JPH0445304Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Industrial Application Field) The present invention relates to a contactless switch device using a light projecting element and a light receiving element.

(Prior Art) As one means for making a switch contactless, it has been considered to combine a light emitting diode and a phototransistor. As an example of this type of switch device, conventionally, a light guide member made of, for example, transparent plastic or optical fiber is used to form an optical path between a light emitting diode and a phototransistor, and this optical path is used for manual operation of an operating section. There is a structure in which a responsive member is provided to cut off the light accordingly, and the phototransistor is determined to be in the on state when the phototransistor is in the non-light receiving state. Further, in this case, in order to save power and the like, it is also considered to have a structure in which the light emitting diode periodically emits light intermittently.

(Problem to be solved by the invention) In the conventional switch device described above, when the phototransistor is in the non-light receiving state, it is determined to be in the on state, so if the light emitting diode fails, the light emission stops. Even when this happens, it will be judged as an on state and will malfunction. In order to deal with the problem of such malfunctions, the phototransistor is configured so that it exhibits a light-receiving state when the operating section is manually operated, and the non-light-receiving state of the phototransistor is determined to be an off state. You should do it. However, when adopting such a configuration,
When a configuration in which the light emitting diode periodically emits light intermittently is also adopted in order to save power, etc., the light receiving state of the phototransistor is intermittent when the operating section is manually operated (on operation).
Therefore, in this case, some kind of additional circuit is required to prevent the phototransistor from erroneously determining that the phototransistor is in an OFF state when the light reception is stopped when the operating section is manually operated, and there is a problem that the circuit configuration becomes complicated.

The present invention was developed in view of the above circumstances, and its purpose is to prevent malfunctions when the light emitting element fails, reduce power consumption, and improve the reliability of on-state judgment with a simple circuit configuration. It is an object of the present invention to provide a non-contact type switch device which has effects such as being able to improve performance.

[Structure of the invention] (Means for solving the problems) The switch device according to the invention includes a light guide member,
and a phosphor that emits fluorescence in response to light irradiation and phosphorescence in response to stop of light irradiation, and an operating member that selectively makes the phosphor and the light guide member face each other in accordance with displacement by operation,
Furthermore, a light projecting element is provided which irradiates the fluorescent substance with periodic light through the light guide member with the light guide member and the fluorescent substance facing each other, and also with the light guide member and the fluorescent substance facing each other. A light receiving element is provided which receives light from the phosphor and generates a switching signal in the state of receiving the light.

(Function) When the operating member is operated with a finger or the like, the light guide member and the phosphor face each other, so that periodic light from the light projecting element is irradiated onto the phosphor via the light guide member. Therefore, the light-receiving element receives light from the phosphor and outputs a switching signal, and is therefore determined to be in an on state. At this time, even when the light emitting element periodically stops emitting light, phosphorescence is emitted from the phosphor and is received by the light receiving element.
The switching signal is output continuously without being intermittent.

(Embodiment) In FIGS. 1 and 2, reference numeral 1 denotes a light guide plate as a light guide member, which is made of, for example, transparent plastic and formed into a rectangular flat plate shape. The light guide plate 1 has, for example, a rectangular through hole 1a formed in the center thereof, and is formed with the right edge in the figure cut so that light can be guided to the edge. Reflective surfaces 1b are formed at an angle of 45 degrees with the upper and lower surfaces of the light plate 1. Reference numeral 2 denotes a light-shielding plate arranged in an overlapping manner on the light-guiding plate 1, and this is formed, for example, from a light-shielding plastic material into a rectangular flat plate shape similar to the light-guiding plate 1. Further, a through hole 2a having a shape that matches the through hole 1a is formed in the center of the light shielding plate 2. 3 is light shielding plate 2
A spacer arranged in an overlapping manner on top of the light-shielding plate 2 made of, for example, a light-shielding plastic material.
It is formed into a rectangular frame shape with the same external shape as
Therefore, in this spacer 3, the through holes 1a and 2 are formed.
A space 4 communicating with a is formed. Reference numeral 5 designates an operation plate as an operation member disposed in an overlapping manner on the spacer 3. This is formed, for example, from an elastic plastic film into a rectangular shape having the same external shape as the spacer 3.

Now, reference numeral 6 denotes a rectangular flat plate-shaped phosphor which is provided to emit fluorescence in response to light irradiation and to emit phosphorescence in response to stop of light irradiation. It is supported by and positioned within the through hole 2a. At this time, the phosphor 6 is set so that its lower surface is located at least above the upper surface of the light guide plate 1, so that the emitted light does not enter into the light guide plate 1 under normal conditions. It is configured. Further, a light-shielding layer 8 is provided on the lower surface of the phosphor 6 by printing black paint or adhering a light-shielding film. In this case, when the central part of the operation plate 5 is pressed with a finger or the like, the operation plate 5 is elastically deformed as shown in FIG. 3, so that the phosphor 6 enters the through hole 1a. It comes to face the end surface 1c of the light guide plate 1. When the pressing operation is released from this state, the operation plate 5 is deformed back to the state shown in FIG. 1. In addition, 9 is a reinforcing plate having a rectangular shape narrower than the light guide plate 1;
The reflective surface 1b is attached to the lower surface of the reflective surface 1b with a portion facing the reflective surface 1b remaining.

10 is a light emitting element, for example a light emitting diode;
This is installed so as to face the reflective surface 1b portion of the light guide plate 1 from below, and is provided so that the projected light is irradiated into the light guide plate 1 through the reflective surface 1b as shown by arrow A. In this case, the light emitting diode 10 is configured to emit light periodically and intermittently using, for example, a pulse signal, and therefore, the light emitting output waveform is as shown in FIG. 4a. Further, 11 is a light receiving element, for example, a phototransistor, which is a reflective surface 1b of the light guide plate 1.
The light emitting diode 10 is placed so as to face the light emitting diode 10 from below. As a result, a part of the light projected into the light guide plate 1 from the light emitting diode 10 is reflected by the end face 1c of the light guide plate 1 as shown by the arrow B, and then reflected by the reflective surface 1b, and is reflected by the phototransistor 11. light will be received. Although not shown, a switching signal is generated when the level of the output voltage of the phototransistor 11 continues to be equal to or higher than a predetermined threshold value Vh for a certain period of time T (for example, a period longer than the light emitting period of the light emitting diode 10). is configured to be
Note that the light guide plate 1, the light shielding plate 2, the spacer 3, the operation plate 5, and the reinforcing plate 9 may be fixed by adhesive, for example, or by a holder that clamps each peripheral portion.

According to the above configuration, when the operating plate 5 is not pressed and deformed as shown in FIG. The light from the body 6 passes through the light guide plate 1
The light is not received by the phototransistor 11 through the light. Therefore, the output of the phototransistor 11 has an intermittent voltage waveform corresponding to the light emission period of the light emitting diode 10, as shown in the periods t ₁ and t ₃ in FIG. 4c. Therefore, in this case, the level of the output voltage of the phototransistor 11 is equal to the threshold value.
A period exceeding Vh will not continue for longer than the predetermined time T, and no switching signal will be output. Further, when the central portion of the operation panel 5 is pressed, the phosphor 6 comes to face the end surface 1c of the light guide plate 1, as shown in FIG. Then, the phosphor 6
receives light through the light guide plate 1 during the light emission period of the light emitting diode 10 and emits fluorescence, and also emits phosphorescence that gradually attenuates during the light emission stop period of the light emitting diode 10. As a result, the phosphorescent light enters the light guide plate 1, is reflected by the reflective surface 1b, and is received by the phototransistor 11. Therefore, during the period when the central part of the operation plate 5 is pressed, the phototransistor 1
The output of 1 is as shown in the period t ₂ in Figure 4c,
Even when the light emitting diode 10 stops emitting light, the phosphorescence is received and the voltage waveform maintains the threshold value Vh or more. Therefore, in this case, the period in which the level of the output voltage of the phototransistor 11 is above the threshold value Vh continues for a certain period of time T or more, and a switching signal as shown in FIG. 4b is output. Become so. In short, when the central part of the operation plate 5 is pressed for a certain period of time T or more,
A switching signal is output, and this output state is stopped when the pressing operation is released and the state shown in FIG. 1 is returned to.

According to the present embodiment described above, since the configuration is such that the ON state is determined when the operation plate 5 is pressed and the phototransistor 11 exhibits a light receiving state, the state in which the light emitting diode 10 has failed and stopped emitting light is determined. There is no risk of erroneously determining that the state is on. Furthermore, since the light emitting diode 10 is configured to be lit intermittently, it is possible to save power. Moreover, in this case, even during the period when the light emitting diode 10 stops emitting light, the light receiving state of the phototransistor 11 is maintained by the phosphorescence from the phosphor 6. Therefore, the reliability of on-state determination can be improved without requiring an additional circuit for preventing erroneous determination as in the conventional case. In addition, the light guide plate 1, the light shielding plate 2, the spacer 3, the operation plate 5, and the reinforcing plate 9, each of which has a simple shape and is relatively inexpensive, can be stacked on top of each other, which is an extremely low-cost and simple structure. Of course, the structure of the movable parts can be extremely simple, and the overall size and thickness can be reduced. Furthermore, in this case, it is sufficient to simply stack the above-mentioned parts on top of each other, and since these parts can be manufactured using only press technology, the productivity can be dramatically increased. Furthermore, by modifying the shapes of the light guide plate 1, the light shielding plate 2, etc., it can be easily configured as a multiple switch, which has the advantage of greatly widening the range of applications.

In the above embodiment, the light guide plate 1 is provided with a reflective surface 1b, but this reflective surface is not necessarily required. It becomes unnecessary when arranged like this. Further, in the above embodiment, the phosphor 6 is configured to be displaced in accordance with the operation of the operation panel 5, but the present invention is not limited to this, and a configuration in which the light guide plate 1 side is displaced may be adopted.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and may be implemented with various modifications without departing from the gist of the invention, for example, changes may be made to the shape of the light guide member, etc. It is possible.

[Effects of the invention] As is clear from the above explanation, according to the present invention, although it is a non-contact type switch device that uses light, it is possible to prevent malfunctions in the event of a failure of the light emitting element, and By intermittent driving of the light emitter, it is possible to reduce power consumption, and furthermore, even though the light emitting element is driven intermittently, the reliability of on-state judgment can be improved without complicating the circuit configuration. This has practical effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view, Fig. 2 is an exploded perspective view of the main parts, Fig. 3 is a longitudinal sectional view in a different state from Fig. 1, and Fig. 4 is a longitudinal sectional view. The figure shows the output waveforms of each part. In the figure, 1 is a light guide plate (light guide member), 2 is a light shielding plate, 3 is a spacer, 5 is an operation plate (operation member), 6
8 is a phosphor, 8 is a light shielding layer, 9 is a reinforcing plate, 10 is a light emitting diode (light emitting element), and 11 is a phototransistor (light receiving element).

Claims (1)

[Scope of utility model registration request] a light guide member, a phosphor that emits fluorescence in response to light irradiation and phosphorescence in response to stop of light irradiation; and a phosphor that is disposed to be displaced by operation, and selectively selects the phosphor and light guide member in accordance with the displacement. an operating member facing the light guide member; and a light projecting element that is provided to periodically project light into the light guide member and irradiates the light onto the fluorescent substance with the light guide member and the fluorescent substance facing each other. , disposed to be able to receive light from the light guide member, with the light guide member and the phosphor facing each other, so as to receive the light from the phosphor, and generating a switching signal in the light receiving state. 1. A switch device characterized by comprising a light-receiving element.