JP4710935B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention belongs to a technical field of an electro-optical device such as a transflective liquid crystal device and an electronic apparatus including such an electro-optical device.

  In general, this type of electro-optical device is connected to a large number of pixel electrodes, a TFT for controlling the switching thereof, and a TFT, for example, in the case of an active matrix driving system driven by a thin film transistor (hereinafter referred to as TFT (Thin Film Transistor)). An element array substrate provided with data lines for supplying image signals and scanning signals, wiring lines such as scanning lines, and the like, and a counter substrate provided with a counter electrode, a color filter, and the like arranged opposite thereto are provided. During the operation, a drive voltage is generated between the pixel electrode and the counter electrode for each pixel. By this driving voltage, each electro-optical material portion is driven in units of pixels, and the display operation is performed, for example, by changing the alignment state of the liquid crystal.

  Accordingly, to accurately control the distance between the two substrates that defines the thickness of the electro-optic material layer (hereinafter referred to as “inter-substrate gap” or simply “gap” as appropriate) is necessary. For this reason, in a relatively large liquid crystal display device having a diagonal size of several inches to several tens of inches, for example, a bead-like or fiber-like gap material having a predetermined particle diameter is dispersed in the liquid crystal to control the gap between the substrates. Alternatively, in a small liquid crystal display device having a diagonal size of several inches or less, for example, a gap material between beads and fibers having a predetermined particle diameter is mixed in a sealing material for bonding both substrates to control the gap between the substrates. It is common.

  Further, as disclosed in JP-A-4-240622, JP-A-2000-19527, JP-A-2001-305552, and the like, a minute height having a predetermined height on the surface of the element array substrate or the counter substrate is disclosed. A technique for controlling a gap between substrates by forming a large number of shell pillars or pillar spacers has been developed.

  On the other hand, this type of electro-optical device performs reflective display using external light in a bright place and performs transmissive display using a built-in light source or light source emitted from a backlight in a dark place. A transflective electro-optical device that can switch the display is also developed. In such a transflective electro-optical device, external light passes through the electro-optical material layer twice during reflective display, whereas light source light passes through the electro-optical material layer only once during transmissive display. Do not pass. Here, in order to perform both types of display properly, it is preferable to align the polarization characteristics of the electro-optic material layer. For this reason, the total thickness of the electro-optic material layer through which the display light passes is set to be transparent. Techniques for aligning between display and reflection display have been proposed. Specifically, in the reflective display region and the transmissive display region, the thickness of the electro-optical material layer in the former, that is, the inter-substrate gap, is set to about half that in the latter.

  However, according to the technology for controlling the gap between the substrates using the above-described conventional bead-like or fiber-like gap material, the area of each pixel is divided into the area for reflection display and the area for transmission display. It is technically difficult to define different inter-substrate gaps.

In addition, the substrate for the reflective display area and the transmissive display area, each of which is divided into two, are divided by the technology for controlling the gap between the substrates using the conventional shell pillar-shaped or columnar spacers described above. It is difficult to define the gap.
More specifically, in addition to the difficulty of forming the two types of spacers themselves, the rubbing treatment of the alignment film formed thereon is performed when two types of spacers exist. It is technically difficult to carry out without causing alignment unevenness. In particular, for a larger shell columnar or columnar spacer that controls the wider gap between substrates, for example, about 4 μm to 10 μm, a considerable amount of rubbing failure occurs depending on the height. As a result, malfunction of the electro-optic material such as alignment failure of the liquid crystal occurs. Therefore, high-quality image display becomes difficult. Alternatively, there is a technical problem that a display image becomes dark because it is necessary to cover a region where such a malfunction occurs in each pixel with a light shielding film.

  The present invention has been made in view of the above problems. For example, the malfunction of electro-optical materials such as liquid crystal alignment failure is reduced, and a high-quality and bright image can be displayed during both transmissive display and reflective display. It is an object of the present invention to provide a transflective electro-optical device capable of display and an electronic apparatus including such an electro-optical device.

In order to solve the above problems, an electro-optical device according to an aspect of the invention includes a pair of a first substrate and a second substrate, an image display region including a plurality of pixels, and one of the first substrate and the second substrate. A light shielding film extending in a first direction and a second direction intersecting the first direction and provided in a lattice shape between the plurality of pixels; and the first and second light shielding films on the light shielding film. includes a columnar portion defining a gap between the substrates, and an alignment film formed to cover the columnar portion, wherein the pixel has a region for transmissive display and the region for reflective display, wherein The gap in the reflective display region is narrower than the gap in the transmissive display region, and the columnar portion is disposed so as to define the gap in the reflective display region. A light shielding film extending in the first direction and the first portion With overlaps and intersections of the light shielding film extending in a direction, a region for the reflection display of the blue pixels on the downstream side of the rubbing direction of the alignment layer as a reference the columnar portion are arranged so as to be located.

  According to the electro-optical device of the present invention, for example, a plurality of transflective display electrodes are provided on a second substrate formed of an element array substrate. Such a display electrode may be a pixel electrode divided for each pixel, or may be a striped electrode or a segmented electrode. In particular, each display electrode has a transmissive display region and a reflective display region. For example, each display electrode is made of a transparent conductive film such as ITO (Indium Tin Oxide) in the transmissive display region that occupies one half or the center half of each pixel, and the others. In the reflective display region, a reflective film such as an Al (aluminum) film is laminated on the transparent conductive film, or the reflective film is made of such a reflective film alone. During operation of the electro-optical device, image signals are supplied to such display electrodes from wiring such as data lines and electronic elements such as TFTs and TFDs. For example, active matrix driving, passive matrix driving, segment driving, etc. For example, reflection display is possible using external light from the side opposite to the electro-optic material layer in the first substrate in a bright place, and light source light from the side opposite to the electro-optic material layer in the second substrate in the dark place. Transparent display is possible using.

  Here, on one of the first and second substrates in the image display region, a columnar portion is erected on the surface facing the electro-optic material layer. That is, the columnar part defines a gap between the first and second substrates as a gap material. Such a columnar portion may be, for example, an island shape such as a cylindrical shape, a prismatic shape, a truncated cone shape, a truncated pyramid shape, or a cross shape or a longitudinal shape slightly extending along the wiring. A convex stepped portion is formed in a predetermined region including a reflective display region on the surface of at least one of the first and second substrates facing the electro-optic material layer. In this case, preferably, the convex stepped portion is not only the reflective display area, but each pixel in which wiring or electronic elements are formed other than the opening area of each pixel through which light that actually contributes to display is transmitted or reflected. The non-opening region, that is, a region serving as a gap between the open regions of the respective pixels, is extended, and the columnar portion is disposed at a position facing the convex stepped portion in the non-opened region of each pixel. In any case, the columnar part is disposed at a position facing the convex stepped part. Therefore, by adjusting the height of the convex stepped portion and adjusting the height of the columnar portion as the gap material, the layer thickness of the electro-optic material layer in the transmissive display region can be changed to the reflective display region. It is possible to make it thicker than that in the case of, for example, about twice. That is, the gap between the substrates can be narrowed in the reflective display region, and at the same time, the gap between the substrates can be widened in the transmissive display region.

In particular, such a columnar portion is arranged at a position facing the convex stepped portion, that is, so as to define a narrower inter-substrate gap, and relatively corresponds to the wider inter-substrate gap. It is not provided on the surface of the concave first or second substrate.
At this time, if the pixel pitch is, for example, about several μ to several tens of μm, or smaller than several hundred to several thousand μm, a gap that defines a wide inter-substrate gap corresponding to the transmissive display region in this way Even if no material is provided, the gap between the two types of substrates can be defined stably. In addition, if the columnar part has a relatively low height in this way, after forming the columnar part during the manufacturing process of the electro-optical device, when an alignment film is applied and further subjected to a rubbing treatment, Compared with the case where the columnar portion having a relatively high height is formed, the occurrence region of the rubbing failure spreading downstream in the rubbing direction with respect to the columnar portion may be small.

  As a result, the polarization characteristics in the electro-optic material layer can be made uniform between the reflective display and the transmissive display by the two kinds of inter-substrate gaps. In addition, it is possible to reduce malfunctions of the electro-optic material such as poor alignment of the liquid crystal in both the reflective display and the transmissive display, so that high-quality image display is finally possible, and further, the malfunction of the electro-optic material is hidden. Therefore, the area where the light shielding film is formed can be narrowed, so that bright display is possible. In one aspect of the electro-optical device of the present invention, the electro-optical device further includes a transparent step forming film for at least partially forming the step portion on one of the first and second substrates.

  According to this aspect, for example, a step portion can be formed on one of the first and second substrates relatively easily due to the presence of a transparent step forming film such as a silicon oxide film, and the height control can be relatively controlled. Easy and highly accurate.

  In another aspect of the electro-optical device according to the aspect of the invention, the stepped portion extends in a predetermined direction across the plurality of display electrodes when seen in a plan view.

  According to this aspect, the stepped portion extends in a band shape across a plurality of display electrodes when viewed in a plan view, for example, in a direction along the array of display electrodes or in a direction along wiring such as a scanning line or a data line. Since it extends, it can be formed more easily than when divided for each pixel, and dimensional control and height control in the planar pattern can be performed with high accuracy.

  However, such a stepped portion may be formed by being divided for each pixel.

  In another aspect of the electro-optical device according to the aspect of the invention, the step portion is formed on the first substrate, and the columnar portion is formed on the first substrate.

  According to this aspect, for example, both the stepped portion and the columnar portion need only be formed on the first substrate side which is the counter substrate, so that the second substrate side manufacturing which is an element array substrate and is relatively difficult to manufacture, for example. These stepped portions and columnar portions can be formed separately from the process. Therefore, manufacturing becomes easy as a whole.

  Alternatively, in another aspect of the electro-optical device according to the aspect of the invention, the step portion is formed on the second substrate, and the columnar portion is formed on the first substrate.

  According to this aspect, for example, the columnar portion may be formed on the first substrate side which is the counter substrate, so that it is separated from the manufacturing process on the second substrate side which is an element array substrate and is relatively difficult to manufacture. A columnar part can be formed. Furthermore, by providing the stepped portion on the second substrate side, it becomes possible to form the stepped portion at least partially by utilizing the presence of wiring, electronic elements, etc. constituting the second substrate.

  However, on the contrary, the step portion may be formed on the first substrate, the columnar portion may be formed on the second substrate, and both the step portion and the columnar portion may be formed on the second substrate. .

  In another aspect of the electro-optical device according to the aspect of the invention, the columnar portion is disposed at a position facing the step portion in a region outside the reflective display region in the predetermined region.

  According to this aspect, the columnar part is arranged in an area outside the reflective display area, such as a non-opening area of each pixel, for example, so that the presence of the columnar part hinders the reflective display. Can be prevented. In this case, the stepped portion may be extended from the reflective display area in the opening area of each pixel to the non-opening area of each pixel when seen in a plan view.

  In another aspect of the electro-optical device according to the aspect of the invention, at least one of the wiring and the electronic element is planarly arranged in a lattice shape or a stripe shape, and the columnar portion is located at a position facing the stepped portion. It is arranged at a position facing at least one of the wiring and the electronic element.

  According to this aspect, since the columnar portion is arranged in the lattice-shaped non-opening region that becomes the gap between the pixels in which the wiring and the electronic element are formed, the presence of the columnar portion prevents the reflective display. Can be prevented, and the presence of the columnar portion can also avoid a situation where the opening area of each pixel is narrowed.

  In another aspect of the electro-optical device of the present invention, at least a part of the step portion is formed by the presence of at least one of the wiring and the electronic element.

  According to this aspect, the step portion is formed at least partially using the presence of various wirings such as a data line, a scanning line, and a capacitance line, and various elements such as TFT and TFD. Therefore, the laminated structure on the substrate and the manufacturing process can be simplified as compared with the case where a dedicated film or a dedicated process is used.

  In another aspect of the electro-optical device of the present invention, a color filter facing the display electrode is further provided on at least one of the first and second substrates, and the color of the color filter is for the transmissive display. The chromaticity regions in the regions are different from each other so as to be wider than the chromaticity regions in the reflective display region.

  According to this aspect, the color of the color filter is such that the chromaticity region in the transmissive display region in which the light source light passes through the color filter only once, and the reflective display region in which the external light passes through the color filter twice. Since it is wider than the chromaticity range, the display can be performed with an appropriate color in both the transmissive display and the reflective display.

  In this aspect of the color filter, the color filter may be configured such that the color material film portion in the transmissive display region is thicker than the color material film portion in the reflective display region. .

  With this configuration, the color filter can be relatively easily changed by changing the film thickness of the color material film so that the chromaticity region in the transmissive display region is wider than the chromaticity region in the reflective display region. Can be constructed. For example, if the film thickness of the color material film in the transmissive display region is about twice that in the reflective display region, it is possible to display with appropriate colors in both the transmissive display and the reflective display.

  However, the color filter may be configured such that the color material concentration in the color material film in the transmissive display region is higher than the color material concentration in the color material film in the reflective display region.

  Furthermore, in this aspect of the color filter, the color filter may be provided on the first substrate.

  With this configuration, for example, a color filter may be formed on the side of the first substrate, which is the counter substrate, so that it is separated from the manufacturing process on the side of the second substrate, which is an element array substrate and is relatively difficult to manufacture. Thus, a color filter can be formed.

  However, the color filter may be formed on the second substrate.

  In another aspect of the electro-optical device of the present invention, the surface of the first and second substrates on which the step portion is formed is applied and rubbed on the surface facing the electro-optical material layer. An alignment film is further provided, and the stepped portion extends toward the downstream side in the rubbing direction of the alignment film with respect to the columnar portion as viewed in plan.

  According to this aspect, the convex stepped portion extends toward the downstream side in the rubbing direction where there is a high possibility that a rubbing failure will occur due to the presence of the columnar portion. Accordingly, it is possible to reduce the rubbing failure in the vicinity of the columnar portion whose height is relatively lowered as compared with the case where such a stepped portion does not extend.

  In this aspect of the alignment film, at least one of the first and second substrates further includes a light shielding film that covers at least one of the wiring and the electronic element and covers a gap between the display electrodes, and the rubbing direction. May be arranged along the direction in which the light shielding film extends.

  With this configuration, the light shielding film extends toward the downstream side in the rubbing direction where there is a high possibility that a rubbing failure will occur due to the presence of the columnar portion. Therefore, as compared with the case where such a light shielding film does not exist, it is possible to efficiently hide the malfunction of the electro-optical material such as a liquid crystal alignment defect in the vicinity of the columnar portion by the light shielding film. In other words, it is possible to reduce the area to be shielded by the light shielding film, thereby making it possible to relatively increase the opening area of each pixel without degrading the image quality.

  In another aspect of the electro-optical device of the present invention, the surface of the first and second substrates on which the step portion is formed is applied and rubbed on the surface facing the electro-optical material layer. An alignment film, and a color filter facing the display electrode on at least one of the first and second substrates, and on the downstream side in the rubbing direction with respect to the columnar portion in plan view. The relative positional relationship between the color filter and the columnar part is defined so that the blue portion of the color filter is located.

  According to this aspect, an operation failure of the electro-optical material such as liquid crystal alignment failure occurs on the downstream side in the rubbing direction with respect to the columnar portion, and the influence of the operation failure constitutes the color filter. Among the colors, there is a blue portion that hardly affects human vision. Therefore, visually, adverse effects due to the presence of the columnar part can be reduced. As a result, the width of the light-shielding film that hides the vicinity of the columnar portion can be reduced, and a bright image display can be performed while maintaining image quality.

  In another aspect of the electro-optical device according to the aspect of the invention, the display electrode includes a pixel electrode, and at least one of the wiring and the electronic element includes a switching element for controlling the switching of the pixel electrode, and the switching element. And a data line for supplying an image signal to the pixel electrode, and a scanning line for driving the switching element.

  According to this aspect, the electro-optical device is driven in an active matrix by supplying a scanning signal to the gate of the switching element, such as a TFT, while supplying an image signal to the source of the data line. It becomes possible.

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

  According to the electronic apparatus of the present invention, since the electro-optical device of the present invention described above is included, the inter-substrate gap is controlled with high accuracy. Therefore, for both transmissive display and reflective display, liquid crystal televisions, mobile phones, electronic notebooks, word processors, viewfinder type or monitor direct view type video tape recorders, workstations, video phones, POSs, which have excellent display quality. Various electronic devices such as a terminal, a touch panel, and a projection display device can be realized.

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

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the electro-optical device of the present invention is applied to a transflective liquid crystal device.

(First embodiment)
First, the overall configuration of the electro-optical device according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. Here, as an example of an electro-optical device, a transflective liquid crystal device having a backlight and a built-in driving circuit type TFT active matrix driving method is taken as an example.

  FIG. 1 is a plan view of a TFT array substrate as viewed from the counter substrate side together with the components formed thereon, and FIG. 2 is a cross-sectional view taken along the line H-H ′ of FIG. 1.

  1 and 2, in the electro-optical device according to the present embodiment, a TFT array substrate 10 and a counter substrate 20 are disposed to face each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are provided with a sealing material 52 provided in a seal region positioned around the image display region 10a. Are bonded to each other.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is.

  Particularly in the present embodiment, a large number of columnar portions 520 are provided in a cell in which the liquid crystal layer 50 is sealed, as a gap material that defines the gap between the substrates over the entire area of the image display region 10a. However, a gap material such as glass fiber or glass beads may be dispersed in the sealing material 52 in addition to the columnar portion 520. The columnar portion 520 will be described in detail later.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. However, a part or all of such a frame light shielding film may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  In the peripheral area located outside the sealing area where the sealing material 52 is arranged, the data line driving circuit 101 and the external circuit connection terminal 102 extend along one side of the TFT array substrate 10 in the area extending around the image display area. The scanning line driving circuit 104 is provided along two sides adjacent to the one side. Further, on the remaining side of the TFT array substrate 10, a plurality of wirings 105 are provided for connecting between the scanning line driving circuits 104 provided on both sides of the image display region 10a. As shown in FIG. 1, vertical conduction members 106 functioning as vertical conduction terminals between the two substrates are arranged at the four corners of the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region facing these corners. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

In FIG. 2, the TFT array substrate 10 includes a transparent second transparent substrate 202 made of a quartz plate, a glass plate or the like as the substrate body. On the second transparent substrate 202, pixel switching TFTs, wiring lines such as scanning lines and data lines, and pixel electrodes 9a are formed, and an alignment film is further formed on the uppermost layer portion. On the other hand, on the counter substrate 20, a transparent first transparent substrate 201 made of a quartz plate, a glass plate or the like is provided as the substrate body. On the 1st transparent substrate 201, the counter electrode 21 and the grid | lattice-like light shielding film 23 are formed, and also the alignment film is formed in the uppermost layer part.
Further, the liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  The counter substrate 20 further includes a polarizing plate 207 and a retardation plate 208 on the opposite side of the first transparent substrate 201 from the liquid crystal layer 50.

  The TFT array substrate 10 further includes a polarizing plate 217 and a retardation plate 218 on the opposite side of the second transparent substrate 202 from the liquid crystal layer 50. In addition, a fluorescent tube 220 and a light guide plate 219 for guiding light from the fluorescent tube 220 from the polarizing plate 217 into the liquid crystal panel are provided outside the polarizing plate 217. The light guide plate 219 is a transparent body such as an acrylic resin plate having a rough surface for scattering formed on the entire back surface or a printed layer for scattering, and receives light from the fluorescent tube 220 serving as a light source at the end surface. Thus, almost uniform light is emitted from the upper surface of the figure. In FIG. 1, the fluorescent tube 220 externally attached to the TFT array substrate 10 is omitted for convenience of explanation.

  In addition to the data line driving circuit 101, the scanning line driving circuit 104, and the like, the image signal on the image signal line is sampled and supplied to the data line on the TFT array substrate 10 shown in FIGS. Sampling circuit, precharge circuit for supplying a precharge signal of a predetermined voltage level to a plurality of data lines in advance of an image signal, for inspecting the quality, defects, etc. of the electro-optical device during production or at the time of shipment An inspection circuit or the like may be formed. Further, in this embodiment, instead of providing the data line driving circuit 101 and the scanning line driving circuit 104 on the TFT array substrate 10, for example, a TFT array is mounted on a driving LSI mounted on a TAB (Tape Automated Bonding) substrate. You may make it connect electrically and mechanically via the anisotropic conductive film provided in the peripheral part of the board | substrate 10. FIG.

  Next, the counter substrate 20 shown in FIG. 1 will be described in detail with reference to FIGS. 3 is a partial plan view of the counter substrate 20, FIG. 4 is a K-K ′ sectional view thereof, and FIG. 5 is a partially enlarged view of FIG. In FIG. 4, the height direction is enlarged to understand the thickness relationship. FIG. 4 shows the counter substrate 20 shown in FIG. 1 upside down, and the polarizing plate and the retardation plate are omitted.

  As shown in FIGS. 3 to 5, the counter substrate 20 constituting an example of the “first substrate” according to the present invention includes a first transparent substrate 201, a light shielding film 23, a color filter 500, a step forming film 510, a counter electrode. 21, a columnar portion 520, and an alignment film 22.

  The light shielding film 23 is formed on the first transparent substrate 201 in a lattice shape so as to define a non-opening region of each pixel in the image display region. The light shielding film 23 is made of a metal such as Cr (chromium) or Ni (nickel). The wiring part and the element part formed on the TFT array substrate side are hidden by the light shielding film 23. That is, it is arranged in the non-opening region of each pixel. The light shielding film 23 defines a non-opening region of each pixel and prevents light leakage in the gaps between the pixels. Further, the light shielding film 23 has a function of preventing color mixing in the color filter 500 and also increases the temperature of the electro-optical device due to incident light. Has a function to prevent.

  The color filter 500 is provided in the image display area, and is divided into red (R), green (G), and blue (B) in a matrix corresponding to each pixel. The color filter portion of each color is further divided into a dark portion formed in the transmissive display region and a light portion formed in the reflective display region. That is, the color filter 500 is constructed as a color filter of 3 colors × 2 = 6 colors of red, green, and blue.

  More specifically, in the color filter 500, the color filter portion RR is for red (R) reflective display, and the color filter portion TR is for red (R) transmissive display. The color filter portion RG is for green (G) reflective display, and the color filter portion TG is for green (G) transmissive display. The color filter portion RB is for blue (B) reflective display, and the color filter portion TB is for blue (B) transmissive display. Among these color filter portions RR to TB, those for transmissive display have a wider chromaticity range so that about half the brightness can be obtained than those for reflective display.

  The color filter 500 is manufactured using photolithography such as a pigment dispersion method, and each of the color filter portions RR to TB is made of an organic insulating material such as acrylic. In this example, the color filter portions RR to TB are formed by changing the chromaticity range by changing the density or changing the pigment component with the same pigment, and the six color filter portions are the same as each other. It is a film thickness.

  In FIG. 3, the color filter 500 has a stripe arrangement, but may be arranged in a delta arrangement, a mosaic arrangement, a triangle arrangement, or the like.

  The step forming film 510 is formed on the color filter portions RR, RG, and RB formed in the reflective display region as shown in FIG. 4, and the planar shape thereof is the right and left pixels as shown in FIG. It is formed in a stripe shape extending along the arrangement direction. The step forming film 510 directly defines the narrower first gap among the inter-substrate gaps in the electro-optical device configured by disposing the counter substrate 20 opposite to the TFT array substrate 10 as described later. Of these, the height is about half of the wider two gaps. More specifically, the height of the step forming film 510 is about 2 to 4 μm, for example, and is formed of a transparent organic insulating material such as acrylic.

  Of the regions in each pixel, the region present on the stepped portion or bank portion that is relatively convex by forming the stripe-shaped step forming film 510 in this manner is a reflective display region. In addition, the flat portion or the bottom portion, which is relatively concave because the step forming film 510 is not formed, is a transmissive display region. That is, due to the presence of such a stepped portion, the polarization in the liquid crystal layer 50 is between the transmissive display in which the light source light passes through the liquid crystal layer 50 only once and the reflective display in which the external light passes through the liquid crystal layer 50 twice. It is possible to align the characteristics. A region between the reflective display region and the transmissive display region is formed with a gentle slope, and the alignment film 22 can be satisfactorily rubbed.

  The counter electrode 21 is formed of a transparent electrode film such as an ITO film over the entire surface of the step forming film 510 and the color filter 500.

  The columnar portion 520 is formed on the counter electrode 21 and in a region where the step forming film 510 is formed. For example, one columnar portion is formed with respect to the color filter 500 portion for six colors, that is, one columnar portion is formed for every three pixels. The height of the columnar portion 520 is about 2 to 4 μm, for example, about half of the second gap, and is made of an organic insulating material such as acrylic. In this example, the columnar portion 520 has a cylindrical shape. However, this may be, for example, an octagonal or hexagonal prism, or a streamlined shape in the rubbing direction in consideration of the rubbing process in the manufacturing process. The diameter of the columnar part 520 is, for example, about 10 to 15 μm. Since the columnar part 520 is not transparent, it is preferably arranged in the non-opening region of each pixel. That is, it is hidden by the light shielding film 23 so that it cannot be seen by the observer at the time of display.

  The alignment film 23 is formed over the entire surface on the columnar portion 520 and the counter electrode 21. The alignment film 23 is formed, for example, by applying an alignment film made of polyimide resin, baking, and then performing a rubbing process.

  As shown in FIG. 5, during this rubbing process, a rubbing failure region 570 is generated on the downstream side in the rubbing direction 550 when viewed from the columnar portion 520. For example, assuming that the horizontal width of the columnar portion 520 is 10 to 15 μm and the height is 2 to 3 μm, the region 570 having a poor rubbing is about 550 in the rubbing direction and about 5 times the height of the columnar portion. It is generated to have a length of ˜6 μm.

  Therefore, the width of the light shielding film 23 that runs in the lateral direction is widened, as shown as a rubbing failure area 570 in FIG. (Ie, upward in FIG. 5) may be biased by a distance S. This makes it easy to hide the rubbing defective area 570 in the non-opening area of each pixel. Here, the distance S is the distance between the horizontal center line 565 of the columnar portion 520 and the center line 560 of the light shielding film 23 running in the horizontal direction.

  In addition, particularly in the present embodiment, the rubbing direction 550 coincides with the direction toward the color filter portion RB. This is because the alignment failure of the liquid crystal layer 50 generated in the defective rubbing region 570 caused by the columnar portion 520 does not stand out as a display when it occurs in a blue display pixel.

  Next, the TFT array substrate 10 shown in FIG. 1 will be described in detail with reference to FIGS. FIG. 6 is an equivalent circuit diagram of wiring, electronic elements, and the like configured on the TFT array substrate, FIG. 7 is a partial plan view of the TFT array substrate, and FIG. 8 is a partially enlarged view of FIG. FIG. 9 is a cross-sectional view of the electro-optical device when cut along the line JJ ′ shown in FIG. In FIG. 9, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing.

  In FIG. 6, a pixel electrode 9 a and a TFT 30 for controlling the switching of the pixel electrode 9 a are formed in each of a plurality of pixels formed in a matrix that forms the image display area of the electro-optical device according to the present embodiment. The data line 6 a to which the image signal is supplied is electrically connected to the source of the TFT 30. The image signals S1, S2,..., Sn written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. good. Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. It is configured. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6a is obtained by closing the switch of the TFT 30 as a switching element for a certain period. Write at a predetermined timing. A predetermined level of image signals S1, S2,..., Sn written in the liquid crystal as an example of the electro-optical material via the pixel electrode 9a is between the counter electrode 21 (see FIG. 2) formed on the counter substrate 20. Is held for a certain period. The liquid crystal modulates light by changing the orientation and order of the molecular assembly according to the applied voltage level, thereby enabling gradation display. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the electro-optical device as a whole. Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9 a and the counter electrode 21. The storage capacitor 70 includes a fixed potential side capacitor electrode formed of a part of the capacitor line 300, and a pixel potential side capacitor electrode connected to the drain side of the TFT 30 and the pixel electrode 9a.

  Next, as shown in FIGS. 7 and 8, the transflective pixel electrodes 9a are arranged in a matrix on the TFT array substrate 10, and the pixel region corresponding to the pixel electrode 9a is transmissively displayed. The display area is divided into a display area and a reflective display area. FIG. 7 corresponds to the plan view of the counter substrate 20 shown in FIG. That is, the two substrates are disposed to face each other so that the line segment AB in FIG. 3 coincides with the line segment A′B ′ in FIG. 7 on the plan view. In addition, in FIG. 7, the color filter portions RR ′ to TB ′ are displayed so as to correspond to the six color filter portions RR to TB, respectively.

  As shown in an enlarged view in FIG. 8, the TFT array substrate 10 is provided with a transflective pixel electrode 9a (outlined by a dotted line portion 9a ′). A data line 6a and a scanning line 3a are provided along each boundary. Further, in the semiconductor layer 1a, the channel region 1a 'is indicated by hatching in FIG. The square gate electrode 405 is formed to protrude from the scanning line 3a so as to face the semiconductor layer 1a in the channel region 1a '. The gate electrode 405 may be integrally formed from the same conductive material as the scanning line 3a or may be formed from a different material. In this way, each pixel is provided with a pixel switching TFT 30 in which the gate electrode 405 connected to the scanning line 3a is opposed to the channel region 1a '.

  As shown in FIGS. 7 to 9, the storage capacitor 70 has a planar shape arranged so as to overlap the pixel electrode 9a. The pixel potential side capacitor electrode of the storage capacitor 70 is a portion extending from the drain region 1e of the semiconductor layer 1a, and the fixed side capacitor electrode is extended from the capacitor line 300 arranged in parallel with the scanning line 3a. It consists of parts. The capacitor line 300 extends from the image display region 10a to the periphery thereof, and is electrically connected to a constant potential source to be a fixed potential. The drain region 1e of the semiconductor layer 1a is electrically connected to the pixel electrode 9a through the contact hole 83, the relay layer 71, and the contact hole 85. The source region 1 d of the semiconductor layer 1 a is connected to the data line 6 a through the contact hole 81.

  As shown in FIG. 8, in the present embodiment, in particular, the pixel area corresponding to the pixel electrode 9a constituting an example of the transflective electrode is divided into a transmissive display area and a reflective display area. More specifically, the upper side of the line KK ′ in FIG. 8 is a reflective display area, which corresponds to the color filter portion RR ′. On the other hand, the lower side of the line KK ′ in FIG. 8 is an area for transmissive display and corresponds to the color filter portion TR ′.

  As shown in FIGS. 8 and 9, in the reflective display region, a reflective film 430 made of an Al (aluminum) film having a large number of minute hemispherical concave portions 420 formed on the surface is provided on the pixel electrode 9a. Laminated so as to overlap. As a result, a reflective electrode is constructed from the pixel electrode 9a and the reflective film 430 in the reflective display region. The concave portion 420 is for avoiding specular reflection, and may be a convex portion.

  On the TFT array substrate 10 side, a pixel electrode 9a, a TFT 30 connected to the pixel electrode 9a, and a wiring portion are provided so that the liquid crystal layer 50 portion can be driven in units of pixels. On the counter substrate 20 side, a solid counter electrode 21 that is solid on the entire surface facing the pixel electrode 9a is formed.

A base insulating film 12 is provided under the pixel switching TFT 30.
In addition to the function of interlayer insulating the TFT 30 from the lower light-shielding film 11a, the base insulating film 12 is formed on the entire surface of the second transparent substrate 202, so that the surface of the base insulating film 12 is roughened during polishing or remains after cleaning. It has a function of preventing changes in the characteristics of the pixel switching TFT 30.

  In FIG. 9, a pixel switching TFT 30 has an LDD (Lightly Doped Drain) structure, and includes a gate 405, a channel region 1 a ′ of a semiconductor layer 1 a in which a channel is formed by an electric field from the gate 405, and a gate 405. An insulating film 2 including a gate insulating film that insulates the semiconductor layer 1a, a low concentration source region 1b and a low concentration drain region 1c of the semiconductor layer 1a, a high concentration source region 1d and a high concentration drain region 1e of the semiconductor layer 1a. ing. As described above, the gate 405 is connected to the scanning line 3 a, the high concentration source region 1 d is connected to the data line 6 a, and the high concentration drain region 1 e is connected to the pixel potential side capacitance electrode of the storage capacitor 70.

  The data line 6a is composed of a low resistance metal film such as Al or an alloy film such as metal silicide.

  A first interlayer insulating film 41 is formed on the scanning line 3 a, the gate 405, and the capacitor line 300. In the first interlayer insulating film 41, a contact hole 81 leading to the high concentration source region 1d and a contact hole 83 leading to the high concentration drain region 1e are opened.

  A relay layer 71 and a data line 6a are formed on the first interlayer insulating film 41, and a contact hole 85 and a concave portion 410 for scattering reflected light are opened on the second layer 71 and the data line 6a. An interlayer insulating film 42 is formed. The recess 410 is formed in a reflective display region and has a mortar shape. The inner diameter of the upper edge of the recess 410 is, for example, about 1 to 10 μm.

  On the second interlayer insulating layer 42, a third interlayer insulating film 43 in which a contact hole 85 is formed is formed. In the third interlayer insulating film 43, a substantially hemispherical recess 420 is formed due to the mortar-shaped recess 410 of the second interlayer insulating film 42. The pixel electrode 9 a is formed on the upper surface of the third interlayer insulating film 43 thus configured, and is connected to the relay layer 71 through the contact hole 85.

  An alignment film 16 that has been subjected to a predetermined alignment process such as a rubbing process is provided above the pixel electrode 9a. The alignment film 16 is made of an organic film such as a polyimide film. As described above, the pixel electrode 9a includes a reflective portion in which the reflective film 430 in the reflective display region is superimposed on the base side and a transmissive portion in which the reflective film 430 in the transmissive display region is not superimposed. . In addition, a large number of hemispherical concave portions 420 are formed in the reflective portion, and reflective display that avoids specular reflection is possible.

  In FIG. 9, the polarizing plate 207 and the retardation plate 208 attached to the outer surface of the first transparent substrate 201 as shown in FIG. 2, and the polarizing plate 217 and the retardation plate 218 attached to the outer surface of the second transparent substrate 202. The light guide plate 219 and the fluorescent tube 220 are omitted for simplification of description.

  Next, the operation of the transflective electro-optical device configured as described above will be described with reference to FIG.

  First, reflective display will be described.

  In this case, in FIG. 2, when external light enters from the side of the polarizing plate 207 (that is, the upper side in FIG. 2), the polarizing plate 207, the phase difference plate 208, the transparent first substrate 201, the liquid crystal layer 50, and the like. Through the transflective pixel electrode 9a provided on the second substrate 202 and reflected by the reflective display region, and is colored in a predetermined color by the color filter 500 through the liquid crystal layer 50 and the like. The light is emitted from the polarizing plate 207 side as color-corrected reflected light by the phase difference plate 208. Here, if an image signal is supplied from an external circuit to the data line 6a at a predetermined timing and a scanning signal is supplied to the scanning line 3a, an electric field corresponding to the image signal is applied to the liquid crystal layer 50 portion of the pixel electrode 9a. The Therefore, by controlling the alignment state of the liquid crystal layer 50 for each pixel by this applied voltage, the amount of light emitted from the polarizing plate 207 is modulated, and color gradation display is possible.

  Next, transmissive display will be described.

  In this case, when light source light from the backlight 220 enters from the lower side of the second substrate 202 in FIG. 2 through the light guide plate 219, the polarizing plate 217, etc., the transmissive display in the transflective pixel electrode 9a is performed. , And is emitted to the polarizing plate 207 side as transmitted light whose color has been corrected by the phase difference plate 208. Here, if an image signal is supplied from an external circuit to the data line 6a at a predetermined timing and a scanning signal is supplied to the scanning line 3a, an electric field corresponding to the image signal is applied to the liquid crystal layer 50 portion of the pixel electrode 9a. The Therefore, by controlling the alignment state of the liquid crystal layer 50 for each pixel by this applied voltage, the amount of light emitted from the polarizing plate 207 is modulated, and color gradation display is possible.

  As a result, according to the first embodiment, the polarization characteristics in the liquid crystal layer 50 can be made uniform between the transmissive display and the reflective display, and the coloring density by the color filter 500 can also be made uniform. Become.

  In FIG. 2, for convenience of explanation, the retardation plate and the polarizing plate are arranged one by one on the outer surface side of the TFT array substrate 10 and the counter substrate 20, respectively. The arrangement location, the number of sheets, and the like depend on, for example, the operation mode such as TN (Twisted Nematic) mode, VA (Vertically Aligned) mode, PDLC (Polymer Dispersed Liquid Crystal) mode, and normally white mode / normally black mode. Various aspects can be adopted.

(Second Embodiment)
Next, the configuration and operation of the electro-optical device according to the second embodiment of the invention will be described with reference to FIGS. FIG. 10 is a partial plan view of the TFT array substrate, and FIG. 11 is a cross-sectional view of the electro-optical device taken along the line LL ′ shown in FIG. 10 and 11, the same reference numerals are given to the same components as those in the first embodiment shown in FIGS. 1 to 9, and description thereof will be omitted as appropriate. In FIG. 11, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing.

  In the first embodiment, both the step forming film and the columnar part are formed on the counter substrate side. However, in the second embodiment, the step forming film is formed on the counter substrate side and on the TFT array substrate side. A columnar part is formed.

  That is, as shown in FIGS. 10 and 11, the light shielding film 23 and the columnar portion 520 are not formed on the counter substrate 20 'side. On the other hand, on the TFT array substrate 10 ′ side, a lattice-shaped light shielding film 11a is formed in close contact with the second transparent substrate 202 in a plane region substantially the same as the light shielding film 23 in the first embodiment, and is formed thereon. A transparent base insulating film 12 is formed, and a TFT 30 and the like are further formed thereon. A columnar portion 53 ′ is formed on the third interlayer insulating film 43 and on the base side of the alignment film 16. In addition, the rubbing direction 550 ′ for the alignment film 16 shown in FIG. 10 is also defined so that the downstream side of the rubbing direction 550 ′ is largely covered with the light shielding film 11a with reference to the columnar portion 520 ′. The relative positional relationship between the rubbing direction 550 ′ and the color filter 500 is defined so that the blue color filter portion RB ′ is located downstream of the rubbing direction 550 ′ with respect to 520 ′. Other configurations and operations are the same as those in the first embodiment described with reference to FIGS. 1 to 9.

  In the second embodiment, the light shielding film 11a is formed on the TFT array substrate 10 ′ side where the columnar portion 520 ′ exists. In the second embodiment, the light shielding is performed as in the case of the first embodiment. Instead of or in addition to the film 11a, the light shielding film 23 may be formed on the counter substrate 20 ′ side.

(Electronics)
Next, an example in which the above-described transflective electro-optical device according to each embodiment is used in an electronic apparatus will be described with reference to FIGS.

  First, an example in which the above-described electro-optical device is applied to a display unit of a mobile computer will be described. FIG. 12 is a perspective view showing this configuration. In FIG. 12, a computer 1200 includes a main body 1204 provided with a keyboard 1202 and a display device 1005 used as a display unit.

  Next, an example in which the above-described electro-optical device is applied to a display unit of a mobile phone will be described. FIG. 13 is a perspective view showing this configuration. In FIG. 13, a mobile phone 1250 includes the above-described electro-optical device as a display device 1005 together with a plurality of operation buttons 1252, an earpiece, and a mouthpiece.

  Next, a digital still camera using the above-described electro-optical device as a finder will be described. FIG. 14 is a perspective view showing this configuration from the back. The above-described electro-optical device is provided as a display device 1005 on the back surface of the case 1302 in the digital still camera 1300, and display is performed based on an imaging signal from the CCD 1304 provided on the front surface of the case 1302. That is, the display device 1005 functions as a finder that displays a subject.

  In addition to these, liquid crystal televisions, viewfinder type, monitor direct view type video tape recorders, car navigation systems, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, touch panels And the like.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Devices and electronic devices are also included in the technical scope of the present invention.

1 is a plan view of an electro-optical device according to an embodiment of the invention. It is H-H 'sectional drawing of FIG. It is a fragmentary top view of the counter substrate which concerns on embodiment. FIG. 4 is a K-K ′ sectional view of FIG. 3. FIG. 4 is a partially enlarged view of FIG. 3. FIG. 3 is an equivalent circuit diagram of wiring, electronic elements, and the like configured on the TFT array substrate according to the embodiment. It is a fragmentary top view of the TFT array substrate which concerns on embodiment. It is the elements on larger scale of FIG. FIG. 8 is a cross-sectional view of the electro-optical device when cut along a JJ ′ line illustrated in FIG. 7. It is a fragmentary top view of the TFT array substrate which concerns on embodiment. FIG. 11 is a cross-sectional view of the electro-optical device when cut along a line LL ′ illustrated in FIG. 10. 1 is a perspective view showing a mobile computer as an example of an electronic apparatus to which an electro-optical device according to an embodiment is applied. FIG. 10 is a perspective view showing a mobile phone as another example of an electronic apparatus to which the electro-optical device according to the embodiment is applied. FIG. 11 is a perspective view illustrating a configuration of a digital still camera as another example of an electronic apparatus to which the electro-optical device according to the embodiment is applied.

Explanation of symbols

  9 ... Pixel electrode, 10 ... TFT array substrate, 20 ... Counter substrate, 21 ... Transparent electrode, 50 ... Liquid crystal layer, 201 ... First transparent substrate, 202 ... Second transparent substrate, 500 ... Color filter, 510 ... Step forming film 520, 520 '... columnar portion, 550, 550' ... rubbing direction.

Claims (10)

A pair of first and second substrates;
An image display area composed of a plurality of pixels;
A light-shielding film that extends in a first direction and a second direction intersecting the first direction on one of the first substrate and the second substrate, and is provided in a lattice shape between the plurality of pixels. When,
A columnar portion defining a gap between the first and second substrates on the light shielding film;
An alignment film formed so as to cover the columnar part,
The pixel has a transmissive display region and a reflective display region, and the gap in the reflective display region is narrower than the gap in the transmissive display region, and the columnar shape The portion is arranged so as to define a gap in the reflective display region,
The columnar portion overlaps with an intersection region between the light shielding film extending in the first direction and the light shielding film extending in the second direction, and on the downstream side in the rubbing direction of the alignment film with respect to the columnar portion. An electro-optical device , wherein the region for reflection display of a blue pixel is positioned. A convex stepped portion is formed so as to overlap the reflective display region,
The electro-optical device according to claim 1, further comprising a transparent step forming film for forming at least part of the step portion on the one substrate. The image display area includes a plurality of display electrodes,
The electro-optical device according to claim 2, wherein the stepped portion extends in a predetermined direction across the plurality of display electrodes when seen in a plan view.   4. The electro-optical device according to claim 1, wherein the columnar portion is disposed at a position that does not overlap with the reflective display region. 5. A wiring and an electronic element for supplying an image signal to the display electrode;
At least one of the wiring and the electronic element is arranged in a plane in a lattice shape or a stripe shape,
The electro-optical device according to claim 3, wherein the columnar portion is disposed at a position facing the stepped portion and facing at least one of the wiring and the electronic element.   The electro-optical device according to claim 5, wherein at least a part of the step portion is formed by the presence of at least one of the wiring and the electronic element. A color filter facing the display electrode is further provided on the one substrate.
4. The electricity according to claim 3, wherein the colors of the color filters are different so that a chromaticity region in the transmissive display region is wider than a chromaticity region in the reflective display region. Optical device.   8. The color filter according to claim 7, wherein the color material film portion in the transmissive display region is configured to have a film thickness larger than that of the color material film portion in the reflective display region. The electro-optical device described. The display electrode comprises a pixel electrode,
At least one of the wiring and the electronic element drives a switching element for switching the pixel electrode, a data line for supplying an image signal to the pixel electrode via the switching element, and the switching element The electro-optical device according to claim 5, further comprising: a scanning line.   An electronic apparatus comprising the electro-optical device according to claim 1.

Images