Capacitive type touch detection means and detection method

Disclosed herein are a capacitive type touch detection means and a detection method using a new scheme, which detects a touch signal using a difference between voltage magnitudes detected by a touch detector according to whether a touch is generated, when an alternating voltage is applied to a line equivalent capacitor formed between a sensing pad which is detecting a touch signal and a non-sensing pad adjacent to the sensing pad. The touch detection means includes: a sensing pad configured to generate the touch capacitance Ct between a sensing pad and the touch input means; an alternating voltage configured to be applied to a line equivalent capacitor Ceq formed between the sensing pad and a non-sensing pad adjacent to the sensing pad; and a touch detector connected to the sensing pad to detect a difference in voltage generated according to whether the touch is generated by the touch input means.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of Korean Patent Application No. 10-2013-0038160, filed on Apr. 8, 2013, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a means and a method for detecting a capacitive type touch input of a touch input means like a finger of a human body or a touch input means having a conductive property similar thereto, and more particularly, to a capacitive type touch detection means and a detection method for applying an alternating driving voltage to one side of a sensing equivalent capacitor formed between a sensing pad and a non-sensing pad and detecting a difference in voltage generated from a touch detector depending on a touch to acquire a touch signal.

Discussion of the Background

Generally, a touch screen panel is attached on display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode (OLED), an active matrix organic light emitting diode (AMOLED) and is one of the input devices which generate signals corresponding to positions where objects such as a finger and a pen are touched. The touch screen panel has been used in wide applications such as small portable terminals, industrial terminals, digital information devices (DID), etc.

Typically, various types of touch screen panels have been disclosed. However, a resistive type touch screen panel having simple manufacturing process and low manufacturing costs has been most widely used. However, since the resistive type touch screen panel has low transmittivity and is applied with a considerable pressure, the resistive type touch screen panel is inconvenient to use, has a difficulty in implementing a multi touch and a gesture cognition, leads to a detection error, etc.

On the other hand, a capacitive type touch screen panel may have high transmittivity, cognize a soft touch, and implement better multi touch and gesture cognition, and as a result has gradually expanded its market share.

FIG. 1illustrates an example of the existing capacitive type touch screen panel. Referring toFIG. 1, transparent conductive layers are formed on upper and lower surfaces of a transparent substrate2made of plastic, glass, etc., and voltage applying metal electrodes4are formed at four corners of the transparent substrate2, respectively. The transparent conductive layer is made of transparent metals such as indium tin oxide (ITO) and antimony tin oxide (ATO). Further, the metal electrodes4formed at four corners of the transparent conductive layer are formed by being printed with conductive metal having low resistivity such as silver Ag. A resistance network is formed around the metal electrodes4. The resistance network is formed in a linearization pattern to equally send out a control signal to the whole surface of the transparent conductive layer. Further, an upper portion of the transparent conductive layer including the metal electrode4is coated with a passivation layer.

In the capacitive type touch screen panel as described above, a high-frequency alternating voltage is applied to the metal electrode4and thus is applied over the whole surface of the transparent substrate2. In this case, when the transparent conductive layer on an upper surface of the transparent substrate2is lightly touched with a finger8or a conductive touch input means, a change in current is sensed by a current sensor embedded in a controller6while a predetermined amount of current is absorbed into a body and current amounts at each of the four metal electrodes4are calculated, thereby cognizing touched points.

However, the capacitive type touch screen panel as illustrated inFIG. 1is based on a method for detecting a magnitude of micro current. As a result, the capacitive type touch screen panel needs an expensive detection apparatus and therefore a price of the capacitive type touch screen panel goes up as well as the capacitive type touch screen panel is hard to implement a multi touch for cognizing a plurality of touches.

To overcome the above problems, the capacitive type touch screen panel as illustrated inFIG. 2has been mainly used in recent years. The touch screen panel ofFIG. 2is configured to include a lateral linear touch detection sensor5a, a longitudinal linear touch detection sensor5b, and a touch drive IC7analyzing a touch signal. The touch screen panel is based on a method for detecting a magnitude of capacitance formed between the linear touch detection sensor5and the finger8(FIG. 1) and scans the lateral linear touch detection sensor5aand the longitudinal linear touch detection sensor5bto detect a signal, thereby cognizing the plurality of touched points.

However, when the touch screen panel as described above is installed on a display device such as an LCD, the touch screen panel is hard to detect the signal due to noise. For example, the LCD uses a common electrode. In some cases, an alternating common voltage Vcom is applied to the common electrode. Further, the common voltage Vcom of the common electrode acts as noise at the time of detecting the touched point.

FIG. 3illustrates an embodiment in which the existing capacitive type touch screen panel is installed on the LCD. A display device200has a structure in which a liquid crystal is sealed between a TFT substrate205and a color filter215disposed thereover to form a liquid crystal layer210. To seal the liquid crystal, outer portions of the TFT substrate205and the color filter215are bonded to each other by a sealant230. Although not illustrated, polarizing plates are attached to upper and lower portions of a liquid crystal panel and back light units (BLUs) are additionally installed thereto.

As illustrated, the touch screen panel is installed on the display device200. The touch screen panel has a structure in which the linear touch detection sensor5is put on the substrate1. A protection panel3for protecting the linear touch detection sensor5is attached on the substrate1. The touch screen panel is bonded to an edge portion of the display device200by an adhesive member9such as a double adhesive tape (DAT) and forms an air-gap9abetween the adhesive member9and the display device200.

In this configuration, when a touch is generated as illustrated inFIG. 3, a capacitance such as Ct is formed between the finger8and the linear touch detection sensor5. However, as illustrated, a capacitance such as common electrode capacitance Cvcom is formed between the linear touch detection sensor5and a common electrode220formed on a lower surface of the color filter215of the display device200and an unknown parasitic capacitance Cp is also applied to the linear touch detection sensor5due to a capacitance coupling between patterns, manufacturing process factors, etc. Therefore, a circuit like an equivalent circuit ofFIG. 4is configured.

Here, the existing touch screen panel detects a variation of Ct which is a touch capacitance to cognize a touch and components such as Cvcom and Cp act as noise in detecting the Ct. In particular, the Cp by the capacitance coupling between the patterns is ten times as large as the Ct which is the touch capacitance, and therefore touch sensitivity may be degraded due to the Cp.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a capacitive type touch detection means and a detection method capable of minimizing an effect of parasitic capacitance and stably acquiring a touch signal, by applying an alternating driving voltage to one side of a sensing equivalent capacitor which is formed between a sensing pad connected to a touch detector and a non-sensing pad adjacent to the sensing pad and typically acts as a parasitic capacitor and acquiring a touch signal using the phenomenon that a difference in a magnitude of voltage detected by the touch detector occurs in response to a magnitude in touch capacitance, when the touch capacitance is formed between a touch input means such as a finger and the sensing pad.

As described above, a characteristic configuration of present invention is as follows for achieving the above objects of the present invention and specific effects of the present invention.

According to an exemplary embodiment of the present invention, there is provided a touch detection means including: a plurality of touch detection sensors; a plurality of sensor signal lines configured to apply a signal to the touch detection sensor or receive a signal acquired from the touch detection sensor; and a touch detector14configured to detect whether a touch is generated by a touch input means based on the acquired signal, wherein the touch detection sensor is classified into at least one sensing pad and at least one non-sensing pad and the generation of the touch is detected based on a change in voltage in a plurality of equivalent capacitors Ceq which are formed between at least one sensing pad sensor signal line connected to the sensing pad and at least one non-sensing pad sensor signal line connected to the non-sensing pad.

The generation of the touch may be detected in a state in which an alternating voltage is applied to the equivalent capacitor and the alternating voltage is applied through the non-sensing pad sensor signal line.

The touch detection means may further include: a three-terminal switching device configured to be a charging means for charging the touch detection sensor prior to detecting whether the touch is generated, wherein the three-terminal switching device supplies a charging signal input to an input terminal by a control signal supplied to a control terminal to the touch detection sensor connected to an output terminal to charge the touch detection sensor.

The input terminal may keep a high impedance state which is equal to or more than 100 Kohm and the output terminal may keep a high impedance state which is equal to or more than 100 Kohm when the touch detector detects whether the touch is generated.

A charging time may be determined by adjusting a turn on time of the control signal of the three-terminal switching device.

The equivalent capacitor may be classified into at least one of a first capacitance between lines and a second capacitance between lines depending on a magnitude of a capacitance of the equivalent capacitor.

The touch detection means may further include: prior to detecting whether the touch is generated, a charging means configured to charge the first capacitance between lines and the second capacitance between lines with a precharge signal having the same voltage.

The second capacitance between lines may be larger than the first capacitance between lines.

The second capacitance between lines and the first capacitance between lines may vary by adjusting a distance between the sensing pad sensor signal line and the non-sensing pad sensor signal line.

The touch may be detected by using only any one of the first capacitance between lines and the second capacitance between lines at the time of detecting whether the touch is generated.

When the generation of the touch is detected using the first capacitance between lines, the non-sensing pad sensor signal line participating in the formation of the second capacitance between lines may keep a floating state or the high impedance state.

The touch detection sensor, the sensing pad sensor signal line, and the non-sensing pad sensor signal line may be formed using the same mask.

A width of the sensor signal line may be differently formed depending on a position of the touch detection sensor.

An alternating voltage may be applied to the equivalent capacitor after the touch detection sensor is charged.

The touch detection means may further include: a means configured to change the magnitude in alternating voltage.

The touch detection means may further include: a means configured to change a gradient of a rising edge or a falling edge of the alternating voltage.

The touch detection means may further include: a touch capacitor Ct configured to be formed by the touch detection sensor and the touch of the touch input means; and a common electrode capacitor Cvcom configured to be formed between the touch detection sensor and the common electrode applying the common voltage to a display device including the touch detection sensor.

When the touch is not sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 1.

The following Equation 1 may be

In the above Equation 1, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Cvcom may represent the capacitance of the common electrode capacitor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

When the touch is sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 2.

The following Equation 2 may be

In the above Equation 2, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Cvcom may represent the capacitance of the common electrode capacitor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The determination on whether the touch is generated by the touch detector may be based on a difference between the voltage acquired by the above Equation 1 and the voltage acquired by the above Equation 2.

The above Equation 1 may be

Vsensornontouch=Vpre+(Vh-Vl)⁢CeqCeq+Cvcom+Cp
and the above Equation 2 may be

In the above Equations 1 and 2, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Cvcom may represent the capacitance of the common electrode capacitor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The touch detection sensors may be arranged in an array and the touch detector may detect signals in each row.

The touch detection means may further include: a compensation capacitor configured to compensate for a difference between the first capacitance between lines and the second capacitance between lines.

One side of the compensation capacitor may be connected to the touch detector and may receive the same alternating voltage as the alternating voltage through the other side of the compensation capacitor.

One side of the compensation capacitor may be connected to the touch detector and may receive the alternating voltage different from the alternating voltage through the other side of the compensation capacitor.

When the touch is not sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 5.

The following Equation 5 may be

In the above Equation 5, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor Cba1, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

When the touch is sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 6.

The following Equation 6 may be

In the above Equation 6, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor Cba1, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The determination on whether the touch is generated by the touch detector may be based on a difference between the voltage acquired by the above Equation 5 and the voltage acquired by the above Equation 6.

The above Equation 5 may be

Vsensornontouch=Vpre+(Vh+Vl)⁢Ceq+CbalCeq+Cabl+Cvcom+Cp
and the following Equation 6 may be

In the above Equations 5 and 6, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor Cba1, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The touch detector may detect whether the touch is generated in synchronization with a rising edge of the alternating voltage or a falling edge of the alternating voltage.

The touch detector may detect whether the touch is generated at a predetermined time interval from the rising edge of the alternating voltage or the falling edge of the alternating voltage.

An alternating voltage generator generating the alternating voltage may have a pen shape and the generated alternating voltage may be transferred through a lead of the pen.

Bonded parts between the touch detection sensors may face each other, having a geometrical shape having at least one inflection point or flexural part.

The touch detection sensor may be partitioned into a plurality of areas, only a part of the partitioned areas may be provided with predetermined patterns, and the formed patterns may be connected to each other.

A width of the sensor signal line may be formed to be wide when the sensor signal line passes through a BM part of a display device.

According to another exemplary embodiment of the present invention, there is provided a touch detection method including: charging a plurality of touch detection sensors with a predetermined charging voltage using a three-terminal switching device; classifying the plurality of touch detection sensors into at least one sensor pad and at least one non-sensing pad; forming a plurality of equivalent capacitors Ceq between at least one sensing pad sensor signal line connected to the sensing pad and at least one non-sensing pad sensor signal line connected to the non-sensing pad; and applying an alternating voltage to the equivalent capacitor through the non-sensing pad sensor signal line by a touch detector and detecting a touch based on a change in voltage generated in the equivalent capacitor according to whether the touch is generated by the touch input means.

The classification of the sensing pad and the non-sensing pad may be sequentially determined based on a defined order.

The touch detector may detect whether the touch is generated in synchronization with a rising edge of the alternating voltage or a falling edge of the alternating voltage.

The touch detector may detect whether the touch is generated at a predetermined time interval from the rising edge of the alternating voltage or the falling edge of the alternating voltage.

The three-terminal switching device may supply a charging signal input to an input terminal by a control signal supplied to a control terminal to the touch detection sensor connected to an output terminal to charge the touch detection sensor.

The input terminal may keep a high impedance state which is equal to or more than 100 Kohm and the output terminal may keep a high impedance state which is equal to or more than 100 Kohm when the touch detector detects whether the touch is generated.

A charging time may be determined by adjusting a turn on time of the control signal of the three-terminal switching device.

The equivalent capacitor may be classified into at least one of a first capacitance between lines and a second capacitance between lines depending on a magnitude of a capacitance of the equivalent capacitor.

The touch detection method may further include: prior to detecting whether the touch is generated, charging the first capacitance between lines and the second capacitance between lines with a precharge signal having the same voltage.

The second capacitance between lines may be larger than the first capacitance between lines.

The second capacitance between lines and the first capacitance between lines may vary by adjusting a distance between the sensing pad sensor signal line and the non-sensing pad sensor signal line.

The generation of the touch may be detected by using only any one of the first capacitance between lines and the second capacitance between lines at the time of detecting whether the touch is generated.

When the generation of the touch is detected using the first capacitance between lines, the non-sensing pad sensor signal line participating in the formation of the second capacitance between lines may keep a floating state or the high impedance state.

The touch detection sensor, the sensing pad sensor signal line, and the non-sensing pad sensor signal line may be formed using the same mask.

A width of the sensor signal line may be differently formed depending on a position of the touch detection sensor.

The touch detection method may further include: changing the magnitude in alternating voltage.

The touch detection method may further include: changing a gradient of a rising edge or a falling edge of the alternating voltage.

When the touch is not sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 1.

The following Equation 1 may be

In the above Equation 1, Vsensornontouchmay represent the voltage detected by the touch detector when the touch is not made, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, V; may represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

When the touch is sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 2.

The following Equation 2 may be

In the above Equation 2, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The determination on whether the touch is generated by the touch detector may be based on a difference between the voltage acquired by the above Equation 1 and the voltage acquired by the above Equation 2.

The above Equation 1 may be

Vsensornontouch=Vpre+(Vh-Vl)⁢CeqCeq+Cvcom+Cp
and the above Equation 2 may be

In the above Equations 1 and 2, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The touch detection sensors may be arranged in an array and the touch detector may detect signals in each row.

The touch detection method may further include: compensating for a difference between the first capacitance between lines and the second capacitance between lines.

One side of the compensation capacitor may be connected to the touch detector and may receive the same alternating voltage as the alternating voltage through the other side of the compensation capacitor.

One side of the compensation capacitor may be connected to the touch detector and may receive the alternating voltage different from the alternating voltage through the other side of the compensation capacitor.

When the touch is not sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 5.

The following Equation 5 may be

In the above Equation 5, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor Cba1, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

When the touch is sensed by the touch detection sensor, the voltage sensed by the touch detector may be calculated by the following Equation 6.

The following Equation 6 may be

In the above Equation 6, Vsensortouchmay represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor Cba1, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

The determination on whether the touch is generated by the touch detector may be based on a difference between the voltage acquired by the above Equation 5 and the voltage acquired by the above Equation 6.

The above Equation 5 may be

Vsensornontouch=Vpre+(Vh-Vl)⁢Ceq+CbalCeq+Cabl+Cvcom+Cp
and the above Equation 6 may be

In the above Equations 5 and 6, Vsensornontouchmay represent the voltage detected by the touch detector14when the touch is not made, Vsensortouch, may represent the voltage detected by the touch detector14when the touch is generated, Vpremay represent a charging voltage of the touch detection sensor, Vhmay represent a high level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor, Vlmay represent a low level voltage of the alternating voltage applied to the non-sensing pad sensor signal line and the compensation capacitor Cba1, Cvcom may represent the capacitance of the common electrode capacitor formed between the touch detection sensor and the common electrode applying the common voltage to the display device including the touch detection sensor, Cp may represent a parasitic capacitance generated by the touch detection means, Ct may represent the capacitance of the touch capacitor formed by the touch detection sensor and the touch of the touch input means, a polarity of Vh-Vlmay be positive when the alternating voltage alternates from low to high, and the polarity of Vh-Vlmay be negative when the alternating voltage alternates from high to low.

An alternating voltage generator generating the alternating voltage may have a pen shape and the generated alternating voltage may be transferred through a lead of the pen.

Bonded parts between the touch detection sensors may face each other, having a geometrical shape having at least one inflection point or flexural part.

The touch detection sensor may be partitioned into a plurality of areas, only a part of the partitioned areas may be provided with predetermined patterns, and the formed patterns may be connected to each other.

A width of the sensor signal line may be formed to be wide when the sensing pad sensor signal line and the non-sensing pad sensor signal line pass through a BM part of a display device.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

First, the present invention relates to a capacitive type touch detection means and a detection method. The existing touch detection means is based on a method for detecting a magnitude of capacitance by a touch by a finger, while the present invention is based on a method for detecting a touch using the phenomenon that a difference in detection voltage due to a difference in magnitude of added touch capacitance occurs, when an alternating driving voltage is applied to a sensing equivalent capacitor formed between a sensing pad (pad connected to a touch detector) which is detecting a touch and a non-sensing pad (pad which is not connected to the touch detector as a pad corresponding to the sensing pad) adjacent to the sensing pad. A touch detection system according to the embodiment of the present invention compares a magnitude of voltage detected when a touch is not generated and a magnitude of a voltage detected when a touch capacitance is added by the generation of the touch and detects a touch based on a difference between the magnitudes of two voltages, thereby minimizing an effect due to a parasitic capacitance, etc., and more stably acquiring a touch signal.

A display device mentioned in the present invention is any one of LCD, PDP, and OLED or includes all means which displays any type of still pictures (for example, JPG, TIF, etc.) or moving pictures (MPEG2, MPEG-4, etc.) to other users.

Among the above listed display devices, the LCD requires a common voltage Vcom to drive a liquid crystal. For example, a small and medium portable LCD uses a line inversion scheme in which a common voltage of a common electrode alternates in one line or each of the plurality of gate lines, to thereby reduce current consumption. As another example, a large LCD uses a dot inversion driving scheme in which a common voltage of a common electrode has a constant DC level. As another example, an in-plane switching mode LCD displays an image by a line inversion or a dot inversion driving scheme in which a common electrode is formed in a part of an area of an LCD TFT substrate. In the case of the in-plane switching mode LCD, a back ground is commonly formed over the whole of a color filter which is exposed to the outside through a back indium tin oxide and is grounded to a ground signal to cut off electrostatic discharge (ESD).

According to the embodiment of the present invention, in addition to the electrode to which the common voltage Vcom is applied as described above, all electrodes commonly acting within the display device are referred to as the “common electrode” and an alternating voltage or a DC voltage applied to the common electrode of the display device or a voltage alternating at a unspecific frequency is referred to as a “common voltage”.

The present invention detects a non-contact touch input of a finger or a touch input means having electrical characteristics similar thereto. Here, the “non-contact touch input” means that the touch input means such as a finger performs the touch input in a state in which the touch input means is spaced apart from a touch detection sensor at a predetermined distance by a substrate present between the input means and the touch detection sensor. The touch input means may contact an outer surface of the substrate. However, even in this case, the touch input means and the touch detection sensor keep a non-contact state. Therefore, a touch behavior of a finger to the touch detection sensor may be expressed by the term “access” Meanwhile, since the finger is in contact with the outer surface of the substrate, the touch behavior of the finger to the substrate may be expressed by the term “contact”. In the present specification, the “access” and the “contact” are commonly used.

According to the present invention, the touch input means includes any type of inputs (for example, object like a conductor having a predetermined form or input like an electromagnetic wave, etc.) which leads to a change in voltage which may be sensed by a key board, a mouse, a finger, a touch pen, a stylus pen, and a touch detection sensor).

Further, components such as “˜unit” described to be below are a set of unit function elements performing specific functions. For example, an amplifier for any signal is a unit function element and a set of amplifiers or signal converters may be named a signal conversion unit. Further, the “˜unit” may be included in an upper-level component or another “˜unit” or may include lower-level components and other “˜units”. Further, the “˜unit” itself may include an operation function or the “˜unit” includes an independent central processing unit (CPU) which may process commands, etc., stored in a memory, etc.

In the following drawings, to clearly represent layers and regions, a thickness or a region is exaggerated in the drawings for clarity. Like reference numerals designate like elements throughout the specification. Provided that parts such as a layer, an area, and a substrate are present “on” another part or “upper surface”, this means that these parts are disposed “just on another part (there is no another part therebetween)” and these parts have another part (for example, medium layer or insulating layer) disposed therebetween.

Further, a “signal” described in the present specification is collectively referred to as a voltage or a current unless specially indicated.

Further, in the present specification, “capacitance” represents a physical magnitude and is used as the same meaning with “electrostatic capacity”. Meanwhile, a “capacitor” is referred to as an element having a capacitance which represents a physical magnitude. In the present invention, a compensation capacitor Cba1may be manufactured by a manufacturing process based on a designed value like being manufactured inside a touch drive integrated circuit (IC) and may be naturally generated like a capacitor between lines in the present specification which is manufactured between two sensor signal lines in parallel with each other at any distance. In the present specification, both a capacitor directly manufactured and a capacitor naturally formed are named “capacitor” without division.

In the present specification, sign C used as a sign of a capacitor is used as a signal representing a capacitor and represents a capacitance which is a magnitude of the capacitor. For example, C1is a sign representing a capacitor and a capacitance which is the magnitude of the capacitor means C1.

Further, in the present specification, the meaning “forcing a signal” means that a level of a signal keeping any state is changed. For example, forcing a signal to an on/off control terminal of a switching device means that the existing low level voltage (for example, ground voltage (0 v) or DC voltage and AC voltage having a predetermined magnitude) is changed to a high (Hi) level (for example, DC voltage or AC voltage having an amplitude value larger than the low level voltage).

Further, in the present specification, a touch detection sensor10(FIG. 9 or 12) includes a sensing pad10a(FIG. 9 or 12) and a non-sensing pad10b(FIG. 9or12). The sensing pad10ais the touch detection sensor10connected to a touch detector14(FIG. 9 or 12) to detect a touch, among the plurality of touch detection sensors10and the non-sensing pad10bis the touch detection sensor10which is not connected to the touch detector14without performing the touch detection. After completing the touch detection, the sensing pad10abecomes the non-sensing pad10band any non-sensing pad10bis converted into the sensing pad10adepending on a previously defined order. Therefore, the sensing pad and the non-sensing pad are not fixed and may be converted over time and a conversion order of each sensing pad and each non-sensing pad may be sequentially determined based on a previously defined order. A time sharing technique is an embodiment defining an ordering.

Further, in the present specification, detecting the touch or detecting the touch signal has the same meaning. A representative embodiment of the touch signal detection detects a difference between a first voltage detected by the touch detector when the conductor like a finger does not contact or access the touch detection sensor10and thus a touch capacitance is not formed and a second voltage detected by the touch detector based on a touch capacitance Ct formed when a conductor such as a finger is opposite to the touch detection sensor.

Further, in the present specification, a TDI stands for a touch drive IC.

Further, in the present specification, a precharge and charging and a precharge voltage and a charging voltage are used as the same meaning.

Further, the sensing pad may mean including a sensor signal line connecting between the sensing pads unless specially indicated in the present specification and the non-sensing pad may mean a non-sensing pad signal line connecting between the non-sensing pads unless specially indicated in the present specification.

FIG. 6is a diagram conceptually illustrating a three-terminal switching device used as one example of a capacitor charging means in the present invention. Referring toFIG. 6, the three-terminal switching device generally includes three terminals of an on/off control terminal Cont, an input terminal In, and an output terminal Out. The on/off control terminal Cont is a terminal controlling a turn on/turn off of the switching device. In this case, when a voltage or a current having a predetermined magnitude is applied to the on/of control terminal Cont, a voltage or a current applied to the input terminal In is output to the output terminal Out as a voltage or current form.

Prior to describing the detailed embodiment of the present invention, a principle of forming a touch capacitance and a capacitance between lines will be briefly described with reference toFIG. 7. In the example ofFIG. 7, suppose that the touch detection sensor10and the finger25are spaced apart from each other at an interval of “d” and have an opposing area (or opposing contact area) called “A” when the finger25or the conductive touch means (for example, capacitive type touch pen) similar thereto approaches the touch detection sensor10. Then, as illustrated in the right equivalent circuit ofFIG. 7and Equation C=(eA)/D, a capacitance “C” is formed between the finger25and the touch detection sensor10. In the present specification, the capacitance formed between the finger25and the touch detection sensor10is called the touch electrostatic capacity or the touch capacitance Ct.

Further, when instead of the finger25and the touch detection sensor10, two parallel signal lines are spaced apart from each other at the interval of “d” and have the opposing area called “A” in the example ofFIG. 7, the capacitance between lines C illustrated in the equivalent circuit ofFIG. 7and Equation C=(eA)/D is also formed between the two signal lines. When the signal line is made of ITO or a metal material, a value obtained by multiplying a coated thickness of the material by an opposing length of the two signal lines becomes the opposing area of two parallel signal lines and a spaced degree between the two opposing signal lines becomes a spaced distance. In the present invention, an optically clear adhesive (OCA) or an air layer is formed between the two signal lines and therefore in the Equation C=(eA)/D ofFIG. 7, as permittivity (e), permittivity of the OCA or the air may be applied.

FIG. 8is a circuit diagram illustrating a basic structure of a touch detection means according to an embodiment of the present invention. Referring toFIG. 8, a specialized touch detection means according to the embodiment of the present invention has a basic structure configured of the charging means12, the touch detection sensor10, the sensor signal line22, a common electrode capacitor Cvcom, a stray capacitance capacitor Cp, and the touch detector14.

The charging means12is a switching device supplying Vpre, which is a precharge signal (or charging signal), to all capacitors connected to the touch detector14and turned off depending on a turn off signal applied to an “on/off control terminal” called “Cont” to make an output terminal12-1high impedance, a linear device such as an operational amplifier (AMP) supplying a signal depending on a control signal, etc.

When as the charging means12, the three-terminal switching device is used as illustrated in an embodiment ofFIG. 8, the appropriate charging voltage may be supplied to all capacitors connected to the output terminal12-1of the charging means12at a required timing by using the control signal supplied to the on/off control terminal and the signal Vpresupplied to the input terminal12-2. As the charging voltage, a direct current (DC) voltage including zero volt or an AC voltage alternating like a square wave, a triangular wave, or a sine wave or a voltage having a form (for example, DC voltage of a first period and AC voltage of a second period are repeated (total period=first period+second period). Here, the first period and the second period may be the same or different) in which the DC voltage and the AC voltage are combined with each other may be used.

The touch detection sensor10(FIG. 9 or 12) is configured to include the sensing pad10a(FIG. 9 or 12) which is connected to the touch detector14(FIG. 9 or 12) to detect the touch signal and the non-sensing pad10b(FIG. 9 or 12) which is not connected to the touch detector14not to detect the touch signal. The sensing pad10aand the non-sensing pad10bare not fixed and the same touch detection sensor10may be switched into time sharing (the sensing pad is switched into the non-sensing pad after a predetermined time interval). The touch detection sensor10which is connected to the touch detector14for touch detection is referred to as the sensing pad10aand the touch detection sensor10which is not connected (or is spaced) to the touch detector14is referred to as the non-sensing pad10b. Therefore, the touch detection sensor10is classified into the sensing pad or the non-sensing pad depending on whether one touch detection sensor10is connected to the touch detector14.

Suppose that in the embodiment ofFIG. 8, one touch detection sensor10is sequentially the sensing pad and the remaining touch detection sensors10is the non-sensing pad. The touch detection sensor10marked by “PC” is operated as the sensing pad10aand all the remaining touch detection sensors10are operated as non-sensing pads PA, PB, PD, PE, PF, PG, PH, PI, and PJ. The touch detection sensor marked by “PB” serves as the sensing pad before the sensing pad marked by “PC” is operated and the touch detection sensor marked by “PD” may be converted from the non-sensing pad into the sensing pad after the sensing pad marked by “PC” is operated. As such, the conversion into the sensing pad and the non-sensing pad of the touch detection sensor10is performed by the control of the timing controller33ofFIG. 13to be described below. As the embodiment of the method for detecting a touch signal using one sensing pad ofFIG. 8and another embodiment of the method for detecting a touch signal, the plurality of touch detection sensors may be operated simultaneously as the sensing pad.

InFIG. 8, when the precharge voltage Vpreis applied to the sensing pad signal line22aand the sensing pad10ahaving a sign of PC and any voltage VLb1having a predetermined potential difference from the Vpreis connected to the non-sensing pad which is adjacent to the sensing pad10aand has a sign of PB, PD, and PF and the non-sensing pad signal lines22b-B,22b-D, and22b-F connected to the non-sensing pad, the capacitance is formed between the sensing pad10aand the non-sensing pad22bbased on the principle described inFIG. 7.

Describing in detail, since the Vprehaving a predetermined potential is applied to the sensing pad signal line22aand the sensing pad10aand the non-sensing pad signal line22b-B connected to the VLb1has the predetermined opposing distance and opposing area from the sensing pad signal line22a, the capacitance between lines C1is formed between the non-sensing pad signal line22b-B and the sensing pad signal line22aby the principle described inFIG. 7, the capacitance between lines C2is formed between the sensing pad signal line22aand the non-sensing pad signal line22b-D by the same principle, and the capacitance between lines C3is formed between the sensing pad (PC)10aand the non-sensing pad signal line22b-F opposite thereto by the same principle.

Referring to <Equation 1> or <Equation 2> to be described below, typically, the capacitance between lines acts as the parasitic capacitance Cp and thus acts as noise which reduces the touch sensitivity. However, the present invention reversely uses the capacitance between lines to detect the touch signal to reduce the Cp in Equations obtaining the voltage detected by the touch detector, to thereby improve the touch sensitivity and the present invention positions the capacitance between lines, which is the reduced Cp, at a numerator of the Equation obtaining the voltage detected by the touch detector to have a plurality of sensitivity improvement effects which improve the touch sensitivity.

Meanwhile, even the non-sensing pad signal line22b-B is present between the sensing pad signal line22aand the non-sensing pad signal line22b-A like C4, the capacitance between lines may be formed. In the present specification, the case in which the capacitance between lines is formed between the sensing pad signal line22aand the non-sensing pad signal line like C1to C3is defined as a primary capacitance between lines and the capacitance formed in the state in which one or a plurality of non-sensing pad signal lines are formed between the sensing pad signal line22aand the non-sensing pad signal line like C4is defined as a secondary capacitance between lines.

Therefore, a plurality of secondary capacitance between lines may be formed between the sensing pad10aand the sensing pad signal line22a. When the secondary capacitance between lines are used for the touch detection, the touch sensitivity is improved and therefore all the non-sensing pad signal lines for forming the secondary capacitance between lines is preferably connected to the VLb1used to form the primary capacitance between lines. The non-sensing pad signal line for forming the secondary capacitance between lines may be connected to a potential different from the VLb1but preferably commonly uses the VLb1to simplify a circuit.

When the simplification of the circuit or the touch sensitivity is much better than expected, the non-sensing pad signal line (signal lines22b-A or22b-E in the embodiment ofFIG. 8) generating the secondary capacitance between lines may keep a floating or high impedance state to weaken the touch sensitivity, such that the secondary capacitance between lines does not occur between the floated non-sensing pad signal line and sensing pad signal line. A touch drive IC (TDI) generates the secondary capacitance between lines and has a means for determining whether the sensing pad signal line22aand the non-sensing pad signal line22badjacent thereto are connected to each other at a predetermined potential or are kept in the floating or high impedance state. The voltage VLb1connected to the non-sensing pad signal line22bis a DC potential or an AC voltage which includes zero (0) V.

In the present specification, the term “closed” is also applied to the non-sensing pad signal line forming the primary capacitance between lines and is also applied to the non-sensing pad signal line forming the secondary capacitance between lines, based on the sensing pad signal line.

The sensing pad10ais commonly connected to the primary capacitance between lines C1to C3and the secondary capacitance between lines, and therefore all of them may be represented by one equivalent capacitor. If the equivalent capacitor is the equivalent capacitor between lines Ceq, this may be represented by the equivalent circuit as illustrated inFIGS. 8 and 9.

Meanwhile, the equivalent capacitor between lines Ceq has the following features.

1. The longer the opposing length of the opposing sensor signal lines22aand22b, the wider the opposing area becomes, such that the equivalent capacitance between lines Ceq is more increased. As a result, as the sensing pad10ais at a longer distance in the TDI, the equivalent capacitance between lines Ceq is getting larger.

2. It is possible to adjust the magnitude of the equivalent capacitance between lines Ceq depending on the opposing distance of the opposing sensor signal lines22aand22b. The opposing distance is a width between the opposing sensor signal lines22aand22b, and therefore the magnitude of the equivalent capacitance between lines Ceq may be changed depending on the design.

Referring toFIG. 9, the equivalent capacitor between lines Ceq is formed between the sensing pad10aand the non-sensing pad10badjacent thereto and the non-sensing pad10bis connected to any voltage VLb1.

InFIG. 9, the non-sensing pad10band the non-sensing pad signal line22bare represented by one equivalent non-sensing pad10band one equivalent non-sensing pad signal line22b, instead of a plurality of non-sensing pads and a plurality of non-sensing pad signal lines forming the primary capacitance and the secondary capacitance. InFIG. 8, all the non-sensing pad signal lines22bother than the sensing pad10aare connected to the predetermined voltage VLb1, and therefore inFIG. 9, the voltage VLb1is connected to the non-sensing pad signal line22b. Therefore, although one non-sensing pad signal line22bis connected to the VLb1inFIG. 9, the plurality of non-sensing pad signal lines generating the primary or secondary capacitance between lines are substantially connected to the VLb1. The VLb1is a voltage applied to one side of the non-sensing pad signal line22bwhen the precharge voltage Vpreis applied and is a voltage for forming the equivalent capacitance between lines Ceq by the precharge. An alternating voltage is applied to the non-sensing pad signal line22bto detect the touch signal and the VLb1includes a low voltage or a high voltage which is the alternating voltage.

The output terminal12-1of the charging means12and all the capacitors connected to the output terminal12-1are connected to the touch detector14. The buffer14-1is one of the components configuring the touch detector14and the input terminal has high impedance (Hi-z) characteristics. When the output terminal12-1of the charging means12is connected to the Hi-z input terminal of the touch detector in the Hi-z state, all the capacitors Ceq, Ct, Cvcom, and Cp connected between the output terminal12-1of the charging means and the buffer14-1are also in the Hi-z state.

Although described below, the magnitude of the Ceq is different depending on the length of the sensing pad signal line22aconnecting the sensing pad10a, and therefore the charging time is also different depending on the position of the sensing pad. When the charging time is determined based on one fixed time, the charging time cannot but be determined as the longest time, which leads to the problem in that the touch detection time may be slow. Therefore, the TDI has a means to determine the charging time. The charging time is determined as the turn-on time of the charging means12.

FIG. 9illustrates that the output terminal12-1of the charging means12is directly connected to the buffer14-1, but all the devices of which the inputs are in the Hi-z state, like a gate of a metal oxide semiconductor (MOS), a gate of a thin film transistor (TFT), or the like may be used instead of the buffer14-1. The reason of making the output terminal12-1of the charging means12and the touch detector14in the Hi-z state is that since no discharge path for charge isolated in the Hi-z state is present, such that the magnitude of voltage formed at point P ofFIG. 9is kept long, it is easy to relatively accurately detect the magnitude of voltage.

The signal output from the buffer14-1is input to the amplifier14-2. Depending on whether the touch is generated, when the variation of the voltage detected at the point P ofFIG. 9is small, it is preferable to amplify the signal using the amplifier14-2. The amplifier may use a DAC14-3which is generated using a reference voltage14-4.

Further, the signal which is detected and amplified by the touch detector14may pass through an ADC converter14-5to be transferred to the signal processor35ofFIG. 13. One or a plurality of ADC converters14-5may be used. When the plurality of ADC converters14-5are used, the signal processing may be more quickly made.

Although not illustrated inFIG. 9, a filter may be used among several function units which are displayed in the touch detector14. For example, a filter may also be used in a previous stage of the buffer14-1and a filter may be used in a previous stage of the amplifier14-2or some of the components of the amplifier. As the filter, various filters such as a bandwidth low pass filter, a bandwidth high pass filter, a grass cut filter (GCF), a ranking filter, and an average filter using chopping may be used.

The touch detection sensor10is made of a transparent conductor or metal. When the touch detection sensor10is installed on a display device and is made of a transparent conductor, the transparent conductor may be transparent conductive materials such as indium tin oxide (ITO), antimony tin oxide (ATO), carbon nano tube (CNT), and indium zinc oxide or transparent materials having conductive properties similar thereto. If the touch detection sensor10is used as touch keyboard which is not used along with the display device and a touch key of a refrigerator or a monitor, the touch detection sensor10may also be made of a non-transmitting material such as metal.

The sensor signal line22is a signal line which connects polarity of the touch capacitance formed when the touch means such as a finger25approaches the touch detection sensor10to the touch detector14and uses the same mask as the touch detection sensor10and may be made of a transparent conductive material. In some case, the sensor signal line22uses a different mask from the touch detection sensor10and may also be made of a non-transmitting material such as metal. The magnitude of resistance of the sensor signal line22is represented by Rt and the magnitude of resistance of the non-sensing pad10bis represented by Rnt.

The resistance components act as a factor of generating a delay of a signal at the time of the detection of the touch signal. Therefore, the smaller the magnitude of the resistance component, the better becomes. Therefore, to reduce the resistance, the width of the sensor signal line22connected to the touch detection sensor10which is disposed at a long distance in the TDI is preferably wide. The width of the sensor signal line22of the touch detection sensor10which is disposed at a short distance in the TDI is narrow, and thus an absolute resistance value is small even though the resistance is increased. Therefore, it is preferable to make the width of the path through which the sensor signal lines pass narrow by making the width of the sensor signal line22of the touch detection sensor10at a shorter distance in the TDI narrow. As such, according to the present invention, the width of the sensor signal lines may be differently formed depending on the position of the touch detection sensor10.

The common electrode capacitor Cvcom ofFIGS. 8 and 9is a capacitance formed when the touch detection sensor10is opposite to the common electrode of the display device and one side thereof is connected to the touch detector14and the other side thereof is connected to the common voltage of the display device. In this case, the common electrode capacitor is applied by being directly connected to the common voltage of the display device, but the common electrode capacitor (Cvcom) is generally electromagnetically induced through medium such as glass or air.

Referring back toFIG. 9, when the finger25of the human body approaches the touch detection sensor10at a predetermined interval, the touch capacitance called “Ct” is formed between the finger25and the touch detection sensor10. The Ct is a value set by the relation Equation C=(eA)/d ofFIG. 7and may be controlled by controlling the interval, the opposing area, etc., of the touch means such as the finger25and the touch detection sensor10. For example, as the area of the touch detection sensor10is increased, the Ct is also increased depending on the relation Equation ofFIG. 7. On the contrary, as the area of the touch detection sensor10is reduced, the Ct is reduced. According to one embodiment, the Ct may be designed from several femto Farada (fF) to tens of micro Farad (uF).

The Cp ofFIG. 9is a parasitic capacitor and is an equivalent circuit of the parasitic capacitors which are formed by a wire bonding between a semiconductor and a package which are formed in the TDI or configure the TDI. The parasitic capacitor may be configured of the plurality of parasitic capacitors Cp of which the grounds are different. In the present specification, only one parasitic capacitor connected to only one ground is illustrated.

Referring back toFIG. 9, the Vprewhich is a precharge voltage is applied to the input terminal12-2(FIG. 8) of the charging means12and when the switching device which is the charging means12is turned on by a control voltage Vg applied to the on/off control terminal cont, the precharge voltage Vpreis output through the output terminal12-1. Therefore, all the capacitors connected to the output terminal12-1of the charging means12are charged with the precharge voltage Vpre.

According to one embodiment, if the switching device which is the charging means12is turned on when the Vpreis 3V and the Vg is changed from zero volt (0V) to 10V, the potentials of the touch capacitor Ct, the equivalent capacitor between lines Ceq, the parasitic capacitor Cp, and the common electrode capacitor Cvcom which are formed between the sensing pad10adetecting the touch and the finger25after the turn on of the switching device are 3V based on a ground potential which is connected to one side of each capacitance. For example, if the Vcom which is the common voltage is 4V, when the potential of the point P ofFIG. 9is 3V, the potential 3V of the common electrode capacitance Cvcom means 3V (that is, P potential is 7V based on Vcom=4V) when the common voltage Vcom is 4V.

After the charging of the point P ofFIG. 9, when the control voltage Vg of the charging means12drops from 10V to 0V to turn off the charging means12, the point P which is the touch detector becomes Hi-z and thus the charge at the point P is isolated in the touch capacitor Ct, the equivalent capacitor between lines Ceq, the parasitic capacitor Cp, and the common electrode capacitor Cvcom. According to one embodiment, when the alternating voltage is applied to the equivalent capacitor Ceq between lines, the magnitude of voltage detected at the point P is proportional to the magnitude of alternating voltage applied to the equivalent capacitor between lines Ceq and has a correlation with the capacitances connected to the point P.

FIG. 10is a cross-sectional view illustrating an example of a configuration of a touch detection sensor according to the embodiment of the present invention andFIG. 11is a cross-sectional view illustrating another example of a configuration of a touch detection sensor according to the embodiment of the present invention.FIG. 10illustrates that the touch detection sensor10is mounted on the substrate separately formed from the display device andFIG. 11illustrates that the touch detection sensor10is embedded in the display device. The formation relationship of the common electrode capacitor Cvcom will be described below with reference toFIGS. 10 and 11.

As illustrated inFIG. 10, a display device200has a common electrode220. An AMOLED or a plasma display panel (PDP) does not have a common electrode with a function for displaying an image quality, but various potentials formed on the TFT substrate of the AMOLED or the driving substrate of the PDP and the Cvcom ofFIGS. 8 and 9is formed between the touch detection sensors10opposite thereto, and therefore a virtual potential formed of various potentials formed on the TFT substrate of the AMOLED or the driving substrate of the PDP is also called the common electrode.

The display device200may be various types of display devices as described above and the common electrode220may be a Vcom electrode of an LCD or other types of electrodes. An embodiment ofFIG. 10illustrates an LCD among the display devices.

The display device200illustrated inFIG. 11has a structure in which a liquid crystal is sealed between a TFT substrate205at a lower portion and a color filter215at an upper portion to form a liquid crystal layer210. To seal the liquid crystal, outer portions of the TFT substrate205and the color filter215are bonded to each other by a sealant230. Although not illustrated, a polarizer is attached to the upper and lower portions of the liquid crystal panel. In addition, optical sheets configuring a back light unit (BLU) and a brightness enhancement film (BEF) may be installed like the BLU.

As illustrated, the touch screen panel50is installed on the display device200. An outer portion of the touch screen panel50illustrated inFIG. 11is attached to the upper portion of the display device200by an adhesive member57(FIG. 11) such as a double adhesive tape (DAT). Further, an air-gap58is formed between the touch screen panel50and the display device200or a contact member58is charged therebetween. The contact member58is materials such as transmitting silicon, an optically clear adhesive (OCA), and adhesive resin which attach between the touch screen panel50and the display device200.

A common voltage level for displaying an image is applied to the common electrode220of the display device200and the common voltage may be a DC voltage having a predetermined magnitude or may be an AC voltage having a predetermined amplitude alternating at a predetermined frequency. For example, in a small LCD with a line inversion, the common voltage of the common electrode220alternates as illustrated inFIG. 5and in the LCD such as a notebook and a monitor/TV with a dot inversion, the common voltage having a DC level which is a voltage having a predetermined magnitude is applied.

As illustrated, the common electrode capacitor Cvcom is formed between the touch detection sensor10and the common electrode220of the display device200and the touch capacitance Ct is formed between the touch detection sensor10and the finger25. As such, the common electrode capacitance Cvcom and the touch capacitance Ct are formed in the touch detection sensor10together.

Meanwhile, reference numeral24inFIG. 11is a protective layer for protecting the touch detection sensor10, and glass, plastic, vinyl, cloth, etc., are used.

FIG. 11is another example of the configuration of the touch detection sensor and illustrates an embodiment that the touch detection sensor10is embedded in the display device. Referring toFIG. 11, the touch screen panel50may be formed on an upper surface of the color filter215which is a part of the display device. As illustrated, the common electrode220is formed under the color filter215and the touch detection sensor10is patterned on the upper surface of the color filter. In the embodiment ofFIG. 11, the protective layer24may be replaced by a polarizer. Even in the embodiment ofFIG. 11, the common electrode capacitance Cvcom is formed between the common electrode220and the touch detection sensor10and thus the common electrode capacitance Cvcom (between the touch detection sensor10and the common electrode220of the display device200) and the touch capacitance Ct (between the touch detection sensor10and the finger25) are formed in the touch detection sensor10together.

FIG. 12illustrates the embodiment that the alternating voltage is applied to the equivalent capacitor between lines Ceq to detect the touch signal.

Referring toFIG. 12, the touch capacitance Ct, the Ceq, the Cvcom, and the Cp formed between the touch detection sensor10and the conductors such as the finger25are connected to the output terminal12-1of the charging means12. Therefore, when the precharge signal Vpreis applied to the input terminal12-2of the charging means12in the state in which the charging means12is turned on, the Ceq, the Ct, the Cvcom, and the Cp are charged at the precharge level Vpreand thus the potential of the input terminal of the touch detector14becomes the precharge level Vpre. Next, when the charging means12is turned off, the signals charged in four capacitors keep the precharge signal level Vpreas long as it is separately discharged.

To stably isolate the charged signal, the output terminal12-1of the charging means12and the input terminal of the touch detector14are in the Hi-z state. Preferably, the output terminal12-1of the charging means12and the input terminal of the touch detector14may have the impedance of at least 100 Kohm.

However, according to another embodiment, the output terminal12-1of the charging means12and the input terminal of the touch detector14may not be in the Hi-z state. For example, when the touch input is observed while the signals charged in four capacitors are discharged, the charged signal by other means is isolated, or the signal is quickly observed at the time of the discharge starting timing, the input terminal of the touch detector14needs to be Hi-z.

The touch detector14detects the voltage (or voltage at the point P) of the sensing pad10a. The touch detector14detects the voltage at the point P when the touch is not generated (that is, when the Ct is not formed) and detects the voltage at the point P to acquire the touch signal using the difference in magnitude between the two detected voltages, when the touch is generated (that is, when the Ct is formed). According to the embodiment ofFIG. 12, the sensing signal line resistance Rt is present at the sensing pad10aand the input terminal of the touch detector which is the point P, but the sizes of the signals across the Rt after a predetermined time are the same and therefore the effect of the Rt disregards. Therefore, in the present specification, the voltage detected by the sensing pad10aand the voltage detected at the point P have the same meaning.

In the present invention, when the point P ofFIG. 12is charged with the charging voltage Vpre, one side of the non-sensing pad signal line22bconnected to the non-sensing pad10bis connected to a predetermined voltage Vlor Vh. The Vlis a low voltage of the alternating voltage of the present invention and the Vhis a high voltage of the alternating voltage of the present invention, in which the alternating voltage alternates between the Vhand the Vl. The Vhor the Vlserves like the VLb1described above, that is, serves to form the equivalent capacitor between lines Ceq.

To detect the touch signal after the charging voltage Vpreis applied and the predetermined time lapses, the alternating voltage is applied to the non-sensing pad signal line22b. An absolute magnitude of the alternating voltage is Vh-Vland the potential may be changed from the high voltage Vhto the low voltage Vlor from low voltage Vlto the high voltage Vh. The alternating voltage is voltages having various forms like a square wave, a triangular wave, a sine wave, or a sawtooth wave and the touch drive IC (TDI) of the present invention may change the magnitude or the frequency of the alternating voltage.

The touch detector14detects a voltage in synchronization with a rising edge or a rising time at which the alternating voltage rises from the low voltage Vlto the high voltage Vhor a falling edge or a falling time at which the alternating voltage falls from the high voltage Vhto the low voltage Vl. When the TDI detects the voltage in synchronization with the rising or falling edge, it is preferable to detect the voltage after being delayed as much as a predetermined time from the edge. The reason is that some time (for example, tens of nano seconds or tens of micro seconds) is required until the detection voltage is stabilized by the resistance component Rt of the sensing pad signal line22aor the resistance component Rnt of the non-sensing pad.

Further, the electromagnetic wave generated at the rising edge or the falling edge of the alternating voltage may affect devices coupled with the capacitive type touch detection means of the present invention and therefore the TDI of the present invention may further include a method for adjusting a gradient of the rising edge or the falling edge of the alternating voltage. As one embodiment of the method for adjusting a gradient in the TDI, a register may be used. In the plurality of registers, the time of the rising edge or the time of the falling edge is mapped and when one of the plurality of registers is selected, the alternating voltage generator42ofFIG. 13may adjust the gradient of the rising edge or the gradient of the falling edge of the alternating voltage.

Suppose that the Vlis 5V and the Vlis 0V, the absolute magnitude Vh-Vlof the alternating voltage is 5V. When the alternating voltage is changed from low to high, the alternating voltage is +5V which is a positive polarity and when the alternating voltage alternates from high to low, the alternating voltage is −5V which is a negative polarity. The polarities are applied to Equation for detecting the touch signal to be described below.

When the P point ofFIG. 12is charged with the charging voltage Vpre, suppose that the voltage applied to the non-sensing pad signal line22bis Vhor Vl, the equivalent capacitor between lines Ceq is charged with a voltage having a difference between the Vpreand the Vhor a difference between the Vpreand the Vl. For example, when the Ceq is charged with the Vpre, if a first voltage connected to the non-sensing pad signal line22bis the high voltage Vh, the alternating voltage alternates from high Vhto low Vland the polarity of the alternating voltage is negative (−). Further, when the Ceq is charged with the Vpre, if the first voltage connected to the non-sensing pad signal line22bis the low voltage Vl, the alternating voltage alternates from low Vlto high Vhand the polarity is positive (+).

The voltage detected by the touch detector14by the alternating voltage applied to the non-sensing pad signal line22bis as follows.

1. The voltage detected when the touch is not generated.

2. The voltage detected when the touch is generated.

When the touch is generated, the touch capacitance Ct is added to the touch detector14and therefore the voltage detected by the touch detector14is determined by the following <Equation 2>.

In the above <Equation 1> and <Equation 2>,

Vsensornontouchrepresents the voltage detected by the touch detector14when the touch is not generated,

Vsensortouchrepresents the voltage detected by the touch detector14when the touch is generated,

Vhrepresents the high level voltage of the alternating voltage applied to the non-sensing pad signal line22b,

Vlrepresents the low level voltage of the alternating voltage applied to the non-sensing pad signal line22b, Cvcom represents the common electrode capacitance, the Cp represents the parasitic capacitance, and the Ct represents the touch capacitance. When the alternating voltage alternates from low to high, the polarity of (Vh-Vl) is positive (or plus) and when the alternating voltage alternates from high to low, the polarity of (Vh-Vl) is negative (or minus).

Describing the difference between the above <Equation 1> and <Equation 2>, the Ct is present at a denominator of the above <Equation 2>. The touch capacitance Ct is the capacitor between the sensing pad10aand the touch means such as a finger25, and therefore the capacitance which is the magnitude of Ct is changed depending on whether the touch is generated or the opposing distance or the opposing area of the touch means and the touch sensing pad10a. Since the difference of Ct induces the difference in voltage which is induced by the above <Equation 1> and <Equation 2>, it is determined whether the touch is generated or it is possible to calculate the touched area by detecting the voltage difference (<Equation 1>−<Equation 2> or <Equation 2>−<Equation 1>).

The above <Equation 1> is the value detected by the touch detector14when the touch is not generated and therefore is a fixed value. However, when the touch capacitance is added like the above <Equation 2>, the voltage detected by the touch detector14has the changed touch capacitance and therefore the magnitude of the voltage detected by the above <Equation 2> is changed. The present invention detects whether the touch is generated or the touched area depending on the voltage difference between the above <Equation 1> and <Equation 2> or the voltage difference between the above <Equation 2> and <Equation 1>, and therefore the voltage of the above <Equation 1> which is the fixed value may be preferably stored in a storage device (memory)28(FIG. 13).

If the voltage of the above <Equation 1> stored in the memory unit28(FIG. 13) is replaced by the DAC14-3, <Equation 1>-<Equation 2> or <Equation 2>-<Equation 1> may be detected by a simple circuit like a differential amplifier. Therefore, when the touch is not generated, the present invention has a means for storing the voltage detected by the touch detector14in the above <Equation 1> form in the memory and has a means for replacing the voltage at the time of the non-touch stored in the memory by the DAC14-3.

For example, when the voltage detected by the touch detector14at the time of the non-touch of the sensing pad10aofFIG. 8is 3V, the DAC displaying the voltage at the time of the non-touch of the sensing pad10aofFIG. 8is 3V. Further, the DAC may display 3V, including a predetermined offset. For example, when the DAC is 3.5 V, the DAC includes an offset of 0.5 V.

As such, the voltage detected by the touch detector14is stored in the memory at the time of the non-touch of all the touch detection sensors10to detect the difference from the voltage detected by the touch detector when the corresponding touch detection sensor10is operated as the sensing pad, thereby easily detecting whether the touch is generated and the touched area.

Meanwhile, the Vhand the Vlare generated in the power supply unit47(FIG. 13) in the TDI and the alternating of the Vhand the Vlis generated by the alternating voltage generator42(FIG. 13) in the TDI.

Meanwhile, the Cvcom may be obtained by the following <Equation 3>.

In the above <Equation 3>, ϵ1is complex permittivity of vehicles which are present between the touch detection sensor10and the common electrode220. In the case ofFIG. 10, the glass, the air layer, the polarizer, and the adhesive for attaching the polarizer to the glass may be present between the touch detection sensor10and the common electrode220, and therefore the complex permittivity thereof is ϵ1of the above Equation 3. S1is the opposing area of the touch detection sensor10and the common electrode220and therefore may be easily obtained. As illustrated in the example ofFIG. 10, when the common electrode220is formed over a lower surface of the color filter215, the opposing area S1is determined by the area of the touch detection sensor10. Further, D1is a distance between the touch detection sensor10and the common electrode220, and therefore corresponds to a thickness of the vehicle.

As described above, the Cvcom is a value which may be easily obtained and a value which may be set in advance.

The Ct may be obtained by the following <Equation 4>.

Ct=ϵ⁢⁢2⁢S⁢⁢2D⁢⁢2[Equation⁢⁢4]
In the above <Equation 4>, ϵ4may be obtained from the vehicle between the touch detection sensor10and the finger25and may be obtained by the complex permittivity of the vehicles when a plurality of vehicles are used. If the tempered glass is attached on the upper surface of the touch screen panel50inFIG. 10, the permittivity ϵ2may be obtained from a value obtained by multiplying specific permittivity of the tempered glass by permittivity of vacuum. S2corresponds to the opposing area of the sensing pad10aand the finger25. If the finger25completely covers any sensing pad10a, S2corresponds to the area of the touch detection sensor10. If the finger25covers a part of the touch detection sensor10, S2is reduced by an area which is not opposite to the finger25in the area of the sensing pad10a. Further, D2is the distance between the sensing pad10aand the finger25, and therefore corresponds to the thickness of the protective layer24which is put on the upper surface of the touch screen panel50. As described, the Ct is a value which may be easily obtained and is a value which may be easily set using a material and a thickness of the protective layer24, the tempered glass, etc., which is put on the upper surface of the touch screen panel50. Depending on the above <Equation 4>, the Ct is proportional to the opposing area of the finger25and the touch detection sensor10, and therefore the touch occupancy ratio of the finger25for the touch detection sensor10may be calculated. A method for calculating the touch occupancy ratio of the finger25is as follows. Referring to the above <Equation 1> and <Equation 2>, the difference is the difference in the existence and non-existence of the touch capacitance Ct depending on whether the touch is generated. Suppose that all the capacitances cited in the above <Equation 1> has the predetermined fixed magnitude and the Vpreis the fixed value, only the Ct may be extracted by the voltage detected in the above <Equation 1> and <Equation 2>. In the above <Equation 4>, when the ϵ2and the D2are fixed values, the touch capacitance Ct is proportional to only the touch area. Therefore, the touched area may be simply obtained by the extracted Ct. When obtaining the area using the above <Equation 1> and <Equation 2>, both of the voltage detected by the above <Equation 1> and the voltage detected by the above <Equation 2> are used. Further, the present invention may operate the touched area based on the voltage detected by the touch detector14.FIG. 13is a configuration diagram illustrating one embodiment of the touch screen panel according to the present invention and illustrates the example in which the touch detection sensors10are arranged in a dot matrix form. A lower portion ofFIG. 13is provided with a configuration of the touch drive IC (TDI)30. The TDI30may include a driver31, the touch detector14, a timing controller33, a signal processor35, a memory unit28, an alternating voltage generator42, a power supply unit47, and a communication unit46and may further include a CPU40. The CPU40is a microprocessor having an operation function and may be positioned outside the TDI30. The driver31has the charging means12and includes a function of selecting the sensing pad and the non-sensing pad among the plurality of touch detection sensors10and connecting the selected pad to the touch detector14. Further, the driver31includes a function of connecting one side of the non-sensing pad signal line22bto the Vl, or Vlduring the charging operation using the charging means12. Referring to the above <Equation 1> or <Equation 2>, the difference in the magnitude of the detection voltage occurs due to the magnitude of Vh-Vlwhich is the alternating voltage, and therefore to adjust the touch sensitivity, the TDI may further include a means for changing the magnitude of the alternating voltage. The larger the alternating voltage, the larger the detection voltage, which means the detection sensitivity is improved. The TDI is provided with a register for controlling the magnitude of Vh-Vlwhich is the size of the alternating voltage therein. According to one embodiment, the register has a plurality of addresses and different magnitudes of alternating voltage is mapped to each address. The magnitude of alternating voltage corresponding to the value of the selected register is transferred to the driver31and is applied at the time of the detection of the touch signal. The timing controller33serves to generate a plurality of different clocks which are required in the TDI. For example, a clock is required to operate the CPU40and a clock is required to operate the ADC or sequentially operate a multiplexer of the driver31. As such, the clocks required for each function may be several and the timing controller33may generate and supply a plurality of various clocks. The signal processor35supplies the ADC value generated by the touch detector14to the CPU40, controls the communication unit46to transmit the ADC value to the outside of the TDI30through an inter integrated circuit (I2C) or a serial peripheral interface bus (SPI) signal line, or generates and supplies signals required in all functional elements inside the TDI30such as the touch detector35or the driver. The functional element or the functional block is called components for performing each function illustrated inFIG. 13. For example, nine functional blocks are included inside the current TDI and the CPU40is one of the functional blocks. The signal processor35accommodates the ADC value generated in the touch detector14in the memory unit28and/or performs the required operation. For example, the signal processor35may refer to the ADC value generated in the touch detector14to operate the touched area due to the touch detection sensor10and the touch of the touch means and may operate the touch coordinates using the ADC value or the operated area value. The memory unit28is configured of a flash memory, an E2PROM, an SRAM, or a DRAM. The flash memory or the E2PROM is stored with several register values required to driving the TDI30or programs required to operate the CPU40. The CPU40may have many functions overlapping with those of the signal processor35. Therefore, the CPU40may not be included in the TDI30or positioned outside the TDI30. Any one of the CPU40and the signal processor35may not temporarily used in a section in which the overlapping performance of the CPU40and the signal processor35is predicted. The CPU may perform most of roles which are performed by the signal processor35and performs various functions of extracting the touch coordinates or performing gestures such as zoom, rotation, and move. Further, the CPU may process data in various forms by operating the area of the touch input to generate a zooming signal, calculating the strength of the touch input, and recognizing only GUI object desired by the user (for example, having large detected area) as a valid input when GUI objects such as a keypad are simultaneously touched, etc., and use the data inside the TDI30or transmit the data to the outside through a communication line.

The program for controlling the CPU40is installed in the memory unit28and may be replaced by new program when modifications are generated. The new program may be performed using a communication bus included in the communication unit46, serial communications of, for example, I2C, SPI, USB, etc., or parallel communication such as a CPU interface (hereinafter, I/F). The communication unit46serves to output the required information to the outside of the TDI30or input information provided from the outside of the TDI30to the inside of the TDI. The communication unit uses the serial communication such as the I2C and the SPI or the parallel I/F such as the CPU interface. The alternating voltage generator42generates the alternating voltage applied to the equivalent capacitor between lines Ceq. The high voltage Vhand the low voltage Vlof the alternating voltage are generated from the power supply unit47and the alternating voltage generator42combines the high voltage Vhand the low voltage VI to generate the alternating voltage, such that the driver31may use the alternating voltage. Further, the alternating voltage generator42has a method for adjusting a gradient of a rising edge or a falling edge of the alternating voltage. The sensing pad detecting the touch signal according to the embodiment ofFIG. 13is configured in one or in plural. However, the sensing pad is preferably configured in plural to reduce the sensing time. The sensing pads may be randomly selected and may be selected column-by-column or row-by-row from 30 touch detection sensors10which are configured of six rows Row1to Row5and five columns Col1to Col5. According to one embodiment of the present invention, row and column coordinates are set based on the position of the TDI. Therefore, the coordinates of row and column of the touch detection sensor are not fixed but are values which may be relatively changed depending on the setting position of the TDI. According to the embodiment of selecting the sensing pads column-by-column, when six touch detection sensors10included in Col1are simultaneously determined as the first sensing pad, all the six touch detection sensors10included in the Col1are operated as the sensing pad. (In this case, Col2to Col5are operated as the non-sensing pad). However, in this case, the foregoing equivalent capacitor between lines Ceq is not formed but even though the equivalent capacitor between lines Ceq is formed, the magnitude of capacitance is small, and therefore the touch detection sensitivity may be reduced. As a result, the sensing row-by-row is more preferable than the sensing column-by-column. The reason is that in the case of the sensing row-by-row, a sensing pad signal line22just next thereto is not present and therefore a problem of malfunction due to the signal interference does not happen. All the touch detection sensor10included in the Row2to Row6are operated as the non-sensing pad while the Row1is selected as the sensing pad and thus five touch detection sensors10included in the Row1are operated as the sensing pad. When the Row1completes a function as the sensing pad, the Row2sequentially becomes the sensing pad and the Row1and the Row3to Row6operated as the non-sensing pad are sequentially repeated. In the Row1, the five touch detection sensors10are operated as the sensing pad and therefore the TDI preferably includes five drivers31. As a result, the five sensing pads are simultaneously driven to reduce the touch detection time. Meanwhile, referring to the first characteristic of the two characteristics of the sensing equivalent capacitor between lines Ceq as described above, the sensing equivalent capacitance Ceq when the Row1is operated as the sensing pad is larger than the sensing equivalent capacitance Ceq when the Row6is operated as the sensing pad. The reason is that a length of the sensor signal line22connected to the touch detection sensor10positioned at the Row1is longer than that of the sensor signal line22connected to the touch detection sensor10positioned at the Row6. As such, the longer distance in the TDI, the larger the magnitude of the sensing equivalent capacitance Ceq formed in the sensing pad. Therefore, it is preferable to compensate for different magnitudes of sensing equivalent capacitances Ceq to detect the uniform touch signal. The compensating for the magnitude of the sensing equivalent capacitance Ceq means that the compensation capacitor is added to the sensing equivalent capacitance Ceq of <Equation 1> or <Equation 2> to detect the same voltage for the same touch capacitance Ct even though the position of the sensing pad is changed.

The present invention has a means for compensating for different magnitudes of sensing equivalent capacitance Ceq to keep the same touch sensitivity at each position based on the different magnitudes of sensing equivalent capacitance Ceq at each position.

FIG. 14illustrates a method for compensating for sensing capacitance Ceq according to the embodiment of the present invention. Referring toFIG. 14, a compensation capacitor Cba1is connected to the touch detector14and one side of the compensation capacitor Cba1is applied with the alternating voltage. As a result, the Ceq and the Cba1are connected to each other in parallel and thus the Ceq may be large as much as the magnitude of Cba1in an equivalent circuit.

According to one embodiment, the alternating voltage applied to the compensation capacitor Cba1may be the same voltage as the alternating voltage applied to the equivalent capacitor between lines Ceq.

According to another embodiment, one side of the compensation capacitor Cba1may be applied with a voltage having a different magnitude (amplitude) from the alternating voltage applied to the equivalent capacitor between lines Ceq. For example, one side of the compensation capacitor Cba1may be connected to GND having a zero volt (V) or a direct current (DC) having a predetermined potential. However, for simplification of the power supply unit47and the alternating voltage generator42, the alternating voltage applied to the equivalent capacitor between lines Ceq and the compensation capacitor Cba1is preferably the same and in the present specification proposes the embodiment of the case in which the alternating voltage is the same.

When five touch detection sensors10included in the Row1ofFIG. 13is used as the sensing pad, suppose that the magnitude of the sensing equivalent capacitance Ceq generated in the sensing pad10aof the col3of the Row1is 15 pF, when the Row2is used as the sensing pad, suppose that the magnitude of the sensing equivalent capacitance Ceq generated in the sensing pad of the col3of the Row2is 13 pF, and when the Row6is used as the sensing pad, suppose that the magnitude of the sensing equivalent capacitance Ceq generated in the sensing pad of the col3of the Row6is 5 pF. If the magnitude of the Cba1is selected as 0 pF when the Row1is used as the sensing pad and the magnitude of the Cba1is selected as 2 pF when the Row2is used as the sensing pad, the magnitude of the capacitor is the same as 15 pF which is the Ceq of the Row1and if the magnitude of the Cba1is selected as 10 pF when the Row6is used as the sensing pad, the Ceq is 5 pF and therefore the magnitudes of all the capacitors in which the Cba1which is 10 pF is compensated for 5 pF which is the Ceq of the Row6are 15 pF which is equal to 15 pF of the Row1. As such, if the capacitance is compensated as much as an amount corresponding to the difference in the Ceq at each Row by adjusting the magnitude of the Cba1so that the sum of the compensated magnitude of the Cba1and the Ceq is a constant value (for example, 15 pF), the sensing equivalent capacitance Ceq having 15 pF at each Row is induced.

In the present specification, the set magnitudes (for example, 0 pF, 2 pF, 10 pF, and 15 pF) of the compensation capacitor are one embodiment and the sum of the sensing equivalent capacitance Ceq and the compensation capacitance Cba1is desirably defined to be matched based on the magnitudes of the sensing equivalent capacitance Ceq detected at each Row.

When one side of the compensation capacitance Cba1is connected to the touch detector14and the other side thereof is applied with the same alternating voltage as the alternating voltage applied to the equivalent capacitor between lines Ceq, the voltage detected by the touch detector14is as follows.

1. The voltage detected when the touch is not generated.

2. The voltage detected when the touch is generated.

When the touch is generated, the touch capacitance Ct is added to the touch detector14and therefore the voltage detected by the touch detector14is determined by the following <Equation 6>.

In the above <Equation 5> and <Equation 6>,

Vsensornontouchrepresents the voltage detected by the touch detector14when the touch is not generated,

Vsensortouchrepresents the voltage detected by the touch detector14when the touch is generated,

Vhrepresents the high level voltage of the alternating voltage applied to the non-sensing pad signal line22band one side of the compensation capacitor Cba1,

Vlrepresents the low level voltage of the alternating voltage applied to the non-sensing pad signal line22band one side of the compensation capacitor Cba1, Cvcom represents the common electrode capacitance, the Cp represents the parasitic capacitance, and the Ct represents the touch capacitance. When the alternating voltage alternates from low to high, the polarity of (Vh-Vl) is positive (or plus) and when the alternating voltage alternates from high to low, the polarity of (Vh-Vl) is negative (or minus).

Referring to <Equation 5> and <Equation 6>, in the embodiment ofFIG. 13, it is possible to equally keep the touch sensitivity at each Row by the compensation capacitance Cba1compensating for different sensing equivalent capacitance Ceq at each Row.

Further, referring to <Equation 5> and <Equation 6>, when the magnitude of the touch equivalent capacitance Ceq generated at each Row is small, it is possible to greatly improve the touch sensitivity using the Cba1.

Further, referring to <Equation 5> and <Equation 6>, in the state in which a portion not applying the alternating voltage to the Ceq but applying the alternating voltage to the Ceq is connected to the GND or floats, when the alternating voltage is applied only to one side of the compensation capacitor Cba1connected to the touch detector14, the Ceq of the <Equation 1> or <Equation 2> is replaced by the Cba1. As such, according to the present invention, the capacitor applied with the alternating voltage is included in a denominator and a numerator of Equation representing the detection voltage.

The present invention has a means for compensating for the magnitude of the sensing equivalent capacitance Ceq based on the different magnitudes of sensing equivalent capacitance Ceq. The TDI30includes a means for determining the magnitude of compensation capacitor Cba1. According to an embodiment of the means, a plurality of registers are mapped with the compensation capacitance Cba1having different magnitudes and in the embodiment ofFIG. 13, are assigned with the Cba1having different magnitudes at each Row.

Meanwhile, referring to the above <Equation 1> or <Equation 2>, the detection voltage detected by the touch detector14is proportional to (Vh-Vl) and therefore when the magnitude of alternating voltage is appropriately adjusted, it is possible to adjust the touch sensitivity by adjusting the magnitude of voltage detected by the touch detector14. The TDI includes a means for changing a magnitude of alternating voltage. According to the embodiment, the plurality of registers in the TDI are assigned with the alternating voltage having different magnitudes and the magnitude of alternating voltage may be determined by the selection of the register.

FIG. 15illustrates an embodiment in which the magnitude of alternating voltage is changed depending on the setting of the register included in the TDI. Referring toFIG. 15, when a register address 00h is selected, the alternating voltage is 2V and when a register address 07h is selected, the alternating voltage is 16V.

As such, the touch detection apparatus according to the foregoing embodiment changes the alternating voltage to adjust the magnitude of detection voltage associated with the touch sensitivity.

Referring toFIG. 12 or 14, according to the capacitive type touch detection means and the detection method according to the present invention, the alternating voltage is applied to one side of the capacitors Ceq and Cba1connected to the touch detector14which is in the Hi-state and the touch may be detected depending on whether the touch capacitance Ct is generated. Therefore, when any capacitor connected to the touch detector14which is in the Hi-z state is applied with the alternating voltage, the touch detection may be made. Here, the fact that the touch detector14is in the Hi-z state means that the charging means12is in the turn off state, the output terminal12-1of the charging means12is in the Hi-z state, the input unit of the touch detector14is in the Hi-z state, and the point P ofFIG. 12is in the Hi-z state.

FIG. 16is a diagram illustrating an embodiment of the present invention having an alternating touch means.FIG. 16is a modification of the embodiment in which the touch capacitance Ct is formed between the touch detection sensor10and the finger25ofFIG. 12, which is different from the fact that the alternating touch means26is adopted instead of the finger25. That is, this is the same as one described inFIG. 12, except that the touch capacitance Ct is formed between the touch detection sensor10and the alternating touch means26.

An embodiment of the alternating touch means26may be a touch pen having a pen shape. Referring toFIG. 16, the alternating touch means26may include the alternating voltage generator42(FIG. 13). In the alternating voltage generator42(FIG. 13), the alternating touch means26includes the connecting line18to a lead of the pen (nib)17, and the alternating voltage generated from the alternating voltage generator42(FIG. 13) is transferred to the lead of the pen through the connecting line18. The alternating voltage generator42(FIG. 13) of the alternating touch means26may include the power supply unit or the charging unit. The power supply unit may include a battery or a chargeable battery. The charging unit detects the rising edge or the falling edge of the alternating voltage applied to the equivalent capacitor between lines Ceq or the compensation capacitor Cba1to charge a voltage in the capacitor included in the charging unit. Therefore, when the charging unit is used, the alternating touch means26is preferably close to the touch detection sensor10.

The alternating voltage is an alternating voltage like a square wave, a triangular wave, a sine wave, etc. The alternating voltage generator42(FIG. 13) may include a means for determining a magnitude or an alternating frequency of the alternating voltage. The magnitude of the alternating voltage may be determined depending on the change in resistance value of variable resistor. Further, the alternating frequency may also be determined depending on the change in a variable resistor, a variable capacitor, etc. The alternating voltage may be formed by the correlation between a primary coil and a secondary coil or may be generated by a combination of a linear circuit such as OPAMP included in the alternating voltage generator42(FIG. 13) and circuit parts such as a resistor R and a capacitor C.

According to one embodiment, the alternating touch means26may include a means for turning on or off an alternating voltage. For example, when the touch pen is used as the alternating touch means26, if a push switch installed at a lower portion of the touch pen is pressed, the alternating voltage may not be generated and if the push switch is not pressed, the alternating voltage may be generated. A position of the push switch may be installed at any portion of the touch pen and therefore it is recognized by those skilled in the art that the position of the push switch and the generation of the alternating voltage are not limited to the above-mentioned embodiment.

The touch capacitance Ct is formed between the touch detection sensor10and the alternating touch means26based on the above Equation 4. When the magnitude of high voltage of the alternating voltage of the alternating touch means26is set to be Vph and the magnitude of low voltage is set to be Vpl, the magnitude of alternating voltage is determined as Vph-Vpl. When the Ct is formed by the alternating touch means26, the magnitude of voltage detected by the touch detector14is determined by the following <Equation 7>.

When the illustrated compensation capacitor Cba1is included in the embodiment illustrated inFIG. 16, the Cba1will be additionally included in a denominator of the above <Equation 7>. The above <Equation 7> is a voltage detected by the touch detector14when only the alternating voltage of the alternating touch means26is applied to the Ct. Therefore, the alternating voltage is not applied to the Ceq, the Cba1, etc., or the alternating voltage applied to the Ceq or the Cba1is applied avoiding the rising edge or the falling edge. To generate the alternating voltage of the alternating touch means26while avoiding the alternating voltage applied to the Ceq or the Cba1, the alternating touch means26may further include a means (not illustrated) for detecting a rising edge or a falling edge of voltage formed in the touch detection sensor10. Further, the alternating touch means26may detect the touch signal in a DC section of the alternating voltage applied to the Ceq or the Cba1or a region in which the alternating voltage is not applied by using a frequency quickly than the alternating voltage applied to the Ceq or the Cba1.

When the CT is not present between the alternating touch means26and the touch detection sensor10, the Equation obtaining the detected voltage is the above <Equation 1> or <Equation 5> and therefore the touch signal of the alternating touch means26is detected by the difference between the first voltage obtained by the above <Equation 1> or <Equation 5> and the second voltage obtained by the above <Equation 7>. Therefore, the present invention may detect the touch by the finger based on the difference between the voltages detected by the above <Equation 1> and <Equation 2> and detect the touch by the finger based on the difference between the voltages detected by the above <Equation 5> and <Equation 6>. In this case, the used touch means is the non-alternating touch means (touch means which itself generates and does not output the alternating voltage) as the finger25(FIG. 12).

Meanwhile, when the alternating voltage is applied to one side of the equivalent capacitor between lines Ceq, if the touch is not generated, it is possible to detect whether the touch is generated by the alternating touch means26, based on the difference between the magnitude of first voltage detected by the touch detector14based on the above <Equation 1> and the magnitude of second voltage detected by the touch detector14based on the above <Equation 7> by the alternating touch means26. Further, when the alternating voltage is applied to the equivalent capacitor between lines Ceq and one side of the compensation capacitor Cba1, it is possible to detect whether the touch is generated by the alternating touch means26, based on the difference between the magnitude of first voltage detected by the touch detector14based on the above <Equation 5> and the second voltage detected by the touch detector14based on the above <Equation 7> by the alternating touch means26.

According to the embodiment of the present invention, the touch signals may be simultaneously detected by the non-alternating touch means (for example, finger25(FIG. 12)) and the alternating touch means (touch pen26(FIG. 16)). The reason is that the magnitude of voltage detected in the state in which the non-alternating touch means or the alternating touch means does not contact the touch detection sensor10, that is, the state in which the Ct is not formed is detected based on the above <Equation 1> or <Equation 5>. Therefore, it is possible to detect the touch by the non-alternating touch means (for example, finger25(FIG. 12)) by using the difference between the voltage detected based on the above <Equation 1> or <Equation 5> and the voltage detected based on the <Equation 2> or <Equation 6> and it is possible to detect the touch by the alternating touch means26(FIG. 12) by using the difference between the voltage detected based on the above <Equation 1> or <Equation 5> and the voltage detected based on the above <Equation 7>. The voltage detected based on the above <Equation 7> may be differentiated from the magnitude of voltage detected by the above <Equation 2> or <Equation 6> by making the magnitude of Vph-Vpl different and therefore the touch detector14may confirm it is the alternating touch means26(FIG. 12) or the non-alternating touch means25(FIG. 12) by using the difference between the detection voltages.

Meanwhile, referring back toFIG. 13, according to the embodiment of the present invention, the touch detection sensor10may detect the touch signal by any combination of the touch detection sensors10included in the Row direction based on the touch drive IC (TDI)30. According to the detailed first example of the combination of the touch detection sensors10, all the touch detection sensors10included in one Row1are simultaneously operated to detect the touch signal, similar to that all of the five touch detection sensors10included in Row1are simultaneously operated to detect the touch signal. According to the detailed second example of the combination of the touch detection sensors10, only even columns Col2/Col4included in the Row1may be operated to detect the touch signal or only the odd columns Col1/Col3/Col5may be operated to detect the touch signal. According to the detailed third example of the combination of the touch detection sensors10, the touch detection sensor10of 50% in any Row detects the touch signal or the touch detection sensor10of 50% does not detect the touch signal and after the operation of the touch detection sensor10of 50% which performs the touch detection is completed, the touch detection sensor10of the remaining 50% which does not detect the touch signal may be configured to detect the touch signal. According to the embodiment of the present invention, the touch detection means may further include a means for selecting the plurality of touch detection sensors10included in one Row to determine whether to detect the touch signal. According to the foregoing embodiment, the operation of detecting the touch signal means that the touch detection sensor10connected to the sensor signal line22is connected to the charging means12and the touch detector14to detect the voltage for touch signal detection.

FIG. 17is a diagram illustrating an embodiment of the setting of a touch detection sensor10and a sensor signal line22. Referring toFIG. 17, the touch detection sensor10and the sensor signal line22are included in a square which is partitioned into Row and Column. According to the embodiment, an area of the virtual square which is partitioned into a Row and a Column in which the touch detection sensor10and the second signal line22are included. According to another embodiment, an outer area in a column direction like Column5or Column1or an outer area in a row direction like Row1or Row6may be smaller or larger than an area of a central portion of the square which is virtually partitioned. When the area of the virtual square of the outer portion of a column or a row is small and the touch detection sensor10and the sensor signal line22are disposed in the square, detection resolution is better and therefore detection power at the outer portion of the touch screen panel50is improved. According to the embodiment of the present invention, the area of the touch detection sensor10positioned at the outer portion of the touch screen panel50may be configured to be smaller than that of the touch detection sensor10positioned at the central portion of the touch screen panel50. According to another embodiment of the present invention, areas of the rest virtual squares other than the virtual square positioned at the outer portion of the touch screen panel50may be the same. Further, according to the present invention, one virtual square includes one touch detection sensor10.

Referring back toFIG. 17, the Row1includes one touch detection sensor10and one sensor signal line22, but like the Row2and the Row3, as the sensor signal line approaches the TDI30, the more sensor signal lines22are included in the virtual square. As such, according to the present invention, the virtual square may include one sensor signal line and the plurality of sensor signal lines22. When the virtual square includes the plurality of sensor signal lines22, as the touch detection sensor10includes the more sensor signal lines22, the area of the touch detection sensor10is getting smaller. For example, the area of the touch detection sensor10having coordinates of the Row1/Col1is smaller than that of the touch detection sensor10having coordinates of the Row6/Col1. This means that the touch detection sensor10positioned to be closer to the TDI than the touch detection sensor10positioned to be at a long distance from the TDI has a smaller area.

Meanwhile, the resistance of the sensor signal line22connected to the touch detection sensor10positioned to be at a long distance from the TDI is larger than that of the sensor signal line22connected to the touch detection sensor10positioned to be closer to the TDI and therefore the detection time of the voltage detected by the touch detector14is delayed. Therefore, to reduce the resistance of the sensor signal line22connected to the touch detection sensor10positioned to be at a long distance from the TDI, a wiring width of the sensor signal line22is preferably wide. According to the embodiment of the present invention, the width of the sensor signal line connected to the touch detection sensor10positioned at a long distance from the TDI is wider than that of the sensor signal line22connected to the touch detection sensor10positioned to be close to the TDI.

According to the embodiment of the present invention, the area of the touch detection sensor10is changed depending on the distance from the TDI and therefore the value of the area detected by the touch means25is changed. A relative ratio of the area value is determined for each Row and therefore the area size detected independent of the area of the touch detection sensor10may be equal by compensating for the area detected based thereon. For example, suppose that the size of the area detected in the Row1by any touch means25is 100 and the size of the area detected in the Row6is 50, only 50% of the area detected in the Row1is used as the touched area but the area detected in the Row6increases twice, which may be used as the detected touch area. The present invention may include a means for compensating for a touched area to make the touched area to be equal based on the position and the area of the touch detection sensor10.

As marked by the Col5ofFIG. 17, the embodiment of the present invention may have the same area of the touch detection sensor10.

According to the embodiment of the present invention, the touch detection sensor10or the sensor signal line22may be positioned at an outside of an active area of the display device displayed by a dotted line inFIG. 17. In this configuration, the touch coordinate detection power is improved at the outer portion of the active area of the display device.

Meanwhile, the mutual opposing area between the sensor signal lines22connected to the touch detection sensors10at a long distance from the TDI is larger than the mutual opposing area between the sensor signal lines22connected to the touch detection sensors10at a close distance from the TDI and therefore the magnitude of the stray capacitance Cp affecting the sensor signal line22connected to the touch detection sensor10at a long distance from the TDI is larger. The size of the equivalent capacitance between lines Ceq has a difference due to the stray capacitance and therefore referring to the <Equation 2> or <Equation 6>, the voltage detected by the touch detector14has a difference due to the difference in magnitude of the Cp. To solve the above problem, the distance between the sensor signal lines22connected to the touch detection sensors10at the long distance from the TDI is preferably formed to be more spaced apart from each other and as the mutual opposing distance of the sensor signal line22may be more spaced apart from each other, the magnitude of Cp derived from the <Equation 3> or the <Equation 4> is small. According to the embodiment of the present invention, the spaced distance between the sensor signal lines22connected to the touch detection sensors10at a long distance from the TDI is wider than that between the sensor signal lines22connected to the touch detection sensors10positioned to be close to the TDI.

The touch detection sensors10disposed in the Row1and the Row2are disposed at upper and lower portions based on the TDI30like being spaced apart from each other by a predetermined distance “d” and the touch detection sensors10between which the sensor signal line22does not pass through needs to be spaced apart from each other at a predetermined distance. The touch detection sensors10are spaced apart from each other at a predetermined distance to prevent the signal interference from occurring therebetween. According to the embodiment, the spaced distance “d” may preferably range from 1 μm to 5000 um.

FIG. 18is a diagram illustrating an embodiment of a form of the touch detection sensor for improving touch coordinates. The touch detection sensor inFIG. 17is formed in a virtual square and the corresponding coordinates are equally detected even though any point within the square is touched. As a modification thereof, referring toFIG. 18, the touch detection sensors are opposite to each other, having a geographical form having inflection points or flexural parts between the Rows disposed in a vertical direction based on the TDI. For example, referring to the Col1of the Row1and the Row2, the bonded portions between the two touch detection sensors10which are opposite to each other are opposite to each other in a triangular form. In the case of the touch means25which is positioned in the Row2/Col1ofFIG. 17, the coordinates in the vertical direction are the same even though the touch means is positioned anywhere within the virtual square ofFIG. 17. To more accurately determine the coordinates in the vertical direction of the touched position, the touch means needs to contact at least two touch detection sensors10but the touch means contacts only the one touch detection sensor10in the virtual square (embodiment ofFIG. 17). However, referring to the Row2/Col1ofFIG. 18, even though the touch means25is at the same position asFIG. 17, the touch means25contacts the touch detection sensor10at the upper end Row1/Col1and the touch detection sensor10at the Row2/Col1together. As such, when the opposing surface of the touch detection sensors10vertically opposing to each other based on the TDI has a triangular form, a squared form, or a trapezoidal form (Col3ofFIG. 18) having the inflection point and the touch means25passes through the opposing inflection points to contact at least two touch detection sensors10, it is possible to more accurately detect the coordinates in the vertical direction by the touch means25.

The Col2ofFIG. 18has a diamond-shaped touch detection sensor10by adjusting a distance between vertexes of the Col1ofFIG. 18. “L” of the Col2ofFIG. 18, that is, a distance between the inflection points having the longest length of the touch detection sensors10opposite to each other, having the inflection point is about 5% to 300% of a longitudinal (vertical based on the TDI) length of the virtual square set inFIG. 17. As such, when the two touch detection sensors10are opposite to each other in a vertical direction, the shape of the opposing inflection points has a triangular form, a sine wave form, a square form, a trapezoidal form, etc., without any limitation and therefore has a form in which the two areas are detected when passing through the virtual opposing surfaces as illustrated inFIG. 17.

“M” ofFIG. 18is a width of the flexural part at which the two touch detection sensors10vertically adjacent to each other are opposite to each other. The wider the width, the more the probability that the touch means25contacts the two touch detection sensors10but the larger the opposing area. As a result, the Cp is increased and thus the touch sensitivity may be reduced. The width of the flexural part defined by the “M” ofFIG. 18at which the two touch detection sensors are opposite to each other may preferably range from 1 mm to 50 mm. Further, inFIG. 18, the flexural part has a triangular form and a point where the opposing gradient of the two touch detection sensors10is changed like the triangular vertex is called the inflection point. The number of inflection points may be one or plural and preferably, at least two inflection points may be used.

The gradient of the opposing part is generally changed at the left and right of the inflection points of the two touch detection sensors10which are vertically opposite to each other but in some cases, it may be assumed that the opposing part ends without the change of the gradient. For example, in the case of the two touch detection sensors10opposite to each other in the triangular form of the Col1ofFIG. 18, the gradient of the triangle rises or falls and then stops at the inflection point, and the shape of the touch detection sensor10is completed. In this case, suppose that the number of inflection points is 0.5, like the case in which the number of inflection points ranges from 0.5 numbers to 1.5 numbers or 2.5 numbers, one or a plurality of inflection points are added that is based on an unitized inflection point of 0.5 numbers and thus the opposing area may be determined. In this case, the overall outer area of the touch detection sensor10is uniform in each touch detection sensor10.

Referring back toFIG. 18, when one touch detection sensor10is formed having the inflection point or the flexural part, the upper and lower flexural parts are symmetrical to each other. Alternatively, the upper and lower flexural parts may be formed to be asymmetrical to each other. When the upper and lower flexural parts are symmetrical to each other, for example, the vertexes of Col2ofFIG. 18face each other and when the upper and lower flexural parts are asymmetrical to each other, the vertexes of the Col2ofFIG. 18mismatch to each other.

FIG. 19is a diagram illustrating an embodiment of the present invention for improving visibility. Referring toFIG. 19, there are two touch detection sensors10vertically opposite to each other based on the TDI and the sensor signal line22connected thereto. In some cases, the pattern illustrated inFIG. 17may appear, which degrades a quality of products. To improve the visibility problem of the pattern, the touch detection sensor is partitioned into plural, only a part of the partitioned region is formed with the pattern, and the formed pattern may be connected to each other. For example, only 50% of the region partitioned inFIG. 19Ais formed with the pattern in a delta structure and when the patterns having the formed delta structure are connected to each other, the detection area of the touch detection sensor10is reduced to 50% but the visibility is improved.FIG. 19Billustrates an embodiment in which only a part of the region of the sensor signal line22is formed with the pattern, in which a dummy pattern23is inserted between the touch detection sensor10and the sensor signal line22and is partitioned to form the patterns only in some region and connect the patterns to each other. As such, the present invention inserts the dummy patterns23in the touch detection sensors10, in the sensor signal lines22, or between the touch detection sensor10and the sensor signal lien22and are partitioned into plural and the touch detection sensor10is patterned only in a part of the partitioned region to improve the visibility.

FIG. 20is an embodiment of the present invention of a design of the sensor signal line22. Referring toFIG. 20,FIG. 20illustrates the tempered glass which is installed on a front surface of a mobile phone which is a portable device and has a touch. Generally, a side of the tempered glass is inserted with a company logo or is formed with colors such as black or white to improve marketability. The color is called a black matrix (BM) and referring to a front ofFIG. 20, a shaded portion is a BM portion. In some region of the BM, the BM is opened to perform an operation of a camera lens, an infrared sensor, etc. When the BM is cut in a direction of A-A′, the bottom of the tempered glass is printed with the BM. The BM is ink having colors or non-conductive materials such as organic BM, chromium BM, and silver oxide (Ag2O) are used for BM.

In the case in which the touch detection sensor10according to the present invention is embedded in a bottom of the tempered glass, the signal line may be cut due to the step generated by the BM when the sensor signal line22passes through the BM. Therefore, referring to a rear ofFIG. 20, in the case in which the touch detection sensor10and the sensor signal line22according to the present invention are installed, the signal line width when the sensor signal line22passes through the BM stepped portion is desirably formed to be wider than the width of the sensor signal line22just before the BM step. According to one embodiment, when a width22-1of the sensor signal line22just before the BM stepped portion is 100%, a width22-2of the sensor signal line22crossing the BM stepped portion may preferably range from 101% to 1000%.

According to the capacitive type touch detection means and the detection method according to the embodiments of the present invention, the alternating driving voltage is applied to the sensing equivalent capacitor formed between the sensing pad and the non-sensing pad adjacent to the sensing pad, the occurrence of the difference in voltage due to the difference in touch capacitance added by the touch input means such as the finger is detected by the touch detector to acquire the touch signal, such that the parasitic capacitance occurring between the sensor signal lines typically acting as noise is reversely used as the touch signal detection means (for example, basic value not affected by the touch signal), thereby facilitating the design of the touch panel and improving the sensitivity.

It will be obvious to those skilled in the art to which the present invention pertains that the present invention described above is not limited to the above-mentioned exemplary embodiments and the accompanying drawings, but may be variously substituted, modified, and altered without departing from the scope and spirit of the present invention.