JP2007333770A - Electrooptical device, driving circuit for electrooptical device, and driving method of electrooptical device, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the display defect such as blurring of moving picture, to reduce cost and to downsize the device. <P>SOLUTION: The human visual sensation is known to be more sensitive to luminance (Y) than to a color difference (Cr) of red and a color difference of (Cb) of blue. Accordingly, relating only to the video signal GDi(fn) corresponding to the green which is a color element most contributing to the luminance (Y), the display defect, such as animation image unsharpness, can be reduced by subjecting gray-scale member to over-drive processing in such a manner that the green is displayed with the gray-scale number which ought to be displayed in a display region 10a. In addition, the circuitry of a liquid crystal device 10 can be simplified to reduce the cost and to downsize the device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electro-optical device such as a liquid crystal device capable of displaying a moving image, a driving circuit for an electro-optical device applicable to such an electro-optical device, a driving method of the electro-optical device, and such an electro-optical device. The present invention relates to a technical field of an electronic apparatus such as a liquid crystal projector including the device.

  In a liquid crystal device which is an example of this type of electro-optical device, each pixel constituting a display screen is sequentially selected for each row, a voltage is applied to the liquid crystal using an electrode of each pixel, and the alignment state of the liquid crystal molecules is changed. Image display is performed by controlling the amount of light transmitted through the liquid crystal by changing. In the liquid crystal device, the amount of transmitted light is controlled and displayed according to the alignment state of the liquid crystal molecules. A moving image is displayed by sequentially displaying frame images corresponding to respective frames constituting a continuous series of frames on a display screen.

  Here, depending on the characteristics of the liquid crystal, liquid crystal molecules in a certain alignment state change their alignment state by a newly applied voltage and become another alignment state determined by the newly applied voltage. A time longer than each frame period may be required. Therefore, when displaying an object moving at high speed, the alignment state of liquid crystal molecules does not reach a desired state within each frame period for displaying a moving image, and an afterimage of the object is perceived, or the outline of the object is blurred. There has been a problem (so-called moving image blur) such as being visible. As an example of means for solving such a problem, a voltage larger than the voltage applied to the liquid crystal in order to restrict the alignment state of the liquid crystal to a desired state is applied to the liquid crystal within one frame period. A technique (so-called overdrive technique) that regulates the alignment state of the liquid crystal to the alignment state is known.

  Further, according to Patent Document 1, when the alignment state of the liquid crystal is regulated by such an overdrive technique, a data table referred to for determining a voltage actually applied to the liquid crystal based on the video signal is described. A technique for reducing memory is disclosed. Patent Document 2 discloses a look-up table referred to for performing color correction of a displayed image and a look-up table referred to for performing overdrive for the purpose of improving the color reproducibility of the image. Discloses a liquid crystal display device capable of color display.

  Further, in the YUV format, which is one of color space management methods and is generally used as a color space management method for images in a display device such as a television, luminance (Y) and blue color differences (usually U or A color image is displayed based on a color space format defined by Cb) and a red color difference (usually displayed by V or Cr). In such a display device using the YUV format, the human vision is insensitive to a change in color difference compared to a change in luminance, so that a band or data in luminance is compared to a blue color difference and a red color difference. By assigning the number of bits, efficient data transmission or data compression is realized.

JP 2003-295838 A JP 2004-45702 A

  In this type of electro-optic device, human vision is less sensitive to changes in chromaticity than changes in luminance, and the degree of moving image blur due to afterimages or contour blurring of objects is The inventors of the present application consider that the wavelength varies depending on the wavelength of light to be felt, that is, the type of color.

  However, in the technique disclosed in Patent Document 1, if the alignment state of the liquid crystal is not restricted to a desired alignment state within one frame period, an afterimage or contour blur of an object that is actually recognized by human vision. A look-up table is not designed by distinguishing the degree of display failure such as for each color. Therefore, according to Patent Document 1, it is difficult to say that the memory such as the lookup table is effectively reduced so that the motion blur actually sensed by human vision is reduced. There are also demands for cost reduction and simplification of the electro-optical device by simplifying the circuit configuration in the drive circuit including a memory such as a lookup table. As described above, there is an increasing demand for a technique capable of simultaneously improving display performance by reducing moving image blur and reducing the cost and size of the electro-optical device.

  Therefore, the present invention has been made in view of the above-described problems. For example, an electro-optical device such as a liquid crystal device that can reduce motion blur, reduce costs, and reduce the size of the device, and such an electro-optical device. It is an object of the present invention to provide an electro-optical device driving circuit applicable to the device, a driving method for the electro-optical device, and an electronic apparatus such as a liquid crystal projector including the electro-optical device.

  In order to solve the above problems, an electro-optical device according to a first aspect of the present invention includes an electro-optical panel having a plurality of pixel portions provided in a display area on a substrate, and an image to be displayed in the display area. For a predetermined video signal corresponding to a color element that contributes most to luminance in a specific color space among video signals supplied to the electro-optical panel to display a series of frame images constituting the image, the predetermined video signal is Video signal processing means for performing overdrive processing on the predetermined video signal so that a specified gradation value is displayed in the pixel portion;

  According to the electro-optical device according to the first aspect of the present invention, for example, an image signal is supplied from the data line to the pixel electrode of the pixel unit, and the alignment control of the electro-optical material such as liquid crystal is performed by a so-called active matrix method. Is called. Thereby, for example, in the display area on the TFT array substrate, the liquid crystal orientation is controlled by controlling the voltage applied to the liquid crystal for each frame, and a series of frame images are displayed. The moving image is displayed in the display area.

  In the electro-optical device according to the first aspect of the present invention, the “video signal” is not a video signal in a broad sense including an image signal and a synchronization signal, but includes, for example, gradation value data of each color element in each pixel unit. It means a signal corresponding to an image signal. Such a video signal is a digitized color video signal. For example, each of the R (red), G (green), and B (blue) color elements included in the frame image displayed in the display area. Correspondingly, the signal source supplies the electro-optical panel. In addition, the video signal corresponds to a predetermined gradation value, and for example, 256 gradations (that is, 256 luminance gradations) can be displayed for each RGB. With such a combination of gradation display for each RGB, 256 × 256 × 256 (= 16777216) colors can be displayed as a color image, for example, in each of picture elements composed of three pixels of RGB.

  In this specification, in the display area, for example, the minimum unit capable of expressing a color in which RGB is mixed in an arbitrary ratio is appropriately referred to as “picture element”, and only R, G only, or B only can be expressed. Such minimum unit is referred to as “pixel” as appropriate. For example, a “picture element” corresponding to each color video signal is typically composed of three adjacent pixels of RGB. However, such as a liquid crystal light valve that optically synthesizes display light emitted from a plurality of electro-optical devices, such as a double-plate color projector, and displays R light, G light, and B light in the same region. In the case of the electro-optical device, a region as one “picture element” in the display region coincides with a region where one “pixel portion” is formed, that is, a region as one “pixel”.

  In the electro-optical device according to the first aspect of the present invention, the image signal processing means is configured to display a video signal supplied to the electro-optical panel for displaying a series of frame images constituting an image to be displayed in the display area. Of the predetermined video signal corresponding to the predetermined color element that contributes most to the luminance in the specific color space, the predetermined video element is displayed so that the predetermined color element is displayed on the pixel portion with the gradation value specified by the predetermined video signal. Apply overdrive processing to the signal.

  Here, the “specific color space” is, for example, a color space defined in the YUV format (hereinafter referred to as YUV color space), and the “luminance” is the luminance defined in the YUV format (ie, YUV format). ). In such a color space defined by the YUV format, the predetermined color element that contributes most to the luminance is green when the color space is defined by the RGB format. In the YUV color space, human vision is less sensitive to changes in chromaticity of blue and red than changes in luminance (Y), and thus a video signal corresponding to green, which is a color element that contributes most to luminance (Y). By applying overdrive processing to the image, green is displayed with the gradation value specified by the video signal corresponding to the green color, display defects such as moving image blur can be reduced, and an image displayed by an electro-optical device such as a liquid crystal device It is possible to improve the image quality. In addition, since a circuit for performing the overdrive process for each of red and blue is not required, the circuit configuration of the electro-optical device can be simplified, and the cost required for the electro-optical device can be reduced. In addition, since a space for providing a circuit for performing overdrive processing on video signals corresponding to color elements such as red and blue can be reduced, the electro-optical device can be reduced in size.

  Therefore, according to the electro-optical device according to the first aspect of the present invention, the cost of the electro-optical device can be reduced and the size of the device can be reduced by simplifying the configuration of the circuit mounted on the electro-optical device. At the same time, the image quality of the moving image can be improved.

  In one aspect of the electro-optical device according to the first aspect of the present invention, the video signal processing means includes a first video corresponding to a first frame image included in the series of frame images in the predetermined video signal. A frame memory for storing first gradation number data included in the signal; (ii) the first gradation number data; and (ii) of the predetermined video signal in the display area following the first frame image. The corrected second video signal output instead of the second video signal or the second floor for each combination of the second gradation number data included in the second video signal corresponding to the displayed second frame image A lookup table storing correction values for the logarithmic data.

  According to this aspect, the frame memory has a first video signal corresponding to the first frame image displayed in the display area prior to the second frame image before the second frame image is supplied to the electro-optical panel. The first gradation number data is stored. Here, the first video signal is a video signal supplied to display the first frame image among the predetermined video signals, and is, for example, a video signal corresponding to green included in the first frame image. The second video signal is a video signal corresponding to, for example, green included in the second frame image.

  The lookup table is a memory in which correction values for the corrected second video signal output instead of the second video signal or the second gradation number data are stored.

  Such a corrected second video signal or correction value includes (i) first gradation number data, and (ii) a second of the predetermined video signals displayed in the display area following the first frame image. It is set for each combination of second gradation number data included in the second video signal corresponding to the frame image, and is stored in the lookup table. More specifically, the lookup table, for example, when a predetermined video signal includes 256 gray scale data, the product of the respective gray scales of the first video signal and the second video signal (256 × 256). = 65536)), the number of corrected second video signals or correction values defined in the above are stored. The video signal processing means, for example, a corrected second video signal set for each combination of the first gradation number data and the second gradation number data by referring to the lookup table under the control of the control unit. Is output to the electro-optical panel. Alternatively, the video signal processing means is supplied to the electro-optical panel to display a predetermined color element that contributes most to the luminance, such as green, by correcting the second video signal based on the correction value for the second video signal. Generate a signal.

  Therefore, according to this aspect, the orientation state of the electro-optical material such as liquid crystal is displayed when the second frame image is displayed by the overdrive process for correcting the gradation value, which is performed on the color element that contributes most to the luminance. Is controlled to a desired alignment state, and display defects such as moving image blurs generated based on alignment defects can be reduced.

  In order to solve the above problems, an electro-optical device according to a second aspect of the present invention includes an electro-optical panel having a plurality of pixel portions constituting a display area on a substrate, and an image to be displayed on the display area. The predetermined video signal for a predetermined video signal corresponding to a predetermined color element that contributes most to luminance in a specific color space among video signals supplied to the electro-optical panel for displaying a series of frame images constituting the predetermined video signal The predetermined color element is displayed at the gradation value specified by the image data under the condition different from the overdrive process applied to another video signal corresponding to another color element different from the predetermined color element. Video signal processing means for performing drive processing.

  According to the electro-optical device according to the second aspect of the present invention, the predetermined video signal corresponding to the predetermined color element that contributes most to the luminance in the specific color space is predetermined with the gradation value specified by the predetermined video signal. By performing overdrive processing under conditions different from overdrive processing applied to other video signals corresponding to other color elements different from the predetermined color element, for example, moving image blurring is displayed. The color element such as green that contributes most to display defects such as green can be displayed with the gradation value that should be originally displayed in the second frame image, and the same overdrive processing is performed on the video signal corresponding to each of the plurality of color elements. Compared to the case, display defects such as moving image blur can be reduced. Here, the “different condition” refers to, for example, a fine gradation value so that an overdrive process applied to a predetermined video signal has a relatively large gradation value compared to an overdrive process applied to another video signal. The case where it applies at intervals is mentioned. In this way, by performing overdrive processing on a predetermined video signal, the alignment state of an electro-optic material such as liquid crystal that is controlled in alignment corresponding to a predetermined color element is more accurately compared to other color elements. It is possible to control the gradation to be displayed. Note that such a condition is a specific processing condition related to overdrive processing as far as the condition is applied so that a predetermined color element is displayed with a gradation value to be displayed in the display area compared to other video signals. It is not limited to.

In an aspect of the electro-optical device according to the second aspect of the present invention, the video signal processing means includes a first video corresponding to a first frame image included in the series of frame images in the predetermined video signal. A first frame memory for storing first gradation number data included in the signal; (i) the first gradation number data; and (ii) the display of the predetermined video signal following the first frame image. For each combination of second gradation number data included in the second video signal corresponding to the second frame image displayed in the region, the corrected second video signal output instead of the second video signal, or the second A first look-up table in which correction values for two-tone number data are stored;
A second frame memory for storing third gradation number data included in a third video signal corresponding to the first frame image among the other video signals; (iii) the third video signal; and (iv) the A corrected fourth video signal output instead of the fourth video signal for each combination of the fourth gradation number data included in the fourth video signal corresponding to the second frame image among other video signals, or And a second lookup table in which correction values for the fourth gradation number data are stored.

  According to this aspect, the first frame memory and the second frame memory are separately provided, and the first lookup table and the second lookup table are separately provided, whereby the predetermined video signal and the other video signal are mutually connected. It is possible to perform overdrive processing under different conditions. According to this aspect, for each of the predetermined video signal and the other video signals, the gradation value of the second video signal included in the predetermined video signal is set to the fourth value so that the moving image blur is reduced in the entire moving image. Corrections can be made with gradation intervals finer than the gradation value of the video signal, and display defects such as moving image blur can be effectively reduced. In addition, since the fourth video signal can also be corrected, in addition to reducing the moving image blur for the color element that contributes the most to the luminance, the moving image blur can also be reduced for the other color elements.

  In this aspect, the size of the third gradation number data may be smaller than the size of the first gradation number data.

  According to this aspect, by reducing the size of the second frame memory compared to the size of the first frame memory in accordance with the size of the third gradation number data, for example, the predetermined video signal and other video signals When each is supplied to the electro-optical panel with the same number of gradations, the first frame stores the number of gradations obtained by digitizing a predetermined video signal with 8 bits for each frame image as it is, and the second frame The memory stores the number of gradations obtained by digitizing other video signals with 8 bits by dropping them to 4 bits or 6 bits. Therefore, a circuit configuration such as a frame memory constituting the video signal processing means can be simplified, and the cost required for the electro-optical device can be reduced. Since the circuit configuration can be simplified, the circuit constituting the video signal processing means can be reduced in size, so that the electro-optical device can be reduced in size.

  In another aspect of the electro-optical device according to the second aspect of the invention, the size of the gradation number data included in the fourth video signal may be smaller than the size of the gradation number data included in the second video signal. Good.

  According to this aspect, since the capacity of the second lookup table can be made smaller than that of the first lookup table in accordance with the second and fourth gradation number data, the cost required for these lookup tables can be reduced. In addition, the cost of the electro-optical device can be reduced, and the electro-optical device can be reduced in size because the circuit configuration is simplified.

  In another aspect of the electro-optical device according to the second aspect of the present invention, the size of the second lookup table may be smaller than the size of the first lookup table.

  According to this aspect, it is possible to reduce the cost required for the electro-optical device and to reduce the size of the electro-optical device according to the size of the lookup table.

  In order to solve the above problem, a drive circuit for an electro-optical device according to a third aspect of the present invention is configured to display a series of frame images constituting an image to be displayed in a display area of an electro-optical panel. For a predetermined video signal corresponding to a color element that contributes most to luminance in a specific color space among video signals supplied to the optical panel, the color element is displayed on the pixel unit with a gradation value specified by the predetermined video signal. Video signal processing means for performing overdrive processing on the predetermined video signal, and driving for driving the pixel unit based on a signal generated by performing the overdrive processing on the predetermined video signal Circuit.

  According to the drive circuit for an electro-optical device according to the third aspect of the present invention, the configuration of the circuit mounted on the electro-optical device can be simplified as in the case of the electro-optical device according to the first aspect of the present invention described above. As a result, the cost required for the electro-optical device can be reduced and the size of the device can be reduced, and the quality of the moving image can be improved.

  In order to solve the above-described problems, a drive circuit for an electro-optical device according to a fourth aspect of the present invention is configured to display the series of frame images constituting an image to be displayed in a display area of an electro-optical panel. For a predetermined video signal corresponding to a predetermined color element that contributes most to luminance in a specific color space among the video signals supplied to the optical panel, the predetermined video signal is input to the pixel unit with a gradation value specified by the predetermined video signal. Video signal processing means for performing overdrive processing under conditions different from overdrive processing applied to other video signals corresponding to other color elements different from the predetermined color elements so that the color elements are displayed; And a drive circuit that drives the pixel unit based on a signal generated by performing overdrive processing performed under the different conditions on the predetermined video signal.

  According to the drive circuit for an electro-optical device according to the fourth aspect of the present invention, the configuration of the circuit mounted on the electro-optical device can be simplified, similarly to the electro-optical device according to the second aspect of the present invention described above. As a result, the cost required for the electro-optical device can be reduced and the size of the device can be reduced, and the quality of the moving image can be improved.

  In order to solve the above problems, a driving method of an electro-optical device according to a fifth aspect of the present invention is configured to display a series of frame images constituting an image to be displayed in a display area of an electro-optical panel. For a predetermined video signal corresponding to a color element that contributes most to luminance in a specific color space among video signals supplied to the optical panel, the color element is displayed on the pixel unit with a gradation value specified by the predetermined video signal. A video signal processing step for performing overdrive processing on the predetermined video signal, and driving for driving the pixel unit based on a signal generated by applying the overdrive processing to the predetermined video signal A process.

  According to the driving method of the electro-optical device according to the fifth aspect of the present invention, similarly to the electro-optical device according to the first aspect of the present invention described above, the configuration of the circuit mounted on the electro-optical device can be simplified. In addition, the cost required for the electro-optical device can be reduced and the size of the device can be reduced, and the quality of the moving image can be improved.

  In order to solve the above problems, a driving method of an electro-optical device according to a sixth aspect of the present invention is configured to display a series of frame images constituting an image to be displayed in a display area of an electro-optical panel. For a predetermined video signal corresponding to a predetermined color element that contributes most to luminance in a specific color space among the video signals supplied to the optical panel, the predetermined video signal is input to the pixel unit with a gradation value specified by the predetermined video signal. A video signal processing step of performing overdrive processing under conditions different from overdrive processing applied to other video signals corresponding to other color elements different from the predetermined color elements so that the color elements are displayed; And a driving step of driving the pixel unit based on a signal generated by applying the overdrive processing performed under the different conditions to the predetermined video signal.

  According to the driving method of the electro-optical device according to the sixth aspect of the present invention, similarly to the electro-optical device according to the second aspect of the present invention described above, the configuration of the circuit mounted on the electro-optical device can be simplified. In addition, the cost required for the electro-optical device can be reduced and the size of the device can be reduced, and the quality of the moving image can be improved.

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

  According to the electronic apparatus according to the present invention, since the electro-optical device according to the present invention described above is provided, a projection display device, a mobile phone, an electronic notebook, a word processor, and a viewfinder type capable of high-quality display. Alternatively, various electronic devices such as a monitor direct-view video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. In addition, as an electronic apparatus according to the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

  Hereinafter, embodiments of an electro-optical device, an electro-optical device drive circuit, an electro-optical device drive circuit, and an electronic apparatus according to the present invention will be described with reference to the drawings.

<First Embodiment>
(Concept of driving method of electro-optical device)
First, referring to FIGS. 1 and 2, the driving of the electro-optical device according to the fifth and sixth inventions employed in the electro-optical device according to the first and second inventions of the present invention is described. The basic principle in the method embodiment will be described. In each embodiment described below, a liquid crystal device is given as an example of the electro-optical device according to the first and second inventions of the present invention. FIG. 1 is a conceptual diagram showing the relationship between the transmittance of a pixel and the applied voltage applied to the liquid crystal in a conventional liquid crystal device. FIG. 2 is a conceptual diagram showing the relationship between the transmittance of the pixel and the applied voltage applied to the liquid crystal in the liquid crystal device according to this embodiment. 1 and 2 exemplify a case where the transmittance of pixels in each frame after the Nth frame is set to the same transmittance as that in the Nth frame for the sake of simplicity.

  In FIG. 1, when switching the transmittance to the transmittance Tn in the Nth frame for the pixel whose light transmittance was the transmittance Tn−1 in the (N−1) th frame, the (N−1) th frame. The applied voltage Vn−1 applied to the liquid crystal is switched to the applied voltage Vn. Here, the applied voltage Vn is an ideal applied voltage obtained by experiment, theory, simulation, or the like in order to restrict the liquid crystal to a predetermined alignment state in the Nth frame.

  However, in accordance with the applied voltages Vn−1 and Vn and the alignment characteristics of the liquid crystal, actually, the light transmittance in the pixel within the frame period of the Nth frame is changed to an ideal transmittance Tn according to the applied voltage Vn. The transmittance realized in the frame period of the Nth frame is the transmittance T′n, and beyond the frame period of the Nth frame, for example, the transmittance of the pixel is (N + 1) th. The transmittance Tn to be realized with the applied voltage Vn is not reached until the frame or the (N + 2) th frame. As described above, when an image is displayed by actually controlling the alignment of the liquid crystal, the alignment of the liquid crystal is delayed and the display quality of the pixel is deteriorated. In particular, a moving image that displays a moving object image or the like that moves at a high speed has a problem in that display defects such as moving image blurring are noticeably caused by a delay in the change in the alignment state of the liquid crystal.

  Therefore, as shown in FIG. 2, in place of the applied voltage Vn obtained to realize the transmittance Tn in the pixel, an applied voltage V′n larger than the applied voltage Vn is applied to the liquid crystal in the Nth frame. The delay caused by the change in the alignment of the liquid crystal is reduced, and the pixel transmittance is switched to the transmittance Tn to be realized in the Nth frame within the frame period of the Nth frame. In this way, a technique for realizing a target transmittance, that is, an ideal transmittance within a predetermined frame period by applying an applied voltage V′n higher than the applied voltage Vn to the liquid crystal is usually “overdrive technology”. It is called. The “overdrive process” in the present specification refers to the application of these applied voltages in order to change the applied voltage Vn to the applied voltage V′n in addition to the “overdrive technology” in the normal sense described above. This includes the process of changing the gradation value data included in the video signal that is the source of the above. In addition, the electro-optical device driving method employed in the electro-optical device according to the present embodiment, as will be described in detail later, overshoots only a specific color among video signals to be overdriven. It is characterized in that it performs a drive process or an overdrive process that controls the gradation value related to the specific color with higher accuracy than other colors.

(Electric circuit configuration of electro-optical device)
Next, an embodiment of the electro-optical device according to the first aspect of the present invention will be described. FIG. 3 is a block diagram showing a basic electric circuit configuration of the liquid crystal device according to the present embodiment. An example of the drive circuit for the electro-optical device according to the third aspect of the present invention is employed in the basic electric circuit configuration of the electro-optical device according to the present embodiment.

  In FIG. 3, the liquid crystal device 1 includes a display panel unit 100p, a signal processing unit 20, a frame memory 30, a lookup table 40, and a D / A converter, which are examples of the “electro-optical panel” according to the first aspect of the present invention. 50, a data line driving circuit 101, a scanning line driving circuit 104, and a video signal supply unit 180. The signal processing unit 20, the frame memory 30, and the look-up table 40 constitute an example of the “video signal processing means” according to the first and third aspects of the present invention, and the data line driving circuit 101 and the scanning line driving The circuit 104 constitutes an example of “driving means” according to the third aspect of the present invention.

  The display panel unit 100p includes a plurality of data lines 6a electrically connected to the data line driving circuit 101 and a plurality of scanning lines 3a electrically connected to the scanning line driving circuit 104, and displays a color image. It can be displayed. These data lines 6a and scanning lines 3a intersect each other along the vertical and horizontal directions in the display area 10a of the display panel unit 100p. Each of the plurality of pixel portions 10p is arranged in the display area 10a in a matrix corresponding to the intersection of the scanning lines 3a and the data lines 6a. One pixel portion 10p is provided for each pixel or each pixel region constituting the display region 10a. When the liquid crystal device 1 is applied to an RGB three-plate projector, the liquid crystal device 1 is configured as a panel module including three liquid crystal panels that are used as R, G, and B light valves. Video signals for R, G, and B are supplied to the valves, respectively.

  Each of the plurality of pixel units 10p applies a voltage corresponding to a video signal supplied from the signal processing unit 20 via a D / A converter 50 described later to the liquid crystal interposed between the pixel electrode (not shown) and the corresponding electrode. To do. That is, according to the gradation number data included in the video signal supplied from the signal processing unit 20, the gradation value in the pixel corresponding to the pixel unit 10p, that is, the light transmittance, changes. The display panel unit 100 can display a desired image by changing the transmittance according to the video signal in each of the pixels provided with the pixel unit 10p constituting the display region 10a.

  The video signal supply unit 180 supplies the signal processing unit 20 with a horizontal synchronization signal HSYNC, a vertical synchronization signal VSYNC, a dot clock DOTCLK, a video signal D, and current data (Current Data).

  The signal processing unit 20 includes a control unit including a timing control circuit (not shown), and based on a dot clock for scanning each pixel, which is a minimum unit clock, a Y clock signal CLY and an inverted Y clock signal CLYinv, X clock signal CLX, inverted X clock signal CLXinv, Y start pulse DY and X start pulse DX, and a plurality of series of enable signals ENB1 and ENB2 are generated. The signal processing unit 20 supplies the Y clock signal CLY, the inverted Y clock signal CLYinv, the Y start pulse DY, and the enable signals ENB1 and ENB2 to the scanning line driving circuit 104, the X clock signal CLX, the inverted X clock signal CLXinv, and An X start pulse DX is supplied to the data line driving circuit 101. The signal processing unit 20 supplies to the D / A converter 50 a video signal D ′ that has been subjected to overdrive processing and is generated from the video signal D by various circuit units included in the signal processing unit 20 as will be described later. The D / A converter 50 converts the video signal D ′, which is a digital signal, into a video signal Dv, which is an analog signal, and supplies the analog video signal Dv to the data line driving circuit 101.

  The data line driving circuit 101 receives the video signal Dv for each of R, G, and B and sends it to the data line 6a at a timing according to the externally supplied clock signal and horizontal synchronization signal HSYNC.

  The scanning line driving circuit 104 sends the scanning signal ScLn1 to the scanning line 3a at a timing according to the dot clock DOTCLK and the vertical synchronization signal VSYNC. With the scanning signal ScLnc1, the video signal Dv can be supplied to the pixel portion 10p electrically connected to one scanning line 3a.

  Next, the circuit configuration of the liquid crystal device 1 will be described in detail with reference to FIGS. FIG. 4 is a block diagram showing a detailed circuit configuration of the signal processing unit 20 together with the frame memory, the lookup table, and the D / A converter 50. FIG. 5 shows the number of gradations stored in the lookup table. It is the table | surface which showed data. FIG. 6 is a block diagram of the comparative example of FIG. 4 to 6, the signal processing unit is used when displaying the (N-1) -th frame image and the N-th frame image among the series of frame images constituting the color moving image displayed in the display area 10a. Various signal processing performed by 20 and the like will be mainly described.

  The overdrive process is performed on each of the pixel units that display green among the pixel units 10p included in the display panel unit 100p. Therefore, video signals corresponding to green, such as the video signals GDi (fn) and GDi (fn−1), are examples of the “predetermined video signal” according to the first and third inventions of the present invention. A subscript i included in a code attached to each video signal indicates an arbitrary picture element among a plurality of picture elements each including a set of three pixel units 10p for displaying three colors, and fn in parentheses. Indicates that the video signal is a video signal corresponding to the Nth frame image to be displayed in the nth frame. In order to simplify the description, the overdrive process applied to the video signal GDi (fn) corresponding to an arbitrary pixel portion (that is, the pixel portion specified by the suffix i) will be described in detail.

  In FIG. 4, the video signal GDi (fn) includes data (that is, gradation number data) related to the pixel portion 10p that displays green among the pixel portions 10p that constitute the display region 10a. More specifically, the video signal GDi (fn) is an 8-bit digital signal and includes gradation number data that enables display of 256 gradations in the pixel portion. Similarly, the video signal RDi (fn) includes data related to the pixel unit 100p that displays red in the pixel unit 100p that configures the display region 10a, and BDi (fn) represents the pixel unit that configures the display region 10a. The data regarding the pixel part 10p which displays blue among 10p is included. Each of these video signals RDi (fn) and BDi (fn) is an 8-bit digital signal, like the video signal GDi (fn). The display panel unit 100p can display 256 × 256 × 256 (= 16777216) colors as a color image, for example, in each of picture elements composed of three pixels of RGB, by a combination of gradation display for each RGB.

  Here, the luminance (Y), red color difference (Cr), and blue color difference (Cb) in the YUV color space are defined by equations (1) to (3).

  Human vision is more sensitive to luminance (Y) than red color difference (Cr) and blue color difference (Cb) in the YUV color space obtained by converting the gradations of the three RGB colors. It has been known. Therefore, overdrive processing is performed only for green, which is the color element that contributes most to luminance (Y) in equation (1), that is, in G in equation (1), the coefficient is larger than the terms R and B. Therefore, it is considered that display defects such as moving image blur can be significantly reduced. More specifically, for the video signal GDi (fn), the gradation value may be overdriven so that green is displayed in the display area 10a with the gradation value specified by the video signal GDi (fn). it is conceivable that.

  In this way, by applying overdrive processing to the gradation value, the orientation angle of the electro-optic material such as liquid crystal is immediately switched to the target orientation angle in each frame, that is, the orientation state that the liquid crystal should take within the frame period. Thus, the target transmittance is realized in the frame period in the pixel displaying green. According to the liquid crystal device 1, as will be described in detail later, the light transmittance of the pixel (more specifically, the transmittance of the pixel that transmits green light) is switched to the target transmittance within each frame period. Therefore, display defects such as moving image blur that occurs in a moving image composed of a series of frame images are reduced, and high-quality moving images can be displayed.

  Next, an overdrive process applied to the video signal GDi (fn) will be described in detail while explaining the operation of each circuit unit of the liquid crystal device 1.

  In FIG. 4, the signal processing unit 20 includes a line buffer (indicated by LB in the figure) 31G. The signal processing unit 20 includes the video signals RDi (fn) and BDi (fn) among the video signals RDi (fn), GDi (fn), and BDi (fn) included in the video signal D supplied from the video signal supply unit 180. As it is to the D / A converters 50R and 50B. The line buffer 31G supplies the video signal GDi (fn) supplied from the video signal supply unit 180 to the frame memory 30G and to the lookup table 40G.

  The frame memory 30G stores a video signal GDi (fn−1), which is an example of the “first video signal” according to the first aspect of the present invention, for all picture elements included in the display panel unit 100p. More specifically, the frame memory 30G corresponds to each of the pixel units 10p that display green for the frame image displayed in the (N−1) th frame, according to the “first” of the present invention. The video signal GDi (fn−1), which is an example of “two video signals”, is stored. Therefore, the frame memory 30G stores data having a size obtained by multiplying 8 bits corresponding to the number of gradations of the video signal GDi (fn) by the number of pixels of the pixel unit 10p that displays green.

  When the video signal GDi (fn) is supplied from the line buffer 31G, the frame memory 30G sends the video signal GDi (fn-1) stored in the frame memory 30G to the look-up table 40G and the video signal GDi ( The video signal GDi (fn) is stored instead of fn−1).

  The look-up table 40G is based on the gradation number data of each of the video signals GDi (fn) and GDi (fn-1) under the control of the control unit 60, and the nth frame instead of the video signal GDi (fn). The video signal GD′i (fn) to be output is output to the D / A converter 50.

  Here, the configuration of data stored in the lookup table 40G will be described with reference to FIG.

  In FIG. 5, the look-up table 40G uses the number of gradations indicated by the gradation number data included in the video signal GDi (fn) as the row number, and the gradation number data included in the video signal GDi (fn-1). A matrix element d (k, l) specified by each of a row and a column is stored with the number of gradations shown as a column number. Here, k and l are integers of 0 or more and M−1 or less. Note that, here, the gradation number data included in each of the video signals GDi (fn) and GDi (fn−1) are “first gradation number data” and “second floor” according to the first aspect of the present invention. It is an example of each of "logarithm data". In the present embodiment, since each of the video signals GDi (fn) and GDi (fn−1) is a digital signal indicating 256 gradations, M is 256. Therefore, the lookup table 40G stores 256 × 256 = 65536 matrix elements d (k, l).

  The matrix element d (k, l) is set for each combination of the numbers of gradations of the video signals GDi (fn) and GDi (fn−1). For example, the matrix element d (k, l) is output instead of the video signal GDi (fn). This is a correction value indicating a correction amount to be applied to the gradation value of the video signal GD′i (fn) or the video signal GDi (fn) that is the corrected video signal.

  The video signal GD′i (fn) is a luminance gradation of green light to be displayed by the pixel unit corresponding to the video signal GDi (fn) in the Nth frame, more specifically, the ideal of the pixel unit in the Nth frame. Gradation number data corresponding to the applied voltage applied to the liquid crystal is included so that a typical transmittance can be realized. Therefore, for example, in the pixel portion specified by the suffix i among the pixel portions that display green, the Nth frame is selected when the transmittance in the (N−1) th frame is switched to the transmittance in the Nth frame according to the frame period. The gradation value included in the video signal GD′i (fn) is set to be larger than the gradation value included in the video signal GDi (fn) so that the transmittance is set to be higher than the transmittance. In this way, by displaying the Nth frame image based on the video signal GD′i (fn) output instead of the video signal GDi (fn), it is possible to reduce display defects such as moving image blur that occurs in the moving image.

  The matrix element d (k, l) may be a correction value for correcting the video signal GDi (fn) so that the Nth frame image is displayed at the luminance gradation to be displayed. The control unit 60 can also generate a new video signal by referring to the matrix element d (k, l) indicating the correction value, and supply the generated video signal to the D / A converter 50G. is there. In this way, the process of outputting the video signal GD′i (fn) instead of the video signal GDi (fn) based on the video signals GDi (fn) and GDi (fn−1) It is an example of "overdrive processing" concerning the 3rd invention.

  As described above, according to the liquid crystal device 1, the human vision is most insensitive to the change in chromaticity of blue and red compared to the change in brightness (Y), and thus contributes most to the brightness (Y). Green is the number of gradations to be displayed in the display area 10a, and an overdrive process is performed on the video signal corresponding to the green to reduce display defects such as moving image blur, and is displayed by an electro-optical device such as a liquid crystal device. It is possible to improve the quality of moving images.

  On the other hand, as shown in FIG. 6, overdrive processing is performed on each of the video signals RDi (fn), GDi (fn), and BDi (fn), and the video signals RD′i (fn) subjected to the overdrive processing are processed. In order to output GD′i (fn) and BD′i (fn), not only the frame memory 30G and the look-up table 40G, but also the frame memories 30R and 30B corresponding to the red and blue video signals, In addition, it is necessary to provide the look-up tables 40R and 40B, and the circuit configuration of the liquid crystal device 1 becomes complicated.

  However, according to the liquid crystal device 1, since the video signal RDi (fn), GDi (fn), and BDi (fn) need only be subjected to overdrive processing on the video signal GDi (fn), the video signal RDi (fn) ) And BDi (fn) need not be provided with a frame memory and a lookup table for performing overdrive processing. Therefore, the circuit configuration of the liquid crystal device 1 can be simplified, and the cost required for the liquid crystal device can be reduced. In addition, since the space for providing a circuit for performing overdrive processing on the video signals RDi (fn) and BDi (fn) corresponding to red and blue can be reduced, there is an advantage that the liquid crystal device 1 can be reduced in size.

(Driving method of liquid crystal device)
Next, with reference to FIG. 7, a liquid crystal device driving method executed by the liquid crystal device driving circuit applied to the liquid crystal device 1 described above will be described. FIG. 7 is a flowchart of the driving method of the liquid crystal device according to the present embodiment. In describing the driving method of the liquid crystal device according to the present embodiment, the respective units illustrated in FIGS. 3 and 4 are referred to as needed.

  In FIG. 7, the frame memory 30G stores the video signal GDi (fn-1) (S10). Next, when the video signal GDi (fn) is supplied to the frame memory 30G under the control of the control unit 60, the video signal GDi (fn-1) is read to the lookup table 40G (S20). At the same time or before and after, the video signal GDi (fn) is supplied from the line buffer 31G to the lookup table 40G, and under the control of the control unit 60, the matrix element d () stored in the lookup table 40G. k, l) is selected. Accordingly, the video signal GD′i (fn) is selected (S30). Next, under the control of the control unit 60, the video signal GD'i (fn) is supplied from the lookup table 40G to the D / A converter 50 (S40), and the video signal GD'i (fn), which is a digital signal, is supplied. Are converted into analog signals (S50). Steps S10 to S50 correspond to an example of the “video signal processing step” according to the fifth aspect of the present invention.

  Next, the data line driving circuit 101 applies the video signal GD′i (fn), which is a digital signal, to the data line 6a as a video signal Dv obtained by converting the video signal GD′i (fn) into an analog signal at a timing according to the clock signal and the horizontal synchronization signal HSYNC. The Nth frame image is displayed in the display area 10a by the operation of each pixel unit according to the sending (S60) and the scanning signal ScLn1 supplied to the scanning line 3a. Step S60 corresponds to an example of a “driving step” according to the fifth aspect of the present invention.

  Next, it is determined whether or not the image display on the display panel 100p has been completed (S70). If the display has been completed, a series of steps consisting of steps S10 to S60 is completed. On the other hand, if the image display has not ended, the process returns to step 10 again, and the (N + 1) th frame image is displayed in the same process as the process of displaying the Nth frame image, and consists of steps S10 to S70. A series of steps is executed until the image display is completed.

  According to the driving method of the liquid crystal device according to the present embodiment described above, an overdrive process is performed by each circuit unit included in the liquid crystal device 1 described above, and high-quality image display can be performed.

Second Embodiment
Next, referring to FIGS. 8 to 11, the electro-optical device according to the second invention of the present invention, the drive circuit for the electro-optical device according to the fourth invention of the present invention, and the sixth invention of the present invention. Embodiments of the driving method of the electro-optical device according to the invention will be described. In the following description, the same reference numerals are assigned to the portions common to the above-described liquid crystal device 1 and its driving method, and detailed description thereof is omitted. FIG. 8 is a block diagram showing the circuit configuration of the signal processing unit 20 in the liquid crystal device according to the present embodiment together with the look-up table 40 and the frame memory 30. FIG. 9 is a list showing a data structure of a lookup table corresponding to a video signal for displaying each of red and blue. FIG. 10 is a flowchart of the driving method of the liquid crystal device according to the present embodiment.

  In FIG. 8, the signal processing unit 20 included in the liquid crystal device according to the present embodiment includes three line buffers 31R, 31G, and 31B corresponding to the video signals RDi (fn), GDi (fn), and BDi (fn), respectively. And a control unit 60. Similarly to the line buffer, the look-up table 40 includes three look-up tables 40G that are examples of “first look-up tables” and look-up tables 40R and 40B that are examples of “second look-up tables”. I have. Similarly, the frame memory 30 includes a frame memory 30G as an example of a “first frame memory” and frame memories 30R and 30B as examples of a “second frame memory”.

  The liquid crystal device according to the present embodiment is different from the liquid crystal device 1 according to the first embodiment in that the video signal GDi (fn) is converted into the video signals RDi (fn) and BDi (fn) as will be described in detail later. The overdrive process is performed under different conditions. That is, in the present embodiment, the “different condition” means that the video signal RDi (fn) is compared with the storage capacity of the frame memory and the lookup table corresponding to the video signal GDi (fn), as will be described in detail later. And the storage capacity of the frame memory and the lookup table corresponding to each of BDi (fn) are set small, and the accuracy of overdrive processing applied to each video signal according to the difference in the storage capacity, more specifically, Means different gradation numbers. As described above, the reason why the video signal GDi (fn) is overdriven with different accuracy from the video signals RDi (fn) and BDi (fn) contributes most to the luminance (Y) of the YUV color space as described above. The color element is based on being green. More specifically, for example, by performing overdrive processing on the video signal GDi (fn) with higher accuracy than the video signals RDi (fn) and BDi (fn), it is most effective in eliminating display defects such as motion blur. This is based on increasing the switching accuracy of the transmittance in the pixel portion that displays the green color considered to be.

  In FIG. 8, the frame memory 30R is specified by 8 bits as an example of gradation number data included in the video signal RDi (fn-1) which is an 8-bit digital signal, that is, "third gradation number data". Among the data capable of displaying 256 luminance gradations, gradation number data for 4 bits is stored. Therefore, the frame memory 30R stores the accuracy of the number of gradations included in the video signal RDi (fn-1) with a reduced accuracy. Similarly, the frame memory 30B is specified by 8 bits as an example of gradation number data included in the video signal BDi (fn-1) which is an 8-bit digital signal, that is, "third gradation number data". Of the data capable of displaying 256 luminance gradations, 4 bits of gradation number data are stored. The frame memory 30B also stores the accuracy of the number of gradations included in the video signal BDi (fn-1) with a reduced accuracy. On the other hand, similarly to the liquid crystal device 1 according to the first embodiment, the frame memory 30G receives the video signal GDi (fn−1) including 8-bit gradation number data, which is an example of “first gradation number data”. I remember it as it is. Therefore, the frame memories 30R and 30B have a simple circuit configuration compared to the frame memory 30G.

  When the video signal RDi (fn) is supplied from the line buffer 31R to the frame memory 30R under the control of the control unit 60, the frame memory 30R receives the video signal RDi (fn−1) stored as a 4-bit digital signal. This is supplied to the lookup table 40R. At the same time or in succession, the video signal RDi (fn) is supplied from the line buffer 31R, and the video signal RDi (fn) including 8-bit gradation number data and the video including 4-bit gradation number data are provided. Based on the signal RDi (fn−1), the video signal RD′i (fn) is output from the lookup table 40R to the D / A converter 50 instead of the video signal RDi (fn). The video signal BD′i (fn) is also output from the lookup table 40B to the D / A converter 50 in the same manner as the video signal RDi (fn). On the other hand, the video signal GD′i (fn) is output to the D / A converter 50 by the same process as the process executed in the liquid crystal device 1 according to the first embodiment.

  Here, the data structure of the lookup tables 40R and 40B will be described with reference to FIG. As shown in FIG. 9, the data structures of the look-up tables 40R and 40B are video signals RDi (fn−1) and BDi (fn−1) that are 4-bit digital signals supplied from the frame memories 30R and 30B, respectively. ) And the number of bits of the video signals RDi (fn) and BDi (fn), which are 8-bit digital signals supplied from the line buffers 31R and 31B, the data stored in the lookup table 40G. It is stored with a capacity smaller than the capacity. More specifically, taking a video signal for displaying red as an example, as shown in FIG. 9, the gradation of a 4-bit video signal RDi (fn−1) that defines a column of the lookup table 40R. The number is a 16 gradation number defined by 4 bits which is smaller than the original gradation number defined by 8 bits (256 luminance gradations). Here, M in FIG. 9 is 256. According to the 8-bit video signal RDi (fn) that defines the rows of the lookup table 40R, the rows of the lookup table 40R are 256 rows. Therefore, it is a matrix element of the look-up table 40R and is referred to for outputting the video signal RD′i (fn) subjected to the overdrive process, or is directly output as the video signal RD′i (fn). The matrix elements d (k, l) are stored in 256 × 16 = 4096, which is smaller than the matrix elements stored in the lookup table 40G. Similarly to the lookup table 40R, the lookup table 40B has fewer matrix elements stored than the lookup table 40G. Therefore, since the data size of the matrix elements stored in each of the lookup tables 40R and 40B is smaller than the data size of the matrix elements stored in the lookup table 40G, the circuit configuration of the entire lookup table can be simplified. it can. In addition, since the frame memory and the lookup table can have a simple circuit configuration, the size of the liquid crystal device can be reduced.

  Even if the data structure of the frame memory and the lookup table for performing the overdrive processing on the video signals corresponding to red and blue is simplified as described above, the overdrive processing on the video signal GDi (fn) is performed on the video. If the number of gradations is smaller than that of the signals RDi (fn) and BDi (fn), display defects such as moving image blur can be effectively reduced.

  Next, a driving method of the liquid crystal device executed by the driving circuit for the liquid crystal device applied to the liquid crystal device according to the present embodiment will be described with reference to FIG.

  In FIG. 10, each of the frame memories 30G, 30R, and 30B stores the video signals GDi (fn-1), RDi (fn-1), and BDi (fn-1) simultaneously or successively (S110). ).

  Next, when the video signals GDi (fn), RDi (fn), and BDi (fn) are respectively supplied to the frame memories 30G, 30R, and 30B under the control of the control unit 60, the video signal GDi (fn) is supplied. -1), RDi (fn-1), and BDi (fn-1) are read into the lookup table 40G (S120). At the same time or in succession, the video signals GDi (fn), RDi (fn), and BDi (fn) from the line buffers 31G, 31R, and 31B are respectively transferred to the look-up tables 40G, 40R, and 40B. The video signals GD′i (fn), RD′i (fn), and BD′i (fn) stored in the lookup tables 40G, 40R, and 40B are selected under the control of the control unit 60. (S130). Such video signals GD′i (fn), RD′i (fn), and BD′i (fn) are matrix elements stored in, for example, the look-up tables 40G, 40R, and 40B.

  Next, under the control of the control unit 60, each of the video signals GD′i (fn), RD′i (fn), and BD′i (fn) from the look-up tables 40G, 40R, and 40B is D / A. The video signal GD′i (fn), RD′i (fn), and BD′i (fn), which are digital signals, are supplied to the converter 50 (S140) and converted into analog signals (S150). Steps S110 to S150 correspond to an example of the “video signal processing step” according to the sixth aspect of the present invention.

  Next, the data line driving circuit 101 converts the video signal GD′i (fn), RD′i (fn), and BD′i (fn), which are digital signals, into a clock signal from the video signal Dv obtained by converting the analog signal. The image is sent to the data line 6a at a timing corresponding to the horizontal synchronization signal HSYNC (S160), and the nth frame image is displayed in the display area 10a by the operation of each pixel unit corresponding to the scanning signal ScLn1 supplied to the scanning line 3a. The Step S160 corresponds to an example of the “driving step” according to the sixth aspect of the present invention.

  Next, it is determined whether or not the image display by the display panel 100p is finished (S70), and when finished, a series of steps consisting of steps S110 to 150 is finished. On the other hand, if the image display has not ended, the process returns to step S110 again, and the (n + 1) th frame image is displayed in the same process as the process of displaying the nth frame image, and consists of steps S110 to S60. A series of steps is executed until the image display is completed.

  As described above, according to the liquid crystal device according to the present embodiment, high-quality image display can be performed similarly to the liquid crystal device according to the first embodiment. In addition, compared to a circuit unit that overdrives a video signal corresponding to green, it can be simplified compared to a circuit unit that overdrives a video signal corresponding to each of red and blue. In addition, the apparatus size can be reduced.

(Modification)
Next, a modification of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 is a block diagram showing the signal processing unit 20 in the liquid crystal device according to this example together with a look-up table and a frame memory. FIG. 12 is a list showing a data structure of a lookup table that is referred to for performing overdrive processing on video signals corresponding to red and blue.

  The liquid crystal device according to this example is characterized in that the capacities of the look-up tables 40R and 40B are smaller than the liquid crystal device according to this embodiment described above. More specifically, as shown in FIG. 11, the video signal GDi (fn) is an 8-bit digital signal, whereas the video signals RDi (fn) and BDi (fn) are 6-bit digital signals. is there. In addition, each of the video signals RDi (fn-1) and BDi (fn-1) supplied from the frame memories 30R and 30B to the look-up tables 40R and 40B, respectively, also includes 6-bit gradation number data. It is a digital signal. Accordingly, as shown in FIG. 12, each of the look-up tables 40R and 40B includes the bits of the video signals RDi (fn) and BDi (fn), and RDi (fn-1) and BDi (fn-1). Depending on the number, 64 × 64 = 4096 matrix elements are stored. The control unit 60 converts the video signals RD′i (fn) and BD′i (fn) subjected to overdrive processing to the D / A converter based on the matrix elements stored in the lookup tables 40R and 40B, respectively. Output to 50. Thus, even if the number of gradations of the video signals RDi (fn) and BDi (fn) is processed to be coarser than that of the video signal GDi (fn), the image quality of the image displayed in the display area 10a is over-drive processed. Compared to the case where it is not applied, it is greatly improved. Further, the same effect can be obtained even if the number of bits of correction data stored in each of the look-up tables 40R and 40B is reduced.

(Electronics)
Next, a case where the liquid crystal device according to the first embodiment or the second embodiment is applied to an electronic device will be described. Here, a projector using the liquid crystal device 1 as a light valve will be described. FIG. 13 is a plan view showing a configuration example of the projector.

  As shown in FIG. 13, a projector 1100 includes a lamp unit 1102 made up of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide, and liquid crystal as a light valve corresponding to each primary color. Incident to devices 100R, 100B, and 100G. The configurations of the liquid crystal devices 100R, 100B, and 100G are the same as those of the above-described liquid crystal device, and R, G, and B primary color signals supplied from the image signal processing circuit are modulated in each. Light modulated by these liquid crystal devices is incident on the dichroic prism 1112 from three directions. In the dichroic prism 1112, R and B light is refracted at 90 degrees, while G light goes straight. As a result, the images of the respective colors are combined, and a color image is projected onto the screen 1120 and the like via the projection lens 1114.

  In the above, a liquid crystal device has been described as a specific example of the electro-optical device of the present invention. However, the electro-optical device of the present invention also uses an electrophoretic device such as electronic paper or an electron-emitting device. It can be realized as a display device (Field Emission Display and Surface-Conduction Electron-Emitter Display). In addition to the projector described above, the electro-optical device of the present invention includes a television receiver, a viewfinder type or a monitor direct-view type video tape recorder, a car navigation device, a pager, and an electronic notebook. It can be applied to various electronic devices such as a calculator, a word processor, a workstation, a video phone, a POS terminal, and a device having a touch panel.

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

It is the conceptual diagram which showed the relationship between the transmittance | permeability of the pixel in the conventional liquid crystal device, and the applied voltage applied to a liquid crystal. It is the conceptual diagram which showed the relationship between the transmittance | permeability of the pixel in the liquid crystal device which concerns on 1st Embodiment, and the applied voltage applied to a liquid crystal. 1 is a block diagram illustrating a basic electric circuit configuration of a liquid crystal device according to a first embodiment. 3 is a block diagram showing a detailed circuit configuration of a signal processing unit together with a frame memory, a lookup table, and a D / A converter 50. FIG. It is the list | wrist which showed the gradation number data memorize | stored in the look-up table with which the liquid crystal device which concerns on 1st Embodiment is equipped. It is a block diagram in the comparative example of FIG. 4 is a flowchart of a driving method of the liquid crystal device according to the first embodiment. It is the block diagram which showed the circuit structure of the signal processing part in the liquid crystal device which concerns on 2nd Embodiment with the look-up table, the frame memory, and the D / A converter. It is the table | surface which showed the data structure of the look-up table corresponding to the video signal for displaying each of red and blue. It is a flowchart of the drive method of the liquid crystal device which concerns on 2nd Embodiment. It is a block diagram which shows the circuit structure of the principal part of the modification of the liquid crystal device which concerns on 2nd Embodiment. 12 is a list showing a data structure of a lookup table referred to in order to perform overdrive processing on video signals corresponding to red and blue in the modification shown in FIG. It is sectional drawing showing the structure of the liquid crystal projector which concerns on one Embodiment of the electronic device which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 20 ... Signal processing part, 30 ... Frame memory, 40 ... Look-up table, 50 ... D / A converter, 60 ... Control part, 101 ... Data line driving circuit, 104... Scanning line driving circuit

Claims (12)

An electro-optical panel having a plurality of pixel portions provided in a display region on the substrate;
A predetermined video corresponding to a color element that contributes most to luminance in a specific color space among video signals supplied to the electro-optical panel for displaying a series of frame images constituting an image to be displayed in the display area An electric signal processing means for performing an overdrive process on the predetermined video signal so that a gradation value specified by the predetermined video signal is displayed on the pixel unit. Optical device. The video signal processing means includes
A frame memory for storing first gradation number data included in a first video signal corresponding to a first frame image included in the series of frame images of the predetermined video signal;
(I) the first gradation number data, and (ii) a second video signal corresponding to a second frame image displayed in the display area following the first frame image among the predetermined video signals. A corrected second video signal output instead of the second video signal for each combination of second gradation number data, or a lookup table storing a correction value for the second gradation number data. The electro-optical device according to claim 1. An electro-optical panel having a plurality of pixel portions constituting a display region on the substrate;
A predetermined color element corresponding to a predetermined color element that contributes most to luminance in a specific color space among video signals supplied to the electro-optical panel for displaying a series of frame images constituting an image to be displayed in the display area. The video signal is applied to another video signal corresponding to another color element different from the predetermined color element so that the predetermined color element is displayed with a gradation value specified by the predetermined video signal. And an image signal processing means for performing overdrive processing under conditions different from those of the overdrive processing. The video signal processing means includes
A first frame memory for storing first gradation number data included in a first video signal corresponding to a first frame image included in the series of frame images of the predetermined video signal;
(I) the first gradation number data, and (ii) a second video signal corresponding to a second frame image displayed in the display area following the first frame image among the predetermined video signals. A corrected second video signal output instead of the second video signal for each combination of second gradation number data, or a first lookup table storing correction values for the second gradation number data; ,
A second frame memory for storing third gradation number data included in a third video signal corresponding to the first frame image among the other video signals;
For each combination of the fourth gradation number data included in the fourth video signal corresponding to the second frame image among (iii) the third video signal and (iv) the other video signal, the fourth video signal. 4. The electro-optic according to claim 3, further comprising: a corrected fourth video signal output instead of the second video signal, or a second look-up table in which correction values for the fourth gradation number data are stored. apparatus. The electro-optical device according to claim 4, wherein a size of the third gradation number data is smaller than a size of the first gradation number data. The electro-optical device according to claim 4, wherein a size of the fourth gradation number data is smaller than a size of the second gradation number data. The electro-optical device according to claim 4, wherein a size of the second lookup table is smaller than a size of the first lookup table. Corresponding to the color element that contributes most to the luminance in a specific color space among the video signals supplied to the electro-optical panel in order to display a series of frame images constituting an image to be displayed in the display area of the electro-optical panel Video signal processing means for performing an overdrive process on the predetermined video signal so that the color element is displayed on the pixel unit with a gradation value specified by the predetermined video signal for the predetermined video signal;
A drive circuit for an electro-optical device, comprising: a drive circuit that drives the pixel unit based on a signal generated by performing the overdrive process on the predetermined video signal. In order to display a series of frame images constituting an image to be displayed in the display area of the electro-optical panel, predetermined color elements that contribute most to the luminance in a specific color space among video signals supplied to the electro-optical panel are displayed. For the corresponding predetermined video signal, the other corresponding to another color element different from the predetermined color element so that the predetermined color element is displayed on the pixel unit with a gradation value specified by the predetermined video signal. Video signal processing means for performing overdrive processing under conditions different from the overdrive processing applied to the video signal;
A drive circuit for driving the pixel unit based on a signal generated by applying an overdrive process performed under the different conditions to the predetermined video signal. circuit. Corresponding to the color element that contributes most to the luminance in a specific color space among the video signals supplied to the electro-optical panel in order to display a series of frame images constituting an image to be displayed in the display area of the electro-optical panel For a predetermined video signal, a video signal processing step of performing an overdrive process on the predetermined video signal so that the color element is displayed in a pixel unit with a gradation value specified by the predetermined video signal;
And a driving step of driving the pixel unit based on a signal generated by performing the overdrive process on the predetermined video signal. In order to display a series of frame images constituting an image to be displayed in the display area of the electro-optical panel, predetermined color elements that contribute most to the luminance in a specific color space among video signals supplied to the electro-optical panel are displayed. For the corresponding predetermined video signal, the other corresponding to another color element different from the predetermined color element so that the predetermined color element is displayed on the pixel unit with a gradation value specified by the predetermined video signal. Video signal processing step of performing overdrive processing under conditions different from the overdrive processing applied to the video signal of
A driving step of driving the pixel unit based on a signal generated by applying an overdrive process performed under the different conditions to the predetermined video signal. Method. An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 7.

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