JP2010169995A - Driving device and method for electro-optical apparatus, and electro-optical apparatus and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the image quality of a display image while reducing the risk of causing flicker and image persistence, which are caused by polarity switching, in a driving device for an electro-optical apparatus. <P>SOLUTION: The driving device for the electro-optical apparatus includes scanning lines (14a), data lines (14b), and pixel parts (14c) arranged at the intersections of the scanning lines and data lines. The driving device further includes: an input means (40) in which an image signals of different frame periods are input; and driving voltage supply means (40, 101) that supply the input image signals to the corresponding pixel parts as driving voltages of predetermined polarities and, at the same time, change at least the frame periods or predetermined polarities so that a first period of time in which the driving voltage of the positive polarity is supplied and a second period of time in which the driving voltage of negative polarity is supplied are almost equal during a predetermined period of time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving device and a driving method for an electro-optical device such as a liquid crystal device, an electro-optical device including the driving device, and an electronic apparatus such as a liquid crystal projector including the electro-optical device. Related to the field.

  In this type of electro-optical device, the alignment state of the electro-optical material is controlled by applying a driving voltage corresponding to the display image to a portion of the electro-optical material such as liquid crystal in each pixel portion. The electro-optical material forms a predetermined alignment state by a driving voltage, and an image is displayed. Here, for example, if a polarity deviation occurs in the applied drive voltage, the display panel will be burned or flicker will occur in the display image. That is, if the drive voltage includes a direct-current voltage component, such a problem occurs.

  For example, in Patent Document 1, the drive voltage is converted into an alternating current by inverting the polarity of the drive voltage applied to the pixel with respect to the reference voltage for each frame. That is, “frame inversion driving” is performed. That is, the polarity reversal kills the DC voltage component included in the drive voltage and prevents the polarity from being biased.

JP 58-169190 A

  However, the number of scanning lines scanned in each frame may be different when converting the resolution of a display image in order to achieve compatibility between image signal standards corresponding to various resolutions and display device standards. Can do. Then, in a predetermined period including a plurality of frames, the total length of the frames to which the positive drive voltage is applied and the total length of the frames to which the negative drive voltage is applied are different from each other. Will occur. That is, by reversing the polarity, the original purpose of inversion driving, which cancels out the positive polarity and the negative polarity, cannot be achieved. This DC voltage component gradually increases as the operation time of the electro-optical device elapses, and increases the risk of image sticking and flickering on the display panel. As a result, the service life of the electro-optical device is shortened. On the other hand, in order to avoid the occurrence of such a case, it is necessary to make sure that the amount of data is consistent between the frames. Especially, there is a big restriction on the specifications of the device that converts the resolution. It becomes a serious problem.

  The present invention has been made in view of, for example, the above-described problems, and is a driving apparatus and method for an electro-optical device that can improve the image quality of a display image while reducing the risk of occurrence of flicker and burn-in associated with polarity switching. It is another object of the present invention to provide an electro-optical device including the driving device and an electronic apparatus including the electro-optical device.

  In order to solve the above-described problem, a drive device for an electro-optical device according to the present invention includes a plurality of scanning lines, a plurality of data lines intersecting the plurality of scanning lines, and intersections of the plurality of scanning lines and the plurality of data lines. An electro-optical device driving device comprising a plurality of correspondingly arranged pixel units, wherein an input means to which image signals having at least two different frame periods are input, and the input image signals are predetermined A first period in which the drive voltage having a positive polarity is supplied in a predetermined period including a plurality of frames, while supplying the drive voltage having a polarity of 1 to the pixel portion via the data line, and the negative polarity. In at least a part of the frame included in the predetermined period, the second period during which the drive voltage is supplied is less than the frame period and the predetermined polarity. And a drive voltage supply means also change one and.

  According to the driving apparatus of the present invention, during the operation, various signals such as a power signal, a data signal, and a control signal are input / output via the input means. Then, for example, a scanning signal is supplied to the pixel portion via a plurality of scanning lines by scanning signal supply means including a scanning line driving circuit or the like built on the substrate. In parallel with this, an image signal is supplied to the pixel portion simultaneously or sequentially by drive voltage supply means including, for example, a data line drive circuit, a sampling circuit, and the like. Here, the “pixel portion” is arranged in a matrix in the image display region, for example, and an electro-optical material such as liquid crystal is sandwiched between a pair of substrates, and active driving is performed by the pixel switching TFT. For example, when a scanning signal is applied to the gate terminal of the pixel switching TFT, the image signal supplied from the data line is written to the pixel electrode constituting the pixel portion via the source / drain of the pixel switching TFT. . As described above, the driving voltage corresponding to the image signal is applied between the pixel electrode constituting the pixel portion and the counter electrode, thereby controlling the operation state of the electro-optical material such as the alignment state of the liquid crystal. Is displayed.

  For example, an image signal having at least two different frame periods is input to the input means in the present invention from an external image signal supply circuit. Here, “having different frame periods” means that, for example, in an external image signal supply circuit, the resolution of a display image is converted in order to achieve compatibility between image signal standards corresponding to various resolutions and display device standards. When the frame period is different between the odd frame and the even frame, for example, the total number of lines in one frame period is different by one scanning line between the odd frame and the even frame.

  Note that the polarity of the image signal input to the input means is biased to the polarity by causing the drive voltage based on the image signal applied to the pixel unit to be AC, as in Patent Document 1, by killing the DC voltage component. In order to prevent this from occurring, it may be inverted every horizontal period or every frame.

  The drive voltage supply means supplies the input image signal to the pixel unit through the data line as a drive voltage having a predetermined polarity. That is, the image signal input to the input means is converted into a format suitable for driving the pixel unit, if necessary, and supplied. That is, when the input image signal itself is already in a format suitable for driving the pixel portion, the image signal and the drive voltage may be the same voltage signal, and the drive voltage supply means Need not be converted.

  Particularly in the present invention, the drive voltage supply means includes a first period in which the drive voltage having a positive polarity is supplied and a second period in which the drive voltage having a negative polarity is supplied in a predetermined period including a plurality of the frame periods. At least one of the frame period and the predetermined polarity in at least some of the frames included in the predetermined period is changed so that the period approaches the same length. Here, “to approach” does not mean only when the first period and the second period are equal, but less than before the change of at least one of the frame period and the predetermined polarity. This is intended to include a wide range of cases.

  Here, as described above, since the image signal input to the input unit has a different frame period, just as in the case of Patent Document 1, if the polarity of the drive voltage is simply inverted for each frame, the image signal is not generated in a predetermined period. Since the period in which the drive voltage having positive polarity is supplied and the period in which the drive voltage having positive polarity are supplied are different from each other, a difference occurs in the time during which the drive voltage having each polarity is applied. As a result, a DC voltage component is generated, and a defect such as image sticking occurs in the pixel portion.

  In order to prevent the occurrence of such a problem, the present invention is configured such that at least one of the frame period and the predetermined polarity in at least a part of the frames included in the predetermined period can be changed by the drive voltage supply means. is doing. For example, if the frame period is changed, the ratio of the first period and the second period to the predetermined period can be adjusted, so that the polarity difference that can occur in the predetermined period can be reduced. Further, for example, also by changing the polarity of the driving voltage, the ratio of the first period and the second period to the predetermined period can be adjusted in the same manner, so that the polarity difference that can occur in the predetermined period is reduced. be able to.

  From the viewpoint of removing the DC voltage component, it is most preferable that the first period and the second period in the predetermined period are completely the same length, but in the first period and the second period. Even if the difference is reduced, the DC voltage component can be reduced relatively, and the risk of image sticking and flickering can be reduced.

  The “predetermined period” only needs to be composed of two or more frames, but setting it as short as possible reduces the adverse effect on the electro-optical material such as liquid crystal due to the application of the DC voltage component or makes the flicker less noticeable. This is desirable from the point of view. In other words, the “predetermined period” may be long as long as the adverse effect on the electro-optical material such as liquid crystal due to the application of the DC voltage component does not become apparent or flicker is not noticeable.

  The timing for inverting the polarity of the driving voltage may be so-called “frame inversion driving” in which the polarity is inverted for each frame, or so-called “1H inversion driving” in which the polarity is inverted for each scanning line. . Furthermore, the present invention can also be applied in the case of “region scanning driving” in which one surface of a pixel region in which a plurality of pixel portions are arranged is inverted so as to have the same polarity for each partial region divided into a plurality of regions. .

  Thus, by changing at least one of the frame period of the drive voltage and the predetermined polarity, the original purpose of polarity inversion driving, which is to cancel the positive polarity and the negative polarity, is This can be achieved even when the frame periods are different. As a result, even when incorporated in an electro-optical device or the like, it is difficult to cause burn-in or the like on the display image by acting on an electro-optical material such as liquid crystal included in the pixel portion, and a driving device having a long lifetime can be realized.

  In one aspect of the electro-optical device drive device according to the present invention, the drive voltage supply unit includes the frame cycle and the frame cycle of a pair of frames having different frame cycles among the frames of the image signal input in the predetermined period. By changing at least one of the predetermined polarities, the first period and the second period are changed to approach the same length.

  According to this aspect, the polarity difference between the first period and the second period can be reduced by exchanging one of the frame period and the polarity of a set of frames having different frame periods. For example, it includes a relatively long frame having a positive polarity (hereinafter referred to as the former) and a relatively short frame having a negative polarity (hereinafter referred to as the latter). If the frame periods of the former and the latter are interchanged with each other by the drive voltage supply means, the latter having the negative polarity becomes longer than the former having the positive polarity. Thus, the negative polarity can be strengthened, that is, the bias toward the positive polarity can be reduced. Similarly, by switching the polarities of the former and the latter (that is, even when the length of each frame period is left unchanged, the former is changed to negative polarity and the latter is changed to positive polarity), the predetermined period is similarly applied. The bias in polarity can be reduced.

  In the above-described aspect, the predetermined period may include a plurality of the pair of frames.

  If the polarity bias in a predetermined period is large, it is possible to expect some correction of the polarity bias just by replacing at least one of the frame period and the predetermined polarity in a pair of frames, but depending on the remaining DC component There is still a risk that defects such as image sticking occur in the pixel portion. Therefore, in this case, by providing a plurality of pairs of frames in which at least one of the frame period and the predetermined polarity is replaced within a predetermined period, it is configured to be able to eliminate even a relatively large polarity deviation. .

  In another aspect of the electro-optical device drive device of the present invention, the drive voltage supply means inverts the polarity of the drive voltage for each horizontal scanning line.

  According to this aspect, in the so-called “1H inversion driving” in which each scanning line is inverted, the original purpose in the inversion driving can be achieved by reducing the polarity difference between the first period and the second period. .

  In another aspect of the electro-optical device driving device of the present invention, the driving voltage supply means is inverted in polarity for each frame.

  According to this aspect, in the so-called “frame inversion driving” in which the polarity of the image signal is inverted every frame, the original purpose in the inversion driving is achieved by reducing the polarity difference between the first period and the second period. It becomes possible.

  As already described, even in the case of “1H inversion driving”, “area scanning driving”, “dot inversion driving”, etc., positive and negative polarities can be obtained by averaging between odd frames and even frames. It is possible to achieve the original purpose of the inversion drive, which is to cancel the above.

  In order to solve the above-described problems, an electro-optical device according to the present invention includes the above-described electro-optical device drive circuit according to the present invention (including various aspects thereof).

  According to the electro-optical device of the present invention, since the above-described driving device of the present invention is provided, high-quality image display is possible without depending on the response characteristic change in each pixel unit.

  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, the liquid crystal device according to the present invention described above is included, so that a projection display device, a mobile phone, an electronic notebook, a word processor, a viewfinder type capable of high-quality display, or 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.

It is a block diagram which shows schematic structure of the drive device of the liquid crystal device which concerns on this embodiment. FIG. 5 is a timing chart showing input / output timings of control signals and the like of the scanning line driving circuit according to the present embodiment. FIG. 10 is a timing chart showing input / output timings of control signals and the like of a scanning line driving circuit according to a modification. 1 is a plan view of an electro-optical device to which the present invention is applied. It is HH 'sectional drawing of FIG. It is an example of the electronic device to which this invention is applied. It is another example of the electronic device to which this invention is applied.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<Liquid crystal device>
First, an overall configuration of a liquid crystal device to which an electro-optical device driving device according to the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of the liquid crystal device according to this embodiment.

  In FIG. 1, a liquid crystal device 100 mainly includes a controller unit 40, a data line driving circuit 101 that partially constitutes an example of the “driving voltage supply means” according to the present invention, a scanning line driving circuit 104, and a display. A panel 200. The display panel 200 acquires a predetermined image signal and an electric signal such as a control signal, and displays an image corresponding to the image signal. Specifically, the controller unit 40 includes a sorting circuit 41, a first memory 42, a second memory 43, and a memory control circuit 44 that partially constitute an example of the “input unit” according to the present invention. The circuit 45 and the LCD control circuit 46 are included.

  The display panel 200 is configured by a plurality of pixel units including liquid crystal (LCD) and the like, and is a display unit that displays an image when a driving voltage corresponding to an image signal is applied to the pixel unit. Specifically, the scanning line 14a, the data line 14b, and the pixel 14c, which is an example of the “pixel portion” according to the present invention, are arranged in a matrix so as to correspond to the intersection of the scanning line 14a and the data line 14b. It has. In the present embodiment, in particular, n scanning lines 14a are formed on the display panel 200 so as to extend in the X (row) direction in the drawing, and m data lines 14b are along the Y (column) direction. It is formed to extend. Further, each of the n scanning lines 14a is supplied with a scanning signal G (however, the scanning signals corresponding to the respective scanning lines are expressed as G1 to Gn), so that the corresponding pixel 14c can be written. Can be.

  The image signal DATA is input to the controller unit 40, and the odd number image signal DATA1 contributing to the image display in the odd number frame by the distribution circuit 41 and the even number image signal D2 contributing to the image display in the even number frame are sequentially arranged for each frame period. Sorted. The odd image signal DATA1 and the even image signal DATA2 output from the distribution circuit 41 are stored in the first memory 42 and the second memory 43, respectively. The selection circuit 45 determines whether the period is an odd-numbered frame or an even-numbered frame during the operation of the liquid crystal device, and corresponding image signals from the first memory 42 and the second memory 43, that is, odd-numbered images for each frame. Either the signal DATA1 or the even image signal DATA2 is selected. The determination of whether the period is an odd frame or an even frame is based on the memory control circuit 44 that operates in synchronization with the vertical scanning signal VSYNC, the horizontal scanning signal HSYNC, and the clock signal CLK input to the controller unit 40. Determined or prescribed.

  The clock signal CLK, the vertical scanning signal VSYNC (that is, the synchronizing signal for vertical scanning), and the horizontal scanning signal HSYNC (that is, the synchronizing signal for horizontal scanning) are the memory control circuit 44 and the LCD control circuit 46 in the controller unit 40. To be supplied. The LCD control circuit 46 sends the vertical synchronization signal VS, the horizontal synchronization signal HS, the scanning side transfer clock CLY, and the data transfer clock CLX to the data line driving circuit 101 and the scanning line driving circuit 104 based on the acquired signals. The data line driving circuit 101 and the scanning line driving circuit 104 are supplied. The vertical synchronization signal VS is a pulse signal output at the scanning start timing for the scanning side (Y side) for each frame. The scanning-side transfer clock CLY is a signal that defines horizontal scanning on the scanning side (Y side). The horizontal synchronization signal HS is a pulse signal that determines the timing for starting data transfer to the data line driving circuit 101 every horizontal period, and is synchronized with the level transition (that is, rising and falling) of the scanning transfer clock CLY. Is output. The data transfer clock CLX is a signal that defines the timing for transferring data to the data line driving circuit 101.

  The data line driving circuit 101 acquires the horizontal synchronization signal HS, the data transfer clock CLX, and the image data signal D from the controller unit 40, and the data signals d1, d2, and d3 to the data line 14b of the display panel 200. ,..., Dm are output. Note that the image data signal D in the present embodiment is appropriately reversed so that the polarity of the drive voltage applied to the pixel 14c is described in detail later in order to prevent burn-in of the pixel 14c arranged in the display panel 200. Applied.

  Next, the input / output timing of each control signal during the operation of the liquid crystal device 100 will be described with reference to FIG. FIG. 2 shows (a) vertical scanning signal VSYNC, (b) horizontal scanning signal HSYNC, (c) image data signal D, (d) vertical synchronization signal VS, (e) horizontal synchronization signal HS, and (f) image data signal. FIG. 4D is a timing chart illustrating input / output timings of D and (g) scanning-side transfer clock CLY.

  When the vertical scanning signal VSYNC is input to the controller unit 40, the controller unit 40 generates a pulsed vertical synchronizing signal VS for each field. Thereafter, the scanning signal G is sequentially output in synchronization with the scanning side transfer clock CLY. Specifically, a shift register is incorporated in the scanning line driving circuit 104, and the scanning signal G is sequentially supplied to the n scanning lines 14a at a timing synchronized with the scanning side transfer clock CLY. When the scanning lines contributing to the image display are completely scanned, the vertical synchronization signal VS is input again through the blanking period, the next frame is shifted, and the scanning signal G is sequentially output again.

  In the present embodiment, five image data signals D are supplied to the pixels 14c in each frame, and each pixel data signal D is supplied with a scanning signal in each horizontal scanning period (displayed as 1H in FIG. 2). The image data corresponding to is included.

  In the first frame, after the vertical synchronization signal VS is input, the five image data signals D (D1, D3, D5, D7, and D9) are driven by data lines in synchronization with the input timing of the horizontal synchronization signal HS. This is supplied to the circuit 101. That is, while the scanning signals G1 to G5 are sequentially supplied, the image data signals D1, D3, D5, D7, and D9 are supplied to the pixels 14c arranged on the driven scanning line. Specifically, the image data signal D1 is supplied while the scanning signal G1 is supplied, the image data signal D3 is supplied while the scanning signal G2 is supplied, and the scanning signal G3 is supplied. The image data signal D5 is supplied, the image data signal D7 is supplied while the scanning signal G4 is supplied, and the image data signal D9 is supplied while the scanning signal G5 is supplied.

  Image data signals D (D1, D3, D5, D7, and D9) are supplied to the data line driving circuit 101 while their polarities are inverted each other for each horizontal period. That is, the image data signals D1, D5, and D9 are positive polarity, and the image data signals D3 and D7 are negative polarity image data signals.

  Here, the polarity of the pixel 14c designated by supplying the image data signal D once is held until the next image data signal D is supplied. Therefore, the polarity of the pixel 14c specified by supplying the image data signal D (D1, D3, D5, D7, and D9) in the first frame is the same until the image data signal D is supplied again in the second frame. It is kept as it is. Therefore, the polarity of each pixel 14c designated in the first frame is designated by the image data signal D (D1, D3, D5, D7 and D9) supplied in the first frame even during the blanking period. Will be held.

  In the second frame, after the vertical synchronization signal VS is input, five image data signals D (D2, D4, D6, D8, and D10) are synchronized with the input timing of the horizontal synchronization signal HS. 101. That is, the image data signals D2, D4, D6, D8, and D10 are supplied to the pixels 14c arranged on the driven scanning line while the scanning signals G1 to G5 are sequentially supplied. Specifically, the image data signal D2 is supplied while the scanning signal G1 is supplied, the image data signal D4 is supplied while the scanning signal G2 is supplied, and the scanning signal G3 is supplied. The image data signal D6 is supplied, the image data signal D8 is supplied while the scanning signal G4 is supplied, and the image data signal D10 is supplied while the scanning signal G5 is supplied.

  The polarities of the image data D supplied in the second frame are also supplied to the data line driving circuit 101 while being inverted. Since the polarity of the image data signal D1 supplied to the first line of the first frame is positive, the polarity of the image data signal D2 supplied to the first line in the second frame is set to be negative. Accordingly, among the image data signals D supplied in the second frame, the image data signals D2, D6, and D10 have a positive polarity, and the image data signals D4 and D8 have a negative polarity.

  Here, a period from the last supply of the image data signal D9 in the first frame to the first supply of the image data signal D2 in the second frame (hereinafter referred to as the first blanking period) is the second period. This is longer than the period from when the image data signal D10 is supplied last in the frame to when the image data signal D1 is supplied for the first time in the third frame (hereinafter referred to as the second blanking period). As described above, since the first blanking period and the second blanking period are different from each other, the polarity of the pixel 14c is biased when the entire first and second frames are viewed. For this reason, if the liquid crystal device is continuously driven in the same pattern as the first and second frames, the polarity difference increases with time, and a defect such as burn-in occurs in the pixel 14c.

  In the liquid crystal device according to the present embodiment, the signal input / output pattern in the subsequent third and fourth frames is configured to be different from those in the first and second frames described above, thereby causing defects such as burn-in in the pixel 14c. To suppress or eliminate. Specifically, a period from the last supply of the image data signal D9 in the third frame to the first supply of the image data signal D2 in the fourth frame (hereinafter referred to as a third blanking period) is In the period from the last supply of the image data signal D10 in the fourth frame to the first supply of the image data signal D1 in the fifth frame (not shown in FIG. 2) (hereinafter referred to as the fourth blanking period). It is configured to be smaller than that. As a result, the polarity bias generated in the first frame and the second frame can be reduced or almost canceled by the reverse polarity bias generated in the third frame and the fourth frame. Accordingly, when viewed between the first to fourth frames, the bias of the polarity generated in the image data signal D applied to the pixel 14c is reduced or almost eliminated, so that the pixel 14c has burn-in caused by a direct current component. Occurrence can be effectively prevented.

  As described above, in the present embodiment, by changing the input / output pattern of the first half and second half signals in four consecutive frames, it is possible to prevent the polarity of the drive voltage supplied to the pixel 14c from being biased. Can do. As a result, it is possible to realize a liquid crystal device that does not easily cause burn-in in the pixel 14c and has a long lifetime.

<Modification>
In the above-described embodiment, an example of so-called 1H inversion driving in which the polarity of the image data signal D is inverted every horizontal scanning period has been described (see FIG. 2). Here, the polarity of the image data signal D is changed for each frame. An example in so-called frame inversion driving, which is reversed to the above, will be described. FIG. 3 is a timing chart for the same purpose as FIG. 2 in this modification.

  The period from the last supply of the image data signal D9 in the first frame to the first supply of the image data signal D2 in the second frame (ie, the first blanking period) is the last in the second frame. After the image data signal D10 is supplied to the first frame, it is longer than the period until the image data signal D1 is supplied for the first time in the third frame (that is, the second blanking period). In this modification, unlike the above-described embodiment (see FIG. 2), display data is supplied to the pixels 14c in the third frame and the fourth frame in the same pattern as the first frame and the second frame. That is, the period from when the image data signal D9 is supplied last in the third frame to when the image data signal D2 is supplied for the first time in the fourth frame (that is, the third blanking period) is the fourth frame. In FIG. 5, the period from the last supply of the image data signal D10 to the first supply of the image data signal D1 in the fifth frame (that is, the fourth blanking period) is longer. Accordingly, if the polarity of the pixel 14c is simply inverted for each frame, the total period of the second frame and the fourth frame is shorter than the total period of the first frame and the third frame. When the entire area from the first frame to the fourth frame is viewed, a bias in polarity occurs. As a result, if the liquid crystal device continues to be driven, the polarity difference increases with time, causing defects such as image sticking to the pixel 14c, which is equivalent to applying a DC voltage component to the pixel 14c. In other words, it causes burn-in and the like on the pixels.

  Therefore, in this modification, instead of simply inverting the polarity of the pixel 14c for each frame, the polarity of the image data signal D supplied in the first frame and the fourth frame is positive, the second frame, and the third frame. The polarity of the image data signal D supplied in is set to be negative. In other words, in this modification, as shown in FIG. 3, the image data signal D having negative polarity is continuously supplied to the pixel 14c in the second frame and the third frame, so that the first to fourth frames are viewed. In this case, the polarity of the polarity of the image data signal D applied to the pixel 14c can be canceled out.

  As described above, even in the liquid crystal device employing the frame inversion driving, by appropriately adjusting the timing for switching the polarity, the occurrence of bias in the polarity applied to the pixel 14c can be reduced or almost eliminated, and the above-described embodiment can be achieved. Similarly, pixel burn-in and the like can be prevented.

<Electro-optical device>
Next, an electro-optical device driving device 100 to which the above-described driving device is applied will be described with reference to FIGS. 4 and 5. In the following embodiments, a TFT (Thin Film Transistor) active matrix driving type liquid crystal device, which is an example of the electro-optical device of the present invention, is taken as an example.

  First, the configuration of the electro-optical panel in the electro-optical device according to the present embodiment will be described. FIG. 4 is a plan view showing the configuration of the electro-optical panel according to this embodiment, and FIG. 5 is a cross-sectional view taken along the line HH ′ of FIG.

  4 and 5, in the electro-optical panel 500 according to the present embodiment, the TFT array substrate 10 and the counter substrate 20 are disposed to face each other. The TFT array substrate 10 is, for example, a transparent substrate such as a quartz substrate or a glass substrate, a silicon substrate, or the like. The counter substrate 20 is a transparent substrate such as a quartz substrate or a glass substrate. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20. 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. 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 such as glass fiber or glass bead is dispersed for setting the distance between the TFT array substrate 10 and the counter substrate 20 (that is, the inter-substrate gap) to a predetermined value.

  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. A 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 area 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.

  On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. Accordingly, electrical conduction is established between the TFT array substrate 10 and the counter substrate 20.

  Subsequently, in FIG. 5, on the TFT array substrate 10, a laminated structure in which pixel switching TFTs as drive elements, wirings such as scanning lines and data lines are formed is formed. Although the detailed structure of this laminated structure is not shown in FIG. 4, pixel electrodes 9a made of a transparent material such as ITO (Indium Tin Oxide) are provided on the laminated structure with a predetermined pattern for each pixel. It is formed in an island shape, and its surface is covered with an alignment film. The alignment film is in contact with the liquid crystal 50.

  The pixel electrode 9 a is formed in the image display area 10 a on the TFT array substrate 10 so as to face the counter electrode 21. On the surface of the TFT array substrate 10 facing the liquid crystal layer 50, that is, on the pixel electrode 9a, an alignment film 16 is formed so as to cover the pixel electrode 9a.

  A light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. For example, the light shielding film 23 is formed in a lattice shape when viewed in plan on the facing surface of the facing substrate 20. In the counter substrate 20, a non-opening area is defined by the light shielding film 23, and an area partitioned by the light shielding film 23 is an opening area that transmits light emitted from, for example, a projector lamp or a direct viewing backlight. The light shielding film 23 may be formed in a stripe shape, and the non-opening region may be defined by the light shielding film 23 and various components such as data lines provided on the TFT array substrate 10 side.

  On the light shielding film 23, a counter electrode 21 made of a transparent material such as ITO is formed so as to face the plurality of pixel electrodes 9a. In addition, in order to perform color display in the image display region 10a, a color filter (not shown in FIG. 5) may be formed on the light shielding film 23 in a region including a part of the opening region and the non-opening region. Good. An alignment film 22 is formed on the counter electrode 21 on the counter surface of the counter substrate 20.

  4 and 5, on the TFT array substrate 10, in addition to the drive circuits such as the data line drive circuit 101 and the scanning line drive circuit 104, an image signal on the image signal line (that is, the data signal). ) For sampling and supplying the data line to the data line, a precharge circuit for supplying a precharge signal of a predetermined voltage level to the plurality of data lines in advance of the image signal, and the electro-optical device during manufacture or at the time of shipment. You may form the inspection circuit etc. for inspecting quality, a defect, etc.

  The liquid crystal composing the liquid crystal layer 50) modulates light and enables gradation display by changing the orientation and order of the molecular assembly according to 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 electro-optical device as a whole.

  In order to prevent the image signal 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 21). 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 supply of an image signal. 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.

<Electronic equipment>
Next, specific examples of electronic devices to which the electro-optical device 500 according to the above-described embodiments can be applied will be described with reference to FIGS.

  First, an example in which the electro-optical device 500 according to the above-described embodiment is applied to a display unit of a portable personal computer (so-called notebook personal computer) will be described. FIG. 6A is a perspective view showing the configuration of this personal computer. As shown in the figure, a personal computer 710 includes a main body 712 having a keyboard 711 and a display 713 to which the liquid crystal display device 100 according to the present invention is applied.

  Next, an example in which the electro-optical device 500 according to the above-described embodiment is applied to a display unit of a mobile phone will be described. FIG. 6B is a perspective view showing the configuration of this mobile phone. As shown in the figure, the cellular phone 720 includes a plurality of operation buttons 721, a reception port 722, a transmission port 723, and a display unit 724 to which the liquid crystal display device 100 according to the present invention is applied.

  Next, a projector using the electro-optical device 500 according to the above-described embodiment as a light valve will be described with reference to FIG.

  As shown in FIG. 7, a projector 1100 includes a lamp unit 1102 made 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 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

  The configurations of the liquid crystal panels 1110R, 1110B, and 1110G are the same as those of the liquid crystal device described above, and are driven by R, G, and B primary color signals supplied from the image signal processing circuit. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In the dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Therefore, as a result of the synthesis of the images of the respective colors, a color image is projected onto the screen or the like via the projection lens 1114.

  Here, paying attention to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display image by the liquid crystal panel 1110G needs to be horizontally reversed with respect to the display images by the liquid crystal panels 1110R and 1110B.

  In addition, since light corresponding to each primary color of R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

  In addition to the electronic devices described with reference to FIGS. 6 and 7, 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, Examples include a pager, electronic notebook, calculator, word processor, workstation, videophone, POS terminal, and a device equipped with a touch panel. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal devices described in the above embodiments, the present invention includes a reflective liquid crystal device (LCOS), a plasma display (PDP), a field emission display (FED, SED), an organic EL display, and a digital micromirror device. (DMD), electrophoresis apparatus and the like are also applicable.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. For electro-optical devices with such changes The substrate, the electro-optical device, and the electronic apparatus including the electro-optical device are also included in the technical scope of the present invention.

  14a scanning line, 14b data line, 14c pixel, 40 controller unit, 41 distribution circuit, 42 first memory, 42 second memory, 44 memory control circuit, 45 selection circuit, 46 LCD control circuit, 100 image display device, 101 data Line driving circuit, 104 scanning line driving circuit, 200 display panel, 500 electro-optical device

Claims (7)

Electro-optical device driving apparatus comprising a plurality of scanning lines, a plurality of data lines intersecting with the plurality of scanning lines, and a plurality of pixel portions arranged corresponding to the intersections of the plurality of scanning lines and the plurality of data lines Because
Input means for inputting image signals having at least two different frame periods;
While the input image signal is supplied to the pixel portion via the data line as a drive voltage having a predetermined polarity, the drive voltage having a positive polarity is supplied in a predetermined period including a plurality of frames. In at least a part of the frame included in the predetermined period, the frame period and the predetermined polarity are set such that one period and the second period in which the negative drive voltage is supplied are close to the same length. And a drive voltage supply means for changing at least one of the drive devices for the electro-optical device.   The drive voltage supply means exchanges at least one of the frame period and the predetermined polarity for a pair of frames having different frame periods among the frames of the image signal input in the predetermined period, The electro-optical device drive device according to claim 1, wherein the first period and the second period are changed so as to approach the same length.   The electro-optical device driving device according to claim 2, wherein the predetermined period includes a plurality of the pair of frames.   4. The electro-optical device driving device according to claim 1, wherein the driving voltage supply unit reverses the polarity of the driving voltage for each horizontal scanning line. 5.   4. The electro-optical device driving device according to claim 1, wherein the driving voltage supply unit is inverted in polarity for each frame. 5.   An electro-optical device comprising the driving device for the electro-optical device according to claim 1.   An electronic apparatus comprising the electro-optical device according to claim 6.

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