JP2006331739A - Pressure-sensitive control switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a structure also excellent in operability while securing strength to external operating pressure in a pressure-sensitive control switch for outputting an electrical signal at a level corresponding to the magnitude of the external operating pressure to be applied. <P>SOLUTION: The pressure-sensitive control switch has a light-emitting element 2 and light-receiving element 3 which are oppositely arranged apart from each other, a transparent resin 4 for molding the light-emitting element 2 and light-receiving element 3, and an operation sheet 5 supported by a support wall 4c integral with or separate from the transparent resin 4, so as to be apart from the upper face of the transparent resin 4 and bent with the application of the external operating pressure. A groove 4b is provided in a space where the light-emitting element 2 and the light-receiving element 3 face each other in the transparent resin 4. A light shield 5a is displaceably fitted into the groove 4b, and controls an amount of incident light from the light-emitting element 2 to the light-receiving element 3 by changing its fitting depth to the groove 4b corresponding to the bending amount of the operation sheet 5. The light shield is provided to the inner face side of the operation sheet 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure-sensitive control switch used in various control devices, home appliances, amusement fields, and the like.

  Various methods for sensing pressure changes and using them as switches, microphones, and the like have been proposed so far, and among them, an optical microphone can be cited as one using light (for example, see Patent Documents 1 to 3).

  A typical configuration will be described with reference to FIG. In the illustrated optical microphone, a light emitting element 12 and a light receiving element 13 are mounted on a substrate 11, and the light emitting element 12 and the light receiving element 13 are sealed with a transparent resin 14. A light blocking film 15 is provided between the light emitting element 12 and the light receiving element 13 to prevent direct light from entering the light receiving element 13 from the light emitting element 12.

  A support frame 17 surrounding the light emitting element 12 and the light receiving element 13 is provided on the substrate 11, and the upper end of the support frame 17 vibrates due to sound pressure P or the like and has a function of reflecting light. The membrane film 16 is adhered. The support frame 17 is made of a light blocking material to prevent stray light.

The operation of this optical microphone will be described. First, outgoing light from the light emitting element 12 is reflected by the membrane film 16 and enters the light receiving element 13. At this time, when the membrane film 16 vibrates, the incident position of the reflected light changes, and the amount of light received by the light receiving element 13, that is, the output of the light receiving element 13 also changes. The principle of the optical microphone is to detect the sound pressure and the like by capturing this output change.
Japanese Patent Laid-Open No. 11-308679 JP 2001-169394 A JP 2001-296310 A

  The optical microphone of the above-described conventional example can be used as a pressure sensor because it can detect a small pressure change in a space.

  However, it is considered extremely difficult to use the above-described optical microphone as it is as a pressure-sensitive control switch provided outside a housing of, for example, a home appliance.

  The first reason is that the optical microphone is highly sensitive to detect the sound pressure level in the first place, and it is considered that the strength and durability are insufficient for a large and strong level such as pressing of the human body (finger). It is done.

  As a second reason, since the optical microphone is expensive when the optical microphone is used as a pressure-sensitive control switch, the cost is inevitably increased. That is, the membrane film 16 that can be said to be the heart of an optical microphone is generally configured by extending PET or the like to a thin film of about 1 μm and coating a reflective material for preventing light transmission by vapor deposition or the like. In addition, the membrane film 16 needs to be attached to the support frame 17 with an appropriate tension, so that the process is complicated and the cost increases.

  By the way, in the case of a pressure-sensitive control switch provided outside a housing of home appliances, for example, the state of the home appliance (operating, stopped, remaining amount, etc.) is displayed on the switch itself so that it can be visually recognized. However, since a film having a high reflectance close to total reflection is formed inside the membrane film 16 so that light from the light emitting element 12 is not emitted to the outside, the display as described above is performed. I can't.

  In addition, for example, Japanese Utility Model Laid-Open No. 61-184229 discloses a structure in which the gap between the transmissive photo interrupters is blocked by a movable section of a cover. The control object of the present invention is completely different from the object of use and usage. Further, in this apparatus, the object to be detected is brought into contact with a convex portion protruding outward from the cover, and this convex portion is in the way.

  An object of the present invention is to provide a pressure-sensitive control switch having a structure excellent in operability while ensuring strength against an external operating pressure.

  The present invention relates to a pressure-sensitive control switch that outputs an electric signal having a level corresponding to the magnitude of an external operation pressure applied, and a light-emitting element and a light-receiving element that are spaced apart from each other and the light-emitting elements And a transparent resin that molds the light receiving element, and an operation sheet that is supported on a supporting wall portion that is integral with or separate from the transparent resin so as to be separated from the upper surface of the transparent resin, and that is bent when an external operation pressure is applied. In the transparent resin, a groove is provided between the light emitting element and the light receiving element facing each other, and the groove is inserted into the groove on the inner surface side of the operation sheet so as to be displaceable and the amount of bending of the operation sheet. Accordingly, a light blocking part for controlling the amount of light incident from the light emitting element to the light receiving element by changing the insertion depth in the groove is provided.

  In short, the pressure-sensitive control switch having the above configuration changes the output of the light receiving element by controlling the amount of light incident from the light emitting element to the light receiving element in accordance with the external operation pressure. It is possible to control the operation of the device to be used by the pressure sensitive control switch according to the output level of the light receiving element.

  When the external operation pressure is a pressing force of a finger or the like, for example, the operation sheet only needs to have operability, strength, and durability in consideration of the above. It can be used and contributes to a reduction in manufacturing cost.

  In the pressure sensitive control switch, it is preferable that a light emitting portion that allows a part of light emitted from the light emitting element to be emitted to the outside is provided only in the vicinity of the light emitting element on the operation sheet.

  According to this configuration, since a part of the light emitted from the light emitting element is emitted to the outside from the light emitting part, the use of the pressure sensitive control switch according to the present invention depends on the presence or absence of the emitted light. It is possible to visually recognize the operating state.

  It is preferable that the light blocking portion of the pressure sensitive control switch is integrally formed of the same material as the operation sheet.

  The light blocking portion of the pressure sensitive control switch is preferably configured to be shorter than the depth of the groove.

  According to the present invention, it is possible to provide a pressure-sensitive control switch having a structure excellent in operability while ensuring strength against external operating pressure.

  An embodiment of the present invention will be described below with reference to FIGS.

  In the illustrated pressure-sensitive control switch, a light-emitting element 2 and a light-receiving element 3 are arranged opposite to each other on a substrate 1 made of a printed circuit board or a heat sink, and the light-emitting element 2 and the light-receiving element 3 are illustrated in FIG. The operation sheet 5 is molded in the shape shown, and a flexible operation sheet 5 is provided above the transparent resin 4.

  A light blocking film 6 is formed on the outer periphery of the transparent resin 4 so as to prevent stray light from the outside.

  Further, the transparent resin 4 has, for example, a prismatic shape, and a depressed portion 4a is provided on the upper portion thereof. In the transparent resin 4 between the light emitting element 2 and the light receiving element 3, a depressed portion is provided. A groove 4b that is recessed from the bottom surface of 4a to the inside is formed.

  The four sides of the operation sheet 5 are bonded to the frame-shaped support wall 4c of the transparent resin 4, and the depressed portion 4a is covered by the operation sheet 5. The frame-shaped support wall 4c corresponds to the support wall described in the claims.

  The operation sheet 5 is made of a material that can be bent so that a central portion thereof enters the recessed portion 4a when pressed down manually with a finger or the like, and has light blocking properties. On the lower surface of the operation sheet 5, a light blocking portion 5a made of a projecting piece is provided. The light blocking portion 5a is fitted in the groove 4b of the transparent resin 4 so as to be displaceable through a slight gap.

  That is, in the operation sheet 5, the light blocking portion 5 a is guided by the groove 4 b of the transparent resin 4 in accordance with the amount of bending of the operation sheet 5, and enters the operation sheet 5 deeply. When the finger is released from the operation sheet 5, the operation sheet 5 returns to a flat state by its elastic restoring force, and the light blocking portion 5a is guided upward by the groove 4b.

  In the region corresponding to the upper part of the light receiving element 3 on the inner bottom surface of the depressed portion 4a of the transparent resin 4, a buffer member 7 that receives the pressure of the finger when the operation sheet 5 is pressed and is compressed and deformed in accordance with the pressed amount. Is provided.

  The buffer member 7 is made of a material that restores its original shape when the finger is no longer pressed, such as urethane, and the elastic restoring operation of the buffer member 7 is useful for returning the operation sheet 5 to a flat state. .

  By the way, in this embodiment, the operation sheet 5 has a light blocking property in order to prevent stray light from the outside. In this operation sheet 5, a light emitting portion 5 b is provided in a region immediately above the light emitting element 2. ing.

  The light emitting portion 5b can be, for example, a circular window formed by penetrating the operation sheet 5 in the thickness direction.

  As a result, a part of the light emitted from the light emitting element 2 can be emitted to the outside from the light emitting portion 5b of the operation sheet 5. Therefore, if the presence or absence of light in the light emitting portion 5b is visually confirmed. In addition, it becomes possible to recognize the operating state (operating, stopped, remaining amount, etc.) of the target device of the pressure-sensitive control switch.

  The light emitting element 2 is preferably a light emitting diode (LED), but may be a semiconductor laser. Further, the light emitting element 2 can be an LED having a wavelength in the visible region such as blue, green, yellow, red, or white.

  Next, the operation principle of the pressure sensitive control switch will be described.

  As shown in FIG. 2, in a state where the operation sheet 5 is not pushed down with a finger, the protruding end side of the light blocking portion 5a of the operation sheet 5 is only slightly inserted into the opening side of the groove 4b of the transparent resin 4. Thus, since the light blocking portion 5a hardly blocks the light L traveling from the light emitting element 2 to the light receiving element 3, a predetermined (initial) maximum light amount is incident on the light receiving element 3. At this time, the amount of light received by the light receiving element 3, that is, the output is the maximum output commensurate with the maximum amount of light received, as indicated by the symbol A in the graph of FIG.

  Here, as shown in FIG. 3 from the state shown in FIG. 2, when the operation sheet 5 is pushed down about half of the maximum bending allowance with a finger, the operation sheet 5 is bent and reaches the groove 4b to the intermediate portion in the protruding direction of the light blocking portion 5a. The light blocking portion 5 a blocks a part of the light L traveling from the light emitting element 2 to the light receiving element 3. Therefore, the amount of light received, that is, the output of the light receiving element 3 at this time decreases as compared with the reference A as indicated by the reference B in the graph of FIG.

  Then, as shown in FIG. 4 from the state of FIG. 3, when the operation sheet 5 is further pressed down until it is brought into contact with the inner bottom surface of the depressed portion 4 a by further applying force to the finger, the operation sheet 5 is further bent and the light blocking unit Substantially the entirety of 5a enters the groove 4b, and the light blocking portion 5a blocks most of the light L traveling from the light emitting element 2 to the light receiving element 3. Therefore, the amount of light received, that is, the output of the light receiving element 3 at this time is smaller than the symbol B as indicated by the symbol C in the graph of FIG.

  As described above, the pressure sensitive control switch is configured such that the output of the light receiving element 3 changes according to the external operating pressure on the operation sheet 5, that is, the amount of pressing by the person. Based on the above, it becomes possible to control the operation of the device to be used for the pressure sensitive control switch.

  Incidentally, as an example of a device to be used for the pressure sensitive control switch, there is a desktop water heater (so-called electric pot) or the like, and the hot water supply amount adjusting switch can be the pressure sensitive control switch. In this case, it is possible to perform an operation control of adjusting the hot water supply amount according to the pressing amount of the operation sheet 5 with a finger, that is, the output of the light receiving element 3.

  In addition, since the operation sheet 5 is flat and has no obstructive parts protruding outward, the operability is improved.

  Furthermore, since the light emission part 5b is provided in the operation sheet 5, if the presence or absence of light emission in the light emission part 5b is visually confirmed, the operation state of the target device of the pressure sensitive control switch (in operation, It is possible to recognize the stop, remaining amount, etc.), and it is advantageous in terms of design and cost, such as eliminating the need for providing an extra display unit in the device to be used.

  Here, an example of the manufacturing method of the pressure-sensitive control switch described above will be described with reference to FIG.

  First, as shown in FIG. 7A, a light emitting element 2 and a light receiving element 3 are mounted on a substrate 1 such as a printed board or a heat sink, and they are appropriately wire-bonded to the substrate 1, respectively.

  Thereafter, the light emitting element 2 and the light receiving element 3 on the substrate 1 are molded with a transparent resin 4 as shown in FIG. At this time, the outer shape of the transparent resin 4 is molded, and the depressed portion 4a and the frame-like support wall portion 4c are formed.

  As shown in FIG. 7C, a light blocking film 6 is formed on the outer periphery of the transparent resin 4 by coating or vapor deposition.

  As shown in FIG. 7D, a groove 4b is cut and formed in the center of the transparent resin 4, that is, between the light emitting element 2 and the light receiving element 3 as shown in FIG. In addition, in order to make the light blocking part 5a of the operation sheet 5 displaceable in the groove 4b of the transparent resin 4, the thickness of the light blocking part 5a is set smaller than the width of the groove 4b.

  Then, as shown in FIG. 7 (e), the buffer member 7 is disposed and bonded to a region corresponding to the upper part of the light receiving element 3 on the inner bottom surface of the depressed portion 4 a of the transparent resin 4.

  Finally, the four sides of the operation sheet 5 are bonded to the frame-like support wall portion 4c of the transparent resin 4 to obtain the state shown in FIG.

  Hereinafter, other embodiments of the present invention will be described.

  (1) About the operation sheet | seat 5, a transparent resin thin film, such as PET, can be used as a base | substrate, and the light shielding film can be coated on the single side | surface. In that case, the transparent part of the resin thin film matrix can be used as the light emitting part by not coating the light blocking film on the region where the light emitting part 5b is to be formed.

  (2) Although the operation sheet 5 is provided with the light emitting portion 5b, the operation sheet 5 is also included in the present invention without the light emitting portion 5b.

  (3) The pressure sensitive control switch described in the above embodiment can have a plurality of light emitting elements instead of only one.

  As an example, as shown in FIG. 8, two light emitting elements 2A and 2B can be used. In this case, if one of the light emitting elements 2B is of a type having a light directivity toward only the light emitting portion 5b, the light emitted from the light emitting element 2B will not enter the light receiving element 3 side. This makes it possible to easily perform operations such as lighting and flashing.

  Further, the light emission wavelength regions of the light emitting elements 2A and 2B may be different types. In that case, it is possible to display the status (operating, stopped, remaining amount, etc.) of the target device of the pressure-sensitive control switch in multiple colors. For example, the pressure-sensitive control switch can be displayed on the casing of the target device. When installed outside, it can contribute to improved visibility.

  In the example of FIG. 8, a structure in which the light emitting elements 2A and 2B and the light receiving element 3 are solidified with a transparent transparent resin 4A as the transparent resin 4 is fitted into a case 4B made of a light blocking material. . The frame-like support wall portion of the case 4B corresponds to the support wall portion described in the claims.

1 is an exploded perspective view showing an embodiment of a pressure sensitive control switch according to the present invention. It is sectional drawing which shows the non-pressing state with the pressure sensitive type | mold control switch of FIG. FIG. 2 is a cross-sectional view showing an intermediate press state of the pressure sensitive control switch of FIG. 1. FIG. 2 is a cross-sectional view showing a maximum pressed state of the pressure sensitive control switch of FIG. 1. It is a top view which shows the operation sheet | seat of the pressure sensitive control switch of FIG. 2 is a graph showing the relationship between the pressing amount of the pressure sensitive control switch of FIG. 1 and the output of the light receiving element. It is explanatory drawing which shows the manufacturing method of the pressure sensitive control switch of FIG. FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing another embodiment of the pressure sensitive control switch according to the present invention. It is sectional drawing which shows the optical microphone of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Light emitting element 3 Light receiving element 4 Transparent resin 4a Depressed part 4b Groove 4c Frame-like support wall part 5 Operation sheet 5a Light blocking part 6 Light blocking film 7 Buffer member

Claims (4)

A pressure-sensitive control switch that outputs an electrical signal at a level corresponding to the magnitude of the external operating pressure applied,
A light-emitting element and a light-receiving element that are spaced apart from each other, a transparent resin that molds the light-emitting element and the light-receiving element, and a support wall that is integral with or separate from the transparent resin and is supported so as to be separated from the upper surface of the transparent resin. And an operation sheet that bends with the application of an external operation pressure,
A groove is provided between the light emitting element and the light receiving element in the transparent resin,
The amount of light incident from the light emitting element to the light receiving element is controlled by being fitted in the groove on the inner surface side of the operation sheet so as to be displaceable, and the depth of insertion into the groove is changed according to the amount of bending of the operation sheet. A pressure-sensitive control switch, which is provided with a light blocking part.   2. The pressure sensitive type according to claim 1, wherein a light emitting portion that allows a part of the emitted light from the light emitting element to be emitted to the outside is provided only in the vicinity of the light emitting element in the operation sheet. Control switch.   The pressure-sensitive control switch according to claim 1, wherein the light blocking unit is integrally formed of the same material as the operation sheet.   The pressure-sensitive control switch according to any one of claims 1 to 3, wherein the light blocking portion is set shorter than a depth of the groove.

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