JP2007219356A - Electro-optical device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device that can effectively eliminate deviation of charges in the electro-optical device. <P>SOLUTION: A liquid crystal device 1 comprises a substrate 10, a substrate 20, an inorganic alignment layer 16 provided on the substrate 10, an inorganic alignment layer 22 provided on the substrate 20 and having a film thickness larger than the film thickness of the inorganic alignment layer 16, a liquid crystal 50 in a tilted vertical alignment mode held between the inorganic alignment layer 16 and the inorganic alignment layer 22, and a voltage applying means to apply a predetermined voltage Ed at predetermined timing to render the inorganic alignment layer 16 into a first potential and the inorganic alignment layer 22 to a second potential lower than the first potential. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus, and more particularly, to an electro-optical device and an electronic apparatus having a tilted vertical alignment mode liquid crystal sandwiched between inorganic alignment films.

  Conventionally, electro-optical devices such as liquid crystal devices have been widely used for display devices and the like. In a liquid crystal display device, it is known that if the same image, character, or the like is displayed for a long time, the portion deteriorates and a phenomenon called so-called burn-in occurs. One of the causes is the application of a DC voltage, and the other is ions that appear on the surface of the alignment film inside the liquid crystal display device.

Therefore, in order to solve the problem of DC charge application, it is common to use inversion driving in which an AC voltage is applied to a pixel electrode of a liquid crystal display device without applying a DC voltage around a certain reference potential. Has been done.
On the other hand, in order to solve the problem of ions, the charge in the liquid crystal display device due to ions adhering to the alignment film surface is achieved by setting the potential of the pixel electrode or the potential of the counter electrode to the ground level in the standby mode in which no image display is performed There has been proposed a technique for eliminating the bias (see, for example, Patent Document 1).
JP 2005-55562 A

  However, in the technique according to the proposal, since it takes time until the charge is dissociated from the surface of the alignment film, if the time during which the potential of the pixel electrode or the counter electrode is set to the ground level is short, ions attached to the surface of the liquid crystal cell Cannot be completely dissociated. Therefore, a flicker phenomenon occurs in the display image when voltages in positive and negative directions are applied to the pixel electrode with respect to the counter electrode having the reference potential by AC driving. Conversely, if the time during which the potential of the pixel electrode or the counter electrode is set to the ground level is lengthened, there is a problem that image display cannot be performed immediately. That is, the technique according to the above-described proposal has a problem that it is not possible to effectively eliminate the charge bias in the liquid crystal display device.

  SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device that can effectively eliminate the charge bias in the electro-optical device.

The electro-optical device of the present invention is provided on the first substrate, the second substrate, the first inorganic alignment film provided on the first substrate, the second substrate, and the first substrate. A second inorganic alignment film having a thickness greater than that of the first inorganic alignment film; and a liquid crystal in a tilted vertical alignment mode sandwiched between the first inorganic alignment film and the second inorganic alignment film. And a predetermined voltage such that the first inorganic alignment film side is set to a first potential and the second inorganic alignment film side is set to a second potential lower than the first potential at a predetermined timing. And voltage applying means for applying at the same time.
According to such a configuration, it is possible to provide an electro-optical device that can effectively eliminate the charge bias in the electro-optical device.

In the electro-optical device according to the aspect of the invention, the predetermined potential may be on a common potential side of the first electrode on the first inorganic alignment film side and the second electrode on the second inorganic alignment film side. It is desirable to be applied.
According to such a configuration, it is possible to provide an electro-optical device that can effectively eliminate the charge bias with a simple configuration.

In the electro-optical device according to the aspect of the invention, the predetermined voltage may be a voltage value that cancels a potential difference caused by positive ions attached to the first inorganic alignment film and negative ions attached to the second inorganic alignment film. It is desirable to have
According to such a configuration, it is possible to provide an electro-optical device that can completely eliminate the charge bias in the electro-optical device.

In the electro-optical device according to the aspect of the invention, it is preferable that the voltage application unit is a switching unit to a voltage supply source that supplies the predetermined voltage.
According to such a configuration, an external power supply can be used without providing a voltage generation circuit in the liquid crystal device.

In the electro-optical device according to the aspect of the invention, it is preferable that the predetermined timing is a timing within a period that does not contribute to the image display by the liquid crystal.
According to such a configuration, it is possible to effectively eliminate the charge bias during a period that does not contribute to image display.

In the electro-optical device according to the aspect of the invention, the predetermined timing may be a first half timing within the non-contributing period, and the voltage applying unit may be configured to contribute to the image display after the first half timing. It is desirable to apply a potential from the drive circuit for image display to the first inorganic alignment film side and the second inorganic alignment film side.
According to such a configuration, the predetermined voltage is applied at the first half timing, and the potential from the drive circuit is applied at the second half timing so that the potential change relaxation time is provided, thereby reversing the potential difference. Can be prevented.

The electronic apparatus of the present invention is an electronic apparatus equipped with the electro-optical device of the present invention.
According to such a configuration, it is possible to provide an electronic apparatus including the electro-optical device that can effectively eliminate the charge bias in the electro-optical device.

Embodiments of the present invention will be described below with reference to the drawings.
First, based on FIG. 1, the structure of the system concerning this Embodiment is demonstrated. In the following embodiments, the electro-optical device of the present invention is applied to a liquid crystal device. In each drawing used for the following description, the scale is different for each member in order to make each member a size that can be recognized on the drawing.

  The overall configuration of the electro-optical device according to the present embodiment will be described with reference to FIGS. Here, FIG. 1 is a plan view of a liquid crystal device when a TFT (Thin Film Transistor) array substrate is viewed from the side of the counter substrate together with each component configured thereon. 2 is a cross-sectional view taken along the line H-H ′ of FIG. 1. Here, as an example of the electro-optical device, an electro-optical device using a TFT active matrix driving type liquid crystal device with a built-in driving circuit is taken as an example.

  1 and 2, in the liquid crystal device 1 according to the present embodiment, a TFT array substrate 10 and a counter substrate 20, which are substantially rectangular substrates, are opposed to each other. The TFT array substrate 10 and the counter substrate 20 are made of glass, quartz, resin, or the like and have translucency. The TFT array substrate 10 and the counter substrate 20 are bonded to each other by a sealing material 31 provided in a seal region located around the image display region 10a, and the TFT array substrate 10 and the counter substrate 20 are inclined. A liquid crystal layer 50 in a vertical alignment mode is enclosed. A light-shielding frame light-shielding film 32 that defines the frame area of the image display region 10a is provided on the counter substrate 20 side in parallel with the inside of the seal region where the sealing material 31 is disposed.

  A data line driving circuit 41 is provided along an external connection side 10 b which is one side of the TFT array substrate 10 in a region located outside the seal region where the sealing material 31 is disposed. The TFT array substrate 10 is formed with a plurality of external circuit connection terminals 42 which are terminals arranged along the external connection side 10b. The scanning line driving circuit 43 is provided along two sides adjacent to one side of the TFT array substrate 10 on which the data line driving circuit 41 and the external circuit connection terminal 42 are provided, and is covered with the frame light shielding film 31. ing. In addition, the TFT array substrate 10 is provided along the remaining side of the TFT array substrate 10, that is, the side facing the one side of the TFT array substrate 10 on which the data line driving circuit 41 and the external circuit connection terminal 42 are provided, and is covered with the frame light shielding film 32. The two scanning line driving circuits 43 are connected to each other by a plurality of wirings 44 provided in the.

  In addition, vertical conduction members 45 functioning as vertical conduction terminals for electrical connection with the TFT array substrate 10 are disposed at the four corners of the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in regions corresponding to the vertical conduction members 45. Electrical connection is made between the TFT array substrate 10 and the counter substrate 20 via the vertical conductive member 45 and the vertical conductive terminal.

  In FIG. 2, on the TFT array substrate 10, an alignment film 16 is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an alignment film 22 are formed in the uppermost layer portion. In the present embodiment, the alignment films 16 and 22 are inorganic alignment films made of an inorganic material. The liquid crystal layer 50 is a liquid crystal made of, for example, a liquid crystal obtained by mixing one kind or several kinds of nematic liquid crystals and having a negative dielectric anisotropy. Therefore, the liquid crystal device 1 is driven in the tilted vertical alignment mode (VA mode). Hereinafter, as shown in FIG. 1, on the plane including the surface on which the external circuit connection terminal 42 of the TFT array substrate 10 is formed, the axis parallel to the external connection side 10b is the X axis, and the axis orthogonal to the X axis is Y. Called the axis.

  A flexible wiring board (not shown) (hereinafter referred to as FPC (Flexible Printed Circuit)) is connected to the liquid crystal device 1 described above via an external circuit connection terminal 42. Based on the image signal supplied via the external circuit connection terminal 42, the liquid crystal device 1 displays an image in the image display area 10a.

  Here, generation of ions in the liquid crystal device 1 will be described with reference to FIG. FIG. 3 illustrates the potential distribution generated between the alignment films when the thickness of the alignment film 16 on the TFT array substrate 10 as the element substrate is larger than the thickness of the alignment film 22 on the counter electrode 21. FIG.

  As shown in FIG. 3, the alignment film 16 is provided on the TFT array substrate 10 via the pixel electrode 9a. The alignment film 22 is provided on the counter substrate 20 via the counter electrode 21. The alignment film 16 has a film thickness d1, and the alignment film 22 has a film thickness d2. The film thickness d1 is thicker than the film thickness d2.

  Conventionally, the film thickness d1 and the film thickness d2 are the same. However, if the film thicknesses of both are the same, negative ions adhere to the surface of one of the alignment films 16 and 22, and positive ions adhere to the surface of the other side. An electric double layer is formed on the surface of each alignment film by the adhesion of ions. Further, it is not definitive whether the positive and negative ions are attached to the surfaces of the alignment films 16 and 22, respectively. That is, it is uncertain whether positive ions or negative ions will adhere to the alignment film 16 on the TFT array substrate 10 or the alignment film 22 on the counter electrode 21.

  However, the inventor of the present application uses an inorganic material as the material of the alignment film, takes a vertically aligned alignment state in which the liquid crystal layer 50 is arranged perpendicular to the alignment film surface, and aligns the alignment film on the TFT array substrate 10. 16 and the thickness of the alignment film 22 on the counter electrode 21 are different, negative ions adhere to the thicker alignment film and positive ions adhere to the thinner alignment film. I found it to be.

  In the case of FIG. 3, the alignment film 16 on the TFT array substrate 10 has a film thickness d 1 that is thicker than the film thickness d 2 of the alignment film 22 on the counter electrode 21, so that negative ions adhere to the surface of the alignment film 16. Positive ions adhere to the surface of the alignment film 22.

  In this case, when the inversion drive is performed so that the counter electrode 21 is set as the reference potential and the voltages + Vh and −Vh are applied to the pixel electrode 9a, the voltage + Vh is applied to the pixel electrode 9a. Due to negative ions, the voltage + Vh decreases to the voltage + Ve1. Although the voltage Vcomh is applied to the counter electrode 21, the voltage + Vcomh rises to the voltage + Vcom1 due to the positive ions on the alignment film 22. When the voltage −Vh is applied to the pixel electrode 9a, the voltage −Vh is lowered to the voltage −Ve due to negative ions on the alignment film 16. That is, at the time of inversion driving, the voltages + Vh and −Vh applied to the pixel electrode 9a become the voltage + Ve and the voltage −Ve as effective voltages, and the reference potential is changed from the voltage Vcomh to the voltage + Vcom1. Note that the optimum reference potential in this case is an intermediate potential Vcomc1 between the voltage + Ve1 and the voltage −Ve1. However, since the potential difference with respect to the reference potential of each of the positive voltage and the negative voltage at the time of inversion driving is different, flicker occurs in the displayed image.

  In the present embodiment, as described above, it is known that negative ions adhere to the thick alignment film 16, so the negative ions attached to the alignment film 16 are canceled and adhered to the alignment film 22. In order to cancel the positive ions, a predetermined voltage Ed1 is applied which is positive on the pixel electrode 9a side and negative on the counter electrode 21 side. That is, a predetermined voltage Ed1 is applied so that the alignment film 16 side is set to the first potential and the alignment film 22 side is set to the second potential lower than the first potential. The predetermined timing for applying the voltage Ed1 is a so-called blanking period for image display (specifically, a horizontal blanking period and a vertical blanking period), and when the liquid crystal device 1 does not display an image. These periods and times are timings within a period that does not contribute to image display. Here, the time when the image is not displayed is when the liquid crystal device 1 is on standby. The blanking period and standby time are times when image display is not affected. The standby time is, for example, a time when image display is not performed, and a period from when the electronic device equipped with the liquid crystal device 1 is turned on until the first image display is performed. Note that in all of these periods, the voltage Ed1 is not applied between the pixel electrode 9a and the counter electrode 21, but the voltage Ed1 is applied to the pixel electrode 9a and the counter electrode in one or two of these periods. You may make it give between 21.

  Here, the standby time is given as an example when the image display is not performed. However, when the image display is not performed, the image display area 10a of the liquid crystal device 1 is not displayed any other time, that is, the liquid crystal device. It is sufficient that the normal image display operation 1 is not performed.

  The value of the voltage Ed1 is, for example, a voltage value obtained experimentally according to the film thickness of each alignment film. That is, the voltage Ed1 is a voltage that cancels out the potentials of the negative ions and the positive ions adhering to the respective alignment films in accordance with the film thickness of each alignment film. The potential deviation caused by each ion is canceled by the voltage Ed1 and is AC driven between the voltages + Vh and -Vh with respect to the reference potential Vcomh.

  Next, when the film thickness relationship between the alignment film 16 and the alignment film 22 is reversed, that is, the film thickness of the alignment film 16 on the TFT array substrate 10 which is an element substrate is the alignment film 22 on the counter electrode 21. The potential distribution generated between the alignment films when the film thickness is smaller than the film thickness will be described.

  As shown in FIG. 4, the alignment film 16 has a film thickness d3, and the alignment film 22 has a film thickness d4. Since the film thickness d3 is thinner than the film thickness d4, positive ions adhere to the surface of the alignment film 16, and negative ions adhere to the surface of the alignment film 22.

  In this case, when the inversion drive is performed so that the counter electrode 21 is set as the reference potential and the voltages + Vh and −Vh are applied to the pixel electrode 9a, the voltage + Vh is applied to the pixel electrode 9a. Due to the positive ions, the voltage + Vh rises to the voltage + Ve2. The voltage Vcomh is applied to the counter electrode 21, but the voltage + Vcomh is lowered to the voltage + Vcom2 due to negative ions on the alignment film 22. When the voltage −Vh is applied to the pixel electrode 9a, the voltage −Vh rises to the voltage −Ve2 due to the positive ions on the alignment film 16. That is, during the inversion drive, the voltages + Vh and −Vh applied to the pixel electrode 9a become the voltage + Ve2 and the voltage −Ve2 as effective voltages, and the reference potential is changed from the voltage Vcomh to the voltage + Vcom2. Note that the optimum reference potential in this case is an intermediate potential Vcomc2 between the voltage + Ve2 and the voltage −Ve2. However, as a result of the inversion driving, the potential difference with respect to each reference potential of the plus voltage and the minus voltage is different, so that flicker occurs in the displayed image.

  Therefore, in the case of FIG. 4, as described above, it is known that positive ions adhere to the thin alignment film 16, so that the positive ions attached on the alignment film 16 are canceled and the alignment film 22 is exposed. A predetermined voltage Ed2 is applied to the pixel electrode 9a side that is negative and the counter electrode 21 side is positive so that negative ions adhering to the negative electrode are canceled. The predetermined timing for applying the voltage Ed2 is the so-called blanking period for image display and the standby time of the liquid crystal device 1, as in the case of FIG. Here again, in all of these periods, the voltage Ed2 is not applied between the pixel electrode 9a and the counter electrode 21, but the voltage Ed2 is applied to the pixel electrode 9a in one or two of these periods. And between the counter electrodes 21.

  The value of the voltage Ed2 is also a voltage value obtained experimentally, for example, according to the film thickness of each alignment film. That is, the voltage Ed2 is a voltage that cancels out the respective potentials of the positive ions and the negative ions attached to the respective alignment films according to the film thickness of each alignment film. Therefore, for example, the potential deviation caused by each ion at a predetermined timing such as a blanking period is canceled by the voltage Ed2, and is AC driven between the voltages + Vh and -Vh with respect to the reference potential Vcomh.

  If the voltages Ed1 and Ed2 are the same as the experimentally obtained voltage values according to the thickness of each alignment film, respectively, the above-described potential bias can be completely eliminated. Even if the voltage value substantially matches the measured voltage value, the flicker should not be visually recognized.

Next, a circuit for supplying the predetermined voltage Ed1 or Ed2 to the pixel electrode 9a and the counter electrode 21 will be described.
FIG. 5 is a schematic configuration diagram showing a circuit configuration of the liquid crystal device 1 according to the embodiment of the present invention. In FIG. 5, on a TFT array substrate 10 which is a glass substrate, a pixel array unit 13 in which pixels 12 are two-dimensionally arranged in a matrix is formed. Each of the pixels 12 includes a TFT 101 which is a pixel transistor, a liquid crystal cell 102 having a pixel electrode connected to the drain electrode of the TFT 101, and a storage capacitor 103 having one electrode connected to the drain electrode of the TFT 101. It has become. Here, the liquid crystal cell 102 means a liquid crystal capacitance generated between the pixel electrode 9a and the counter electrode 21 formed facing the pixel electrode 9a.

  In this pixel structure, the TFT 101 has a gate electrode connected to a gate line (scanning line) 14 and a source electrode connected to a data line 15. The counter electrode of each liquid crystal cell 102 is connected in common to each pixel with respect to the VCOM line 16A. A common voltage Vcomh (Vcomh potential) is applied to the common electrode of each liquid crystal cell 102 via the VCOM line 16A. In the storage capacitor 103, the other electrode (terminal on the counter electrode side) is connected to the capacitor line 17 in common for each pixel.

  Here, in the case of performing 1H (H is a horizontal period) inversion driving or 1F (F is a field period) inversion driving, the display signal written to each pixel is inverted in polarity with respect to the Vcomh potential.

  As described above, on the same glass substrate 11 as the pixel array unit 13, for example, the scanning line driving circuit 43 is mounted on the left and right of the pixel array unit 13, and the data line driving circuit 41 is mounted on one end of the pixel array unit 13. ing. Each of the two scanning line driving circuits 43 includes a shift register. In these scanning line drive circuits 43, the shift register starts a shift operation in response to a vertical start pulse supplied from a timing generator (not shown), and is also synchronized with a vertical clock pulse supplied from the timing generator. Scan pulses that are sequentially transferred in one vertical period are generated.

  Scan pulses generated by the scan line driving circuit 43 are sequentially supplied to the gate lines 14 from the left and right sides of the pixel array unit 13 through the buffers 46, respectively.

  The plurality of data lines 15 are connected to a power supply circuit 47 that generates a predetermined potential Ed via a switch SW1. The switch SW1 includes a plurality of switches S corresponding to the signal lines 15. That is, the switch SW1 switches each data line 15 to connect to a voltage supply source that supplies a predetermined voltage Ed, whereby a predetermined potential Ed is applied to the data line 15.

  The VCOM line 16A has one end connected to the counter electrode 21 and the other end connected to the reference potential Vcomh or a predetermined potential Ed via the switch SW2. That is, the switch SW2 switches the VCOM line 16A to a voltage supply source that supplies a predetermined voltage Ed, so that the reference potential Vcomh or the predetermined potential Ed is applied to the counter electrode 21. In the example described above, the predetermined potential Ed is the potential Ed1 or Ed2. In the switch SW1, a switch SW1 is provided at the end of each signal line 15. The switch SW1 is normally in an off state and is turned on at the predetermined timing T described above. Therefore, the switches SW1 and SW2 constitute voltage application means for applying the predetermined voltage Ed at a predetermined timing.

  More specifically, in the blanking period and the standby mode (or at least one of the vertical and horizontal blanking periods and the standby mode), the switches SW1 and SW2 apply a predetermined voltage Ed to each data line 15. Switch to the voltage supply source side to supply. Further, at that time, in order to apply a predetermined voltage Ed supplied to each data line 15 to each pixel electrode 9a, a scanning pulse signal is simultaneously supplied to all the scanning lines 14n.

  As shown in FIG. 3, when the alignment film 16 on the pixel electrode 9a of the TFT array substrate 10 is thicker than the alignment film 22 on the counter electrode 22 of the counter substrate 20, each data line 15 has a predetermined voltage. A predetermined voltage Ed is applied so that a positive potential of Ed and a negative potential of the predetermined voltage Ed are applied to the VCOM line 16A.

  Conversely, as shown in FIG. 4, when the film thickness of the alignment film 16 on the pixel electrode 9a of the TFT array substrate 10 is thinner than the alignment film 22 on the counter electrode 22 of the counter substrate 20, each data line 15 has The predetermined voltage Ed is applied so that a negative potential of the predetermined voltage Ed is applied and a positive potential of the predetermined voltage Ed is applied to the VCOM line 16A.

  At the time of image display, the data line driving circuit 41 selects the selected 1 when each pixel 12 of the pixel array unit 13 is sequentially selected in units of rows (lines) by vertical scanning by the scanning line driving circuit 43. A video signal for one line is written to each line of pixels 12 via each data line 15. By repeating this video signal writing operation in units of lines, an image for one screen is displayed.

  Therefore, the switches SW1 and SW2 are controlled so as to apply a predetermined potential Ed to the data line 15 and the VCOM line 16A, respectively, during the blanking period and the standby mode. Timing signals in the blanking period and the standby mode are generated by timing generators (not shown). At the time of image display, no timing signal is input to the switches SW1 and SW2, the data line 15 is connected only to the data line driving circuit 41, and the VCOM line 16A is connected to the reference potential Vcomh.

  The voltage supply source described above may be a voltage generation circuit built in the liquid crystal device 1 or an external voltage source. In the case of an external voltage source, a predetermined voltage Ed is supplied to one end of each of the switches SW1 and SW2 which are switching means via the external circuit connection terminal 42. If an external voltage source can be used, there is a merit that it is not necessary to provide a voltage generation circuit on the TFT array substrate 10.

  Further, the predetermined timing at which the predetermined potential Ed is reached may be the first half of the period that does not contribute to image display. The switches SW1 and SW2 are controlled so that a predetermined potential Ed is applied to the two alignment films at the first half timing, and the potential from the drive circuit, for example, a normal potential is applied to the two orientations at the second half timing within the non-contributing period. Apply to membrane.

  With such a configuration, in addition to being able to effectively eliminate the charge bias within a period that does not contribute to image display, it is possible to prevent the potential difference from being reversed by providing a potential change relaxation time.

  As described above, when the image is not displayed, a predetermined potential is applied to the alignment films 16 and 22, so that the negative ions attached to the thick alignment film and the thin alignment film are attached. Potential bias due to positive ions can be eliminated.

  In the above embodiment, a predetermined voltage is simultaneously applied to both the alignment film 16 of the TFT array substrate 10 and the alignment film 22 of the counter substrate 20, but only the alignment film 22 of the counter substrate 20 is grounded. Alternatively, a predetermined potential Ed may be applied. That is, the predetermined potential is applied only to the counter electrode 21 on the common potential side. Since the pixel electrode 9a is usually at a certain potential, the potential deviation due to the negative ions attached to the thick alignment film and the positive ions attached to the thin alignment film with respect to the potential and the ground. The same effect can be produced with a simple configuration by applying the potential Edd to be eliminated.

  Next, an overall configuration, particularly an optical configuration, of an example of a projection color display device as an example of an electronic apparatus using the liquid crystal device 1 described in detail above as a light valve will be described. FIG. 6 is an explanatory diagram of the projection type color display device.

  In FIG. 6, a liquid crystal projector 1100 as an example of a projection type color display device according to the present embodiment prepares three liquid crystal modules including a liquid crystal device 1 having a drive circuit mounted on a TFT array substrate 10, each for RGB. The light bulbs 100R, 100G, and 100B are used as projectors. In the liquid crystal projector 1100, when projection light is emitted from a lamp unit 1102 of a white light source such as a metal halide lamp, light components R, G, and R corresponding to the three primary colors of RGB are obtained by three mirrors 1106 and two dichroic mirrors 1108. The light is divided into B and led to the light valves 100R, 100G and 100B corresponding to the respective colors. At this time, in particular, the B light is guided through a relay lens system 1121 including an entrance lens 1122, a relay lens 1123, and an exit lens 1124 in order to prevent light loss due to a long optical path. The light components corresponding to the three primary colors modulated by the light valves 100R, 100G, and 100B are synthesized again by the dichroic prism 1112 and then projected as a color image on the screen 1120 via the projection lens 1114. Since the projected color image is formed by a liquid crystal device with few alignment defects, the color image has a good image quality.

  Electronic devices to which the electro-optical device according to this embodiment can be applied include, in addition to a projection color display device (projector), a mobile phone, a PDA (Personal Digital Assistants (portable information terminal), a portable personal computer, There are digital cameras, in-vehicle monitors, digital video cameras, liquid crystal televisions, viewfinder type or direct view type video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, video phones, POS terminals, and the like.

  The electro-optical device of the present invention is not limited to an active matrix type liquid crystal display device using TFTs, but also a liquid crystal display panel including a TFD (thin film diode) as a switching element, a passive matrix type liquid crystal display device, and the like. The present invention can be similarly applied to various electro-optical devices.

  As described above, according to the embodiment of the present invention, the thicknesses of the two alignment films are made different from each other, thereby determining the polarity of the ions attached to the respective alignment film surfaces. With a simple configuration in which a predetermined DC voltage having a polarity corresponding to the attached ions is applied, it is possible to eliminate the potential bias caused by the attached ions.

  The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

1 is a plan view of a liquid crystal device according to an embodiment of the present invention. H-H 'sectional drawing of FIG. The figure for demonstrating the electric potential distribution which arises between alignment films. The figure for demonstrating the electric potential distribution which arises between alignment films. 1 is a schematic configuration diagram illustrating a circuit configuration of a liquid crystal device according to an embodiment of the present invention. Explanatory drawing of a projection type color display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal device, 9a Pixel electrode, 10 TFT array substrate, 10a Image display area, 16, 22 Orientation film, 21 Counter electrode, 23 Light shielding film, 31 Seal material, 41 Data line drive circuit, 42 External circuit connection terminal, 43 Scan Line drive circuit

Claims (7)

A first substrate;
A second substrate;
A first inorganic alignment film provided on the first substrate;
A second inorganic alignment film provided on the second substrate and having a thickness greater than the thickness of the first inorganic alignment film;
An inclined vertical alignment mode liquid crystal sandwiched between the first inorganic alignment film and the second inorganic alignment film;
A predetermined voltage is applied at a predetermined timing such that the first inorganic alignment film side is set to a first potential and the second inorganic alignment film side is set to a second potential lower than the first potential. An electro-optical device comprising: a voltage applying unit for detecting the voltage.   The predetermined electric potential is applied to a common potential side among the first electrode on the first inorganic alignment film side and the second electrode on the second inorganic alignment film side. apparatus.   2. The predetermined voltage has a voltage value that cancels a potential difference caused by positive ions attached to the first inorganic alignment film and negative ions attached to the second inorganic alignment film. Or the electro-optical device according to 2;   The electro-optical device according to claim 1, wherein the voltage applying unit is a switching unit to a voltage supply source that supplies the predetermined voltage.   5. The electro-optical device according to claim 1, wherein the predetermined timing is a timing within a period that does not contribute to image display by the liquid crystal. The predetermined timing is a first half timing within the non-contributing period,
The voltage application means applies the potential from the drive circuit for the image display to the first inorganic alignment film side and the second inorganic alignment after the first half timing and before the period contributing to the image display. 6. The electro-optical device according to claim 5, wherein the electro-optical device is applied to the film side. An electronic apparatus equipped with the electro-optical device according to claim 1.

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