JP2011017891A - Liquid crystal device and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem wherein an FFS panel increases disturbance of liquid crystal alignment due to the influence of a lateral electric field of adjacent pixels, as gradual narrowing among pixels takes place by accompanying high definition.SOLUTION: In a liquid crystal device, the width of a slit-like opening SL2 positioned at the outermost side out of a plurality of the slit-like openings provided on the region of a pixel electrode 11 is set narrower than that of another slit-like openings SL1. According to this constitution, an electric field generated between a common electrode 131 and the pixel electrode 11 suppresses influence exerted for alignment control of liquid crystal molecules in adjacent pixels G, by narrowing the width of the slit-like opening SL2 provided at a position closest to the adjacent pixel electrode 11.

Description

  The present invention relates to a liquid crystal device and an electronic apparatus including the liquid crystal device.

  A liquid crystal layer is sandwiched between a pair of opposing glass substrates, and on one glass substrate surface, a predetermined voltage is applied between a pixel electrode formed for each pixel and a common electrode formed by sandwiching an insulating layer with respect to the pixel electrode. Is applied to generate a lateral electric field along the in-plane direction of the glass substrate, and rotationally control the orientation direction of the liquid crystal molecules in the liquid crystal layer to display an image or the like. Hereinafter referred to as “FFS panel”). In the FFS panel, liquid crystal molecules rotate in a direction parallel to the substrate. Therefore, when viewed obliquely, the direction of polarized light by the liquid crystal molecules does not rotate. Therefore, the display quality is low and the viewing angle is wide and the viewing angle is wide. Widely used as a liquid crystal display device.

  In recent years, in order to meet the demand for higher resolution of images to be displayed, it has been attempted to increase the definition of FFS panels by reducing the space between pixels. For example, Patent Document 1 discloses a technique for achieving high definition without reducing the pixel aperture ratio by disposing a common electrode across pixels.

JP 2007-226199 A

  However, in the FFS panel, as the distance between the pixels becomes narrower as the definition becomes higher, the liquid crystal alignment is greatly disturbed by the influence of the lateral electric field of the adjacent pixels. For example, when a pixel adjacent to a pixel displaying black displays white, the liquid crystal alignment of the pixel displaying black is disturbed due to the influence of a horizontal electric field for displaying white. As a result, light is partially lost (also referred to as “black floating”) in the area of the pixel displaying black, and display quality is deteriorated. In particular, in a high-definition FFS panel in which the width of a light-shielding portion that is normally provided between pixels is less than 5 μm, for example, the degree of light leakage increases and the display quality is further deteriorated.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A plurality of pixel electrodes, each of which is formed by interposing an insulating layer between a plurality of pixel electrodes arranged corresponding to the plurality of pixels and the pixel electrode. A plurality of slit-like openings that are arranged in a plane and overlap with each other in a plane with respect to the region of the pixel electrode, and the pixel electrode and the pixel electrode A liquid crystal device that controls the orientation of liquid crystal molecules for each pixel by an electric field generated between the common electrode and the most of the plurality of slit-shaped openings provided in the pixel electrode region. The width of the slit-shaped opening located on the outside is narrower than the width of other slit-shaped openings.

  According to this configuration, the width of the slit-shaped opening located on the outermost side provided in the region of the pixel electrode, that is, the slit-shaped opening provided closest to the adjacent pixel electrode is reduced. It is possible to suppress the influence of the electric field generated between the electrode and the pixel electrode on the alignment control of the liquid crystal molecules in the adjacent pixel. Therefore, since the orientation of the liquid crystal molecules can be correctly controlled for each pixel, the occurrence of light leakage is suppressed, and a liquid crystal device with good display quality can be obtained.

  Application Example 2 In the above liquid crystal device, the pixel electrode has an end side along a longitudinal direction of the slit-shaped opening, and the end side is located in the outermost slit-shaped opening. It is formed so that it may do.

  According to this configuration, the pixel electrode is formed so that the end side of the pixel electrode is positioned in the slit-like opening narrower than the width of the other slit-like opening. Therefore, since the probability that the electric field generated between the common electrode and the pixel electrode stays in the narrow slit-shaped opening is increased, the influence on the alignment control of the liquid crystal molecules in the adjacent pixel is further suppressed. be able to. As a result, the orientation of the liquid crystal molecules can be controlled more correctly for each pixel.

  Application Example 3 In the liquid crystal device, the plurality of slit-shaped openings are provided so that the longitudinal directions of the slit-shaped openings are aligned between adjacent pixel electrodes, and the slit-shaped openings are arranged between the slit-shaped openings. Of the strip-shaped common electrodes to be formed, the width of the strip-shaped common electrode formed between the regions of the adjacent pixel electrodes is equal to the width of the strip-shaped common electrode formed in the region of the pixel electrodes. It is characterized by being wider than the electrode width.

  According to this configuration, since the electrode width of the strip-shaped common electrode formed between adjacent pixel electrodes is widened, the electric field generated between the common electrode and the pixel electrode controls the alignment of liquid crystal molecules in the adjacent pixels. The influence which it has on can be further suppressed. Therefore, the orientation of the liquid crystal molecules can be correctly controlled for each pixel.

  Application Example 4 In the liquid crystal device described above, the distance between the center lines of the strip-shaped common electrodes formed between the slit-shaped openings is the same.

  According to this configuration, it is possible to suppress the influence of the electric field generated between the common electrode and the pixel electrode on the adjacent pixel electrode without reducing the pixel density.

  Application Example 5 In the liquid crystal device, the pixels are arranged in a certain direction, and the longitudinal direction of the slit-shaped openings is a direction along the certain direction in which the pixels are arranged. It is characterized by that.

  According to this configuration, the electric field generated between the common electrode and the pixel electrode has an influence on the alignment control of the liquid crystal molecules in the adjacent pixels without reducing the pixel density in the direction intersecting the pixel arrangement direction. The influence can be suppressed.

  Application Example 6 Electronic equipment including the liquid crystal device.

  According to this configuration, it is possible to provide an electronic apparatus including a display device with good display quality by suppressing the display from being mutually affected between adjacent pixels.

1 is a schematic configuration diagram of a projector including a liquid crystal device according to an embodiment of the invention. An explanatory view schematically showing a configuration of a liquid crystal device. FIG. 3 is a schematic plan view showing a state of wiring formed in each pixel of the liquid crystal device. The schematic diagram which shows the partial cross section about a liquid crystal device. (A) is explanatory drawing which shows the display state between the conventional adjacent pixels. (B) is explanatory drawing which shows the display state between the conventional adjacent pixels when the pixel electrodes are separated. It is a figure which shows the shape of the common electrode and pixel electrode of 1st Example, (a) is a top view, (b) is explanatory drawing which shows each dimensional relationship of an electrode. The figure which showed the display state in the pixel of 1st Example for each half pixel, (a) is explanatory drawing which showed the state of the transmittance | permeability, (b) is explanatory drawing which showed the display state of the pixel. It is a figure which shows the shape of the common electrode and pixel electrode of 2nd Example, (a) is a top view, (b) is explanatory drawing which shows each dimensional relationship of an electrode. The figure which showed the display state in the pixel of 2nd Example for each half pixel, (a) is explanatory drawing which showed the state of the transmittance | permeability, (b) is explanatory drawing which showed the display state of the pixel. It is a figure which shows the shape of the common electrode and pixel electrode of a 1st modification, (a) is a top view, (b) is explanatory drawing which shows each dimensional relationship of an electrode. The top view which showed the slit-shaped opening part provided in the common electrode in the 2nd modification.

  Hereinafter, the present invention will be described based on examples. In the drawings used in the description of the following embodiments, components and the like may be exaggerated for convenience of description, and needless to say, they do not necessarily indicate actual sizes and lengths.

  FIG. 1 is a configuration diagram showing a schematic configuration when a liquid crystal device 100 according to an embodiment embodying the present invention is used as a light modulation element (light valve) and is provided in a projector 1 as an electronic apparatus. In the projector 1, the irradiation light emitted from the light source 101 is aligned with predetermined polarized light by the polarization beam splitter 102. Then, the polarized light is applied to the liquid crystal device 100 and light modulation is performed when the light passes through each pixel provided in the liquid crystal device 100. The irradiation light that is light-modulated for each pixel is projected by a projection lens 103 onto a screen (not shown) installed at a predetermined distance. In this way, the image displayed on the liquid crystal device 100 is projected. Of course, the projector 1 may include a plurality of (for example, three) liquid crystal devices 100 and an optical system (for example, a mirror or a cross prism) corresponding to the plurality of liquid crystal devices 100 may be formed.

  Now, in the projector, the arrangement direction of the pixels included in the liquid crystal device 100 is often a direction along one side (vertical direction or horizontal direction) of a projection screen that usually has a rectangular shape. Therefore, in the projector 1 of the present embodiment, the arrangement direction of the pixels in the liquid crystal device 100 is the horizontal direction (this is referred to as “row direction”) that is one side of the projection screen, and the vertical direction that is one side orthogonal to the horizontal direction. This will be described as being arranged in a certain direction (referred to as “column direction”).

  In addition, it is preferable in use that the projector is in a black display state when nothing is projected onto the screen. Therefore, in the projector 1 of the present embodiment, normally black display in which black is displayed is performed in each pixel in the liquid crystal device 100 in an initial state where a voltage is not applied between a pixel electrode and a common electrode, which will be described later. Of course, it is possible to perform normally white display in which white is displayed in an initial state where no voltage is applied between the pixel electrode and the common electrode.

  Next, the liquid crystal device 100 will be described. FIG. 2 is an explanatory diagram schematically showing the configuration of the liquid crystal device 100 having a plurality of pixels G for displaying an image. The liquid crystal device 100 has a structure in which a substrate 10 and a substrate 30 are overlapped with a liquid crystal layer (not shown) sandwiched in a sealed state. In FIG. 2, the horizontal direction of the drawing is shown as the row direction, and the vertical direction of the drawing is shown as the column direction. Accordingly, the pixels G are arranged in the horizontal direction (row direction) and the vertical direction (column direction) in the drawing.

  The substrate 10 has a scanning line driving circuit 120, a data line driving circuit 110, and a common terminal 130 formed on the outer peripheral portion thereof on a transparent substrate (the drawing surface side) such as glass, quartz, or resin. . As shown in FIG. 2, the scanning lines 121 are arranged in the row direction from the scanning line driving circuit 120, and the data lines 111 are arranged in the column direction from the data line driving circuit 110, as shown in FIG. A thin film transistor (not shown) corresponding to each pixel G is formed near the intersection of the scanning line 121 and the data line 111. Each thin film transistor is controlled to be turned on / off by a voltage supplied by the scanning line 121. When the thin film transistor is turned on, a voltage supplied by the data line 111 is applied to a pixel electrode (described later). Yes.

  The common terminal 130 is electrically connected to the common electrode 131 formed across the pixels G, and supplies a common voltage (for example, ground potential) to the common electrode 131. Therefore, in each pixel G, the differential voltage between the voltage supplied from the data line 111 when the thin film transistor is turned on and the voltage supplied by the common electrode 131 (the voltage of the ground potential in this embodiment) corresponds to the pixel G. The liquid crystal layer is configured to be applied to the liquid crystal layer.

  The substrate 30 has an area corresponding to the pixel G as an opening area (light transmission area), and a predetermined light shielding layer such as a metal film is transparent such as glass, quartz, or resin so that the other area becomes a light shielding area. It is formed on the substrate (the back side of the drawing). Accordingly, between the regions of the pixels G, the light shielding regions BM are formed in the row direction and the column direction, respectively. That is, the light shielding region BM is formed so as to partition the pixels G and cover the data lines 111, the scanning lines 121, and the thin film transistors when the substrate 30 is superimposed on the substrate 10.

  Next, in the liquid crystal device 100 according to the present embodiment, the state of the pixel electrode arranged corresponding to each pixel G and the common electrode 131 formed across each pixel G will be described with reference to FIGS. I will explain. FIG. 3 is a schematic plan view showing the state of the wiring formed in each pixel G for the four pixels G illustrated in the upper left part of the liquid crystal device 100 in FIG. 2. The liquid crystal device 100 is viewed from the substrate 30 side. The substrate 30 is shown in a see-through state. FIG. 4 is a schematic diagram showing a partial cross section of the liquid crystal device 100 taken along line BB in FIG. In order to facilitate understanding of the effect of the shape of the common electrode 131 (first and second examples described later) provided in the liquid crystal device 100 of the present embodiment, the common electrode 131 in FIGS. 3 and 4 is used. The shape of is shown in the conventional shape.

  As shown in FIG. 3, the data line 111 is formed in the column direction and the scanning line 121 is formed in the row direction on the substrate 10. A thin film transistor (hereinafter simply referred to as “transistor”) 20 is formed in the vicinity of the intersection of these wirings. That is, the transistor 20 including the source electrode 20s formed by extending the wiring of the data line 111, the semiconductor layer 20a in which the channel region is formed, the gate electrode 20g serving as the scanning line 121, and the drain electrode 20d is provided. Is formed. The drain electrode 20d is electrically connected to the pixel electrode 11 through the contact hole CH1. Therefore, when the transistor 20 is turned on by the voltage supplied to the scanning line 121, that is, the gate electrode 20g, the voltage supplied to the data line 111 is applied to the pixel electrode 11 via the drain electrode 20d. Yes.

  The pixel electrode 11 is disposed corresponding to each pixel G, and in this embodiment, each side is formed to have a rectangular shape along the row direction and the column direction. The common electrode 131 formed across the plurality of pixels G with the insulating layer interposed between the pixel electrode 11 and the plurality of pixels G has a plurality of longitudinal directions parallel to each other. The slit-shaped openings SL are provided so as to overlap in a plane. In this embodiment, for each of the pixel electrodes 11, the longitudinal direction is a direction along the extending direction of the data line 111, and four slit-shaped openings SL that are substantially parallel to each other are provided. Therefore, the common electrode 131 has a single strip-shaped common electrode (hereinafter simply referred to as “band-shaped electrode”) 13g between two adjacent pixels G by the provided slit-shaped opening SL. In addition, three strip-shaped common electrodes (hereinafter simply “band-shaped electrodes”) 13 are formed.

  For the convenience of the following description, the slit-shaped opening SL is located on the outermost side of the four slit-shaped openings SL provided on both sides of the strip-shaped electrode 13g, that is, the region of each pixel electrode 11. The slit-shaped opening SL is referred to as a slit-shaped opening SL2, and the other slit-shaped opening SL is referred to as a slit-shaped opening SL1. Of course, when these are not distinguished, they are referred to as slit-shaped openings SL.

  By the way, in this embodiment, the initial orientation of the liquid crystal molecules is to suppress the reverse twist in which the liquid crystal molecules rotate in the direction opposite to the original rotation direction because the longitudinal direction of the strip electrodes 13 and 13g is the column direction. In addition, it is assumed that it is formed in a direction inclined α degrees (for example, about 5 degrees to 20 degrees) counterclockwise (left rotation direction in FIG. 3) with respect to the row direction. Of course, the initial orientation may be formed to be inclined by α degrees (for example, 5 degrees to 20 degrees) in a clockwise direction (right rotation direction in FIG. 3). Further, it is sufficient that three or more slit-shaped openings SL are formed for each region of the pixel electrode 11.

  By forming the slit-shaped opening SL in this way, the voltage from the data line 111 is applied between the strip electrodes 13 and 13g provided in the common electrode 131 and the pixel electrode 11, thereby liquid crystal. A transverse electric field is generated in the direction along the substrate 10 with respect to the layer. As a result, as described above, the alignment control of the liquid crystal molecules by the FFS method is performed in each pixel G. Note that the pixel electrode 11 and the common electrode 131 are formed of a light-transmitting material having conductivity (for example, ITO). Of course, if the reduction in the amount of irradiation light transmitted through the pixel G has no practical effect, the pixel electrode 11 or the common electrode 131 may be formed of a metal material (such as aluminum).

  Next, a cross-sectional configuration of the liquid crystal device 100 will be described with reference to FIG. FIG. 4 is a schematic diagram showing a cross section taken along line BB in FIG. As shown in the figure, the liquid crystal device 100 has a configuration in which a liquid crystal layer 40 is sandwiched between a substrate 10 and a substrate 30. A polarizing plate 44 is attached to the opposite side of the substrate 30 to the liquid crystal layer 40, and a polarizing plate 45 is attached to the opposite side of the substrate 10 to the liquid crystal layer 40 so as to exhibit a predetermined polarization axis direction. In the present embodiment, it is assumed that the liquid crystal layer 40 is formed of positive liquid crystal molecules whose polarization direction is the same as the alignment direction. Of course, it may be formed of negative liquid crystal molecules whose polarization direction is orthogonal to the alignment direction.

  The substrate 30 is obtained by sequentially forming a light shielding layer 32 and an alignment film 39 for forming a light shielding region BM on a substrate surface on the liquid crystal layer 40 side with respect to a base material 31 as a flat plate. The light shielding layer 32 is made of a metal film (for example, chromium) or a resin. The alignment film 39 is made of, for example, polyimide resin, and is formed so as to cover the light shielding region BM and the pixel G region. In the substrate 30, a planarization layer or an overcoat layer for planarizing the alignment film 39 may be formed between the alignment film 39 and the light shielding layer 32. In the substrate 30, a light transmission region corresponding to at least the region of the pixel G is provided between the base material 31 and the alignment film 39, and a color filter layer that transmits a predetermined color is formed in the light transmission region. It may be done.

  The substrate 10 has a scanning line 121 (gate electrode 20g), a gate insulating layer 15, a semiconductor layer 20a, and a data line 111 (source electrode 20s) on the substrate surface on the liquid crystal layer 40 side with respect to the base material 14 as a flat plate. The drain electrode 20d, the interlayer insulating layer 16, the planarizing layer 17, the pixel electrode 11, the insulating layer 18, the common electrode 131, and the alignment film 19 are sequentially formed.

  The scanning line 121 (gate electrode 20g), the data line 111 (source electrode 20s), and the drain electrode 20d are formed of a metal material (for example, aluminum). A semiconductor such as amorphous silicon or polysilicon is used for the semiconductor layer 20a. The gate insulating layer 15 is made of, for example, silicon oxide, the interlayer insulating layer 16 is made of, for example, silicon oxide or silicon nitride, the planarizing layer 17 is made of a resin material, and the insulating layer 18 is made of, for example, silicon oxide or silicon nitride. Both are formed as a light-transmitting layer. The alignment film 19 is made of, for example, polyimide resin, and is formed on the side of the common electrode 131 in contact with the liquid crystal layer 40 so as to cover at least the regions of all the pixels G.

  In the present embodiment, as described above, the liquid crystal device 100 is configured to perform normally black display. Further, the alignment film 19 and the alignment film 39 are rubbed or the like so that the liquid crystal layer is formed of positive liquid crystal molecules and the initial alignment direction of the liquid crystal molecules is inclined α degrees counterclockwise with respect to the column direction. Oriented. In addition, the alignment film 39 and the alignment film 19 are subjected to an alignment process in an antiparallel state so that the pretilt angles of the liquid crystal molecules are opposite to each other.

  Further, the polarizing plate 44 has a transmission axis in the initial alignment direction, and the polarizing plate 45 is attached so that the transmission axis is in a crossed Nicol arrangement in a direction perpendicular to the transmission axis of the polarizing plate 44. Of course, when the irradiation light incident on the substrate 30 is polarized light that vibrates substantially in the direction of the initial alignment of the liquid crystal molecules, the polarizing plate 44 on the irradiation light incident side may be omitted.

  Now, the conventional shapes of the pixel electrode 11 and the common electrode 131 (strip-like electrodes 13 and 13g) in the liquid crystal device 100 configured as described above are formed with respective dimensions as shown in the enlarged view in the lower part of FIG. Yes. That is, in the conventional shape, the electrode width of the strip electrode 13 formed on the common electrode 131 and the electrode width of the strip electrode 13g are the same dimension d1. Further, the width of the slit-shaped opening SL2 and the width of the slit-shaped opening SL1 are the same dimension s1. Accordingly, all the distances between the center lines of the strip electrodes 13 and 13g have the same dimension p1. Further, the distance between adjacent pixel electrodes 11 is the same dimension d1 as the electrode width of the strip electrode 13g. In other words, the end sides along the column direction of the pixel electrodes 11 are separated from the center line of the strip electrode 13g, that is, the intermediate line of the adjacent pixels G, by a dimension g1 (= d1 / 2). In addition, between the adjacent pixel electrodes 11, there is a case where the conventional shape does not necessarily have the same dimension d1 as the electrode width of the strip-like electrode 13g (small or large). Further, the end side along the row direction of the pixel electrode 11 is formed so as to overlap with the common electrode 131 in a plane as shown in FIG.

  A display state of the pixel G in which the strip electrodes 13 and 13g and the pixel electrode 11 are formed in the conventional shape will be described with reference to FIG. FIG. 5A shows a display state when two pixels G adjacent in the row direction have one (left side in the drawing) displayed black and the other (right side in the drawing) displayed white. FIG. 5A shows half-pixels of pixels located on both sides in the row direction, with the center between the pixels G adjacent in the row direction as a reference (0).

  In the liquid crystal device 100 of the present embodiment, the voltage “0V” is applied to the pixel electrode 11 corresponding to the pixel G that performs black display, the voltage “5V” is applied to the pixel electrode 11 that corresponds to the pixel G that performs white display, and A ground voltage “0 V” is applied to each common electrode 131. Further, as specific dimensions of the conventional shape, a case where d1 = 1 μm, s1 = 1.5 μm, p1 = 2.5 μm, and g1 = 0.5 μm is shown. The width of the light shielding region BM is 2 μm, and therefore the region of the pixel G is 8 × 8 μm, and the pixel pitch is 10 μm in both the matrix directions.

  In the conventional shape having such dimensions, as shown on the right side of FIG. 5A, the pixel G that performs black display is affected by the lateral electric field from the pixel G that performs white display and performs white display. There is a problem that light leakage (black floating) occurs in the region R1 close to the pixel.

  Here, in the conventional shape, if the distance in the row direction between the adjacent pixel electrodes 11 is increased, the pixel G that performs black display is less likely to be affected by the lateral electric field from the pixel G that performs white display. Assumed. Therefore, the distance in the row direction between the adjacent pixel electrodes 11 is increased, and as shown in FIG. 5B, the end side of the pixel electrode 11 is positioned within the opening of the slit-shaped opening SL2.

  The results are shown on the right side of FIG. As shown in the drawing, in the pixel G that performs black display, light leakage (black floating) that occurs in the region R1 close to the pixel that performs white display is suppressed. However, in the pixel G that performs white display, the state of occurrence of the horizontal electric field changes, and a liquid crystal molecule misalignment region (domain) occurs in the region R2 close to the pixel G that performs black display. For this reason, it will be in the state which causes the fall of the transmittance | permeability.

  As described above, with respect to the display state of the pixel G in which the strip electrodes 13 and 13g and the pixel electrode 11 are formed in the conventional shape, black floating occurs in black display, and the transmittance decreases in white display. Since a defect occurs, display quality is degraded.

  Therefore, the liquid crystal device 100 according to the present embodiment can suppress the occurrence of black floating and transmittance reduction in the region of the pixel G, so that the strip-like electrodes 13 and 13g (that is, the slit-like opening SL) in the common electrode 131 are suppressed. Or the shape of the pixel electrode 11 is changed from the conventional shape. Hereinafter, two examples of the shape change of the slit-shaped opening SL and the pixel electrode 11 will be described, and these will be sequentially described with reference to FIGS.

(First embodiment)
First, the first embodiment will be described. FIG. 6 is a schematic diagram showing the shape of the common electrode 131 of the first example that is changed in the pixel G provided in the liquid crystal device 100 of the present embodiment. FIG. 6A is a schematic diagram illustrating in plan view the slit-shaped openings SL1 and SL2 formed in the common electrode 131 for two adjacent pixels G arranged in the row direction. FIG. 6B is a schematic diagram showing a cross section along the line CC in FIG. 6A, and the strip electrodes 13 and 13g formed by the slit-shaped openings SL1 and SL2, and the pixel electrode 11 is an explanatory diagram showing a dimensional relationship of 11.

  As shown in FIG. 6, in this embodiment, the width of the slit-shaped opening SL2 is set to a dimension s2 smaller than the conventional dimension s1. At this time, the distance p1 between the center lines of the strip electrode 13g and the strip electrode 13 is not changed, and the electrode width of the strip electrode 13g formed between the adjacent pixels G is increased to a dimension d2 larger than the dimension d1. It is what I did.

  FIG. 7 shows a display state of the pixel G in which the strip electrodes 13 and 13g are changed and formed so that the width of the slit opening SL2 is reduced. FIG. 7 shows, as shown in FIG. 6A, the display states of the pixels located on both sides in the row direction with respect to the center between the adjacent pixels G in the row direction as a reference (0). -X μm to + X μm). FIG. 7A is an explanatory diagram showing the state of transmittance of the pixel G at a position corresponding to the CC cross section in FIG. 6A, and FIG. 4 is an explanatory diagram showing a display state of a pixel G. FIG.

  In the present embodiment, for comparison with the conventional shape of the slit-shaped opening SL (also referred to as a conventional example), the specific dimensions are d2 = 2.6 μm and s2 = 0.7 μm. . Of course, the width of the light shielding region BM is 2 μm, the region of the pixel G is 8 × 8 μm, and the pixel pitch is 10 μm in both the matrix directions. Further, the voltage “0 V” is applied to the pixel electrode 11 corresponding to the pixel G (left side of the drawing) that performs black display, and the voltage “5 V” is applied to the pixel electrode 11 that corresponds to the pixel G (right side of the drawing) that performs white display. The common electrode 131 is applied with a ground voltage “0 V”.

  As shown in FIG. 7A, according to the shape of the common electrode 131 of the first embodiment, the transmittance of the black display pixel G is lower at the end of the pixel region than in the conventional example. That is, it can be seen that the influence on the alignment control of the liquid crystal molecules in the adjacent black display pixel G is suppressed, and light leakage is suppressed. On the other hand, the transmittance of the white display pixel G remains at a slight decrease at the end of the pixel region. Therefore, the white transmittance of the entire pixel is almost the same as the conventional example. As a result, as shown in FIG. 7B, in the display state in the entire region of the pixel G, light leakage in the region R1 (see FIG. 5A) that occurs in the conventional example is suppressed.

  As described above, according to the present embodiment, by narrowing the width of the slit-shaped opening SL2 provided at the position closest to the adjacent pixel electrode 11, the gap between the strip-shaped electrode 13g and the pixel electrode 11 is reduced. The influence of the generated electric field on the alignment control of liquid crystal molecules in the adjacent pixel G can be suppressed. Therefore, since the orientation of the liquid crystal molecules can be controlled correctly for each pixel, the occurrence of light leakage is suppressed, and a liquid crystal device with good display quality can be obtained.

(Second embodiment)
Next, a second embodiment will be described. In the first embodiment, when the electrode width of the strip electrode 13g of the common electrode 131 is increased and the width of the slit opening SL2 is reduced, the distance between the pixel electrodes 11 is not changed. In this embodiment, in addition to the modification of the first embodiment, the distance between the pixel electrodes 11 is further increased so that the end sides of the pixel electrodes 11 are planarly located in the openings of the slit-shaped openings SL2. is there.

  FIG. 8 is a schematic diagram showing the shapes of the common electrode 131 and the pixel electrode 11 of the second example modified in the pixel G provided in the liquid crystal device 100 of the present embodiment. FIG. 8A is a plan view showing the strip-like electrodes 13 and 13g modified and formed in the common electrode 131 and the pixel electrode 11 similarly modified and formed for the two adjacent pixels G arranged in the row direction. It is a schematic diagram. FIG. 8B is a schematic diagram showing a cross section taken along the line DD in FIG. 8A, and is an explanatory diagram showing a dimensional relationship between the strip electrodes 13 and 13 g and the pixel electrode 11.

  As shown in FIG. 8, in this embodiment, in addition to the change in the width of the slit-shaped opening SL2 performed in the first embodiment, the change in the distance between the pixel electrodes 11 is performed. That is, in addition to expanding the electrode width of the strip electrode 13g to a dimension d2 that is larger than the dimension d1, the pixel electrode extends from the center line of the strip electrode 13g (that is, the center line between two pixels G adjacent in the row direction). The distance to the edge 11 is set to a dimension g2 that is larger than the dimension g1 (= d1 / 2). In this way, the end side of the pixel electrode 11 is positioned in a plane within the opening of the slit-shaped opening SL2.

  FIG. 9 shows a display state of the pixel G in which the strip-like electrode 13g and the pixel electrode 11 are changed and formed as described above. As shown in FIG. 8A, the display states of the pixels located on both sides in the row direction are set to half pixels (0) with the center between the pixels G adjacent in the row direction as a reference (0). -X μm to + X μm). 9A is an explanatory diagram showing a state of transmittance at the DD cross-sectional position in FIG. 8A, and FIG. 9B is a display state of two adjacent pixels G. FIG. It is explanatory drawing which showed.

  In the present embodiment, as in the first embodiment, for comparison with the conventional example, the specific dimensions are shown as d2 = 2.6 μm, s2 = 0.7 μm, g2 = 1.7 μm. Yes. Of course, the width of the light shielding region BM is 2 μm, the region of the pixel G is 8 × 8 μm, and the pixel pitch is 10 μm in both the matrix directions. Further, the voltage “0 V” is applied to the pixel electrode 11 corresponding to the pixel G (left side of the drawing) that performs black display, and the voltage “5 V” is applied to the pixel electrode 11 that corresponds to the pixel G (right side of the drawing) that performs white display. The common electrode 131 is applied with a ground voltage “0 V”.

  As shown in FIG. 9A, according to the shapes of the common electrode 131 and the pixel electrode 11 of the second embodiment, the transmittance of the black display pixel G is higher at the end of the pixel region than in the conventional example. It is lower than in the case of the first embodiment. That is, it can be seen that the influence on the alignment control of the liquid crystal molecules in the adjacent black display pixel G is suppressed, and light leakage is further suppressed. On the other hand, the transmittance of the white display pixel G is slightly reduced at the end of the pixel region, as in the first embodiment. That is, the white transmittance of the entire pixel is almost the same as the conventional example. As a result, as shown in FIG. 9B, in the display state in the entire region of the pixel G, light leakage of the region R1 (see FIG. 5A) that occurs in the conventional example is further suppressed. Become.

  In this embodiment, when the edge of the pixel electrode 11 is positioned in the opening of the slit-shaped opening SL2, the edge of the pixel electrode 11 is formed as a slit-shaped opening as shown in FIG. Although it is set as the direction along the longitudinal direction of SL2, of course, it is not restricted to this. For example, the direction of the edge of the pixel electrode 11 may be different from the longitudinal direction of the slit-shaped opening SL2. Alternatively, the direction may include a difference in inclination angle that occurs according to variations in the formation of the pixel electrode 11 and the slit-shaped opening SL2. If the edge of the pixel electrode 11 is positioned within the opening of the slit-shaped opening SL2, a similar effect is obtained in that the influence on the alignment control of the liquid crystal molecules in the adjacent black display pixel G is suppressed.

  As described above, according to this embodiment, in addition to narrowing the opening width of the slit-shaped opening SL2 provided at the position closest to the adjacent pixel electrode 11, the edge of the pixel electrode region is Further, by being positioned within the opening of the slit-shaped opening SL2, the distance between the adjacent pixel electrodes can be increased. In this embodiment in which the distance from the pixel electrode is thus separated, unlike the conventional example described above, the electric field generated between the common electrode and the pixel electrode is aligned with the liquid crystal molecules in the adjacent pixel. Since the influence on the control can be further suppressed, the occurrence of light leakage is suppressed, and a liquid crystal device with good display quality can be obtained.

  In addition, according to the said Example, when the width | variety of slit-shaped opening part SL2 is set to the dimension s2 smaller than the dimension s1, the distance between the centerline of the strip | belt-shaped electrode 13g and the strip | belt-shaped electrode 13 is not changed, The electrode width was expanded to a dimension d2 larger than the dimension d1. In this case, since the arrangement pitch of the pixels G does not change, the influence of the electric field generated between the common electrode and the pixel electrode on the adjacent pixel electrode in the same pixel density without reducing the pixel density. There is an effect that can be suppressed.

  In addition, since the width of the strip-shaped electrode 13g formed between adjacent pixel electrodes is widened, the electric field generated between the common electrode 131 and the pixel electrode 11 controls the alignment control of liquid crystal molecules in the adjacent pixels G. There is an effect that the influence can be further suppressed.

  The embodiments of the present invention have been described with reference to the examples. However, the present invention is not limited to these examples, and can be implemented in various forms without departing from the spirit of the present invention. Of course. Hereinafter, a modification will be described.

(First modification)
In the above embodiment, when the width of the slit-shaped opening SL2 is set to the dimension s2 smaller than the dimension s1, the distance between the center lines of the strip-shaped electrode 13g and the strip-shaped electrode 13 is not changed. It may be changed instead. Depending on the pixel density allowed in the liquid crystal device 100, the distance between the center line of the strip electrode 13g and the center line of the strip electrode 13 located next to the strip electrode 13g may be reduced or increased.

  As an example of this modification, a case where the distance between the center lines of the strip electrode 13g and the adjacent strip electrode 13 is increased will be described with reference to FIG. FIG. 10 is a schematic diagram showing the shapes of the common electrode 131 and the pixel electrode 11 to which the present modification is applied in the first embodiment. FIG. 10A is a schematic diagram showing in plan view the slit-shaped openings SL1 and SL2 formed in the common electrode 131 for two adjacent pixels G arranged in the row direction. FIG. 10B is a schematic diagram showing a cross section taken along the line E-E in FIG. 10A, and the strip electrodes 13 and 13 g formed by the slit-shaped openings SL and the pixel electrodes 11. It is explanatory drawing which showed the dimensional relationship.

  As shown in FIG. 10, in this modification, the width of the slit-shaped opening SL2 is set to a dimension s2 smaller than the dimension s1, and the distance between the center lines of the strip-shaped electrode 13g and the strip-shaped electrode 13 is larger than the dimension p1. Change to dimension p2. In addition, the distance from the center line of the strip electrode 13g to the edge of the pixel electrode 11 is set to a dimension g3 larger than the dimension g1 (= d1 / 2).

  According to this modification, although the arrangement pitch of the pixels G is increased and the pixel density in the row direction is reduced as compared with the above embodiment, the width of the strip electrode 13g formed between adjacent pixel electrodes is increased. Therefore, for example, since the position of the electric field generated between the strip electrode 13g and the pixel electrode 11 is separated from the adjacent pixel G, the influence on the alignment control of the liquid crystal molecules in the adjacent pixel G can be suppressed. The effect that it can be expected.

  Conversely, as another example of this modification, the case where the distance between the center line of the strip electrode 13g and the adjacent strip electrode 13 is shortened will be described with reference to FIG. In this case, in FIG. 10, the width of the slit-shaped opening SL2 is set to a dimension s2 smaller than the dimension s1, and the distance between the center lines of the strip electrode 13g and the strip electrode 13 is changed to a dimension p2 smaller than the dimension p1. To do. By doing so, the arrangement pitch of the pixels G becomes narrower in the row direction than in the above embodiment, so that the pixel density can be increased and the width of the slit-shaped opening SL2 is narrowed as in the above embodiment. Accordingly, an effect that the influence on the alignment control of the liquid crystal molecules in the adjacent pixel G can be suppressed can be expected.

  At this time, it is preferable to make the dimension p2 as small as possible within a range in which the influence on the alignment control of the liquid crystal molecules between the pixels G adjacent in the row direction is not problematic in practice. In this way, the pixel density in the row direction can be increased. Accordingly, there is a case where the distance from the center line of the strip electrode 13g, that is, the intermediate line of the adjacent pixel G, to the edge of the pixel electrode 11 is a dimension g3 smaller than the dimension g1 (= d1 / 2).

(Second modification)
In the above embodiment, the plurality of slit-shaped openings SL formed in the common electrode 131 are formed for each pixel electrode 11 arranged and formed corresponding to the pixel G. However, the present invention is not limited to this. Of course. For example, the slit-shaped opening SL may be formed so that the openings are connected to each other between the adjacent pixels G. An example of this is shown in FIG. FIG. 11 is a diagram corresponding to FIG. 3 in the above embodiment, and is a plan view showing the slit-shaped opening SL provided in the common electrode 131 formed across the four pixels G. FIG.

  As shown in the figure, in the present modification, the slit-shaped opening SL is formed in the common electrode 131 so that the slit-shaped opening SL formed corresponding to each pixel electrode 11 is connected in the column direction. Also in this modified example, in each pixel G, the strip electrodes 13 and 13g are formed in the same manner as in the above embodiment. Therefore, the shape change of the slit opening SL described in the above embodiment or the shape of the pixel electrode 11 is performed. The effect of the change is equally achieved.

(Third Modification)
In the above embodiment, the common electrode 131 is described as having the slit-shaped opening SL whose longitudinal direction is the direction along the data line extending direction, that is, the column direction. However, the present invention is not limited thereto. A slit-shaped opening SL whose longitudinal direction is the direction along the extending direction of the scanning line, that is, the row direction may be formed. Even if the longitudinal direction is the row direction, for example, the effect obtained by narrowing the width of the slit-shaped opening SL2 described above is the same, for example, the shape change of the slit-shaped opening SL described in the above embodiment or the pixel The effect of changing the shape of the electrode 11 is equivalently achieved.

(Fourth modification)
In the above embodiment, the liquid crystal device 100 has been described as being used as a light modulation element in the projector 1, but it is needless to say that the present invention is not limited to this. For example, the liquid crystal device 100 may be used as a direct-view display device. In this case, it is preferable to integrally form a backlight using a light source such as a fluorescent tube on the back surface of the liquid crystal device 100. Since the liquid crystal device 100 can display an image in which the deterioration of display quality is suppressed as described above, the liquid crystal device 100 can be used in electronic devices such as a television, a digital still camera, a digital video camera, a mobile phone, and a computer. It may be provided as a direct-view display device. In this way, an electronic device that provides an image with good display quality can be realized.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 10 ... Substrate, 11 ... Pixel electrode, 13, 13g ... Strip electrode, 14 ... Base material, 15 ... Gate insulating layer, 16 ... Interlayer insulating layer, 17 ... Planarization layer, 18 ... Insulating layer, 19 ... Alignment film, 20 ... transistor, 20a ... semiconductor layer, 20d ... drain electrode, 20g ... gate electrode, 20s ... source electrode, 30 ... substrate, 31 ... base material, 32 ... light shielding layer, 39 ... alignment film, 40 ... liquid crystal layer 44 ... Polarizing plate, 45 ... Polarizing plate, 100 ... Liquid crystal device, 101 ... Light source, 102 ... Polarizing beam splitter, 103 ... Projection lens, 110 ... Data line driving circuit, 111 ... Data line, 120 ... Scanning line driving circuit, 121 ... Scanning line, 130 ... Common terminal, 131 ... Common electrode, CH1 ... Contact hole, SL1 ... Slit-like opening, SL2 ... Slit-like opening, SL ... Slit-like opening

Claims (6)

Having a plurality of pixels,
A plurality of pixel electrodes arranged corresponding to the plurality of pixels;
A plurality of slit-shaped openings formed between the pixel electrodes with an insulating layer interposed therebetween and disposed across the plurality of pixel electrodes and having longitudinal directions substantially parallel to the pixel electrode region. And a common electrode provided to overlap in a plane,
A liquid crystal device that controls alignment of liquid crystal molecules for each pixel by an electric field generated between the pixel electrode and the common electrode;
Of the plurality of slit-like openings provided for the pixel electrode region, the width of the outermost slit-like opening is narrower than the width of the other slit-like openings. Liquid crystal device. The liquid crystal device according to claim 1,
The pixel electrode has an end along the longitudinal direction of the slit-shaped opening,
The liquid crystal device according to claim 1, wherein the end side is formed so as to be positioned in the outermost slit-shaped opening. The liquid crystal device according to claim 1 or 2,
The plurality of slit-shaped openings are provided so that the longitudinal directions of the slit-shaped openings are aligned between the adjacent pixel electrodes,
Of the strip-shaped common electrodes formed between the slit-shaped openings, the electrode width of the strip-shaped common electrode formed between the adjacent pixel electrode regions is formed in each pixel electrode region. A liquid crystal device having a width wider than an electrode width of the strip-shaped common electrode. The liquid crystal device according to claim 3,
2. A liquid crystal device according to claim 1, wherein the distance between the center lines of the respective strip-shaped common electrodes formed between the slit-shaped openings is the same. The liquid crystal device according to claim 1, wherein the liquid crystal device is a liquid crystal device according to claim 1.
The pixels are arranged in a certain direction,
The longitudinal direction of the slit-shaped opening is a direction along the certain direction in which the pixels are arranged.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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