Patent Description:
Various kinds of input devices are being used to operate a computing system. For example, the input device includes a button, key, joystick and touch screen. Since the touch screen is easy and simple to operate, the touch screen is increasingly being used in operation of the computing system.

The touch screen may constitute a touch surface of a touch input device including a touch sensor panel which may be a transparent panel including a touch-sensitive surface. The touch sensor panel is attached to the front side of a display screen, and then the touch-sensitive surface may cover the visible side of the display screen. The touch screen allows a user to operate the computing system by simply touching the touch screen by a finger, etc. Generally, the computing system recognizes the touch and the touch position on the touch screen and analyzes the touch, and thus, performs the operations in accordance with the analysis.

Document <CIT>) relates to input devices which include a capacitive force sensor; the input device includes a structural component having first and second substantially opposing sides, a plurality of sensor electrodes located on the first side of the structural component, the plurality of sensor electrodes configured to capacitively sense positional information associated with user input in a sensing region, a first capacitive electrode located on the second side of the structural component, the first capacitive electrode being configured to capacitively couple to a second capacitive electrode that is separated from the first capacitive electrode by a gas and moveable relative to the first capacitive electrode, and a biasing member configured to be physically coupled to the structural component such that a force associated with the user input causes a change in a separation distance between the first and second capacitive electrodes based on the force.

Document <CIT>) relates to a display device, wherein a digitizer sensor board is integrated on an upper substrate or a lower substrate of a display panel to provide the display device. In the display device, the display panel displays images, and the digitizer sensor board is integrated into the display panel to sense position of a position pointer or finger contact on a surface.

Document <CIT>) relates to an input device having a sensor controller disposed in close proximity to a plurality of sensing elements that are used to sense and acquire positional information of an input object. The sensor controller and at least portions of the sensor electrodes are disposed between two transparent substrates that are positioned near a display device. The sensor controller is disposed in an edge region of a substrate which has a sensing region through which the adjacently positioned sensor electrodes are configured to sense the presence of an input object.

Document <CIT>) relates to a liquid crystal device comprises an array of active matrix type of sensor circuits. Each sensor circuit comprises a liquid crystal sensing capacitor connected to a transistor arranged as a source-follower. A sensor selecting voltage dependent capacitor is connected between the transistor and a row select line. The capacitance of the voltage dependent capacitor has a larger value for a small voltage and a smaller value for a large voltage.

Document <CIT>) relates to a sensor unit including a first substrate, first and second electrodes, an input portion disposed so that a gap exists between the substrate and the input portion, a plurality of first structures disposed in the gap and extending at least partially between the first substrate and the input portion, and a second insulating structure disposed on a side of the first structures that is away from the input portion, or between adjacent first structures. The sensor unit is configured to detect a change in capacitance between the first and second electrodes upon a change in position of the input portion relative to the first substrate.

Here, there is a demand for a touch input device capable of detecting not only the touch position according to the touch on the touch screen but the magnitude of the touch pressure without degrading the performance of the display module.

The object of the present invention is to provide a touch input device which includes a display module and is capable of detecting a magnitude of a touch pressure as well as a touch position on a touch screen.

The object of the present invention is to provide a touch input device which includes a display module and is configured to be able to detect the touch position and the magnitude of the touch pressure without reducing the visibility and optical transmittance of the display module.

The invention is a touch input device according to the features of claim <NUM>.

One example of touch input device is a smartphone.

According to the embodiment of the present invention, it is possible to provide a touch input device which includes a display module and is capable of detecting a magnitude of a touch pressure as well as a touch position on a touch screen.

Further, it is possible to provide a touch input device which includes a display module and is capable of detecting the touch position and the magnitude of the touch pressure without reducing the visibility and optical transmittance of the display module.

The following detailed description of the present invention shows embodiments and examples of the present invention and will be provided with reference to the accompanying drawings. The embodiment will be described in enough detail that those skilled in the art are able to embody the present invention. It should be understood that various embodiments of the present invention are different from each other and need not be mutually exclusive. Similar reference numerals in the drawings designate the same or similar functions in many aspects.

A touch input device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<FIG> is a schematic view of a configuration of the capacitance touch sensor panel <NUM> and the operation thereof in accordance with the embodiment of the present invention. Referring to <FIG>, the touch sensor panel <NUM> according to the embodiment of the present invention includes a plurality of drive electrodes TX1 to TXn and a plurality of receiving electrodes RX1 to RXm, and may include a drive unit <NUM> which applies a drive signal to the plurality of drive electrodes TX1 to TXn for the purpose of the operation of the touch sensor panel <NUM>, and a sensing unit <NUM> which detects the touch and the touch position by receiving a sensing signal including information on the capacitance changing according to the touch on the touch surface of the touch sensor panel <NUM>.

As shown in <FIG>, the touch sensor panel <NUM> includes the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm. While <FIG> shows that the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm of the touch sensor panel <NUM> form an orthogonal array, the present invention is not limited to this. The plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm has an array of arbitrary dimension, for example, a diagonal array, a concentric array, a <NUM>-dimensional random array, etc., and an array obtained by the application of them. Here, "n" and "m" are positive integers and may be the same as each other or may have different values. The magnitude of the value may be changed depending on the embodiment.

As shown in <FIG>, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be arranged to cross each other. The drive electrode TX may include the plurality of drive electrodes TX1 to TXn extending in a first axial direction. The receiving electrode RX may include the plurality of receiving electrodes RX1 to RXm extending in a second axial direction crossing the first axial direction.

In the touch sensor panel <NUM> according to the embodiment of the present invention, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed in the same layer. For example, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on the same side of an insulation layer (not shown). Also, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed in the different layers. For example, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on both sides of one insulation layer (not shown) respectively, or the plurality of drive electrodes TX1 to TXn may be formed on a side of a first insulation layer (not shown) and the plurality of receiving electrodes RX1 to RXm may be formed on a side of a second insulation layer (not shown) different from the first insulation layer.

The plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be made of a transparent conductive material (for example, indium tin oxide (ITO) or antimony tin oxide (ATO) which is made of tin oxide (SnO<NUM>), and indium oxide (In<NUM>O<NUM>), etc.), or the like. However, this is only an example. The drive electrode TX and the receiving electrode RX may be also made of another transparent conductive material or an opaque conductive material. For instance, the drive electrode TX and the receiving electrode RX may be formed to include at least any one of silver ink, copper or carbon nanotube (CNT). Also, the drive electrode TX and the receiving electrode RX may be made of metal mesh or nano silver.

The drive unit <NUM> according to the embodiment of the present invention may apply a drive signal to the drive electrodes TX1 to TXn. In the embodiment of the present invention, one drive signal may be sequentially applied at a time to the first drive electrode TX1 to the n-th drive electrode TXn. The drive signal may be applied again repeatedly. This is only an example. The drive signal may be applied to the plurality of drive electrodes at the same time in accordance with the embodiment.

Through the receiving electrodes RX1 to RXm, the sensing unit <NUM> receives the sensing signal including information on a capacitance (Cm) <NUM> generated between the receiving electrodes RX1 to RXm and the drive electrodes TX1 to TXn to which the drive signal has been applied, thereby detecting whether or not the touch has occurred and where the touch has occurred. For example, the sensing signal may be a signal coupled by the capacitance (Cm) <NUM> generated between the receiving electrode RX and the drive electrode TX to which the drive signal has been applied. As such, the process of sensing the drive signal applied from the first drive electrode TX1 to the n-th drive electrode TXn through the receiving electrodes RX1 to RXm can be referred to as a process of scanning the touch sensor panel <NUM>.

For example, the sensing unit <NUM> may include a receiver (not shown) which is connected to each of the receiving electrodes RX1 to RXm through a switch. The switch becomes the on-state in a time interval during which the signal of the corresponding receiving electrode RX is sensed, thereby allowing the receiver to sense the sensing signal from the receiving electrode RX. The receiver may include an amplifier (not shown) and a feedback capacitor coupled between the negative (-) input terminal of the amplifier and the output terminal of the amplifier, i.e., coupled to a feedback path. Here, the positive (+) input terminal of the amplifier may be connected to the ground. Also, the receiver may further include a reset switch which is connected in parallel with the feedback capacitor. The reset switch may reset the conversion from current to voltage that is performed by the receiver. The negative input terminal of the amplifier is connected to the corresponding receiving electrode RX and receives and integrates a current signal including information on the capacitance (Cm) <NUM>, and then converts the integrated current signal into voltage. The sensing unit <NUM> may further include an analog to digital converter (ADC) (not shown) which converts the integrated data by the receiver into digital data. Later, the digital data may be input to a processor (not shown) and processed to obtain information on the touch on the touch sensor panel <NUM>. The sensing unit <NUM> may include the ADC and processor as well as the receiver.

A controller <NUM> may perform a function of controlling the operations of the drive unit <NUM> and the sensing unit <NUM>. For example, the controller <NUM> generates and transmits a drive control signal to the drive unit <NUM>, so that the drive signal can be applied to a predetermined drive electrode TX1 at a predetermined time. Also, the controller <NUM> generates and transmits the drive control signal to the sensing unit <NUM>, so that the sensing unit <NUM> may receive the sensing signal from the predetermined receiving electrode RX at a predetermined time and perform a predetermined function.

In <FIG>, the drive unit <NUM> and the sensing unit <NUM> may constitute a touch detection device (not shown) capable of detecting whether the touch has occurred on the touch sensor panel <NUM> according to the embodiment of the present invention or not and where the touch has occurred. The touch detection device according to the embodiment of the present invention may further include the controller <NUM>. The touch detection device according to the embodiment of the present invention may be integrated and implemented on a touch sensing integrated circuit (IC, see reference numeral <NUM> of <FIG>) in a touch input device <NUM> including the touch sensor panel <NUM>. The drive electrode TX and the receiving electrode RX included in the touch sensor panel <NUM> may be connected to the drive unit <NUM> and the sensing unit <NUM> included in the touch sensing IC <NUM> through, for example, a conductive trace and/or a conductive pattern printed on a circuit board, or the like. The touch sensing IC <NUM> may be located on a circuit board on which the conductive pattern has been printed, for example, a first printed circuit board (hereafter, referred to as a first PCB) indicated by a reference numeral <NUM> of <FIG>. According to the embodiment, the touch sensing IC <NUM> may be mounted on a main board for operation of the touch input device <NUM>.

As described above, a capacitance (Cm) with a predetermined value is generated at each crossing of the drive electrode TX and the receiving electrode RX. When an object like a finger approaches close to the touch sensor panel <NUM>, the value of the capacitance may be changed. In <FIG>, the capacitance may represent a mutual capacitance (Cm). The sensing unit <NUM> senses such electrical characteristics, thereby being able to sense whether the touch has occurred on the touch sensor panel <NUM> or not and where the touch has occurred. For example, the sensing unit <NUM> is able to sense whether the touch has occurred on the surface of the touch sensor panel <NUM> comprised of a two-dimensional plane consisting of a first axis and a second axis.

More specifically, when the touch occurs on the touch sensor panel <NUM>, the drive electrode TX to which the drive signal has been applied is detected, so that the position of the second axial direction of the touch is detected. Likewise, when the touch occurs on the touch sensor panel <NUM>, the capacitance change is detected from the reception signal received through the receiving electrode RX, so that the position of the first axial direction of the touch is detected.

The mutual capacitance type touch sensor panel as the touch sensor panel <NUM> has been described in detail in the foregoing. However, in the touch input device <NUM> according to examples outside of the scope of the claims, the touch sensor panel <NUM> for detecting whether or not the touch has occurred and where the touch has occurred may be implemented by using any touch sensing method like a self-capacitance type method, a surface capacitance type method, a projected capacitance type method, a resistance film method, a surface acoustic wave (SAW) method, an infrared method, an optical imaging method, a dispersive signal technology, and an acoustic pulse recognition method, etc..

The touch sensor panel <NUM> for detecting where the touch has occurred in the touch input device <NUM> according to the embodiment of the present invention may be positioned outside or inside a display module <NUM>.

The display module of the touch input device <NUM> according to the embodiment of the present invention is a display included in an organic light emitting diode (OLED). In examples not covered by the claims, the display module may be included in a display panel included in a liquid crystal display (LCD), a plasma display panel (PDP), etc. Accordingly, a user may perform the input operation by touching the touch surface while visually identifying an image displayed on the display panel. Here, the display module <NUM> may include a control circuit which receives an input from an application processor (AP) or a central processing unit (CPU) on a main board for the operation of the touch input device <NUM> and displays the contents that the user wants on the display panel. The control circuit may be mounted on a second printed circuit board (hereafter, referred to as a second PCB) (<NUM>) in <FIG>. Here, the control circuit for the operation of the display module <NUM> may include a display panel control IC, a graphic controller IC, and a circuit required to operate other display panels <NUM>.

<FIG>, <FIG> are conceptual views showing a relative position of the touch sensor panel with respect to the display module in the touch input device according to the embodiment of the present invention. While <FIG> show an LCD panel as a display panel, this is an example outside of the scope of the claims.

In this specification, the reference numeral <NUM> designates the display panel. Also, in <FIG> and the description of <FIG>, the reference numeral <NUM> may designate not only the display module but also the display panel. As shown in <FIG>, the LCD panel may include a liquid crystal layer <NUM> including a liquid crystal cell, a first glass layer <NUM> and a second glass layer <NUM> which are disposed on both sides of the liquid crystal layer <NUM> and include electrodes, a first polarizer layer <NUM> formed on a side of the first glass layer <NUM> in a direction facing the liquid crystal layer <NUM>, and a second polarizer layer <NUM> formed on a side of the second glass layer <NUM> in the direction facing the liquid crystal layer <NUM>. It is clear to those skilled in the art that the LCD panel may further include other configurations for the purpose of performing the displaying function and may be transformed.

<FIG> shows that the touch sensor panel <NUM> of the touch input device <NUM> is disposed outside the display module <NUM>. The touch surface of the touch input device <NUM> may be the surface of the touch sensor panel <NUM>. In <FIG>, the top surface of the touch sensor panel <NUM> is able to function as the touch surface. Also, according to the embodiment, the touch surface of the touch input device <NUM> may be the outer surface of the display module <NUM>. In <FIG>, the bottom surface of the second polarizer layer <NUM> of the display module <NUM> is able to function as the touch surface. Here, in order to protect the display module <NUM>, the bottom surface of the display module <NUM> may be covered with a cover layer (not shown) like glass.

<FIG> show that the touch sensor panel <NUM> of the touch input device <NUM> is disposed inside the display panel <NUM>. Here, in <FIG>, the touch sensor panel <NUM> for detecting the touch position is disposed between the first glass layer <NUM> and the first polarizer layer <NUM>. Here, the touch surface of the touch input device <NUM> is the outer surface of the display module <NUM>. The top surface or bottom surface of the display module <NUM> in <FIG> may be the touch surface. <FIG> shows that the touch sensor panel <NUM> for detecting the touch position is included in the liquid crystal layer <NUM>. Here, the touch surface of the touch input device <NUM> is the outer surface of the display module <NUM>. The top surface or bottom surface of the display module <NUM> in <FIG> may be the touch surface. In <FIG>, the top surface or bottom surface of the display module <NUM>, which can be the touch surface, may be covered with a cover layer (not shown) like glass.

The foregoing has described whether the touch has occurred on the touch sensor panel <NUM> according to the embodiment of the present or not and where the touch has occurred. Further, through use of the touch sensor panel <NUM> according to the embodiment of the present, it is possible to detect the magnitude of the touch pressure as well as whether the touch has occurred or not and where the touch has occurred. Also, apart from the touch sensor panel <NUM>, it is possible to detect the magnitude of the touch pressure by further including the pressure detection module which detects the touch pressure.

<FIG> is a cross sectional view of the touch input device configured to detect the touch position and touch pressure in accordance with an example of the present invention.

In the touch input device <NUM> including the display module <NUM>, the touch sensor panel <NUM> and the pressure detection module <NUM> which detect the touch position may be attached on the front side of the display module <NUM>, As a result, the display screen of the display module <NUM> can be protected and the touch detection sensitivity of the touch sensor panel <NUM> can be improved.

Here, the pressure detection module <NUM> may be operated apart from the touch sensor panel <NUM> which detects the touch position. For example, the pressure detection module <NUM> may be configured to detect only the touch pressure independently of the touch sensor panel <NUM> which detects the touch position. Also, the pressure detection module <NUM> may be configured to be coupled to the touch sensor panel <NUM> which detects the touch position and to detect the touch pressure. At least one of the drive electrode TX and the receiving electrode RX included in the touch sensor panel <NUM> which detects the touch position are used to detect the touch pressure.

<FIG> shows that the pressure detection module <NUM> is coupled to the touch sensor panel <NUM> and detects the touch pressure. In <FIG>, the pressure detection module <NUM> includes a spacer layer <NUM> which leaves a space between the touch sensor panel <NUM> and the display module <NUM>. The pressure detection module <NUM> may include a reference potential layer spaced from the touch sensor panel <NUM> by the spacer layer <NUM>. Here, the display module <NUM> may function as the reference potential layer.

The reference potential layer may have any potential which causes the change of the capacitance <NUM> generated between the drive electrode TX and the receiving electrode RX. For instance, the reference potential layer may be a ground layer having a ground potential. The reference potential layer may be the ground layer of the display module <NUM>. Here, the reference potential layer may have a parallel plane with the two-dimensional plane of the display module <NUM>.

As shown in <FIG>, the touch sensor panel <NUM> is disposed apart from the display module <NUM>, i.e., the reference potential layer. Here, depending on a method for adhering the touch sensor panel <NUM> to the display module <NUM>, the spacer layer <NUM> may be implemented in the form of an air gap between the touch sensor panel <NUM> and the display module <NUM>.

Here, a double adhesive tape (DAT) <NUM> may be used to fix the touch sensor panel <NUM> and the display module <NUM>. For example, the areas the touch sensor panel <NUM> and the display module <NUM> are overlapped with each other. The touch sensor panel <NUM> and the display module <NUM> are adhered to each other by adhering the edge portions of the touch sensor panel <NUM> and the display module <NUM> through use of the DAT <NUM>. The rest portions of the touch sensor panel <NUM> and the display module <NUM> may be spaced apart from each other by a predetermined distance " d ".

In general, even when the touch surface is touched without bending the touch sensor panel <NUM>, the capacitance (Cm) <NUM> between the drive electrode TX and the receiving electrode RX is changed. That is, when the touch occurs on the touch sensor panel <NUM>, the mutual capacitance (Cm) <NUM> may become smaller than a base mutual capacitance. This is because, when the conductive object like a finger approaches close to the touch sensor panel <NUM>, the object functions as the ground GND, and then a fringing capacitance of the mutual capacitance (Cm) <NUM> is absorbed in the object. The base mutual capacitance is the value of the mutual capacitance between the drive electrode TX and the receiving electrode RX when there is no touch on the touch sensor panel <NUM>.

When the object touches the top surface, i.e., the touch surface of the touch sensor panel <NUM> and a pressure is applied to the top surface, the touch sensor panel <NUM> is bent. Here, the value of the mutual capacitance (Cm) <NUM> between the drive electrode TX and the receiving electrode RX may be more reduced. This is because the bend of the touch sensor panel <NUM> causes the distance between the touch sensor panel <NUM> and the reference potential layer to be reduced from " d " to " d' ", so that the fringing capacitance of the mutual capacitance (Cm) <NUM> is absorbed in the reference potential layer as well as in the object. When a nonconductive object touches, the change of the mutual capacitance (Cm) <NUM> is simply caused by only the change of the distance " d-d' " between the touch sensor panel <NUM> and the reference potential layer.

As described above, the touch input device <NUM> is configured to include the touch sensor panel <NUM> and the pressure detection module <NUM> on the display module <NUM>, so that not only the touch position but also the touch pressure can be simultaneously detected.

However, as shown in <FIG>, when the pressure detection module <NUM> as well as the touch sensor panel <NUM> is disposed on the display module <NUM>, the display properties of the display module is deteriorated. Particularly, when the air gap <NUM> is included on the display module <NUM>, the visibility and optical transmittance of the display module may be lowered.

Accordingly, in order to prevent such problems, the air gap is not disposed between the display module <NUM> and the touch sensor panel <NUM> for detecting the touch position. Instead, the touch sensor panel <NUM> and the display module <NUM> can be completely laminated by means of an adhesive like an optically clear adhesive (OCA).

<FIG> is a cross sectional view of the touch input device according to an embodiment of the present invention. In the touch input device <NUM> according to the embodiment of the present invention, the complete lamination is made by an adhesive between the touch sensor panel <NUM> and the display module <NUM> for detecting the touch position. As a result, the display color clarity, visibility and optical transmittance of the display module <NUM>, which can be recognized through the touch surface of the touch sensor panel <NUM>, can be improved.

In <FIG> and <FIG> and the description with reference to <FIG> and <FIG>, it is shown that as the touch input device <NUM> according to the embodiment of the present invention, the touch sensor panel <NUM> is laminated and attached on the display module <NUM> by means of an adhesive. However, the touch input device <NUM> according to the embodiment of the present invention may include, as shown in <FIG>, that the touch sensor panel <NUM> is disposed inside the display module <NUM>. More specifically, while <FIG> and <FIG> show that the touch sensor panel <NUM> covers the display module <NUM>, the touch input device <NUM> which includes the touch sensor panel <NUM> disposed inside the display module <NUM> and includes the display module <NUM> covered with a cover layer like glass may be used as the embodiment of the present invention.

The touch input device <NUM> according to the embodiment of the present invention may include an electronic device including the touch screen, for example, a cell phone, a personal data assistant (PDA), a smart phone, a tablet personal computer, an MP3 player, a laptop computer, etc..

In the touch input device <NUM> according to the embodiment of the present invention, a substrate <NUM>, together with an outermost cover <NUM> of the touch input device <NUM>, functions as, for example, a housing which surrounds a mounting space <NUM>, etc., where the circuit board and/or battery for operation of the touch input device <NUM> are placed. Here, the circuit board for operation of the touch input device <NUM> may be a main board. A central processing unit (CPU), an application processor (AP) or the like may be mounted on the circuit board. Due to the substrate <NUM>, the display module <NUM> is separated from the circuit board and/or battery for operation of the touch input device <NUM>. Due to the substrate <NUM>, electrical noise generated from the display module <NUM> can be blocked.

The touch sensor panel <NUM> or front cover layer of the touch input device <NUM> may be formed wider than the display module <NUM>, the substrate <NUM>, and the mounting space <NUM>. As a result, the cover <NUM> is formed such that the cover <NUM>, together with the touch sensor panel <NUM>, surrounds the display module <NUM>, the substrate <NUM>, and the circuit board.

The touch input device <NUM> according to the embodiment of the present may detect the touch position through the touch sensor panel <NUM> and may detect the touch pressure by disposing the pressure detection module <NUM> between the display module <NUM> and the substrate <NUM>. Here, the touch sensor panel <NUM> may be disposed inside or outside the display module <NUM>. The pressure detection module <NUM> is formed to include, for example, the spacer layer <NUM> consisting of the air gap. This will be described in detail with reference to <FIG>. The spacer layer <NUM> may be made of an impact absorbing material in accordance with the embodiment. The spacer layer <NUM> may be filled with a dielectric material in accordance with the embodiment.

<FIG> is a perspective view of the touch input device according to the embodiment of the present invention. As shown in <FIG>, in the touch input device <NUM> according to the embodiment of the present, the pressure detection module <NUM> includes the spacer layer <NUM> which leaves a space between the display module <NUM> and the substrate <NUM> and includes electrodes <NUM> and <NUM> disposed within the spacer layer <NUM>. Hereafter, for the purpose of clearly distinguishing the electrodes <NUM> and <NUM> from the electrode included in the touch sensor panel <NUM>, the electrodes <NUM> and <NUM> for detecting the pressure are designated as pressure electrodes <NUM> and <NUM>. Here, since the pressure electrodes <NUM> and <NUM> are included in the rear side instead of in the front side of the display panel, the pressure electrodes <NUM> and <NUM> may be made of an opaque material as well as a transparent material.

Here, the adhesive tape <NUM> with a predetermined thickness is formed along the border of the upper portion of the substrate <NUM> in order to maintain the spacer layer <NUM>. While <FIG> shows the adhesive tape <NUM> is formed on the entire border (e.g., four sides of the quadrangle) of the substrate <NUM>, the adhesive tape <NUM> may be formed only on at least some (e.g., three sides of the quadrangle) of the border of the substrate <NUM>. According to the embodiment, the adhesive tape <NUM> may be formed on the top surface of the substrate <NUM> or on the bottom surface of the display module <NUM>. The adhesive tape <NUM> may be a conductive tape in order that the substrate <NUM> and the display module <NUM> have the same electric potential. The adhesive tape <NUM> may be a double adhesive tape. In the embodiment of the present invention, the adhesive tape <NUM> may be made of an inelastic material. In the embodiment of the present invention, when a pressure is applied to the display module <NUM>, the display module <NUM> is bent. Therefore, the magnitude of the touch pressure can be detected even though the adhesive tape <NUM> is not transformed by the pressure.

<FIG> is a cross sectional view of the touch input device including a pressure electrode pattern according to an example. As shown in <FIG>, the pressure electrodes <NUM> and <NUM> according to the example may be formed within the spacer layer <NUM> and on the substrate <NUM>.

The pressure electrode for detecting the pressure may include the first electrode <NUM> and the second electrode <NUM>. Here, any one of the first electrode <NUM> and the second electrode <NUM> may be a drive electrode and the other may be a receiving electrode. A drive signal is applied to the drive electrode, and a sensing signal may be obtained through the receiving electrode. When voltage is applied, the mutual capacitance may be generated between the first electrode <NUM> and the second electrode <NUM>.

<FIG> is a cross sectional view showing a case where a pressure has been applied to the touch input device <NUM> shown in <FIG>. The bottom surface of the display module <NUM> may have a ground potential so as to block the noise. When the pressure is applied to the surface of the touch sensor panel <NUM> by an object <NUM>, the touch sensor panel <NUM> and the display module <NUM> is bent. As a result, the distance " d " between the ground potential surface and the pattern of the pressure electrodes <NUM> and <NUM> may be decreased to " d' ". In this case, due to the decrease of the distance " d ", the fringing capacitance is absorbed in the bottom surface of the display module <NUM>, so that the mutual capacitance between the first electrode <NUM> and the second electrode <NUM> may be reduced. Therefore, the magnitude of the touch pressure can be calculated by obtaining the reduction amount of the mutual capacitance from the sensing signal obtained through the receiving electrode.

In the touch input device <NUM> according to example, the display module <NUM> is bent by the touch pressure. The display module <NUM> may be bent in such a manner as to show the biggest transformation at the touch position. When the display module <NUM> is bent according to the example, a position showing the biggest transformation may not match the touch position. However, the display module <NUM> may be shown to be bent at least at the touch position. For example, when the touch position approaches close to the border, edge, etc., of the display module <NUM>, the most bent position of the display module <NUM> may not match the touch position, however, the display module <NUM> may be shown to be bent at least at the touch position.

Here, the top surface of the substrate <NUM> may also have the ground potential in order to block the noise. Therefore, in order to prevent a short-circuit from occurring between the substrate <NUM> and the pressure electrodes <NUM> and <NUM>, the pressure electrodes <NUM> and <NUM> may be formed on an insulation layer <NUM>. <FIG> shows an attachment structure of the pressure electrode according embodiments and examples of the present invention. Referring to <FIG>, the first insulation layer <NUM> is positioned on the substrate <NUM>, and then the pressure electrodes <NUM> and <NUM> are formed. Also, according to the embodiment, the first insulation layer <NUM> on which the pressure electrodes <NUM> and <NUM> have been formed may be attached on the substrate <NUM>. Also, the pressure electrode according to the embodiment may be formed by positioning a mask, which has a through-hole corresponding to the pressure electrode pattern, on the substrate <NUM> or on the first insulation layer <NUM> positioned on the substrate <NUM>, and then by spraying a conductive material.

Also, when the bottom surface of the display module <NUM> has the ground potential, the pressure electrodes <NUM> and <NUM> may be covered with an additional second insulation layer <NUM> in order to prevent a short-circuit from occurring between the display module <NUM> and the pressure electrodes <NUM> and <NUM> positioned on the substrate <NUM>. Also, the pressure electrodes <NUM> and <NUM> formed on the first insulation layer <NUM> are covered with the additional second insulation layer <NUM> and then are integrally attached on the substrate <NUM>, so that the pressure detection module <NUM> is formed.

The pressure electrodes <NUM> and <NUM> attachment structure and method, which have been described with reference to (a) of <FIG>, may be applied to the attachment of the pressure electrodes <NUM> and <NUM> to the display module <NUM>. The attachment of the pressure electrodes <NUM> and <NUM> to the display module <NUM> will be described in more detail with reference to <FIG>.

Also, depending on the kind and/or implementation method of the touch input device <NUM>, the substrate <NUM> or the display module <NUM> on which the pressure electrodes <NUM> and <NUM> are attached may not have the ground potential or may have a weak ground potential. In this case, the touch input device <NUM> according to the embodiment of the present may further include a ground electrode (not shown) between the first insulation layer <NUM> and either the substrate <NUM> or the display module <NUM>. According to the embodiment, another insulation layer (not shown) may be included between the ground electrode and either the substrate <NUM> or the display module <NUM>. Here, the ground electrode (not shown) is able to prevent the size of the capacitance generated between the first electrode <NUM> and the second electrode <NUM>, which are pressure electrodes, from increasing excessively.

The above-described method for forming and attaching pressure electrodes <NUM> and <NUM> can be applied in the same manner to the following embodiments.

<FIG> is a cross sectional view of the touch input device including a pressure electrode according to an embodiment of the present invention. While an example shows that the pressure electrodes <NUM> and <NUM> are formed on the substrate <NUM>, the pressure electrodes <NUM> and <NUM> are formed on the bottom surface of the display module <NUM>. Here, the substrate <NUM> may have the ground potential. Therefore, the distance " d " between the substrate <NUM> and the pressure electrodes <NUM> and <NUM> is reduced by touching the touch surface of the touch sensor panel <NUM>. Consequently, this may cause the change of the mutual capacitance between the first electrode <NUM> and the second electrode <NUM>.

<FIG> shows a pattern of the pressure electrode according to an example. <FIG> shows that the first electrode <NUM> and the second electrode <NUM> are formed on the substrate <NUM>. The capacitance between the first electrode <NUM> and the second electrode <NUM> may be changed depending on the distance between the bottom surface of the display module <NUM> and the pressure electrodes <NUM> and <NUM>.

<FIG> shows a pattern of the pressure electrode according to the embodiment of the present invention. <FIG> shows that the pressure electrode patterns <NUM> and <NUM> have been formed on the bottom surface of the display module <NUM>.

<FIG> show patterns of the pressure electrodes <NUM> and <NUM> which can be applied to the embodiment of the present invention. When the magnitude of the touch pressure is detected as the mutual capacitance between the first electrode <NUM> and the second electrode <NUM> is changed, it is necessary to form the patterns of the first electrode <NUM> and the second electrode <NUM> so as to generate the range of the capacitance required to improve the detection accuracy. With the increase of a facing area or facing length of the first electrode <NUM> and the second electrode <NUM>, the size of the capacitance that is generated may become larger. Therefore, the pattern can be designed by adjusting the size of the facing area, facing length and facing shape of the first electrode <NUM> and the second electrode <NUM> in accordance with the range of the necessary capacitance. <FIG> show that the first electrode <NUM> and the second electrode <NUM> are formed in the same layer, and show that the pressure electrode is formed such that the facing length of the first electrode <NUM> and the second electrode <NUM> becomes relatively longer.

The embodiments show that the first electrode <NUM> and the second electrode <NUM> are formed in the same layer. However, it can be considered that the first electrode <NUM> and the second electrode <NUM> are formed in different layers in accordance with the embodiment. It is shown in (b) of <FIG> that an attachment structure in which the first electrode <NUM> and the second electrode <NUM> are formed in different layers. As shown in (b) of <FIG>, the first electrode <NUM> may be formed on the first insulation layer <NUM>, and the second electrode <NUM> may be formed on the second insulation layer <NUM> positioned on the first electrode <NUM>. According to the embodiment, the second electrode <NUM> may be covered with a third insulation layer <NUM>. Here, since the first electrode <NUM> and the second electrode <NUM> are disposed in different layers, they can be implemented so as to overlap each other. For example, the first electrode <NUM> and the second electrode <NUM> may be formed similarly to the pattern of the drive electrode TX and receiving electrode RX which are arranged in the form of M × N array and are included in the touch sensor panel <NUM> described with reference to <FIG>. Here, M and N may be natural numbers greater than <NUM>.

The examples shows that the touch pressure is detected from the change of the mutual capacitance between the first electrode <NUM> and the second electrode <NUM>. However, the pressure electrodes <NUM> and <NUM> may be configured to include only any one of the first electrode <NUM> and the second electrode <NUM>. In this case, it is possible to detect the magnitude of the touch pressure by detecting the change of the capacitance between the one pressure electrode and the ground layer (either the display module <NUM> or the substrate <NUM>).

For instance, in <FIG>, the pressure electrode may be configured to include only the first electrode <NUM>. Here, the magnitude of the touch pressure can be detected by the change of the capacitance between the first electrode <NUM> and the display module <NUM>, which is caused by the distance change between the display module <NUM> and the first electrode <NUM>. Since the distance " d " is reduced with the increase of the touch pressure, the capacitance between the display module <NUM> and the first electrode <NUM> may be increased with the increase of the touch pressure. This can be applied in the same manner to the embodiment related to <FIG>. Here, the pressure electrode should not necessary have a comb teeth shape or a trident shape, which is required to improve the detection accuracy of the mutual capacitance change amount. The pressure electrode may have, as shown in <FIG>, a plate shape (e.g., quadrangular plate).

It is shown in (c) of <FIG> that an attachment structure in which the pressure electrode is formed to include only the first electrode <NUM>. As shown in (c) of <FIG>, the first electrode <NUM> may be formed on the first insulation layer <NUM> positioned on the substrate <NUM> or display module <NUM>. Also, according to the embodiment, the first electrode <NUM> may be covered with the second insulation layer <NUM>.

<FIG> is a cross sectional view of the touch input device including the pressure electrode according to an example. The pressure electrodes <NUM> and <NUM> according to the embodiment may be formed within the spacer layer <NUM> and on the top surface of the substrate <NUM> and on the bottom surface of the display module <NUM>.

The pressure electrode pattern for detecting the pressure may include the first electrode <NUM> and the second electrode <NUM>. Here, any one of the first electrode <NUM> and the second electrode <NUM> may be formed on the substrate <NUM>, and the other may be formed on the bottom surface of the display module <NUM>. <FIG> shows that the first electrode <NUM> is formed on the substrate <NUM>, and the second electrode <NUM> is formed on the bottom surface of the display module <NUM>.

When the pressure is applied to the surface of the touch sensor panel <NUM> by the object <NUM>, the touch sensor panel <NUM> and the display module <NUM> is bent. As a result, the distance " d " between the first electrode <NUM> and the second electrode <NUM> may be reduced. In this case, the mutual capacitance between the first electrode <NUM> and the second electrode <NUM> may be increased with the reduction of the distance " d ". Therefore, the magnitude of the touch pressure can be calculated by obtaining the increase amount of the mutual capacitance from the sensing signal obtained through the receiving electrode.

<FIG> shows a pattern of the pressure electrode according to the embodiment of the present invention. <FIG> shows that the first electrode <NUM> is formed on the top surface of the substrate <NUM> and the second electrode <NUM> is formed on the bottom surface of the display module <NUM>. As shown in <FIG>, since the pressure electrodes <NUM> and <NUM> are formed in different layers, the pressure electrodes <NUM> and <NUM> should not necessarily have a comb teeth shape or a trident shape unlike the previous embodiments and examples. The pressure electrodes <NUM> and <NUM> may have a plate shape (e.g., quadrangular plate).

It is shown in example (d) of <FIG> that an attachment structure in which the first electrode <NUM> is attached on the substrate <NUM> and the second electrode <NUM> is attached to the display module <NUM>. As shown in (d) of <FIG>, the first electrode <NUM> may be positioned on the first insulation layer <NUM>-<NUM> formed on the substrate <NUM> and may be covered with the second insulation layer <NUM>-<NUM>. Also, the second electrode <NUM> may be positioned on the first insulation layer <NUM>-<NUM> formed on the bottom surface of the display module <NUM> and may be covered with the second insulation layer <NUM>-<NUM>.

As with the description related to (a) of <FIG>, when substrate <NUM> or the display module <NUM> on which the pressure electrodes <NUM> and <NUM> are attached may not have the ground potential or may have a weak ground potential, a ground electrode (not shown) may be further included between the first insulation layers <NUM>, <NUM>-<NUM>, and <NUM>-<NUM> in (a) to (d) of <FIG>. Here, an additional insulation layer (not shown) may be further included between the ground electrode (not shown) and either the substrate <NUM> or the display module <NUM> on which the pressure electrodes <NUM> and <NUM> are attached.

As described above, the touch input device <NUM> according to the embodiment of the present invention senses the capacitance change occurring in the pressure electrodes <NUM> and <NUM>. Therefore, it is necessary for the drive signal to be applied to the drive electrode out of the first and second electrodes <NUM> and <NUM>, and it is required to detect the touch pressure by the capacitance change amount by obtaining the sensing signal from the receiving electrode. According to the embodiment, it is possible to additionally include the touch sensing IC for the operation of the pressure detection module <NUM>. In this case, the touch input device repeatedly has a configuration similar to the configuration of <FIG> including the drive unit <NUM>, sensing unit <NUM>, and controller <NUM>, so that the area and volume of the touch input device <NUM> increase.

According to the embodiment, the pressure detection module <NUM> applies the drive signal for the operation of the touch sensor panel <NUM> through the touch detection device and receives the sensing signal, so that the touch pressure can be detected. Hereafter, the following description will be provided by assuming that the first electrode <NUM> is the drive electrode and the second electrode <NUM> is the receiving electrode.

For this, in the touch input device <NUM> according to the embodiment of the present invention, the drive signal may be applied to the first electrode <NUM> from the drive unit <NUM>, and the second electrode <NUM> may transmit the sensing signal to the sensing unit <NUM>. The controller <NUM> may perform the scanning of the touch sensor panel <NUM>, and simultaneously perform the scanning of the pressure detection module <NUM>, or the controller <NUM> performs the time-sharing, and then may generate a control signal such that the scanning of the touch sensor panel <NUM> is performed in a first time interval and the scanning of the pressure detection module <NUM> is performed in a second time interval different from the first time interval.

Therefore, in the embodiment of the present invention, the first electrode <NUM> and the second electrode <NUM> should be electrically connected to the drive unit <NUM> and/or the sensing unit <NUM>. Here, it is common that the touch detection device for the touch sensor panel <NUM> corresponds to the touch sensing IC <NUM> and is formed on one end of the touch sensor panel <NUM> or on the same plane with the touch sensor panel <NUM>. The pattern of the pressure electrodes <NUM> and <NUM> may be electrically connected to the touch detection device of the touch sensor panel <NUM> by any method. For example, the pattern of the pressure electrodes <NUM> and <NUM> may be connected to the touch detection device through a connector by using the second PCB <NUM> included in the display module <NUM>. For example, as shown in <FIG>, the conductive traces <NUM> and <NUM> which electrically extend from the first electrode <NUM> and the second electrode <NUM> respectively may be electrically connected to the touch sensing IC <NUM> through the second PCB <NUM>, etc..

<FIG> show an attachment method of the pressure electrode according the embodiment of the present invention. <FIG> show that the pressure electrodes <NUM> and <NUM> according to the embodiment of the present invention are attached to the bottom surface of the display module <NUM>. <FIG> show the second PCB <NUM> on which a circuit for the operation of the display panel has been mounted is disposed on a portion of the bottom surface of the display module <NUM>.

<FIG> shows that the pattern of the pressure electrodes <NUM> and <NUM> are attached to the bottom surface of the display module <NUM> such that the first electrode <NUM> and the second electrode <NUM> are connected to one end of the second PCB <NUM> of the display module <NUM>. Here, <FIG> shows that the first electrode <NUM> and the second electrode <NUM> are manufactured on the insulation layer <NUM>. The pattern of the pressure electrodes <NUM> and <NUM> is formed on the insulation layer <NUM> and may be attached as an integrated formed sheet on the bottom surface of the display module <NUM>. A conductive pattern may be printed on the second PCB <NUM> in such a manner as to electrically connect the pattern of the pressure electrodes <NUM> and <NUM> to a necessary component like the touch sensing IC <NUM>, etc. The detailed description of this will be provided with reference to <FIG>.

<FIG> shows that the pressure electrodes <NUM> and <NUM> are integrally formed on the second PCB <NUM> of the display module <NUM>. For example, when the second PCB <NUM> of the display module <NUM> is manufactured, a certain area is separated from the second PCB <NUM>, and then not only the circuit for the operation of the display panel but also the pattern corresponding to the first electrode <NUM> and the second electrode <NUM> can be printed on the area. A conductive pattern may be printed on the second PCB <NUM> in such a manner as to electrically connect the first electrode <NUM> and the second electrode <NUM> to a necessary component like the touch sensing IC <NUM>, etc..

<FIG> show how the pressure electrode is connected to the touch sensing IC <NUM> in accordance with the embodiment of the present invention. In <FIG>, the touch sensor panel <NUM> is included outside the display module <NUM>. <FIG> show that the touch detection device of the touch sensor panel <NUM> is integrated in the touch sensing IC <NUM> mounted on the first PCB <NUM> for the touch sensor panel <NUM>.

<FIG> shows that the pressure electrodes <NUM> and <NUM> attached to the display module <NUM> are connected to the touch sensing IC <NUM> through a first connector <NUM>. As shown in <FIG>, in a mobile communication device such as a smart phone, the touch sensing IC <NUM> is connected to the second PCB <NUM> for the display module <NUM> through the first connector <NUM>. The second PCB <NUM> may be electrically connected to the main board through a second connector <NUM>. Therefore, through the first connector <NUM> and the second connector <NUM>, the touch sensing IC <NUM> may transmit and receive a signal to and from the CPU or AP for the operation of the touch input device <NUM>.

Here, while <FIG> shows that the first electrode <NUM> is attached to the display module <NUM> by the method shown in <FIG>, the first electrode <NUM> can be attached to the display module <NUM> by the method shown in <FIG>. A conductive pattern may be printed on the second PCB <NUM> in such a manner as to electrically connect the first electrode <NUM> and the second electrode <NUM> to the touch sensing IC <NUM> through the first connector <NUM>.

<FIG> shows that the pressure electrodes <NUM> and <NUM> attached to the display module <NUM> are connected to the touch sensing IC <NUM> through a third connector <NUM>. In <FIG>, the pressure electrodes <NUM> and <NUM> may be connected to the main board for the operation of the touch input device <NUM> through the third connector <NUM>, and in the future, may be connected to the touch sensing IC <NUM> through the second connector <NUM> and the first connector <NUM>. Here, the pressure electrodes <NUM> and <NUM> may be printed on the additional PCB <NUM> separated from the second PCB <NUM>. Otherwise, according to the embodiment, the pattern of the pressure electrodes <NUM> and <NUM> may be formed on the insulation layer <NUM> and may be connected to the main board through the third connector <NUM> by extending the conductive trace, etc., from the pressure electrodes <NUM> and <NUM>.

<FIG> shows that the pattern of the pressure electrodes <NUM> and <NUM> are directly connected to the touch sensing IC <NUM> through a fourth connector <NUM>. In <FIG>, the pressure electrodes <NUM> and <NUM> may be connected to the first PCB <NUM> through the fourth connector <NUM>. A conductive pattern may be printed on the first PCB <NUM> in such a manner as to electrically connect the fourth connector <NUM> to the touch sensing IC <NUM>. As a result, the pressure electrodes <NUM> and <NUM> may be connected to the touch sensing IC <NUM> through the fourth connector <NUM>. Here, the pressure electrodes <NUM> and <NUM> may be printed on the additional PCB <NUM> separated from the second PCB <NUM>. The second PCB <NUM> may be insulated from the additional PCB <NUM> so as not to be short-circuited with each other. Also, according to the embodiment, the pressure electrodes <NUM> and <NUM> may be formed on the insulation layer <NUM> and may be connected to the first PCB <NUM> through the forth connector <NUM> by extending the conductive trace, etc., from the pressure electrodes <NUM> and <NUM>.

The connection method of <FIG> and <FIG> can be applied to the case where the pressure electrodes <NUM> and <NUM> are formed on the substrate <NUM> as well as on the bottom surface of the display module <NUM>.

<FIG> have been described by assuming that a chip on board (COB) structure in which the touch sensing IC <NUM> is formed on the first PCB <NUM>. However, this is just an example. The present invention can be applied to the chip on board (COB) structure in which the touch sensing IC <NUM> is mounted on the main board within the mounting space <NUM> of the touch input device <NUM>. It will be apparent to those skilled in the art from the descriptions of <FIG> that the connection of the pressure electrodes <NUM> and <NUM> through the connector can be also applied to another embodiment.

The foregoing has described the pressure electrodes <NUM> and <NUM>, that is to say, has described that the first electrode <NUM> constitutes one channel as the drive electrode and the second electrode <NUM> constitutes one channel as the receiving electrode. However, this is just an example. According to the embodiment, the drive electrode and the receiving electrode constitute a plurality of channels respectively, so that a plurality of pressure detection can be made based on the multi-touch.

<FIG> show that the pressure electrode according to the embodiment of the present invention constitutes the plurality of channels. <FIG> shows the first electrode <NUM>-<NUM> and <NUM>-<NUM> and the second electrode <NUM>-<NUM> and <NUM>-<NUM> constitute two channels respectively. <FIG> shows that the first electrode <NUM> constitutes two channels <NUM>-<NUM> and <NUM>-<NUM> and the second electrode <NUM> constitutes one channel. <FIG> shows the first electrode <NUM>-<NUM> to <NUM>-<NUM> and the second electrode <NUM>-<NUM> to <NUM>-<NUM> constitute five channels respectively.

<FIG> show that the pressure electrode constitutes a single or a plurality of channels. The pressure electrode may be comprised of a single or a plurality of channels by a variety of methods. While <FIG> do not show that the pressure electrodes <NUM> and <NUM> are electrically connected to the touch sensing IC <NUM>, the pressure electrodes <NUM> and <NUM> can be connected to the touch sensing IC <NUM> by the method shown in <FIG> and other methods.

<FIG> is a graph that, when an experiment where the central portion of the touch surface of the touch input device <NUM> according to the embodiment of the present invention is pressed by the non-conductive object is performed, represents a capacitance change amount according to a gram force of the object. As shown in <FIG>, the greater the force which is applied to the central portion of the touch surface of the touch input device <NUM> according to the embodiment of the present invention, the greater the capacitance change amount of the pattern of the pressure electrodes <NUM> and <NUM> included in the pressure detection module <NUM>.

The foregoing has described the capacitance type detection module as the pressure detection module <NUM>. However, so long as the spacer layer <NUM> and the pressure electrodes <NUM> and <NUM> are used as the pressure detection module <NUM>, the touch input device <NUM> according to the embodiment of the present is able to use any type pressure.

Although embodiments of the present invention were described above, these are just examples and do not limit the present invention. Further, the present invention may be changed and modified in various ways, by those skilled in the art. For example, the components described in detail in the embodiments of the present invention may be modified.

Claim 1:
A touch input device comprising:
a cover layer;
an organic light emitting display module (<NUM>) which comprises a polarizer layer (<NUM>, <NUM>), a first glass layer (<NUM>), and a second glass layer (<NUM>), which are disposed in the order listed, and comprises an organic light emitting material between the first glass layer (<NUM>) and the second glass layer (<NUM>);
a pressure sensor which is attached under the organic light emitting display module (<NUM>), the pressure sensor comprising a pressure electrode (<NUM>, <NUM>);
a shielding member which is located under the pressure electrode;
a spacer layer (<NUM>) formed between the organic light emitting display panel (<NUM>) and a substrate (<NUM>);
and
a plurality of drive electrodes (TX1, ..., TXn) to which a driving signal is applied and a plurality of receiving electrodes (RX1, ..., RXn) outputting a sensing signal used to detect a touch position,
wherein a magnitude of a touch pressure is detected based on a capacitance which is detected from the pressure electrode and is changed according to a distance between the pressure electrode and the shielding member,
wherein the organic light emitting display module (<NUM>) is bent by the touch, and the capacitance which is detected from the pressure electrode (<NUM>, <NUM>) changes as the organic light emitting display module (<NUM>) bends,
and wherein the pressure electrode (<NUM>, <NUM>) is located under the display module (<NUM>),
characterized in that a distance between the organic light emitting display module (<NUM>) and the substrate (<NUM>) is maintained by an adhesive tape (<NUM>) formed along the border of the upper portion of the substrate (<NUM>).