CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2019-0174317, filed on Dec. 24, 2019 in the Republic of Korea, the entire contents of which are hereby expressly incorporated by reference for all purposes as if fully set forth herein into the present application.

BACKGROUND

Field of the Present Disclosure

The embodiments of the present invention relate to a touch driver, a touch display device, and a method of driving a touch display device.

Discussion of the Related Art

With advancement in information-oriented society, requirements for various types of display devices that display an image have increased. Recently, various types of display devices such as a liquid crystal display device (LCD), a plasma display panel (PDP), an organic light emitting display device (OLED), a quantum-dot display device, and a micro LED have been widely used.

As such a display device, a touch display device with a touch-based input system that allows a user to intuitively and conveniently input information or a command instead of a normal input system using buttons, a keyboard, a mouse, and the like.

In order to provide a touch-based input system, such a touch display device has to ascertain a user's touch and accurately detect touch coordinates (a touch position).

For this purpose, a capacitance touch system that detects a touch, touch coordinates, and the like on the basis of a change in capacitance between touch electrodes or capacitance between a touch electrode and a pointer such as a finger using a plurality of touch electrodes which are arranged as touch sensors in a touch panel (a touch screen panel) is often employed.

In order to determine whether there has been a touch, the capacitance touch system has to sense a plurality of touch electrodes and apply a touch driving signal to the plurality of touch electrodes.

Recently, it has been variously tried to recognize a pattern of a fingerprint on a touch display device. In general, in order to recognize a fingerprint pattern on a touch display device, a particularly fingerprint sensor is attached to a touch display device and a fingerprint pattern is identified by sensing a fingerprint of a user's finger and comparing the sensed fingerprint with a fingerprint image or the like registered in advance.

When a particular fingerprint sensor is attached to a touch display device for the purpose of recognition of a fingerprint pattern in this way, costs for the fingerprint sensor are added and thus a price of a touch display device can be increased.

On the other hand, in order to decrease costs for manufacturing touch display devices, it has been variously tried to incorporate fingerprint sensor electrodes into a display device. However, there are technical limits in disposing fingerprint sensors and fingerprint sensor lines for the fingerprint sensors in a touch display device due to structural and physical characteristics of the touch display device. Incorporation of additional fingerprint sensors and fingerprint sensor lines into a touch display device can cause a decrease in aperture ratio of a display screen of the touch display device and can have difficulty in actual application thereof.

SUMMARY OF THE PRESENT DISCLOSURE

The present disclosure provides a touch display device that can sense a finger touch and a fingerprint without using a fingerprint sensing electrode or a fingerprint sensing line for sensing a fingerprint, be easily designed, and reduce manufacturing costs. The present disclosure also provides a touch display device that can decrease a parasitic capacitance or noise which can be generated in electrode arranged in the touch display device.

According to embodiments of the present disclosure, there is provided a touch display device including: a display panel that includes a plurality of data lines, a plurality of gate lines, and a plurality of pixel electrodes which are arranged in areas adjacent to points at which the data lines and the gate lines cross each other and that includes a display image update area and a fingerprint sensing area; a gate driver that supplies a first gate driving voltage to the gate lines corresponding to the display image update area out of the plurality of gate lines in a display period of the display panel and supplies a second gate driving voltage to the gate lines corresponding to the fingerprint sensing area out of the plurality of gate lines in a fingerprint sensing period of the display panel; and a touch driver that supplies a data voltage to the data lines corresponding to the display image update area out of the plurality of data lines in the display period of the display panel and supplies a fingerprint driving signal to the data lines corresponding to the fingerprint sensing area out of the plurality of data lines in the fingerprint sensing period of the display panel, wherein the second gate driving voltage supplied to the gate lines corresponding to the fingerprint sensing area in the fingerprint sensing period of the display panel is higher than the first gate driving voltage supplied to the gate lines corresponding to the display image update area in the display period of the display panel, and wherein a time in which the second gate driving voltage is supplied to the gate lines corresponding to the fingerprint sensing area in the fingerprint sensing period of the display panel is longer than a time in which the first gate driving voltage is supplied to the gate lines corresponding to the display image update area in the display period of the display panel.

In the touch display device according to the embodiments of the present disclosure, the second gate driving voltage supplied to the gate lines corresponding to the fingerprint sensing area in the fingerprint sensing period of the display panel can be a voltage having a noise reduction signal added thereto.

In the touch display device the embodiments of the present disclosure, a noise reduction signal can be supplied to the gate lines around the gate lines corresponding to the pixel electrodes which are sensed out of the gate lines corresponding to the fingerprint sensing area in the fingerprint sensing period of the display panel.

In the touch display device the embodiments of the present disclosure, the gate lines around the gate lines corresponding to the pixel electrodes which are sensed out of the gate lines corresponding to the fingerprint sensing area in the fingerprint sensing period of the display panel can be maintained in a floating state.

In the touch display device the embodiments of the present disclosure, a noise reduction signal can be supplied to the data lines which are arranged around the fingerprint sensing area in the fingerprint sensing period of the display panel.

In the touch display device the embodiments of the present disclosure, the data lines which are arranged around the fingerprint sensing area can be updated in display image or maintained in a floating state in the fingerprint sensing period of the display panel.

In the touch display device the embodiments of the present disclosure, the display panel can further include a plurality of touch electrodes and a plurality of touch lines, and a touch driving signal can be supplied to the plurality of touch electrodes via the plurality of touch lines.

In the touch display device the embodiments of the present disclosure, the display panel can sense a touch which occurs in a plurality of touch electrodes, recognize a touch position in a touch electrode sensing period, and specify the fingerprint sensing area on the basis of the recognized touch position.

In the touch display device the embodiments of the present disclosure, the display panel can supply a voltage or a signal which is predetermined for the fingerprint sensing area to the data lines or the gate lines after having specified the fingerprint sensing area.

In the touch display device the embodiments of the present disclosure, the touch driver can include a plurality of touch line multiplexers, a plurality of data line multiplexers, and a plurality of touch sensors, a first down-terminal of at least one data line multiplexer out of the plurality of data line multiplexers can be electrically connected to a data terminal of at least one touch line multiplexer out of the plurality of touch line multiplexers, and the fingerprint driving signal can be supplied to the data lines corresponding to the fingerprint sensing area.

In the touch display device the embodiments of the present disclosure, the touch driver can include a plurality of touch line multiplexers, a plurality of data line multiplexers, and a plurality of touch sensors, and a noise reduction signal can be supplied to a third down-terminal of at least one data line multiplexer out of the plurality of data line multiplexers.

In the touch display device the embodiments of the present disclosure, the touch driver can include a plurality of touch line multiplexers, a plurality of data line multiplexers, a plurality of line selection multiplexers, and a plurality of touch sensors, a first down-terminal of at least one data line multiplexer out of the plurality of data line multiplexers can be electrically connected to at least one line selection multiplexer out of the plurality of line selection multiplexers, and the fingerprint driving signal can be supplied to the data lines corresponding to the fingerprint sensing area.

According to embodiments of the present disclosure, there is provided a method of driving a touch display device including a plurality of data lines, a plurality of gate lines, a plurality of pixel electrodes which are arranged in areas adjacent to points at which the data lines and the gate lines cross each other, a plurality of touch electrodes, and a plurality of touch lines, the method including: a step of sensing a finger touch which occurs in the touch display device; a step of recognizing a position at which the finger touch has occurred; a step of specifying a fingerprint sensing area on the basis of the position at which the finger touch has occurred; a step of preparing for sensing of a fingerprint in the fingerprint sensing area; and a step of sensing at least a part of the fingerprint sensing area and recognizing a fingerprint of the sensed part.

In the method of driving the touch display device the embodiments of the present disclosure, the step of specifying the fingerprint sensing area can include specifying the fingerprint sensing area on the basis of a density of the touch electrodes in which a sensed touch raw value is equal to or greater than a predetermined reference value out of the plurality of touch electrodes.

In the method of driving the touch display device the embodiments of the present disclosure, the step of specifying the fingerprint sensing area can include specifying the fingerprint sensing area on the basis of the number of touch electrodes or a degree of closeness or a degree of separation of the touch electrodes associated with the position at which the touch has occurred.

In the method of driving the touch display the embodiments of the present disclosure, the step of preparing for sensing of a fingerprint can include displaying a predetermined pattern (a black, white, or specific pattern image) or a predetermined image in the specified fingerprint sensing area or supplying a predetermined voltage or signal to the data lines corresponding to the specified fingerprint sensing area, the gate lines corresponding to the specified fingerprint sensing area, or the touch electrodes corresponding to the specific fingerprint sensing area.

In the method of driving the touch display device according to the embodiments of the present disclosure, the step of sensing at least a part of the fingerprint sensing area can include supplying a second gate driving voltage to the gate lines corresponding to the fingerprint sensing area.

In the method of driving the touch display device according to the embodiments of the present disclosure, the second gate driving voltage which is supplied to the gate lines corresponding to the fingerprint sensing area in the step of sensing at least a part of the fingerprint sensing area can be higher than a first gate driving voltage which is supplied to the gate lines corresponding to the display image update area in a display period of the display panel, or a time in which the second gate driving voltage is supplied to the gate lines corresponding to the fingerprint sensing area in the step of sensing at least a part of the fingerprint sensing area can be longer than a time in which a first gate driving voltage is supplied to the gate lines corresponding to the display image update area in the display period of the display panel.

According to embodiments of the present disclosure, there is provided a touch driver that drives a touch display device including a plurality of data lines, a plurality of gate lines, a plurality of pixel electrodes which are arranged in areas adjacent to points at which the data lines and the gate lines cross each other, and a plurality of touch lines, the touch driver including: a plurality of touch line multiplexers that transmit a touch driving signal to the plurality of touch lines via a plurality of touch line channel portions; a plurality of data line multiplexers that transmit a data voltage to the corresponding data lines out of the plurality of data lines via the data line channel portions; and a plurality of touch sensors that are electrically connected to the corresponding data line multiplexers out of the plurality of data line multiplexers, wherein a first down-terminal of at least one data line multiplexer out of the plurality of data line multiplexers is electrically connected to a data terminal of at least one touch line multiplexer out of the plurality of touch line multiplexers and a fingerprint driving signal is supplied to the data lines corresponding to a fingerprint sensing area of the touch display device.

The touch driver according to the embodiments of the present disclosure can further include a plurality of touch line multiplexers, a first down-terminal of at least one data line multiplexer out of the plurality of data line multiplexers can be electrically connected to at least one line selection multiplexer out of the plurality of line selection multiplexers, and the fingerprint driving signal can be supplied to the data lines corresponding to the fingerprint sensing area of the touch display device.

According to the embodiments of the present disclosure, it is possible to provide a touch display device that can sense a finger touch and a fingerprint without using a particularly fingerprint sensing electrode or any particular fingerprint sensing line, be easily designed, and reduce manufacturing costs.

According to the embodiments of the present disclosure, it is possible to provide a touch display device that can sense a finger touch position, accurately recognize the finger touch position, and specify a fingerprint sensing area when a finger touch occurs in the touch display device.

According to the embodiments of the present disclosure, it is possible to provide a touch display device that can decrease a parasitic capacitance or noise which can be generated therein by applying a noise reduction signal to the electrodes arranged in the touch display device at the time of sensing a fingerprint.

According to the embodiments of the present disclosure, since only a necessary area can be accurately sensed by setting a fingerprint sensing area of the touch display device to the same size or the same shape as a finger touch area, it is possible to provide a touch display device that can save a time required for sensing a fingerprint.

According to the embodiments of the present disclosure, it is possible to provide a touch display device that can improve accuracy of fingerprint sensing by setting a fingerprint sensing area to be larger than an estimated finger touch area when the size and shape of the finger touch area of the touch display device is difficult to estimate.

According to the embodiments of the present disclosure, it is possible to provide a touch display device that can decrease a turn-on resistance of a drive transistor and enhance accuracy of fingerprint sensing by applying a gate voltage which is higher than a gate voltage for display driving to the gate lines corresponding to a fingerprint sensing area in the fingerprint sensing period.

According to the embodiments of the present disclosure, it is possible to provide a touch display device that can enhance accuracy of fingerprint sensing and satisfactorily secure a fingerprint sensing time by setting the time in which a gate voltage is applied to the gate lines corresponding to a fingerprint sensing area to be longer than the time in which a gate voltage is applied to the gate lines corresponding to the display image update area for display driving in the fingerprint sensing period.

