JP2005227627A - Driving device for display device, display device, and method for driving display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device for a display device capable of reducing electric power consumption during standing by, and to provide a display device, and a method for driving the display device. <P>SOLUTION: The display device is provided with a scanning signal line driving circuit GD which outputs a scanning signal at a prescribed timing to a plurality of scanning signal lines GL, a data signal line driving circuit SD which outputs an image display data signal to a plurality of data signal lines SL, a multi-gradation display data signal generation circuit 20 which supplies a multi-gradation data signal DAT to the data signal line driving circuit SD, a binary display data signal generation circuit 30 which supplies a binary data signal BINDAT to the data signal line driving circuit SD, and a selector 10 which switches the outputs from the multi-gradation display data signal generation circuit 20 to the data signal line driving circuit SD and the outputs from the binary display data signal generation circuit 30 to the data signal line driving circuit SD. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drive device for a display device such as a liquid crystal display device, a display device, and a drive method for the display device.

  As one of conventional display devices, an active matrix drive type liquid crystal display device is known. By the way, in the conventional image display apparatus 100, as shown in FIG. 11, one set of the data signal line driving circuit 101 and the scanning signal line driving circuit 102 is generally arranged. Therefore, the format of the video to be displayed is often limited to one type. There are also image display devices that can display video in multiple formats, but they only convert control signals and video signals input to the display device by an external circuit, and the drive of the display device itself is almost the same. . In other words, in the case of displaying video in any format, the same data signal line driving circuit and scanning signal line driving circuit operate, so that the power consumption hardly changes. For example, as shown in the figure, multi-gradation data and binary data are individually created by a multi-gradation data storage unit 103 and a binary data storage unit 104, which are external circuits, neither of which is shown. Digital data is converted into analog data by a digital-analog converter (DAC) and output via the data signal line driving circuit 101.

  By the way, in recent years, with the demand for longer use time of portable devices, there is a strong demand for lower power consumption for display devices. Here, in a portable device, it is not always in use, and most of the time is in a standby state in many cases. Also, the displayed video and format are often different between in use and in standby.

  For example, at the time of standby, it is sufficient that the menu screen, the time, and the like can be displayed, and the definition, the number of display colors, and the like may be low. Rather, it is important to extend the usage time by reducing power consumption. On the other hand, in use, a large amount of images such as sentences, figures and photographs are often displayed, and a high-quality display is required. At this time, power consumption increases in other parts of the portable device, for example, the communication module, the input interface unit, and the arithmetic processing unit, so the power consumption ratio in the display module decreases. Therefore, the demand for low power consumption during use is generally not as strong as during standby.

  In order to solve this problem, for example, in the image display device 200 disclosed in Patent Document 1, as shown in FIG. 12, a first data signal line drive circuit (see FIG. SD1) 201a and scanning signal line drive circuit (GD) 202 display display 203, while waiting, second data signal line drive circuit (SD2) 201b that handles binary data signal BINDAT and the above-described scanning signal line drive The display unit 203 is displayed by the circuit (GD) 202. This is a so-called multi-driver method.

As a result, a large amount of images such as text, figures, and photos are displayed in multiple gradations during use, and high-quality display is performed. On the other hand, during standby, for example, low-power consumption is performed using binary data signals such as black and white. It can be displayed by power.
JP 2002-202747 A (published July 19, 2002)

  By the way, in the above conventional driving method of the liquid crystal display device, two types of data, that is, the first data signal line drive circuit (SD1) 201a for multi-gradation and the second data signal line drive circuit (SD2) 201b for binary. A signal line driver circuit is used.

  Here, the first data signal line driver circuit (SD1) 201a for multi-gradation and the second data signal line driver circuit (SD2) 201b for binary include a shift register SR1, a shift register SR1, a latch circuit Latch, and the like. These circuits have a large number of transistors in a flip-flop, but these transistors tend to generate a leakage current.

  Therefore, since the leakage current increases as the number of transistors increases, the number of transistors in each driving circuit increases as the number of driving circuits increases, leading to an increase in the leakage current, which in turn increases the power consumption of the liquid crystal display device. Has the problem.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a display device driving device, a display device, and a display device driving method capable of reducing power consumption during standby. There is.

  In order to solve the above problems, a display device driving device according to the present invention includes a plurality of data signal lines, a plurality of scanning signal lines, and an intersection of the plurality of data signal lines and the plurality of scanning signal lines. A display device including a plurality of pixels formed and a display unit that outputs an image display data signal to each pixel through each data signal line in synchronization with a scanning signal output from each scanning signal line In the driving device, a scanning signal line driving circuit that outputs scanning signals to the plurality of scanning signal lines at a predetermined timing, a data signal line driving circuit that outputs image display data signals to the plurality of data signal lines, and the data A multi-grayscale display data signal generation circuit for supplying a multi-grayscale image display data signal to the signal line drive circuit, and a binary display data signal generation circuit for supplying a binary image display data signal to the data signal line drive circuit. And switching means for switching between the output from the multi-gradation display data signal generation circuit to the data signal line driving circuit and the output from the binary display data signal generation circuit to the data signal line driving circuit. It is characterized by.

  According to another aspect of the invention, there is provided a driving method of a display device, in order to solve the above-described problem, a plurality of data signal lines, a plurality of scanning signal lines, and a plurality of data signal lines and the plurality of scanning signal lines. A display having a plurality of pixels formed in each portion, and a display unit that outputs an image display data signal to each pixel through each data signal line in synchronization with a scanning signal output from each scanning signal line In the driving method of the apparatus, a scanning signal line driving circuit that outputs scanning signals to the plurality of scanning signal lines at a predetermined timing, a data signal line driving circuit that outputs image display data signals to the plurality of data signal lines, and A multi-grayscale display data signal generation circuit for supplying a multi-grayscale image display data signal to the data signal line drive circuit, and a binary display data signal for supplying a binary image display data signal to the data signal line drive circuit And a data signal line driving circuit for switching between the multi-grayscale image display data signal from the multi-grayscale display data signal generation circuit and the binary image display data signal from the binary display data signal generation circuit. It is characterized by supplying to.

  By the way, conventionally, since a binary image display data signal is output during a non-display period in which a multi-tone image display data signal is not output, that is, during standby, it is different from a data signal line driving circuit for a multi-tone image display data signal. A data signal line driving circuit for another binary image display data signal is provided.

  For this reason, the data signal line driving circuit has a problem that a leakage current is generated in the transistor in the flip-flop circuit, and a large amount of power is used.

  However, according to the above-described invention, the multi-grayscale image display data signal from the multi-grayscale display data signal generation circuit to the data signal line driving circuit, and the two-level data from the binary display data signal generation circuit to the data signal line driving circuit The value image display data signal is switched by the switching means. As a result, the data signal line driving circuit for the binary image display data signal for outputting within the non-display period can be shared with the data signal line driving circuit for the multi-tone image display data signal. Power consumption due to leakage currents of a large number of transistors included in the data signal line driver circuit can be reduced.

  Accordingly, it is possible to provide a display device driving device and a display device driving method capable of reducing power consumption during standby.

  According to the display device driving apparatus of the present invention, in the display device driving device described above, the switching unit supplies a binary image display data signal within a non-display period of the multi-tone image display data signal. Each output is switched as described above.

  The display device driving method of the present invention is the display device driving method described above, wherein each output is supplied so as to supply a binary image display data signal within a non-display period by the multi-tone image display data signal. It is characterized by switching.

  According to the above invention, the switching means switches each output so as to supply the binary image display data signal within the non-display period by the multi-tone image display data signal. Therefore, it is possible to provide a display device driving device and a display device driving method capable of reliably reducing power consumption during standby.

  According to the display device driving apparatus of the present invention, the binary display data signal generation circuit outputs to the pixels within a non-display period by the multi-gradation image display data signal. For generating a non-display period data write voltage, and the switching means supplies the non-display period data write voltage within the non-display period of the multi-tone image display data signal. It is characterized by switching each output.

  The display device drive method of the present invention is the display device drive method described above, wherein the binary display data signal generation circuit further generates a non-display period data write voltage having a constant voltage, In the non-display period by the multi-tone image display data signal, the non-display period data write voltage is also switched so as to be supplied.

  According to the above invention, the binary display data signal generation circuit generates a non-display period data write voltage consisting of a constant voltage to be output to the pixels within the non-display period by the multi-tone image display data signal. . The switching means switches each output so as to supply the non-display period data write voltage within the non-display period by the multi-tone image display data signal.

  Therefore, during standby during the non-display period by the multi-tone image display data signal, for example, a voltage for binary image display such as black and white or a voltage to be applied at the time of constant uniform color display, a so-called solid image display voltage is applied. can do.

  The display device drive method of the present invention is the display device drive method described above, wherein the binary image display data signal or the non-display period data write voltage is output to the plurality of data signal lines. Control means for outputting at a frequency slower than the multi-tone image display data signal is provided.

  That is, when the multi-tone image display data signal is used, since the image change is severe, it is necessary to output at a fast frequency. However, there is almost no change in the standby screen during standby during the non-display period due to the multi-tone image display data signal. At this time, for example, in a display device such as a liquid crystal display device in which the voltage of the pixel is held, the voltage may be applied again before the holding voltage of the pixel naturally disappears. The non-display period data write voltage may be output sporadically.

  Therefore, in the present invention, when the control means outputs the binary image display data signal or the non-display period data write voltage to the plurality of data signal lines, the control means outputs the data at a frequency slower than that of the multi-tone image display data signal. Let

  As a result, it is possible to provide a display device drive device and a display device drive method capable of further reducing power consumption during standby.

  The display device driver according to the present invention is the display device driver described above, wherein the non-display period data write voltage generated by the binary display data signal generation circuit is the multi-grayscale display. The multi-tone image display data signal supplied from the data signal generation circuit is equal to a precharge voltage for sufficiently applying to the pixel.

  According to the above invention, the non-display period data write voltage generated by the binary display data signal generation circuit is the multi-gradation image display data signal supplied from the multi-gradation display data signal generation circuit. It is equal to the precharge voltage for ensuring sufficient application to the pixel.

  Therefore, the non-display period data write voltage can be used as the precharge voltage.

  According to another aspect of the present invention, there is provided a driving device for a display device according to the above-described driving device for a display device. The built-in voltage is characterized by having the same potential as the voltage applied during white display.

  According to the above invention, the voltage of the binary image display data signal generated by the binary display data signal generation circuit or the data write voltage for the non-display period is the same potential as the voltage applied during white display. Therefore, in the normally black mode, white display is possible by applying a voltage that enables white display, and in the normally white mode, white display is possible by applying a voltage of 0 potential or nearly 0 potential. It becomes.

  According to another aspect of the present invention, there is provided a driving device for a display device according to the above-described driving device for a display device. The built-in voltage is characterized by having the same potential as the voltage applied during black display.

  According to the above invention, the voltage of the binary image display data signal generated by the binary display data signal generation circuit or the data write voltage for the non-display period is the same potential as the voltage applied during black display. Therefore, in the normally white mode, black display is possible by applying a voltage that enables black display, and in the normally black mode, black display is possible by applying a voltage of 0 potential or nearly 0 potential. It becomes.

  According to the display device driving apparatus of the present invention, the voltage of the non-display period data write voltage generated by the binary display data signal generation circuit is constant and uniform. It is characterized by having the same potential as the voltage applied during color display.

  According to the above invention, since the voltage of the non-display period data write voltage generated by the binary display data signal generation circuit is the same potential as the voltage applied at the time of constant uniform color display, for example, black and white In other words, a so-called solid image display of intermediate colors can be performed.

  The display device driver according to the present invention is the display device driver described above, wherein the data signal line drive circuit converts a multi-tone image display data signal or a binary image display data signal into the plurality of data signal lines. The frequency when outputting a multi-tone image display data signal and the frequency when outputting a binary image display data signal or a voltage signal applied during constant color display are different. It is a feature.

  According to the above invention, when the data signal line driving circuit outputs the multi-tone image display data signal or the binary image display data signal to the plurality of data signal lines, the multi-tone image display data signal is output. Since the frequency at the time and the frequency at which the binary image display data signal or the voltage signal to be applied at the time of the uniform color display is output are different, as described above, the binary image display data signal or the constant at the time of standby. The frequency of the voltage signal applied during uniform color display can be reduced. As a result, power consumption during standby can be reduced.

  According to another aspect of the present invention, there is provided a driving device for a display device, wherein the multi-grayscale display data signal generation circuit, the binary display data signal generation circuit, and the switching means are a single integrated circuit chip. It is characterized by being included in.

  According to the above invention, the multi-gradation display data signal generation circuit, the binary display data signal generation circuit, and the switching means are included in one integrated circuit chip. The binary display data signal generation circuit and the switching means can be accommodated in a compact manner. Further, since the number of output terminals of the integrated circuit is reduced, the chip area can be reduced and the cost can be reduced.

  The display device driving apparatus according to the present invention is the display device driving device described above, wherein the multi-grayscale display data signal generation circuit, the binary display data signal generation circuit, the switching unit, and the control unit are one unit. It is characterized by being included in an integrated circuit chip.

  According to the above invention, the multi-grayscale display data signal generation circuit, the binary display data signal generation circuit, the switching unit, and the control unit are included in one integrated circuit chip. The generation circuit, the binary display data signal generation circuit, the switching unit, and the control unit can be accommodated in a compact manner. Further, since the number of output terminals of the integrated circuit is reduced, the chip area can be reduced and the cost can be reduced.

  According to another aspect of the present invention, there is provided a driving device for a display device, wherein the wiring from the switching means to the data signal line driving circuit is connected to the supply wiring from the multi-grayscale display data signal generation circuit, and 2 The supply wiring from the value display data signal generation circuit is a common wiring.

  According to the above invention, the wiring from the switching means to the data signal line driving circuit is a common wiring between the supply wiring from the multi-gradation display data signal generation circuit and the supply wiring from the binary display data signal generation circuit. Therefore, the wiring from the switching means to the data signal line driving circuit can be simplified.

  Further, in order to solve the above-described problems, a display device according to the present invention includes the display device driving device described above.

  According to the above invention, since the display device includes the display device driving device described above, it is possible to provide a display device capable of reducing power consumption during standby.

  In the display device drive device, display device, and display device drive method according to the present invention, a multi-tone image display data signal and a binary display data signal from the multi-tone display data signal generation circuit to the data signal line drive circuit are provided. The binary image display data signal from the generation circuit to the data signal line driving circuit is switched by the switching means. Accordingly, the data signal line driving circuit for outputting within the non-display period can be shared with the data signal line driving circuit for the multi-tone image display data signal, and is included in one data signal line driving circuit. The power consumption due to the leakage currents of a large number of transistors can be reduced.

  Therefore, it is possible to provide a display device driving device and a display device driving method capable of reducing power consumption during standby.

[Embodiment 1]
An embodiment of the present invention will be described with reference to FIGS. 1 to 6 as follows.

  As shown in FIG. 1, a liquid crystal display device 1 as a display device of the present embodiment includes a plurality of pixels 2 arranged in a matrix and a plurality of data signal lines arranged in each column of the pixels 2. SL and a plurality of scanning signal lines GL arranged corresponding to the rows of pixels 2... And each pixel 2... Through each data signal line SL in synchronization with the scanning signal output from each scanning signal line GL. 2 has a display unit 3 as a display unit for outputting an image display data signal.

  As shown in FIG. 2, the pixel 2 includes a switching element SW formed of a field effect transistor as a switching element, and a pixel capacitor (including a liquid crystal capacitor CL and an auxiliary capacitor CS added as necessary). Composed. A data signal line SL is connected to the source of the switch element SW, one electrode of a pixel capacitor is connected to the drain of the switch element SW, and a scanning signal line GL is connected to the gate of the switch element SW. The other electrode of the pixel capacitor is connected to a common electrode line common to all pixels. Then, the transmittance or reflectance of the liquid crystal is modulated by a voltage that is an image display signal applied to each liquid crystal capacitor CL, and is used for display.

  In the present embodiment, in order to drive the pixels 2... Of the display unit 3, a scanning signal line drive circuit GD is provided, for example, on the left side of the display unit 3 as shown in FIG. Is provided with a data signal line driving circuit SD. Note that the positions of the scanning signal line driving circuit GD and the data signal line driving circuit SD are not necessarily limited to this, and may be interchanged vertically and horizontally. However, the scanning signal line driving circuit GD and the data signal line driving circuit SD are interchangeable. Are provided one by one.

  The scanning signal line driving circuit GD outputs scanning signals to the plurality of scanning signal lines GL in synchronization with a timing signal such as the clock signal GCK. The data signal line driving circuit SD is a multi-tone image display data signal DAT (hereinafter simply referred to as “multi-tone data signal DAT”) or a binary signal input in synchronization with a timing signal such as a clock signal SCK. An image display data signal BINDAT (hereinafter simply referred to as “binary data signal BINDAT”) is sampled, amplified as necessary, and written to each data signal line SL.

  Control signals such as the clock signals GCK and SCK are supplied from the control signal circuit 4.

  Here, in the present embodiment, the multi-gradation data signal DAT and the binary data signal BINDAT are switched by a selector 10 as a switching unit. Therefore, the multi-grayscale data signal DAT is generated by the multi-grayscale display data signal generation circuit 20, while the binary data signal BINDAT is generated by the binary display data signal generation circuit 30.

  The selector 10, the multi-gradation display data signal generation circuit 20, and the binary display data signal generation circuit 30 are mounted on one integrated circuit chip 5, as shown in FIG. The configuration is not limited to this, and the control signal circuit 4 may be included.

  As shown in the figure, the multi-gradation display data signal generation circuit 20 includes a DAC (Digital-to-Analog Converter) 21 and an amplifier 22, for example, a 256-gradation digital signal. The multi-gradation data DIGDATA is converted into an analog signal by the DAC 21, amplified by the amplifier 22, and supplied to the selector 10 as the multi-gradation data signal DAT.

  On the other hand, the binary display data signal generation circuit 30 is provided with, for example, a changeover switch 31 for switching a voltage 3.3V terminal on one side and a voltage 0V terminal on the other side, so that the voltage 3.3V and the voltage 0V are binary-switched. Switching is performed by a signal BINDATA. As a result, the binary display data signal generation circuit 30 outputs a binary data signal BINDAT to the selector 10.

  This voltage value of 3.3 V is the same potential as the voltage applied during white display or black display, whereby one of the two values can be displayed.

  The selector 10 has a first changeover switch 11 so that the multi-grayscale data signal DAT and the binary data signal BINDAT are switched by the select signal MODESEL. The select signal MODESEL is output from the control signal circuit 4.

  As a result, either the multi-gradation data signal DAT or the binary data signal BINDAT selected by the selector 10 is supplied to the data signal line driving circuit SD.

  Accordingly, when the liquid crystal display device 1 is in use, the multi-gradation data signal DAT is output to the pixel 2 of the display unit 3, while the binary data signal BINDAT is output to the pixel 2 of the display unit 3 during standby. Yes.

  Note that the driving device 6 including the scanning signal line driving circuit GD, the data signal line driving circuit SD, the control signal circuit 4, the selector 10, the multi-gradation display data signal generation circuit 20, and the binary display data signal generation circuit 30 is as follows. The drive device of the present invention is configured.

  In the liquid crystal display device 1 having the above configuration, a method for writing the multi-gradation data signal DAT or the binary data signal BINDAT selected by the selector 10 to the data signal line SL will be described. As a driving method of the data signal line SL, there are a dot sequential driving method and a line sequential driving method.

  In the dot sequential driving method, for example, the data signal line driving circuit SD having the configuration shown in FIG. 4 is used. In the dot sequential driving method, as shown in the figure, the multi-gradation data signal DAT or the binary data signal BINDAT inputted to the video signal line (referred to as DATLINE) is converted into the shift register including a plurality of flip-flop circuits FF. The data signal line SL (ie, SL1, SL2,...) Is written by opening / closing the analog switch ASW as the sampling circuit SAMP in synchronization with the output signal N (ie, N1, N2,...) Of each SR latch stage. .

  Here, in the configuration of the figure, sampling signals S and SB (that is, S1, S2,..., S1B, S2B,...) Are generated from overlapping pulses of output signals N in two adjacent flip-flop circuits FF. Therefore, the multi-gradation data signal DAT or the binary data signal BINDAT at the timing of falling (termination) of the sampling signal is written to the data signal line SL.

  On the other hand, a line sequential type data signal line driving circuit having the configuration shown in FIG. 5 is used. In the line sequential drive system, as shown in the figure, the multi-gradation data signal DAT or the binary data signal BINDAT is synchronized with the output signal N of each latch stage of the shift register SR composed of a plurality of flip-flop circuits FF. After taking in by opening and closing the analog switch ASW for sampling, the signal for one horizontal scanning period is simultaneously transferred to the next stage by the transfer instruction signal TFG, and written to the data signal line SL through the amplifier AM. Come on.

  On the other hand, as shown in FIG. 6, the scanning signal line driving circuit GD scans as a scanning signal by a product (AND) signal of a pulse signal transferred in synchronization with the clock signal GCK and a signal GEN defining a pulse width. Output to line GL (ie, GL1, GL2,...). The scanning signal controls writing and holding of the multi-gradation data signal DAT or the binary data signal BINDAT to the pixels 2.

  As described above, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 of the present embodiment, the multi-gradation data signal from the multi-gradation display data signal generation circuit 20 to the data signal line driving circuit SD. The selector 10 switches between DAT and the binary data signal BINDAT from the binary display data signal generation circuit 30 to the data signal line drive circuit SD. As a result, the data signal line drive circuit SD for the binary data signal BINDAT to be output within the non-display period can be shared with the data signal line drive circuit SD for the multi-grayscale data signal DAT. It is possible to reduce power consumption caused by leakage currents of a large number of transistors included in one data signal line driving circuit SD.

  Therefore, it is possible to provide a driving device 6 of the liquid crystal display device 1 and a driving method of the liquid crystal display device 1 that can reduce power consumption during standby.

  In the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the selector 10 supplies the binary data signal BINDAT within the non-display period by the multi-gradation data signal DAT. Switch each output to. Therefore, it is possible to provide the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 that can surely reduce the power consumption during standby.

  Further, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 of the present embodiment, the voltage of the binary data signal BINDAT generated by the binary display data signal generation circuit 30 is the white display time. Alternatively, since the potential is the same as the voltage applied during black display, one of the two values can be displayed.

  In the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 of the present embodiment, the multi-gradation display data signal generation circuit 20, the binary display data signal generation circuit 30, and the selector 10 are Since it is included in one integrated circuit chip 5, the multi-gradation display data signal generation circuit 20, the binary display data signal generation circuit 30, and the selector 10 can be accommodated in a compact manner. Further, since the number of output terminals of the integrated circuit is reduced, the chip area can be reduced and the cost can be reduced.

  Further, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the multi-gradation display data signal generation circuit 20, the binary display data signal generation circuit 30, the selector 10, and the control signal circuit. 4 can be included in one integrated circuit chip 5. Accordingly, the multi-gradation display data signal generation circuit 20, the binary display data signal generation circuit 30, the selector 10, and the control signal circuit 4 can be accommodated in a compact manner. Further, since the number of output terminals of the integrated circuit is reduced, the chip area can be reduced and the cost can be reduced.

  In the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the wiring from the selector 10 to the data signal line driving circuit SD is provided from the multi-gradation display data signal generation circuit 20. Since the supply wiring and the supply wiring from the binary display data signal generation circuit 30 are the common wiring 7, the wiring from the selector 10 to the data signal line driving circuit SD can be simplified.

  In addition, since the liquid crystal display device 1 of the present embodiment includes the driving device 6 described above, it is possible to provide the liquid crystal display device 1 that can reduce power consumption during standby.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. Configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are given the same reference numerals, and explanation thereof is omitted.

  In the liquid crystal display device 1 of the first embodiment, for example, white or black binary display is performed during standby, which is a non-display period of the multi-gradation data signal DAT.

  In the present embodiment, not only white or black during standby, which is a non-display period of the multi-tone data signal DAT, but also a voltage applied at the time of displaying a uniform color, that is, a voltage for displaying a solid image on the pixel 2, or It has a function of performing preliminary charging for displaying the multi-gradation data signal DAT.

  That is, the binary display data signal generation circuit 30a of the present embodiment can supply not only the voltage 3.3V but also the voltage 1.5V as shown in FIG. The switching between the voltage 3.3V and the voltage 1.5V is performed by operating the changeover switch 31 with a signal (not shown) from the control signal circuit 4.

  Here, the voltage of 1.5 V is a voltage application for a constant uniform color display, that is, a solid image display on the pixel 2 or a multi-gradation data in a standby state where the multi-gradation data signal DAT is not displayed. This signal is used for precharging during the non-display period of the signal, and is supplied as the non-display period data write signal PVI. Therefore, the voltage value of 1.5 V is the same potential as the precharge voltage or the voltage applied during a certain solid display.

  However, the voltage value of 1.5 V is not necessarily limited thereto, and is set to the same potential as the voltage applied during black display, for example, 3.3 V (in the case of normally white) or 0 V (in the case of normally black). For example, 0 V (in the case of normally white) or 3.3 V (in the case of normally black), which is the same potential as the voltage applied during white display.

  The selector 10a as the switching means is provided with a second changeover switch 12. When the second changeover switch 12 is turned on, the non-display period data write signal PVI is supplied to the data signal line drive circuit SD. It comes to be supplied. In the present embodiment, the non-display period data write signal PVI is coupled to a wiring to which the multi-grayscale data signal DAT and the binary data signal BINDAT are supplied, and one data signal drive circuit SD is connected to the data signal line driver circuit SD. Supplied by the common wiring 7.

  In this embodiment, as shown in FIGS. 8A, 8B, and 8C, when the multi-grayscale data signal DAT is output to the data signal line SL, the multi-grayscale data signal DAT is output. Although the fast frequency is used, when the binary data signal BINDAT or the non-display period data write signal PVI is output to the data signal line SL, the slower frequency is used. Therefore, the frequency at which the multi-tone data signal DAT is output is different from the frequency at which the binary data signal BINDAT or the non-display period data write signal PVI is output. This control is performed by a control signal circuit 4 as control means, as shown in FIG.

This is because, when displaying the multi-grayscale data signal DAT, a fast frequency is necessary because there is a fast moving image such as a moving image. However, once the multi-grayscale data signal DAT is displayed by the binary data signal or the non-display period data write signal PVI during the non-display period, the display is performed due to the voltage holding characteristics of the liquid crystal of the liquid crystal display device 1. Is held for a while, so it can be applied again before the display disappears.
Thus, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 of the present embodiment, the binary display data signal generation circuit 30 is within the non-display period by the multi-gradation data signal DAT. A non-display period data write signal PVI having a constant voltage to be output to the data signal line SL is generated. The selector 10a switches each output so as to supply the non-display period data write voltage within the non-display period by the multi-tone image display data signal.

  Accordingly, at the time of standby within the non-display period by the multi-tone image display data signal, for example, the voltage of the binary data signal BINDAT such as black and white or the voltage applied at the time of constant uniform color display, so-called solid image display voltage, that is, non The voltage of the display period data write signal PVI can be applied.

  By the way, when the multi-grayscale data signal DAT is used, the image changes drastically, so that it is necessary to output at a fast frequency. However, there is almost no change in the standby screen during standby during the non-display period due to the multi-gradation data signal DAT. At this time, in the liquid crystal display device 1 in which the voltage of the pixel 2 is held, for example, the voltage may be applied again before the holding voltage of the pixel 2 naturally disappears, so the binary data signal BINDAT or the non-display period Data write signal PVI may be output sporadically.

  Therefore, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the control signal circuit 4 outputs the binary data signal BINDAT or the non-display period data write signal PVI to a plurality of data. When outputting to the signal line SL, it is output at a slower frequency than the multi-gradation data signal DAT.

  As a result, it is possible to provide a driving device 6 of the liquid crystal display device 1 and a driving method of the liquid crystal display device 1 that can further reduce power consumption during standby.

  Further, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the non-display period data write signal PVI generated by the binary display data signal generation circuit 30 is large. The multi-gradation data signal DAT supplied from the gradation display data signal generation circuit 20 can be made equal to a precharge voltage for sufficiently applying to the pixel 2.

  Therefore, the non-display period data write signal PVI can be used as a precharge voltage.

  Further, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the voltage of the binary data signal BINDAT generated by the binary display data signal generation circuit 30 or the non-display period is used. Since the voltage of the data write signal PVI is the same potential as the voltage applied during white display or black display, one of the two values can be displayed.

  Further, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 of the present embodiment, the voltage of the non-display period data write signal PVI generated by the binary display data signal generation circuit 30 is Since the voltage is the same as the voltage applied at the time of constant uniform color display, for example, a so-called solid image display of an intermediate color that is not black and white can be performed. Therefore, a uniform background screen can be obtained.

  Further, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 of the present embodiment, the data signal line driving circuit SD generates a plurality of multi-gradation data signals DAT or non-display period data write signals PVI. The frequency when outputting a multi-tone image display data signal and the frequency when outputting a binary image display data signal or a voltage signal applied at the time of constant color display are output to the data signal line SL. Since they are different, as described above, the frequency of the binary data signal BINDAT or the non-display period data write signal PVI can be delayed during standby. As a result, power consumption during standby can be reduced. On the other hand, when the rise or fall time of the voltage applied to the pixel is considered microscopically, it is possible to reduce power consumption by making the frequency faster than the multi-gradation data signal DAT even in the standby state. There is a case.

  In addition, since the liquid crystal display device 1 of the present embodiment includes the driving device 6 described above, it is possible to provide the liquid crystal display device 1 that can reduce power consumption during standby.

[Embodiment 3]
The following will describe another embodiment of the present invention with reference to FIGS. The configurations other than those described in the present embodiment are the same as those in the first embodiment and the second embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 and Embodiment 2 are given the same reference numerals, and the description thereof is omitted.

  In the first embodiment and the second embodiment, for example, as shown in FIG. 1, the wiring from the selector 10 or the selector 10 a is supplied to the data signal line driving circuit SD as one common wiring as the common wiring 7. However, it is not necessarily limited to this.

  That is, in the present embodiment, as shown in FIG. 9, the first wiring 7a that supplies the multi-grayscale data signal DAT and the binary data signal BINDAT to the data signal line driving circuit SD and the application at the time of constant uniform color display. Each signal is sampled by the data signal line driving circuit SD by two wirings with the second wiring 7b for supplying the data writing signal PVI for the non-display period consisting of the voltage or the precharge voltage to the data signal line driving circuit SD. The circuit SAMP is supplied.

  The sampling circuit SAMP is separately supplied with a selection signal PCLT for selecting the non-display period data write signal PVI from the data generation unit LCDC. Therefore, the multi-grayscale data signal DAT and the binary data signal BINDAT are selected by the flip-flop circuit FF from the shift register SR of the data signal line driving circuit SD and output to the data signal line SL. The non-display period data write signal PVI is selected by the selection signal PCLT and output to the data signal line SL.

  Here, the data creation unit LCDC includes the control signal circuit 4, the selector 10, the multi-gradation display data signal generation circuit 20, and the binary display data signal generation circuit 30 shown in FIG. .

  In the present embodiment, the output from the selector 10a is supplied to the data signal line drive circuit SD in two systems as described above. Therefore, as shown in FIG. 10, from the selector 10a, the two first wirings 7a and the second wirings 7b of the multi-gradation data signal DAT, the binary data signal BINDAT, and the non-display period data write signal PVI are provided. Is output.

  Thus, in the driving device 6 of the liquid crystal display device 1 and the driving method of the liquid crystal display device 1 according to the present embodiment, the multi-gradation data signals DAT and 2 are transmitted from the selector 10a by the first wiring 7a and the second wiring 7b. The value data signal BINDAT or the non-display period data write signal PVI is supplied to the data signal line drive circuit SD.

  Therefore, the multi-tone data signal DAT and the binary data signal BINDAT or the non-display period data write signal PVI can be supplied to the data signal line drive circuit SD without necessarily using the common wiring 7.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

  The display device and the driving method thereof according to the present invention can be used for a driving device for an active matrix liquid crystal display device, a driving method for a liquid crystal display device, and a liquid crystal display device, and in particular, mobile phones such as mobile phones and PDAs. Application to information tools is preferred.

It is a block diagram which shows one Embodiment of the liquid crystal display device in this invention. It is a block diagram which shows the structure of the pixel in the said liquid crystal display device. It is a block diagram which shows the structure of the selector in the said liquid crystal display device. It is a block diagram which shows the structure of the data signal line drive circuit of the dot sequential drive system in the said liquid crystal display device. It is a block diagram which shows the structure of the data signal line drive circuit of the line sequential drive system in the said liquid crystal display device. It is a block diagram which shows the structure of the scanning signal line drive circuit in the said liquid crystal display device. The other embodiment of the liquid crystal display device in this invention is shown, and it is a block diagram which shows the structure of a selector. (A), (b), and (c) are timing charts showing a driving method of the liquid crystal display device. FIG. 24 is a block diagram illustrating a configuration of a liquid crystal display device according to still another embodiment of the liquid crystal display device of the present invention. It is a block diagram which shows the structure of the selector in the said liquid crystal display device. It is a block diagram which shows the structure of the conventional liquid crystal display device. It is a block diagram which shows the structure of the other conventional liquid crystal display device.

Explanation of symbols

1 Liquid crystal display device (display device)
2 pixels 3 display unit 4 control signal circuit (control means)
7 Common wiring 10 Selector (switching means)
10a selector (switching means)
11 First changeover switch 12 Second changeover switch 20 Multi-gradation display data signal generation circuit 30 Binary display data signal generation circuit 31 Changeover switch BINDAT Binary data signal (binary image display data signal)
DAT multi-gradation data signal (multi-gradation image display data signal)
GD Scanning signal line drive circuit GL Scanning signal line PVI Non-display period data write signal SD Data signal line drive circuit SL Data signal line

Claims (17)

A plurality of data signal lines, a plurality of scanning signal lines, and a plurality of pixels respectively formed at intersections of the plurality of data signal lines and the plurality of scanning signal lines, and output from each scanning signal line In a drive device for a display device including a display unit in which an image display data signal is output to each pixel through each data signal line in synchronization with the scanning signal,
A scanning signal line driving circuit for outputting a scanning signal to the plurality of scanning signal lines at a predetermined timing;
A data signal line driving circuit for outputting an image display data signal to the plurality of data signal lines;
A multi-gradation display data signal generation circuit for supplying a multi-gradation image display data signal to the data signal line driving circuit;
A binary display data signal generation circuit for supplying a binary image display data signal to the data signal line driving circuit;
Switching means for switching between the output from the multi-gradation display data signal generation circuit to the data signal line driving circuit and the output from the binary display data signal generation circuit to the data signal line driving circuit is provided. A display device drive device.   2. The display device driving device according to claim 1, wherein the switching unit switches each output so as to supply a binary image display data signal within a non-display period by the multi-tone image display data signal. The binary display data signal generation circuit generates a non-display period data write voltage composed of a constant voltage for outputting to a pixel within a non-display period by the multi-tone image display data signal,
3. The display device according to claim 1, wherein the switching unit switches each output so that a non-display period data write voltage is supplied within a non-display period based on the multi-tone image display data signal. Drive device.   Control means is provided for outputting the binary image display data signal or the non-display period data write voltage to the plurality of data signal lines at a frequency slower than that of the multi-tone image display data signal. 4. A drive device for a display device according to claim 1, 2, or 3.   The non-display period data write voltage generated by the binary display data signal generation circuit is sufficiently applied to the pixel by the multi-gradation image display data signal supplied from the multi-gradation display data signal generation circuit. 4. The display device driving device according to claim 3, wherein the driving voltage is equal to a pre-charging voltage for causing the display device to operate.   The voltage of the binary image display data signal generated by the binary display data signal generation circuit or the data write voltage for the non-display period is the same potential as the voltage applied during white display. A drive device for a display device according to 2 or 3.   The voltage of the binary image display data signal generated by the binary display data signal generation circuit or the data write voltage for non-display period is the same potential as the voltage applied during black display. A drive device for a display device according to 2 or 3.   4. The display according to claim 3, wherein the voltage of the non-display period data write voltage generated by the binary display data signal generation circuit is the same potential as a voltage applied at the time of a constant uniform color display. Device drive device.   When the data signal line driving circuit outputs a multi-tone image display data signal or a binary image display data signal to the plurality of data signal lines, a frequency and a binary value when the multi-tone image display data signal is output. 9. The drive device for a display device according to claim 1, wherein a frequency for outputting an image display data signal or a voltage signal applied at the time of displaying a uniform color is different.   10. The multi-grayscale display data signal generation circuit, the binary display data signal generation circuit, and the switching unit are included in one integrated circuit chip. Display device drive device.   5. The display device drive according to claim 4, wherein the multi-grayscale display data signal generation circuit, the binary display data signal generation circuit, the switching unit, and the control unit are included in one integrated circuit chip. apparatus.   The wiring from the switching means to the data signal line driving circuit is characterized in that the supply wiring from the multi-gradation display data signal generation circuit and the supply wiring from the binary display data signal generation circuit are a common wiring. The drive device for a display device according to any one of claims 1 to 11.   A display device comprising the display device drive device according to claim 1. A plurality of data signal lines, a plurality of scanning signal lines, and a plurality of pixels respectively formed at intersections of the plurality of data signal lines and the plurality of scanning signal lines, and output from each scanning signal line In a driving method of a display device including a display unit in which an image display data signal is output to each pixel through each data signal line in synchronization with a scanning signal,
A scanning signal line driving circuit for outputting a scanning signal to the plurality of scanning signal lines at a predetermined timing;
A data signal line driving circuit for outputting an image display data signal to the plurality of data signal lines;
A multi-gradation display data signal generation circuit for supplying a multi-gradation image display data signal to the data signal line driving circuit;
A binary display data signal generation circuit for supplying a binary image display data signal to the data signal line driving circuit;
The multi-tone image display data signal from the multi-tone display data signal generation circuit and the binary image display data signal from the binary display data signal generation circuit are switched and supplied to the data signal line driving circuit. A display device driving method.   15. The method of driving a display device according to claim 14, wherein each output is switched so that a binary image display data signal is supplied within a non-display period by the multi-tone image display data signal. The binary display data signal generation circuit further generates a non-display period data write voltage consisting of a constant voltage,
16. The method of driving a display device according to claim 15, wherein switching is performed so that the non-display period data write voltage can also be supplied within the non-display period of the multi-tone image display data signal.   The output of the binary image display data signal or the non-display period data write voltage to the plurality of data signal lines is output at a frequency slower than that of the multi-tone image display data signal. 17. A method for driving a display device according to 15 or 16.

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