Patent Publication Number: US-2016240160-A1

Title: Electro-optical device, driving method of electro-optical device, and electronic apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to an electro-optical device such as a liquid crystal device, for example, a driving method of the electro-optical device, and a technical field of an electronic apparatus such as a liquid crystal projector, for example, which is configured of the electro-optical device. 
     BACKGROUND ART 
     In a high resolution display which is referred to as 2K1K, since an influence of a transverse electric field which occurs between pixels is high, and it is not possible to adopt an H-line inversion driving system in which a polarity of a pixel electrode potential is inverted in each one line of pixel, a frame inversion driving system in which a polarity of a pixel electrode potential is inversed in each frame is adopted. In a general frame inversion driving system, a frame frequency of 60 Hz is used, however, when the frame frequency of 60 Hz is used in the high resolution display which is referred to as 2K1K, an influence of a flicker becomes high. Therefore, in the high resolution display which is referred to as 2K1K, double speed driving of which a frame frequency is 120 Hz is adopted. 
     However, when the double speed driving is adopted, there is a problem in that a selection period of one signal line becomes short, a problem occurs in writing of a display data signal with respect to a pixel, and an image quality deteriorates. Therefore, in the related art, the selection time is set not to be short, for example, by using four or six driving ICs, and by driving two or three driving ICs by sharing the ICs in both the horizontal direction and the vertical direction (for example, refer to PTL 1, PTL 2, and PTL 3). 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: JP-A-2012-194326 
         PTL 2: JP-A-2000-242194 
         PTL 3: JP-A-2009-168849 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, when four or six driving ICs are used, there is a problem in that a manufacturing cost increases. In addition, when the four or six driving ICs are used, it is necessary to perform wiring of two signal lines per one pixel row, and a structure of the pixel becomes complicated. When the driving IC is not increased, there is a problem in that a selection period of one signal line becomes short, a trouble occurs in writing of a display data signal with respect to a pixel, and an image quality deteriorates. 
     It is an object of the invention to provide an electro-optical device which can prevent deterioration of an image without making a pixel structure complicated, and without increasing a manufacturing cost, a driving method of the electro-optical device, and an electronic apparatus which includes the electro-optical device. 
     Solution to Problem 
     According to an aspect of the invention, in order to solve the object, there is provided an electro-optical device which includes a plurality of scanning lines; a plurality of signal lines; a pixel which is provided so as to correspond to each intersection of the plurality of scanning lines and the plurality of signal lines; a scanning line driving unit which supplies a scanning signal to a scanning line; a signal line driving unit which supplies an image signal in which a data voltage with at least a size which corresponds to a grayscale to be displayed is subjected to time division multiplexing to the pixel through the signal line; a signal line selection unit which selects the signal line which supplies the image signal according to a control signal; and a control unit which selects another signal line while selecting one of the signal lines, and outputs the control signal so that an overlapping period occurs at a part of the selection period of the signal line, in which the pixel includes a pixel electrode, a common electrode, a liquid crystal which is interposed between the pixel electrode and the common electrode, and a switching element which is provided between the pixel electrode and the signal line, and is controlled so as to be either an ON state or an OFF state based on a scanning signal which is supplied through the scanning line. 
     According to the aspect, a scanning signal is supplied to a scanning line using a scanning line driving unit, and an image signal of which a data voltage with at least a size corresponding to a grayscale to be displayed is subjected to time division multiplexing is supplied to a pixel through the signal line. At this time, the signal line which supplies an image signal is selected using the signal line selection unit according to a control signal, however, in the control unit, another signal line is selected while one signal line is selected, and the control signal is output so that an overlapping period occurs at a part of the selection period of the signal line. Accordingly, it is possible to sufficiently secure a writing time of the data voltage with respect to a pixel, and to improve an image quality, since the overlapping period occurs at a part of the selection period of the signal line for writing the data voltage, even when the writing period of the data voltage per pixel becomes short due to high resolution. 
     In the electro-optical device, the control unit may output the control signal which selects the signal line at timing earlier than timing which is synchronized with an individual data voltage of the image signal which is subjected to time division multiplexing. According to the aspect, it is possible to sufficiently secure a writing time of the data voltage with respect to a pixel, and to improve an image quality. 
     In the electro-optical device, the signal line driving unit may supply a precharge voltage to the signal line at least in a precharge period before supplying the data voltage to the pixel, and the control unit may output the control signal which selects all of the signal lines in the precharge period. According to the aspect, it is possible to prevent uneven luminance, or a vertical cross talk by preventing an influence of leaking from a pixel. 
     In the electro-optical device, the scanning line driving unit may supply the scanning signal which causes the switching element to be in ON state to the scanning line in the precharge period. According to the aspect, it is possible to prevent uneven luminance, or a vertical cross talk by preventing the influence of leaking from the pixel. 
     In the electro-optical device, the signal line driving unit may output the control signal which selects the signal line which is firstly selected, in the entire period of the precharge period and the selection period of the signal line which is firstly selected in one horizontal scanning period. According to the aspect, it is possible to prevent uneven luminance, or a vertical cross talk by preventing the influence of leaking from the pixel due to writing of the precharge voltage with respect to the signal line, to sufficiently secure writing time of a data voltage with respect to a pixel, and to improve an image quality. 
     In the electro-optical device, the signal line driving unit may frequently change selection order of the signal line using the control signal. According to the aspect, it is possible to make an influence on a pixel corresponding to a signal line which is selected later uniform, using a data voltage of a pixel corresponding to a signal line which is selected in advance, among signal lines which are selected during the overlapping period. 
     According to another aspect of the invention, there is provided a control method of an electro-optical device which includes a plurality of scanning lines, a plurality of signal lines, a pixel which is provided so as to correspond to each intersection of the plurality of scanning lines and the plurality of signal lines, in which the pixel includes a pixel electrode, a common electrode, a liquid crystal which is interposed between the pixel electrode and the common electrode, and a switching element which is provided between the pixel electrode and the signal line, and is controlled so as to be in either ON state or OFF state based on a scanning signal which is supplied through the scanning line, the method including supplying the scanning signal to the scanning line; supplying an image signal in which a data voltage with at least a size which corresponds to a grayscale to be displayed is subjected to time division multiplexing to the pixel through the signal line; selecting the signal line which supplies the image signal according to a control signal; selecting another signal line while selecting one of the signal lines; and outputting the control signal so that an overlapping period occurs at a part of a selection period of the signal line. 
     According to still another aspect of the invention, there is provided an electronic apparatus which includes the electro-optical device according to the aspect of the invention. Such an electronic apparatus can sufficiently secure a writing time of a data voltage with respect to a pixel, and to improve an image quality in a display device such as a liquid crystal display since an overlapping period occurs at a part of a selection period of a signal line for writing a data voltage, even when the writing time of the data voltage per pixel becomes short due to high resolution. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an explanatory diagram of an electro-optical device according to a first embodiment of the invention. 
         FIG. 2  is a block diagram which illustrates a configuration of the electro-optical device according to the embodiment. 
         FIG. 3  is a circuit diagram which illustrates a configuration of pixels. 
         FIG. 4  is a timing chart which illustrates operations of the electro-optical device according to the embodiment. 
         FIG. 5  is a timing chart which illustrates operations of an electro-optical device according to a second embodiment of the invention. 
         FIG. 6  is a timing chart which illustrates operations of an electro-optical device according to a third embodiment of the invention. 
         FIG. 7  is a timing chart which illustrates operations of an electro-optical device according to a modification example. 
         FIG. 8  is a timing chart which illustrates operations of an electro-optical device in the related art. 
         FIG. 9  is an explanatory diagram which illustrates an example of an electronic apparatus. 
         FIG. 10  is an explanatory diagram which illustrates another example of the electronic apparatus. 
         FIG. 11  is an explanatory diagram which illustrates another example of the electronic apparatus. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       FIG. 1  is a diagram which illustrates a configuration of a signal transmission system with respect to an electro-optical device  1 . As illustrated in  FIG. 1 , the electro-optical device  1  includes an electro-optical panel  100 , a driving integrated circuit  200 , and a flexible circuit board  300 , and the electro-optical panel  100  is connected to the flexible circuit board  300  on which the driving integrated circuit  200  is mounted. The electro-optical panel  100  is connected to a host CPU (not illustrated) through the flexible circuit board  300  from the host CPU, and the driving integrated circuit  200 . Here, the driving integrated circuit  200  is a unit which receives an image signal, and various control signals for controlling driving through the flexible circuit board  300 , and drives the electro-optical panel  100  through the flexible circuit board  300 . 
       FIG. 2  is a block diagram which illustrates configurations of the electro-optical panel  100 , and the driving integrated circuit  200 . As illustrated in  FIG. 2 , the electro-optical panel  100  includes a pixel unit  10 , a scanning line driving circuit  22  as a scanning line driving unit, and J demultiplexers  57 [ 1 ] to  57 [J] as a signal line selection unit. The driving integrated circuit  200  includes a data line driving circuit  30  as a signal line driving unit, and a control circuit  40  as a control unit. 
     The pixel unit  10  is formed of M scanning lines  12  and N signal lines  14  which are intersecting each other (M and N are natural numbers). A plurality of pixel circuits PIX are provided by corresponding to intersections of each scanning line  12  and each signal line  14 , and are arranged in a matrix of vertical M rows x horizontal N columns. 
       FIG. 3  is a circuit diagram of each pixel circuit PIX. As illustrated in  FIG. 3 , each pixel circuit PIX includes a liquid crystal element  60  and a switching element SW such as a TFT. The liquid crystal element  60  is an electro-optical element which is configured of a pixel electrode  62  and a common electrode  64  which are facing each other, and a liquid crystal  66  therebetween. Transmittivity (display grayscale) of the liquid crystal  66  is changed according to an applied voltage between the pixel electrode  62  and the common electrode  64 . In addition, a configuration in which an auxiliary capacitor is connected to the liquid crystal element  60  in parallel can also be adopted. The switching element SW is configured of, for example, an N-channel transistor of which a gate is connected to the scanning line  12 , is provided between the liquid crystal element  60  and the signal line  14 , and controls an electrical connection therebetween (conduction/insulation). When a scanning signal Y[m] is set to a selection potential, a switching element SW in each pixel circuit PIX on the mth row transits to an ON state simultaneously. 
     When a scanning line  12  corresponding to a pixel circuit PIX is selected, and a switching element SW of the pixel circuit PIX is controlled to enter the ON state, a voltage corresponding to an image signal D[n] which is supplied to the pixel circuit PIX is applied to the liquid crystal element  60  of the pixel circuit PIX from the signal line  14 , and a liquid crystal  66  of the pixel circuit PIX is set so as to have transmittivity corresponding to the image signal D[n]. In addition, when a light source (not illustrated) enters an ON (lighting) state, and light is emitted from the light source, the light penetrates the liquid crystal  66  of the liquid crystal element  60  which is included in the pixel circuit PIX, and proceeds to a viewer side. That is, when a voltage corresponding to the image signal D[n] is applied to the liquid crystal element  60 , and the light source enters the ON state, the pixel corresponding to the pixel circuit PIX displays a grayscale corresponding to the image signal D[n]. 
     When the switching element SW enters the OFF state, after the voltage corresponding to the image signal D[n] is applied to the liquid crystal element  60  of the pixel circuit PIX, ideally, an applied voltage corresponding to the image signal D[n] is maintained. Accordingly, ideally, each pixel displays a grayscale corresponding to the image signal D[n] in a period between the ON state and the subsequent ON state of the switching element SW. 
     As illustrated in  FIG. 3 , a capacitance Ca is parasitic on the signal line  14  and the pixel electrode  62  therebetween (or between signal line  14  and wiring which electrically connects pixel electrode  62  and switching element SW). For this reason, there is a case in which a potential fluctuation of the signal line  14  is propagated to the pixel electrode  62  through the capacitance Ca, and the applied voltage of the liquid crystal element  60  fluctuates while the switching element SW is OFF state. 
     In addition, a common voltage LCCOM which is a constant voltage is supplied to the common electrode  64  through a common line (not illustrated). As the common voltage LCCOM, a voltage of approximately −0.5 V is used when setting a center voltage of the image signal D[n] to 0 V. The voltage value is determined depending on a property such as the switching element SW. 
     According to the embodiment, in order to prevent so-called a burn-in, a polarity inversion driving in which a polarity of a voltage which is applied to the liquid crystal element  60  is inversed at a predetermined period is adopted. In the example, a level of the image signal D[n] which is supplied to the pixel circuit PIX through the signal line  14  is inversed in each unit period with respect to a center voltage of the image signal D[n]. The unit period is a period of one unit of an operation in which the pixel circuit PIX is driven. In the example, the unit period is set to a vertical scanning period. However, the unit period can be arbitrarily set, and for example, may be times of a natural number of the vertical scanning period. According to the embodiment, a case in which the image signal D[n] becomes a high voltage with respect to the center voltage of the image signal D[n] is set to a positive polarity, and a case in which the image signal D[n] becomes a low voltage with respect to the center voltage of the image signal D[n] is set to a negative polarity. 
     Returning to descriptions in  FIG. 2 , the control circuit  40  synchronously controls the scanning line driving circuit  22  and the data line driving circuit  30  based on an external signal such as a vertical synchronization signal Vs, a horizontal synchronization signal Hs, a dot clock signal DCLK, or the like, which is input from an external device (not illustrated). The scanning line driving circuit  22  and the data line driving circuit  30  control a display of the pixel unit  10  by mutually cooperating, under the synchronous control. 
     The scanning line driving circuit  22  outputs scanning signals G[ 1 ] to G[M] to each of M scanning lines  12 . The scanning line driving circuit  22  sequentially sets the scanning signals G[ 1 ] to G[M] with respect to each scanning line  12  to active levels by one horizontal scanning period H according to an output of a horizontal synchronization signal Hs from the control circuit  40 . 
     Here, in a period in which the scanning signal G[M] corresponding to the mth row is in the active level, and a scanning line corresponding to the row is selected, each switching element SW of N pixel circuits PIX of the mth row enters the ON state, and each of the N signal lines  14  is connected to each pixel electrode  62  of the N pixel circuits PIX of the mth row through each of the switching elements SW. 
     The N signal lines  14  in the pixel unit  10  are divided into J wiring blocks B[ 1 ] to B[J] by setting four signal lines which are neighboring to be a unit (J=N/4). Each of the demultiplexers  57 [ 1 ] to  57 [J] corresponds to the J wiring blocks B[ 1 ] to B[J]. 
     Each of the demultiplexers  57 [j] (j=1 to J) is configured of four switches  58 [ 1 ] to  58 [ 4 ]. In each of the demultiplexers  57 [j] (j=l to J), a contact point on one side of each of the four switches  58 [ 1 ] to  58 [ 4 ] is commonly connected. In addition, each of the common connection points of the contact point on one side of the four switches  58 [ 1 ] to  58 [ 4 ] of each of the demultiplexers  57 [j] (j=1 to J) is respectively connected to the J signal lines  15 . The J signal lines  15  are connected to the data line driving circuit  30  of the driving integrated circuit  200  through the flexible circuit board  300 . In addition, in each of the demultiplexers  57 [j] (j=1 to J), each contact point on the other side of the four switches  58 [ 1 ] to  58 [ 4 ] is connected to the four signal lines  14  which configure the wiring block B[j] corresponding to the demultiplexers  57 [j]. 
     The ON/OFF of four switches  58 [ 1 ] to  58 [ 4 ] of each of demultiplexers  57 [j] (j=1 to J) is respectively switched by four selection signals S 1  to S 4 . The four selection signals S 1  to S 4  are supplied from the control circuit  40  of the driving integrated circuit  200  through the flexible circuit board  300 . Here, when one selection signal S 1  is at the active level, and the other three selection signals S 2  to S 4  are at a non-active level, only the switch  58 [ 1 ] of J switches which respectively belong to the demultiplexers  57 [j] (j=1 to J) enters the ON state. Accordingly, each of the demultiplexers  57 [j] (j=1 to J) respectively outputs the image signals D[ 1 ] to D[J] on the J signal lines  15  to the first signal line  14  of each of wiring blocks B[ 1 ] to B[J]. Hereinafter, similarly, the image signals D[ 1 ] to D[J] on the J signal lines  15  are respectively output to the second, third, and fourth signal line  14  of each of the wiring blocks B[ 1 ] to B[J]. 
     The control circuit  40  has a frame memory, includes at least a memory space of M×N bits corresponding to resolution of the pixel unit  10 , and stores and maintains display data which is input from an external device in a frame unit. Here, the display data which defines the grayscale of the pixel unit  10  is data of 64 grayscales which is configured of 6 bits, as an example. The display data which is read from the frame memory is transferred to the data line driving circuit  30  serially as the display data through a bus of 6 bits. In addition, a precharge signal which will be described later is also included in the display data. 
     In addition, the control circuit  40  may also have a configuration in which a line memory of at least one line is included. In this case, the display data is transferred to each pixel by accumulating display data of one line in the line memory. 
     The data line driving circuit  30  outputs data to be supplied in each pixel row which is a writing target of data to the signal line  14  in cooperation with the scanning line driving circuit  22 . The data line driving circuit  30  generates latch signals based on the selection signals S 1  to S 4  which are output from the control circuit  40 , and sequentially latches display data signals of 6 bits of N which are supplied as serial data. The display data signals are made into a group of four pixels as time sequential data. In addition, the data line driving circuit  30  is provided with a digital to analog (D/A) conversion circuit, performs D/A conversion with respect to the digital data group, and generates a voltage as analog data. In this manner, the precharge signal is converted into a predetermined precharge voltage Vpre, and also a display data signal which is a time sequential signal in unit of 4 pixels is converted into a predetermined data voltage. In addition, a set of the precharge voltage and a data voltage of four pixels is supplied to each of the signal lines  15  in this order. 
     The electrical connection of each of switches  58 [ 1 ] to  58 [ 4 ] of the demultiplexers  57 [j] (j=l to J) is controlled by the selection signals S 1  to S 4  which are output from the control circuit  40 , and the switches enter the ON state at predetermined timing. In this manner, in 1H, the set of the precharge voltage and the data voltage of four pixels which is supplied to each signal line  15  is time sequentially output to the signal line  14  using the switches  58 [ 1 ] to  58 [ 4 ]. 
     Hitherto is the configuration of the electro-optical device  1 . 
       FIG. 4  illustrates a timing chart of the driving integrated circuit  200 . When the horizontal synchronization signal Hs is input to the control circuit  40  from an external device, the control circuit  40  drives the scanning line driving circuit  22  in synchronization with the horizontal synchronization signal Hs. The scanning line driving circuit  22  generates scanning signals G[ 1 ], G[ 2 ], . . . , G[n] by performing the sequential shift with respect to signals corresponding to a Y transfer start pulse DY of one frame (1F) cycle according to a Y clock signal CLY. The scanning signals G[ 1 ], G[ 2 ], . . . , G[n] become sequentially active in each horizontal scanning period (1H). The data line driving circuit  30  generates sampling pulses SP 1 , SP 2 , . . . , SPz (not illustrated) based on an X transfer start pulse DX (not illustrated) of a horizontal scanning cycle, and an X clock signal CLX (not illustrated). In addition, the data line driving circuit  30  generates the image signals D[ 1 ] to D[j] by performing sampling with respect to image signals VID 1  to VIDj (not illustrated) using the sampling pulses SP 1 , SP 2 , . . . , SPz (not illustrated). 
     The control circuit  40  outputs the selection signals S 1  to S 4  to the data line driving circuit  30  and the four switches  58 [ 1 ] to  58 [ 4 ] of the demultiplexers  57 [j] (j=1 to J) in synchronization with the horizontal synchronization signal Hs. The data line driving circuit  30  outputs the image signals D[ 1 ] to D[j] from output terminals d 1  to dj to the signal lines  15 . The four switches  58 [ 1 ] to  58 [ 4 ] of the demultiplexers  57 [ j ] (j=1 to J) enter the ON/OFF state based on the selection signals S 1  to S 4 , and the image signals D[ 1 ] to D[j] which include the precharge signals are respectively output to the signal lines  14 . 
     The control circuit  40  makes the selection signals S 1  to S 4  active at the same time, in timing t 1  after a predetermined time from timing t 0  at which the scanning signal G[ 1 ] becomes active, and maintains the active state of the selection signals S 1  to S 4  over a period T 0 . At this time, since the image signals D[ 1 ] to D[j] are set to the precharge voltage Vpre, the precharge voltage Vpre is written in the signal line  14  and the pixel. 
     The control circuit  40  makes the selection signal S 1  active in timing t 3  after a predetermined time, after making the selection signals S 1  to S 4  non-active at timing t 2 . In the related art, as illustrated in  FIG. 8 , the selection signal S 1  is made to be active at timing t 4  which is later than the timing t 3 , however, according to the embodiment, the selection signal S 1  is made to be active at the timing t 3  which is earlier than the timing t 4 . As a result, a period in which the selection signal S 1  becomes active is longer than a period T 10  in the related art which is illustrated in  FIG. 8 , and becomes the period T 1  as illustrated in  FIG. 4 . 
     Similarly, the control circuit  40  makes the selection signal S 1  non-active at timing t 5 , however, the selection signal S 2  is made to be active at the timing t 4  which is earlier than the timing t 5  by a predetermined time. In the related art, as illustrated in  FIG. 8 , the selection signal S 2  is made to be active at the timing t 5  which is later than the timing t 4 , however, according to the embodiment, the selection signal S 2  is made to be active at the timing t 4  which is earlier than the timing t 5 . As a result, a period in which the selection signal S 2  becomes active is longer than a period T 11  in the related art which is illustrated in  FIG. 8 , and the period becomes a period T 3  as illustrated in  FIG. 4 . In addition, since the selection signals S 1  and S 2  are controlled in this manner, an overlapping period T 2  in which both the selection signals S 1  and S 2  become active is generated. 
     Hereinafter, similarly, since the control circuit  40  makes the selection signal S 3  active at the timing t 5 , a period in which the selection signal S 3  becomes active is longer than a period T 12  in the related art which is illustrated in  FIG. 8 , and the period becomes a period T 5  as illustrated in  FIG. 4 . As a result, an overlapping period T 4  in which both the selection signals S 2  and S 3  become active is generated. In addition, since the control circuit  40  makes the selection signal S 4  active at timing t 6 , a period in which the selection signal S 4  becomes active is longer than a period T 13  in the related art which is illustrated in  FIG. 8 , and the period becomes a period T 7  as illustrated in  FIG. 4 . As a result, an overlapping period T 6  in which both the selection signals S 3  and S 4  become active is generated. 
     As described above, according to the embodiment, since the selection signal is driven so as to provide the overlapping period in which the plurality of signal lines  14  are selected at the same time, while making the period in which the signal line  14  is selected longer than that in the related art, it is possible to sufficiently secure the application time of the image signal with respect to the pixel without increasing the data line driving circuit, even when resolution of the electro-optical panel  100  is set to be high. As a result, it is possible to improve the image quality of the electro-optical panel  100 . In particular, when a three-dimensional display (stereoscopic display) is performed in the electro-optical panel  100 , an application time of a pixel voltage to a pixel corresponding to one signal line  14  becomes short, however, it is possible to perform a three-dimensional display with high image quality by applying the embodiment. 
     According to the embodiment, when two signal lines  14  are selected at the same time in each of wiring blocks B[ 1 ] to B[J] in the overlapping period, a pixel corresponding to a signal line  14  which is selected later in time is influenced by a pixel voltage which is written in a pixel corresponding to a signal line  14  which is selected earlier in time. However, for example, when contrast is high as the case in which a pixel voltage with the lowest luminance is applied to the pixel corresponding to the signal line  14  which is selected earlier in time, and a pixel voltage with the highest luminance is applied to the pixel corresponding to the signal line  14  which is selected later in time, it is difficult to recognize the influence with naked eyes. In addition, since the same pixel voltage is applied to the entire pixel when a pixel voltage with intermediate luminance is applied to the entire pixel, there is no influence which is described above. Instead, the image quality is improved since the application time of the pixel voltage with respect to the entire pixel becomes long. 
     Second Embodiment 
     In the first embodiment, the example in which the scanning signals G[ 1 ], G[ 2 ], . . . , G[n] are made to be active at the timing t 0  which is a little earlier than the timing t 1  at which the precharge signal is applied has been described. However, according to the embodiment, as illustrated in  FIG. 5 , when applying the precharge signal, the scanning signals G[ 1 ], G[ 2 ], . . . , G[n] are made to be active at timing t 0 ′ which is a little earlier than the timing t 3  at which a firstly selected selection signal is made to be active, while making the scanning signals G[ 1 ], G[ 2 ], . . . , G[n] non-active. 
     The application of the precharge signal is performed in order to suppress display un-evenness which is influenced by a leak from a pixel transistor which is in the OFF state to the signal line  14 , and as in the embodiment, it is possible to suppress the leak of the pixel transistor even in OFF states of the scanning signals G[ 1 ], G[ 2 ], . . . , G[n] at a time of applying the precharge signal. 
     Also in the embodiment, since the selection signal is driven so that a period in which the selection signals S 1 , S 2 , S 3 , and S 4  are made to be active is set to be long compared to the related art, after making the scanning signals G[ 1 ], G[ 2 ], . . . , G[n] active at the timing t 0 ′, and the overlapping period for selecting the plurality of signal lines  14  at the same time is provided, it is possible to sufficiently secure the application time of the pixel voltage with respect to the pixel without increasing the data line driving circuit even when resolution of the electro-optical panel  100  is set to be high, and as a result, it is possible to improve the image quality of the electro-optical panel  100 . 
     Third Embodiment 
     In the first embodiment, the example in which the selection signals S 1 , S 2 , S 3 , and S 4  are made to be active at the timing t 1  in order to apply the precharge signal, the selection signal S 1  is made to be non-active once thereafter, and then the selection signal S 1  is made to be active in order to apply the image signal at the timing t 3  has been described. According to the embodiment, as illustrated in  FIG. 6 , the selection signals S 1 , S 2 , S 3 , and S 4  are made to be active at the timing t 1  in order to apply the precharge signal, the active state of the selection signal S 1  is continued as is thereafter, and then the selection signal S 1  is made to be non-active at the timing t 5 . 
     According to the embodiment, since the active state of the selection signal S 1  is continued from starting of the application time of the precharge signal to ending of the selection of the selection signal S 1  which is firstly selected, a period T 1 ′ in which the selection signal S 1  becomes active becomes longer than that in the first embodiment. As a result, it is possible to sufficiently secure the application time of the pixel voltage with respect to the pixel while reliably applying the precharge signal, and to improve the image quality of the electro-optical panel  100 . 
     Modification Example 
     The invention is not limited to each of the above described embodiments, and for example, it is possible to perform various modifications which will be described later. In addition, as a matter of course, each embodiment and each modification example may be appropriately combined. 
     (1) In the above described each embodiment, the example in which the selection signal S 1  is firstly made to be active, and then the selection signals S 2 , S 3 , and S 4  are made to be active in this order has been described, however, the invention is not limited to such an example. For example, as illustrated in  FIG. 7 , the selection signal S 4  is firstly made to be active, and then the selection signals S 1 , S 2 , and S 3  may be made to be active in this order. In this case, an overlapping period of the selection signal S 4  and the selection signal S 1  is set to T 2 , an overlapping period of the selection signal S 1  and the selection signal S 2  is set to T 4 , and an overlapping period of the selection signal S 2  and the selection signal S 3  is set to T 6 . Even in this case, it is possible to drive the selection signal so that the overlapping period for selecting the plurality of signal lines  14  at the same time is provided, while making a period for selecting the signal line  14  longer than that in the related art. In addition, the order of making the selection signal active may be any order. 
     In addition, a configuration in which order of making the selection signal active is switched in every horizontal scanning period, or switched in every vertical scanning period may be adopted. In addition, a combination in which the order of making the selection signal active is also switched in every vertical scanning period, while switching the order in every horizontal scanning period may be adopted. The switching of the order for making the selection signal active may be the order of the selection signal S 1 , S 2 , S 3 , and S 4  in the first horizontal scanning period, may be the order of the selection signal S 2 , S 3 , S 4 , and S 1  in the second horizontal scanning period, may be the order of the selection signal S 3 , S 4 , S 1 , and S 2  in the third horizontal scanning period, may be the order of the selection signal S 4 , S 1 , S 2 , and S 3  in the fourth horizontal scanning period, and may be a repetition of these on or after the fifth horizontal scanning period. 
     (2) The example in which the N signal lines  14  are divided into J wiring blocks B[ 1 ] to B[J] by setting four signal lines which are neighboring to be a unit has been described, however, the block of the signal line may not be four signal lines which are neighboring, and may be two lines, three lines, five lines, six lines, seven lines, eight lines, . . . , and n lines (n is natural number). 
     (3) In the above described embodiments, a liquid crystal has been adopted as an example of the electro-optical material, however, the invention can be applied to an electro-optical device in which an electro-optical material other than the liquid crystal is used. As the electro-optical material, there is a material of which an optical property such as transmittivity or luminance is changed according to a supply of an electrical signal (current signal or voltage signal). For example, similarly to the embodiment, it is possible to apply the invention to various electro-optical devices such as a display panel using an organic electroluminescence (EL), an inorganic EL, or light emitting element such as light emitting polymer, an electrophoretic display panel in which a microcapsule containing colored liquid and white particles which are dispersed in the liquid is used as an electro-optical material, a twisting ball display panel in which twisting balls which are painted in different colors in each region of which a polarity is different from each other are used as an electro-optical material, a toner display panel in which black toner is used as an electro-optical material, or a plasma display panel in which high pressure gas such as helium or neon is used as an electro-optical material. 
     Application Example 
     The invention can be used in various electronic apparatuses.  FIGS. 9 to 11  exemplify specific forms of electronic apparatuses as an application target of the invention. 
       FIG. 9  is a perspective view of a portable personal computer in which an electro-optical device is adopted. A personal computer  2000  includes an electro-optical device  1  which displays various images, and a main body  2010  in which a power switch  2001 , or a keyboard  2002  is provided. 
       FIG. 10  is a perspective view of a mobile phone. A mobile phone  3000  includes a plurality of operation buttons  3001 , scroll buttons  3002 , and an electro-optical device  1  which displays various images. A screen which is displayed on the electro-optical device  1  is scrolled when the scroll button  3002  is operated. The invention can also be applied to such a mobile phone. 
       FIG. 11  is a schematic diagram which illustrates a configuration of a projection type display device (three plate type projector)  4000  in which an electro-optical device is adopted. The projection type display device  4000  includes three electro-optical devices  1  ( 1 R,  1 G, and  1 B) which respectively correspond to display colors of R, G, and B which are different from each other. A lighting optical system  4001  supplies a red color component r to the electro-optical device  1 R, supplies a green color component g to the electro-optical device  1 G, and supplies a blue color component b to the electro-optical device  1 B among emission light beams from a lighting device (light source)  4002 . Each electro-optical device  1  functions as a light modulator (light bulb) which modulates each monochromatic light which is supplied from the lighting optical system  4001  according to a display image. A projection optical system  4003  projects emission light from each electro-optical device  1  to a projection surface  4004  by compositing the light. The invention can also be applied to such a liquid crystal projector. 
     In addition to the apparatuses exemplified in  FIGS. 1, 9, and 10 , as an electronic apparatus to which the invention can be applied, there is a mobile information terminal (Personal Digital Assistant (PDA)), a digital still camera, a television, a video camera, a car navigation device, a display for vehicle (instrument panel), an electronic organizer, electronic paper, a calculator, a word processor, a work station, a videophone, a POS terminal, a printer, a scanner, a copy machine, a video player, a device including a touch panel, or the like. 
     REFERENCE SIGNS LIST 
       1  Electro-optical device 
       10  Pixel unit 
       12  Scanning unit 
       14  Signal line 
       15  Signal line 
       22  Scanning line driving circuit 
       30  Data line driving circuit 
       40  Control circuit 
       57  Demultiplexer 
       58  Switch 
       60  Liquid crystal element 
       62  Pixel electrode 
       64  Common electrode 
       66  Liquid crystal 
       100  Electro-optical panel 
       200  Driving integrated circuit