# US 10,120,432 B2 · Touch sensing system and method of controlling power consumption thereof

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- Number: US 10,120,432 B2
- Document ID: US10120432B2
- Status: Granted
- Kind: B2
- Application number: 15/096,016
- Filed: 2016-04-11
- Published: 2016-08-04
- Granted: 2018-11-06
- Earliest claimed: 2012-11-13
- Assignees: LG Display Co., Ltd.
- Applicants: LG Display Co., Ltd.
- Inventors: Kyungjin Jang
- Web page: https://patentgrep.com/patent/US10120432B2

## CPC

- G06F 1/3262: {Power saving in digitizer or tablet}
- G06F 3/04166: {Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184)}
- G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes}
- G06F 3/05: Digital input using the sampling of an analogue quantity at regular intervals of time {, input from a/d converter or output to d/a converter}
- G06F 3/04164: {Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads}
- Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

A touch sensing system and a method of controlling power consumption thereof are disclosed. The touch sensing system includes a plurality of sensing units, which sample a voltage received from a touch screen and accumulate the sampled voltage, and a plurality of analog-to-digital converters converting an output of the sensing units into digital data. The sensing units and the analog-to-digital converters are divided into a plurality of groups in an idle state. Each of the plurality of groups includes at least two sensing units and one analog-to-digital converter. At least one sensing unit included in at least one group is powered down in the idle state. An analog-to-digital converter is powered on during the group it belongs to is powered on.

## Claims

### Claim 1

A touch sensing system, comprising:
a plurality of sensing units configured to:
sample a voltage received from a touch screen; and
accumulate a sampled voltage; and
a plurality of analog-to-digital converters configured to convert an output of the sensing units into digital data,
wherein the sensing units and the analog-to-digital converters are divided into a plurality of groups and driven in a time division manner,
wherein each of the plurality of groups includes:
at least one of the sensing units, and
at least one of the analog-to-digital converters,
wherein one of sensing units that is included in a group other than a group that is powered on is powered down, and
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis.

### Claim 2 (depends on 1)

The touch sensing system of claim 1, wherein a plurality of sensing units are connected to one analog-to-digital converter in each of the plurality of groups.

### Claim 3 (depends on 2)

The touch sensing system of claim 2, wherein, among the analog-to-digital converters, only an analog-to-digital converter included in the group that is powered on is driven.

### Claim 4 (depends on 3)

The touch sensing system of claim 3, wherein only the group that is powered on among the plurality of groups outputs touch raw data.

### Claim 5 (depends on 2)

The touch sensing system of claim 2, wherein the sensing units connected to the one analog-to-digital converter included in the group that is powered on are driven sequentially.

### Claim 6 (depends on 1)

The touch sensing system of claim 1, wherein the plurality of groups comprise:
a first group including first and third sensing units and a first analog-to-digital converter that converts an output of the first and third sensing units into digital data to generate touch raw data; and
a second group including second and fourth sensing units and a second analog-to-digital converter configured to convert an output of the second and fourth sensing units into digital data to generate touch raw data,
wherein, after the first sensing unit and the first analog-to-digital converter are driven, the second sensing unit and the second analog-to-digital converter are driven, and
wherein, subsequently, after the third sensing unit and the first analog-to-digital converter are driven, the fourth sensing unit and the second analog-to-digital converter are driven.

### Claim 7 (depends on 1)

The touch sensing system of claim 1, further comprising:
a timing generator configured to control drive timings of the sensing units and drive timings of the analog-to-digital converters;
a buffer memory configured to store touch raw data output from the analog-to-digital converters;
a first controller configured to:
analyze the touch raw data in an active state; and
calculate a coordinate of each touch input to output coordinate information;
a second controller connected to the first controller; and
a clock generator configured to:
receive a first clock from an oscillator and a second external clock from the first controller; and
transmit the first clock to the timing generator, the buffer memory, and the second controller in an idle state.

### Claim 8 (depends on 7)

The touch sensing system of claim 7, wherein:
when the touch raw data is equal to or greater than a predetermined threshold value, the timing generator is further configured to generate an interrupt signal; and
the first controller is further configured to:
be converted to an active state in response to the interrupt signal; and
output coordinate information in the active state.

### Claim 9 (depends on 8)

The touch sensing system of claim 8, wherein:
the first controller comprises an interrupt receiving circuit configured to receive the interrupt signal; and
the interrupt receiving circuit of the first controller alone is configured to be driven in the idle state so that the coordinate information is not output from the first controller.

### Claim 10 (depends on 9)

The touch sensing system of claim 9, wherein the timing generator is further configured to:
receive an operation mode command from the first controller; and
drive the plurality of groups in a time division manner when the operation mode command indicates an idle state.

### Claim 11 (depends on 10)

The touch sensing system of claim 10, wherein:
the timing generator is further configured to:
control power of each of the plurality of sensing units in the idle state; and
generate a plurality of power-down signals indicating a power-down timing of each of the plurality of analog-to-digital converters; and
the plurality of power-down signals are respectively supplied to the sensing units and the analog-to-digital converters.

### Claim 12 (depends on 11)

The touch sensing system of claim 11, wherein:
after generating the operation mode command, the first controller is converted to the idle state; and
the first controller is further configured to turn off a power applied to circuits other than the interrupt receiving circuit.

### Claim 13 (depends on 12)

The touch sensing system of claim 12, wherein the second controller is further configured to:
transmit data received from the first controller to the timing generator;
read the touch raw data stored in the buffer memory;
transmit the touch raw data; and
in response to receipt of an operation mode command indicating the idle state, control the clock generator by generating a clock selection signal for selecting the first clock.

### Claim 14 (depends on 9)

The touch sensing system of claim 9, wherein:
the first controller is converted to the active state in response to receipt of the interrupt signal;
all the circuits in the first controller are driven in the active state; and
all the sensing units and all the analog-to-digital converters are driven in the active state under control of the timing generator.

### Claim 15 (depends on 7)

The touch sensing system of claim 7, wherein the clock generator is further configured to transmit the second clock received from the first controller to the timing generator, the buffer memory, and the second controller in the active state.

### Claim 16 (depends on 1)

The touch sensing system of claim 1, wherein each touch sensor of the touch screen comprises a self-capacitance type or a mutual capacitance type.

### Claim 17

A touch sensitive display device, comprising:
a display driving circuit configured to:
apply video data of an input image to pixels of a display panel; and
accumulate a sampled voltage;
a plurality of sensing units configured to sample a voltage received from touch sensors coupled to the display panel; and
a plurality of analog-to-digital converters configured to convert an output of the plurality of sensing units into digital data,
wherein the sensing units and the analog-to-digital converters are divided into a plurality of groups and driven in a time division manner,
wherein each of the plurality of groups comprises:
at least one sensing unit, and
at least one analog-to-digital converter,
wherein at least one sensing unit included in a group other than a group that is powered on is powered down, and
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis.

### Claim 18 (depends on 17)

The touch sensitive display device of claim 17, wherein:
the touch sensors are embedded in the display panel; and
each of the touch sensors comprises a self-capacitance type or a mutual capacitance type.

### Claim 19

A touch sensing system, comprising:
a plurality of sensing units configured to:
sample a voltage received from a touch screen; and
accumulate a sampled voltage;
a plurality of analog-to-digital converters configured to convert an output of the sensing units into digital data; and
a touch screen driving circuit configured to drive the sensing units and the analog-to-digital converters on a per group basis in a time division manner,
wherein each of the plurality of groups comprises:
at least one sensing unit, and
at least one analog-to-digital converter,
wherein only a group that is powered on in an idle state among a plurality of groups outputs touch raw data,
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis,
wherein, when the touch raw data is equal to or greater than a predetermined threshold value, the touch screen driving circuit generates an interrupt signal to be converted to an active state, and
wherein the touch screen outputs coordinate information of a touch input only in the active state.

### Claim 20 (depends on 19)

The touch sensing system of claim 19, wherein a plurality of sensing units are connected to one analog-to-digital converter in each of the plurality of groups.

### Claim 21 (depends on 20)

The touch sensing system of claim 20, wherein the plurality of groups are sequentially powered on, on a per group basis, in an idle state.

### Claim 22 (depends on 21)

The touch sensing system of claim 21, wherein, among the analog-to-digital converters, only an analogy-to-digital converter included in the group that is powered on is driven in an idle state.

### Claim 23 (depends on 20)

The touch sensing system of claim 20, wherein the sensing units connected to the one analog-to-digital converter included in the group that is powered on is driven sequentially in an idle state.

### Claim 24 (depends on 19)

The touch sensing system of claim 19, wherein:
the plurality of groups include:
a first group including first and third sensing units and a first analog-to-digital converter that converts an output of the first and third sensing units into digital data to generate touch raw data; and
a second group including second and fourth sensing units and a second analog-to-digital converter that converts an output of the second and fourth sensing units into digital data to generate touch raw data; and
after the first sensing unit and the first analog-to-digital converter are driven:
the second sensing unit and the second analog-to-digital converter are driven; and
subsequently, after the third sensing unit and the first analog-to-digital converter are driven, the fourth sensing unit and the second analog-to-digital converter are driven, in an idle state.

### Claim 25 (depends on 19)

The touch sensing system of claim 19, wherein the touch screen driving circuit comprises:
a timing generator configured to control:
drive timings of the sensing units; and
drive timings of the analog-to-digital converters;
a buffer memory configured to store touch raw data output from the analog-to-digital converters;
a first controller configured to:
analyze the touch raw data in an active state; and
calculate a coordinate of each touch input to output coordinate information;
a second controller connected to the first controller; and
a clock generator configured to:
receive a first clock from an oscillator and a second external clock from the first controller; and
transmit the first clock to the timing generator, the buffer memory, and the second controller in an idle state.

### Claim 26 (depends on 25)

The touch sensing system of claim 25, wherein:
when the touch raw data is equal to or greater than a predetermined threshold value, the timing generator generates an interrupt signal;
the first controller is further configured to:
be converted to an active state in response to the interrupt signal; and
output coordinate information in the active state.

### Claim 27 (depends on 26)

The touch sensing system of claim 26, wherein:
the first controller comprises an interrupt receiving circuit configured to receive the interrupt signal; and
the interrupt receiving circuit of the first controller alone is driven in the idle state so that the coordinate information is not output from the first controller.

### Claim 28 (depends on 27)

The touch sensing system of claim 27, wherein:
the first controller is converted to the active state in response to receipt of the interrupt signal;
all the circuits in the first controller are driven in the active state; and
all the sensing units and all the analog-to-digital converters are driven in the active state under control of the timing generator.

### Claim 29 (depends on 26)

The touch sensing system of claim 26, wherein the timing generator is further configured to:
receive an operation mode command from the first controller; and
drive the plurality of groups in a time division manner when the operation mode command indicates an idle state.

### Claim 30 (depends on 29)

The touch sensing system of claim 29, wherein:
the timing generator is further configured to:
control power of each of the plurality of sensing units in the idle state; and
generate a plurality of power-down signals indicating a power-down timing of each of the plurality of analog-to-digital converters; and
the plurality of power-down signals are respectively supplied to the sensing units and the analog-to-digital converters.

### Claim 31 (depends on 30)

The touch sensing system of claim 30, wherein:
after generating the operation mode command, the first controller is converted to the idle state; and
the first controller turns off a power applied to circuits other than the interrupt receiving circuit.

### Claim 32 (depends on 31)

The touch sensing system of claim 31, wherein: the second controller is further configured to:
transmit data received from the first controller to the timing generator,
reads read the touch raw data stored in the buffer memory;
transmit the touch raw data; and
in response to receipt of an operation mode command indicating the idle state, control the clock generator by generating a clock selection signal for selecting the first clock.

### Claim 33 (depends on 25)

The touch sensing system of claim 25, wherein the clock generator is further configured to transmit the second clock received from the first controller to the timing generator, the buffer memory, and the second controller in the active state.

### Claim 34 (depends on 19)

The touch sensing system of claim 19, wherein each touch sensor of the touch screen comprises a self-capacitance type or a mutual capacitance type.

### Claim 35

A touch sensitive display device, comprising:
a display driving circuit configured to write data of an input image to pixels of a display panel;
a plurality of sensing units configured to:
sample a voltage received from touch sensors coupled to the display panel; and
accumulate a sampled voltage;
a plurality of analog-to-digital converters configured to convert an output of the sensing units into digital data; and
a touch screen driving circuit configured to drive the sensing units and the analog-to-digital converters on a per group basis in an idle state,
wherein each group comprises:
at least one sensing unit, and
at least one analog-to-digital converter,
wherein only a group that is powered on in the idle state among a plurality of groups outputs touch raw data,
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis,
wherein, when the touch raw data is equal to or greater than a predetermined threshold value, the touch screen driving circuit is converted to an active state, and
wherein the touch screen driving circuit outputs coordinate information of a touch input only in the active state.

### Claim 36 (depends on 35)

The touch sensitive display device of claim 35, wherein, when the touch raw data is equal to or greater than the predetermined threshold value, the touch screen driving circuit generates an interrupt signal to be converted to the active state.

### Claim 37 (depends on 35)

The touch sensitive display device of claim 35, wherein:
the touch sensors are embedded in the display panel; and
each of the touch sensors comprises a self-capacitance or a mutual capacitance.

### Claim 38

A touch sensing system, comprising:
a plurality of sensing units configured to:
sample a voltage received from a touch screen; and
accumulate a sampled voltage;
a plurality of analog-to-digital converters configured to convert an output from the sensing units into digital data; and
a touch screen driving circuit configured to drive the sensing units and the analog-to-digital converters on a per group basis in a time division manner,
wherein only a group that is powered on in the idle state outputs touch raw data,
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis,
wherein when the touch raw data is equal to or greater than a predetermined threshold value, the touch screen driving circuit is converted to an active state, and
wherein the touch screen driving circuit outputs coordinate information of a touch input only in the active state.

### Claim 39 (depends on 38)

The touch sensing system of claim 38, wherein, when the touch raw data is equal to or greater than the predetermined threshold value, the touch screen driving circuit generates an interrupt signal to be converted to the active state.

### Claim 40

A touch sensitive display device, comprising:
a display driving circuit configured to write data of an input image to pixels of a display panel;
a plurality of sensing units configured to:
sample a voltage received from touch sensors coupled to the display panel; and
accumulate a sampled voltage;
a plurality of analog-to-digital converters configured to convert an output of the sensing units into digital data; and
a touch screen driving circuit configured to drive the sensing units and the analog-to-digital converters on a per group basis in an idle state,
wherein each group includes:
at least one sensing unit, and
at least one analog-to-digital converter,
wherein only a group that is powered on in the idle state among the plurality of groups outputs touch raw data,
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis,
wherein, when the touch raw data is equal to or greater than a predetermined threshold value, the touch screen driving circuit is converted to an active state, and
wherein the touch screen driving circuit outputs coordinate information of a touch input only in the active state.

### Claim 41 (depends on 40)

The touch sensitive display of claim 40, wherein, when the touch raw data is equal to or greater than the predetermined threshold value, the touch screen driving circuit generates an interrupt signal to be converted to the active state.

### Claim 42

A touch sensing system, comprising:
a plurality of sensing units configured to:
sample a voltage received from a touch screen; and
accumulate a sampled voltage; and
a plurality of analog-to-digital converters configured to convert an output of the sensing units into digital data,
wherein the sensing units and the analog-to-digital converters are divided into a plurality of groups and driven in a time division manner,
wherein at least one group including at least one sensing unit and at least one analog-to-digital converter, other than a group that is powered on, is powered down, and
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis.

### Claim 43 (depends on 42)

The touch sensing system of claim 42, wherein the at least one sensing unit, in the group that is powered on, is powered down.

### Claim 44 (depends on 42)

The touch sensing system of claim 42, wherein the at least one sensing unit, other than the sensing units that is powered down, is powered on.

### Claim 45 (depends on 44)

The touch sensing system of claim 44, wherein the at least one analog-to-digital converter, in the group that is powered on, is powered on.

### Claim 46

A touch sensitive display device, comprising:
a display driving circuit configured to:
apply video data of an input image to pixels of a display panel; and
accumulate a sampled voltage;
a plurality of sensing units configured to:
sample a voltage received from a touch screen; and
accumulate a sampled voltage; and
a plurality of analog-to-digital converters configured to convert an output of the sensing units into digital data,
wherein the sensing units and the analog-to-digital converters are divided into a plurality of groups and driven in a time division manner,
wherein at least one group including at least one sensing unit and at least one analog-to-digital converter other than a group that is powered on is powered down, and
wherein the analog-to-digital converters are powered on, sequentially, on a per group basis.

### Claim 47 (depends on 46)

The touch sensitive display device of claim 46, wherein the at least one sensing unit, in the group that is powered on, is powered down.

### Claim 48 (depends on 47)

The touch sensitive display device of claim 47, wherein the at least one sensing unit, other than the sensing units that is powered down, is powered on.

### Claim 49 (depends on 48)

The touch sensitive display device of claim 48, wherein the at least one analog-to-digital converter, in the group that is powered on, is powered on.

### Claim 50 (depends on 49)

The touch sensitive display device of claim 49, wherein:
the touch sensors are embedded in the display panel; and
each of the touch sensors comprises a self-capacitance type or a mutual capacitance type.