JP5494196B2 - Display device, electronic device, and projection display device - Google Patents

Description

  The present invention relates to a liquid crystal device, a driving method thereof, and a projection display device, and more particularly to a liquid crystal device suitable for use in a liquid crystal light valve mounted on the projection display device and a configuration of the driving method thereof.

  A liquid crystal light valve is known as a light modulation means mounted on a projection display device such as a liquid crystal projector. The liquid crystal light valve is mainly composed of a pair of substrates which are disposed to face each other with a liquid crystal layer interposed therebetween and which have electrodes for applying a voltage to the liquid crystal layer. In general, an active matrix type liquid crystal cell is used for a liquid crystal light valve, and higher definition of an image is being promoted.

  Conventionally, inversion driving methods such as dot inversion, line inversion, and surface inversion have been adopted as driving methods for liquid crystal light valves in order to prevent burn-in and deterioration of the liquid crystal. Each of the above inversion driving methods has advantages and disadvantages. However, dot inversion and line inversion have an advantage that crosstalk can be suppressed. On the other hand, a reverse polarity potential is written to adjacent pixel electrodes. An electric field is generated, and light leakage may occur due to disclination due to the transverse electric field. As described above, since liquid crystal light valves are required to have high definition, this light leakage causes a decrease in contrast and a reduction in aperture ratio, which is a major factor in reducing display quality. Therefore, from this point of view, it is required to adopt a surface inversion driving method that does not generate a lateral electric field.

However, the surface inversion driving method has another problem.
That is, in the surface inversion drive, when attention is paid to one data line, assuming that the inversion period is 1 field for all pixels to which signals are supplied from the data line, the same polarity is obtained in a predetermined 1 field. An image signal (potential) is written. At the moment of moving to the next field, the polarity of the image signal supplied to the data line is reversed. At this time, when the scanning line is scanned from the upper side to the lower side of the display area, the image signal is applied to the data line in most of the holding period after the image signal is written in the pixels on the upper side of the display area. While the polarity of the signal is the same as the potential of the pixel, in the lower pixel, the image signal having the opposite polarity to the pixel is applied to the data line in most of the holding period after the image signal is written. Is applied. As described above, there is a difference in the influence of the potential of the data line on the pixel electrode between the upper side and the lower side of the display area, and thus there is a problem that the display becomes uneven depending on the location on the screen.

  Therefore, as a means for suppressing crosstalk and ensuring the uniformity of the screen, one horizontal period is divided into a first period and a second period, and a drive pulse is supplied to the scanning line and the data line in the first period. In the second period, an image signal is applied to each pixel electrode by supplying an image signal to the data line, and a drive pulse is not supplied to the scanning line and an image signal having a reverse polarity to the previous one is supplied to the data line. It has been proposed (for example, Patent Document 1).

JP-A-5-313608

However, the technique described in Patent Document 1 has a problem that the time that can be used for pixel writing becomes half of the normal time and writing becomes insufficient.
The present invention has been made in order to solve the above-described problems, and is a liquid crystal device capable of suppressing crosstalk, ensuring uniformity of display quality in a screen, and preventing problems such as insufficient writing. And a driving method thereof.

  In order to achieve the above object, a liquid crystal device according to the present invention includes a plurality of data lines and a plurality of scanning lines intersecting with each other, pixels connected to the data lines and the scanning lines, and a positive potential for each unit period. An image signal whose polarity is inverted to a negative potential is supplied to each of the plurality of data lines, and a plurality of pulse signals rising at different timings are skipped over a part of the plurality of scanning lines for each horizontal period. A plurality of scans, each of which has a drive circuit unit that supplies each of the plurality of scan lines and is supplied with a pulse signal that rises at a timing corresponding to a positive potential application period of the image signal in any one horizontal period The drive circuit unit allows the scanning lines to be adjacent to each other, and so that a plurality of scanning lines to which a pulse signal that rises at a timing corresponding to a negative potential application period is adjacent to each other. Wherein the driving is performed.

  The drive circuit unit in the liquid crystal device of the present invention outputs an image signal whose polarity is inverted every unit period on the data line side. For example, when the unit period is one horizontal period, the polarity inversion is conventional. The same operation as the line inversion driving is performed. On the other hand, on the scanning line side, instead of performing line-sequential scanning from the upper side to the lower side of the screen, over all scanning lines while moving back and forth while skipping some (multiple) scanning lines. Scanning is performed. Based on the operation of the drive circuit unit, either a pulse signal that rises at a timing corresponding to a positive potential application period or a pulse signal that rises at a timing corresponding to a negative potential application period in an image signal. Is supplied for each scan line.

  At this time, paying attention to an arbitrary one vertical period, a plurality of scanning lines to which a pulse signal rising at a timing corresponding to a positive potential application period is adjacent to each other and at a timing corresponding to a negative potential application period. Since a plurality of scanning lines to which the rising pulse signal is supplied are adjacent to each other, a pixel in which a positive potential is written and a negative potential are written in a region corresponding to the plurality of adjacent scanning lines. Only one of the pixels will be present. Therefore, a positive potential application region and a negative potential application region having a certain size in the screen are formed, and these are reversed at a predetermined cycle, and surface inversion driving is performed for a specific region. Similarly, the same polarity can be used between adjacent pixels.

  However, in the case of the present invention, although the surface inversion drive is performed for a specific region as a result, the data line side is operated in the same manner as the conventional line inversion drive, so the data line side is surface-inverted. As in the case of driving by the method, there is no great difference in the temporal potential relationship between the pixel electrode and the data line between the upper pixel and the lower pixel of the screen, and while suppressing crosstalk, It is possible to avoid display unevenness depending on the location. Further, as described in the section “Problems to be Solved by the Invention”, one horizontal period is divided into a first period and a second period, and in the second period, a driving pulse is not supplied to the data line. Unlike the conventional technique in which an image signal having a polarity opposite to that of the previous one is supplied, a large part of one horizontal period is spent on writing to a pixel, so that a problem such as insufficient writing does not occur.

Further, in one vertical period, it is desirable that the application time of the positive potential and the application time of the negative potential of the image signal supplied for each data line are substantially equal.
According to this configuration, the data lines can be almost completely exchanged, and the number of pixels written to the positive polarity and the number of pixels written to the negative polarity connected to the data lines is almost the same. Therefore, the effect that the relationship between the data lines and the pixel electrodes in the screen can be made more uniform can be obtained.

Further, in one vertical period, it is desirable that two pixel groups corresponding to two adjacent scanning lines are in a state where potentials of the same polarity are written for 50% or more of the time of one vertical period.
In the case of the present invention, unlike conventional general surface inversion driving, when viewed in an arbitrary vertical period, there are a plurality of regions consisting of a positive potential application region and a negative potential application region in one screen. Will do. Therefore, although the same polarity potential is applied to adjacent pixels in each region, a reverse polarity potential is applied to adjacent pixels at the boundary between the regions. Here, since each region moves on the screen by one scanning line every unit period, when attention is paid to one pixel, the time during which a potential of the same polarity is written to adjacent pixels in one vertical period There is a time during which a reverse polarity potential is written. Here, if the time during which the potential of the same polarity is written is 50% or more of one vertical period, it is possible to reduce the light leakage due to the lateral electric field that occurs when the adjacent pixel has the reverse polarity. Is obtained.

  Note that “regions” such as “positive potential application region” and “negative potential application region” in this specification are not used to indicate absolute locations on the screen, but are used for a certain minute time. Is a term used to indicate a range in which the polarity of the applied potential is in the same state. Therefore, this “region” moves on the screen over time.

The unit period during which the polarity of the image signal is inverted is preferably one horizontal period.
In the present invention, the “unit period in which the polarity of the image signal is inverted” is not limited to one horizontal period, and the operation and effect of the present invention can be performed even in a plurality of horizontal period units such as two horizontal periods and four horizontal periods. Can be obtained. However, in the case of one horizontal period, there is an effect that all the scanning lines can be in the same state. Conversely, in a case other than one horizontal period, there is a slight difference in the relationship between the data line and the pixel electrode between the scanning line selected at the beginning of the period and the scanning line selected at the end.

  As a specific scanning order in the liquid crystal device of the present invention, for example, when the number of the plurality of scanning lines is 2 m, the driving circuit unit applies a positive potential to a predetermined scanning line during the application period. After supplying a pulse signal that rises at a corresponding timing, a pulse signal that rises at a timing corresponding to an application period of a negative potential is supplied to a scan line separated m from a predetermined scan line. The operation may be repeated so that the same polarity potential is written to the pixel group corresponding to the adjacent scanning line every two horizontal periods.

  Alternatively, when the number of the plurality of scanning lines is 4 m, the driving circuit unit supplies a pulse signal that rises at a timing corresponding to the application period of the positive potential to the predetermined scanning line, and performs predetermined scanning. A pulse signal that rises at a timing corresponding to an application period of a negative polarity potential is supplied to a scan line separated m lines from the line, and a positive potential is applied to a scan line separated by 2 m from a predetermined scan line A pulse signal that rises at a timing corresponding to a period is supplied, and a pulse signal that rises at a timing corresponding to a negative potential application period is supplied to a scanning line separated by 3 m from a predetermined scanning line. It is sufficient to operate so as to write a potential having the same polarity to a pixel group corresponding to an adjacent scanning line every four horizontal periods.

The former method is an example in which one screen is divided into two regions of one positive potential application region and one negative potential application region, and the latter method is a method in which one screen is divided into two positive potential application regions and two regions. In this example, four negative potential application regions are divided into four regions.
When the number of divisions is reduced (in the case of two divisions), the time during which adjacent pixels have the same polarity in one vertical period can be maximized. On the other hand, when the number of divisions is increased (in the case of four divisions), the bias of the data line potential due to the display image can be made more uniform, and the crosstalk can be made less noticeable.

The drive circuit unit is preferably provided with a frame memory.
According to this configuration, after the image data is temporarily stored in the frame memory, the image data to be written to the pixels is read according to the scanning order of the scanning lines and supplied to the data lines.

  The liquid crystal device of the present invention includes a plurality of pixels arranged in an image display area, and a drive circuit unit that drives these pixels in a matrix. The drive circuit unit stores one field data. As a plurality of continuous field data, the writing start time is shifted within one vertical period while writing alternately every horizontal period, and the data writing polarity is reversed between consecutive fields.

  For example, consider a case where one field data is written as even (2m) field data. In this case, in the driving circuit unit, when writing of a certain field starts, writing of the next field is started at a timing shifted by, for example, a 1/2 m vertical period in the video signal. In these fields, after one line of a certain field is written, the drawing is performed so that data is written to the line of the next field existing at a position where a part (plurality) of scanning lines are skipped from this line. Is done. At this time, by inverting the polarity of data output to the data line every horizontal period, the polarity of data in one field can be made equal and the polarity of data can be made different between consecutive fields.

  As described above, in the present liquid crystal device, on the scanning line side, scanning is performed over all the scanning lines while moving back and forth over a plurality of scanning lines. When viewed in any one vertical period, there are a plurality of regions consisting of a positive potential application region and a negative potential application region corresponding to each field in the screen. That is, this configuration expresses the configuration of the above-described liquid crystal device from a macroscopic viewpoint, and thus the same effect as described above can be obtained. In other words, while the surface inversion drive is performed in each region in a pseudo manner, the operation on the data line side is almost the same as the conventional line inversion drive. In addition, there is no significant difference in the temporal potential relationship between the pixel electrode and the data line between the upper pixel and the lower pixel of the screen, and non-uniform display depending on the screen location while suppressing crosstalk. Can be avoided.

Further, as described in the section “Problems to be Solved by the Invention”, one horizontal period is divided into a first period and a second period, and in the second period, a driving pulse is not supplied to the data line. Unlike the conventional technique in which an image signal having a polarity opposite to that of the previous one is supplied, a large part of one horizontal period is spent on writing to a pixel, so that a problem such as insufficient writing does not occur.
In addition, by driving in this manner, the scanning lines are moved at a timing synchronized with the video signal, and the two scanning lines are written in the horizontal period for writing set to half the time with respect to the input video signal. By alternately allocating to, the frequency of writing scanning can be doubled that of the video signal.

  In such a liquid crystal device, the drive circuit unit includes a memory. When the drive circuit unit writes one field data as the first and second field data that are continuous, the external circuit While the input image signal is written as first field data as it is, the image signal is stored in the memory to generate second field data delayed with respect to the image signal. Preferably, the field data is alternately written every horizontal period, and the polarity of the second field data is reversed with respect to the first field data. With such a configuration, the memory capacity can be reduced and the member cost can be reduced.

  For example, consider a case where the writing start time of the second field data is delayed by a ½ vertical period in the video signal with respect to the first field data. In this example, while the upper half image is output to the data line by the image signal input from the outside, the upper half image data is also output to the memory and stored therein. Then, while the lower half image of the screen is output to the data line by the image signal, the image data before 1/2 vertical period in the video signal (that is, the upper half image data) from the memory to the data line is output from the memory. Is output. Data from the outside and the memory are alternately output to the data line every horizontal period.

  On the other hand, on the scanning line side, the upper and lower scanning lines on the screen are alternately selected every horizontal period, so that images are alternately written on the screen between the upper and lower stages. In other words, in this configuration, the image is written by the image data read from the memory while the image is written for each line by the image signal from the outside. Is written at a frequency twice that of the image signal to be processed. Normally, when driving at double speed, memory for two fields is required. However, in this configuration, half of the screen is written by outputting the image signal from the outside as it is to the data line, so the memory capacity is displayed. It only needs half the capacity of the entire screen. For this reason, the memory capacity can be reduced to 1/4 compared with a normal one, and the member cost can be greatly reduced. Further, in this configuration, since double speed writing is performed on the pixel, flicker is suppressed.

  Further, when the above-described liquid crystal device is viewed from the structural aspect, the present liquid crystal device is characterized as follows. That is, the liquid crystal device of the present invention includes a plurality of data lines and a plurality of scanning lines intersecting each other, and a plurality of data lines arranged in the image display area corresponding to the intersections of the data lines and the scanning lines. Pixels and a drive circuit unit that drives these pixels in a matrix, and the drive circuit unit outputs an image signal whose polarity is inverted between a positive potential and a negative potential every horizontal period of the plurality of data lines. Each of the data drivers to be supplied and a scan driver that sequentially shifts the gate output pulse in synchronization with a clock signal that rises every horizontal period. In the scan driver, n gates within one vertical period in the video signal The output pulses are output at different timings, and these gate output pulses are alternately shifted in synchronization with the clock signal, and are alternately set on each scanning line. Assigned either up the m enable signal is output scanning signals to each scanning line is characterized in that it is controlled. Note that n and m represent integers of 2 or more.

  In this configuration, n gate output pulses rise at different scanning line positions in the image display area within one vertical period of the video signal, and each of them rises from the upper side to the lower side of the image display area in synchronization with the clock signal. Shift towards. The scanning signal is output to the scanning line selected by the enable signal among the scanning lines where the gate output pulse rises. As a result, it is possible to perform scanning with a part (a plurality) of scanning lines skipped.

  As a form in which m is 2, in the scanning driver, two gate output pulses are simultaneously output to a position shifted by the half vertical period in the video signal, and each scanning line at the shifted position When either one of the first and second enable signals rising alternately is assigned and the image display area is divided into the first and second display areas from the upper side along the arrangement direction of the scanning lines In addition, each enable signal is assigned to a plurality of scanning lines arranged in any one of the display areas, and the scanning signal is alternated in the first and second display areas corresponding to the rising position of each enable signal. An example of a configuration that can be output automatically is an example.

  In this configuration, two gate output pulses rise simultaneously at a position shifted by 1/2 screen in the video signal, and each shifts from the upper side to the lower side of the image display area in synchronization with the clock signal. The scanning signal is output to the scanning line selected by the enable signal among the scanning lines where the gate output pulse rises. At this time, since the first enable signal is assigned to the first display area and the second enable signal is assigned to the second display area, the scanning lines are assigned to the upper side and the lower side of the image display area. Are selected alternately. Accordingly, it is possible to scan over all the scanning lines while moving back and forth between the upper side and the lower side of the image display area while skipping the scanning lines for 1/2 screen.

  As a form in which m is 4, in the scanning line driver, four gate output pulses are simultaneously output sequentially to positions shifted by a quarter vertical period in the video signal, and alternately to each scanning line. When any one of the first to fourth enable signals that rise is assigned, and the image display area is divided into the first to fourth display areas from the upper side along the arrangement direction of the scanning lines, The enable signals are respectively assigned to a plurality of scanning lines arranged in any one of the display areas, and the scanning signals are alternately output to the first to fourth display areas corresponding to the rising positions of the enable signals. The thing of the structure to be mentioned can be mentioned as an example.

  In this configuration, four gate output pulses rise simultaneously at a position shifted by ¼ screen in the video signal, and each shifts from the upper side to the lower side of the image display area in synchronization with the clock signal. The scanning signal is output to the scanning line selected by the enable signal among the scanning lines where the gate output pulse rises. At this time, the first enable signal is the first display area, the second enable signal is the second display area, the third enable signal is the third display area, and the fourth enable signal is the fourth display area. Therefore, the scanning lines in the first, second, third and fourth display areas are alternately selected. Thereby, it is possible to scan over all the scanning lines while moving back and forth between the display areas while skipping the scanning lines for ¼ screen.

As another form in which m is 2, in the scanning driver, two gate output pulses are simultaneously output to a position shifted by the half vertical period in the video signal, and each scanning line has an alternating pattern. One of the first and second enable signals rising up is assigned, and the first and second enable signals are respectively applied to the odd-numbered and even-numbered scanning lines from the uppermost side of the image display area. When the assigned image display area is divided into the first and second display areas from the upper side along the arrangement direction of the scanning lines, the scanning signal corresponds to the rising position of each enable signal. The thing of the structure output alternately to the 1st, 2nd display area can be mentioned as an example.
In this configuration, the two gate output pulses rise to a position shifted by 1/2 screen within one vertical period in the video signal, and each shifts from the upper side to the lower side of the image display area in synchronization with the clock signal. I will do it.

  For example, the two gate output pulses can rise to the k-th and s + k-th (s is an odd number) scanning line positions from the uppermost side. At this time, the scanning signal is output to the scanning line selected by the enable signal among the scanning lines on which the gate output pulses rise. At this time, since the first enable signal is assigned to the odd-numbered scanning line from the uppermost side of the image display area and the second enable signal is assigned to the even-numbered scanning line, the first and second enable signals are assigned to the scanning lines. For example, by starting in the order of the first, first, second, second, first, first,... While shifting the phase with the shift clock of the driver, the first one from the uppermost side of the image display area, s + 1 The scanning lines on the upper and lower sides of the screen are alternately selected in the order of the main line, the second line, the s + 2 line, the third line, the s + 3 line,.

  Further, in these configurations, the drive circuit unit includes a memory, and an image signal input from the outside is stored in the memory while being supplied to the data driver, and the data driver is input from the outside. Alternately supplying the image signal read from the memory and the image data read from the memory every horizontal period, and inverting the polarity of the image data read from the memory with respect to the image signal, It is preferable to supply an image signal whose polarity is inverted between a positive potential and a negative potential every horizontal period to each of the plurality of data lines. With such a configuration, the memory capacity can be reduced and the member cost can be reduced.

  In other words, in this configuration, the image is written by the image data read from the memory while the image is written for each line by the image signal from the outside. Is written at a frequency twice that of the image signal to be processed. Usually, when double-speed driving is performed, memory for two screens (for two fields) is required. In this configuration, half of the screen is written by outputting an externally input image signal to the data line as it is. Therefore, it is sufficient that the memory capacity is half of the entire display screen. For this reason, the memory capacity can be reduced to 1/4 compared with a normal one, and the member cost can be greatly reduced. Further, in this configuration, since double speed writing is performed on the pixel, flicker is suppressed.

  A driving method of a liquid crystal device according to the present invention is a driving method of a liquid crystal device having a plurality of data lines and a plurality of scanning lines intersecting with each other, and pixels connected to the data lines and the scanning lines. An image signal whose polarity is inverted between a positive potential and a negative potential is supplied to each of the plurality of data lines, and a plurality of pulse signals that rise at different timings for each horizontal period are part of the plurality of scanning lines. Are supplied to each of the plurality of scanning lines while jumping over each other, and in one arbitrary horizontal period, the plurality of scanning lines to which a pulse signal rising at a timing corresponding to the application period of the positive potential of the image signal is supplied are adjacent to each other In addition, the driving is performed such that a plurality of scanning lines to which a pulse signal that rises at a timing corresponding to a negative potential application period is supplied are adjacent to each other.

According to the driving method of the liquid crystal device of the present invention, the same operation and effect as the liquid crystal device of the present invention can be obtained.
That is, every arbitrary horizontal period, a plurality of scanning lines to which a pulse signal that rises at a timing corresponding to a positive potential application period is adjacent to each other and rises at a timing corresponding to a negative potential application period. Since a plurality of scanning lines to which signals are supplied are adjacent to each other, the positive potential application region and the negative potential application region having a certain size in the screen are inverted at a predetermined cycle, Surface inversion driving is performed. In the case of the present invention, as a result, the surface inversion drive is performed for each region, but the operation on the data line side is the same as the conventional line inversion drive. It is possible to avoid display unevenness depending on the location. In addition, since most of one horizontal period is spent on writing to the pixels, problems such as insufficient writing do not occur.

  Further, in one vertical period, it is desirable that the application time of the positive potential and the application time of the negative potential of the image signal supplied for each data line are substantially equal. In one vertical period, it is desirable to write a potential having the same polarity to two pixel groups corresponding to two adjacent scanning lines for a time of 50% or more of one vertical period. Further, it is desirable that the unit period in which the polarity of the image signal is inverted is one horizontal period.

  As a specific scanning sequence, for example, when the number of the plurality of scanning lines is 2 m, a pulse signal that rises at a timing corresponding to a positive potential application period is supplied to a predetermined scanning line, A pulse signal that rises at a timing corresponding to the negative potential application period is supplied to the scan lines separated m from the predetermined scan line, and the above operation is repeated thereafter to the adjacent scan lines every two horizontal periods. A potential having the same polarity can be written to the corresponding pixel group.

  Alternatively, when the number of the plurality of scanning lines is 4 m, a pulse signal that rises at a timing corresponding to the application period of the positive potential is supplied to the predetermined scanning line, and m lines from the predetermined scanning line. A pulse signal that rises at a timing corresponding to an application period of a negative potential is supplied to a distant scanning line, and a timing corresponding to an application period of a positive potential is applied to a scanning line separated by 2 m from a predetermined scanning line. And a pulse signal that rises at a timing corresponding to a negative potential application period is supplied to a scanning line separated by 3 m from a predetermined scanning line, and then the above operation is repeated for 4 horizontal lines. A potential having the same polarity can be written to a pixel group corresponding to a scanning line adjacent to each other for each period.

Further, it is desirable that the writing scanning frequency is 100 Hz or more.
Thereby, it becomes possible to make the flicker caused by the difference in the polarity of writing to the pixel inconspicuous.

  The liquid crystal device driving method of the present invention is a liquid crystal device driving method in which a plurality of pixels are arranged in a matrix in an image display area, and one field data is written as a plurality of continuous field data. While the start timing is shifted within one vertical period in the video signal, writing is performed alternately every horizontal period, and the data writing polarity is reversed between consecutive fields.

  In such a driving method, the data line is subjected to line inversion driving substantially the same as the conventional one to suppress crosstalk, while on the other hand, a positive potential application region having a certain extent in the screen and a negative potential By forming the application region, it is possible to avoid non-uniform display depending on the location of the screen. Further, since most of one horizontal period is spent writing pixels, problems such as insufficient writing do not occur.

  Further, such a liquid crystal device may be provided with a memory, and may be driven using an image signal input from the outside and image data read from the memory. That is, the driving method of the liquid crystal device according to the present invention is a driving method of a liquid crystal device including a plurality of pixels arranged in a matrix in an image display region and a memory. , When writing as the second field data, the image signal inputted from the outside is written as it is as the predetermined field data, and the image signal is stored in the memory, and the second signal delayed with respect to the image signal is stored. Field data is created, and the first and second field data are alternately written every horizontal period, and the polarity of the second field data is inverted with respect to the first field data. .

  This driving method can also prevent display non-uniformity depending on the screen location while suppressing crosstalk. Further, in this driving method, since one frame data is divided into a plurality of field data, it is driven substantially at a double speed or more, and therefore flicker can be suppressed. Normally, when driving at double speed or the like, a memory capacity of two fields is required. However, in this method, a part of the screen is written by outputting an external image signal to the data line as it is. The required memory capacity is less than one field. For example, when one frame data is divided into two field data, the drive is performed at a double speed, and the memory may be ½ field. For this reason, member cost is significantly reduced, which is advantageous in terms of cost.

The projection display device of the present invention includes a lighting device, a light modulation device that modulates light emitted from the lighting device, and a projection device that projects light modulated by the light modulation device. Then, the liquid crystal device of the present invention is provided as the light modulation device.
According to this configuration, it is possible to realize a projection display device having excellent display quality by including the liquid crystal device of the present invention.

It is a top view which shows schematic structure of the liquid crystal light valve of the 1st Embodiment of this invention. It is sectional drawing which follows the H-H 'line | wire of FIG. FIG. 3 is an equivalent circuit diagram of a plurality of pixels formed in a matrix form constituting the liquid crystal light valve. FIG. 2 is a block diagram including a driving circuit unit of the liquid crystal light valve. FIG. 3 is a circuit diagram showing a configuration of a scan driver in the drive circuit unit. It is a detailed circuit diagram of the principal part in FIG. 3 is a timing chart for explaining the operation of the liquid crystal light valve. It is a timing chart which takes out and shows the principal part in FIG. It is a figure which shows the image of the screen of a liquid crystal light valve. It is a figure for demonstrating the motion of a screen similarly. It is a figure which shows the image of the screen of the liquid crystal light valve of the 2nd Embodiment of this invention. 3 is a timing chart for explaining the operation of the liquid crystal light valve. It is a timing chart for demonstrating operation | movement of the liquid crystal light valve of the 3rd Embodiment of this invention. It is a schematic block diagram which shows an example of the projection type display apparatus using the liquid crystal device of this invention. It is a block diagram including the drive circuit part of the liquid crystal light valve of the 4th Embodiment of this invention. FIG. 3 is a circuit diagram showing a configuration of a scan driver in the drive circuit unit. It is a detailed circuit diagram of the principal part in FIG. 3 is a timing chart for explaining the operation of the liquid crystal light valve.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
In this embodiment, an example of a liquid crystal light valve (liquid crystal device) used as a light modulation device of a projection display device will be described.
1 is a schematic configuration diagram of a liquid crystal light valve according to the present embodiment, FIG. 2 is a cross-sectional view taken along line HH ′ of FIG. 1, and FIG. 3 is a plurality of pixels formed in a matrix configuration of the liquid crystal light valve. 4 is a block diagram including a drive circuit unit, FIG. 5 is a circuit diagram showing a configuration of a scan driver in the drive circuit unit, FIG. 6 is a detailed circuit diagram of a main part in FIG. 5, and FIG. FIG. 8 is a timing chart showing the main part in FIG. 7, FIG. 9 is a diagram showing an image of the screen, and FIG. 10 is a diagram for explaining the movement of the screen. It is. In each figure, the scales are different for each layer and each member so that each layer and each member can be recognized on the drawing.

(Overall configuration of liquid crystal light valve)
As shown in FIGS. 1 and 2, the configuration of the liquid crystal light valve 1 of the present embodiment is such that a sealing material 52 is provided on the TFT array substrate 10 along the edge of the counter substrate 20, and the inner side thereof. In parallel with this, a light shielding film 53 (peripheral parting) is provided as a frame. A data driver (data line driving circuit) 201 and an external circuit connection terminal 202 are provided along one side of the TFT array substrate 10 in a region outside the sealing material 52, and a scanning driver (scanning line driving circuit) 104 is provided. It is provided along two sides adjacent to this one side.

  Furthermore, a plurality of wirings 105 are provided on the remaining side of the TFT array substrate 10 for connecting the scan drivers 104 provided on both sides of the image display area. Further, at least one corner portion of the counter substrate 20 is provided with a vertical conductive material 106 for electrical conduction between the TFT array substrate 10 and the counter substrate 20. As shown in FIG. 2, the counter substrate 20 having substantially the same outline as the seal material 52 shown in FIG. 1 is fixed to the TFT array substrate 10 by the seal material 52, and the TFT array substrate 10, the counter substrate 20, In between, a liquid crystal layer 50 made of TN liquid crystal or the like is sealed. An opening 52 a provided in the sealing material 52 shown in FIG. 1 is a liquid crystal injection port and is sealed by the sealing material 25.

  In FIG. 3, each of a plurality of pixels formed in a matrix that forms an image display area of the liquid crystal light valve 1 in the present embodiment has a pixel electrode 9 and a TFT 30 for switching control of the pixel electrode 9. The formed data line 6 a to which an image signal is supplied is electrically connected to the source region of the TFT 30. The liquid crystal light valve 1 of the present embodiment has n data lines 6a and 2m scanning lines 3a (n and m are both natural numbers). The image signals S1, S2,..., Sn written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. good.

  Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., G2m are applied to each scanning line 3a in a pulsed manner at a predetermined timing while skipping as will be described later. It is configured. The pixel electrode 9 is electrically connected to the drain of the TFT 30, and the image signal S1, S2,... Sn supplied from the data line 6a is obtained by turning on the TFT 30 as a switching element for a certain period. Write at a predetermined timing. Image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 are held for a certain period with the common electrode formed on the counter substrate 20. Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is provided in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the common electrode.

  The drive circuit unit 60 of the liquid crystal light valve 1 according to the present embodiment includes a controller 61, a first frame memory 62, and a second frame memory 63 as shown in FIG. It consists of a frame memory for two screens, a DA converter 64, and the like. One of the first frame memory 62 and the second frame memory 63 is for temporarily storing an image of one frame input from the outside, and the other is used for display, and has a role for each frame. It will be replaced. The controller 61 receives the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the dot clock signal dotclk, and the image signal DATA, controls the first frame memory 62 and the second frame memory 63, and data corresponding to the scanning line 3a to be written. Read from the frame memory. The DA converter 64 DA-converts data read from the frame memory and supplies it to the data driver 201.

  As shown in FIG. 5, the scan driver 104 has a shift register 66 to which a gate output pulse DY, a clock signal CLY, and an inverted clock signal CLY ′ are respectively input from a controller 61, and an output from the shift register 66. 2m AND circuits 67 are provided. The 2m scanning lines 3a are divided into two blocks with the mth and m + 1th lines at the center of the screen as a boundary, and one of the two enable signals is connected to each output from the shift register 66. That is, the output from the shift register 66 and the enable signal ENB1 are input to the AND circuit 67 corresponding to the scanning lines G1 to Gm, and the output and enable from the shift register 66 are input to the AND circuit 67 corresponding to the scanning lines Gm + 1 to G2m. The signal ENB2 is input. FIG. 6 shows the internal structure of the shift register 66 in the center of the screen.

(Operation of liquid crystal light valve)
The operation of the drive circuit unit 60 configured as described above will be described with reference to FIGS.
In the driving circuit unit 60, as shown in FIG. 7, the gate output pulse DY is output twice during one vertical period of the input video signal. The gate output pulse DY is shifted in the shift register 66 of the scan driver 104 by the clock signal CLY that rises one pulse every horizontal period. Here, as shown in FIG. 8 (enlarged portion of reference A in FIG. 7), an area (specifically, Gm + 1th scanning line) where the gate output pulse DY is controlled by a different enable signal at the center of the screen. ), The phases of the enable signal ENB1 and the enable signal ENB2 are reversed. Through the above operation, gate pulses are alternately output to two places on the screen separated by m scanning lines. That is, jumping to a scanning line that is m lines away from a predetermined scanning line returns to the scanning line that is next to the predetermined scanning line, and jumping to a scanning line that is m lines away from the scanning line The output is sequentially performed so as to return to the scanning line (that is, in the order of scanning line G ₁ , scanning line G _{m + 1} , scanning line G ₂ , scanning line G _{m + 2} , G ₃ ,...). Here, the enable signals ENB1 and ENB2 have a pulse width of about ½ of one horizontal period of the input video signal. By outputting the gate output pulse DY and the enable signals ENB1 and ENB2 in this way, one horizontal period for the light valve becomes 1/2 of the input video signal.

On the other hand, the polarity of the data signal Sx, which is an output from the data driver 201, is inverted between a positive potential and a negative potential every horizontal period with the common potential LCCOM as a center. Therefore, the polarity of the data signal Sx side is inverted every horizontal period, while the gate pulse side is alternately output to two places on the screen separated by m scanning lines in the above order. As a result, on the screen, as shown in FIG. 9, when attention is paid to a certain horizontal period, for example, dots corresponding to the scanning lines G _{3 to} G _{m + 2} are regions in which positive potential data is written (hereinafter simply referred to as “dot”). The dots corresponding to the scanning lines G _{1 to} G ₂ and G _{m + 3 to} G _2m are areas where negative potential data is written (hereinafter simply referred to as negative areas). Thus, the screen is divided into three areas, a positive polarity area and a negative polarity area, in which data of different polarities are written.

FIG. 9 shows an image of the screen when the moment of an arbitrary horizontal period is seen, and FIG. 10 shows the state of polarity change on the screen over time. If the horizontal axis in FIG. 10 is time (unit: 1 horizontal period), for example, a negative potential is written in the dot corresponding to the scanning line G _2m in the first horizontal period, and in the first horizontal period in the next second horizontal period. A positive potential is written to the dot corresponding to the scanning line G _{m + 1} in which the negative potential has been written, and in the next third horizontal period, the scanning line G _{1 in} which the positive potential has been written in the first and second horizontal periods. A negative potential is written to the dot corresponding to, and this writing operation is repeated thereafter. Therefore, the positive polarity region and the negative polarity region move by one line every two horizontal periods, and when the scanning line moves half of the screen, the positive polarity region and the negative polarity region are completely reversed. That is, one screen has been rewritten. According to this method, the scanning line moves across the entire screen, so that the rewriting is performed twice. As a result, one vertical period is halved with respect to the input video signal.

  In other words, in this embodiment, one field data is written as a plurality of continuous field data, alternately writing every horizontal period while shifting the writing start time within one vertical period, and data between consecutive fields. The writing polarity is reversed. Specifically, one field data is divided into first and second field data having different polarities, and these field data are overwritten by being shifted by 1/2 vertical period. For this reason, on the scanning line side, scanning is performed over all the scanning lines while moving back and forth while skipping some (a plurality of) scanning lines. For this reason, when viewed in any one vertical period, there are a plurality of regions consisting of a positive potential application region and a negative potential application region corresponding to each field in the screen.

In the liquid crystal light valve according to the present embodiment, the positive polarity region and the negative polarity region having a half width of the screen are inverted in one vertical period, and surface inversion driving is performed for each region. Done. In one vertical period, between one arbitrary dot and one adjacent dot, a reverse polarity potential is obtained only for a time of 2/2 m, but most of the remaining time (2m−2) / 2 m is the same polarity potential. Therefore, disclination hardly occurs. On the other hand, on the data line 6a side, as shown in the signal waveform of FIG. 8, since the signal polarity is the same as that of the conventional line inversion driving, the screen is the same as when driving by the conventional surface inversion method. No significant difference occurs in the temporal potential relationship between the pixel electrode and the data line between the upper pixel and the lower pixel of the pixel, and non-uniform display depending on the location of the screen is avoided while suppressing crosstalk. be able to. Further, unlike the conventional technique, since most of one horizontal period is spent on writing to the pixel, problems such as insufficient writing do not occur.
In the present embodiment, the scanning frequency is 100 Hz or more, which is twice the input video signal frequency, so that flicker can be reliably suppressed.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the liquid crystal light valve (liquid crystal device) of the present embodiment is substantially the same as that of the first embodiment, except that the screen is divided into four and the surface is inverted. That is, in the present embodiment, one field data is used as four consecutive first, second, third, and fourth field data, and overwriting is performed by shifting the writing start time by a ¼ vertical period. It is. The writing polarity of data is the same in one field, and the data is the same in adjacent fields (that is, the first and second, second and third, third and fourth, fourth and first fields). The writing polarities are different from each other.
FIG. 11 is a diagram showing an image of a screen viewed at an instant of an arbitrary horizontal period in the liquid crystal light valve of the present embodiment, and FIG. 12 is a timing chart for explaining the operation of the liquid crystal light valve. In the present embodiment, the description of the basic configuration of the liquid crystal light valve is omitted, and only the operation is described.

In the first embodiment, the number of scanning lines 3a is 2 m, but in this embodiment, it is 4 m for convenience. Then, the scanning driver 104 is divided into four blocks of scanning lines G _{1 to} G _m , scanning lines G _{m + 1 to} G _2m , scanning lines G _{2m + 1 to} G _3m , and scanning lines G _{3m + 1 to} G _4m. Divide and use 4 enable signals. At this time, the gate output pulse DY is output four times during one vertical period of the input video signal.

In the case of this embodiment, as shown in FIG. 12, gate pulses are sequentially output to four locations on the screen separated by m scanning lines. That is, it jumps to a scanning line that is m lines away from a predetermined scanning line, and further jumps to a scanning line that is m lines away from the scanning line (a scanning line that is 2 m lines away from the first scanning line). After jumping to a scanning line that is separated by a distance (a scanning line that is 3 m away from the first scanning line), the scanning line returns to the scanning line next to the predetermined scanning line (that is, scanning line G ₁ , scanning line) G _{m + 1} , scanning line G _{2m + 1} , scanning line G _{3m + 1} , scanning line G ₂ , scanning line G _{m + 2} , scanning line G _{2m + 2} , scanning line G _{3m + 2,.} Output sequentially.

On the other hand, the polarity of the data signal Sx, which is an output from the data driver 201, is inverted between a positive potential and a negative potential every horizontal period with the common potential LCCOM as a center. Therefore, the polarity of the data signal Sx side is inverted every horizontal period, while the gate pulse side is sequentially output to four locations on the screen separated by m scanning lines in the above order. As a result, as shown in FIG. 11, when focusing on a certain horizontal period on the screen, for example, dots corresponding to the scanning lines G _{1 to} G ₂ become negative regions, and correspond to G _{3 to} G _{m + 2} . The dots corresponding to the scanning lines G _{m + 3 to} G _{2m + 2} become negative polarity areas, the dots corresponding to the scanning lines G _{2m + 3 to} G _{3m + 2} become positive polarity areas, The dots corresponding to the scanning lines G _{3m + 3 to} G _4m are divided into five areas, that is, the positive area and the negative area where data of different polarities are written, such that the dots are in the negative area. It will be in such a state.

  This writing operation is repeated thereafter, and the positive polarity region and the negative polarity region move by one dot every four horizontal periods, and move 1/4 of the screen in one vertical period. That is, the positive polarity region and the negative polarity region are completely inverted in one vertical period.

  In the present embodiment as well, the first embodiment in which non-uniformity of display depending on the location of the screen can be avoided and problems such as insufficient writing will not occur while suppressing crosstalk. The same effect as the form can be obtained.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the liquid crystal light valve (liquid crystal device) of this embodiment is almost the same as that of the first and second embodiments, and only the scanning order of the scanning lines is different.
FIG. 13 is a timing chart for explaining the operation of the liquid crystal light valve of the present embodiment. In the present embodiment, the description of the basic configuration of the liquid crystal light valve is omitted, and only the operation is described.

  In the present embodiment, the number of scanning lines 3a is 2m. In the first and second embodiments, the polarity of the data signal Sx output from the data driver 201 is inverted between the positive potential and the negative potential every horizontal period with the common potential LCCOM as the center. On the other hand, in the present embodiment, as shown in FIG. 13, the polarity of the data signal Sx is inverted between a positive potential and a negative potential every two horizontal periods around the common potential LCCOM.

In this embodiment, after the gate pulse is continuously output to two adjacent scanning lines, the gate pulse is skipped over m scanning lines and continuously output to two adjacent scanning lines. . That is, it is output to a predetermined scanning line, is output to a scanning line adjacent to the scanning line, is output by jumping to a scanning line that is m lines away from the predetermined scanning line, and is output to a scanning line adjacent to the scanning line. And the output is returned to the scanning line adjacent to the scanning line adjacent to the predetermined scanning line, and this order is repeated thereafter (that is, the scanning line G ₁ , the scanning line G ₂ , the scanning line G _{m + 1} , Scan line G _{m + 2} , scan line G ₃ , scan line G ₄ , scan line G _{m + 3} , scan line G _{m + 4} ,...

In the case of the present embodiment, focusing on a certain horizontal period, for example, the dots corresponding to the scanning lines G _{3 to} G _{m + 2} are positive regions on the screen as in the first embodiment shown in FIG. The dots corresponding to the scanning lines G _{1 to} G ₂ and G _{m + 3 to} G _2m are in the negative polarity region, so that the positive polarity region and the negative polarity region in which data of different polarities are written in the screen are displayed. The state is divided into three regions. This writing operation is repeated in the subsequent horizontal periods, and the positive polarity region and the negative polarity region move by one dot every two horizontal periods, and move half of the screen in one vertical period. That is, the positive polarity region and the negative polarity region are completely inverted in one vertical period.

  In the present embodiment as well, first and second problems such as non-uniformity of display depending on the location of the screen can be avoided and problems such as insufficient writing can be prevented while suppressing crosstalk. The same effect as in the embodiment can be obtained.

[Fourth Embodiment]
The fourth embodiment of the present invention will be described below with reference to FIGS.
The basic configuration of the liquid crystal light valve (liquid crystal device) of the present embodiment is almost the same as that of the first embodiment, and only the forms of the memory and scan driver provided in the drive circuit are different.

  As shown in FIG. 15, the drive circuit unit 80 of the liquid crystal light valve 1 according to the present embodiment includes a data driver 201, a scan driver 108, a controller 81, a memory 82, a DA converter 64, and the like. The memory 82 temporarily stores a half-screen image (1/2 field) inputted from the outside, and creates an image signal delayed by a 1/2 vertical period by the stored data. . The controller 81 receives the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the dot clock signal dotclk, and the image signal DATA, and controls the memory 82 and reads out data corresponding to the scanning line 3a to be written from the memory. The DA converter 64 DA-converts the image signal DATA input from the outside and the image data read from the memory 82 in parallel with the image signal DATA and supplies it to the data driver 201. Note that the image signal DATA from the outside and the image data read from the memory 82 are alternately output to the DA converter 64 every horizontal period for writing.

As shown in FIG. 16, the scan driver 108 is configured such that a shift register 66 to which a gate output pulse DY, a clock signal CLY, and an inverted clock signal CLY ′ are input from a controller 81 and an output from the shift register 66 are input. 2m AND circuits 67 are provided. The 2m scanning lines 3a are divided into two blocks, one arranged at the odd number and the one arranged at the even number from the top of the image display area, and two outputs are provided for each output from the shift register 66. One of the signals is connected. That is, the even-th scanning lines _{G 2, G 4, ...,} G m, G m + 2, ..., output enable signal ENB1 from the shift register 66 is inputted to the AND circuit 67 corresponding to G _2m, odd scan lines G ₁ of the present _{first, G 3, ..., G m} + 1, G m + 3, ..., output enable signal ENB2 from the shift register 66 is input to the aND circuit 67 corresponding to G _2m-1 It has a configuration. FIG. 17 shows the internal structure of the shift register 66 in the center of the screen.

The operation of the drive circuit unit 80 configured as described above will be described with reference to FIG.
In the drive circuit unit 80, the gate output pulse DY is output twice during one vertical period of the video signal. Here, each DY is output at an odd number of scanning lines. The gate output pulse DY is shifted in the shift register 66 of the scan driver 108 by the clock signal CLY that rises one pulse every horizontal period of the video signal. On the other hand, the enable signals ENB1 and ENB2 rise alternately every two horizontal periods of writing in the order of ENB1, ENB1, ENB2, ENB2, ENB1, ENB1, ENB2, ENB2,. A scanning signal is output to the corresponding scanning line. Here, since the two scanning lines are located at an odd number apart according to the output timing of DY, the outputs are controlled by different enable signals. Through the above operation, gate pulses are alternately output to two places on the screen separated by m scanning lines. That is, jumping to a scanning line that is m lines away from a predetermined scanning line returns to the scanning line that is next to the predetermined scanning line, and jumping to a scanning line that is m lines away from the scanning line The output is sequentially performed so as to return to the scanning line (that is, in the order of scanning line G ₁ , scanning line G _{m + 1} , scanning line G ₂ , scanning line G _{m + 2} , G ₃ ,...).

On the other hand, the polarity of the data signal Sx, which is the output from the data driver 201, is inverted between a positive potential and a negative potential every horizontal period of writing with the common potential LCCOM as the center. Therefore, the polarity of the data signal Sx side is inverted every writing horizontal period, while the gate pulse side is alternately output to two places on the screen separated by m scanning lines in the above order. As a result, on the screen, for example, as shown in FIG. 9, when attention is paid to a certain horizontal period, for example, dots corresponding to the scanning lines G _{3 to} G _{m + 2} The dots corresponding to the scanning lines G _{1 to} G ₂ and G _{m + 3 to} G _2m become areas where negative potential data is written (hereinafter simply referred to as negative areas). In addition, the screen is divided into three regions, a positive polarity region and a negative polarity region, in which data of different polarities are written. That is, in the present embodiment, although the method of setting the enable signal is different, the same scanning as in the first embodiment is performed.

  In other words, in the present embodiment, one field data is continuously written as the first and second field data, and the image signal input from the outside is directly written as the first field data, and the image signal is stored in the memory. Second field data that is stored and delayed with respect to the image signal is created, and these field data are written alternately, and the polarity of the second field data is inverted with respect to the first field data. .

  For this reason, also in this embodiment, it is possible to avoid uneven display depending on the location of the screen while suppressing crosstalk. In this embodiment, since one frame data is used as two field data and an image signal input from the outside is used as it is for one field data, the image is substantially double speed (that is, input from the outside). Is written at a frequency twice that of the image signal). Normally, when double-speed driving is performed, a memory capacity of two screens (two fields) is required, but in this configuration, half of the screen is written by outputting an external image signal to the data line as it is. Therefore, the memory capacity only needs to be half the capacity of the entire display screen (that is, 1/2 field). For this reason, the memory capacity can be reduced to 1/4 compared with a normal one, and the member cost can be greatly reduced. In this embodiment, since double speed writing is performed on the pixel, flicker is suppressed.

[Projection type liquid crystal device]
FIG. 14 is a schematic configuration diagram showing an example of a so-called three-plate projection type liquid crystal display device (liquid crystal projector) using three liquid crystal light valves of the above embodiment. In the figure, reference numeral 1100 denotes a light source, 1108 denotes a dichroic mirror, 1106 denotes a reflection mirror, 1122, 1123 and 1124 denote relay lenses, 100R, 100G and 100B denote liquid crystal light valves, 1112 denotes a cross dichroic prism, and 1114 denotes a projection lens system. .

  The light source 1100 includes a lamp 1102 such as a metal halide and a reflector 1101 that reflects light from the lamp 1102. The blue / green light reflecting dichroic mirror 1108 transmits red light of white light from the light source 1100 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 1106 and is incident on the red light liquid crystal light valve 100R.

  On the other hand, of the color light reflected by the dichroic mirror 1108, green light is reflected by the dichroic mirror 1108 reflecting green light and is incident on the green liquid crystal light valve 100G. On the other hand, the blue light also passes through the second dichroic mirror 1108. For blue light, in order to compensate for the difference in optical path length from green light and red light, light guide means 1121 comprising a relay lens system including an incident lens 1122, a relay lens 1123, and an output lens 1124 is provided, Through this, the blue light is incident on the blue light liquid crystal light valve 100B.

  The three color lights modulated by the light valves 100R, 100G, and 100B are incident on the cross dichroic prism 1112. In this prism, four right-angle prisms are bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 1120 by the projection lens system 1114 which is a projection optical system, and the image is enlarged and displayed.

  In the projection type liquid crystal display device having the above configuration, the projection type liquid crystal display device having excellent display uniformity can be realized by using the liquid crystal light valve of the above embodiment.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, an example is shown in which the screen is divided into two areas or four areas for writing different polar potentials. However, the number of divisions is not limited to this, and the number of divisions may be increased. . However, the greater the number of divisions, the longer the time during which the reverse polarity potential is applied to the adjacent scanning lines. Even in that case, it is desirable that the same polarity potential is applied at a rate of 50% or more of at least one vertical period in time. The order of scanning within each region is not limited to the above embodiment, and can be changed as appropriate.

  In the fourth embodiment, one field data is divided into two field data, but instead, one field data can be divided into three or more field data. In this case, an image signal from the outside is used for one of the field data, and data stored in separate memories is used for the other field data.

  In the above embodiment, an active matrix type liquid crystal device using TFTs has been described as an example. However, the present invention is not limited to this. For example, a pixel switching element using a TFD (Thin Film Diode) is used. The present invention can also be applied to various display devices that drive a plurality of pixels in a matrix, such as a passive matrix type.

(Effect of the invention)
As described above in detail, according to the present invention, while suppressing crosstalk, it is possible to avoid nonuniform display depending on the location of the screen and to prevent problems such as insufficient writing. An apparatus can be realized.

  DESCRIPTION OF SYMBOLS 1 Liquid crystal light valve 3a Scan line 6a Data line 9 Pixel electrode 30 TFT (switching element) 60,80 Drive circuit part 61,81 Controller 62 1st frame memory 63 2nd frame memory 82 Memory (FIFO) 104,108 Scan driver 201 Data driver

Claims (10)

Multiple data lines,
A plurality of scan lines;
A pixel provided corresponding to an intersection of the data line and the scanning line;
A scanning driver for outputting a scanning signal to the scanning line;
A data driver that outputs an image signal to pixels corresponding to a scanning line to which the scanning signal is supplied;
The scan driver is
A shift register unit that shifts the first signal and the second signal and outputs the first shift signal and the second shift signal in accordance with the shift operation;
A plurality of shift signal lines to which the first shift signal or the second shift signal is supplied;
A first enable line to which a first enable signal that is effective during the first period is supplied;
A second enable line to which a second enable signal that is effective in a second period different from the first period is supplied;
An output control unit for controlling the output of the scanning signal,
The output control unit
One of the first shift signal or the second shift signal supplied to one of the plurality of shift signal lines and the first enable signal supplied to the first enable line. A first logic circuit to be supplied;
The second enable signal supplied to the other one of the first shift signal or the second shift signal supplied to the other one of the plurality of shift signal lines and the second enable line. And a second logic circuit supplied with
The first logic circuit includes a first one of the plurality of scan lines based on one of the first shift signal or the second shift signal and the first enable signal. Outputs a scanning signal,
The second logic circuit includes a first shift signal or a second enable signal based on the other of the first shift signal or the second shift signal and the other one of the plurality of scan lines. 2 scanning signal is output,
The data driver outputs one of a positive or negative image signal with respect to a predetermined potential to a pixel corresponding to a scanning line to which the first scanning signal is supplied, and the second scanning signal By outputting the other of the positive or negative image signals with respect to the predetermined potential to the pixel corresponding to the scanning line to which is supplied,
A display device, wherein a position of a pixel to which the positive image signal is supplied and a position of a pixel to which the negative image signal is supplied move in accordance with the shift operation. The time during which the positive image signal is applied to each data line and the time during which the negative image signal is applied to each data line in one vertical period are substantially equal to each other. The display device according to 1. 2. In one vertical period, two pixel groups corresponding to two adjacent scanning lines are in a state where potentials of the same polarity are written for 50% or more of time in one vertical period. The display device described in 1. The display device according to claim 1, wherein the positive image signal and the negative image signal are alternately output to the data line every horizontal period. The scan driver is
When the number of the plurality of scanning lines is 2p (p is a natural number), the p first logic circuits connected to the p scanning lines and the p first logic circuits connected to the p scanning lines. The display device according to claim 1, further comprising: 2 logic circuits. Multiple data lines,
A plurality of scan lines;
A pixel provided corresponding to an intersection of the data line and the scanning line;
A scanning driver for outputting a scanning signal to the scanning line;
A data driver that outputs an image signal to pixels corresponding to a scanning line to which the scanning signal is supplied;
The scan driver is
A shift register unit that shifts the first, second, third, and fourth signals and outputs the first, second, third, and fourth shift signals in accordance with the shift operation;
A plurality of shift signal lines to which the first, second, third or fourth shift signal is supplied;
A first enable line to which a first enable signal that is effective during the first period is supplied;
A second enable line to which a second enable signal that is effective in a second period different from the first period is supplied;
A third enable line to which a third enable signal that is effective in a third period different from the first and second periods is supplied;
A fourth enable line to which a fourth enable signal that is effective in a fourth period different from the first, second, and third periods is supplied;
An output control unit for controlling the output of the scanning signal,
The output control unit
One of the first, second, third or fourth shift signals supplied to one of the plurality of shift signal lines and the first enable signal supplied to the first enable line. A first logic circuit supplied with
The other one of the first, second, third, or fourth shift signals supplied to the other one of the plurality of shift signal lines and the second enable line supplied to the second enable line. A second logic circuit supplied with two enable signals;
Different from the one of the first, second, third or fourth shift signals supplied to the one different from the one of the plurality of shift signal lines and the other one and the other one. A third logic circuit to which the first enable signal supplied to the third enable line is supplied;
Said plurality of said first and said first to said supplied another one and one excluding the different one of the shift signal line, the second, the one and the other of the third or fourth shift signal And a fourth logic circuit to which the fourth enable signal supplied to the fourth enable line and one other than the different one and the fourth enable line are supplied,
The first logic circuit includes a first one of the plurality of scan lines based on one of the first, second, third, or fourth shift signals and the first enable signal. 1 scan signal is output,
The second logic circuit may include another one of the plurality of scan lines based on the other one of the first, second, third, or fourth shift signals and the second enable signal. A second scanning signal is output to
The third logic circuit is configured to select the one of the plurality of scan lines based on the one of the first, second, third, or fourth shift signals and the one different from the other one. Outputting a third scanning signal to one and one different from the other,
Based on one of the first, second, third or fourth shift signals except the one different from the other and the different one of the first, second, third or fourth shift signals, A fourth scanning signal is output to one of the one and the other, and the one other than the different one;
The data driver outputs a first image signal having one polarity of positive polarity or negative polarity with respect to a predetermined potential to a pixel corresponding to a scanning line to which the first scanning signal is supplied, A second image signal having a positive polarity or a negative polarity with respect to the predetermined potential is output to a pixel corresponding to a scanning line to which a second scanning signal is supplied, and the third scanning signal is output. The third image signal having the one polarity is output to the pixel corresponding to the scanning line to which the fourth scanning signal is supplied, and the second polarity is applied to the pixel corresponding to the scanning line to which the fourth scanning signal is supplied. By outputting 4 image signals,
The position of the pixel to which the first image signal is supplied, the position of the pixel to which the second image signal is supplied, the position of the pixel to which the third image signal is supplied, and the fourth image signal are supplied. A display device in which the position of a pixel to be moved moves according to the shift operation. The display device according to claim 1, further comprising a frame memory in which an image signal is temporarily stored and then an image signal to be written to a pixel is read in accordance with a scanning order of the scanning lines. The electronic apparatus according to claim 1, comprising the display device. A projection display device comprising: an illumination device; a light modulation device that modulates light emitted from the illumination device; and a projection device that projects light modulated by the light modulation device,
A projection display device comprising the display device according to claim 1 as the light modulation device. The projection display device according to claim 9, further comprising a frame memory that stores an image signal and then reads an image signal to be written to a pixel in accordance with a scanning order of the scanning lines.

Images