CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2019-0180173, filed on Dec. 31, 2019, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

Technical Field

The present disclosure relates to a touch display apparatus.

Description of the Related Art

With the advancement of the information age, the demand for a display apparatus for displaying an image has increased with various forms. Therefore, various types of display apparatuses such as a liquid crystal display (LCD) apparatus, a plasma display panel (PDP), and an organic light emitting display (OLED) apparatus have been recently used.

Among such display apparatuses, touch display apparatuses provide touch-based input systems enabling users to intuitively and conveniently input information or instructions, rather than using conventional data input systems, such as buttons, a keyboard, or a mouse.

To provide such touch-based input systems, touch display apparatuses should be able to sense a touch performed by a user and accurately detect touch coordinates (or a touched point).

In this regard, capacitance-based touch sensing is commonly used to sense a touch and to detect touch coordinates based on a change in capacitance occurring in a plurality of touch electrodes disposed on a touch panel (or a touchscreen panel) as touch sensors or between the touch electrodes and a pointer, such as a finger.

A touch display apparatus based on such capacitance-based touch sensing should sense a plurality of touch electrodes to sense a touch, and to this end, should apply a touch driving signal to the plurality of touch electrodes.

Meanwhile, a touch display apparatus having a touch sensing function should satisfy a condition that an electromagnetic interference (EMI) level should be a certain level or less.

However, in the existing touch display apparatus, EMI level should be increased due to a touch driving signal for touch sensing. Particularly, when a touch driving signal applied to a touch electrode for touch sensing may be more affected by EMI when a high voltage signal (e.g., 7V) is a pulse type signal having a predetermined frequency.

Such EMI may deteriorate system stability of the touch display apparatus, and may affect a sensing voltage obtained during touch sensing to deteriorate touch sensing performance or adversely affect another peripheral electronic device, whereby various problems may be caused.

The disclosure of the above-described background art is owned by the inventor of the present disclosure to devise this specification or is technical information acquired by a process of devising this specification, but cannot be regarded as the known art disclosed to the general public before this specification is disclosed.

BRIEF SUMMARY

The present disclosure has been made in view of the above problems, and it is an object of the present disclosure to provide a touch display apparatus that may effectively improve (or reduce) EMI level by using an inverse phase signal corresponding to a touch driving signal for touch driving.

In addition to the objects of the present disclosure as mentioned above, additional objects and features of the present disclosure will be clearly understood by those skilled in the art from the following description of the present disclosure.

In accordance with various embodiments of the present disclosure, the above and other objects can be accomplished by the provision of a touch display apparatus comprising a display panel on which pixels and touch electrodes are disposed, a main power integrated circuit (main power IC or PMIC) generating a common voltage signal applied to the touch electrodes and at least one gate voltage signal applied to the pixels, a touch power integrated circuit (touch power IC or TPIC) outputting a touch driving signal of a pulse type (in other words, a touch driving signal of a pulse signal type; in still other words, a touch driving signal being a pulse signal) in accordance with a touch synchronization signal that defines a display driving period and a touch driving period, outputting a load free driving signal of the pulse type by using a gate low voltage signal of the at least one gate voltage signal, and outputting at least one pseudo touch driving signal corresponding to a pulse pattern of the touch driving signal and the load free driving signal and having reverse phase which is inverted, by using at least one gate high voltage signal of the at least one gate voltage signal, and a gate driving circuit supplying a gate pulse based on the at least one gate voltage signal to gate lines connected to the pixels for the display driving period, and supplying the load free driving signal to the gate lines for the touch driving period.

In accordance with one or more embodiments of the present disclosure, the above and other objects can be accomplished by the provision of a touch display apparatus comprising a display panel on which pixels and touch electrodes are disposed, a main power IC generating a common voltage signal applied to the touch electrodes and at least one gate voltage signal applied to the pixels, a touch power IC outputting a first touch driving signal of a pulse type (in other words, a first touch driving signal of a pulse signal type; in still other words, a first load free driving signal being a pulse signal) in accordance with a touch synchronization signal that defines a display driving period and a touch driving period, and outputting a first load free driving signal of the pulse type by using a gate low voltage signal of the at least one gate voltage signal, a signal converter outputting a pseudo touch driving signal by converting phase of the first load free driving signal, and a signal recovery unit disposed at an input front end of the pixels, recovering the first load free driving signal from the pseudo touch driving signal.

In accordance with some embodiments of the present disclosure, the above and other objects can be accomplished by the provision of a touch display apparatus comprising a display panel on which pixels and touch electrodes are disposed, a main power IC generating a common voltage signal applied to the touch electrodes and at least one gate voltage signal applied to the pixels, a touch power IC outputting a load free driving signal of a pulse type (in other words, a load free driving signal of a pulse signal type; in still other words, a load free driving signal being a pulse signal) in accordance with a touch synchronization signal that defines a display driving period and a touch driving period, and outputting the load free driving signal of the pulse type by using a gate low voltage signal of the at least one gate voltage signal, a gate driving circuit including a level shifter generating a gate pulse based on the at least one gate voltage signal and a shift register sequentially supplying the gate pulse output from the level shifter to gate lines connected to the pixels, and a gate signal selector disposed at an input front end of the shift register, supplying the gate pulse output from the level shifter to the shift register for the display driving period and supplying the load free driving signal to the shift register for the touch driving period.

In accordance with some embodiments of the present disclosure, the above and other objects can be accomplished by the provision of a touch display apparatus comprising a touch panel including a plurality of touch electrodes and a plurality of touch lines, a touch driving circuit sensing the plurality of touch electrodes through the plurality of touch lines, and a touch power circuit transferring a touch driving signal to the touch driving circuit through a touch signal line, wherein the touch power circuit may apply the touch driving signal to the touch signal line for a touch sensing period of the touch panel, and may apply a pseudo touch driving signal corresponding to a pulse (e.g., a pulse pattern) of the touch driving signal and having reverse phase which is inverted, to a pseudo touch signal line disposed to adjoin the touch signal line.

The touch display apparatus according to the present disclosure may effectively improve (or reduce) EMI level by using a reverse phase signal corresponding to the touch driving signal for touch driving.

Also, the touch display apparatus according to the present disclosure may effectively improve (or reduce) EMI level by removing a current field caused by a touch driving signal even without increasing additional lines or pins in the display panel or printed circuit board.

In addition to the effects of the present disclosure as mentioned above, additional advantages and features of the present disclosure will be clearly understood by those skilled in the art from the above description of the present disclosure.

