CN111725018B - Key, control circuit and electronic equipment - Google Patents

Key, control circuit and electronic equipment Download PDF

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Publication number
CN111725018B
CN111725018B CN202010572015.0A CN202010572015A CN111725018B CN 111725018 B CN111725018 B CN 111725018B CN 202010572015 A CN202010572015 A CN 202010572015A CN 111725018 B CN111725018 B CN 111725018B
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CN
China
Prior art keywords
key
pressing
cantilever beam
piezoelectric device
control circuit
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CN202010572015.0A
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CN111725018A (en
Inventor
许明
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Guangdong Oppo Mobile Telecommunications Corp Ltd
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Guangdong Oppo Mobile Telecommunications Corp Ltd
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Priority to CN202010572015.0A priority Critical patent/CN111725018B/en
Publication of CN111725018A publication Critical patent/CN111725018A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/02—Details
    • H01H13/26—Snap-action arrangements depending upon deformation of elastic members
    • H01H13/36—Snap-action arrangements depending upon deformation of elastic members using flexing of blade springs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/02—Details
    • H01H13/12—Movable parts; Contacts mounted thereon
    • H01H13/14—Operating parts, e.g. push-button
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/54—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere

Abstract

The application provides a key, a control circuit and an electronic device. The key comprises a keycap, a base, a cantilever beam and a piezoelectric device; the key cap is installed on the base, has in the base and holds the chamber, and the cantilever beam has elasticity, and on the one end of cantilever beam was fixed in the base, the other end of cantilever beam stretched into and held the chamber, and piezoelectric device installed on the cantilever beam, and piezoelectric device is used for detecting the deformation of cantilever beam and is used for driving the cantilever beam vibration so that the other end elasticity top of cantilever beam touches the key cap. The application provides a button has elastic cantilever beam through the support on the base, sets up piezoelectric device on the cantilever beam, detects the deformation of cantilever beam and drives the cantilever beam vibration through piezoelectric device to the realization is pressed and is detected and tactile feedback, need not to set up detecting element and actuating unit respectively, has simplified the structure.

Description

Key, control circuit and electronic equipment
Technical Field
The application belongs to the field of electronic products, and particularly relates to a key, a control circuit and electronic equipment.
Background
The key is a man-machine interaction device commonly used in electronic products. The keys are classified into passive tactile keys and active tactile keys. The passive feedback key provides tactile feedback through the restoring force of elastic structures such as key springs. The key generally comprises a key unit, an electric actuating unit and a detection unit, wherein the detection unit is used for detecting the pressing action of the key, and then an internal or external controller controls the electric actuating unit to vibrate the key so as to realize active tactile feedback. Such a key is complicated in structure and the electric actuation unit and the detection unit tend to interact with each other.
Disclosure of Invention
An object of the embodiments of the present application is to provide a key, a control circuit and an electronic device, so as to solve the problems that the active feedback key in the related art has a complex structure and the detection unit and the actuation unit can affect each other.
A first aspect of an embodiment of the present application provides a key, including a keycap, a base, a cantilever beam, and a piezoelectric device; the key cap is installed on the base, has in the base and holds the chamber, and the cantilever beam has elasticity, and on the one end of cantilever beam was fixed in the base, the other end of cantilever beam stretched into and held the chamber, and the piezoelectric device was installed on the cantilever beam, and the piezoelectric device was used for detecting the deformation of cantilever beam and was used for driving the cantilever beam vibration so that the key cap was touched on the other end elasticity top of cantilever beam.
In one embodiment, the key further comprises an adhesive layer bonding the piezoelectric device to the cantilever beam.
In one embodiment, the key further includes a first electrode and a second electrode electrically connected to both electrode terminals of the piezoelectric device, respectively; the first electrode and the second electrode are both arranged on the cantilever beam; alternatively, the first electrode and the second electrode are both mounted on the piezoelectric device; alternatively, the first electrode is mounted on the piezoelectric device and the second electrode is mounted on the cantilever beam.
In one embodiment, the base is provided with signal pins electrically connected to two electrode terminals of the piezoelectric device, respectively.
In one embodiment, the cantilever beam is provided with piezoelectric devices on both sides.
In one embodiment, a plurality of cantilever beams are mounted in the base, and each cantilever beam is provided with a piezoelectric device.
In one embodiment, when the cantilever beam and the keycap are in the initial position, the cantilever beam is integrally arranged at a distance from the keycap.
In one embodiment, one end of the cantilever beam is arranged at a distance from the keycap, and the other end of the cantilever beam is in contact with the middle of the keycap.
In one embodiment, the middle part of the keycap is convexly provided with a bulge towards the base, and the other end of the cantilever beam is contacted with the bulge.
A second aspect of an embodiment of the present application provides a control circuit, configured to control a key according to any one of the above embodiments;
the control circuit comprises a pressing detection module, a feedback excitation module and a processor;
the pressing detection module receives pressing signals generated by a pressing device in the key, processes the pressing signals to form pressing detection signals, and outputs the pressing detection signals to the processor;
the feedback excitation module is used for outputting an excitation signal to the piezoelectric device to drive the piezoelectric device to deform so as to drive the cantilever beam of the key to vibrate;
the processor is used for controlling the feedback excitation module to output an excitation signal according to the pressing detection signal.
In one embodiment, the processor controls the feedback excitation module to output an excitation signal through the interaction strategy; the interaction strategy comprises the following steps:
judging whether the key is in a key feedback excitation flow, shielding a pressing detection signal under the condition that the key is in the key feedback excitation flow, and controlling a feedback excitation module to output an excitation signal; and
and judging whether the key is in a key detection flow, and closing the feedback excitation module and receiving a pressing detection signal under the condition that the key is in the key detection flow.
In one embodiment, the processor determines the pressing characteristics of the key according to the pressing detection signal, and controls the feedback excitation module to output the excitation signal according to the pressing characteristics, wherein the pressing characteristics comprise a pressing duration characteristic and/or a pressing force degree characteristic.
In one embodiment, the pressing detection module comprises a plurality of detection units which respectively form pressing detection signals according to intensity processing of the pressing signals, and the processor obtains pressing force degree characteristics according to the pressing detection signals output by the plurality of detection units.
In one embodiment, each detection unit comprises a hysteresis comparison circuit and a blocking capacitor, two ends of the blocking capacitor are respectively connected with an input end of the hysteresis comparison circuit and the piezoelectric device, an output end of the hysteresis comparison circuit is connected with the processor, and a reference end of each hysteresis comparison circuit applies a reference voltage; the reference voltages of the reference terminals of the plurality of hysteresis comparison circuits are set to be unequal.
In one embodiment, the processor starts timing when detecting that the pressing detection signal is changed from the normal state to the set state, and stops timing when detecting that the pressing detection signal is changed from the set state back to the normal state, so as to obtain the pressing duration characteristic.
In one embodiment, the control circuit further comprises an amplifying unit for amplifying the pressing signal and outputting the amplified pressing signal to the pressing detection module.
In one embodiment, the control circuit and the keys are disposed in an electronic device, and the control circuit is located in a processing chip of the electronic device.
In one embodiment, the control circuit is a control chip of the key.
A third aspect of an embodiment of the present application provides an electronic device, including a housing, a key according to any one of the above embodiments, and a control circuit according to any one of the above embodiments, where the key is disposed on the housing, and the key is connected to the control circuit.
One or more technical solutions in the embodiments of the present application have at least one of the following technical effects:
the button that this application embodiment provided has elastic cantilever beam through the support on the base, sets up piezoelectric device on the cantilever beam, detects the deformation of cantilever beam and drives the cantilever beam vibration through piezoelectric device to the realization is pressed and is detected and tactile feedback, need not to set up detecting element and actuating unit respectively, has simplified the structure.
The control circuit that this application embodiment provided receives and handles the pressure signal that piezoelectric device produced through pressing detection module, uses feedback excitation module to export the excitation signal to piezoelectric device to drive piezoelectric device and drive the cantilever beam vibration, so that piezoelectric device both can realize pressing the detection, can carry out tactile feedback again, and then realizes simplifying the structure of button.
According to the electronic equipment provided by the embodiment of the application, the key and the control circuit are used, active touch feedback of the key can be realized, touch experience is improved, and the structure is simplified.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or exemplary technical descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a key according to an embodiment of the present application.
Fig. 2 is a schematic structural diagram of a key according to another embodiment of the present application.
Fig. 3 is a schematic structural diagram of a key according to another embodiment of the present application.
Fig. 4 is a schematic structural diagram of a key according to another embodiment of the present application.
Fig. 5 is a schematic structural diagram of a key according to another embodiment of the present application.
Fig. 6 is a block diagram of a connection structure between a control circuit and a key according to an embodiment of the present disclosure.
Fig. 7 is a flowchart of an interaction policy provided in an embodiment of the present application.
Fig. 8 is a structural diagram of a control circuit connected to a key according to another embodiment of the present application.
Fig. 9 is a circuit diagram of a detection unit according to an embodiment of the present application.
Fig. 10 (a) is a waveform diagram of a pressing signal output from the piezoelectric device when a key is pressed; fig. (b) is a waveform diagram of a pressing detection signal output by the first detection unit according to the pressing signal; fig. c is a waveform diagram of the pressing detection signal output by the second detection unit according to the pressing signal.
Fig. 11 is a flow chart of the control circuit determining the press duration feature of the present application.
Fig. 12 is a circuit diagram of a detection unit according to another embodiment of the present application.
Fig. 13 is a circuit diagram of a detection unit according to another embodiment of the present application.
Fig. 14 is a circuit diagram of a detection unit according to another embodiment of the present application.
Fig. 15 is a structural diagram of a control circuit and a key according to another embodiment of the present application.
Fig. 16 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Wherein, in the drawings, the reference numerals are mainly as follows:
100-an electronic device;
10-push button; 11-a keycap; 111-bumps; 12-a base; 121-a cavity; 13-cantilever beam; 14-a piezoelectric device; 15-an adhesive layer; 161-a first electrode; 162-a second electrode; 17-a signal pin;
20-a control circuit; 21-a processor; 22-a press detection module; 220-a detection unit; 221-hysteresis comparison circuit; 23-a feedback excitation module; 24-an amplifying unit;
30-a housing.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.
In the description of the present application, it is to be understood that the terms "middle", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.
In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
Reference throughout this specification to "one embodiment," "some embodiments," or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Referring to fig. 1, a key 10 provided in the present application will now be described. A key 10 including a key cap 11, a base 12, a cantilever beam 13 and a piezoelectric device 14; the key cap 11 is used for pressing operation by a user, is convenient for the user to press operation, and can protect devices and structures in the base 12. The key cap 11 is mounted on the base 12, and the key cap 11 is supported by the base 12. The base 12 has a cavity 121 therein to facilitate receiving the cantilever beam 13 and the piezoelectric device 14. Cantilever beam 13 has elasticity, and the one end of cantilever beam 13 is fixed in on base 12, and the other end of cantilever beam 13 stretches into and holds chamber 121 to the other end of cantilever beam 13 is used for the elasticity top to touch key cap 11, and at the within range of the elastic vibration of cantilever beam 13 promptly, key cap 11 can be touched on the other end of cantilever beam 13 top, so as to feed back key cap 11, and when pressing key cap 11, can make key cap 11 roof pressure cantilever beam 13, so that cantilever beam 13 warp. The piezoelectric device 14 is mounted on the cantilever beam 13, and the piezoelectric device 14 is used for detecting the deformation of the cantilever beam 13 and driving the cantilever beam 13 to vibrate; that is, pressing key cap 11 makes cantilever beam 13 warp, and cantilever beam 13 drives piezoelectric device 14 and warp, then piezoelectric device 14 can detect this deformation, realizes pressing the detection to can also be through applying voltage to piezoelectric device 14's both electrodes end, with the deformation of drive piezoelectric device 14, and then drive cantilever beam 13 vibration, make cantilever beam 13's other end elasticity top touch key cap 11, realize main tributary tactile feedback, simple structure.
The key 10 of the embodiment of the application has elastic cantilever beam 13 through supporting on the base 12, sets up the piezoelectric device 14 on the cantilever beam 13, detects the deformation of the cantilever beam 13 and drives the cantilever beam 13 to vibrate through the piezoelectric device 14 to realize pressing detection and tactile feedback, need not to set up detecting element and actuating element respectively, has simplified the structure.
In one embodiment, referring to fig. 1, the key 10 further includes an adhesive layer 15, and the piezoelectric device 14 is adhered to the cantilever beam 13 through the adhesive layer 15, so that the piezoelectric device 14 is mounted and fixed on the cantilever beam 13, which is convenient to assemble, simple in structure and low in cost. In some embodiments, other ways of fixing the piezoelectric device 14 on the cantilever beam 13 may be used, such as providing a groove in the cantilever beam 13, placing the piezoelectric device 14 in the groove, and covering the groove with a plate, so that the cantilever beam 13 and the plate press and fix the piezoelectric device 14. In still other embodiments, the piezoelectric device 14 may be fabricated directly on the cantilever beam 13 when the piezoelectric device 14 is fabricated. Of course, if the cantilever beam 13 is a plastic part, the piezoelectric device 14 may be injection molded in the cantilever beam 13, and so on.
In one embodiment, the adhesive layer 15 may use a conductive adhesive, such as an epoxy conductive adhesive, a phenolic conductive adhesive, a polyurethane conductive adhesive, a thermoplastic conductive adhesive, or a polyimide conductive adhesive. Of course, in some embodiments, the adhesive layer 15 may also use an insulating glue, such as epoxy glue, phenolic glue, polyurethane glue, thermoplastic glue, or polyimide glue.
In one embodiment, the key 10 further includes a first electrode 161 and a second electrode 162, and the first electrode 161 and the second electrode 162 are electrically connected to two electrode terminals of the piezoelectric device 14, respectively. The first electrode 161 and the second electrode 162 are provided to facilitate application of a voltage to the piezoelectric device 14 and also to facilitate output of a signal detected by the piezoelectric device 14. In some embodiments, both the first electrode 161 and the second electrode 162 may be mounted on the cantilever beam 13. In some embodiments, both the first electrode 161 and the second electrode 162 may be mounted on the piezoelectric device 14. In some embodiments, the first electrode 161 may be mounted on the piezoelectric device 14 and the second electrode 162 may be mounted on the cantilever beam 13.
In one embodiment, the first electrode 161 may be mounted on a side of the piezoelectric device 14 away from the cantilever beam 13 and the second electrode 162 may be mounted on the cantilever beam 13 to facilitate connection to external circuitry or other devices.
In one embodiment, when the piezoelectric device 14 is bonded to the cantilever beam 13 using the adhesive layer 15, the adhesive layer 15 may be made of conductive adhesive, and the adhesive layer 15 is connected to the second electrode 162, thereby connecting the second electrode 162 to the corresponding electrode terminal of the piezoelectric device 14. Of course, in some embodiments, wires or traces on the cantilever beam 13 may also be used to connect the corresponding electrode terminals of the piezoelectric device 14 to the second electrode 162.
In one embodiment, the cantilever beam 13 may also be made of a conductive material, such that the second electrode 162 is connected to the corresponding electrode terminal of the piezoelectric device 14 via the cantilever beam 13.
In one embodiment, the cantilever beam 13 may be made of a metal material having elasticity, such as beryllium bronze, phosphor bronze, rolled manganese bronze, stainless steel, nickel alloy, or the like. In some embodiments, the cantilever beam 13 may also be made of other elastic materials, such as elastic plastic or elastic composite material, such as PET (Polyethylene terephthalate, thermoplastic polyester or saturated polyester, abbreviated as PET) material, PVC (Polyvinyl chloride, abbreviated as PVC) material, and the like.
In one embodiment, the key cap 11 may be an elastic member such as an elastic metal member, an elastic plastic member, an elastic silicone member, or an elastic rubber member, so as to facilitate the pressing operation and facilitate the cantilever beam 13 to drive the key cap 11 to vibrate. Of course, in some embodiments, the middle portion of the key cap 11 can be made of a hard material, and the periphery of the key cap 11 is made of an elastic material, so as to elastically support the middle portion of the key cap 11 in the base 12, and also facilitate pressing the key cap 11, and facilitate the cantilever beam 13 to drive the key cap 11 to vibrate.
In one embodiment, two signal pins 17 are disposed on the base 12, and the two signal pins 17 are electrically connected to two electrode terminals of the piezoelectric device 14, respectively, so as to facilitate connection of the key 10 to an external circuit, other device or component. In some embodiments, the two signal pins 17 may be electrically connected to the first electrode 161 and the second electrode 162, respectively, that is, the first electrode 161 and the second electrode 162 are led out through the two signal pins 17, which is convenient for connection and use. In still other embodiments, the two signal pins 17 may be directly electrically connected to the two electrode terminals of the piezoelectric device 14, respectively.
In one embodiment, one end of the cantilever beam 13 is spaced apart from the key cap 11, and the other end of the cantilever beam 13 contacts the middle of the key cap 11. In this application, one end of the cantilever beam 13 is spaced from the key cap 11, and particularly, one end of the cantilever beam 13 connected to the base 12 is spaced from the inner surface of the key cap 11 far from the base 12, that is, one end of the cantilever beam 13 extending into the cavity 121 close to the side wall of the cavity 121 is spaced from the inner surface of the key cap 11. And cantilever beam 13 is close to the one end and the key cap 11 contact in key cap 11 middle part to after pressing key cap 11, when cantilever beam 13 kick-backs towards the direction of key cap 11, can avoid key cap 11 to support cantilever beam 13, so that cantilever beam 13 can have great deformation space, and then when pressing key cap 11, the drive cantilever beam 13 that can be better warp, the cantilever beam 13 that is also convenient for drives key cap 11 vibration.
In one embodiment, a protrusion 111 is protruded from the middle of the key cap 11 toward the base 12, and the other end of the cantilever beam 13 contacts the protrusion 111. The middle part of the key cap 11 is provided with a protrusion 111 to be conveniently contacted with the other end of the cantilever beam 13, when the key cap 11 is pressed, the cantilever beam 13 can be conveniently jacked, the end, connected with the base 12, of the cantilever beam 13 is conveniently arranged at intervals with the key cap 11, and the cantilever beam 13 is conveniently mounted and fixed. Of course, in some embodiments, the inner surface of the key cap 11 may be configured as a planar structure, and the cantilever beam 13 is disposed obliquely to the inner surface of the key cap 11, so that the end of the cantilever beam 13 connected to the base 12 may be spaced apart from the key cap 11, and the other end of the cantilever beam 13 contacts the middle of the key cap 11. In still other embodiments, the shape of the cantilever beam 13 may be adapted to the inner surface of the key cap 11 so as to attach the cantilever beam 13 to the inner surface of the key cap 11.
In one embodiment, the piezoelectric device 14 may be disposed on a side of the cantilever beam 13 near the key cap 11, so that the key cap 11 better protects the piezoelectric device 14. Of course, in some embodiments, the piezoelectric device 14 may also be disposed on a side of the cantilever beam 13 facing away from the key cap 11.
In one embodiment, the piezoelectric device 14 is a device made of piezoelectric material, and may be made of piezoelectric single crystal, piezoelectric ceramic, piezoelectric polymer, or piezoelectric composite material.
In one embodiment, a groove may be formed on the base 12 to form the cavity 121. In still other embodiments, the base 12 may be perforated to define the cavity 121.
In an embodiment, please refer to fig. 2, when the cantilever beam 13 and the key cap 11 are at the initial positions, the initial positions of the cantilever beam 13 and the key cap 11 refer to positions when the key cap 11 is not pressed and the key cap 11 and the cantilever beam 13 are in the static state, the cantilever beam 13 and the key cap 11 are arranged at an interval, that is, the key cap 11 is in the non-pressed state, and when the cantilever beam 13 is not vibrated, the cantilever beam 13 and the key cap 11 are arranged at an interval, so as to prevent the cantilever beam 13 from vibrating due to mistakenly touching the key cap 11, that is, the structure can play a certain role of preventing mistaken touching.
In one embodiment, referring to fig. 3, a first electrode 161 and a second electrode 162 are disposed in the key 10, the first electrode 161 and the second electrode 162 are electrically connected to two electrode terminals of the piezoelectric device 14, respectively, the first electrode 161 is mounted on a side of the piezoelectric device 14 away from the cantilever beam 13, and the second electrode 162 is mounted on a side of the piezoelectric device 14 close to the cantilever beam 13, so that the first electrode 161 and the second electrode 162 are electrically connected to the two electrode terminals of the piezoelectric device 14.
In one embodiment, referring to fig. 4, two sides of the cantilever beam 13 are respectively provided with the piezoelectric devices 14, so that when detecting, one piezoelectric device 14 can be used to detect the deformation of the cantilever beam 13; the piezoelectric devices 14 on the two sides of the cantilever beam 13 can also be used for simultaneously detecting the deformation of the cantilever beam 13, so that the detection is more accurate. When the active touch feedback is performed, the cantilever beam 13 can be driven to vibrate synchronously through the two piezoelectric devices 14, so that the vibration amplitude and strength of the cantilever beam 13 are improved, the vibration sense is improved, and the user experience is further improved.
In one embodiment, referring to fig. 5, a plurality of cantilever beams 13 are installed in the base 12, and each cantilever beam 13 is installed with a piezoelectric device 14, so that during detection, the piezoelectric device 14 on one cantilever beam 13 can be used to detect the deformation of the cantilever beam 13; the deformation of the cantilever beams 13 can be detected simultaneously by using the piezoelectric devices 14 on a plurality of cantilever beams 13, so that the detection is more accurate. When the initiative sense of touch feedback, can make a plurality of cantilever beams 13 vibrate simultaneously to promote the sense of shaking that drives the vibration of key cap 11, and then promote user experience. In some embodiments, when there are a plurality of cantilever beams 13, the piezoelectric device 14 may be disposed on one surface of each cantilever beam 13, or the piezoelectric devices 14 may be disposed on both surfaces of each cantilever beam 13.
The key 10 of the embodiment of the application can be applied to electronic devices such as smart phones, game machines, game pads, remote controllers and the like, so as to improve the experience of users in operating the electronic devices.
Referring to fig. 6, an embodiment of the present application provides a control circuit 20, and the control circuit 20 can be used to control the key 10 according to any of the above embodiments. The control circuit 20 includes a compression detection module 22, a feedback activation module 23, and a processor 21. Referring to fig. 1, the pressing detection module 22 receives the pressing signal generated by the piezoelectric device 14 in the key 10, processes the pressing signal to form a pressing detection signal, and outputs the pressing detection signal to the processor 21. The feedback excitation module 23 is configured to output an excitation signal to the piezoelectric device 14, and drive the piezoelectric device 14 to deform through the excitation signal, so as to drive the cantilever 13 of the key 10 to vibrate, thereby implementing active tactile feedback. The processor 21 is configured to control the feedback excitation module 23 to output an excitation signal according to the pressing detection signal, that is, the processor 21 receives the pressing detection signal to determine whether the key 10 is in the detection state or in the active tactile feedback state of vibration, and controls the feedback excitation module 23 to operate to control the feedback excitation module 23 to output the excitation signal, so as to drive the key 10 to vibrate.
The control circuit 20 of the embodiment of the application receives and processes the pressing signal generated by the piezoelectric device 14 through the pressing detection module 22, and outputs the excitation signal to the piezoelectric device 14 through the feedback excitation module 23 to drive the piezoelectric device 14 to drive the cantilever beam 13 to vibrate, so that the piezoelectric device 14 can realize pressing detection and can also perform tactile feedback, thereby simplifying the structure of the key 10.
The Processor 21 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
In one embodiment, the press detection module 22 may be used to detect a voltage signal generated when the piezoelectric device 14 is deformed. Of course, in some embodiments, the pressing detection module 22 may also be used to detect the current signal generated when the piezoelectric device 14 is deformed.
In one embodiment, referring to fig. 6 and 7, processor 21 controls feedback excitation module 23 to output an excitation signal through interaction strategy S10, so as to better control the vibration of key 10 through feedback excitation module 23. The interaction strategy S10 includes determining whether the key 10 is in the key feedback excitation flow S11, and in a case that the key 10 is in the key feedback excitation flow, shielding the pressing detection signal, and controlling the feedback excitation module 23 to output the excitation signal S12; and
it is determined whether the key 10 is in the key detection flow S13, and if the key 10 is in the key detection flow, the feedback excitation module 23 is turned off and the press detection signal is received S14.
That is, the processor 21 determines whether the key 10 is in the key feedback activation flow S11, and in the case where the key 10 is in the key feedback activation flow, the processor 21 masks the depression detection signal, and the processor 21 controls the feedback activation module 23 to output the activation signal S12. Specifically, the processor 21 may determine whether the key 10 is in the key feedback activation process according to whether the received pressing detection signal sends an instruction for controlling the feedback activation module 23 to output. For example, when the external application such as WeChat, SMS, game, etc. needs vibration feedback, or after pressing the key 10, the processor 21 confirms that the key 10 has been pressed according to the received pressing detection signal, and when vibration feedback is needed, the processor 21 needs to send an instruction to the feedback excitation module 23 to control the feedback excitation module 23 to output an excitation signal, and during the period from the time when the processor 21 sends the instruction to the time when the feedback excitation module 23 outputs the excitation signal, the processor 21 may determine that the key 10 is in the key feedback excitation process. That is, the processor 21 may determine that the key 10 is in the key feedback activation process by issuing a control instruction to the feedback activation module 23.
In addition, the processor 21 determines whether the key 10 is in the key detection process S13, and in the case where the key 10 is in the key detection process, the processor 21 controls to turn off the feedback excitation module 23, and the processor 21 receives the press detection signal S14. The processor 21 can determine that the key 10 is in the key detection process through the received pressing detection signal; the processor 21 may also determine whether the key 10 is in the key detection process according to the detection timing or cycle when it is determined that the key 10 is not in the key feedback activation process.
When the processor 21 determines that the key 10 is in the key feedback excitation process, the processor controls the feedback excitation module 23 to control the piezoelectric device 14 in the key 10 to vibrate, and drives the cantilever beam 13 to vibrate, so as to drive the key 10 to vibrate; that is, the processor 21 controls the feedback excitation module 23 to control the key 10 to actively feed back the vibration if it determines that the key 10 is in the key feedback excitation process. When the key 10 actively feeds back the vibration, the pressing signal output by the key 10 may change, and the pressing detection signal generated by the pressing detection module 22 may also disappear or change, which is actually the interference and influence of the active vibration feedback of the key 10 on the pressing detection module 22. When the key 10 actively feeds back the vibration, the processor 21 shields the pressing detection signal; that is, the processor 21 masks the pressing detection signal when determining that the key 10 is in the key feedback excitation process, so as to mask these interferences and influences, that is, when actively feeding back the vibration of the key 10, the processor 21 does not make a determination error.
The processor 21 receives the pressing detection signal to determine whether the key 10 is pressed if the key 10 is determined to be in the key detection process. When the key 10 is in the key detection process, the processor 21 closes the feedback excitation module 23, so that the feedback excitation module 23 can be prevented from outputting an excitation signal by mistake to affect the key 10; it is also possible to avoid that an external application or other vibration feedback requirement causes the feedback excitation module 23 to erroneously output an excitation signal to affect the key 10. So that the detection accuracy of the pressing detection module 22 can be ensured.
Through the interaction strategy S10, the key detection process and the feedback excitation process are carried out in a time-sharing manner, so that the mutual influence of the pressing detection and the active tactile feedback of the piezoelectric devices 14 in the key 10 can be avoided, and the same piezoelectric device 14 in the key 10 can realize the pressing detection and the tactile feedback; in addition, the processor 21 may execute the interaction policy S10, so that the external application may need vibration feedback, that is, when the key 10 is not pressed, the key 10 may also be actively vibrated, thereby improving the functional function of the key 10.
In one embodiment, referring to fig. 6 and fig. 7, the processor 21 executes a one-time interaction policy S10, determines that the key 10 is in the key feedback excitation process, and if the key 10 is in the key feedback excitation process, masks the pressing detection signal, and controls the key 10 to perform vibration feedback through the feedback excitation module 23; after the vibration feedback is finished, the processor 21 executes the interaction strategy S10 again; if the key 10 is still in the key feedback excitation process, the pressing detection signal is shielded, and the feedback excitation module 23 continues to control the key 10 to perform vibration feedback. When the processor 21 executes an interaction policy S10, it determines that the key 10 is in the non-key feedback activation process, and then determines whether the key 10 is in the key detection process, if the key 10 is in the key detection process, the feedback activation module 23 is turned off, the processor 21 receives the pressing detection signal, determines whether the key 10 is pressed, and if the key 10 is detected to be pressed, executes the interaction policy S10 again, and the re-executed interaction policy S10 inevitably determines that the key 10 is in the key feedback activation process. When the processor 21 executes an interaction policy S10, the processor 21 determines that the key 10 is in the non-key feedback activation process and determines that the key 10 is also in the non-key detection process, and may execute an interaction policy S10 again.
Of course, in some embodiments, the processor 21 executes the one-time interaction policy S10, the processor 21 may first determine whether the key 10 is in the key detection process S13, in the case that the key 10 is in the key detection process, the processor 21 controls to turn off the feedback excitation module 23, and the processor 21 receives the press detection signal S14. The processor 21 executes the one-time interaction policy S10, and if the processor 21 determines that the key 10 is in the non-key-detection flow, whether the key 10 is in the key feedback activation flow S11, and if the key 10 is in the key feedback activation flow, the processor 21 masks the pressing detection signal, and the processor 21 controls the feedback activation module 23 to output the activation signal S12.
In one embodiment, referring to fig. 6, the processor 21 determines a pressing characteristic of the key 10 according to the pressing detection signal, and controls the feedback excitation module 23 to output an excitation signal according to the pressing characteristic, wherein the pressing characteristic includes a pressing duration characteristic and/or a pressing force degree characteristic. The processor 21 controls the feedback excitation module 23 to output the excitation signal through the pressing feature, so that the vibration of the key 10 can be better controlled, and the vibration feedback experience is improved. For example, when the processor 21 controls the feedback excitation module 23 to output the excitation signal according to the pressing duration characteristic, the duration of the feedback excitation module 23 outputting the excitation signal may be controlled to realize the follow-up feedback. For example, when the feedback excitation module 23 is controlled to output the excitation signal according to the pressing force characteristic, the intensity of the excitation signal output by the feedback excitation module 23 may be controlled to increase the vibration intensity of the key 10.
The feedback excitation module 23 is used for outputting an excitation signal to excite the cantilever beam 13 of the key 10 to vibrate. The feedback excitation module 23 may be an ASIC (Application Specific Integrated Circuit, ASIC for short) or a waveform generation Circuit. The excitation signal is generally a sine wave, and may be a sine wave derived waveform (e.g., truncated sine wave), a triangular wave, or the like. When the frequency of the excitation signal is the natural frequency of the cantilever beam 13, resonance can be caused to enhance the vibration of the cantilever beam 13, thereby enhancing the vibration strength of the key 10. Therefore, the feedback excitation module 23 can adjust the feedback strength of the key 10 (i.e. the vibration strength of the cantilever beam 13, which may also be referred to as the vibration strength of the key 10) by adjusting the amplitude of the excitation signal, and the larger the amplitude of the excitation signal is, the larger the feedback strength is; the feedback strength of the key 10 can be adjusted by adjusting the frequency of the excitation signal, and the closer the frequency of the excitation signal is to the natural frequency of the cantilever beam 13, the greater the vibration of the cantilever beam 13 is, that is, the greater the feedback strength of the key 10 is; or the amplitude of the excitation signal may be combined with the frequency to control the feedback strength of the key 10.
In one embodiment, processor 21 may dynamically adjust the amplitude, frequency and waveform of the output excitation signal of feedback excitation module 23 to dynamically adjust the feedback strength of key 10 according to interaction policy S10.
In an embodiment, referring to fig. 8, the pressing detection module 22 includes a plurality of detection units 220, the detection units 220 respectively process the pressing signals according to the intensity of the pressing signals to form pressing detection signals, and respectively output the pressing detection signals to the processor 21, and the processor 21 obtains the pressing force characteristics according to the pressing detection signals output by the detection units 220. Because the pressing force of the key 10 is different, the deformation amplitudes of the piezoelectric device 14 are also different, the intensities of the pressing signals generated by the piezoelectric device 14 are also different, the plurality of detection units 220 respectively receive the pressing signals generated by the piezoelectric device 14, the plurality of detection units 220 respectively generate pairs of pressing detection signals according to the intensities of the pressing signals, and when the processor 21 detects the pressing detection signals output by the plurality of detection units 220, the pressing force of the key 10 can be determined, that is, the pressing force characteristics of the key 10 can be obtained. Of course, in some embodiments, the pressing detection module 22 may also include only one detection unit 220, and may also detect whether the key 10 is pressed.
Taking two detecting units 220 as an example, for convenience of description, the two detecting units 220 are respectively a first detecting unit 220a and a second detecting unit 220 b; the first detecting unit 220a generates a pressing detection signal when the pressing signal output by the key 10 is low in intensity, that is, when the key 10 is pressed with a small force, the first detecting unit 220a generates the pressing detection signal; the second detecting unit 220b generates a pressing detection signal when the intensity of the pressing signal output by the key 10 is greater, that is, the second detecting unit 220b generates the pressing detection signal when the key 10 is pressed with greater force; when the processor 21 detects that only the detection signal output from the first detection unit 220a is detected, it may be determined that the key 10 is pressed with a small force; if the processor 21 detects that only the detection signal output by the first detection unit 220a and the detection signal output by the second detection unit 220b are detected, it can be determined that the key 10 is pressed with a large force, that is, the pressing force characteristic can be obtained. More detection units 220 are provided, so that more accurate pressing force characteristics can be obtained.
In one embodiment, referring to fig. 9, the detecting unit 220 includes a hysteresis comparing circuit 221a and a blocking capacitor C11, two ends of the blocking capacitor C11 are respectively connected to the input terminal of the hysteresis comparing circuit 221a and the key 10, the output terminal output of the hysteresis comparing circuit 221a is connected to the processor 21, and the reference terminal Vref of the hysteresis comparing circuit 221a applies a reference voltage. The end of the dc blocking capacitor C11 connected to the key 10 forms the signal input terminal input of the detecting unit 220, and the output terminal output of the hysteresis comparing circuit 221a is also the output terminal of the detecting unit 220. When the hysteresis comparator 221a detects the pressing signal, the pressing signal detected by the detector 220 may be a voltage signal. By applying a reference voltage to the reference terminal Vref of the hysteresis comparison circuit 221a, a comparison threshold of the hysteresis comparison circuit 221a can be set; the pressing signal passes through the blocking capacitor C11, and then is input to the hysteresis comparator 221a, and compared with the comparison threshold to output a pressing detection signal, so that the detection unit 220 can process the intensity of the pressing signal to generate a corresponding pressing detection signal. If the reference voltages of the reference terminals Vref of the hysteresis comparison circuits 221a of the plurality of detection units 220 are set differently and the comparison thresholds of the corresponding hysteresis comparison circuits 221a are different, the strength of the pressing signal can be detected by the plurality of detection units 220, so as to detect the force for pressing the key 10.
Referring to fig. 1, when the piezoelectric device 14 deforms in different directions, the voltage directions on the two sides of the piezoelectric device are different, and the waveforms of the output voltages are different, so that when the different surfaces of the piezoelectric device 14 are connected to the cantilever beam 13, and the key cap 11 is pressed to drive the cantilever beam 13 to deform, the directions of the waveforms output by the piezoelectric device 14 may be opposite. In one embodiment, referring to fig. 9 and 10, when one side of the piezoelectric device 14 is connected to the cantilever beam 13, when the key cap 11 is pressed to drive the cantilever beam 13 to deform, the waveform output by the piezoelectric device 14 is a peak, and when the key cap 11 is released, the waveform output by the piezoelectric device 14 is a valley; accordingly, the reference terminal Vref of the hysteresis comparator 221a may be connected to the negative input terminal of the comparator Comp11 in the hysteresis comparator 221a, and the input terminal of the hysteresis comparator 221a may be the positive input terminal of the comparator Comp 11. Of course, in some embodiments, when the other side of the piezoelectric device 14 is connected to the cantilever beam 13, when the key cap 11 is pressed to drive the cantilever beam 13 to deform, the waveform output by the piezoelectric device 14 is a wave trough, and when the key cap 11 is released, the waveform output by the piezoelectric device 14 is a wave crest; accordingly, the reference terminal Vref of the hysteresis comparator 221 may be connected to the positive input terminal of the comparator of the hysteresis comparator 221, and the input terminal of the hysteresis comparator 221 may be the negative input terminal of the comparator.
Referring to fig. 8, 9 and 10, the present application describes an exemplary detection process of the detection unit 220. The reference voltage of the reference terminal Vref of the hysteresis comparator 221a in the first detector cell 220a is set such that the upper limit of the comparison threshold of the hysteresis comparator 221a in the first detector cell 220a is VH1 and the lower limit of the comparison threshold is VL 1. The reference voltage of the reference terminal Vref of the hysteresis comparator 221a in the second detection unit 220b is set such that the upper limit of the comparison threshold of the hysteresis comparator 221a in the second detection unit 220b is VH2, the lower limit of the comparison threshold is VL2, VH2> VH1, and VL2< VL 1.
In the time period T1, the time period T3 and the time period T5, if the key 10 has no pressing operation, the waveform of the pressing signal is a middle straight line; the press detection signals output by the corresponding first and second detection units 220a and 220b are both high levels VOH.
In a time period T2, when the key 10 is lightly pressed, the waveform of the pressing signal waveform changes from the starting point to the peak, then to the valley, and then resets to the starting point, the peak value of the pressing signal waveform is greater than VH1 and smaller than VH2, and the valley value of the corresponding pressing signal waveform is greater than VL2 and smaller than VL 1; the press detection signals output by the second detection unit 220b are all high level VOH. When the pressing signal strength reaches VH1, the pressing detection signal output by the first detection unit 220a is at low level VOL, and when the pressing signal strength reaches VL1, the pressing detection signal output by the first detection unit 220a changes to high level VOH again, and the processor 21 detects that the first detection unit 220a outputs the low level VOL pressing detection signal, and confirms that the key 10 has been lightly pressed once. When the processor 21 detects that the first detection unit 220a outputs the low-level VOL press detection signal, and starts the timer, when the processor 21 detects that the press detection signal output by the first detection unit 220a changes to the high-level VOH again, the timer is stopped, and the press duration characteristic t1 of the light press can be obtained.
In the time period T4, when the key 10 is pressed again, the waveform of the pressing signal waveform changes from the starting point to the peak, then to the valley, and then resets to the starting point, the peak value of the pressing signal waveform will be greater than VH2, and the valley value of the corresponding pressing signal waveform will be less than VL 2. When the intensity of the pressing signal reaches VH1, the pressing detection signal output by the first detection unit 220a is at a low level VOL; when the intensity of the pressing signal reaches VH2, the pressing detection signal output by the second detection unit 220b is at a low level VOL; when the pressing signal strength reaches VL1, the pressing detection signal output by the first detection unit 220a changes to the high level VOH again; when the pressing signal strength reaches VL2, the pressing detection signal output by the second detection unit 220b changes to the high level VOH again, and the processor 21 detects that the first detection unit 220a outputs the low level VOL pressing detection signal and detects that the second detection unit 220b outputs the low level VOL pressing detection signal, and confirms that the key 10 has performed one re-pressing operation. When the processor 21 detects that the first detection unit 220a outputs the low-level VOL press detection signal, and starts the timer, when the processor 21 detects that the press detection signal output by the first detection unit 220a changes to the high-level VOH again, the timer is stopped, and one press duration characteristic t2 of the re-press can be obtained. When the processor 21 detects that the second detecting unit 220b outputs the low-level VOL press detection signal and starts the timer, when the processor 21 detects that the press detection signal output by the second detecting unit 220b changes to the high-level VOH again, the timer stops, and another press duration characteristic t4 of the press can be obtained, then the time portion where t4 and t2 coincide can be regarded as the duration of the press, and t2 can be regarded as the duration of the press.
In the time period of T6, the key 10 is pressed lightly for a long time, that is, the key 10 is pressed lightly for a long time, the waveform of the pressing signal waveform changes from the starting point to the wave peak, then forms a section of straight line to the starting point, then changes to the wave trough, and then resets to the starting point, that is, when pressed down, the waveform changes from the starting point to the wave peak, in the process of pressing for a long time, the waveform returns to the starting point to form the straight line, when released, the waveform changes to the wave trough, and finally resets. The peak value of the pressing signal waveform is larger than VH1 and smaller than VH2, and the valley value of the corresponding pressing signal waveform is larger than VL2 and smaller than VL 1; the press detection signals output by the second detection unit 220b are all high level VOH. When the pressing signal strength reaches VH1, the pressing detection signal output by the first detection unit 220a is at low level VOL, and when the pressing signal strength reaches VL1, the pressing detection signal output by the first detection unit 220a changes to high level VOH again, and the processor 21 detects that the first detection unit 220a outputs the low level VOL pressing detection signal, and confirms that the key 10 has been lightly pressed once. When the processor 21 detects that the first detection unit 220a outputs the low-level VOL press detection signal, the timer is started, and when the processor 21 detects that the press detection signal output by the first detection unit 220a changes to the high-level VOH again, the timer is stopped, so that the press duration characteristic of the long light press can be obtained. Of course, if the key 10 is pressed for a long time, that is, pressed for a long time and pressed again, the pressing detection signal output by the first detection unit 220a also changes from the high level VOH to the low level VOL, and then returns to the high level VOH, and the processor 21 may also detect the long press operation t 3.
Referring to fig. 8, 10 and 11, when the processor 21 detects that the detection unit 220 outputs the low level VOL pressing detection signal and starts the timer, when the processor 21 detects that the pressing detection signal output by the detection unit 220 changes to the high level VOH again and the timer stops, the pressing duration characteristic of the operation of the key 10 can be obtained. That is, the processor 21 determines whether the received press detection signal is at the low level S21, and calculates the low level time period S22 when the press detection signal is at the low level, so that the press time period characteristic can be obtained.
In the embodiment of the present application, the processor 21 may start timing when detecting that the pressing detection signal changes from the normal state to the set state, and the processor 21 stops timing when detecting that the pressing detection signal changes from the set state back to the normal state, so as to obtain the pressing duration characteristic. The normal state is an output state of the detection signal when the operation key 10 is not pressed; when the operation key 10 is pressed, the output state of the detection signal is pressed. That is, the processor 21 detects whether the pressing detection signal is in the set state, and calculates the set state duration to obtain the pressing duration characteristic when the pressing detection signal is in the set state. As in the above embodiments, when the key 10 is pressed, the pressing detection signal is at the bottom level VOL; when the key 10 is not pressed, the pressing detection signal is at the high level VOH, the high level VOH is the normal state of the pressing detection signal, and the bottom level VOL is the set state of the pressing detection signal. In some embodiments, when the key 10 is pressed, the pressing detection signal is at the high level VOH; when the key 10 is not pressed, the pressing detection signal is at the low level VOL, the high level VOH is the set state of the pressing detection signal, and the bottom level VOL is the normal state of the pressing detection signal. In some embodiments, when the pressing detection signal is a current signal and the key 10 is pressed, the pressing detection signal is a forward current, the pressing detection signal outputs the forward current as a set state, and other states of the pressing detection signal are normal states. In some embodiments, when the key 10 is pressed, the pressing detection signal output by the pressing detection module 22 is at a high level or a low level, and when the key 10 is not pressed, the pressing detection module 22 outputs a high impedance state; the high level or the low level is the set state of the pressing detection signal, and the high impedance state is the normal state of the pressing detection signal.
The detecting unit 220 of the embodiment of the present application may adopt various kinds of hysteresis comparing circuits 221 with different topology, as long as the corresponding level signal can be compared and outputted according to the intensity change of the pressing signal. Several hysteresis comparison circuits 221, which can be used in the embodiments of the present application, are described below with reference to the embodiments, and form the detection unit 220.
In one embodiment, referring to fig. 9, the hysteresis comparator 221a of the detection unit 220 includes a comparator Comp 11; the non-inverting input terminal of the comparator Comp11 is connected to the resistor R11, forming the reference terminal Vref of the hysteresis comparator 221 a; the negative phase input terminal of the comparator Comp11 is connected to one terminal of the dc blocking capacitor C11, and the other terminal of the dc blocking capacitor C11 forms the input terminal of the detecting unit 220; the output terminal output of the hysteresis comparator 221a is connected to the resistor R12 and the resistor R13, the other terminal of the resistor R12 is connected to the non-inverting input terminal of the comparator Comp11, and the other terminal of the resistor R13 is connected to the power supply terminal VCC. Setting the voltage of the reference terminal Vref to obtain the upper limit and the lower limit of the comparison threshold of the hysteresis comparison circuit 221 a; when the input voltage of the input end of the detection unit 220 is increased from low to high and exceeds the upper limit of the comparison threshold, the output end output of the hysteresis comparison circuit 221a outputs a low level VOL; when the input voltage at the input end of the detection unit 220 is smaller than the lower limit of the comparison threshold from high to low, the output end output of the hysteresis comparison circuit 221a outputs a high level VOH.
In one embodiment, referring to fig. 12, the hysteresis comparator 221b of the detection unit 220 comprises a comparator Comp 21; the non-inverting input terminal of the comparator Comp21 is connected to the resistor R21, forming the reference terminal Vref of the hysteresis comparator 221 b; the negative phase input end of the comparator Comp21 is connected to one end of the dc blocking capacitor C21, and the other end of the dc blocking capacitor C21 forms the input end of the detection unit 220; the output terminal output of the hysteresis comparator 221b is connected to the anode of the diode D21, the cathode of the diode D21 is connected to one end of the resistor R22, and the other end of the resistor R22 is connected to the non-inverting input terminal of the comparator Comp 21. Therefore, the voltage of the reference terminal Vref can be set, and the upper limit and the lower limit of the comparison threshold of the hysteresis comparison circuit 221b can be obtained; when the input voltage of the input end of the detection unit 220 is increased from low to high and exceeds the upper limit of the comparison threshold, the output end output of the hysteresis comparison circuit 221b outputs a low level VOL; when the input voltage at the input end of the detection unit 220 is smaller than the lower limit of the comparison threshold from high to low, the output end output of the hysteresis comparison circuit 221b outputs a high level VOH.
In one embodiment, referring to fig. 13, the hysteresis comparator 221c of the detection unit 220 includes a comparator Comp 31; the positive phase input end of the comparator Comp31 is connected to the resistor R31, the positive phase input end of the comparator Comp31 is connected to one end of the resistor R33, the other end of the resistor R33 is connected to the power supply terminal VCC, the positive phase input end of the comparator Comp31 is also connected to the cathode of the tunnel diode D31, the anode of the tunnel diode D31 is grounded, and the reference terminal Vref of the hysteresis comparison circuit 221c is formed; the negative phase input terminal of the comparator Comp21 is connected to one terminal of the dc blocking capacitor C31, and the other terminal of the dc blocking capacitor C31 forms the input terminal of the detecting unit 220; the output terminal output of the hysteresis comparator 221c is connected to one terminal of the resistor R32, and the other terminal of the resistor R32 is connected to the non-inverting input terminal of the comparator Comp 31. Therefore, the voltage of the reference terminal Vref can be set, and the upper limit and the lower limit of the comparison threshold of the hysteresis comparison circuit 221c can be obtained; when the input voltage of the input end of the detection unit 220 is increased from low to high and exceeds the upper limit of the comparison threshold, the output end output of the hysteresis comparison circuit 221c outputs a low level VOL; when the input voltage at the input terminal of the detection unit 220 is smaller than the lower limit of the comparison threshold from high to low, the output terminal output of the hysteresis comparison circuit 221c outputs the high level VOH.
In one embodiment, referring to fig. 14, the hysteresis comparator 221d of the detection unit 220 includes a comparator Comp 41; the negative phase input terminal of the comparator Comp41 forms the reference terminal Vref of the hysteresis comparator 221 d; the positive phase input terminal of the comparator Comp41 is connected to one terminal of the resistor R41, the other terminal of the resistor R41 is connected to one terminal of the dc blocking capacitor C41, and the other terminal of the dc blocking capacitor C41 forms the input terminal of the detecting unit 220; the output terminal output of the hysteresis comparator 221d is connected to one terminal of the resistor R42, and the other terminal of the resistor R42 is connected to the non-inverting input terminal of the comparator Comp 41. Setting the reference terminal Vref voltage to obtain the upper limit and the lower limit of the comparison threshold of the hysteresis comparison circuit 221 d; when the input voltage of the input terminal of the detection unit 220 is smaller than the lower limit of the comparison threshold from high to low, the output terminal output of the hysteresis comparison circuit 221d outputs a high level VOH; when the input voltage at the input end of the detection unit 220 increases from low to high and exceeds the upper limit of the comparison threshold, the output end output of the hysteresis comparison circuit 221d outputs a low level VOL.
In an embodiment, referring to fig. 15, the control circuit 20 further includes an amplifying unit 24, and the amplifying unit 24 is configured to amplify the pressing signal and output the amplified signal to the pressing detection module 22. The amplifying unit 24 is arranged, when the key 10 is pressed, the pressing signal output by the key 10 can be amplified by the amplifying unit 24 and then output to the pressing detection module 22, so that the pressing detection module 22 can detect and process, and the detection accuracy of the pressing detection module 22 is improved.
In one embodiment, the control circuit 20 may be a control chip of the key 10. For example, the control circuit 20 may be directly installed in the key 10 as a control chip of the key 10. Alternatively, the control circuit 20 may be installed separately from the key 10, for example, referring to fig. 16, when the control circuit 20 and the key 10 are installed in the electronic device 100, the control circuit 20 is located in a processing chip of the electronic device 100, and the key 10 is installed on the housing 30 of the electronic device 100. The control circuit 20 may be integrated within a central processor, an application processor, or an auxiliary processor of the electronic device 100. If the control circuit 20 is integrated in a central processing unit, an application processor or an assistant processor of the electronic device 100, the processor 21 in the control circuit 20 may be a part of a core in the central processing unit, the application processor or the assistant processor of the electronic device 100. A co-processor (co-processor) is a chip for alleviating specific processing tasks of a system microprocessor, and is a processor developed and applied for assisting a central processing unit to complete processing tasks that the cpu cannot execute or has low execution efficiency and effect. Of course, the control circuit 20 may also be configured as a hardware circuit independent from the main chip or the central processing unit, which is not limited in this embodiment of the application. In still other embodiments, the control circuit 20 may be disposed on a printed circuit board.
Referring to fig. 16, an electronic device 100 is further provided in an embodiment of the present application, where the electronic device 100 includes a housing 30, a key 10 according to any of the above embodiments, and a control circuit 20 for controlling the key 10, the key 10 is disposed on the housing 30, the control circuit 20 is connected to the key 10, and the control circuit 20 may be the control circuit according to any of the above embodiments. The electronic device 100 of the embodiment of the application uses the key 10 and the control circuit 20 of the above embodiment, so that key active tactile feedback can be realized, tactile experience can be improved, and the structure can be simplified.
In this embodiment, the electronic device 100 is a smart phone, and in other embodiments, the electronic device 100 may also be an electronic device 100 such as a tablet computer, a game console, a game pad, and a remote controller.
It is obvious to those skilled in the art that, for convenience and simplicity of description, the foregoing functional units and modules are merely illustrated in terms of division, and in practical applications, the foregoing functional allocation may be performed by different functional units and modules as needed, that is, the internal structure of the circuit is divided into different functional units or modules to perform all or part of the above described functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.

Claims (19)

1. The button, its characterized in that: comprises a keycap, a base, a cantilever beam and a piezoelectric device; the key cap is arranged on the base, the base is provided with a containing cavity, the cantilever beam is elastic, one end of the cantilever beam is fixed on the base, the other end of the cantilever beam extends into the containing cavity, the piezoelectric device is arranged on the cantilever beam and is used for detecting the deformation of the cantilever beam and driving the cantilever beam to vibrate so that the other end of the cantilever beam elastically pushes against the key cap; the cavity is formed by arranging a groove body on the base or arranging an opening on the base.
2. The key of claim 1, wherein: the key further includes an adhesive layer adhering the piezoelectric device to the cantilever beam.
3. The key of claim 1, wherein: the key further comprises a first electrode and a second electrode which are respectively electrically connected with the two electrode ends of the piezoelectric device; the first electrode and the second electrode are both arranged on the cantilever beam; alternatively, the first electrode and the second electrode are both mounted on the piezoelectric device; alternatively, the first electrode is mounted on the piezoelectric device and the second electrode is mounted on the cantilever.
4. The key of claim 1, wherein: and the base is provided with signal pins which are respectively and electrically connected with the two electrode ends of the piezoelectric device.
5. The key of any of claims 1-4, wherein: the two surfaces of the cantilever beam are respectively provided with the piezoelectric devices.
6. The key of any of claims 1-4, wherein: the base is internally provided with a plurality of cantilever beams, and each cantilever beam is respectively provided with the piezoelectric device.
7. The key of any of claims 1-4, wherein: when the cantilever beam and the keycap are at initial positions, the cantilever beam is integrally arranged at intervals with the keycap.
8. The key of any of claims 1-4, wherein: one end of the cantilever beam is arranged at an interval with the keycap, and the other end of the cantilever beam is contacted with the middle part of the keycap.
9. The key of claim 8, wherein: the middle part of the keycap faces the direction of the base and is convexly provided with a bulge, and the other end of the cantilever beam is in contact with the bulge.
10. A control circuit, characterized by: for controlling a key according to any one of claims 1-9;
the control circuit comprises a pressing detection module, a feedback excitation module and a processor;
the pressing detection module receives pressing signals generated by a pressing device in the key, processes the pressing signals to form pressing detection signals, and outputs the pressing detection signals to the processor;
the feedback excitation module is used for outputting an excitation signal to the piezoelectric device to drive the piezoelectric device to deform so as to drive the cantilever beam of the key to vibrate;
the processor is used for controlling the feedback excitation module to output an excitation signal according to the pressing detection signal.
11. The control circuit of claim 10, wherein the processor controls the feedback excitation module to output an excitation signal through an interaction strategy; the interaction strategy comprises the following steps:
judging whether the key is in a key feedback excitation flow, shielding the pressing detection signal and controlling the feedback excitation module to output an excitation signal under the condition that the key is in the key feedback excitation flow; and
and judging whether the key is in a key detection process, and closing the feedback excitation module and receiving the pressing detection signal under the condition that the key is in the key detection process.
12. The control circuit of claim 10, wherein: the processor determines the pressing characteristics of the key according to the pressing detection signals, and controls the feedback excitation module to output excitation signals according to the pressing characteristics, wherein the pressing characteristics comprise pressing duration characteristics and/or pressing intensity characteristics.
13. The control circuit of claim 12, wherein: the pressing detection module comprises a plurality of detection units which respectively form pressing detection signals according to the intensity processing of the pressing signals, and the processor obtains the pressing force degree characteristics according to the pressing detection signals output by the plurality of detection units.
14. The control circuit of claim 13, wherein: each detection unit comprises a hysteresis comparison circuit and a blocking capacitor, two ends of the blocking capacitor are respectively connected with the input end of the hysteresis comparison circuit and the piezoelectric device, the output end of the hysteresis comparison circuit is connected with the processor, and the reference end of each hysteresis comparison circuit applies a reference voltage; the reference voltages of the reference terminals of the plurality of hysteresis comparison circuits are set to be unequal.
15. The control circuit of claim 12, wherein: the processor starts timing when detecting that the pressing detection signal is changed from a normal state to a set state, and stops timing when detecting that the pressing detection signal is changed from the set state back to the normal state so as to obtain the pressing duration characteristic.
16. The control circuit of any of claims 10-15, wherein: the control circuit further comprises an amplifying unit which is used for amplifying the pressing signal and then outputting the amplified pressing signal to the pressing detection module.
17. The control circuit of any of claims 10-15, wherein: the control circuit and the key are arranged in the electronic equipment, and the control circuit is located in a processing chip of the electronic equipment.
18. The control circuit of any of claims 10-15, wherein: the control circuit is a control chip of the key.
19. An electronic device comprising a housing, characterized in that: the keyboard further comprises a key according to any one of claims 1-9 and a control circuit according to any one of claims 10-18, wherein the key is arranged on the shell, and the key is connected with the control circuit.
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