JP3596958B2 - Display device and display device driving method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a display device and a method for driving the display device, and more particularly, to a display device for driving a capacitive load such as a common electrode of a liquid crystal display panel and a method for driving the display device.
In recent years, a large-screen color liquid crystal display device is mounted on a notebook personal computer, a word processor, and the like, and an increase in power consumption has become a problem. That is, a low-power color liquid crystal display device has been demanded, and a drive technique (electrode drive device) for achieving this has been demanded.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an active matrix type liquid crystal display device using a thin film transistor (TFT) to improve the image quality of a liquid crystal has been provided. Further, in order to increase the number of display colors, a low-voltage (for example, +5 V single power supply) data line driving circuit (data driver) has been developed. By the way, since the liquid crystal requires AC driving, in the related art, the common electrode is driven by inverting the potential of the common electrode for each horizontal line by a buffer (such as a voltage follower of an operational amplifier).
[0003]
FIG. 5 is a block diagram showing an example of an active matrix type liquid crystal display device, FIG. 6 is a diagram for explaining the configuration of each pixel in the liquid crystal display device of FIG. 5, and FIG. 7 is a liquid crystal display device of FIG. 5 is a timing chart for explaining the operation of the device.
5, reference numeral 101 denotes an LCD panel, 102 denotes a data line drive circuit, 103 denotes a gate line drive circuit, 106 and 108 denote shift registers, 107 denotes a data hold circuit, and 109 denotes a gate drive circuit.
[0004]
As shown in FIG. 5, the active matrix type LCD (Liquid Crystal Display) includes an LCD panel 101, a data line driving circuit 102, and a gate line driving circuit 103. The LCD panel 101 has a structure in which a liquid crystal material (105) is sealed in a gap between two glass plates (TFT substrate and common substrate), and pixel electrodes are formed in a matrix on the inner surface of each glass plate. Have been.
[0005]
The data line drive circuit 102 includes a shift register 106 and a data hold circuit 107. The data line drive circuit 102 sequentially holds an input data voltage in accordance with a data clock from a first output, and stores one line of data in a vertical pixel line (data Line). The gate line driving circuit 103 includes a shift register circuit 108 and a gate driving circuit 109. The gate line driving circuit 103 sequentially outputs a gate driving voltage according to a shift clock from a first output, and selects and writes data for each line. Has become.
[0006]
As shown in FIG. 6, each pixel in the LCD panel 101 is constituted by a transistor (TFT) 104 whose gate electrode is supplied with the output of the gate line driving circuit 103 and whose drain electrode is supplied with the output of the data line driving circuit 102. Switching is controlled. That is, the TFT 104 for one line is switched on by the output of the gate line driving circuit 103, the data for one line from the data line driving circuit 102 is applied to the pixel electrode of each pixel (105), Writing is performed.
[0007]
As shown in FIG. 7, first, the data line driving circuit 102 and the gate line driving circuit 103 are reset once, and then the data of one horizontal line (data output No. 1 to No. n), and when the hold is completed, a drive voltage (gate drive signal No. 1) is output from the gate line drive circuit 103 to the first horizontal line. Accordingly, each TFT 104 on the first horizontal line is turned on, and writing to each pixel is performed. Further, in the next cycle, the data voltages (data outputs No. 1 to No. n) for the second horizontal line are set in the data line driving circuit 102, and the second horizontal line is output from the gate line driving circuit 103. A drive voltage (gate drive No. 2) is output to the line. When the above operations are sequentially repeated and the data writing to the last horizontal line is completed, the operation returns to the first horizontal line, starts a new data writing operation, and sequentially displays a predetermined image.
[0008]
[Problems to be solved by the invention]
FIG. 8 is a diagram showing an equivalent circuit of an example of an active matrix type liquid crystal display device. As is clear from FIG. 8, the common electrode (common electrode and storage capacitor electrode) is a capacitive load, so that the charge and discharge of this capacitance must be repeated every two horizontal lines. Here, the liquid crystal display device shown in FIG. 8 is provided with a storage capacitor Cs and a storage capacitor electrode so as to reduce image quality deterioration due to the capacitance Clc of each pixel. Further, the storage capacitor electrode is driven by a storage capacitor electrode drive circuit (capacitive electrode drive circuit) 111, and the common electrode (counter electrode) is driven by a common electrode drive circuit (capacitive electrode drive circuit) 112. Has become. The present invention is directed to an electrode driving device for a display device for driving a capacitive electrode (storage capacitor electrode and common electrode) 1 in a display panel (LCD panel) as shown in FIG. A display device including the device (for example, an active matrix liquid crystal display device).
[0009]
In the liquid crystal display device shown in FIG. 8, the common electrode and the storage capacitor electrode are common to all the pixels in the panel, and the capacitance is large. Further, with the recent progress in liquid crystal display devices having a larger screen, this increase in capacity is to be further accelerated. As a result, there arises a problem of increasing power consumption as described below.
[0010]
FIG. 9 is a block diagram showing an example of a driving circuit of a conventional display device, and FIG. 10 is a timing chart for explaining the operation of the driving circuit of FIG.
In FIG. 9, reference numeral 201 denotes a capacitive electrode (common electrode), and reference numeral 202 denotes a buffer unit that outputs a drive signal So in response to an input signal (logic signal) Si.
[0011]
As shown in FIG. 10, the buffer unit 202 drives the load capacitance of the common electrode by AC, and each time, the electric charge moves and a predetermined current flows. Further, as the size of the display panel increases, the load capacity of the common electrode also increases, and the power consumption of the liquid crystal display device is further increased.
The present invention has been made in consideration of the above-described problems of a display device such as a conventional liquid crystal display device, and has as its object to reduce driving power of a capacitive electrode to reduce power consumption of the display device.
[0012]
[Means for Solving the Problems]
According to the present invention, there is provided a display device including a display panel having a capacitive electrode exhibiting an input characteristic of a capacitive load, wherein the drive is performed by periodically changing the capacitive electrode between at least two drive potentials. A circuit, a capacitor group including two or more capacitors having a potential between the drive potentials, a connection between the capacitive electrode and the drive circuit, and a connection between the capacitive electrode and the capacitor group. A connection control circuit for controlling the liquid crystal display device , wherein the display device is an active matrix type liquid crystal display device, and the capacitive electrode is a counter electrode in a liquid crystal display panel of the liquid crystal display device ; There is provided a display device, wherein a charge stored in the capacitor group is used for a change in the drive potential applied to an electrode.
[0013]
Further, according to the present invention, there is provided a method of driving a display device including a display panel having a capacitive electrode exhibiting an input characteristic of a capacitive load, wherein the capacitive electrode is periodically driven between at least two drive potentials. The display device is an active matrix type liquid crystal display device, and the capacitive electrode is a counter electrode in a liquid crystal display panel of the liquid crystal display device, and is used for changing a driving potential of the capacitive electrode. And providing a period in which the capacitive electrode is connected to a capacitor group having two or more capacitors , the potential of which is pre-biased to a potential between the drive potentials, and wherein the driving applied to the capacitive electrode is performed. A method for driving a display device, characterized in that a change in potential is performed by using charges accumulated in the capacitor group, is provided.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
According to the display device of the present invention, the drive circuit drives the capacitive electrode by periodically changing it between at least two drive potentials. In addition, one or more capacitance groups are provided and have a potential between the driving potentials. Further, the connection control circuit controls the connection between the capacitive electrode and the drive circuit and the connection between the capacitive electrode and the capacitor group. Then, the charge accumulated in the capacitor group is used for the change of the driving potential applied to the capacitive electrode. Thus, the driving power of the capacitive electrode can be reduced, and the power consumption of the display device can be reduced.
[0015]
According to the driving method of the display device, when changing the drive potential of the capacitive electrode, the capacitive electrode is connected to one or more capacitor groups in which the potential is biased in advance to a potential between the drive potentials. There is a period of time. The driving potential applied to the capacitive electrode is changed using the charge stored in the capacitor group. Thus, the driving power of the capacitive electrode can be reduced, and the power consumption of the display device can be reduced.
[0016]
FIG. 1 is a block diagram showing the principle configuration of a drive circuit of a display device according to the present invention, and FIG. 2 is a timing chart for explaining the operation of the drive circuit of FIG. That is, FIG. 2 is a timing chart showing a case where the capacitive electrode (counter electrode) is line-inverted (inverted every one horizontal period). In FIG. 2, reference numeral _TH indicates one horizontal period, and TM indicates _TM. It shows the first few μs of one horizontal period, and can be set to about 1/10 of one horizontal period.
[0017]
The voltage SC is 2.5 volts, _{V A} is 5 volts and,, _{V B} is zero volts. Furthermore, in the Teimingu view of FIG. 2, it is omitted for the portion of the charge of the initialization of C _M1 in FIG. It is to be noted that the above-described respective voltage values and the like are merely examples and do not limit the present invention.
In FIG. 1, reference numeral 1 denotes a capacitive electrode (common electrode: common electrode and storage capacitor electrode) in the display panel 101, 2 denotes a buffer unit that outputs a drive signal SO1 in accordance with an input signal (logic signal) SI, 3 ( Reference numerals 3-1 to 3-n) denote capacitance groups (capacities 1 to n), and reference numeral 10 denotes a connection control unit including the switch unit 4 and the control unit 5.
[0018]
As shown in FIG. 1, for example, a capacitive electrode drive circuit (a storage capacitor electrode drive circuit 111 and a common electrode drive circuit 112) that drives a common electrode (storage capacitor electrode and common electrode) 1 in an active matrix type liquid crystal display device. ) Includes a buffer unit 2, a capacity group 3 (3-1 to 3-n), a switch unit 4, and a control unit 5.
[0019]
The switch unit 4 connects the capacitive electrode 1 to the buffer unit 2 and connects the capacitive electrode 1 to the capacitance group 3 (for example, one of the capacitance groups 3-1 to 3-n). , And control (connection / disconnection control) according to a control signal SS from the control unit 5. That is, the output (SO1) of the buffer unit 2 selected by the switch unit 4 or one of the electrodes (Sc-1 to Sc-n) of one of the capacitances in the capacitance groups 3-1 to 3-n is the capacitance. To the input line (SO2) of the conductive electrode 1.
[0020]
As illustrated in FIG. 2, the control unit 5 controls any one of the electrodes of the capacitors 3-1 to 3-n in the capacitor group 3 for a certain period (T _M ) from the edge at which the input signal SI changes (inverts). The switch unit 4 is controlled so that the lines SC-1 to SC-n are connected to the capacitive electrode 1 and the output (drive signal) SO1 of the buffer unit 2 is connected to the capacitive electrode 1 during the other periods. . Here, the potentials of the electrode lines SC-1 to SC-n are set substantially equal to the central potential of the output (inverted voltage) SO1 of the buffer unit 2, so that the buffer unit 2 The current flows and consumes the power of the power supply only during the period when the output SO1 and the capacitive electrode 1 are connected. However, the current does not flow and the power supply does not consume during the other periods.
[0021]
Further, the buffer section 2, the center potential _{V Mi [= (V A +} V B) ÷ 2] output from the SO1 (inversion voltage _{V A} or V of the output of the buffer portion 2 SO1 (inversion voltage _{V A} and _{V B) Since} the potential difference up to _B ) only needs to be driven, the current itself can be reduced. That is, according to the electrode driving apparatus of the present invention, the driving potential applied to the capacitive electrode 1: stored (the output of the buffer portion 2 SO1 inversion voltage V _A, V _B) the change in the capacitor group 3 By using the stored charge, power consumption can be reduced. Although variations in [Delta] V _Mi by driving in the electric potential of the electrode lines SC (SC-1~SC-n) ] inversion voltage _V centers in the potential of the _A and _{V B V Mi} occurs, external capacitance (capacitor group 3 Are set to be sufficiently large (for example, 10 times or more) with respect to the capacitance of the capacitive load, the fluctuation of ΔV _Mi can be ignored.
[0022]
Here, the capacitance of the capacitive electrodes _{C LD,} 1 horizontal period _{T H} and the average consumption current Ia Ia _{= C LD} × _{(V B} as the average of the amount of charge moved from _{V A} to _{V B} in 2 horizontal periods represented by -V _A) ÷ 4T _H. Note the conventional example is shown in FIG. 3, the average consumption current Ib in this _{case, Ib = C LD × (V} B -V A) ÷ 2T H , and becomes double the case of the present invention. However, the load of the capacitive electrode actually has a resistance component, so the difference between the two becomes small.
[0023]
【Example】
Hereinafter, an embodiment of an electrode driving device for a display device according to the present invention will be described with reference to the drawings.
FIG. 3 is a circuit diagram showing one embodiment of a drive circuit of a display device according to the present invention. In the embodiment shown in FIG. 3, reference numeral 1 denotes a capacitive load (C _LD ), 2 denotes a buffer unit, 3 denotes a capacitance group (capacitance), 4 denotes a switch unit, 5 denotes a control unit, 6 denotes a reference voltage generation unit, Reference numeral 7 denotes an initialization unit. Here, in FIG. 3, the capacitance of the capacitive load 1 _{(C LD),} for example, about 200～300NF, the operating voltage (inverting voltage) _{V A} 5V Furthermore,, _{V B} has a 0V. Further, the capacitance of the capacitance group 3 (C _M1 ) is about 2 to 3 μF, and the reference voltage SC is about 2.5V. The high-potential power supply _VDD is 12 V, the low-potential power supply _VSS is 0 V, and the output voltage obtained by voltage division of the resistors R1 and R2 is 2.5V. Also, the period of charging the capacitor C _M1 defined by the initialization unit 7, a short time immediately after the power is turned on, for example, about several Ms～10ms (is available in this timing, it is shown in Figure 2 Not). The above-described voltage values and the like are merely examples, and do not limit the present invention.
[0024]
The capacitive load 1 is, for example, a common electrode such as a common electrode and a storage capacitor electrode in a display panel (101) of an active matrix type liquid crystal display device, and the buffer unit 2 is driven according to an input signal (logic signal) SI. An operational amplifier (op-amp) that outputs the signal SO1 is provided. Here, in the conventional configuration, the output of the buffer unit 2 is directly supplied to the capacitive load (common electrode) 1.
[0025]
As is clear from the comparison between FIG. 1 and FIG. 3, in the embodiment shown in FIG. 3, the capacitance group 3 is constituted by one capacitance _CM1 . The switch unit 4 includes, for example, a delay circuit and an exclusive-OR (EX-OR) gate. The reference voltage generator 6 is configured to reduce the impedance of the voltage divided by the resistors R1 and R2 with an operational amplifier (M2) and output the same. The initialization unit 7 operates immediately after power-on (at the time of initialization). The output voltage of the reference voltage generator 6 is applied to the capacitor C _M1 (3) only for a short period of time, and the reference voltage (the high-potential power supply voltage V _DD (V _B ) and the low-potential power supply voltage _VSS (V _A ) voltage between _{(V Mi; V a <V} Mi <V B), for example, so as to bias the substantially intermediate voltage _{(V M ≒ (V a +} V B) ÷ 2)). The timing of the switch SW2 in the initializing unit 7 to the ON state, the inverter accumulated electric charge in the capacitor C1 from power is short immediately after power-on until turned off, thereby the capacitance C _M1 Are biased to the reference voltage.
[0026]
In the present embodiment, at the time of steady driving, the inverted signal (input signal) SI is differentiated by the delay circuit and the EX-OR gate, and the control signal SS is supplied to the switch unit 4 for a certain period after the change of the input signal SI. Only the capacitive load (common electrode 1) C _LD is connected to the capacitance C _M1 (3), and during other periods, the capacitive load C _LD is connected to the buffer unit 2. That is, every time the input signal SI is inverted, control is performed such that the capacitance _CM1 of the capacitance group 3 and the capacitive load _CLD are connected for a short time immediately after the inversion, thereby reducing the driving power of the capacitive load. The power consumption of the display device is reduced.
[0027]
FIG. 4 is a circuit diagram showing another embodiment of the drive circuit of the display device according to the present invention. In the present embodiment, the capacitance group 3 is constituted by two capacitances _CM11 and _CM12 , and an appropriate one of the two capacitances is selected and connected to the capacitive load _CLD . That is, the control unit 5, the control unit shown in FIG. 3, further, EX-OR gate, a comparator and latch circuits, the potential _(V M1 capacitance _{C M11} and _{C M12} constituting the capacitor group 3, V _M2) and a buffer section (driving circuit) 2 for potential after driving _(V a; compares the potential difference between _{V B),} of these two capacitors _{(C M1, C M2),} the larger one of the capacity of the potential difference and controls the switching unit 4 (SW11, SW12) so as to connect the capacitive load _{C LD.}
[0028]
4, the same reference numerals as those in FIG. 3 indicate the same values as those in FIG. The capacitances of the capacitors C _M11 and C _M12 correspond to about ten times the capacitive load 1 (C _LD ), and are about 2 to 3 μF, respectively. Furthermore, the capacitance _{C M11,} the potential of the _{C M12 V} M1, _{V M2} is the initial state (immediately after power-on) can several patterns, in the initial state, the capacitance _{C M11,} the potential _V M1 of _{C M12,} V _There are cases where _{M2 is set} to the same potential and cases where the potentials _VM1 and _VM2 are set to different potentials.
[0029]
First, when the potentials V _M1 and V _M2 of the capacitors C _M11 and C _M12 are set to the same potential in the initial state, some more cases can be considered (logically, the potential between V _A and V _B). If, can take any value), for example, ▲ 1 ▼ for _V M1, _{V M2} are both 0V, ▲ 2 ▼ _V M1, if _{V M2} are both 2.5V, and, ▲ 3 ▼ _V M1, _{V M2} are both considered, such as the case of 5V is.
[0030]
Specifically, (1) when the potentials V _M1 and V _M2 of the capacitors C _M11 and C _M12 in the initial state are both 0 V, charging for initialization is unnecessary, and the reference voltage generator shown in FIG. The circuit such as 6 or the initialization unit 7 becomes unnecessary. Then, as the operation, while going connected is selected, the charge in the capacitor _{C M11, C M12} is accumulated, the potential _V M1, _{V M2} will be both approaches from 0V to 2.5V. If the ▲ 1 ▼ V _M1, V _M2 are both 0V is, the initial charge is not required, further, there is an effect that it is possible also to unnecessary circuit for charging, FIG. 4 this initial in the state, ▲ 1 ▼ capacitor _{C M11, C M12} potential _V M1, _{V M2} is what both showing a configuration corresponding to the case of 0V.
[0031]
(2) When the potentials V _M1 and V _M2 of the capacitors C _M11 and C _M12 in the initial state are both 2.5 V, the capacitances C _M11 and C _M12 that fluctuate around 2.5 V (that is, , Potential V _M1 , V _M2 ) and select an appropriate one (the larger potential difference) and connect. Further, when the potentials V _M1 and V _M2 of the capacitors _{CM 11} and _{CM 12} in the initial state are both 5 V, the operation is performed in the same manner as the operation of the capacitors _{CM 11} and _{CM 12 in} the initial state described above. potential _V M1, _{V M2} are both reversed in the case of 0V, the electric potential _V M1, _{V M2} approaches the 2.5V from 5V together.
[0032]
Here, ▲ 2 ▼ _V M1, if the _{V M2} are both 2.5V, or, ▲ 3 ▼ when the _V M1, _{V M2} are both 5V is, the initial charging is necessary, in this case, the initial It provided a charging circuit for charging only one may be configured to divide the said charging circuit into two systems to charge each capacitor C _M11, C _M12.
Next, when the potentials V _M1 and V _M2 of the capacitors C _M11 and C _M12 are set to different potentials in the initial state, some more cases are conceivable (logically, between V _A and V _B ). If potential, can take any value), for example, ▲ 4 ▼ for _V M1, _{V M2,} respectively _{0V, 5V, ▲ 5 ▼ V} M1, V M2 Gaga respectively 2V, when the 3V like Can be considered. In either of the cases (4) and (5), the operation is to select and connect an appropriate one (the one with the larger potential difference) from the capacitances _CM11 and _CM12 (that is, the potentials _VM1 and _VM2 ), potential _V M1, _{V M2} will be approaches to gradually 2.5V.
[0033]
Here, when the potentials V _M1 and V _M2 of the capacitors C _M11 and C _M12 are set to different potentials in the initial state (for example, in the case of (4) and (5)), the potentials of the capacitors C _M11 and C _M12 are changed. There are several ways to charge. Specifically, for example, two circuits such as the above-described reference voltage generator 6 shown in FIG. 3 are provided to generate different reference voltages, respectively, and each of the capacitors C _M11 and C _M12 is charged by the different reference voltages. method of performing a method of changing the charging time of the capacitor _{C M11, C M12,} or a method of changing the volume itself at each capacitance _{C M11, C M12,} furthermore, such a method to combine the above methods are conceivable.
[0034]
As described above, in the embodiment of FIG. 4, various cases can be considered as described above, but these should be appropriately selected as needed. In any case, as shown in FIG. 4, the switch SW11 in the switch unit 4 controls the connection between the capacitive load C _LD (1) and the buffer unit 2 or the capacitance group 3, and the switch SW12 is One of the two capacitances C _M1 and C _M2 of the capacitance group 3 (the one having a larger potential difference from the potential after driving the buffer unit 2) is selected. That is, when the capacitive load _CLD is driven from the low level “L” to the high level “H”, the higher potential capacitor (C _M1 or C _M2 ) in the capacitor group 3 is selected. When the load _CLD is driven from the high level “H” to the low level “L”, the capacitor ( _CM1 or _CM2 ) having the lower potential in the capacitor group 3 is selected. The configuration of the reference voltage generator 6 and the initialization unit 7 described with reference to FIG. 3 may be included in this embodiment.
[0035]
In the above-described embodiment, for example, a device such as a ceramic capacitor can be used as the capacitor C _Mi , and the capacitor can be externally provided in the form of a liquid crystal panel together with a driver IC or the like. In addition, a capacitor other than a ceramic capacitor can be used as the capacitive element, and it is a matter of course that the present invention is not limited to this.
[0036]
Further, in the above description, as the capacitive load, a common electrode such as a common electrode and a storage capacitor electrode in an active matrix type liquid crystal display device is taken as an example. The present invention is not limited to the common electrode drive circuit and the storage electrode drive circuit in the liquid crystal display device described above, and can be applied to a device that drives a capacitive electrode whose input impedance is capacitive in various display devices.
[0037]
【The invention's effect】
As described above in detail, according to the display device and the method of driving the display device of the present invention, by utilizing the fact that the common electrode is a capacitive load, a part of the electric charge is stored in the newly provided capacitance. By reusing, it is possible to reduce the driving power when inverting and driving the capacitive load such as the common electrode of the liquid crystal panel, so that the power consumption of the display device can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a principle configuration of a driving circuit of a display device according to the present invention.
FIG. 2 is a timing chart for explaining the operation of the drive circuit of FIG. 1;
FIG. 3 is a circuit diagram showing one embodiment of a drive circuit of a display device according to the present invention.
FIG. 4 is a circuit diagram showing another embodiment of the drive circuit of the display device according to the present invention.
FIG. 5 is a block diagram illustrating an example of an active matrix liquid crystal display device.
FIG. 6 is a diagram illustrating a configuration of each pixel in the liquid crystal display device of FIG.
FIG. 7 is a timing chart for explaining the operation of the liquid crystal display device of FIG.
FIG. 8 is a diagram showing an equivalent circuit of an example of an active matrix type liquid crystal display device.
FIG. 9 is a block diagram illustrating an example of a driving circuit of a conventional display device.
FIG. 10 is a timing chart for explaining the operation of the drive circuit of FIG. 9;
[Explanation of symbols]
1: Capacitive electrode (common electrode)
2. Drive circuit (buffer unit)
3 (3-1 to 3-n) Capacitance group 4 Switch unit 5 Control unit 6 Reference voltage generation unit 7 Initialization unit 10 Connection control circuit 101 Display panel (LCD panel)
102 data line drive circuit 103 gate line drive circuit 104 thin film transistor (TFT)
105: liquid crystal 111: storage capacitor electrode drive circuit (capacitive electrode drive circuit)
112 ... Common electrode drive circuit (capacitive electrode drive circuit)

Claims (9)

A display device including a display panel having a capacitive electrode indicating an input characteristic of a capacitive load,
A drive circuit that drives the capacitive electrode by periodically changing the drive voltage between at least two drive potentials;
A capacitor group including two or more capacitors having a potential between the driving potentials;
A connection control circuit that controls connection between the capacitive electrode and the drive circuit, and connection between the capacitive electrode and the capacitor group,
The display device is an active matrix type liquid crystal display device, and the capacitive electrode is a counter electrode in a liquid crystal display panel of the liquid crystal display device,
A display device, wherein the charge accumulated in the capacitor group is used for a change in the drive potential applied to the capacitive electrode. The connection control circuit,
A switch unit for connecting / disconnecting the capacitive electrode of the display panel and the drive circuit, and connecting / disconnecting the capacitive electrode and the capacitor group;
When the switching operation of the switch unit drives the capacitive electrode, the capacitive electrode is connected to any one of the capacitance groups for a certain period after the output of the drive circuit changes between the drive potentials. The display device according to claim 1, further comprising a control unit configured to control connection to the display device. The capacitor group is composed of two capacitors, a first capacitor and a second capacitor, and the control unit determines a potential difference between the potential of the first and second capacitors and the potential after driving the driving circuit. 3. The display device according to claim 2, wherein the switch unit is controlled so as to be connected to one of the first and second capacitors having a large potential difference. The display device according to claim 1, wherein the driving potential is a first driving potential and a second driving potential. 5. The display device according to claim 4, wherein the capacitance group is formed of one capacitance which is biased in advance to a substantially intermediate potential between the first and second drive potentials. A method of driving a display device, comprising: a display panel having a capacitive electrode exhibiting an input characteristic of a capacitive load; and periodically driving the capacitive electrode between at least two drive potentials.
The display device is an active matrix liquid crystal display device, and the capacitive electrode is a counter electrode in a liquid crystal display panel of the liquid crystal display device,
When the drive potential of the capacitive electrode is changed, a period is provided in which the capacitive electrode is connected to a capacitor group including two or more capacitors whose potential is pre-biased to a potential between the drive potentials. A method of driving the display device, wherein the change of the drive potential applied to the capacitive electrode is performed by using charges accumulated in the group of capacitors. 7. The method according to claim 6, wherein a period during which the capacitive electrode is connected to the capacitor group is a fixed initial period in which a drive potential of the capacitive electrode is changed. The capacitance group is composed of two capacitances, a first capacitance and a second capacitance, and when changing the driving potential of the capacitive electrode, the potential of the first and second capacitors and the capacitance of the capacitive electrode are changed. 8. The method of driving a display device according to claim 7, wherein a potential difference from the driving potential is compared, and one capacitor having a large potential difference is connected to the capacitive electrode . 7. The method according to claim 6 , wherein the driving potential is two potentials, a first driving potential and a second driving potential .

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