KR20130051877A - Touch sensing apparatus - Google Patents

Abstract

PURPOSE: A touch sensing device is provided to perform a partial sensing step when the touch input is detected in a block sensing step, thereby increasing the touch reporting rate. CONSTITUTION: A touch screen includes Tx lines(T1-T5), Rx lines(R1-R6), and touch sensors(Cm) which are formed between the Tx lines and the Rx lines. A touch screen driving circuit detects the touch input by firstly sensing the total touch sensors in the touch screen. The touch screen driving circuit detects the position of the touch input by secondly sensing the touch sensors which the touch input are detected. When the touch sensors, where the touch input is detected, are not existed, the touch screen driving circuit repeats the first sensing step. [Reference numerals] (AA) Tx channel; (BB) Rx channel

Description

{TOUCH SENSING APPARATUS}

The present invention relates to a touch sensing device.

User input means has been replaced with a touch screen in a button-type switch in accordance with the trend of lightening and slimming of household appliances and portable information devices. The touch screen includes a plurality of touch sensors.

US Published Patent Application No. 2010/0200310 (published Dec. 12, 2010) discloses a touch screen including a capacitive touch sensor at each intersection of X lines and Y lines intersecting each other Method touch screen "). The self capacitance type touch screen scans the X lines to convert the signals received from the X lines into digital data through analog to digital conversion (ADC) And converts the signal received from the Y lines into digital data through the ADC process. Self-capacitance touch screen recognizes the touch sensor located at the intersection of the X-line and Y-line with large capacitance change before and after touch as the touch position. This self capacitance touch screen senses each of the X and Y lines and converts them into ADCs to analyze the digital data obtained to determine the touch position. Therefore, a ghost point (ghost point) to the touch position. Therefore, the self-capacitance type touch screen is disadvantageous in that the multi-touch recognition sensitivity is lowered, and a complicated ghost detection and removal algorithm is additionally applied.

The Self-capacitance type touch screen disclosed in U.S. Patent Application Publication No. US20030 / 2003103 senses X lines and Y lines on a group basis in a pre-scan step. Subsequently, the self-capacitance touch screen disclosed in U.S. Patent Application Publication No. US20030 / 030010 increases the accuracy of touch recognition through a re-scan process and a touch position detection process after an ADC process and a touch position detection process. The self capacitance touch screen disclosed in US Patent Application Publication No. US 2010/0200310 simultaneously scans the X lines (or Y lines) in the group during the pre-scan process, so that every X line and Y The speed of touch sensing can be reduced compared to a method of sequentially sensing lines. However, the self capacitance touch screen disclosed in U.S. Publication No. US 2010/0200310 needs to sequentially perform a pre-scan, an ADC, a touch recognition algorithm execution, a rescan, an ADC, and a touch recognition algorithm every time the touch position is recognized There is a limit to reducing the speed of touch sensing.

The touch report rate is a frequency (Hz) at which coordinates data obtained after sensing all the touch sensors existing in the touch screen are transmitted to the outside. The higher the touch report rate, the higher the continuity of the touch input trajectory and the higher the touch sensitivity the user feels. This touch report rate is inversely proportional to the total sensing time required to sense all the touch sensors in the touch screen. As the total sensing time becomes longer, the touch report rate decreases. Therefore, the self capacitance type touch screen disclosed in US Patent Application Publication No. US20030 / 030010 can not sufficiently increase the touch report rate because it repeatedly performs the prescan and re-scan irrespective of whether or not the touch is present.

The conventional touch screen has a problem that the ghost point is easily mistaken as a touch input, and when the instantaneous generated noise is synchronized with the sensing timing, the noise is recognized as a touch input and the sensing sensitivity is low. Accordingly, the conventional touch screen is less linear in lining drawing or dragging on the touch screen. In order to improve the touch sensitivity felt by the user, the performance of the touch screen should be improved such as improvement of the touch report rate and sensing sensitivity.

The present invention provides a touch sensing device capable of improving the performance of a touch screen.

The touch sensing apparatus of the present invention includes a touch screen including Tx lines, Rx lines intersecting the Tx lines, and touch sensors formed between the Tx lines and the Rx lines; And first senses all the touch sensors in the touch screen to detect presence / absence of touch input. Then, in the second sensing step, the touch sensors detected as a result of the first sensing are sensed secondarily, And a touch screen driving circuit for detecting the position of the touch screen. The touch screen driving circuit repeats the first sensing step if no touch sensor detects a touch input as a result of the primary sensing.

The present invention can increase the touch report rate by reducing the total sensing time of the touch screen by shifting to the partial sensing stage only when the touch (or proximity) input is detected in the block sensing step. In addition, the present invention can increase the touch sensitivity by adding the pulley sensing result and the partial sensing result.

1 is a block diagram showing a display device according to an embodiment of the present invention.
FIG. 2 is a plan view showing in detail an electrode pattern by enlarging a part of the touch screen in FIG.
3 to 5 illustrate various combinations of a touch screen and a display panel.
6 is a block diagram showing the ROIC circuit configuration of the present invention.
7 is a flowchart illustrating a method of driving the touch sensing apparatus according to the first embodiment of the present invention.
8 and 9 are views showing block sensing time and partial sensing time.
10 to 12 are views showing a block sensing method and a partial sensing method when the touch screen is dividedly driven by two or more Tx blocks.
13 is a waveform diagram showing driving signals supplied to Tx lines when a single touch input is detected as a result of block sensing.
14 is a diagram illustrating a block sensing method and a partial sensing method when multi-touch input is detected in a plurality of Tx blocks as a result of block sensing.
15 is a waveform diagram showing driving signals supplied to Tx lines when a multi-touch input is detected as a result of block sensing.
16 is a diagram illustrating a block sensing method and a partial sensing method when a touch input is generated at a boundary between neighboring blocks.
FIG. 17 is a waveform diagram showing a driving signal supplied to the Tx lines in the case of FIG. 16; FIG.
18 to 22 are diagrams showing a block sensing method and a partial sensing method when the touch screen is dividedly driven into two or more Rx blocks.
23 is a flowchart illustrating a method of driving a touch sensing apparatus according to a second embodiment of the present invention.
FIG. 24 is a diagram for assuming two touch inputs.
25 is a waveform diagram showing a drive signal applied to the Tx lines in the pulley sensing step.
FIG. 26 is a diagram showing regions to be subjected to partial sensing when the touch inputs as shown in FIG. 24 are detected in the pulley sensing step.
FIG. 27 is a waveform diagram showing driving signals applied to areas subjected to partial sensing as shown in FIG. 26; FIG.
28 is a waveform diagram showing the effect of improving the touch sensitivity in the method of driving the touch sensing apparatus according to the second embodiment of the present invention.
29 is a circuit diagram showing a sampling circuit and an analog-to-digital converter of the Rx driver circuit.
Fig. 30 is an equivalent circuit diagram of the sampling circuit when the switches S11, S12, S11 ', S12' shown in Fig. 29 are turned on.
FIG. 31 is an equivalent circuit diagram of the sampling circuit when the switches S21, S22, S21 ', and S22' shown in FIG. 29 are turned on.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like numbers refer to like elements throughout. In the following description, when it is determined that a detailed description of known functions or configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The touch screen of the present invention is implemented as a mutual capacitance type touch screen. The mutual capacitive touch screen includes Tx lines, Rx lines that intersect the Tx lines, and touch sensors formed between the Tx lines and the Rx lines. Each of the touch sensors has a mutual capacity formed between the Tx line and the Rx line. The mutual capacitance type touch screen supplies a driving signal to the Tx lines and individually senses the capacitance change of each touch sensor through the Rx lines in synchronization with the driving signal. In this mutual capacitance type touch screen, the Tx lines to which the driving signal is applied and the Rx lines to sense the touch sensors are separated from each other. The drive signal is illustrated as a square wave pulse for convenience in the figures, but is not limited thereto. For example, the driving signal may be generated in various forms such as a square-wave pulse, a sinusoidal wave, and a triangular wave. Since the mutual capacitive touch screen can sense the voltage change before and after the touch in each of the touch sensors, each touch (or proximity) input can be accurately recognized in a multi-touch situation without a ghost point.

1 and 2, a display device according to an embodiment of the present invention includes a display panel DIS, a display driving circuit, and a touch sensing device. The touch sensing device includes a touch screen (TSP) and a touch screen driving circuit.

The display device of the present invention is a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting diode display (Organic Light Emitting Display) , OLED), and electrophoretic display devices (Electrophoresis, EPD) can be implemented based on a flat panel display device. In the following embodiments, a display device is described as a liquid crystal display device as an example of a flat panel display device, but it should be noted that the display device of the present invention is not limited to a liquid crystal display device.

The display panel (DIS) has a liquid crystal layer formed between two glass substrates. A plurality of gate lines G1 to Gn, n, which intersect with the data lines D1 to Dm, are connected to the lower substrate of the display panel DIS, A plurality of thin film transistors (TFTs) formed at intersections of the data lines D1 to Dm and the gate lines G1 to Gn, a plurality of pixels An electrode, and a storage capacitor connected to the pixel electrode to maintain the voltage of the liquid crystal cell.

The pixels of the display panel DIS are formed in a pixel region defined by the data lines D1 to Dm and the gate lines G1 to Gn and arranged in a matrix form. Each liquid crystal cell of the pixels is driven by an electric field applied according to a voltage difference between a data voltage applied to the pixel electrode and a common voltage applied to the common electrode to control the amount of incident light. The TFTs are turned on in response to gate pulses from the gate lines G1 to Gn to supply a voltage from the data lines D1 to Dm to the pixel electrodes of the liquid crystal cell.

The upper substrate of the display panel DIS may include a black matrix, a color filter, and the like. The lower substrate of the display panel DIS may be implemented with a COT (Color Filter On TFT) structure. In this case, the black matrix and the color filter can be formed on the lower substrate of the display panel DIS.

A polarizing plate is attached to each of the upper and lower substrates of the display panel DIS, and an alignment layer for setting the pretilt angle of the liquid crystal is formed on an inner surface of the display panel DIS. A column spacer for maintaining a cell gap of the liquid crystal cell is formed between the upper substrate and the lower substrate of the display panel DIS.

A backlight unit may be disposed on the back surface of the display panel DIS. The backlight unit is implemented as an edge type or direct type backlight unit to emit light to the display panel DIS. The display panel DIS may be implemented in any known liquid crystal mode such as TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In Plane Switching) mode and FFS (Fringe Field Switching) mode.

The display driver circuit includes a data driver circuit 12, a scan driver circuit 14, and a timing controller 20, and writes data of an input image to pixels.

The data driving circuit 12 converts the digital video data RGB input from the timing controller 20 into an analog positive / negative gamma compensation voltage and outputs a data voltage. The data voltage is supplied to the data lines D1 to Dm. The scan driving circuit 14 sequentially supplies a gate pulse (or scan pulse) synchronized with the data voltage to the gate lines G1 to Gn to select a line of the display panel DIS to which data is to be written.

The timing controller 20 receives timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE and a main clock MCLK from an external host system . The timing controller 20 generates a scan timing control signal and a data timing control signal for controlling the operation timings of the data driving circuit 12 and the scan driving circuit 14. The scan timing control signal includes a gate start pulse (GSP), a gate shift clock, a gate output enable signal (GOE), and the like. The data timing control signal includes a source sampling clock (SSC), a polarity control signal (Polarity), a source output enable signal (SOE), and the like.

The touch screen TSP may be bonded onto the upper polarizer POL1 of the display panel DIS as shown in FIG. 3 or may be formed between the upper polarizer POL1 and the upper glass substrate GLS1 as shown in FIG. In addition, the touch sensors Cm of the touch screen TSP may be embedded in the lower substrate in an in-cell type together with the pixel array in the display panel DIS as shown in FIG. In Fig. 3 to Fig. 5, "PIX" means a pixel electrode of a liquid crystal cell, "GLS2" means a lower substrate, and "POL2" means a lower polarizer.

The touch screen TSP includes Tx lines (T1 to Tj, j is a positive integer less than n), Rx lines (R1 to Ri, i being an amount less than m) crossing the Tx lines And ix j number of touch sensors Cm formed between the Tx lines T1 to Tj and the Rx lines R1 to Ri. Each of the touch sensors Cm has mutual capacitance. The touch screen TSP may be divided into two or more Tx blocks and two or more Rx blocks to enable block sensing. Accordingly, the touch screen TSP is divided into a matrix form by the intersection structure of Tx blocks and Rx blocks. Each of the blocks in which the Tx block and the Rx block intersect includes two or more touch sensors Cm.

The touch screen driving circuit includes a Tx driving circuit 32, an Rx driving circuit 34, a touch screen timing controller (hereinafter referred to as "TSP timing controller") 36, and a touch recognition processor 30. The touch screen driving circuit supplies a driving signal to the Tx lines T1 to Tj and senses the voltage of the touch sensor through the Rx lines R1 to Ri in synchronization with the driving signal. The Tx driving circuit 32, the Rx driving circuit 34 and the TSP timing controller 36 may be integrated into one ROIC (Read-out IC) 40 as shown in FIG. In addition, the touch recognition processor 30 may also be integrated into the ROIC 40.

The touch screen driving circuit firstly senses all the touch sensors in the touch screen TSP at the first sensing step, then senses only the touch sensors detected as a result of the first sensing at the second sensing stage, Position. In the primary sensing step, the touch sensors of the touch screen (TSP) are scanned by using a block sensing method or a full sensing method. In the second sensing step, a partial sensing method is used to precisely sense only the touch sensors whose touch input has been detected in the primary sensing. When the touch input is not detected in the primary sensing step, the primary sensing step can be repeated.

The Tx driving circuit 32 selects the Tx line in response to the setup signal (SUTx in FIG. 6) input from the TSP timing controller 36 and supplies the driving signal to the selected Tx lines T1 to Tj. The present invention can increase the voltage change of the touch sensor before and after the touch by accumulating the voltage of the touch sensor Cm in the sampling capacitor of the N (N is a positive integer of 2 or more) times repeated Rx driving circuit 34. [ To this end, the driving signal applied to each of the Tx lines T1 to Tj may include N driving signals generated at predetermined time intervals. If j touch sensors are connected to one Tx line, the driving signals including the N driving signals may be supplied to the Tx line successively j times, and then the driving signals may be supplied to the next Tx line in the same manner.

The Rx driving circuit 34 selects the Rx lines to receive the touch sensor voltage in response to the Rx setup signal (SURx in FIG. 6) input from the TSP timing controller 36. The Rx driving circuit 34 receives and samples the voltage of the touch sensor through the selected Rx lines. The Rx drive circuit 34 converts the voltage sampled using the analog-to-digital converter into digital data and outputs touch raw data (TData in FIG. 6). Touch raw data (TData) is transmitted to the touch recognition processor (30).

The TSP timing controller 36 is connected to the Tx drive circuit 32 and the Rx drive circuit 34 via an interface such as an I ² C bus, a SPI (serial peripheral interface), a system bus, 32 and the Rx drive circuit 34 are synchronized with each other. The TSP timing controller 36 controls the Tx / Rx channel setting of the Tx driving circuit 32 and the Rx driving circuit 34, the sampling timing of the Rx driving circuit 34, the ADC timing of the Rx driving circuit 34, and the like . The TSP timing controller 36 generates control signals necessary for controlling the Tx / Rx channel setup and operation timing of the Tx driving circuit 32 and the Rx driving circuit 34. [

The touch recognition processor 30 analyzes the touch raw data inputted from the Rx driving circuit 34 by a preset touch recognition algorithm. The touch recognition algorithm compares touch primitive data with a predetermined threshold value, estimates touch primitive data of a threshold value or more as touch (or proximity) input data, and calculates coordinates of the touch (or proximity) input position. The touch recognition algorithm can be applied to any known algorithm applicable to the mutual capacity type touch screen. The touch recognition processor 30 transmits the coordinate data (HIDxy) including the coordinate information of the touch (or proximity) input position obtained as a result of the operation of the touch recognition algorithm to the external host system. The touch recognition processor 30 may include a buffer memory for storing the calculation result of the touch recognition algorithm and the touch coordinate data. The touch recognition processor 30 may be implemented as an MCU (Micro Controller Unit).

The host system may be implemented by any one of a TV system, a set-top box, a navigation system, a DVD player, a Blu-ray player, a personal computer (PC), a home theater system, and a phone system. The host system converts the data of the input image into a format suitable for display on the display panel (DIS), and transmits the format to the timing controller (20). Further, the host system executes an application program associated with the coordinate data input from the touch recognition processor 30. [

A method of driving a touch sensing apparatus according to the present invention is a method of sensing a touch sensor of a touch screen (TSP) by virtually dividing the touch sensors into two or more blocks when a block sensing method is used as a primary sensing method, It is possible to quickly determine whether or not touch (or proximity) input is performed in units of blocks. In the touch screen sensing method of the present invention, a partial sensing method is applied only to a block in which a touch (or proximity) input is detected, and the touch input position can be precisely sensed in the block. Therefore, the touch screen sensing method of the present invention can reduce the total sensing time of the touch screen to increase the touch report rate and increase the sensing sensitivity.

Hereinafter, a driving method of a touch sensing apparatus to which a block sensing method and a partial sensing method are applied together with FIGS. 7 to 24 will be described.

The touch screen TSP is divided into virtual Tx / Rx blocks along the x and / or y axis directions (see FIGS. 1 and 2), and each of the blocks includes two or more Tx lines and two or more Rx lines And a plurality of touch sensors.

As shown in FIGS. 7 to 24, the touchscreen driving circuit first senses touch sensors on a block basis by firstly scanning touch sensors of a touch screen (TSP), and then detects touch (or proximity) The touch sensor in the block is partially sensed (or secondary scanned) to precisely detect the touch position. The block sensing period is only one sensing time in the prior art. Therefore, the touch screen driving apparatus of the present invention can reduce the total sensing time required to sense all the touch sensors in the touch screen. In addition, the sensitivity of the touch sensor can be increased by increasing the touch sensing accuracy by sensing the touch (or proximity) input position two or more times in each frame period through the block sensing step and the partial sensing step.

The Tx driving circuit 32 applies a driving signal to the Tx lines Tl through Tj on a Tx block basis during a block sensing period under the control of the TSP timing controller 36 and detects touch (or proximity) during a partial sensing period The driving signals are sequentially supplied to the Tx lines T1 to Tj in the Tx block. The Tx blocks are divided along the major axis direction of the Rx lines. Each of the Tx blocks includes two or more Tx lines. The Tx driving circuit 32 sequentially applies driving signals to the Tx lines T1 to Tj one by one during the pulley sensing period under the control of the TSP timing controller 36 in the other embodiment, Or proximity) is sequentially supplied to the Tx lines T1 to Tj in the detected area, one line at a time.

Under the control of the TSP timing controller 36, the Rx driving circuit 34 simultaneously senses the voltages of the touch sensors through the Rx lines R1 to Ri in units of Rx blocks under the control of the touch recognition processor 30 during the block sensing period And sequentially convert the voltages of the touch sensors received through the Rx lines in the block to the Rx block in which the touch (or proximity) input is detected as block sensing result during the partial sensing period, have. Rx blocks are divided along the major axis direction of the Tx lines. The Rx block includes two or more Rx lines.

The Tx driving circuit 32 selects Tx lines in block units during the block sensing period in response to the setup signal SUTx input from the TSP timing controller 36, and selects Tx lines in line units during the partial sensing period. The Tx driving circuit 32 supplies driving signals to the selected Tx lines Tl through Tj according to the Tx set-up signal. In order to increase the charging amount of the sampling capacitor by repeatedly accumulating the voltage of the touch sensor Cm N times, the driving signals applied to each of the Tx lines T1 to Tj as shown in Figs. 13, 15, And may include N generated driving signals. If j touch sensors are connected to one Tx line, the driving signals including the N driving signals are supplied to the Tx line successively j times, and then the driving signals are also supplied to the next Tx line in the same manner.

The Rx drive circuit 34 can greatly reduce the time for receiving and sampling the touch sensor voltages through the block sensing step. The Rx driving circuit 34 selects the Rx lines R1 to Ri to receive the touch sensor voltage in response to the setup signal SURx input from the TSP timing controller 36. [ The Rx driving circuit 34 receives and samples the touch sensor voltage through the selected Rx lines in accordance with the set-up signal SURx.

The Rx driving circuit 34 simultaneously receives and samples the voltage of the touch sensors through the Rx lines R1 to Ri in units of Rx blocks during the block sensing period, and converts them into digital data. The Rx driving circuit 34 may sequentially receive and sample the voltages of the touch sensors through the Rx lines in the Rx block of the Rx block in which the touch (or proximity) input is detected as a result of block sensing, and convert the sampled data into digital data. The digital data output from the Rx driving circuit 34 is transferred to the touch recognition processor 30 as touch raw data (TData).

The touch recognition processor 30 analyzes the touch raw data (TData) obtained as a result of the block sensing by executing a touch recognition algorithm to touch (or proximity) data in which the change value of the touch sensor voltage is greater than or equal to a predetermined threshold before and after the touch. The presence or absence of a touch (or proximity) input may be determined based on the data of the input position. The touch recognition processor 30 controls the Tx driving circuit 32 and the Rx driving circuit 34 to the partial sensing stage when a touch (or proximity) input is detected as a result of block sensing. The touch recognition processor 30 performs a partial sensing step to analyze the touch source data (TData) obtained by precisely sensing the touch sensors only in the block in which the touch (or proximity) input is detected in the block sensing step. The touch recognition processor 30 executes a touch recognition algorithm and judges the data having a change amount before and after the touch as a result of partial sensation as data obtained from the touch sensors at the actual touch (or proximity) input position, Estimates the coordinate values for the sensors. The touch recognition processor 30 transmits final touch coordinate data including coordinate information of the touch sensor detected as a touch (or proximity) input to the host system in both the block sensing step and the partial sensing step.

If the touch (or proximity) input is not detected in the block sensing step, the touch recognition processor 30 repeats the block sensing step without shifting to the partial sensing step. Accordingly, the touch recognition processor 30 can omit the partial sensing step according to the result of the block sensing, thereby reducing the total sensing time of the touch screen without deteriorating the touch sensitivity.

7 to 10, the block sensing step senses all the touch sensors in the touch screen TSP during the first sensing period TB by sensing the touch sensors in units of blocks. (S71) I simultaneously supplies driving signals to Tx lines existing in I (I is a positive integer) block to simultaneously sense voltages of all the touch sensors existing in the I block. The block sensing step simultaneously applies a driving signal to the Tx lines existing in the (I + 1) -th block to simultaneously sense the voltages of all the touch sensors existing in the (I + 1) -th block. Since the driving signals are simultaneously supplied to all the Tx lines in one block in the first sensing period as shown in FIGS. 13 and 15, the time required for one block sensing is only the time required for one line sensing of the touch screen in the prior art.

When a touch (or proximity) input is detected as a result of the block sensing, the touch screen driving circuit shifts to the partial sensing step and outputs a driving signal to the Tx lines in the block in which the touch (or proximity) input is detected during the second sensing period TP (Or proximity) input position by sensing the voltage of the touch sensors existing in the block by sequentially supplying the touch (or proximity) input line by line. (S72 and S73) Depends on the number of detected blocks.

Only when the touch (or proximity) input is detected in the block sensing step, the partial sensing step is performed after the block sensing step as shown in FIG. On the other hand, if no touch (or proximity) input is detected in the block sensing step, the block sensing step is performed again after the block sensing step as shown in FIG.

In order to reduce the power consumption of the touch screen driving circuit, the Tx driving circuit 32, the Rx driving circuit 34, and the TSP timing controller 32 are turned on for a predetermined time before the transition to the next block sensing step, It is possible to disable the operation unit 36 and stop its operation.

The total sensing time Ttotal required to sense all the touch sensors of the touch screen TSP is the sum of the first sensing period TB and the second sensing period TP as shown in FIGS. As a result of the block sensing, if a touch (or proximity) input is detected in a plurality of blocks, that is, a multi-touch (or proximity) input is detected, the blocks are subjected to partial sensing. 8, the first sensing period TB required for block sensing is fixed, whereas when the multi-touch sensing (or proximity) is detected as a result of the block sensing, the second sensing period TP becomes long, 2 sensing period TP can be varied.

10 to 12 are views showing a block sensing step and a partial sensing step when the touch screen TSP is divided and driven into a plurality of Tx blocks along the y axis. Here, the y-axis is parallel to the major axis direction of the Rx lines as shown in Figs.

The touch screen TSP may be divided into the first and second Tx blocks B1 and B2 as shown in FIG. In this case, the touch screen driving circuit simultaneously supplies drive signals to all the Tx lines in the first Tx block B1 and then simultaneously outputs driving signals to all the Tx lines in the second Tx block B2 at the same time And detects the presence or absence of touch (or proximity) input in units of Tx blocks. When touch (or proximity) input is detected in the first Tx block B1 as a result of block sensing, the touch screen drive circuit shifts to the partial sensing step. The touch screen driving circuit sequentially supplies driving signals to the Tx lines in the first Tx block B1 to precisely sense the touch sensors in the first Tx block B1 so that the final touch Proximity) input position. The second Tx block B2 in which no touch (or proximity) input is detected in the block sensing step is not sensed in the partial sensing step.

The touch screen TSP may be divided into the first to third Tx blocks B1 to B3 as shown in FIG. In this case, the touch screen driving circuit simultaneously supplies drive signals to all the Tx lines in the first Tx block B1 and then simultaneously outputs driving signals to all the Tx lines in the second Tx block B2 at the same time And detects the presence or absence of touch (or proximity) input in units of Tx blocks. Then, the touch screen driving circuit simultaneously supplies driving signals to all the Tx lines in the third block B3 to detect the presence or absence of touch (or proximity) input in the third Tx block. As a result of the block sensing, if the touch (or proximity) input is detected in the second Tx block B2, the touch screen driving circuit shifts to the partial sensing step. The touch screen driving circuit sequentially supplies the driving signals to the Tx lines in the second Tx block B2 to precisely sense the touch sensors in the second Tx block B2 so that the final touch Proximity) input position. The first and third Tx blocks B1 and B3 for which no block sensing connected touch (or proximity) input is detected are not sensed in the partial sensing step.

The touch screen TSP may be divided into the first to fourth Tx blocks B1 to B4 as shown in FIG. 13 is a waveform diagram showing a driving signal supplied to the Tx lines in the case of FIG.

12 and 13, in the block sensing step, the touch screen driving circuit supplies driving signals simultaneously to all the Tx lines in the first Tx block B1, and then supplies all the Tx lines in the second Tx block B2 And simultaneously supplies the driving signals to the driving circuits. Subsequently, the touch screen driving circuit simultaneously supplies driving signals to all the Tx lines in the third Tx block B3, then simultaneously supplies driving signals to all the Tx lines in the fourth Tx block B4, (Or proximity) input is detected. When touch (or proximity) input is detected in the second Tx block B2 as a result of block sensing, the touch screen driving circuit shifts to the partial sensing step. The touch screen driving circuit sequentially supplies the driving signals to the Tx lines in the second Tx block B2 to precisely sense the touch sensors in the second Tx block B2 so that the final touch Proximity) input position. The first, third, and fourth Tx blocks B1, B3, and B4 that are not detected as a result of block sensing are not sensed in the partial sensing step.

14 is a diagram illustrating a block sensing step and a partial sensing step in a multi-touch (or proximity) input. 15 is a waveform diagram showing a driving signal supplied to the Tx lines in the case of FIG.

Referring to FIGS. 14 and 15, the block sensing step detects the presence or absence of touch (or proximity) input in units of Tx by applying a driving signal in units of Tx blocks. As a result of the block sensing, if a touch (or proximity) input is detected in each of the second and third Tx blocks B2 and B3, a partial sensing step is performed. In the partial sensing step, the driving signals are sequentially supplied to the Tx lines in the second Tx block B2, and then the driving signals are sequentially supplied to the Tx lines in the third Tx block B3 to generate the second and third Tx And precisely senses the touch sensors within the blocks B2 and B3. Accordingly, if a touch (or proximity) input is detected in a plurality of blocks as a result of block sensing, the second sensing period TP may be longer. The partial sensing step does not sense the touch sensors of the first and fourth blocks B1 and B4 in which the touch (or proximity) input is not detected in the block sensing step.

When a touch (or proximity) input is detected at the boundary between neighboring Tx / Rx blocks as shown in FIG. 16 and FIG. 22, . FIG. 17 is a waveform diagram showing a driving signal supplied to the Tx lines in the case of FIG. 16; FIG.

Referring to FIGS. 16 and 17, a touch sensing (or proximity) input is detected at the boundary between the first and second Tx blocks B1 and B2 as a result of block sensing, so that a partial sensing step is performed. The partial sensing step sequentially supplies the driving signals to the Tx lines in the first Tx block B1 and then sequentially supplies the driving signals to the Tx lines in the second Tx block B2, (B2, B3). Therefore, if the touch (or proximity) input is detected at the boundary between the blocks as a result of the block sensing, the second sensing period TP may be long. The partial sensing step does not sense the touch sensors of the third and fourth blocks B3 and B4 in which the touch (or proximity) input is not detected in the block sensing step.

FIGS. 18 to 22 are diagrams showing a block sensing step and a partial sensing step when the touch screen TSP is divided and driven into a plurality of Rx blocks C1 to C4 along the x axis. Here, the x-axis is parallel to the major axis direction of the Tx lines as shown in Figs.

18 to 22, a touch screen driving circuit applies a driving signal to Tx blocks in units of Tx blocks in a block sensing step, receives and samples voltages of touch sensors in units of first to fourth Rx blocks, The sampled voltage can be converted into digital data. For example, the touch screen driving circuit simultaneously supplies the first driving signal to the Tx lines of the first Tx block B1 to simultaneously receive the voltages of the touch sensors through the Rx lines of the first Rx block C1 , The second driving signal may be simultaneously supplied to the Tx lines of the first Tx block to simultaneously receive the voltages of the touch sensors through the Rx lines of the second Rx block C2. Then, the touch screen driving circuit simultaneously supplies the third driving signal to the Tx lines of the first Tx block B1 to simultaneously receive the voltages of the touch sensors through the Rx lines of the third Rx block C3, The fourth driving signal may be simultaneously supplied to the Tx lines of the one Tx block to simultaneously receive the voltages of the touch sensors through the Rx lines of the fourth Rx block C4. In this way, all the touch sensors in the first Tx block are sensed in the block sensing step, and then the touch sensors of the next Tx block are sensed.

When the touch (or proximity) input is detected by the block sensing step, the touch screen driving circuit shifts to the partial sensing step. The touch screen driving circuit precisely senses all the touch sensors in the block where the blocks touch the Tx block and the Rx block connected to the touch sensor in which the touch (or proximity) input is detected as the block sensing result in the partial sensing step. Specifically, the touch screen driving circuit sequentially applies a driving signal to Tx lines of a Tx block in which a touch (or proximity) input is detected as a result of block sensing in a partial sensing step, and a touch (or proximity) Simultaneously or sequentially receiving and sampling touch sensor voltages through the Rx lines of the detected Rx block, and converting the sampled voltage into digital data. The touch screen driving circuit does not apply a driving signal to the Tx blocks in which the touch (or proximity) input is not detected as a result of the block sensing in the partial sensing step and the Rx And does not receive touch sensor voltages through the blocks. As a result of the block sensing, if no touch (or proximity) input is detected in all the blocks, the partial sensing step is not performed and the block sensing step is performed again.

When a multi-touch (or proximity) input is detected in a plurality of Rx blocks by the block sensing step as shown in FIG. 21, the touch screen driving circuit may detect the touch (or proximity) input of each of the Tx blocks And sequentially applies driving signals to the Tx lines. The touch screen driving circuit simultaneously or sequentially receives and samples the touch sensor voltages through the Rx lines of each of the detected Rx blocks, and converts the sampled voltage into digital data. Also in this case, the partial sensing step does not apply the driving signal to the Tx blocks in which the touch (or proximity) input is not detected by the block sensing step and the touch (or proximity) input is not detected by the block sensing step And does not receive touch sensor voltages through Rx blocks. As a result of the block sensing, if no touch (or proximity) input is detected in all the blocks, the partial sensing step is not performed and the block sensing step is performed again.

When the touch (or proximity) input is detected at the boundary of the neighboring Rx blocks as shown in FIG. 22 by the block sensing step, the partial sensing step sequentially outputs the driving signals to the Tx lines of the Tx block in which the touch . The touch screen driver circuit simultaneously or sequentially receives and samples the touch sensor voltages through the Rx lines of the Rx blocks neighboring the touch (or proximity) input position, and converts the sampled voltage into digital data. Also in this case, the partial sensing step does not apply the driving signal to the Tx blocks in which the touch (or proximity) input is not detected by the block sensing step and the touch (or proximity) input is not detected by the block sensing step And does not receive touch sensor voltages through Rx blocks. As a result of the block sensing, if no touch (or proximity) input is detected in all the blocks, the partial sensing step is not performed and the block sensing step is performed again.

23 is a flowchart illustrating a method of driving a touch sensing apparatus according to a second embodiment of the present invention. FIG. 24 is a diagram for explaining an example of a method of driving a touch sensing apparatus according to a second embodiment of the present invention, assuming two touch inputs. 25 is a waveform diagram showing a drive signal applied to the Tx lines in the pulley sensing step. FIG. 26 is a diagram showing regions to be subjected to partial sensing when the touch inputs as shown in FIG. 24 are detected in the pulley sensing step. FIG. 27 is a waveform diagram showing driving signals applied to areas subjected to partial sensing as shown in FIG. 26; FIG. 28 is a waveform diagram showing the effect of improving the touch sensitivity in the method of driving the touch sensing apparatus according to the second embodiment of the present invention.

23 to 28, the touch screen driving circuit first senses the touch sensors by touching the touch sensors of the touch screen (TSP) by a full sensing method (S231) The driving signals are sequentially supplied from the first Tx line T1 to the jth Tx line Tj to sense the touch sensors. In order to reduce the pulley sensing period, the touch sensors may be sensed in units of Rx blocks as shown in FIGS. 18 to 22. FIG.

The touch screen drive circuit converts the voltage of the touch sensors received in the pulley sensing step into digital data, and compares the digital data with a threshold value to determine whether to input a touch (or proximity). When the touch (or proximity) input (FIGS. 24 and 51) is detected as the result of the pulley sensing, the touch screen driving circuit shifts to the partial sensing step as the secondary scanning process. In the pulsing sensing step, The driving signals are sequentially supplied line by line only for the touch sensing areas 52 (Figs. 24 and 26, T3 to T5, and T31 to T33) to precisely sense the voltages of the touch sensors existing in the areas 52 to be subjected to the cell sensing And S233) The Rx driving circuit 34 receives the pixel data through the Rx lines R7 through R12 and R25 through R30 passing through the Paxel sensing target areas 52 in the partial sensing steps S232 and S233, Lt; RTI ID = 0.0 > 52 < / RTI >

The partial sensing target areas 52 are previously set to a predetermined size area including the touch input area 51 and its peripheral area. The peripheral area is located on the upper, lower, left, and right sides of the touch input area 51 and includes touch sensors 51 and neighboring touch sensors. The size of the peripheral area is set in advance and is variable by the designer.

In the pulley sensing step, only the touch (or proximity) input is detected, the routine proceeds to the partial sensing step. (S234) On the other hand, if no touch (or proximity) input is detected in the pulley sensing step, do.

The touch screen driving circuit converts the voltages of the touch sensors received in the partial sensing step into digital data (S235). Then, the touch screen driving circuit sums up the pulley sensing data and the partial sensing data stored in advance for each touch sensor (S236 As a result, since the difference between the non-touch signal and the touch (or proximity) input signal when there is no touch input is increased as shown in FIG. 28, the touch sensitivity of the present invention can be further improved.

29 to 31 are diagrams showing the circuit configuration of the Rx driving circuit 34 and its operation. 29, the pulse signal shown at the top illustrates a driving signal supplied to the Tx lines T1 to Tj. The drive signal is generated at a high logic level voltage for t1 time and is generated at a low logic level voltage for t2 time. 29 and 30, Tx (i) is an i-th Rx line and Rx (i + 1) is an i + 1 th Rx (i + 1) th Tx line Tx Line. Touch sensors are formed between the Tx line Tx (i) and the Rx lines Rx (i) and Rx (i + 1).

29 to 31, the sampling circuit of the Rx driving circuit 34 receives the voltages of the touch sensors received via the neighboring Rx lines Rx (i), Rx (i + 1) And supplies the difference between the sampled voltages to the analog-to-digital converter 341. To this end, the sampling circuit comprises a first and a second sampling circuit, and a comparator (COMP) for comparing the outputs of the sampling circuits. The comparator COMP may be implemented as an operational amplifier (OP). The first and second sampling circuits supply the voltages of the touch sensors received through the i-th Rx line Rx (i) each time a drive signal is applied to the i-th Tx line (Tx (i)) to a first sampling capacitor The voltage of the touch sensors accumulated in the (i + 1) th Rx line Rx (i + 1) is accumulated in the second sampling capacitor Ca1 ' The voltage of the touch sensors is sampled.

The first sampling circuit includes first to fourth switches S11 to S22, a first sensing capacitor Cs and a first sampling capacitor Ca1 to be received through the i-th Rx line Rx (i) The voltage of the touch sensors is sampled. The first switch S11 is connected to the i-th Rx line Rx (i). The third switch S21 is connected between the first switch S11 and the ground voltage source GND. The second switch S12 is connected between the fourth switch S22 and the ground voltage source GND. The fourth switch S22 is connected between the second switch S12 and the non-inverting input terminal of the comparator COMP. One end of the first sensing capacitor Cs is connected to the first node between the first switch S11 and the third switch S21. The other end of the first sensing capacitor Cs is connected to the second node between the second switch S12 and the fourth switch S22. One end of the first sampling capacitor Ca1 is connected to the node between the fourth switch S22 and the non-inverting input terminal of the comparator COMP. The other end of the first sampling capacitor Ca1 is connected to the first output terminal of the comparator COMP.

The first and second switches S11 and S12 are turned on at the time t1 when the drive pulse is generated. 30, the voltage of the first touch sensor connected to the i-th Rx line Rx (i) is stored in the first sensing capacitor Cs. Then, the third and fourth switches S21 and S22 are turned on at time t2 when the voltage of the i-th Tx line Tx (i) falls to a low logic level. 31, the voltage of the first touch sensor stored in the first sensing capacitor Cs is stored in the first sampling capacitor Ca1.

The second sampling circuit includes the fifth to eighth switches S11 'to S22', the second sensing capacitor Cs ', and the second sampling capacitor Ca1' so that the (i + 1) th Rx line Rx (i +1)) of the touch sensor. The fifth switch S11 'is connected to the (i + 1) -th Rx line Rx (i + 1). The seventh switch S21 'is connected between the fifth switch S11' and the ground voltage source GND. The sixth switch S12 'is connected between the eighth switch S22 and the ground voltage source GND. The eighth switch S22 'is connected between the sixth switch S12' and the inverting input terminal of the comparator COMP. One end of the second sensing capacitor Cs' is connected to the third node between the fifth switch S11 'and the seventh switch S21'. The other end of the second sensing capacitor Cs' is connected to a fourth node between the sixth switch S12 'and the eighth switch S22'. One end of the second sampling capacitor Ca1 'is connected to the node between the eighth switch S22' and the inverting input terminal of the comparator COMP. The other end of the second sampling capacitor Ca1 'is connected to the second output terminal of the comparator COMP.

The fifth and sixth switches S11 'and S12' are turned on at time t1 when the drive pulse is generated. 30, the voltage of the second touch sensor connected to the (i + 1) th Rx line Rx (i + 1) is stored in the second sensing capacitor Cs'. Then, the seventh and eighth switches S21 'and S22' are turned on at time t2 when the voltage of the i-th Tx line Tx (i) falls to a low logic level. 31, the voltage of the second touch sensor stored in the second sensing capacitor Cs 'is sampled in the second sampling capacitor Ca1'.

The comparator COMP supplies the voltage of the first touch sensor stored in the first sampling capacitor Ca1 and the voltage of the second touch sensor stored in the second sampling capacitor Ca1 'to the analog-digital converter 341.

The analog-to-digital converter 341 converts the difference between the voltage of the first touch sensor and the voltage of the second touch sensor into digital data in each of the block sensing and the partial sensing, and supplies the digital data to the touch recognition processor 30.

The touch recognition processor 30 stores the digital data received as the block sensing result or the pulley sensing result in the memory 301. [ The touch recognition processor 30 detects the touch (or proximity) input position by comparing the digital data obtained in the partial sensing step performed after the block sensing in the first embodiment with a preset threshold, and touches (or proximity) the touch. Calculate the coordinates of the location.

The touch recognition processor 30 sums the digital data of the pulley sensing result read from the memory 301 in the second embodiment and the digital data obtained in the partial sensing step performed after the pulley sensing as shown in Fig. Then, the touch recognition processor 30 detects the touch (or proximity) input position by comparing the summed result with a preset threshold value, and calculates coordinates of the touch (or proximity) position.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the present invention should not be limited to the details described in the detailed description, but should be defined by the claims.

DIS: Display panel TSP: Touch screen
12: data driving circuit 14: scan driving circuit
20: timing controller 30: touch recognition processor
32: Tx driving circuit 34: Rx driving circuit

Claims (9)

A touch screen comprising Tx lines, Rx lines intersecting the Tx lines, and touch sensors formed between the Tx lines and the Rx lines; And
In the first sensing step, all the touch sensors in the touch screen are firstly sensed to detect the presence or absence of touch input. Then, in the second sensing step, the touch sensors detected as a result of the primary sensing result are sensed secondarily, And a touch screen driving circuit for detecting a position of the touch screen,
Wherein the touch screen driving circuit repeats the first sensing step if there is no touch sensor whose touch input is detected as a result of primary sensing. The method of claim 1,
The touch screen driving circuit includes:
The touch screen is divided into at least two Tx blocks and the driving signals are simultaneously supplied to the Tx lines in the first Tx block in the primary sensing step to simultaneously sense the touch sensors in the first Tx block, Simultaneously supplying driving signals to the Tx lines in the Tx block to simultaneously sense the touch sensors in the second Tx block,
Each of the first and second Tx blocks is divided along the major axis direction of the Rx lines,
Wherein each of the first and second Tx blocks comprises at least two Tx lines and at least two Rx lines. The method of claim 2,
The touch screen driving circuit includes:
Wherein the second sensing step sequentially supplies driving signals to Tx lines existing in the Tx block in which the touch input is detected so as to precisely sense the touch sensors in the Tx block in which the touch input is detected. Device. The method of claim 3, wherein
The touch screen driving circuit includes:
Dividing the touch screen into at least two Rx blocks and simultaneously or sequentially sampling the voltage of the touch sensors received through the Rx lines in the first Rx block in the primary sensing step to convert the voltages into the touch raw data, Simultaneously or sequentially sampling the voltages of the touch sensors received through the Rx lines in the second Rx block to convert them into touch raw data,
The voltage of the touch sensors is received through only the Rx lines in the Rx block in which the touch input is detected in the secondary sensing step, and the voltages of the touch sensors are simultaneously or sequentially sampled and converted into the touch raw data,
Each of the first and second Rx blocks is divided along the major axis direction of the Tx lines,
Wherein each of the first and second Rx blocks comprises at least two Tx lines and at least two Rx lines. The method of claim 3, wherein
The touch screen driving circuit includes:
Storing the sensing result obtained in the primary sensing step in a memory,
And summing the sensing result obtained in the first sensing step and the sensing result obtained in the second sensing step and estimating the position of the touch input based on the touch raw data generated as the sum result. The method of claim 5, wherein
The touch screen driving circuit includes:
In the first sensing step, driving signals are sequentially supplied to Tx lines to sense touch sensors to sense a touch input area.
In the secondary sensing step, the driving signals are sequentially supplied only to the Tx lines existing in the partial sensing target area including the touch input area and its periphery to precisely sense the touch sensors in the partial sensing target area,
Wherein the sensing result obtained in the first sensing step and the sensing result obtained in the second sensing step are digital data, respectively. The method according to claim 6,
Storing the sensing result obtained in the primary sensing step in a memory,
And summing the sensing result obtained in the first sensing step and the sensing result obtained in the second sensing step and estimating the position of the touch input based on the touch raw data generated as the sum result. The method of claim 7, wherein
The touch screen driving circuit includes:
Dividing the touch screen into at least two Rx blocks and simultaneously or sequentially sampling the voltage of the touch sensors received through the Rx lines in the first Rx block in the primary sensing step to convert the voltages into the touch raw data, Simultaneously or sequentially sampling the voltages of the touch sensors received through the Rx lines in the second Rx block to convert them into touch raw data,
The voltage of the touch sensors is received through only the Rx lines in the Rx block in which the touch input is detected in the secondary sensing step, and the voltages of the touch sensors are simultaneously or sequentially sampled and converted into the touch raw data,
Each of the first and second Rx blocks is divided along the major axis direction of the Tx lines,
Wherein each of the first and second Rx blocks comprises at least two Tx lines and at least two Rx lines. The method of claim 1,
The touch screen driving circuit includes:
A Tx driving circuit for supplying a driving signal to the Tx lines;
An Rx driver circuit for sampling the voltage of the touch sensors received through the Rx lines and converting the sampled voltages into digital data to output touch raw data;
And a controller for synchronizing the operation timings of the Tx driving circuit and the Rx driving circuit and setting the channel of the Tx driving circuit and the Rx driving circuit, the sampling timing of the Rx driving circuit, and the ADC timing of the Rx driving circuit Controller; And
And a touch recognition processor for comparing the touch source data with a predetermined threshold value and estimating the touch source data equal to or higher than the threshold value as the touch input data.

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