JP2008292861A - Liquid crystal display device and video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of suppressing the effect of ionic impurities in liquid crystal, preventing defective display such as burning and display irregularity, and as a result, giving high-quality image. <P>SOLUTION: The liquid crystal display device comprises: a first substrate 10 having a first electrode part EL1; a second substrate 20 which is oppositely arranged apart from the first substrate 10 by a prescribed gap and has a second electrode part EL2; a liquid crystal layer 30 which is held in the gap between the first substrate 10 and the second substrate 20; and a driving control part 104 which drives the first electrode part EL1 and the second electrode part EL2, wherein the driving control part 104 performs the control such that the first electrode part EL1 or the second electrode part EL2 is divided into a plurality of regions and amplitudes of voltages applied to adjacent regions among the plurality of regions are differentiated from each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a liquid crystal panel capable of suppressing deterioration of display characteristics in the liquid crystal panel and a video display device including the liquid crystal display device.

  In recent years, video display devices including liquid crystal display elements have been replaced by CRT (Cathode ray tube) and are used not only for PC display devices but also for various devices such as TVs and portable devices. Projection-type video display devices such as projectors and direct-view type video display devices such as flat displays are required to have higher brightness and longer life, and in order to achieve both of them, strong light does not deteriorate. A liquid crystal display element using an inorganic material has been applied.

  A liquid crystal display element constituting an image display device is configured by sandwiching a liquid crystal layer between a first substrate and a second substrate which are arranged to face each other, and a pixel region (effective pixel region) of the first substrate. The common electrode is provided on the entire opposite surface side of the second substrate and the opposite surface side of the second substrate.

  The electrodes are each covered with an alignment film, and the alignment state of the liquid crystal molecules contained in the liquid crystal layer is controlled by these alignment films. Further, the space between the first substrate and the second substrate is sealed with a sealant provided in the peripheral region of the pixel region, and the liquid crystal layer is filled and sealed between the first substrate and the second substrate. It has become a state.

  By the way, in the liquid crystal display element configured as described above, ionic impurities mixed during liquid crystal injection or eluted from the sealing agent surrounding the liquid crystal layer are caused to enter the pixel region by the subsequent driving of the liquid crystal display device. It is known that the display characteristics of the liquid crystal display element are deteriorated by diffusion and aggregation.

  In view of this, video display apparatuses having various configurations for the purpose of suppressing such deterioration of display characteristics have been proposed.

  For example, in Patent Document 1, by performing surface modification by ultraviolet irradiation, the surface energy of the alignment film located in the peripheral region is set to be higher than the surface energy of the alignment film in the pixel region located in the center of the liquid crystal display element. A video display device has been proposed in which the ionic impurities dissolved from the sealant are absorbed and trapped in the alignment film portion in the peripheral region with a high surface energy by suppressing the diffusion of the ionic impurities to the pixel region. Yes. In addition, there have been proposed those provided with an ion adsorbing substance for the purpose of suppressing the diffusion of ionic impurities and those provided with a protrusion for physically preventing the diffusion of ionic impurities.

  However, as disclosed in Patent Document 1, it is very difficult to control the state of the alignment film in the peripheral region, and providing an ion-adsorbing substance or the like has led to an increase in manufacturing steps. Further, regarding the provision of the protrusions, it is difficult to completely introduce impurities dissolved in the liquid crystal outside the display region.

JP-A-10-260406

  Therefore, the present invention has been made in view of the problems as described above, and can suppress the influence of ionic impurities in the liquid crystal and prevent display defects such as image sticking and display unevenness, and thus high-quality image quality. An object of the present invention is to provide a liquid crystal display device and a video display device capable of obtaining the above.

  In order to achieve the above-described object, a liquid crystal display device according to the present invention includes a first substrate having a first electrode portion, a first substrate having a predetermined gap, and a second substrate. A drive control unit for driving a second substrate having an electrode unit, a liquid crystal layer held in a gap between the first substrate and the second substrate, and the first electrode unit and the second electrode unit With. The drive control unit performs control so that the first electrode unit or the second electrode unit is divided into a plurality of regions and the amplitudes of voltages applied to the adjacent regions are different. Features.

  The video display device according to the present invention includes a light source, an illumination optical system for converging a light beam emitted from the light source in a predetermined optical path, and a liquid crystal display element that optically modulates the light beam condensed by the illumination optical system. The liquid crystal display element is disposed opposite to the first substrate having a first electrode portion with a predetermined gap and a second electrode portion having a second electrode portion. A substrate; a liquid crystal layer held in a gap between the first substrate and the second substrate; and a drive control unit that drives the first electrode unit and the second electrode unit. The drive control unit performs control so that the first electrode unit or the second electrode unit is divided into a plurality of regions and the amplitudes of voltages applied to the adjacent regions are different. Features.

  According to the present invention, since the ionic impurities can be moved to a desired position in the pixel region or outside the pixel region, it is possible to prevent the ionic impurities from being retained. Therefore, display defects such as display unevenness due to ionic impurities in the pixel region can be prevented, and higher quality image quality can be maintained for a long time.

  According to the present invention, the influence of ionic impurities in the liquid crystal layer can be suppressed, display defects such as image sticking can be prevented, and higher image quality can be obtained.

  Hereinafter, a liquid crystal display device to which the present invention is applied will be described in detail with reference to the drawings.

  The liquid crystal display device 1 of the present embodiment is configured as, for example, an active matrix liquid crystal display element that performs frame inversion driving that inverts a voltage applied to each pixel electrode for each frame with respect to a counter electrode voltage.

  As shown in FIGS. 1 and 2, the liquid crystal display device 1 according to the present invention includes a TFT (Thin Film Transistor) substrate 10 serving as a first substrate and a TFT substrate 10 facing (facing) the second substrate. And a transparent counter substrate 20 serving as a substrate. A liquid crystal 31 is sealed between the TFT substrate 10 and the counter substrate 20 disposed so as to face each other, and a liquid crystal layer 30 as a light modulation layer is formed by the sealed liquid crystal 31.

  The liquid crystal 31 is sealed in a space formed by the TFT substrate 10, the counter substrate 20, and a sealing material 40 that surrounds the periphery of the TFT substrate 10 and the counter substrate 20 in a frame shape, whereby the liquid crystal layer 30. Form. A pair of opposing substrates (TFT substrate 10 and counter substrate 20) are held by a sealing material 40 at a predetermined interval.

  The TFT substrate 10 includes a first electrode portion EL1 including a pixel electrode 11 formed in the pixel region 12 and a plurality of peripheral electrodes 13A and 13B formed in a peripheral region 13 that is the periphery of the pixel region 12. . The TFT substrate 10 is formed of a light-transmitting material such as quartz, glass, or plastic. In the TFT substrate 10, a plurality of substantially rectangular pixel electrodes 11 formed of a transparent conductive film such as an ITO film (indium tin oxide film) are arranged in a matrix on the inner surface facing the counter substrate 20. . The pixel electrode 11 is formed in the effective pixel region (pixel region) 12. A plurality of adjacent peripheral electrodes 13A and 13B are formed in the peripheral region 13 of the pixel region 12, and the pixel electrode 11 and the peripheral electrode 13A are formed. , 13B, an inorganic alignment film 50 formed of an inorganic material is formed.

  The counter substrate 20 is made of a light-transmitting material such as quartz, glass, or plastic. In the counter substrate 20, a common electrode 21 formed of a transparent conductive film such as an ITO film is formed on the inner surface facing the TFT substrate 10, and an inorganic material formed of an inorganic material so as to cover the common electrode 21. An alignment film 51 is formed.

  The common electrode 21 formed on the counter substrate 20 does not have a structure in which the pixel electrode 11 and the peripheral electrodes 13A and 13B are separated as in the TFT substrate 10, but the pixel electrode in the pixel region 12 and the peripheral electrode in the peripheral region 13 And the pixel region 12 and the peripheral region 13 are configured as one common electrode. The common electrode 21 in the counter substrate 20 constitutes a second electrode portion EL2. The common electrode 21 has been described as having the above-described configuration for the sake of convenience. However, the common electrode 21 may be separated into a pixel electrode and a peripheral electrode as in the TFT substrate 10.

  As shown in FIG. 1, the TFT substrate 10 is provided with an effective pixel region 12 in which a pixel electrode 11 and the like are formed at the center, and a peripheral region 13 is provided around the effective pixel region 12.

  In the peripheral region 13, as shown in FIG. 2, the first peripheral electrode 13A and the second peripheral electrode 13B are formed adjacent to each other. The first peripheral electrode 13A is provided annularly adjacent to the outer periphery of the pixel region 12 and over the outer periphery of the pixel region 12, and the second peripheral electrode 13B is connected to the outer periphery of the first peripheral electrode 13A. Adjacent to the first peripheral electrode 13A, the first peripheral electrode 13A is annularly provided.

  As shown in FIG. 3A, the TFT substrate 10 includes a horizontal transfer circuit 101 and vertical transfer circuits 102A and 102B formed over the entire effective pixel region 12 and peripheral region 13 in which pixels are arranged in an array. (Hereinafter also collectively referred to as a vertical transfer circuit 102), a precharge circuit 103, and a voltage control circuit 104 serving as a drive control unit. In the pixel region 12 on the TFT substrate 10, a plurality of data lines 105 and a plurality of scanning lines (gate wirings) 106 are wired in a grid pattern, and a horizontal transfer circuit 101 is connected to one end side of each data line 105. A precharge circuit 103 is connected to the other end side, and a vertical transfer circuit 102 is connected to the end of each scanning line 106.

  As shown in FIG. 3B, a pixel switching thin film transistor (TFT) 107 for controlling switching and a liquid crystal 108 (31) are provided for a plurality of pixels PX formed in a matrix that constitutes the effective pixel region 12 of the TFT substrate 10. , And an auxiliary capacity (storage capacity) 109 are provided. In the pixel PX, a data line 105 to which a pixel signal is supplied is electrically connected to the source of the transistor 107, and a pixel signal Vsig to be written is supplied. In addition, the scanning line 106 is electrically connected to the gate of the transistor 107 in the pixel PX, and a scanning signal is applied to the scanning line 106 in a pulse manner at a predetermined timing.

  The pixel electrode 11 is electrically connected to the drain of the transistor 107, and by turning on the transistor 107, which is a switching element, for a certain period, the pixel signal Vsig supplied from the data line 105 has a predetermined timing. Write in.

  A pixel signal of a predetermined level written to the liquid crystal 108 through the pixel electrode 11 is held for a certain period with the common electrode 21 formed on the counter substrate 20. The liquid crystal 108 modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level.

  In the liquid crystal display device 1, incident light can pass through the liquid crystal portion according to the applied voltage, and light having a contrast corresponding to the pixel signal is emitted from the liquid crystal display device 1 as a whole.

  Here, in order to prevent the held pixel signal from leaking, an auxiliary capacitor (storage capacitor) 109 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 11 and the common electrode 21. Thereby, the holding characteristics are further improved, and the liquid crystal display device 1 with a high contrast ratio can be realized.

  Further, in order to form such a storage capacitor (storage capacitor) 109, a common wiring 110 is provided.

  In the present embodiment, the voltage control circuit 104 sets the applied voltage V13A to the first peripheral electrode 13A formed in the peripheral region 13 and the applied voltage V13B to the second peripheral electrode 13B in opposite phases ( (Or reverse polarity). The voltage control circuit 104 is configured to control the voltage applied to each electrode as a drive control unit of the liquid crystal display device 1.

  Next, the movement of impurities in the liquid crystal 31 in the liquid crystal display device 1 having the above-described configuration will be described. For simplification, FIG. 4 shows a state in which the liquid crystal molecules are viewed from the side in an antiparallel alignment state.

  The voltage applied to the liquid crystal layer 30 is alternating current, and the polarity is reversed between positive and negative every frame period. Corresponding to the alternating waveform, the liquid crystal molecules also slightly change in the orientation in the polar angle direction, and the speed differs between the tilt direction and the relaxation direction (α in the figure). When a voltage is applied to the liquid crystal layer 30 in this way, a minute flow occurs in the liquid crystal layer 30. In the intermediate layer of the liquid crystal layer 30, fluctuations occur with the center of gravity of the liquid crystal molecules as the rotation axis, so that the minute flow (+ γ, −γ in the figure) is canceled out and does not serve as a force to move the impurity ions.

  On the other hand, at the liquid crystal layer interface (inorganic alignment films 50 and 51) with the substrates 10 and 20 facing each other, one of the molecular chains of the liquid crystal molecules is fixed to the alignment film. The above-mentioned minute flow appears in the alignment direction of the liquid crystal 31 (+ β, −β in the figure).

  The flow in the alignment direction of the liquid crystal 31 is reversed in the opposing substrates 10 and 20 and is offset as a whole. However, in the interface, the flow is minute in one direction, and this flow causes ionic impurities to flow. Moved. Accordingly, the ionic impurities move in a direction parallel to the orientation direction of the liquid crystal. Such a phenomenon is described in JP-A-4-86812.

  FIG. 5 is a diagram for explaining the situation using a plan view. In FIG. 5, 25 is an alignment vector indicating the liquid crystal alignment direction of the counter substrate 20, 15 is an alignment vector indicating the liquid crystal alignment direction of the TFT substrate 10, and the ionic impurities 200 at the substrate interfaces are respectively the vector direction of the substrate. Move along. That is, the ionic impurity 200 moves to the lower left corner and the upper right corner of the pixel region 12 in FIG. 5 and is observed as display unevenness 201 and 202. It is known that this occurs because the voltage of the pixel electrode 11 is leaked by the ionic impurities 200 and the voltage actually applied to the liquid crystal 31 is lowered. The above-described display unevenness is observed as black in the normally black mode and as white unevenness in the normally white mode.

  In the present embodiment, display unevenness is suppressed by utilizing such movement of ionic impurities present in the liquid crystal 31 according to the voltage applied to each electrode. Specifically, the ionic impurities are moved by optimizing the amplitude value of the voltage applied to the first electrode portion EL1 or the second electrode portion EL2 in the voltage control circuit 104.

  In the liquid crystal display device 1 shown as the first embodiment, in the voltage control circuit 104, as shown in FIG. 6, the effective pixel region 12 of the TFT substrate 10 is divided into a plurality of regions and applied to adjacent regions. The voltage amplitude is controlled to be different. Specifically, the TFT substrate 10 of the liquid crystal display device 1 shown as the first embodiment is divided into a first region A1 to a sixth region A6 in the pixel region 12, and adjacent regions, for example, first The amplitude values of the voltages applied to the first region A1 and the second region A2 are different from each other. In FIG. 6A, the TFT substrate 10 is adjusted such that the relationship between the amplitude values of the voltages applied to the respective regions is A3 = A6> A2 = A5> A1 = A4. As described above, in the TFT substrate 10 which is divided into a plurality of regions in the effective pixel region 12 and has different amplitude values of voltages applied to adjacent regions, the ionic impurities in the liquid crystal 31 are in the direction indicated by the arrows in the drawing, that is, Move to a region with a large amplitude value. In FIG. 6A, the ionic impurity moves to the third region A3 and the sixth region A6.

  Next, as shown in FIG. 6B, the TFT substrate 10 is adjusted so that the relationship between the amplitude values of the voltages applied to the respective regions is A2 = A5> A1 = A4> A3 = A6. ing. In this case, the ionic impurities in the liquid crystal 31 move to the second region A2 and the fifth region A5 as indicated by arrows in the drawing.

  Further, as shown in FIG. 6C, the TFT substrate 10 is adjusted such that the relationship between the amplitude values of the voltages applied to the respective regions is A1 = A4> A3 = A6> A2 = A5. Yes. In this case, the ionic impurities in the liquid crystal 31 move to the first region A1 and the fourth region A4 as indicated by arrows in the drawing.

  Thus, in the liquid crystal display device 1, the voltage control circuit 104 controls the liquid crystal 31 by dividing the pixel region 12 into a plurality of regions and controlling the amplitude values of the voltages applied to the adjacent regions to be different. The ionic impurities inside can be moved to a specific position. Further, by utilizing this fact, in the liquid crystal display device 1, the voltage control circuit 104 further changes the amplitude value of the applied voltage at every predetermined time (amplitude value temporal change means). It is possible to prevent the ionic impurities from staying at a specific location in the pixel region 12, and thus display unevenness in the pixel region 12 can be prevented. Specifically, the amplitude value of the voltage applied to the pixel electrode 11 that drives the effective pixel in the pixel region 12 of the TFT substrate 10 of the liquid crystal display device 1 is shown in FIGS. 6 (A), 6 (B), and 6. By changing over time in the order of (C), stagnation of ionic impurities in the liquid crystal 31 in the pixel region 12 can be prevented, and display unevenness can be prevented.

  In the liquid crystal display device 1 shown as the first embodiment, the pixel area 12 is divided into six equal parts. However, the present invention is not limited to this, and any area may be used as long as it is divided into two or more areas. You may make it divide | segment into. As shown in FIG. 6, when the amplitude value of the voltage applied to the pixel electrode 11 that drives the effective pixel in the pixel region 12 of the TFT substrate 10 is changed over time, the present invention is not limited to the above. The direction may be changed every predetermined time so that the movement of the ionic impurities does not become a certain direction. Further, the amplitude value of the voltage applied to the pixel electrode 11 has been described in the order of FIGS. 6A, 6B, and 6C. However, the present invention is not limited to this, and the amplitude is determined by any law. The value may be changed. Further, the control of the amplitude value of the voltage applied to the first electrode portion EL1 of the TFT substrate 10 has been described. However, the present invention is not limited to this, and the same control is performed in the second electrode portion EL2 of the counter substrate 20. You may do it.

  Further, since the liquid crystal display device 1 shown as the first embodiment applies a voltage to the pixel electrode 11 that drives the effective pixel in the pixel region 12, when the light source described later is not activated, that is, This is preferably performed when no video is displayed.

  Subsequently, in the liquid crystal display device 1 shown as the second embodiment, the voltage control circuit 104 applies a voltage to the peripheral electrode 13A in the peripheral region 13 of the TFT substrate 10 as shown in FIG. The voltage amplitude value is adjusted to be higher than the voltage amplitude value applied to the pixel electrode that drives the effective pixel in the pixel region 12. Specifically, the TFT substrate 10 of the liquid crystal display device 1 shown as the second embodiment has a voltage applied to the peripheral electrode 13A provided around the pixel region 12 as shown in FIG. By adjusting the amplitude value to be larger than the amplitude value of the voltage applied to the pixel electrode 11, the ionic impurities move out of the pixel region 12 as indicated by arrows in the figure.

  Further, in the peripheral region 13, the TFT substrate 10 is further provided with an annular peripheral electrode 13B on the outer periphery of the peripheral electrode 13A, and the amplitude value of the voltage applied to the peripheral electrode 13B is larger than that of the peripheral electrode 13A. You may make it do. In this way, the peripheral electrodes 13A and 13B are divided into a plurality of regions, and the amplitude values of the voltages applied to the electrodes in the respective regions are made different, so that the ionic impurities are illustrated as shown in FIG. It can be moved in the direction indicated by the middle arrow. In other words, by adjusting the amplitude value of the voltage applied to the electrodes in each region so that, for example, the peripheral electrode 13B> the peripheral electrode 13A> the pixel electrode 11, the ionic impurities in the liquid crystal 31 are adjusted to the effective pixel region. 12 can be moved outside.

  Thus, in the liquid crystal display device 1 shown as the second embodiment, in the voltage control circuit 104, the peripheral electrode 13A is provided in the peripheral region 13 outside the pixel region 12, and applied to the pixel electrode 11 and the peripheral electrode 13A. The ionic impurities in the liquid crystal 31 can be moved out of the pixel region 12 by controlling the amplitude value of the applied voltage to be different. Further, by providing the peripheral electrode 13B on the outer periphery of the peripheral electrode 13A and making the amplitude values of the voltages applied to the peripheral electrode 13B and the peripheral electrode 13A different, the ionic impurities can be further moved away from the pixel region 12. it can. Similarly to the first embodiment, in the liquid crystal display device 1, the voltage control circuit 104 changes the amplitude value of the applied voltage at every predetermined time (amplitude value temporal change means). Thus, ionic impurities can be discharged out of the pixel region 12, and display unevenness can be prevented.

  The present invention is not limited to the above, and the first embodiment and the second embodiment may be combined to move ionic impurities in the liquid crystal 31 to prevent display unevenness. That is, the entire first electrode portion EL1 of the TFT substrate 10 may be divided into a plurality of regions so that the amplitude values of the voltages applied to the adjacent regions are different, and further applied to each region. The amplitude value of the voltage may be changed every predetermined time.

  Further, when the image is not displayed, that is, when the light source described later is not activated, the pixel region 12 is divided into a plurality of regions, and the amplitude values of the voltages applied to the adjacent regions are made different. When the ionic impurities are moved to the vicinity of the boundary between the pixel region 12 and the peripheral region 13 and an image is displayed, that is, when the light source is activated, each of the peripheral electrodes 13A and 13B in the peripheral region 13 The amplitude value of the voltage applied to may be made different, and ionic impurities may be discharged out of the pixel region 12.

  Subsequently, a third embodiment will be described. The liquid crystal display device shown as the third embodiment has the same configuration as the liquid crystal display devices shown as the first and second embodiments, and removes ionic impurities present in the liquid crystal 31 from the voltage control circuit. In 104, an ionic impurity is moved by optimizing the voltage value applied to the first electrode portion EL1 or the second electrode portion EL2.

  In the liquid crystal display device shown as the third embodiment, in the voltage control circuit 104, the effective pixel region 12 of the TFT substrate 10 is divided into a plurality of regions as shown in FIG. The values are controlled to be different. Specifically, the TFT substrate 10 of the liquid crystal display device 1 shown as the third embodiment is divided into three regions of a first region B1 to a third region B3 in the vertical direction in the pixel region 12, The voltage values applied to the adjacent regions, for example, the first region B1 and the second region B2 are different from each other. In FIG. 8, the TFT substrate 10 is adjusted so that the relationship between the voltage values applied to the respective regions satisfies B3> B2> B1. Thus, in the TFT substrate 10 that is divided into a plurality of regions in the effective pixel region 12 and has different voltage values applied to adjacent regions, the ionic impurities in the liquid crystal 31 are in the direction indicated by the arrows in the drawing, Move from the potential to the low potential region. In FIG. 8, ionic impurities move to the first region B1.

  Next, in the liquid crystal display device shown as the third embodiment, a method for applying different voltage values to the respective regions B1 to B3 will be described. As shown in FIG. 9, in the liquid crystal display device shown as the third embodiment, the voltage control circuit 104 (see FIG. 3) detects the position in the pixel region 12 and the voltage value applied at the detected position. By controlling, a video signal control circuit 104A that controls a video signal to be displayed, a drive driver 104B that controls driving of the horizontal transfer circuit 101 and the like according to a control signal from the video signal control circuit 104A, and a video signal control circuit 104A And an electrode voltage setting circuit 104C for setting the voltage values of the pixel electrode 11 and the peripheral electrodes 13A and 13B and applying a predetermined voltage to each electrode.

  The video signal control circuit 104A detects the position in each of the areas B1 to B3 and converts the input video signal for each of the areas B1 to B3. For example, the video signal control circuit 104A refers to a look-up table (LUT) as shown in Table 1, changes the polarity of the liquid crystal 31 and the voltage value to be applied, and sets the voltage value to be applied to the counter substrate 20. Also make changes.

  The liquid crystal display device shown as the third embodiment can change the voltage value applied to the electrodes in the regions B1 to B3 as shown in FIG. it can. Thus, in the liquid crystal display device, the voltage control circuit 104 divides the pixel region 12 into a plurality of regions, and controls the voltage values applied to the adjacent regions to be different, thereby controlling the ions in the liquid crystal 31. Sex impurities can be moved to a specific position. Further, by utilizing this fact, in the liquid crystal display device, the voltage control circuit 104 further changes the amplitude value of the applied voltage at every predetermined time (amplitude value temporal change means). It is possible to prevent ionic impurities from staying at a specific location in the pixel region 12, and thus display unevenness in the pixel region 12 can be prevented.

  In the liquid crystal display device shown as the third embodiment, the pixel region 12 has been shown to be divided into three equal parts. However, the present invention is not limited to this, and any region can be used as long as it is divided into two or more regions. You may make it divide | segment. Similarly to the second embodiment, in the third embodiment, the voltage value applied only to the pixel electrode 11 in the pixel region 12 is not limited to be different, and the same applies to the peripheral region 13. Can be realized.

  Furthermore, by making the voltage applied to the peripheral electrodes 13A and 13B larger than that of the pixel region 12, it is possible to speed up the flow due to minute fluctuations of the liquid crystal, that is, to quickly release ionic impurities to the outside of the pixel region 12. Can be moved.

  In the present embodiment, the TFT substrate 10 is a transparent substrate. However, for example, a reflective substrate in which a reflective pixel electrode is arranged using a silicon (Si) substrate may be used.

  Further, in the configuration of FIG. 2, an example in which a plurality of peripheral electrodes 13A and 13B adjacent to the peripheral region 13 of the TFT substrate 10 is provided as the first substrate is shown, but on the counter substrate 20 side as the second substrate. However, instead of using the common electrode, the second electrode portion EL2 is configured by providing a plurality of adjacent peripheral electrodes in the pixel region 12 and the peripheral region 13 in the same manner as the TFT substrate 10 in the peripheral region 13. Also good.

  Further, the peripheral electrodes 13A and 13B constituting the first electrode portion EL1 of the TFT substrate 10 as the first substrate may be formed by a single electrode.

  Next, as an example of an electronic apparatus using the above-described liquid crystal display element, a configuration of a projection type liquid crystal display device will be described with reference to the schematic configuration diagram of FIG.

  The liquid crystal display device 1 as shown in FIG. 1 is used for a projection type video display device as shown in FIG. 11 as an example.

  The video display device 300 illustrated in FIG. 11 separates light from a light source into three primary colors of red, blue, and green, and performs color image display using one liquid crystal display element for each color. This is a three-plate projector. A liquid crystal display panel corresponding to each of the three primary colors corresponds to the liquid crystal display device shown in FIG. 1, and all three have substantially the same structure.

  Hereinafter, for convenience, a liquid crystal display device that receives red light is referred to as a liquid crystal display device 325R, a liquid crystal display device that receives green light is referred to as a liquid crystal display device 325G, and a liquid crystal display device that receives blue light is referred to as a liquid crystal display device 325B.

  The image display apparatus 300 in FIG. 11 reflects a light source 311 that emits light, a first lens array 312 that is disposed on the light emission side of the light source 311, and light emitted from the first lens array 312. A mirror 314 that changes the optical path (optical axis 310) of the emitted light by 90 ° and a second lens array 313 on which the reflected light from the mirror 314 enters are provided.

  The mirror 314 is preferably a total reflection mirror.

  A plurality of microlenses 312M and 313M are two-dimensionally arranged in the first lens array 312 and the second lens array 313, respectively. The first lens array 312 and the second lens array 313 are for uniformizing the illuminance distribution of light, and have a function of dividing incident light into a plurality of small light beams.

  A UV (Ultra Violet) / IR (Infrared) cut filter (not shown) may be installed between the light source 311 and the first lens array 312.

  The light source 311 emits white light including red light, blue light, and green light, which is necessary for color image display. The light source 311 includes a light emitting body (not shown) that emits white light, and a reflector that reflects and collects light emitted from the light emitting body.

  As the light emitter, for example, a lamp such as an extra-high pressure mercury lamp, a halogen lamp, a metal halide lamp, or a xenon lamp is used. The reflector desirably has a shape with good light collection efficiency, and has a concave shape that is rotationally symmetric, such as a spheroid mirror or a paraboloid of revolution. The light emitting point of the light emitter is arranged at the focal position of the concave reflector.

  White light emitted from the light emitter of the light source 311 becomes substantially parallel light by the reflector, passes through the first lens array 312, and enters the total reflection mirror 314. White light whose optical axis 310 is bent by 90 ° by the total reflection mirror 314 enters the second lens array 313.

  The video display device 300 illustrated in FIG. 11 includes a PS combining element 315, a condenser lens 316, and a dichroic mirror 317 on the light emission side from the second lens array 313.

  The PS combining element 315 is provided with a plurality of retardation plates 315A at positions corresponding to adjacent microlenses in the second lens array 313. The half-wave plate is an example of the retardation plate 315A.

  The PS combining element 315 separates incident light into polarized light of P-polarized component and S-polarized component. The PS combining element 315 emits one of the two separated polarized lights from the polarization conversion element while maintaining the polarization direction (for example, P-polarized light), and outputs the other polarized light (for example, the S-polarized light component). The half-wave plate 315A is converted into another polarization component (for example, a P-polarization component) and emitted.

  The light emitted from the PS combining element 315 is collected by the condenser lens 316 and enters the dichroic mirror 317.

  The dichroic mirror 317 separates the incident light into the red light LR and other colors by reflecting, for example, the red light LR of the incident light and transmitting the light of other colors.

  Further, the video display device 300 includes a mirror 318, a field lens 324R, an incident side polarizing plate 330I, a liquid crystal display device 325R, and an outgoing side polarization along the optical path of the red light LR separated by the dichroic mirror 317. Plate 330S.

  As the mirror 318, a total reflection mirror is preferably used. Total reflection mirror 318 reflects red light LR color-separated by dichroic mirror 317 toward incident-side polarizing plate 330I and liquid crystal display device 325R.

  As described above, the incident-side polarizing plate 330I passes light in the direction that coincides with the polarization axis 330a among the red light LR incident from the total reflection mirror 318.

  The liquid crystal display device 325R has the same structure as that of the liquid crystal display device shown in FIG. 1 as described above, and the red light LR incident through the incident side polarizing plate 330I is spatially changed according to input image data. Modulate to

  Outgoing-side polarizing plate 330S passes light in a direction that coincides with polarization axis 330b among modulated red light LR from liquid crystal display panel 325R.

  The video display device 300 includes a dichroic mirror 319 along the optical path of light of other colors separated by the dichroic mirror 317. The dichroic mirror 319 separates the incident light into green light LG and blue light LB by reflecting, for example, the green light LG and transmitting the blue light LB among the incident light.

  In the optical path of the green light LG separated by the dichroic mirror 319, a field lens 324G, an incident side polarizing plate 330I, a liquid crystal display panel 325G, and an output side polarizing plate 330S are provided.

  The incident-side polarizing plate 330I allows light in the direction matching the polarization axis 330a out of the green light LG incident from the dichroic mirror 319.

  The liquid crystal display device 325G spatially modulates the green light LG incident through the incident side polarizing plate 330I according to input image data.

  Outgoing side polarizing plate 330S passes light in a direction that coincides with polarization axis 330b among modulated green light LG from liquid crystal display panel 325G.

  Further, along the optical path of the blue light LB color-separated by the dichroic mirror 319, the relay lens 320, the mirror 321, the relay lens 322, the mirror 323, the field lens 324B, the incident side polarizing plate 330I, and the liquid crystal A display device 325B and an emission side polarizing plate 330S are provided.

  The mirrors 321 and 323 are preferably total reflection mirrors. The total reflection mirror 321 reflects the blue light LB incident through the relay lens 320 toward the total reflection mirror 323. The total reflection mirror 323 reflects the blue light LB reflected by the total reflection mirror 321 and incident via the relay lens 322 toward the incident side polarizing plate 330I and the liquid crystal display panel 325B.

  The incident-side polarizing plate 330I passes light in the direction matching the polarization axis 330a among the green light LG incident from the total reflection mirror 323.

  The liquid crystal display device 325B spatially modulates the blue light LB reflected by the total reflection mirror 323 and incident through the field lens 324B and the incident side polarizing plate 330I according to input image data.

  The emission-side polarizing plate 330S transmits light in a direction that coincides with the polarization axis 330b among the modulated blue light LB from the liquid crystal display panel 325B. A cross prism 326 having a function of combining these three color lights is installed at a position where the optical paths of the red light LR, the green light LG, and the blue light LB intersect.

  As an example, the cross prism 326 includes incident surfaces 326R, 326G, and 326B on which the red light LR, the green light LG, and the blue light LB are incident, and light obtained by combining the red light LR, the green light LG, and the blue light LB. Four right-angle prisms each having an exit surface 326T that exits are joined to each other.

  In the video display device 300, the green light LG that has entered the cross prism 326 is transmitted toward the exit surface 326T, and the red light LR and the blue light LB that have entered the cross prism 326 are directed toward the exit surface 326T. A dichroic film is coated on the joint surface of each right-angle prism so as to reflect.

  As described above, the cross prism 326 combines the three color lights incident on the incident surfaces 326R, 326G, and 326B and outputs the combined light from the output surface 326T.

  Further, the video display device 300 includes a projection lens 327 for projecting the combined light emitted from the cross prism 326 toward the screen 328. The projection lens 327 is preferably composed of a plurality of lenses, and has a zoom function for adjusting the size of an image projected on the screen 328 and a focusing function.

  Note that the above-described effects can be obtained when the present invention is applied not only to a projection type liquid crystal display element but also to a reflection type liquid crystal display element or an LCOS device.

  In addition, a liquid crystal display element with a built-in drive, a liquid crystal display element with an external drive circuit, a liquid crystal display element with various sizes of about 1 to 15 inches diagonal or larger, a simple matrix system, and a TFD active matrix system The above-described effects can be obtained by applying to any type of liquid crystal display element such as a passive matrix driving method, an optical rotation mode, and a birefringence mode.

  As described above, according to the present embodiment, the liquid crystal display device 1 includes the TFT substrate (first substrate) 10 and the counter substrate (second substrate) disposed facing the TFT substrate 10 with a predetermined gap therebetween. The pixel region 12 and the peripheral region 13 in the gap between the TFT substrate 10 and the counter substrate 20, the inorganic alignment films 50 and 51 formed on the opposing surfaces of the TFT substrate 10 and the counter substrate 20, respectively. The liquid crystal layer 30 held together, the first electrode part EL1 formed on the TFT substrate 10, the second electrode part EL2 formed on the counter substrate 20, the first electrode part and the second electrode Voltage control circuit 104 for driving the unit. The first electrode portion EL1 includes a pixel electrode 11 formed in the pixel region 12 and peripheral electrodes (13A, 13B) formed in the peripheral region 13, and the second electrode portion EL2 includes the common electrode 21. And at least one of the first electrode portion EL1 and the second electrode portion EL2 is divided into a plurality of regions in the voltage control circuit 104, and the amplitude value of the voltage applied to the adjacent region Is controlled to be different from each other, the above-described effects can be obtained. Similarly, at least one of the first electrode portion EL1 and the second electrode portion EL2 is controlled so that a voltage value applied to an adjacent region is different in the above-described region. From the above, the above-described effect can be obtained by combining the above-described amplitude value, voltage value, and region to be divided.

  Also, when an inorganic material is used for the alignment film, the occurrence of image sticking due to ionic impurities can be suppressed.

  In addition, a high-quality liquid crystal display device can be manufactured without causing an increase in manufacturing cost due to a significant change in the drive circuit.

  In the present invention, the first to third embodiments are not limited to being performed alone, but are combined, for example, the second embodiment and the third embodiment are combined to generate a voltage. The control circuit 104 controls the pixel region 12 to vary the voltage value, thereby moving the ionic impurities to the outside of the pixel region 12, and in the peripheral region 13, the amplitude value of the applied voltage. It is also possible to guide to the outermost periphery by controlling so as to be different.

It is a top view which shows schematic structure of the liquid crystal display device to which this invention is applied. It is sectional drawing in A-A 'in FIG. It is a figure which shows the example of arrangement | positioning in the array board | substrate (liquid crystal panel part) of the active matrix type liquid crystal display element to which this invention is applied. It is sectional drawing of the liquid crystal display device for demonstrating the phenomenon generate | occur | produced by the influence of an ionic impurity. It is a top view of the liquid crystal display device for demonstrating the phenomenon generate | occur | produced by the influence of an ionic impurity. It is the figure which showed a mode that the pixel area | region in the liquid crystal display device shown as 1st Embodiment was divided | segmented. It is the figure which showed a mode that the 1st electrode part in the liquid crystal display device shown as 2nd Embodiment was divided | segmented. It is the figure which showed a mode that the pixel area | region in the liquid crystal display device shown as 3rd Embodiment was divided | segmented. It is the block diagram which showed the structure of the voltage control circuit. It is a figure which shows the time-dependent change of the electric potential in a counter electrode. It is a block diagram which shows a more specific example of the 3 plate type | mold projection-type liquid crystal display device which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 10 TFT substrate, 11 Pixel electrode, 12 Pixel region, 13A, 13B Peripheral electrode, 13 Peripheral region, 20 Opposite substrate, 21 Common electrode, 30 Liquid crystal layer, 31 Liquid crystal, 40 Seal material, 50, 51 Inorganic Alignment film, 101 horizontal transfer circuit, 102 vertical transfer circuit, 103 precharge circuit, 104 voltage control circuit, 104A video signal control circuit, 104B drive driver, 104C electrode voltage setting circuit, 105 data line, 106 scan line, 107 transistor, 108 liquid crystal, 110 common wiring, 200 ionic impurities, 201 display unevenness, 300 video display device, 310 optical axis, 311 light source, 312, 313 lens array, 314, 318, 321, 323 total reflection mirror, 315 synthesis element, 315A Phase difference plate, 316con Nsarenzu, 317, 319 dichroic mirror, 320 and 322 relay lens, 324 a field lens, 326 cross prism, 327 a projection lens, 328 screen, 330I incident side polarizing plate, 330S output polarizer

Claims (7)

A first substrate having a first electrode portion;
A second substrate disposed opposite to the first substrate with a predetermined gap and having a second electrode portion;
A liquid crystal layer held in a gap between the first substrate and the second substrate;
A drive control unit for driving the first electrode unit and the second electrode unit,
The drive control unit controls the first electrode unit or the second electrode unit to be divided into a plurality of regions so that the amplitudes of voltages applied to the adjacent regions are different. Liquid crystal display device. The first electrode portion includes a pixel electrode formed in the pixel region and a peripheral electrode formed around the pixel electrode,
The second electrode portion includes a pixel electrode formed in the pixel region and a peripheral electrode formed around the pixel electrode,
The drive control unit sets the pixel region and the peripheral region of the first electrode unit or the second electrode as the plurality of regions, and an amplitude of a voltage applied to the peripheral electrode is applied to the pixel electrode. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is controlled to be larger than the amplitude of the voltage.   The drive control unit is divided into a plurality of annularly provided regions on the outer periphery of the pixel region in the peripheral electrode of the first electrode unit or the second electrode unit, and an inner periphery of the divided regions 3. The liquid crystal display device according to claim 2, wherein control is performed so that the amplitude of the voltage applied to the outer peripheral region is larger than that of the outer region.   The drive control unit divides the pixel region into the plurality of regions in the pixel electrode of the first electrode unit or the second electrode unit, and an amplitude value of a voltage applied to the adjacent regions The liquid crystal display device according to claim 2, wherein the liquid crystal display devices are controlled so as to be different.   The said drive control part is controlled so that the voltage value applied to each of the said divided | segmented several area | region differs in the said 1st electrode part or the 2nd electrode part. Liquid crystal display device.   The drive control unit controls the amplitude value of the voltage applied to the plurality of divided regions to change with time in the first electrode unit or the second electrode unit. The liquid crystal display device according to claim 1. A light source;
An illumination optical system that converges a light beam emitted from the light source into a predetermined optical path;
A liquid crystal display element that optically modulates the light beam collected by the illumination optical system,
The liquid crystal display element is
A first substrate having a first electrode portion;
A second substrate disposed opposite to the first substrate with a predetermined gap and having a second electrode portion;
A liquid crystal layer held in a gap between the first substrate and the second substrate;
A drive control unit for driving the first electrode unit and the second electrode unit,
The drive control unit controls the first electrode unit or the second electrode unit to be divided into a plurality of regions so that the amplitudes of voltages applied to the adjacent regions are different. Video display device.

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