JP2011221218A - Method for adjusting liquid crystal device, liquid crystal device and electronic equipment equipped with liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress change in initial and temporal flickers.SOLUTION: In an electro-optical device 1, a common electrode potential LCcom is set to a level with which a flicker is not visible, resulting in that an initial flicker is reduced, and an application time ratio of positive voltage application time to negative voltage application time is set to an appropriate value. Thereby change not only in an initial flicker but also in a temporal flicker can be suppressed.

Description

  The present invention relates to a liquid crystal device adjustment method, a liquid crystal device, and an electronic apparatus using the same.

  In a liquid crystal display device, when a DC voltage component acts on a liquid crystal layer, disturbance of charge balance occurs due to polarization of the liquid crystal and the like, and phenomena such as flicker and display image burn-in appear. Therefore, in general, inversion driving is performed to invert the polarity of the driving voltage of each pixel electrode for each frame in the image signal, for example. Surface inversion driving, such as frame inversion driving, is a method in which the polarity of the driving voltage of all the pixel electrodes constituting the image display region is all the same, and the driving voltage is inverted at a constant period.

  However, in a display having TFTs, parasitic capacitances are generated between the gate and drain of the TFT and between the source and drain, respectively. When the gate voltage of the TFT is turned off, the charge accumulated in the storage capacitor and the charge accumulated in the pixel capacitor composed of the pixel electrode and the common electrode are redistributed including the parasitic capacitance. At this time, since the gate voltage when the gate is turned off is generally lower than when the gate is turned on, the voltage of the pixel electrode is lowered and the voltage applied to the liquid crystal is also lowered. This is a so-called field-through phenomenon. In inversion driving, this field-through causes asymmetry in the voltage applied to the liquid crystal layer due to the polarity of the applied driving voltage, a DC voltage component is generated, and the transmittance changes depending on the polarity of the driving voltage. Flicker occurs and the display quality deteriorates.

  Therefore, the invention of Patent Document 1 sets the common potential to a potential at which the initial flicker is minimized, so that the voltage applied to the liquid crystal layer is higher than the common electrode potential during positive polarity application, Resolving flicker and image sticking by eliminating the asymmetry of the applied voltage by equalizing the negative polarity, which is lower than the common electrode potential, and compensating for the difference in characteristics between the pixel electrode substrate and the common electrode substrate To do.

JP 2002-189460 A

  However, even if the voltage applied to the liquid crystal layer is equal between the positive electrode and the negative electrode, the influence of the characteristic difference between the pixel electrode substrate and the common electrode substrate sandwiching the liquid crystal layer may not be eliminated. This is because the pixel electrode substrate and the common electrode substrate have different physical structures, so that a positive polarity that is higher than the common electrode potential is applied and a negative electrode that is lower than the common electrode potential. When the polarity is applied, the resistance values at the sea surface of the electrode and the alignment film, the alignment film and the liquid crystal layer, and the like are different between when the positive polarity is applied and when the negative polarity is applied. For this reason, although the effective voltage to a liquid crystal layer is equal by positive polarity and negative polarity, the amount of currents will differ. This causes asymmetry in the amount of charge transfer.

  As a result, when the asymmetry of the positive and negative currents between the pixel electrode substrate and the common electrode substrate is large, the common electrode potential is set so as to eliminate the asymmetry of the voltage applied to the liquid crystal layer due to the difference in substrate characteristics. Even so, due to the asymmetry of this current amount, the distribution of impurity ions inside the liquid crystal is biased, and an internal electric field is generated due to this bias of charge. Under the influence of the internal electric field, the voltage actually applied to the liquid crystal becomes asymmetric again depending on the polarity of the driving voltage, and a DC voltage component is applied. As a result, the flicker may increase with time or burn-in may occur.

  Therefore, in order to solve this problem, the present invention not only eliminates the asymmetry of the voltage applied to the liquid crystal layer, but also adjusts the application time ratio of the positive electrode and the negative electrode to adjust the amount of current at the positive electrode and the negative electrode. The method of adjusting the application time of the positive electrode and the negative electrode, which can reduce the increase in time flicker and the occurrence of image sticking by eliminating the asymmetry of charge and balancing the amount of charge movement, and realize this driving method Is.

An adjustment method of a liquid crystal device according to the present invention includes a plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode, and a common electrode. In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field between the pixel electrode and the common electrode, the pixel electrode is applied to the common electrode via the data line. When the high voltage is positive and the low voltage is negative with reference to the common electrode potential, a data signal in which the positive polarity and the negative polarity alternately appear is supplied. In the predetermined period consisting of the period, the pixel electrode is supplied with a first voltage having a polarity of one of the positive polarity and the negative polarity in the first period, and the second Before the period A first step of supplying a second voltage having a polarity different from that of the first voltage to drive the liquid crystal device, and flicker generated by alternately repeating the first period and the second period are measured and stored. A second step of driving the liquid crystal device with the above ratio, a fourth step of measuring the flicker again when a predetermined time has elapsed, and comparing with the stored value, And a fifth step of adjusting a ratio between the length of the first period and the length of the second period based on the comparison result.
As a result, the asymmetry of the amount of charge transfer between the positive polarity application and the negative polarity application is eliminated, and as a result, there is no bias in charge over time, so that changes in flicker over time can be suppressed. .

In the liquid crystal device adjustment method described above, the predetermined value of the common electrode potential in the first step is effectively applied to the liquid crystal layer in the first period and the second period. The voltages are set to be equal.
As a result, the initial flicker is reduced, and a higher quality image can be obtained.

In the liquid crystal device adjustment method described above, the second to fifth steps are repeated a plurality of times.
Thereby, adjustment with higher accuracy is possible.

  In the liquid crystal device adjustment method described above, a plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at intersections of the scanning lines and the data lines, and the pixel electrode are common. In a method for adjusting a liquid crystal device comprising: an electrode; and a liquid crystal layer driven by an electric field between the pixel electrode and the common electrode, the pixel electrode is connected to the common electrode via the data line. Supplying a data signal in which the positive polarity and the negative polarity alternately appear when the high voltage is positive and the low voltage is negative with reference to the applied common electrode potential; In a predetermined period consisting of a second period, in the first period, a first voltage that is one of the positive polarity and the negative polarity is supplied, and in the second period The first A first step of supplying a second voltage having a polarity different from the voltage to drive the liquid crystal device, and an effective voltage applied to the liquid crystal layer in the first period and the second period to be equal. A second step of setting and storing the set value of the common electrode potential; a third step of driving the liquid crystal device at the ratio; and the first period and the first again when a predetermined time has elapsed. In a period of 2, the common electrode potential is set again so that the effective voltage applied to the liquid crystal layer becomes equal, and the comparison with the stored set value is performed, and based on the comparison result, It has a 5th process of adjusting the ratio of the length of the 1st period, and the length of the 2nd period.

  In the liquid crystal device adjustment method described above, the second to fifth steps are repeated a plurality of times.

In the liquid crystal device adjustment method described above, a plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at intersections of the scanning lines and the data lines, and the pixel electrode are common. In a method for adjusting a liquid crystal device comprising: an electrode; and a liquid crystal layer driven by an electric field between the pixel electrode and the common electrode, the pixel electrode is connected to the common electrode via the data line. Supplying a data signal in which the positive polarity and the negative polarity alternately appear when the high voltage is positive and the low voltage is negative with reference to the applied common electrode potential; In a predetermined period consisting of a second period, a high voltage is positive with respect to the pixel electrode and a low voltage is negative with respect to the common electrode potential applied to the common electrode via the data line. In the predetermined period consisting of the first period and the second period, the data signal in which the positive polarity and the negative polarity alternately appear is supplied in the second period. A first step of supplying a second voltage having a polarity different from the voltage to drive the liquid crystal device, and an effective voltage applied to the liquid crystal layer in the first period and the second period to be equal. A second step of setting and storing the value of the common electrode potential; driving the liquid crystal device with the ratio; measuring the common electrode potential at which the effective voltage applied to the liquid crystal layer is equal; and storing the stored A third step of measuring the amount of change from the set value, a fourth step of measuring the time taken to reach when the amount of change reaches a predetermined value, and the first step based on the measurement result. Adjusting the ratio of the length of the second period to the length of the second period It characterized by having a fifth step.
Thereby, adjustment with higher accuracy is possible.

In the liquid crystal device adjustment method described above, the second to fifth steps are repeated a plurality of times.
Thereby, adjustment with higher accuracy is possible.

An adjustment method of a liquid crystal device according to the present invention includes: a plurality of scanning lines; a plurality of data lines; a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line; the pixel electrode and the common electrode; In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field between the pixel electrode and the common electrode, the pixel electrode is applied to the common electrode via the data line. When the high voltage is positive and the low voltage is negative with reference to the common electrode potential, a data signal in which the positive polarity and the negative polarity alternately appear is supplied. In the predetermined period consisting of the period, the first period is supplied with a first voltage that is one of the positive polarity and the negative polarity in the first period, and in the second period, the first period What is the first voltage? A first step of driving the liquid crystal device by supplying a second voltage of the polarity, and the effective voltage applied to the liquid crystal layer is set to be equal in the first period and the second period, The second step of storing the value of the common electrode potential, and driving the liquid crystal device with the ratio, measuring the common electrode potential at which the effective voltage applied to the liquid crystal layer becomes equal, and from the stored setting value A third step of measuring the amount of change, and if the amount of change reaches a predetermined value, or if a predetermined time elapses before the amount of change reaches a predetermined value, In the second period, the common electrode potential is set again so that the effective voltage applied to the liquid crystal layer becomes equal, and the comparison with the stored set value is performed, and based on the comparison result, The length of the first period and the length of the second period It characterized by having a fifth step of adjusting the proportions.
Accordingly, the ratio between the first period and the second period can be adjusted in a shorter time without flicker being visually recognized by the user.

  In the liquid crystal device adjustment method described above, the second to fifth steps may be repeated a plurality of times.

  In the liquid crystal device adjustment method according to the present invention, a plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning lines and the data line, and the pixel electrode are common. In a method for adjusting a liquid crystal device comprising: an electrode; and a liquid crystal layer driven by an electric field between the pixel electrode and the common electrode, the pixel electrode is connected to the common electrode via the data line. Supplying a data signal in which the positive polarity and the negative polarity alternately appear when the high voltage is positive and the low voltage is negative with reference to the applied common electrode potential; In a predetermined period consisting of a second period, in the first period, a first voltage that is one of the positive polarity and the negative polarity is supplied, and in the second period The above The effective voltage applied to the liquid crystal layer is equal in the first step of driving the liquid crystal device by supplying a second voltage having a polarity different from one voltage, and in the first period and the second period. The second step of storing the flicker value at that time, the third step of driving the liquid crystal device while keeping the ratio and measuring the flicker, and when the flicker reaches a predetermined value or when the flicker is predetermined. A fourth step of measuring flicker again when a predetermined time elapses before reaching the value of and comparing with the stored value, and based on the comparison result, the length of the first period And a fifth step of adjusting a ratio with the length of the second period.

  In the liquid crystal device adjustment method described above, the second to fifth steps are repeated a plurality of times.

In the liquid crystal device adjustment method described above, when the process is repeated a plurality of times, the ratio between the first period and the second period is different from the other at least once. .
As a result, the ratio between the first period and the second period is adjusted based on the results at a plurality of different ratios, so that adjustment with higher accuracy is possible.

In the liquid crystal device adjustment method described above, the process is repeated a predetermined number of times, and the ratio between the first period and the second period is adjusted based on the result. To do.
In the liquid crystal device adjustment method described above, in the fifth step, the liquid crystal device is driven for a predetermined time after the first period and the second period are set to a predetermined ratio in advance. The amount of flicker change and the set values of the first period and the second period are created as a LUT (Look Up Table), and based on this, the liquid crystal device is driven at the predetermined ratio for a predetermined time. The ratio between the first period and the second period is adjusted from the amount of change in flicker.

  In the liquid crystal device adjustment method described above, in the fifth step, the liquid crystal device is driven for a predetermined time after the first period and the second period are set to a predetermined ratio in advance. In addition, in the first period and the second period, a change amount of the common electrode potential at which the voltage applied to the liquid crystal layer becomes equal, and a set value of the first period and the second period are set as LUT (Look (Look)). Up Table), and based on this, the ratio between the first period and the second period is adjusted from the amount of flicker change when the liquid crystal device is driven at the predetermined ratio for a predetermined time. Features.

  In the liquid crystal device adjustment method described above, in the fifth step, the first period and the second period are set to a predetermined ratio in advance, and then the first period and the second period are set. In the period 2, the time required for the amount of change in the common electrode potential at which the voltages applied to the liquid crystal layers become equal to a predetermined value and the set values of the first period and the second period are set as LUT (Look Up Table), and based on this, the first period and the second period are calculated from the time required for the amount of change in the previous period when the liquid crystal device is driven at the predetermined ratio to reach the predetermined time. The ratio is adjusted.

  In the liquid crystal device adjustment method described above, the fifth step may be performed when the liquid crystal is driven for a predetermined time after setting the first period and the second period to a predetermined ratio. In the first period and the second period, a change amount of the common electrode potential at which the voltage applied to the liquid crystal layer becomes equal, and a set value of the first period and the second period are set to LUT (Look Up Table), and the time required to reach a predetermined flicker value after setting the first period and the second period to a predetermined ratio, the first period, and the second period Is set as a LUT (Look Up Table), and based on this, the first period and the second period are calculated from the amount of flicker change when the liquid crystal device is driven at the predetermined ratio for a predetermined time. The ratio is adjusted.

  In the liquid crystal device adjustment method described above, the fifth step may be performed when the liquid crystal is driven for a predetermined time after setting the first period and the second period to a predetermined ratio. The flicker change, the set values of the first period and the second period are created as a LUT (Look Up Table), and the first period and the second period are set to a predetermined ratio. The time required to reach a predetermined flicker value and the set values of the first period and the second period are created as an LUT (Look Up Table), and based on this, the liquid crystal is liquidated for the predetermined time at the predetermined ratio. The ratio between the first period and the second period is adjusted from the amount of change in flicker when the apparatus is driven.

  In the first step of the method for adjusting a liquid crystal device described above, the common electrode potential is adjusted as a step of equalizing the effective voltage applied to the liquid crystal layer in the first period and the second period. It is characterized by doing.

  In the second step of the method for adjusting a liquid crystal device described above, the common electrode potential is adjusted as a step of equalizing the effective voltage applied to the liquid crystal layer in the first period and the second period. It is characterized by doing.

  In the liquid crystal device adjustment method described above, when the flicker is measured or when the effective voltage applied to the liquid crystal layer is equalized between the first period and the second period, The ratio between the period of 1 and the second period is set to a predetermined ratio.

  In the liquid crystal device adjustment method described above, the predetermined ratio is 1: 1.

The liquid crystal device according to the present invention includes a plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, In a liquid crystal device including a pixel having a liquid crystal layer driven by an electric field between the pixel electrode and the common electrode, a high voltage is positive with reference to a common electrode potential applied to the common electrode, Data transmitting means for supplying a data signal in which the positive polarity and the negative polarity alternately appear via the data line to the pixel electrode when a low voltage is set to a negative polarity; An image capturing unit that captures images at a timing, a counting unit that measures time, and a frame that analyzes luminance information of the image captured by the image capturing unit at a predetermined timing. Among the positive polarity or the negative polarity, a storage means for storing data analyzed by the flicker analysis means, a comparison means for comparing the data stored in the storage means with the current data, A first period in which a first voltage that is one of the polarities is supplied to the pixel electrode, and a second period in which a second voltage having a polarity different from the first voltage is supplied to the pixel electrode And an application time adjusting means for adjusting a ratio between the length of the first period and the length of the second period in the predetermined period.
This adjustment device enables automatic adjustment.

An electronic apparatus according to the present invention includes the liquid crystal device described above.
As a result, even when the electronic device is actually used as a product and the optimum value changes due to deterioration or the like and flicker occurs, the optimum value can be set again by the user's operation. It is also possible to always monitor the flicker value during use and automatically adjust the flicker value when it exceeds a specified value so that the user can always keep the flicker invisible.

FIG. 3 is a diagram illustrating a configuration of a projector using the electro-optical device according to the embodiment. It is a schematic block diagram of the display panel which concerns on embodiment. It is an equivalent circuit diagram of a pixel. It is a figure which shows the timing chart of the operation signal type | system | group when the value of the register | resistor B is "0". It is a figure which shows the timing chart in the 1st field of a data signal system. It is a figure which shows the timing chart in the 2nd field of a data signal system. It is the figure which showed the writing state of each line in the case where the value of a register | resistor B is "0" with time passage over the continuous frame. It is a circuit diagram of an optical sensor. It is a schematic block diagram of a data analysis part. It is a figure which shows the timing chart of a scanning signal system when the value of the register | resistor B is "+1". When the value of a register B is "+1", it is the figure which showed the writing state of each line with progress of time over the continuous flame | frame. It is a figure which shows the timing chart of a scanning signal system when the value of the register | resistor B is "-1." When the value of a register B is "-1", it is the figure which showed the writing state of each line with progress of time over the continuous flame | frame. It is a graph which shows the relationship between voltage LCcom and the application time ratio of positive polarity and negative polarity in which flicker becomes the minimum. 1 is a diagram illustrating a flowchart according to Embodiment 1. FIG. It is the figure which showed the relationship between the period of positive polarity and negative polarity applied to a liquid-crystal layer, and the amount of flicker. FIG. 10 is a diagram illustrating a flowchart according to a second embodiment. It is a figure which shows the flowchart which concerns on Example 2,3,4,5,6,7. FIG. 10 is a flowchart illustrating an application example of the second embodiment. FIG. 10 is a diagram illustrating a flowchart according to a third embodiment. FIG. 10 is a diagram illustrating a flowchart according to a fourth embodiment. FIG. 10 is a diagram illustrating a flowchart according to a fifth embodiment. FIG. 10 is a diagram illustrating a flowchart according to a sixth embodiment. FIG. 10 is a diagram illustrating a flowchart according to a seventh embodiment. FIG. 10 is a conceptual diagram of an LUT according to a seventh embodiment. FIG. 10 is a diagram illustrating a specific example of an LUT according to the seventh embodiment. FIG. 10 is a diagram illustrating a configuration of a projector using an electro-optical device according to an eighth embodiment. It is an example of the definition of predetermined time and the said 1st period and 2nd period other than having shown in the present Example.

(Embodiment)
First, the configuration of the present invention will be described using an electro-optical device as an example. A block diagram of this embodiment is shown in FIG.

  As shown in FIG. 1, the electro-optical device 1 is roughly divided into a display panel 10, a processing circuit 50, an optical sensor 70, and a data analysis unit 72. Among these, the processing circuit 50 includes a control circuit 52, a display data processing circuit 54, and a D / A conversion circuit 56, and is a circuit module that controls the operation of the display panel 10, and the display panel 10 For example, they are connected by an FPC (flexible printed circuit) substrate.

  The control circuit 52 generates various control signals for controlling the display panel 10 in synchronization with the synchronization signal Vsync supplied from the electronic device. These control signals will be described later as appropriate. The control circuit 52 generates various control signals and controls the display data processing circuit 54.

  The optical sensor 70 is a luminance sensor that detects a flicker component from the image displayed by the display panel 10, and supplies the output signal Vpd to the data analysis unit 72. The data analysis unit 72 converts the value of the output signal Vpd into digital data by the A / D conversion unit based on the output signal supplied from the optical sensor 70, and performs an FFT (Fast Fourier Transform) operation to display the display panel. 10 is used to detect the flicker amount of the image displayed. The data analyzed by the data analysis unit 72 is supplied to the control circuit 52. The control circuit 52 temporarily stores the result in an internal memory (not shown), and then based on the result of comparison with the previous value, the first circuit. And the ratio of the second time to the second time and the common electrode potential LCcom are adjusted.

  The display data processing circuit 54 temporarily stores display data Video supplied from an external host device in an internal memory (not shown) under the control of the control circuit 52 and then reads it in synchronization with the driving of the display panel 10. It is.

  Note that the display data Video is data for designating the gradation of the pixels in the display panel 10, and the waveform is not particularly shown, but for one frame (total of the display panel 10 with a period of 16.7 milliseconds (frequency 60 Hz)). (For pixel). The D / A conversion circuit 56 converts the read display data into an analog data signal Vid.

Next, the display panel 10 will be described. FIG. 2 is a diagram illustrating a configuration of the display panel 10.
As shown in this figure, the display panel 10 is a peripheral circuit built-in type in which a scanning line driving circuit 130 and a data line driving circuit 140 are built around the display region 100. In the display area 100, 480 scanning lines 112 are provided so as to extend in the row (X) direction, and 640 columns of data lines 114 are provided so as to extend in the column (Y) direction. The pixels 110 are arranged so as to be electrically insulated from the scanning lines 112 and correspond to the intersections of the scanning lines 112 of 480 rows and the data lines 114 of 640 columns. Accordingly, in the present embodiment, the pixels 110 are arranged in a matrix of 480 rows × 640 columns in the display region 100, but the present invention is not limited to this arrangement.

  The configuration of the pixel 110 will be described with reference to FIG. FIG. 3 shows a total of 4 pixels of 2 × 2 corresponding to the intersection of the i row and the (i + 1) row adjacent to it by 1 row and the j column and the (j + 1) column adjacent to the right by 1 column. The structure of is shown. Note that i and (i + 1) are symbols for generally indicating the row in which the pixels 110 are arranged, and are integers of 1 to 480 in this description. J and (j + 1) are symbols for generally indicating a column in which the pixels 110 are arranged, and are integers of 1 to 640.

As shown in FIG. 3, each pixel 110 includes an n-channel TFT 116 and a liquid crystal capacitor 120.
Here, since each pixel 110 has the same configuration, the gate electrode of the TFT 116 in the pixel 110 in the i row and j column will be described as the pixel in the i row and j column. On the other hand, the source electrode is connected to the data line 114 in the j-th column, and the drain electrode is connected to the pixel electrode 118 which is one end of the liquid crystal capacitor 120. The other end of the liquid crystal capacitor 120 is connected to the common electrode 108. The common electrode 108 is common to all the pixels 110 and is applied with a constant voltage LCcom over time.

  Although not particularly shown, the display panel 10 has a configuration in which a pair of substrates of an element substrate and a common substrate are bonded together with a certain gap therebetween, and a liquid crystal layer in which liquid crystal is sealed is provided in the gap. Yes. Among them, the scanning line 112, the data line 114, the TFT 116, and the pixel electrode 118 are formed on the element substrate together with the scanning line driving circuit 130 and the data line driving circuit 140, while the common electrode 108 is formed on the common substrate. These electrode forming surfaces are bonded to each other with a certain gap therebetween. For this reason, in this embodiment, the liquid crystal capacitor 120 is configured by sandwiching the liquid crystal 105 between the pixel electrode 118 and the common electrode 108.

  In this embodiment, if the effective voltage value held in the liquid crystal capacitor 120 is close to zero, the transmittance of light passing through the liquid crystal capacitor is maximized to display white, while the effective voltage value increases. The normally white mode in which the amount of transmitted light decreases and finally the black display with the minimum transmittance is set.

  In this configuration, a selection voltage is applied to the scanning line 112 to turn on the TFT 116, and the voltage corresponding to the gradation (brightness) is applied to the pixel electrode 118 via the data line 114 and the on-state TFT 116. When the data signal is supplied, the liquid crystal capacitor 120 corresponding to the intersection of the scanning line 112 to which the selection voltage is applied and the data line 114 to which the data signal is supplied can hold the effective voltage value corresponding to the gradation.

  Therefore, the light transmitted through the liquid crystal capacitor 120 can be different for each pixel, whereby an image is formed in the display region 100. The formed image is viewed directly by the user or enlarged and projected as in a projector described later. In any case, the formed image is picked up by the optical sensor 70.

  Note that when the scanning line 112 becomes a non-selection voltage, the TFT 116 is turned off (non-conducting). However, since the off resistance at this time is not ideally infinite, the charge accumulated in the liquid crystal capacitor 120 is small. Leak. In order to reduce the influence of off-leakage, a storage capacitor 109 is formed for each pixel. One end of the storage capacitor 109 is connected to the pixel electrode 118 (the drain of the TFT 116), while the other end is commonly connected to the capacitor line 107 over all pixels. The capacitor line 107 is maintained at a constant potential, for example, the same voltage LCcom as the common electrode 108.

  The scanning line driving circuit 130 supplies scanning signals G1, G2, G3,..., G480 to the scanning lines 112 in the 1, 2, 3,. Here, the scanning line driving circuit 130 sets the scanning signal to the selected scanning line to the H level corresponding to the voltage Vdd, and sets the scanning signals to the other scanning lines to L corresponding to the non-selection voltage (ground potential Gnd). Level.

FIG. 4 is a timing chart showing the scanning signals G1 to G480 output from the scanning line driving circuit 130 in relation to the start pulses Dya and Dyb and the clock signal Cly.
As shown in the figure, each scanning line 112 is selected twice in one frame period. Here, the frame refers to a period required to display one image on the display panel 10, but the display data Video is supplied at a period of 16.7 milliseconds as described above, so Corresponds to 16.7 milliseconds of this period.

  The control circuit 52 outputs a clock signal Cly having a duty ratio of 50% for 480 periods equal to the number of scanning lines over a period of one frame. Note that a period of one cycle of the clock signal Cly is denoted as H.

  Further, the control circuit 52 outputs start pulses Dya and Dyb having a pulse width corresponding to one cycle of the clock signal Cly when the clock signal Cly rises to the H level as follows. That is, the control circuit 52 outputs the start pulse Dya at the beginning of one frame period (that is, at the beginning of the first field), while outputting the start pulse Dyb for 240 cycles of the clock signal Cly after outputting the start pulse Dyb. Is output at a timing T at which a half period of one frame has passed. However, the control circuit 52 generates the start pulse Dyb in accordance with the output result of the optical sensor 70 from the front side or the rear side in terms of time with respect to the timing T by the unit of the period of the clock signal Cly, as will be described later. May be output.

  Note that the period from when the start pulse Dya is output until the start pulse Dyb is output is set as the first field in the period of one frame, and the next start pulse Dya is output after the start pulse Dyb is output. The period until is the second field.

  Here, the start pulses Dya and Dyb are alternately output, and among these, the start pulse Dya is output at the start timing of one frame, that is, every 16.7 milliseconds. For this reason, if the start pulse Dya is specified, the start pulse Dyb can be specified inevitably. Therefore, in FIG. 1, FIG. 2, etc., there is a case where both are indicated as the start pulse Dy.

  The scanning line driving circuit 130 outputs the scanning signals G1 to G480 shown in FIG. 4 from the start pulses Dya and Dyb and the clock signal Cly. That is, when the start pulse Dya is supplied to the scanning signals G1 to G480, the scanning line driving circuit 130 sequentially sets the clock signal Cly to the H level during the L level period, while when the start pulse Dyb is supplied. The clock signal Cly is sequentially set to the H level during the H level period.

  Therefore, by supplying the start pulse Dya, the scanning line is shifted in the order of the clock signal Cly in the order of 1, 2, 3, 4,. On the other hand, when the start pulse Dyb is supplied, the scanning line is selected from the second field of a certain frame to the first field of the next frame toward the bottom of the screen. 4,..., In the order of the 480th row, the selection is made between selections triggered by the supply of the start pulse Dya.

  The data line driving circuit 140 includes a sampling signal output circuit 142 and n-channel TFTs 146 provided corresponding to the data lines 114, respectively. As shown in FIG. 5 or FIG. 6, the sampling signal output circuit 142 selects one of the scanning lines 112 according to the control signal Ctrl-x from the control circuit 52, and the scanning signal supplied to the scanning line is at the H level. In this period, sampling signals S1, S2, S3,..., S640 that sequentially become H level exclusively are output so as to correspond to each of the data lines 114. Note that the control signal Ctrl-x is actually a start pulse or a clock signal, but is not directly related in the present invention, and thus the description thereof is omitted. Further, the period during which the scanning signal is at the H level is actually slightly narrower than the half-period period of the clock signal Cly, as shown in FIG. 5 or FIG.

Incidentally, the D / A conversion circuit 56 in FIG. 1 converts display data Video for one row of pixels located on the scanning line 112 selected by the scanning line driving circuit 130 into sampling signals S1 to S640 by the sampling signal output circuit 142. The data signal Vid having the following polarity is converted in accordance with the output.
That is, the D / A conversion circuit 56 has positive polarity for the display data Vid of the pixels located in the selected row when the clock signal Cly is at the L level, and the selected row when the clock signal Cly is at the H level. The display data Vid of the pixel located at is converted to negative polarity. In other words, the D / A conversion circuit 56 sets the display data Vid of the pixels located in the row selected in response to the supply of the start pulse Dya to a positive polarity and the row selected in response to the supply of the start pulse Dyb. The display data Vid of the pixel located at is converted to negative polarity.

  The positive polarity means a voltage higher than the reference voltage Vc (see FIG. 5) set higher than the applied voltage LCcom to the common electrode 108, and the negative polarity means the reference voltage Vc. On the other hand, it refers to the lower voltage. In this embodiment, the polarity of the data signal is based on the voltage Vc. However, unless otherwise specified, the voltage is based on the ground potential Gnd corresponding to the L level of the logic level. .

Next, the operation of the electro-optical device will be described.
First, the control circuit 52 stores the display data Video supplied from the external host device in the internal memory of the display data processing circuit 54, and then selects a scanning line of a row on the display panel 10, and The display signal is read out at a speed twice the storage speed, and the sampling signal output circuit 142 is connected via the control signal Ctrl-x so that the sampling signals S1 to S640 are sequentially set to the H level in accordance with the reading of the display data. Control. The read display data is converted into an analog data signal Vid by the D / A conversion circuit 56.

  Here, when the control circuit 52 supplies the start pulse Dyb at the timing T, in the first field, the scanning lines 112 are in the order of the 241, 241, 2, 243,. Selected. Therefore, the control circuit 52 controls the scanning line driving circuit 130 so that the scanning line 112 of the 241st row is selected first, while the display data processing circuit 54 is controlled by the 241st row stored in the memory. The corresponding display data Video is read at double speed, and the D / A conversion circuit 56 is controlled to convert it to the negative polarity data signal Vid, and the sampling signals S1 to S640 are in this order in accordance with this reading. The sampling signal output circuit 142 is controlled so as to be exclusively at the H level. When the sampling signals S1 to S640 are sequentially set to the H level, the TFTs 146 are sequentially turned on, and the data signals Vid supplied to the image signal lines 171 are sequentially sampled on the data lines 114 in the 1st to 640th columns.

  On the other hand, when the scanning line 112 in the 241st row is selected and the scanning signal G241 becomes H level, all the TFTs 116 in the pixels 110 located in the 241st row are turned on. Therefore, the negative voltage of the data signal Vid sampled on the data line 114 is applied to the pixel electrode 118 as it is. For this reason, the negative voltage corresponding to the gradation specified by the display data Video is written in the liquid crystal capacitor 120 in the pixels of the 241st row and the columns 1, 2, 3, 4,..., 639, 640. Will be held.

  Next, the control circuit 52 controls the scanning line driving circuit 130 so that the scanning line 112 in the first row is selected, while corresponding to the first row stored in the memory with respect to the display data processing circuit 54. The display data Video to be read is read at double speed, and the D / A conversion circuit 56 is controlled to convert it to the positive polarity data signal Vid, and the sampling signals S1 to S640 are in this order in accordance with this reading. The sampling signal output circuit 142 is controlled so as to be exclusively at the H level.

  When the scanning line 112 in the first row is selected and the scanning signal G1 becomes H level, all the TFTs 116 in the pixels 110 located in the first row are turned on, whereby the voltage of the data signal Vid sampled on the data line 114 is turned on. Is applied to the pixel electrode 118. Therefore, a positive voltage corresponding to the gradation specified by the display data Video is written and held in the liquid crystal capacitor 120 in the pixels of the first row and the 1st to 640th columns.

  Hereinafter, in the first field, the same voltage writing operation is executed in the order of the 242nd, 2nd, 24th, 3rd,..., 480th, and 240th rows. Thereby, a positive voltage corresponding to the gradation is written to the pixels in the first to 240th rows, and a negative voltage corresponding to the gradation is written to the pixels in the 241st to 480th rows. Each will be held.

  In the case where the start pulse Dyb is supplied at the timing T, the scanning line 112 is referred to as the first, second, second, second, third, second, fourth, second,. While being selected in order, the write polarity in the same row is inverted. Therefore, a negative voltage corresponding to the gradation is written to the pixels in the first to 240th rows, and a positive voltage corresponding to the gradation is written to the pixels in the 241st to 480th rows. Each will be held.

FIG. 5 is a diagram illustrating an example of a voltage waveform of the data signal Vid during a period in which the (i + 240) -th scanning line and the i-th scanning line are selected in the first field.
In this figure, voltages Vb (+) and Vb (−) are positive and negative voltages corresponding to the black of the lowest gradation, respectively, and have a symmetrical relationship with respect to the reference voltage Vc. In the present embodiment, when the decimal value of the gradation value designated by the display data Video is “0”, black of the lowest gradation is designated, and thereafter a bright gradation is designated as the decimal value increases. Is a normally white mode, so that the voltage of the data signal Vid becomes a voltage swung from the voltage Vb (+) to the lower side as the gradation value increases in the case of converting to the positive polarity. In the case of converting to V, the voltage is swung from the voltage Vb (−) to the higher side.

  In the first field, since the (i + 240) -th scanning line is selected before the i-th row, for example, the period during which the sampling signal S1 is at the H level during the period when the scanning signal (i + 240) is at the H level. In addition, the data signal Vid becomes a negative voltage corresponding to the gradation of the pixel in the i row and the first column, and thereafter, the gradation of the pixels in the second, third, fourth,. It changes to the negative polarity voltage according to.

  In the i-th row that is subsequently selected, since positive polarity writing is designated, the data signal Vid is i during the period in which the scanning signal Gi is at the H level, for example, the period in which the sampling signal S1 is at the H level. It becomes a positive voltage according to the gradation of the pixel in the row 1 column, and thereafter changes to a positive voltage according to the gradation of the pixel in the 2, 3, 4,... .

  In the second field, since the (i + 240) -th scanning line is selected after the i-th row, the scanning signal Gi first goes to the H level and the writing polarity is inverted, so that the data signal Vid The voltage waveform is as shown in FIG.

  5 and 6, the vertical scale indicating the voltage of the data signal Vid is enlarged for the sake of convenience than the vertical scales of other signals. Further, the voltage corresponds to black over a period from when the sampling signal S640 changes to the L level to when the sampling signal S1 changes to the H level. This is because it does not contribute to the display even if it is written on.

  FIG. 7 is a diagram showing the writing state of each row with the passage of time over successive frames when the start pulse Dyb is supplied at the timing T. FIG. As shown in this figure, in the present embodiment, in the first field, negative polarity writing is performed on the pixels of 241, 242, 243,. In the pixel, the positive writing is performed and held until the next writing, while in the second field, the negative writing is performed in the pixels in the first, second, third,..., 240th rows, and 241, 242, 243,. In the pixel on the 480th row, positive writing is performed and similarly held until the next writing.

  When the start pulse Dyb is supplied at the timing T, the period of the first and second fields is 240 periods of the clock signal Cly, so that the positive voltage is held in the liquid crystal capacitor 120 in each pixel and the negative electrode The period during which the sexual voltage is held is halved.

  By the way, when the voltage LCcom applied to the common electrode 108 is matched with the reference voltage Vc, the field-through described in the background art column (this is the first word that appears. If used as a synonymous word, the background art The effective voltage value of the liquid crystal capacitor 120 due to negative polarity writing is slightly larger than the effective value due to positive polarity writing due to the difference in the leak amount (TFT 116 is n). In the case of a channel), flicker occurs initially.

  However, as described in the background art section, when the operation is continued in this state, the electric charge is biased due to the positive and negative current asymmetry due to the characteristic difference between the substrates. As a result, the amount of flicker increases with time.

  Therefore, in order to suppress the initial flicker and the change of flicker over time, it is necessary to adjust these values to appropriate values. In order to reduce the initial flicker, the voltage LCcom is adjusted, and in order to suppress the change in flicker over time, the ratio between the first period and the second period is adjusted. These adjustments are performed based on the result of the control circuit 52 analyzing the output signal from the optical sensor 70 by the data analysis unit 72.

  Therefore, the operation of the optical sensor 70 will be described next. FIG. 8 shows the configuration of the optical sensor 70. The optical sensor 70 includes a photodiode 700, a voltage amplification circuit 701, and a resistor 702. When the photodiode 700 is irradiated with light, a current corresponding to the luminance flows, and the voltage amplification circuit 701 converts the current into a voltage. And output as an output voltage Vpd.

  The data analysis unit 72 analyzes the output voltage Vpd from the optical sensor 70 and displays the flicker amount. In this embodiment, an FFT analyzer is used as the data analysis unit 72. This configuration is as shown in FIG. The output voltage Vpd and the signal Vsync from the optical sensor 70 are input to the AD converter 721 and converted from analog data to digital data. The digital data is calculated by the FFT calculation unit, and the flicker amount-time data is converted into flicker amount-frequency data, and the flicker amount in the drive frequency component is transmitted to the control circuit 52. From here, the control circuit 52 monitors and adjusts flicker in the drive frequency component. At this time, the output voltage Vpd is taken with the signal Vsync as a trigger, and information on this phase is also transmitted. As a result, after the signal Vsync is input, in the case of writing that first holds the positive voltage and then holds the negative voltage, the luminance is higher when the negative voltage is held when the phase is 0 °. When the phase is 180 °, it can be seen that the luminance is higher when the positive voltage is held. In this embodiment, the FFT analyzer is used as the data analysis unit. However, the present invention is not limited to this. For example, the output waveform of the light sensor is directly monitored using an oscilloscope. Any method can be used as long as it can detect the above.

  Next, the operation when the control circuit 52 adjusts the common electrode potential LCcom and the application time ratio between the positive voltage and the negative voltage based on the data transmitted from the data analysis unit 72 will be described. These set values are set as register values in the internal memory of the control circuit 52. Of these, the register value for setting LCcom is referred to as register A, and the register value for setting the application time ratio is referred to as register B. Initially, an appropriate value is set for both the register A and the register B.

When adjusting LCcom, if the value of register A is +1, the value of voltage LCcom is +1 mV, and if the value of register A is -1, the value of voltage LCcom is -1 mV.
When adjusting the application time ratio, if the set value of the register B is 0, the start pulse Dyb is output at the timing T. As a result, the application time of the positive voltage and the negative voltage is equal as described above. Become.

  Next, assuming that the set value of the register B is +1, the start pulse Dyb output from the control circuit 52 is delayed by one cycle of the clock signal Cly from the timing T (T + 1) as shown in FIG. Will be output. As a result, the period of the first field is 241 cycles of the clock signal Cly, while the period of the second field is 239 cycles of the clock signal Cly.

Therefore, as shown in FIG. 11, the holding period of the negative voltage written by the selection triggered by the supply of the start pulse Dyb is the holding period of the positive voltage written by the selection triggered by the supply of the start pulse Dya. Shorter than the period.
On the contrary, when the set value of the register B is set to −1, the start pulse Dyb output from the control circuit 52 is earlier than the timing T by one cycle of the clock signal Cly as shown in FIG. -1). As a result, the period of the first field is 239 periods of the clock signal Cly, while the period of the second field is 241 periods of the clock signal Cly.

  For this reason, as shown in FIG. 13, the holding period of the negative voltage written by the selection triggered by the supply of the start pulse Dyb is the holding of the positive voltage written by the selection triggered by the supply of the start pulse Dya. Longer than the period.

  Here, FIG. 14 shows the relationship regarding the change with time of flicker after a lapse of a fixed time when the application time ratio between the positive voltage and the negative voltage is used as a parameter. The vertical axis represents the amount of change in voltage LCcom that minimizes flicker after a certain time has elapsed, and the horizontal axis represents the application time ratio. When the application time ratio is 0, the application time of the positive voltage and the negative voltage is equal. The positive voltage application time is long in the positive case, and the negative voltage application time is long in the negative case.

The fact that the flicker changes with time is considered that the relationship between the application time ratio and the amount of change in the voltage LCcom that minimizes the flicker is in a state as shown in (1) or (2) in FIG. In any case, by setting the application time ratio to an appropriate value, it is possible to eliminate the change in the voltage LCcom that minimizes flicker, that is, to suppress the change in flicker over time.
Therefore, adjustment for setting the application time ratio to an appropriate value is necessary.

Therefore, a specific adjustment method using this electro-optical device will be described.
FIG. 15 shows a flowchart of the adjustment method of the electro-optical device in the present embodiment.
An appropriate value of LCcom is set so that the initial flicker is within a certain reference value for each register A, for example, for each model, and the ratio of the holding period of the positive polarity voltage and the negative polarity voltage is equal in the register B Is set to

  First, the flicker amount is measured and recorded. Continue projecting video for a certain period of time (about 5-15 minutes). Thereafter, the data analysis unit 72 is monitored, the flicker amount is measured, and the difference from the previous flicker amount, that is, the flicker change amount is measured. Here, if the amount of change in flicker is equal to or less than a specified value (± 5 dB), the adjustment is completed.

  If the amount of change in flicker is equal to or greater than a specified value, it is determined from the FFT phase whether the luminance at the time of positive voltage application or negative voltage application has increased. When the luminance at the time of applying a negative polarity voltage is increased, the set value of the ratio between the first time and the second time is set to +1, and conversely, the luminance at the time of applying a positive voltage is increased. Decreases the set value of register B by -1. Here, the amount of change in the register set value when the amount of change in flicker is equal to or greater than the specified value need not be in increments of 1. In particular, when the amount of change in the ratio between the first period and the second period depends on the scanning line width as described above, the scanning line increases as the resolution of the display panel increases. Since the time for one line is shortened, the change in the ratio between the first period and the second period due to changing the register setting value by 1 becomes small. Therefore, the amount of change depends on the resolution of the display panel 10. The optimal value is ideal. This is the same in the embodiments other than the present embodiment. Thereafter, projection is continued for a certain time, and the flicker amount is measured again after a certain time has elapsed, and the amount of change in flicker is measured in comparison with the previous value. Here, if the change amount of the flicker is within the specified value, the adjustment is finished, and the application time ratio is further changed by one in the same direction as the previous change.

This procedure is repeated until the flicker change amount falls within the reference value, and when the flicker change amount falls within the reference value, the set value at that time is stored.
As a result, it is possible to provide a liquid crystal device in which initial flicker is reduced and change in flicker over time is suppressed.

  In this embodiment, no matter what the ratio between the first period and the second period when the liquid crystal is driven, when the flicker amount is measured, the ratio in the previous period is once determined in advance. It may be measured after setting the value again. As shown in FIG. 16, when the ratio between the first period and the second period is changed, the flicker amount with respect to the set value of the common electrode potential LCcom changes slightly. This is because, when the condition is constant, the error factor is reduced and the adjustment can be performed with high accuracy. In addition, it is desirable that the ratio at this time is positive polarity: negative polarity = 1: 1. The same applies to the following embodiments.

  In this embodiment, the amount of flicker before and after driving the liquid crystal for a predetermined time is measured, and the ratio between the first period and the second period is adjusted based on the amount of change in the flicker. The ratio between the first period and the second period may be adjusted based on the amount of change in the voltage LCcom that minimizes the flicker before and after driving the liquid crystal for a predetermined time instead of the amount of change in flicker. Good.

  Also in this case, when measuring the value of the voltage LCcom at which flicker is minimized, the ratio may be measured after once resetting the previous period ratio to a predetermined value. This is because, as shown in FIG. 16, the value of the voltage LCcom that minimizes flicker also changes depending on the ratio between the first period and the second period. In addition, it is desirable that the ratio at this time is positive polarity: negative polarity = 1: 1. The same applies to the following embodiments.

17 and 18 are flowcharts of the adjustment method of the electro-optical device in the present embodiment.
In the adjustment method in the first embodiment, the voltage LCcom value is set to an appropriate value such that the initial flicker is equal to or less than a specified value, and then the application time ratio is adjusted. On the other hand, in the present embodiment, the adjustment is performed after the applied voltage to the liquid crystal layer becomes equal between the positive polarity and the negative polarity at the start of the adjustment.

  Therefore, in this embodiment, the voltage LCcom is adjusted so that the flicker of the display panel 10 is minimized. As a result, the execution voltage applied to the liquid crystal layer is equal between the first period and the second period, and the application time ratio can be determined with higher accuracy.

  The control circuit 52 changes the value of the register A while referring to the value of the data analysis unit 72 at the start of adjustment in the procedure as shown in FIG. 17, and sets the voltage LCcom so that the flicker is minimized. First, the amount of flicker is measured. Next, the value of the register A is set to +1, the flicker amount is measured again, and compared with the previous measurement result. If the amount of flicker has increased, the current value of register A is stored and then the value of register A is decreased by 1. If the amount of flicker has decreased, the current value of register A is stored. After that, the value of the register A is set to +1. Next, the flicker amount is measured again, and if the flicker amount is decreased, the value of the register A is stored again, and the value of the register A is changed by 1 in the same direction as changed previously. If the register value has increased, it is determined that the currently stored setting value of the register A is the setting value of the voltage LCcom that minimizes the flicker amount, and the value is read and set. By repeating this procedure, the voltage LCcom becomes the minimum flicker value.

  The image is continuously projected for a certain time (about 5 to 15 minutes) with the ratio of the holding period of the positive voltage and the negative voltage set to be equal. Thereafter, the amount of flicker change is measured from the measurement value of the data analysis unit 72. Here, if the difference between the current flicker amount and the previously stored flicker amount, that is, the amount of change in flicker is equal to or less than a specified value (± 5 dB), the adjustment is completed.

  If the amount of change in flicker is equal to or greater than a specified value, it is determined from the FFT phase whether the luminance at the time of positive voltage application or negative voltage application has increased. When the luminance at the time of applying the negative polarity voltage is increased, the set value of the register B is set to +1. Conversely, when the luminance at the time of applying the positive voltage is increased, the set value of the register B is set to -1. Thereafter, the projection is continued again for a certain time, and the amount of change in flicker is measured again after the certain time has elapsed. Here, if the change amount of the flicker is within the specified value, the adjustment is finished, and the application time ratio is further changed by one in the same direction as the previous change.

This procedure is repeated until the flicker change amount falls within the reference value, and when the flicker change amount falls within the reference value, the set value at that time is stored.
As a result, it is possible to provide an electro-optical device that reduces initial flicker and suppresses changes in flicker over time.

  In this embodiment, the voltage LCcom is adjusted to a value that minimizes flicker in order to equalize the value of the effective voltage applied in the liquid crystal layer between the positive polarity and the negative polarity. For example, the driving of the display panel 10 may be temporarily stopped and the generated internal electric field may be waited for to be naturally eliminated by diffusion. Further, if the characteristics shown in FIG. 14 are used, the ratio between the first period and the second period changes to a biased value regardless of whether the panel has the characteristics (1) or (2). By doing so, the value of the voltage LCcom that minimizes flicker can be changed in an arbitrary direction. This means that the internal charge bias can be controlled by the ratio between the first period and the second period, thereby controlling the flicker to a minimum at the initially set voltage LCcom. May be.

  In this embodiment, the voltage LCcom is adjusted and the value of the register A is saved and then the value of the register B is changed. However, as shown in FIG. It doesn't matter.

  The flowchart of the adjustment method in a present Example is shown in FIG. 18, FIG. The block diagram of the electro-optical device in the present embodiment is the same as FIG.

In the adjustment methods in the first and second embodiments, the value of the voltage LCcom always remains the initially set value during the adjustment.
However, the fact that the flicker changes with time during the adjustment means that the electric charge is biased accordingly. Therefore, the application time ratio can be adjusted with higher accuracy by canceling the charge bias every time a change with time is measured. Therefore, in this embodiment, the voltage LCcom is adjusted every time the change with time is measured, and the applied voltage to the liquid crystal that has become asymmetric due to the internal charge bias is made symmetric, thereby canceling the charge bias.

  First, the control circuit 52 sets the voltage LCcom so as to reduce the initial flicker by operating the register A based on the data of the data analysis unit 72 in a state where an image is projected by the electro-optical device according to the flowchart of FIG. . At the same time, the amount of flicker at this time is stored in the internal memory.

  Next, the image is continuously projected for a certain time (about 5 to 15 minutes) in a state where the ratio between the holding periods of the positive voltage and the negative voltage is set to be equal. Thereafter, the voltage LCcom is adjusted again from the data of the data analysis unit 72 according to the flowchart of FIG. 18 so that the flicker is minimized. Here, the current value of the register A is compared with the previously recorded value of the register A. If the amount of change in the value is equal to or less than the specified value, the adjustment is completed.

  If the change in the value of the register A is equal to or greater than the specified value, the control circuit 52 determines whether the value of the register A has changed to the plus side or to the minus side compared to the previous time. Here, when the set value of the register A has changed to the plus side, the set value of the register B is set to +1. Conversely, when the set value of the register A has changed to the minus side, the set value of the register B -1 and save. Thereafter, projection is continued for a certain time, and after a certain time has elapsed, the voltage LCcom is adjusted according to FIG. 18 and the change in the set value of the register A is measured again. Here, if the change in the set value of the register A is within the specified value, the adjustment is terminated, and if not, the value of the register B is changed according to the change direction of the set value of the register A.

Thereafter, the set value of the current voltage LCcom is stored.
This procedure is repeated until the amount of change in the value of register A falls within the reference value.
As a result, it is possible to provide an electro-optical device that reduces initial flicker and suppresses changes in flicker over time.

  In the present embodiment, the adjustment is performed based on the value of the register A when the voltage LCcom is adjusted so that the flicker is minimized after driving for a predetermined time. Adjustment may be performed based on the amount of flicker change after time drive.

  In this embodiment, the value of the register B is changed after the voltage LCcom is adjusted and the value of the register A at that time is saved. However, this order may be reversed.

  The flowchart of the adjustment method in a present Example is shown in FIG. 18, FIG. The block diagram of the electro-optical device in the present embodiment is the same as FIG.

  In the adjustment methods in the first embodiment, the second embodiment, and the third embodiment, the flicker amount after a predetermined time has elapsed or the amount of change in the voltage LCcom that minimizes the flicker as a means for observing the bias in the display panel. Adjustments were made based on However, the amount of change after a lapse of a predetermined time becomes smaller as the ratio between the first time and the second time becomes smaller in the direction of suppressing the bias of charge. Depending on the restrictions, a sufficient adjustment system may not be ensured.

  Therefore, in this embodiment, as a means for observing the electric charge bias in the display panel, the amount of change in flicker or the amount of change in voltage LCcom that minimizes flicker is based on the time until it reaches a specified value. The ratio between the first period and the second period is adjusted.

  At this time, if the specified value of the change amount of the flicker or the change amount of the voltage LCcom that minimizes the flicker is set to a level at which the flicker is not visually recognized by humans, the flicker always changes at a level at which the human eyes cannot visually recognize the flicker. For this reason, even if the adjustment is performed during actual use of the liquid crystal device of the present invention, the optimum value can be adjusted without being visually recognized by the user.

In this case, the more the ratio of the first time and the second time is in the direction of suppressing the bias of the charge, the longer the time until the specified value is reached, thereby improving the accuracy.
First, the control circuit 52 sets the voltage LCcom so as to reduce the initial flicker by operating the register A based on the data of the data analysis unit 72 in a state where the image is projected by the electro-optical device, and stores the value. At the same time, the elapsed time starts to be counted.

  Next, the display panel is continuously driven in a state where the ratio of the holding period of the positive voltage to the negative voltage is set to be equal. Then, every time a certain time (1 minute) elapses, the voltage LCcom is adjusted so that the flicker is minimized, and the value of the register A at this time is compared with the value of the stored register A. Here, if the register A has changed to a specified value (± 50) or more, the elapsed time is measured. If the elapsed time is equal to or greater than the specified value (60 minutes), the adjustment is completed.

If the elapsed time is less than the specified value, the control circuit 52 determines whether the value of the register A has changed to the plus side or to the minus side compared to the previous time. Here, when the set value of the register A has changed to the plus side, the set value of the register B is set to +1. Conversely, when the set value of the register A has changed to the minus side, the set value of the register B -1 and save. Thereafter, every time a certain time (1 minute) elapses again, the voltage LCcom is adjusted so that the flicker is minimized, and the value of the register A at this time is compared with the value of the stored register A. Here, if the register A has changed to a specified value (± 50) or more, the elapsed time is measured. If the elapsed time is equal to or greater than the specified value (60 minutes), the adjustment is completed. Otherwise, the control circuit 52 determines whether the value of the register A has changed to the plus side or the minus side compared to the previous time. judge. Here, when the set value of the register A has changed to the plus side, the set value of the register B is set to +1. Conversely, when the set value of the register A has changed to the minus side, the set value of the register B Set to −1 and save.
This procedure is repeated until the elapsed time exceeds the specified value.

  As a result, it is possible to provide an electro-optical device that reduces initial flicker and suppresses changes in flicker over time.

  In the present embodiment, since the voltage LCcom is adjusted so as to minimize flicker, the effective voltage applied to the liquid crystal layer in this state is symmetrical between the positive polarity and the negative polarity. For this reason, in this embodiment, the measurement and the step of equalizing the effective voltage applied to the liquid crystal layer are completed in one step, but means other than adjusting the voltage LCcom as means for equalizing the effective voltage of the liquid crystal layer. Is preferably performed at the timing of the setting value storing step after the value of the register B in FIG.

  In the present embodiment, the adjustment is performed based on the value of the register A when the voltage LCcom is adjusted so that the flicker is minimized after driving for a predetermined time. Adjustment may be performed based on the amount of flicker change after time drive.

  In this embodiment, the adjustment is performed based on the elapsed time when the change in the value of the register A reaches the specified value when the voltage LCcom is set so that the flicker is minimized. Adjustment may be performed based on the elapsed time when the amount of change in flicker reaches a specified value.

  In the present embodiment, the interval for measuring the amount of change in the value of the register A, the specified value for the amount of change in the value of the register A, and the specified value for the elapsed time are merely examples, and the present invention is not limited thereto. Note that it is desirable to select a time equal to or longer than the time constant until the charge bias in the display panel is saturated as the specified value of the elapsed time.

  In this embodiment, the value of the register B is changed after the voltage LCcom is adjusted and the value of the register A at that time is saved. However, this order may be reversed.

  The flowchart of the adjustment method in a present Example is shown in FIG. 18, FIG. The block diagram of the electro-optical device in the present embodiment is the same as FIG.

In the adjustment methods in the first, second, and third embodiments, as a means for observing the charge bias in the panel, the amount of change in flicker after a predetermined time has elapsed, or the voltage LCcom that minimizes flicker. The amount of change was measured.
However, when the time constant of the charge bias in the panel is very large, or the ratio between the first period and the second period that can suppress the charge bias is far from the initial set value, After a predetermined time elapses, the charge bias becomes very large, and a large flicker may occur. In addition, when the bias of charge is very large, it may be a cause of image sticking even for a predetermined time.

  In such a case, until the ratio between the first period and the second period is able to suppress the charge bias to some extent, the information that the charge bias is large and the flicker is minimized. It only has to know whether the voltage LCcom is increasing or decreasing.

  Therefore, in the present embodiment, the amount of change in flicker or the amount of change in voltage LCcom that minimizes flicker is measured at a certain interval, and these values reach a certain value or a predetermined time has elapsed. Make adjustments, whichever comes first.

  First, the control circuit 52 sets the voltage LCcom so as to reduce the initial flicker by operating the register A based on the data of the data analysis unit 72 in a state where an image is projected by the electro-optical device according to the flowchart of FIG. . At the same time, the amount of flicker at this time is stored in the internal memory.

  Next, the liquid crystal is continuously driven in a state where the ratio of the holding period of the positive voltage and the negative voltage is set to be equal. Meanwhile, the voltage LCcom is adjusted according to FIG. 18 at regular intervals (1 minute), and the change in the value of the register A is measured. At this time, if the change amount of the register A is smaller than the specified value and the elapsed time from the start of driving is less than the predetermined time, the control circuit 52 sets the value of the register A to the currently stored value. Then, drive again.

  When the change amount of the register A reaches a predetermined value, it is determined in which direction the value of the register A has changed. When the change amount has changed to the plus side, the value of the register B is changed to +1, −side. If it has changed to 1, the value of the register B is decremented by 1. Then, the current value of the register A is saved, the count is reset, and driving is started.

When the predetermined amount of time has elapsed without the amount of change in the value of the register A reaching the specified value, the adjustment is completed if the amount of change in the value of the register A is equal to or less than the specified value.
If the change in the value of the register A is equal to or greater than the specified value, the control circuit 52 determines whether the value of the register A has changed to the plus side or to the minus side compared to the previous time. Here, when the set value of the register A has changed to the plus side, the set value of the register B is incremented by +1, and conversely, when the set value of the register A has changed to the minus side, the set value of the register B -1 and save.
This procedure is repeated until the amount of change in the value of register A falls within the reference value.
As a result, it is possible to provide an electro-optical device that reduces initial flicker and suppresses changes in flicker over time.

  In the present embodiment, since the voltage LCcom is adjusted so as to minimize flicker, the effective voltage applied to the liquid crystal layer in this state is symmetrical between the positive polarity and the negative polarity. Therefore, in this embodiment, the voltage LCcom at which flicker is minimized is measured, and the effective voltage applied to the liquid crystal layer is equalized by driving at that value. As a means for equalizing the effective voltage of the liquid crystal layer, When using means other than adjusting the voltage LCcom, it is desirable to carry out at the timing of the set value storing step after the value of the register B in FIG.

In the present embodiment, the adjustment is performed based on the value of the register A when the voltage LCcom is adjusted so that the flicker is minimized after driving for a predetermined time. Adjustment may be performed based on the amount of flicker change after time drive.
In this embodiment, the value of the register B is changed after the voltage LCcom is adjusted and the value of the register A at that time is saved. However, this order may be reversed.

  The block diagram of the electro-optical device in the present embodiment is the same as FIG. The flowcharts of this embodiment are shown in FIGS.

  In the adjustment methods in the first to fifth embodiments, the amount of change in flicker when driven for a predetermined time or the amount of change in voltage LCcom that minimizes flicker falls within a specified value, or the amount of change in flicker or This is a method of determining the optimum value of the register B by changing the value of the register B until the time until the change amount of the voltage LCcom at which the flicker is minimized becomes equal to or more than the specified value becomes abnormal. For this reason, it is possible to obtain the optimum register B value with very high accuracy, but depending on the optimum register B value, it takes a very long time to complete the adjustment. Since it is unclear how long it takes, it may not be suitable for use in inspection of the electro-optical device at the time of shipment.

Therefore, in this embodiment, the number of adjustments is fixed and the time required for adjustment is fixed.
In the adjustment method according to the present embodiment, the number of time-dependent changes is determined in advance, and the value of the register B set for each time is also determined in advance. First, the control circuit 52 sets the voltage LCcom according to the flowchart of FIG. 18 while monitoring the data of the data analysis unit 72 in a state where an image is projected by the electro-optical device.

  Next, the register B is set to “0” and energized for a certain period of time. Thereafter, the value of the voltage LCcom is set according to FIG. 18, and the amount of change from the previous set value is measured. Next, the value of the register B is set to “+10”, and the same procedure is repeated. Thereafter, the value of the register B is set to “−10”, and the same procedure is repeated.

When the above measurement is completed, the value of register B that is assumed to have a change amount of register A of 0 is calculated from the correlation between the value of register B and the change amount of register A, and is stored as a set value at the time of driving. Let For example, when the correlation between the value of the register B and the change amount of the register A is linear as shown in FIG. 14, the set value can be calculated from linear interpolation.
With this adjustment method, it is possible to adjust the change of flicker over time shorter than in the first to third embodiments and in a fixed time.

In this embodiment, the value of the register B is changed after the voltage LCcom is adjusted and the value of the register A at that time is saved. However, this order may be reversed.
Further, in this embodiment, the adjustment is performed based on the value of the register A when the voltage LCcom is adjusted so that the flicker is minimized after driving for a predetermined time in this embodiment. Without limitation, as in the first embodiment, adjustment is performed based on the amount of change in flicker after driving for a predetermined time. Similarly to the fourth embodiment, the voltage LCcom at which the amount of flicker change or flicker is minimized is adjusted. Adjustment may be performed based on the time required for the value of to reach the specified value.

  The block diagram of the electro-optical device in the present embodiment is the same as FIG. FIG. 24 is a flowchart, and FIGS. 18 and 26 show an example of a lookup table (LUT) necessary for adjustment.

  As a method for completing the adjustment in a shorter time than in the sixth embodiment, the amount of change in the voltage LCcom that minimizes the flicker when energized for a certain time under a certain condition in advance, and the value of the register B that can suppress the change in flicker over time are set. There is a method of determining an appropriate register B value from a single measurement by creating a relationship as an LUT. A conceptual diagram of this LUT is shown in FIG. 24, and a specific example is shown in FIG.

In this adjustment method, the control circuit 52 first sets the voltage LCcom according to FIG. 18 in a state where an image is projected by the electro-optical device.
Next, the register B is set to “0” and energized for a certain period of time. Thereafter, the value of the voltage LCcom is set so that the flicker is minimized, and the amount of change from the stored value is measured.

When the above measurement is completed, the value of register B is determined so that the change in voltage LCcom over time falls within the reference value using the LUT indicating the correlation between the value in register B and the change in register A. This is stored as a set value at the time of driving.
By this adjustment method, it is possible to adjust the change of flicker over time even shorter than in the fourth embodiment and at a fixed time.

  Further, in this embodiment, the adjustment is performed based on the value of the register A when the voltage LCcom is adjusted so that the flicker is minimized after driving for a predetermined time in this embodiment. Without limitation, as in the first embodiment, adjustment is performed based on the amount of change in flicker after driving for a predetermined time. Similarly to the fourth embodiment, the voltage LCcom at which the amount of flicker change or flicker is minimized is adjusted. Adjustment may be performed based on the time required for the value of to reach the specified value.

  An electronic apparatus incorporating the electro-optical device 1 will be described. FIG. 27 shows a circuit configuration of this electronic device. FIG. 27 is a plan view showing a configuration of a three-plate projector using the display panel 10 of the electro-optical devices 1 and 2 as a light valve.

  In the electro-optical device 2100, light to be incident on the light valve is R (red), G (green), and B (blue) by three mirrors 2106 and two dichroic mirrors 2108 disposed inside. The three primary colors are separated and guided to the light valves 100R, 100G, and 100B corresponding to the primary colors, respectively. Note that B light has a longer optical path than other R and G colors, and therefore, in order to prevent loss thereof, the B light passes through a relay lens system 2121 including an incident lens 2122, a relay lens 2123, and an exit lens 2124. Led.

Here, the light valves 100R, 100G, and 100B are respectively driven by image data corresponding to each color of R, G, and B supplied from an external host device (not shown).
The lights modulated by the light valves 100R, 100G, and 100B are incident on the dichroic prism 2112 from three directions. In the dichroic prism 2112, the R and B light beams are refracted at 90 degrees, while the G light beam travels straight. Therefore, after the images of the respective colors are combined, they are projected forward and enlarged by the lens unit 1820, so that a color image is displayed on the screen 2120.
The optical sensors 200R, 200G, and 200B are disposed on the dichroic prism 2112 and detect the illuminance of each of the R, G, and B.

  In addition to the electronic apparatus described with reference to FIG. 27, the rear projection type television or direct view type, for example, a mobile phone, a personal computer, a video camera monitor, a car navigation device, a pager, an electronic device Examples include notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, and devices with touch panels. Needless to say, the electro-optical device according to the present invention is applicable to these various electronic devices.

  In Examples 1 to 7, as a method of changing the ratio between the first period and the second period, the predetermined period is set as one frame, and the positive / negative application time within one frame is set. The driving method is not limited to this driving method. For example, as shown in FIG. 28, when the predetermined period is a time spanning a plurality of frames, the first period during which one of the positive polarity and the negative polarity is applied and the other is applied during the period. The same effect can be obtained even when the driving method is to change the ratio of the second period. In FIG. 27, the length of the first period and the second period is changed by applying a positive polarity at a timing when a negative polarity is supposed to be applied in a plurality of frames as unit frames. This is an example.

Further, the measurement time and the reference value are also examples, and it is actually necessary to select the optimal time depending on the characteristics of the liquid crystal panel and the like.
Further, in this embodiment, the index related to the amount of change in flicker is set as “the amount of change in flicker when energized for a certain period of time”, but this is not limited to this index. “Time required for flicker to change” may be used as an index.

  DESCRIPTION OF SYMBOLS 1 ... Electro-optical apparatus, 10 ... Display panel, 50 ... Processing circuit, 52 ... Control circuit, 54 ... Display data processing circuit, 56 ... D / A conversion circuit, 70 ... Optical sensor, 72 ... Data analysis part.

Claims (24)

A plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, and the pixel electrode and the common electrode. In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field of
When the high voltage is positive and the low voltage is negative with reference to the common electrode potential applied to the common electrode via the data line with respect to the pixel electrode, the positive and negative electrodes Supply data signals that appear alternately,
In a predetermined period consisting of a first period and a second period,
In the pixel electrode,
In the first period, supplying a first voltage which is a voltage of one of the positive polarity and the negative polarity,
A first step of driving the liquid crystal device by supplying a second voltage having a polarity different from the first voltage in the second period;
Measuring a flicker generated by alternately repeating the first period and the second period, and storing the second flicker;
A third step of driving the liquid crystal device with the above ratio;
A fourth step of measuring the flicker again when a predetermined time has elapsed and comparing with the stored value;
A method for adjusting a liquid crystal device, comprising: a fifth step of adjusting a ratio between the length of the first period and the length of the second period based on a comparison result. The method of adjusting a liquid crystal device according to claim 1,
The predetermined value of the common electrode potential in the first step is set so that effective voltages applied to the liquid crystal layer are equal in the first period and the second period. The method of adjusting a liquid crystal device according to claim 1. The method of adjusting a liquid crystal device according to claim 1 or 2,
A method for adjusting a liquid crystal device, wherein the second to fifth steps are repeated a plurality of times. A plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, and the pixel electrode and the common electrode. In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field of
When the high voltage is positive and the low voltage is negative with reference to the common electrode potential applied to the common electrode via the data line with respect to the pixel electrode, the positive and negative electrodes Supply data signals that appear alternately,
In a predetermined period consisting of a first period and a second period,
In the first period, supplying a first voltage which is a voltage of one of the positive polarity and the negative polarity,
A first step of driving the liquid crystal device by supplying a second voltage having a polarity different from the first voltage in the second period;
A second step of setting the effective voltage applied to the liquid crystal layer to be equal in the first period and the second period, and storing the set value of the common electrode potential;
A third step of driving the liquid crystal device with the above ratio;
When a predetermined time elapses, the common electrode potential is set again so that the effective voltage applied to the liquid crystal layer becomes equal again in the first period and the second period, and the stored set value A fourth step for comparison with
A method for adjusting a liquid crystal device, comprising: a fifth step of adjusting a ratio between the length of the first period and the length of the second period based on a comparison result. The method for adjusting a liquid crystal device according to claim 4,
A method for adjusting a liquid crystal device, wherein the second to fifth steps are repeated a plurality of times. A plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, and the pixel electrode and the common electrode. In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field of
When the high voltage is positive and the low voltage is negative with reference to the common electrode potential applied to the common electrode via the data line with respect to the pixel electrode, the positive and negative electrodes Supply data signals that appear alternately,
In a predetermined period consisting of a first period and a second period,
When the high voltage is positive and the low voltage is negative with reference to the common electrode potential applied to the common electrode via the data line with respect to the pixel electrode, the positive and negative electrodes Supply data signals that appear alternately,
In a predetermined period consisting of a first period and a second period,
A first step of driving the liquid crystal device by supplying a second voltage having a polarity different from the first voltage in the second period;
A second step of setting the effective voltage applied to the liquid crystal layer to be equal in the first period and the second period, and storing the value of the common electrode potential;
A third step of driving the liquid crystal device with the ratio, measuring a common electrode potential at which effective voltages applied to the liquid crystal layer are equal, and measuring a change amount from the stored set value;
A fourth step of measuring the time taken to reach when the amount of change reaches a predetermined value;
A method for adjusting a liquid crystal device, comprising: a fifth step of adjusting a ratio between the length of the first period and the length of the second period based on a measurement result. The method for adjusting a liquid crystal device according to claim 6,
A method for adjusting a liquid crystal device, wherein the second to fifth steps are repeated a plurality of times. A plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, and the pixel electrode and the common electrode. In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field of
When the high voltage is positive and the low voltage is negative with reference to the common electrode potential applied to the common electrode via the data line with respect to the pixel electrode, the positive and negative electrodes Supply data signals that appear alternately,
In a predetermined period consisting of a first period and a second period,
In the first period, supplying a first voltage which is a voltage of one of the positive polarity and the negative polarity,
A first step of driving the liquid crystal device by supplying a second voltage having a polarity different from the first voltage in the second period;
A second step of setting the effective voltage applied to the liquid crystal layer to be equal in the first period and the second period, and storing the value of the common electrode potential;
A third step of driving the liquid crystal device with the ratio, measuring a common electrode potential at which effective voltages applied to the liquid crystal layer are equal, and measuring a change amount from the stored set value;
When the change amount reaches a predetermined value or when a predetermined time elapses before the change amount reaches a predetermined value, the change amount is applied to the liquid crystal layer in the first period and the second period. A fourth step of setting the common electrode potential again so that the effective voltages to be equalized are compared with the stored set value;
A method for adjusting a liquid crystal device, comprising: a fifth step of adjusting a ratio between the length of the first period and the length of the second period based on a comparison result. The method for adjusting a liquid crystal device according to claim 8,
A method of adjusting a liquid crystal device, wherein the steps from the second step to the fifth step are repeated a plurality of times. A plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, and the pixel electrode and the common electrode. In a method for adjusting a liquid crystal device comprising a liquid crystal layer driven by an electric field of
When the high voltage is positive and the low voltage is negative with reference to the common electrode potential applied to the common electrode via the data line with respect to the pixel electrode, the positive and negative electrodes Supply data signals that appear alternately,
In a predetermined period consisting of a first period and a second period,
In the first period, supplying a first voltage which is a voltage of one of the positive polarity and the negative polarity,
A first step of driving the liquid crystal device by supplying a second voltage having a polarity different from the first voltage in the second period;
A second step of setting the effective voltage applied to the liquid crystal layer to be equal in the first period and the second period, and storing the flicker value at that time;
A third step of driving the liquid crystal device with the ratio and measuring flicker;
A fourth step of measuring flicker again when the flicker reaches a predetermined value or when a predetermined time elapses before the flicker reaches the predetermined value and comparing with the stored value;
A method for adjusting a liquid crystal device, comprising: a fifth step of adjusting a ratio between the length of the first period and the length of the second period based on a comparison result. The method for adjusting a liquid crystal device according to claim 10,
A method for adjusting a liquid crystal device, wherein the second to fifth steps are repeated a plurality of times. In the adjustment method of the liquid crystal device according to any one of claims 3, 5, 7, 9, and 11,
A method for adjusting a liquid crystal device, wherein when the process is repeated a plurality of times, the ratio between the first period and the second period is different from the other at least once. The adjustment method according to claim 12,
A method of adjusting a liquid crystal device, characterized in that the process is repeated a predetermined number of times and the ratio between the first period and the second period is adjusted based on the result. The method of adjusting a liquid crystal device according to claim 1 or 2,
In the fifth step, the amount of flicker change when the liquid crystal device is driven for a predetermined time after setting the first period and the second period to a predetermined ratio, the first period, A set value for the second period is created as an LUT (Look Up Table), and based on this, the first period and the above-mentioned period are calculated from the amount of flicker change when the liquid crystal device is driven at the predetermined ratio for a predetermined time. A method for adjusting a liquid crystal device, wherein the ratio of the second period is adjusted. The method for adjusting a liquid crystal device according to claim 4,
In the fifth step, when the liquid crystal device is driven for a predetermined time after the first period and the second period are set to a predetermined ratio in advance, the first period and the second period , The amount of change in the common electrode potential at which the voltage applied to the liquid crystal layer becomes equal, and the set values of the first period and the second period are created as a LUT (Look Up Table), and based on this, the predetermined value is generated. A method for adjusting a liquid crystal device, wherein the ratio between the first period and the second period is adjusted based on the amount of change in flicker when the liquid crystal device is driven at a ratio of a predetermined time. The method for adjusting a liquid crystal device according to claim 6,
In the fifth step, the voltage applied to the liquid crystal layer in the first period and the second period is set in advance after setting the first period and the second period to a predetermined ratio. The time required for the amount of change in common electrode potential to be equal to a predetermined value and the set values of the first period and the second period are created as a LUT (Look Up Table), and based on this, the predetermined value is generated. Adjusting the ratio between the first period and the second period based on the time required for the amount of change in the previous period when the liquid crystal apparatus is driven at the ratio to reach a predetermined time. Method. The method for adjusting a liquid crystal device according to claim 8,
In the fifth step, the first period and the second period when the liquid crystal is driven for a predetermined time after setting the first period and the second period to a predetermined ratio in advance. The amount of change of the common electrode potential at which the voltages applied to the liquid crystal layer become equal, the set values of the first period and the second period are created as a LUT (Look Up Table), and the first period And the second period is set to a predetermined ratio, and the time required to reach a predetermined flicker value, and the set values of the first period and the second period are created as a LUT (Look Up Table). Based on this, the ratio between the first period and the second period is adjusted from the amount of change in flicker when the liquid crystal apparatus is driven at the predetermined ratio for a predetermined time. Adjustment method. The method for adjusting a liquid crystal device according to claim 10,
In the fifth step, the flicker changes when the liquid crystal is driven for a predetermined time after setting the first period and the second period to a predetermined ratio in advance, the first period, and the second period The set value of the period is created as an LUT (Look Up Table), and the time required to reach a predetermined flicker value after setting the first period and the second period to a predetermined ratio, A set value of the first period and the second period is created as a LUT (Look Up Table), and based on this, from the amount of change in flicker when the liquid crystal device is driven at the predetermined ratio for a predetermined time, A method for adjusting a liquid crystal device, comprising adjusting a ratio between a first period and the second period.   15. The first step according to claim 2 or 14, wherein the common electrode potential is adjusted as a step of equalizing effective voltages applied to the liquid crystal layer in the first period and the second period. Adjustment method of liquid crystal device.   The second step according to any one of claims 4 to 13, 15 to 18, wherein the common electrode potential is adjusted as a step of equalizing an effective voltage applied to the liquid crystal layer in the first period and the second period. A method for adjusting a liquid crystal device characterized by the above.   When measuring the flicker or when equalizing the effective voltage applied to the liquid crystal layer in the first period and the second period, the ratio between the first period and the second period is set. The method for adjusting a liquid crystal device according to claim 1, wherein the ratio is set to a predetermined ratio.   The method of adjusting a liquid crystal device according to claim 22, wherein the predetermined ratio is 1: 1. A plurality of scanning lines, a plurality of data lines, a switching transistor and a pixel electrode provided at an intersection of the scanning line and the data line, the pixel electrode and the common electrode, and the pixel electrode and the common electrode. In a liquid crystal device including a pixel having a liquid crystal layer driven by an electric field of
When the high voltage is positive and the low voltage is negative with respect to the common electrode potential applied to the common electrode, the positive and negative electrodes are connected to the pixel electrode via the data line. Data transmitting means for supplying a data signal in which characteristics appear alternately;
Image capturing means for capturing the pixels at a predetermined timing;
A counting means for measuring time;
Flicker analysis means for analyzing luminance information of the image captured by the image capture means at a predetermined timing;
Storage means for storing data analyzed by the flicker analysis means;
Comparing means for comparing the data stored in the storage means with the current data;
A first period in which a first voltage that is one of the positive polarity and the negative polarity is supplied to the pixel electrode, and a second voltage having a polarity different from the first voltage is the first voltage. In the second period supplied to the pixel electrode, there is provided application time adjusting means for adjusting a ratio between the length of the first period and the length of the second period in the predetermined period. Liquid crystal device.   An electronic apparatus comprising the liquid crystal device according to claim 23.

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