JP5472428B2 - Display device driving method and circuit, electro-optical device, and electronic apparatus - Google Patents

Description

  The present invention includes a display device driving method and circuit for driving a display device by a field sequential (FS) method, an electro-optical device such as a liquid crystal device driven by the driving method, and the electro-optical device. It is related with the technical field of the electronic device comprised.

  In the field sequential (FS) system, in a display device, typically, one frame period for displaying a single color frame image has red (R), green (G), It is composed of three field periods for displaying each field image of three colors of blue (B). In each field period, after writing image data for each color to each pixel, the light source is turned on to supply the corresponding color light.

  For example, according to Patent Document 1, the display area is divided into a plurality of divided areas, and a plurality of light sources are arranged for each divided area. In each field period, after each scanning line in the segmented region is selected and image data has been written to the corresponding pixel, the light source is turned on. However, in this case, the brightness of the adjacent light sources is different, thereby causing luminance unevenness at the boundary between the divided areas, degrading the display quality of the color image, and complicating the operation control of each of the plurality of light sources. is there.

  On the other hand, Patent Document 2 discloses a technique for ensuring a longer lighting period of a light source in each field period without arranging a plurality of light sources. More specifically, each field period is divided into first and second subfield periods, and after writing image data for displaying a low-resolution image is performed in the first subfield period, While the light source is turned on in the subfield period, the lacking image data is complementarily written in the low resolution image in the first subfield period, and the high resolution image is displayed.

JP 2002-211702 A JP 2006-163358 A

  However, the technique disclosed in Patent Document 2 may cause the following problems. That is, in the second subfield period following the low-resolution line scan in the first subfield period, most of the other scans except for one scan line to which the corresponding image signal has already been supplied in the first subfield period. The line needs to be line scanned. For this reason, an irregular selection may occur in the second subfield period. In particular, the number of scanning line selections in the second subfield period is significantly greater than the number of scanning line group selections in the first subfield period. Therefore, the operations related to the selection of the scanning line are different between the first and second subfield periods, and the operation in the second subfield period is complicated and sophisticated, and the required scanning speed is particularly high. There arises a technical problem that can be realized.

  The present invention has been made in view of, for example, the above-described problems, and driving a display device capable of driving a display device by the FS method while simplifying selection of a scanning line or reducing a scanning speed. It is an object to provide a method and a circuit, an electro-optical device including the driving circuit, and an electronic apparatus including the electro-optical device.

  In order to solve the above problems, a first display device driving method of the present invention includes a plurality of scanning lines and data lines that intersect with each other, and a plurality of pixels that are formed corresponding to the intersection of the scanning lines and data lines. And a light source capable of supplying light corresponding to a plurality of unit colors to the pixel unit in a time-sharing manner, and a display device driving method for driving each unit color constituting a frame image An image signal for each scanning line corresponding to each of the first to nth (where n is a natural number greater than or equal to 2) subfield periods obtained by dividing each field period for each unit color is represented by each of the field images. The image signal supplying step for supplying to the data line, and the first subfield period includes the i th (m) (where m is a natural number of 2 or more) scanning lines included in a group of scanning lines. However, i is less than m In addition, in synchronization with the supply of the image signal corresponding to the scanning line, the scanning signal is collectively supplied to the scanning line for each group, so that the line scanning in the group unit is performed in the direction along the data line. In synchronization with the supply of the image signal corresponding to the j-th scanning line (where j is a natural number less than m different from i) included in the group during the first sub-field period and the second subfield period. Then, by supplying a scanning signal to the j-th scanning line, a second scanning is performed in which a predetermined number of line scans are performed with the j-th scanning line as a scanning target at the same scanning speed as the group-unit line scanning. A process.

  According to the first display device driving method of the present invention, for example, a display device which is a liquid crystal device is driven by the FS method as follows.

  That is, on the other hand, for example, an image signal indicating each of the field images for each RGB unit color for each scanning line corresponding to the first to n-th subfield period is, for example, a data line driving circuit, or a data signal or an image signal supply It is supplied to the data line by the device.

  On the other hand, first, in the first subfield period, the scanning signal is divided into groups in synchronization with the supply of the image signal corresponding to the i-th scanning line included in the group of m scanning lines. Collectively, the scanning lines are supplied. Thereby, typically, so-called low-resolution line scanning is performed in units of m groups adjacent to each other in a direction along the data line (for example, the Y direction or the vertical direction). At this time, it is only the i-th scanning line among the m scanning lines that the image signal for each scanning line to be finally displayed and the scanning line are properly matched. That is, the resolution at this time corresponds to 1 / m with respect to the resolution of the original field image in the direction along the data line. However, in an image that can be inspected by humans such as a landscape, a human figure, an animation, and a computer image, for example, a difference in luminance and color of an image to be displayed between a plurality of pixels arranged along a data line is generally small. Therefore, even if such a low-resolution subfield image is displayed by supplying light from the light source at this time or after the subsequent second scanning step, an image that can be visually understood appropriately. It becomes.

  Preferably, light is not supplied from the light source during the first scanning step, and such a low resolution image may not actually be displayed.

  Next, in the second scanning step, the scanning signal is supplied to the j-th scanning line in synchronization with the supply of the image signal corresponding to the j-th scanning line included in the group by the second scanning process. As a result, every predetermined number of line scans with the jth scan line as the scan target are executed at the same scanning speed as the group unit line scan. At this time, the image signal for each scanning line to be finally displayed and the scanning line are in regular agreement with respect to two of the i-th scanning line and the j-th scanning line among the m scanning lines.

  Thus, the resolution after the second scanning step is improved to correspond to 2 / m with respect to the resolution of the original field image in the direction along the data line. Therefore, by supplying light at this time, it is possible to display a subfield image that significantly exceeds the resolution immediately after the first scanning step.

  Note that such an image may not actually be displayed by not supplying light during the second scanning step. That is, a subfield image that is superior to the resolution immediately after the second scanning step may be displayed by supplying light after further increasing the resolution after the third subfield. However, if the light supply by the light source is delayed, the display image becomes dark. Therefore, it is only necessary to determine from which time point the light is supplied according to the device specifications and requests regarding the resolution and brightness.

  In addition, in the second scanning process in which the j-th scanning line is a scanning target, a predetermined number of line scans are executed at the same scanning speed as the group-unit line scanning in the first scanning process. For this reason, since the scanning signal may be supplied at a constant scanning speed, the apparatus configuration and the control operation related to the supply of the scanning signal may be simple or easy. For example, if an enable signal described later is used, line scanning at a constant scanning speed can be easily performed. At this time, unlike the background art described above, variable or high-speed line scanning is unnecessary after the second subfield period. In particular, in the second subfield period or later, unlike the first subfield period, it is only necessary to scan one scanning line per group, so that the apparatus configuration and control operation for that purpose are basically simple or easy. It ’s easy.

  On the other hand, as for the supply timing of the image signal, it is only necessary to sequentially supply the image signal for each scanning line for each subfield period, so that the apparatus configuration and control operation relating to the supply of the image signal are basically simple or easy. Just do it.

  As described above, the selection of the scanning line can be simplified, and the display device can be driven by the FS method while the scanning speed is relatively decreased or the increase in the scanning speed is suppressed.

  In one aspect of the driving method of the first display device of the present invention, after the third subfield period, the scanning lines including the i-th scanning line and the j-th scanning line are excluded from the scanning lines. A scanning signal is sequentially supplied to the other scanning lines in synchronization with the supply of the image signals corresponding to the other scanning lines, so that the other scanning lines are scanned at the same scanning speed. In the subsequent scanning step, the line scanning is performed until the corresponding image signal is supplied to all of the scanning lines in each field period. A scan is performed.

  According to this aspect, in the subsequent scanning step, after the third subfield period, the scanning signal excludes scanning lines that have been scanned for lines that have already been supplied with the corresponding image signal in the previous subfield period. Are sequentially supplied to the other scanning lines in synchronization with the supply of the image signals corresponding to the other scanning lines.

  Typically, in the third subfield period, the scanning signal is kth (however, excluding the ith and jth scanning lines for which the corresponding image signals have already been supplied in the first and second subfield periods. , K is a natural number different from i or j) and is supplied to the kth scanning line in synchronization with the supply of the image signal corresponding to the scanning line. Further, in the fourth subfield period, the scanning signals are excluded from the i-th, j-th and k-th scanning lines for which supply of corresponding image signals has already been performed in the first, second and third subfield periods. L (where L is a natural number different from i, j or k) is supplied to the Lth scanning line in synchronization with the supply of the image signal corresponding to the scanning line. Further, similar line scanning is performed on the remaining scanning lines in each group for which the corresponding image signal is not supplied.

  In the subsequent scanning step, such line scanning is repeatedly executed while changing the scanning target until the supply of the corresponding image signal to all the scanning lines is executed for each field period.

  Therefore, in the subsequent scanning process, the image signal for each scanning line to be finally displayed and the scanning line are more regularly matched with the later subfield period, and finally, See a match for all scan lines.

  As described above, the resolution obtained by the subsequent scanning process is remarkably improved in the direction along the data line. Therefore, by supplying light at an arbitrary time point in the subsequent scanning process, it is possible to display a subfield image that significantly exceeds the resolution immediately after the first scanning process. In other words, during the same field period, the resolution gradually improves visually as line scanning is performed for each subfield period in the subsequent scanning process. Therefore, by increasing the scanning speed, the presence of the subfield image immediately after the first scanning step (or in addition to the presence of the subfield image immediately after the second scanning step) gives an impression of low resolution visually. It is also possible to give almost no.

  In addition, in the subsequent scanning process that scans other scanning lines, a predetermined number of line scans are executed at the same scanning speed as the group-unit line scanning in the first scanning process. For this reason, since it is sufficient to supply the scanning signal at a constant scanning speed, the apparatus configuration and the control operation relating to the supply of the scanning signal are very simple or easy. In particular, in the third subfield period or later, unlike the first subfield period, it is sufficient to scan one scanning line per group as in the second subfield. However, it can be very simple or easy.

  In order to solve the above problems, a second display device driving method of the present invention includes a plurality of scanning lines and data lines that intersect with each other, and a plurality of pixels that are formed corresponding to the intersections of the scanning lines and data lines. And a light source capable of supplying light corresponding to a plurality of unit colors to the pixel unit in a time-sharing manner, and a display device driving method for driving each unit color constituting a frame image An image signal for each scanning line corresponding to each of the first to nth (where n is a natural number greater than or equal to 2) subfield periods obtained by dividing each field period for each unit color is represented by each of the field images. The image signal supplying step for supplying to the data line, and the first subfield period includes the i th (m) (where m is a natural number of 2 or more) scanning lines included in a group of scanning lines. However, i is less than m In addition, in synchronization with the supply of the image signal corresponding to the scanning line, the scanning signal is collectively supplied to the scanning line for each group, so that the line scanning in the group unit is performed in the direction along the data line. In synchronization with the supply of the image signal corresponding to the j-th scanning line (where j is a natural number less than m different from i) included in the group during the first sub-field period and the second subfield period. And removing the i-th scan line from the group and supplying a scan signal for each remaining group including the j-th scan line at the same scan speed as the group-unit line scan. And a second scanning step for performing line scanning in units of groups.

  According to the second display device driving method of the present invention, for example, a display device which is a liquid crystal device is driven by the FS method as follows.

  That is, on the other hand, for example, an image signal indicating each of the field images for each RGB unit color for each scanning line corresponding to the first to n-th subfield period is, for example, a data line driving circuit, or a data signal or an image signal supply It is supplied to the data line by the device.

  On the other hand, first, in the first subfield period, the scanning signal is divided into groups in synchronization with the supply of the image signal corresponding to the i-th scanning line included in the group of m scanning lines. Collectively, the scanning lines are supplied. Thereby, typically, so-called low-resolution line scanning is performed in units of m groups adjacent to each other in a direction along the data line (for example, the Y direction or the vertical direction). At this time, it is only the i-th scanning line among the m scanning lines that the image signal for each scanning line to be finally displayed and the scanning line are properly matched. That is, the resolution at this time corresponds to 1 / m with respect to the resolution of the original field image in the direction along the data line. However, in an image that can be inspected by humans such as a landscape, a human figure, an animation, and a computer image, for example, a difference in luminance and color of an image to be displayed between a plurality of pixels arranged along a data line is generally small. Therefore, even if such a low-resolution subfield image is displayed by supplying light from the light source at this time or after the subsequent second scanning step, an image that can be visually understood appropriately. It becomes.

  Preferably, light is not supplied from the light source during the first scanning step, and such a low resolution image may not actually be displayed.

  Next, in a second subfield period, the scanning signal excludes the i-th scanning line from the group in synchronization with the supply of the image signal corresponding to the j-th scanning line included in the group by the second scanning process. The remaining groups including the jth scan line are supplied together. Thus, the remaining group unit line scan is executed at the same scanning speed as the group unit line scan. Typically, of the m scanning lines, the line scanning is executed in a format in which every other line or one line is thinned with the m−1 scanning lines excluding the i-th scanning line as the remaining group. The At this time, the image signal for each scanning line to be finally displayed and the scanning line are in regular agreement with respect to two of the i-th scanning line and the j-th scanning line among the m scanning lines.

  Thus, the resolution after the second scanning step is improved to correspond to 2 / m with respect to the resolution of the original field image in the direction along the data line. Therefore, by supplying light at this time, it is possible to display a subfield image that significantly exceeds the resolution immediately after the first scanning step.

  Note that such an image may not actually be displayed by not supplying light during the second scanning step. That is, a subfield image that is superior to the resolution immediately after the second scanning step may be displayed by supplying light after further increasing the resolution after the third subfield. However, if the light supply by the light source is delayed, the display image becomes dark. Therefore, it is only necessary to determine from which time point the light is supplied according to the device specifications and requests regarding the resolution and brightness.

  In addition, in the second scanning step, the remaining group unit line scanning is executed at the same scanning speed as the group unit line scanning in the first scanning step. For this reason, since the scanning signal may be supplied at a constant scanning speed, the apparatus configuration and the control operation related to the supply of the scanning signal may be simple or easy. For example, if an enable signal described later is used, line scanning at a constant scanning speed can be easily performed. At this time, unlike the background art described above, variable or high-speed line scanning is unnecessary after the second subfield period.

  On the other hand, as for the supply timing of the image signal, it is only necessary to sequentially supply the image signal for each scanning line for each subfield period, so that the apparatus configuration and control operation relating to the supply of the image signal are basically simple or easy. Just do it.

  As described above, the selection of the scanning line can be simplified, and the display device can be driven by the FS method while the scanning speed is relatively decreased or the increase in the scanning speed is suppressed. In particular, as compared with the above-described driving method of the first display device of the present invention in which the image signal corresponding to the i-th scanning line remains until the last line scanning, the image signal supplied to the pixel for each scanning line is: Even if it is not an image signal corresponding to each scanning line, the resolution is raised earlier by the amount of sequential replacement with an image signal corresponding to a scanning line located closer to it.

  In one aspect of the driving method of the second display device of the present invention, after the third subfield period, the scanning lines including the i-th scanning line and the j-th scanning line are excluded from the scanning lines. Synchronously with the supply of the image signals corresponding to the other scanning lines, the jth scanning line is excluded from the remaining group, and the remaining scanning groups including the other scanning lines are further combined into scanning signals. A subsequent scanning step of sequentially executing the remaining group-unit line scanning at the same scanning speed by sequentially supplying the scanning lines; and in the subsequent scanning step, the scanning lines are all applied to the scanning lines every field period. On the other hand, the line scanning is executed until the supply of the corresponding image signal is executed.

  According to this aspect, in the subsequent scanning step, after the third subfield period, the scanning signal excludes scanning lines that have been scanned for lines that have already been supplied with the corresponding image signal in the previous subfield period. In synchronization with the supply of the image signals corresponding to the other scanning lines, the scanning lines that have already been scanned are excluded and the other scanning lines including the other scanning lines are sequentially supplied together.

  Typically, in the third subfield period, the scanning signal is kth (however, excluding the ith and jth scanning lines for which the corresponding image signals have already been supplied in the first and second subfield periods. , K is a natural number different from i or j), and is supplied to “the remaining group” including the k-th scanning line in synchronization with the supply of the image signal corresponding to the scanning line. Here, “the remaining group” is m−2 scanning lines excluding the i-th and j-th scanning lines among the m scanning lines. Further, in the fourth subfield period, the scanning signals are excluded from the i-th, j-th and k-th scanning lines for which supply of corresponding image signals has already been performed in the first, second and third subfield periods. L (where L is a natural number different from i, j, or k) is supplied to “the remaining group” including the Lth scanning line in synchronization with the supply of the image signal corresponding to the scanning line. Here, “the remaining group” is m−3 scanning lines excluding the i-th, j-th and k-th scanning lines among the m scanning lines. Further, a similar line scan is performed on a “more residual group” consisting of the remaining scanning lines in each group to which no corresponding image signal is supplied.

  In the subsequent scanning step, the number of scanning lines constituting one “remaining group” is one until the supply of the corresponding image signal to all the scanning lines is executed for each field period. Such line scanning is repeatedly executed while the scanning target is changed until the line scanning is completed.

  Therefore, in the subsequent scanning process, the image signal for each scanning line to be finally displayed and the scanning line are more regularly matched with the later subfield period, and finally, See a match for all scan lines.

  As described above, the resolution obtained by the subsequent scanning process is remarkably improved in the direction along the data line. Therefore, by supplying light at an arbitrary time point in the subsequent scanning process, it is possible to display a subfield image that significantly exceeds the resolution immediately after the first scanning process. In other words, during the same field period, the resolution gradually improves visually as line scanning is performed for each subfield period in the subsequent scanning process. Therefore, by increasing the scanning speed, the presence of the subfield image immediately after the first scanning step (or in addition to the presence of the subfield image immediately after the second scanning step) gives an impression of low resolution visually. It is also possible to give almost no.

  In addition, in the subsequent scanning process in which “the remaining group” including other scanning lines is the scanning target, the line scanning is performed every predetermined number at the same scanning speed as the group-unit line scanning in the first scanning process. The For this reason, since it is sufficient to supply the scanning signal at a constant scanning speed, the apparatus configuration and the control operation relating to the supply of the scanning signal are very simple or easy.

  In another aspect of the driving method of the first or second display device of the present invention, the light is not supplied by the light source during the first subfield period, and the light source is used after the second subfield period. The light is supplied.

  According to this aspect, in the first subfield period in which the resolution in the subfield image is the lowest, image display is not performed by not supplying light from the light source. Subsequently, after the second subfield period in which the resolution of the subfield image is significantly increased, light is supplied from the light source to perform image display. Therefore, it is possible to achieve both the resolution and brightness appropriately in practice.

  In order to solve the above problems, a driving circuit of a first display device of the present invention includes a plurality of scanning lines and data lines that intersect with each other, and a plurality of pixels that are formed corresponding to the intersection of the scanning lines and data lines. And a display device driving circuit for driving a display device comprising a light source capable of supplying light corresponding to a plurality of unit colors to the pixel unit in a time-sharing manner, and for each unit color constituting a frame image An image signal for each scanning line corresponding to each of the first to nth (where n is a natural number greater than or equal to 2) subfield periods obtained by dividing each field period for each unit color is represented by each of the field images. The image signal supply means for supplying to the data line, and the i-th group included in a group of m (m is a natural number of 2 or more) scanning lines among the scanning lines in the first subfield period. However, i is less than m In addition, in synchronization with the supply of the image signal corresponding to the scanning line, the scanning signal is collectively supplied to the scanning line for each group, so that the line scanning in the group unit is performed in the direction along the data line. In the second subfield period, in synchronization with the supply of the image signal corresponding to the jth scan line (where j is a natural number less than m different from i) included in the group, the jth Scanning means for supplying a scanning signal to the scanning lines, and performing a predetermined number of line scans on the j-th scanning line at the same scanning speed as the group-unit line scanning.

  The driving circuit of the first display device of the present invention can simplify the selection of the scanning line and scan the scanning speed relatively or in the same manner as the driving method of the first display device of the present invention described above. The display device can be driven by the FS method while suppressing the speed increase.

  Note that the drive circuit for the first display device of the present invention can also adopt various aspects similar to the various aspects of the drive method for the first display device of the present invention described above.

  In order to solve the above problems, a driving circuit of a second display device of the present invention includes a plurality of scanning lines and data lines that intersect with each other, and a plurality of pixels that are formed corresponding to the intersections of the scanning lines and data lines. And a display device driving circuit for driving a display device comprising a light source capable of supplying light corresponding to a plurality of unit colors to the pixel unit in a time-sharing manner, and for each unit color constituting a frame image An image signal for each scanning line corresponding to each of the first to nth (where n is a natural number greater than or equal to 2) subfield periods obtained by dividing each field period for each unit color is represented by each of the field images. The image signal supply means for supplying to the data line, and the i-th group included in a group of m (m is a natural number of 2 or more) scanning lines among the scanning lines in the first subfield period. However, i is less than m In addition, in synchronization with the supply of the image signal corresponding to the scanning line, the scanning signal is collectively supplied to the scanning line for each group, so that the line scanning in the group unit is performed in the direction along the data line. In the second subfield period, in synchronization with the supply of the image signal corresponding to the j-th scanning line (where j is a natural number less than m different from i) included in the group, from the group The remaining group unit lines are supplied at the same scanning speed as the group unit line scanning by supplying a scan signal collectively for each remaining group excluding the i th scan line and including the j th scan line. Scanning means for executing scanning.

  The driving circuit of the second display device of the present invention can simplify the selection of the scanning line and scan the scanning speed relatively or similarly to the above-described driving method of the second display device of the present invention. The display device can be driven by the FS method while suppressing the speed increase.

  Note that the driving circuit for the second display device of the present invention can also adopt various aspects similar to the various aspects of the driving method for the second display device of the present invention described above.

  In order to solve the above problems, an electro-optical device according to the present invention includes the above-described drive circuit of the first or second display device according to the present invention, the scanning line and the data line, the pixel portion, and the light source. Prepare.

  According to the electro-optical device of the present invention, similarly to the driving circuit of the first or second display device of the present invention described above, the selection of the scanning line can be simplified, and the scanning speed is relatively reduced or the scanning is performed. The display device can be driven by the FS method while suppressing the speed increase.

  In order to solve the above-described problems, an electronic apparatus according to the present invention includes the above-described electro-optical device according to the present invention.

  According to the electronic apparatus of the present invention, since the electro-optical device of the present invention described above is included, a projection display device, a mobile phone, an electronic notebook, a word processor, and a viewfinder that can perform high-quality display. Various electronic devices such as a video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized.

  Such an operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

It is a block diagram which shows the whole structure of a liquid crystal device. It is a block diagram which shows the electrical structure of a liquid crystal panel. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms an image display area of the liquid crystal device according to the present embodiment. 2 is a diagram illustrating an example of a configuration of a scanning line driving circuit 104. FIG. It is a timing chart for demonstrating the vertical scanning of the scanning line in 1 frame. 6 is a timing chart for explaining the operation of the scanning line driving circuit. It is a schematic diagram for demonstrating selection of the scanning line in 1 field. FIG. 3 is a schematic enlarged plan view of an image display area showing a state in which an image signal is written to a pixel starting from a low-resolution line scan in one field in the first embodiment. FIG. 5 is a schematic enlarged plan view of an image display area showing a state in which an image signal is written to a pixel in one field without low-resolution line scanning. It is a timing chart which shows a time-dependent change of various signals for driving a pixel part in one field about a comparative example. It is a schematic diagram for demonstrating selection of the scanning line in 1 field about a comparative example. It is a timing chart for explaining the vertical scanning of the scanning line in 1 frame about a 2nd embodiment. 12 is a timing chart for explaining the operation of the scanning line driving circuit in the second embodiment. It is a schematic diagram for demonstrating selection of the scanning line in 1 field about 2nd Embodiment. FIG. 9 is a schematic enlarged plan view of an image display area showing a state in which an image signal is written to pixels starting from a low-resolution line scan in one field in the second embodiment. It is a top view which shows the structure of a liquid crystal device. It is the HH 'sectional view taken on the line of FIG. It is a top view which shows the structure of the projector which is an example of the electronic device to which the electro-optical apparatus is applied.

  Hereinafter, embodiments of a driving method and circuit according to the present invention, an electro-optical device driven by the driving method according to the present invention, and an electronic apparatus will be described with reference to the drawings. In the following embodiments, a TFT active matrix driving type liquid crystal device with a built-in driving circuit will be described as an example of an electro-optical device which is an example of a display device.

<First Embodiment>
First, the overall configuration of the liquid crystal device will be described with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of the liquid crystal device, and FIG. 2 is a block diagram showing the electrical configuration of the liquid crystal panel.

  As shown in FIG. 1, the liquid crystal device includes a liquid crystal panel 100, a light source 200, a controller 500, a frame memory 600, and a power supply circuit 700 as main parts.

  The controller 500 includes a logical operation circuit such as a CPU (Central Processing Unit). Specifically, the controller 500 includes an image signal supply circuit 502, a timing control circuit 504, and a light source control circuit 506.

  The controller 500 is supplied with a horizontal synchronization signal Hs and a vertical synchronization signal Vs, a dot clock DCLK, and display data R-DATA, G-DATA, and B-DATA. These various supply signals are generated by, for example, an external device (not shown) such as a video deck outside the liquid crystal device, or a circuit (not shown) in the liquid crystal device based on a source signal from such an external device. And supplied to the controller 500.

  The image signal supply circuit 502 is supplied with a horizontal synchronization signal Hs, a vertical synchronization signal Vs, a dot clock DCLK, and display data R-DATA, G-DATA, and B-DATA.

  Here, in the present embodiment, as an example, display data R-DATA, G-DATA, and B-DATA are R, G, B as field images of a plurality of unit colors constituting one color frame image. It is assumed that the image data is for displaying field images of the three colors. That is, in this case, display data R-DATA for displaying an R image (that is, an R field image), display data G-DATA for displaying a G image (that is, a G field image), and a B image (that is, a B field image). ) Is displayed to the controller 500.

  For example, the image signal supply circuit 502 performs R, R, and R for each frame (i.e., frame period) for displaying one color frame image based on display data R-DATA, G-DATA, and B-DATA. Three types of field data (that is, image data indicating a field image) for displaying each image of G and B sequentially for each field (that is, a field period) are generated. The image signal supply circuit 502 temporarily accumulates the generated three types of field data in the frame memory 600, and among the three types of field data in each subfield constituting one field, the corresponding color (R, G, The field data for displaying the image of one color of B) is read in the order for line scanning.

  The image signal supply circuit 502 performs predetermined processing on the read one type of field data, and synchronizes with a cycle in which the scanning signal is supplied to one scanning line, for each pixel row along the scanning line. That is, the image signal Vd for each scanning line is generated. As the predetermined processing here, for example, the image signal supply circuit 502 serial-parallel converts one type of field data to generate N-phase, for example, six-phase (N = 6) image signals Vd1 to Vd6. Also good. Further, in the image signal supply circuit 502, the potential of the generated image signal Vd is set to a predetermined period (for example, a period in which a scanning signal is supplied to one scanning line, one subfield period, or one field period, The image signal Vd may be output after being inverted to a positive polarity (+) and a negative polarity (−) with respect to a predetermined reference potential in a frame period).

  The timing control circuit 504 is configured to output various timing signals. Specifically, the timing control circuit 504 generates a Y clock signal CLY (and an inverted Y clock signal CLYinv that is an inverted signal thereof) and an X clock signal CLX based on the horizontal synchronization signal Hs, the vertical synchronization signal Vs, and the dot clock DCLK. (And an inverted X clock signal XCLinv that is an inverted signal thereof), a Y start pulse DY and an X start pulse DX are generated. Further, the timing control circuit 504 generates four types of enable signals ENB1 to ENB4 that determine the output timing of scanning signals, which will be described later.

  These various timing signals are output from the timing control circuit 504, and are used not only in each part in the controller 500 but also in each part of an internal drive circuit mounted on the liquid crystal panel 100 described later.

  In addition, the light source 200 is not shown in detail for its internal structure, but as a plurality of unit colors, each of the three colors R, G, B is provided for each of R, G, B. The corresponding light is configured to be supplied to each pixel portion of the liquid crystal panel 100 in a time-sharing manner. Specifically, the light source 200 includes, for example, a plurality of light emitting diodes (LEDs), and the plurality of LEDs correspond to R (red), G (green), and B (blue), respectively. Light is emitted in a time division manner. That is, the plurality of LEDs periodically emit light so that the light emission periods do not overlap each other. The emitted light is combined by, for example, a combining prism, and is irradiated onto the liquid crystal panel 100. A plurality of lights having different color tones may be emitted from one light source 200 in a time division manner.

  The light source control circuit 506 controls the operation of the light source 200 in each field in one frame.

  The power supply circuit 700 supplies a common power supply having a predetermined common potential LCC to the liquid crystal panel 100. In the liquid crystal panel 100, for example, a counter electrode is formed so as to be opposed to a pixel electrode provided for each pixel unit (details will be described later), but a common power supply LCC is supplied from the power supply circuit 700 to the counter electrode. . Note that the power supply circuit 700 may be provided in the controller 500.

  Next, the electrical configuration of the liquid crystal panel 100 will be described with reference to FIG.

  In FIG. 2, a plurality of scanning lines 11a and a plurality of data lines 6a intersect with each other in the image display area 10a of the liquid crystal panel 100, and pixel portions 9 corresponding to the pixels correspond to these intersections in a matrix form. Is provided. The pixel portion 9 is electrically connected to each of the scanning line 11a and the data line 6a.

  In FIG. 2, a data line driving circuit 101, a sampling circuit 7, and a scanning line driving circuit 104 are provided in a peripheral area located around the image display area 10a.

  The scanning line driving circuit 104 constitutes an example of the “scanning unit” according to the present invention, and the timing control circuit 504 receives the Y clock signal CLY (and the inverted Y clock signal CLYinv (not shown)) and the Y start pulse DY. Supplied. When the Y start pulse DY is input, the scanning line driving circuit 104 sequentially generates a scanning signal at a timing based on the Y clock signal CLY and the inverted Y clock signal CLYinv and outputs the scanning signal to the scanning line 11a.

  More specifically, as will be described later, by supplying a Y clock signal CLY (inverted Y clock signal CLYinv) and a Y start pulse DY, basic line-sequential horizontal scanning is possible. Further, the scanning line driving circuit 104 outputs the scanning signals in the order as described later at the timing based on the enable signals ENB1 to ENB4 supplied from the timing control circuit 504.

  The data line driving circuit 101 is supplied with an X clock signal CLX (and an inverted X clock signal CLXinv (not shown)) and an X start pulse DX from the timing control circuit 504. When the X start pulse DX is input, the data line driving circuit 101 generates sampling signals S1,..., Sn at the timing based on the X clock signal CLX (and the inverted X clock signal CLXinv) and sequentially outputs them. To do.

  The sampling circuit 7 includes a switching element (that is, a sampling switch) 71 provided for each data line 6a in order to select the data line 6a to which the image signal is supplied from the image signal line 6. Timing control is performed by sampling signals S1,..., Sn from the line drive circuit 101.

  The image signal Vd is supplied to the sampling circuit 7 via the six image signal lines 6 as image signals Vd1 to Vd6 which are serial-parallel converted into six phases by the image signal supply circuit 502, that is, phase-expanded. . Each of the six image signal lines 6 is routed around the data line driving circuit 101 from the input terminal (external circuit connection terminal described later) of the image signal Vd, and the arrangement direction of the data lines 6a (ie, the data line 6a). Wiring along (X direction).

  In the sampling circuit 7, N sampling switches 71 in this embodiment are grouped into one group, and sampling signals Si (i = 1, 2,..., N) are respectively supplied to the sampling switches 71 belonging to the group. Is entered. The sampling switch 71 belonging to the first group is composed of N data lines 6a in this embodiment, six data lines 6a, and samples the image signal Vd from the data lines 6a belonging to the first group according to the sampling signal Si. And supply. That is, the data line 6a belonging to the first group and the image signal line 6 are electrically connected via the sampling switch 71 belonging to the first group. Therefore, in this embodiment, since the plurality of data lines 6a wired to the image display area 10a are driven for each data line 6a belonging to one group, the drive frequency can be suppressed.

  Note that the configuration is not limited to the configuration in which the image signal is supplied to the group of data lines 6a as described above, and the image signal may be sequentially supplied to each data line 6a.

  Here, in this embodiment, an example of the “image signal supply unit” according to the present invention includes the image signal supply circuit 502 in the controller 500, the data line driving circuit 101 and the sampling circuit 7 mounted in the liquid crystal panel 100. Consists of including.

  In FIG. 2, a common potential LCC supplied as a common power supply from the power supply circuit 700 is supplied to an input terminal (upper and lower conduction terminal described later) 106 that is electrically connected to the counter electrode. The common potential LCC is a reference potential of the counter electrode for appropriately holding a potential difference with the pixel electrode of each pixel unit 9 to form a liquid crystal holding capacitor.

  Here, an electrical configuration of the pixel portion 9 shown in FIG. 2 will be described with reference to FIG. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix forming the image display area of the liquid crystal device according to this embodiment.

  In FIG. 2, a pixel electrode 9a and a TFT 30 are formed in each of the plurality of pixel portions 9 formed in a matrix form constituting the image display region 10a, as shown in FIG. The TFT 30 is electrically connected to the pixel electrode 9a, and performs switching control of the pixel electrode 9a during operation of the liquid crystal device. The data line 6 a is electrically connected to the source of the TFT 30, and the scanning line 11 a is electrically connected to the gate of the TFT 30. The pixel electrode 9 a is electrically connected to the drain of the TFT 30.

  When the scanning signal from the scanning line driving circuit 104 is applied in a pulse manner to the scanning line 11a at a predetermined timing, the TFT 30 as a switching element is supplied from the data line 6a by closing the switch for a certain period. The image signal Vd is written to the pixel electrode 9a at a predetermined timing. The applied voltage corresponding to the image signal Vd of a predetermined level written in the liquid crystal as an example of the electro-optic material via the pixel electrode 9a is held for a certain period with the counter electrode.

  The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The transmittance for light is increased, and light having a contrast corresponding to an image signal is emitted from the liquid crystal device as a whole.

  In order to prevent the image signal Vd held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. The storage capacitor 70 is a capacitive element that functions as a storage capacitor that temporarily holds the potential of each pixel electrode 9a in response to the supply of the image signal Vd. One electrode of the storage capacitor 70 is connected to the drain of the TFT 30 in parallel with the pixel electrode 9a, and the other electrode is connected to the capacitor line 300 with a fixed potential so as to have a constant potential. According to the storage capacitor 70, the potential holding characteristic in the pixel electrode 9a is improved, and display characteristics such as contrast improvement and flicker reduction can be improved.

  Next, the operation of the liquid crystal device will be described with reference to FIGS. 4 to 9 in addition to FIGS.

  First, a detailed configuration of the scanning line driving circuit 104 shown in FIG. 2 will be described with reference to FIG. FIG. 4 shows an example of the configuration of the scanning line driving circuit 104. In FIG. 2, the two scanning line driving circuits 104 facing each other across the image display region 10a preferably have the same configuration. Hereinafter, focusing on one of the two scanning line driving circuits 104, the configuration will be described in detail.

  4, the main part of the scanning line driving circuit 104 is provided corresponding to each scanning line 11a and a shift register 141 to which a Y clock signal CLY (and an inverted Y clock signal CLYinv) and a Y start pulse DY are input. AND circuit 142 to be included.

  In the present embodiment, the output of the shift register 141 is made for each scanning line group including four scanning lines 11a as a group, and each of the scanning lines 11a in each scanning line group has four types of enable signals ENB1 to ENB4. Are selected by the corresponding AND circuit 142, and the scanning signals G1,..., Gm are supplied. For example, if the enable signals ENB1 to ENB4 are supplied simultaneously, the scanning signals G1 to G4 are simultaneously supplied to the scanning line group corresponding to the output signal SR1 of the shift register 141. Alternatively, if the enable signals ENB1 to ENB4 are sequentially supplied, the scan signals G1 to G4 are sequentially supplied to the scan line group in response to the output signal SR1 of the shift register 141.

  Next, the operation of the liquid crystal device when displaying one color frame image by the FS method will be described in more detail. FIG. 5 is a timing chart for explaining the vertical scanning of the scanning lines in one frame (that is, scanning of one screen). FIG. 6 is a timing chart for explaining the operation of the scanning line driving circuit, and FIG. 7 is a schematic diagram for explaining the selection of the scanning line in one field. FIG. 8 is a schematic enlarged plan view of an image display area showing how an image signal is written to each pixel in the first embodiment.

  In the following, in order to simplify the explanation and make it easier to understand the features of the present invention, as shown in FIG. 7, the total number of scanning lines 11a is set to m = 8, and the output signals SR1 to SR2 of the cyst register 141 are set. In the following description, the scanning signals G1 to G8 are supplied. Actually, as already shown in FIG. 4, more scanning signals G1 to Gm are supplied in accordance with the output signals SR1 to SR1 / m of the shift register 141.

  As shown in FIG. 5, one frame for displaying one color frame image includes an R field, a G field, and an R field for displaying each of the three colors R, G, and B over time. And B fields. That is, in the present embodiment, as a typical example, in order to display a single color frame image, field images of three colors of R, G, and B as a plurality of unit colors are sequentially displayed in each field. Is displayed.

  Here, the operation of the liquid crystal device for each of the R field, the G field, and the B field in FIG. 5 will be described with reference to FIGS.

  As shown in FIG. 6, one field is divided into first to fourth (n = 4) subfields SF1 to SF4 which are equally spaced on the time axis.

  In FIG. 6, in each of the first to fourth subfields SF <b> 1 to SF <b> 4, in the scanning line driving circuit 104, output signals SR <b> 1 and SR <b> 2 are output for each horizontal scanning period sequentially from the shift register 141. Here, since the total number of scanning lines 11a is assumed to be m = 8, only in this case, the output signals SR1 and SR2 are output alternately every horizontal scanning period.

  In FIG. 6, among the first to fourth subfields SF1 to SF4, in the first subfield SF1, the four types of enable signals ENB1 to ENB4 rise from the low level to the high level all at once in every horizontal scanning period.

  Here, in FIG. 5 to FIG. 7, symbol 1 to symbol 8 in the figure are scanning signals Gj in one field (where j = 1, 2, 3,..., M, where m = 8). ) And the selection order of the scanning lines 11a corresponding thereto. That is, in one field, the scanning signal Gj means that the symbol mark 1 is output first, the symbol mark 2 means that it is output second, and hereinafter the symbol mark 1 is output. 3 to the symbol 8 means the same output order. This is the same for each drawing described later.

  In FIG. 6, in the first subfield SF1, the scanning signals G1 to G4 are simultaneously output based on the output signal SR1 and the four types of enable signals ENB1 to ENB4 in the first horizontal scanning period, and then the next In one horizontal scanning period, the scanning signals G5 to G8 are simultaneously output based on the output signal SR2 and the four types of enable signals ENB1 to ENB4. Thus, in the first subfield, line scanning is executed in the vertical direction in units of scanning line groups to which the four scanning lines 11a belong.

  As shown in FIG. 7A, in the first subfield SF1, first, an image signal corresponding to the scanning line to which the scanning signal G1 is supplied is supplied from the image signal supply circuit 502 shown in FIG. 1 to the data line 6a. The Then, the same image signal corresponding to the scanning signal G1 is written in four pixel rows (upper four rows) corresponding to the scanning line group including the four scanning lines 11a.

  That is, as shown in the first subfield SF1 of FIG. 8, in the image display area 10a, low-resolution writing is performed on the four pixel rows corresponding to the scanning line group SG including the four scanning lines surrounded by the thick lines. Is done. That is, among these four pixel rows, only the pixel row corresponding to the top scanning line is written with an image signal to be originally supplied as indicated by the symbol “T” given to each pixel. It is. For the three pixel rows corresponding to the other three scanning lines, as indicated by the symbol “〃” given to each pixel, an image signal that should not be supplied (but the scanning Since the lines are close, a somewhat similar image signal) is provisionally written.

  Subsequently, as shown in FIG. 7A, in the first subfield SF1, an image signal corresponding to the scanning line to which the scanning signal G5 is supplied is further sent from the image signal supply circuit 502 shown in FIG. 1 to the data line 6a. To be supplied. Then, the same image signal corresponding to the scanning signal G5 is written in four pixel rows (lower four rows) corresponding to the scanning line group including the four scanning lines 11a.

  That is, as shown in the first subfield SF1 of FIG. 8, in the image display area 10a, low-resolution writing is performed on the four pixel rows corresponding to the scanning line group SG including the four scanning lines surrounded by the thick lines. Is done. That is, among these four pixel rows, only the pixel row corresponding to the top scanning line is written with an image signal to be originally supplied. For the other three pixel rows corresponding to the other three scanning lines, image signals that should not be supplied are provisionally written.

  In the first subfield SF1, as described above, the same image signal Vd is supplied for each of the four pixel rows corresponding to the scanning line group, so that R, G, B of the image display region 10a is supplied. It is possible to display a low-resolution subfield image of one corresponding color. The resolution at this point is defined by a vertically long rectangular area composed of four pixels surrounded by a thick line in FIG.

  Preferably, as shown in FIG. 5, the light source control circuit 506 shown in FIG. 1 turns off the light source 200 until the writing period of the image signal Vd in the first subfield SF1 starts and ends. . Therefore, no image is displayed during the writing period in the first subfield SF1.

  Next, in each of the second to fourth subfields SF2 to SF4 following the first subfield SF1, as shown in FIGS. 5 and 6, three types of enable signals among the four types of enable signals ENB1 to ENB4 are used. Any one of the signals ENB2 to ENB4 rises from a low level to a high level every horizontal scanning period.

  In the second subfield SF2, as shown in FIGS. 5 and 6, the scanning signals G2 and G6 whose supply order is the third and fourth are sequentially output for each horizontal scanning period.

  As shown in FIG. 7B, in the second subfield SF2, first, an image signal corresponding to the scanning line to which the scanning signal G2 is supplied is supplied from the image signal supply circuit 502 shown in FIG. 1 to the data line 6a. The Then, for the scanning line group composed of the upper four scanning lines 11a, the image signal corresponding to the scanning signal G2 is written to the second pixel row from the top.

  That is, as shown in the second subfield SF2 of FIG. 8, in the image display region 10a, two rows from the top surrounded by a thick line among the four pixel rows corresponding to the scanning line group SG composed of four scanning lines. The image signal to be originally supplied is written to the eye as indicated by the symbol “T” given to each pixel. On the other hand, the image signal that should be originally supplied in the first subfield SF1 is already written in the uppermost row. For the other two lower pixel rows corresponding to the other two scanning lines, as indicated by the symbol “〃” given to each pixel, an image signal that should not be originally supplied is provisional. Written state continues.

  Subsequently, as shown in FIG. 7B, in the second subfield SF2, an image signal corresponding to the scanning line to which the scanning signal G6 is supplied is further sent from the image signal supply circuit 502 shown in FIG. 1 to the data line 6a. To be supplied. Then, for the scanning line group including the lower four scanning lines 11a, the image signal corresponding to the scanning signal G6 is written to the second pixel row from the top.

  That is, as shown in the second subfield SF2 of FIG. 8, in the image display region 10a, two rows from the top surrounded by a thick line among the four pixel rows corresponding to the scanning line group SG composed of four scanning lines. An image signal to be originally supplied is written to the eye. On the other hand, the image signal that should be originally supplied in the first subfield SF1 is already written in the uppermost row. A state in which image signals that should not be supplied are temporarily written in the lower two pixel rows corresponding to the other two scanning lines continues.

  Similarly, as shown in FIGS. 5, 6, and 7 (c), in the third subfield SF <b> 3, the scanning signals G <b> 3 and G <b> 7 whose supply order is the fifth and sixth are sequentially one horizontal. Output every scanning period. As a result, as in the third subfield SF3 in FIG. 8, the image signal to be originally supplied is written into the pixel row surrounded by the thick lines corresponding to the scanning signals G3 and G7.

  Similarly, as shown in FIGS. 5, 6, and 7 (d), in the fourth subfield SF <b> 4, the scanning signals G <b> 4 and G <b> 8 whose supply order is the seventh and eighth are sequentially one horizontal. Output every scanning period. As a result, as in the fourth subfield SF4 in FIG. 8, the image signal to be originally supplied is written in the pixel row surrounded by the thick lines corresponding to the scanning signals G4 and G8.

  Since the image signal Vd is written in each of the second to fourth subfields SF2 to SF4 as described above, the potential of the pixel electrode 9a of each pixel portion is temporarily set in the first subfield SF1. The potential based on the image signal Vd to be originally written is changed from the potential based on the written image signal Vd.

  Preferably, as shown in FIG. 5, in each field, after the writing period of the image signal Vd in the first subfield SF1 is completed, or the writing period of the image signal Vd in the second subfield SF2 is set. Before the start, the light source control circuit 506 shown in FIG. Therefore, in the second subfield SF2 and later, the display image is displayed while the resolution is improved from the low resolution to the original resolution. Note that the lighting period of the light source 200 ends at the end of the blanking period T0 after the fourth subfield.

  As described above, in the image display area 10a, after the writing of the image signal Vd in the fourth subfield SF4 is completed, a field image of one color corresponding to R, G, B is converted into the original resolution in each pixel unit. That is, it becomes possible to display with high resolution. Prior to the display at the high resolution, after the writing of the image signal Vd in the first subfield SF1 is completed, a field image of one color corresponding to R, G, B is reduced in each pixel unit. It is possible to display at a resolution.

  Here, with reference to FIG. 8 and FIG. 9, the effect of executing the low-resolution line scan in the first subfield SF1 will be examined. FIG. 9 is an enlarged plan view having the same concept as in FIG. 8 and showing a state in which the image signal is written to the pixel when the low-resolution line scanning is not performed.

  As shown in FIG. 9, in the first subfield SF1, without performing low-resolution line scanning, for a pixel row surrounded by a thick line, which simply corresponds to the top row of the scanning line group, Assume that the original image signal is written. In this case, the image signal writing operation itself in the second subfield SF2 to the fourth subfield SF4 is the same as can be seen from FIGS. However, in FIG. 9, the provisional image signal is not supplied until the line scanning order is reached. For this reason, pixel rows to which no writing has been performed remain until the fourth subfield SF4 ends. For pixels that have not been written, an image signal from the previous field remains, or an image signal that has been reset to black or the like remains in the blanking period. Therefore, the resolution is inferior and the brightness is also inferior.

  On the other hand, according to the present embodiment, as shown in FIGS. 5 to 8, since the low-resolution line scanning is performed in the first subfield, the resolution at an arbitrary time is increased or decreased. Become. Thus, according to this embodiment, it is possible to improve brightness and resolution in a balanced manner.

  By driving the liquid crystal device as described above with reference to FIGS. 5 to 9, in the R field in FIG. 5, an R image balanced in brightness and resolution is displayed in the image display area 10a. . Similarly, in the G field in FIG. 5, a G image balanced in brightness and resolution is displayed in the image display area 10a. In the B field in FIG. 5, a B image balanced in brightness and resolution is displayed. It is displayed in the display area 10a.

  In particular, when an R image, a G image, and a B image that are sequentially displayed in the image display area 10a are visually observed, the R image, the G image, and the B image are limited due to the limit of temporal resolution in vision (human eyes). The image is perceived as a mixed color image. Here, for each of the R image, the G image, and the B image, a pixel unit to which a voltage is applied based on provisional image signals in a plurality of pixel units from the start of lighting of the light source 200 to the end of each field. Therefore, the rate at which the low-resolution part is visually recognized becomes low. Therefore, the decrease in resolution in the images displayed in the first to third subfields is not so noticeable or hardly noticeable in the actual visual perception recognized as a single color image composed of three color images. it can.

  In addition, according to the present embodiment, the light of the color corresponding to each field from the common light source 200 is provided to the plurality of pixel units without disposing a plurality of light sources as disclosed in Patent Document 1. It is possible to supply and ensure a longer lighting period of the light source 200.

  Note that the R, G, and B fields can be arranged in a predetermined order on the time axis for each frame.

  Next, a comparative example for the present embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a timing chart showing changes with time of various signals for driving the pixel portion in one field in the comparative example, and FIG. 11 is for explaining selection of scanning lines in one field in the comparative example. FIG. In the following, only differences from the present embodiment will be described for the comparative example.

  In the comparative example, as shown in FIG. 10, one field is divided into first and second subfields SF1 and SF2 having different lengths on the time axis.

  In the first subfield SF1, in the scanning line driving circuit 104 (see FIG. 4), the first subfield SF1 is based on the output signal SR1 of the shift register 141 and the four types of enable signals ENB1 to ENB4 in the first horizontal scanning period. Scanning signals G1 to G4 are output all at once, and then, in the next one horizontal scanning period, the second scanning signals G5 to G8 are simultaneously output based on the output signal SR2 and the four types of enable signals ENB1 to ENB4. Is output.

  On the other hand, in the image signal supply circuit 502 shown in FIG. 1, in the first subfield SF1, the first image signal Vd1k is generated every horizontal scanning period.

  Accordingly, as shown in FIG. 11A, in the first subfield SF1, based on the first scanning signals G1 to G4, the pixel portions belonging to the four pixel rows corresponding to the first scanning line group. The first image signal Vd1k is written to the pixel portion, and the first image signal Vd1k is written to the pixel portions belonging to the four pixel rows corresponding to the second scanning line group based on the second scanning signals G5 to G8. It is.

  Subsequently, in the second subfield SF2, the third to fifth scanning signals G2 to G4 are sequentially output every horizontal scanning period, and the sixth to eighth scanning signals G6 to G8 are respectively output. Sequentially, it is output every horizontal scanning period.

  Accordingly, in the second subfield SF2, in each scanning line group, the scanning signals G2 to G4 or the scanning signals G6 to G8 are supplied and the second image signal Vd2k is supplied through the first scanning line 11a. No scan line 11a is selected sequentially.

  On the other hand, the image signal supply circuit 502 shown in FIG. 1 generates the second image signal Vd2k for each horizontal scanning period in the second subfield SF2.

  Therefore, as shown in FIG. 11 (b), the first scanning line is set in each scanning line group in accordance with the third to fifth scanning signals G2 to G4 and the sixth to eighth scanning signals G6 to G8. 11a, the second to fourth scanning lines 11a are selected, respectively, and the second image signal Vd2k is written in the pixel portion of each row corresponding to these scanning lines 11a.

  Therefore, in the comparative example, in the second subfield SF2, the selection of the scanning lines 11a is not regularly performed every predetermined number, and the scanning lines of the second subfield SF2 are compared with the first subfield SF1. The number of selections also increases. Therefore, the operation related to the selection of the scanning line 11a becomes complicated in the first and second subfields SF1 and SF2, and the scanning speed for selecting the scanning line 11a in the second subfield SF2 is remarkably increased. A point is created.

  On the other hand, as described above, according to the present embodiment, the rule of the scanning line 11a is the same in the subfields of the second to fourth subfields SF2 to SF4 having the same length as the first subfield and equally spaced. Selection can be made, and in each of the second to fourth subfields SF2 to SF4, it is possible to prevent the timing for selecting the scanning line 11a from becoming complicated, in other words, to simplify the selection. Is possible. Further, by selecting the scanning line 11a in each of the second to fourth subfields SF2 to SF4, it is possible to prevent the scanning speed of the scanning line 11a from being significantly increased in each subfield.

  As described above in detail, according to the present embodiment, a brighter and higher-definition image can be more easily displayed by the FS method in the liquid crystal device.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the selection of scanning lines after the second subfield in one field is different from that in the first embodiment. Accordingly, hereinafter, only differences from the first embodiment will be described with reference to the drawings, and configurations similar to those of the first embodiment will be described with reference to FIGS. 1 to 5 and FIGS. In FIG. 12, the same reference numerals are given, and redundant description may be omitted.

  FIG. 12 is a timing chart for explaining the vertical scanning of the scanning lines in one frame in the second embodiment. FIG. 13 is a timing chart for explaining the operation of the scanning line driving circuit in the second embodiment, and FIG. 14 is a schematic diagram for explaining selection of scanning lines in one field in the second embodiment. is there. FIG. 15 is an enlarged plan view having the same concept as in FIG. 9, showing a state in which an image signal in the second embodiment is written to each pixel.

  In the following, in order to simplify the explanation and make it easy to understand the features of the present invention, as shown in FIG. 14, the total number of scanning lines 11a is set to m = 8, and the output signals SR1 to SR2 of the cyst register 141 are set. In the following description, the scanning signals G1 to G8 are supplied. Actually, as shown in FIG. 4, more scanning signals G1 to Gm are supplied in accordance with the output signals SR1 to SR1 / m of the shift register 141.

  As shown in FIG. 12, in the second embodiment, for each of the R field, G field, and B field constituting one frame, one field includes the first to fourth (n = 4) subfields SF1 to SF4. It is divided into The operation in the first subfield SF1 is the same as that of the first embodiment, in which low-resolution line scanning is performed in units of four scanning line groups.

  As shown in FIG. 12, in the second subfield SF2, for each scanning line group, one scanning line corresponding to the pixel row to which the image signal originally supplied in the first subfield SF1 has already been supplied is excluded. Line scanning is performed in units of the remaining three scanning line groups (ie, “remaining groups”). In the third subfield SF3, for each scanning line group, the remaining signals except for the two scanning lines corresponding to the pixel rows to which the image signals originally supplied in the first and second subfields SF1 and SF2 have already been supplied are left. Line scanning is performed in units of two scanning line groups (ie, “remaining groups”). Further, in the fourth subfield SF4, for each scanning line group, three scanning lines corresponding to the pixel rows to which the image signals to be originally supplied in the first to third subfields SF1 to SF3 are already supplied are excluded. The line scanning is performed in units of the remaining one scanning line group (that is, “remaining group”).

  As shown in FIG. 13, in the first subfield SF1, in the scanning line driving circuit 104 (see FIG. 4), each of the output signals SR1 and SR2 of the shift register 141 is set to the high level every horizontal scanning period. In addition, the first scanning signals G1 to G4 are simultaneously output based on the four types of enable signals ENB1 to ENB4, and then the second scanning signals G5 to G8 are simultaneously output.

  Accordingly, in the first subfield SF1, as shown in FIG. 14A, the image signal Vd is supplied to each pixel unit as in the first embodiment, so that the corresponding one of R, G, and B can be used. Therefore, it is possible to display a low-resolution image of one color.

  In FIG. 13, in each of the second to fourth subfields SF2 to SF4, one of the three enable signals ENB2 to ENB4 among the four enable signals ENB1 to ENB4, and the one enable signal. At the same time, other enable signals rise from the low level to the high level every horizontal scanning period.

  More specifically, in the second subfield SF2, one enable signal ENB2 and the other enable signals ENB3 and ENB4 rise from the low level to the high level all at once in one horizontal scanning period, and the third subfield SF2 Then, one enable signal ENB3 and the other enable signal ENB4 rise from the low level to the high level all at once in one horizontal scanning period. In the fourth subfield SF4, only one enable signal ENB4 rises from the low level to the high level every horizontal scanning period.

  Therefore, in the second subfield SF2, the third scanning signals G2 to G4 and the fourth scanning signals G6 to G8 are sequentially output for each horizontal scanning period. In the third subfield SF3, the fifth scanning signals G3 and G4 and the sixth scanning signals G7 and G8 are sequentially output for each horizontal scanning period. In the fourth subfield SF4, the seventh scanning signal G4 and the eighth scanning signal G8 are sequentially output for each horizontal scanning period.

  As shown in FIG. 14B, in the second subfield SF2, first, an image signal corresponding to the scanning line to which the scanning signal G2 is supplied is supplied from the image signal supply circuit 502 shown in FIG. 1 to the data line 6a. The Then, in the scanning line group consisting of the upper four scanning lines 11a, three pixel rows (that is, “residuals”) including the pixel row corresponding to the scanning signal G2 and not including the pixel row corresponding to the scanning signal G1. The image signal corresponding to the scanning signal G2 is written to the group “)”.

  That is, as shown in the second subfield SF2 of FIG. 15, low-resolution writing is performed on the three pixel rows corresponding to the three scanning lines surrounded by the thick lines in the image display region 10a. That is, among these three pixel rows, only the pixel row corresponding to the top scanning line is written with an image signal to be originally supplied as indicated by the symbol “T” given to each pixel. It is. For the other two pixel rows, as indicated by the symbol “〃” assigned to each pixel, an image signal that should not be supplied originally (but because the scan lines are closer, A similar image signal) is temporarily written.

  At this time, the temporarily written image signal should be originally supplied by the amount corresponding to the scanning line located closer than the image signal temporarily written in the first subfield SF1. It can be considered that it is close to the image signal. Therefore, when the line scanning in the second subfield SF2 is completed, the resolution is remarkably improved.

  As shown in FIG. 14B, in the second subfield SF2, the image signal corresponding to the scanning line to which the scanning signal G6 is supplied is supplied from the image signal supply circuit 502 shown in FIG. 1 to the data line 6a. Is done. Then, in the scanning line group composed of the lower four scanning lines 11a, three pixel rows including the pixel row corresponding to the scanning signal G6 and not including the pixel row corresponding to the scanning signal G5 (that is, “residual”). The image signal corresponding to the scanning signal G6 is written to the group “).

  That is, as shown in the second subfield SF2 of FIG. 15, low-resolution writing is performed on the three pixel rows corresponding to the three scanning lines surrounded by the thick lines in the image display region 10a. That is, among these three pixel rows, only the pixel row corresponding to the top scanning line is written with an image signal to be originally supplied. For the other two pixel rows, image signals that should not be supplied are provisionally written.

  Similarly, as shown in FIGS. 12, 13 and 14C, in the third subfield SF3, the scanning signals G3 and G7 whose supply order is the fifth and sixth are sequentially one horizontal. Output every scanning period. As a result, as in the third subfield SF3 in FIG. 15, the image signal to be originally supplied is written in the two pixel rows surrounded by the thick lines corresponding to the scanning signals G3 and G7.

  Similarly, as shown in FIGS. 12, 13 and 14 (d), in the fourth subfield SF4, the scanning signals G4 and G8 whose supply order is the seventh and eighth are sequentially one horizontal. Output every scanning period. As a result, as in the fourth subfield SF4 in FIG. 15, the image signal to be originally supplied is written in one pixel row surrounded by the thick lines corresponding to the scanning signals G4 and G8.

  Since the image signal Vd is written in each of the second to fourth subfields SF2 to SF4 as described above, the potential of the pixel electrode 9a of each pixel portion is temporarily set in the first subfield SF1. The potential based on the image signal Vd to be originally written is changed from the potential based on the written image signal Vd.

  As described above, in the image display area 10a, after the writing of the image signal Vd in the fourth subfield SF4 is completed, a field image of one color corresponding to R, G, B is converted into the original resolution in each pixel unit. That is, it becomes possible to display with high resolution. Prior to the display at the high resolution, after the writing of the image signal Vd in the first subfield SF1 is completed, a field image of one color corresponding to R, G, B is reduced in each pixel unit. It is possible to display at a resolution.

  By driving the liquid crystal device as described above with reference to FIGS. 12 to 15, in the R field in FIG. 12, an R image balanced in brightness and resolution is displayed in the image display area 10a. . Similarly, in the G field in FIG. 12, a G image balanced in brightness and resolution is displayed in the image display area 10a, and in the B field in FIG. 12, a B image balanced in brightness and resolution is displayed. It is displayed in the display area 10a.

  As described above in detail, according to the present embodiment, a brighter and higher-definition image can be more easily displayed by the FS method in the liquid crystal device.

<Electro-optical device>
Next, the configuration of the electro-optical device to which the above-described embodiments are applied will be described with reference to FIGS. 16 and 17. FIG. 16 is a plan view showing the configuration of the liquid crystal device according to this embodiment, and FIG. 17 is a cross-sectional view taken along the line HH ′ of FIG. In the following, as an example of the electro-optical device of the present invention, a TFT (Thin Film Transistor) active matrix driving type liquid crystal device with a built-in driving circuit is taken as an example.

  16 and 17, in the liquid crystal device according to this embodiment, the TFT array substrate 10 and the counter substrate 20 are arranged to face each other. The TFT array substrate 10 is a transparent substrate such as a quartz substrate, a glass substrate, or a silicon substrate. The counter substrate 20 is also a transparent substrate, like the TFT array substrate 10. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20. The TFT array substrate 10 and the counter substrate 20 are bonded to each other by a sealing material 52 provided in a sealing region located around the image display region 10a provided with a plurality of pixel electrodes.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. In the sealing material 52, a gap material 56 such as glass fiber or glass bead for dispersing the distance between the TFT array substrate 10 and the counter substrate 20 (that is, the inter-substrate gap) to a predetermined value is dispersed.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region in which the sealing material 52 is disposed in the peripheral region. The scanning line driving circuit 104 is provided along two sides adjacent to the one side so as to be covered with the frame light shielding film 53. Further, in order to connect the two scanning line driving circuits 104 provided on both sides of the image display region 10 a in this way, a plurality of the pixel lines are covered along the remaining side of the TFT array substrate 10 and covered with the frame light shielding film 53. Wiring 105 is provided. The sampling circuit 7 is provided along one side of the TFT array substrate 10 and covered with the frame light-shielding film 53, similarly to the data line driving circuit 101.

  On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with a vertical conduction material are disposed in regions facing the four corner portions of the counter substrate 20. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

  In FIG. 17, an alignment film 16 is formed on the TFT array substrate 10 on the pixel electrode 9a after the formation of pixel switching TFTs, scanning lines, data lines, and the like. The pixel electrode 9a is made of a transparent conductive film such as an ITO (Indium Tin Oxide) film, and the alignment film 16 is made of an organic film such as a polyimide film. On the other hand, on the counter substrate 20, after forming a lattice-shaped or striped light-shielding film 23, a counter electrode 21 is provided over the entire surface, and an alignment film 22 is formed on the uppermost layer portion. ing. The counter electrode 21 is made of a transparent conductive film such as an ITO film, and the alignment film 22 is made of an organic film such as a polyimide film. A liquid crystal layer 50 is formed between the TFT array substrate 10 and the counter substrate 20 that are configured as described above and are arranged so that the pixel electrode 9a and the counter electrode 21 face each other. The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  In addition to the drive circuits such as the data line drive circuit 101 and the scan line drive circuit 104 on the TFT array substrate 10 shown in FIGS. 16 and 17, a plurality of data lines are precharged at a predetermined voltage level. A precharge circuit for supplying a signal prior to an image signal, an inspection circuit for inspecting the quality, defects, etc. of the electro-optical device during manufacture or at the time of shipment may be formed.

<Electronic equipment>
Next, the case where the liquid crystal device which is the above-described electro-optical device is applied to various electronic devices will be described. FIG. 18 is a plan view schematically showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 18, the projector 1100 includes LEDs 110R, 110G, and 110B corresponding to the three primary colors RGB. The LEDs 110R, 110G, and 110B sequentially project light, for example, at a period of 60 Hz. The projection lights emitted from the LEDs 110R, 110G, and 110B are incident on the synthesis prism 1300 and then emitted to the liquid crystal panel 1200 as a light valve.

  The configuration of the liquid crystal panel 1200 is the same as that of the liquid crystal device described above, and is driven by a signal supplied from the image signal processing circuit. Then, the light modulated by the liquid crystal panel 1200 is projected through the projection lens 1400. As a result, a color image is projected onto a screen or the like.

  In the projector 1100 according to the present embodiment, the LEDs 110R, 110G, and 110B corresponding to the primary colors of R, G, and B are provided, so that it is not necessary to provide a color filter. Therefore, the cost can be reduced, and since the projection light does not pass through the color filter, high luminance can be obtained.

  In addition to the electronic device described with reference to FIG. 18, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic device Examples include a notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel. Needless to say, the present invention can be applied to these various electronic devices.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and driving of a display device accompanied by such a change. A method and a drive circuit, an electro-optical device, and an electronic apparatus are also included in the technical scope of the present invention.

  6a ... data line, 7 ... sampling circuit, 9 ... pixel unit, 11a ... scanning line, 100 ... liquid crystal panel, 101 ... data line driving circuit, 104 ... scanning line driving circuit, 200 ... light source, 502 ... image signal supply circuit, 506: Light source control circuit.

Claims (7)

A display device for driving a display device comprising a plurality of scanning lines and data lines intersecting each other, a plurality of pixel units, and a light source capable of supplying light corresponding to a plurality of unit colors to the plurality of pixel units in a time-division manner Driving method,
Each of the plurality of scanning lines includes first to nth (n is a natural number of 2 or more) groups each including m (m is a natural number of 4 or more) scanning lines,
Each of the field images for each unit color constituting the frame image is composed of a first to m-th subfield period,
A first scanning step of sequentially supplying a scanning signal to m scanning lines included in each group in the first subfield period, sequentially from the first to nth groups ;
A first image signal supplying step of supplying an image signal corresponding to a first scanning line included in a selected group to the data line in the first subfield period;
In the second subfield period, the first to nth groups are sequentially supplied to the m−1 scanning lines included in each group except for the first scanning lines . Two scanning steps;
A second image signal supplying step of supplying an image signal corresponding to a second scanning line included in the selected group to the data line in the second subfield period;
In the third subfield period, the scanning signals are simultaneously applied to m-2 scanning lines included in each group except for the first and second scanning lines in order from the first to nth groups. A third scanning step of supplying
A third image signal supplying step of supplying an image signal corresponding to a third scanning line included in the selected group to the data line in the third subfield period ;
In the fourth subfield period, the scan signals are simultaneously applied to the m-3 scan lines included in each group except for the first to third scan lines in order from the first to nth groups. Supplying a fourth scanning step;
And a fourth image signal supplying step of supplying an image signal corresponding to a fourth scanning line included in the selected group to the data line in the fourth subfield period. Driving method. In the m-th sub-field period, from said first sequentially the n-th group, from said first Except the first m-1 of the scanning line, included in each group m-(m-1) of scanning lines The m-th scanning step for supplying the scanning signal;
The m-th image signal supplying step of supplying an image signal corresponding to the m-th scanning line included in the selected group to the data line in the m-th subfield period. 2. A method for driving the display device according to 1. In the first subfield period, the light is not supplied by the light source,
3. The display device driving method according to claim 1, wherein the light is supplied from the light source after the second subfield period. 4. A plurality of scanning lines and data lines arranged crossing each other, a plurality of pixel portions arranged corresponding to the intersection of the scanning lines and data lines, and light corresponding to a plurality of unit colors in a time division manner A driving circuit of a display device including a light source that can be supplied to the pixel unit,
Each of the plurality of scanning lines includes first to nth (n is a natural number of 2 or more) groups each including m (m is a natural number of 4 or more) scanning lines,
Each of the field images for each unit color constituting the frame image is composed of a first to m-th subfield period,
The drive circuit is
In the first subfield period, the first to nth groups are sequentially supplied to m scanning lines included in each group, and a scanning signal is simultaneously supplied.
Supplying an image signal corresponding to a first scanning line included in a selected group to the data line in the first subfield period;
In the second subfield period, the scan signals are simultaneously supplied to m-1 scan lines included in each group except for the first scan line in order from the first to nth groups ,
Supplying the image signal corresponding to the second scanning line included in the selected group to the data line in the second subfield period;
In the third subfield period, the scanning signals are simultaneously applied to m-2 scanning lines included in each group except for the first and second scanning lines in order from the first to nth groups. Supply
Supplying an image signal corresponding to a third scan line included in the selected group to the data line in the third subfield period ;
In the fourth subfield period, the scan signals are simultaneously applied to the m-3 scan lines included in each group except for the first to third scan lines in order from the first to nth groups. Supply
In the fourth subfield period, an image signal corresponding to a fourth scanning line included in a selected group is supplied to the data line, a driving circuit of a display device. The drive circuit further includes:
In the m-th sub-field period, from said first sequentially the n-th group, from said first Except the first m-1 of the scanning line, included in each group m-(m-1) of scanning lines To supply the scanning signal,
5. The display device driving circuit according to claim 4, wherein, in the m-th subfield period, an image signal corresponding to the m-th scanning line included in the selected group is supplied to the data line.   An electro-optical device comprising the drive circuit for the display device according to claim 4.   An electronic apparatus comprising the electro-optical device according to claim 6.

Images