KR101297595B1 - Apparatus for sensing charge of multi touch panel with removing low frequency noise - Google Patents

Abstract

Disclosed is a charge sensing device of a multi-touch panel in which low frequency noise is removed. The charge detection device of the multi-touch panel generates a sensing signal including information on a sampling time point, and outputs the sensing signal to a corresponding input terminal of a capacitance sensor in response to an input selection signal. A capacitance sensor comprising a plurality of output stages which sequentially and repeatedly output a first charge quantity having a positive value sensed in response to the sensed sensing signal and a second charge quantity having a negative value, in parallel from the output terminals of the capacitance sensor A signal receiver configured to sample and accumulate the first charge amounts and the second charge amounts n times (n is a natural number), respectively, and adjust gain to output first accumulated voltages and second accumulated voltages; The voltage difference between the first cumulative voltage and the second cumulative voltage is sequentially received by receiving the first cumulative voltages and the second cumulative voltages. Noise removal unit for calculating and outputting, mux for sequentially selecting and outputting the voltage difference one by one in response to a voltage selection signal and AD (analog to to convert the voltage difference sequentially output from the mux to a digital signal and sequentially output digital) converter may be provided.

Description

Apparatus for sensing charge of multi touch panel with removing low frequency noise}

The present invention relates to a device for detecting a charge amount of a multi-touch panel, and in particular, attenuates low-frequency noise generated by the touch of a panel and a conductor as well as noise included in a signal itself, thereby minimizing noise and ensuring sufficient sensitivity even for small charge amount changes. The present invention relates to a device for sensing the amount of charge in a multi-touch panel that maximizes the dynamic range of the system.

In general, the amount of charge of a multi-touch panel is used to detect whether a conductor (for example, a finger, a pen, etc.) is touched on a multi-touch panel (for example, a touch key or a touch screen) and output it as a digital signal for use in an application. Use a device to detect.

In order to detect the amount of charge in the multi-touch panel, the method of sensing the amount of charge in the capacitance sensor on the multi-touch panel side is to detect a change in the amount of charge generated by the influence of the touched conductor, which is currently used in various applications including portable devices. The change in the amount of charge by the sensor is not large. The change in the charge amount is proportional to the change in the capacitance value of the capacitance sensor, and the change generally has a capacitance value of several tens fF to several hundred fF.

To amplify the signal sensed by the capacitance sensor in order to increase the change in the amount of charge due to the touch of the conductor, it is generally used, but this method is contrary to the current development trend of low voltage and low power, and is caused by the use of additional external devices. It causes problems in cost increase and battery use applications. In addition, noise is present in the signal sensed by the capacitance sensor. When the multi-touch panel and the conductor touch, power noise is generated by a power applied to the system including the multi-touch panel, and the conductor is between the multi-touch panel and the conductor. Noise occurs. However, in the case of simply amplifying the sensed signal, the noise is also amplified by amplifying the noise at the same ratio as described above. In addition, when the power supply noise and the conductor noise are not removed, an inaccuracy and shaking of touch coordinates may occur during touch recognition.

The problem to be solved by the present invention is to attenuate the low frequency noise generated by the touch of the panel and the conductor as well as the noise contained in the signal itself to minimize the noise while ensuring sufficient sensitivity even for small charge changes and the dynamic range of the system (dynamic The present invention provides a charge detection device of a multi-touch panel that maximizes a range.

According to an aspect of the present invention, there is provided a device for detecting a charge amount of a multi-touch panel, the sensing signal including information about a sampling time point to a corresponding input terminal among input terminals of a capacitance sensor in response to an input selection signal. A signal transmission unit for outputting the received signal through the corresponding input terminal, and in response to the received sensing signal, the first charge amount having a sensed positive value and the second charge amount having a negative value sequentially A capacitance sensor including a plurality of output terminals repeatedly output and a plurality of first charge amounts output in parallel from the output terminals of the capacitance sensor are sampled n times (n is a natural number) and adjusted by adjusting gain. Outputting the first accumulated voltages in parallel and outputting the second voltages in parallel from the output terminals of the capacitance sensor; A signal receiver configured to sample and accumulate loads n times each time, and adjust gain to output second accumulated voltages in parallel, and sequentially receive the first accumulated voltages and the second accumulated voltages, respectively. A noise removing unit configured to calculate a voltage difference between the first accumulated voltage and the second accumulated voltage and output the voltage differences from which low frequency noise generated when the conductor touches the multi-touch panel; A mux for sequentially selecting and outputting the voltage differences output in parallel from the noise removing unit and an AD (analog to digital) converter for converting the voltage differences sequentially output from the mux into digital signals and sequentially outputting the digital signals; It can be provided.

The low frequency noise includes power supply noise generated by power applied to a system including the multi-touch panel and conductor noise generated between the multi-touch panel and the conductor when the conductor touches the multi-touch panel. Each of the first cumulative voltages and the second cumulative voltages includes a noise voltage corresponding to the power supply noise and the conductor noise, and a voltage difference between the corresponding first cumulative voltage and the second cumulative voltage is The voltage difference between the voltage corresponding to the first charge amount and the voltage corresponding to the second charge amount in which the noise voltage is canceled by the subtraction operation of the corresponding first cumulative voltage and the second cumulative voltage.

The sensing signal is a signal in which the first logic state and the second logic state are repeated in a section in which the signal receiver samples and accumulates the first and second charges, and the capacitance sensor indicates that the sensing signal is in the first logic state. Outputs the first amounts of charge in parallel at a time point when the state changes to the second logic state, and at the time when the sensing signal changes from the second state to the first logic state, the second amounts of charge in parallel You can print

The noise canceller may include a CDS controller configured to generate a plurality of CDS control signals in response to the digital signal, and correlated double sampling of the corresponding first accumulated voltage and the second accumulated voltage in response to the CDS control signals. And a plurality of CDS units for outputting a voltage difference between the corresponding first accumulated voltage and the second accumulated voltage whose low frequency noise is removed and gain is adjusted.

The signal receiver may include a plurality of sampling units configured to sample the first charge amount and the second charge amount n times output from a corresponding one of the output terminals of the capacitance sensor in response to sampling control signals including information regarding the number of sampling times. A gain controller configured to generate and output a plurality of gain control signals using the digital signal output from the AD converter; a first sampled n times by a corresponding one of the sampling units in response to the gain control signals; A plurality of first charge amount accumulators accumulating charge amounts and adjusting gain to output the first cumulative voltage, and the second charge amounts sampled n times in a corresponding one of the sampling units in response to the gain control signals. A plurality of second charges that accumulate and adjust gain to output the second accumulated voltage; Accumulators may be provided.

The signal transfer unit is a sensing controller configured to generate and output a sensing control signal in response to the digital signal output from the AD converter, is enabled in response to the input selection signal, and generates at least one driving signal in response to the sensing control signal. A plurality of sensing drivers to generate and output and a plurality of sensing signal output unit for generating the sensing signal in response to the at least one driving signal to output to the corresponding input terminal of the input terminal of the capacitor.

According to another aspect of the present invention, there is provided a device for detecting a charge amount of a multi-touch panel, the sensing device including information on a sampling time point to a corresponding input terminal among input terminals of a capacitance sensor in response to an input selection signal. A signal transmission unit for outputting a signal, receiving the sensing signal through the corresponding input terminal, and sequentially the first charge amount having a positive value sensed in response to the received sensing signal and the second charge amount having a negative value A capacitance sensor including a plurality of output terminals repeatedly outputting a plurality of offsets, and a plurality of offset control signal groups for setting offset charge amounts corresponding to respective charge amounts using the charge amounts output from the output terminals of the capacitance sensor during an offset charge amount setting period And in response to the offset control signal groups An automatic correction unit outputting first correction charge amounts and second correction charge amounts obtained by removing the offset charge amount from the first charge amounts and the second charge amounts output in parallel from a capacitance sensor; Sampling and accumulating the first charge amounts output n times (n is a natural number) and adjusting gain to output first accumulated voltages in parallel, and outputting the first accumulated voltages in parallel from the automatic correction unit. A signal receiver configured to sample and accumulate two charge amounts n times each time, and adjust gain to output second accumulated voltages in parallel, and sequentially receive the first accumulated voltages and the second accumulated voltages, respectively; Low frequency noise generated when the conductor touches the multi-touch panel by calculating a voltage difference between a first accumulated voltage and the second accumulated voltage. A noise removing unit for outputting the removed voltage differences in parallel, a mux for sequentially selecting and outputting the voltage differences output in parallel from the noise removing unit in response to a voltage selection signal, and sequentially outputting from the mux An analog to digital (AD) converter which converts the voltage difference into a digital signal and sequentially outputs the same may be provided.

The capacitance sensor sequentially processes first charge amounts having a positive value sensed and a second charge amount having a negative value while the conductor is not touched by the touch panel in response to the sensing signal during the offset charge amount setting period. The signal receiver is configured to sample and accumulate the first charge amounts and the second charge amounts output from the capacitance sensor n times during the offset charge amount setting period, adjust gain to remove noise, and reduce gain. The adjusted first cumulative voltages and the second cumulative voltages are output, and the mux is outputted from the noise removing unit in response to the voltage selection signal during the offset charge amount setting period. Selects and outputs the voltage differences sequentially one by one, and the AD converter During charge amount setting section, and converts the voltage difference of the output from the multiplexer into a digital signal,

The automatic correction unit generates an offset control signal generation unit and the offset for generating the offset control signal groups corresponding to respective charge amounts output from the capacitance sensor using the digital signal output from the AD converter during the offset charge amount setting period. Sequentially generating the offset charge amount having a positive value or a negative value and the same absolute value of the charge amount in response to a corresponding offset control signal group among the control signal groups, and an offset having the negative value in the first charge amount A plurality of offset compensators may be provided to generate the first corrected charge amount, which is the sum of the charge amounts, and to generate and output the second corrected charge amount, which is the sum of the offset charge amounts having the positive value in the second charge amount.

The offset charge amount setting period is when a system including the multi-touch panel and the charge amount sensing device of the multi-touch panel is initialized, when the system is reset, and the power voltage is applied to the multi-touch panel during the system operation. The electronic device may be a predetermined section of a state in which a conductor is not touched by the multi-touch panel at a point in time or after a predetermined time elapses after the offset charge amount setting section ends.

The low frequency noise includes power supply noise generated by power applied to a system including the multi-touch panel and conductor noise generated between the multi-touch panel and the conductor when the conductor touches the multi-touch panel. Each of the first cumulative voltage and the second cumulative voltage includes a noise voltage corresponding to the power supply noise and the conductor noise, and the voltage difference between the first cumulative voltage and the second cumulative voltage is the first cumulative voltage. And a voltage difference between the voltage corresponding to the first amount of charge and the voltage corresponding to the second amount of charge, in which the noise voltage is canceled by the subtraction operation of the second cumulative voltage.

According to an exemplary embodiment of the present invention, an apparatus for detecting a charge amount of a multi-touch panel cancels low-frequency noise such as power supply noise and conductor noise generated by a touch of a multi-touch panel and a conductor, and applies to a touch state of the multi-touch panel. By accumulating without amplifying the charges, the noise is averaged to attenuate the noise contained in the signal, thereby minimizing the noise, and thus improving the signal-to-noise ratio (SNR) compared to the conventional method. There is an advantage that can be guaranteed. In addition, the charge amount sensing device of the multi-touch panel removes the offset charge amount from the charge amount according to the touch state of the multi-touch panel and then attenuates the noise included in the signal and cancels the low frequency noise to detect the charge amount of the multi-touch panel and the multi-touch panel. There is an advantage that can maximize the dynamic range of the system including the device (maximum).

BRIEF DESCRIPTION OF THE DRAWINGS A brief description of each drawing is provided to more fully understand the drawings recited in the description of the invention.
1 is a block diagram of an apparatus for detecting a charge amount of a multi-touch panel according to an embodiment of the inventive concept.
FIG. 2 is a circuit diagram illustrating an embodiment of a charge amount sensing device of the multi-touch panel of FIG. 1.
3 is a waveform diagram of signals used in the amount of charge sensing device of the multi-touch panel of FIG. 2.
4 is a circuit diagram schematically illustrating a first charge amount accumulating part, a second charge amount accumulating part, and a CDS part of FIG. 2.
5 is a block diagram of an apparatus for detecting a charge amount of a multi-touch panel according to another exemplary embodiment of the inventive concept.
FIG. 6 is a circuit diagram illustrating an embodiment of a charge amount sensing device of the multi-touch panel of FIG. 5.
FIG. 7 is a circuit diagram schematically illustrating the first charge amount accumulating part, the second charge amount accumulating part, and the CDS part of FIG. 6.
8 is a view for explaining a change in the amount of charge according to the touch state of the conductor when the capacitance sensor of FIG. 1 or FIG. 5 according to an embodiment.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

1 is a block diagram of an apparatus 100 for detecting a charge amount of a multi-touch panel according to an exemplary embodiment of the inventive concept.

Referring to FIG. 1, the charge sensing device 100 of the multi-touch panel includes a signal transmitter 110, a capacitance sensor 120, a signal receiver 130, a noise remover 140, a mux 155, and an AD ( an analog to digital converter 150 may be provided.

The signal transfer unit 110 may generate and output sensing signals SEN1,..., SENj including information about a sampling time point. Each of the sensing signals SEN1,..., SENj is a sinusoidal signal having a first logic state and a second logic state, or a first logic state and a second logic state in a period in which the signal receiver 130 samples and accumulates charge amounts. May be a repeated signal, and the information on the sampling time point may be a time point at which a logic state is changed among the sensing signals SEN1, ..., SENj. For example, the point in time when the sensing signal SEN1 is changed from the first logic state to the second logic state is the sampling time point, or the point in time when the sensing signal SEN1 is changed from the second logic state to the first logic state. It may be the sampling time point. In the following description, it is assumed that the first logic state is a logic low state and the second logic state is a logic high state. However, the present invention is not limited to this case and conversely, the first logic state may be a logic high state and the second logic state may be a logic low state.

In addition, the signal transmitter 110 transmits the sensing signals SEN1,... To the corresponding input terminal among the input terminals IN1,..., INj (j is a natural number) of the capacitance sensor 120 in response to the input selection signal IN_SEL. , SENj) may transmit a corresponding sensing signal. For example, the signal transmitter 110 may select the input terminals IN1,..., INj of the capacitance sensor 120 one by one in response to the input selection signal IN_SEL, and sequentially transmit corresponding sensing signals. An embodiment of the configuration of the signal transmitter 110 will be described in more detail with reference to FIG. 2.

The capacitance sensor 120 receives a corresponding sensing signal output from the signal transmission unit 110 through a corresponding input terminal among the input terminals IN1,..., INj, and senses a positive value sensed in response to the received sensing signal. It may include a plurality of output terminals (OUT1, ..., OUTk) for sequentially outputting the first charge amount (S) having a second and the second charge amount (-S) having a negative value. That is, the output terminals OUT1,..., And OUTk output the sensed first charge amount S in parallel, and then output the sensed second charge amount S in parallel, and repeats such an operation. To do it. For example, the capacitance sensor 120 may be a mutual capacitance sensor that senses and outputs charge amounts between the input terminals IN1,..., And INj and the output terminals OUT1,..., And OUTk. The multi-touch panel may include all of a touch key and a touch screen capable of detecting a touch of a conductor (for example, a finger or a pen). Hereinafter, the term 'touch' refers to a capacitance sensor 120. This means that the conductor is in close proximity to or directly in contact with the multi-touch panel so that the amount of charge output from the panel is changed.

When the conductor touches the multi-touch panel, the first charge amount S and the second charge amount −S may include a low frequency noise component. For example, when the conductor touches the multi-touch panel, capacitance is generated between the multi-touch panel and the conductor, causing unwanted low frequency noise (N) (eg, conductor noise) due to the voltage of the conductor. Will occur. Since the conductor noise has the same sign and the same magnitude and is added to the first charge amount S and the second charge amount −S, the first charge amount output from the capacitance sensor 120 substantially reduces the charge amount of S + N. In addition, the second charge amount output from the capacitance sensor 120 may have a charge amount of -S + N.

The capacitance sensor 120 outputs the first charge amount S at the time when the sensing signal SEN is changed from the first logic state to the second logic state, and the sensing signal SEN is in the first logic state in the second logic state. The second charge amount (-S) may be output at the point of time changed to. However, the present invention is not limited to this case, and the second charge amount S is output at the time when the sensing signal SEN is changed from the first logic state to the second logic state, and the sensing signal SEN is the second. The first charge amount S may be output at the time when the logic state is changed to the first logic state. Hereinafter, for convenience, S + N in which the conductor noise N is added to the first charge amount S output from the capacitance sensor 120 is referred to as a first charge amount, and the second charge amount -S output from the capacitance sensor 120 is referred to as a first charge amount. The sum of the conductor noises N and -S + N is referred to as the second charge amount.

The signal receiver 130 samples and accumulates the first charge amounts S + N output in parallel from the output terminals OUT1,... And OUTk of the capacitance sensor 120 n times (n is a natural number). The gain is adjusted to output the first cumulative voltages V11,..., And V1k in parallel, and the first charge amount from the output terminals OUT1, ..., OUTk of the capacitance sensor 120. After the S + Ns are output, the second charges (-S + N) output in parallel are sampled n times (n is a natural number), respectively, and the gain is adjusted to adjust the second accumulated voltages V21, ..., V2k) can be output in parallel. That is, each of the first cumulative voltages V11,..., V1k is accumulated by sampling the corresponding first charge amount S + N n times and adjusting the gain, thereby sensing the capacitance sensor 120 in addition to the low frequency noise. The noise included in the corresponding first charge amount S itself may be removed and the gain may be adjusted. Each of the second cumulative voltages V21,..., And V2k is accumulated by sampling the corresponding second charge amount (-S + N) n times and adjusting gain, thereby adjusting the gain in the capacitance sensor 120 in addition to the low frequency noise. The noise included in the corresponding second charge amount (S) itself may be removed and the gain may be adjusted.

The signal receiver 130 includes a plurality of sampling units 131_1,..., 131_k, a plurality of first charge accumulation units 133_1, ..., 133_k, and a plurality of second charge accumulation units 134_1, ... , 134_k) and a gain control unit 135.

Each of the sampling units 131_1,..., 131_k has a first charge amount S + N output from a corresponding output terminal of the capacitance sensor 120 in response to sampling control signals SCON including information on the number of sampling times. ) And the second charge amount (-S + N) can be sampled n times. The information about the number of sampling may be determined as the number of times the logic state of the first sampling control signal or the second sampling control signal is changed among the sampling control signals SCON. For example, the information about the number of sampling is determined as the number of times that the first sampling control signal or the second sampling control signal is changed from the first logic state to the second logic state, or the first sampling control signal or the first sample. 2 may be determined by the number of times the sampling control signal is changed from the second logic state to the first logic state. An embodiment of each of the sampling units 131_1,..., 131_k will be described in more detail with reference to FIG. 2.

The gain controller 135 generates a plurality of gain control signals GCON using the digital signal Vo output from the AD converter 150 to generate the first charge accumulation units 133_1,..., 133_k and The two charge accumulation units 134_1,..., 134_k may be output. That is, the gain control unit 135 of the first charge accumulation units 133_1, 133_k and the second charge accumulation units 134_1, 134_k according to the digital signal Vo having a plurality of bits. It generates and outputs gain control signals GCON that can control the degree of amplification.

Each of the first charge accumulation units 133_1,..., 133_k accumulates the first charge amount S + N sampled n times by a corresponding sampling unit among the sampling units 131_1,. By adjusting, the noise included in the charge amount S itself may be removed and the first cumulative voltage V11,..., Or V1k corresponding to the accumulated charge amount whose gain is adjusted may be output. That is, by accumulating the charge amount sampled n times in the first charge accumulation units 133_1,..., 133_k, the noise is averaged as the noise having a positive value and the noise having a negative value are canceled. (S) It can minimize the noise included in itself and have the effect of amplification by accumulation. Also, each of the first charge accumulation units 133_1,..., 133_k may adjust the gain of the first cumulative voltage V11,..., Or V1k in response to the gain control signals GCON. That is, each of the first charge accumulators 133_1,..., 133_k has a first cumulative value when the voltage input to the AD converter 150 through the MUX 155 exceeds the input voltage range of the AD converter 150. Reduce the voltage (V11, ..., or V1k) and increase the first voltage (V1) if the voltage input to the AD converter 150 via the mux 155 is too small to obtain the desired value. The gain of the first cumulative voltages V11, ..., V1k may be adjusted. An embodiment of the first charge accumulation units 133_1, ..., 133_k will be described in more detail with reference to FIG. do.

Each of the second charge accumulation units 134_1,..., 134_k accumulates the second charge amount (-S + N) sampled n times by a corresponding sampling unit among the sampling units 131_1, ..., 131_k and gains. The second cumulative voltage V21,..., Or V2k corresponding to the cumulative charge amount of which the noise included in the charge amount (S) itself is removed and the gain is adjusted may be output by adjusting. That is, by accumulating the charge amount sampled n times in the second charge accumulation units 134_1,..., 134_k, the noise is averaged as the noise having a negative value and the noise having a negative value are canceled. (-S) can minimize the noise included in itself and have the effect of amplification by accumulation. Also, the second charge accumulation units 134_1,..., 134_k may adjust the gains of the second cumulative voltages V21,..., V2k in response to the gain control signals GCON. That is, each of the second charge accumulation units 134_1,..., 134_k is accumulated in the second charge when the voltage input to the AD converter 150 through the MUX 155 exceeds the input voltage range of the AD converter 150. Reduce the voltage (V21, ..., or V2k) and increase the second cumulative voltage (V21, ..., or V2k) if the input voltage of the AD converter 150 is too small to obtain the desired value. The gain of the second cumulative voltages V21,..., Or V2k may be adjusted so that an embodiment of the second charge accumulation units 134_1,..., 134_k is described in more detail with reference to FIG. 2. Explain.

The noise removing unit 140 sequentially receives the first cumulative voltages V11,..., V1k and the second cumulative voltages V21,..., V2k. The voltage difference V31, ..., or V3k between ..., or V1k and the second cumulative voltage V21, ..., or V2k is calculated to correspond to the corresponding first cumulative voltage V11, ... , Or V1k and the voltage difference (V31, ..., or V3k) between the second cumulative voltage (V21, ..., or V2k) may be output. That is, the noise removing unit 140 may generate and output a voltage difference between the first cumulative voltage and the second cumulative voltage corresponding to the first charge amount and the second charge amount output from the output terminal of the same capacitance sensor 120. have. Power noise generated by the power applied to the system including the multi-touch panel to the first cumulative voltages V11, ..., V1k output from the first charge accumulation units 133_1, ..., 133_k. Is included, and the second cumulative voltages V21, ..., V2k output from the second charge accumulation units 134_1, ..., 134_k are applied to a power source applied to a system including the multi-touch panel. It may include power supply noise generated by. That is, when the conductor touches the multi-touch panel, the power noise is generated. For example, when the smartphone is used, the power noise is generated when power is supplied from an external power source. The power supply noise may also be included in the low frequency noise N described above, and the low frequency noise N may refer to noise including the conductor noise and the power supply noise.

That is, the first cumulative voltages V11,..., V1k and the second cumulative voltages V21,..., V2k include noise voltages corresponding to the power supply noise and the conductor noise. The noise voltage included in the corresponding first cumulative voltage and the second cumulative voltage among the first cumulative voltages V11, ..., V1k and the second cumulative voltages V21,. It is a voltage having the same magnitude. Accordingly, the noise removing unit 140 calculates and outputs a voltage difference V31,..., Or V3k between the corresponding first cumulative voltage and the second cumulative voltage, thereby reducing the first cumulative voltages V11,. The noise voltage included in the second and second cumulative voltages V21,..., V2k may be canceled by canceling each other. Therefore, the voltage differences V31,..., V3k output in parallel from the noise removing unit 140 may be voltages from which low frequency noise generated when the conductor touches the panel is removed.

The noise removing unit 140 may include a CDS control unit 143 and a plurality of CDS units 145_1,..., 145_k.

The CDS controller 143 may generate a plurality of CDS control signals CCON using the digital signal Vo output from the AD converter 150 and output the generated CDS control signals CCON to the CDS units 145_1,..., 145_k. . That is, the CDS control unit 143 generates CDS gain control signals CCON that can adjust the degree of amplification of the CDS units 145_1,..., 145_k according to the digital signal Vo having a plurality of bits. Output

Each of the CDS units 145_1,..., 145_k performs correlated double sampling of the corresponding first and second cumulative voltages in response to CDS control signals CCON to remove low frequency noise. And output the voltage difference V31,..., Or V3k between the corresponding first cumulative voltage and the second cumulative voltage whose gain is adjusted. That is, each of the CDS units 145_1,..., 145_k subtracts the corresponding first and second accumulated voltages in response to the CDS control signals CCON to calculate a noise voltage corresponding to the low frequency noise. Can be removed and the gain-adjusted voltage difference (V31, ..., or V3k) can be output. An embodiment and a specific operation of the noise removing unit 140 will be described in more detail with reference to FIGS. 2 to 4.

The mux 155 may sequentially select and output voltages output from the noise removing unit 140 in response to the voltage selection signal OUT_SEL. The voltage differences V31,..., And V3k output from the noise removing unit 140 may be simultaneously applied to the mux 155 in parallel. In this case, the mux 155 may be applied to the voltage selection signal OUT_SEL. In response, one by one may be sequentially selected and output to the AD converter 150. For example, the mux 155 outputs the voltage difference V31 output from the CDS unit 145_1 to change the digital signal Vo from the AD converter 150 and then outputs the voltage difference output from the next CDS unit. By repeating the operation of transferring to the AD converter 150, the input voltage differences V31,..., And V3k may be sequentially output to the AD converter 150. The operation of the mux 155 will be described in more detail with reference to FIGS. 2 and 3.

The AD converter 150 may convert the voltage differences V31,..., V3k sequentially output from the mux 155 into a digital signal Vo. The digital signal Vo converted by the AD converter 150 may be used for an application.

2 is a circuit diagram illustrating an embodiment of the charge amount sensing device 100 of the multi-touch panel of FIG. 1, and FIG. 3 is a waveform diagram of signals used in the charge amount sensing device 100 of the multi-touch panel of FIG. 2. . Hereinafter, an embodiment of each component and an operation of each component of the charge amount sensing device 100 of the multi-touch panel will be described with reference to FIGS. 1 to 3.

The signal transmitter 110 may include a sensing controller 270, a plurality of sensing drivers 273_1,..., 273_j, and a plurality of sensing signal output units 275_1,..., 275_j. The sensing controller 270 may generate and output a sensing control signal SECON in response to the digital signal Vo output from the AD converter 150. Each of the sensing drivers 273_1,..., And 273_j is enabled or disabled in response to the input selection signal IN_SEL, and in response to the sensing control signal SECON when enabled in response to the input selection signal IN_SEL. At least one driving signal controlling the corresponding sensing signal output unit among the sensing signal output units 275_1,..., And 275_j may be generated and output to the corresponding sensing signal output unit.

Each of the sensing drivers 273_1,..., 273_j may include at least one driver for generating at least one driving signal. For example, as illustrated in FIG. 2, each of the sensing drivers 273_1,..., And 273_j includes the first driver DR1 and the NMOS transistor N1 that generate a driving signal for turning on or off the PMOS transistor P1. ) May be provided with a second driver DR2 that generates a driving signal for turning on or off. The first driver DR1 and the second driver DR2 may output signals having opposite logic states. Alternatively, one driving signal may be output from each of the sensing drivers 273_1,..., And 273_j and applied to the gates of the PMOS transistor P1 and the NMOS transistor N1 to be one of the PMOS transistor P1 and the NMOS transistor N1. It can also be controlled to turn on only transistors.

Each of the sensing signal output units 275_1,..., 275_j has a first voltage VH in a first logic state or a second voltage in a second logic state in response to the at least one driving signal received from a corresponding sensing driver. The sensing signal SEN1,..., Or SENj of the VL may be output. As illustrated in FIG. 3, each of the sensing signals SEN1,..., And SENj has a first voltage VH in a section in which a corresponding input selection signal among the input selection signals IN_SEL1, ..., IN_SELj is in a second logic state. The first logic state and the second logic state of the second voltage (VL) may be a sine wave signal is repeated. For example, each of the sensing signal output units 275_1,..., 275_j may have a PMOS transistor P1 and an NMOS connected in series between the first voltage VH and the second voltage VL, as shown in FIG. 2. It may be an inverter including the transistor N1.

In the above, an embodiment of the signal transmission unit 110 has been described with reference to FIG. 2, but the signal transmission unit 110 of the present invention is not limited thereto, and the signal reception unit 130 samples the charges. If the first logic state and the second logic state are generated in the accumulating section, the signal may be generated and output to a corresponding input terminal of the capacitance sensor 120.

The capacitance sensor 120 may be modeled as a capacitor emf (C _MUT1 , ..., C _MUTk ) connected between the input terminals IN1, ..., INj and the output terminals OUT1, ..., OUTk. In response to the sensing signal SEN, the first charge amount S + N and the second charge amount −S + N may be sequentially and repeatedly output through the corresponding output terminal.

Each of the sampling units 131_1,..., 131_k includes a first sampling switching unit 211, a second sampling switching unit 212, and a third sampling unit for sampling the amount of charge output from a corresponding output terminal of the capacitance sensor 120. The sampling switching unit 213 may be provided. Since the first sampling switching unit 211, the second sampling switching unit 212, and the third sampling switching unit 213 included in each of the sampling units 131_1,..., 131_k may have the same configuration, For convenience of description, the first sampling switching unit 211, the second sampling switching unit 212, and the third sampling switching unit 213 included in the sampling unit 131_1 will be described.

The first sampling switching unit 211 is an output of the sampling sensor 131_1 from the output terminal OUT1 of the capacitance sensor 120 in response to the first sampling control signal SCON1 among the sampling control signals SCON. One charge amount (S + N) can be sampled and output. That is, the first sampling switching unit 211 may connect or disconnect the output terminal OUT1 of the capacitance sensor 120 and the input terminal of the first charge accumulation unit 133_1 in response to the first sampling control signal SCON1. The second sampling switching unit 212 outputs the output of the sampling sensor 131_1 to the output terminal OUT1 of the capacitance sensor 120 in response to the second sampling control signal SCON2 among the sampling control signals SCON. 2 charges (-S + N) can be sampled and output. That is, the second sampling switching unit 212 may connect or disconnect the output terminal OUT1 of the capacitance sensor 120 and the input terminal of the second charge accumulation unit 134_1 in response to the second sampling control signal SCON2. The third sampling switching unit 213 may connect or disconnect the output terminal OUT1 of the capacitance sensor 120 and the ground voltage source VSS in response to the third sampling control signal SCON3 among the sampling control signals SCON. .

The first sampling switching unit 211 and the second sampling switching unit 212 are selectively operated, and the third sampling switching unit 213 operates an operation section of the first sampling switching unit 211 and the second sampling switching unit ( It operates between the operation sections of 212). The operation of the first to third sampling switching units 211, 212, and 213 will be described in more detail with reference to the overall operation of the signal receiving unit 130.

Each of the first charge accumulation units 133_1,..., 133_k may include a first operational amplifier 225, a first initialization switching unit 220, a plurality of first capacitors C1,. The first gain control switching unit of the (233_1, ..., 233_n) may be provided. The first operational amplifier 225, the first initialization switching unit 220, and the plurality of first capacitors C1, Cn included in each of the first charge accumulation units 133_1,..., 133_k. Since the plurality of first gain control switching units 233_1,..., And 233_n may have the same configuration, the first operational amplifier 225 included in the first charge accumulation unit 133_1 will be described below for convenience of description. The first initialization switching unit 220, the plurality of first capacitors C1 to Cn, and the plurality of first gain control switching units 233_1 to 233_n will be described.

The first operational amplifier 225 mux 155 the input terminal (-) connected to the output terminal of the sampling unit 131_1, the ground voltage input terminal (+) and the first accumulated voltage V1 connected to the ground voltage source VSS. It may include an output terminal for outputting. The first initialization switching unit 220 may connect or disconnect the input terminal (−) and the output terminal of the first operational amplifier 225 in response to the first initialization signal RST1. That is, when the touch state of the multi-touch panel is changed or when the first charge amount S + N is sampled and accumulated n times, the first initialization switching unit 220 receives an input terminal of the first operational amplifier 225. The first cumulative voltage V1 may be initialized by connecting the negative terminal and the output terminal.

The first capacitors C1, ..., Cn are connected in parallel between the input terminal (-) and the output terminal of the first operational amplifier 225, and the first gain control switching units 233_1, ..., 233_n The corresponding first gain control switching unit may be connected between the input terminal (−) of the first operational amplifier 225 and the corresponding first capacitor or between the output terminal of the first operational amplifier 225 and the corresponding first capacitor. That is, each of the first gain control switching units 233_1,..., 233_n corresponds to an input terminal of the first operational amplifier 225 in response to a corresponding gain control signal among the gain control signals GCON_1,..., GCON_n. A corresponding first capacitor may be connected or disconnected between the negative terminal and the output terminal. Therefore, the gain control signals GCON_1, ..., GCON_n and the first gain control switching units 233_1, ..., 233_n are used between the input terminal (-) and the output terminal of the first operational amplifier 225. By adjusting the number of connected first capacitors, the first charge amounts S + N sampled by the sampling unit 131 may be accumulated and gain may be adjusted.

As the sum of capacitances of the first capacitors connected between the input terminal (−) and the output terminal of the first operational amplifier 225 decreases, the first accumulated voltage V11 output from the first charge accumulation unit 133_1 increases, and As the sum of capacitances of the first capacitors connected between the input terminal (−) and the output terminal of the first operational amplifier 225 increases, the first accumulated voltage V11 output from the first charge accumulation unit 133_1 decreases. Therefore, as the number of gain control switching units turned on among the first gain control switching units 233_1, ..., 233_n is adjusted using the gain control signals GCON_1,. The first accumulation voltage V11 output from the charge accumulation unit 133_1 may be amplified or attenuated.

That is, the gain control unit 135 uses the digital signal Vo output from the AD converter 150 to output the first accumulated voltages V11,... Which are output from the first charge accumulation units 133_1,. In order to increase V1k, gain control signals GCON_1, ..., GCON_n to reduce the number of the first capacitors connected between the input terminal (-) and the output terminal of the first operational amplifier 225. ) And the first cumulative voltages V11, ..., output from the first charge accumulation units 133_1, ..., 133_k using the digital signal Vo output from the AD converter 150. In order to decrease V1k), gain control signals GCON_1, ..., GCON_n are generated to increase the number of the first capacitors connected between the input terminal (-) and the output terminal of the first operational amplifier 225. Can be output.

Each of the second charge accumulation units 134_1,..., 134_k is similar to the first charge accumulation unit except that a second charge amount (-S + N) is input instead of the first charge amount S + N. It can work similarly with configuration.

Similar to the first charge accumulation unit, the second charge accumulation units 134_1,..., 134_k may include the second operational amplifier 235, the second initialization switching unit 230, and the plurality of second capacitors C1, ..., Cn) and a plurality of second gain control switching units 234_1, ..., 234_n. The second operational amplifier 235, the second initialization switching unit 230, and the plurality of second capacitors C1, ..., Cn included in each of the second charge accumulation units 134_1,..., 134_k. Since the plurality of second gain control switching units 234_1,..., 234_n may have the same configuration, the second operational amplifier 235 included in the second charge accumulation unit 134_1 will be described below for convenience of description. The second initialization switching unit 230, the plurality of second capacitors C1, ..., Cn and the plurality of second gain control switching units 234_1, ..., 234_n will be described.

The second operational amplifier 235 mux 155 the input terminal (-) connected to the output terminal of the sampling unit 131_1, the ground voltage input terminal (+) and the second accumulated voltage V21 connected to the ground voltage source VSS. It may include an output terminal for outputting. The second initialization switching unit 230 may connect or disconnect the input terminal (−) and the output terminal of the second operational amplifier 235 in response to the second initialization signal RST2. That is, when the touch state of the multi-touch panel is changed or when the second charge amount (-S + N) is sampled and accumulated n times, the second initialization switching unit 230 of the second operational amplifier 235 The second cumulative voltage V21 may be initialized by connecting the input terminal (−) and the output terminal.

The second capacitors C1, ..., Cn are connected in parallel between the input terminal (-) and the output terminal of the second operational amplifier 235, and the second gain control switching units 234_1, ..., 234_n The corresponding second gain control switching unit may be connected between the input terminal (−) of the second operational amplifier 235 and the corresponding second capacitor or between the output terminal of the second operational amplifier 235 and the corresponding second capacitor. That is, each of the second gain control switching units 234_1,..., 234_n is an input terminal of the second operational amplifier 235 in response to a corresponding gain control signal among the gain control signals GCON_1,..., GCON_n. A corresponding second capacitor may be connected or disconnected between the negative terminal and the output terminal. Therefore, between the input terminal (-) and the output terminal of the second operational amplifier 235 by using the gain control signals GCON_1, ..., GCON_n and the second gain control switching units 233_1, ..., 233_n. By adjusting the number of connected second capacitors, the second charge amounts (S + N) sampled by the sampling unit 131_1 may be accumulated and gain may be adjusted. The same reference numeral among the first capacitors and the second capacitors may have the same capacitance value.

As the capacitance sum of the second capacitors connected between the input terminal (−) and the output terminal of the second operational amplifier 235 decreases, the second cumulative voltage V21 output from the second charge accumulation unit 134_1 increases, and As the capacitance sum of the second capacitors connected between the input terminal (−) and the output terminal of the second operational amplifier 235 increases, the second accumulated voltage V21 output from the second charge accumulation unit 134_1 decreases. Accordingly, the second gain control switching units 234_1, ..., 234_n are adjusted using the gain control signals GCON_1,..., GCON_n to adjust the number of gain control switching units turned on. The second accumulation voltage V21 output from the charge accumulation unit 134_1 may be amplified or attenuated.

In other words, the gain control unit 135 uses the digital signal Vo output from the AD converter 150 to generate the second accumulated voltages V21 and V21 output from the second charge accumulation units 134_1,. In order to increase the V2k, gain control signals GCON_1, ..., GCON_n to reduce the number of the second capacitors connected between the input terminal (-) and the output terminal of the second operational amplifier 235. ) And the second cumulative voltages V21, ..., output from the second charge accumulation units 134_1, ..., 134_k using the digital signal Vo output from the AD converter 150. In order to decrease V2k), gain control signals GCON_1, ..., GCON_n are generated to increase the number of the second capacitors connected between the input terminal (-) and the output terminal of the second operational amplifier 235. Can be output.

The first to third sampling control signals SCON_1, SCON_2, and SCON_3, the first and second initialization signals RST_1 and RST_2, and the gain control signals GCON_1,..., GCON_n described above are gains. The control unit 135 may generate and output the output signal, or the gain control unit 135 and other components may generate and output the divided signals.

Each of the CDS units 145_1,..., 145_k performs correlated double sampling of the corresponding first and second cumulative voltages in response to CDS control signals CCON to remove low frequency noise. And the gain-adjusted voltage difference (V31, ..., V3k) between the first accumulated voltage and the second accumulated voltage. That is, each of the CDS units 145_1,..., 145_k subtracts the corresponding first and second accumulated voltages in response to the CDS control signals CCON to calculate a noise voltage corresponding to the low frequency noise. The voltage difference V31,..., V3k between the first cumulative voltage and the second cumulative voltage whose gain is adjusted and removed may be output.

Each of the CDS units 145_1,..., 145_k includes a selector 243, a first CDS capacitor Cs, a CDS operational amplifier 265, a CDS initialization switching unit 260, and second CDS capacitors CC1,. , CCn) and a plurality of CDS gain control switching units 267_1,..., 267_n. The selector 243, the first CDS capacitor Cs, the CDS operational amplifier 265, the CDS initialization switching unit 260, and the second CDS capacitors included in each of the CDS units 145_1,..., 145_k. CC1,..., CCn) and the plurality of CDS gain control switching units 267_1,..., 267_n may have the same configuration. Hereinafter, for convenience of explanation, the selection unit included in the CDS unit 145_1 ( 243, the first CDS capacitor Cs, the CDS operational amplifier 265, the CDS initialization switching unit 260, the second CDS capacitors CC1, CCn, and a plurality of CDS gain control switching units 267_1. , ..., 267_n) will be described.

The selector 243 may output the first cumulative voltage V11 and the second cumulative voltage output from the signal receiver 130 in response to the first and second selection signals SEL1 and .SEL2 among the CDS control signals CCON. (V21) can be output sequentially. The selector 243 may include a first select switch 243 and a second select switch 245. The first selection switching unit 243 connects or disconnects an output terminal of the first charge accumulation unit 133_1 and one end of the first CDS capacitor Cs in response to the first selection signal SEL1 to prevent the first leakage voltage ( V11) may be delivered to or disconnected from the first CDS capacitor Cs. The second selection switching unit 245 connects or disconnects an output terminal of the second charge accumulation unit 134_1 and one end of the first CDS capacitor Cs in response to the second selection signal SEL2 to prevent the second leakage voltage ( V21) may be delivered or interrupted to the first CDS capacitor Cs. The first selective switching unit 243 and the second selective switching unit 243 may be selectively turned on without being turned on at the same time.

The first CDS capacitor Cs may be connected between an output terminal of the selector 240 and an input terminal (−) of the CDS operational amplifier 265. The CDS operational amplifier 265 has an input terminal (-) connected to the other end of the first CDS capacitor Cs, a ground voltage input terminal (+) connected to the ground voltage source VSS, and a first cumulative voltage V11 and a second accumulation. An output terminal for outputting a voltage difference V31 of the voltage V21 may be provided. The CDS initialization switching unit 260 may output the CDS control signals in a section other than a section in which the CDS operational amplifier 265 outputs the voltage difference V31 and a section in which the AD converter 150 outputs the digital signal Vo. The voltage difference V31 may be initialized by connecting an input terminal (−) and an output terminal of the CDS operational amplifier 265 in response to the CDS initialization signal CRST. The second CDS capacitors CC1,..., CCn may be connected in parallel between the input terminal (−) and the output terminal of the CDS operational amplifier 265, and the CDS gain control switching units 267_1,..., 267_n. The CDS operational amplifier 265 selects each of the second CDS capacitors CC1,..., CCn in response to the corresponding CDS gain control signals CCON_1,..., Or CCON_n among the CDS control signals CCON. It can be connected or disconnected between the input terminal (-) and the output terminal of.

By the operation of the first CDS capacitor Cs, the CDS operational amplifier 265, the second CDS capacitors CC1, ..., CCn and the CDS gain control switching units 267_1, ..., 267_n, The voltage difference V31 between the first cumulative voltage V11 and the second cumulative voltage V21 may be generated and the gain of the voltage difference V31 may be adjusted. That is, each of the CDS gain control switching units 267_1,..., 267_n is an input terminal of the CDS operational amplifier 265 in response to the corresponding CDS gain control signal among the CDS gain control signals CCON1,..., CCONn. Since the corresponding second CDS capacitor can be connected or disconnected between the negative terminal and the output terminal, the voltage difference V3 is adjusted by adjusting the number of second CDS capacitors connected between the input terminal (-) and the output terminal of the CDS operational amplifier 265. You can adjust the gain. As the capacitance sum of the second CDS capacitors connected between the input terminal (-) and the output terminal of the CDS operational amplifier 265 decreases, the voltage difference V31 increases, and between the input terminal (-) and the output terminal of the CDS operational amplifier 265. As the sum of capacitances of the second CDS capacitors connected to the voltage increases, the voltage difference V31 decreases. Accordingly, as the number of CDS gain control switching units turned on among the CDS gain control switching units 267_1, ..., 267_n is adjusted using the CDS gain control signals CCON_1,. The difference V31 can be amplified or attenuated.

Therefore, when the CDS controller 143 is to amplify the voltage differences V31,..., V3k by using the digital signal Vo output from the AD converter 150, the CDS controller 143 input terminal ( And CDS gain control signals CCON_1, ..., CCON_n to reduce the number of the second CDS capacitors connected between-) and the output terminal, and output the digital signal Vo output from the AD converter 150. In order to attenuate the voltage differences (V31, ..., V3k) by using the CDS gain to increase the number of the second CDS capacitors connected between the input terminal (-) and the output terminal of the CDS operational amplifier 265 Control signals CCON_1, ..., CCON_n may be generated and output.

Each of the CDS units 145_1,..., 145_k has the other end of the first CDS capacitor Cs and the input terminal (-) of the CDS operational amplifier 265 in response to the holding signal HOL among the CDS control signals CCON. It may further include a holding unit 255 for connecting or blocking the. For example, in the period in which the AD converter 150 converts the voltage difference V31 into the digital signal Vo, the holding unit 255 included in the CDS units 145_1,..., 145_k transmits a signal. The first cumulative voltage and the second cumulative voltage output from the unit 130 may be prevented from being applied to the input terminal of the CDS operational amplifier 265. That is, when the operation is performed at the stage after the holding unit 255 and the first or second accumulated voltage is not applied to the input terminal of the CDS operational amplifier 265, the holding unit 255 is formed. One input terminal of the CDS capacitor Cs and the CDS operational amplifier 265 may be blocked. The operation of the holding unit 255 will be described in more detail with reference to FIG. 3 with reference to the charge amount sensing device 100 of the multi-touch panel.

The first and second selection signals SEL1 and SEL2, the CDS initialization signal CRST, the holding signal HOL, and the CDS gain control signals CCON1,..., CCONn described above are stored in the CDS controller 143. May be generated and output, or may be generated and output by dividing the signals by the CDS control unit 143 and other components.

Hereinafter, an operation of the charge amount detecting device 100 of the multi-touch panel will be described with reference to FIGS. 1 to 3.

When the multi-touch panel is initialized to recognize a touch state (for example, when power is applied to the multi-touch panel), when the touch state of the multi-touch panel is changed or when the first charge amount is n times When sampling and accumulating, the first initialization signal RST1 is changed from the first logic state to the second logic state so that the first initialization switching unit 220 is turned on. In this case, since the input terminal (−) and the output terminal of the first operational amplifier 225 are directly connected, the outputs of the first charge accumulation units 133_1,..., 133_k are initialized to the ground voltage. When the multi-touch panel is initialized to recognize the touch state, when the touch state of the multi-touch panel is changed or when the second charge amount is sampled and accumulated n times, the second initialization signal RST2 is generated. The second initialization switching unit 230 is turned on by changing from the first logic state to the second logic state. In this case, since the input terminal (−) and the output terminal of the second operational amplifier 235 are directly connected, the outputs of the second charge accumulation units 134_1,..., 134_k are initialized to the ground voltage.

Thereafter, at time t0, the input selection signal IN_SEL1 is changed to a second logic state, and at time t1, the capacitance sensor 120 is connected to the multi-touch panel in relation to the input terminal IN1 in response to an applied sensing signal SEN1. Starts to output the first charge amount S + N according to the touch state of the sensor, and at a time t2, the capacitance sensor 120 responds to the sensing signal SEN1 applied to the second charge amount according to the touch state of the multi-touch panel. Start printing (-S + N).

Each of the sampling units 131_1,..., 131_k corresponds to the capacitance of the capacitance sensor 120 in response to the first sampling control signal SCON1 when the sensing signal SEN1 changes from the second logic state to the first logic state. The first charge amount S + N output from the corresponding output terminal is sampled, and the capacitance is responsive to the second sampling control signal SCON2 at the time when the sensing signal SEN1 changes from the first logic state to the second logic state. The second charge amount (-S + N) output from the corresponding output terminal of the sensor 120 may be sampled. Each of the sampling units 131_1,..., 131_k is a first sampling control signal SCON1 which is an interval between an operation period of the first sampling switching unit 211 and an operation period of the second sampling switching unit 212. The corresponding output terminal of the capacitance sensor 120 may be connected to the ground voltage source VSS in a section in which the second sampling control signal SCON2 is simultaneously in the first logic state.

That is, when the third sampling control signal SCON_3 is in the second logic state and the second and third sampling control signals SCON_2 and SCON_3 are in the first logic state, the third sampling switching unit 213 is turned on and the first sampling state is turned on. The first and second sampling switching units 211 and 212 are turned off so that the corresponding output terminal of the capacitance sensor 120 is connected to the ground voltage source VSS and does not sample the first charge amount or the second charge amount. When the first sampling control signal SCON_1 is in the first logic state and the second and third sampling control signals SCON_2 and SCON_3 are in the second logic state, the first sampling switching unit 211 is turned on and the second and The third sampling switching units 212 and 213 may be turned off so that a corresponding output terminal of the capacitance sensor 120 may be input to a corresponding first charge accumulation unit to sample the first charge amount. When the second sampling control signal SCON_2 is in the first logic state and the first and third sampling control signals SCON_1 and SCON_3 are in the second logic state, the second sampling switching unit 212 is turned on and the first and second sampling control signals SCON_1 and SCON_2 are turned on. The third sampling switching units 211 and 213 may be turned off so that the corresponding output terminal of the capacitance sensor 120 may be input to the corresponding second charge accumulation unit to sample the second charge.

In FIG. 3, the sampling count and the cumulative number n are 4, but the present invention is not limited thereto, and the sampling count and the cumulative number n may be other various times. In the case of FIG. 3, each of the sampling units 131_1,..., 131_k has four points of time when the first sampling control signal SCON_1 is changed from the first logic state to the second logic state (the sensing signal SEN1 is the second time). The first charge amount is sampled at the four time points of changing from the logic state to the first logic state, and each of the first charge amount accumulators 133_1,..., 133_k accumulates and gains the first charge amounts sampled four times. The first cumulative voltage V11,..., Or V1k corresponding to the cumulative charge amount may be output by adjusting. In addition, the sampling units 131_1,..., 131_k have four points in time when the second sampling control signal SCON_2 is changed from the first logic state to the second logic state (the sensing signal SEN1 is in the first logic state). The second charge amount is sampled at the fourth time point changed to the second logic state, and each of the second charge amount accumulators 134_1,..., 134_k accumulates the second charge amounts sampled four times and adjusts gain. Second cumulative voltages V21,..., And V2k corresponding to the cumulative charge amount may be output. Since the method of accumulating the sampled first charge amounts or the second charge amounts and adjusting the gain has been described in detail above, a detailed description thereof will be omitted.

In response to the first selection signal SEL1, the first selection switching unit 243 may output the first cumulative voltage output by the corresponding first charge accumulation unit to the first CDS capacitor Cs until t3. In response to the second selection signal SEL2, the second selection switching unit 245 receives the first CDS capacitor Cs in the period between the time t3 and the time t4 of the second accumulated voltage output by the corresponding second charge accumulation unit. Can be printed as

The output voltage of each of the CDS units 145_1,..., 145_k corresponds to the CDS initialization signal CRST at time t2 (the AD converter 150 changes the previously input voltage difference to the digital signal Vo). Is initialized to the ground voltage VSS in the period between the time point t3 and the time point t3, and each of the CDS units 145_1,... The voltage difference V31,..., V3k between the first cumulative voltage and the second cumulative voltage from which low frequency noise N is removed may be output by subtracting a voltage and adjusting gain.

In addition, during the time t4 to the time t6, the mux 155 outputs the voltage differences V31, ..., output from the noise removing units 145_1, 145_k in parallel in response to the voltage selection signal OUT_SEL. V3k) is sequentially selected and output one by one, and the AD converter 150 is enabled in response to the AD converter enable signal ADC_EN, so that the voltage difference between the first and second cumulative voltages V31, ... Or V3k may be converted into a digital signal Vo and output. That is, in FIG. 3, one of voltage differences V31,..., And V3k may be selected and output for each section in which the voltage selection signal OUT_SEL is in the second logic state, and the voltage difference into which the mux 155 is input. The AD converter 150 continues to change the output voltage of the mux 155 to the digital signal Vo until all of the fields V31, ..., V3k are output.

In this case, the holding unit 255 cuts off the connection between the first CDS capacitor Cs and the input terminal (-) of the CDS operational amplifier 265 in response to the holding signal HOL in the period between the time points t4 and t6. Thus, before the operation of the AD converter 150 is completed, the voltage difference between the new first accumulated voltage and the second accumulated voltage may be prevented from being input to the AD converter 150.

In addition, since the other input selection signal IN_SEL2 is enabled from the time t4, the capacitance sensor 120 responds to the sensing signal SEN2 applied at the time t5 according to the touch state of the multi-touch panel in relation to the other input terminal. Starting to output a new first charge amount, the sampling units 131_1,..., 131_k may start sampling the new first charge amount. That is, such an operation is performed whenever a corresponding sensing signal of the sensing signals SEL1, ..., SELj is input to one of the input terminals IN1,…, INj of the capacitor sensor 120. Sensing signals corresponding to the input terminals IN1,…, INj of the sensor 120 may be sequentially input.

3 illustrates signals for operating the charge amount sensing device 100 of the multi-touch panel according to an embodiment of the present invention, the charge amount sensing device 100 of the multi-touch panel according to an embodiment of the present invention is shown. Signals for operation do not necessarily have a waveform as shown in FIG. 3, and the signals shown in FIG. 3 may have other waveforms as long as they can operate as described above.

FIG. 4 is a circuit diagram schematically illustrating the first charge amount accumulator 133_1, the second charge amount accumulator 134_1, and the CDS unit 145_1 of FIG. 2.

1 to 4, a parallel connection is made between an input terminal (−) and an output terminal of the first operational amplifier 225 among the first capacitors C1,..., Cn of the first charge accumulation unit 133_1. The first capacitors may be modeled as one capacitor C _F as shown in FIG. 4. Also, among the second capacitors C1,..., Cn of the second charge accumulation unit 134_1, second capacitors connected in parallel between the input terminal (−) and the output terminal of the second operational amplifier 235 are also illustrated in FIG. 4. As shown in FIG. 1, one capacitor C _F may be modeled. The capacitance of the first capacitors connected between the input terminal (-) and the output terminal of the first operational amplifier 225 and the capacitance of the second capacitors connected between the input terminal (-) and the output terminal of the second operational amplifier 235 have the same capacitance. Therefore, in FIG. 4, the same capacitor C _F was modeled. In addition, the second CDS capacitors connected between the input terminal (−) and the output terminal of the CDS operational amplifier 265 among the second CDS capacitors CC1,..., CCn also have one capacitor ( C _H ).

As described above, the first charge amount accumulator 133_1 outputs the first accumulated voltage V11 in which the sampled first charge amount S + N is accumulated n times and the gain is adjusted, and the second charge amount accumulator ( 134_1 may output the second accumulated voltage V21 in which the sampled second charge amount (-S + N) is accumulated n times and the gain is adjusted. In addition, since the first selective switching unit 243 and the second selective switching unit 245 are selectively operated, the first selective switching unit 243 performs the first selection signal in the interval between the time t1 and the time t3 in FIG. 3. In response to SEL1, the first cumulative voltage V1 is output, and in a period between a time point t3 and a time point t5 in FIG. 3, the second selection switching unit 245 responds to the second selection signal SEL2 in response to the second selection signal SEL2. The accumulated voltage V2 may be output. In this case, the CDS unit 145_1 may subtract the first cumulative voltage V1 and the second cumulative voltage V2 and adjust the gain to output the third voltage V3. That is, since the CDS unit 145_1 subtracts the second cumulative voltage V21 from the first cumulative voltage V11, the noise that is commonly included in the first cumulative voltage V11 and the second cumulative voltage V21. The voltage (low frequency noise component (N)) is canceled out of each other, the sampled charge amounts S and S except for the noise component are subtracted to generate a voltage corresponding to the charge amount of 2S, and gain by C _S / C _H. The voltage difference V31 in this adjusted state can be output.

By the above operation, the voltage difference V31 between the first cumulative voltage V11 and the second cumulative voltage V21 output from the CDS unit 145_1 may be expressed as Equation 1 below, and the remaining CDS The voltage output from the units can be expressed in the same way.

In Equation 1, C _F denotes a sum of capacitances of first capacitors connected between an input terminal (−) and an output terminal of the first operational amplifier 225 among the first capacitors C1,..., Cn. Among the first capacitors C1, ..., Cn, the capacitance sum of the first capacitors connected between the input terminal (-) and the output terminal of the first associative amplifier 225 and the second capacitors C1, ..., Cn. , Cn is equal to the sum of capacitances of the second capacitors connected between the input terminal (-) and the output terminal of the second operational amplifier 235, so that C _F is the second of the capacitors (C1, ..., Cn). It may mean the sum of capacitances of the second capacitors connected between the input terminal (−) and the output terminal of the second operational amplifier 235. In Equation 1, C _H is a sum of capacitances of second CDS capacitors connected between an input terminal (−) and an output terminal of the CDS operational amplifier 265 among the second CDS capacitors CC1,..., CCn. it means. V _N denotes a noise voltage included in the first cumulative voltage V11 and the second cumulative voltage V21 due to the low frequency noise.

5 is a block diagram of an apparatus 500 for detecting a charge amount of a multi-touch panel according to another exemplary embodiment of the inventive concept.

Referring to FIG. 5, the charge detection device 500 of the multi-touch panel includes a signal transmitter 510, a capacitance sensor 520, a signal receiver 530, a noise remover 540, a mux 555, and an AD ( An analog to digital converter 550 and an automatic corrector 560 may be provided. In comparison with the embodiment of FIG. 1 and the embodiment of FIG. 5, in the embodiment of FIG. 5, an automatic correction unit 560 is added in the embodiment of FIG. 1, and the remaining elements are the same elements. Therefore, hereinafter, description will be made mainly of parts different from the embodiment of FIG. 1, and descriptions overlapping with the embodiment of FIG. 1 will be omitted.

The signal transfer unit 510 generates sensing signals SEN1,..., SENj including information about a sampling time point in response to the input selection signal IN_SEL to the corresponding inputs of the inputs of the capacitance sensor 520. The capacitance sensor 520 may output a sensing signal corresponding to one of the sensing signals SEN1, SENj output from the signal transmission unit 510 through a corresponding input terminal among the input terminals IN1, ..., INj. And a plurality of output terminals OUT1 and OUT for sequentially outputting a first charge amount S having a sensed positive value and a second charge amount -S having a negative value in response to the received sensing signal. .., OUTk).

The automatic correction unit 560 sets the offset charge amounts Qoff1, ..., Qoffk by using the charge amounts output from the output terminals OUT1, ..., OUTk of the capacitance sensor 520 during the offset charge amount setting period. A plurality of offset control signal groups may be generated, and in a period other than the offset charge amount setting period, offset charge amounts Qoff1,..., In each of the first charge amounts S + N output from the capacitance sensor 520. , Qoffk generates and outputs a first corrected charge amount from which the corresponding offset charge amount is removed, and offset charge amounts Qoff1, ..., in each of the second charge amounts -S + N output from the capacitance sensor 520. The second correction charge amount from which the corresponding offset charge amount is removed from Qoffk) may be generated and output. That is, when the automatic correction unit 560 outputs the first charge amount S + N having a positive value at the output terminal of the capacitance sensor 520, the offset charge amount having a negative value (-Qoff1, ..., ... Alternatively, the offset charge amount can be removed by generating -Qoffk) and adding it to the first charge amount S + N. The automatic correction unit 560 outputs the second charge amount (-S + N) having a negative value at the output terminal of the capacitance sensor 520, and has a positive offset value Qoff1, ..., ... Alternatively, the offset charge amount can be removed by generating Qoffk) and adding it to the second charge amount (-S + N).

The offset charge amount setting period is when the system including the multi-touch panel and the charge detection device 500 of the multi-touch panel is initialized, when the system is reset, the power supply voltage to the multi-touch panel during the system operation The terminal may be a predetermined section in which a conductor is not touched by the multi-touch panel at a point in time at which application is started or a predetermined time elapses after the offset charge setting section ends. For example, assuming that the multi-touch panel is a liquid crystal panel of a smartphone and the charge sensing device 100 of the multi-touch panel is included in the smartphone, when the smartphone is initialized, the smartphone When the power is turned on and the power is applied to the smartphone, the power is supplied to the smartphone, but when the liquid crystal panel of the smartphone is turned off and the power is turned on, or the power of the smartphone is applied. When the offset charge amount is set to be reset at predetermined time intervals, the offset charge may be a predetermined section in which the conductor is not touched by the multi-touch panel when the predetermined time elapses.

During the offset charge setting period, the automatic correction unit 560 may generate offset control signal groups using the digital signal Vo output from the AD converter 550. That is, during the offset charge amount setting period, the capacitance sensor 520 senses the first charge amount S and the second charge amount (-S) which are sensed while the conductor is not touched by the multi-touch panel in response to a sensing signal SEN. ) Can be output sequentially. In the offset charge setting period, since the conductor does not touch the multi-touch panel, the low frequency noise N described above may not occur. Therefore, in the offset charge amount setting period, the first charge amount having a positive value output from the capacitance sensor 120 may be represented by 'S', and the second charge amount having a negative value may be represented by '-S'.

During the offset charge setting period, the signal receiving unit 530 samples the first charge amounts S and the second charge amounts −S sequentially output from the capacitance sensor 520 and accumulates n times to obtain a gain. The first cumulative voltages V11,..., V1k and the second cumulative voltages V21,..., V2k of which noise is removed and gain is adjusted may be sequentially output. The noise removing unit 540 may include first cumulative voltages V11,..., V1k and second cumulative voltages V21,..., V2k output from the signal receiver 530 during the offset charge amount setting period. Are sequentially inputted to calculate the voltage difference (V31, ..., or V3k) between the first cumulative voltage and the second cumulative voltage and the voltage difference between the corresponding first cumulative voltage and the second cumulative voltage in parallel. You can output The mux 555 may sequentially select and output voltages V31,..., And V3k input in parallel in response to the voltage selection signal OUT_SEL. In addition, the AD converter 550 may convert the voltages sequentially output from the mux 555 during the offset charge amount setting period into digital signals Vo and output them. In this case, the automatic correction unit 560 generates the offset charges Qoff1, ..., Qoffk using the digital signal Vo output from the AD converter 550 during the offset charge setting period. Offset control signal groups may be generated, and offset charge amounts Qoff1, ..., Qoffk may be generated in response to the offset control signal groups. For example, when the AD converter 550 receives the voltage difference V31 and converts the voltage difference V31 into a digital signal Vo, the automatic correction unit 560 converts the voltage difference V31 into the digital signal Vo. In response to this, the offset control signal group for generating the offset charge amount Qoff1 may be generated. As another example, when the AD converter 550 receives the voltage difference V3k and converts the voltage difference V3k into a digital signal Vo, the automatic compensator 560 is applied to the digital signal Vo converted from the voltage difference V3k. In response, the offset control signal group for generating the offset charge amount Qoffk may be generated.

As described above, the offset charge amount Qoff may have a positive value and a negative value repeatedly, and the offset charge amount Qoff having a positive value and an absolute value of the offset charge amount Qoff having a negative value may have a negative value. The absolute value can be the same. That is, the auto-adjustment unit 560 generates the offset control signal groups that can repeatedly generate the offset charge amount (-Qoff) having a negative value and the offset charge amount Qoff having a positive value during the offset charge amount setting period. can do.

After the offset charge amount setting period ends, in the period in which the signal receiver 530 samples and accumulates the first charge amounts S + N, the automatic compensator 560 responds to the capacitance control signal groups. The corresponding offset charges of the offset charges Qoff1, ..., Qoffk are removed from the first charge amounts S + N output in parallel from the output terminals OUT1, ..., OUTk of 520. The first corrected charge amount may be generated and output. After the offset charge amount setting period ends, the automatic correction unit 560 responds to the offset control signal groups in a period in which the signal receiver 530 samples and accumulates the second charge amounts (-S + N). Corresponding to one of the offset charges Qoff1, ..., Qoffk in the second charge amounts (-S + N) output in parallel at the output terminals OUT1, ..., OUTk of the capacitance sensor 520. The second corrected charge amount may be generated and output from the offset charge amount. In order to perform such an operation, the automatic compensator 560 may include an offset control signal generator and an offset compensator. An exemplary embodiment of the offset control signal generator and the offset compensator will be described with reference to FIG. 2. It demonstrates in more detail.

The offset charge amounts Qoff1, ..., Qoffk have the same amount of charge as the amount of charge output from the capacitance sensor 520 without the conductor being touched on the multi-touch panel or the conductor touches the multi-touch panel. In the non-state, it may have a smaller amount of charge than the amount of charge output from the capacitance sensor 520.

In the period in which the signal receiver 530 samples and accumulates the charges, the signal receiver 530 outputs the first correction charges S + N-Qoff1,. -Qoffk) is sampled n times (n is a natural number) and accumulated, and the gain is adjusted to output the first cumulative voltages V11, ..., V1k in parallel, and the automatic compensator 560 Sampling the second correction charge amounts (-S + N + Qoff1, ..., -S + N + Qoffk) outputted by n times (n is a natural number) and accumulating the second gain by adjusting gain. The voltages V21, ..., V2k may be output in parallel.

As described with reference to the automatic correction unit 560, in the offset charge setting period, the signal receiving unit 530 sequentially outputs the first charge amounts S and the second charge amounts (S) sequentially output from the capacitance sensor 520. -S) is accumulated by sampling n times (n is a natural number) and adjusting gain, so that the first cumulative voltages V11, ..., V1k corresponding to the amount of accumulated charge with noise removed and gain adjusted. And second cumulative voltages V21,..., And V2k.

The signal receiver 530 includes a plurality of sampling units 531_1,..., 531_k, a plurality of first charge accumulation units 533_1, ..., 533_k, and a plurality of second charge accumulation units 534_1, ... , 534_k) and a gain control unit 535, and the operation of each component has been described in detail with reference to FIG. That is, except that the charge amounts input to the sampling units 531_1,..., 531_k are changed to the corrected charge amounts, the sampling units 531_1,..., 531_k, the first charge accumulation units 533_1, ... , 533_k), the second charge accumulation units 534_1, ..., 534_k, and the gain control unit 535 are the sampling units 131_1, ..., 131_k, the first charge accumulation units 133_1, ... , 133_k), second charge accumulation units 134_1,..., 134_k, and gain control unit 135. In addition, the noise removing unit 545 also operates in the same manner as the noise removing unit 145 of FIG. 1, and the operation of the CDS control unit 543 and the plurality of CDS units 545 included in the noise removing unit 540 is also illustrated. Since it has been described in detail with respect to 1, detailed description thereof will be omitted.

The mux 555 sequentially selects and outputs the voltages output from the noise removing unit 540 one by one in response to the voltage selection signal OUT_SEL, and the AD converter 550 converts the output voltage of the mux 555 into a digital signal ( Vo) can be converted and output.

FIG. 6 is a circuit diagram illustrating an embodiment of a charge detection device 500 of the multi-touch panel of FIG. 5. Hereinafter, an embodiment of each component and an operation of each component of the charge amount sensing device 500 of the multi-touch panel will be described with reference to FIGS. 3, 5, and 6. The waveform diagram of FIG. 3 may be equally applied to the embodiment of FIG. 6. However, as described with reference to FIG. 5, except for the automatic correction unit 560, the description is similar to that described with reference to FIG. 2, and thus overlapping descriptions will be omitted.

The signal transmitter 510 may include a sensing controller 680, a plurality of sensing drivers 683_1,..., 683_j, and a plurality of sensing signal output units 685_1,..., 685_j, and the sensing controller 680. The sensing drivers 683_1 to 683_j and the sensing signal output units 685_1 to 685_j include the sensing control unit 270, the sensing drivers 273_1 to 273_j, and the sensing signal output units 275_1 of FIG. 2. ,..., 275_j).

The capacitance sensor 520 may be modeled as capacitors C _MUT1 ,..., C _MUTk connected between the input terminals IN1,..., INj and the output terminal OUT, and sensed in the offset charge amount setting section. In response to a corresponding sensing signal among the signals SEN1,..., SENj, the first charges Q and the second charge amounts -Q are sequentially repeatedly output, or the conductor touches the multi-touch panel. In the interval, the first charge amount Q + ΔQ + N and the second charge amount −Q−ΔQ + N may be sequentially and repeatedly outputted in response to the sensing signal SEN. ΔQ denotes the amount of charge generated when the conductor touches the multi-touch panel, and N denotes low frequency noise described with reference to FIG. 1. In the offset charge amount setting section, since the conductor and the multi-touch panel are not touched, ΔQ is not included in the first charge amount and the second charge amount.

The automatic correction unit 560 may include an offset control signal generator 670 and a plurality of offset compensators 675_1,..., 675_k. The offset control signal generator 670 uses the digital signal output from the AD converter 550 during the offset charge amount setting period. The offset control signal groups D11, D12, ..., D1i, ..., Dk1. , Dk2, ..., Dki) (i is a natural number). Each of the offset compensators 675_1, ..., 675_k corresponds to the offset control signal of the offset control signal groups D11, D12, ..., D1i, ..., Dk1, Dk2, ..., Dki. Offset charge amounts in the first charge amount Q + ΔQ and the second charge amount Q-ΔQ output from the corresponding output terminal among the output terminals OUT1,..., And OUTk of the capacitance sensor 520 in response to the group. The first corrected charge amount and the second corrected charge amount from which the corresponding offset charge amount is removed from (Qoff1, ..., Qoffk) can be sequentially and repeatedly output. For example, the offset compensator 675_1 may offset the amount of offset charge from the first charge amount Q + ΔQ + N output from the capacitance sensor 520 in response to the offset control signals D11, D12,..., D1i. By removing Qoff1, a first correction charge amount Q + ΔQ + N-Qoff1 is generated and output, or output from the capacitance sensor 520 in response to the offset control signals D11, D12, ..., D1i. The offset charge amount Qoff1 is removed from the second charge amount -Q-ΔQ + N to generate and output the second correction charge amount -Q-ΔQ + N + Qoff1.

The offset control signal groups may include i offset control signals. The method of generating the offset control signal groups D11, D12, ..., D1i, ..., Dk1, Dk2, ..., Dki has been described in detail with reference to FIG. Next, an embodiment of the offset compensators 675_1 to 675_k disclosed in FIG. 6 will be described. Each of the offset compensators 675_1,..., 675_k is different from each other in that the input offset control signal groups are different. Therefore, the offset compensators 675_1,. Explain.

The offset compensator 675_1 may include a plurality of correction capacitors CA1, CA2,..., And CAk and a plurality of offset compensation switches 677_11, 677_12,..., 677_1i. Correction capacitors CA1, CA2, ..., CAi have one end connected between the output terminal OUT1 of the capacitance sensor 520 and the input terminal of the signal receiver 530 (the input terminal of the sampling unit 531_1) and the offset compensation. The other end of the switches 677_11, 677_12,..., 677_1i may be connected to one end of a corresponding offset compensation switch. Each of the correction capacitors CA1, CA2,..., CAi may have a different capacitance value. Each of the offset compensation switches 677_11, 677_12,..., 677_1i corresponds to the first voltage source VL and the first in response to a corresponding offset control signal among the offset control signals D11, D12,..., D1i. One voltage source of the two voltage sources VH and the other end of a corresponding correction capacitor among the correction capacitors CA1, CA2,..., CAi may be connected. That is, according to the number of offset compensation switches connected to the first voltage source VL and the number of offset compensation switches connected to the second voltage source VH among the offset compensation switches 677_11, 677_12,..., 677_1i. The magnitude of the offset charge amount can be determined. In addition, since the offset charge amount has a positive value and a negative value repeatedly, the offset compensation switches are connected to the first voltage source VL, then to the second voltage source VH, and again to the first voltage source VL. By repeating the operation connected to, the sign of the offset charge amount can be changed. For example, when the offset compensation switches 677_11 and 677_12 are connected to the first voltage source VL, a negative value offset charge Q- is generated, and the offset compensation switches 677_11 and 677_12 are generated by the offset voltage. When connected to the two voltage sources VH, an offset charge amount Qoff having a positive value may be generated.

Each of the sampling units 531_1,..., And 531_k includes first and second charge amounts Q + ΔQ and −Q− that are output from a corresponding output terminal among the output terminals OUT1,..., And OUTk of the capacitance sensor 520. ΔQ) or the first sampling switching unit 611 and the second sampling switching unit (1) to sample the first and second correction charges output from the corresponding offset compensator among the offset compensators 675_1, ..., 675_k. 612 and the third sampling switching unit 613. The first sampling switching unit 611, the second sampling switching unit 612, and the third sampling switching unit 613 included in the sampling units 531_1,. 211), since it is similar to the second sampling switching unit 212 and the third sampling switching unit 213, detailed description thereof will be omitted. Each of the first charge accumulation units 533_1,..., 533_k may include an operational amplifier 625, an initialization switching unit 620, a plurality of capacitors C1, ..., Cn, and a plurality of gain control switching units ( 633_1,..., 633_n, and each of the second charge accumulation units 534_1,..., 534_k may include an operational amplifier 635, an initialization switching unit 630, and a plurality of capacitors C1, ..., Cn) and a plurality of gain control switching units 634_1, ..., 634_n, which have been described in detail with reference to FIG. In addition, each of the CDS units 545_1,..., 545_k may include a selector 640, a first CDS capacitor Cs, a CDS operational amplifier 665, a CDS initialization switching unit 660, and second CDS capacitors ( CC1,..., CCn) and a plurality of CDS gain control switching units 667_1,..., 667_n, which have been described in detail with reference to FIG. 2, will not be described below.

Hereinafter, the operation of the charge amount detecting device 500 of the multi-touch panel will be described with reference to FIGS. 3, 5, and 6.

First, the operation of the charge amount detecting device 500 of the multi-touch panel during the offset charge amount setting period will be described. When the offset setting period starts, the capacitance sensor 520 sequentially repeats the first charge amount Q and the second charge amount −Q in response to a corresponding sensing signal among the sensing signals SEN1,..., SENj. Can be output. Hereinafter, it is assumed that the offset charge amount setting section is a section in which the touch of the conductor is not present in the multi-touch panel. The signal receiver 530 samples and accumulates the first charge amount Q sensed and output by the capacitance sensor 520 n times, and adjusts the gain to remove noise and to adjust the first accumulated voltages V11 and. Outputs .., V1k). In addition, the signal receiver 530 samples and accumulates the second amount of charge (-Q) sensed and output by the capacitance sensor 520 n times, and adjusts the gain to remove the noise and to adjust the gains. Outputs V21, ..., V2k). The first cumulative voltages V11,..., V1k and the second cumulative voltages V21,..., V2k sequentially output are subtracted by the noise removing unit 540, and the noise eliminating unit ( 540 generates and outputs the voltage differences V31,..., V3k between the corresponding first accumulated voltage and the second accumulated voltage in parallel.

The mux 555 sequentially selects the voltage differences V31,..., And V3k input in parallel to the AD converter 550 in response to the voltage selection signal OUT_SEL, and outputs the AD converter 550 to the AD converter 550. ) Converts the voltage difference V31,..., Or V3k output from the mux 555 into a digital signal Vo and outputs the digital signal Vo. The offset control signal generator 670 of the automatic correction unit 560 uses the digital signal Vo to provide the offset control signal groups D11, D12, ..., D1i, ..., Dk1, Dk2, ... , Dki) to output a corresponding offset control signal group to a corresponding offset compensator among the offset compensators 675_1, ..., 675_k, and each of the offset compensators 675_1, ..., 675_k is offset. The offset charge amount Qoff1, ..., or Qoffk in response to the corresponding offset control signal group among the control signal groups D11, D12, ..., D1i, ..., Dk1, Dk2, ..., Dki. ) Can be created. The offset charge amounts Qoff1, ..., Qoffk may be generated by one loop described above, or may be generated by repeating such a loop a plurality of times. Hereinafter, the offset control signal groups D11, D12, ..., D1i, ..., Dk1, Dk2, ..., Dki are generated by the above method, and the offset charge amounts Qoff1, ..., Qoffk. After the) is determined, a section in which the signal receiver 530 samples and accumulates the charges will be described.

When the multi-touch panel is initialized to recognize a touch state (for example, when power is applied to the multi-touch panel), when the touch state of the multi-touch panel is changed or when the first charge amount is n times When sampling and accumulating, the first initialization signal RST1 is changed from the first logic state to the second logic state so that the first initialization switching unit 620 is turned on. In this case, since the input terminal (−) and the output terminal of the first operational amplifier 625 are directly connected, the output of the first charge accumulation units 533_1,..., 533_k is initialized to the ground voltage. When the multi-touch panel is initialized to recognize the touch state, when the touch state of the multi-touch panel is changed or when the second charge amount is sampled and accumulated n times, the second initialization signal RST2 is generated. The second initialization switching unit 530 is turned on by changing from the first logic state to the second logic state. In this case, since the input terminal (−) and the output terminal of the second operational amplifier 535 are directly connected, the output of the second charge accumulation units 534_1,..., 534_k is initialized to the ground voltage.

Thereafter, at time t0, the input selection signal IN_SEL1 is changed to a second logic state, and at time t1, the capacitance sensor 520 is connected to the multi-touch panel in relation to the input terminal IN1 in response to an applied sensing signal SEN1. The first charge amount S + N is outputted according to the touch state of, and the automatic correction unit 560 of the offset charge amounts -Qoff1, ..., -Qoffk is included in the first charge amount S + N. The first correction charges may be output in parallel by removing the corresponding offset charges. At the time t2, the capacitance sensor 520 starts to output the second charge amount (-S + N) according to the touch state of the multi-touch panel in response to the sensing signal SEN1 applied thereto, and the automatic correction unit 160 ) Removes the corresponding offset charge amount among the offset charge amounts Qoff1, ..., Qoffk from the second charge amount -S + N and outputs the second correction charge amounts in parallel.

That is, when the capacitance sensor 520 outputs the first charge amount S + N, the automatic correction unit 560 generates offset charges having a negative value to offset offset amount corresponding to the first charge amount S + N. The first correction charge amount is generated by performing a summation operation, and when the second charge amount (-S + N) is output from the capacitance sensor 520, the offset charge amounts having a positive value are generated to generate the second charge amount (-S). The second correction charge amount may be generated by adding the offset charge amount corresponding to + N).

As illustrated in FIG. 3, each of the sensing signals SEN1,..., And SENj includes a first logic state and a first logic state in a section in which a corresponding input selection signal among the input selection signals IN_SEL1,..., IN_SELj is a second logic state. 2 The logic state is a repeating signal. Each of the sampling units 531_1,..., 531_k corresponds to the first correction charge amounts in response to the first sampling control signal SCON1 at the time when the sensing signal SEN1 is changed from the second logic state to the first logic state. Of the second corrected charge amounts in response to the second sampling control signal SCON2 at the time when the sensing signal SEN1 is changed from the first logic state to the second logic state; The corresponding second corrected charge amount can be sampled. In addition, the sampling units 531_1,..., 531_k may include the first sampling control signal SCON1 which is an interval between an operation period of the first sampling switching unit 611 and an operation period of the second sampling switching unit 612. The output terminal of the automatic compensator 560 may be connected to the ground voltage source VSS in a section in which the second sampling control signal SCON2 is simultaneously in the first logic state.

That is, when the third sampling control signal SCON_3 is in the second logic state and the second and third sampling control signals SCON_2 and SCON_3 are in the first logic state, the third sampling switching unit 613 is turned on and the first sampling state is turned on. The first and second sampling switching units 611 and 612 are turned off so that the output of the automatic correction unit 560 is connected to the ground voltage source VSS and does not sample the first charge amount or the second charge amount. When the first sampling control signal SCON_1 is in the first logic state and the second and third sampling control signals SCON_2 and SCON_3 are in the second logic state, the first sampling switching unit 611 is turned on and the second and third sampling control signals SCON_1 and SCON_1 are turned on. The third sampling switching unit 612, 613 is turned off so that the output of the automatic correcting unit 560 is input to a corresponding first charge accumulation unit among the first charge accumulation units 533_1,. 1 Corrected charge amount can be sampled. When the second sampling control signal SCON_2 is in the first logic state and the first and third sampling control signals SCON_1 and SCON_3 are in the second logic state, the second sampling switching unit 612 is turned on and the first and second sampling control signals SCON_2 and SCON_2 are turned on. The third sampling switching unit 611, 613 is turned off so that the output of the automatic correcting unit 560 is input to a corresponding second charge accumulation unit among the second charge accumulation units 534_1,. 2 Corrected charge amount can be sampled.

Thereafter, the first cumulative voltages accumulating the first correction charge amount and outputting the first cumulative voltages of which the gain is adjusted, and the second cumulative voltages accumulating the second correction charge amount and the gains of the gain are output, corresponding to the first cumulative voltage and the second cumulative accumulation. The contents of generating the voltage difference of the voltage and outputting the generated voltage difference to the mux 555 have been described in detail with reference to FIGS. 2 and 3, and thus detailed description thereof will be omitted.

FIG. 7 is a circuit diagram schematically illustrating the first charge amount accumulator 533_1, the second charge amount accumulator 534_1, and the CDS unit 545_1 of FIG. 6.

5 to 7, a parallel connection is made between an input terminal (−) and an output terminal of the first operational amplifier 625 among the first capacitors C1,..., Cn of the first charge accumulation unit 533_1. The first capacitors may be modeled as one capacitor C _F as shown in FIG. 7. In addition, among the second capacitors C1,..., Cn of the second charge accumulation unit 534_1, second capacitors connected in parallel between the input terminal (−) and the output terminal of the second operational amplifier 635 are also illustrated in FIG. 7. As shown in FIG. 1, one capacitor C _F may be modeled. The capacitances of the first capacitors connected between the input terminal (-) and the output terminal of the first operational amplifier 625 and the capacitances of the second capacitors connected between the input terminal (-) and the output terminal of the second operational amplifier 635 have the same capacitance. Therefore, in FIG. 7, the same capacitor C _F was modeled. In addition, the second CDS capacitors connected between the input terminal (−) and the output terminal of the CDS operational amplifier 665 among the second CDS capacitors CC1,..., CCn also have one capacitor ( C _H ).

As described above, the first charge amount accumulator 533_1 outputs the first accumulated voltage V11 in which the sampled first correction charge amount S + N-Qoff1 is accumulated n times and gain is adjusted, and the second charge amount is adjusted. The accumulator 534_1 may output the second cumulative voltage V21 in which the sampled second correction charge amount (−S + N + Qoff1) is accumulated n times and gain is adjusted. In addition, since the first selective switching unit 643 and the second selective switching unit 645 operate selectively, the first selective switching unit 643 may select the first selection signal in a period between the time t1 and the time t3 of FIG. 3. In response to SEL1, the first cumulative voltage V11 is output, and in a period between a time t3 and a time t5 of FIG. 3, the second selection switching unit 645 responds to the second selection signal SEL2 in response to the second selection signal SEL2. The accumulated voltage V21 may be output. In this case, the CDS unit 545_1 may subtract the first cumulative voltage V11 and the second cumulative voltage V21 and adjust a gain to output the voltage difference V31. That is, since the CDS unit 545_1 subtracts the second cumulative voltage V21 from the first cumulative voltage V11, noise that is commonly included in the first cumulative voltage V11 and the second cumulative voltage V21. The voltage (low frequency noise component (N)) is canceled out of each other and subtracted to remove the noise component and the offset charge amount (S-Qoff1 and S + Qoff1) to generate a voltage corresponding to the charge amount of 2S-2Qoff1, The voltage difference V31 having a gain adjusted by C _S / C _H may be output.

By the above operation, the voltage difference V31 between the first cumulative voltage V11 and the second cumulative voltage V21 output from the first charge accumulation unit 533_1 may be expressed as Equation 2 below. The voltages output from the remaining CDS units may also be expressed in the same manner.

In Equation 2, C _F represents the sum of capacitances of the first capacitors connected between the input terminal (−) and the output terminal of the first operational amplifier 625 among the first capacitors C1,..., Cn. Capacitance sum of the first capacitors connected between the input terminal (−) and the output terminal of the first associative amplifier 625 among the first capacitors C1,..., Cn and the second capacitors C1,... The sum of the capacitances of the second capacitors connected between the input terminal (-) and the output terminal of the second operational amplifier 635 of Cn is the same, so that C _F is the value of the second capacitors C1, ..., Cn. It may also mean the sum of capacitances of the second capacitors connected between the input terminal (−) and the output terminal of the second operational amplifier 635. In addition, in Equation 2, C _H is a sum of capacitances of second CDS capacitors connected between an input terminal (−) and an output terminal of the CDS operational amplifier 665 among the second CDS capacitors CC1,..., CCn. it means. V _N denotes a noise voltage included in the first cumulative voltage V11 and the second cumulative voltage V21 due to the low frequency noise.

FIG. 8 is a diagram for describing a change in charge amount according to a touch state of a conductor when the capacitance sensor 120 of FIG. 1 or the capacitance sensor 520 of FIG. 5 is used.

1 to 8, in the capacitance sensor 120 or 520, a plurality of input terminals IN1 and IN2 and a plurality of output terminals OUT1, OUT2 and OUT3 may be formed on different planes. That is, each of the input terminals share the output terminals. When the conductor is not touched by the multi-touch panel, a charge amount of Q is generated between the input terminal and the output terminal to output the charge amount of Q to the output terminal. However, when the conductor is touched by the multi-touch panel, a charge amount of Q + ΔQ is generated between the input terminal IN and the output terminals OUT1 and OUT3, so that the charge amount of Q + ΔQ is transmitted to the output terminals OUT1 and OUT3. Output

 FIG. 8 illustrates a case in which three outputs are provided at one input terminal IN1 or IN2. However, the present invention is not limited thereto, and k output terminals may be provided at one input terminal as described with reference to FIGS. 1 to 7. This may include. In addition, as shown in FIG. 8, the number of input terminals may be different from two. In this case, as described in connection with the embodiment of FIGS. 1 to 4 or the embodiment of FIGS. The amount of charge can be detected by performing an operation.

The structure of the capacitance sensor 120 or 520 of FIG. 8 is merely an embodiment of the present invention, and the capacitance sensor 120 or 520 of the present invention is not limited to the structure of FIG. 8. That is, the capacitive sensor 120 or 520 may have various other structures if the amounts of charges according to the touch state of the multi-touch panel can be output in response to a sensing signal applied to the input terminal with the input terminals and the output terminals.

As described above, optimal embodiments have been disclosed in the drawings and the specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (23)

A signal transfer unit configured to output a sensing signal including information on a sampling time point to corresponding ones of the input terminals of the capacitance sensor in response to the input selection signal;
Receiving the sensing signal through the corresponding input terminal, a plurality of output terminals for sequentially outputting the first charge amount having a positive value sensed in response to the received sensing signal and the second charge amount having a negative value sequentially A capacitance sensor comprising a dog;
The first charges output in parallel from the output terminals of the capacitance sensor are sampled and accumulated n times (n is a natural number), respectively, and a gain is adjusted to output first accumulated voltages in parallel, and the capacitance sensor A signal receiver configured to sample and accumulate the second charges output in parallel from the output terminals of n times and adjust gain to output second accumulated voltages in parallel;
Low frequency noise generated when the conductor touches a multi-touch panel by receiving the first cumulative voltages and the second cumulative voltages sequentially and calculating a voltage difference between the corresponding first cumulative voltage and the second cumulative voltage. A noise removing unit for outputting the voltage differences from which is removed;
A mux for sequentially selecting and outputting the voltage differences output in parallel from the noise removing unit in response to a voltage selection signal; And
And an AD (analog to digital) converter for converting the voltage difference sequentially output from the MUX into a digital signal and sequentially outputting the digital signal. The method of claim 1, wherein the low frequency noise,
When the conductor touches the multi-touch panel, power noise generated by power applied to a system including the multi-touch panel and conductor noise generated between the multi-touch panel and the conductor,
Each of the first cumulative voltages and the second cumulative voltages may include:
A noise voltage corresponding to the power supply noise and the conductor noise,
The voltage difference between the corresponding first cumulative voltage and the second cumulative voltage is
And a voltage difference between the voltage corresponding to the first charge amount and the voltage corresponding to the second charge amount, the noise voltage being canceled by the subtraction operation of the corresponding first accumulated voltage and the second accumulated voltage. Panel charge detector. The method of claim 1, wherein the sensing signal,
A first logic state and a second logic state are repeated in a section in which the signal receiver samples and accumulates the first and second charges,
The capacitance sensor,
When the sensing signal is changed from the first logic state to the second logic state and the first charge amounts are output in parallel, and when the sensing signal is changed from the second logic state to the first logic state The charge amount sensing device of the multi-touch panel, characterized in that for outputting the second charge in parallel. The method of claim 1, wherein the noise removing unit,
A CDS controller generating a plurality of CDS control signals in response to the digital signal; And
Correlating double sampling of the corresponding first cumulative voltage and the second cumulative voltage in response to the CDS control signals to remove the low-frequency noise and adjust the gain; And a plurality of CDS units for outputting a voltage difference between the second cumulative voltages. The method of claim 4, wherein each of the CDS portion,
A selector configured to sequentially output a first cumulative voltage and a second cumulative voltage output from the signal receiver in response to first and second selection signals among the CDS control signals;
A first CDS capacitor having one end connected to an output end of the selection unit;
A CDS operational amplifier including an input terminal connected to the other end of the first CDS capacitor, a ground voltage input terminal connected to a ground voltage source, and an output terminal outputting a voltage difference between the first accumulated voltage and the second accumulated voltage;
In a section other than a section for outputting the voltage difference in the CDS operational amplifier and a section for outputting the digital signal in the AD converter, an input terminal and an output terminal of the CDS operational amplifier are connected in response to a CDS initialization signal among the CDS control signals. A CDS initialization switching unit configured to initialize the voltage difference by connecting;
A plurality of second CDS capacitors connected in parallel between an input terminal and an output terminal of the CDS operational amplifier; And
And a plurality of CDS gain control switching units for connecting or disconnecting each of the second CDS capacitors between an input terminal and an output terminal of the CDS operational amplifier in response to a corresponding CDS gain control signal among the CDS control signals. Charge amount sensing device of a multi-touch panel. The method of claim 5, wherein the selection unit,
A first selective switching unit configured to transfer or block the first accumulated voltage to the first CDS capacitor in response to the first selection signal; And
And a second selection switching unit configured to transfer or block the second cumulative voltage to the first CDS capacitor in response to the second selection signal. The method of claim 5, wherein each of the CDS portion,
And a holding unit for connecting or disconnecting the other end of the first CDS capacitor and the input end of the CDS operational amplifier in response to a holding signal among the CDS control signals. The method of claim 1, wherein the signal receiving unit,
A plurality of sampling units configured to sample the first charge amount and the second charge amount n times output from a corresponding one of the output terminals of the capacitance sensor in response to sampling control signals including information regarding the number of sampling;
A gain controller configured to generate and output a plurality of gain control signals using the digital signal output from the AD converter;
A plurality of first charge amount accumulators accumulating the first charge amounts sampled n times in a corresponding one of the sampling units in response to the gain control signals and adjusting gain to output the first accumulated voltage; And
And a plurality of second charge accumulation accumulators for accumulating the second charge amounts sampled n times in the corresponding one of the sampling units in response to the gain control signals and adjusting the gain to output the second accumulated voltage. Charge amount sensing device of the multi-touch panel, characterized in that. The method of claim 8, wherein each of the sampling units,
A first sampling switching unit sampling the first charge amount in response to a first sampling control signal among the sampling control signals and outputting the first charge amount to a corresponding first charge amount accumulator among the first charge amount accumulators;
A second sampling switching unit for sampling the second charge amount in response to a second sampling control signal among the sampling control signals and outputting the second charge amount to a corresponding second charge amount accumulator of the second charge amount accumulators; And
A third sampling switching unit for connecting or disconnecting a corresponding output terminal among the output terminals of the capacitance sensor and a ground voltage source in response to a third sampling control signal among the sampling control signals,
The first sampling switching unit and the second sampling switching unit selectively operate, the third sampling switching unit operates between an operation section of the first sampling switching unit and an operation section of the second sampling switching unit,
Each of the first charge accumulation units,
A first operational amplifier including an input terminal connected to an output terminal of a corresponding sampling unit among the sampling units, a ground voltage input terminal connected to a ground voltage source, and an output terminal outputting the first accumulated voltage to a corresponding noise removing unit among the noise removing units; ;
When the touch state of the multi-touch panel changes or when the first charge amount is sampled and accumulated n times, the first accumulated voltage is connected by connecting an input terminal and an output terminal of the first operational amplifier in response to a first initialization signal. A first initialization switching unit to initialize;
A plurality of first capacitors connected in parallel between an input terminal and an output terminal of the first operational amplifier; And
A plurality of first gain control switching units for connecting or disconnecting each of the first capacitors between an input terminal and an output terminal of the first operational amplifier in response to a corresponding gain control signal among the gain control signals,
Each of the second charge accumulation units
A second operation including an input terminal connected to an output terminal of a corresponding sampling unit among the sampling units, a ground voltage input terminal connected to the ground voltage source, and an output terminal outputting the second accumulated voltage to a corresponding noise removing unit among the noise removing units; amplifier;
When the touch state of the multi-touch panel changes or when the second charge amount is sampled and accumulated n times, the second accumulated voltage is connected by connecting an input terminal and an output terminal of the second operational amplifier in response to a second initialization signal. A second initialization switching unit to initialize;
A plurality of second capacitors connected in parallel between an input terminal and an output terminal of the second operational amplifier; And
And a plurality of second gain control switching units for connecting or disconnecting each of the second capacitors between an input terminal and an output terminal of the second operational amplifier in response to a corresponding gain control signal among the gain control signals. Charge amount sensing device of a multi-touch panel. The method of claim 1, wherein the signal transmission unit,
A sensing controller configured to generate and output a sensing control signal in response to the digital signal output from the AD converter;
A plurality of sensing drivers enabled in response to the input selection signal and generating and outputting at least one driving signal in response to the sensing control signal; And
And a plurality of sensing signal output units generating the sensing signal in response to the at least one driving signal and outputting the sensing signal to a corresponding one of the input terminals of the capacitance sensor. A signal transfer unit configured to output a sensing signal including information on a sampling time point to corresponding ones of the input terminals of the capacitance sensor in response to the input selection signal;
Receiving the sensing signal through the corresponding input terminal, a plurality of output terminals for sequentially outputting the first charge amount having a positive value sensed in response to the received sensing signal and the second charge amount having a negative value sequentially A capacitance sensor comprising a dog;
Generate a plurality of offset control signal groups for setting offset charge amounts corresponding to each charge amount by using the charge amounts output from the output terminals of the capacitance sensor during the offset charge amount setting period, and in response to the offset control signal groups An automatic correction unit configured to output first correction charge amounts and second correction charge amounts from which the offset charge amount is removed from the first charge amounts and the second charge amounts output in parallel from a capacitance sensor;
Sampling and accumulating the first charge amounts output in parallel from the automatic compensator n times (n is a natural number), respectively, and adjusting gain to output first accumulated voltages in parallel, and from the automatic compensator. A signal receiver configured to sample and accumulate the second charges output in parallel n times and adjust gain to output second accumulated voltages in parallel;
Low frequency noise generated when the conductor touches a multi-touch panel by receiving the first cumulative voltages and the second cumulative voltages sequentially and calculating a voltage difference between the corresponding first cumulative voltage and the second cumulative voltage. A noise remover configured to output the voltage differences removed in parallel;
A mux for sequentially selecting and outputting the voltage differences output in parallel from the noise removing unit in response to a voltage selection signal; And
And an AD (analog to digital) converter for converting the voltage difference sequentially output from the MUX into a digital signal and sequentially outputting the digital signal. The method of claim 11, wherein the capacitance sensor,
In response to the sensing signal during the offset charge amount setting period, the first charge amount having a positive value sensed and the second charge amount having a negative value are sequentially output to the touch panel while the conductor is not touched,
Wherein the signal receiver comprises:
Sampling the first charge amounts and the second charge amounts output from the capacitance sensor n times and accumulating n gains during the offset charge setting period, and adjusting gain to remove noise and adjust gain; Output second cumulative voltages,
The mux,
In response to the voltage selection signal during the offset charge amount setting period, the voltage difference between the first cumulative voltage and the second cumulative voltage output from the noise removing unit is sequentially selected and output one by one,
The AD converter,
Converts the voltage difference output from the MUX to the digital signal during the offset charge amount setting period, and outputs the digital signal;
The automatic correction,
An offset control signal generator configured to generate the offset control signal groups corresponding to respective charge amounts output from the capacitance sensor using the digital signal output from the AD converter during the offset charge amount setting period; And
Sequentially generating the offset charge amount having a positive value or a negative value and the same absolute value of the charge amount in response to a corresponding offset control signal group among the offset control signal groups, and adding the negative value to the first charge amount. And a plurality of offset compensators for generating the first corrected charge amount in which the offset charge amount is added and generating and outputting the second corrected charge amount in which the offset charge amount having the positive value is added from the second charge amount. Charge detector of multi-touch panel. The method of claim 12, wherein each of the offset compensation unit,
A plurality of correction capacitors having one end connected between a corresponding output terminal among the output terminals of the capacitance sensor and a corresponding input terminal among the input terminals of the signal receiver; And
In response to a corresponding offset control signal of the offset control signal of the corresponding offset control signal group, a plurality of connecting the voltage source of one of the first voltage source and the second voltage source and the other end of the corresponding correction capacitor of the correction capacitors A charge amount sensing device of a multi-touch panel comprising offset compensation switching units. The method of claim 11, wherein the offset charge amount setting section,
When the system including the multi-touch panel and the charge amount sensing device of the multi-touch panel is initialized, when the system is reset, when the power voltage starts to be applied to the multi-touch panel during the system operation or the offset charge amount is set And a predetermined period in which a conductor is not touched by the multi-touch panel when a predetermined time elapses after the end of the section. The method of claim 11, wherein the low frequency noise,
When the conductor touches the multi-touch panel, power noise generated by power applied to a system including the multi-touch panel and conductor noise generated between the multi-touch panel and the conductor,
Each of the first cumulative voltage and the second cumulative voltage is:
A noise voltage corresponding to the power supply noise and the conductor noise,
The voltage difference between the first cumulative voltage and the second cumulative voltage is
The voltage difference between the voltage corresponding to the first charge amount and the voltage corresponding to the second charge amount, the noise voltage is canceled by the subtraction operation of the first cumulative voltage and the second cumulative voltage of the multi-touch panel Charge detector. The method of claim 11, wherein the sensing signal,
A first logic state and a second logic state are repeated in a section in which the signal receiver samples and accumulates the first and second charges,
The capacitance sensor,
Outputting the first charge amount at a time point when the sensing signal is changed from the first logic state to the second logic state, and at the time point when the sensing signal is changed from the second logic state to the first logic state; A charge amount sensing device of a multi-touch panel, characterized in that for outputting two charge amounts. The method of claim 11, wherein the noise removing unit,
A CDS controller generating a plurality of CDS control signals in response to the digital signal; And
Correlated double sampling of the corresponding first cumulative voltage and the second cumulative voltage in response to the CDS control signals to remove the low-frequency noise and adjust the gain; And a plurality of CDS units for outputting a voltage difference between the second cumulative voltages. The method of claim 17, wherein each of the CDS portion,
A selector for sequentially outputting corresponding first and second cumulative voltages output from the signal receiver in response to first and second selection signals among the CDS control signals;
A first CDS capacitor having one end connected to an output end of the selection unit;
A CDS operational amplifier including an input terminal connected to the other end of the first CDS capacitor, a ground voltage input terminal connected to a ground voltage source, and an output terminal outputting a voltage difference between the first accumulated voltage and the second accumulated voltage;
In a section other than a section for outputting the voltage difference in the CDS operational amplifier and a section for outputting the digital signal in the AD converter, an input terminal and an output terminal of the CDS operational amplifier are connected in response to a CDS initialization signal among the CDS control signals. A CDS initialization switching unit configured to initialize the voltage difference by connecting;
A plurality of second CDS capacitors connected in parallel between an input terminal and an output terminal of the CDS operational amplifier; And
And a plurality of CDS gain control switching units for connecting or disconnecting each of the second CDS capacitors between an input terminal and an output terminal of the CDS operational amplifier in response to a corresponding CDS gain control signal among the CDS control signals. Charge amount sensing device of a multi-touch panel. The method of claim 18, wherein the selection unit,
A first selective switching unit configured to transfer or block the first accumulated voltage to the first CDS capacitor in response to the first selection signal; And
And a second selection switching unit configured to transfer or block the second cumulative voltage to the first CDS capacitor in response to the second selection signal. The method of claim 18, wherein each of the CDS portion,
And a holding unit for connecting or disconnecting the other end of the first CDS capacitor and the input end of the CDS operational amplifier in response to a holding signal among the CDS control signals. The method of claim 11, wherein the signal receiving unit,
A plurality of sampling units configured to sample the first corrected charge amount and the second corrected charge amount n times in response to sampling control signals including information about a sampling number;
A gain controller configured to generate and output a plurality of gain control signals using the digital signal output from the AD converter;
A plurality of first charge amount accumulators accumulating the first corrected charge amounts sampled n times in response to the gain control signals and adjusting gain to output the first accumulated voltage; And
And a plurality of second charge amount accumulators for accumulating the second corrected charge amounts sampled n times in response to the gain control signals and adjusting gain to output the second accumulated voltage. Charge detector. The method of claim 21, wherein each of the sampling units,
A first sampling switching unit sampling the corresponding first corrected charge amount in response to a first sampling control signal among the sampling control signals and outputting the first corrected charge amount to the first charge amount accumulator;
A second sampling switching unit configured to sample the corresponding second corrected charge amount in response to a second sampling control signal among the sampling control signals and output the sample to the second charge amount accumulator; And
A third sampling switching unit for connecting or disconnecting a corresponding output terminal of the automatic correction unit and a ground voltage source in response to a third sampling control signal among the sampling control signals,
The first sampling switching unit and the second sampling switching unit selectively operate, the third sampling switching unit operates between an operation section of the first sampling switching unit and an operation section of the second sampling switching unit,
Each of the first charge accumulation units,
A first operational amplifier including an input terminal connected to an output terminal of the corresponding sampling unit, a ground voltage input terminal connected to a ground voltage source, and an output terminal outputting the first accumulated voltage to the noise removing unit;
When the touch state of the multi-touch panel changes or when the first charge amount is sampled and accumulated n times, the first accumulated voltage is connected by connecting an input terminal and an output terminal of the first operational amplifier in response to a first initialization signal. A first initialization switching unit to initialize;
A plurality of first capacitors connected in parallel between an input terminal and an output terminal of the first operational amplifier; And
A plurality of first gain control switching units for connecting or disconnecting each of the first capacitors between an input terminal and an output terminal of the first operational amplifier in response to a corresponding gain control signal among the gain control signals,
Each of the second charge accumulation units
A second operational amplifier including an input terminal connected to an output terminal of the corresponding sampling unit, a ground voltage input terminal connected to the ground voltage source, and an output terminal outputting the second accumulated voltage to the noise removing unit;
When the touch state of the multi-touch panel changes or when the second charge amount is sampled and accumulated n times, the second accumulated voltage is connected by connecting an input terminal and an output terminal of the second operational amplifier in response to a second initialization signal. A second initialization switching unit to initialize;
A plurality of second capacitors connected in parallel between an input terminal and an output terminal of the second operational amplifier; And
And a plurality of second gain control switching units for connecting or disconnecting each of the second capacitors between an input terminal and an output terminal of the second operational amplifier in response to a corresponding gain control signal among the gain control signals. Charge amount sensing device of a multi-touch panel. The method of claim 11, wherein the signal transmission unit,
A sensing controller configured to generate and output a sensing control signal in response to the digital signal output from the AD converter;
A plurality of sensing drivers enabled in response to the input selection signal and generating and outputting at least one driving signal in response to the sensing control signal; And
And a plurality of sensing signal output units generating the sensing signal in response to the at least one driving signal and outputting the sensing signal to a corresponding one of the input terminals of the capacitance sensor.

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