KR20130137424A - Touch controller, method thereof, and system having the touch controller - Google Patents

Abstract

A touch controller is disclosed. The touch controller comprises a first pin, a current delivering device, a switch circuit, and a charge integrator. The current delivering device senses the current which flows in the first pin and outputs the current as delivery current. The switch circuit is connected to the current delivering device and is switched according to a sensing method of a touch panel. The charge integrator converts the delivery current into voltage.

Description

Touch controller, method of operation thereof and system comprising same {Touch controller, method approximately, and system having the touch controller}

The present invention relates to a touch controller, and more particularly, to a touch controller for detecting whether a touch panel is detected, a method of operating the same, and a system including the same, regardless of a sensing method of a touch panel.

There is an increasing demand for touchable electronic devices. The electronic device includes a touch panel to sense a touch. The touch panel includes electrodes.

Capacitive sensing is a technique of sensing touch using a change in capacitance. When a finger or conductive stylus approaches the electrodes, the capacitance changes. The change in capacitance is measured by a touch controller connected to the touch panel, and the change in capacitance may be converted into X and Y coordinates.

The capacitive sensing can be divided into self capacitive sensing and mutual capacitive sensing. The self capacitance sensing is a technique of sensing a touch by measuring a capacitance between a finger and an electrode. The self capacitance sensing cannot detect multi-touch.

The mutual capacitance sensing is a technique of sensing a touch by measuring a mutual capacitance between two electrodes when a finger touches the touch panel. The mutual capacitance detection may detect a multi-touch, but takes a long detection speed.

According to whether the touch panel sensing method is self capacitance sensing or mutual capacitive sensing, a touch controller that senses touch has to be implemented with different circuits.

The technical problem to be achieved by the present invention is to provide a touch controller capable of detecting whether the touch panel is touched regardless of the sensing method of the touch panel, an operation method thereof, and a system including the same.

The touch controller according to an embodiment of the present invention is connected to a current transmitter for sensing a current flowing from the first pin and the first pin and outputting the sensed current as a transfer current, and the current transmitter. A switch circuit switched in accordance with, and a charge integrator converting the transfer current into a voltage.

The touch controller further includes a second pin, a third pin, and a selector for connecting any one of the first pin, the second pin, and the third pin to the switch circuit.

When the sensing method of the touch panel is mutual capacitance sensing, the second pin and the third pin are not used.

When the sensing method of the touch panel is self capacitance sensing, the second pin and the third pin are used.

The switch circuit includes switches connected in series between a power node and ground, and a first switch for switching the first pin and the current transmitter.

When the sensing method of the touch panel is mutual capacitance sensing, the switches are all turned off and the first switch is turned on.

When the sensing scheme of the touch panel is self capacitance sensing, when one of the switches is turned on, the other of the switches is turned off.

The charge integrator includes a first output node, a first switch connected between the current transmitter and the first output node, a first variable capacitor connected between the first output node and ground, the first output node and the reference. A first reset switch connected between the nodes, a second output node connected to the switch circuit, a second switch and a mode switch connected between the current transmitter and the second output node, between the second output node and the ground A second variable capacitor connected to the second reset capacitor, and a second reset switch connected between the second output node and the reference node.

When the sensing method of the touch panel is mutual capacitance sensing, the mode switch is turned on. When the sensing method of the touch panel is self capacitance sensing, the mode switch is turned off.

According to an embodiment of the present disclosure, a method of operating a touch controller detects a current flowing from a receiving pin and outputs the sensed current as a transfer current, when the pulse signal applied to the touch panel is a rising edge, Converting the first voltage to a first output terminal and outputting the first voltage to a second output terminal when the pulse signal is a falling edge; .

According to another exemplary embodiment of the present disclosure, a method of operating a touch controller includes precharging a capacitance, sharing charges accumulated in the capacitance with a variable capacitor, and converting charges shared in the capacitance into a voltage. It includes.

A touch system according to an embodiment of the present invention includes a touch panel and the touch controller for controlling the touch panel.

The touch system is a portable electronic device.

According to an embodiment of the present disclosure, a touch controller, a method of operating the same, and a system including the same may include a switch circuit and a variable capacitor to detect whether the touch panel is touched using a single touch controller regardless of a sensing method of the touch panel. It can work.

In addition, the touch controller, an operation method thereof, and a system including the same according to an exemplary embodiment of the present invention can detect only a change in capacitance by using a variable capacitor to detect a self capacitance, thereby reducing power consumption by reducing current flowing through the touch controller. In this case, the effect of the variation of the self capacitance of the patch panel and the parasitic capacitance can be eliminated.

In addition, the touch controller, an operation method thereof, and a system including the same according to an exemplary embodiment of the present invention can detect only a change amount of capacitance by adjusting a reset voltage to detect a self capacitance, thereby reducing power flowing through the touch controller. In this case, the effect of the variation of the self capacitance of the patch panel and the parasitic capacitance can be eliminated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully understand the drawings recited in the detailed description of the present invention, a detailed description of each drawing is provided.
1 is a block diagram of a touch system including a touch controller according to an exemplary embodiment of the present invention.
2 is a block diagram of a touch system according to an exemplary embodiment of the touch panel illustrated in FIG. 1.
3 is a block diagram of a touch system according to another exemplary embodiment of the touch panel illustrated in FIG. 1.
4 is a circuit diagram of the sensing circuit shown in FIGS. 2 and 3.
5 is a waveform diagram according to an exemplary embodiment of the signals illustrated in FIG. 4.
6 is a waveform diagram according to another exemplary embodiment of the signals illustrated in FIG. 4.
FIG. 7 is a circuit diagram illustrating an example of the sensing circuit shown in FIG. 4.
8 is a circuit diagram illustrating another sensing circuit shown in FIG. 4.
FIG. 9 is a circuit diagram of another sensing circuit of FIG. 4. Referring to FIG.
10 is a flowchart illustrating an operation of the touch controller shown in FIG. 2.
11 is a flowchart illustrating an operation of the touch controller shown in FIG. 3.

Specific structural and functional descriptions of embodiments of the present invention disclosed herein are illustrated for purposes of illustrating embodiments of the inventive concept only, And can be embodied in various forms and should not be construed as limited to the embodiments set forth herein.

The embodiments according to the concept of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail herein. It is to be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms of disclosure, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms such as first and / or second may be used to describe various components, but the components should not be limited by the terms. The terms are intended to distinguish one element from another, for example, without departing from the scope of the invention in accordance with the concepts of the present invention, the first element may be termed the second element, The second component may also be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. Do not.

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.

1 is a block diagram of a touch system including a touch controller according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the touch system 100 is a portable electronic device such as a smart phone, a tablet PC or a notebook. The touch system 100 includes a touch panel 110 and a touch controller 120.

The touch panel 110 includes electrodes 111 arranged in the X-axis direction and electrodes 113 arranged in the Y-axis direction. The electrodes 111 arranged in the X-axis direction and the electrodes 113 arranged in the Y-axis direction may be implemented as two layers. According to an embodiment, the electrodes 111 and the electrodes 113 may be implemented in one layer.

The touch controller 120 is used to detect whether the touch panel 110 is touched when the touch panel 110 is touched by a human finger or a stylus pen. The touch controller 120 includes an analog front end (AFE) 130, a micro control unit (MCU) 160, and a memory 170.

The AFE 130 drives the touch panel 110, receives a current from the touch panel 110, performs various operations on the current, and converts the digital signal into a digital signal for processing by the MCU 160. . The AFE 130 includes a driver 140 and a receiver 150. The driver 140 supplies a pulse signal (eg, a voltage) to drive the touch panel 110. The driver 140 is used when the sensing method of the touch panel 110 is mutual capacitance sensing. The receiver 150 will be described in detail with reference to FIGS. 2 through 11.

The MCU 160 processes the digital signal output from the AFE 130. For example, the MCU 160 calculates touch coordinates using the digital signal.

The memory 170 may store a digital signal output from the AFE 130 or a digital signal processed by the MCU 160. The memory 170 may be implemented as a nonvolatile memory such as flash memory or a volatile memory such as static random-access memory (SRAM).

2 is a block diagram of a touch system according to an exemplary embodiment of the touch panel illustrated in FIG. 1. 2 is a block diagram of a touch system when the sensing method of the touch panel is mutual capacitance sensing.

1 and 2, the touch system 100-1 includes a touch panel 110-1 and a receiver 150-1. For convenience of description, other components 140, 160, and 170 of the touch controller 120 shown in FIG. 1 are omitted.

When the sensing scheme of the touch panel 110-1 is mutual capacitance sensing, the receiver 150-1 senses a capacitance (eg, Cm) between two electrodes (eg, RL1 and CL2). In this case, a pulse signal for driving each of the electrodes RL1 to RLm (m is a natural number) of the touch panel 110-1 is supplied by the driver 140 shown in FIG. 1. Receiver 150-1 includes sensing circuits 10-11, 10-12, 10-13, ..., and 10-1n; n is a natural number and an analog digital converter (ADC) 151-1. ).

Each of the sensing circuits 10-11, 10-12, 10-13,..., And 10-1n is a respective current output from each of the electrodes CL1, CL2, and CLn of the panel 110-1. And convert each of the currents into respective voltages (eg, VOUT1 and VOUT2). Voltages VOUT1 and VOUT2 are analog signals.

The ADC 151-1 converts the voltages (eg, VOUT1 and VOUT2) output from the sensing circuits 10-11, 10-12, 10-13,..., And 10-1n into digital signals. do.

3 is a block diagram of a touch system according to another exemplary embodiment of the touch panel illustrated in FIG. 1. 3 is a block diagram of a touch system when the sensing method of the touch panel is self capacitance sensing.

1 and 3, the touch system 100-2 includes a touch panel 110-2 and a receiver 150-2. For convenience of description, other components 140, 160, and 170 of the touch controller 120 shown in FIG. 1 are omitted.

When the sensing method of the touch panel 110-2 is self capacitance sensing, the receiver 150-2 senses a capacitance (eg, Cself) between a human finger or a stylus pen and an electrode. Receiver 150-2 includes sensing circuits 10-21, 10-22, 10-23, ..., and 10-2n; n is a natural number and an analog digital converter (ADC) 151-2. ).

Each of the sensing circuits 10-21, 10-22, 10-23,..., And 10-2n supplies a pulse signal to an electrode (eg, RL1 or CL1) of the panel 110-2. A current output from the electrode is received and the current is converted into a voltage (eg, VOUT1). Voltage VOUT1 is analog signals.

The ADC 151-2 converts the voltage VOUT1 output from the sensing circuits 10-21, 10-22, 10-23,..., And 10-2n into a digital signal.

4 is a circuit diagram of the sensing circuit shown in FIGS. 2 and 3.

1 to 4, the sensing circuit 10 shows an embodiment of the sensing circuit 10-11 shown in FIG. 2 or the sensing circuits 10-21 shown in FIG. 3. That is, the sensing circuit 10 may be used regardless of the sensing method of the touch panel 110. The sensing circuit 10 includes pins P1, P2, and P3, a selector 11, a switch circuit 13, a current transmitter 23, and a charge integrator 33.

The pins P1, P2, and P3 are connected to the electrodes of the touch panel 110. For example, when the sensing method of the touch panel 110 is mutual capacitance sensing, the pin P3 is connected to the electrode (eg, CL1), and the pins P1 and P2 are not used. When the sensing scheme of the touch panel 110 is self capacitance sensing, the pins P1, P2, and P3 may be connected to the electrodes (eg, RLm, RL1, and CL1).

The selector 11 connects any one of the pins P1, P2, and P3 with the switch circuit 13. The selector 11 is controlled by the selection signal SEL generated by the selection signal generator (not shown).

The switching circuit 13 comprises switches 15, 17, and 19 connected in series between the power node VTX and ground, and a switch 21 for switching the selector 11 and the current transmitter 23. do. The switch 21 is controlled by the switch control signal S3. The switching circuit 13 is switched according to the sensing method of the touch panel 10. For example, when the sensing scheme of the touch panel 10 is mutual capacitance sensing, the switches 15, 17, and 19 are turned off, and the switch 21 is turned on. When the sensing scheme of the touch panel 10 is self capacitance sensing, the switches 15, 17, and 19 are turned on or off over time. The switches 15 and 19 are controlled by the switch control signal S1, and the switch 17 is controlled by the switch control signal S2.

The current transmitter 23 senses a current flowing through any one of the pins P1, P2, and P3 and outputs the sensed current as a transfer current IC. The current transmitter 23 may include current mirrors 25, 27, 29, and 31 and a reference current source IREF.

The charge integrator 33 converts the transfer current IC into a voltage VOUT1 or VOUT2. The charge integrator 33 may be implemented with a switched capacitor array. The switch 35 is connected between the current transmitter 23 and the first output node N1. The switch 35 is controlled by the switch control signal V1.

The first variable capacitor CVAR1 is connected between the first output node N1 and ground. The first reset switch 37 is connected between the first output node N1 and the reference node VREF. The first reset switch 37 is controlled by the first reset signal RST1.

The second switch 39 and the mode switch 41 are connected between the current transmitter 23 and the second output node N2. The second switch 39 is controlled by the switch control signal / V1. The switch control signal / V1 is an inverted signal of the switch control signal V1. The mode switch 41 is controlled by the mode control signal MODE.

The second variable capacitor CVAR2 is connected between the second output node N2 and ground. The second reset switch 43 is connected between the second output node N2 and the reference node VREF. The second reset switch 43 is controlled by the second reset signal RST2.

5 is a waveform diagram according to an exemplary embodiment of the signals illustrated in FIG. 4.

1, 2, 4, and 5, when the sensing method of the touch panel 110-1 shown in FIG. 2 is mutual capacitance sensing, FIG. 5 illustrates an operation of the touch controller 120. The waveform diagram for the following is shown.

The switch control signals S1 and S2 have a low level, and the switches 15, 17, and 19 are turned off. The switch control signal S3 has a high level, and the switch 21 is turned on. The mode control signal MODE has a high level, and the mode switch 41 is turned on.

The reset switches 37 and 43 are turned on by the first reset signal RST1 and the second reset signal RST2 at the first time point T1, and the first reset signal RST1 at the second time point T2. ) And the reset switches 37 and 43 are turned off by the second reset signal RST2.

The pulse signal Vtx is generated by the driver 140 and is applied to any one of the electrodes RL1 to RLm of the touch panel 110-1 at the second time point T2. When the pulse signal Vtx is applied to any one of the electrodes RL1 to RLm of the touch panel 110-1, current flows through the pin P3. The charge of the current may be represented by Cm * Vtx.

 When the pulse signal Vtx is at the rising edge, the transfer current IC is transferred to the second output node N2 and converted to the voltage VOUT2.

When the pulse signal Vtx is at the falling edge, the transfer current IC is transferred to the first output node N1 and converted to the voltage VOUT1.

The ADC 151-1 converts the voltage difference between the voltages VOUT1 and VOUT2 into a digital signal.

6 is a waveform diagram according to another exemplary embodiment of the signals illustrated in FIG. 4.

1, 3, 4, and 6, when the sensing method of the touch panel 110-2 shown in FIG. 3 is self capacitance sensing, FIG. 6 illustrates an operation of the touch controller 120. The waveform diagram for the following is shown.

The switch control signal V1 has a high level, the switch 35 is turned on, and the switch 39 is turned off. The second reset signal RST2 has a low level, and the second reset switch 43 is turned off. The mode control signal MODE has a low level, and the mode switch 41 is turned off.

The first reset switch 37 is turned on at the first time point T1 by the first reset signal RST1, and the first switch 37 is turned on at the second time point T2 by the first reset signal RST1. Is turned off.

 When the switch control signal S1 has a high level, the switch control signal S2 has a low level, and the switch control signal S3 has a low level, the touch controller 10 performs a pre charge operation. Do this. The precharge operation will be described in detail with reference to FIG. 7.

  When the switch control signal S1 has a low level, the switch control signal S2 has a high level, and the switch control signal S3 has a low level, the touch controller 10 performs a charge sharing operation. Do this. The charge sharing operation will be described in detail with reference to FIG. 8.

 When the switch control signal S1 has a low level, the switch control signal S2 has a high level, and the switch control signal S3 has a high level, the touch controller 10 performs a charge transfer operation. Do this. The charge transfer operation will be described in detail in FIG. 9.

FIG. 7 is a circuit diagram illustrating an example of the sensing circuit shown in FIG. 4.

3, 4, 6, and 7, capacitance Cself represents the capacitance between the finger or the stylus pen and the electrode. The internal resistance Ri means a resistance between the pin P3 and the capacitance Cself. Only some components of the touch controller 10 are shown for convenience of description.

When the switch control signal S1 has a high level, the switch 15 is turned on. The voltage of the power supply node VTX is applied to the electrode of the touch panel 110-2 through the pin P3 as a pulse signal. At this time, the switches 17 and 21 are turned off. When the switch 15 is turned on, the capacitance Cself is precharged with the voltage of the power supply node VTX.

When the switch 19 is turned on, the second variable capacitor CVAR2 is reset to the ground voltage.

8 is a circuit diagram illustrating another sensing circuit shown in FIG. 4.

3, 4, 6, and 8, after the precharge operation is performed, the charge sharing operation is performed. When the switch control signals S1 and S3 have a low level, the switches 15, 19, and 21 are turned off. When the switch control signal S2 has a high level, the switch 17 is turned on. Therefore, the charges Irx accumulated in the capacitance Cself are shared by the second variable capacitor CVAR2. That is, the charge sharing operation is performed.

FIG. 9 is a circuit diagram of another sensing circuit of FIG. 4. Referring to FIG.

3, 4, 6, and 9, the charge transfer operation is performed after the charge sharing operation is performed. When the switch control signal S1 has a low level, the switches 15 and 19 are turned off. When the switch control signals S2 and S3 have a high level, the switches 17 and 21 are turned on. Charges Iself shared in the capacitance Cself are transferred to the current transmitter 23.

When the touch panel 110-2 is not touched by a finger or a stylus pen, the voltage VOUT1 is expressed by Equation 1 below.

[Equation 1]

Here, VDD means the voltage of the current transmitter 23.

The second variable capacitor CVAR2 is adjusted such that the voltage VOUT1 becomes 0V.

According to an exemplary embodiment, instead of adjusting the second variable capacitor CVAR2, the reset voltage connected to one end of the switch 19 may be adjusted so that the voltage VOUT1 becomes OV. For example, assuming that Cself is 20pF, Vtx is 3.3, VDD / 2 is 1.65, and CVAR2 is 50pF, the reset voltage connected to one end of the switch 19 is set to be 0.99. The reset voltage may be set by a digital to analog converter (DAC).

When the touch panel 110-2 is touched by a finger or a stylus pen, the voltage VOUT1 is expressed by Equation 2 below.

&Quot; (2) "

Therefore, the change amount of capacitance Cself is changed by the ADC 151-2. Therefore, the current flowing through the charge integrator 33 can be reduced to reduce the power consumption of the sensing circuit 10.

10 is a flowchart illustrating an operation of the touch controller shown in FIG. 2.

2, 4, 5, and 10, the current transmitter 23 senses a current flowing from the pin P3 and outputs the sensed current as a transfer current IC (S10).

When the pulse signal Vtx applied to the touch panel 110-1 is the rising edge, the charge integrator 33 converts the current IC into the first voltage VOUT1 and outputs the first output terminal N1. (S20).

When the pulse signal Vtx is at the falling edge, the charge integrator 33 converts the transfer current IC into the second voltage VOUT2 and outputs it to the second output terminal N2 (S30).

11 is a flowchart illustrating an operation of the touch controller shown in FIG. 3.

3, 4, 6 to 9, and 11, the switch control signal S1 has a high level, the switch control signal S2 has a low level, and the switch control signal S3 is When having a low level, the touch controller 10 performs a precharge operation (S110). When the switch 15 is turned on, the capacitance Cself is precharged.

When the switch control signal S1 has a low level, the switch control signal S2 has a high level, and the switch control signal S3 has a low level, the touch controller 10 performs a charge sharing operation ( S120). The charges Irx accumulated in the capacitance Cself are shared by the second variable capacitor CVAR2.

 When the switch control signal S1 has a low level, the switch control signal S2 has a high level, and the switch control signal S3 has a high level, the touch controller 10 performs a charge transfer operation. Perform (S130). Charges Iself shared in the capacitance Cself are transferred to the current transmitter 23.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

100; Touch system
110; Touch panel
120; Touch controller
130; Analog front end
160; Micro control unit
170; Memory
10; Sensing circuit

Claims (13)

First pin;
A current transmitter which senses a current flowing from the first pin and outputs the sensed current as a transfer current;
A switch circuit connected to the current transmitter and switched according to a sensing method of a touch panel; And
And a charge integrator for converting the transfer current to a voltage. The method of claim 1, wherein the touch controller,
Second pin;
Third pin; And
And a selector for connecting any one of the first pin, the second pin, and the third pin to the switch circuit. The method of claim 2, wherein when the sensing method of the touch panel is mutual capacitance sensing,
The second pin and the third pin is not used. The method of claim 2, wherein when the sensing method of the touch panel is magnetic capacitance sensing,
The second pin and the third pin is used touch controller. The method of claim 1, wherein the switch circuit,
Switches in series between the power node and ground; And
And a first switch for switching the first pin and the current transmitter. The method of claim 5, wherein when the sensing method of the touch panel is mutual capacitance sensing,
The switches are all turned off,
And the first switch is turned on. The method of claim 5, wherein when the sensing method of the touch panel is magnetic capacitance sensing,
And when one of the switches is turned on, the other of the switches is turned off. The method of claim 1, wherein the charge integrator,
A first output node;
A first switch connected between the current transmitter and the first output node;
A first variable capacitor connected between the first output node and ground;
A first reset switch connected between the first output node and a reference node;
A second output node connected with the switch circuit;
A second switch and a mode switch connected between the current transmitter and the second output node;
A second variable capacitor connected between the second output node and the ground; And
And a second reset switch connected between the second output node and the reference node. The method of claim 8, wherein when the sensing method of the touch panel is mutual capacitance sensing,
The mode switch is turned on,
When the sensing method of the touch panel is magnetic capacitance sensing,
And the mode switch is turned off. Sensing a current flowing from a receiving pin and outputting the sensed current as a transfer current;
Converting the transfer current into a first voltage and outputting the transferred current to a first output terminal when the pulse signal applied to the touch panel is a rising edge; And
And converting the transfer current into a second voltage and outputting the transferred current to a second output terminal when the pulse signal is a falling edge. Precharging the capacitance;
Charge sharing in the capacitance with a variable capacitor; And
Converting charges shared in the capacitance into voltage. Touch panel; And
It includes a touch controller for controlling the touch panel,
The touch controller includes:
A current transmitter which senses a current flowing from a pin connected to an electrode of the touch panel and outputs the sensed current as a transfer current;
A switch circuit connected to the current transmitter and switched according to a sensing method of a touch panel; And
And a charge integrator that converts the transfer current to a voltage. The method of claim 12, wherein the touch system,
Touch system as a portable electronic device.

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