Patent Publication Number: US-9430086-B2

Title: Display panel, driver circuit, driving method, and electronic apparatus

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 13/718,634, filed Dec. 18, 2012, which claims priority to Japanese Priority Patent Application JP 2012-010743 filed in the Japan Patent Office on Jan. 23, 2012, the entire content of which is hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a display panel having a function of detecting a touch of an external adjacent object, a driver circuit and a driving method used in such a display panel, and an electronic apparatus having such a display panel. 
     Recently, a display panel which allows an input of information instead of using normal mechanical buttons by mounting a touch detecting device called a touch panel on a display panel such as a liquid crystal display panel or incorporating a touch panel and a display panel into a body and displaying various button images on the display panel has attracted attention. Such a display panel having a touch detecting function does not employ an input device such as a keyboard, a mouse, and a keypad and thus has been increasingly used for portable information terminals such as mobile phones in addition to computers. 
     Touch panels are classified into several types such as an optical type, a resistance type, and a capacitance type. For example, JP-T-2006-511879 proposes a capacitance type touch panel in which plural electrodes extending in a direction are arranged to cross each other. In the touch panel, the electrodes are connected to a control circuit and are supplied with an excitation current from the control circuit to detect an external adjacent object. 
     For example, JP-A-2009-258182 proposes a so-called in-cell display panel in which a common electrode for display originally disposed in a display panel is used together as one electrode of a pair of touch-sensor electrodes and the other electrode (touch detecting electrode) is arranged to cross the common electrode. Several kinds of so-called on-cell display panels in which a touch panel is formed on a display surface of a display panel have been proposed. 
     SUMMARY 
     However, recently, increases in precision or size of a display panel have progressed. For example, when a display panel and a touch panel are made to operate in synchronization with each other, the ratio of the writing period of a pixel signal in one frame period increases with an increase in the number of horizontal lines and thus the time to detect a touch is shortened. Accordingly, it is necessary for the touch panel to perform a touch detecting operation for a short time while maintaining touch detection accuracy which is the original objective. 
     It is therefore desirable to provide a display panel, a driver circuit, a driving method, and an electronic apparatus, which can detect a touch for a short time while suppressing a decrease in touch detection accuracy. 
     An embodiment of the present disclosure is directed to a display panel including display elements, plural drive electrodes, one or more touch detecting electrodes, a main driver unit, and a first auxiliary driver unit. The one or more touch detecting electrodes form a capacitor along with the corresponding drive electrode. The main driver unit generates a basic drive signal including a pulse part supplied to the drive electrodes. The first auxiliary driver unit includes a capacitive element and exchanges electric charges between the capacitive element and the drive electrodes in synchronization with the pulse part. 
     Another embodiment of the present disclosure is directed to a driver circuit including a capacitive element and causing electric charges to be exchanged between the capacitive element and a drive electrode in synchronization with a pulse part, which is supplied to the drive electrode, of a basic drive signal. 
     Still another embodiment of the present disclosure is directed to a driving method including supplying a pulse part of a basic drive signal to a drive electrode, and exchanging electric charges between a capacitive element and the drive electrode in synchronization with the pulse part. 
     Yet another embodiment of the present disclosure is directed to an electronic apparatus including the above-mentioned display panel and examples thereof include a television set, a digital camera, a personal computer, a video camera, and a portable terminal such as a mobile phone. 
     In the display panel, the driver circuit, the driving method, and the electronic apparatus according to the embodiments of the present disclosure, the pulse part of the basic drive signal is applied to the plural drive electrodes and the pulse part is transmitted to the touch detecting electrode via the capacitor. At this time, electric charges are exchanged between the capacitive element and the drive electrodes in synchronization with the pulse part. 
     In the display panel, the driver circuit, the driving method, and the electronic apparatus according to the embodiments of the present disclosure, since electric charges are exchanged between the capacitive element and the drive electrodes in synchronization with a pulse part, it is possible to detect a touch for a short time while suppressing a decrease in touch detection accuracy. 
     Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIGS. 1A and 1B  are diagrams illustrating the fundamental principle of a touch detection system in a display panel according to an embodiment of the present disclosure and shows a state where a finger does not touch nor approach the display panel; 
         FIGS. 2A and 2B  are diagrams illustrating the fundamental principle of the touch detection system in the display panel according to the embodiment of the present disclosure and shows a state where a finger touches or approaches the display panel; 
         FIGS. 3A and 3B  are diagrams illustrating the fundamental principle of the touch detection system in the display panel according to the embodiment of the present disclosure and shows examples of waveforms of a drive signal and a touch detection signal; 
         FIG. 4  is a block diagram illustrating a configuration example of a display panel according to a first embodiment of the present disclosure; 
         FIG. 5  is a block diagram illustrating a configuration example of a selection switch unit shown in  FIG. 4 ; 
         FIG. 6  is a cross-sectional view illustrating a schematic sectional structure of a display device with a touch detecting function shown in  FIG. 4 ; 
         FIG. 7  is a circuit diagram illustrating a pixel arrangement in a liquid crystal display device shown in  FIG. 4 ; 
         FIG. 8  is a perspective view illustrating configuration examples of a drive electrode and a touch detection electrode in a touch detecting device shown in  FIG. 4 ; 
         FIGS. 9A to 9C  are schematic diagrams illustrating an operational example of a touch detection scanning operation in the display panel shown in  FIG. 4 ; 
         FIG. 10  is a schematic diagram illustrating an operational example of a display scanning operation and a touch detection scanning operation in the display panel shown in  FIG. 4 ; 
         FIG. 11  is a block diagram illustrating a configuration example of a drive electrode scanning unit shown in  FIG. 4 ; 
         FIG. 12  is a schematic diagram illustrating a mounting example of the display panel shown in  FIG. 4 ; 
         FIG. 13  is a circuit diagram illustrating a configuration example of an auxiliary driver unit shown in  FIG. 4 ; 
         FIG. 14  is a cross-sectional view illustrating a configuration example of a capacitive element shown in  FIG. 13 ; 
         FIGS. 15A to 15I  are timing waveform diagrams illustrating an operational example of the display panel shown in  FIG. 4 ; 
         FIGS. 16A to 16F  are timing waveform diagrams illustrating an example of a touch detecting operation in the display panel shown in  FIG. 4 ; 
         FIGS. 17A to 17G  are timing waveform diagrams illustrating an operational example of an auxiliary driver unit shown in  FIG. 13 ; 
         FIG. 18  is a characteristic diagram illustrating a characteristic example of the auxiliary driver unit shown in  FIG. 13 ; 
         FIGS. 19A and 19B  are cross-sectional views illustrating a configuration example of a capacitive element according to a modified example of the first embodiment; 
         FIGS. 20A to 20G  are timing waveform diagrams illustrating an operational example of an auxiliary driver unit according to a modified example of the first embodiment; 
         FIG. 21  is a block diagram illustrating a configuration example of a display panel according to second and third embodiments of the present disclosure; 
         FIG. 22  is a circuit diagram illustrating a configuration example of an auxiliary driver unit according to the second embodiment; 
         FIGS. 23A to 23G  are timing waveform diagrams illustrating an operational example of the auxiliary driver unit shown in  FIG. 22 ; 
         FIG. 24  is a circuit diagram illustrating a configuration example of an auxiliary driver unit according to the third embodiment; 
         FIGS. 25A to 25G  are timing waveform diagrams illustrating an operational example of the auxiliary driver unit shown in  FIG. 24 ; 
         FIG. 26  is a perspective view illustrating the outer configuration of a television set to which the display panel according to the embodiments is applied; 
         FIG. 27  is a block diagram illustrating a configuration example of a display panel according to a modified example; 
         FIG. 28  is a circuit diagram illustrating a configuration example of an auxiliary driver unit shown in  FIG. 27 ; 
         FIGS. 29A to 29G  are timing waveform diagrams illustrating an operational example of the auxiliary driver unit shown in  FIG. 28 ; and 
         FIG. 30  is a cross-sectional view illustrating a schematic sectional structure of a display device with a touch detecting function according to a modified example. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The description may be made in the following order. 
     1. Fundamental Principle of Capacitance Type Touch Detection 
     2. First Embodiment 
     3. Second Embodiment 
     4. Third Embodiment 
     5. Application Examples 
     &lt;1. Fundamental Principle of Capacitance Type Touch Detection&gt; 
     First, the fundamental principle of touch detection in a display panel according to an embodiment of the present disclosure will be described with reference to  FIGS. 1A to 3B . This touch detection system is embodied as a capacitance type touch sensor and a capacitive element is constructed using a pair of electrodes (a drive electrode E 1  and a touch detecting electrode E 2 ) disposed to face each other with a dielectric D interposed therebetween, for example, as shown in  FIG. 1A . This structure is expressed by an equivalent circuit shown in  FIG. 1B . The drive electrode E 1 , the touch detecting electrode E 2 , and the dielectric D constitute a capacitive element C 1 . One end of the capacitive element C 1  is connected to an AC signal source (a drive signal source) S, and the other end P thereof is grounded via a resistor R and is connected to a voltage detector (a touch detecting circuit) DET. When an AC rectangular wave Sg ( FIG. 3B ) of a predetermined frequency (for example, several kHz to several tens of kHz) is applied to the drive electrode E 1  (one end of the capacitive element C 1 ) from the AC signal source S, an output waveform (a touch detection signal Vdet) appears at the touch detecting electrode E 2  (the other end P of the capacitive element C 1 ), as shown in  FIG. 3A . 
     In a state where a finger does not touch (or approach) the capacitive element, as shown in  FIGS. 1A and 1B , a current I 0  flows based on the capacitance value of the capacitive element C 1  with charging and discharging of the capacitive element C 1 . The potential waveform of the other end P of the capacitive element C 1  at this time is the same as the waveform V 0  shown, for example, in  FIG. 3A  and is detected by the voltage detector DET. 
     On the other hand, in a state where a finger touches (or approaches) the capacitive element, as shown in  FIGS. 2A and 2B , a capacitive element C 2  formed by the finger is added in series to the capacitive element C 1 . In this state, currents I 1  and I 2  flow with the charging and discharging of the capacitive elements C 1  and C 2 . The potential waveform of the other end P of the capacitive element C 1  at this time is the same as the waveform V 1  shown, for example, in  FIG. 3A  and is detected by the voltage detector DET. At this time, the potential of the point P is a partial potential determined by the values of currents I 1  and I 2  flowing in the capacitive elements C 1  and C 2 . Accordingly, the waveform V 1  has a value smaller than that of the waveform V 0  in the non-touched state. The voltage detector DET compares the detected voltage with a predetermined threshold voltage Vth, determines that it is in a non-touched state when the detected voltage is higher than or equal to the threshold voltage, and determines that it is in a touched state when the detected voltage is less than the threshold voltage. In this way, it is possible to detect a touch. 
     &lt;2. First Embodiment&gt; 
     [Configuration Example] 
     (Overall Configuration) 
       FIG. 4  is a diagram illustrating a configuration example of a display panel according to a first embodiment. This display panel  1  is a so-called in-cell display panel in which a liquid crystal display device and a capacitance type touch detecting device are incorporated into a body. 
     The display panel  1  includes a control unit  11 , a gate driver  12 , a source driver  13 , a selection switch unit  14 , a drive signal generating unit  15 , a drive electrode scanning unit  16 , an auxiliary driver unit  18 , a display device with a touch detecting function  10 , and a touch detecting unit  40 . 
     The control unit  11  is a circuit that supplies a control signal to the gate driver  12 , the source driver  13 , the drive signal generating unit  15 , the drive electrode scanning unit  16 , the auxiliary driver unit  18 , and the touch detecting unit  40  on the basis of an image signal Vdisp and controls the units to operate in synchronization with each other. 
     The gate driver  12  has a function of sequentially selecting one horizontal line which is a target of a display driving operation of the display device with a touch detecting function  10  on the basis of the control signal supplied from the control unit  11 . Specifically, the gate driver  12  generates a scanning signal Vscan on the basis of the control signal supplied from the control unit  11  and supplies the scanning signal Vscan to the gates of TFT elements Tr of pixels Pix via scanning signal lines GCL, whereby one line (one horizontal line) of pixels Pix which are formed in a matrix on the liquid crystal display device  20  of the display device with a touch detecting function  10  is sequentially selected as a display driving target. 
     The source driver  13  serves to generate and output a pixel signal Vsig on the basis of an image signal and a source driver control signal supplied from the control unit  11 . Specifically, as described later, the source driver  13  generates pixel signals Vsig, which are obtained by multiplexing pixel signals Vpix of plural (three in this example) sub pixels SPix of the liquid crystal display device  20  of the display device with a touch detecting function  10  in a time-divisional manner, from the image signal corresponding to one horizontal line and supplies the generated pixel signals to the selection switch unit  14 . The source driver  13  also has a function of generating switch control signals Vsel (VselR, VselG, and VselB) necessary for separating the pixel signals Vpix multiplexed into the pixel signals Vsig and supplying the generated switch control signals to the selection switch unit  14  along with the pixel signals Vsig. This multiplexing is carried out to reduce the number of lines between the source driver  13  and the selection switch unit  14 . 
     The selection switch unit  14  separates the pixel signals Vpix, which are multiplexed into the pixel signals Vsig on the basis of the pixel signals Vsig and the switch control signal Vsel supplied from the source driver  13 , and supplies the separated pixel signals to the liquid crystal display device  20  of the display device with a touch detecting function  10 . 
       FIG. 5  shows a configuration example of the selection switch unit  14 . The selection switch unit  14  includes plural switch groups  17 . In this example, each switch group  17  includes three switches SWR, SWG, and SWB. An end of each of the switches is connected and is supplied with the pixel signal Vsig from the source driver  13 , and the other ends thereof are connected to the three sub pixels SPix (R, G, and B) of a pixel Pix via a pixel signal line SGL of the liquid crystal display device  20  of the display device with a touch detecting function  10 . ON and OFF states of the three switches SWR, SWG, and SWB are controlled by the switch control signals Vsel (VselR, VselG, and VselB) supplied from the source driver  13 . According to this configuration, the selection switch unit  14  serves to separate the pixel signals Vpix (VpixR, VpixG, and VpixB) from the multiplexed pixel signal Vsig by sequentially turning on the three switches SWR, SWG, and SWB in a time-divisional manner in response to the switch control signals Vsel. The selection switch unit  14  supplies the pixel signals Vpix to the three sub pixels SPix. 
     The drive signal generating unit  15  generates a DC drive signal VcomDC and an AC drive signal VcomAC and supplied the generated drive signals to the drive electrode scanning unit  16 . In this example, the DC drive signal VcomDC is a DC signal with a voltage of 0 V. The AC drive signal VcomAC is a signal including two pulses Pt and Pi with a low-level voltage of 0 V and a high-level voltage of VH. As described later, the pulse Pt is supplied to the drive electrodes COML and the pulse Pi is used to initialize the auxiliary driver unit  18 . 
     The drive electrode scanning unit  16  is a circuit that selects one of the DC drive signal VcomDC and the AC drive signal VcomAC supplied from the drive signal generating unit  15  on the basis of the control signal supplied from the control unit  11  and that supplies the selected drive signal as a drive signal Vcom to the drive electrodes COML (to be described later) of the display device with a touch detecting function  10 . Specifically, the drive electrode scanning unit  16  supplies the DC drive signal VcomDC to the drive electrodes COML in a display operation. In a touch detecting operation, the drive electrode scanning unit  16  supplies the pulse Pt of the AC drive signal VcomAC to the drive electrodes COML associated with the touch detecting operation and supplies the DC drive signal VcomDC to the other drive electrodes COML. At this time, the drive electrode scanning unit  16  supplies the drive signal Vcom to each block (drive electrode block B to be described later) including a predetermined number of drive electrodes COML. 
     The auxiliary driver unit  18  is a circuit that assists the driving operation of the drive signal generating unit  15  on the basis of the control signals CTL (CTLH and CTLL) supplied from the control unit  11 . Specifically, as described later, the auxiliary driver unit  18  assists the driving operation of the drive signal generating unit  15  so as to reduce the transition time (the rising time tr and the falling time tf) of the drive signal Vcom (pulse Pt) supplied to the drive electrodes COML via the drive electrode scanning unit  16 . 
     The display device with a touch detecting function  10  is a display device having a touch detecting function. The display device with a touch detecting function  10  includes a liquid crystal display device  20  and the touch detecting device  30 . The liquid crystal display device  20  is a device that sequentially scans each horizontal line and performs a display operation on the basis of the scanning signal Vscan supplied from the gate driver  12  as described later. The touch detecting device  30  serves to operate on the basis of the fundamental principle of a capacitance type touch detection and to output a touch detection signal Vdet. As described later, the touch detecting device  30  is sequentially scanned to detect a touch on the basis of the drive signal Vcom supplied from the drive electrode scanning unit  16 . 
     The touch detecting unit  40  is a circuit that checks whether a touch with the touch detecting device  30  is present on the basis of the touch detection control signal supplied from the control unit  11  and the touch detection signal Vdet supplied from the touch detecting device  30  of the display device with a touch detecting function  10  and that calculates the coordinates of a touch in the touch detection area. The touch detecting unit  40  includes an LPF (Low-Pass Filter) unit  42 , an A/D conversion unit  43 , a signal processing unit  44 , a coordinate extracting unit  45 , and a detection time control unit  46 . The LPF unit  42  is a low-pass analog filter that removes a high-frequency component (noise component) included in the touch detection signal Vdet supplied from the touch detecting device  30  and extracts and outputs a touch component. A resistor R giving a DC potential (for example, 0 V) is connected between the input terminals of the LPF unit  42  and the ground. The DC potential (0 V) may be given, for example, by providing a switch instead of the resistor R and turning on the switch at a predetermined time. The A/D conversion unit  43  is a circuit that samples an analog signal output from the LPF unit  42  and converts the sampled analog signal into a digital signal in synchronization with the pulse Pt of the AC drive signal VcomAC. The signal processing unit  44  is a logic circuit that detects a touch with the touch detecting device  30  on the basis of the output signal of the A/D conversion unit  43 . The coordinate extracting unit  45  is a logic circuit that calculates the coordinates on the touch panel when a touch is detected by the signal processing unit  44 . The detection time control unit  46  controls such circuits to operate in synchronization with each other. 
     (Display Device with Touch Detecting Function  10 ) 
     A configuration example of the display device with a touch detecting function  10  will be described in detail below. 
       FIG. 6  shows an example of a cross-sectional structure of a part of the display device with a touch detecting function  10 . The display device with a touch detecting function  10  includes a pixel substrate  2 , a counter substrate  3  disposed to face the pixel substrate  2 , and a liquid crystal layer  6  interposed between the pixel substrate  2  and the counter substrate  3 . 
     The pixel substrate  2  includes a TFT substrate  21  as a circuit board, drive electrodes COML, and pixel electrodes  22 . The TFT substrate  21  serves as a circuit board in which various electrodes or interconnections (such as pixel signal lines SGL or scanning signal lines GCL to be described later), thin film transistors (TFT), and the like are formed. The TFT substrate  21  is formed of, for example, glass. The drive electrodes COML are formed on the TFT substrate  21 . The drive electrodes COML are electrodes used to supply a common voltage to plural pixels Pix (to be described later). The drive electrodes COML serve as a common drive electrode for a liquid crystal display operation and also serve as a drive electrode for a touch detecting operation. An insulating layer  23  is formed on the drive electrodes COML and the pixel electrodes  22  are formed thereon. The pixel electrodes  22  are electrodes used to supply a pixel signal for a display and have transparency. The drive electrodes COML and the pixel electrodes  22  are formed of, for example, ITO (Indium Tin Oxide). 
     The counter substrate  3  includes a glass substrate  31 , a color filter  32 , and a touch detecting electrode TDL. The color filter  32  is formed on one surface of the glass substrate  31 . In the color filter  32 , three-color color filter layers of red (R), green (G), and blue (B) are periodically arranged and three colors of R, G, and B as a set correspond to each display pixel. The touch detecting electrode TDL is formed on the other surface of the glass substrate  31 . The touch detecting electrode TDL is an electrode that is formed of, for example, ITO and that has transparency. A polarizing film  35  is formed on the touch detecting electrode TDL. 
     The liquid crystal layer  6  serves as a display functional layer and serves to modulate light passing through the liquid crystal layer depending on an electric field state. This electric field is formed by a potential difference between the voltage of the drive electrodes COML and the voltage of the pixel electrodes  22 . A liquid crystal of a transverse electric field mode such as an FFS (Fringe Field Switching) or an IPS (In-Plane Switching) is used for the liquid crystal layer  6 . 
     An alignment film is disposed between the liquid crystal layer  6  and the pixel substrate  2  and between the liquid crystal layer  6  and the counter substrate  3  and an incidence-side polarizing film is disposed on the bottom surface of the pixel substrate  2 , which are not shown therein. 
       FIG. 7  shows a configuration example of a pixel structure in the liquid crystal display device  20 . The liquid crystal display device  20  includes plural pixels Pix which are arranged in a matrix. Each pixel Pix includes three sub pixels SPix. The three sub pixels SPix are arranged to correspond to three colors (R, G, and B) of the color filters  32  shown in  FIG. 6 . Each sub pixel SPix includes a TFT element Tr and a liquid crystal element LC. The TFT element Tr is formed of a thin film transistor and is formed of an N-channel MOS (Metal Oxide Semiconductor) TFT in this example. The source of the TFT element Tr is connected to the pixel signal line SGL, the gate thereof is connected to the scanning signal line GCL, and the drain thereof is connected to an end of the liquid crystal element LC. An end of the liquid crystal element LC is connected to the drain of the TFT element Tr and the other end thereof is connected to the drive electrode COML. 
     The sub pixel SPix is connected to the other sub pixels SPix belonging to the same row of the liquid crystal display device  20  via a scanning signal line GCL. The scanning signal line GCL is connected to the gate driver  12  and is supplied with a scanning signal Vscan from the gate driver  12 . The sub pixel SPix is connected to the other sub pixels SPix belonging to the same column of the liquid crystal display device  20  via a pixel signal line SGL. The pixel signal line SGL is connected to the selection switch unit  14  and is supplied with a pixel signal Vpix from the selection switch unit  14 . 
     The sub pixel SPix is connected to the other sub pixels SPix belonging to the same row of the liquid crystal display device  20  via a drive electrode COML. The drive electrode COML is connected to the drive electrode scanning unit  16  and is supplied with a drive signal Vcom from the drive electrode scanning unit  16 . 
     According to this configuration, in the liquid crystal display device  20 , one horizontal line is sequentially selected by driving the gate driver  12  to line-sequentially scan the scanning signal lines GCL in a time-divisional manner, and a display operation is performed for each horizontal line by causing the source driver  13  and the selection switch unit  14  to supply the pixel signals Vpix to the pixels Pix belonging to the selected horizontal line. 
       FIG. 8  is a perspective view illustrating a configuration example of the touch detecting device  30 . The touch detecting device  30  includes the drive electrodes COML formed on the pixel substrate  2  and the touch detecting electrodes TDL formed on the counter substrate  3 . Each drive electrode COML has a striped electrode pattern extending in the horizontal direction of the drawing. When performing a touch detecting operation, as described later, a drive signal Vcom (pulse Pt) is sequentially supplied to the electrode patterns for every block (drive electrode block B to be described later) including a predetermined number of drive electrodes COML to perform a sequential scanning driving operation in a time-divisional manner. Each touch detecting electrode TDL has a striped electrode pattern extending in the direction perpendicular to the extending direction of the electrode patterns of the drive electrodes COML. The electrode patterns of the touch detecting electrode TDL are connected to the inputs of the LPF unit  42  of the touch detecting unit  40 . The electrode patterns in which the drive electrodes COML and the touch detecting electrodes TDL intersect each other form capacitors at the intersections. 
     According to this configuration, in the touch detecting device  30 , a touch detection signal Vdet is output from the touch detecting electrodes TDL to detect a touch by causing the drive electrode scanning unit  16  to supply a drive signal Vcom to the drive electrodes COML. That is, the drive electrodes COML correspond to the drive electrode E 1  in the fundamental principle of touch detection shown in  FIGS. 1A to 3B , the touch detecting electrodes TDL correspond to the touch detecting electrode E 2 , and the touch detecting device  30  detects a touch on the basis of the fundamental principle. As shown in  FIG. 8 , the electrode patterns intersecting each other from the capacitance type touch sensor in a matrix shape. Accordingly, by scanning the overall touch detection plane of the touch detecting device  30 , it is also possible to detect a position of an approach or a contact of an external adjacent object. 
     The drive electrode scanning unit  16  drives the drive electrodes COML for each block (drive electrode block B) including a predetermined number of drive electrodes COML to perform a touch detection scanning operation. 
       FIGS. 9A to 9C  schematically illustrate a touch detection scanning operation. In  FIGS. 9A to 9C , an operation of supplying a drive signal Vcom to the drive electrode blocks B 1  to B 20  is shown when the touch detection plane includes 20 drive electrode blocks B 1  to B 20 . In  FIGS. 9A to 9C , the hatched drive electrode block B indicates that the pulse Pt of the AC drive signal VcomAC is supplied thereto and the other drive electrode blocks B indicate that the DC drive signal VcomDC is supplied thereto. In this example, the number of drive electrode blocks B is 20 for the purpose of convenience of explanation, but is not limited to this number. 
     The drive electrode scanning unit  16  supplies the drive signal Vcom to the drive electrodes COML for each drive electrode block B. Each drive electrode block B is set to a width (for example, about 5 mm) corresponding to the size of a user&#39;s finger. The drive electrode scanning unit  16  sequentially selects the drive electrode blocks B as a target of the touch detecting operation and supplies the pulse Pt to the drive electrodes COML belonging to the selected drive electrode block B, whereby all the drive electrode blocks B are scanned, as shown in  FIGS. 9A to 9C . 
       FIG. 10  schematically illustrates a display scanning operation and a touch detection scanning operation. In the display panel  1 , the gate driver  12  performs a display scanning Scand by line-sequentially scanning the scanning signal lines GCL in a time-divisional manner, and the drive electrode scanning unit  16  performs a touch detection scanning Scant by sequentially selecting and driving the drive electrode blocks B. In this example, the touch detection scanning Scant is performed at double the scanning speed of the display scanning Scand. In this way, in the display panel  1 , since the scanning speed of the touch detection scanning is set to be higher than that of the display scanning, it is possible to rapidly respond to a touch of an external adjacent object and thus to improve the response characteristic to a touch detection. The scanning speed is not limited to this example, but the touch detection scanning Scant may be performed at a scanning speed which is two or more times the scanning speed of the display scanning Scand or may be performed at a scanning speed which is two or less times the scanning speed of the display scanning Scand. 
     (Drive Electrode Scanning Unit  16 ) 
       FIG. 11  shows a configuration example of the drive electrode scanning unit  16 . The drive electrode scanning unit  16  includes a scanning control unit  51 , a touch detection scanning unit  52 , and a driver unit  530 . The driver unit  530  includes 20 driver units  53 ( 1 ) to  53 ( 20 ). Hereinafter, when it is intended to mention any one of 20 driver units  53 ( 1 ) to  53 ( 20 ), the driver unit  53  is simply described. 
     The scanning control unit  51  supplies a control signal to the touch detection scanning unit  52  on the basis of the control signal supplied from the control unit  11 . The scanning control unit  51  also has a function of supplying a Vcom selection signal VCOMSEL, which indicates which of the DC drive signal VcomDC and the AC drive signal VcomAC to supply to the drive electrodes COML, to the driver unit  530 . 
     The touch detection scanning unit  52  includes a shift register and generates a scanning signal St for selecting the drive electrode block B to which the pulse Pt of the AC drive signal VcomAC should be applied. Specifically, the touch detection scanning unit  52  generates plural scanning signals St corresponding to the drive electrode blocks B on the basis of the control signal supplied from the scanning control unit  51  as described later. When the touch detection scanning unit  52  supplies, for example, a high-level signal as a k-th scanning signal St(k) to the k-th driver unit  53 ( k ), the driver unit  53 ( k ) supplies the pulse Pt of the AC drive signal VcomAC to the plural drive electrodes COML belonging to the k-th drive electrode block B(k). 
     The driver unit  530  selects one of the DC drive signal VcomDC and the AC drive signal VcomAC supplied from the drive signal generating unit  15  on the basis of the scanning signals St supplied from the touch detection scanning unit  52  and the Vcom selection signal VCOMSEL supplied from the scanning control unit  51  and supplies the selected drive signal as the drive signal Vcom to the drive electrodes COML. The driver unit  53  is provided for each output signal of the touch detection scanning unit  52  and supplies the drive signal Vcom to the corresponding drive electrode block B. 
     The driver unit  53  includes a logical product circuit  54 , an inverter  55 , buffers  56  and  57 , and switches SW 1  and SW 2 . The logical product circuit  54  generates and outputs a logical product (AND) of the scanning signal St supplied from the touch detection scanning unit  52  and the Vcom selection signal VCOMSEL supplied from the scanning control unit  51 . The inverter  55  generates and outputs the inverted logic of the output signal of the logical product circuit  54 . The buffer  56  has a function of amplifying a signal supplied from the logical product circuit  54  to an amplitude level which can control the ON and OFF states of the switch SW 1 . The ON and OFF states of the switch SW 1  are controlled on the basis of the signal supplied from the buffer  56 , one end thereof is supplied with the AC drive signal VcomAC, and the other end thereof is connected to plural drive electrodes COML belonging to the drive electrode block B. The buffer  57  has a function of amplifying a signal supplied from the inverter  55  to an amplitude level which can control the ON and OFF states of the switch SW 2 . The On and OFF states of the switch SW 2  are controlled on the basis of the signal supplied from the buffer  57 , one end thereof is supplied with the DC drive signal VcomDC, and the other end thereof is connected to the other end of the switch SW 1 . 
     According to this configuration, the driver unit  53  outputs the AC drive signal VcomAC as the drive signal Vcom when the scanning signal St is at a high level and the Vcom selection signal VCOMSEL is at a high level, and outputs the DC drive signal VcomDC as the drive signal Vcom when the Vcom selection signal VCOMSEL is at a low level. The driver unit  53  outputs the DC drive signal VcomDC as the drive signal Vcom when the scanning signal St is at a low level. The driver unit  53  supplies the drive signal Vcom output in this way to the plural drive electrodes COML belonging to the drive electrode block B corresponding to the driver unit  53 . 
     (Auxiliary Driver Unit  18 ) 
     The arrangement of the blocks in the display panel  1  will be first described before describing the auxiliary driver unit  18 . 
       FIG. 12  schematically illustrates a mounting example of the display panel  1 . The control unit  11 , the source driver  13 , and the drive signal generating unit  15  are mounted as a COG (Chip On Glass) on the pixel substrate  2 . The selection switch unit  14  is formed of TFT elements in the vicinity of the display area Ad on the TFT substrate  21 . 
     The gate driver  12  ( 12 A and  12 B) is formed of TFT elements on the TFT substrate  21 . In this example, the gate driver  12  is disposed on each of the upper side ( 12 A) and the lower side ( 12 B) of the pixel substrate  2  in  FIG. 12  and can drive the pixels Pix (not shown) arranged in a matrix in the display area Ad from both sides. 
     The drive electrode scanning unit  16  ( 16 A and  16 B) is formed of TFT elements on the TFT substrate  21 . In this example, the drive electrode scanning unit  16  is disposed on each of the upper side ( 16 A) and the lower side ( 16 B) of the pixel substrate  2  in  FIG. 12 , is supplied with the DC drive signal VcomDC via a line LDC from the drive signal generating unit  15 , and is supplied with the AC drive signal VcomAC via a line LAC. The drive electrode scanning units  16 A and  16 B can drive the plural drive electrode blocks B arranged in parallel from both sides. 
     The auxiliary driver unit  18  ( 18 A and  18 B) is formed of TFT elements on the TFT substrate  21 . The auxiliary driver unit  18  is disposed in the vicinity of an end of the line LAC extending from the drive signal generating unit  15 . Specifically, in this example, the auxiliary driver unit  18 A is disposed in the vicinity of the end of the line LAC for supplying the AC drive signal VcomAC to the drive electrode scanning unit  16 A and the auxiliary driver unit  18 B is disposed in the vicinity of the end of the line LAC for supplying the AC drive signal VcomAC to the drive electrode scanning unit  16 B. 
     The touch detecting unit  40  is mounted on a flexible printed circuit board T and is connected to the plural touch detecting electrodes TDL arranged in parallel. 
     As shown in  FIG. 12 , in the display panel  1 , the auxiliary driver unit  18  ( 18 A and  18 B) is disposed at a position separated from the drive signal generating unit  15 . Accordingly, the auxiliary driver unit  18  serves to reduce the transition time (the rising time tr and the falling time tf) of the pulse Pt supplied to the block B of the drive electrodes COML. That is, since the line LAC includes parasitic resistance or the like and the drive electrodes COML belonging to the drive electrode block B supplied with the pulse Pt via the line LAC have parasitic capacitance or the like, the transition time of the pulse Pt may be elongated in the drive electrode block B located at a position separated from the drive signal generating unit  15 . Particularly, this tendency is marked in the drive electrode block B disposed at the end of the line LAC and thus the waveform may be broken. In the display panel  1 , by providing the auxiliary driver unit  18  to the vicinity of the end of the line LAC, it is possible to reduce the transition time of the pulse Pt. 
       FIG. 13  shows a configuration example of the auxiliary driver unit  18 . The auxiliary driver unit  18  includes capacitive elements CH and CL and switches SWH and SWL. One end of the capacitive element CH is connected to one end of the switch SWH and the other end thereof is grounded. The ON and OFF states of the switch SWH are controlled on the basis of the control signal CTLH supplied from the control unit  11 , one end thereof is connected to one end of the capacitive element CH, and the other end thereof is connected to the line LAC. One end of the capacitive element CL is connected to one end of the switch SWL and the other end thereof is grounded. The ON and OFF states of the switch SWL are controlled on the basis of the control signal CTLL supplied from the control unit  11 , one end thereof is connected to one end of the capacitive element CL, and the other end thereof is connected to the other end of the switch SWL and the line LAC. 
     According to this configuration, in the auxiliary driver unit  18 , since the switch SWH is changed to the ON state on the basis of the control signal CTLH at the rising time of the pulse Pt of the AC drive signal VcomAC, electric charges are exchanged between the capacitive element CH and the drive electrode block B as a target of the touch detecting operation, thereby reducing the rising time tr of the pulse Pt in the corresponding drive electrode block B. Similarly, in the auxiliary driver unit  18 , since the switch SWL is changed to the ON state on the basis of the control signal CTLL at the falling time of the pulse Pt of the AC drive signal VcomAC, electric charges are exchanged between the capacitive element CL and the drive electrode block B as a target of the touch detecting operation, thereby reducing the falling time tf of the pulse Pt in the corresponding drive electrode block B. 
     The auxiliary driver unit  18  has a function of initializing the voltages of the capacitive elements CH and CL before turning on the switches SWH and SWL using the pulse Pi of the AC drive signal VcomAC as described later. 
     A configuration example of the capacitive elements CH and CL of the auxiliary driver unit  18  will be described below. The capacitive element CH will be described representatively below, but the same is true of the capacitive element CL. 
       FIG. 14  shows an example of a partial sectional structure of the capacitive element CH. The capacitive element CH is formed on the pixel substrate  2  shown in  FIG. 6 . The capacitive element CH includes electrodes  61  and  62  and an insulating layer  63  interposed between the electrodes  61  and  62 . The electrode  61  is formed in the same layer as the pixel electrodes  22  ( FIG. 6 ) and is formed of, for example, ITO. The electrode  62  is formed in the same layer as the drive electrodes COML ( FIG. 6 ) and is formed of, for example, ITO. The insulating layer  63  corresponds to the insulating layer  23  ( FIG. 6 ). The electrode  62  is connected to the interconnection layer  65  formed on the TFT substrate  21  via plural contacts CONT. The interconnection layer  65  is formed in the same layer as the pixel signal line SGL ( FIG. 7 ) and is formed of, for example, aluminum. In this example, the electrode  61  (the interconnection layer  65 ) is connected to one end of the switch SWH and the electrode  62  is grounded. In the capacitive element CL, the electrode  61  (the interconnection layer  65 ) is connected to one end of the switch SWL and the electrode  62  is grounded. 
     In this way, the capacitive elements CH and CL can be formed at the same time as forming the display device with a touch detecting function  10  without performing any additional manufacturing process through the manufacturing processes of the display device with a touch detecting function  10  shown in  FIG. 6  and the like. 
     Here, the liquid crystal element LC corresponds to a specific example of the “display element” in the embodiment of the present disclosure. The drive signal generating unit  15  corresponds to a specific example of the “main driver unit” in the embodiment of the present disclosure. The AC drive signal VcomAC corresponds to a specific example of the “basic drive signal” in the embodiment of the present disclosure and the pulse Pt corresponds to a specific example of the “pulse part” in the embodiment of the present disclosure. One of the capacitive element CH and switch SWH and the capacitive element CL and switch SWL corresponds to a specific example of the “first auxiliary driver unit” in the embodiment of the present disclosure and the other end thereof corresponds to a specific example of the “second auxiliary driver unit” in the embodiment of the present disclosure. 
     [Operations and Advantages] 
     The operations and advantages of the display panel  1  according to this embodiment will be described below. 
     (Overall Operations) 
     The overall operations of the display panel  1  will be described below in brief with reference to  FIG. 4 . The control unit  11  supplies the control signals to the gate driver  12 , the source driver  13 , the drive signal generating unit  15 , the drive electrode scanning unit  16 , the auxiliary driver unit  18 , and the touch detecting unit  40  on the basis of the image signal Vdisp, and controls the units to operate in synchronization with each other. 
     The gate driver  12  supplies the scanning signal Vscan to the liquid crystal display device  20  and sequentially selects one horizontal line as a target of a display driving operation. The source driver  13  generates a pixel signal Vsig into which the pixel signal Vpix is multiplexed and a switch control signal Vsel corresponding thereto and supplies the generated signals to the selection switch unit  14 . The selection switch unit  14  separates the pixel signal Vpix on the basis of the pixel signal Vsig and the switch control signal Vsel and supplies the separated pixel signal Vpix to the sub pixels SPix constituting one horizontal line. The drive signal generating unit  15  generates a DC drive signal VcomDC and an AC drive signal VcomAC. The drive electrode scanning unit  16  selects one of the DC drive signal VcomDC and the AC drive signal VcomAC and supplies the selected drive signal as the drive signal Vcom for each drive electrode block B. The auxiliary driver unit  18  assists the driving operation of the drive signal generating unit  15 . The display device with a touch detecting function  10  performs the touch detecting operation at the same time as performing the display operation and outputs the touch detection signal Vdet from the touch detecting electrodes TDL. 
     The touch detecting unit  40  detects a touch on the basis of the touch detection signal Vdet. Specifically, the LPF unit  42  removes a high frequency component (noise component) included in the touch detection signal Vdet and extracts and outputs a touch component. The A/D conversion unit  43  converts an analog signal output from the LPF unit  42  into a digital signal. The signal processing unit  44  detects a touch with the display device with a touch detecting function  10  on the basis of the output signal of the A/D conversion unit  43 . The coordinate extracting unit  45  calculates the coordinates on the touch panel when a touch is detected by the signal processing unit  44 . The detection time control unit  46  controls the LPF unit  42 , the A/D conversion unit  43 , the signal processing unit  44 , and the coordinate extracting unit  45  to operate in synchronization with each other. 
     (Detailed Operations) 
     The detailed operations of the display panel  1  will be described below. 
       FIGS. 15A to 15I  are diagrams illustrating a timing waveform of the display panel  1 , where  FIG. 15A  represents the waveform of the scanning signal Vscan,  FIG. 15B  represents the waveform of the pixel signal Vsig,  FIG. 15C  represents the waveform of the switch control signal Vsel,  FIG. 15D  represents the waveform of the pixel signal Vpix,  FIG. 15E  represents the waveform of the Vcom selection signal VCOMSEL,  FIG. 15F  represents the waveforms of the drive signal Vcom, and  FIG. 15G  represents the waveform of the touch detection signal Vdet. 
     In the display panel  1 , a touch detecting operation and a display operation are performed in each horizontal period ( 1 H). In the touch detecting operation, the drive electrode scanning unit  16  performs the touch detection scanning by sequentially supplying the pulse Pt of the AC drive signal VcomAC to the drive electrodes COML associated with the touch detecting operation for each drive electrode block B, and the touch detecting unit  40  detects a touch on the basis of the touch detection signal Vdet output from the touch detecting electrodes TDL. In the display operation, the gate driver  12  sequentially supplies the scanning signal Vscan to the scanning signal lines GCL and the source driver  13  and the selection switch unit  14  write the pixel signal Vpix to the sub pixels SPix constituting the selected horizontal line. The details thereof will be described below. 
     First, at time t 1 , one horizontal period ( 1 H) is started and the scanning control unit  51  of the drive electrode scanning unit  16  changes the voltage of the Vcom selection signal VCOMSEL from a low level to a high level ( FIG. 15G ). Accordingly, in the k-th driver unit  53 ( k ) associated with the touch detecting operation in the drive electrode scanning unit  16 , the switch SW 1  is turned on, the switch SW 2  is turned off, the AC drive signal VcomAC ( FIG. 15A ) generated by the drive signal generating unit  15  is supplied as the drive signal Vcom(B(k)) to the drive electrodes COML belonging to the k-th drive electrode block B(k) via the switch SW 1  ( FIG. 15H ). In the driver units  53  other than the driver unit  53 ( k ), the switch SW 1  is turned off, the switch SW 2  is turned on, and the DC drive signal VcomDC ( FIG. 15B ) generated by the drive signal generating unit  15  is supplied to the drive electrodes COML belonging to the corresponding drive electrode block B via the switch SW 2  ( FIG. 15H ). 
     Then, the drive signal generating unit  15  generates the pulse Pt and outputs the generated pulse as the AC drive signal VcomAC in the period of times t 2  to t 3  ( FIG. 15A ). Accordingly, the pulse Pt also appears in the drive signal Vcom(B(k)) supplied to the k-th drive electrode block B(k) ( FIG. 15H ). The drive signal Vcom(B(k)) is transmitted to the touch detecting electrodes TDL via an electrostatic capacitor and the touch detection signal Vdet is changed ( FIG. 15I ). 
     The A/D conversion unit  43  of the touch detecting unit  40  converts the output signal of the LPF unit  42  to which the touch detection signal Vdet ( FIG. 15I ) is input in an A/D conversion manner at the sampling time ts. The signal processing unit  44  of the touch detecting unit  40  performs the touch detecting operation on the basis of the A/D conversion results collected in plural horizontal periods, as described later. 
     Then, the scanning control unit  51  of the drive electrode scanning unit  16  changes the voltage of the Vcom selection signal VCOMSEL from a high level to a low level at time t 4  ( FIG. 15G ). Accordingly, in the driver unit  53 ( k ) of the drive electrode scanning unit  16 , the switch SW 1  is turned off, the switch SW 2  is turned on, the DC drive signal VcomDC ( FIG. 15B ) generated by the drive signal generating unit  15  is supplied as the drive signal Vcom(B(k)) to the drive electrodes COML belonging to the corresponding drive electrode block B(k) via the switch SW 2  ( FIG. 15H ). 
     Thereafter, the drive signal generating unit  15  generates the pulse Pi and outputs the generated pulse as the AC drive signal VcomAC ( FIG. 15A ), until the horizontal period ( 1 H) is ended. This pulse Pi is used to initialize the auxiliary driver unit  18  as described below. 
     The gate driver  12  supplies the scanning signal Vscan to the n-th scanning signal line GCL(n) associated with the display operation at time t 5  and thus the scanning signal Vscan(n) is changed from a low level to a high level ( FIG. 15C ). Accordingly, the gate driver  12  selects one horizontal line as a target of the display operation. 
     The source driver  13  supplies a pixel voltage VR for the red sub pixels SPix as the pixel signal Vsig to the selection switch unit  14  ( FIG. 15D ), and generates a switch control signal VselR which is at a high level in the period in which the pixel voltage VR is supplied ( FIG. 15E ). The selection switch unit  14  separates the pixel voltage VR supplied from the source driver  13  from the pixel signal Vsig by turning on the switch SWR in the period in which the switch control signal VselR is at a high level, and supplies the separated pixel voltage as the pixel signal VpixR to the red sub pixels SPix via the pixel signal line SGL ( FIG. 15F ). Since the pixel signal line SGL is in a floating state after the switch SWR is turned off, the voltage of the pixel signal line SGL is maintained ( FIG. 15F ). 
     Similarly, the source driver  13  supplies a pixel voltage VG for the green sub pixels Spix to the selection switch unit  14  along with the corresponding switch control signal VselG ( FIGS. 15D and 15E ), and the selection switch unit  14  separates the pixel voltage VG from the pixel signal Vsig on the basis of the switch control signal VselG and supplies the separated pixel voltage as the pixel signal VpixG to the green sub pixels SPix via the pixel signal line SGL ( FIG. 15F ). 
     Thereafter, similarly, the source driver  13  supplies a pixel voltage VB for the blue sub pixels Spix to the selection switch unit  14  along with the corresponding switch control signal VselB ( FIGS. 15D and 15E ), and the selection switch unit  14  separates the pixel voltage VB from the pixel signal Vsig on the basis of the switch control signal VselB and supplies the separated pixel voltage as the pixel signal VpixB to the blue sub pixels SPix via the pixel signal line SGL ( FIG. 15F ). 
     The gate driver  12  changes the scanning signal Vscan(n) of the n-th scanning signal line GCL from a high level to a low level at time t 9  ( FIG. 15C ). Accordingly, the sub pixels Spix of one horizontal line associated with the display operation are electrically isolated from the pixel signal line SGL. 
     At time t 11 , one horizontal period ( 1 H) is ended and a new horizontal period ( 1 H) is started. 
     Thereafter, by repeating the above-mentioned operation, the display panel  1  performs the display operation on the overall display plane through the line sequential scanning, and performs the touch detecting operation on the overall touch detection plane by scanning the drive electrodes for each drive electrode block B as described later. 
       FIGS. 16A to 16F  show operational examples of a touch detection scanning operation, wherein  FIG. 16A  represents the waveform of the AC drive signal VcomAC,  FIG. 16B  represents the waveform of the DC drive signal VcomDC,  FIG. 16C  represents the waveform of the Vcom selection signal VCOMSEL,  FIG. 16D  represents the waveform of the scanning signal St,  FIG. 16E  represents the waveform of the drive signal Vcom, and  FIG. 16F  represents the waveform of the touch detection signal Vdet. In the drawing, the transition time of the drive signal Vcom or the like is shown to be sufficiently small for the purpose of convenience of explanation. 
     As shown in  FIGS. 16A to 16F , the drive electrode scanning unit  16  performs the touch detection scanning operation by supplying the pulse Pt of the AC drive signal VcomAC ( FIG. 16A ) to the corresponding drive electrode block B ( FIG. 16E ) on the basis of the scanning signal St ( FIG. 16D ) generated by the touch detection scanning unit  52 . At this time, the drive electrode scanning unit  16  supplies the pulse Pt to the respective drive electrode blocks B over a predetermined number of horizontal periods. The touch detecting unit  40  samples the touch detection signal Vdet based on the pulse Pt in each horizontal period, and the signal processing unit  44  detects a touch to the area corresponding to the drive electrode block B on the basis of the plural sampling results after the sampling, in the final horizontal period of the predetermined number of horizontal periods, is ended. In this way, since a touch is detected on the basis of the plural sampling results, it is possible to statically analyze the sampling results, thereby suppressing the degradation of the S/N ratio due to the difference between the sampling results and enhancing the touch detection accuracy. 
     (Detailed Operation of Auxiliary Driver Unit  18 ) 
     The operation of the auxiliary driver unit  18  will be described in detail below. 
       FIGS. 17A to 17G  show timing waveform examples of the touch detecting operation in the display panel  1 , where  FIG. 17A  represents the waveform of the AC drive signal VcomAC in the output of the drive signal generating unit  15 ,  FIG. 17B  represents the waveform of the Vcom selection signal VCOMSEL,  FIG. 17C  represents the waveform of the control signal CTLH,  FIG. 17D  represents eh waveform of the control signal CTLL,  FIG. 17E  represents the waveform of the voltage Vch of the capacitive element CH,  FIG. 17F  represents the waveform of the voltage Vcl of the capacitive element CL, and  FIG. 17G  represents the waveform of the drive signal Vcom supplied to the drive electrode block B as a target of the touch detecting operation. Times t 1  to t 4  and t 11  in  FIGS. 17A to 17G  correspond to times t 1  to t 4  and t 11  in  FIGS. 15A to 15I , respectively. 
     In the auxiliary driver unit  18 , at the rising and falling of the pulse Pt of the AC drive signal VcomAC, electric charges are exchanged between the capacitive elements CH and CL and the drive electrodes COML belonging to the drive electrode block B as a target of the touch detecting operation. The details thereof will be described below. 
     First, at time t 1 , the scanning control unit  51  of the drive electrode scanning unit  16  changes the Vcom selection signal VCOMSEL from a low level to a high level ( FIG. 17B ). Accordingly, in the driver unit  53  associated with the touch detecting operation in the drive electrode scanning unit  16 , the switch SW 1  is turned on and the line LAC and the drive electrode block B as a target of the touch detecting operation are connected to each other. 
     Then, the control unit  11  changes the control signal CTLH to a high level in a predetermined period which is started from time t 2  at which the pulse Pt ( FIG. 17A ) rises ( FIG. 17C ). Accordingly, the switch SWH of the auxiliary driver unit  18  is turned on, the electric charges move from the capacitive element CH to the drive electrode block B via the line LAC, and the voltage of the drive electrode block B ( FIG. 17G ) rises for a short time. Accordingly, the voltage Vch of the capacitive element CH is lowered and the level thereof is maintained up to time t 6  (to be described later) ( FIG. 17E ). 
     The control unit  11  changes the control signal CTLL to a high level in a predetermined period which is started from time t 3  at which the pulse Pt ( FIG. 17A ) falls ( FIG. 17D ). Accordingly, the switch SWL of the auxiliary driver unit  18  is turned on, electric charges move from the drive electrode block B to the capacitive element CL via the line LAC, and the voltage of the drive electrode block B ( FIG. 17G ) falls for a short time. Accordingly, the voltage Vcl of the capacitive element CL rises and maintains the level up to time t 8  (to be described later) ( FIG. 17F ). 
     At time t 4 , the scanning control unit  51  of the drive electrode scanning unit  16  changes the Vcom selection signal VCOMSEL from a high level to a low level ( FIG. 17B ). Accordingly, in the driver unit  53  associated with the touch detecting operation in the drive electrode scanning unit  16 , the switch SW 1  is turned off and the line LAC and the drive electrode block B are electrically isolated from each other. 
     Thereafter, in the period of times t 6  to t 11 , the voltages of the capacitive elements VH and VL are initialized using the pulse Pi of the AC drive signal VcomAC. Specifically, in the period of times t 6  to t 8 , the drive signal generating unit  15  changes the AC drive signal VcomAC to a high level (voltage VH) ( FIG. 17A ). At the same time, the control unit  11  changes the control signal CTLH to a high level in a predetermined period started from time t 6  and shorter than the pulse width of the pulse Pi ( FIG. 17C ). Accordingly, the switch SWH of the auxiliary driver unit  18  is turned on, the capacitive element CH is charged via the line LAC by the drive signal generating unit  15 , and the voltage Vch of the capacitive element CH varies to the voltage VH. Thereafter, in a predetermined period started from time t 8  in which the AC drive signal VcomAC is at a low level (0 V), the control unit  11  changes the control signal CTLL to a high level ( FIG. 17D ). Accordingly, the switch SWL of the auxiliary driver unit  18  is turned on, the capacitive element CL is discharged via the line LAC, and the voltage Vcl of the capacitive element CL varies to 0 V. 
     In this way, in the display panel  1 , since electric charges are exchanged between the capacitive element CH of the auxiliary driver unit  18  and the drive electrodes COML belonging to the drive electrode block B as a target of the touch detecting operation at the rising of the pulse Pt of the AC drive signal VcomAC, it is possible to shorten the rising time tr of the voltage (the drive signal Vcom) of the drive electrodes COML. Similarly, since electric charges are exchanged between the capacitive element CL of the auxiliary driver unit  18  and the drive electrodes COML at the falling of the pulse Pt, it is possible to shorten the falling time tf of the voltage (the drive signal Vcom) of the drive electrodes COML. Accordingly, for example, even when the drive signal Vcom is supplied to the drive electrode block B separated from the drive signal generating unit  15  and located in the vicinity of the end of the line LAC, it is possible to shorten the transition time (the rising time tr and the falling time tf) of the drive signal Vcom. 
     In this way, by shortening the transition time of the drive signal Vcom (pulse Pt), it is possible to reduce the possibility of lowering the touch detection accuracy in the display panel  1 . That is, for example, when the auxiliary driver unit  18  is not provided, the transition time of the drive signal Vcom may increase and thus the pulse waveform may collapse. In this case, since the collapsed pulse signal is transmitted to the touch detecting electrodes TDL and is output as the touch detection signal Vdet, there is a possibility of lowering the touch detection accuracy. On the contrary, in the display panel  1 , since the transition time of the drive signal Vcom (pulse Pt) can be shortened, it is possible to reduce the possibility of collapsing of the waveform of the drive signal Vcom and thus to reduce the possibility of lowering the touch detection accuracy. 
     By shortening the transition time of the drive signal Vcom, it is possible to cope with an increase in precision or an increase in size of the display panel  1  and the like. Specifically, for example, when a high-precision liquid crystal display device  20  is used, the ratio of the writing time of a pixel signal in a period of one frame increases with an increase in the number of horizontal lines and thus it is difficult to guarantee the time for the touch detecting operation. In the display panel  1 , since the transition time of the drive signal Vcom can be shortened as described above, it is possible to shorten the time for the touch detecting operation and to cope with an increase in precision or an increase in size of the display panel  1 . 
     The capacitance values of the capacitive elements CH and CL of the auxiliary driver unit  18  will be described below. 
       FIG. 18  shows the relationship between the capacitance values of the capacitive elements CH and CL and the transition time (the rising time tr and the falling time tf) of the drive signal Vcom in the drive electrode block B disposed in the vicinity of the end of the line LAC. In  FIG. 18 , the capacitance values of the capacitive elements CH and CL are expressed with the parasitic capacitance Cb of each drive electrode block B as a unit. That is, since the touch detection scanning is performed in the display panel  1  by supplying the drive signal Vcom to each drive electrode block B, the capacitance values of the capacitive elements CH and CL are expressed with the parasitic capacitance Cb of each drive electrode block B as a unit. 
     As shown in  FIG. 18 , with an increase in capacitance values of the capacitive elements CH and CL, the transition time of the drive signal Vcom becomes shortened and the transition time is almost saturated when the capacitance values become about seven to ten times the parasitic capacitance Cb. On the other hand, when the capacitance values of the capacitive elements CH and CL increase, a larger arrangement area is necessary. Accordingly, it is necessary to determine the capacitance values of the capacitive elements CH and CL in consideration of both the arrangement areas of the capacitive elements CH and CL and the transition time. Specifically, in this example, it is preferable that the capacitance values of the capacitive elements CH and CL be set to about three times the parasitic capacitance Cb. 
     [Advantages] 
     As described above, in this embodiment, since the auxiliary driver unit is disposed, it is possible to shorten the transition time of the drive signal and thus to drive the respective drive electrode blocks for a shorter time. 
     In this embodiment, since the transition time of the drive signal is shortened, it is possible to reduce the possibility of collapsing of the waveform of the drive signal and thus to suppress the lowering of the touch detection accuracy. 
     In this embodiment, since the auxiliary driver unit is disposed at a position separated from the drive signal generating unit, it is possible to shorten the transition time of the drive signal in the drive electrode separated from the drive signal generating unit. 
     In this embodiment, since the capacitive elements are initialized via the line LAC, it is not necessary to provide a dedicated line for initializing the capacitive elements and it is thus to possible to reduce the space for the line. 
     In this embodiment, since the capacitive elements are formed through the processes of manufacturing the display device with a touch detecting function, it is not necessary to add a manufacturing process and it is thus possible to simplify the manufacturing processes. 
     MODIFIED EXAMPLE 1-1 
     In the above-mentioned embodiment, the electrodes  61  of the capacitive elements CH and CL are formed in the same layer as the pixel electrodes  22  and the electrodes  62  are formed in the same layer as the drive electrodes COML, but the embodiment of the present disclosure is not limited to this configuration. For example, the electrodes may be formed as shown in  FIGS. 19A and 19B . The capacitive element CH will be described below as an example. 
     In the configuration shown in  FIG. 19A , the capacitive element CH includes electrodes  67  and  68  and an insulating layer  69  interposed between the electrodes  67  and  68 . The electrode  67  is formed in the same layer as the scanning signal line GCL ( FIG. 7 ) and is formed of, for example, aluminum. The electrode  68  is formed on the TFT substrate  21  in the same layer as the gate electrode of the TFT element Tr and is formed of, for example, molybdenum. The electrode  67  is connected to an interconnection layer  65  via plural contacts CONT 2 . In this example, the electrode  67  (the interconnection layer  65 ) is connected to one end of the switch SWH and the electrode  68  is grounded. In the case of the capacitive element CL, the electrode  67  (the interconnection layer  65 ) is connected to one end of the switch SWL and the electrode  68  is grounded. 
     The configuration shown in  FIG. 19B  is obtained by combining the configuration ( FIG. 14 ) according to the above-mentioned embodiment and the configuration shown in  FIG. 19A . That is, in this configuration, the capacitor constructed by the electrodes  61  and  62  and the insulating layer  63  and the capacitor constructed by the electrodes  67  and  68  and the insulating layer  69  are superimposed. In this example, the electrodes  62  and  67  (the interconnection layer  65 ) are connected to one end of the switch SWH and the electrodes  61  and  68  are grounded. In the case of the capacitive element CL, the electrodes  62  and  67  (the interconnection layer  65 ) are connected to one end of the switch SWL and the electrodes  61  and  68  are grounded. 
     In this way, even when the capacitive elements CH and CL are constructed with any configuration of  FIGS. 19A and 19B , it is possible to form the capacitive elements at the same time as forming the display device with a touch detecting function  10  without adding any manufacturing process. 
     MODIFIED EXAMPLE 1-2 
     In the above-mentioned embodiment, as shown in  FIGS. 17A to 17G , the control unit  11  changes the control signal CTLH from a low level to a high level at time t 2  at which the AC drive signal VcomAC is changed from a low level to a high level and changes the control signal CTLL from a low level to a high level at time t 3  at which the AC drive signal VcomAC is changed from a high level to a low level, but the embodiment of the present disclosure is not limited to this configuration. Alternatively, for example, as shown in  FIGS. 20A to 20G , the control signal CTLH may be changed from a low level to a high level before time t 2  and the control signal CTLL may be changed from a low level to a high level before time t 3 . 
     &lt;3. Second Embodiment&gt; 
     A display panel  7  according to a second embodiment of the present disclosure will be described below. In this embodiment, the capacitive elements CH and CL of the auxiliary driver unit are initialized by the use of a dedicated line. Substantially the same elements as in the display panel  1  according to the first embodiment are referenced by the same reference numerals and description thereof will not be repeated. 
       FIG. 21  shows a configuration example of the display panel  7  according to this embodiment. The display panel  7  includes a drive signal generating unit  75 , an auxiliary driver unit  78 , and a control unit  71 . 
     The drive signal generating unit  75  generates a DC drive signal VcomDC, an AC drive signal VcomAC 2 , and DC signals Vchl and Vcl 1 . The AC drive signal VcomAC 2  is a signal including a pulse Pt with a low-level voltage of 0 V and a high-level voltage of VH. That is, the AC drive signal VcomAC 2  is a signal including a pulse Pi unlike the AC drive signal VcomAC in the above-mentioned embodiment. The voltage of the DC signal Vchl is a voltage VH in this example, and the voltage of the DC signal Vcl 1  is 0 V in this example. That is, in this example, the voltage of the DC signal Vchl is the same as the high-level voltage of the AC drive signal VcomAC 2  and the voltage of the DC signal Vcl 1  is the same as the low-level voltage of the AC drive signal VcomAC 2 . The drive signal generating unit  75  supplies the DC signal Vchl to the auxiliary driver unit  78  via a dedicated line LH and supplies the DC signal Vcl 1  to the auxiliary driver unit  78  via a dedicated line LL. 
     The auxiliary driver unit  78  assists the driving operation of the drive signal generating unit  75 , similarly to the auxiliary driver unit  18  in the first embodiment. At this time, the auxiliary driver unit  78  initializes the capacitive elements CH and CL using the DC signals Vchl and Vcl 1  supplied from the drive signal generating unit  75  via the lines LH and LL. The control unit  71  supplies control signals CTL 2  (CTLH 2  and CTLL 2 ) to the auxiliary driver unit  78 . 
       FIG. 22  shows a configuration example of the auxiliary driver unit  78 . In the auxiliary driver unit  78 , one end of the capacitive element CH is connected to one end of the switch SWH and is also connected to the line LH. Similarly, one end of the capacitive element CL is connected to one end of the switch SWL and is also connected to the line LL. 
       FIGS. 23A to 23G  show timing waveform examples of a touch detecting operation in the display panel  7 , where  FIG. 23A  represents the waveform of the AC drive signal VcomAC 2  in the output of the drive signal generating unit  75 ,  FIG. 23B  represents the waveform of the Vcom selection signal VCOMSEL,  FIG. 23C  represents the waveform of the control signal CTLH 2 ,  FIG. 23D  represents eh waveform of the control signal CTLL 2 ,  FIG. 23E  represents the waveform of the voltage Vch of the capacitive element CH,  FIG. 23F  represents the waveform of the voltage Vcl of the capacitive element CL, and  FIG. 23G  represents the waveform of the drive signal Vcom supplied to the drive electrode block B as a target of the touch detecting operation. 
     In the auxiliary driver unit  78 , the capacitive element CH is normally supplied with the DC signal Vchl (voltage VH) via the line LH and the capacitive element CL is normally supplied with the DC signal Vcl 1  (0 V) via the line LL. Accordingly, the voltage Vch of the capacitive element CH is changed to the voltage VH when the control signal CTLH 2  is changed from a high level to a low level and the switch SWH is turned off as shown in  FIG. 23E , and the voltage Vcl of the capacitive element CL is changed to 0 V when the control signal CTLL 2  is changed from a high level to a low level and the switch SWL is turned off as shown in  FIG. 23F . 
     In this way, in the display panel  7 , since the capacitive elements CH and CL are initialized by normally supplying the DC signals Vchl and Vcl 1  to the capacitive elements CH and CL, it is possible to simplify the circuit operation. That is, in the first embodiment, the drive signal generating unit  15  generates the pulse Pi and the auxiliary driver unit  18  initializes the capacitive elements CH and CL on the basis of the pulse Pi and the control signal CTL supplied from the control unit  11 . However, in this embodiment, since the capacitive elements CH and CL are initialized on the basis of the DC signals Vchl and Vcl 1  normally supplied, it is possible to simplify the circuit operation for initialization. 
     In this way, in this embodiment, since the DC signals are normally supplied to the capacitive elements, it is possible to simplify the circuit operation of initializing the capacitive elements. The other advantages are the same as in the first embodiment. 
     Modified Example 2-1 
     Modified Examples 1-1 and 1-2 of the first embodiment may be applied to the display panel  7  according to the second embodiment. 
     Modified Example 2-2 
     Although it is stated in the above-mentioned embodiment that the voltage of the DC signal Vchl is set to be equal to the high-level voltage (the voltage VH) of the AC drive signal VcomAC 2  and the voltage of the DC signal Vcl 1  is set to be equal to the low-level voltage (0 V) of the AC drive signal VcomAC 2 , the embodiment of the present disclosure is not limited to this configuration and such voltages can be arbitrarily set. Specifically, For example, the voltage of the DC signal Vchl may be set to a voltage higher than the voltage VH and the voltage of the DC signal Vcl 1  may be set to a voltage lower than 0 V. 
     &lt;4. Third Embodiment&gt; 
     A display panel  8  according to a third embodiment will be described below. In this embodiment, in the auxiliary driver unit  78  according to the second embodiment, a switch is disposed between the line LH and the capacitive element CH and a switch is disposed between the line LL and the capacitive element CL similarly. Substantially the same elements as in the display panel  7  according to the second embodiment will be referenced by the same reference numerals and description thereof will not be repeated. 
     The display panel  8  includes an auxiliary driver unit  88  as shown in  FIG. 21 . In this example, the voltage of the DC signal Vchl generated by the drive signal generating unit  75  is a voltage VH 2  which is higher than the voltage VH and the voltage of the DC signal Vcl 1  is a voltage VL 2  which is lower than 0 V. 
       FIG. 24  shows a configuration example of the auxiliary driver unit  88  according to this embodiment. The auxiliary driver unit  88  includes inverters IVH and IVL and switches SWH 2  and SWL 2 . The inverter IVH generates and outputs the inverted logic of a control signal CTLH 2 . The ON and OFF states of the switch SWH 2  are controlled on the basis of the output signal of the inverter IVH, one end thereof is connected to one end of the capacitive element CH, and the other end thereof is connected to the line LH. The inverter IVL generates and outputs the inverted logic of a control signal CTLL 2 . The ON and OFF states of the switch SWL 2  are controlled on the basis of the output signal of the inverter IVL, one end thereof is connected to one end of the capacitive element CL, and the other end thereof is connected to the line LL. 
     According to this configuration, in the auxiliary driver unit  88 , one end of the capacitive element CH is connected to the line LAC when the control signal CTLH 2  is at a high level, and is connected to the line LH when the control signal CTLH 2  is at a low level. Similarly, one end of the capacitive element CL is connected to the line LAC when the control signal CTLL 2  is at a high level, and is connected to the line LL when the control signal CTLL 2  is at a low level. 
     Here, the switches SWH 2  and SWL 2  correspond to a specific example of the “voltage supply switch” in the embodiment of the present disclosure. 
       FIGS. 25A to 25G  show timing waveform examples of a touch detecting operation in the display panel  8 , where  FIG. 25A  represents the waveform of the AC drive signal VcomAC 2  in the output of the drive signal generating unit  75 ,  FIG. 25B  represents the waveform of the Vcom selection signal VCOMSEL,  FIG. 25C  represents the waveform of the control signal CTLH 2 ,  FIG. 25D  represents eh waveform of the control signal CTLL 2 ,  FIG. 25E  represents the waveform of the voltage Vch of the capacitive element CH,  FIG. 25F  represents the waveform of the voltage Vcl of the capacitive element CL, and  FIG. 25G  represents the waveform of the drive signal Vcom supplied to the drive electrode block B as a target of the touch detecting operation. 
     In the auxiliary driver unit  88 , in the period in which the control signal CTLH 2  is at a low level, the switch SWH 2  is turned on and the voltage Vch of the capacitive element CH is initialized to be a voltage VH 2  ( FIG. 25E ). In the period in which the control signal CTLH 2  is at a high level, similarly to the second embodiment or the like, the switch SWH is turned on and electric charges are exchanged between the capacitive element CH and the drive electrode block B. Similarly, in the auxiliary driver unit  88 , in the period in which the control signal CTLL 2  is at a low level, the switch SWL 2  is turned on and the voltage Vcl of the capacitive element CL is initialized to be a voltage VL 2  ( FIG. 25F ). In the period in which the control signal CTLL 2  is at a high level, the switch SWL is turned on and electric charges are exchanged between the capacitive element CL and the drive electrode block B. That is, when the control signals CTLH 2  and CTLL 2  are at a high level, the display panel  8  operates so that the voltage (the drive signal Vcom) of the drive electrodes COML is changed for a short time by so-called overdrive. 
     In the display panel  8 , in order to achieve the overdrive effect, the drive signal generating unit  75  generates a voltage VH 2  higher than the voltage VH and supplies the generated voltage as the DC signal Vchl to the auxiliary driver unit  88 , and generates a voltage VL 2  lower than 0 V and supplies the generated voltage as the DC signal Vcl 1  to the auxiliary driver unit  88 . In the auxiliary driver unit  88 , the switches SWH and SWH 2  work complementarily and the switches SWL and SWL 2  work complementarily. Accordingly, in the display panel  8 , since the line LAC and the line LH are not directly connected to each other and the line LAC and the line LL are not directly connected to each other, it is possible to reduce the possibility in which the circuit operation is unstable. 
     As described above, in this embodiment, since the switch SWH 2  working to be complementary to the switch SWH is provided and the switch SWL 2  working to be complementary to the switch SWL is provided, it is possible to reduce the possibility in which the circuit operation is unstable. The other advantages are the same as in the second embodiment. 
     Modified Example 3-1 
     Although it is described in the above-mentioned embodiment that the voltage of the DC signal Vchl is set to a voltage VH 2  higher than the voltage VH and the voltage of the DC signal Vcl 1  is set to a voltage VL 2  lower than 0 V, the embodiment of the present disclosure is not limited to this configuration and, for example, the voltage of the DC signal Vchl may be set to a voltage VH and the voltage of the DC signal Vcl 1  may be set to 0 V. 
     &lt;5. Application Examples&gt; 
     Application examples of the display panel described in the above-mentioned embodiments and modified examples will be described below. 
       FIG. 26  shows the appearance of a television set to which the display panel according to the above-mentioned embodiments is applied. The television set includes, for example, includes an image display screen unit  510  including a front panel  511  and a filter glass  512 . The image display screen unit  510  is constructed by the display panel according to the above-mentioned embodiments or the like. 
     The display panel according to the above-mentioned embodiments or the like can be applied to electronic apparatuses in all the fields such as portable terminals such as a digital camera, a notebook personal computer, and a mobile phone, portable game machines, and video cameras, in addition to the television set. In other words, the display panel according to the above-mentioned embodiments or the like can be applied to electronic apparatuses of all the fields displaying an image. 
     Although the present disclosure is described above with reference to several embodiments, modified examples thereof, and application examples of the electronic apparatus, the present disclosure is not limited to the embodiments and the like and can be modified in various forms. 
     For example, in the above-mentioned embodiments and the like, the configuration of the capacitive element CH and the configuration of the capacitive element CL in each auxiliary driver unit  18 ,  78 , or  88  are set to be equal to each other, but the present disclosure is not limited to this configuration. An example thereof will be described below in detail. 
       FIG. 27  shows a configuration example of a display panel  7 B according to this modified example. The display panel  7 B includes a drive signal generating unit  75 B, an auxiliary driver unit  78 B, and a control unit  71 B. The drive signal generating unit  75 B generates a DC drive signal VcomDC, and AC drive signal VcomAC 2 , and a DC signal Vchl. That is, the drive signal generating unit  75 B does not generate the voltage Vcl 1 , unlike the drive signal generating unit  75  according to the second embodiment. Similarly to the auxiliary driver unit  78  according to the second embodiment, the auxiliary driver unit  78 B assists the driving operation of the drive signal generating unit  75 B. At this time, the auxiliary driver unit  78 B initializes the capacitive element CH using the DC signal Vchl supplied from the drive signal generating unit  75 B. The control unit  71 B supplies control signals CTLH 2  and CTLL to the auxiliary driver unit  78 B. 
       FIG. 28  shows a configuration example of the auxiliary driver unit  78 B. In the auxiliary driver unit  78 B, one end of the capacitive element CH is connected to one end of the switch SWH and is also connected to the line LH. On the other hand, one end of the capacitive element CL is connected to only one end of the switch SWL. That is, in the auxiliary driver unit  78 B, the configuration of the capacitive element CH is different from the configuration of the capacitive element CL. Specifically, the auxiliary driver unit  78 B combines the configuration ( FIG. 22 ) of the capacitive element CH in the auxiliary driver unit  78  according to the second embodiment and the configuration ( FIG. 13 ) of the capacitive element CL in the auxiliary driver unit  18 . 
       FIGS. 29A to 29G  show a timing waveform example of a touch detecting operation in the display panel according to this modified example, where  FIG. 29A  represents the waveform of the AC drive signal VcomAC 2  in the output of the drive signal generating unit  75 B,  FIG. 29B  represents the waveform of the Vcom selection signal VCOMSEL,  FIG. 29C  represents the waveform of the control signal CTLH 2 ,  FIG. 29D  represents eh waveform of the control signal CTLL 2 ,  FIG. 29E  represents the waveform of the voltage Vch of the capacitive element CH,  FIG. 29F  represents the waveform of the voltage Vcl of the capacitive element CL, and  FIG. 29G  represents the waveform of the drive signal Vcom supplied to the drive electrode block B as a target of the touch detecting operation. In the auxiliary driver unit  78 B, the capacitive element CH is initialized by being normally supplied with the DC signal Vchl (the voltage VH) via the line LH, similarly to the auxiliary driver unit  78  according to the second embodiment, and the capacitive element CL is initialized by being supplied with 0 V via the line LAC in a predetermined period started from time t 8 , similarly to the auxiliary driver unit  18  according to the first embodiment. 
     By employing this configuration, it is possible to reduce the space for the line LL, compared with the display panel  7  according to the second embodiment, and it is possible to simplify the circuit operation of initializing the capacitive elements CH and CL, compared with the display panel  1  according to the first embodiment. 
     For example, in the above-mentioned embodiments and the like, as shown in  FIG. 6 , the drive electrodes COML are formed on the TFT substrate  21  and the pixel electrodes  22  are formed thereon with the insulating layer  23  interposed therebetween, but the present disclosure is not limited to this configuration. For example, the pixel electrode  22  may be formed on the TFT substrate  21  and the drive electrodes COML may be formed thereon with the insulating layer  23  interposed therebetween. 
     For example, in the above-mentioned embodiments and the like, the liquid crystal display device using liquid crystal of a transverse electric field mode such as FFS or IPS and the touch detecting device are incorporated into a body. However, a liquid crystal display device using liquid crystal of various modes such as TN (Twisted Nematic), VA (Vertically Aligned), and ECB (Electric field Controlled Birefringence) and a touch detecting device may be incorporated into a body. When such liquid crystal is used, the display device with a touch detecting function can be constructed as shown in  FIG. 30 .  FIG. 35  shows an example of a partial sectional structure of a display device with a touch detecting function  10 D according to this modified example and shows a state where a liquid crystal layer  6 B is interposed between a pixel substrate  2 B and a counter substrate  3 B. Names or functions of the other elements are the same as shown in  FIG. 6  and description thereof will not be repeated. In this example, unlike the configuration shown in  FIG. 6 , the drive electrodes COML used both for display and for touch detection are formed on the counter substrate  3 B. 
     For example, in the above-mentioned embodiments, the liquid crystal display device and the capacitance type touch detecting device are incorporated into a body to construct a so-called in-cell type, but the present disclosure is not limited to this configuration. For example, a so-called on-cell type may be employed in which a capacitance type touch detecting device is formed on the surface of a liquid crystal display device. In the on-cell type, for example, when noise of a display driving operation propagates from the liquid crystal display device to the touch detecting device, the noise can be reduced by driving the display panel as described in the above-mentioned embodiments, and it is thus possible to suppress the lowering of the touch detection accuracy. 
     For example, in the above-mentioned embodiments, the display device employs the liquid crystal device, but the present disclosure is not limited to this configuration. For example, EL (Electroluminescence) device may be employed. 
     The present disclosure may be implemented as the following configurations. 
     (1) A display panel including: display elements; a plurality of drive electrodes; one or more touch detecting electrodes that form a capacitor along with the corresponding drive electrode; a main driver unit that generates a basic drive signal including a pulse part supplied to the drive electrodes; and a first auxiliary driver unit that includes a capacitive element and that exchanges electric charges between the capacitive element and the drive electrodes in synchronization with the pulse part. 
     (2) The display panel according to (1), wherein the first auxiliary driver unit further includes a first switch that controls the exchange of electric charges between the capacitive element and the drive electrode, wherein the pulse part changes between two voltage levels, and wherein the first switch is turned on at the time corresponding to the rising or falling of the pulse part. 
     (3) The display panel according to (2), wherein the pulse part changes from a voltage of a first level to a voltage of a second level, and wherein the capacitive element is set to a voltage of a third level previously determined depending on the voltage of the second level in a period in which the first switch is turned off. 
     (4) The display panel according to (3), wherein the basic drive signal includes a DC part which is maintained at the voltage of the third level in a period other than the period in which the pulse part appears, and wherein the first switch is also turned on in the period in which the DC part appears in the basic drive signal. 
     (5) The display panel according to (3), further including a voltage supply unit that generates and supplies the voltage of the third level to the capacitive element. 
     (6) The display panel according to (3), further including a voltage generating unit that generates the voltage of the third level, wherein the first auxiliary driver unit further includes a voltage supply switch that controls the supply of the voltage of the third level, which is generated by the voltage generating unit, to the capacitive element. 
     (7) The display panel according to (6), wherein the voltage supply switch is turned on in a period in which the first switch is turned off. 
     (8) The display panel according to any one of (3) to (7), wherein the voltage of the third level is at the same voltage level as the voltage of the second level. 
     (9) The display panel according to any one of (3) to (7), wherein the voltage of the third level is higher than the voltage of the second level when the voltage of the second level is higher than the voltage of the first level, and is lower than the voltage of the second level when the voltage of the second level is lower than the voltage of the first level. 
     (10) The display panel according to any one of (2) to (9), wherein the first switch is turned on at the same time as or just before the rising of the pulse part or at the same time as or just before the falling of the pulse part. 
     (11) The display panel according to any one of (1) to (10), wherein the plurality of drive electrodes are formed to extend in a predetermined direction and are arranged to be perpendicular to the predetermined direction, wherein the main driver unit is disposed in the vicinity of the drive electrode which is disposed at one end of each of the plurality of drive electrodes, and wherein the first auxiliary drive unit is disposed in the vicinity of the drive electrode which is disposed at the other end thereof. 
     (12) The display panel according to any one of (1) to (11), further including a scanning unit that supplies the pulse part of the basic drive signal to the plurality of drive electrodes at every predetermined number of drive electrodes, wherein the capacitance value of the capacitive element is less than or equal to ten times the capacitance value of the predetermined number of drive electrodes. 
     (13) The display panel according to any one of (1) to (12), further including a second auxiliary driver unit that includes a capacitive element and a second switch controlling exchange of electric charges between the capacitive element and the drive electrodes, wherein the second switch is turned on at the time other than the time at which the first switch is turned on out of the rising time and the falling time of the pulse part. 
     (14) The display panel according to any one of (1) to (13), wherein each display element includes a liquid crystal layer, and a pixel electrode that is formed between the liquid crystal layer and the corresponding drive electrode or is formed to face the liquid crystal layer with the corresponding drive electrode interposed therebetween. 
     (15) The display panel according to (14), wherein the capacitive element includes an electrode formed in the same layer as the drive electrodes and an electrode formed in the same layer as the pixel electrodes. 
     (16) The display panel according to (14) or (15), wherein each display element further includes a pixel transistor, and wherein the capacitive element includes an electrode formed in the same layer as the gate electrode of the pixel transistor. 
     (17) The display panel according to any one of (1) to (13), wherein each display element includes a liquid crystal layer, and a pixel electrode that is disposed to face the corresponding drive electrode with the liquid crystal layer interposed therebetween. 
     (18) A driver circuit including a capacitive element, wherein electric charges are exchanged between the capacitive element and a drive electrode in synchronization with a pulse part, which is supplied to the drive electrode, of a basic drive signal. 
     (19) A driving method of supplying a pulse part of a basic drive signal to a drive electrode and exchanging electric charges between a capacitive element and the drive electrode in synchronization with the pulse part. 
     (20) An electronic apparatus including: a display panel; and a control unit that controls an operation of the display panel, wherein the display panel includes display elements, a plurality of drive electrodes, one or more touch detecting electrodes that form a capacitor along with the corresponding drive electrode, a main driver unit that generates a basic drive signal including a pulse part supplied to the drive electrodes, and a first auxiliary driver unit that includes a capacitive element and that exchanges electric charges between the capacitive element and the drive electrodes in synchronization with the pulse part. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.