Patent Description:
A touch screen device is a type of input device that allows a user to input information through a screen contact of a display device without an additional input device in electronic devices. The touch screen device is generally used as the input device for various kinds of products such as television, notebook computer and monitor as well as portable electronic devices such as electronic notebook, electronic book (e-book), PMP (Portable Multimedia Player), navigation, UMPC (Ultra Mobile PC), mobile phone, smart phone, smart watch, tablet PC (tablet Personal Computer), watch phone, and mobile communication terminal.

Recently, with an establishment of a user interface environment such as application which requires touch information for a force touch, an electronic device having a force touch function for sensing a touch force has been developed and studied.

<FIG> illustrates a related art electronic device having a force touch function.

Referring to <FIG>, the related art electronic device having a force touch function may include a support cover <NUM> having a receiving space, a backlight unit <NUM> received in the receiving space, a liquid crystal display panel <NUM> disposed on the backlight unit <NUM>, and a force sensing panel <NUM> disposed on the liquid crystal display panel <NUM>.

The backlight unit <NUM> may include a light guiding plate <NUM> disposed at a rear surface of the liquid crystal display panel <NUM>, a light source <NUM> for emitting light to a light-incidence portion prepared at a lateral side of the light guiding plate <NUM>, a reflective sheet <NUM> disposed between a rear surface of the light guiding plate <NUM> and a bottom surface of the support cover <NUM>, and optical sheets <NUM> disposed on the light guiding plate <NUM>.

The liquid crystal display panel <NUM> displays an image by the use of light emitted from the backlight unit <NUM> in accordance with light-transmittance properties by an alignment of liquid crystal. The liquid crystal display panel <NUM> may include pixel and common electrodes of forming an electric field for the alignment of liquid crystal. In this case, the common electrode is used as a touch electrode for sensing a user's touch position in a touch sensing mode, and is also used as a liquid crystal driving electrode in a display mode. This liquid crystal display panel <NUM> may be an in-cell touch type liquid crystal display panel.

The force sensing panel <NUM> may include force sensing electrodes for sensing a touch force on a user's touch.

The related art electronic device having a force touch function senses a touch position and a touch force in response to a user's touch, and performs an application corresponding to the sensed touch position and / or touch force.

In the related art electronic device having a force touch function, a heat is generated in accordance with a driving of the light source <NUM>, for example, a light emitting diode array, and then the generated heat radiates toward the support cover <NUM> of a metal material through the reflective sheet <NUM>. However, the heat generated from the light source <NUM> remains inside the electronic device instead of the smooth radiation toward the support cover <NUM>, whereby a picture quality may be degraded due to wrinkles in the optical sheets <NUM> caused by the remaining heat, and deterioration of the liquid crystal caused by the remaining heat.

The invention to which this European patent relates is set out in the appended claims.

Disclosed herein is an electronic device having a force touch function that substantially obviate one or more problems due to limitations and disadvantages of the related art.

Also disclosed herein is an electronic device having a force touch function which is capable of minimizing degradation of picture quality caused by heat.

Also disclosed herein is an electronic device having a force touch function which is capable of improving heat-radiation efficiency to prevent an image display module from being damaged by an external shock.

Additional advantages and features of examples disclosed herein will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of embodiments disclosed herein. The objectives and other advantages of examples disclosed herein may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Also disclosed herein is an electronic device having a force touch function that includes a housing with a receiving space, an image display module disposed in the receiving space, and a force sensing panel disposed between a bottom surface of the housing and the image display module.

At this time, the electronic device having a force touch function may further include a radiation member disposed between the bottom surface of the housing and the force sensing panel.

It is to be understood that both the foregoing general description and the following detailed description of examples are exemplary and explanatory and are intended to provide further explanation of the subject matter as claimed.

The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments and together with the description serve to explain the principle of the present disclosure. In the drawings:.

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings.

Terms disclosed in this specification should be understood as follows.

The term of a singular expression should be understood to include a multiple expression as well as the singular expression if there is no specific definition in the context. The terms such as "the first" and "the second" are used only to differentiate one element from other elements. Thus, a scope of claims is not limited by these terms. Also, it should be understood that the term such as "include" or "have" does not preclude existence or possibility of one or more features, numbers, steps, operations, elements, parts or their combinations. It should be understood that the term "at least one" includes all combinations related with any one item. For example, "at least one among a first element, a second element and a third element" may include all combinations of two or more elements selected from the first, second and third elements as well as each element of the first, second and third elements. Also, if it is mentioned that a first element is positioned "on or above" a second element, it should be understood that the first and second elements may be brought into contact with each other, or a third element may be interposed between the first and second elements. The terms "prepared" and "provided" may be used to mean "disposed", "positioned", or "formed". For example, the terms "prepared on", "prepared in", or "provided on" may be used to mean "disposed on", "positioned on", "formed in", or "formed on"; the term "prepared between" may be used to mean "disposed between", "positioned between", or "formed between"; and the term "prepared along" may be used to mean "disposed along", "positioned along", or "formed along".

Hereinafter, an electronic device having a force touch function according to the embodiment will be described in detail with reference to the accompanying drawings. Also, in the following description, if detailed description of elements or functions known in respect of the present disclosure is determined to make the subject matter of the present disclosure unnecessarily obscure, the detailed description will be omitted.

<FIG> is a perspective view illustrating an electronic device having a force touch function (hereinafter, referred to as "electronic device") according to one embodiment, and <FIG> is a cross sectional view along I-I' of <FIG>.

Referring to <FIG> and <FIG>, the electronic device according to one embodiment may include a housing <NUM>, a support cover <NUM>, an image display module <NUM>, and a force sensing panel <NUM>.

The housing <NUM> has a receiving space defined by a bottom surface <NUM> and a housing sidewall <NUM>. That is, the housing <NUM> may be formed in a case shape whose upper surface is opened. The housing <NUM> may be formed of a metal material or a plastic material. For example, the housing <NUM> may include a metal material of a magnesium (Mg) material, an aluminum (Al) material, or an invar material.

The receiving space is prepared on the bottom surface <NUM> of the housing <NUM>. The support cover <NUM>, the force sensing panel <NUM> and the image display module <NUM> are received in the receiving space.

At least one of system receiving space may be prepared in a rear surface of the housing <NUM>. In the system receiving space, there are a system driving circuit <NUM> of the electronic device, a battery <NUM> for supplying a driving power, a communication module (not shown), a power circuit (not shown), and a memory (not shown). This rear surface of the housing <NUM> is covered by a rear cover <NUM>. For replacement of the battery <NUM>, the rear cover <NUM> may be detachably connected with the rear surface of the housing <NUM>, but not limited to this structure. If using the electronic device with the internal-type battery <NUM>, the rear cover <NUM> may be fixedly connected with the rear surface of the housing <NUM>.

The support cover <NUM> has a support space defined by a support plate <NUM> and a sidewall <NUM>. The support cover <NUM>, which is formed in a case shape whose upper surface is opened, supports the force sensing panel <NUM> and the image display module <NUM>. The support cover <NUM> emits radiation of heat transferred via the force sensing panel <NUM>. To this end, the support cover <NUM> may include a metal material for a rapid radiation of heat generated in the image display module <NUM>, for example, an aluminum (Al) material, an invar material, or a magnesium (Mg) material.

The image display module <NUM> displays an image corresponding to a video signal supplied from the system driving circuit <NUM>, or senses a touch position for a user's touch. For a display mode, the image display module <NUM> displays an image corresponding to a video signal supplied form the system driving circuit <NUM>. For a touch sensing mode, the image display module <NUM> senses a touch position for a user's touch, and provides the sensed touch position to the system driving circuit <NUM>.

The image display module <NUM> according to an example includes a backlight unit <NUM>, and may include a guide frame <NUM>, a liquid crystal display panel <NUM>, and a cover window <NUM>.

The backlight unit <NUM> may include a light guiding plate <NUM>, a light source <NUM>, a reflective sheet <NUM>, and optical sheets <NUM>.

The light guiding plate <NUM> is formed in a quadrangle plate shape including a light-incidence portion prepared in at least any one side thereof. The light guiding plate <NUM> includes an optical pattern (not shown) which advances light, which is incident on the light-incidence portion, toward an upper direction, that is, toward the liquid crystal display panel <NUM>.

The light source <NUM>, which faces the light-incidence portion of the light guiding plate <NUM>, is provided at a lateral side of the light guiding plate <NUM>. The light source <NUM> emits light to the light-incidence portion of the light guiding plate <NUM>. The light source <NUM> according to an embodiment may include a light emitting diode array with a plurality of light emitting diode packages. The light emitting diode array may include a printed circuit board disposed close to the light-incidence portion of the light guiding plate <NUM>, and the plurality of light emitting diode packages mounted on the printed circuit board. In this case, the printed circuit board is a flexible circuit board, and the printed circuit board includes a power line for supplying a driving power to the plurality of light emitting diode packages. Each of the plurality of light emitting diode packages may include a light emitting diode chip, and a wavelength conversion layer for covering the light emitting diode chip. The plurality of light emitting diode packages transmit a white light to the light guiding plate <NUM>, wherein the white light is obtained by mixing a first color light, which is emitted from the light emitting diode chip in accordance with a driving power supplied through a power line, with a second color light whose wavelength is converted from the first color light by the wavelength conversion layer.

The reflective sheet <NUM> is provided to cover a rear surface of the light guiding plate <NUM>. That is, the reflective sheet <NUM> is interposed between the light guiding plate <NUM> and the support plate <NUM> of the support cover <NUM>. In more detail, the reflective sheet <NUM> is disposed between the light guiding plate <NUM> and the force sensing panel <NUM>. The reflective sheet <NUM> reflects light, which is incident through a lower surface of the light guiding plate <NUM>, to the inside of the light guiding plate <NUM>, thereby minimizing a light loss. Also, the reflective sheet <NUM> emits radiation of heat, which is generated in the light guiding plate <NUM> by heat and light generated for driving the light source <NUM>, toward the support cover <NUM>.

The optical sheets <NUM> are disposed on the light guiding plate <NUM>, wherein the optical sheets <NUM> improve luminance properties of the light guided by the light guiding plate <NUM>. For example, the optical sheets <NUM> may include a lower diffusion sheet, a prism sheet, and an upper diffusion sheet, but not limited to this structure. The optical sheets <NUM> may be formed in a deposition structure of two or more elements selected among a diffusion sheet, a prism sheet, a dual brightness enhancement film, and a lenticular sheet.

The guide frame <NUM> is formed in a rectangular band shape, and the guide frame <NUM> is disposed in the support plate <NUM> of the support cover <NUM>. The guide frame <NUM> supports the edge of a rear surface of the liquid crystal display panel <NUM>. The guide frame <NUM> surrounds each lateral surface of the backlight unit <NUM>, to thereby minimize a movement of the backlight unit <NUM>. Herein, lateral sides of the guide frame <NUM> are surrounded by the sidewall <NUM> of the support cover <NUM>.

The guide frame <NUM> is physically connected with the edge of the rear surface of the liquid crystal display panel <NUM> through a panel adhesion member <NUM>. In this case, the panel adhesion member <NUM> may be a double-sided tape, a thermal-curing resin, a photocuring resin, or a double-sided adhesive foam pad.

The liquid crystal display panel <NUM> may include a lower substrate <NUM>, an upper substrate <NUM>, and a liquid crystal layer interposed between the lower substrate <NUM> and the upper substrate <NUM>. The liquid crystal display panel <NUM> displays a predetermined image by the use of light emitted from the backlight unit <NUM>.

The lower substrate <NUM> is a thin film transistor array substrate. The lower substrate <NUM> may include a plurality of pixels (not shown) provided every pixel region defined by crossing a plurality of gate lines (not shown) and a plurality of data lines (not shown). Each pixel may include a thin film transistor (not shown) connected with the gate and data lines, a pixel electrode connected with the thin film transistor, and a common electrode provided close to the pixel electrode and supplied with a common voltage.

A pad (not shown), which is connected with each signal line, is prepared in a lower edge of the lower substrate <NUM>. The pad is connected with the panel driving circuit <NUM>. Also, a gate driving circuit (not shown) for supplying a gate signal to the gate line of the liquid crystal display panel <NUM> may be prepared in a left and / or right edge of the lower substrate <NUM>. In this case, the gate driving circuit is connected with each gate line, and is manufactured for a process of forming the thin film transistor of each pixel.

The upper substrate <NUM> may include a pixel-defining pattern for defining an opening region overlapped with each pixel region of the lower substrate <NUM>, and a color filter provided in the opening region. The upper substrate <NUM>, which confronts the lower substrate <NUM>, is bonded to the lower substrate <NUM> by the use of sealant, wherein the liquid crystal layer is interposed between the lower substrate <NUM> and the upper substrate <NUM>. Accordingly, an entire area of the lower substrate <NUM> except the pad is covered by the upper substrate <NUM>.

An alignment film (not shown) for aligning a pretilt angle of liquid crystal is provided on at least any one of the lower substrate <NUM> and the upper substrate <NUM>. The liquid crystal layer is interposed between the lower substrate <NUM> and the upper substrate <NUM>. The liquid crystal layer includes liquid crystal molecules which are horizontally aligned in an in-plane mode electric field formed by common and data voltages applied to the pixel electrode every pixel.

A lower polarizing member <NUM> having a first polarizing axis is attached to a rear surface of the lower substrate <NUM>, and an upper polarizing member <NUM> having a second polarizing axis which is perpendicular to the first polarizing axis is attached to a front surface of the upper substrate <NUM>.

For the touch sensing mode, the common electrode is used as a touch sensing electrode in the liquid crystal display panel <NUM>. For the display mode, the common electrode together with the pixel electrode is used as a liquid crystal driving electrode in the liquid crystal display panel <NUM>. That is, the liquid crystal display panel <NUM> may be an in-cell touch type liquid crystal display panel, and more particularly, a self capacitive in-cell touch type liquid crystal display panel. For example, the in-cell touch type liquid crystal display panel may be a liquid crystal display panel in a liquid crystal display device with a touch sensor, which is disclosed in <CIT>, but not limited to this type.

According as the panel driving circuit <NUM> is connected with the pad of the lower substrate <NUM>, each pixel of the liquid crystal display panel <NUM> is driven so that a predetermined color image is displayed on the liquid crystal display panel <NUM>. The panel driving circuit <NUM> according to one example of the present disclosure may include a flexible circuit film <NUM>, and a display driving integrated circuit <NUM>.

The flexible circuit film <NUM> is connected with the pad of the lower substrate <NUM>, and is also connected with the system driving circuit <NUM>. The flexible circuit film <NUM> relays an interface between the display driving integrated circuit <NUM> and the system driving circuit <NUM>, and transmits a signal output from the display driving integrated circuit <NUM> to the pad.

For the display mode, the display driving integrated circuit <NUM> drives each pixel by the use of control signal and video data supplied from the system driving circuit <NUM>. For the touch sensing mode, the display driving integrated circuit <NUM> supplies a touch driving pulse to the common electrode through a touch driving line, senses a change of capacitance in the common electrode in accordance with a user's touch through the touch driving line, generates touch position data based on the sensed change of capacitance, and provides the generated touch position data to the system driving circuit <NUM>.

Additionally, the liquid crystal display panel <NUM> may further include a load offset wiring overlapped with the gate line and / or data line and overlapped with the common electrode. The load offset wiring is connected with the display driving integrated circuit <NUM> through the pad. For the touch sensing mode, the display driving integrated circuit <NUM> applies the touch driving pulse to the common electrode through the touch driving line, and synchronously supplies a load offset pulse corresponding to the touch driving pulse to the load offset wiring. Accordingly, it is possible to reduce noise for the touch position sensing time based on the change of capacitance in the common electrode, and thus to improve sensitivity to the touch position sensing.

The cover window <NUM>, which covers an entire front surface of the liquid crystal display panel <NUM>, is supported by the housing sidewall <NUM> of the housing <NUM>. In this case, the cover window <NUM> is physically attached to the entire front surface of the liquid crystal display panel <NUM> by the use of transparent adhesive <NUM>, for example, OCA (Optical Clear Adhesive) or OCR (Optical Clear Resin), to thereby protect the liquid crystal display panel <NUM> from an external impact. The cover window <NUM> may be formed of a tempered glass, a transparent plastic, or a transparent film. According to an example, the cover window <NUM> may include at least any one of sapphire glass and gorilla glass. According to another example, the cover window <NUM> may include any one among PET (polyethyleneterephthalate), PC (polycarbonate), PES (polyethersulfone), PEN (polyethylenapthanate), and PNB (polynorborneen). In consideration of scratches and transparency, the cover window <NUM> may include the tempered glass, preferably.

The force sensing panel <NUM> is interposed between the support plate <NUM> of the support cover <NUM> and the reflective sheet <NUM> of the backlight unit <NUM>, wherein the force sensing panel <NUM> senses a touch force for a user's force touch. Also, the force sensing panel <NUM> serves as a heat transfer medium for transferring the heat generated in the light source <NUM> of the backlight unit <NUM> to the support cover <NUM> so that it is possible to distribute the residual heat, which remains inside the electronic device, to thereby overcome a problem of inferior picture quality caused by the heat generated in the light source <NUM>. In this case, the heat of the reflective sheet <NUM> may radiate toward the support cover <NUM> along a heat transfer path via a contact portion of the force sensing panel <NUM> being in a physical contact with the reflective sheet <NUM> and the support cover <NUM>, and the heat of the reflective sheet <NUM> may radiate toward the support cover <NUM> through a heat radiation of the force sensing panel <NUM> at the same time.

The force sensing panel <NUM> according to one example of the present disclosure may include a force sensor whose resistance value is changed in accordance with a user's force touch, wherein the force sensor may be provided between first and second electrodes facing each other. As shown in <FIG>, the force sensing panel <NUM> includes a first substrate <NUM>, a second substrate <NUM>, an elastic resistor member <NUM>, and a substrate attachment member <NUM>.

The first substrate <NUM> is disposed below the reflective sheet <NUM> of the backlight unit <NUM>, wherein the first substrate <NUM> includes a plurality of first electrodes (Tx) arranged at fixed intervals in parallel. As one possibility, the plurality of first electrodes (Tx) are carried on the first substrate <NUM> such that the plurality of first electrodes (Tx) are disposed on the first substrate <NUM>. The first substrate <NUM> transfers the heat from the reflective sheet <NUM> toward the support cover <NUM>.

The second substrate <NUM> is disposed below the first substrate <NUM>, wherein the second substrate <NUM> includes a plurality of second electrodes (Rx) arranged at fixed intervals in parallel and provided to cross the plurality of first electrodes (Tx). As one possibility, the plurality of second electrodes (Rx) are carried on the second substrate <NUM> such that the plurality of second electrodes (Rx) are disposed on the second substrate <NUM>.

The first and second substrates <NUM> and <NUM> may be formed of PET (polyethyleneterephthalate) material.

The first substrate <NUM> may include a circuit connector <NUM>, wherein the circuit connector <NUM> may be provided at one side of the first substrate <NUM>. The circuit connector <NUM> having a predetermined width and length extends from one side of the first substrate <NUM>. A force touch pad is prepared in the circuit connector <NUM>. The force touch pad may include a plurality of first pads which are connected with the plurality of first electrodes (Tx) in an one-to-one correspondence through a first routing wiring (not shown), and a plurality of second pads which are connected with the plurality of second electrodes (Rx) in an one-to-one correspondence through a second routing wiring (not shown). As shown in <FIG> and <FIG>, the circuit connector <NUM> is bent toward a rear surface of the housing <NUM> passing through the sidewall <NUM> of the support cover <NUM>, and is then electrically connected with the system driving circuit <NUM>. In this case, the support cover <NUM> may includes a sidewall cut portion <NUM> prepared at the sidewall <NUM>, wherein the circuit connector <NUM> of the force sensing panel <NUM> may pass through the sidewall cut portion <NUM> of the sidewall <NUM>.

Referring once again to <FIG>, the elastic resistor member <NUM> is prepared between each crossing portion of the first and second electrodes (Tx, Rx). The force sensor is prepared between the first and second electrodes (Tx, Rx) facing each other with the elastic resistor member <NUM> interposed in-between. Thus, a resistance value of the force sensor is changed in accordance with a user's force touch, to thereby sense a user's force touch. The elastic resistor member <NUM> therefore functions as a force sensor.

The elastic resistor member <NUM> according to a first example may be prepared in a rear surface of the first substrate <NUM> facing the second substrate <NUM>, to thereby cover the plurality of first electrodes (Tx).

The elastic resistor member <NUM> according to a second example may be prepared in a front surface of the second substrate <NUM> facing the first substrate <NUM>, to thereby cover the plurality of second electrodes (Rx).

The elastic resistor member <NUM> according to the first and second examples is formed as a single body, which is appropriate for sensing a single-force touch.

The elastic resistor member <NUM> according to a third example may include a plurality of first elastic resistor patterns <NUM>, and a plurality of second elastic resistor patterns <NUM>.

The plurality of first elastic resistor patterns <NUM> may be prepared in a rear surface of the first substrate <NUM>, wherein the plurality of first elastic resistor patterns <NUM> may cover the plurality of first electrodes (Tx) in an one-to-one correspondence. That is, one of the first elastic resistor pattern <NUM> is patterned in the rear surface of the first substrate <NUM> so as to cover one of the first electrode (Tx).

The plurality of second elastic resistor patterns <NUM> may be prepared in a front surface of the second substrate <NUM>, wherein the plurality of second elastic resistor patterns <NUM> may cover the plurality of second electrodes (Rx) in an one-to-one correspondence. That is, one of the second elastic resistor pattern <NUM> is patterned in the front surface of the second substrate <NUM> so as to cover one of the second electrode (Rx).

In case of the elastic resistor member <NUM> according to the third example, the plurality of first elastic resistor patterns <NUM> are separated from one another, and the plurality of second elastic resistor patterns <NUM> are separated from one another, which is appropriate for sensing a multi-force touch.

The elastic resistor member <NUM> may be formed of a piezo-resistive based material or a pressure-sensitive adhesive material based on any one of QTC (quantum tunneling composites), EAP (electro-active polymer) and acrylic and rubber based solvent. In this case, a resistance of the pressure-sensitive adhesive material is changed according to an area. In case of the piezo-resistive based material, if an external pressure is applied to silicon semiconductor crystals, conduction energy is generated and an electric charge is transferred to a conduction band, whereby it is possible to have a piezo-resistive effect by a change of resistivity. The resistivity is largely changed according to a size of the pressure. The elastic resistor member <NUM> may be coated onto the first and / or second substrate <NUM> and / or <NUM> by a printing process, or may be attached to the first and / or second substrate <NUM> and / or <NUM> by an attaching process using an adhesive.

By the substrate attachment member <NUM>, a gap space (GS) is prepared between the first and second substrates <NUM> and <NUM>, and the first and second substrates <NUM> and <NUM> facing each other are bonded to each other. The substrate attachment member <NUM> is an adhesive of a cushion material. The substrate attachment member <NUM> structurally functions as a supporter for supporting the first and second substrates <NUM> and <NUM>, and functionally prevents the image display module <NUM> from being damaged by absorbing a strong impact from the first substrate <NUM>.

Additionally, an upper insulating layer <NUM> may be provided in a contact portion of the first substrate <NUM> being in contact with an upper surface of the substrate attachment member <NUM>. Also, a lower insulating layer <NUM> may be provided in a contact portion of the second substrate <NUM> being in contact with a lower surface of the substrate attachment member <NUM>. The upper insulating layer <NUM> and lower insulating layer <NUM> electrically insulate the first routing wiring and the second routing wiring from each other.

A force touch driving integrated circuit <NUM> may be mounted in the circuit connector <NUM>. The force touch driving integrated circuit <NUM> is connected with the plurality of first electrodes (Tx) through the force touch pad and the first routing wiring, and is also connected with the plurality of second electrodes (Rx) through the force touch pad and the second routing wiring. The force touch driving integrated circuit <NUM> generates a touch force by generating a force sensing driving pulse, sequentially supplying the generated force sensing driving pulse to the plurality of first electrodes (Tx) and sensing a change of resistance value in the force sensor according to a user's force touch through the plurality of second electrodes (Rx), generates touch force data corresponding to the sensed touch force, and provides the generated touch force data to the system driving circuit <NUM>.

Meanwhile, the force touch driving integrated circuit <NUM> may be not mounted in the circuit connector <NUM>. The force touch driving integrated circuit <NUM> may be substituted by MCU (micro controller unit) of the system driving circuit <NUM>.

The force sensing panel <NUM> according to the present disclosure further includes a spacer <NUM>.

The spacer <NUM> is interposed between the first and second electrodes (Tx, Rx) facing each other, thereby maintaining the gap space (GS) between the first and second substrates <NUM> and <NUM>, or restoring the first substrate <NUM>, which is pressed by a user's force touch, to its original state. That is, the spacer <NUM> structurally functions as a supporter for supporting the first and second substrates <NUM> and <NUM>, and functionally prevents the image display module <NUM> from being damaged by absorbing a strong impact from the first substrate <NUM>. Accordingly, the force sensing panel <NUM> absorbs an impact applied to the image display module <NUM> through the spacer <NUM> and the substrate attachment member <NUM>, to thereby minimize a damage of the image display module <NUM> by an impact.

The force sensing panel <NUM> is disposed between the image display module <NUM> and the support cover <NUM>. The force sensing panel <NUM> senses a user's force touch on the image display module <NUM>, functions as a heat transfer medium for transferring the heat generated in the light source <NUM> of the backlight unit <NUM> toward the support cover <NUM>, and also absorbs the impact applied to the image display module <NUM> at the same time.

Additionally, the electronic device according to the present disclosure may further include a radiation member <NUM> for improving radiation efficiency through the force sensing panel <NUM>.

The radiation member <NUM> according to one example may be disposed between the support plate <NUM> of the support cover <NUM> and the force sensing panel <NUM>. For an efficient heat radiation of the reflective sheet <NUM>, the radiation member <NUM> according to one example may be attached to the support plate <NUM> of the support cover <NUM> and the force sensing panel <NUM>. That is, a rear surface of the radiation member <NUM> is attached to the support plate <NUM> of the support cover <NUM> by a first transparent adhesive <NUM>, and a front surface of the radiation member <NUM> is attached to the second substrate <NUM> of the force sensing panel <NUM> by a second transparent adhesive <NUM>. In this case, the first and second transparent adhesives <NUM> and <NUM> may be OCA (optical clear adhesive) or OCR (optical clear resin). The radiation member <NUM> according to one example may be a radiation sheet including a material with good heat resistance and heat radiation, for example, carbon fiber, acrylic elastomer, graphite or silicone/ceramic, and more preferably, graphite.

The radiation member <NUM> according to another example may be coated onto the second substrate <NUM> of the force sensing panel <NUM> facing the support plate <NUM> of the support cover <NUM>. For an efficient heat radiation of the reflective sheet <NUM>, the radiation member <NUM> according to another example may be attached to the support plate <NUM> of the support cover <NUM>. That is, the radiation member <NUM> according to another example is coated onto a rear surface of the second substrate <NUM> of the force sensing panel <NUM>, and is attached to the support plate <NUM> of the support cover <NUM> by the transparent adhesive <NUM>. The radiation member <NUM> according to another example may include carbon fiber, acrylic elastomer, graphite or silicone/ceramic, and a thickness of the radiation member <NUM> may be the same as or less than a half of a thickness of the second substrate <NUM>.

<FIG> illustrates a force touch sensing process in the electronic device according to one embodiment.

The force touch sensing process will be described in detail with reference to <FIG>.

First, if a user's force touch (FT) applied to the image display module <NUM> is the same as or more than a reference pressure level, the force sensing panel <NUM> is pressed so that the first elastic resistor pattern <NUM> for covering the first electrode (Tx) is physically brought into contact with the second elastic resistor pattern <NUM> for covering the second electrode (Rx). According as the first and second electrodes (Tx, Rx) are in a conduction state by the elastic resistor member <NUM> at a time point of contact between the first and second elastic resistor patterns <NUM> and <NUM> in accordance with a user's force touch (FT), a current flows between the first and second electrodes (Tx, Rx) of the conduction state, and the current flow is formed in the force sensor (FS), whereby a force touch event occurs. That is, if the first and second elastic resistor patterns <NUM> and <NUM> are brought into contact with each other, the first and second electrodes (Tx, Rx) facing each other are electrically connected with each other through the elastic resistor member <NUM>, whereby a resistance (Rm) is formed between the first and second electrodes (Tx, Rx), and thus the force touch event occurs.

The touch force data is generated by sensing the change of resistance value (Rm) formed in the force sensor (FS) in accordance with the force touch event. That is, in case of occurrence of the force touch event, an analog force sensing signal is generated by amplifying a sensing voltage in accordance with the change of resistance value of the force sensor (FS) through the second electrode (Rx), and then the analog force sensing signal is converted into a digital signal, to thereby generate the touch force data. In this case, the sensing voltage may be amplified by an inverting amplifier.

In case of the electronic device according to one embodiment, the impact applied to the image display module <NUM> is absorbed by the force sensing panel <NUM> disposed between the image display module <NUM> and the support cover <NUM> so that it is possible to minimize a damage of the image display module <NUM> by the impact. Especially, in case of the electronic device according to one embodiment, as shown in <FIG>, the heat (H) generated in the light source <NUM> of the backlight unit <NUM> radiates toward the support cover <NUM> through the reflective sheet <NUM> and the force sensing panel <NUM> so that it is possible to minimize a degradation of picture quality caused by deterioration of liquid crystal and wrinkles in the optical sheets <NUM>.

<FIG> illustrates an electronic device having a force touch function (hereinafter, referred to as 'electronic device') according to another embodiment, which is another cross sectional view along I-I' of <FIG>.

Referring to <FIG>, the electronic device according to another embodiment is obtained by omitting the support cover from the electronic device according to one embodiment. Hereinafter, only structures of reflective sheet and force sensing panel, which relate to the omission of the support cover, will be described in detail. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts, and a detailed description for the same parts will be omitted.

In the electronic device according to another embodiment, a guide frame <NUM> is supported by a reflective sheet <NUM> of a backlight unit <NUM> so that it is possible to omit a support cover for supporting the guide frame <NUM>, thereby realizing a light weight. According as the support cover of metal material is omitted, a housing <NUM> may include a metal material for radiation of a heat generated in a light source <NUM> of the backlight unit <NUM>, for example, aluminum (Al), invar or magnesium (Mg) material.

The reflective sheet <NUM> includes an expansion region for supporting a lower surface of the guide frame <NUM> connected with a rear edge of a liquid crystal display panel <NUM>. The expansion region of the reflective sheet <NUM>, which expands from each lateral side of the reflective sheet <NUM>, is overlapped with the lower surface of the guide frame <NUM>, and is connected with the lower surface of the guide frame <NUM> by the use of adhesive <NUM>. Thus, even though the support cover is omitted, the guide frame <NUM> is connected with the expansion region of the reflective sheet <NUM>, whereby the guide frame <NUM> is fixedly provided inside the housing <NUM>.

A force sensing panel <NUM> is disposed between a bottom surface <NUM> of the housing <NUM> and an image display module <NUM>. In more detail, the force sensing panel <NUM> is interposed between the bottom surface <NUM> of the housing <NUM> and the reflective sheet <NUM> of the backlight unit <NUM>. The force sensing panel <NUM> senses a user's force touch on the electronic device.

The force sensing panel <NUM> serves as a heat transfer medium for transferring a heat generated in the light source <NUM> of the backlight unit <NUM> to the housing <NUM>. Thus, the force sensing panel <NUM> distributes a residual heat, which remains inside the electronic device, so that it is possible to prevent a picture quality from being degraded by the heat generated in the light source <NUM>. In this case, the heat of the reflective sheet <NUM> may radiate toward the housing <NUM> along a heat transfer path via a contact portion of the force sensing panel <NUM> being in a physical contact with the reflective sheet <NUM> and the housing <NUM>, and the heat of the reflective sheet <NUM> may radiate toward the housing <NUM> through a heat radiation of the force sensing panel <NUM> at the same time. Except that the force sensing panel <NUM> is disposed between the housing <NUM> and the reflective sheet <NUM>, a structure of the force sensing panel <NUM> shown in <FIG> is the same as a structure of the force sensing panel <NUM> shown in <FIG>, whereby a detailed description for the same parts will be omitted.

If omitting the support cover, an impact-absorbing sheet of PU (polyurethane) material may be attached to the bottom surface <NUM> of the housing <NUM> so as to absorb an impact applied to the image display module <NUM>. However, in case of the electronic device according to another embodiment, the force sensing panel <NUM> is disposed between the bottom surface <NUM> of the housing <NUM> and the reflective sheet <NUM>, whereby it is possible to absorb an impact applied to the image display module <NUM>. That is, there is no need for the impact-absorbing sheet.

The electronic device according to another embodiment may further include a radiation member <NUM> for improving radiation efficiency through the force sensing panel <NUM>.

The radiation member <NUM> according to one example may be disposed between the bottom surface <NUM> of the housing <NUM> and the force sensing panel <NUM>. For an efficient heat radiation of the reflective sheet <NUM>, the radiation member <NUM> according to one example may be attached to the bottom surface <NUM> of the housing <NUM>, and the force sensing panel <NUM>. That is, a rear surface of the radiation member <NUM> is attached to the bottom surface <NUM> of the housing <NUM> by a first transparent adhesive <NUM>, and a front surface of the radiation member <NUM> is attached to a second substrate <NUM> of the force sensing panel <NUM> by a second transparent adhesive <NUM>. In this case, the first and second transparent adhesives <NUM> and <NUM> may be OCA (optical clear adhesive) or OCR (optical clear resin). The radiation member <NUM> according to one example may be a radiation sheet including a material with good heat resistance and heat radiation, for example, carbon fiber, acrylic elastomer, graphite or silicone/ceramic, and more preferably, graphite.

The radiation member <NUM> according to another example may be coated onto the second substrate <NUM> of the force sensing panel <NUM> facing the bottom surface <NUM> of the housing <NUM>. For an efficient heat radiation of the reflective sheet <NUM>, the radiation member <NUM> according to another example may be attached to the bottom surface <NUM> of the housing <NUM>. That is, the radiation member <NUM> according to another example is coated onto a rear surface of the second substrate <NUM> of the force sensing panel <NUM>, and is then attached to the bottom surface <NUM> of the housing <NUM> by the transparent adhesive <NUM>. The radiation member <NUM> according to another example may include carbon fiber, acrylic elastomer, graphite or silicone/ceramic, and a thickness of the radiation member <NUM> may be the same as or less than a half of a thickness of the second substrate <NUM>.

Additionally, the housing <NUM> may be a central frame of the electronic device, and the central frame may support the image display module <NUM>. In this case, the electronic device according to another embodiment may further include a rear frame (not shown) for covering various circuits disposed in a rear space of the housing <NUM>, and a rear surface of the rear frame may be covered by the aforementioned rear cover <NUM>.

In case of the electronic device according to another embodiment, the impact applied to the image display module <NUM> is absorbed by the force sensing panel <NUM> disposed between the image display module <NUM> and the housing <NUM> so that it is possible to minimize a damage of the image display module <NUM> by the impact. Especially, in case of the electronic device according to another embodiment, as shown in <FIG>, a heat (H) generated in the light source <NUM> of the backlight unit <NUM> radiates toward the housing <NUM> through the reflective sheet <NUM> and the force sensing panel <NUM> so that it is possible to minimize a degradation of picture quality caused by deterioration of liquid crystal and wrinkles in the optical sheets <NUM>.

In the electronic device having a force touch function according to the present disclosure, the image display module <NUM> includes the aforementioned backlight unit and the liquid crystal display panel, but not limited to this structure. The aforementioned image display module may include an organic light emitting display panel. In this case, the aforementioned force sensing panel is disposed between the organic light emitting display panel and the support cover, or between the organic light emitting display panel and the housing so that a heat generated in an organic light emitting device provided in each pixel of the organic light emitting display panel radiates toward the support cover or housing.

As described above, the electronic device having a force touch function according to the present disclosure is not limited to a mobile terminal, that is, a smart phone.

The electronic device having a force touch function according to the embodiment may be any mobile device and mobile communication terminal having an application corresponding to a user's touch force, for example, electronic notebook, electronic book, PMP (portable multimedia player), navigation, UMPC (ultra mobile PC), mobile phone, smart phone, smart watch, tablet PC (personal computer), watch phone, and game console.

According to the present disclosure, the force sensing panel disposed below the image display module is used as the heat transfer medium so that it is possible to improve radiation efficiency of the heat generated in the light source. Thus, it is possible to minimize a degradation of picture quality caused by deterioration of liquid crystal and wrinkles in the optical sheets.

Also, the impact is absorbed by the force sensing panel so that it is possible to prevent the image display module from being damaged by the impact.

Claim 1:
An electronic device configured to sense a force of a user's touch, the electronic device comprising:
a housing (<NUM>) having a receiving space defined by a bottom surface (<NUM>) and a sidewall (<NUM>);
an image display module (<NUM>) disposed in the receiving space; and
a force sensing panel (<NUM>) disposed between the bottom surface (<NUM>) of the housing (<NUM>) and the image display module (<NUM>), the force sensing panel (<NUM>) serving as a heat transfer medium for transferring heat generated in a light source (<NUM>) of a backlight unit (<NUM>) in the image display module (<NUM>) to the housing (<NUM>),
wherein the force sensing panel (<NUM>) includes:
a first substrate (<NUM>) upon which a plurality of first electrodes (Tx) are disposed at fixed intervals in parallel;
a second substrate (<NUM>) upon which a plurality of second electrodes (Rx) are disposed at fixed intervals in parallel, the plurality of second electrodes (Rx) provided to cross the plurality of first electrodes (Tx) and to face the plurality of first electrodes (Tx);
an elastic resistor member (<NUM>) disposed between the first and second electrodes (Tx, Rx);
a substrate attachment member (<NUM>) for attaching the first and second substrates (<NUM>, <NUM>) to each other with a gap (GS) provided therebetween; wherein the substrate attachment member (<NUM>) is an adhesive of a cushion material; and
a spacer (<NUM>) disposed between the first and second electrodes (Tx, Rx).