JP2021018917A - Capacitive input device - Google Patents

Abstract

To provide a capacitive input device that operates in a large number of states including the contact state and midway operation state of a conductive operation body and contributes to the improvement of performance.SOLUTION: A capacitive input device is a device including: a first electrode 10 for capacitance detection; an operation button 20 that contacts to the first electrode 10 by operation of a finger; a protective panel 30 that exposes part of the operation button 20; a second electrode 40 for capacitance detection that contacts to the operation button 20; and capacitance detection determination means connected to the first and second electrodes 10 and 40. The operation button 20 includes an elastic click body 21 that detachably faces the first electrode 10 and a key top 27 for pressing operation that is attached to the elastic click body 21 and partly exposes from the protective panel 30. The key top 27 is given conductivity and is detachably pressed to the second electrode 40. The capacitance detection determination means detects any of the non-contact state, contact state, midway operation state, and final operation state of the operation button 20 by the detected capacitance.SELECTED DRAWING: Figure 1

Description

The present invention relates to a capacitance type input device used in music players, home appliances, portable devices, computer devices, information communication devices, automobile-mounted devices, and the like.

There are various types of conventional capacitance type input devices, but types that operate in several states have been proposed (see Patent Documents 1, 2, 3, and 4). For example, Patent Document 1 discloses an input device and an electronic device that can operate in three stages: a finger non-contact state with respect to a key top, a finger contact state, and a final operation state in which the finger is completely pressed. Further, Patent Document 2 describes an electronic device that can be operated in three stages: a non-contact state of a finger with respect to an operation key top, a contact state of a finger / an intermediate operation state during pressing with a finger, and a final operation state in which the finger is completely pressed. , Control methods and programs in electronic devices are disclosed.

In Patent Document 3, a change in capacitance is detected in three stages when the keypad of the capacitance detection switch is not touched by a finger, when the finger touches the keypad, and when the keypad is pressed. , Capacitance detection switch that utilizes the detected value is shown. Further, Patent Document 4 describes whether the current switching means is in the non-contact state of the finger, the contact state of the finger / the halfway operation state in which the finger is being pushed, or the final operation state in which the finger is completely pushed. A capacitive input device that can be grasped is shown.

JP-A-2018-60766 JP-A-2010-74689 Japanese Unexamined Patent Publication No. 2011-175839 Japanese Patent No. 6246111

Although the conventional capacitance type input device is configured as described above and can be expected to have excellent effects, further improvement in performance is required as the performance of home appliances, mobile devices, automobile-mounted devices, etc. is improved. There is. For example, it stands by when the finger is not in contact with the key top, stands by when it is in contact with the finger to prepare for the predetermined function expression, and maintains the prepared state for the predetermined function expression when the finger is being pushed in the middle of operation. It would be really convenient if a predetermined function could be exhibited in the final operation state when the finger was completely pushed.

Regarding this point, in the case of Patent Document 1, since it is not possible to detect an intermediate operation state during pushing with a finger, a state in which the finger is not pushed and released and a state in which the finger is touched and then pushed is in progress. It is difficult to improve the performance because it cannot be distinguished from the operating state of. Further, in the case of Patent Documents 2, 3 and 4, it is not possible to clearly distinguish between the contact state of the finger and the halfway operation state during pushing with the finger, so that it is easy to contribute to the improvement of the performance. Absent.

The present invention has been made in view of the above, and it is intended to provide a capacitance type input device that operates in a number of states including a contact state and a halfway operation state of a conductive operation body and can contribute to improvement of performance. I am aiming.

In the present invention, in order to solve the above problems, a first electrode for detecting capacitance formed on a substrate, an operation button capable of contacting the first electrode by operating a conductive operating body, and this operation button A protective material that exposes at least a part of the above, a second electrode formed on the protective material for detecting capacitance that can contact the operation button, and a capacitance connected to the first and second electrodes. A device equipped with detection and determination means,
The operation buttons include an elastic click body that is supported by a substrate and faces the first electrode so as to be contactable and detachable, and a key top for pressing operation that is attached to the elastic click body and partially exposed from the protective material. The peripheral edge of this key top is pressed against the opposing second electrode so that it can be attached and detached.
Based on the detected capacitance, the capacitance detection determination means is in a non-contact state in which the conductive operation body is not touching the key top of the operation button, a contact state in which the conductive operation body is in contact with the key top of the operation button, and the operation button. The key top of is pressed against the conductive operating body, the peripheral edge of the key top is separated from the second electrode, and the key top of the operation button is strongly pressed against the conductive operating body, and the key top is pressed from the second electrode. It is characterized in that it is possible to detect any of the final operation states in which the elastic click body of the operation button is in contact with the first electrode while the peripheral portions of the operation button are separated from each other.

The elastic click body of the operation button is formed on the main body portion that faces the first electrode in a contactable manner, the skirt portion that extends from the main body portion in the direction of the substrate and bends flexibly, and the substrate. A skirt is provided on the main body to form a convex portion protruding in the direction of the substrate so that the end face thereof can be brought into contact with the first electrode, and the leg portion has a skirt when the operation button is pressed. It is possible to cut out an air groove that exhausts the gas inside the part to the outside.

Further, conductive films are formed on the contact surface of the peripheral edge of the key top of the operation button with respect to the second electrode and at least a part of the surface for operating the key top, and these conductive films are connected to form a conductive layer. Can be formed.
Further, the protective material is provided with a through-hole that exposes the key top of the operation button, and a second electrode that surrounds the through-hole is formed in the facing portion facing the substrate of the protective material. The flange protruding from the key top can be pressed and brought into surface contact.

Further, the capacitance detection determination means has a function of capturing the detection values detected by the first and second electrodes, and whether or not the detection values detected by the second electrodes are within the upper and lower limits of the first detection value. If it is determined that the detection value detected by the second electrode is within the upper and lower limits of the first detection value, the detection value detected by the first electrode is the fifth. A function to determine whether the detection value is within the upper and lower limits, and when it is determined that the detection value detected by the first electrode is within the upper and lower limits of the fifth detection value, an operation is performed. The function of determining that the conductive operating body is in contact with the key top of the button, and the case where the detection value detected by the first electrode is determined to be outside the upper and lower limits of the fifth detection value. Can also realize a function of determining that the conductive operating body is not in contact with the key top of the operation button in a non-contact state.

Further, when the capacitance detection determination means determines that the detection value detected by the second electrode is outside the range of the upper limit and the lower limit of the first detection value, the detection value detected by the second electrode Is a function to determine whether or not is within the upper and lower limits of the third detection value, and when it is determined that the detection value detected by the second electrode is within the upper and lower limits of the third detection value. Is a function to determine whether the detected value detected by the first electrode is within the upper and lower limits of the fifth detected value, and the detected value detected by the first electrode is the upper and lower limits of the fifth detected value. When it is determined that the key top is within the range of, the key top of the operation button is pressed by the conductive operating body, and the peripheral portion of the key top is separated from the second electrode. When it is determined that the detected value detected by the second electrode is outside the range of the upper limit and the lower limit of the third detected value, it is considered that the conductive operating body is not in contact with the key top of the operation button. It is possible to realize a function of determining.

Further, when the capacitance detection determination means determines that the detection value detected by the first electrode is outside the range of the upper limit and the lower limit of the fifth detection value, the detection value detected by the first electrode Is a function to determine whether or not is within the upper and lower limits of the fourth detection value, and when it is determined that the detection value detected by the first electrode is within the upper and lower limits of the fourth detection value. Is the final operation state in which the key top of the operation button is strongly pressed by the conductive operation body, the peripheral edge of the key top is separated from the second electrode, and the elastic click body of the operation button comes into contact with the first electrode. And when it is determined that the detected value detected by the first electrode is outside the range of the upper and lower limits of the fourth detected value, the conductive operating body does not touch the key top of the operation button. It is possible to realize a function of determining a non-contact state.

Here, the number of the first electrode, the operation button, and the second electrode in the claims can be increased or decreased as necessary. The first electrode can be formed into a plane circle, an ellipse, a rectangle, a polygon, or the like. Further, examples of the conductive operating body for operating the operation button include a conductive finger and a dedicated operating tool. The elastic click body of the operation button and the key top may be transparent, opaque, or translucent. The contact surface of the key top with respect to the second electrode may be in surface contact with the second electrode, but point contact or the like may be made by protrusions as long as conductivity can be ensured. Further, the second electrode can be formed endlessly in a plan view, for example, in a flat ring shape or a frame shape.

Further, it waits in a non-contact state of the conductive operation body with respect to the key top of the operation button, and waits in a contact state of the conductive operation body with respect to the key top of the operation button to prepare for the predetermined function expression. In the middle operation state during the pressing operation with the conductive operating body, the state of preparation for the predetermined function expression is maintained, and the predetermined function is exhibited in the final operating state in which the key top of the operation button is completely pressed by the conductive operating body. Can be done.

According to the present invention, since it operates in a number of states including a contact state and a halfway operation state of the conductive operation body, there is an effect that it can contribute to the improvement of the performance of the capacitance type input device.

According to the invention of claim 2, conductive films are formed on at least a part of the contact surface of the peripheral edge of the key top of the operation button with respect to the second electrode and the surface for operating the key top, and the conductivity thereof is formed. Since the films are connected to form a conductive layer, it is possible to improve the detection sensitivity of the capacitance.
According to the invention of claim 3, the substrate, the first electrode, and the second electrode can be coated and protected by the protective material. Further, since the flange of the key top of the operation button is pressed against the second electrode to make surface contact, the conduction range between the second electrode and the key top of the operation button is expanded, and the second electrode and the operation button It is possible to prevent poor continuity with the key top.

According to the invention of claim 4, it is possible to clearly determine and distinguish a non-contact state in which the conductive operating body does not touch the key top of the operation button and a contact state in which the conductive operating body touches the key top. Become.
According to the invention of claim 5, in a non-contact state where the conductive operating body is not touching the key top of the operation button, the key top is pressed by the conductive operating body, and the peripheral edge of the key top is separated from the second electrode. It is possible to clearly determine and distinguish the intermediate operation state.

According to the invention of claim 6, in a non-contact state where the conductive operating body is not touching the key top of the operation button, the key top is strongly pressed by the conductive operating body, and the peripheral edge of the key top is separated from the second electrode. At the same time, it becomes possible to clearly determine and grasp the final operation state in which the elastic click body of the operation button comes into contact with the first electrode.

It is sectional drawing which shows typically the embodiment of the capacitance type input device which concerns on this invention. It is sectional drawing which shows typically the non-contact state of the finger with respect to the operation button in embodiment of the capacitance type input device which concerns on this invention. It is sectional drawing which shows typically the contact state of the finger with the key top of the operation button in embodiment of the capacitance type input device which concerns on this invention. It is sectional drawing explanatory view schematically showing the intermediate operation state during the operation of pressing a finger with respect to the key top of the operation button in embodiment of the capacitance type input device which concerns on this invention. It is sectional drawing which shows typically the final operation state in which the key top of the operation button in embodiment of the capacitance type input device which concerns on this invention is completely pressed with a finger. It is a circuit explanatory drawing of the non-contact state and the contact state of the operation button in embodiment of the capacitance type input device which concerns on this invention. It is a circuit explanatory drawing of the intermediate operation state and the final operation state of the operation button in embodiment of the capacitance type input device which concerns on this invention. It is a flowchart which shows typically the embodiment of the capacitance type input device which concerns on this invention. The detected values A, B, and C in the embodiment of the capacitance type input device according to the present invention, the non-contact state of the operation button, the contact state of the operation button, the intermediate operation state of the operation button, and the final operation state of the operation button. It is a graph which shows the relationship schematically. Relationship between the detected values D and E in the embodiment of the capacitance type input device according to the present invention, the non-contact state of the operation button, the contact state of the operation button, the intermediate operation state of the operation button, and the final operation state of the operation button. Is a graph schematically showing. It is a flowchart which shows typically the 2nd Embodiment of the capacitance type input device which concerns on this invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. The capacitance type input device in the present embodiment has a capacitance formed on the printed circuit board 1 as shown in FIGS. 1 to 10. A first electrode 10 for detection, an operation button 20 that contacts the first electrode 10 by operating a finger 60, a protective panel 30 that exposes a part of the operation button 20, and the protective panel 30 are formed. Self-capacity including a second electrode 40 for detecting capacitance that can be conductively contacted with the operation button 20 and a capacitance detection determining means 50 connected to the first and second electrodes 10 and 40. It is a type input device, and the capacitance detection determination means 50 detects and determines a large number of states including a contact state of the finger 60 with the operation button 20 and an intermediate operation state.

As shown in FIGS. 1 to 5, the printed circuit board 1 is formed by, for example, printing a wiring pattern on an insulating substrate, and a flat surface faces the back surface of the protective panel 30 with a gap. A required number of first electrodes 10 and operation buttons 20 are arranged on opposite surfaces. The first electrodes 10 and the operation buttons 20 are arranged, for example, about 1, 5, 10, and 20.

As shown in FIGS. 1 to 5, the first electrode 10 is exposed and formed on a flat circular thin film by screen-printing a conductive material such as silver paste or carbon paste on the surface of the printed circuit board 1, for example. It faces the operation button 20 with a gap and detects the capacitance. An elongated wire wiring line extends from the peripheral edge of the first electrode 10, and the wiring line is electrically connected to the input terminal of the capacitance detection determination means 50.

As shown in FIGS. 1 to 5, the operation buttons 20 are an elastic click body 21 which is a dielectric material supported by the surface of the printed circuit board 1 and facing the first electrode 10 so as to be in contact with the first electrode 10, and the elastic click body. A key top 27 for pressing operation, which is brought into close contact with the flat upper portion of 21 and most of which is exposed from the protective panel 30, is provided, and the flange 28 of the key top 27 is pressed against the facing second electrode 40 so as to be detachable. Be done.

The elastic click body 21 is not particularly limited, but can be deformed by using a molding material containing, for example, an insulating silicone rubber, a urethane rubber, EPDM, a thermoplastic elastomer, etc., which can obtain a good click feeling. It is molded and has a shore A hardness of 40 ° or more and 70 ° or less. When silicone rubber is used as a molding material, it is a normal permittivity type that does not contain zinc oxide, a medium permittivity type that contains zinc oxide of about 28%, and a high content of zinc oxide and titanium oxide of about 56%. Permittivity type and the like are selectively used.

The elastic click body 21 has a main body 22 that faces the first electrode 10 so as to be detachable from above, and a substantially hollow conical trapezoid or pyramid that extends flexibly from the peripheral edge of the main body 22 in one direction of the printed circuit board. A skirt portion 24 having a trapezoidal shape, a substantially hemispherical trapezoidal shape, a substantially inverted bowl shape, or the like, and a leg portion 25 formed at the lower end of the skirt portion 24 and supported on the surface of the printed circuit board 1 are integrally formed.

The main body 22 is formed in a cylindrical shape that is shorter than the gap between the printed circuit board 1 and the protective panel 30, for example, and a flat circular convex portion 23 that protrudes in the printed circuit board 1 direction is formed in the center of the back surface. The flat back surface of the convex portion 23 is pressed against the surface of the first electrode 10 facing the surface from above. The back surface of the convex portion 23 facing the first electrode 10 is formed as necessary on a conductive layer (conductive rubber containing carbon or metal, a metal plate) that contributes to improving the sensitivity of capacitance. Further, the leg portion 25 is formed with a rectangular cross section, and the air groove 26 is partially cut out in the radial direction of the skirt portion 24, and the air groove 26 is formed in the skirt portion 24 when the operation button 20 is pressed. It functions to exhaust air to the outside.

The key top 27 is formed into a flat rectangular shape using a conductive material such as aluminum in order to ensure conductivity, and a flat frame-shaped flange 28 projects horizontally outward in the width direction from the lower part of the peripheral surface. The flat surface of the conductive flange 28 is pressed against the facing second electrode 40 from below by the repulsive force of the elastic click body 21 compressed by about 0.2 mm to make surface contact. The key top 27 is touched or pressed by the finger 60, but from the viewpoint of improving the operability of the finger 60, a pattern for identification is printed on the surface 29 for operation, and at least the central portion of the surface 29. Is formed as a dent in a substantially hemispherical shape.

As shown in the figure, the protective panel 30 is formed into a substantially plate shape by, for example, a polycarbonate resin or the like to partition a part of the exterior of an electronic device on which a capacitance type input device is mounted, and the printed circuit board 1 below. The first electrode 10 and the second electrode 40 are coated and protected from the outside. In the protective panel 30, a through hole 31 that is engaged from below with the flange 28 of the key top 27 of the operation button 20 is perforated in a flat rectangular shape, and the through hole 31 covers most of the key top 27 other than the flange 28. It is exposed so that it can be pressed.

As shown in FIGS. 1 to 7, the second electrode 40 is screen-printed with a conductive material such as silver paste or carbon paste on the flat back surface of the protective panel 30 facing the printed circuit board 1. It is exposed and formed on a flat frame-shaped thin film surrounding 31, and an elongated wire wiring line 41 extends from the outer peripheral edge portion, and this wiring line 41 is electrically connected to another input terminal of the capacitance detection determination means 50. Is connected. Such a second electrode 40 is pressed against a conductive flange 28 projecting from the peripheral surface of the key top 27 and electrically surface-contacted to detect the capacitance.

The capacitance detection determination means 50 is composed of, for example, a microcomputer or the like, and is in a non-contact state of the finger 60 with respect to the key top 27 of the operation button 20 and a contact state of the finger 60 with respect to the key top 27 based on the detected change in capacitance. , The halfway operation state during the pressing operation of the finger 60 against the key top 27, and the final operation state in which the key top 27 is completely pressed by the finger 60 are detected.

The microcomputer is not particularly limited, but PSoC (registered trademark of Cypress Semiconductor) or the like, which can integrate peripheral functions by a block configuration function, is preferable. This is because if PSoC is adopted, one or more input terminals for detecting capacitance can be easily set by setting software. PSoC detects the capacitance between the input terminal and its own GND, outputs an output value corresponding to the detected capacitance, and operates as a self-capacitance type capacitance detection determination circuit.

When the capacitance detection determination means 50 is PSoC, the capacitance between all the input terminals for detecting the capacitance and its own GND is sequentially detected, and the output value corresponding to the detected capacitance is calculated. Output. When the output value is output, the capacitance between all the input terminals and its own GND is sequentially detected, and the operation of outputting the output value according to the detected capacitance is repeated. This cycle is about 20 ms. That is, for all the input terminals, the capacitance between the input terminal and its own GND is detected about once every 20 ms, and the output value corresponding to the detected capacitance is output. .. When detecting or outputting at a cycle of about 20 msec or less, in most cases, the reaction after being touched by a person is not felt to be bad, and it is often felt that the reaction is responsive.

As shown in FIG. 8, such a capacitance detection determination means 50 has a function of taking in the capacitance detected by the first and second electrodes 10 and 40 as a detection value and a detection of the second electrode 40. It was determined that the detected value was within the upper and lower limits of the detected value A, and that the detected value detected by the second electrode 40 was within the upper and lower limits of the detected value A. In this case, the function of determining whether or not the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value E, and the detected value detected by the first electrode 10 is the upper limit of the detected value E. When it is determined that the value is within the lower limit range, the function of determining that the key top 27 of the operation button 20 is in contact with the finger 60 and the detected value detected by the first electrode 10 are detected. When it is determined that the value E is out of the upper and lower limit ranges, the function of determining that the key top 27 of the operation button 20 is not touched by the finger 60 is realized.

Further, the capacitance detection determination means 50 detects the second electrode 40 when it is determined that the detection value detected by the second electrode 40 is outside the range of the upper limit and the lower limit of the detection value A. A function for determining whether or not the detected value is within the upper and lower limits of the detected value C, and when it is determined that the detected value detected by the second electrode 40 is within the upper and lower limits of the detected value C. The function is to determine whether the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value E, and the detected value detected by the first electrode 10 is the upper limit of the detected value E. When it is determined that it is within the lower limit range, it is determined that the key top 27 of the operation button 20 is pressed by the finger 60 and the flange 28 of the key top 27 is separated from the second electrode 40 in the middle operation state. When it is determined that the detection value detected by the second electrode 40 is outside the upper and lower limits of the detection value C, the key top 27 of the operation button 20 is not touched by the finger 60. It realizes a function to determine that it is in contact.

Further, the capacitance detection determination means 50 detects the first electrode 10 when it is determined that the detection value detected by the first electrode 10 is outside the range of the upper limit and the lower limit of the detection value E. A function for determining whether or not the detected value is within the upper and lower limits of the detected value D, and when it is determined that the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value D. The key top 27 of the operation button 20 is strongly pressed by the finger 60, the flange 28 of the key top 27 is separated from the second electrode 40, and the elastic click body 21 of the operation button 20 comes into contact with the first electrode 10. When it is determined that the final operation state is reached and the detected value detected by the first electrode 10 is outside the range of the upper limit and the lower limit of the detection value D, the key top 27 of the operation button 20 The function of determining that the finger 60 is not in contact with the electrode 60 is realized.

Next, the determination principle of the capacitance detection determination means 50 and the like will be described. First, if two conductors are present, the capacitance is proportional to the facing area of the two conductors and inversely proportional to the distance between the two conductors, but is always formed. Therefore, between the input terminal of the capacitance detection and determination means 50 shown in FIGS. 6 and 7 and the GND, between the wiring line 41 of the second electrode 40 and the GND, and between the second electrode 40 and the GND. , And a capacitance is always formed between the key top 27, which is a conductor, and the GND, which is a conductor.

The capacitance between the input terminal of the capacitance detection and determination means 50 and the GND, and the capacitance between the wiring line 41 of the second electrode 40 and the GND are not intended by the designer, or the existence is not preferable. It is a capacitance and is often called a parasitic capacitance.

Here, the capacitance value detected at the input terminal of the capacitance detection / determination means 50 is the capacitance between the input terminal of the capacitance detection / determination means 50 and the GND, and the wiring line 41 of the second electrode 40. The capacitance between the and GND, the capacitance between the second electrode 40 and the GND, and the capacitance between the key top 27 and the GND are the values of the capacitance connected in parallel, and each capacitance. It is the sum of the capacitance values. The capacitance value detected at the input terminal of the capacitance detection determination means 50 is indicated by the detection value B in FIG.

Next, in the non-contact state of FIG. 2 in which the finger 60 does not touch the key top 27 of the operation button 20, the space between the key top 27 and the GND is occupied by air having a relative permittivity of about 1. .. On the other hand, in the case of the contact state of FIG. 3 in which the finger 60 simply touches the key top 27 of the operation button 20, the space between the key top 27 and the GND has a relative permittivity of 10 in addition to air. It is also occupied by the human body, which is more than double. Therefore, the capacitance is larger in the contact state of FIG. 3 than in the non-contact state of FIG.

As described above, the capacitance value detected at the input terminal of the capacitance detection / determination means 50 is the capacitance between the input terminal of the capacitance detection / determination means 50 and the GND, and the wiring of the second electrode 40. It is the total value of the capacitance between the line 41 and the GND, the capacitance between the second electrode 40 and the GND, and the capacitance between the key top 27 and the GND. Therefore, the capacitance value detected at the input terminal of the capacitance detection determination means 50 is larger in the contact state of FIG. 3 than in the non-contact state of FIG. The capacitance value in this case is indicated by the detection value A in FIG. 9, and the relationship of detection value A> detection value B.

Next, the case where the key top 27 of the operation button 20 is pressed by the finger 60 and the flange 28 of the key top 27 is separated from the second electrode 40 will be described in the middle operation state of FIG. The key top 27 of the operation button 20 and the second electrode 40 were electrically conductively connected in the non-contact state of FIG. 2 and the contact state of FIG. Therefore, the capacitance between the key top 27 and the GND is connected in parallel with other capacitance detected at the input terminal of the capacitance detection determination means 50.

On the other hand, when the key top 27 is pressed by the finger 60 and the flange 28 of the key top 27 is separated downward from the second electrode 40, the capacitance between the key top 27 and the GND is detected. Rather than being directly connected in parallel with another capacitance detected at the input terminal of the determination means 50, the capacitance between the second electrode 40 and the key top 27 (Cg in FIG. 7) is used. , The input terminal of the capacitance detection determination means 50 is connected in parallel with another capacitance to be detected. That is, the combined capacitance (Cs) in which the capacitance (Ck) between the key top 27 and the GND and the capacitance shown by Cg in FIG. 7 are connected in series is connected to the input terminal of the capacitance detection determination means 50. It will be connected in parallel with other detected capacitances.

Here, since 1 / Cs = 1 / Ck + 1 / Cg, Cs <Ck, no matter how large Cg is. That is, the capacitance value detected at the input terminal of the capacitance detection / determination means 50 in the halfway operation state of FIG. 4 is static electricity detected at the input terminal of the capacitance detection / determination means 50 in the contact state of FIG. It is smaller than the capacitance value.

When the key top 27 of the operation button 20 is pressed more by the finger 60, the flange 28 of the key top 27 is further separated from the second electrode 40, and the distance between the second electrode 40 and the flange 28 becomes longer. The Cg in FIG. 7 decreases in inverse proportion to the distance. In the above formula 1 / Cs = 1 / Ck + 1 / Cg, the fact that Cg becomes smaller means that 1 / Cg becomes larger, and Cs becomes smaller.

When the distance between the second electrode 40 and the flange 28 becomes long and Cs becomes small accordingly, Cs becomes negligibly small in the capacitance value detected at the input terminal of the capacitance detection determination means 50. Become. As a result, the capacitance value detected at the input terminal of the capacitance detection / determination means 50 is the capacitance between the input terminal of the capacitance detection / determination means 50 and the GND, and the wiring line 41 of the second electrode 40. It is a substantially total value of the capacitance between the and GND and the capacitance between the second electrode 40 and the GND. The capacitance value in this case is indicated by the detection value C in FIG. 9, and the relationship of detection value B> detection value C.

Next, the key top 27 of the operation button 20 is strongly pressed by the finger 60, the flange 28 of the key top 27 is separated from the second electrode 40, and the elastic click body 21 of the operation button 20 comes into contact with the first electrode 10. The case of the final operation state of FIG. 5 will be described. In this case, the capacitance value detected at the input terminal of the capacitance detection / determination means 50 is the capacitance between the input terminal of the capacitance detection / determination means 50 and the GND, and the wiring line 41 of the second electrode 40. It is a substantially total value of the capacitance between the and GND and the capacitance between the second electrode 40 and the GND, which is substantially the same as in the case of the intermediate operation state of FIG.

As described above, the capacitance value detected at the input terminal of the capacitance detection determination means 50 is indicated by the detection values A, B, and C. Therefore, between the detection value A and the detection value B, and the detection value B. If a threshold value is set between the and the detection value C and the capacitance value detected at the input terminal of the capacitance detection determination means 50 is compared with each threshold value, the capacitance detection determination means 50 can be used. There are three types: the non-contact state of the operation button 20 shown in FIG. 2, the contact state of the operation button 20 shown in FIG. 3, the intermediate operation state of the operation button 20 shown in FIG. 4, and the final operation state of the operation button 20 shown in FIG. The state can be determined.

In the above description, the second electrode 40 has been used, but the same applies to the case where the first electrode 10 is used, and the capacitance value detected at the input terminal of the capacitance detection determination means 50. Is indicated by the detected values D and E shown in FIG. Therefore, if a threshold value is set between the detection value D and the detection value E and the capacitance value detected at the input terminal of the capacitance detection determination means 50 is compared with the threshold value, the capacitance detection determination means 50 shows a non-contact state of the operation button 20 shown in FIG. 2, a contact state of the operation button 20 shown in FIG. 3, an intermediate operation state of the operation button 20 shown in FIG. 4, or a final operation of the operation button 20 shown in FIG. It is possible to determine two states.

When setting the detection value, first, the non-contact state of the operation button 20 shown in FIG. 2, the contact state of the operation button 20 shown in FIG. 3, the intermediate operation state of the operation button 20 shown in FIG. 4, and the operation shown in FIG. The detected values of the first and second electrodes 10 and 40 in the final operating state of the button 20 are measured, and the detected values of the second electrodes 40 in the contact state of the operation button 20 are the detected values A and the non-contact of the operation button 20. The detected value of the second electrode 40 in the state is the detected value B, the detected value of the second electrode 40 in the intermediate operation state of the operation button 20 and the final operation state of the operation button 20 is the detection value C, and the final operation of the operation button 20. The detection value of the first electrode 10 in the state is the detection value D, the detection value of the first electrode 10 in the non-contact state of the operation button 20, the contact state of the operation button 20, and the intermediate operation state of the operation button 20 is the detection value E. And. After measuring the detected values of the first and second electrodes 10 and 40, the detected values can be set by repeating this measurement and finding the average value and standard deviation of the detected values A, B, C, D, and E. it can.

Further, when setting the detection value, the upper limit and the lower limit of the detection values A, B, C, D, and E are preferably obtained by the following formula. The upper and lower limits of the detected values A, B, C, D, and E are constants and can be used as threshold values when determining the detected values of the first and second electrodes 10 and 40 in the program. .. In view of this point, in the present embodiment, the upper and lower limits of the detected values A, C, D, and E are used as the threshold values.

Upper limit of detection value A = average value of detection value A + 3 x standard deviation of detection value A Lower limit of detection value A = average value of detection value A-3 × standard deviation of detection value A Upper limit of detection value B = detection value B Average value + 3 x standard deviation of detection value B Lower limit of detection value B = average value of detection value B-3 x standard deviation of detection value B Upper limit of detection value C = average value of detection value C + 3 x detection value C Standard deviation Lower limit of detection value C = Average value of detection value C-3 x Standard deviation of detection value C Upper limit of detection value D = Average value of detection value D + 3 x Standard deviation of detection value D Lower limit of detection value D = Detection Average value of value D-3 x standard deviation of detection value D Upper limit of detection value E = average value of detection value E + 3 x standard deviation of detection value E Lower limit of detection value E = average value of detection value E-3 x detection Standard deviation of value E

Comparing the capacitance values detected by the first and second electrodes 10 and 40 described above with the detection values serving as threshold values and the upper and lower limit values thereof, the capacitance detection determination means 50 can be seen in FIG. The non-contact state of the operation button 20 shown, the contact state of the operation button 20 shown in FIG. 3, the intermediate operation state of the operation button 20 shown in FIG. 4, and the final operation state of the operation button 20 shown in FIG. 5 are determined. Can be made to.
The detection values detected by the first and second electrodes 10 and 40, the non-contact state of the operation button 20 shown in FIG. 2, the contact state of the operation button 20 shown in FIG. 3, and the operation button shown in FIG. The relationship between the intermediate operation state of 20 and the final operation state of the operation button 20 shown in FIG. 5 is as shown in Table 1.

In the above configuration, when the capacitance type input device detects the capacitance and determines the state of the operation button 20, the capacitance detection determination means 50 first determines the first and second electrodes 10. The capacitance detected by 40 is taken in as a detection value (S1), and it is determined whether or not the detection value detected by the second electrode 40 is within the upper and lower limits of the detection value A (S2).

As a result of the determination, when the detected value detected by the second electrode 40 is within the upper and lower limits of the detected value A, the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value E. When it is determined whether or not the value is within (S3) and the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value E, the finger 60 touches the key top 27 of the operation button 20. When it is determined that the contact state is stopped (S4) and the detected value detected by the first electrode 10 is outside the upper and lower limits of the detected value E, the finger 60 is placed on the key top 27 of the operation button 20. It is determined that it is in a non-contact state without touching (S5).

If the detected value detected by the second electrode 40 is outside the upper and lower limits of the detected value A, is the detected value detected by the second electrode 40 within the upper and lower limits of the detected value C? Whether or not it is determined (S6), and when the detected value detected by the second electrode 40 is within the upper and lower limits of the detected value C, the detected value detected by the first electrode 10 is the detected value E. It is determined whether or not it is within the range of the upper limit and the lower limit (S7).

As a result of the determination, when the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value E, the key top 27 of the operation button 20 is pushed into the finger 60 to operate the second electrode 40. It is determined that the flange 28 of the key top 27 is separated from the key top 27 in the middle operation state (S8). When the detected value detected by the second electrode 40 is outside the range of the upper limit and the lower limit of the detected value C, it is determined that the key top 27 of the operation button 20 is not in contact with the finger 60. (S9).

Further, when the detected value detected by the first electrode 10 is outside the upper and lower limits of the detected value E, is the detected value detected by the first electrode 10 within the upper and lower limits of the detected value D? When it is determined (S10) and the detected value detected by the first electrode 10 is within the upper and lower limits of the detected value D, the key top 27 of the operation button 20 is completely pushed into the finger 60. Then, the flange 28 of the key top 27 is separated from the second electrode 40, and it is determined that the elastic click body 21 of the operation button 20 is in pressure contact with the first electrode 10 (S11). When the detected value detected by the electrode 10 is outside the range of the upper limit and the lower limit of the detected value D, it is determined that the key top 27 of the operation button 20 is not in contact with the finger 60 (S12).

According to the above, four states of the non-contact state of the operation button 20, the contact state of the operation button 20, the intermediate operation state of the operation button 20, and the final operation state of the operation button 20 can be detected and clearly distinguished. Since it can be applied, various applications can be expected, and the performance of the capacitance type input device can be further improved. Further, the key top 27 stands by in a non-contact state of the finger 60, stands by in the contact state of the finger 60 to prepare for the predetermined function expression, and prepares for the predetermined function expression in the intermediate operation state during the pressing operation with the finger 60. While maintaining the state, a predetermined function (for example, ringing of a buzzer, lighting of a light, etc.) can be exhibited in the final operation state in which the finger 60 is completely pressed.

Further, if the finger 60 is brought into contact with the key top 27 and then the finger 60 is released without pressing, the standby state can be restored. Further, since the entire part of the key top 27 is formed of the conductive material, the key top 27 and the second electrode 40 can be connected to each other without imparting conductivity only to the contact surface of the flange 28 with respect to the second electrode 40. It is possible to appropriately secure the conductivity.

Next, FIG. 11 shows a second embodiment of the present invention. In this case, the buzzer device and the capacitance type input device are combined, and the key top 27 of the operation button 20 presses over time. When the operation button 20 is operated and the operation button 20 is operated for a long time, the buzzer sounds at a low volume when the operation button 20 is completely operated, the key top 27 of the operation button 20 is quickly pressed, and the operation button 20 is operated halfway. When the state is short, the buzzer sounds at a loud volume when the operation button 20 is completely operated. Since the other parts are the same as those in the above embodiment, the description thereof will be omitted.

It is clear that the same effects as those of the above-described embodiment can be expected in this embodiment, and that a wide range of applications can be expected.

Although the printed circuit board 1 is shown in the above embodiment, the present invention is not limited to this, and for example, a flexible printed circuit board 1 having flexibility may be used. Further, the first and second electrodes 10 and 40 may be exposed, but may not be exposed due to corrosion countermeasures. Further, the entire part of the key top 27 is formed of a conductive material, but the present invention is not limited to this.

For example, the key top 27 is molded from an insulating material such as polycarbonate resin, and conductive carbon or the like is applied to the contact surface of the flange 28 of the key top 27 with respect to the second electrode 40 to impart conductivity, or the entire flange 28 is provided. Conductive carbon or the like may be applied to the surface to impart conductivity. Further, conductive carbon or the like may be applied to the entire surface 29 for operation of the key top 27 to impart conductivity. Further, conductive carbon or the like is coated on at least a part of the contact surface of the flange 28 of the key top 27 with respect to the second electrode 40 and the surface 29 for operation of the key top 27 to form a conductive film, and these flanges 28 are formed. The conductive film of the above and the conductive film of the surface 29 for operation may be connected to form a circuit-shaped conductive layer. Further, the key top 27 can be made of a high dielectric material.

Further, instead of applying conductive carbon or the like, conductive plating can be applied to impart conductivity. Further, the elastic click body 21 of the operation button 20 may be detachably supported on the surface of the printed circuit board 1, but it can also be adhered and fixed.

Further, when at least one of the flange 28 of the key top 27 and the second electrode 40 facing each other is not exposed, the Cg shown in FIG. 7 is present even in the non-contact state or the contact state of the operation button 20. However, if the facing area between the flange 28 of the key top 27 and the second electrode 40 is increased and the distance between the flange 28 and the second electrode 40 is shortened, the Cg shown in FIG. 7 can be increased. When the Cg shown in FIG. 7 becomes large, the capacitance value detected at the input terminal of the capacitance detection determination means 50 in the non-contact state of the operation button 20 and the capacitance detection determination in the contact state of the operation button 20 are determined. Since the difference from the capacitance value detected at the input terminal of the means 50 can be increased, the non-contact state and the contact state of the operation button 20 can be clearly distinguished by setting a threshold value between them. it can.

When the Cg shown in FIG. 7 is large, the capacitance value detected at the input terminal of the capacitance detection determining means 50 in the contact state of the operation button 20 and the capacitance detection in the intermediate operation state of the operation button 20 Since the difference from the capacitance value detected at the input terminal of the determination means 50 can be increased, if a threshold value is set between them, the contact state of the operation button 20 and the halfway operation state can be clearly distinguished. Can be done. Further, in the second embodiment, when the key top 27 of the operation button 20 is pressed over time and the operation button 20 is in the middle of operation for a long time, the buzzer is emitted when the operation button 20 is completely operated. It is also possible to make it sound at a loud volume.

The capacitance type input device according to the present invention is used in the manufacturing field of music players, home appliances, portable devices, computer devices, information communication devices, automobile-mounted devices, and the like.

1 Printed circuit board (board)
10 First electrode 20 Operation button 21 Elastic click body 22 Main body 23 Convex part 24 Skirt part 25 Leg part 26 Air groove 27 Key top 28 Flange (peripheral part)
29 Surface 30 Protective panel (protective material)
31 Through port 40 Second electrode 41 Wiring line 50 Capacitance detection and determination means 60 Fingers (conductive operating body)
A detection value (first detection value)
B detection value (second detection value)
C detection value (third detection value)
D Detected value (4th detected value)
E detection value (fifth detection value)

Claims (6)

A first electrode formed on the substrate for detecting capacitance, an operation button capable of contacting the first electrode by operating a conductive operating body, and a protective material that exposes at least a part of the operating button. Capacitance type equipped with a second electrode for detecting capacitance formed on this protective material and capable of contacting an operation button, and a capacitance detection determining means connected to the first and second electrodes. It is an input device
The operation buttons include an elastic click body that is supported by a substrate and faces the first electrode so as to be contactable and detachable, and a key top for pressing operation that is attached to the elastic click body and partially exposed from the protective material. The peripheral edge of this key top is pressed against the opposing second electrode so that it can be attached and detached.
Based on the detected capacitance, the capacitance detection determination means is in a non-contact state in which the conductive operation body does not touch the key top of the operation button, a contact state in which the conductive operation body touches the key top of the operation button, and the operation button. The key top of is pressed against the conductive operating body, the peripheral edge of the key top is separated from the second electrode, and the key top of the operation button is strongly pressed against the conductive operating body, and the key top is pressed from the second electrode. A capacitance type input device characterized in that the peripheral portions of the two are separated and one of the final operating states in which the elastic click body of the operation button is in contact with the first electrode can be detected. A conductive film was formed on the contact surface of the peripheral edge of the key top of the operation button with respect to the second electrode and at least a part of the surface for operating the key top, and these conductive films were connected to form a conductive layer. The capacitance type input device according to claim 1. The protective material is provided with a through-hole that exposes the key top of the operation button, a second electrode that surrounds the through-hole is formed in the facing portion facing the substrate of the protective material, and the key top is formed on this second electrode. The capacitance type input device according to claim 1 or 2, wherein the flanges protruding from the surface are brought into surface contact with each other by pressure contact. The capacitance detection determination means has a function of capturing the detection values detected by the first and second electrodes, and whether or not the detection values detected by the second electrodes are within the upper and lower limits of the first detection value. When the determination function and the detection value detected by the second electrode are determined to be within the upper and lower limits of the first detection value, the detection value detected by the first electrode is the fifth detection value. The function to determine whether or not it is within the range of the upper and lower limits of, and when it is determined that the detected value detected by the first electrode is within the range of the upper and lower limits of the fifth detection value, the operation button When it is determined that the key top is in contact with the conductive operating body and the detection value detected by the first electrode is outside the upper and lower limits of the fifth detection value, The capacitance type input device according to claim 1, 2 or 3, which realizes a function of determining that the conductive operating body is not in contact with the key top of the operation button. When the capacitance detection determination means determines that the detection value detected by the second electrode is outside the range of the upper limit and the lower limit of the first detection value, the detection value detected by the second electrode is the first. (Iii) A function to determine whether or not the detection value is within the upper and lower limits, and when it is determined that the detection value detected by the second electrode is within the upper and lower limits of the third detection value, A function to determine whether the detected value detected by the first electrode is within the upper and lower limits of the fifth detected value, and the range of the upper and lower limits of the fifth detected value detected by the first electrode. When it is determined to be inside, the key top of the operation button is pressed by the conductive operating body, and the peripheral portion of the key top is separated from the second electrode, and the function is determined to be in the middle operation state. When it is determined that the detected value detected by the electrode of is outside the range of the upper limit and the lower limit of the third detected value, it is determined that the conductive operating body is not in contact with the key top of the operation button. The capacitance type input device according to claim 4, which realizes the function. When the capacitance detection determination means determines that the detection value detected by the first electrode is outside the upper and lower limits of the fifth detection value, the detection value detected by the first electrode is the first. (Iv) A function to determine whether or not the detection value is within the upper and lower limits, and when it is determined that the detection value detected by the first electrode is within the upper and lower limits of the fourth detection value, It is determined that the key top of the operation button is strongly pressed by the conductive operation body, the peripheral edge of the key top is separated from the second electrode, and the elastic click body of the operation button is in contact with the first electrode in the final operation state. When it is determined that the detection value detected by the first electrode is outside the upper and lower limits of the fourth detection value, the key top of the operation button is not touched by the conductive operation body. The capacitance type input device according to claim 5, which realizes a function of determining a state.

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