JPH10186316A - Color liquid crystal display device and driving method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a frame response and also to suppress a momentary current by impressing scanning signals of sine waveforms on plural scanning electrodes simultaneously and impressing data signals corresponding to display colors on respective signal electrodes. SOLUTION: A scan side driving circuit 33 generates a scanning signal Ci (t) by using a voltage supplied from a driving voltage generating circuit 37 according to a timing signal from a controller 35 to impress it on an i-th ((i) row) scanning electrode 15. The scanning signal Ci (t) is shown by a trigonometric function and signals of sine waveforms are impressed on scanning electrodes. Besides, a signal side driving circuit 34 calculates a data signal Sp(t) to be impressed on a p-th ((p) column) signal electrode 16 based on display data (display colors) equivalent to one line stored in a internal memory and scanning signals C1 (t)∼CN+1 (t) with the linear joins among scanning signals C1 (t)∼CN+1 (t) and generates a signal corresponding to the data signal Sp(t) by a voltage from the driving voltage generating circuit 37 to impress it on the p-th signal electrode 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device and a method of driving a color liquid crystal display device, and more particularly to a color liquid crystal display device and a color liquid crystal display device for performing color display by utilizing birefringence of liquid crystal. Driving method.

[0002]

2. Description of the Related Art A liquid crystal display panel of a color liquid crystal display device is a transmissive type in which a liquid crystal cell formed of a glass substrate or the like is sandwiched between a pair of polarizing plates and a backlight is disposed outside one of the polarizing plates. Is common. In this case, RGB color filters are arranged at positions corresponding to each pixel of the liquid crystal cell, and color display is performed by selectively setting the liquid crystal layer of each pixel to a light transmitting state.

However, since color filters generally have low light transmittance, the display tends to be dark in a color liquid crystal display device using the color filters. For this reason, a high-luminance light source is required, and there is a problem that power consumption increases.

[0004] On the other hand, when a reflection type color liquid crystal display device is constructed using color filters, the display becomes very dark.
For this reason, there has been a problem that it is difficult to perform color display using a color filter even in a reflective liquid crystal display device.

In order to solve the above problem, Japanese Patent Application No.
333590 discloses a color liquid crystal display device capable of performing bright color display without using a color filter by using the birefringence of liquid crystal, and a driving method thereof.

[0006] The first disclosed in Japanese Patent Application No. 6-333590.
In the driving method, the liquid crystal is driven by simple matrix driving for supplying a display signal while sequentially scanning a plurality of scanning electrodes. However, in this driving method, a so-called frame response occurs, which causes a problem such as a flickering display.

[0007]

SUMMARY OF THE INVENTION Accordingly, Japanese Patent Application No. Hei 6-3
No. 33590 discloses a second driving method for removing a frame response and displaying an appropriate color image by simultaneously applying a rectangular wave selection signal to a plurality of scanning electrodes.

However, according to the second driving method, a rectangular wave is applied to each scanning electrode and each signal electrode. For this reason, a signal whose voltage changes sharply is applied to each pixel, and an instantaneous current flows through each electrode. There is a problem that this instantaneous current hinders efficient operation of the liquid crystal display device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a color liquid crystal display device and a method of driving a color liquid crystal display element capable of suppressing a frame response and suppressing generation of an instantaneous current. And

[0010]

In order to achieve the above object, a color liquid crystal display device according to a first aspect of the present invention comprises: a pair of transparent substrates opposed to each other at a predetermined interval; A plurality of scanning electrodes formed to be arranged in a predetermined direction on a facing surface of one of the transparent substrates, and a plurality of scanning electrodes are arranged in a predetermined direction so as to face the plurality of scanning electrodes on a facing surface of the other transparent substrate. A plurality of signal electrodes formed, a liquid crystal layer formed by sealing liquid crystal between the pair of transparent substrates,
A polarizing plate disposed on the outer surface side of at least one of the transparent substrates of the pair of transparent substrates, and elliptically polarized light transmitted through the liquid crystal layer by a birefringent action of the liquid crystal, and applied to the liquid crystal layer. A color liquid crystal display device that changes a retardation of the liquid crystal layer by changing a driving voltage, and changes a polarization state of elliptically polarized light to change a color of transmitted light. Scanning electrode driving means for simultaneously applying a sine waveform scanning signal, and signal electrode driving means for applying a data signal corresponding to a display color of each pixel to each signal electrode, I do.

Further, the scanning electrode driving means includes, for example,
The scan signal having an orthonormal function as shown in Expression 2 is applied to the scan electrode.

Further, the signal electrode driving means, for example, calculates each of the scanning signals and the imaginary scanning signal according to Equation 3 according to a coupling coefficient determined based on the display color of each pixel and the total number of display colors. The data signal obtained by the linear combination is applied to each of the signal electrodes.

According to the above arrangement, a scanning signal indicating a sine waveform is applied to the plurality of scanning electrodes, and a signal corresponding to a display color, for example, a signal obtained by linearly combining the scanning signals is applied to the signal electrodes. For this reason, the driving voltage of the liquid crystal of the synthetic wave by the linear combination of the sine waveforms is applied to each pixel, and the temporal change of the driving voltage becomes gentle. Therefore, when the temporal change of the drive voltage is steep as in the case of applying the drive voltage of the rectangular wave, the instantaneous current flows, but in the composite wave of the sine waveform,
There is no instantaneous current. Thus, a color liquid crystal display device in which an instantaneous current that hinders efficient operation of the liquid crystal does not flow can be obtained.

A method of driving a color liquid crystal display element according to a second aspect of the present invention includes a pair of transparent substrates opposed to each other at a predetermined interval, and one of the pair of transparent substrates. A plurality of scanning electrodes formed in a predetermined direction on the opposite surface of the transparent substrate, and a plurality of signal electrodes formed in a predetermined direction on the other surface of the transparent substrate facing the plurality of scanning electrodes. A liquid crystal layer formed by enclosing liquid crystal between the pair of transparent substrates, and a polarizing plate disposed on an outer surface side of at least one of the pair of transparent substrates, and transmitting through the liquid crystal layer. A color that changes the color of transmitted light by changing the liquid crystal driving voltage applied to the liquid crystal layer to change the retardation of the liquid crystal layer, changing the polarization state of the elliptically polarized light, and changing the polarization state of the liquid crystal driving voltage applied to the liquid crystal layer. Driving method of liquid crystal display element A scan signal having a sine waveform as shown in, for example, Equation 1 is simultaneously applied to a plurality of scan electrodes, and a data signal corresponding to a display color of each pixel on the scan electrode selected as a signal electrode. Is applied.

The scanning signal is constituted by, for example, a signal having an orthonormal function.

The data signal comprises, for example, as shown in Equation 3, the scanning signal, a virtual scanning signal, and a signal corresponding to the display color of each pixel.

The data signal is a signal obtained by linearly combining each of the scanning signals and the virtual scanning signal in accordance with a coefficient determined based on a display color and the total number of display colors.

According to the above arrangement, a scanning signal showing a sine waveform is applied to the plurality of scanning electrodes. For this reason, the driving voltage of the liquid crystal of the synthetic wave by the linear combination of the sine waveforms is applied to each pixel, and the temporal change of the driving voltage becomes gentle.

When a temporal change of the drive voltage is steep, such as when a rectangular drive voltage is applied, an instantaneous current flows. However, an instantaneous current does not occur in a composite wave of a sine waveform. Thus, a color liquid crystal display device in which an instantaneous current that hinders efficient operation of the liquid crystal does not flow can be obtained.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present embodiment will be described below with reference to FIGS.

First, the configuration of the color liquid crystal display device according to the present embodiment will be described. FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display panel 11 of a color liquid crystal display device.

In FIG. 1, a liquid crystal cell 12 of a liquid crystal display panel 11 has an upper glass substrate 13 and a lower glass substrate 14.
Are arranged facing each other with a fine interval (interval of several μm) enclosing the liquid crystal layer. Glass substrates 13, 14
A plurality of scanning electrodes 15 and a plurality of signal electrodes 16 made of a transparent conductive material such as ITO are disposed on each of the facing surfaces in such a manner as to cross each other.

The alignment films 17 and 18 are formed on the scanning electrodes 1 disposed on the inner surfaces of the respective glass substrates 13 and 14 of the liquid crystal cell 12.
5 and the surface of the signal electrode 16 for regulating the alignment direction of the liquid crystal molecules. For example, alignment film 1
The liquid crystal molecules 7 and 18 are subjected to an alignment treatment such as a rubbing method in which the surface is rubbed with a cloth, so that the liquid crystal molecules approach the major axis direction in the direction of the alignment treatment.

The sealing material 19 comprises upper and lower glass substrates 13,
It is arranged around the space between the substrates 14 and holds the glass substrates at a predetermined interval, and seals the liquid crystal in that region.

The liquid crystal layer 20 has a structure in which the liquid crystal molecules 20 a move from one glass substrate 13 to the other glass substrate 14.
They are arranged so as to be twisted at an angle of 80 ° to 270 °. That is, the liquid crystal cell 1 according to the present embodiment
2 is a super twisted nematic (STN) type liquid crystal cell.

The phase difference plate 21 elliptically polarizes the linearly polarized light transmitted through the upper polarizing plate 22, and sets its optical axis (fast or slow axis) to the upper polarizing plate 22 adjacent to the phase difference plate 21. Are arranged so as to be obliquely shifted by a predetermined angle with respect to the transmission axis (22a).

The upper polarizer 22 and the lower polarizer 23 block the polarization component of the incident light entering the liquid crystal display panel 11 in the direction of the absorption axis and transmit the polarization component orthogonal thereto.

The reflecting plate 24 is provided on the lower surface of the lower polarizing plate 23, and reflects light incident on the upper polarizing plate 22 and transmitted through the liquid crystal cell 12 and the lower polarizing plate 23 to the liquid crystal cell 12 side. Things.

FIG. 2 shows the alignment direction in the liquid crystal cell 12, the optical axis of the phase difference plate 21, the polarization plate 22,
It is the figure which showed typically an example of the combination of 23 transmission axes by the top view for every component.

The straight lines 22a and 23a with double arrows in FIGS. 2A and 2D are the transmission axes of the upper polarizing plate 22 and the lower polarizing plate 23, respectively, and the straight line 21a in FIG. The optical axis of the plate 21.

The straight line 20b with a single arrow in FIG.
20c is the upper alignment film 1 in the liquid crystal cell 12, respectively.
7 and the alignment processing direction applied to the lower alignment film 18.

The dashed line S in FIG. 2 is a reference line along the left-right direction of the display surface, and is provided for convenience of explanation.

As shown in FIG. 2C, the alignment processing directions 20b and 20c of the liquid crystal cell 12 are set to directions inclined by a predetermined angle θ _{3 in} opposite directions with respect to the reference line S. As a result, the alignment state of the liquid crystal molecules 20a changes from the lower glass substrate 14 toward the upper glass substrate 13 by an arrow θ _4.
The orientation state twisted in the angle and direction indicated by.

The optical axis 21a of the phase difference plate 21 shown in FIG. 2B is a slow axis here and obliquely intersects the reference line S at a predetermined inclination angle θ ₂ .

Further, as shown in FIGS. 2A and 2D, in this embodiment, a pair of upper and lower polarizing plates 2 is used.
The transmission axes 22a and 23a of the reference numerals 2 and 23 are obliquely inclined by θ ₁ and θ _{5 with} respect to the reference line S, respectively.

In the color liquid crystal display device having the liquid crystal display panel 11 having the above structure, the light enters the liquid crystal display panel 11 by the polarization action of the phase difference plate 21 and the polarization action of the liquid crystal cell 12 and is reflected by the reflection plate 24. To color light emitted outside the liquid crystal display panel 11. At that time, the liquid crystal driving method of the liquid crystal cell 12 modulates a liquid crystal driving signal to control an effective voltage applied to each pixel to display a desired color.

Next, the coloring principle of the color liquid crystal display device will be described. The light incident from above the liquid crystal display panel 11 in FIG. 1 is converted into linearly polarized light by transmitting through the upper polarizing plate 22, and further, in the process of transmitting through the phase difference plate 21, the position of the optical axis 21 a of the phase difference plate 21 and the like. Is subjected to a polarization action in accordance with the optical arrangement condition and the retardation value, and becomes elliptically polarized light. In the process of passing through the liquid crystal cell 12, the elliptically polarized light is further subjected to a polarization action according to the optical arrangement conditions and the retardation value of the liquid crystal cell 12, so that its polarization state changes.

When the elliptically polarized light subjected to the polarization action by the phase difference plate 21 and the liquid crystal cell 12 is incident on the lower polarizing plate 23, the elliptically polarized light of the elliptically polarized light coincides with the transmission axis 23a of the lower polarizing plate 23. Only the component wavelength light is the lower polarizer 2
3 is transmitted. Therefore, light (linearly polarized light) emitted from the lower polarizing plate 23 is in a colored state. The hue is
It is determined mainly by the retardation value of the phase difference plate 21 and the retardation value of the liquid crystal cell 12.

Further, the light having passed through the lower polarizing plate 23 is reflected by the reflecting plate 24 and is emitted to the upper surface side of the liquid crystal display panel 11 through a path opposite to the above-described optical path. Is obtained.

The retardation of the phase difference plate 21 is
The product Δn · of the refractive index anisotropy Δn of the retardation plate 21 and the plate thickness d
It is determined by d. Further, the retardation of the liquid crystal cell 12 is determined by the alignment state of the liquid crystal molecules 20a. Therefore, the voltage value applied to the liquid crystal cell 12 is changed to change the liquid crystal molecules 2
By changing the alignment state of the liquid crystal cell 12a,
Of the liquid crystal cell 12 can be changed.

Specifically, when no voltage is applied to the liquid crystal cell 12, the light incident on the liquid crystal display panel 11 is
The polarization action of the retardation plate 21 and the polarization action according to the initial twist angle θ ₄ of the liquid crystal molecules 20a are received, and the light is converted into elliptically polarized light. Then, the liquid crystal display panel 1 transmits through the lower polarizing plate 23, is reflected by the reflecting plate 24, and passes through a reverse path.
The color of the emitted light at the time of emission to the upper surface side of 1 is a color corresponding to the retardation of both the retardation plate 21 and the liquid crystal layer 20 oriented at the initial twist angle θ ₄ .

The transparent electrodes 15 and 16 of the liquid crystal cell 12
When a voltage is applied in between and the effective voltage value is gradually increased, the liquid crystal molecules 20a gradually rise from the initial twisted state. The retardation of the liquid crystal cell 12 changes according to the rising alignment state, and the light incident on the liquid crystal display panel 11 is deflected by the polarization action of the retardation plate 21 and the liquid crystal cell 1.
2 and a polarization action corresponding to the changed retardation, and the light becomes elliptically polarized light according to the polarization action. Therefore, the display color at that time is different from the color when no voltage is applied to the liquid crystal cell 12 described above.

Further, the liquid crystal cell 12 is provided with liquid crystal molecules 20a.
When a voltage having a voltage that rises substantially vertically is applied, the retardation of the liquid crystal cell 12 also becomes substantially “0”. Therefore, the polarization action of the liquid crystal cell 12 is almost eliminated, and the light incident on the liquid crystal display panel 11 is
It becomes elliptically polarized light by only one polarization action. Then, the elliptically polarized light is emitted from the liquid crystal display panel 11 through the lower polarizing plate 23, the reflecting plate 24, and the reverse path, and is colored in a color corresponding to the retardation of the retardation plate 21. For each of the angles θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ described above,
For example, θ ₁ is 5 °, θ ₂ is 140 °, θ ₃ is 35 °,
theta ₄ 250 °, theta ₅ is preferably about 80 °. The retardation of the retardation plate 21 is about 430 nm, the Δn of the liquid crystal cell 12 is 0.13, the liquid crystal layer thickness d is 6.8 μm, and the Δn · d at that time is preferably about 884 nm. In this case, in the liquid crystal display panel 11 having the above configuration, by applying a predetermined effective driving voltage value (hereinafter, represented by * Vk) to the liquid crystal cell 12, the red,
Green and blue color displays are obtained.

FIG. 3 is a block diagram showing a configuration of the color liquid crystal display device 31 of the present embodiment. As shown in FIG. 3, the color liquid crystal display device 31 includes a liquid crystal display panel 11,
It comprises a scanning side drive circuit 33, a signal side drive circuit 34, a controller 35, and a drive voltage generation circuit 37.

The liquid crystal display panel 11 has the configuration described with reference to FIGS.

The scanning side driving circuit 33 includes a controller 35
Is a driver that supplies a scan signal having a predetermined waveform to the scan electrode 15 using a voltage supplied from the drive voltage generation circuit 37 in accordance with a timing signal supplied from the scan electrode 15.

The signal side driving circuit 34 includes a memory for storing, for example, display data for one line or one frame, and displays the display color (gradation) of each pixel and the scanning signal in accordance with the timing signal supplied from the controller 35. Is a driver that generates a signal voltage determined by the following formula and supplies the signal voltage to each signal electrode 16.

The controller 35 controls the liquid crystal display panel 11
Is used to control the overall timing when display control is performed. For example, from the display data input to the controller 35, the vertical synchronization signal φV and the horizontal synchronization signal φ
H and the scanning side drive circuit 33
And a timing signal (a frame clock, a line clock, and a dot clock) for driving the signal-side drive circuit 34. Further, the controller 35 includes a drive voltage generation circuit 3 for generating various drive voltages for driving the liquid crystal.
7 to output a control signal.

The drive voltage generation circuit 37 is
Various drive voltages are supplied to the signal-side drive circuit 34 and the scan-side drive circuit 33 based on the control signals from the control circuit 5.

Next, the operation of the color liquid crystal display device having the above configuration will be described. Here, the number of the scanning electrodes 15 is N, and the frame period is _Tf . According to the timing signal supplied from the controller 35, the scanning-side driving circuit 33 generates the scanning signal C _i (t) shown in Expression 1 using the voltage supplied from the driving voltage generating circuit 37, and generates the i-th (i-th) signal (i). To the scanning electrode 15 in the row (1).

[0051]

(Equation 1)

The scanning signal C _i (t) satisfies the condition shown in Expression 2. As is clear from Equation 2, the scanning signal C _i (t) has an inner product of the operation voltage Vo and an inner product of the scanning signal C _i (t) of 0.
Which is an orthonormal function. Scan signal C
_{Since i} (t) is represented by a trigonometric function according to Equation 1, a sine waveform signal is applied to the scan electrodes. In addition,
The N + 1-th virtual scanning signal C _{N + 1} (t) that is not actually applied is also considered.

[0053]

(Equation 2)

On the other hand, the signal-side drive circuit 34 generates a signal p based on one line of display data (display color) stored in the internal memory and the scanning signals C ₁ (t) to C _{N + 1} (t). The data signal Sp (t) to be applied to the (th p-th) signal electrode 16 is obtained by a linear combination of the scanning signals C ₁ (t) to C _{N + 1} (t) as shown in Expression 3. Further, the signal side drive circuit 34 generates a signal corresponding to the obtained data signal Sp (t) by the voltage from the drive voltage generation circuit 37 and applies the signal to the p-th (p-th column) signal electrode 16.

[0055]

Equation 3] _{Sp (t) = a 1p C} 1 (t) + a 2p C 2 (t) + a 3p C 3 (t)
+ ・ ・ ・ ・ ・ ・ + A _Np C _N (t) + a _{N + 1p} C _{N + 1} (t)

Here, M is the total number of gradations (0, 1, 2,...).
.., M-1 gradation), and _Kip means the gradation of the pixel in the i-th row and p-th column (the pixel at the intersection of the i-th scanning electrode and the p-th signal electrode).

The scanning side driving circuit 33 and the signal side driving circuit 34
By applying these signals to the scanning electrode 15 and the signal electrode 16, the liquid crystal of the pixel in the i-th row and p-th column displays the difference ｛C _i (t) between the scanning signal C _i (t) and the data signal _Sp (t). t) -S _p (t)} is applied. The effective value _Vip of the applied voltage of each pixel is represented by Expression 4.

[0058]

(Equation 4)

Variables M and M are set so that the effective voltage _Vip is a voltage for displaying each color desired to be displayed due to the characteristics of the liquid crystal display element.
If N and Vo are selected, a plurality of scanning electrodes 15 can be simultaneously selected and an arbitrary color can be displayed using the birefringence effect of the liquid crystal layer 20.

Next, the above-mentioned driving method will be described in detail by taking as an example a case where the liquid crystal display panel 11 having the configuration shown in FIGS. 1 and 2 is driven. The liquid crystal display panel 11 having the configuration shown in FIGS. 1 and 2 displays “red” when the effective value of the applied voltage is 1.98 V or less, and displays “green” when the effective value of the applied voltage is 2.10 V to 2.18 V.
2. Display "blue" at 30V or more. When display is performed using these three display colors, the above-mentioned variable (the number of gradations or the number of colors) M is 3, and the voltage when k _ip = 0 is 1.9.
8V or less, the voltage when k _ip = 1 is 2.10V to 2.18
The voltage Vo and the number N of scan electrodes are selected so that the voltage when V, k _ip = 2 is 2.30 V or more.

As described above, the voltage Vo and the number of scanning electrodes N
Is selected, and the above-mentioned signals C _i (t) and _Sp (t) are applied to the scanning electrode 15 and the signal electrode 16, whereby an arbitrary color image can be displayed.

Assuming that the number of the scanning electrodes 15 is four, for example, when Vo = 1.5 V, red display (k _ip =
The voltage at the time of 0) is 1.5V, the voltage at the time of green display (k _ip = 1) is 2.12V, and the voltage at the time of blue display (k _ip = 2) is 2.60V. Can be displayed.

The scanning signal C ₁ satisfying the relationship shown in Expression 2
Shown -C ₄ and the virtual scanning signal C ₅ to FIG. 4, respectively. Further, the pixels in the first to fourth rows of the first column (p = 0) are blue, green,
Consider a case where green and red (k ₁₁ = 2, k ₂₁ = k ₃₁ = 1, k ₄₁ = 0) are displayed, respectively. In this case, the coupling coefficients a _{11 to} a ₅₁ in Expression 3 are as follows. a ₁₁ = − ／, a ₂₁ = 0, a ₃₁ = 0, a ₄₁ = １ ／, a ₅₁ = 1 / √2 = 0.707 tone signals S ₁ to be applied to one row of the signal electrode 16 has a waveform shown in FIG.

When the scanning signals C _{1 to} C ₄ and the data signal S ₁ are applied to the corresponding scanning electrodes 15 and signal electrodes 16, the liquid crystal of the pixels in the first column and first row has the structure shown in FIG. A voltage waveform {C ₁ -S ₁ } is applied, and its effective value is 2.6.
It becomes 0 V and blue is displayed. Similarly, the liquid crystal of the second to fourth pixels has voltage waveforms {C ₂ −S ₁ }, {C ₃ } shown in FIG.
−S ₁ }, {C ₄ −S ₁ } are applied, and the effective values of the applied voltages are 2.12 V, 2.12 V, 1.50 V, green,
Green and red are displayed respectively.

As described above, according to the present embodiment,
If each scan electrode 15 has a sine
A scanning signal having a waveform is applied and a signal electrode 16 is applied to each pixel.
Hopeful A voltage signal for displaying a color is applied. this
Is combined with each pixel by linear combination of sine waveform
Is applied, and the voltage of the conventional square wave is applied.
The instantaneous current generated when is applied disappears.

In this embodiment, in order to facilitate understanding, the display colors are red (green) and blue (three gradations) and the number of scanning electrodes is four. The number and the number of scanning electrodes are arbitrary. For example, if the number of display colors is 5 (the voltage is V ₁
Hereinafter, V _{1 to} V ₂ , V _{2 to} V ₃ , V _{3 to} V ₄ , and 5 types of colors displayed by V ₄ or more), the gradation for displaying red is 0, and the gradation for displaying green is 0. The voltage value or the like may be obtained by setting the gray level for displaying 3 and 5 for blue.

In the above embodiment, the signal side driving circuit 37
In the above, it has been described that the data signal is generated by performing the calculation represented by Expression 3. However, a signal corresponding to the calculation result may be supplied to the signal side driving circuit 34 by performing a necessary calculation outside.

In the above description, the scanning side driving circuit 33 and the signal side driving circuit 34 generate the scanning signal and the data signal using the driving voltage generated by the driving voltage generating circuit 34. 33 and the signal side drive circuit 34 may respectively generate necessary voltages.

[0069]

As described above, according to the color liquid crystal display device and the method for driving the color liquid crystal display element of the present invention, the driving voltages applied to the respective pixels are synthesized by the linear combination of the sine waveforms. For this reason, the instantaneous voltage generated when the drive voltage is synthesized by inputting the rectangular wave in the related art is eliminated, and an efficient operation of the liquid crystal can be obtained.

Further, according to the color liquid crystal display device and the method of driving the color liquid crystal display element of the present invention, a high-quality image free from the influence of the frame response can be displayed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display panel of a color liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view schematically showing an example of a combination of an alignment processing direction, an optical axis of a phase difference plate, and a transmission axis of a polarizing plate in a liquid crystal cell in a plan view of each component.

FIG. 3 is a block diagram illustrating a configuration of a color liquid crystal display device according to the present embodiment.

FIG. 4 is a diagram showing waveforms of signals applied to a scanning electrode and a signal electrode in the present embodiment.

FIG. 5 is a diagram showing a combined driving waveform applied to each pixel in the present embodiment.

[Explanation of symbols]

11 ... liquid crystal display panel, 12 ... liquid crystal cell,
13 upper glass substrate, 14 lower glass substrate, 15 scanning electrode, 16 signal electrode,
17 ... alignment film, 18 ... alignment film, 19 ...
Sealing material, 20 ... Liquid crystal layer, 20a ... Liquid crystal molecules, 21 ... Retardation plate, 22 ... Upper polarizing plate, 2
3 ... Lower polarizing plate, 24 ... Reflector, 31 ...
-Color liquid crystal display device, 33 ... Scanning side drive circuit, 34 ... Signal side drive circuit, 35 ... Controller, 37 ... Drive voltage generation circuit

Claims (7)

[Claims] A pair of transparent substrates opposed to each other at a predetermined interval; and a plurality of scanning electrodes formed in a predetermined direction on a facing surface of one of the pair of transparent substrates; A plurality of signal electrodes formed in a predetermined direction facing the plurality of scanning electrodes on the other surface of the transparent substrate, and a liquid crystal layer formed by enclosing liquid crystal between the pair of transparent substrates. A polarizing plate disposed on the outer surface side of at least one of the pair of transparent substrates, wherein the light transmitted through the liquid crystal layer is elliptically polarized by the birefringence of the liquid crystal, and applied to the liquid crystal layer. A color liquid crystal display device that changes the retardation of the liquid crystal layer by changing a liquid crystal driving voltage and changes the polarization state of elliptically polarized light to change the color of transmitted light, wherein the plurality of scan electrodes simultaneously have a sine waveform. Run to apply signal And electrode driving means, to each of said signal electrodes, a color liquid crystal display device comprising: the signal electrode driving means for applying a data signal corresponding to the display color of each pixel, a. 2. The color liquid crystal display device according to claim 1, wherein said scanning electrode driving means applies a scanning signal having a relationship of an orthonormal function to said plurality of scanning electrodes. 3. The signal electrode driving means obtains the scanning signal and the virtual scanning signal by linearly combining them in accordance with a combination coefficient determined based on the display color of each pixel and the total number of display colors. 3. The color liquid crystal display device according to claim 2, wherein the applied data signal is applied to each of the signal electrodes. 4. A pair of transparent substrates opposed to each other at a predetermined interval, and a plurality of scanning electrodes formed in a predetermined direction on an opposing surface of one of the pair of transparent substrates; A plurality of signal electrodes formed in a predetermined direction facing the plurality of scanning electrodes on the other surface of the transparent substrate, and a liquid crystal layer formed by enclosing liquid crystal between the pair of transparent substrates. A polarizing plate disposed on the outer surface side of at least one of the pair of transparent substrates, wherein the light transmitted through the liquid crystal layer is elliptically polarized by the birefringence of the liquid crystal, and applied to the liquid crystal layer. A method of driving a color liquid crystal display element that changes the retardation of the liquid crystal layer by changing the liquid crystal driving voltage to be changed, and changes the polarization state of elliptically polarized light to change the color of transmitted light. Sine waveform scanning signal It applied to, and method of driving a color liquid crystal display element characterized by applying a data signal corresponding to the display color of each pixel on the scanning electrode selected in the signal electrode. 5. The method according to claim 4, wherein the scanning signal comprises a signal having an orthonormal function. 6. A color liquid crystal display device according to claim 5, wherein said data signal comprises the scanning signal, a virtual scanning signal, and a signal corresponding to a display color of each pixel. Drive method. 7. The data signal is a signal obtained by linearly combining each of the scanning signals and the virtual scanning signal according to a coefficient determined based on a display color and the total number of display colors. The method for driving a color liquid crystal display element according to claim 6, wherein: