TOUCH INTEGRATED CIRCUIT, TOUCH SENSING DEVICE INCLUDING THE SAME AND DRIVING METHOD THEREOF

A touch sensing device includes a touch panel, a touch integrated circuit configured to scan the touch panel at a scan frequency, and an application processor configured to provide application information on an application activated at the touch sensing device. The touch integrated circuit is configured to adjust the scan frequency in response to the application information.

DETAILED DESCRIPTION

FIG. 1is a block diagram schematically illustrating a touch sensing device100according to an embodiment of inventive concepts. Referring toFIG. 1, a touch sensing device100may include a touch panel110, a touch integrated circuit120, and an application processor130.

The touch sensing device100may control a scan frequency based on a busy application. The touch sensing device100may control a scan frequency according to a touch sensing speed required for the busy application. When an application not requiring high-speed touch sensing is running, the touch sensing device100may scan the touch panel110with a low scan frequency to reduce power consumption.

The touch panel110may include a plurality of sensing nodes, each of which includes a sensor for sensing a touch of a user. The touch panel110may convert a sensing result into an electrical signal, and may provide the electrical signal to the touch integrated circuit120. In example embodiments, a touch sensing method of the touch panel110may not be limited thereto.

For example, the touch panel110may sense a capacitance value of a sensing node. If a user touches a panel, a capacitance value of a peripheral sensing node of a touch point may vary by mutual capacitance between the user and the panel. The touch panel110may provide the touch integrated circuit120with the electrical signal indicating a capacitance value. This will be more fully described with reference toFIG. 2.

The touch panel110may include a user interface or a display unit for providing a display. For example, the touch panel110may include as a display means a liquid crystal display (LCD) device, an organic light emitting display (OLED) device, a field emission display (FED) device, or a plasma display device (PDP).

The touch integrated circuit120may control an operation of the touch panel110. The touch integrated circuit120may sense a touch operation of a user from an electrical signal transferred from the touch panel110. The touch integrated circuit120may scan the touch panel110with a scan frequency to sense a touch operation.

As a scan frequency for scanning the touch panel110increases, the touch integrated circuit120may rapidly recognize a touch operation of a user. On the other hand, as a scan frequency for scanning the touch panel110decreases, an operation of recognizing the touch operation of the user may be delayed. However, as a scan frequency for scanning the touch panel110increases, power consumption of the touch sensing device100may increase.

The touch integrated circuit120may be connected with the application processor130. The touch integrated circuit120may recognize a type of application running at the touch sensing device100through the application processor130.

An application running at the touch sensing device100may require different touch recognition speeds according to characteristics. For example, in the case that an application for drawing a picture on a panel through a touch operation is executed, the touch operation may be recognized rapidly without a delay. On the other hand, in the event that an application for playing a moving picture is running, a predetermined delay time may be allowed at recognition of a touch operation.

The touch integrated circuit120may adjust a scan frequency in response to a control of the application processor130. The touch sensing device100may provide recognition speed and power consumption on a busy application by adjusting of a scan frequency through the touch integrated circuit120.

The application processor130may control an operation of the touch sensing device100. The application processor130may drive an operating system (OS) and an application running at the touch sensing device100. The application processor130may include a central processing unit (CPU), a graphics processing unit (GPU), and so on.

The application processor130may provide the touch integrated circuit120with a scan frequency adjusting signal FRE based on a type of an application currently running. In example embodiments, an application currently running may mean an application, occupying a use of a touch panel, from among applications currently stored at a memory. The touch integrated circuit120may adjust a scan frequency of the touch panel110in response to the scan frequency adjusting signal FRE.

The touch sensing device100may adjust a scan frequency based on a type of application running. The touch sensing device100may determine the recognition speed and power consumption on a busy application by adjusting the scan frequency.

FIG. 2is a detailed block diagram illustrating a touch panel110and a touch integrated circuit120ofFIG. 1. Referring toFIG. 2, the touch integrated circuit120may include a touch driver121, a signal processing unit122, and a control unit123.

The touch panel110may include a plurality of TX driving lines111ato111d, a plurality of RX sensing lines112ato112d, and a sensing node array113of sensing nodes disposed at intersections of the lines. InFIG. 2, there are illustrated four TX driving lines and four RX sensing lines. Since the sensing nodes of the sensing node array113have the same structure, a detailed description of one sensing node113awill be made.

The sensing node113amay have mutual capacitance113bvaried by a driving current flowing through the TX driving line111aand an external factor. The external factor causing a variation in the mutual capacitance113bof the sensing node113amay include a touch of a user.

The mutual capacitance113bof the sensing node113agenerated by the driving current flowing through the TX driving line111amay be transferred as an electrical signal through the RX sensing line112a. The electrical signal may be a current or a voltage. A level of the electrical signal may vary according to the mutual capacitance113bof the sensing node113a.

The touch driver121may provide driving currents to the TX driving lines111ato111d. The touch driver121may sense mutual capacitance values of the sensing node array113through the RX sensing lines112ato112d.

The touch driver121may change a scan frequency of a driving current applied to each of the TX driving lines111ato111d. The touch driver121may change the scan frequency in response to the scan frequency control signal FRE from the application processor130(refer toFIG. 1). As the scan frequency of the driving current varies, a touch recognizing speed and power consumption of a touch sensing device100(refer toFIG. 1) may vary.

The signal processing unit122may process electrical signals received from the RX sensing lines112ato112dthrough the touch driver121to generate touch data. The signal processing unit122may include an ADC (Analog-to-Digital Converter). An electrical signal which the signal processing unit122receives from the touch driver121may be an analog signal. The signal processing unit122may convert an analog signal into a digital signal using the ADC to output touch data as a conversion result.

The control unit123may decide a touch state of the touch panel110based on the touch data provided from the signal processing unit122. The control unit123may compare the touch data with a reference value to decide a touch state of each sensing node. The control unit123may send the decided touch states to the application processor130.

The touch integrated circuit120may change the scan frequency of a driving current provided to each of the TX driving lines111ato111dof the touch pane110in response to the scan frequency control signal FRE. The scan frequency control signal FRE may be generated based on a type of application running. Thus, the touch integrated circuit120may change a scan frequency in response to a type of application, so that power consumption of the touch sensing device100is adjusted.

FIG. 3is a block diagram schematically illustrating layers of the application processor130ofFIG. 1. Referring toFIG. 3, the application processor130may include hardware131, an operating system layer132, and an application layer133.

The operating system layer132may provide an interface for controlling the hardware131. The operating system layer132may include a hardware abstraction layer (HAL) for controlling the hardware131. In example embodiments, the operating system layer132may not be limited thereto.

The application layer133may be an application program (i.e., an application) for executing a specific function of the touch sensing device100. The application layer133may use an API (Application Programming Interface) library for communication with the operating system layer132.

The application layer133may include a scan frequency control program. The scan frequency control program may recognize a type of application running at the application layer133. The scan frequency control program may enable the application processor130to control a scan frequency of the touch integrated circuit120, based on the recognized application type.

The application processor130may control a scan frequency using the scan frequency control program running at the application layer133. However, inventive concepts are not limited thereto.

FIG. 4is a block diagram schematically illustrating a touch sensing device200according to another example embodiment of inventive concepts. Referring toFIG. 4, a touch sensing device200may include a touch panel210, a touch integrated circuit220, and an application processor230. The touch panel210ofFIG. 4may be configured substantially the same as a touch panel110ofFIG. 1.

The touch integrated circuit220may be connected with the application processor230. The touch integrated circuit220may be provided with information APP (hereinafter, referred to as application information) on a currently running application from the application processor230. The touch integrated circuit220may adjust a scan frequency on the touch panel210in response to the application information APP.

The touch integrated circuit220may include a register221. The register221may store a plurality of scan frequencies different from one another. The touch integrated circuit220may selectively load a scan frequency from the register221in response to the application information APP. The touch integrated circuit220may drive the touch panel210with the loaded scan frequency.

The application information APP may include information associated with a type of application currently running. The register221may store a scan frequency corresponding to a specific application. If the specific application is recognized from the application information APP, the touch integrated circuit220may load and use a scan frequency corresponding to the application from the register221.

Also, the application information APP may include a result of classifying a busy application based on a predetermined reference. For example, applications may be divided into a plurality of groups according to touch recognition speeds. The application information APP may direct a group to which the busy application belongs.

The register221may store scan frequencies corresponding to the groups. If a specific group is recognized from the application information APP, the touch integrated circuit220may load and use a scan frequency corresponding to the group from the register221.

Also, the register221may store a default scan frequency as an initial setting value. At booting of the touch sensing device200and during execution of an unclassified application, the touch integrated circuit220may drive the touch panel210with the default scan frequency.

The touch integrated circuit220may selectively load a scan frequency from the register221in response to the application information APP to drive the touch panel210with the loaded scan frequency. Thus, the touch integrated circuit220may change a scan frequency in response to a type of application, so that power consumption of the touch sensing device200is adjusted.

FIG. 5is a flow chart illustrating a driving method of a touch sensing device according to an example embodiment of inventive concepts.

In operation S110, an application may be executed by an application processor. The application processor may recognize a type of application running/executed.

In operation S120, a touch panel IC decides a scan frequency for driving a touch panel according to the recognized application type. The scan frequency may be decided according to a touch sensing speed which the recognized application requires. The higher a touch sensing speed required by an application, the higher the scan frequency. A level of the scan frequency may be selected from among a plurality of levels.

In operation S130, a touch panel may be driven with the decided scan frequency by the touch panel IC. Since the scan frequency is decided based on an application currently running, the touch sensing speed and power consumption of a touch sensing device may be adjusted according to a type of application.

If an application running at the touch sensing device is changed, a scan frequency may be also changed. This will be more fully described with reference toFIG. 6.

FIG. 6is a flow chart illustrating a method of controlling an operation of a touch sensing device according to an example embodiment of inventive concepts.

In operation S210, a touch sensing device may be booted. The touch sensing device may be booted by an operating system stored at an application processor.

In operation S220, a touch panel may be driven by a touch panel IC with a default scan frequency. The default scan frequency may be predetermined by the touch panel IC. However, the default scan frequency may not be limited to a specific value.

In operation S230, an application may be executed by the application processor. The application may be provided with a touch state through a touch integrated circuit. The touch integrated circuit may drive a touch panel to provide the touch state.

In operation S240, the touch panel IC may determine a scan frequency by which the touch panel is driven. The scan frequency based on a touch sensing speed which the executed application requires. The higher a touch sensing speed of the application, the higher the scan frequency. The touch panel IC may select a level of the scan frequency from among a plurality of levels.

In operation S250, the touch panel may be driven with the decided scan frequency by the touch panel IC. Since the scan frequency is decided based on an application currently running, the touch sensing speed and power consumption of a touch sensing device may be adjusted according to a type of application.

In operation S260, whether an application is switched may be determined by the touch panel IC. Herein, switching of the application may mean that an application enters a sleep mode without deleting of the application from a memory and a new application is executed. If switching of the application is made, in operation S240, a scan frequency corresponding to the new application may be decided.

In operation S270, an application previously executed may be ended. If the application previously executed is ended, the touch panel may be driven with the default scan frequency in operation S280.

With the operating method of the touch sensing device, if an application running is switched or ended, a scan frequency may be again adjusted. Thus, the touch sensing speed and power consumption of a touch sensing device may be adjusted according to switching of the application.

FIG. 7is a diagram illustrating a handheld phone to which a touch sensing device of inventive concepts is applied. Referring toFIG. 7, a handheld phone1000may include a touch panel1100and a touch integrated circuit1200.

The touch panel1100may provide a user interface according to a control of an application processor. The touch panel1100may include a plurality of sensing nodes. The touch panel1100may sense a touch of a user to provide an electrical signal indicating a mutual capacitance variation of the sensing node to the touch integrated circuit1200.

The touch integrated circuit1200may decide a touch state of the sensing node based on the input electrical signal. The touch integrated circuit1200may calculate a coordinate of a sensing node touched to provide it to the application processor.

Also, the touch integrated circuit1200may receive information of an application running from the application processor, and may control a scan frequency of the touch panel1100in response to the received information. The touch integrated circuit1200may be configured substantially the same as a touch integrated circuit120(refer toFIG. 1).

The handheld phone1000including the touch sensing device of inventive concepts may adjust the touch sensing speed and power consumption according to an application running.

FIG. 8is a diagram illustrating a personal computer to which a touch sensing device of inventive concepts is applied. Referring toFIG. 8, a personal computer2000may include a first touch panel unit2100, a touch integrated circuit2200, and a second touch panel unit2300.

The first touch panel unit2100may provide a user interface according to a control of an application processor. The first touch panel unit2100may include a plurality of sensing nodes. The first touch panel unit2100may sense a touch of a user to provide an electrical signal indicating a mutual capacitance variation of the sensing node to the touch integrated circuit2200.

The second touch panel unit2300may include a plurality of sensing nodes. The second touch panel unit2300may sense a touch of a user to provide an electrical signal indicating a mutual capacitance variation of the sensing node to the touch integrated circuit2200.

The touch integrated circuit2200may decide a touch state of a sensing node in at least one of the first and second touch panel unit2100and2300based on an electrical signal received from at least one of the first and second touch panel unit2100and2300. The touch integrated circuit2200may calculate a coordinate of a sensing node touched to provide it to the application processor.

Also, the touch integrated circuit2200may receive information of an application running from the application processor, and may control a scan frequency of the touch panel2100in response to the received information. The touch integrated circuit2200may be configured substantially the same as a touch integrated circuit120(refer toFIG. 1).

The personal computer2000including the touch sensing device of inventive concepts may adjust the touch sensing speed and power consumption according to an application running.

Inventive concepts may be modified or changed variously. For example, a touch panel, a touch integrated circuit, and an application processor may be changed or modified variously according to environment and use. While inventive concepts have been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. Therefore, it should be understood that the above embodiments are not limiting, but illustrative.