WO2018024216A1

WO2018024216A1 - Touch pressure sensing device and electronic product

Info

Publication number: WO2018024216A1
Application number: PCT/CN2017/095666
Authority: WO
Inventors: 王冬立; 柯有和; 余晓艳
Original assignee: 华为技术有限公司
Priority date: 2016-08-05
Filing date: 2017-08-02
Publication date: 2018-02-08
Also published as: CN107688405B; CN107688405A

Abstract

The present invention discloses a touch pressure sensing device comprising a touch body and a touch pressure sensor. The touch pressure sensor comprises at least two pressure sensitive resistors and a thin film. The thin film comprises a first region and a second region. The pressure sensitive resistors are fixed in the first region and the second region, respectively. The rigidity of a first connection medium on a touch pressure transmission path between the pressure sensitive resistor in the first region and a touch region is greater than the rigidity of a second connection medium on a touch pressure transmission path between the pressure sensitive resistor in the second region and the touch region. The first connection medium at least comprises the first region, and the second connection medium at least comprises the second region. When the touch region transmits a touch pressure to the thin film, a strain difference is caused between the pressure sensitive resistor in the first region and the pressure sensitive resistor in the second region. The present invention further provides an electronic product. The present invention is capable of accurately measuring a touch pressure.

Description

Touch pressure sensing device and electronic products

The present application claims priority to Chinese Patent Application No. 20161063532 7.5, filed on Aug. 5, 2016, entitled,,,,,,,,,,,,,,,,,,, in.

Technical field

The present invention relates to a pressure sensing device for a touch screen and an electronic product having the touch pressure sensing device.

Background technique

In order to enhance the interaction between people and mobile devices, watches, wearable devices and other terminal devices, pressure sensors have been widely used in touch screens and housings to identify the user's touch pressure while recognizing the user's touch pressure. , a more content-rich operating experience.

How to design a pressure sensor that can accurately measure the touch pressure is the development direction of the industry.

Summary of the invention

The invention provides a touch pressure sensing device and an electronic product capable of accurately measuring a touch pressure.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

In a first aspect, the present invention provides a touch pressure sensing device including a haptic body and a touch pressure sensor, the haptic body including a touch region for a user to apply a touch pressure, the touch pressure sensor being located away from the haptic body One side of the touch zone;

The touch pressure sensor includes at least two pressure sensitive resistors and a film, the film is elastically deformed under stress, and the film includes first and second regions adjacent to each other;

At least one of the pressure sensitive resistors is fixed to the first region, and the remaining pressure sensitive resistors are fixed to the second region;

a rigidity of the first connection medium on the touch pressure transmission path between the pressure sensitive resistor and the touch region in the first region is greater than the pressure sensitive resistance and the touch in the second region The rigidity of the second connection medium on the touch pressure transmission path between the regions, the first connection medium includes at least the first region, and the second connection medium includes at least the second region;

The second region is capable of elastically deforming relative to the first region when the touch pressure transmits a touch pressure to the pressure sensitive resistor, thereby generating strain between the first region and the second region The difference is sensed and the strain difference is sensed by the pressure sensitive resistor.

The present invention has an advantageous effect that the rigidity of the first connection medium on the touch pressure transmission path between the pressure sensitive resistor and the touch pressure zone in the first region is greater than that in the second region The rigidity of the second connection medium on the touch pressure transmission path between the pressure sensitive resistor and the touch sensitive area, that is, the difference in rigidity of the connection medium at the first area and the second area corresponding to the decompression zone, makes the pressure sensitive The strain sensed by the resistance forms a difference, and the touch pressure is further measured by the difference in strain, and the present invention can accurately measure the touch pressure.

In conjunction with the first aspect, in a first possible implementation, the first connection medium further includes a first connector between the first region and the haptic body, the thinner the first connector it is good.

In conjunction with the first aspect, in a second possible implementation, the first connection medium further includes a first combination between the first region and the pressure sensitive resistor, the thinner the first combination The better.

In conjunction with the first aspect, in a third possible embodiment, the first region is as thin as possible.

The thinner the first link, the first bond, the first region (the three can be individually changed or combined with each other, or collectively thinned), the more sensitive the pressure sensitive resistor in the first region is to the touch pressure, the greater the strain. Thus, the more obvious the strain difference of the pressure sensitive resistors in the first region and the second region, the more accurate the measurement.

Further, the smaller the elastic deformation coefficient of the first linker, the first bond, and the first region, the better, and the elastic coefficients of the three may be changed individually or combined with each other. The smaller the elastic deformation coefficient, the greater the strain of the pressure sensitive resistor in the first region on the touch pressure.

In conjunction with the first aspect, in a fourth possible implementation, the second connection medium further includes a second connector between the second region and the haptic body, the thicker the second connector it is good.

In conjunction with the first aspect, in a fifth possible implementation, the first connection medium further includes a second combination between the second region and the pressure sensitive resistor, the thicker the second combination The better.

In conjunction with the first aspect, in a sixth possible embodiment, the thicker the second region, the better.

The second connector, the second combination, and the second region are thicker (the three can be individually changed or combined with each other, or thickened together), and the pressure sensitive resistor in the second region is less sensitive to the touch pressure, and the strain is smaller. . Thus, the more obvious the strain difference of the pressure sensitive resistors in the first region and the second region, the more accurate the measurement.

The above-mentioned thin or thick refers to the dimension in the direction of the touch pressure transmission path, for example, the direction of the path in which the first region of the film is transmitted by the touch pressure in the direction perpendicular to the film.

In one embodiment, the thickness of the first region and the second region of the film are the same, and the first bond and the second bond between the pressure sensitive resistor and the film are also the same, and the pressure sensitive resistor can be printed. The method is formed on the film. In this case, the difference between the first linker and the second linker causes a difference in stress between the first region and the second region.

Further, the greater the elastic deformation coefficient of the second connector, the second combination, and the second region, the better, and the elastic coefficients of the three may be changed individually or combined with each other. The larger the coefficient of elastic deformation, the smaller the strain of the pressure sensitive resistor in the second region on the touch pressure.

In one embodiment, the first region of the film is attached to the haptic body by means of an adhesive, and the first region and the haptic body are integrated into one body, and when the touch pressure region is subjected to the touch pressure, the haptic body transmits the touch pressure to The first region causes a change in the resistance of the pressure sensitive resistor on the first region, and the rigid connection between the first region and the haptic body is achieved by means of adhesive bonding. In one embodiment, the second region is not connected to the touch body or connected by a flexible material to achieve the force of the touch body, and the second region receives the force or contacts the small force. effect. The connection by the flexible material means that the structure of the connection between the second region of the film and the tactile body is elastic, for example, by a foam or a shrapnel disposed between the film and the tactile body, and the touch region of the tactile body is subjected to the touch pressure. Flexible materials, such as foam, absorb the touch pressure so that the film is unaffected by touch pressure or is less affected by touch pressure. Thus, the resistance of the pressure sensitive resistor in the second region does not change or the change is very small.

Further, the foam and the touch body are fixed by an adhesive, the foam and the second region It is also fixed by glue. When the film is not connected to the touch main body, when the touch body is subjected to the touch pressure, the film is deformed by the stress, so that the influence of the touch pressure on the resistance of the pressure sensitive resistor on the film is also very small. The difference in the resistance of the pressure sensitive resistor in the first region and the second region (i.e., the strain difference) is used to measure the magnitude of the touch pressure of the touch region.

In conjunction with the first aspect, in a seventh possible implementation, the strain received by the pressure sensitive resistor on the first region is the pressure on the second region for the same touch pressure of the user The strain received by the sensitive resistor is more than 1.2 times.

In combination with the first aspect, in an eighth possible embodiment, the film has a thickness ranging from 0.02 to 0.2 mm.

In conjunction with the first aspect, in a ninth possible implementation, the second region is provided with a recess to increase the elastic deformation capability of the second region relative to the first region.

The arrangement of the grooves enables the second region to be further elastically deformed relative to the first region under the action of the touch pressure to absorb the touch pressure.

The manner in which the grooves are grooved includes hollowing out all of the material in the thickness direction of the film, that is, the grooves open both sides of the film. Of course, the way of grooving can also be to dig away only a portion of the material in the thickness direction of the film. This grooving structure is similar to a blind hole structure. Regardless of the structure of the grooving, the flexibility of the second region of the film can be increased.

In conjunction with the ninth possible implementation of the first aspect, in a tenth possible implementation, the recess extends in a U shape, and the pressure sensitive resistor in the second region is located in the recess Surrounded by the area.

Further, the pressure detecting bridge arm circuit can be used, and at least two pressure sensitive resistors are used as the bridge arms of the pressure detecting bridge arm circuit, and the strain sensitive systems of the two pressure sensitive resistors are identical. When the touch region of the touch body is subjected to the touch pressure, the pressure sensitive resistance in the first region is affected by the touch pressure, that is, the strain is generated, and the pressure sensitive resistor in the second region is not affected by the touch pressure, and the strain is zero. That is, the change in the resistance in the same pressure detecting bridge arm circuit produces a difference, and the force of the touch pressure can be detected by the difference in the resistance change.

The specific pressure sensing bridge arm circuit implementation is as follows.

With reference to the first aspect, in an eleventh possible implementation manner, the number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are a first resistor, a second resistor, a third resistor, and a fourth The resistors are connected end to end in sequence, and each of the pressure sensitive resistors forms a bridge arm of the resistance bridge, and a connection point of the first resistor and the second resistor forms a first input node, and the third resistor and the a connection point of the fourth resistor forms a second input node, a supply voltage is connected between the first input node and the second input node, and a first output node is formed between the first resistor and the third resistor Forming a second output node between the second resistor and the fourth resistor, and outputting a measurement voltage between the first output node and the second output node; the measuring voltage is used to output a voltage to measure a touch a pressure value; the first resistor, the second resistor, and the third resistor are fixed to the first region, and the fourth resistor is fixed to the second region, when a user applies a touch pressure to the touch Ram zone The first resistor, the resistance of the second resistor and said third resistor generates a first strain, the resistance of the fourth resistor generating a second strain, the first strain is less than the second strain.

In conjunction with the first aspect, in a twelfth possible implementation, the number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are a first resistor, a second resistor, a third resistor, and a fourth The resistors are connected end to end in sequence, and each of the pressure sensitive resistors forms a bridge arm of the resistance bridge, and a connection point of the first resistor and the second resistor forms a first input node, and the third resistor and the a connection point of the fourth resistor forming a second input node, the first a supply voltage is connected between the input node and the second input node, a first output node is formed between the first resistor and the third resistor, and a second is formed between the second resistor and the fourth resistor An output node, a measurement voltage is output between the first output node and the second output node; the measurement voltage is used to output a voltage to measure a touch pressure value; the first resistance, the second resistance, and the a third resistor is located in the second region, and the fourth resistor is located in the first region, when the user applies a touch pressure to the touch region, the first resistor, the second resistor, and the first The resistance of the three resistors produces a second strain, the resistance of the fourth resistor producing a first strain, the second strain being less than the first strain.

With reference to the first aspect, in a thirteenth possible implementation manner, the number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are a first resistor, a second resistor, a third resistor, and a fourth The resistors are connected end to end in sequence, and each of the pressure sensitive resistors forms a bridge arm of the resistance bridge, and a connection point of the first resistor and the second resistor forms a first input node, and the third resistor and the a connection point of the fourth resistor forms a second input node, a supply voltage is connected between the first input node and the second input node, and a first output node is formed between the first resistor and the third resistor Forming a second output node between the second resistor and the fourth resistor, and outputting a measurement voltage between the first output node and the second output node; the measuring voltage is used to output a voltage to measure a touch a pressure value; the first resistor and the second resistor are located in a first region, and the third resistor and the fourth resistor are located in the second region, when a user applies a touch pressure to the touch region The first Resistance of the resistor and the second resistor to generate a first strain resistance of the third resistor and the fourth resistor generating a second strain, the first strain is less than the second strain.

In conjunction with the first aspect, in a fourteenth possible implementation, the number of the second regions is two, and the two second regions are distributed on both sides of the first region, the pressure sensitive resistor The number of the four pressure sensitive resistors is a first resistance, a second resistance, a third resistance, and a fourth resistance, respectively, connected end to end, and each of the pressure sensitive resistors forms a bridge of the resistance bridge An arm, a connection point of the first resistor and the second resistor forms a first input node, and a connection point of the third resistor and the fourth resistor forms a second input node, the first input node and the Connecting a supply voltage between the second input nodes, forming a first output node between the first resistor and the third resistor, and forming a second output node between the second resistor and the fourth resistor a measurement voltage is output between the first output node and the second output node; the measurement voltage is used to output a voltage to measure a touch pressure value; the first resistance and the fourth resistance are respectively located in the two Two areas, said a second resistor and the third resistor are located in the first region, and when a user applies a touch pressure to the touch region, a resistance of the first resistor and the fourth resistor generates a second strain, but The resistance of the second resistor and the third resistor produces a first strain, the second strain being less than the first strain.

In conjunction with the first aspect, in a fifteenth possible implementation, the temperature coefficients of the at least two pressure sensitive resistors are the same.

In conjunction with the first aspect, in a sixteenth possible implementation, the touch sensitive body is a display screen of an electronic product, the touch pressure area is disposed on an outer surface of the display screen, and the touch pressure sensor is configured to It is light transmissive and is located on the inner surface of the display screen.

In conjunction with the first aspect, in a seventeenth possible implementation, the touch sensing body includes a display screen and a backlight module, the touch area is disposed on an outer surface of the display screen, and the backlight module is stacked On one side of the inner surface of the display screen, the touch pressure sensor is located on a side of the backlight module facing away from the display screen, the display screen and the A backlight mode is used to transfer a touch stress received by the touch region to the touch pressure sensor, the touch pressure sensor being configured to be opaque.

Further, the design is: four resistors in each detection circuit are arranged adjacent to each other, and the maximum area of each touch pressure sensor is 10 mm×10 mm, and the design of the maximum area of the touch pressure sensor is related to the area of the touch pressure area when used. When the finger is pressed against the touch zone, the area that the finger can cover is the maximum area of the touch pressure sensor. The temperature changes of all the resistors in each touch pressure sensor are the same or the temperature is the same, so as to reduce the temperature difference between the resistors. When the temperature of the electronic product changes, all the resistances in each detection circuit change uniformly, thereby ensuring the electric power. The bridge output voltage remains the same, ie the temperature has no effect on the output of the bridge.

Specifically, in the above several embodiments, the four resistors may be arranged in a row, or may be arranged in two rows and two columns (ie, a square structure).

In combination with any of the above embodiments, the film includes front and back faces disposed opposite to each other, the front surface being bonded to the touch sensitive body, and the pressure sensitive resistor in the first region is disposed on the front surface The pressure sensitive resistor in the second region is disposed on the reverse side.

In combination with any of the above embodiments, all of the pressure sensitive resistors have the same temperature coefficient. The same temperature coefficient makes it possible to measure the touch pressure more accurately.

Further, the temperature coefficients of all of the pressure sensitive resistors are substantially the same, and the basics are the same here, meaning that all pressure sensitive resistors will produce the same change during temperature change, but also allow different The temperature coefficient of the pressure sensitive resistor is different. The specific difference may be: when the strain sensitivity coefficient is close to the temperature sensitivity coefficient, the allowable difference of the temperature sensitivity coefficient is also strict, for example, the strain sensitivity coefficient is 50 (normalized value, The same below, the temperature sensitivity coefficient is also the normalized value) and the temperature sensitivity coefficient is 10, then the allowable difference of the temperature sensitivity coefficient is 20%; when the strain sensitivity coefficient and the temperature sensitivity coefficient are different, the temperature sensitivity coefficient allows The difference can be appropriately amplified, for example, the strain sensitivity coefficient is 100 (normalized value, the same below, the temperature sensitivity coefficient is also the normalized value) and the temperature sensitivity coefficient is 10, then the allowable difference of the temperature sensitivity coefficient is 60%. .

In combination with any one of the above embodiments, the touch sensing body is a display screen of an electronic product, the touch pressure area is disposed on an outer surface of the display screen, and the touch pressure sensor is configured to be capable of transmitting light, and is located at the The inner surface of the display (because the light emitted by the backlight module needs to be illuminated by the touch pressure sensor, the display can be illuminated), a transparent film can be used, and a resistor can be fabricated on the film by a transparent material. Specifically, the touch pressure sensor is disposed between the backlight module and the display panel, and when the touch pressure is subjected to the touch pressure, the pressure sensitive resistor in the first region can generate strain in a faster time, thereby improving the sensing speed. And because of the closer proximity to the touch zone, the accuracy of the sensing is also improved.

In combination with any of the above embodiments, the touch sensing body includes a display screen and a backlight module, the touch area is disposed on an outer surface of the display screen, and the backlight module is stacked on an inner surface of the display screen. The touch pressure sensor is located at a side of the backlight module facing away from the display screen, and the touch stress received by the touch region can be transmitted through the display screen and the backlight module To the touch pressure sensor, the touch pressure sensor is configured to be opaque. The touch pressure sensor of the present embodiment does not need to be formed into a light transmissive structure. Therefore, the touch pressure sensor of the present embodiment has a low cost and is attached to the side of the backlight module facing away from the touch screen, since a precise bonding process is not required. Also, it is not required to be made into a light-transmitting structure, so that the manufacturing method is also easy, and the film and the resistor are made of an opaque material, and the manufacturing cost is lower than that of using a light-transmitting material to form a film and a resistor.

In a second aspect, the present invention also provides an electronic product (for example, a mobile phone, a tablet, a watch, a wearable device) The terminal device includes any one of the above-mentioned touch pressure sensing devices and a main board, wherein the main board is provided with a sensor circuit, and all of the pressure sensitive resistors are electrically connected to the sensor circuit, and the sensor circuit And comparing a strain difference between the pressure sensitive resistor in the first region and the pressure sensitive resistor in the second region to achieve measurement of the touch pressure.

DRAWINGS

In order to more clearly illustrate the technical solutions of the present invention, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention, which are common in the art. For the skilled person, other drawings can be obtained as shown in these drawings without any creative work.

FIG. 1 is a schematic side view of a touch pressure sensing device according to an embodiment of the present invention.

2 is a schematic diagram of a touch pressure sensor in a touch pressure sensing device according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a bridge circuit of a touch pressure sensing device according to an embodiment of the present invention.

4 is a schematic view showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the first embodiment.

FIG. 5 is a schematic diagram showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the second embodiment.

Fig. 6 is a schematic view showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the third embodiment.

Fig. 7 is a schematic view showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the fourth embodiment.

FIG. 8 is a schematic diagram showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the fifth embodiment.

9 is a schematic view showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the sixth embodiment.

FIG. 10 is a schematic diagram showing the distribution of pressure sensitive resistors in the touch pressure sensing device in the seventh embodiment.

FIG. 11 is a schematic diagram of a touch pressure sensor provided on an inner surface of a touch screen of an electronic product according to an embodiment of the present invention.

Fig. 12 is a partial enlarged view of Fig. 11;

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings.

Referring to FIG. 1 , the present invention provides a touch pressure sensing device including a touch sensitive body 100 and a touch pressure sensor 200 including a touch region 101 (located on an outer surface of the touch sensitive body 100 ) for a user to apply a touch pressure. The touch pressure sensor 200 is located on a side of the touch sensitive body 100 facing away from the touch pressure zone (ie, located on an inner surface of the touch sensitive body 100), wherein the touch pressure zone 101 is an area touched by a user's finger, that is, touch pressure The area of the area 101 is designed to refer to the contact area on the surface of the touch body 100 when the user's finger is pressed.

As shown in FIG. 2, the touch pressure sensor 200 includes a film 10 and a plurality of detecting circuits 20 (that is, a plurality of pressure detecting units 20). Specifically, the film 10 may be a plastic material such as FPC or PET, and the film 10 is subjected to a force to be elastically deformed. The film 10 includes a plurality of load-bearing regions 11 distributed in an array, and a film is shown in FIG. The load-bearing area 11 of 5 rows and 3 columns is included. The plurality of detecting circuits 20 are respectively disposed in the plurality of bearing regions 11 of the film 10 in a one-to-one correspondence, that is, a detecting circuit 20 is disposed in each of the carrying regions 11. Each of the bearing regions 11 has an elastic deformation capability. Specifically, a film having elastic deformation ability can be used. The "elastic deformation ability" as used herein refers to: in the case of a force, each of the films The portions may be elastically oscillated in the thickness direction of the film, or a groove (or slit) S may be provided in each of the load-bearing regions 11 to enhance the elastic deformation capability of the load-bearing region. Each of the detecting circuits 20 includes at least two pressure sensitive resistors R. In each detecting circuit 20, the film 10 includes a first region A1 and a second region A2 adjacent to each other (see FIGS. 4 to 10). In the drawings of the embodiment, the area inside the dotted line frame is the first area A1, and the area outside the dotted line frame is the second area A2). At least one of the pressure sensitive resistors R is fixed to the first region A1, and the remaining pressure sensitive resistors R are fixed to the second region A2.

a rigidity of the first connection medium on the touch pressure transmission path between the pressure sensitive resistor R and the touch pressure region 101 in the first area A1 is greater than the pressure sensitive resistance in the second area A2 Rigidity of the second connection medium on the touch pressure transmission path between the R and the touch sensitive area 101, the first connection medium includes at least the first area A1, and the second connection medium includes at least the second Area A2.

The first connection medium further includes a first connector between the first area A1 and the touch body 100, and the thinner the first connection, the better. The first connector may be a colloid, that is, the first region A1 and the touch body 100 are connected by an adhesive.

The first connection medium further includes a first combination between the first area A1 and the pressure sensitive resistor R, and the thinner the first combination, the better. The first combination may also be a gel, that is, the pressure sensitive resistor R is fixed to the first region A1 by means of an adhesive.

The thinner the first region A1, the better.

The thinner the first connector, the first combination, and the first region A1 (the three may be individually changed or combined with each other, or collectively thinned), the more sensitive the pressure sensitive resistor R in the first region A1 is to the touch pressure, the strain The bigger. Thus, the more distinct the strain difference of the pressure sensitive resistors in the first region A1 and the second region A2, the more accurate the measurement.

Further, the smaller the elastic deformation coefficient of the first linker, the first bond, and the first region A1, the better, and the elastic coefficients of the three may be changed individually or combined with each other. The smaller the elastic deformation coefficient, the greater the strain of the pressure sensitive resistor in the first region A1 on the touch pressure.

The second connection medium further includes a second connection between the second area A2 and the touch sensitive body 100, and the thicker the second connection is, the better. The second connector may be a foam having an adhesive layer on both sides, that is, the foam is bonded between the second region A2 and the haptic body 100.

The first connection medium further includes a second combination between the second region A2 and the pressure sensitive resistor R, and the thicker the second combination, the better. The second conjugate can also be a colloid.

The thicker the second area A2, the better.

The thicker the second connector, the second combination, and the second region A2 (the three may be individually changed or combined with each other, or thickened together), the pressure sensitive resistor in the second region A2 is less sensitive to the touch pressure, strain The smaller. Thus, the more distinct the strain difference of the pressure sensitive resistor R in the first region A1 and the second region A2, the more accurate the measurement.

Further, the larger the elastic deformation coefficient of the second connector, the second combination, and the second region A2, the better, and the elastic coefficients of the three may be changed individually or combined with each other. The greater the coefficient of elastic deformation, the pressure sensitivity in the second region A2 The strain of the sense resistor R on the touch pressure is smaller.

Specifically, the first area A1 and the touch sensitive body 100 may be adhered together by adhesive. When the touch pressure area 101 is subjected to touch pressure, the touch sensitive body 100 transmits the touch pressure to the first area A1. Therefore, the resistance value of the pressure sensitive resistor R on the first area A1 is changed, and the rigid connection can be realized by means of adhesive bonding.

The second area A2 and the haptic body 100 may be isolated by force. The "force isolation" includes no connection or connection by a flexible material, and as long as the force of the touch body 100 can be achieved, the second area A2 does not receive a force or receives a small force. The connection by the flexible material means that the structure of the connection between the second region A2 of the film 10 and the haptic body 100 is elastic, for example, is disposed between the film 10 and the haptic body 100 by foam or shrapnel, and the touch of the haptic body 100 is performed. When the zone 101 is subjected to touch pressure, the flexible material (e.g., foam) can absorb the touch pressure, so that the film 10 is not affected by the touch pressure or is affected by the small touch pressure. Thus, the resistance value of the pressure sensitive resistor R in the second region A2 is small.

The second region A2 may be provided with a recess so that when the touch region 101 transmits a touch pressure to the film 10, the second region A2 can be elastic with respect to the first region A1. Deformation such that a strain difference is generated between the pressure sensitive resistor R in the first region A1 and the pressure sensitive resistor R in the second region A2.

The change in the resistance value (i.e., strain difference) of the pressure sensitive resistor R in the first region A1 and the second region A2 is used to measure the magnitude of the touch pressure of the touch region 101.

In one embodiment, the touch sensitive body 100 is a display screen of an electronic product, and the film of the touch pressure sensor is attached to an inner surface of the display screen. In other embodiments, the haptic body 100 can also be a touch pad or an electronic product back case.

Further, the pressure detecting bridge arm circuit can be used, at least two pressure sensitive resistors R are used as the bridge arms of the pressure detecting bridge arm circuit, and the strain sensitive systems of the two pressure sensitive resistors R are identical. When the touch region 101 of the touch sensitive body 100 is subjected to the touch pressure, the pressure sensitive resistor R in the first region A1 is affected by the touch pressure, that is, strain is generated, and the pressure sensitive resistor R in the second region A2 is not subjected to the touch pressure. Impact, the strain is zero. That is, the change in the resistance in the same pressure detecting bridge arm circuit produces a difference, and the force of the touch pressure can be detected by the difference in the resistance change.

In the embodiment shown in FIG. 2, the number of the pressure sensitive resistors R in each of the detecting circuits 20 is four, but the detecting circuit 20 protected by the present invention is not limited to including four pressure sensitive resistors R, for example, two The resistor forms a half bridge circuit and can also perform the function of detection. Therefore, in each of the detecting circuits 20, the number of the pressure sensitive resistors R is at least two.

In one embodiment, in each detection circuit, the resistor includes a first pressure sensitive resistor and a second pressure sensitive resistor, and the first pressure sensitive resistor and the second pressure sensitive resistor form a half bridge circuit, In other words, the first pressure sensitive resistor and the second pressure sensitive resistor constitute two adjacent bridge arms of the pressure detecting bridge arm circuit, and the film at the first pressure sensitive resistor is rigidly connected with the tactile body of the electronic product. The film at the second pressure sensitive resistor is not connected or flexibly connected to the touch body. The second pressure sensitive resistor is consistent with a strain sensitivity coefficient of the first pressure sensitive resistor. In this embodiment, the two resistors in each detection circuit form a half bridge circuit. When the touch screen is pressed, the first pressure sensitive resistor is caused by the rigid connection between the film and the touch sensitive body of the first pressure sensitive resistor. The resistance value changes, because the film of the second pressure sensitive resistor is not connected or flexibly connected to the touch body, and the resistance of the second pressure sensitive resistor is changed, further passing the first pressure sensitive resistor and The difference in resistance variation of the second pressure sensitive resistor enables an accurate measurement of the touch pressure experienced by the touch screen.

In another embodiment, in each of the detecting circuits 20, the number of the pressure sensitive resistors R is four, and a bridge circuit is formed. The HR circuit in this embodiment is based on the strain original principle of the Wyster bridge, for example, the resistance value change of the two pressure sensitive resistors R is greater than the resistance value change of the other two pressure sensitive resistors R, so that The change in the output voltage is also an accurate measurement of the touch pressure experienced by the touch region 101 of the touch sensitive body 100 by the difference in the resistance change of the pressure sensitive resistor.

Please refer to FIG. 3. FIG. 3 is a schematic diagram of a bridge circuit (Wheatstone bridge). Ui is a power supply voltage, Uo is an output, that is, a measurement voltage, and the four pressure sensitive resistors are respectively a first resistor R1 and a second. The resistor R2, the third resistor R3 and the fourth resistor R4 are connected end to end in sequence, and each pressure sensitive resistor forms a bridge arm of the resistor bridge, one diagonal connection of the resistance bridge is connected to the supply voltage, and the other diagonally connects the output voltage. The specific structure is: a connection point of the first resistor R1 and the second resistor R2 forms a first input node, and a connection point of the third resistor R3 and the fourth resistor R4 forms a second input node. Connecting a supply voltage Ui between the first input node and the second input node, a connection point of the first resistor R1 and the third resistor R3 forming a first output node, the second resistor R2 and the The connection point of the fourth resistor R4 forms a second output node, and the measurement voltage Uo is connected between the first output node and the second output node. The measurement voltage Uo is used to output a voltage to measure a touch pressure value. When the user presses the contact zone 101, the resistance of one or more of the resistors produces a first strain, and the resistance of the other resistors produces a second strain. The second strain is less than the first strain. At the same time, Ui remains unchanged, Uo will produce a corresponding output, and the force of the user pressing the touch zone 101 can be measured.

In order to make the resistance of some resistors in the bridge circuit produce the first strain, the resistance of the other resistors produces the second strain. These resistors are composed of strain-sensitive materials, and the following relationship usually exists:

ΔR/R=S*ε

Where R is the resistance of the original resistance, ΔR is the resistance change caused by strain, S is the resistance strain sensitivity coefficient, and ε is the strain.

That is, the resistance value can be changed by causing a strain change in the structure at the resistor, that is, the touch pressure sensor structure rigidly connected to the touch body is subjected to strain change and resistance change by the user pressing the touch surface of the touch body.

At the same time, the pressure sensitive resistors R1, R2, R3, R4 are made of strain-sensitive materials, and the strain-sensitive materials are also very sensitive to temperature, that is, when the temperature rises/decreases, the resistance also rises/decreases accordingly, so for precise In the embodiment of the present invention, the materials of the at least two resistors are the same, and further, four resistors in each detection circuit are disposed adjacent to each other, and each detection circuit ( That is, the overall maximum area of the touch pressure sensor is 10 mm×10 mm, and the design of the maximum area of the touch pressure sensor is related to the area of the touch pressure area 101. When the user's finger presses the touch area 101, the area that the finger can cover is Is the maximum area of the touch pressure sensor. The temperature changes of the pressure sensitive resistors are the same or the temperature is the same, so as to reduce the temperature difference between the resistors. When the temperature of the electronic product changes, all the resistances in each detection circuit change uniformly, thereby ensuring that the bridge output voltage remains unchanged. Change, that is, temperature has no effect on the output of the bridge. Specifically, the temperature coefficients of the first pressure sensitive resistor and the second pressure sensitive resistor are substantially the same, and are basically the same herein, and refer to: in the process of temperature change, the first pressure sensitive resistor and the first The two pressure sensitive resistors will produce the same change, but also allow the temperature coefficient of the first pressure sensitive resistor and the second pressure sensitive resistor to be different. The specific difference may be: when the strain sensitivity coefficient is close to the temperature sensitivity coefficient, the temperature sensitivity is The allowable difference of the coefficients is also strict, such as the strain sensitivity coefficient is 50. (Normalized value, the same below, temperature sensitivity coefficient is also normalized value) and the temperature sensitivity coefficient is 10, then the allowable difference of temperature sensitivity coefficient is 20%; when the strain sensitivity coefficient and temperature sensitivity coefficient are different When the temperature sensitivity coefficient allows the difference to be properly amplified, such as the strain sensitivity coefficient is 100 (normalized value, the same below, the temperature sensitivity coefficient is also the normalized value) and the temperature sensitivity coefficient is 10, then the temperature sensitivity coefficient The allowable difference is 60%.

The four resistors in the bridge circuit can be arranged in such a way that four resistors are arranged in a row (forming a rectangular structure); or four resistors are arranged in two rows and two columns (forming a square structure).

The specific distribution of the four resistors and the structure of the film 10 corresponding to the corresponding resistors connected to the contact zone 101 are described in the following four specific embodiments.

The first embodiment is as follows: Referring to FIG. 4, the four pressure sensitive resistors are respectively a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4, which are sequentially arranged end to end in a row, the first The resistor R1, the second resistor R2 and the third resistor R3 are located in the first area A1 (the area inside the dotted line frame), and the fourth resistor R4 is located in the second area A2 (the area outside the dotted line frame) When the user applies a touch pressure to the touch region 101, the resistances of the first resistor R1, the second resistor R2, and the third resistor R3 generate a first strain, but the fourth resistor The resistance of R4 produces a second strain. The second strain is less than the first strain. In this embodiment, two slits S are disposed on the film, and two slits S are oppositely disposed and respectively located on two sides of the four resistors R1, R2, R3, and R4, and the slit S is used to lift the bearing of the film 10. The elastic deformation ability of the region 11 is mainly used to lift the elastic deformation ability of the second region A2.

The second embodiment: Referring to FIG. 5, in the detecting circuit 20, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are arranged in two rows and two columns, wherein the first resistor R1 and the second resistor The resistor R2 and the third resistor R3 are disposed in the first region A1. The first region A1 is in an L-shaped region (ie, a region in a broken line frame), and the fourth resistor R4 is disposed in the second region A2. In the embodiment, the film is provided with a slit S, and the slit S is located on a side of the fourth resistor R4 in the second region A2 away from the first resistor R1, the second resistor R2, and the third resistor R3.

The third embodiment is shown in FIG. 6. In contrast to the first embodiment, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are arranged in a row. The first resistor R1, the second resistor R2, and the third resistor R3 are disposed in the second region A2 and are used to generate a second strain. The fourth resistor R4 is located in the first region A1 and is used to generate the first strain. The second strain is less than the first strain. In this embodiment, two slits S are provided on the film, and the two slits S are oppositely disposed and respectively located on two sides of the four resistors R1, R2, R3, and R4.

The fourth embodiment is as follows: Referring to FIG. 7 , contrary to the second embodiment, the first resistor R1 , the second resistor R2 , the third resistor R3 , and the fourth resistor R4 are arranged in two rows and two columns, wherein Three adjacent resistors (a first resistor R1, a second resistor R2, and a third resistor R3) are located in the second region A2, and the second region A2 is in an L-shaped region; the fourth resistor R4 is located in the first region A1. In this embodiment, a slit S is disposed on the film, and the slit is located on a side of the first resistor R1, the second resistor R2, and the third resistor R3 that is away from the fourth resistor R4, and partially surrounds the first resistor R1 and the second resistor. Resistor R2, third resistor R3.

A fifth embodiment: Referring to FIG. 8, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are arranged in a row, wherein two adjacent resistors (the first resistor R1) The second resistor R2) is located in the first region A1; the other two resistors (the third resistor R3 and the fourth resistor R4) are located in the second region A2. In this embodiment, two slits S are provided on the film, and the two slits S are oppositely disposed and respectively located on two sides of the four resistors R1, R2, R3, and R4.

Sixth embodiment: Referring to FIG. 9, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 is in two rows and two columns, wherein two adjacent resistors (the first resistor R1 and the second resistor R2) are located in the first region A1; and the other two resistors (the third resistor R3 and the fourth resistor R4) ) is located in the second area A2. In this embodiment, a slit S is disposed on the film, and is located on a side of the third resistor R3 and the fourth resistor R4 that is away from the first resistor R1 and the second resistor R2.

In the seventh embodiment, referring to FIG. 10, in the embodiment, the film 10 includes two second regions A2 and one first region A1, and the two second regions A2 are respectively located at two sides of the first region A1. The first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are arranged in a row, wherein two adjacent resistors (the first resistor R1 and the second resistor R2) located at the middle are located at the first In the region A1; the third resistor R3 and the fourth resistor R4 are respectively located in the two second regions A2. In this embodiment, two slits S are provided on the film, and two slits S are oppositely disposed and respectively located in the two second regions A2, and respectively surrounding the third resistor R3 and the fourth resistor R4.

In all of the above embodiments, the resistance of the pressure sensitive resistor R in the first region A1 produces a first strain, and the resistance of the pressure sensitive resistor R in the second region A2 produces a second strain. The second strain is less than the first strain. Thus, the magnitude of the touch pressure is measured by the strain difference of the pressure sensitive resistors in the first area A1 and the second area A2.

The invention distributes an array of a plurality of detecting circuits 20 on the film 10, and the film 10 has elastic deformation capability. Generally, the film 10 itself is a soft material, and has a function of elastic swinging itself; if the film 10 is relatively hard, it can be in the film 10 The upper slot (i.e., the slot S in each of the above embodiments), such as a U-shaped slot or a C-shaped slot, or a similar semi-enclosed slot, is isolated from the rest of the film by the slot surrounded by the slotted area The region of the film surrounded by the groove has a function of elastic swing. In one embodiment, the film 10 is provided with a plurality of slits S distributed in a region where the film 10 and the touch screen are not connected or connected by a soft material. The method of grooving involves hollowing out all the material in the thickness direction of the film, that is, the groove is opened on both sides of the film. Of course, the way of slotting can also be to dig away only a portion of the material in the thickness direction of the film. This slotted structure is similar to a blind hole structure. Regardless of the structure of the grooving, the flexibility of the film can be increased, particularly the flexibility of the film in the region where the film is not connected or connected by the soft material.

Further, an array of the plurality of detecting circuits 20 is distributed on the film 10, and may be distributed on the same surface of the film 10 or on both sides of the film 10. The thickness of the film 10 is very thin, and the thickness of the film 10 of the present invention in combination with the electric resistance R can be about 0.1 mm.

In one embodiment, the film 10 includes a front surface and a reverse surface disposed opposite to each other, the front surface is adhered to the touch sensitive body 100, and the pressure sensitive resistor in the first area A1 is disposed on the front surface. The pressure sensitive resistor of A2 in the second region is disposed on the reverse side.

Referring to FIG. 11 and FIG. 12, the present invention further provides an electronic product, a touch pressure sensing device and a main board (not shown), wherein the main board is provided with a sensor circuit, and all of the pressure sensitive resistors are electrically connected to the a sensor circuit for comparing a strain difference between the pressure sensitive resistor in the first region and the pressure sensitive resistor in the second region to achieve measurement of the touch pressure .

Wherein, the touch sensitive body 100 of the touch pressure sensor may be a display screen, and the film 10 is attached to the inner surface of the display screen, and the touch pressure sensor needs to be designed to be transparent, a transparent film may be used, and a transparent material may be used. A resistor is fabricated on the film. The film of the touch pressure sensor is attached to the inner surface of the touch screen such that the touch pressure sensor is close to the touch screen, so that the touch stress can be measured more accurately.

In another embodiment, the haptic body 100 can include a display screen and a backlight module, and the film is attached to the The backlight module faces away from one side of the display screen. The touch pressure sensor of the present embodiment does not need to be formed into a light-transmitting structure. Therefore, the touch pressure sensor of the present embodiment has a low cost and is attached to the side of the backlight module facing away from the touch screen, and the manufacturing method is also easy, and the manufacturing cost is also low. low. Just because the distance from the display screen is farther than the previous embodiment, the accuracy of detecting the touch application is not as good as the previous embodiment.

Some electronic devices, such as mobile phones, have a fingerprint module disposed on the rear case. In this case, the touch main body 100 is a rear case of the electronic device. In the present embodiment, the film is attached to the inner surface of the rear case.

The above is a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It is the scope of protection of the present invention.

Claims

A touch pressure sensing device, comprising: a touch sensing body and a touch pressure sensor, the touch sensing body including a touch pressure area for a user to apply a touch pressure, the touch pressure sensor being located away from the touch of the touch sensitive body One side of the nip;

The touch pressure sensor includes at least two pressure sensitive resistors and a film, the film being elastically deformed under stress, the film including a first region and a second region adjacent to each other, wherein at least one of the pressure sensitive a resistor is fixed to the first region, and the remaining pressure sensitive resistors are fixed to the second region;

a rigidity of the first connection medium on the touch pressure transmission path between the pressure sensitive resistor and the touch region in the first region is greater than the pressure sensitive resistance and the touch in the second region The rigidity of the second connection medium on the touch pressure transmission path between the regions, the first connection medium includes at least the first region, and the second connection medium includes at least the second region;

The second region is capable of elastically deforming relative to the first region when the touch pressure transmits a touch pressure to the pressure sensitive resistor, thereby generating strain between the first region and the second region The difference is sensed and the strain difference is sensed by the pressure sensitive resistor.
The touch pressure sensing device according to claim 1, wherein the first connection medium further comprises a first connector between the first region and the haptic body, and the first connector The thinner the better.
The touch pressure sensing device of claim 1 wherein said first connection medium further comprises a first bond between said first region and said pressure sensitive resistor, said first bond The thinner the better.
The touch pressure sensing device of claim 1 wherein the first region is as thin as possible.
The touch pressure sensing device according to claim 1, wherein said second connection medium further comprises a second connector between said second region and said haptic body, said second connector The thicker the better.
The touch pressure sensing device of claim 1 wherein said first connection medium further comprises a second bond between said second region and said pressure sensitive resistor, said second bond The thicker the better.
The touch pressure sensing device of claim 1 wherein the second region is as thick as possible.
The touch pressure sensing device according to claim 1, wherein the strain received by the pressure sensitive resistor on the first region is the same on the second region for the same touch pressure of the user More than 1.2 times the strain received by the pressure sensitive resistor.
The touch pressure sensing device according to claim 1, wherein the film has a thickness ranging from 0.02 to 0.2 mm.
The touch pressure sensing device according to claim 1, wherein a groove is provided in the second region to increase an elastic deformation capability of the second region relative to the first region.
A touch pressure sensing device according to claim 10, wherein said groove extends in a U shape, and said pressure sensitive resistor in said second region is located in a region surrounded by said groove.
The touch pressure sensing device according to claim 1, wherein the number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are a first resistor, a second resistor, a third resistor, and a first Four resistors, and are connected end to end in sequence, each of the pressure sensitive resistors forming a bridge arm of the resistance bridge, a connection point of the first resistor and the second resistor forming a first input node, the third resistor And a connection point of the fourth resistor forms a second input section Point, a power supply voltage is connected between the first input node and the second input node, a first output node is formed between the first resistor and the third resistor, and the second resistor and the fourth Forming a second output node between the resistors, and outputting a measurement voltage between the first output node and the second output node; the measuring voltage is used to output a voltage to measure a touch pressure value; the first resistor, the first resistor The second resistor and the third resistor are fixed to the first region, and the fourth resistor is fixed to the second region, when the user applies a touch pressure to the touch region, the first resistor, the The resistances of the second resistor and the third resistor generate a first strain, and the resistance of the fourth resistor produces a second strain, the second strain being less than the first strain.
The touch pressure sensing device according to claim 1, wherein the number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are a first resistor, a second resistor, a third resistor, and a first Four resistors, and are connected end to end in sequence, each of the pressure sensitive resistors forming a bridge arm of the resistance bridge, a connection point of the first resistor and the second resistor forming a first input node, the third resistor And a connection point of the fourth resistor forms a second input node, a power supply voltage is connected between the first input node and the second input node, and a first gap is formed between the first resistor and the third resistor An output node, a second output node is formed between the second resistor and the fourth resistor, and a measurement voltage is output between the first output node and the second output node; the measured voltage is used to output a voltage Measuring a touch pressure value; the first resistor, the second resistor, and the third resistor are located in the second region, the fourth resistor is located in the first region, when a user applies a touch pressure to the touch Ram The resistance of the first resistor, the second resistor, and the third resistor generates a second strain, the resistance of the fourth resistor generates a first strain, and the second strain is less than the first strain.
The touch pressure sensing device according to claim 1, wherein the number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are a first resistor, a second resistor, a third resistor, and a first Four resistors, and are connected end to end in sequence, each of the pressure sensitive resistors forming a bridge arm of the resistance bridge, a connection point of the first resistor and the second resistor forming a first input node, the third resistor And a connection point of the fourth resistor forms a second input node, a power supply voltage is connected between the first input node and the second input node, and a first gap is formed between the first resistor and the third resistor An output node, a second output node is formed between the second resistor and the fourth resistor, and a measurement voltage is output between the first output node and the second output node; the measured voltage is used to output a voltage Measuring a touch pressure value; the first resistor and the second resistor are located in a first region, and the third resistor and the fourth resistor are located in the second region, when a user applies a touch pressure to the touch region Time, The resistances of the first resistor and the second resistor generate a first strain, and the resistances of the third resistor and the fourth resistor generate a second strain, the second strain being less than the first strain.
The touch pressure sensing device according to claim 1, wherein the number of the second regions is two, and the two second regions are distributed on both sides of the first region, the pressure sensitive The number of the resistors is four, and the four pressure sensitive resistors are respectively a first resistor, a second resistor, a third resistor, and a fourth resistor, and are sequentially connected end to end, and each of the pressure sensitive resistors forms a resistance bridge. Each of the bridge arms, a connection point of the first resistor and the second resistor forms a first input node, and a connection point of the third resistor and the fourth resistor forms a second input node, the first input node Connecting a supply voltage to the second input node, forming a first output node between the first resistor and the third resistor, and forming a second output node between the second resistor and the fourth resistor a measurement voltage is output between the first output node and the second output node; the measurement voltage is used to output a voltage to measure a touch pressure value; the first resistance and the fourth resistance are respectively located in the two Second area The second resistor and the third resistor Located in the first region, when a user applies a touch pressure to the touch region, the resistances of the first resistor and the fourth resistor generate a second strain, but the second resistor and the third The resistance of the resistor produces a first strain that is less than the first strain.
A touch pressure sensing device according to claim 1, wherein said film comprises front and back faces disposed opposite each other, said front face being bonded to said haptic body, said pressure in said first region A sensitive resistor is disposed on the front surface, and the pressure sensitive resistor in the second region is disposed on the reverse surface.
The touch pressure sensing device of claim 1 wherein said at least two pressure sensitive resistors have the same temperature coefficient.
The touch pressure sensing device according to claim 1, wherein the touch sensing body is a display screen of an electronic product, the touch pressure region is disposed on an outer surface of the display screen, and the touch pressure sensor is configured To be transparent, and located on the inner surface of the display screen.
The touch pressure sensing device of claim 1 , wherein the touch sensing body comprises a display screen and a backlight module, the touch area is disposed on an outer surface of the display screen, and the backlight module is stacked a touch pressure sensor is disposed on a side of the inner surface of the display screen, the touch pressure sensor is located at a side of the backlight module facing away from the display screen, and the display screen and the backlight mold are used to press the touch The touch stress experienced by the zone is transmitted to the touch pressure sensor, which is configured to be opaque.
An electronic product, comprising: the touch pressure sensing device and the main board according to any one of claims 1 to 19, wherein the main board is provided with a sensor circuit, and the at least two pressure sensitive a resistor electrically coupled to the sensor circuit, the sensor circuit for comparing a strain difference between the pressure sensitive resistor in the first region and the pressure sensitive resistor in the second region, The strain difference is used to measure the touch pressure.