This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2016-0092130 filed Jul. 20, 2016, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference.
Exemplary embodiments consistent with the inventive concept relate to a display device, and more particularly, to a touch display driving integrated circuit (IC) and an operating method thereof.
A display device includes gate lines, data lines, and a plurality of pixels. The pixels are connected to the gate lines and the data lines, respectively. The display device includes a gate driving circuit controlling the gate lines and a data driving circuit controlling the data lines. The gate driving circuit provides a gate signal to each gate line, the data driving circuit provides a data signal to each data line, and each pixel displays image information based on the signals received through the data lines and the gate lines.
As a user terminal is miniaturized, an in-cell type touch display device in which a display device and a touch panel are integrated is being developed. In the in-cell type touch display device, an area that is occupied by the touch panel and a panel of the display device may be reduced by integrating the touch panel and the display panel of the display device. However, various issues occur due to driving methods as the touch panel and the display panel are integrated. Various driving methods for addressing these issues are being developed.
It is an aspect to provide a touch display driving IC with improved performance and reliability and an operating method thereof.
According to an aspect of an exemplary embodiment, there is provided an operating method of a touch display driving integrated circuit that is connected with a touch display panel through touch sensing lines and data lines. The method includes applying a common voltage to each touch sensing line, increasing voltages of the touch sensing lines and the data lines by a predetermined level, providing a first touch sensing signal to each touch sensing line, and sensing a touch of a user based on signal variations of the touch sensing lines.
According to another aspect of an exemplary embodiment, a touch display driving integrated circuit includes a touch driver connected to touch electrodes and touch sensing lines to provide a common voltage to each touch sensing line during a display period and to provide a first touch sensing signal to each touch sensing line during a touch period, a transition voltage controller configured to output a first output voltage during the display period and to output a second output voltage higher than by a predetermined level than the first output voltage during a transition period from the display period to the touch period, and a source driver connected with pixels through data lines to provide a data signal to each data line during the display period and to provide the second output voltage to each data line during the transition period.
According to another aspect of an exemplary embodiment, a touch display device includes a touch display panel including a touch electrode and a pixel, and a touch display driving integrated circuit configured to control the touch display panel. The touch display driving integrated circuit includes a touch driver connected with the touch electrode through a touch sensing line to apply a common voltage to the touch sensing line during a display period and to provide a first touch sensing signal to the touch sensing line during a touch period, a transition voltage controller configured to output a first output voltage in the display period and to output a second output voltage higher than by a predetermined level than the first output voltage during a transition period from the display period to the touch period, and a source driver connected with the pixel through a data line to provide a data signal to the data line during the display period and to provide the second output voltage to the data line during the transition period.
According to another aspect of an exemplary embodiment, a touch display device comprises a touch display panel including a plurality of touch electrodes and a plurality of pixels, each touch electrode provided as a common electrode for one or more pixels of the plurality of pixels; and a touch display driving integrated circuit (TDDIC) connected to each touch sensing electrode by a touch sensing line, and connected to each pixel by a data line and a gate line, wherein the TDDIC is configured to apply a common voltage to the touch electrodes during a display period to perform a display operation during the display period, increase voltages of one ore more of the touch sensing lines, one or more of the data lines, and one or more of the gate lines by a predetermined level during a first transition period, detect a touch via the touch sensing lines, the data lines, and the gate lines during a touch period, and decrease the voltages of the one or more touch sensing lines, the one or more of the data lines, and the one or more of the gate lines by the predetermined level during a second transition period.
The above and other aspects will become apparent from the following description with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified, and wherein:
Below, exemplary embodiments of the inventive concept are described in detail and clearly to such an extent that one of ordinary skill in the art may easily implement the inventive concept.
The touch display panel 110 may include a plurality of pixels PIX and a plurality of touch electrodes TE. The pixels PIX may be connected with gate lines GL and data lines DL, respectively. The pixels PIX may display image information based on voltages of the gate lines GL and data lines DL. In example embodiments, the pixels PIX may be classified into a plurality of groups based on colors to be displayed. Each pixel PIX may display one of the primary colors. The primary colors may include, but are not limited to, red, green, blue, and white. For example, the primary colors may further include various colors such as yellow, cyan, and magenta.
The touch electrodes TE may be used as common electrodes of the pixels PIX, or as electrodes for sensing a touch of a user. For example, the touch display panel 110 may be an in-cell type touch display panel. The in-cell type touch display panel may be implemented such that the pixels PIX and the touch electrodes TE are arranged on the same panel.
The touch electrodes TE may be used as a common electrode of the pixels PIX. For example, each of the pixels PIX may output image information based on a difference between a data signal received through the data line DL and a common voltage VCOM. Each of the pixels PIX may compare a data signal received through the data line DL with the common voltage VCOM of the touch electrode TE and may output image information based on the comparison result.
In example embodiments, an area of one touch electrode TE may be larger than that of one pixel PIX. One touch electrode TE may be used as the common electrode of one or more pixels PIX. In other words, one touch electrode TE may correspond to one or more pixels PIX. In example embodiments, the common voltage VCOM may be a negative voltage of about −1.3 V. In example embodiments, the touch electrode TE may be a transparent conductive layer such as indium tin oxide (ITO).
Although not illustrated in
The TDDIC 120 may be connected with the touch display panel 110 through the gate lines GL, the data lines DL, and touch sensing lines TSL.
For example, the TDDIC 120 may be connected with the pixels PIX included in the touch display panel 110 through the gate lines GL. The TDDIC 120 may control voltages of the gate lines GL connected with the pixels PIX or may provide gate signals through the gate lines GL.
The TDDIC 120 may be connected with the pixels PIX through the data lines DL. The TDDIC 120 may provide data signals (or image signals) to the pixels PIX through the data lines DL. Each pixel PIX may output (or display) image information in response to the received data signal.
The TDDIC 120 may be connected with the touch electrodes TE through the touch sensing lines TSL. The TDDIC 120 may provide a touch sensing signal to each touch sensing line TSL and may sense whether a touch of the user is made, based on a variation of the touch sensing signal. For example, in the case where the user brings a portion (e.g., a finger) of his/her body into contact with at least one touch electrode TE of the touch electrodes TE, capacitance of the at least one touch electrode TE may change according to capacitance between the portion of his/her body and the at least one touch electrode TE. The TDDIC 120 may sense a variation in the capacitance based on a variation of the touch sensing signal provided to the at least one touch electrode TE.
The TDDIC 120 is capable of determining that a user touch has occurred at a touch electrode TE from which a variation in capacitance is sensed. In example embodiments, the above-described touch sensing method is called a “self-capacitance method” or “mutual capacitance method”. However, example embodiments are not limited thereto. For example, the touch sensing method may be variously changed or modified without departing from the scope and spirit of the inventive concept.
In example embodiments, the TDDIC 120 may operate in synchronization with control signals received from a separate control circuit (not illustrated) (e.g., a timing controller). For example, the control signals may include a vertical synchronization signal and a horizontal synchronization signal. The vertical synchronization signal may be a signal for distinguishing frames to be output through the pixels PIX. The horizontal synchronization signal may be a signal for distinguishing a row corresponding to data signals provided through the data lines DL, that is, a row distinguishing signal. In response to the control signals, the TDDIC 120 may control a voltage of the gate line connected with a pixel PIX and may provide a data signal through the data line DL connected with the pixel PIX.
The touch display device 100 may include at least one display period and at least one touch period during an output of one frame (i.e., during one period of the vertical synchronization signal). The touch display device 100 may display all or part of one frame during at least one display period and may perform a touch scan operation on all or some of the touch electrodes TE during at least one touch period.
To perform the touch scan operation on touch electrodes TE during at least one touch period, a predetermined signal (e.g., a touch sensing signal) may be provided to each touch electrode TE. Since the touch electrode TE is used as a common electrode during at least one display period, the common voltage VCOM may be applied to all or part of the touch electrodes during at least one display period. As the touch display device 100 repeatedly performs the above-described display and touch periods, the touch display device 100 may display image information and may sense a touch of the user.
Referring to
In example embodiments, a liquid crystal layer (not illustrated) may be arranged between the first pixel electrode PE1 and the touch electrode TE. In such a case, a liquid crystal capacitor Clc may exist between the first pixel electrode PE1 and the touch electrode TE. The common voltage VCOM may be applied to the touch electrode TE. Under control of the TDDIC 120, an electric field may be formed by a voltage received through the data line DL and the common voltage VCOM of the touch electrode TE. The arrangement of liquid crystal directors of the liquid crystal layer (not illustrated) may change according to the electric field that is formed by the voltage of the data line DL and the common voltage VCOM. On the basis of the arrangement of the liquid crystal directors, light incident on the liquid crystal layer may pass through the liquid crystal layer or may be blocked. Image information may be displayed based on the above-described operation of the first pixel PIX1.
During a touch period of the touch display device 110, the TDDIC 120 may drive the touch sensing line TSL connected with the touch electrode TE. For example, the TDDIC 120 may provide the touch sensing signal to the touch sensing line TSL. In the case where a portion of a user's body touches the touch electrode TE or approaches the touch electrode TE, a signal of the touch sensing line TSL may change by capacitance between the touch electrode TE and the portion of the user's body. The TDDIC 120 may sense a signal variation (or change) of the touch sensing line TSL and may recognize that the user touches the touch electrode TE, based on the sensing result.
In example embodiments, as illustrated in
In example embodiments, a gate signal may be a signal that is synchronized with a control signal (e.g., a vertical synchronization signal). In example embodiments, a gate signal may be a signal that is toggled between the gate voltage VGL and a gate voltage VGH (not illustrated). In example embodiments, the gate voltage VGH may be a turn-on voltage of a transistor included in a pixel PIX.
During the display period DP, the touch display device 100 may display image information in response to signals from the TDDIC 120. After the display period DP ends, the touch period TP may start. For example, after the TDDIC 120 provides a touch sensing signal to each of the touch sensing lines TSL, the data lines DL, and the gate lines GL, the TDDIC 120 may sense signal variations of the touch sensing lines TSL to determine whether a touch of the user is made. In example embodiments, the touch sensing signal may be a signal that is toggled between specific levels.
In example embodiments, during the touch period TP, the TDDIC 120 may perform the touch scan operation at a voltage level greater than or equal to that of a first voltage V1. For example, from a first time point t1 at which the display period DP ends to a second time point t2 at which the touch period TP starts, the TDDIC 120 may increase a voltage of each touch sensing line TSL from the common voltage VCOM to the first voltage V1. In example embodiments, the common voltage VCOM may be a negative voltage of about −1.3 V. The first voltage V1 may be a ground voltage GND. That is, the TDDIC 120 may perform the touch scan operation at a positive voltage level. Likewise, after the touch period TP ends, the TDDIC 120 may lower a voltage of each touch sensing line TSL from the first voltage V1 to the common voltage VCOM.
As described above, in a period (e.g., from t1 to t2) from the display period DP to the touch period TP, a voltage of each touch sensing line TSL may be changed from the common voltage VCOM to the first voltage V1. Also, in a period (e.g., from t3 to t4) from the touch period TP to the display period DP, a voltage of each touch sensing line TSL may be changed from the first voltage V1 to the common voltage VCOM.
Below, for convenience of description, a period from the display period DP to the touch period TP, and a period from the touch period TP to the display period DP is referred to as a “transition period”. However, the term “transition period” is only used is to easily describe example embodiments of the inventive concept, and a period corresponding to the transition period may be viewed as being included in the display period DP or the touch period TP.
In example embodiments, as illustrated in
For example, as described with reference to
In an operation S120, the TDDIC 120 may increase voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level. For example, after the display period ends, a voltage level of each touch sensing line TSL may correspond to the common voltage VCOM. For a touch sensing operation in the touch period, the TDDIC 120 may increase a voltage of each touch sensing line TSL to the first voltage V1. In example embodiments, the first voltage V1 may be a ground voltage GND, but is not limited thereto.
After the display period ends, a voltage level of each data line DL may be a level of the ground voltage GND, and a voltage level of each gate line GL may be a level of the gate voltage VGL. While the TDDIC 120 increases a voltage of each touch sensing line TSL to the first voltage V1 (in other words, a switching period from the display period to the touch period, that is, the transition period), the TDDIC 120 may increase a voltage of each data line DL to a second voltage V2 and a voltage of each gate line GL to a third voltage V3. In this case, a difference between the second voltage V2 and the ground voltage GND and a difference between the third voltage V3 and the gate voltage VGL may be substantially the same as a difference between the first voltage V1 and the common voltage VCOM. That is, the TDDIC 120 may increase voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level.
That is, as described above, during the transition period, an influence (e.g., a voltage coupling) of the above-described parasitic capacitances may be removed as the TDDIC 120 increases voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level together with each other. That is, as an operation of the operation S120 is performed, a time needed to settle the touch sensing lines TSL to the first voltage V1 may decrease, and the transition period may become shorter than that described with reference to
In an operation S130, the TDDIC 120 may provide the touch sensing signals to the touch sensing lines TSL, the data lines DL, and the gate lines GL. In example embodiments, the touch sensing signals provided to the touch sensing lines TSL, the data lines DL, and the gate lines GL may have the same waveform, but the touch sensing signals may have different voltage levels. For example, a voltage level of a first touch sensing signal provided to each touch sensing line TSL may be lower than that of a second touch sensing signal provided to each data line DL and may be higher than that of a third touch sensing signal provided to each gate line GL.
In an operation S140, the TDDIC 120 may sense a touch of the user based on signal variations (or changes) of the touch sensing lines TSL.
After the touch period ends, in an operation S150, the TDDIC 120 may decrease voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level. For example, after the touch period ends, a voltage level of each touch sensing line TSL may correspond to a level of the first voltage V1. For a display operation in the display period, the TDDIC 120 may decrease voltage levels of the touch sensing lines TSL to the common voltage VCOM.
After the touch period ends, a voltage level of each data line DL may correspond to a level of the second voltage V2, and a voltage level of each gate line GL may correspond to a level of the third voltage V3. While the TDDIC 120 decreases a voltage of each touch sensing line TSL to the common voltage VCOM (in other words, a switching period from the touch period to the display period, that is, the transition period), the TDDIC 120 may decrease voltages of the data lines DL and voltages of the gate lines GL by a predetermined level. In this case, the predetermined level may correspond to a difference between the common voltage VCOM and the first voltage V1.
That is, as described above, during the transition periods, an influence (e.g., a voltage coupling) of the above-described parasitic capacitances may be removed as the TDDIC 120 decreases voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level together with each other. In other words, as an operation of the operation S150 is performed, the transition period may become shorter than that described with reference to
In example embodiment, as the TDDIC 120 repeatedly performs operations of the operation S110 to the operation S150, the TDDIC 120 may display image information and may sense a touch of the user.
As described above, as the TDDIC 120 according to an exemplary embodiment of the inventive concept controls voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL together with each other, the settling speed at which the touch sensing line TSL is increased to the first voltage or decreased to the common voltage VCOM may be improved. Accordingly, the TDDIC 120 with improved performance is provided.
After the display period ends, in the transition period, the TDDIC 120 may increase voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level. For example, in the transition period from t5 to t6, the TDDIC 120 may increase a voltage of each touch sensing lines TSL to the first voltage V1, may increase a voltage of each data line DL to the second voltage V2, and may increase a voltage of each gate line GL to the third voltage V3.
The first voltage V1 may be a voltage that is higher by a predetermined level than the common voltage VCOM. In example embodiment, the first voltage V1 may be the ground voltage GND. The second voltage V2 may be a voltage that is higher by a predetermined level than the ground voltage GND. The third voltage V3 may be a voltage that is higher by a predetermined level than the gate voltage VGL.
As described above, as the TDDIC 120 increases voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL together with each other by a predetermined level during the transition period, a voltage of each touch sensing line TSL may be quickly settled to the first voltage V1, thereby making a start time point of the following touch period TP earlier.
During the touch period TP, after the TDDIC 120 provides touch sensing signals to the touch sensing lines TSL, the data lines DL, and the gate lines GL, the TDDIC 120 may determine whether a touch of the user is made, based on signal variations of the touch sensing lines TSL.
After the touch period TP ends, the TDDIC 120 may decrease voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL by a predetermined level. For example, in the transition period from t7 to t8, the TDDIC 120 may decrease a voltage of each touch sensing line TSL to the common voltage VCOM, may decrease a voltage of each data line DL to the ground terminal GND, and may decrease a voltage of each gate line GL to the gate voltage VGL. As the TDDIC 120 decreases voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL together with each other by a predetermined level during the transition period, voltages thereof may be quickly settled to target voltages, thereby making a start time point of the display period earlier.
As described above, as the TDDIC 120 according to an embodiment of the inventive concept controls voltages of the touch sensing lines TSL, the data lines DL, and the gate lines GL together with each other during the transition period, the transition period may be reduced. Accordingly, the TDDIC 120 with improved performance is provided.
Referring to
The touch driver 121 may be connected with the touch display panel 110. In more detail, the touch driver 121 may be connected with the plurality of touch electrodes TE of the touch display panel 110 through the touch sensing lines TSL. The touch driver 121 may provide the common voltage VCOM to each touch sensing line TSL during the display period DP and may provide a touch sensing signal to each touch sensing line TSL during the touch period TP. During the touch period TP, the touch driver 120 may sense a touch of the user based on signal variations of the touch sensing lines TSL.
The source driver 122 may be connected with the touch display panel 110. In more detail, the source driver 122 may be connected with the plurality of pixels PIX of the touch display panel 110 through the data lines DL. During the display period DP, the source driver 122 may provide data signals to the pixels PXI through the data lines DL in response to a separate control signal.
The gate driver 123 may be connected with the touch display panel 110. In more detail, the gate driver 123 may be connected with the plurality of pixels PIX of the touch display panel 110 through the gate lines GL. During the display period DP, the gate driver 123 may provide gate signals through the gate lines GL in response to a separate control signal.
The transition voltage controller 124 may control voltages to be provided to the source driver 122 and the gate driver 123 in the transition period from the display period DP to the touch period TP. For example, on the basis of an output voltage VOUT from the transition voltage controller 124, the source driver 122 and the gate driver 123 may respectively provide the touch sensing signals to the data lines DL and the gate lines DL during the touch period TP.
The transition voltage controller 124 may receive a touch sensing signal TS from the touch driver 121 and may receive the common voltage VCOM and the first voltage V1 from a voltage generator (not illustrated). In the transition period from the display period DP to the touch period TP, the transition voltage controller 124 may control the output voltage VOUT such that voltages of the data lines DL and voltages of the gate lines GL are increased by a predetermined level.
For example, as described with reference to
At a time point at which the touch period TP starts after the transition period ends, the transition voltage controller 124 may provide the touch sensing signal TS from the touch driver 121 as the output voltage VOUT. The source driver 122 may provide the touch sensing signal TS to each data line DL based on the output voltage VOUT, and the gate driver 123 may provide the touch sensing signal TS to each gate line GL based on the output voltage VOUT.
As described above, in the transition period, the transition voltage controller 124 may control the output voltage VOUT to be provided to the source driver 122 and the gate driver 123 such that voltages of the data lines DL and the gate lines GL are increased by a predetermined level. Afterwards, the transition voltage controller 124 may provide the touch sensing signal TS as the output voltage VOUT. The source driver 122 may control the data lines DL based on the output voltage VOUT, and the gate driver 123 may control the gate lines GL based on the output voltage VOUT.
Referring to
The transition voltage controller 124 includes first to sixth switches S1 to S6, a capacitor CAP, and a buffer BF. The first switch S1 is configured to connect a second node n2 and a ground terminal. The second switch S2 is configured to connect a terminal of the output voltage VOUT and the ground terminal. The third switch S3 is configured to connect a terminal of the common voltage VCOM and a first node n1. The fourth switch S4 is configured to connect a terminal of the first voltage V1 and the first node n1. The fifth switch S5 is configured to connect a terminal, to which the touch sensing signal TS from the touch driver 121 is applied, and the first node n1. The sixth switch S6 is configured to connect the terminal, to which the touch sensing signal TS from the touch driver 121 is applied, and the terminal of the output voltage VOUT.
The capacitor CAP is connected between the first node n1 and the second node n2. The buffer BF is connected between the second node n2 and the terminal of the output voltage VOUT and is configured to buffer a voltage of the second node n2 and to provide the buffered voltage as the output voltage VOUT. In example embodiments, the capacitor CAP may be an external capacitor that is placed outside of the TDDIC 120. Alternatively, the capacitor CAP may be implemented with some of capacitors that are used in a separate voltage generator.
The transition voltage controller 124 may provide the source driver 122 and the gate driver 123 with the output voltage VOUT based on the common voltage VCOM, the first voltage V1, and the touch sensing signal TS. An operation of the transition voltage controller 124 will be more fully described with reference to
Referring to
During the display period DP, the first to third switches S1 to S3 of the transition voltage controller 124 are turned on, and the fourth to sixth switches S4 to S6 thereof are turned off. That is, the transition voltage controller 124 is configured as illustrated in a first section of
After the display period DP ends, during the transition period, the fourth switch S4 is turned on, and the first to third, fifth, and sixth switches S1 to S3, S5, and S6 are turned off. That is, the transition voltage controller 124 is configured as illustrated in a second section of
In other words, the output voltage VOUT of the transition voltage controller 124 may be the ground voltage GND during the display period, and the output voltage VOUT of the transition voltage controller 124 may increase by a predetermined level (i.e., corresponding to a difference between the first voltage V1 and the common voltage VCOM) during the transition period.
The buffer BF may buffer a voltage of the second node n2 and may provide the source driver 122 and the gate driver 123 with the buffered voltage as the output voltage VOUT. The source driver 122 may control voltages of the data lines DL based on the output voltage VOUT, and the gate driver 123 may control voltages of the gate lines GL based on the output voltage VOUT. That is, on the basis of the output voltage VOUT increasing by a predetermined level, the source driver 122 and the gate driver 123 may increase voltages of the data lines DL and the voltages of the gate lines GL by the predetermined level.
For example, the source driver 122 may be configured to provide a data signal to each data line DL during the display period and to provide the output voltage VOUT to each data line DL during the transition period and the touch period. Although not illustrated in
For example, the gate driver 123 may provide each gate line GL with a gate signal for turning on the transistors TR (refer to
After the transition period ends (i.e., after a voltage of each touch sensing line TSL is settled to the first voltage V1), the fifth switch S5 is turned on, and the fourth switch S4 is turned off. As the fifth switch S5 is turned on and the fourth switch S4 is turned off, the touch sensing signal TS from the touch driver 121 is provided to the first node n1. A voltage level of the first node n1 may be toggled by the touch sensing signal TS. As the voltage level of the first node n1 is toggled, a voltage level of the second node n2 may be toggled, and a voltage of the second node n2 may be provided as the output voltage VOUT through the buffer BF. Accordingly, during the touch period TP, the touch sensing signal TS may be provided to the source driver 122 and the gate driver 123 as the output voltage VOUT. In this case, the touch sensing signal provided as the output voltage VOUT is higher than the touch sensing signal TS provided from the touch driver 121 by a difference between the common voltage VCOM and the first voltage V1. As illustrated in
After the touch period TP ends, the fourth switch S4 may be turned on, and the fifth switch S5 may be turned off. This may be a switching operation for preventing the touch sensing signal TS from being output as the output voltage VOUT when the touch period TS ends.
Afterwards, during the transition period from the touch period TP to the display period DP in
In the display period DP following the transition period, the first and second switches S1 and S2 may be turned on. Accordingly, a voltage of the second node n2 and the output voltage VOUT may be reset to the ground voltage GND.
In example embodiments, the sixth transistor S6 may remain at a turn-off state during an operation of the TDDIC 120 according to an example embodiment of the inventive concept. In example embodiments, the sixth switch S6 may be a switch for a typical operation of the TDDIC 120, that is, an operation described with reference to
Although not illustrated in
As described above, during the transition period from the display period to the transition period, the TDDIC 120 according to an example embodiment of the inventive concept may increase, by a predetermined level, voltages of the data lines DL and the gate lines GL as well as voltages of the touch sensing lines TSL. Also, during the transition period from the touch period TP to the display period DP, the TDDIC 120 may decrease, by a predetermined level, voltages of the data lines DL and the gate lines GL as well as voltages of the touch sensing lines TSL. As such, an influence of parasitic capacitances in the touch display panel 110 may be removed. Accordingly, a settling speed at which the touch sensing line TSL is increased to the first voltage or decreased to the common voltage VCOM may be improved. This means that the TDDIC 120 with improved performance is provided.
Referring to
The TDDIC 220 may include a touch driver 221, a source driver 222, and a gate driver 223. Since the touch driver 221, the source driver 222, and the gate driver 223 are above described, a detailed description thereof is omitted.
The source driver 222 and the gate driver 223 may include a switching circuit 222A and a switching circuit 223A, respectively. The switching circuit 222A and the switching circuit 223A may be configured to provide the second voltage V2 and the third voltage V3 to each data line DL and each gate line GL during the transition period, respectively.
For example, the switching circuit 222A of the source driver 222 may provide a data signal DS to each data line DL during the display period. In example embodiments, the data signal DS may indicate a signal that the source driver 222 generates based on image data provided from an external device.
During the transition period from the display period to the touch period, the switching circuit 222A may perform a switching operation such that the second voltage V2 is supplied to each data line DL. In an example embodiment, a level of the second voltage V2 may correspond to a level of a voltage generated from a separate voltage generator (not illustrated). The second voltage V2, as described above, may be a voltage higher by a predetermined level (i.e., a difference between the common voltage VCOM and the first voltage V1) than the ground voltage GND. That is, a voltage of each data line DL may increase to the second voltage V2 by an operation of the switching circuit 222A. During the touch period TP, the source driver 222 may provide the touch sensing signal TS, which is provided from the touch driver 221, to each data line DL having a level of the second voltage V2.
Likewise, the gate driver 223 may provide the gate signal GS to each gate line GL during the display period DP. In example embodiments, the gate signal GS may be a switching signal or a clock signal that is synchronized with a control signal (e.g., a horizontal synchronization signal).
During the transition period from the display period to the touch period, the switching circuit 223A may perform a switching operation such that the third voltage V3 is supplied to each gate line GL. In example embodiments, a level of the third voltage V3 may correspond to a level of a voltage generated from a separate voltage generator (not illustrated). The third voltage V3, as described above, may be a voltage higher by a predetermined level (i.e., a difference between the common voltage VCOM and the first voltage V1) than the gate voltage VGL. That is, a voltage of each gate line GL may increase to the third voltage V3 by an operation of the switching circuit 223A. During the touch period TP, the gate driver 223 may provide the touch sensing signal TS, which is provided from the touch driver 221, to each gate line GL having a level of the third voltage V3.
In example embodiments, an operation of the transition period from the touch period to the display period may be similar to that described above. For example, the switching circuit 222A of the source driver 222 may perform a switching operation such that the data signal DS is provided to each data line DL. In this case, a voltage level of the data signal DS may correspond to a level of the ground voltage GND. Likewise, the switching circuit 223A of the gate driver 223 may perform a switching operation such that the gate signal GS is provided to each gate line GL. In this case, a voltage level of the gate signal GS may correspond to a level of the gate voltage VGL.
As described above, during the transition period, the switching circuit 222A of the source driver 222 may provide the second voltage V2 from a separate voltage generator (not illustrated) to each data line DL, and the switching circuit 223A of the gate driver 223 may provide the third voltage V3 from a separate voltage generator (not illustrated) to each gate line GL. As described above, during the transition period, as voltages of the data lines DL and the gate lines GL increase by a predetermined level together with each other, a settling speed at which the touch sensing line TSL is increased to the first voltage or decreased to the common voltage VCOM may become faster. This makes the following touch operation time point earlier.
Referring to
Unlike the above-described TDDIC, the TDDIC 320 of
In example embodiments, as illustrated in
As illustrated in
The first end of the external capacitor CAP_e may be connected with the common voltage generator 325 to receive the common voltage VCOM from the common voltage generator 325. A second end of the external capacitor CAP_e may be connected with the first terminal T1.
The common voltage generator 325 may apply the common voltage VCOM to the first end of the external capacitor CAP_e in the display period DP. That is, the common voltage generator 325 may use the external capacitor CAP_e as a stabilization capacitor.
After the display period DP ends, the common voltage generator 325 may provide the first voltage V1 to the first end of the external capacitor CAP_e. That is, the common voltage generator 325 may be configured to perform operations of the third and fourth switches S3 and S4 of
In example embodiments, the first, second, third, and fourth switches S1, S2, S3, and S4 of
As described above, the transition voltage controller 324 may generate the output voltage VOUT for controlling voltages of the gate lines GL and the data lines DL in the transition period, by using the external capacitor CAP_e connected with the common voltage generator 325.
In example embodiment, although not illustrated in
A configuration of function blocks and circuits described with reference to
As described above, as the TDDIC 420 repeatedly performs the display period and the touch period, the TDDIC 420 may display image information and may sense a touch of the user. In this case, a touch scan operation may be performed on some of the touch electrodes TE11 to TE55 in one touch period. For example, in one touch period (i.e., a first touch period), the TDDIC 420 may perform the touch scan operation on touch electrodes TE11, TE21, TE31, TE41, and TE51 arranged in a first column COL_1. That is, in the first touch period, the TDDIC 420 may provide a touch sensing signal to each of touch sensing lines TSL connected with the touch electrodes TE11 to TE51 arranged in the first column COL_1 and may sense a touch of the user based on signal variations of the touch sensing lines TSL.
In this case, the TDDIC 420 may be configured to control data lines DL and gate lines GL that are connected with pixels corresponding to the touch electrodes TE11 to TE51 of the first column COL_1. In a more detail, to perform the touch scan operation on the touch electrodes TE11 to TE51 of the first column COL_1 in the first touch period, the TDDIC 420 may increase voltages of the touch sensing lines TSL connected with the touch electrodes TE11 to TE51 of the first column COL_1 from the common voltage VCOM to the first voltage V1 (refer to
Alternatively, the TDDIC 420 may perform the touch scan operation on touch electrodes TE11, TE12, TE13, TE14, and TE15 of a first row ROW_1. As described above, the TDDIC 420 may be configured to control data lines DL and gate lines GL that are connected with pixels corresponding to the touch electrodes TE11 to TE15 of the first row ROW_1.
As such, the TDDIC 420 may be configured to control voltages of some touch sensing lines, some data lines, and some gate lines during the transition period. In this case, some touch sensing lines may indicate touch sensing lines connected with touch electrodes on which the touch scan operation will be performed, and some data lines and some gate lines may indicate lines connected with pixels corresponding to the touch electrodes on which the touch scan operation will be performed.
Although not illustrated in
The touch driver (TSC) block 1310 may include various components for the touch screen operation. For example, the touch driver (TSC) block 1310 may include a readout circuit 1311, a parasitic capacitance compensator 1312, an analog-to-digital converter (ADC) 1313, a power supply 1314, a memory 1315, a micro control unit (MCU) 1316, a filter 1317, an oscillator 1318, an interface 1319, and control logic 1320.
The readout circuit 1311 may generate touch data. The parasitic capacitance compensator 1312 may reduce or compensate for parasitic capacitance components of a sensing unit. The ADC 1313 may convert analog data into a digital signal. The power supply voltage generation part 1314 may generate a power supply voltage, for example, about 4V to about 5V. The filter 1317 may provide digital filtering, and may be, for example, a digital FIR low pass filter. The oscillator 1318 may generate a low-power oscillation signal. The interface 1319 may exchange signals with a host controller 1400, and may be, for example, an SPI or I2C interface in some example embodiments.
The display driver block 1330 may include a source driver 1331, a grayscale voltage generator 1332, a display memory 1333, timing control logic 1334, a power generator 1335, a central processing unit (CPU) and RGB interface (CPU & RGB interface) 1336.
The source driver 1331 may generate grayscale data. The display memory 1333 may store display data. The timing control logic 1334 may generate a control signal (or synchronization signal) for controlling each component of the display driver block 1330. The power generator 1335 may generate one or more power supply voltages. The CPU and RGB interface 1336 may control overall operations of the display driver block 1330 and/or may communicate with the host controller 1400.
The touch driver block 1310 may receive at least a piece of timing information from the display driver block 1330. For example, the control logic 1320 of the touch driver block 1310 may receive various timing information (e.g., VSYCN, HSYCN, and DOTCLK) that are synchronized with a display output signal from the timing control logic 1334 of the display driver block 1330. The control logic 1320 may generate a control signal for controlling a generation time point of touch data by using the received timing information.
In example embodiments, the display driver block 1330 may receive at least a piece of information from the touch driver block 1310. For example, as illustrated in
That the touch driver block 1310 is at a sleep state indicates that a touch operation is not performed during a uniform period. In this case, the display driver block 1330 may interrupt an operation of providing timing information to the touch driver block 1310, thereby making it possible to efficiently use power of a device (e.g., a mobile device) including the integrated circuit 1300.
In example embodiments, the display driver block 1330 may perform an operation described with reference to
As illustrated in
For convenience of description and for ease of illustration, the simplified touch driver block 1310 and the simplified display driver block 1330 are illustrated in
The touch driver block 1310 of the display device according to an example embodiment of the inventive concept may provide the sleep status information to the display driver block 1330. In example embodiments, also, an operation in which a power supply voltage used in the touch driver block 1310 is provided from the display driver block 1330 is as follows.
As illustrated in
In the case where a touch input is deactivated and only a display is activated (in the case where TSC: sleep and display: normal), the display driver block 1330 may generate a power supply voltage for one's own consumption, but the display driver block 1330 may not provide the power supply voltage to the touch driver block 1310 because the touch driver block 1310 does not consume power. Also, the display driver block 1330 may not provide the timing information to the touch driver block 1310.
In the case where the touch input is activated and the display is inactivated (in the case where TSC: normal and display: sleep), since the touch input is activated, whether a touch operation is performed is determined periodically. In this case, the display driver block 1330 operates in a low-power mode and maintains an inactive state. However, to determine whether the touch operation is performed, the display driver block 1330 may generate the timing information and a power supply voltage to be used in the touch driver block 1310 and may provide the timing information and the power supply voltage to the touch driver block 1310.
Meanwhile, as a normal case, in the case where both the touch input and the display are activated (in the case where TSC: normal and display: normal), the display driver block 1330 may generate timing information and a power supply voltage and may provide the timing information and the power supply voltage to the touch driver block 1310.
It may be understood from the above-described cases with reference to
According to an example embodiment of the inventive concept, when a display period and a touch period are switched, as a time used to increase a voltage of a touch sensing line from a common voltage to a ground voltage and/or a time used to decrease a voltage of the touch sensing line from the ground voltage to the common voltage is reduced, a touch display driving integrated circuit with improved performance and an operating method thereof may be provided.
While the inventive concept has 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 inventive concept. Therefore, it should be understood that the above example embodiments are not limiting, but illustrative.
Number | Date | Country | Kind |
---|---|---|---|
10-2016-0092130 | Jul 2016 | KR | national |