JP2005208600A - Liquid crystal display device, and method and circuit for driving the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with which a high-speed response, the high performance of displaying a moving image, the high efficiency of utilizing light, and low electric power consumption are realized, and the display is less deteriorated in spite of a change in environmental temperature. <P>SOLUTION: The liquid crystal display device includes a display section 200, an image signal drive circuit 201, a scan signal drive circuit 202, a common electrode potential control circuit 203, and a synchronous circuit 204. The display section 200 has scan electrodes, image signal electrodes, a plurality of pixel electrodes arranged in a matrix, a plurality of switching elements for transmitting an image signal to the pixel electrodes, and a common electrode. The common electrode potential control circuit 203 changes an electric potential of the common electrode into a pulse shape, after the scan signal drive circuit 202 has scanned all the scan electrodes and the image signal has been transmitted to the pixel electrodes. Alternatively, the image signal is overdriven. Alternatively, torque for returning to a no-voltage-application state is increased. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, a driving method thereof, and a driving circuit thereof, and more particularly to a highly efficient liquid crystal display device capable of high-speed response, a driving method thereof, and a driving circuit thereof.

  With the progress of the multimedia era, liquid crystal display devices are rapidly changing from small ones used in projector devices, mobile phones, viewfinders, etc. to large ones used in notebook PCs, monitors, televisions, etc. The spread is progressing. In addition, medium-sized liquid crystal display devices are indispensable for electronic devices such as viewers and PDAs, as well as game machines such as portable game machines and pachinko machines. On the other hand, liquid crystal display devices are used everywhere from home appliances such as refrigerators and microwave ovens. At present, most liquid crystal display elements are of the twisted nematic (twisted nematic, hereinafter referred to as TN) type. This TN type liquid crystal display element uses a nematic liquid crystal composition. When the conventional TN type is driven in a simple matrix, the display quality is not high and the number of scanning lines is limited. Therefore, in the simple matrix drive, an STN (Super Twisted Nematic) system is mainly used instead of the TN type. This method has improved contrast and viewing angle dependency compared to the initial simple matrix driving method using the TN type. However, the STN liquid crystal display device has a slow response speed and is not suitable for moving image display. In order to improve the display performance of this simple matrix drive, an active matrix system in which a switching element is provided for each pixel has been developed and widely used. For example, a TN-TFT method using a thin film transistor (TFT) is generally used for the TN display method. Since the active matrix method using TFTs has higher display quality than simple matrix driving, the TN-TFT method is currently the mainstream in the market.

  On the other hand, in response to a demand for higher image quality, a method for improving the viewing angle has been researched and developed and put into practical use. As a result, the current mainstream of high-performance liquid crystal displays is a method using a compensation film in the TN type, an in-plane switching (IPS) mode, or a multi-domain vertical alignment (MVA). Three types of TFT type active matrix liquid crystal display devices in domain vertical aligned mode are mainstream.

  In these active matrix liquid crystal display devices, since an image signal of 30 Hz is normally used and positive / negative writing is performed, it is rewritten every 60 Hz and the time for one field is about 16.7 ms (milliseconds). That is, the total time of both positive and negative fields is called one frame and is about 33.3 ms. On the other hand, the response speed of the current liquid crystal is about this frame time even in the fastest state, considering the response between halftone displays. Therefore, when displaying a video signal composed of a moving image, when displaying a high-speed computer image (CG), and when displaying a high-speed game image, a response speed faster than the current frame time is required. .

  On the other hand, currently, the mainstream pixel size is about 100 ppi (pixel per inch), and further high definition has been achieved by the following two methods. One method is to increase the processing accuracy and reduce the pixel size, and the other method is to switch the backlight, which is the illumination light of the liquid crystal display device, to red, green, and blue in time, and to synchronize with it, red A field sequential color liquid crystal display that displays green and blue images. In this method, since it is not necessary to spatially arrange the color filters, the resolution can be increased to three times that of the conventional method. In the field sequential liquid crystal display device, since one color needs to be displayed in 1/3 time of one field, the time available for display is about 5 ms. Accordingly, the liquid crystal itself is required to respond faster than 5 ms.

  Various technologies have been studied from the necessity of such high-speed liquid crystals, and several high-speed display mode technologies have been developed. These high-speed liquid crystal technologies are roughly divided into two tides. One is a technique for speeding up the above-described nematic liquid crystal, which is the mainstream, and the other is a technique using a spontaneous polarization type smectic liquid crystal having spontaneous polarization and capable of high-speed response. The speed of the nematic liquid crystal, which is the first trend, is mainly based on the following means. (1) Thinning the cell gap and increasing the electric field strength at the same voltage, (2) Applying a high voltage to increase the electric field strength and promoting state change (overdrive method), (3) Viscosity (4) Use a mode considered to be high speed in principle.

  The following problems also occur in such a high-speed nematic liquid crystal. In the high-speed nematic liquid crystal, since the liquid crystal response is almost completed within the frame, the capacitance change of the liquid crystal layer due to the dielectric anisotropy becomes extremely large. This capacitance change causes a change in the holding voltage to be written and held in the liquid crystal layer. Such a change in holding voltage, that is, a change in effective applied voltage lowers contrast because of insufficient writing. If the same signal is continuously written, the luminance continues to change until the holding voltage does not change, and several frames are required to obtain a stable luminance.

  In order to prevent such a response requiring several frames, it is necessary to have a one-to-one correspondence between the applied signal voltage and the obtained transmittance. In active matrix driving, the transmittance after the liquid crystal response is determined not by the applied signal voltage but by the amount of charge stored in the liquid crystal capacitance after the liquid crystal response. This is because the active drive is a constant charge drive in which the liquid crystal responds with the held charge. The amount of charge supplied from the active element is determined by accumulated charge before writing a predetermined signal and newly written write charge, if a minute leak or the like is ignored. In addition, the accumulated charge after the liquid crystal has responded also varies depending on pixel design values such as the physical constants and electrical parameters of the liquid crystal and the accumulation capacitance. Therefore, in order to obtain the correspondence between the signal voltage and the transmittance, (1) the correspondence between the signal voltage and the write charge, (2) the accumulated charge before writing, and (3) the information for calculating the accumulated charge after the response. And actual calculations are required. As a result, a frame memory for storing (2) over the entire screen and the calculation units (1) and (3) are required.

  On the other hand, as a method of taking a one-to-one correspondence without using the frame memory and the calculation unit, a reset pulse method in which a reset voltage that aligns with a predetermined liquid crystal state before writing new data is often used. It is done. As an example, a technique described on pages L-66 to L-69 (Non-Patent Document 1) of IDC 1997 will be described. In this non-patent document 1, an OCB (Optical Compensated Birefrigence or Optical Compensated Bend) mode in which the alignment of a nematic liquid crystal is a pi-type alignment and a compensation film is added is used. Yes. The response speed of the liquid crystal mode is about 2 to 5 milliseconds, which is much faster than the conventional TN mode. As a result, the response should end within one frame, but as described above, several frames are required until a stable transmittance is obtained due to a drastic decrease in holding voltage due to a change in dielectric constant due to the response of the liquid crystal. Cost. Therefore, FIG. 5 of Non-Patent Document 1 shows a method of always writing black display after writing white display within one frame. This figure is referred to as FIG. In FIG. 44, the horizontal axis represents time, and the vertical axis represents luminance. A dotted line represents a luminance change in the case of normal driving, and has reached a stable luminance in the third frame. According to this reset pulse method, since a predetermined state is always obtained when new data is written, a one-to-one correspondence of constant transmittance is seen with respect to the written constant signal voltage. This one-to-one correspondence makes it very easy to generate a driving signal, and at the same time, means such as a frame memory for storing previous writing information is not necessary.

  Here, the pixel configuration of the active matrix liquid crystal display device is summarized. FIG. 41 shows an example of a pixel circuit for one pixel of a conventional active matrix liquid crystal display device. As shown in the figure, in a pixel of an active matrix liquid crystal display device, a gate electrode is connected to a scanning line (or scanning signal electrode) 901, and one of a source electrode and a drain electrode is a signal line (or video signal electrode). ) 902, and the other of the source electrode and the drain electrode is connected to the pixel electrode 903, a MOS transistor (Qn) (hereinafter referred to as transistor (Qn)) 904, the pixel electrode 903 and the storage capacitor electrode 905 And a liquid crystal 908 sandwiched between a pixel electrode 903 and a counter electrode (or common electrode) Vcom 907.

  In a notebook personal computer (notebook PC) that currently forms a large application market for liquid crystal display devices, an amorphous silicon thin film transistor (hereinafter referred to as a-Si TFT) or polysilicon is usually used as the transistor (Qn) 904. Thin film transistors (hereinafter referred to as p-Si TFTs) are used, and TN liquid crystal is used as a liquid crystal material. FIG. 42 shows an equivalent circuit of a TN liquid crystal. As shown in the figure, the equivalent circuit of the TN liquid crystal is a liquid crystal capacitance component C3 (its capacitance Cpix), a resistor R1 (its resistance value Rr) and a capacitor C1 (its capacitance Cr) connected in parallel. Can be represented by a circuit. In this equivalent circuit, the resistance value Rr and the capacitance Cr are components that determine the response time constant of the liquid crystal.

  When such a TN liquid crystal is driven by the pixel circuit shown in FIG. 41, the scanning line voltage Vg, the signal line voltage (or video signal voltage) Vd, and the voltage of the pixel electrode 903 (hereinafter referred to as pixel voltage) Vpix. The timing chart is shown in FIG. As shown in FIG. 43, when the scanning line voltage Vg becomes the high level VgH during the horizontal scanning period, the n-type MOS transistor (Qn) 904 is turned on, and the signal line voltage Vd input to the signal line 902 is obtained. Is transferred to the pixel electrode 903 via the transistor (Qn) 904. A TN liquid crystal normally operates in a so-called normally white mode in which light is transmitted when no voltage is applied.

  Here, a voltage that increases the light transmittance through the TN liquid crystal is applied as the signal line voltage Vd over several fields. When the horizontal scanning period ends and the scanning line voltage Vg becomes low level, the transistor (Qn) 904 is turned off, and the signal line voltage transferred to the pixel electrode 903 is held by the storage capacitor 906 and the liquid crystal capacitor Cpix. . At this time, the pixel voltage Vpix causes a voltage shift called a feedthrough voltage via the gate-source capacitance of the transistor (Qn) 904 at the time when the transistor (Qn) 904 is turned off. This voltage shift is indicated by Vf1, Vf2, and Vf3 in FIG. 43. The amount of the voltage shifts Vf1 to Vf3 can be reduced by designing the value of the storage capacitor 906 to be large.

  The pixel voltage Vpix is held in the next field period until the scanning line voltage Vg becomes high level again and the transistor (Qn) 904 is selected. The TN liquid crystal is switched according to the held pixel voltage Vpix, and the transmitted light of the liquid crystal transitions from a dark state to a bright state as indicated by the light transmittance T1. At this time, as shown in FIG. 43, the pixel voltage Vpix fluctuates by ΔV1, ΔV2, and ΔV3 in each field during the holding period. This is because the capacitance of the liquid crystal changes according to the response of the liquid crystal. Normally, the storage capacitor 906 is designed with a large value of 2 to 3 times or more the pixel capacitance Cpix so as to minimize this variation. As described above, the TN liquid crystal can be driven by the pixel circuit shown in FIG.

  Now, as a technique having the effect of mixing the overdrive method and the reset method, the common voltage (common electrode voltage (or counter electrode voltage)) shown in JP-T-2001-506376 (Patent Document 1) is modulated. There is technology. FIG. 2C of Patent Document 1 is cited as FIG. In the present technology, a common voltage that is a voltage of a common electrode disposed to face the pixel electrode is usually modulated. In FIG. 45, the upper diagram shows the temporal change of the common voltage (VCG), and the lower diagram shows the temporal change of the light transmittance (I) due to the liquid crystal response. That is, the voltage waveform 151 is a voltage waveform applied to the common electrode, the light intensity waveform 152 is a corresponding light intensity waveform at a time corresponding to the waveform 151, and the line segments 153 to 156 are pixel light intensity curves. In the technology prior to this technology, the common voltage is driven to be maintained at a constant value, or changes between two voltage values in a constant cycle with each period from t0 to t2 and t2 to t4 in FIG. 45 as one frame cycle. The common inversion drive was performed. In this Patent Document 1, one frame period is divided into two, and a voltage having substantially the same amplitude as that of the conventional common inversion drive is applied in each period from t1 to t2 and from t3 to t4. On the other hand, during each period from t0 to t1 and from t2 to t3 in one frame period, a voltage higher than the amplitude of common inversion, for example, a voltage higher than the amplitude of common inversion by the voltage during black display is applied. In this technique, the entire display region can be changed to black display at high speed due to the effect of increasing the voltage difference between the pixel electrode and the common electrode during a period from t0 to t1 when a high voltage is applied to the common electrode. That is, driving corresponding to reset driving is performed. Further, even if image data is written on the pixel electrode side during the period from t0 to t1, the potential difference from the common electrode is sufficiently large (for example, equal to or higher than the black display voltage), so that it is not observed on the display. After writing the image data in the entire display area, the voltage of the common electrode is returned to the common inversion amplitude at the timing t1. As a result, the liquid crystal layer starts to respond to the transmittance corresponding to each gradation level in accordance with the voltage stored in the pixel electrode. That is, when the response is started, the voltage difference always changes from the high voltage difference state to the gradation voltage value. In this respect, a kind of overdrive is performed during the period from t0 to t1.

  Here, attention is paid to the fact that the response time of liquid crystal is generally given by the following two formulas (Baifukan "Liquid Crystal Dictionary", Japan Society for the Promotion of Science, Organic Materials for Information Science, 142nd Committee, Liquid Crystal Division, page 24 (non-patent literature) 2)). That is, in the rising response (ON response) in which the voltage higher than the threshold voltage is applied and turned on, the following Equation 1 is established.

  On the other hand, in the falling response (response in OFF state) in which the applied voltage exceeding the threshold is suddenly set to 0, the following formula 2 is established.

  Where d is the thickness of the liquid crystal layer, η is the rotational viscosity, Δε is the dielectric anisotropy, V is the applied voltage according to each gradation level, Vc is the threshold voltage, and K is a constant based on the Frank elastic constant. In the TN mode, it is given by Equation 3 below.

Here, K ₁₁ is an elastic constant of spread, K ₂₂ is an elastic constant of torsion, and K ₃₃ is an elastic constant of bending. As can be seen from Equation 1, in the rising response (on-time response), the response time of the liquid crystal depends on the reciprocal of the square of the magnitude of the applied voltage. That is, it depends on the reciprocal of the square according to the voltage value that differs for each gradation level. Therefore, the response time varies greatly depending on the gradation level, and when there is a voltage difference of 10 times, a difference in response time of 100 times occurs. On the other hand, there is a difference in response time depending on the gradation level even in response to falling (off-time response), but it falls within the range of about twice.

  Now, paying attention to the technique of Non-Patent Document 2, the speed is increased by an overdrive effect in which a very high voltage is applied during the rising response (response at the time of ON). Further, since all responses used for actual image display are falling responses (responses when OFF), the dependence on the gradation level is extremely small. As a result, almost the same response time can be obtained over all gradations.

JP-T-2001-506376 IDR 1997, H. Nakamura, K. Miwa and K. Sueoka, L-66 to L-69. Baifukan "Liquid Crystal Dictionary" Japan Society for the Promotion of Science Information Science Organic Material 142nd Committee Liquid Crystal Division, 24

  However, the above-described liquid crystal display device, that is, a display device using overdrive, a display device using reset driving, and a display device disclosed in documents such as Patent Document 1 have several problems.

  The first problem is that in the overdrive system, the rising response speed (response at on-time) of the liquid crystal can be increased, but the response speed is still several tens to several tens of milliseconds due to material constraints. . Further, as will be described later, the falling response (off-time response) speed cannot be increased much.

This can be explained as follows. In order to improve the response speed of the liquid crystal element itself, as can be seen from Equation 1 and Equation 2,
(1) reducing the thickness d of the liquid crystal layer;
(2) Decrease the viscosity η
(3) Increasing the dielectric anisotropy Δε (rising response (response at ON) only)
(4) Increase applied voltage (rising response (response at ON) only)
(5) Of the elastic constants, K ₁₁ and K ₃₃ are reduced and K ₂₂ is increased (only falling response (off-time response)).
Such a device is effective. However, the thickness of the liquid crystal layer (1) can be changed only within a certain relationship with the refractive index anisotropy Δn in order to obtain a sufficient optical effect. Moreover, since the viscosity, dielectric anisotropy, and elastic constant of (2), (3), and (5) are all physical property values, it greatly depends on the material, and it is difficult to set it above a certain condition. Furthermore, it is extremely difficult to change only each physical property value alone, and it is difficult to realize the speed-up effect assumed from the mathematical formula. For example, K ₁₁ , K _22, and K ₃₃ are independent elastic constants, but according to the actual measurement results of the material, the relationship of K ₁₁ : K ₂₂ : K ₃₃ = 10: 5: 14 is almost satisfied, and It cannot be treated as an independent constant. That is, from this relation and Equation 3, for example, _K = 11 · K _{22/5, and the} only _{K 22} is independent. For this reason, although some adjustments are possible, it is difficult to improve more than a few percent. On the other hand, the method of increasing the applied voltage value in (4) is also greatly restricted from the viewpoint of power consumption and the high cost driving circuit. At the same time, when an active element such as a thin film transistor is provided in the display device for driving, the display device is restricted by the withstand voltage of the element. As described above, there is a large limit in principle to increase the response speed by a conventional device such as overdrive.

  The second problem is that in the overdrive method, the rising response (response at on-time) can be speeded up, but the falling response (response at off-time) can hardly be accelerated. This is because, as is clear from Equations 1 and 2, the rising response (on-time response) changes the response time depending on the potential difference, but the falling response (off-time response) does not depend on the potential difference. . That is, the rise response (response at on-time) can be increased by increasing the potential difference, but the fall response (response at off-time) cannot be increased by the potential difference. As a result, in the conventional overdrive system, the falling response that is not speeded up (response at the time of OFF) is dominantly determining the response speed of the entire system.

  The third problem is that the voltage required for overdrive is high in the conventional overdrive system. The video signal is a high-frequency signal in the display device, and in the overdrive system that increases the voltage of the video signal, the increase in power consumption determined from the voltage value and the frequency is significant. In addition, since it is necessary to generate a high-frequency / high-voltage signal, it is difficult to use the same driving IC and signal processing system as in the past, and it is often necessary to use an IC using a special process or an expensive IC. It was happening.

  The fourth problem is that, in the reset method, the method of applying the reset signal via the pixel switch makes the structure of the drive system complicated and increases the power consumption. In other words, scanning for writing a video signal means that it is necessary to drive scanning lines having different scanning periods and scanning methods. When resetting the pixel switch, a method of resetting all scanning lines at once, not sequentially scanning, is often used, and a structure for sending signals to the scanning system all at once is required. In addition to the writing of the video signal, driving of the scanning line also occurs when the reset signal is written, which corresponds to an increase in the frequency of the signal for the scanning line having the highest voltage amplitude in the display device. Power consumption increases. From these points, it is desirable not to perform reset via the pixel switch.

  The fifth problem is that the display state greatly changes due to excessive or insufficient reset in the reset method. This problem also applies to the method described in Patent Document 1 in which the overdrive method and the reset method are mixed.

  First, if the reset is excessive, the start of the optical response of the liquid crystal after the reset is delayed, or an abnormal optical response is observed before the normal optical response starts. The reason is that at the time of transition from a predetermined orientation state realized by reset to a normal response, the direction of operation at the time of response is not clear, and the response is uneven and unstable. An example of an abnormal optical response is shown in FIG. As shown in FIG. 13, when the reset is excessive, a delay in optical response and a display abnormality (for example, a temporary increase in transmittance) occur.

  On the other hand, if the reset is insufficient, the same transmittance may not be obtained even if the same data is written a plurality of times in the reset method. When the reset is insufficient, the predetermined orientation state is not completely obtained at the time of reset, and thus the response after the reset shows a transmittance according to the history of the previous frame. As a result, there is no one-to-one correspondence between applied voltage and transmittance. For this reason, a desired gradation cannot be obtained, or the luminance changes greatly even if the same gradation is displayed. This change in luminance may cause, for example, a difference in luminance between when a positive signal voltage is applied and when a negative signal voltage is applied, that is, flicker (flicker).

  The sixth problem is that it is difficult to obtain a stable display over a wide range of temperatures. The reason is that the viscosity η of the liquid crystal is highly dependent on temperature, and as a result, the response speed is also highly dependent on temperature. In particular, in the reset method and the method described in Patent Document 1, when the temperature changes, the above-described reset excess or deficiency occurs remarkably. As a result, at a low temperature, the response speed becomes slow, so that, for example, a significant reduction in luminance occurs. On the other hand, at a high temperature, for example, the response of the halftone becomes fast and the brightness increases as a whole and becomes close to the white display, so that the entire display becomes whitish. At low temperatures, resetting is insufficient, causing a problem that the correspondence between the applied voltage and the transmittance cannot be obtained, and a desired gradation cannot be obtained or flicker occurs.

  The present invention has been made in view of such problems, and a liquid crystal display device capable of improving display performance, increasing response speed, improving temperature dependency, and improving reliability, and a driving method and driving thereof. An object is to provide a circuit.

  Specifically, the object of the present invention is to enable a high-speed response, to have high light utilization efficiency, to be able to operate with low power consumption, to be able to stabilize an image within one frame, and to cause image degradation due to the influence of history. Therefore, an object of the present invention is to provide a liquid crystal display device capable of displaying a clear moving image without causing a moving image blur in the moving image display, a driving method thereof, and a driving circuit.

  Further, another specific object of the present invention is to eliminate the non-uniformity and instability of the liquid crystal response caused by reset driving and the like, and it is possible to achieve a good display with little display change even when the environmental temperature changes. Accordingly, it is an object of the present invention to provide a liquid crystal display device with high reliability and capable of reducing cost without increasing required performance for a driving IC and a signal processing circuit, and a driving method and a driving circuit thereof. For example, an object of the present invention is to eliminate flicker and the like, to realize a smooth gradation change, to improve the reliability with respect to an environmental change, and to reduce the cost of the entire display system.

  Furthermore, another specific object of the present invention is a frequency (for example, 70 Hz, 80 Hz, 200 Hz) faster than a normal frame frequency (for example, 60 Hz), or a frequency that is an integral multiple of the normal frame frequency (for example, 120 Hz, The object is to provide a high-speed liquid crystal display device capable of writing data at 180 Hz and 360 Hz).

  Furthermore, another specific object of the present invention is to divide a display image into several color images, display the color images of each color sequentially in time, and synchronize with the color image. Providing a liquid crystal display device capable of field sequential color display that lights a light source of the same color as an image, in particular, providing a liquid crystal display device capable of field sequential drive in a TN liquid crystal display mode, and also a transmissive type To provide a liquid crystal display device capable of field sequential driving in a TN liquid crystal display mode, and to provide a liquid crystal display device capable of field sequential driving in various liquid crystal display modes other than the TN liquid crystal display mode. It is to provide these with high light utilization efficiency.

  As shown in FIGS. 1 and 4, the display device of the first invention of this application includes a common electrode potential control circuit (203) and a synchronization circuit (204), and the common electrode potential control circuit (203) is driven by a scanning signal. After the circuit (202) scans all of the scanning electrodes (212) and transmits the video signal to the pixel electrode (214), the potential of the common electrode (215) is changed in a pulse shape.

  Further, as shown in FIGS. 2 and 5, the display device of the second invention of this application includes a storage capacitor electrode potential control circuit (205) and a synchronization circuit (204), and the storage capacitor electrode potential control circuit (205) After the scanning signal driving circuit (202) scans all of the scanning electrodes (212) and transmits the video signal to the pixel electrode (214), the potential of the storage capacitor electrode (216) is changed in a pulse shape.

  Further, as shown in FIGS. 3 and 6, the display device of the third invention of the present application includes a common electrode potential control circuit (203), a storage capacitor electrode potential control circuit (205), and a synchronization circuit (204), and the common electrode The potential control circuit (203) is configured to pulse the potential of the common electrode (215) after the scanning signal driving circuit (202) scans all of the scanning electrodes (212) and transmits a video signal to the pixel electrode (214). The storage capacitor electrode potential control circuit (205) changes the storage capacitor electrode (205) after the scanning signal drive circuit (202) scans all of the scan electrodes (212) and transmits the video signal to the pixel electrode (214). 216) is changed in pulses.

  Further, as shown in FIGS. 1 and 4, the display device of the fourth invention of the present application includes a common electrode potential control circuit (203) and a synchronization circuit (204), and a plurality of common electrodes (215) electrically separated from each other. The common electrode potential control circuit (203) includes a scanning signal driving circuit (202) after the scanning signal driving circuit (202) scans a part of the scanning electrode (212) and transmits a video signal to the pixel electrode (214). The potential of the common electrode (215) corresponding to the scan electrode scanned by is changed in a pulse shape.

  Further, as shown in FIGS. 2 and 5, the display device of the fifth invention of the present application has a plurality of storage capacitor electrodes (216) that are electrically separated from the storage capacitor electrode potential control circuit (205) and the synchronization circuit (204). The storage capacitor electrode potential control circuit (205) scans a part of the scan electrode (212) and transmits a video signal to the pixel electrode (214) after the scan signal drive circuit (202) scans the scan electrode (212). The potential of the storage capacitor electrode (216) corresponding to the scan electrode scanned by the signal driving circuit is changed in a pulse shape.

  Further, as shown in FIGS. 3 and 6, the display device of the sixth invention of the present application is electrically separated from the common electrode potential control circuit (203), the storage capacitor electrode potential control circuit (205), and the synchronization circuit (204). A plurality of storage capacitor electrodes (216) electrically separated from each other, and the common electrode potential control circuit (203) includes a scanning signal driving circuit (202) and a scanning electrode (202). 212), after scanning a part of the image signal and transmitting the video signal to the pixel electrode (214), the potential of the common electrode (215) corresponding to the scan electrode scanned by the scan signal driving circuit is changed in pulses. The storage capacitor electrode potential control circuit (205) scans the scanning signal driving circuit after the scanning signal driving circuit (202) scans a part of the scanning electrode (212) and transmits the video signal to the pixel electrode (214). The potential of the storage capacitor electrode (216) corresponding to the scanning electrodes which are scanned is varied in pulse form by.

  In the display device of the present invention, in the display device, the potential of the common electrode (215) changed in the pulse shape and the potential of the storage capacitor electrode (216) changed in the pulse shape are displayed on the display portion ( 200) is a potential that does not reset the display.

  In the display device of the present invention, in the display device, the potential of the common electrode (215) varies between at least three potentials, more preferably between four or more potentials. Further, the potential of the storage capacitor electrode (216) varies between at least three potentials, more preferably between four or more potentials.

  In the display device of the present invention, in the display device, the potential of the common electrode (215) or the potential of the storage capacitor electrode (216) that is changed in a pulse shape is the same as the pixel electrode (214) and the common electrode. (215) or the potential difference with the storage capacitor electrode (216) is changed in a pulse shape in the direction of temporarily increasing.

  In the display device of the present invention, in the display device described above, the potential of the video signal is equal to the potential of the video signal in a stable display state in static driving in consideration of the response characteristics of the display unit (200) during charge holding driving. Is different.

  Furthermore, in the display device of the present invention, in the display device, the potential of the video signal is determined by comparing the data held in each pixel before writing the video signal with the display data to be newly displayed.

  In the display device of the present invention, an electric field responsive substance is sandwiched between the pixel electrode (214) and the common electrode (215) of the display unit (200) in the display device. The electric field responsive material is made of a liquid crystal material.

  In the display device of the present invention, the liquid crystal material is a nematic liquid crystal and has a twisted nematic orientation.

  Further, a relationship of p / d <20 is established between the twist pitch p (μm) of the nematic liquid crystal and the average thickness d (micron) of the nematic liquid crystal layer. More preferably, a relationship of p / d <8 is established between the twist pitch p (μm) of the twisted nematic liquid crystal and the average thickness d (micron) of the twisted nematic liquid crystal material layer.

  Further, in the liquid crystal display device of the present invention, the twisted nematic liquid crystal substance is polymer-stabilized in a structure in which the twist is almost continuously twisted.

  In the liquid crystal display device of the present invention, the liquid crystal material is used in a voltage controlled birefringence mode.

  In the liquid crystal display device of the present invention, the liquid crystal material has a pi-type orientation (bend-type orientation). Preferably, an optical compensator is provided and used in the OCB (Optically Compensated Birefringence or Optically Compensated Bend) mode.

  In the liquid crystal display device of the present invention, the liquid crystal material is used in a VA (vertical alignment) mode in which homeotropic alignment is performed. Preferably, a wide viewing angle is achieved by multi-domaining or the like.

  In the liquid crystal display device of the present invention, the liquid crystal material is used in an IPS (in-plane switching) mode in which the liquid crystal material responds by an electric field parallel to the substrate surface.

  Furthermore, in the liquid crystal display device of the present invention, the liquid crystal material is used in an FFS (fringe field switching) mode or an AFFS (advanced fringe field switching) mode.

  In the display device of the present invention, the liquid crystal material is a ferroelectric liquid crystal material, an antiferroelectric liquid crystal material, or a liquid crystal material exhibiting an electroclinic response.

  In the display device of the present invention, the liquid crystal material is a cholesteric liquid crystal material.

  Furthermore, in the display device of the present invention, the above-described liquid crystal substance is polymer-stabilized in a structure in which no voltage is applied or a low voltage is applied.

  In the display device of the present invention, a lenticular lens sheet, a lenticular film, or a double-sided prism sheet is used, and a one-eye video signal, that is, a right-eye image and a left-eye image are separately displayed on each of the pixels arranged in parallel to perform stereoscopic display. Preferably, a scanning backlight is formed by alternately inputting light from two locations in the backlight, and in synchronization with this, the video signal is temporally converted into a right-eye video signal, a left-eye video signal, and a normal video signal. A stereoscopic display that switches at a frequency more than doubled.

  In the display device of the present invention, the video signal is divided into a plurality of color video signals corresponding to a plurality of colors, and the light sources corresponding to the plurality of colors and the light sources are separated from each other with a predetermined phase difference. The plurality of color video signals are sequentially displayed in time synchronization.

  Furthermore, in the display device of the present invention, the video signal is composed of a right-eye video signal and a left-eye video signal, and each one-eye video signal is divided into a plurality of color video signals corresponding to a plurality of colors. And the light source arranged in two places, the light source is synchronized with the one-eye video signal with a predetermined phase difference, and is synchronized with the plurality of color video signals, The signals are sequentially displayed in time, and the one-eye video signal is sequentially displayed in time as a plurality of divided color video signals.

  In the display device of the present invention, the pixel switch is formed of an amorphous silicon thin film transistor, a polysilicon thin film transistor, or a single crystal silicon thin film transistor including SOI (silicon on insulator).

  In the display device of the present invention, the polarity of the video signal is inverted at a predetermined timing, and the applied period of the potential of the common electrode that changes between a plurality of potentials is longer than other potentials. One or two potentials are approximately equal to the intermediate potential between the maximum potential and the minimum potential among all potentials applied as the video signal.

  In the display device of the present invention, the polarity of the video signal is inverted at a predetermined timing, and the applied period of the potential of the common electrode that changes between a plurality of potentials is longer than other potentials. One or two potentials are approximately equal to one of the maximum potential and the minimum potential among all potentials that can be applied as the video signal.

  Furthermore, in the display device of the present invention, the scanning signal driving circuit (202) scans the common electrode potential just before the scanning electrode (212) starts scanning the first scanning electrode and the scanning signal driving circuit (202). Immediately after scanning all of the electrodes (212) and transmitting the video signal to the pixel electrode (214), and before changing the pulse signal, the common electrode potential is equal.

  Furthermore, in the display device of the present invention, the scanning signal driving circuit (202) scans the common electrode potential just before the scanning electrode (212) starts scanning the first scanning electrode and the scanning signal driving circuit (202). Immediately after scanning all of the electrodes (212) and transmitting the video signal to the pixel electrodes (214), and before changing to a pulse shape, the common electrode potential is different.

  In the display device driving method of the present invention, the common electrode potential is composed of four potentials, and the first potential is a scanning signal driving circuit (202 for transmitting a video signal having one polarity of the video signal to be inverted. ) Is a common electrode potential during a period of scanning the scan electrode (212), and the second potential is a pulse height portion when the potential of the common electrode (215) is changed in a pulse shape following the first potential. The third potential is the potential after the end of the pulse when the potential of the common electrode (215) is changed into a pulse shape following the second potential, and the other polarity of the video signal to be inverted Is a common electrode potential during a period in which the scan signal driving circuit (202) scans the scan electrode (212) to transmit the video signal, and the fourth potential follows the third potential and the common electrode (215). Pulse height when changing the potential of Part is of potential.

  In the driving method of the display device of the present invention, the common electrode potential is composed of six potentials, and the first potential is a scanning signal driving circuit for transmitting a video signal of one polarity of the video signal to be inverted. (202) is a common electrode potential during a period of scanning the scan electrode (212), and the second potential is a pulse height when the potential of the common electrode (215) is changed in a pulse shape following the first potential. The third potential is the potential after the end of the pulse when the potential of the common electrode (215) is changed in a pulse shape following the second potential, and the fourth potential is inverted. Is a common electrode potential during a period in which the scan signal driving circuit (202) scans the scan electrode (212) in order to transmit a video signal of the other polarity of the video signal, and the fifth potential is the fourth potential. Following this, the potential of the common electrode (215) is changed in pulses. The potential of the pulse height of the case that the potential of the sixth is the potential after the end of the pulse when changing the potential of the common electrode following the fifth potential (215) in a pulsed manner.

  The display device of the present invention has a light irradiating unit that makes light incident on the display unit, and a synchronizing circuit that modulates the light intensity of the light irradiating unit in synchronization with the video signal with a predetermined phase. .

  Further, the display device of the present invention has a light irradiating unit that makes light incident on the display unit, and the light color of the light irradiating unit is changed in synchronization with the video signal with a predetermined phase. It has a circuit.

  In the driving method of the display device of the present invention, the light intensity of the light irradiation unit is modulated or the light color is changed. When the timing is divided into each field or a plurality of colors, each subfield corresponding to the color At the end of, i.e., immediately before writing the video signal of the next field.

  In the display device of the present invention, the potential of the video signal is the data held in each pixel before the video signal is written and the potential of the common electrode (215) changed in the pulse shape or the storage capacitor changed in the pulse shape. It is determined by comparing the fluctuation of the pixel electrode potential accompanying the change in the potential of the electrode (216) or both potentials with the display data to be newly displayed. Further, the data to be newly displayed is determined in consideration of the fluctuation of the pixel electrode potential due to the capacitive coupling accompanying the polarity inversion of the data signal.

  In the display device of the present invention, the comparison of the data and the potential fluctuation is performed by successive comparison. Alternatively, in the display device of the present invention, the comparison of the data and the variation in potential is performed using a prepared LUT (lookup table, correspondence table).

  In the display device of the present invention, the data and potential fluctuations are compared in advance according to the LUT (look-up table, correspondence table) prepared according to the polarity of the video signal with respect to the common electrode and the type of color signal to be displayed. Do.

  In the display device of the present invention, an LUT (lookup table, correspondence table) that defines the correspondence between the video signal and the gradation luminance obtained from the video signal is used. This LUT differs depending on the polarity of the video signal and the type of color signal to be displayed.

  After the scanning signal driving circuit scans all of the scanning electrodes and transmits the video signal to the pixel electrode, the pixel electrode after transmitting the video signal is changed by changing the potential of the common electrode and / or the potential of the storage capacitor electrode in pulses. The potential difference between the common electrode and the common electrode becomes a different potential difference in each period before the pulse change, the pulse height part changed in the pulse form, and after the pulse change is finished (however, in the pulse form) The potential difference before the change and after the pulse-like change ends may be the same). As a result, it is possible to adjust the state change and response speed of the display substance in each period. As a result, the response speed can be increased, and the response speed can be decreased as necessary. In particular, temporarily increasing the potential difference between the pixel electrode and the common electrode works extremely effectively to increase the response speed.

  In addition, by having the electrically separated common electrode and / or the storage capacitor electrode, only a part of the display portion can be changed into a pulse shape. As a result, a region having an arbitrary shape in the display unit can be changed in a pulse shape in an arbitrary order, and a response state can be changed for each region.

  In addition, when the potential of the common electrode and / or the potential of the storage capacitor electrode is changed in a pulse shape, the following operation occurs by setting the potential not to be reset. In general, in a reset, a predetermined state is set. As a result, a delay often occurs when transitioning from the predetermined state to another state. By setting the potential not to be reset, the occurrence of delay can be prevented, and the speed can be further increased.

  There are two types of delays that occur during transition from the reset state. The first delay is a delay that occurs because it is not immediately determined in which direction the display substance should respond due to fluctuations in the substance itself when transitioning from the reset state to another state. In this delay, the optical state such as transmission / reflection of light stagnates in almost the same state as the reset state, and there is a time delay until the change of the optical state starts to occur. The second delay is a delay that occurs when the display material temporarily responds in a direction other than the target direction, for example, in the reverse direction, when the reset state transitions to another state. In this delay, an optical state such as light transmission / reflection is different from the reset state, but a state different from a desired control state is generated. There is a longer time delay than the first delay to respond from this different direction response to the desired direction. Further, as a phenomenon that occurs more frequently, in the system in which the second delay occurs, the first delay also occurs at the same time, and the delay time becomes longer.

  By setting the potential so as not to be reset, it is possible to realize the response speed expected from the two delays and the combined delay.

  Furthermore, as a result of not resetting, the display dependency on the excess or deficiency of the reset is eliminated. Therefore, a stable display can be obtained over a wide temperature range.

  The video signal is manipulated by changing the common electrode potential or the storage capacitor electrode potential to be changed in a pulse shape in the direction of temporarily increasing the potential difference between the pixel electrode and the common electrode or the storage capacitance electrode. The overdrive (feed forward) effect can be obtained without any problems. In the present invention, unlike an overdrive that operates a conventional video signal, it is possible to simultaneously give an overdrive effect to all electrically connected regions.

  Further, by overdriving the video signal itself, it is possible to increase the speed in two steps in combination with the above effect. Unlike the conventional overdrive, it is not necessary to increase the speed of the overdrive alone. Therefore, it is only necessary to apply a relatively small voltage.

  On the other hand, the falling response (off-time response) cannot be accelerated only by the above method. Therefore, in the twisted nematic liquid crystal, the torque for returning to the twisted state is increased by setting the twist pitch p to p / d <8. Also, in all liquid crystal display modes including twisted nematics, the torque returned when no voltage is applied due to polymer stabilization or the like is increased. This speeds up the falling response (off-time response).

  Now, in order to compare the speeding up of the present invention with the conventional method, the difference in response time is compared in principle. This comparison is directed to twisted nematic liquid crystal display devices. As the response time, two response times corresponding to the rise response (on-time response) and the fall response (off-time response) of the background art are examined. FIG. 33 shows an outline of a method for determining an on-time response and an off-time response in a normally white display twisted nematic liquid crystal. FIG. 33 is a graph in which the horizontal axis represents each gradation level and the vertical axis represents luminance, where (a) shows a rising response (response when on) and (b) shows a falling response (response when off). Referring to FIG. 33A, in the rising response, the response time when transitioning from the gray level having the highest luminance to each gray level is defined as an on-time response. Referring to FIG. 33 (b), in the falling response, the response time in the case of transition from a gradation with lower luminance to each gradation level is defined as an off-time response. In a twisted nematic liquid crystal other than normally white display and other liquid crystal display modes, the brightness level may be reversed. Now, for the four types of twisted nematic liquid crystal display devices with different driving methods and the like, the on-time response and the off-time response are schematically shown in the figure, with the horizontal axis representing each gradation level and the vertical axis representing the response time. Hereinafter, the display device shown in the figure is (1) a liquid crystal display device by normal driving (FIG. 34), (2) a liquid crystal display device by overdrive (feed forward driving) (FIG. 35), and (3) the above-mentioned special table. No. 2001-506376, that is, a liquid crystal display device driven by adding overdrive and reset (FIG. 36), and (4) a liquid crystal display device according to the present invention (FIG. 37).

  In the normal drive of FIG. 34, the on-time response (broken line) is fast when a high voltage is applied, but extremely slow when a low voltage is applied. This is a response that approximately follows equation (1). Further, the off-time response (solid line) is the same time over almost the entire voltage range (actually, it varies depending on the voltage value, but often falls within a range of about twice at most). As a result, the rate-determining stage for the response speed of this display device (the stage of the dominant factor that determines the reaction speed. Here, the slower of the on-time response and the off-time response) is indicated by a dotted line in the figure. It shows a slow response in the low voltage range. In this figure, the voltage when the on-time response and the off-time response cross each other is the square root of 2 of the threshold voltage Vtc in an ideal state according to the equations (1) and (2). When Vtc = 1.5V, it is slightly over 2V.

  In the case of the overdrive in FIG. 35, the on-time response (broken line) is faster than the on-time response of normal drive shown in FIG. However, since the off-time response (solid line) hardly changes, the rate-determining step is as shown by the dotted line in the figure. That is, the response time is the same as that of normal driving at a voltage higher than the intersection between the on-time response and the off-time response, and the speed is increased at a voltage lower than the intersection. As described above, the effect on the high voltage side is small, but the slowest response time is on the low voltage side, so the display state is considerably improved by overdrive. However, if a high voltage is excessively applied in overdrive, the same response delay as that of the transition from the above-described reset state occurs, and in particular, the response at the OFF time becomes slow.

  In the method of Japanese Patent Application Publication No. 2001-506376 in FIG. 36, in which driving is performed by adding overdrive and reset, the reset state is once performed in all displays, and therefore the on-time response acts only at the time of this reset. That is, the response time is determined approximately by the OFF response (solid line), and the rate-determining step indicated by the dotted line is determined only by the OFF response. Compared with the normal drive OFF response of FIG. 40 indicated by the broken line, the OFF response (solid line) of this method is slower than the normal drive due to the delay associated with the transition from the reset state. However, since there is no slow response on the low voltage side, the slowest value of response time is much shorter than normal drive and faster than overdrive drive. On the other hand, on the high voltage side, the response at off time is slower than the normal drive or overdrive drive, but the on-time response that is often used as the response time and the off-time response do not contribute substantially, The value is smaller than normal drive and overdrive drive.

  In the display device of the present invention shown in FIG. 37, since a change corresponding to overdrive is given by two stages of overdrive and pulse-like change, the response at the time of ON (dashed line) is faster than the conventional overdrive drive (FIG. 35). Is done. Furthermore, since the state in which no voltage is applied is stabilized, the torque for returning to the state in which no voltage is applied is strong, and the response at the time of OFF (solid line) is also speeded up. In addition, in order to obtain a potential change in a state where reset is not performed, there is no delay associated with the transition from the reset state as seen in FIG. As a result, the present invention is the fastest of these four types. Here, only the on-time response and the off-time response are shown, but it goes without saying that the response between halftones is also speeded up.

  The first effect of the present invention is that the response speed of the display substance can be increased.

  The reason is that at the time of start-up, speeding up corresponding to two-stage overdrive, that is, video signal overdrive and pulse-like change of the common electrode or storage capacitor electrode after video signal writing is performed. Furthermore, in order to obtain a potential and potential fluctuation within a range where the display substance is not reset at these stages, there is no delay. On the other hand, it is possible to increase the torque at the time of falling and to change to a state in which no voltage is applied at high speed. This effect is obtained by controlling the twist pitch, stabilizing the polymer, controlling the electric field, controlling the interface orientation, and the like. That is, in the present invention, it is possible to increase the speed at all stages including falling / rising and even halftone response.

  The second effect of the present invention is that high reliability capable of good display is obtained even when the environmental temperature changes.

  This is because the response speed of the liquid crystal is fast and an unstable alignment state such as bounce does not occur. In particular, this is to give potential fluctuations that are not reset.

  A third effect of the present invention is that a liquid crystal display device with high light utilization efficiency and low power consumption can be obtained.

  The first reason is that the optical response of the liquid crystal is increased in speed and reaches a stable transmittance quickly. The second reason is that since the two-stage overdrive is performed, the voltage required for overdrive of the high-frequency video signal is low, and the power consumption can be suppressed as compared with the conventional overdrive system.

  The fourth effect of the present invention is that an image can be stabilized within one frame, and a liquid crystal display device free from image deterioration (gradation variation and flicker) due to the influence of history can be obtained.

  This is because there is no response delay such as bounce and delay. Another reason is to produce a video signal that provides a desired display state by means of a comparator and a look-up table (LUT). In particular, the pixel electrode that accompanies a change in the retention data of each pixel before the writing of the video signal and the potential of the common electrode that changes in a pulse shape, the potential of the storage capacitor electrode (216) that changes in a pulse shape, or both potentials. This is because it is determined by comparing the fluctuation of the potential with the display data to be newly displayed. The fluctuation of the common electrode potential includes a fluctuation of the pixel electrode potential at the time of polarity inversion when driving with the common electrode potential reversed in polarity. Furthermore, it is to determine data to be newly displayed in consideration of the polarity inversion of the data signal, that is, the fluctuation of the pixel electrode potential due to capacitive coupling at the time of frame switching. By applying the waveform in consideration of such variations, gradation variations and flicker are not observed.

  A fifth effect of the present invention is to provide a liquid crystal display device that does not cause moving image blur.

  The reason is that a good display can be obtained by combination with the field sequential drive and the drive of the present invention. That is, the moving image blur based on the hold-type display is improved by switching the light source at a higher frequency than usual. Furthermore, when the light source is turned on only for a specific period in the sub-frame period, a response close to an impulse type can be realized, so that moving image blur does not occur further.

  A sixth effect of the present invention is that an inexpensive overdrive display device having a simple system configuration can be realized.

  The reason is that by adopting the field sequential method, it is not necessary to compare the data of all the colors of the previous screen and the data of all the colors of the next screen, and a specific color (or one color that combines multiple colors) of the previous screen. ) And the data of a specific color (or one color obtained by combining a plurality of colors) on the next screen need only be compared. As a result, the required memory size is reduced, and the size of the comparison operation means and the LUT used at a time can be reduced.

  Another reason is that the overdrive voltage for the video signal is lower than the voltage of the conventional overdrive system in order to perform the drive corresponding to the two-stage overdrive. The video signal is a signal with a high frequency among the signals used in the display device, and the voltage of the high-frequency video signal is increased in the conventional overdrive method. It was necessary to use expensive drive ICs that use processes. Also, special use was required for ICs that produce video signals. In the method of the present invention, since the voltage at the overdrive is lower than that of the conventional overdrive, it is not necessary to use a special IC, so that an increase in cost can be suppressed.

  The seventh effect of the present invention is that a stereoscopic display device with high presence can be obtained. The reason is that color reproducibility is high by using LEDs or the like. Another reason is that a stereoscopic image can be displayed regardless of spatial division, and color display can be achieved regardless of spatial division. As a result, it is possible to easily realize a display device having a much larger number of pixels than in the prior art and to improve the sense of reality.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  First, a first embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device of this embodiment includes a display unit 200, a video signal drive circuit 201, a scanning signal drive circuit 202, a common electrode potential control circuit 203, and a synchronization circuit 204. The display unit 200 includes a scanning signal electrode 212, a video signal electrode 211, a plurality of pixel electrodes 214 arranged in a matrix, a plurality of switching elements 213 that transmit a video signal to the pixel electrode 214, and a common electrode. 215. The common electrode potential control circuit 203 changes the potential of the common electrode 215 in a pulse shape after the scanning signal driving circuit 202 scans all of the scanning electrodes 212 and transmits a video signal to the pixel electrode 214.

  Next, the operation of the liquid crystal display device of the present embodiment configured as described above will be described with reference to FIGS. FIG. 7 is a diagram illustrating an example of timing according to the present embodiment, and FIG. 8 is a diagram illustrating an example of a waveform according to the present embodiment. In this embodiment mode, after the video signal is transmitted to the pixel electrode 214, the potential of the common electrode is changed in a pulse shape. By changing the pulse shape, the potential difference between the pixel electrode and the common electrode after the transmission of the video signal is the period 301 before changing to the pulse shape, the period 302 of the pulse height portion changed to the pulse shape, the pulse shape The potential difference is different in each period of the period 303 after the change of. However, the potential difference before the pulse change and after the pulse change may be the same. As a result, it is possible to adjust the state change and response speed of the display substance in each period. As a result, the response speed can be increased, and the response speed can be decreased as necessary. The effect of adjusting the response speed is that the potential value to be changed in a pulse shape (period 301 before the pulse change, period 302 of the pulse height portion changed in the pulse shape, and after the change in the pulse shape is finished. The potential of each period of the period 303 is adjusted and the length of the period to be changed in a pulse shape is adjusted.

  Further, the potential difference between the period 301 before the pulse-like change and the period 303 after the pulse-like change ends is adjusted to compensate for the effect of the potential fluctuation of the pixel electrode due to capacitive coupling accompanying the pulse-like change. Is done. Furthermore, it is adjusted according to a display state or the like to be realized after the pulse-like change is finished.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device of this embodiment includes a display unit 200, a video signal drive circuit 201, a scanning signal drive circuit 202, a storage capacitor electrode potential control circuit 205, and a synchronization circuit 204. The display unit 200 includes a scanning signal electrode 212, a video signal electrode 211, a plurality of pixel electrodes 214 arranged in a matrix, a plurality of switching elements 213 that transmit a video signal to the pixel electrode 214, and a storage capacitor. An electrode 216. The storage capacitor electrode potential control circuit 205 changes the potential of the storage capacitor electrode 216 in a pulse shape after the scan signal driving circuit 202 scans all of the scan electrodes 212 and transmits a video signal to the pixel electrode 214.

  Next, the operation of the present embodiment will be described. In the present embodiment, the same effect as that of the first embodiment is obtained by changing the storage capacitor electrode potential in a pulse shape after transmitting the video signal to the pixel electrode 214. However, the adjustment effect in this embodiment is caused by the fluctuation of the pixel electrode potential due to the capacitive coupling, and the fluctuation of the pixel electrode potential due to the common electrode potential and the capacitive coupling as in the first embodiment. Not both. In other words, the present embodiment is based not on direct means such as the common electrode potential but on indirect means such as fluctuation of the pixel electrode potential due to capacitive coupling.

  Next, a third embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device of this embodiment includes a display portion 200, a video signal drive circuit 201, a scanning signal drive circuit 202, a common electrode potential control circuit 203, a storage capacitor electrode potential control circuit 205, and a synchronization circuit 204. It has. The display unit 200 includes a scanning signal electrode 212, a video signal electrode 211, a plurality of pixel electrodes 214 arranged in a matrix, a plurality of switching elements 213 that transmit a video signal to the pixel electrode 214, and a common electrode. 215 and a storage capacitor electrode 216. The common electrode potential control circuit 203 changes the potential of the common electrode 215 in a pulse shape after the scanning signal driving circuit 202 scans all of the scanning electrodes 212 and transmits a video signal to the pixel electrode 214. The storage capacitor electrode potential control circuit 205 changes the potential of the storage capacitor electrode 216 in a pulse shape after the scan signal driving circuit 202 scans all of the scan electrodes 212 and transmits a video signal to the pixel electrode 214.

  Next, the operation of the present embodiment will be described. In the present embodiment, the display state and response speed are adjusted by changing both the common electrode and the storage capacitor electrode in a pulse shape. Therefore, this embodiment is an operation in which both the first embodiment and the second embodiment are combined.

  However, in the present embodiment, it is possible to expect an excellent operation that is not just a combination of the first embodiment and the second embodiment described above. For example, by reversing the polarity of the pulse-like change between the common electrode and the storage capacitor electrode, it is possible to suppress fluctuations due to capacitive coupling of the pixel electrode potential. On the other hand, by setting the polarity of both pulse-like changes to the same polarity, it is possible to increase the width of fluctuation and obtain a double effect. Furthermore, more complicated adjustments can be made by shifting the timing of the synchronization between the two or by changing the length of the period of each pulse-like change.

  Next, a fourth embodiment of the present invention will be described. In the present embodiment, the configuration of the liquid crystal display device and the configuration of the display unit are the same as those of the first embodiment shown in FIGS. That is, the liquid crystal display device of this embodiment also includes a display unit 200, a video signal drive circuit 201, a scanning signal drive circuit 202, a common electrode potential control circuit 203, and a synchronization circuit 204. Is electrically separated from the scanning electrode 212, the video signal electrode 211, the plurality of pixel electrodes 214 arranged in a matrix, and the plurality of switching elements 213 that transmit the video signal to the pixel electrode 214. A plurality of common electrodes 215. In this embodiment, after the scanning signal driving circuit 202 scans a part of the scanning electrode 212 and transmits the video signal to the pixel electrode 214, the common electrode potential control circuit 203 is scanned by the scanning signal driving circuit 202. The difference from the first embodiment is that the potential of the common electrode 215 corresponding to the scanning electrode 212 is changed in a pulse shape.

  Next, a fifth embodiment of the present invention will be described. In the present embodiment, the configuration of the liquid crystal display device and the configuration of the display unit are the same as those of the second embodiment, and FIG. 2 and FIG. 5 are used for the description of the configuration. The liquid crystal display device of this embodiment also includes a display unit 200, a video signal drive circuit 201, a scanning signal drive circuit 202, a storage capacitor electrode potential control circuit 205, and a synchronization circuit 204. The display unit 200 is electrically connected to the scanning electrode 212, the video signal electrode 211, the plurality of pixel electrodes 214 arranged in a matrix, and the plurality of switching elements 213 that transmit a video signal to the pixel electrode 214. And a plurality of storage capacitor electrodes 216 separated into each other. In this embodiment, after the scanning signal driving circuit 202 scans a part of the scanning electrode 212 and transmits the video signal to the pixel electrode 214, the storage capacitor electrode potential control circuit 205 is scanned by the scanning signal driving circuit 202. The second embodiment is different from the second embodiment in that the potential of the storage capacitor electrode 216 corresponding to the scanning electrode 212 is changed in a pulse shape.

  Next, a sixth embodiment of the present invention will be described. The configuration of this embodiment is the same as that of the third embodiment shown in FIGS. 3 and 6, and the liquid crystal display device of this embodiment also includes a display unit 200, a video signal driving circuit 201, a scanning signal driving circuit 202, and the like. , A common electrode potential control circuit 203, a storage capacitor electrode potential control circuit 205, and a synchronization circuit 204. The display unit 200 is electrically connected to the scanning electrode 212, the video signal electrode 211, the plurality of pixel electrodes 214 arranged in a matrix, and the plurality of switching elements 213 that transmit the video signal to the pixel electrode 214. A plurality of common electrodes 215 separated from each other and a plurality of storage capacitor electrodes 216 electrically separated from each other. In this embodiment, after the scanning signal driving circuit 202 scans a part of the scanning electrode 212 and transmits the video signal to the pixel electrode 214, the common electrode potential control circuit 203 is scanned by the scanning signal driving circuit 202. The potential of the common electrode 215 corresponding to the scanning electrode 212 is changed in a pulse shape. After the scanning signal driving circuit scans a part of the scanning electrode 212 and transmits a video signal to the pixel electrode 214, the storage capacitor electrode The third embodiment is different from the third embodiment in that the potential control circuit 205 changes the potential of the storage capacitor electrode 216 corresponding to the scanning electrode 212 scanned by the scanning signal driving circuit 202 in a pulse shape.

  Next, operations of the above-described fourth to sixth embodiments of the present invention will be described with reference to FIGS. 9 to 12. FIG. 9 is a diagram illustrating an example of the order of scanning the electrically separated electrodes of the display units of the fourth to sixth embodiments, and FIG. 10 is an electrical diagram of the display units of the fourth to sixth embodiments. It is a figure which shows the example of the shape of the isolate | separated electrode. FIG. 11 is a diagram showing an example of a mobile phone display to which the fourth to sixth embodiments are applied. FIG. 12 is a diagram showing an example of the arrangement of a plurality of electrically separated common electrodes and a plurality of electrically separated storage capacitor electrodes in the display units of the fourth to sixth embodiments.

  In the fourth to sixth embodiments of the present invention, the common electrode and / or the storage capacitor electrode is divided into a plurality of electrically separated portions, so that only the first portion of the display portion is provided. The potential change similar to that of the third embodiment can be given. Thus, in the first to third embodiments, the effect on the entire display unit can be limited to a part of the display unit in the fourth to sixth embodiments. That is, the potential change can be sequentially applied to each sub display unit while the display unit is divided into a plurality of sub display units and sequentially scanned. It is also possible to change the potential simultaneously to the plurality of sub display portions. In either case, the position in the display unit of the sub display unit that sequentially scans can be arbitrarily selected. For example, in the order shown by the numbers in FIG. 9, that is, a potential change is performed by sequentially scanning an appropriately selected region, and a potential change that simultaneously changes a plurality of regions in scan order 3 or scan order 5 is performed. It is possible to give. Further, for example, it is possible to give changes in different areas and shapes as shown in FIG.

  Further, it is possible to selectively change the potential only to some of the display portions of the entire display portion. Thereby, it is possible to change the display state in the selected display part and the display part which was not selected. For example, the display area A portion of the mobile phone display of FIG. 11 can execute a high-speed response, and the other display area B portions can respond at a normal speed. As a result, for example, a portion that requires high-speed video display such as a TV image and a portion that requires a still-image display in which images are not updated so much are divided to reduce overall power consumption. Is possible.

  On the other hand, in the sixth embodiment of the present invention, as shown in FIG. 12, by making the shapes of the plurality of electrically separated common electrodes and the plurality of electrically separated storage capacitor electrodes different, There are four types of regions: a region where only the common electrode is changed in a pulse shape, a region where only the storage capacitor electrode is changed in a pulse shape, a region where both the common electrode and the storage capacitor electrode are changed in a pulse shape, and a region where no change in the pulse shape is allowed. Can be divided.

  By these operations, for example, it is possible to speed up the response in a region where the response speed is particularly slow in the display unit. In addition, it is possible to correct luminance unevenness due to viewing angle dependency by adjusting the response speed in the display unit so as to correct the viewing angle dependency occurring in the display unit. Furthermore, it is possible to correct display unevenness and flicker differences caused by the display position in the screen that occur according to the scanning order of the scanning lines. In other words, the region that changes in a pulse shape at a certain time is limited to a part, and the display unevenness and flicker in other regions are suppressed, or the display unevenness and flicker in the region changed in a pulse shape are conversely suppressed. The common electrode and the storage capacitor electrode divided into the plurality of regions can be scanned in synchronization with the scanning timing of the scanning line in a certain relationship, for example. Thereby, display unevenness and flicker due to scanning can be effectively suppressed.

  In the seventh embodiment of the present invention, in the first, third, fourth, or sixth embodiment, the potential of the common electrode 215 changed in a pulse shape does not reset the display of the display unit 200. It is intended to be.

  In the eighth embodiment of the present invention, in the second, third, fifth, or sixth embodiment, the potential of the storage capacitor electrode 216 changed in the pulse shape does not reset the display of the display unit 200. It is made to be an electric potential.

  In the seventh and eighth embodiments of the present invention, the potential that is changed in a pulse shape is set to a potential that does not reset the display of the display unit, so that the above-described delay can be prevented and the speed can be increased. To do. Since this principle has been described in the means for solving the problem, it will not be repeated, but the operation and effect of an example in which the liquid crystal display device of the seventh embodiment was actually manufactured will be compared with a comparative example. I will explain.

  An example of the seventh embodiment is shown in comparison with a comparative example in which a resetting voltage is applied. In this example and the comparative example, a thin film transistor made of amorphous silicon, which will be described later, was used as the switching element, a nematic liquid crystal material was used as the display material of the display portion, and the twisted nematic orientation described later was used.

  FIG. 13 is a diagram showing a change with time in transmittance when a pulse-like change to be reset is given, similarly to the conventional reset driving. On the other hand, FIG. 14 is a diagram showing a temporal change in transmittance when a pulse-like change that is not reset according to the present invention is given. In order to compare the effect of the reset state on the speed of response, the drive sequence was the same and both provided pulse-like changes. That is, the video signal was first written to all the pixels, and then a pulse-like change (reset state in FIG. 13 and not reset in FIG. 14) was given. When the pulse-like change similar to the conventional reset of FIG. 13 is given, after the pulse-like change is finished, the first delay shown in the section of means for solving the problem occurs, and then the second delay There is a delay. On the other hand, in the pulse-like change of the present invention shown in FIG. 14, neither the first delay nor the second delay occurs, and the response toward the desired transmittance immediately after the pulse-like change is completed. Has occurred. As a result, in the conventional reset state, the desired transmittance (indicated by a two-dot chain line in the figure) is not reached. On the other hand, in the pulse-like change of the present invention, the maximum transmittance (dashed line in the figure) that can be secured in the conventional reset state is reached immediately after the pulse-like change, and then reaches a desired transmittance and stabilizes.

  Next, a ninth embodiment of the present invention will be described. This embodiment is the same as the first, third, fourth, sixth, or seventh embodiment described above, in which the potential of the common electrode 215 is at least between three potentials, more preferably between four or more potentials. It will change.

  In the tenth embodiment of the present invention, the potential of the storage capacitor electrode 216 is more preferably between at least three potentials in the second, third, fifth, sixth, or eighth embodiment described above. Changes between four or more potentials.

  Next, operations of the ninth and tenth embodiments of the present invention will be described with reference to FIG. Also in these embodiments, by giving a voltage change as shown in FIG. 8, a pulse-like change can be effectively given to both polarities of the video signal whose polarity is inverted.

  Next, an eleventh embodiment of the present invention will be described. In the present embodiment, the potential of the common electrode 215 or the potential of the storage capacitor electrode 216 that is changed in a pulse shape in the first to tenth embodiments is different from that of the pixel electrode 214 and the common electrode 215 or the storage capacitor electrode 216. Is changed in a pulse shape in the direction of temporarily increasing the potential difference.

  Next, the operation of the eleventh embodiment of the present invention will be described. In the present embodiment, by temporarily increasing the potential difference from the pixel electrode, an overdrive (feed forward) effect can be obtained without manipulating the video signal. In the present invention, unlike the conventional overdrive for manipulating a video signal, it is possible to simultaneously give an overdrive effect to all electrically connected regions.

  Next, a twelfth embodiment of the present invention will be described. In this embodiment, in the first to eleventh embodiments, the video signal in the stable display state in the static drive is considered in consideration of the response characteristic of the display unit 200 when the potential of the video signal is in the charge holding drive. This is different from the potential of. For example, the arrival time to the predetermined transmittance is shortened by providing an overshoot characteristic.

  In the present invention, since the video signal is transmitted to the pixel electrode 214 via the switching element, the display unit is not driven by static driving in which voltage is always applied, but the charge at the moment when the switching element is turned off is held. This is charge holding driving in which the display substance is driven.

  Next, a thirteenth embodiment of the present invention will be described. In the present embodiment, in the twelfth embodiment described above, the potential of the video signal should be newly displayed with the holding data of each pixel before writing the video signal, while taking into account the response characteristics of the display unit 200. It is determined by comparing the display data. Specifically, a video signal that can obtain a desired display state is determined by using a comparator and a lookup table (LUT). In particular, the holding data of each pixel before video signal writing, the potential of the common electrode to be changed in a pulse shape, the potential of the storage capacitor electrode (216) to be changed in a pulse shape, or the potential of the pixel electrode accompanying the change in both potentials. It is determined by comparing the fluctuation with the display data to be newly displayed. The fluctuation of the common electrode potential includes a fluctuation of the pixel electrode potential at the time of polarity reversal when driving by inverting the polarity of the common electrode potential and / or the storage capacitor electrode potential. Furthermore, the polarity of the data signal is inverted, that is, a change in the pixel electrode potential due to capacitive coupling associated with frame switching or the like is taken into consideration to determine data to be newly displayed. By applying the waveform in consideration of such fluctuations, gradation variations and flicker are not observed.

  The operation in some special usage methods of this embodiment will be specifically described with reference to FIGS. 46 and 47. FIG. FIG. 46 shows the relationship of wirings electrically connected to a certain pixel. The video signal data group is written into the liquid crystal capacitor 501 and the storage capacitor 502 via the pixel TFT 503. The potential of the node (point) to be written is referred to as a pixel potential VLC (507). The potential of the counter electrode of the liquid crystal capacitor, the counter electrode potential VCOM (506) is supplied from an external power source, but there is an additional resistance and an additional capacitor between the external electrode and the counter electrode. The portion for determining the time constant to be determined is shown as a counter electrode time constant circuit 504 in the figure. Similarly, the potential on the non-liquid crystal side of the storage capacitor, that is, the storage capacitor potential VST (508) is also supplied from an external power source. Similarly, there is a time constant circuit 505 for the storage capacitor line. Considering these time constants, the fluctuation of the potential shows a complicated change. This is shown in FIG. FIG. 47 shows the time variation of each potential shown in FIG. 46, that is, the variation dVLC of the counter electrode potential VCOM (506), the storage capacitor line potential VST (508), and the pixel potential VLC (507). The counter electrode is usually formed of a transparent electrode, and its wiring resistance is relatively high. As a result, the time constant of the wiring, that is, the response time of the potential change is, for example, 130 microseconds. Here, the response time indicates the time required to reach 90% of the difference between the target potential (5 V in this figure) and the initial potential, where the initial potential (0 V in this figure) is 0%. On the other hand, metal is used for the storage capacitor electrode line, and the wiring resistance is low. As a result, the time constant of the storage capacitor line potential is, for example, 8 microseconds. Even when the counter electrode and the storage capacitor electrode line are changed at the same timing at the same voltage value (for example, 0 V to 5 V as shown in FIG. 47), the difference between the time constant of the counter electrode potential and the time constant of the storage capacitor line potential As a result, the fluctuation dVLC of the potential of the pixel electrode occurs. Such a change in the potential of the pixel electrode causes a difference in display state and is recognized as flicker or the like.

  Furthermore, voltage fluctuations also occur due to capacitive coupling via parasitic capacitance between the gate and source of the pixel TFT 503 and between the gate and drain. Further, voltage fluctuation due to leakage current of the pixel TFT 503 also occurs. These voltage fluctuations occur particularly when changing frames, i.e. when the signal is inverted from frame to frame. By taking these voltage fluctuations into consideration, display unevenness and flicker can be reduced.

  In the present invention, the retained data is approximately equal to the sum of the charges retained between the pixel electrode 214 and the common electrode 215 and the charges retained between the pixel electrode 214 and the storage capacitor electrode 216. The display data to be newly displayed is the average of the sum of the charges between the pixel electrode 214 and the common electrode 215 and the charges between the pixel electrode 214 and the storage capacitor electrode 216 in the display period, or the display data. This is approximately equal to the sum of the charge between the pixel electrode 214 and the common electrode 215 and the charge between the pixel electrode 214 and the storage capacitor electrode 216 at the end of the period.

  In the twelfth embodiment of the present invention, a potential suitable for driving using a pixel switch can be applied by applying a potential different from that of static driving. Further, by providing the video signal with an overshoot characteristic, high speed due to the overdrive effect is realized.

  Furthermore, a more effective video signal can be selected by determining by comparing the data held in each pixel before writing the video signal with the display data to be newly displayed. For example, a circuit as disclosed in Japanese Patent No. 3039506 can be used. FIG. 15 shows an example of a drive device described in this publication. This display device displays an image of each display frame by applying a write signal voltage corresponding to display data to each sequentially designated pixel. A driving device 80 that drives the liquid crystal display 64 is connected between the signal source 65 and a liquid crystal display (LCD) 64. The driving device 80 includes an analog-digital converter circuit (hereinafter abbreviated as an ADC circuit) 66 connected to the signal source 65, a first latch circuit 69 connected to the ADC circuit 66, and an output connected to the ADC circuit 66. And a control buffer 68. The driving device 80 further includes a memory 71 connected to the output control buffer 68, a second latch circuit 70 connected to the memory 71 via a node connecting the output control buffer 68 and the memory 71, and a first An arithmetic unit 72 connected to the latch circuit 69 and the second latch circuit 70 and a timing control circuit 67 are provided. The ADC circuit 66 converts the analog signal from the signal source 65 into a digital signal in synchronization with the clock ADCLK. The output control buffer 68 has an output control function, receives the control signal OE, and puts the output terminal into a high impedance (hereinafter referred to as Hi-Z) state. Here, it is assumed that Hi-Z is set when the control signal OE is at the low level in the output enabled state where the input data is output when the control signal OE is at the high level. The memory 71 has a capacity of one frame or more and is controlled by an address signal ADR and a control signal R / W. Here, the memory 71 performs a read operation when R / W is at a high level, and performs a write operation when R / W is at a low level. The first and second latch circuits 69 and 70 are circuits that receive and hold input data while receiving the clock LACLK. Here, data is taken in at the clock rising edge, and data is held until the next rising edge. The first latch circuit 69 latches the video signal voltage VS (m, n), and the second latch circuit 70 latches the video signal voltage VS (m, n-1). The write signal voltage Vex (m, n) of the mth pixel in the nth frame is equal to the video signal voltage VS (m, n-1) of the mth pixel in the previously displayed frame n-1 and the following. The linear sum with the m-th video signal voltage VS (m, n) in the frame n to be displayed on: Vex (m, n) = AVS (m, n) + BVS (m, n−1) (where A, B is obtained from a constant). Therefore, the computing unit 72 calculates the video signal voltage VS of the mth pixel of the previous display frame n−1 by the equation Vex (m, n) = AVS (m, n) + BVS (m, n−1). From the linear sum of (m, n-1) and the mth video signal voltage VS (m, n) of frame n to be displayed next, the write signal voltage Vex (m, n) of the mth pixel of frame n is displayed. ) Is set. The timing control circuit 67 controls the timing of each signal. The memory 71 and the calculator 72 constitute display control means.

  However, in the present invention, in order to increase the speed by a pulse-like change in the common electrode potential, the voltage applied when the overdrive effect is given can be set lower than in the conventional overdrive system. In the conventional overdrive, since the voltage applied at the time of overdrive is high, the alignment state of the liquid crystal often occurs in a reset state, which causes, for example, a slow response speed for returning to white display. It was. In the present invention, since the voltage applied at the time of overdrive is low, the alignment state of the liquid crystal is not reset.

  Next, a fourteenth embodiment of the present invention will be described. In the liquid crystal display device of the present embodiment, an electric field responsive material is sandwiched between the pixel electrode 214 and the common electrode 215 of the display unit 200 in the first to thirteenth embodiments. Preferably, the electric field responsive material of the display unit 200 is made of a liquid crystal material.

  The pixel electrode 214 and the common electrode 215 may be provided on different substrates, may be provided on the same substrate, or may be provided between the substrates.

  When an electric field responsive material is used, the response state of the material can be changed according to the potential changed in a pulse shape. In particular, by using a liquid crystal material, the alignment of the liquid crystal material and the response speed thereof change in accordance with the potential changed in a pulse shape.

  Next, a fifteenth embodiment of the present invention is described. This embodiment is the same as the fourteenth embodiment described above, in which the liquid crystal substance is a nematic liquid crystal and has a twisted nematic orientation. Preferably, there is a relationship of p / d <20 between the twist pitch p (μm) of the twisted nematic alignment liquid crystal material and the average thickness d (μm) of the twisted nematic alignment liquid crystal material layer. To establish. More preferably, a relationship of p / d <8 is established between the twist pitch p (μm) of the twisted nematic liquid crystal material and the average thickness d (μm) of the twisted nematic liquid crystal material layer. To do.

  In the present liquid crystal display device, an optical compensator is provided as necessary in order to widen the viewing angle. Preferably, the optical compensator compensates optical characteristics of the liquid crystal material in a predetermined state. For example, the optical compensator is configured to compensate for the optical characteristics obtained from the alignment structure of the liquid crystal material when a voltage is applied.

  By using a twisted nematic liquid crystal, a continuous gradation change can be obtained. In particular, since the above relationship exists between the twist pitch p and the thickness d, it is possible to increase the torque for the twisted nematic liquid crystal to return to the twisted state. This makes it possible to increase the response speed when returning to the state of no voltage application or low voltage application. That is, the falling response can be speeded up.

  Next, effects of the fifteenth embodiment will be described using the examples. The effects of this embodiment are obtained when liquid crystals with different twist pitches are prepared, liquid crystal panels are produced for each, and a pair of polarizing plates are arranged outside the panel so that a normally white display can be obtained. It was confirmed. A liquid crystal having a substrate gap (liquid crystal layer thickness) of 2 μm and a twist pitch of 6 μm, 20 μm, or 60 μm was used. The thickness of the liquid crystal layer acts as a square on the response speed. For example, if the thickness of the liquid crystal layer is 6 μm (three times the thickness), the response speed becomes 1/9. For this reason, the thickness of the liquid crystal layer is preferably 4 μm or less, and more preferably 3 μm or less. Although there is no limitation on the thickness, the thickness is preferably 0.5 μm or more, more preferably 1 μm or more in consideration of the limitation of the twist pitch of the liquid crystal and the difficulty in manufacturing the gap between the substrates. In this state, the time-transmittance characteristic of the liquid crystal at the time of rising (optical response at the time of falling of the liquid crystal (that is, response from a dark state to a bright state in the normally white arrangement)) was observed. From the black display state to the completely transmissive white display state, the slope of the transmittance change when the transmittance is around 50% was determined from the observed time-transmittance characteristics. The reason why the vicinity of the transmittance of 50% is selected is that the transmittance change in this vicinity is the largest. FIG. 16 is a graph plotting the relationship between the calculated slope (% / ms) on the vertical axis and (p (twist pitch) / d (liquid crystal layer thickness)) on the horizontal axis. Needless to say, the thickness of the liquid crystal layer is equivalent to the distance between the substrates. FIG. 16 shows that as (twist pitch / liquid crystal layer thickness) decreases, the tilt increases, and the response at the fall of the liquid crystal increases. In particular, when the (twist pitch / liquid crystal layer thickness) is about 15, a sharp increase in inclination is observed. When the (twist pitch / liquid crystal layer thickness) is about 3, the inclination exceeds 50 (% / ms). . That is, ideally, a response within 2 milliseconds is possible. In this figure, when the twist pitch / thickness (p / d) is 30 and 3 is compared, when p / d is 3, the inclination of p / d is almost twice that of 30. It can be seen that the optical response time at the fall can be halved. Further, even when p / d is 30 and p / d is 10, the speed can be increased by 15% or more. In short, this effect is achieved by a large torque that returns to an initial alignment state in which no voltage or the like is applied (that is, an alignment state that is twisted almost uniformly between the substrates).

  Next, a sixteenth embodiment of the present invention will be described. In the fourteenth embodiment, the polymer is stabilized in a structure in which the liquid crystal substance having the twisted nematic alignment is twisted substantially continuously. Preferably, the liquid crystal substance is polymer-stabilized in a structure when no voltage is applied or a low voltage is applied.

  The twisted nematic liquid crystal is preferably polymerized by adding a photocurable monomer and irradiating with light. More preferably, the photocurable monomer is a liquid crystalline monomer having a liquid crystal skeleton. More preferably, the liquid crystalline monomer is a diacrylate, or a monoacrylate in which a polymerizable functional group and a liquid crystal skeleton are bonded without interposing a methylene spacer.

Next, the operation of the sixteenth embodiment of the present invention will be described below with examples. As the liquid crystal, twisted nematic liquid crystal added with 2% of a photocurable diacrylate liquid crystalline monomer having the structural formula shown in the following chemical formula 1 is injected, and light irradiation (ultraviolet (1 mW / cm ² × 600 seconds), a normally white display TN type display device was obtained, and a polymerizable functional group having a structural formula shown in the following chemical formula 2 and a liquid crystal skeleton were passed through a methylene spacer. In the same manner as in the case of diacrylate liquid crystal monomer, a twisted nematic liquid crystal added with 2% of a photocurable monoacrylate liquid crystalline monomer bonded without being injected is injected and polymerized by light irradiation without applying voltage. Results were obtained.

  This is because the use of a monomer that does not have a methylene spacer is less likely to be limited in response to the liquid crystal voltage when the monomer is added. It goes without saying that other liquid crystalline monomers can be used by adjusting the amount of monomer added. In order to stabilize the orientation of the liquid crystal with respect to the unevenness of the substrate, the amount of the monomer added may be 0.5% or more with respect to the liquid crystal, but more preferably 1% or more. If the response of the liquid crystal is 5% or less, it will not be disturbed, but it is more preferably 3% or less.

  By stabilizing the polymer in this way, the same effect as that of the fifteenth embodiment can be obtained. This is because the torque for returning to the polymer stabilized state increases.

  Next, a seventeenth embodiment of the present invention will be described. This embodiment is the same as the fourteenth embodiment, but the liquid crystal substance is in a voltage controlled birefringence mode.

  Alternatively, in the fourteenth embodiment, the liquid crystal material may have a pi-type orientation (bend-type orientation). Preferably, the liquid crystal display device according to the present pi-type alignment is provided with an optical compensation plate and is in an OCB (Optically Compensated Birefringence) mode.

  Alternatively, in the fourteenth embodiment described above, the liquid crystal material may be in a VA (vertical alignment) mode in which homeotropic alignment is performed. Preferably, a wide viewing angle is achieved by multi-domaining or the like. As a multi-domain method, an MVA (multi-domain vertical alignment) method, a PVA (patterned vertical alignment) method, an ASV (advanced super-vii) method, or the like can be used. . More preferably, a wider viewing angle can be achieved by providing an optical compensator as necessary.

  Furthermore, in the fourteenth embodiment, the liquid crystal substance can be in an IPS (in-plane switching) mode in which it responds by an electric field parallel to the substrate surface. Preferably, it is possible to further improve the characteristics by using a zigzag-structured electrode so as to be in a Super-IPS (super-IPS) mode.

  Furthermore, in the fourteenth embodiment, the liquid crystal material may be in an FFS (fringe field switching) mode or an AFFS (advanced fringe field) mode.

  In the fourteenth embodiment, the liquid crystal material may be a ferroelectric liquid crystal material, an antiferroelectric liquid crystal material, or a liquid crystal material exhibiting an electroclinic response. Preferably, the liquid crystal material has a transmittance response to a voltage exhibiting a V-shaped response or a Half-V-shaped response.

  In the fourteenth embodiment, the liquid crystal material may be a cholesteric liquid crystal material.

  Next, an eighteenth embodiment of the present invention will be described. In this embodiment, in the seventeenth embodiment, the polymer is stabilized in a structure in which the alignment of the liquid crystal substance is a state in which no voltage is applied or a low voltage is applied.

  Preferably, the twisted nematic liquid crystal is polymerized by adding a photocurable monomer and irradiating with light.

  More preferably, the photocurable monomer is a liquid crystalline monomer having a liquid crystal skeleton.

  More preferably, the liquid crystalline monomer is a diacrylate, or a monoacrylate in which a polymerizable functional group and a liquid crystal skeleton are bonded without interposing a methylene spacer.

  In the seventeenth and eighteenth embodiments of the present invention described above, liquid crystal modes other than the twisted nematic type are used.

  The pie type and OCB modes are modes that can achieve both high-speed response and a wide viewing angle. By applying the present invention, it is possible to further increase the rising response.

  The VA mode series has a wide viewing angle and a high-speed response excluding the halftone response. By applying the present invention, it is possible to increase the speed including halftone response.

  The IPS mode has a wide viewing angle, and the rising response does not reach VA, but the halftone response is faster than VA. By applying the present invention, it is possible to increase the speed including the rising response. The FFS mode has a wide viewing angle and exhibits response characteristics similar to the IPS mode. By applying the present invention, it is possible to increase the speed including the rising response.

  Ferroelectric liquid crystals, antiferroelectric liquid crystals, electroclinic liquid crystals, etc. have an extremely fast response and a wide viewing angle. Even when these liquid crystals are used, by applying the present invention, it is possible to further increase the response speed. On the other hand, it is possible to slow down the response speed.

  The present invention also works effectively for cholesteric liquid crystals.

  Now, the falling response of these liquid crystal modes cannot be increased by the twist pitch as in the twisted nematic type. Therefore, the polymer is stabilized in the state where no voltage is applied.

  In the display device of the present invention, the display substance and the display mode are not limited to the several types shown in the above embodiment. That is, the present invention is effective for all electric field responsive substances as long as the response changes depending on the intensity of the electric field, the application period, the magnitude relationship with the threshold, and the like.

  The nineteenth embodiment of the present invention is a color liquid crystal display device according to any of the first to eighteenth embodiments, which performs color display by using a color filter in the display section.

  By applying the present invention, the response time of a liquid crystal display device using a color filter can be increased. As a result, a liquid crystal display device suitable for moving image display or the like is obtained.

  The twentieth embodiment of the present invention performs stereoscopic display using the lenticular lens sheet (lenticular film) shown in FIG. 17 or the double-sided prism sheet shown in FIG. 18 in the first to eighteenth embodiments. This is a stereoscopic display liquid crystal display device. Preferably, a scanning backlight is formed by alternately inputting light from two locations in the backlight, and in synchronization with this, the video signal is temporally converted into a right-eye video signal, a left-eye video signal, and a normal video signal. A time-division type stereoscopic display system that performs stereoscopic display switching at a frequency of twice or more is used.

  Next, the operation of the twentieth embodiment of the present invention will be described with reference to FIGS. A lenticular lens (lenticular film) 121 shown in FIG. 17 includes a plurality of cylindrical lenses 122. If this is used, it is possible to distribute the image for the right eye and the image for the left eye to each eye according to the positional relationship with the pixel. The double-sided prism sheet shown in FIG. 18 has a lenticular lens 123 similar to that in FIG. 17 provided on one side and a light separation prism 124 provided on the other side. Accordingly, the double-sided prism sheet shown in FIG. 18 can divide light at a wider angle than the single lenticular lens shown in FIG. In the scan backlight, for example, light sources are arranged on the left and right of the light guide plate of the backlight, and one is used as the left-eye light source and the other as the right-eye light source. By selecting the left-eye image and the right-eye image displayed on the display unit and the light source to be turned on in synchronization, stereoscopic display is enabled. For example, it is necessary to switch images at a frequency of 120 Hz or higher, and the speeding up according to the present invention works extremely effectively.

  In the present invention, even when a lenticular lens is used or when a scan backlight is used, there is no difference in the number of pixels when switching between 2D display and 3D display. In addition, when the scan backlight is used, since the inside of the pixel is not divided into two, high resolution or a high aperture ratio can be easily realized.

  Next, a twenty-first embodiment of the present invention will be described. In the present embodiment, in the first to eighteenth embodiments described above, the video signal is divided into a plurality of color video signals corresponding to a plurality of colors, and light sources corresponding to the plurality of colors are used to perform predetermined processing. The color field sequential (color time division) type liquid crystal display device which sequentially displays the plurality of color video signals in time in synchronization with the plurality of color video signals with a phase difference of.

  In the twenty-first embodiment of the present invention, a color field sequential drive type display device is realized. FIG. 19 is a block diagram illustrating an example of an outline of a field sequential display system. Normal image data is processed by a controller IC 103 including a controller 105, a pulse generator 104, and a high-speed frame memory 106, thereby converting the image data into image data for each color of red, blue, and green. This image data is input to the liquid crystal panel (LCD) 100 via the DAC 102. The scanning circuit in the LCD 100 is controlled by drive pulses from a pulse generator of the controller IC. Further, three-color LEDs 101 are used as light sources, and these LEDs are controlled by an LED control signal 108 from the controller IC.

  In this configuration, it is necessary to switch the image of each color at a frequency of 180 Hz or higher, and the high-speed response according to the present invention works effectively. In the 180 Hz display, a phenomenon called “color breakup” occurs in which images of the respective colors appear to be separated when the eye line is rapidly moved by blinking or the like. Therefore, adding white to the three colors of red, blue, and green, repeating one color such as red, green, blue, and green twice, or trying to drive at a double frequency (eg, 360 Hz or more) Is made. Thus, in order to eliminate color breakup, a high frequency is often required, and the speeding up of the present invention works particularly effectively.

  In the present invention, since the inside of a pixel is not divided into three as in the color filter method, high resolution or a high aperture ratio can be easily realized.

  Next, a twenty-second embodiment of the present invention is described. This embodiment is the same as the twenty-first embodiment, wherein the video signal is composed of a right-eye video signal and a left-eye video signal, and each one-eye video signal is divided into a plurality of color video signals corresponding to a plurality of colors. The one-eye video signal corresponding to the plurality of colors and synchronized with the one-eye video signal with a predetermined phase difference between the light sources arranged at two places, and with the plurality of color video signals. A color field sequential (color time division) type time-division type three-dimensional liquid crystal display device that sequentially displays the one-eye video signal as a plurality of divided color video signals. is there.

  In the twenty-second embodiment of the present invention, the color field sequential display of the twenty-first embodiment and the field sequential stereoscopic display of the twentieth embodiment are simultaneously performed. For this purpose, it is preferable to switch images at a frequency of at least 360 Hz. In order to obtain a sufficient response at this frequency, the speeding up of the present invention works effectively.

  In the present invention, even when the two-dimensional display and the three-dimensional display are switched, there is no difference in the number of pixels. Further, since the inside of the pixel is not divided into six for three-dimensional and color filters, high resolution or high aperture ratio can be realized very easily. That is, the area efficiency is 6 times that in the case where the pixels are spatially divided. As a result, a stereoscopic display device with extremely high presence can be obtained. Further, since the number of wirings is 1/6, each wiring can be made thicker, and the delay in the wiring is reduced.

  In the twenty-second embodiment of the present invention, the color field sequential display of the twenty-first embodiment and the stereoscopic display using the cylindrical lens of FIG. 17 or 18 of the twentieth embodiment are performed. In this case, it can be realized even at a frequency of 180 Hz. In these embodiments, since the stereoscopic display method and the color field sequential display method are used at the same time, the number of pixels characteristic of the color field sequential display method can be reduced from the color filter method. Also decreases. By reducing the wiring routing, the frame portion of the display panel can be reduced.

  Next, a twenty-third embodiment of the present invention is described. This embodiment is a display device in which the pixel switch is formed of a thin film transistor made of amorphous silicon in the first to the twenty-second embodiments described above.

  In the first to twenty-second embodiments, the pixel switch is a display device including a thin film transistor made of polysilicon. In addition, the thin film transistor made of polysilicon includes not only a thin film transistor sequentially manufactured on a substrate but also a thin film transistor which is formed on a temporary substrate and then transferred onto another substrate.

  Furthermore, in the first to twenty-second embodiments, the pixel switch is a display device including a transistor made of single crystal silicon. As a transistor using single crystal silicon, a transistor using bulk silicon technology, an SOI (silicon-on-insulator) technology, an amorphous silicon whose channel is single-crystallized by a crystallization technology, or the like is applicable. In addition, a transistor using single crystal silicon includes not only a transistor sequentially manufactured over a substrate but also a transistor which is manufactured over a temporary substrate and then transferred onto another substrate.

  On the other hand, in the first to twenty-second embodiments described above, the pixel switch is a display device configured by an MIM (metal insulator metal) element.

  Next, a twenty-fourth embodiment of the present invention will be described. In this embodiment, in the first to 23rd embodiments, the polarity of the video signal is reversed at a predetermined timing, and a period of time during which the potential of the common electrode that changes between a plurality of potentials is applied. The display device is configured such that one or two potentials that are longer than other potentials are approximately equal to an intermediate potential between the maximum potential and the minimum potential among all potentials applied as the video signal.

  For example, a waveform as shown in FIG. 20 is applied to the liquid crystal display device according to the twenty-fourth embodiment of the present invention. By giving a voltage change as shown in FIG. 20, it is possible to increase the response speed during the pulse-like change period. Further, the video signal is inverted with respect to the common electrode potential, and the minimum values in the respective polarities are substantially close to each other.

  Next, a twenty-fifth embodiment of the present invention is described. In this embodiment, in the first to 23rd embodiments, the polarity of the video signal is reversed at a predetermined timing, and a period of time during which the potential of the common electrode that changes between a plurality of potentials is applied. In the display device, one or two potentials that are longer than other potentials are approximately equal to one of the maximum potential and the minimum potential among all potentials that can be applied as the video signal.

  For example, a waveform as shown in FIG. 21 is applied to the liquid crystal display device of this embodiment. By giving a voltage change as shown in FIG. 21, it is possible to increase the response speed during the pulse-like change period. In addition, the video signal is inverted with respect to the common electrode potential, and the maximum value of one polarity and the minimum value of the other polarity are approximately close to each other.

  Next, a twenty-sixth embodiment of the present invention is described. In the present embodiment, in the first to twenty-third embodiments, the common electrode potential immediately before the scanning signal driving circuit 202 starts scanning the first scanning electrode of the scanning electrode 212 and the scanning signal driving circuit 202 include the scanning electrode 212. The liquid crystal display device is configured such that the common electrode potential is the same as that immediately after scanning all of the above and transmitting the video signal to the pixel electrode 214 and before changing to a pulse shape.

  An example of the waveform of the twenty-sixth embodiment is the same as that shown in FIG.

  Next, a twenty-seventh embodiment of the present invention is described. In this embodiment, in the first to twenty-third embodiments, the common electrode potential immediately before the scanning signal driving circuit 202 starts scanning the first scanning electrode of the scanning electrode 212 and the scanning signal driving circuit 202 are the scanning electrode. Immediately after scanning all of 212 and transmitting a video signal to the pixel electrode 214 and before changing to a pulse shape, the common electrode potential is different.

  In this configuration, the common electrode potential immediately before the scanning signal driving circuit 202 starts scanning the first scanning electrode of the scanning electrode 212 is preferably set to one of the maximum voltage or the minimum voltage that can be taken as a video signal to be applied. The common electrode potential after the scanning signal driving circuit 202 scans all of the scanning electrodes 212 and transmits the video signal to the pixel electrode 214 and before the pulse signal is changed is the image that has been applied. It is approximately equal to the other of the maximum voltage or the minimum voltage that can be taken as a signal.

  An example of the waveform of the 27th embodiment is the same as that of FIG.

  Next, a twenty-eighth embodiment of the present invention is described. In this embodiment, in the twenty-fourth and twenty-sixth embodiments, the common electrode potential is composed of four potentials, and the first potential transmits a video signal having one polarity of the inverted video signal. The second potential is a pulse height when the potential of the common electrode 215 is changed in a pulse shape following the first potential. The third potential is a potential after the end of the pulse when the potential of the common electrode 215 is changed into a pulse shape following the second potential, and the other polarity of the inverted video signal. Is a common electrode potential during a period in which the scan signal driving circuit 202 scans the scan electrode 212 to transmit the video signal, and the fourth potential is a pulse of the potential of the common electrode 215 following the third potential. When changing Scan is a liquid crystal display device which is the potential of the height portion.

  An example of a waveform according to the twenty-eighth embodiment of the present invention is the same as that shown in FIG.

  Next, a twenty-ninth embodiment of the present invention is described. In this embodiment, in the 25th and 27th embodiments, the common electrode potential consists of six potentials, and the first potential transmits a video signal of one polarity of the inverted video signal. And the second potential is a pulse height when the potential of the common electrode 215 is changed in a pulsed manner following the first potential. The third potential is a potential after the end of the pulse when the potential of the common electrode 215 is changed in a pulse shape following the second potential, and the fourth potential is inverted. The fifth potential is a common electrode potential during a period in which the scan signal driving circuit 202 scans the scan electrode 212 in order to transmit a video signal having the other polarity of the video signal. Change the potential of 215 in pulses And the sixth potential is a potential after the end of the pulse when the potential of the common electrode 215 is changed in a pulse shape following the fifth potential. This is a driving method.

  An example of the waveform of the 29th embodiment is the same as that of FIG.

  Next, a thirtieth embodiment of the present invention is described. In the first to 29th embodiments, the present embodiment includes a light irradiation unit 252 that makes light incident on the display unit 200 as shown in FIG. 22, and the light intensity of the light irradiation unit 252 is set as a video signal. And a synchronizing circuit 251 for synchronizing and modulating with a predetermined phase.

  Further, in the first to 29th embodiments described above, as shown in FIG. 23, the light irradiation unit 254 that makes light incident on the display unit 200 is included, and the light color of the light irradiation unit 254 is imaged. A synchronization circuit 253 that changes the signal in synchronization with a predetermined phase can also be provided.

  Further, in the first to 29th embodiments described above, as shown in FIG. 24, it has a light irradiation part 256 for making light incident on the display part 200, and the light intensity of the light of the light irradiation part is It is configured to have a synchronizing circuit 255 that modulates and synchronizes the video signal with a predetermined phase, and changes the color of the light of the light irradiator 256 in synchronism with the video signal with a predetermined phase. You can also.

  The light irradiating unit in this embodiment may use a surface-emitting light source, a backlight composed of a light guide plate and a light source or other optical elements, or a laser or other beam or line. The light source may be scanned.

  The light intensity may be modulated by luminance modulation and blinking of the light source itself, or by a modulation filter that can modulate the transmission or reflection intensity.

  Next, a thirty-first embodiment of the present invention is described. In this embodiment, in the thirty-third embodiment, when the light intensity of the light irradiation unit is modulated or the timing of changing the color of light is divided into each field or a plurality of colors, the color is changed to that color. This is a driving method of a display device located at the end of each corresponding subfield, that is, immediately before writing the video signal of the next field.

  The operation of the thirty-first embodiment will be described. By performing light intensity modulation or light color change for a certain period at the end of each subfield, it is possible to irradiate light with a relatively stable response of the display substance in the display portion. As a result, light utilization efficiency is high, display is stable, and high-quality display is possible. By modulating the intensity of light, for example, the brightness of the entire screen or each of the divided areas can be adjusted according to the content of the video data. Specifically, if the content of the video data is mainly dark gradation, the light intensity is reduced, and if the content of the video data is mainly light gradation, the light intensity is increased. The sense of dynamics of expression can be improved. In addition, when a luminance abnormality such as flicker occurs, it is possible to suppress the luminance abnormality such as flicker by modulating the light intensity according to the luminance abnormality.

  Next, a thirty-second embodiment of the present invention is described. In this embodiment, in the first to 31st embodiments, the potential of the video signal is changed to the holding data of each pixel before writing the video signal and the potential of the common electrode 215 to be changed in a pulse shape or the pulse shape. This is determined by comparing the change in the pixel electrode potential accompanying the change in the potential of the storage capacitor electrode 216 or both potentials with the display data to be newly displayed.

  Next, a thirty-third embodiment of the present invention is described. The present embodiment is the display device according to the thirty-second embodiment that compares the data and potential fluctuations by successive comparison.

  Further, in order to perform the successive comparison, the storage means for storing the original video signal data in the previous field or the video signal data including the finally applied correction in the previous field, and the stored data It has comparison operation means for comparing video signal data to be newly displayed and determining new signal data.

  Next, a thirty-fourth embodiment of the present invention is described. In this embodiment, in the thirty-second embodiment, comparison of data and potential fluctuation is performed using a prepared LUT (look-up table, correspondence table).

  Further, in order to select necessary data from the correspondence table, storage means for storing the original video signal data in the previous field or video signal data including the finally applied correction in the previous field, and stored Search means or address designating means for searching the correspondence table and the video signal data to be newly displayed on the correspondence table to determine the new signal data.

  Next, the operation of the thirty-second to thirty-fourth embodiments of the present invention will be described. In the mere overdrive method, as shown in Japanese Patent No. 3039506, the image data to be applied is basically compared by comparing the image data of the previous field and the image data of the new field and taking into account the response of the display substance. Signal data can be determined. On the other hand, in the present invention, in order to change the common electrode potential, the storage capacitor electrode potential, or both in a pulse shape, it is necessary to consider the effect of changing the pulse shape. This effect is mainly a change in potential due to capacitive coupling and a temporary response time caused thereby. By providing a video signal considering this, the display of the present invention has the best image quality. This video signal can be produced by sequential calculation, or a lookup table may be prepared in advance.

  Next, a thirty-fifth embodiment of the present invention is described. In the present embodiment, in the first to thirty-fourth embodiments using the twisted nematic liquid crystal, the pulse-like change that is not reset is the average rise of the liquid crystal while the pulse-like change is applied. The angle is 81 degrees or less. Preferably, the average rising angle of the liquid crystal is 65 degrees or less.

  Next, the operation of the thirty-fifth embodiment will be described. According to the experiment and measurement of the present inventor and a comparison by computer simulation, the delay in the transition from the reset state in the twisted nematic liquid crystal depends on the average rise angle of the liquid crystal. Then, it was found that when the average rising angle is 81 degrees or more, a delay occurs in which the orientation is opposite to the desired orientation. Further, it has been found that when the average rising angle is 65 degrees or more, the direction of orientation change is temporarily unknown and a delayed state is generated. When the potential fluctuation that is not reset is realized, it is possible to obtain an excellent response characteristic without delay by being within an angle lower than these average rising angles.

  Next, a thirty-sixth embodiment of the present invention is described. In this embodiment, in the first to thirty-fifth embodiments, the video signal is used as a digital signal, the potential applied to the display substance is a binary signal, and the light integration digital drive is used to express gradation in the time axis direction. A display device that performs display.

  The operation of the 36th embodiment will be described. In this embodiment mode, digital driving is performed. For example, Japanese Patent No. 3402602 discloses digital driving. The digital drive will be described with reference to FIGS. FIG. 25 shows a conventional driving method in which the potential of the common electrode is fixed and a video signal having an amplitude within a predetermined range with respect to the common electrode potential is driven with the polarity reversed within one subfield period, and It is a schematic diagram which shows the waveform of digital drive in the case of performing digital drive using the same amplitude as the maximum voltage amplitude of the video signal of the driving method. The fixed common electrode potential is indicated by a one-dot chain line, and the maximum potential and the minimum potential of the video signal are indicated by broken lines. In the conventional driving shown in the upper diagram of FIG. 25, the gradation is expressed by the magnitude of the voltage value. That is, gradation is realized by electric field intensity modulation. On the other hand, in the digital drive shown in the lower diagram of FIG. 25, the voltage value is binary, and the subfield period is divided into a plurality of periods, and the gradation is digitally expressed by the number of times the voltage is turned on and off. That is, gradation is realized by the number of pulses. In the digital drive shown in the figure below, since the amplitude of the video signal voltage can be doubled as compared with the conventional one, the response at the on time is extremely fast. On the other hand, a delay similar to the delay in the transition from the reset state may occur. In addition, since the video signal cannot be inverted, the electrical neutrality of the display substance cannot be maintained.

  In FIG. 26, the potential of the common electrode is inverted within one subfield period, and a video signal having an amplitude within a predetermined range with respect to the common electrode potential is driven with the polarity inverted within one subfield period. It is a schematic diagram showing a digital driving waveform when the digital driving is performed using the same amplitude as the maximum voltage amplitude of the video signal of the driving method and the conventional driving method. The inverted common electrode potential is represented by a one-dot chain line, and the maximum potential and the minimum potential of the video signal are represented by broken lines. In the conventional driving shown in the upper diagram of FIG. 26, the gradation is expressed by the magnitude of the voltage value. That is, gradation is realized by electric field intensity modulation. Further, the amplitude of the entire video signal is about half that of FIG. On the other hand, in the digital drive shown in the lower diagram of FIG. 26, the voltage value is binary, and the subfield period is divided into a plurality of periods, and the gradation is digitally expressed by the number of times the voltage is turned on and off. That is, gradation is realized by the number of pulses. Unlike the digital drive shown in the lower diagram of FIG. 25, in the digital drive shown in the lower diagram of FIG. 26, the amplitude of the video signal voltage is the same as that of the prior art, and the on-time response is similar. On the other hand, there is little occurrence of delay similar to the delay in transition from the reset state. In addition, since the video signal can be inverted, the electrical neutrality of the display substance can be maintained.

  Even in such digital drive, speeding up by the method of the present invention is effective. In particular, this is extremely effective in a configuration where a sufficient on-time response cannot be obtained as shown in FIG. The display unit and various circuits in the present invention may be formed on different substrates, or may be formed on the same substrate. In addition, some circuits may be formed over the same substrate and other circuits may be formed over different substrates.

  The pixel electrodes arranged in a matrix may be arranged in a stripe shape, a delta shape or a Bayer arrangement (checkered pattern), or a pen tile arrangement that can increase the substantial resolution from the normal level. . This pen tile arrangement was announced by the Clair Voyante Institute, and an example of the arrangement is shown in FIG.

  Next, a thirty-seventh embodiment of the present invention is described. In this embodiment, in each embodiment that performs field sequential display of the present invention, an LUT prepared by comparing the fluctuation of data and potential in advance according to the polarity of the video signal with respect to the common electrode and the type of color signal to be displayed. (Lookup table, correspondence table).

  In the thirty-eighth embodiment of the present invention, an LUT (Look Up Table, Correspondence Table) that defines the correspondence between a video signal and the gradation luminance obtained from the video signal is used. The LUT varies depending on the polarity of the video signal and the type of color signal to be displayed.

  Next, the operation of the thirty-seventh and thirty-eighth embodiments of the present invention will be described. By preparing an LUT according to the polarity of each color signal and each video signal, it is possible to apply an optimum voltage for each color subfield, and it is possible to perform an optimum display for each color subfield. In the field sequential display, the optimum voltage / transmittance characteristics are different for each color. By preparing an LUT corresponding to a color signal, the characteristics for each color can be optimized. Further, the fluctuation of the pixel potential varies slightly depending on the polarity of the video signal. By preparing an LUT according to the polarity of the video signal, the characteristics for each polarity can be optimized.

  More simply, an LUT for converting input video signal data and a signal voltage to be output to the display unit is prepared in accordance with the polarity of each color signal and each video signal and the order of change. In this method, it is difficult to completely suppress the potential fluctuation, but the input video signal data and the output signal to the display unit when a still image is displayed under each display condition (for example, a red image with positive polarity). An LUT can be created by measuring the voltage relationship for each gradation. Also, the size of the LUT can be extremely small. Such an LUT can be substantially the same as an LUT for adjusting a so-called voltage / transmittance curve and gradation curve (γ curve). FIG. 48 shows an example of a simple LUT with a red image. As shown in FIG. 48, the output voltage for the same video signal data is made different between positive polarity and negative polarity.

  Next, a thirty-ninth embodiment of the present invention is described. This embodiment is a near-eye device using the liquid crystal display device of the first to thirty-eighth embodiments. Near-eye devices include viewfinders such as cameras or video cameras, head-mounted displays or head-up displays, and other devices used in the immediate vicinity of eyes (for example, within 5 cm).

  In the thirty-ninth embodiment, since it is used for near-eye applications, high image quality such as good color reproduction, sharpness of images, and cut off of moving image display is required, and the effect of applying the present invention is great. .

  Next, a fortieth embodiment of the present invention is described. The present embodiment is a projection device that uses the liquid crystal display devices according to the first to thirty-eighth embodiments and projects an original image of the display device using a projection optical system. The projection device includes a projector such as a front projector and a rear projector, or a magnification observation device.

  Since this projection device is used in projection applications, the image is often magnified very greatly. Therefore, the effect of the application of the present invention, in which high image quality is strictly required, is great.

  Next, a forty-first embodiment of the present invention is described. The present embodiment is a portable terminal using the liquid crystal display device according to the first to thirty-eighth embodiments. This portable terminal includes a mobile phone, an electronic notebook, a PDA (Personal Digital Assistance), a wearable personal computer, and the like.

  This portable terminal is used for applications that are always carried, and many use a battery or a dry cell, so that low power consumption is required. The effect of application of the present invention is also great for such applications. In addition, since mobile terminals are often used both indoors and outdoors, application of the present invention with high light utilization efficiency is desired so that sufficient brightness can be obtained. Furthermore, since it is used in a wide range of temperatures depending on the environment in which it is carried, the application of the liquid crystal display device of the present invention having a wide temperature range has a great effect.

  Next, a forty-second embodiment of the present invention is described. This embodiment is a monitor device using the liquid crystal display devices according to the first to thirty-eighth embodiments. This monitor device includes monitor devices for personal computers, AV (audio / visual) devices (for example, televisions), medical uses, design uses, painting appreciation uses, and the like.

  This monitor device is a monitor device used on a desk or the like, and is often observed carefully, so that it is desired to have high image quality, and application of the present invention is effective.

  Next, a forty-third embodiment of the present invention is described. The present embodiment is a mobile display device using the liquid crystal display devices according to the first to thirty-eighth embodiments. The moving body includes a car, an airplane, a ship, a train and the like.

  This mobile display device is not a device carried by a person as in the forty-first embodiment, but is a device attached to the mobile unit. Since the moving body is subject to various environmental changes, it is preferable to apply the liquid crystal display device of the present invention which is less dependent on environmental changes such as light intensity and temperature as described above. Further, since the power source is limited, a liquid crystal display device with low power consumption as in the present invention is useful.

  Next, the effect of the example to which the liquid crystal display device according to the embodiment of the present invention is applied will be described.

  FIG. 38 is a cross-sectional view showing the structure of a TFT array used in the embodiment of the present invention. A unit structure of a polysilicon TFT array in which amorphous silicon is modified into polysilicon will be described with reference to FIG.

  The polysilicon TFT shown in FIG. 38 is obtained by growing amorphous silicon after forming a silicon oxide film 28 on a glass substrate 29. Next, annealing was performed using an excimer laser, the amorphous silicon was turned into polysilicon, a polysilicon film 27 was formed, and a 10 nm silicon oxide film 28 was further grown. After the patterning, the photoresist was patterned slightly larger than the gate shape (to form the LDD regions 23 and 24 later), and a source region (electrode) 26 and a drain region (electrode) 25 were formed by doping phosphorus ions. Thereafter, a silicon oxide film 28 to be a gate oxide film is grown, then amorphous silicon to be a gate electrode and tungsten silicide (WSi) are grown, and then a photoresist is patterned, and the amorphous silicon and tungsten are masked using the photoresist as a mask. Silicide (WSi) was patterned into a gate electrode shape. Further, LDD regions 23 and 24 were formed by doping phosphorus ions only in necessary regions using the patterned photoresist as a mask. Thereafter, after the silicon oxide film 28 and the silicon nitride film 21 were continuously grown, a contact hole was formed, and aluminum and titanium were formed by sputtering and patterned to form the source electrode 26 and the drain electrode 25. Thereafter, a silicon nitride film 21 was formed on the entire surface, a contact hole was formed, an ITO film was formed on the entire surface, and a transparent pixel electrode 22 was formed by patterning. In this way, a planar TFT pixel switch as shown in FIG. 38 was prepared and a TFT array was formed, so that a pixel array and a scanning circuit by the TFT switch were provided on the glass substrate.

  In FIG. 38, a TFT in which amorphous silicon is converted into polysilicon is formed. However, after growing the polysilicon, the TFT may be formed by a method of improving the grain size of polysilicon by laser irradiation. In addition to the excimer laser, a continuous wave (CW) laser may be used as the laser.

  Furthermore, an amorphous silicon TFT array can be formed by omitting the step of converting amorphous silicon into polysilicon by laser irradiation.

  39A to 39D and FIGS. 40E to 40H are cross-sectional views showing a method of manufacturing a polysilicon TFT (planar structure) array in the order of steps. A method of manufacturing a polysilicon TFT array will be described in detail with reference to FIGS. 39A to 39D and FIGS. 4E to 4H. After forming the silicon oxide film 11 on the glass substrate 10, the amorphous silicon 12 was grown. Next, annealing was performed using an excimer laser to convert amorphous silicon into polysilicon (FIG. 39A). Further, after a 10 nm-thickness silicon oxide film 13 is grown and patterned (FIG. 39B), a photoresist 14 is applied and patterned (masking the p-channel region) and doped with phosphorus (P) ions. As a result, n-channel source and drain regions were formed (FIG. 39C). Further, after a 90 nm-thick silicon oxide film 15 to be a gate insulating film is grown, amorphous silicon 16 and tungsten silicide (WSi) 17 for forming a gate electrode are grown and patterned into a gate shape (FIG. 39 (d)).

  Photoresist 18 was applied and patterned (masking the n-channel region), and boron (B) was doped to form n-channel source and drain regions (FIG. 40 (e)). After the silicon oxide film and the silicon nitride film 19 were continuously grown, a contact hole was formed (FIG. 40 (f)), and aluminum and titanium 20 were formed by sputtering, followed by patterning (FIG. 40 (g)). ). By this patterning, CMOS source / drain electrodes of the peripheral circuit, data line wiring connected to the drain of the pixel switch TFT, and contacts to the pixel electrode are formed. Next, a silicon nitride film 21 as an insulating film was formed, a contact hole was formed, ITO (indium tin oxide) 22 as a transparent electrode was formed for the pixel electrode, and patterned (FIG. 40 (h)).

  Thus, a TFT pixel switch having a planar structure was produced, and a TFT array was formed. Tungsten silicide is used for the gate electrode, but other electrodes such as clonium can also be used.

  A liquid crystal panel is formed by sandwiching the liquid crystal between the TFT array substrate thus manufactured and the counter substrate on which the counter electrode is formed. The counter electrode is formed by forming an ITO film on the entire surface of a glass substrate serving as a counter substrate and patterning it, and then forming a light-shielding chromium patterning layer. The light shielding chromium patterning layer may be formed before the ITO film is formed on the entire surface. Further, a 2 μm patterned pillar was produced on the counter substrate side. This pillar was used as a spacer for maintaining the cell gap and at the same time had impact resistance. This column is for maintaining the cell gap, and the height of the column can be appropriately changed depending on the design of the liquid crystal panel. An alignment film was printed on the surfaces of the TFT array substrate and the counter substrate facing each other and rubbed so that an alignment direction having an angle of 90 degrees was obtained after assembly. Thereafter, an ultraviolet curing sealing material was applied to the outside of the pixel region of the counter substrate. After the TFT array substrate and the counter substrate are bonded to face each other, liquid crystal is injected to form a liquid crystal panel.

  Although the patterning layer made of chromium serving as a light shielding film is provided on the counter substrate side, it can also be provided on the TFT array substrate side. Needless to say, the light shielding film may be made of any material that can shield light even if it is other than chromium. For example, WSi (tungsten silicide), aluminum, silver alloy, or the like can be used.

  When forming a light-shielding chromium patterning layer on a TFT array substrate, there are three types of structures. In the first structure, a light-shielding chromium patterning layer is formed on a glass substrate. After the light-shielding patterning layer is formed, it can be produced in the same manner as in the above process. In the second structure, a TFT array substrate is manufactured in the same way as the above structure, and finally a light-shielding chromium patterning layer is provided. In the third structure, a chromium patterning layer for light shielding is provided in the process of producing the above structure. When the light shielding chromium patterning layer is formed on the TFT array substrate side, it is not necessary to form the light shielding chromium patterning layer on the counter substrate. The counter substrate can be formed by patterning after forming the ITO film on the entire surface.

  In the embodiment of the present invention, a nematic liquid crystal is sandwiched between the TFT array substrate and the counter substrate, and an orientation twisted by 90 degrees is realized between the two substrates so as to be in the TN mode. In addition, a part of the scan electrode driving circuit, the signal electrode driving circuit, the synchronization circuit, and the common electrode potential control circuit were formed on a glass substrate.

  Using the TFT panel manufactured in this way, overdrive to the video signal, driving to give a pulse-like change in the common electrode potential, and liquid crystal with p / d = 3 were used. Also, a comparison operation circuit for producing a video signal was added. With this configuration, 180 Hz color field sequential driving was performed. As the color time-division light source, an LED backlight was used.

  The pixel pitch is set to 17.5 μm, and a display with a resolution of VGA (horizontal 640, vertical 480) is performed in a display area of 0.55 inches diagonal. Further, the pixel at the corner of the display area was provided with a buffer amplifier made of a thin film transistor, and the state of variation in pixel potential was measured. In addition, a buffer amplifier for measuring buffer amplifier characteristics, which was similarly manufactured and connected to the pixel electrode, was manufactured in the substrate. The pixel potential given below is a value obtained by correcting the output voltage of the buffer amplifier in consideration of the gain and offset based on the measurement result of the buffer amplifier characteristic measurement buffer amplifier.

  FIG. 28 shows temporal changes in the common electrode potential, the pixel electrode potential, each potential of the potential difference of the liquid crystal layer obtained from the two, and the transmittance in this embodiment. Note that in the potential measurement, three types of voltages were used as grayscale voltages: white display and black display, and gray display in a halftone state. As can be seen from the top view of FIG. 28, the common electrode potential was changed in the same manner as in FIG. As shown in the second diagram from the top in FIG. 28, the pixel potential changes by writing the video signal. Even during a period when there is no signal writing, the value increases or decreases with the response of the liquid crystal. This is because even if the charge accumulated between the pixel electrode and the common electrode is kept almost constant, the capacitance of the liquid crystal layer is changed by the response of the liquid crystal, so that the potential change of the pixel potential occurs. Furthermore, when a pulse-like change is applied to the common electrode potential, the pixel potential varies greatly due to capacitive coupling. The third diagram from the top in FIG. 28 shows the potential difference of the liquid crystal layer corresponding to the absolute value of the difference between the pixel electrode potential and the common electrode potential. In the pulse height portion of the pulse-like change, the potential difference is large compared to other periods. This shows that an overdrive effect is obtained. In the period of the pulse height portion, the fluctuation of the pixel potential accompanying the liquid crystal response is large. That is, the response of the liquid crystal becomes faster, suggesting that the change in the capacitance of the liquid crystal layer is abruptly generated. When the pulse-like change ends, the pixel potential again varies due to capacitive coupling. The lowest diagram in FIG. 28 shows the temporal change in transmittance obtained by these waveforms. The unit of transmittance is an arbitrary unit. When a video signal is written, the transmittance starts to change, and a rapid transmittance change occurs during a period in which a pulse-like change is given. When the pulse-like change is finished, the transmittance changes so as to reach a stable state under each condition.

  Next, the characteristics of the display device of the example of the present invention when the environmental temperature changed were measured. In addition, a comparison is made between the characteristics of the example and the comparative example, using a 180 Hz color field sequential display device using the method of JP-T-2001-506376, which is a drive that combines overdrive and reset drive, as a comparative example. did. In order to accurately grasp the influence of temperature, in the measurement, a display device is installed in the thermostatic chamber, the temperature sensor attached to the display unit is monitored, and after waiting for 30 minutes from the desired temperature, measurement is performed. By doing so, the display unit was stably controlled to a desired temperature. FIG. 29 shows how the transmittance changes with time in white display according to the embodiment of the present invention when the temperature is changed to −10 ° C., 25 ° C., and 70 ° C. FIG. 30 shows the temporal change in transmittance in white display when the temperature is changed to −10 ° C., 25 ° C., and 70 ° C. in the comparative example. In the embodiment of the present invention, it can be seen that after the pulse-like change is finished, the transmittance goes to a stable state and reaches almost the same transmittance at any temperature. On the other hand, in the comparative example, the transmittance increased rapidly after resetting at 70 ° C., but remained moderately increased at 25 ° C. Further, at −10 ° C., the transmittance hardly increases, and the maximum reached transmittance is about one fifth of 70 ° C. FIG. 31 is a diagram showing the temperature dependence of the integrated light transmittance obtained by integrating the transmittance during the period when the light source is turned on in the color field sequential method, in the example of the present invention and the comparative example. In actual use, since the average transmittance during the light source lighting period is more important than the maximum reached transmittance, the light integrated transmittance is used as an index. In the comparative example, a rapid change in the integrated light transmittance occurs with a change in temperature. −10 ° C. is about 1/10 compared with 70 ° C., and the device of the comparative example cannot be used at low temperatures.

  Furthermore, the characteristics of the display device of the present invention were measured when the frequency of the color field sequential method was increased. Similar to FIGS. 29 to 31, a display device using the method disclosed in JP-T-2001-506376 was used as a comparative example. The integrated light transmittance and contrast ratio were measured using 180 Hz and 360 Hz as frequencies. FIG. 32 shows the result. As can be seen from FIG. 32, at 180 Hz, the optical integrated transmittance and contrast ratio of the example and the comparative example are substantially the same. In the case of 360 Hz, in the comparative example, the optical integrated transmittance and the contrast ratio both show a sharp drop. As a result, it has become difficult to visually recognize the image. On the other hand, when 360 Hz is used in the embodiment of the present invention, the optical integrated transmittance is about 60% when 180 Hz, and the contrast ratio is hardly changed. As a result, although it becomes a little dark compared with 180 Hz, the display visually recognized favorably is obtained.

  In the liquid crystal display device of this example, a luminance of 150 candela square meters or more was obtained, and the display could be seen well even under relatively strong external light. Furthermore, under intense light, it was possible to use as a black and white type display device by turning off the backlight by the signal of the optical sensor.

  As described above, according to the present invention, in the transmission type twisted nematic liquid crystal display device, it is possible to obtain an extremely high speed response that enables color field sequential driving at 360 Hz.

  In the present invention, a lower voltage than the conventional overdrive system is sufficient for overdrive of the video signal. In the present embodiment, a voltage of 6V is applied to black display like the pixel potential of FIG. When the liquid crystal material used here is driven normally, an applied voltage of 5 V is required for black display, so the voltage in overdrive is 1 V. On the other hand, in the conventional overdrive system, a voltage of 2V to 3V is usually applied. That is, for the material of the present embodiment, 7V to 8V is required in the conventional method, compared to 6V of the present embodiment. In the present invention, this difference occurs because the speed is effectively increased by a pulse-like change in the common electrode potential or the like corresponding to two-stage overdrive.

  The present invention is extremely useful for increasing the response speed of a liquid crystal display device.

It is a figure which shows the structure of the 1st Embodiment of this invention. It is a figure which shows the structure of the 2nd Embodiment of this invention. It is a figure which shows the structure of the 3rd Embodiment of this invention. It is a figure which shows the structural example of the display part of this invention. It is a figure which shows the structural example of the display part of this invention. It is a figure which shows the structural example of the display part of this invention. It is a figure which shows the example of the timing of the 1st Embodiment of this invention. It is a figure which shows the example of the waveform of the 1st Embodiment of this invention. It is a figure which shows the example of the order which scans the electrically isolated electrode of the 4th thru | or 6th embodiment of this invention. It is a figure which shows the example of the shape of the electrode electrically isolated of the display part of the 4th thru | or 6th embodiment of this invention. It is a figure which shows the example of the display for mobile phones to which the 4th thru | or 6th embodiment of this invention is applied. It is a figure which shows the example of arrangement | positioning of the several electrically isolated common electrode of the display part of the 4th thru | or 6th Embodiment of this invention, and the some storage capacitor electrode electrically separated. It is a figure which shows the time change of the transmittance | permeability at the time of giving the pulse-like change which has the effect similar to the conventional reset. It is a figure which shows the time change of the transmittance | permeability at the time of giving the pulse-like change which is not reset of this invention. It is a block diagram which shows an example of the drive device which drives the display apparatus which concerns on the 12th and 13th Embodiment of this invention. It is a figure which shows the relationship between the twist pitch / thickness in the response at the time of the fall of 15th Example of this invention, and the inclination in the transmittance | permeability 50%. It is a perspective view which shows a lenticular lens sheet (lenticular film). It is a perspective view which shows a double-sided prism sheet. It is the schematic of the whole field sequential display system based on the 21st Embodiment of this invention. It is a figure which shows the example of the waveform of 24th Embodiment of this invention. It is a figure which shows the example of the waveform of 25th Embodiment of this invention. It is a block diagram which shows an example of the display apparatus of the 30th Embodiment of this invention. It is a block diagram which shows the other example of the display apparatus of the 30th Embodiment of this invention. It is a block diagram which shows the other example of the display apparatus of the 30th Embodiment of this invention. It is a figure which shows an example of the waveform of the digital drive of the display apparatus of the 36th Embodiment of this invention. It is a figure which shows the other example of the waveform of the digital drive of the display apparatus of the 36th Embodiment of this invention. An example of a pen tile arrangement is shown. It is a figure which shows the measurement result of the time change of the electric potential in the Example of this invention, and the transmittance | permeability. In the Example of this invention, it is a figure which shows the time change of the transmittance | permeability measured by changing temperature. In a comparative example, it is a figure which shows the time change of the transmittance | permeability measured by changing temperature. It is a figure which shows the dependence to the temperature of the optical integrated transmittance | permeability in the Example and comparative example of this invention. It is a figure which shows the dependence with respect to the drive frequency of the contrast ratio and the optical integrated transmittance in the Example and comparative example of this invention. It is a figure which shows the outline of the method of determination of the response at the time of ON, and the response at the time of OFF in the twisted nematic liquid crystal of normally white display. It is a conceptual diagram which shows an example of the response time in the liquid crystal display device using a normal drive method. It is a conceptual diagram which shows an example of the response time in the liquid crystal display device using overdrive. It is a conceptual diagram which shows an example of the response time in the method of the Japanese translations of PCT publication No. 2001-506376, ie, the liquid crystal display device by the drive which added overdrive and reset. It is a conceptual diagram which shows an example of the response time in the liquid crystal display device of this invention. It is sectional drawing which shows the cross-section of the planar type | mold polysilicon TFT switch used in the 1st Example of this invention. It is sectional drawing for demonstrating the main processes of preparation of the display panel board | substrate used by this invention. It is sectional drawing for demonstrating the main processes of preparation of the display panel board | substrate used by this invention. It is a figure which shows the example of the pixel circuit which comprises the conventional liquid crystal display device. It is a figure which shows the equivalent circuit of TN liquid crystal. It is a timing chart in the case of driving a TN liquid crystal with a conventional liquid crystal display device. It is a figure which shows the effect of the conventional reset drive, A dotted line is a figure which shows the normal drive and a solid line is a figure which shows the light intensity change of the drive by reset drive. It is a figure explaining the drive which modulates the conventional common voltage, the upper figure shows the voltage waveform applied to a common electrode, and the lower figure is a figure which shows light intensity. It is a figure which shows the relationship between the wiring electrically connected to a certain pixel, and electric potential. It is a figure which shows the time change of the variation of the liquid crystal capacitance potential and the time variation of the counter electrode potential and the storage capacitance line potential when the common electrode potential and the storage capacitance line potential are determined by the time constant circuit. It is a figure which shows the example of LUT according to the polarity of each color signal and video signal utilized with a simple system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Glass substrate 11 Silicon oxide film 12 Amorphous silicon 13 Silicon oxide film 14 Photoresist 15 Silicon oxide film 16 Microcrystal silicon (μ-c-Si)
17 Tungsten silicide (WSi) 17
18 photoresist 19 silicon oxide film / silicon nitride film 20 metal (aluminum and titanium)
21 Silicon nitride film 22 Pixel electrode (ITO)
23, 24 LDD region 25 Drain electrode 26 Source electrode 27 Polysilicon 28 Silicon oxide film 29 Glass substrate 51 Signal electrode line 52 Thin film transistor 53 Scan electrode line 54 Pixel electrode 64 Liquid crystal display 65 Signal source 66 Analog digital converter circuit 67 Timing control circuit 68 Output control buffer 69 First latch circuit 70 Second latch circuit 71 Memory 72 Arithmetic unit 80 Drive device 100 LCD
101 LED
102 DAC
103 Controller IC
104 Pulse generator 105 Controller 106 High-speed frame memory 107 Synchronization signal 108 LED control signal 109 Drive pulse 110 Image data 121 Lenticular lens sheet (lenticular film)
122 Cylindrical lens 123 Lenticular lens 124 Light separation prism 151 Voltage waveform 152 applied to the common electrode 152 Corresponding light intensity waveforms 153, 154, 155, 156 at the time corresponding to the waveform 151 Pixel light intensity curve 200 Display unit 201 Video signal drive Circuit 202 Scanning Signal Driving Circuit 203 Common Electrode Potential Control Circuit 204 Synchronization Circuit 205 Capacitance Electrode Potential Control Circuit 211 Video Signal Electrode ”
212 Scanning Signal Electrode 213 Switching Element 214 Pixel Electrode 215 Common Electrode 216 Storage Capacitance Electrode 251 Modulation Synchronization Circuit 252 Light Intensity Variable Light Irradiation Unit 253 Switching Synchronization Circuit 254 Color Variable Light Irradiation Unit 255 Modulation / Switching Synchronization Circuit 256 Light Intensity Variable / Color Variable light irradiation unit 301 Period before pulse-like change 302 Pulse height period 303 Period after pulse-like change 501 Liquid crystal capacitor 502 Storage capacitor 503 Pixel TFT
504 Counter electrode time constant circuit 505 Storage capacitor line time constant circuit 506 Counter electrode potential (VCOM)
507 Pixel potential (VLC)
508 Storage capacitor potential (VST)
901 Scan line (or scan electrode)
902 Signal line (or video signal electrode)
903 Pixel electrode 904 MOS transistor 905 Storage capacitor electrode 906 Storage capacitor 907 Counter electrode (or common electrode)
908 liquid crystal

Claims (63)

In a liquid crystal display device including a liquid crystal display unit, a video signal driving circuit, a scanning signal driving circuit, a common electrode potential control circuit, and a synchronization circuit, the display unit includes a scanning electrode, a video signal electrode, and a matrix A plurality of pixel electrodes arranged in a shape, a plurality of switching elements that transmit video signals to the pixel electrodes, and a common electrode. The common electrode potential control circuit includes all of the scan electrodes. The liquid crystal display device is characterized in that after the image signal is scanned and the video signal is transmitted to the pixel electrode, the potential of the common electrode is changed in pulses. In a liquid crystal display device including a liquid crystal display unit, a video signal driving circuit, a scanning signal driving circuit, a storage capacitor electrode potential control circuit, and a synchronization circuit, the display unit includes a scanning electrode, a video signal electrode, A plurality of pixel electrodes arranged in a matrix; a plurality of switching elements that transmit video signals to the pixel electrodes; and a storage capacitor electrode. The storage capacitor electrode potential control circuit is scanned by the scanning signal drive circuit. A liquid crystal display device, wherein after scanning all of the electrodes and transmitting a video signal to the pixel electrode, the potential of the storage capacitor electrode is changed in pulses. In a liquid crystal display device including a liquid crystal display unit, a video signal driving circuit, a scanning signal driving circuit, a common electrode potential control circuit, a storage capacitor electrode potential control circuit, and a synchronization circuit, the display unit includes scanning electrodes. A plurality of pixel electrodes arranged in a matrix, a plurality of switching elements that transmit a video signal to the pixel electrodes, a common electrode, and a storage capacitor electrode, and the common electrode potential After the scanning signal driving circuit scans all of the scanning electrodes and transmits the video signal to the pixel electrode, the control circuit changes the potential of the common electrode in a pulse shape, and the storage capacitor electrode potential control circuit drives the scanning signal A liquid crystal display device characterized in that after the circuit scans all of the scanning electrodes and transmits a video signal to the pixel electrode, the potential of the storage capacitor electrode is changed in pulses. In a liquid crystal display device including a liquid crystal display unit, a video signal driving circuit, a scanning signal driving circuit, a common electrode potential control circuit, and a synchronization circuit, the display unit includes a scanning electrode, a video signal electrode, and a matrix A plurality of pixel electrodes arranged in a shape, a plurality of switching elements that transmit video signals to the pixel electrodes, and a plurality of common electrodes that are electrically separated from each other, and the common electrode potential control circuit includes: After the scanning signal driving circuit scans a part of the scanning electrode and transmits the video signal to the pixel electrode, the potential of the common electrode corresponding to the scanning electrode scanned by the scanning signal driving circuit is changed in pulses. A display device characterized by that. In a liquid crystal display device including a liquid crystal display unit, a video signal driving circuit, a scanning signal driving circuit, a storage capacitor electrode potential control circuit, and a synchronization circuit, the display unit includes a scanning electrode, a video signal electrode, A plurality of pixel electrodes arranged in a matrix; a plurality of switching elements that transmit video signals to the pixel electrodes; and a plurality of storage capacitor electrodes that are electrically separated from each other; The circuit scans a part of the scanning electrode by the scanning signal driving circuit and transmits a video signal to the pixel electrode, and then pulses the potential of the storage capacitor electrode corresponding to the scanning electrode scanned by the scanning signal driving circuit. A display device characterized by being changed into a shape. In a liquid crystal display device including a liquid crystal display unit, a video signal driving circuit, a scanning signal driving circuit, a common electrode potential control circuit, a storage capacitor electrode potential control circuit, and a synchronization circuit, the display unit includes scanning electrodes. A plurality of pixel electrodes arranged in a matrix, a plurality of switching elements transmitting a video signal to the pixel electrodes, a plurality of common electrodes electrically separated from each other, and A plurality of storage capacitor electrodes separated from each other, and the common electrode potential control circuit drives the scan signal after the scan signal drive circuit scans a part of the scan electrode and transmits a video signal to the pixel electrode. The potential of the common electrode corresponding to the scanning electrode scanned by the circuit is changed in a pulse shape, and the storage capacitor electrode potential control circuit scans a part of the scanning electrode by the scanning signal driving circuit. The liquid crystal display device after transmitting the pixel electrodes, and wherein the changing a potential of said storage capacitor electrode corresponding to the scanning electrode which is scanned by the scanning signal drive circuit in a pulse form to issue. 7. The liquid crystal display device according to claim 1, wherein the potential of the common electrode that is changed in a pulse shape is a potential that does not reset the display of the liquid crystal display unit. 8. . 7. The liquid crystal display device according to claim 2, wherein the potential of the storage capacitor electrode that is changed in a pulse shape is a potential that does not reset the display of the display unit. 8. . 8. The liquid crystal display device according to claim 1, wherein the potential of the common electrode changes between at least three potentials. 9. 9. The liquid crystal display device according to claim 2, wherein a potential of the storage capacitor electrode changes between at least three potentials. The potential of the common electrode or the potential of the storage capacitor electrode that is changed in a pulse shape is changed in a pulse shape in a direction that temporarily increases the potential difference between the pixel electrode and the common electrode or the storage capacitor electrode. The liquid crystal display device according to claim 1. The potential of the video signal is different from the potential of the video signal in a stable display state in static driving in consideration of response characteristics of the display unit during charge holding driving. A liquid crystal display device according to 1. The potential of the video signal is determined by considering the response characteristics of the display unit and comparing the data held in each pixel before writing the video signal with the display data to be newly displayed. The liquid crystal display device according to claim 12. 14. The liquid crystal display device according to claim 1, wherein an electric field responsive material is sandwiched between the pixel electrode and the common electrode of the display portion. 15. The liquid crystal display device according to claim 14, wherein the electric field responsive material is a liquid crystal material. The liquid crystal display device according to claim 15, wherein the liquid crystal substance is a nematic liquid crystal and has a twisted nematic alignment. A relationship of p / d <20 is established between the twist pitch p (μm) of the liquid crystal material having the twisted nematic orientation and the average thickness d (μm) of the layer of the liquid crystal material having the twisted nematic orientation. The liquid crystal display device according to claim 16. A relationship of p / d <8 is established between the twist pitch p (μm) of the liquid crystal material having the twisted nematic orientation and the average thickness d (μm) of the liquid crystal material layer having the twisted nematic orientation. The liquid crystal display device according to claim 17. 19. The liquid crystal display device according to claim 16, wherein the liquid crystal substance having the twisted nematic alignment is polymer-stabilized in a substantially continuously twisted structure. The liquid crystal display device according to claim 15, wherein the liquid crystal material is in a voltage-controlled birefringence mode. The liquid crystal display device according to claim 15, wherein the liquid crystal material has a pi-type orientation (bend-type orientation). The liquid crystal display device according to claim 21, wherein an optical compensator is used and an OCB (optically compensated birefringence) mode is used. The liquid crystal display device according to claim 15, wherein the liquid crystal material is in a VA (vertical alignment) mode in which homeotropic alignment is performed. 24. The liquid crystal display device according to claim 23, wherein the liquid crystal material is multi-domained. 16. The liquid crystal display device according to claim 15, wherein the liquid crystal material is in an IPS (in-plane switching) mode in which the liquid crystal material responds by an electric field substantially parallel to the substrate surface. The liquid crystal display device according to claim 15, wherein the liquid crystal material is in an FFS (fringe field switching) mode or an AFFS (advanced fringe field) mode. The liquid crystal display device according to claim 15, wherein the liquid crystal material is a ferroelectric liquid crystal material, an antiferroelectric liquid crystal material, or a liquid crystal material exhibiting an electroclinic response. The liquid crystal display device according to claim 15, wherein the liquid crystal material is a cholesteric liquid crystal material. 29. The liquid crystal display device according to claim 20, wherein the liquid crystal substance is polymer-stabilized in a structure in which no voltage is applied or low voltage is applied. 30. The liquid crystal display device according to claim 1, wherein the display unit is provided with a color filter to perform color display. The liquid crystal display device according to any one of claims 1 to 30, wherein a lenticular lens sheet, a lenticular film, or a double-sided prism sheet is provided on the display unit to perform stereoscopic display. The video signal is divided into a plurality of color video signals corresponding to a plurality of colors, a light source corresponding to the plurality of colors is synchronized with the plurality of color video signals with a predetermined phase difference, and the plurality of color video signals are temporally converted. 30. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a color field sequential (color time division) system for sequentially displaying images. The video signal is composed of a right-eye video signal and a left-eye video signal, and each one-eye video signal is divided into a plurality of color video signals corresponding to a plurality of colors, corresponding to the plurality of colors, and two locations The one-eye video signal is sequentially displayed temporally in synchronization with the one-eye video signal with a predetermined phase difference and in synchronization with the plurality of color video signals. The liquid crystal display device according to claim 32, wherein the video signal is a color field sequential (color time division) type time-division type three-dimensional display method in which the video signal is sequentially displayed as a plurality of divided color video signals in time. . The liquid crystal display device according to any one of claims 1 to 33, wherein the pixel switch is an amorphous silicon thin film transistor display device including a thin film transistor made of amorphous silicon. 34. The liquid crystal display device according to claim 1, wherein the pixel switch is a polysilicon thin film transistor display device including a thin film transistor made of polysilicon. The liquid crystal display device according to any one of claims 1 to 33, wherein the pixel switch includes a transistor made of single crystal silicon. The video signal is inverted in polarity at a predetermined timing, and one or two potentials of the potential of the common electrode that changes between a plurality of potentials are applied for a longer period than other potentials. 37. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is substantially equal to an intermediate potential between a maximum potential and a minimum potential among all potentials applied as signals. The video signal is inverted in polarity at a predetermined timing, and one or two potentials of the potential of the common electrode that changes between a plurality of potentials are applied for a longer period than other potentials. 37. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is substantially equal to one of a maximum potential and a minimum potential among all potentials that can be applied as a signal. The common electrode potential immediately before the scanning signal driving circuit starts scanning the first scanning electrode of the scanning electrode, and immediately after the scanning signal driving circuit scans all of the scanning electrodes and transmits the video signal to the pixel electrode, and 37. The liquid crystal display device according to claim 1, wherein the common electrode potential before being changed in a pulse shape is equal. The common electrode potential immediately before the scanning signal driving circuit starts scanning the first scanning electrode of the scanning electrode, and immediately after the scanning signal driving circuit scans all of the scanning electrodes and transmits the video signal to the pixel electrode, and 37. The liquid crystal display device according to claim 1, wherein the common electrode potential before being changed in a pulse shape is a different potential. The common electrode potential immediately before the scanning signal driving circuit starts scanning the first scanning electrode of the scanning electrode is approximately equal to one of the maximum voltage and the minimum voltage that can be taken as a video signal to be applied, and the scanning Immediately after the signal driving circuit scans all of the scan electrodes and transmits the video signal to the pixel electrode, and before changing the pulse shape, the common electrode potential is the maximum voltage that can be taken as the video signal after application, or 41. The liquid crystal display device according to claim 40, wherein the liquid crystal display device is substantially equal to the other of the minimum voltages. 40. The method of driving a liquid crystal display device according to claim 37 or 39, wherein the common electrode potential is composed of four potentials, and the first potential transmits a video signal having one polarity of the inverted video signal. Therefore, the common electrode potential is a period during which the scan signal driving circuit scans the scan electrode, and the second potential is a pulse height when the potential of the common electrode is changed in a pulse shape following the first potential. The third potential is a potential after the end of the pulse when the potential of the common electrode is changed in a pulse shape following the second potential, and the other polarity of the inverted video signal Is the common electrode potential during a period in which the scan signal driving circuit scans the scan electrode to transmit the video signal, and the fourth potential changes the potential of the common electrode in a pulsed manner following the third potential. Of the pulse height when The driving method of a display device which is a position. 42. The driving method of a liquid crystal display device according to claim 38, wherein the common electrode potential is composed of six potentials, and the first potential is one of the video signals to be inverted. The common signal potential is a period during which the scan signal driving circuit scans the scan electrodes in order to transmit the polar video signal, and the second potential is a pulse of the common electrode potential following the first potential. The third potential is a potential after the end of the pulse when the potential of the common electrode is changed in a pulse shape following the second potential. The potential is the common electrode potential during a period in which the scanning signal driving circuit scans the scanning electrode in order to transmit the video signal having the other polarity of the inverted video signal, and the fifth potential is the fourth potential. Following this, the potential of the common electrode is pulsed The sixth potential is a potential after the end of the pulse when the potential of the common electrode is changed in a pulse shape following the fifth potential. For driving a liquid crystal display device. 2. A light irradiation unit that makes light incident on a display unit, and a synchronization circuit that modulates the light intensity of the light irradiation unit in synchronization with the video signal with a predetermined phase. 42. The liquid crystal display device according to any one of 1 to 41. A light irradiating unit that makes light incident on the display unit, and a synchronizing circuit that changes the color of light of the light irradiating unit in synchronization with the video signal with a predetermined phase. Item 42. The liquid crystal display device according to any one of items 1 to 41. A light irradiating unit for making light incident on the display unit, and modulating the light intensity of the light irradiating unit in synchronization with the video signal with a predetermined phase; The liquid crystal display device according to any one of claims 1 to 41, further comprising a synchronizing circuit that changes colors in synchronization with the video signal with a predetermined phase. 47. The liquid crystal display device according to claim 44, wherein the light intensity of the light irradiation unit is modulated in synchronization with the video signal with a predetermined phase according to the polarity of the video signal. 48. The method of driving a liquid crystal display device according to claim 44, wherein the timing for modulating the light intensity of the light irradiation unit or changing the color of the light is divided into each field or a plurality of colors. And a display device driving method, wherein the display device is positioned in a certain period at the end of each subfield corresponding to the color, and in a certain period immediately before writing the video signal of the next field. The potential of the video signal is the change in the holding data of each pixel before writing the video signal, the potential of the common electrode changed in the pulse shape, the potential of the storage capacitor electrode changed in the pulse shape, or both potentials. 48. The liquid crystal display device according to any one of claims 1 to 41 and 44 to 47, wherein the liquid crystal display device is determined by comparing a change in pixel electrode potential accompanying the display with display data to be newly displayed. . 50. The liquid crystal display device according to claim 49, wherein the comparison between the data and the variation in potential is sequentially performed. 50. The liquid crystal display device according to claim 49, wherein the comparison of fluctuations in the data and the potential is performed by a LUT (look-up table, correspondence table) prepared in advance. 52. The LUT (look-up table, correspondence table) is different according to a color of light of the light irradiation unit that is changed in synchronization with the video signal with a predetermined phase. Liquid crystal display device. 52. The liquid crystal display device according to claim 51, wherein the LUT (look-up table, correspondence table) differs according to the polarity of the video signal. The LUT (look-up table, correspondence table) is different according to the color of light of the light irradiation unit and the polarity of the video signal that are changed in synchronization with the video signal with a predetermined phase. The liquid crystal display device according to claim 51. The LUT (look-up table, correspondence table) shows the relationship between the input video data and the output voltage to the display unit in the order of change in the polarity of the video signal and the order of change in the color of light of the light irradiation unit. 55. The liquid crystal display device according to claim 54, wherein the liquid crystal display device is an LUT described in response. 45. The liquid crystal display device using twisted nematic liquid crystal, wherein a pulse-like change that is not reset causes an average rising angle of the liquid crystal to be 81 degrees or less while the pulse-like change is given. 56. The liquid crystal display device according to any one of 47 to 49 and 49 to 55. 57. The liquid crystal display device according to claim 56, wherein the non-reset pulse-like change causes an average rise angle of the liquid crystal to be 65 degrees or less while the pulse-like change is given. 45. The display is performed by optical integration digital driving in which a video signal is used as a digital signal, a potential applied to a display substance is a binary signal, and gradation is expressed in a time axis direction. 58 to 47, 49 to 57. The liquid crystal display device according to any one of items 49 to 57. A near-eye device using the liquid crystal display device according to any one of claims 1 to 41, 44 to 47, and 49 to 58. A projection device that projects an original image of a display device using a projection optical system, wherein the liquid crystal display device according to any one of claims 1 to 41, 44 to 47, and 49 to 58 is used. Projection equipment. A mobile terminal using the liquid crystal display device according to any one of claims 1 to 41, 44 to 47, 49 to 58. 59. A monitor device using the liquid crystal display device according to any one of claims 1 to 41, 44 to 47, 49 to 58. 59. A moving body display device comprising the liquid crystal display device according to any one of claims 1 to 41, 44 to 47, and 49 to 58.

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