plates 13A-13D do not shut off the reflected light. When the key top 5 is pushed, the supporting shaft 3A swings and inclines. At this time, the shaft 3A is guided by a slit 7B so that the swinging direction is specified, and the inclination is restricted by a slope 7C, As a result, the lower part of a swinging piece 3, for example the plate 13A, shuts off the reflected light released from the end face 21A of a branch 2A from the photo-guide 2. Accordingly the light incident to the photo-sensor 4A is shut off, and the output of the sensing current from the photo-sensor 4A is ceased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light detection type switch, and more particularly to a light detection type switch mounted on an automobile or the like.

[0002]

2. Description of the Related Art A number of switches for controlling the operation of electric components and circuits are incorporated in transportation equipment such as automobiles. It has always been the case to arrange individual key tops for such a large number of switches, but with such a configuration, the operation of the key tops is complicated, and the switch cannot be downsized. There was a problem. Therefore,
When one key top is pushed in various directions, the key top oscillates to develop a structure for switching multiple circuits. As a switch applied to such an oscillating type key top, conventionally, for example, a structure of a contact (contact) that is mounted in an electrical system and can interrupt a current has been widely used. However, such contact switches are
There are drawbacks such as contact failure due to wear of the contact portion and surface contamination, and failure due to damage of the contact portion. Therefore, a contactless type non-contact switch has been adopted.

As a typical example of such a non-contact type non-contact switch, there is a light detection type push button switch disclosed in Japanese Patent Application Laid-Open No. 61-253727. This structure will be described with reference to FIG. 14. This light detection type push button switch has various shapes of the light shielding plate 10 by pressing one push button 102 or 103 in multiple stages.
6, 142 and the like are moved and inserted between the light emitting diodes LED and the optical sensor PT, which are provided in pairs in one circuit, and various kinds of operations are performed according to the output of the optical sensor.

[0004]

However, according to this configuration, since one pair of light emitting diodes LED and optical sensor PT are used for one circuit, in a switch for operating multiple circuits, a plurality of pairs of light emitting diodes are used. Since the LED and the optical sensor PT are required, it is difficult to miniaturize the switch and it is disadvantageous in terms of cost. Furthermore, since the action mechanism 130 for performing the pushing operation in multiple stages and other components are also complicated in shape and the number of parts is very large, mass productivity is poor and the mechanism is easily broken. was there. The present invention has been made to solve such problems and drawbacks, and an object thereof is to provide an optical detection switch which has a small number of parts and can be miniaturized, has a simple mechanism, is excellent in reliability, and is suitable for mass production. It is in.

[0005]

In order to achieve the above object, a photo-sensing switch according to the present invention splits light from at least one light emitting diode, a plurality of photo sensors, and the light emitting diode. A light guide that transmits to a plurality of optical sensors, a swingable key top, and a light shielding plate that moves with the swing of the key top to open or block an optical path of the light to the optical sensor. It is characterized in that it is equipped with. Alternatively, it is characterized in that the light shielding plate is provided with a transmission hole that allows the light to pass through the light sensor.

Alternatively, a swingable key top, at least one light emitting diode, and a plurality of optical sensors,
A light guide for branching the light from the light emitting diode and transmitting it to the plurality of photosensors, and a transmission hole existing between the light guide and the plurality of photosensors and directed in the branching direction of the light. An elastic body having an elastic body, the elastic body being deformed when the key top is directly or indirectly pressed by the swing of the key top, and the position of the transmission hole is moved. To do.

[0007]

In the light detection type switch according to the present invention, the light guide body splits the light from one light emitting diode and transmits it to the plurality of light sensors, while the light shield plate or the elastic member moves in accordance with the swing of the key top. The body moves or deforms to open or block the optical path of the light to the optical sensor. A plurality of circuits are turned on / off based on a change in the photodetection current generated by opening or blocking the optical path.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of an embodiment of the light detection type switch according to the present invention. FIG. 2 is an overall perspective view of the light detection type switch shown in FIG.

The light detection type switch 1 according to the present invention is used to switch four kinds of circuits with one key top. The key top 5 is provided so as to be swingable, and is connected to the key top 5. And a spring 8 for winding the swing body 3 to support the swing of the swing body 3 and for returning the swing body 3 from the swing state to the current state. A housing 7 for guiding the swinging direction of the swinging body 3, a cross-shaped light guide 2 arranged below the swinging body 3, a light emitting diode fixed below the center of the light guide 2 and projecting light upward 9. Four optical sensors 4A, 4B respectively arranged adjacent to each cross-shaped branch of the light guide 2.
4C, 4D, the light guide 2 and the light emitting diode 9, and the lower cover 10 to which the four optical sensors 4A, 4B, 4C, 4D are attached.

A protrusion 7A having a substantially circular cross section is provided at the upper end of the housing 7, and a cross-shaped slit 7B extending in the diametrical direction (horizontal direction in the drawing) is bored at the center of the protrusion 7A. There is. The slit 7B is formed on an inclined surface 7C that is inclined downward, and the center of the slit 7B is opened in a circular shape. The oscillating body 3 is provided with a tubular support shaft 3A whose upper portion extends in the axial direction, a square plate 3B vertically attached to the lower end of the support shaft 3A in the axial direction, and a substantially rectangular center of the square plate 3B. Also, four shading plates 13A to 13D
It has. The light-shielding plates 13A to 13D respectively correspond to the branch portions 2A to 2A of the light guide 2 which will be described later as the key top 5 swings.
It is provided so that it can be inserted into the optical path formed between the 2D end faces 21A to 21D and the optical sensors 4A to 4D (see FIGS. 5 and 6), and blocks the light emitted from the end faces 21A to 21D. A light guiding through hole 3C is bored from the lower end to the upper end inside the support shaft 3A, and the upper end of the light guiding through hole 3C is connected to an illumination portion 6 provided at the center of the key top 5 so as to communicate therewith. The support shaft 3A is provided so as to pass through a slit 7B having a circular opening in the center of the housing 7,
Moreover, it has a thickness that allows it to swing inside the slit 7B.
The spring 8 is for returning the key top 5 and the rocking body 3 which are rocked in the cross direction by the operation of the operator.

FIG. 3 is an external perspective view of the light guide 2 shown in FIG. 1, and FIG. 4 is a sectional view thereof. The light guide 2 is for reducing the number of light emitting diodes incorporated in the light detection type switch, and is formed of an optically transparent material (acrylic or the like) such that the branch portions have a cross shape. As shown in FIG. 3, the light guide 2 reflects the incident light I1 and reflects each of the branches 2A to 2D.
Reflective surfaces 20A-20D designed to be evenly distributed over
And branching the light from the light emitting diode 9 into each branch 2
Radiation lights R1 to R4 are emitted from the end faces 21A to 21D of A to 2D. On the other hand, the transmitted light T1 transmitted upward through the light guide 2
Is introduced into the light guide through hole 3C inside the support shaft 3A.

This light guide body 2 can have the same function as a plurality of light emitting diodes by one light emitting diode by arbitrarily setting the number of branches, and further, there is no change with time and the initial characteristics. Because it can be maintained, it is highly reliable,
Further, since it can be manufactured by integral molding, it is excellent in mass productivity.

The radiated lights R1 to R4 emitted from the end faces 21A to 21D of the light guide body 2 are respectively incident on the optical sensors 4A to 4D arranged at a slight distance from the end faces 21A to 21D. To be done.

FIG. 5 is a sectional view of the light detection type switch shown in FIG. 1 when the switch is not operated. Further, FIG. 6 is a cross-sectional view of the light detection type switch shown in FIG. 1 during operation. The operation will be described below with reference to both figures. If the key top 5 is not operated, neither the key top 5 nor the support shaft 3A is swinging as shown in FIG. In this state, the light beam emitted from the light emitting diode 9 is reflected by the light guide 2 and is incident on all the optical sensors such as the optical sensors 4A and 4C.
As a result, all the optical sensors output the detection current.

At this time, the light-shielding plate 13A below the oscillator 3
13A to 13D are all located on the upper side, and therefore, the light shielding plates 13A to 1D
3D does not block the reflected light. On the other hand, the transmitted light T1 that has passed through the light guide 2 upward is introduced into the light guiding through hole 3C inside the support shaft 3A, passes through the light guiding through hole 3C, and passes through the illumination portion 6 at the center of the key top 5. Illuminate.

Then, as shown in FIG. 6, when the key top 5 is operated, the key top 5 and the support shaft 3A rock and tilt. At this time, the support shaft 3A is guided by the slit 7B to specify the swinging direction, and the inclination is regulated by the inclined surface 7C. As a result, a specific light-shielding plate below the rocking body 3, for example, the light-shielding plate 13A descends to a state where it does not come into contact with the light guide 2, so that the light-shielding plate 13A is guided by the light guide 2A.
The reflected light emitted from the end face 21A of the branch portion 2A is blocked. Therefore, the light incident on the optical sensor 4A is blocked, and the output of the detection current of the optical sensor 4A is stopped. The switch operation is performed based on the stop of the detected current output. In addition,
The reason why the light-shielding plate 13A is prevented from coming into contact with the light guide 2 by the swinging of the key tops 5 is to prevent damage such as displacement of the light guide 2 or damage to the end surface of the light guide 2 due to the contact. And prevents the radiation light from the light guide body 2 from being scattered due to, for example, damage.

FIG. 7 is a perspective view of an essential part of another embodiment of the photo-detecting switch according to the present invention. In this example,
While the above-described embodiment specifies the switch operation by blocking the light, it is configured to specify the switch operation by transmitting the light. FIG. 8 is an operation explanatory view of the light detection type switch of FIG. 7 when the switch is not operated. Further, FIG. 9 is an operation explanatory diagram when the light detection type switch of FIG. 7 is operated. In this embodiment, similarly to the above, the light detection type switch 21 performs switch operation of four kinds of circuits with one key top, and each light shielding plate, for example, the light shielding plate 13A is provided with the transmission hole 30A. . The transmission hole 30A is provided on the tip side of the light-shielding plate 13A, and its position is such that when the key top (not shown) is not operated, the light beam from the light emitting diode 9 is reflected by the light guide body 2 and comes from the branch portion 2A. Emitted, light sensor 4
It is formed so as to block the reflected light R1 reaching A and to allow the reflected light R1 to pass when the key top is operated. That is, each light shielding plate is inserted between the optical paths of the respective branch portions 2A to 2D (see FIG. 3) of the light guide 2 and the optical sensor 4A in the steady state when the key top is not operated.

Therefore, when not in operation, as shown in FIG. 8, the transmission hole 30A is located away from the optical path of the reflected light R1 to the optical sensor 4A, and prevents the reflected light R1 from entering the optical sensor 4A. Therefore, there is no light detection output from the light sensor 4A. This is the same for all the other reflected lights R2 to R4 and the optical sensors 4B to 4D. Next, as shown in FIG. 9, when the key top is operated and rocks, a light blocking plate in a direction diagonal to the rocking direction, for example, the light blocking plate 13A moves up and the transmission hole 30A also moves upward to reflect the reflected light. R1 comes to be located in the optical path leading to the optical sensor 4A, and the reflected light R
1 is incident on the optical sensor 4A. Therefore, a light detection output is generated from the light sensor 4A. On the other hand, with respect to all the other reflected lights R2 to R4 and the optical sensors 4B to 4D, the optical path interruption is established at all, so that no optical detection output is generated from the optical sensors 4B to 4D. As a result, of the switches of the four types of circuits, only the operated one is specified and driven.

FIG. 10 is a perspective view of an essential part of still another embodiment of the photo-detecting switch according to the present invention.
You can perform 4 kinds of operations with one key top. The light detection type switch 41 in this embodiment replaces the light shielding plate, and has an elastic body 15A having transmission holes 18A to 18D in the light branching direction.
.About.15D block the light path. FIG. 11 is a cross-sectional view of the light detection type switch 41 shown in FIG. 10 when it is not operated.
FIG. 12 is a cross-sectional view illustrating a state when the elastic body shown in FIG. 10 is not operated. Further, FIG. 13 is a cross-sectional view illustrating a state when the elastic body shown in FIG. 10 is operated.

The light detection type switch 41 includes a housing 47.
A key top 45 that is swingable around a bearing ball 49 that is slidably embedded therein, and four pistons 46A that come into contact with the back surface of the key top 45 and that move vertically as the key top 45 swings. ~ 46D with housing 4
A light guide 2 having four branch portions is arranged on a substrate 48 fixed below 7. The light-emitting diode 9 is incorporated in the lower center of the light guide 2, and the light guide 2
Each of the optical sensors 4A-
4D is arranged. Further, four elastic bodies 15A to 15D are provided in the space from the tip of the branch portion of the light guide 2 to the optical sensors 4A to 4D, the substrate 48 and the pistons 46A to 46D.
It is arranged to be inserted between them.

The elastic members 15A to 15D are made of a material such as rubber and have both a spring function and an optical path blocking function, and are formed in a dome shape as shown in FIG. 10 or FIG. For example, the elastic body 15A will be described. As shown in FIG. 12, a dome-shaped interior has a shield portion 16A protruding toward the substrate 48, and a spring portion 17A forming a dome-shaped peripheral wall has a light-shielding portion 16A. Has a pair of transmission holes 18A that allow the light to pass therethrough in the horizontal direction. When no external force is applied to the upper end of the elastic body 15A, the reflected light R1 from the light guide body 2 passes through the transmission hole 18A as shown in FIG. Key top 4
When 5 is operated to swing, for example, the piston 46A is pushed down as the key top 45 swings, and the dome-shaped elastic body 15A is deformed by receiving a pressing force F from above as shown in FIG. As a result, the elastic body 15A has the spring portion 1
As a result of 7A being distorted and the shield 16A being lowered, the optical path is blocked, and the reflected light R1 is blocked and the optical sensor 4A is blocked.
Will not reach. As described above, in this embodiment, the optical path of the reflected light to the optical sensor is opened or blocked by the deformation of the elastic body to perform the switching.

By the way, when the number of branches of the light guide increases,
Since the amount of light per branch is reduced, the light emitted from the end face is weakened. Therefore, for the purpose of enhancing the emitted light from the end face, the light incident portion from the light emitting diode,
It is also effective to apply paint to parts other than the end faces. In each of the above-mentioned embodiments, the light guide is described as one in which the light from the light emitting diode is branched as reflected light into a plurality of photosensors. By bending one end of the fiber array formed by bundling to open radially, and by arranging optical sensors on the bent front ends respectively, the light from the light emitting diode is made to enter the optical sensor as transmitted light. Good.

[0023]

As described above, the photo-sensing switch according to the present invention has a light guide for branching light from one light emitting diode and transmitting it to a plurality of photo sensors, and a swing of a key top. Therefore, a light-shielding plate or an elastic body that opens or blocks the optical path of the light to move to the optical sensor is provided, so that a single light-emitting diode is used to turn on / off a plurality of circuits. To be done. Moreover, since the number of parts is small, the device can be miniaturized, and since the mechanism is simple, there are few failures, which is excellent in reliability and suitable for mass production. Therefore, its industrial effect is great.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of a light detection type switch according to the present invention.

FIG. 2 is an overall perspective view of the light detection type switch shown in FIG.

FIG. 3 is an external perspective view of the light guide body shown in FIG.

FIG. 4 is a side view of the light guide body shown in FIG.

5 is a cross-sectional view of the light detection switch shown in FIG. 1 when not operated.

FIG. 6 is a cross-sectional view of the light-sensitive switch shown in FIG. 1 during operation.

FIG. 7 is a perspective view of a main part of another embodiment of the photo-detecting switch according to the present invention.

FIG. 8 is an operation explanatory view of the light detection type switch of FIG. 7 when not operated.

FIG. 9 is an operation explanatory diagram when the light detection type switch of FIG. 7 is operated.

FIG. 10 is a perspective view of a main part of still another embodiment of the photo-detecting switch according to the present invention.

11 is a cross-sectional view of the light detection type switch of FIG. 10 when not operated.

12 is a cross-sectional view illustrating a state of the elastic body shown in FIG. 10 when not operated.

13 is a cross-sectional view illustrating a state when the elastic body illustrated in FIG. 10 is operated.

FIG. 14 is an exploded perspective view of a conventional push button switch.

[Explanation of reference numerals] 1 light detection type switch 2 light guide 3 swinger 3A support shaft 3C light guiding through hole 4A to 4D optical sensor 5 key top 6 illumination part 7 housing 7A protrusion 7B slit 8 spring 9 light emitting diode 10 Lower cover 13A-13D Light shield

Claims (3)

[Claims] 1. At least one light emitting diode, a plurality of light sensors, a light guide body for branching light from the light emitting diodes and transmitting the light to the plurality of light sensors, and a swingable key top. A light-sensing switch, comprising a light-shielding plate that is moved with the swing of the key top to open or block an optical path of the light reaching the optical sensor. 2. The light detection switch according to claim 1, wherein the light shielding plate is provided with a transmission hole that allows the light to pass through the light sensor. 3. A swingable key top, and at least one key top.
A plurality of light emitting diodes, a plurality of light sensors, a light guide for branching light from the light emitting diodes and transmitting the light to the plurality of light sensors, and between the light guide and the plurality of light sensors And an elastic body having a transmission hole extending in the direction of branching of the light, the elastic body being deformed when directly or indirectly pressed by the keytop with the swing of the keytop, An optical detection type switch characterized in that the position of the hole is moved.