JP4042757B2 - Liquid crystal device and electronic device - Google Patents

Description

  The present invention belongs to the technical field of liquid crystal devices, and particularly to the technical field of liquid crystal devices capable of switching between reflective display and transmissive display and electronic devices using the liquid crystal devices.

  Conventionally, reflective liquid crystal devices have been used extensively in mobile devices and attached display parts of devices due to their low power consumption. However, since they are visible using external light, they can be displayed in dark places. There was a problem that it could not be read. For this reason, a liquid crystal device has been proposed in which outside light is used in a bright place in the same manner as a normal reflective liquid crystal device, but in a dark place, the display can be visually recognized by an internal light source. As described in Japanese Utility Model Laid-Open No. 57-042771, a polarizing plate, a transflective plate, and a backlight are sequentially arranged on the outer surface of the liquid crystal panel opposite to the observation side. In this liquid crystal device, when the surroundings are bright, external light is taken in and reflection type display is performed using the light reflected by the semi-transmissive reflecting plate. When the surrounding becomes dark, the backlight is turned on and the semi-transmissive reflecting plate is turned on. A transmissive display in which the display can be visually recognized by the light transmitted through is performed.

  Another liquid crystal device is described in Japanese Patent Application Laid-Open No. 8-292413 in which the brightness of the reflective display is improved. This liquid crystal device has a configuration in which a transflective plate, a polarizing plate, and a backlight are sequentially arranged on the outer surface of the liquid crystal panel opposite to the observation side. When the surroundings are bright, outside light is taken in and reflected light is reflected on the transflective plate. When the surroundings become dark, the backlight is turned on and transmitted through the polarizing plate and the transflective plate. A transmissive display in which the display can be visually recognized by the emitted light is performed. With such a configuration, since there is no polarizing plate between the liquid crystal cell and the transflective plate, a reflective display brighter than the liquid crystal device described above can be obtained.

  However, in the liquid crystal device described in the above Japanese Patent Laid-Open No. 8-292413, a transparent substrate is interposed between the liquid crystal layer and the transflective plate, so that double reflection or display blurring occurs. There is a problem.

  Further, with the recent development of portable devices and OA devices, colorization of liquid crystal displays has been required, and colorization is often required even for devices using reflective liquid crystal devices. However, in the method in which the liquid crystal device and the color filter described in the above publication are combined, the transflective plate is disposed behind the liquid crystal panel, so that the liquid crystal layer or the color filter is interposed between the transflective plate and the liquid crystal panel. A thick transparent substrate of the liquid crystal panel is interposed, so that double reflection or blurring of display occurs due to parallax, and there is a problem that sufficient color development cannot be obtained.

  In order to solve this problem, Japanese Patent Application Laid-Open No. 9-258219 proposes a reflective color liquid crystal device in which a reflector is disposed in contact with the liquid crystal layer. However, in this liquid crystal device, the display cannot be recognized when the surroundings become dark.

  On the other hand, Japanese Patent Application Laid-Open No. 7-318929 proposes a transflective liquid crystal device in which a pixel electrode serving also as a transflective film is provided on the inner surface of a liquid crystal cell. In addition, a configuration is disclosed in which a transparent pixel electrode made of an ITO (Indium Tin Oxide) film is overlapped with an insulating film on a transflective film made of a metal film. However, in this liquid crystal device, a minute defect portion such as a hole defect or an indentation defect or a minute opening portion with respect to a pixel electrode that also serves as a semi-transmissive reflective film or a semi-transmissive reflective film on which a transparent pixel electrode is superimposed. Therefore, it is difficult to manufacture a reliable pixel electrode or a semi-transmissive reflective film because the device configuration is complicated and a special process is additionally required.

  The present invention has been made in view of the above-described problems, and in a liquid crystal device capable of switching between a reflective display and a transmissive display, a double image due to parallax and blurring of display using a relatively simple device configuration. The transflective liquid crystal device and the electronic device using the liquid crystal device are capable of high-quality image display in both reflective display and transmissive display and at the same time having high device reliability. It is an issue to provide.

In order to solve the above problems, a liquid crystal device of the present invention sandwiches a liquid crystal layer between a pair of first and second substrates, and on the surface of the second substrate on the liquid crystal layer side, wiring and An island-like reflective layer connected to the wiring via an active element and used for reflective display, and an island-like transparent electrode formed and superimposed directly on the reflective layer; A liquid crystal device in which an illumination device is disposed on the opposite side of the second substrate to the liquid crystal layer, and the reflective layer is disposed close to an end of the transparent electrode on the side where the active element is disposed. The transparent electrode is formed so as to have a region overlapping with the reflective layer, and the reflective layer is brought close to the end of the transparent electrode so that the transparent electrode does not overlap the reflective layer. It is characterized by performing.

According to the liquid crystal device of the present invention, during the reflective display, the external light incident from the first substrate side is reflected to the liquid crystal layer side by the reflective layer. At this time, since the reflective layer is disposed on the liquid crystal layer side of the second substrate, there is almost no gap between the reflective layer and the liquid crystal layer. Does not occur. On the other hand, at the time of transmissive display, the light source light emitted from the illumination device and incident from the second substrate side is transmitted to the liquid crystal layer side through the gap of the reflective layer and the transparent electrode. Therefore, bright display is possible using light source light in a dark place. In addition, when viewed in plan, a reflective display can be performed by an island-shaped transparent electrode portion superimposed on the island-shaped reflective layer at the center or one side, and the island-shaped reflective layer does not overlap with the surroundings. A transmissive display can be performed by the electrode portion. Therefore, for example, in an active matrix liquid crystal device, a reflective display and a transmissive display can be performed with high quality using a relatively simple configuration.
Moreover, since the transparent electrode is directly formed on the reflective layer, both are electrically connected. For this reason, by constructing the reflective layer from a conductive material such as Al, it is possible to make each of the reflective layers in a stripe shape or island shape function as a redundant structure of the corresponding transparent electrode, and the low resistance as an electrode of the transparent electrode Or lowering the resistance of the wiring. On the other hand, if the reflection layer is made of an insulating material, the outer reflection layer can also have a function of insulating the transparent electrode from other layers and a function of protecting the transparent electrode, thereby simplifying the entire laminated structure. It becomes possible.

  In the liquid crystal device of the present invention, in particular, the external light reflected by the reflective region (non-transmissive region) where the transparent electrode overlaps in the reflective layer passes through the liquid crystal portion driven by the transparent electrode portion in the reflective region. That is, a reflective display can be performed by using a liquid crystal portion driven by a vertical electric field by the transparent electrode portion in the reflection region. On the other hand, the light source light emitted from the illumination device and transmitted through the transmissive region (non-reflective region) that hits the gap of the reflective layer passes through the transparent electrode portion that does not overlap the reflective layer, and is transmitted by the transparent electrode portion in the transmissive region. Passes through the driven liquid crystal part. That is, transmissive display can be performed using a liquid crystal portion driven by a vertical electric field by the transparent electrode portion in the transmissive region. In this way, the liquid crystal drive at the time of reflective display is performed using the transparent electrode portion overlapping the reflective layer, and the liquid crystal drive at the time of transmissive display is performed using the transparent electrode portion not overlapping the reflective layer. It is possible to drive the liquid crystal satisfactorily with a vertical electric field even during display of this type, and the alignment direction of the liquid crystal becomes uniform within each dot or pixel, and deterioration of display quality due to disorder of the alignment direction can be prevented. . In addition, since the portion where the transparent electrode does not overlap in the reflective layer does not contribute to display (that is, the contrast ratio is reduced), it is basically unnecessary, and from the viewpoint of effective use of a limited image display area, It is preferable to perform a planar layout so that the reflective layer portion where the transparent electrode does not overlap is not provided.

  Further, in the liquid crystal device of the present invention, fine defects such as hole defects and indentation defects are formed on the pixel electrode that also serves as the semi-transmissive reflective film or on the semi-transmissive reflective film on which the transparent pixel electrode is superimposed as in the conventional example described above. Since it is not necessary to provide a large number of defective portions and fine openings, the apparatus configuration is not complicated, and no special process is required in the manufacture thereof. As a result, it is possible to construct a laminated structure in which a reliable reflective layer and transparent electrode are laminated. Finally, a relatively simple device configuration is used for reflective display and transmissive display. In both cases, a high-quality image display is possible, and at the same time, a liquid crystal device with high device reliability is realized.

  As a material for such a reflective layer, a metal mainly composed of Al (aluminum) is used, but any metal that can reflect outside light in the visible light region such as Cr (chromium) or Ag (silver) can be used. For example, the material is not particularly limited.

  As a driving method of the liquid crystal device of the present invention, various known driving methods such as a passive matrix driving method, a TFT (Thin Film Transistor) active matrix driving method, a TFD (Thin Film Diode) active matrix driving method, a segment driving method, etc. are adopted. Is possible. At this time, since the voltage-reflectance (transmittance) characteristics of the liquid crystal cell are often different between the reflective display and the transmissive display, the drive voltage is different between the reflective display and the transmissive display. It is preferable to optimize with. On the first substrate, a plurality of striped or segmented transparent electrodes are appropriately formed according to the driving method, or a transparent electrode is formed on almost the entire surface of the first substrate. Or you may drive by a horizontal electric field parallel to a board | substrate between the transparent electrodes on a 2nd board | substrate, without providing a counter electrode on a 1st board | substrate. Further, in the liquid crystal device, a polarizing plate, a retardation plate, and the like are appropriately disposed on the opposite side of the liquid crystal layer of the first substrate and the second substrate depending on the display method.

  In one aspect of the liquid crystal device of the present invention, the transparent electrode is formed so that the area thereof is larger than the area of the reflective layer.

  According to this aspect, since the transparent electrode is larger than the reflective layer in plan view, the transparent electrode portion on which the reflective layer contributing to the reflective display is superimposed or the reflective layer contributing to the transmissive display is not superimposed. The proportion of the transparent electrode portion in the image display region can be efficiently increased, and at the same time, the proportion of the reflective layer portion not overlapping with the transmissive electrode that does not contribute to either type of display can be reduced.

  For example, in a plan view, it is possible to form a small reflective layer on one side of a large transparent electrode. If comprised in this way, the liquid crystal part through which the external light reflected by the said reflection layer at the time of reflection type display can be driven with a vertical electric field by the transparent electrode part by the side where the reflection layer has overlapped. In addition, the transparent electrode portion on the side where the reflective layer does not overlap can drive the liquid crystal portion through which the light source light transmitted through the transparent electrode portion passes by a vertical electric field during transmissive display.

  Further, for example, if the transparent electrode is formed to be slightly larger than the reflective layer when seen in a plan view, the external light reflected by the reflective layer at the time of reflective display is displayed by the transparent electrode portion near the center on which the reflective layer is superimposed. The liquid crystal portion through which the light passes can be driven by a vertical electric field. In addition, by the transparent electrode portion near the periphery where the reflective layer is not overlapped, the liquid crystal portion through which the light source light transmitted through the transparent electrode portion passes can be driven by a vertical electric field during transmissive display.

  In another aspect of the liquid crystal device of the present invention, the non-driven state is a dark (black) state.

  According to this aspect, since the non-driving state is a dark state, light leakage from between pixels or dots where the liquid crystal is not driven can be suppressed during transmissive display, and a transmissive display with higher contrast can be obtained. it can. In addition, since reflection light unnecessary for display from between pixels or dots can be suppressed during reflective display, a display with higher contrast can be obtained. As described above, it is possible to improve the contrast in the transmissive display and the reflective display without providing a light shielding film generally called a black matrix or a black mask at a position facing the gap between the reflective electrodes. In addition, by providing such a light-shielding film, it is possible to prevent a situation in which the brightness at the time of reflective display is lowered.

  In another aspect of the liquid crystal device of the present invention, a resin having irregularities is formed on the surface of the second substrate on the liquid crystal layer side, and the island-shaped reflective layer is formed on the surface of the resin. It is formed so as to be provided with unevenness.

  According to this aspect, the specular feeling of the reflection layer can be eliminated by the unevenness and can be shown on the scattering surface (white surface). Further, wide viewing angle can be displayed by scattering due to unevenness. This uneven shape can be formed by using a photosensitive acrylic resin or the like for the base of the reflective layer, or by roughening the base glass substrate itself with hydrofluoric acid. It is desirable to further form a transparent flattening film on the uneven surface of the reflective layer and to flatten the surface facing the liquid crystal layer (the surface on which the alignment film is formed) from the viewpoint of preventing liquid crystal alignment defects. .

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described liquid crystal device according to the present invention.

  According to the electronic apparatus of the present invention, using a relatively simple device configuration, there is no double reflection due to parallax or blurring of display, and device reliability that can be switched between reflective display and transmissive display. Various electronic devices using a high transflective liquid crystal device or a transflective color liquid crystal 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.

(First embodiment)
A liquid crystal device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic longitudinal sectional view showing the structure of a liquid crystal device according to a first embodiment of the present invention. This embodiment basically relates to a simple matrix type liquid crystal display device, but can be applied to an active matrix type device, other segment type devices, and other liquid crystal devices with the same configuration. .

  In FIG. 1, in the liquid crystal device of the first embodiment, a liquid crystal cell in which a liquid crystal layer 203 is sealed with a frame-shaped sealing material 204 is formed between two transparent substrates 201 and 202. The liquid crystal layer 203 is composed of nematic liquid crystal having a predetermined twist angle. A color filter 213 is formed on the inner surface of the upper transparent substrate 201, and three colored layers of R (red), G (green), and B (blue) are arranged in a predetermined pattern on the color filter 213. ing. A transparent protective film 212 is coated on the surface of the color filter 213, and a plurality of striped transparent electrodes 211 are formed on the surface of the protective film 212 with an ITO (Indium Tin Oxide) film or the like. An alignment film 210 is formed on the surface of the transparent electrode 211 and is rubbed in a predetermined direction.

  On the other hand, on the inner surface of the lower transparent substrate 202, a striped transparent electrode 215 having a slightly larger area than the reflective layer 216 is formed on the striped reflective layer 216 formed for each colored layer of the color filter 213. A plurality of arrays are arranged so as to intersect the transparent electrode 211.

  In the case of an active matrix type device provided with a TFD element and a TFT element, each transparent electrode 215 is formed in a rectangular shape and connected to a wiring via the active element.

  The reflective layer 216 is formed of Cr, Al, or the like, and its surface is a reflective surface that reflects light incident from the transparent substrate 201 side. An alignment film 214 is formed on the surface of the transparent electrode 215, and is rubbed in a predetermined direction.

  As described above, in the first embodiment, each gap between the plurality of reflective layers 216 arranged in stripes at a predetermined interval has a function of transmitting the light source light from the backlight. The interval between the reflective layers 216 is preferably 0.01 μm or more and 20 μm or less. By doing so, it is difficult for humans to recognize, and deterioration of display quality caused by providing a gap can be suppressed, and reflective display and transmissive display can be realized simultaneously. The gap between the reflective layers 216 is preferably formed with an area ratio of 5% to 30% with respect to the reflective layer 216. By doing so, it is possible to suppress a decrease in the brightness of the reflective display, and it is possible to realize a transmissive display by the light source light introduced into the liquid crystal layer from the gap between the reflective layers.

  Here, the electric field applied to the liquid crystal layer 203 by the transparent electrode 215 laminated on the reflective layer 216 in the first embodiment will be described with reference to FIG. FIG. 2A shows a comparative example using a semi-transmissive reflective electrode 216 ′ having a single-layer structure that serves as both a semi-transmissive reflective layer provided with a fine (for example, 2 μm diameter) opening 216a ′ and a pixel electrode. It is the conceptual diagram which showed typically the mode of the electric field applied to a liquid-crystal layer by this transflective electrode 216 '. FIG. 2B is a conceptual diagram schematically showing the state of the electric field applied to the liquid crystal layer by the transparent electrode 215 laminated on the reflective layer 216 in the first embodiment.

  As shown in FIG. 2A, in the comparative example, when the transflective electrode 216 ′ made of a single conductive layer is used, the external reflection that is reflected in the non-transmissive area excluding the transmissive area At is performed during the reflective display. The liquid crystal portion through which light passes can be driven by a longitudinal electric field Fr (electric field in a direction perpendicular to the substrate) by the transflective electrode 216 ′ in the non-transmissive region. However, at the time of transmissive display, the liquid crystal portion in the transmissive region At through which the light source light incident from the opening 216a ′ of the semi-transmissive reflective electrode 216 ′ passes is more obliquely formed by the semi-transmissive reflective electrode 216 ′ portion in the non-transmissive region. It must be driven by the electric field Ft ′. That is, at the time of transmissive display, display is performed by driving the liquid crystal with a distorted electric field in the transmissive region At, so that the display quality is deteriorated due to the disorder of the liquid crystal alignment as compared with the case where the liquid crystal is driven with a vertical electric field.

  As shown in FIG. 2B, when a slightly larger transparent electrode 215 laminated on the reflective layer 216 divided in the first embodiment is used, the reflective layer is used during reflective display. It can be driven by the vertical electric field Fr by the transparent electrode 215 portion overlapped with H.216. In addition, even during transmissive display, the liquid crystal portion in the transmissive region At through which the light source light incident from the gap of the reflective layer 216 passes can be driven by the vertical electric field Ft by the transparent electrode 215 portion facing the gap of the reflective layer 216. As described above, since the electric field applied to the liquid crystal layer by the transparent electrode 215 is not affected regardless of the pattern of the reflective layer 216, the vertical length applied from the transparent electrode 215 is independent of the gap pattern in the reflective layer 216. The electric field makes the alignment direction of the liquid crystal uniform in each dot or each pixel, and display quality deterioration due to the disorder of the alignment direction can be prevented.

  In FIG. 1 again, a polarizing plate 205 is disposed on the outer surface of the upper transparent substrate 201, and a retardation plate 206 and a scattering plate 207 are disposed between the polarizing plate 205 and the transparent substrate 201. A retardation plate 209 is disposed behind the transparent substrate 202 below the liquid crystal cell, and a polarizing plate 208 is disposed behind the retardation plate 209. A backlight having a fluorescent tube 218 that emits white light and a light guide plate 217 having an incident end surface along the fluorescent tube 218 is disposed below the polarizing plate 208. The light guide plate 217 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. The light guide plate 217 receives light from the fluorescent tube 218 as a light source at the end surface. In the figure, almost uniform light is emitted from the upper surface. As the other backlight, LED (light emitting diode), EL (electroluminescence), or the like can be used.

  On the other hand, the scattering plate 207 can emit the reflected light reflected by the Al reflecting layer 216 at a wide angle, and the specular feeling of the reflecting layer 216 can be shown on the scattering surface (white surface) by the scattering plate 207. The position of the scattering plate 207 is not particularly limited as long as it is opposite to the liquid crystal layer 203 of the transparent substrate 201. Considering the influence of backscattering of the scattering plate 207 (when external light is incident, scattering to the incident light side), it is desirable to dispose between the polarizing plate 205 and the transparent substrate 201 as in this embodiment. Backscattering is scattered light that has nothing to do with the display of the liquid crystal device, and the presence of this backscattering lowers the contrast during reflective display. By arranging it between the polarizing plate 205 and the transparent substrate 201, the amount of backscattered light can be reduced to about half by the polarizing plate 205.

  As described above, in the first embodiment, the polarizing plate 205 and the retardation plate 206 are disposed on the upper side of the liquid crystal cell, and the polarizing plate 208 and the retardation plate 209 are disposed on the lower side of the liquid crystal cell. Good display control can be performed in both type display and transmission type display. More specifically, the retardation plate 206 reduces the influence on the color tone such as coloring due to the wavelength dispersion of light at the time of reflection type display (that is, the phase difference plate 206 is used to display at the time of reflection type display. In addition, the phase difference plate 209 reduces the influence on the color tone such as coloring due to the wavelength dispersion of light in the transmission type display (that is, the phase difference plate 206 optimizes the display in the reflection type display). In addition, it is possible to optimize the display at the time of transmissive display using the phase difference plate 209 under the condition of achieving the above. For the retardation plates 206 and 209, a plurality of retardation plates can be arranged by color compensation or viewing angle compensation of the liquid crystal cell, respectively. As described above, if a plurality of retardation plates are used as the retardation plate 206 or 209, the color compensation or the viewing angle compensation can be optimized more easily. Furthermore, the optical characteristics of the polarizing plate 205, the retardation plate 106, the liquid crystal layer 103, and the reflection layer 216 are set to increase the contrast during the reflective display, and the optical properties of the polarizing plate 208 and the retardation plate 209 are set under these conditions. By setting the characteristics to increase the contrast during transmissive display, high contrast characteristics can be obtained in both reflective display and transmissive display.

  Next, a reflective display and a transmissive display according to the present embodiment configured as described above will be described with reference to FIG.

  First, in the case of a reflective display, external light incident on the liquid crystal device from above is transmitted through the polarizing plate 205, the retardation plate 206, and the scattering plate 207, and is reflected after passing through the color filter 213 and the liquid crystal layer 203. The light is reflected by the layer 216 and emitted from the polarizing plate 205 again. At this time, the bright state and the dark state, and the brightness between them can be controlled by the voltage applied to the liquid crystal layer 203.

  In the case of transmissive display, light from the backlight is converted into predetermined polarized light by the polarizing plate 208 and the phase difference plate 209 and introduced into the liquid crystal layer 203 and the color filter 213 from the gap portion where the reflective layer 216 is not formed. Then, the light passes through the scattering plate 207 and the retardation plate 206. At this time, according to the voltage applied to the liquid crystal layer 203, a state of transmitting (bright) the polarizing plate 205, a state of absorbing (dark), and an intermediate state (brightness) can be controlled.

  Here, the reflective display and the transmissive display will be described in more detail with reference to FIGS. FIG. 3 is a schematic front view of the lower transparent substrate 202 when the present invention is applied to an active matrix liquid crystal device using a TFD element. A TFD element (or MIM element) 502 connected to the scanning line 501 is laminated on the island-shaped Al reflective layer 503, and is formed on the island-shaped ITO transparent electrode 504 having a larger area than the Al reflective layer 503. It is connected. In FIG. 3, the ITO transparent electrode 504 is not formed so as to completely cover the Al reflective layer 503. Of course, the ITO transparent electrode 504 is formed so as to completely cover the Al reflective layer 503. It does not matter. If the ITO transparent electrode 504 is formed so as to completely cover the Al reflective layer 503, more light from the backlight can be transmitted to the liquid crystal layer, so that a brighter transmissive display is realized. FIG. 4 is a schematic front view of an example of the lower transparent substrate 202 when the present invention is applied to a simple matrix type liquid crystal device. Striped ITO having an area slightly wider than the Al reflective layer 602 and the Al reflective layer 602 on the inner surface of the lower transparent substrate so as to intersect with the striped ITO transparent electrode 601 formed on the inner surface of the upper transparent substrate of the liquid crystal cell. A transparent electrode 603 is formed. In FIG. 4, the ITO transparent electrode 603 is not formed so as to completely cover the Al reflective layer 602. Of course, the ITO transparent electrode 603 is formed so as to completely cover the Al reflective layer 602. It doesn't matter. If the ITO transparent electrode 603 is formed so as to completely cover the Al reflection layer 602, more light from the backlight can be transmitted to the liquid crystal layer, so that a brighter transmissive display is realized. FIG. 5 is a schematic front view of another example of the lower transparent substrate 202 when the present invention is applied to a simple matrix type liquid crystal device. A stripe shape whose width is slightly wider than each side of the island-shaped Al reflective layer 602 ′ on the inner surface of the lower transparent substrate so as to intersect with the striped ITO transparent electrode 601 formed on the inner surface of the upper transparent substrate of the liquid crystal cell. The ITO transparent electrode 603 is formed. FIG. 6 is a schematic front view of another example of the lower transparent substrate 202 when the present invention is applied to a simple matrix type liquid crystal device. A stripe shape whose area is slightly wider than the Al reflective layer 602 ″ and the Al reflective layer 602 ″ on the inner surface of the lower transparent substrate so as to intersect the striped ITO transparent electrode 601 formed on the inner surface of the upper transparent substrate of the liquid crystal cell. The ITO transparent electrode 603 is formed. In the example of FIG. 4, the Al reflective layer 602 overlaps the center of the ITO transparent electrode 603, whereas in the example of FIG. 6, the Al reflective layer 602 ″ overlaps on one side of the ITO transparent electrode 603.

  In the reflective display, external light incident on the liquid crystal cell is reflected by the reflective layer 503 (in the case of FIG. 3), the reflective layer 602 (in the case of FIG. 4), the reflective layer 602 ′ (in the case of FIG. 5), or the reflective layer 602 ″ (FIG. 6), that is, only external light incident on the reflective layer 503, 602, 602 ′ or 602 ″ is modulated by the voltage applied to the liquid crystal layer. During transmissive display, only the light source light that has passed through the gap between the reflective layers 503, 602, 602 ′, or 602 ″ out of the light incident on the liquid crystal cell from the backlight is introduced into the liquid crystal layer. Alternatively, light incident on other than the dot electrode is not related to display and only reduces the contrast of the transmissive display. Therefore, the display mode of the light-shielding film (black matrix layer) and the liquid crystal layer can be set to normally black. In other words, the light from the backlight incident on the ITO transparent electrode 504 or 603 portion that does not overlap the Al reflective layer 503, 602, 602 ′, or 602 ″ enables a transmissive display.

  For example, the line width (L) of the ITO transparent electrode 601 on the inner surface of the upper transparent substrate in FIG. 4 is 198 μm, the line width (W1) of the Al reflective layer 602 on the inner surface of the lower substrate is 46 μm, and the ITO transparent electrode formed thereon If the line width (W2) of 603 is 56 μm, about 70% of the external light introduced into the liquid crystal layer is reflected, and about 10% of the light emitted from the backlight and introduced into the lower transparent substrate. Can be transmitted.

  According to the configuration of the present embodiment as described above, a color liquid crystal device that can switch and display between a reflective display and a transmissive display that do not have double projection or display blur is realized. In particular, according to the present embodiment, in order to transmit the light source light from the backlight at the time of transmissive display, the reflective layer 216 has many fine defects such as hole defects and indentation defects and fine openings. Since it is not necessary to provide the device, the configuration of the device is not complicated, a special process is not additionally required in the manufacture, and the reliability of the liquid crystal device is increased.

  In addition, since the Al reflective layer 216 of the present embodiment has the ITO transparent electrode 215 formed on the surface thereof, the Al reflective layer 216 can be hardly damaged, and the Al reflective layer 216 and the ITO transparent electrode 215 are two. Since it becomes an electrode line, the resistance of the electrode line can be reduced. Such a reflective layer 216 preferably contains 95% by weight or more of Al and has a layer thickness of 10 nm to 40 nm.

  Furthermore, since the scattering plate 207 disposed on the upper surface of the liquid crystal cell can emit the reflected light reflected by the Al reflective layer 216 at a wide angle, a wide viewing angle liquid crystal device is realized.

(Second Embodiment)
A second embodiment of the liquid crystal device according to the present invention will be described with reference to FIG. FIG. 7 is a schematic longitudinal sectional view showing the structure of the second embodiment of the liquid crystal device according to the present invention. This embodiment basically relates to a simple matrix type liquid crystal display device, but can be applied to an active matrix type device, other segment type devices, and other liquid crystal devices with the same configuration. .

  In this embodiment, as in the case of the first embodiment, a liquid crystal cell in which a liquid crystal layer 303 is sealed with a frame-shaped sealing material 304 is formed between two transparent substrates 301 and 302. The liquid crystal layer 303 is composed of nematic liquid crystal having a predetermined twist angle. A color filter 313 is formed on the inner surface of the upper transparent substrate 301, and three color layers of R, G, and B are arranged in a predetermined pattern on the color filter 313. A transparent protective film 312 is coated on the surface of the color filter 313, and a plurality of striped transparent electrodes 311 are formed of ITO or the like on the surface of the protective film 312. An alignment film 310 is formed on the surface of the transparent electrode 311 and is rubbed in a predetermined direction.

  On the other hand, on the inner surface of the lower transparent substrate 302, a striped transparent electrode 315 having a larger area than the reflective layer 317 is formed on the striped reflective layer 317 formed for each colored layer of the color filter 313. Is formed through a protective film 316. A plurality of the electrodes are arranged so as to intersect with the transparent electrode 311. In the case of an active matrix type device including a TFD element or a TFT element, each reflective layer 317 and transparent electrode 315 are formed in a rectangular shape and connected to a wiring via the active element. The reflective layer 317 is formed of Cr, Al, or the like, and the surface thereof is a reflective surface that reflects light incident from the transparent substrate 301 side. An alignment film 314 is formed on the surface of the transparent electrode 315, and is rubbed in a predetermined direction.

  As described above, in the second embodiment, each gap between the reflective layers 317 arranged in stripes at a predetermined interval has a function of transmitting the light source light from the backlight.

  A polarizing plate 305 is disposed on the outer surface of the upper transparent substrate 301, and a retardation plate 306 and a scattering plate 307 are disposed between the polarizing plate 305 and the transparent substrate 301, respectively. Further, on the lower side of the liquid crystal cell, a retardation plate 309 is disposed behind the transparent substrate 302, and a polarizing plate 308 is disposed behind the retardation plate 309. A backlight having a fluorescent tube 319 that emits white light and a light guide plate 318 having an incident end surface along the fluorescent tube 319 is disposed below the polarizing plate 308. The light guide plate 318 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. The light guide plate 318 receives light from the fluorescent tube 319 as a light source at the end surface. In the figure, almost uniform light is emitted from the upper surface. As the other backlight, LED (light emitting diode), EL (electroluminescence), or the like can be used.

  Next, a reflective display and a transmissive display according to the present embodiment configured as described above will be described with reference to FIG.

  First, in the case of reflective display, external light incident on the liquid crystal device from the upper side of the drawing is transmitted through the polarizing plate 305, the retardation plate 306, and the scattering plate 307, and is reflected after passing through the color filter 313 and the liquid crystal layer 303. The light is reflected by the layer 317 and emitted from the polarizing plate 305 again. At this time, the bright state and the dark state, and the brightness between them can be controlled by the voltage applied to the liquid crystal layer 303.

  In the case of transmissive display, light from the backlight is converted into predetermined polarized light by the polarizing plate 308 and the retardation plate 309 and is introduced into the liquid crystal layer 303 and the color filter 313 from the gap portion where the reflective layer 317 is not formed. The light passes through the scattering plate 307 and the phase difference plate 306. At this time, according to the voltage applied to the liquid crystal layer 303, a state of transmitting (bright) the polarizing plate 305, a state of absorbing (dark), and an intermediate state (brightness) can be controlled.

  The planar shapes of the transparent electrode 315 and the reflective layer 317 described above are as shown in FIG. 3 when applied to an active matrix liquid crystal device using a TFD element, as in the first embodiment. When applied to a simple matrix type liquid crystal device, it is as shown in FIGS.

  For example, the line width (L) of the ITO transparent electrode 601 on the inner surface of the upper transparent substrate in FIG. 4 is 240 μm, the line width (W1) of the Al reflective layer 602 on the inner surface of the lower substrate is 60 μm, and a protective film is interposed thereon. When the line width (W2) of the formed ITO transparent electrode 603 is 70 μm, about 75% of the external light introduced into the liquid crystal layer is reflected, emitted from the backlight, and introduced into the lower transparent substrate. About 8% of the light can be transmitted.

  According to the configuration of the present embodiment as described above, a color liquid crystal device that can switch and display between a reflective display and a transmissive display that do not have double projection or display blur is realized. In particular, since it is not necessary to provide a large number of fine defects such as hole defects and indentation defects and fine openings in the reflective layer 317, the apparatus configuration is not complicated, and a special process is used in its manufacture. Is not additionally required.

  In addition, since the Al reflective layer 317 of the present embodiment forms the ITO transparent electrode 315 after forming the protective film 316 on the surface thereof, the Al reflective layer 317 is composed of a developer and an etching solution for the ITO transparent electrode 315. There is no direct touch. Further, since the protective film 316 is provided, it can be made difficult to be damaged. By short-circuiting the Al reflective layer 317 and the ITO transparent electrode 315, the probability of disconnection can be reduced and the resistance of the electrode line can be reduced.

  Furthermore, since the scattering plate 307 disposed on the upper surface of the liquid crystal cell can emit the reflected light reflected by the Al reflecting layer 317 at a wide angle, a wide viewing angle liquid crystal device is realized.

(Third embodiment)
A third embodiment of the liquid crystal device according to the present invention will be described with reference to FIG. FIG. 8 is a schematic longitudinal sectional view showing the structure of the third embodiment of the liquid crystal device according to the present invention. The third embodiment has substantially the same configuration as the second embodiment described above, and the only difference is the structure of the reflective layer. In FIG. 8, the same components as those in FIG. 7 according to the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  That is, in FIG. 8, the reflective layer 317 'is formed as follows.

  First, a photosensitive resist is applied on the inner surface of the transparent substrate 302 by spin coating or the like, and exposure is performed with a light amount adjusted through a mask having a minute opening. Thereafter, the photosensitive resist is baked and developed as necessary. The portion corresponding to the opening of the mask is partially removed by development, and a support layer having a corrugated cross-sectional shape is formed. Here, only the portion corresponding to the opening of the mask is removed by the above photolithography process, or only the portion corresponding to the opening of the mask is left, and then the uneven shape is smoothed by etching, heating, etc. The cross-sectional shape may be formed, or another layer may be laminated on the surface of the support layer once formed to form a smoother surface.

  Next, a metal film having a reflective surface is formed by depositing a metal on the surface of the support layer by vapor deposition, sputtering, or the like, and then forming a stripe shape (see FIG. 4 or FIG. 6) or island shape (see FIG. 3 or FIG. 5). As the metal, Al, CrAg, Au, or the like is used. Since the reflective layer 317 ′ is formed reflecting the shape according to the corrugated irregularities on the surface of the support layer, the entire surface is roughened.

  According to the configuration of the present embodiment as described above, it is possible to realize a color liquid crystal device capable of switching between a reflective display and a transmissive display that do not have double projection or display blur.

  In particular, according to the present embodiment, the reflective layer 317 ′ having irregularities can reflect the reflected light at a wide angle, so that a liquid crystal device with a wide viewing angle is realized.

(Fourth embodiment)
A fourth embodiment of the liquid crystal device according to the present invention will be described with reference to FIGS. FIG. 9 is a schematic longitudinal sectional view showing the structure of the fourth embodiment of the liquid crystal device according to the present invention. This embodiment basically relates to a simple matrix type liquid crystal display device, but can be applied to an active matrix type device, other segment type devices, and other liquid crystal devices with the same configuration. .

  In this embodiment, a liquid crystal cell in which a liquid crystal layer 403 is sealed with a frame-shaped sealing material 404 is formed between two transparent substrates 401 and 402. The liquid crystal layer 403 is composed of nematic liquid crystal having negative dielectric anisotropy. On the inner surface of the upper transparent substrate 401, a plurality of striped transparent electrodes 409 are formed of ITO or the like, and an alignment film 410 for vertically aligning liquid crystals is formed on the surface of the transparent electrode 409, and a predetermined film is formed. The direction is rubbed. By this rubbing treatment, the liquid crystal molecules have a pretilt angle of about 85 degrees in the rubbing direction. In the case of an active matrix type device provided with a TFD element or a TFT element, the transparent electrode 409 is formed in a rectangular shape and connected to a wiring through the active element.

  On the other hand, on the inner surface of the lower transparent substrate 402, irregularities having a height of about 0.8 μm are formed by a photosensitive acrylic resin, and Al added with 1.0% by weight of Nd on the surface is formed. Sputtering is performed with a thickness of 25 nm, and then patterning is performed in a stripe shape (see FIG. 4 or FIG. 6) or an island shape (see FIG. 3 or FIG. 5) to form the reflective layer 411. A color filter 414 is formed on the reflective layer 411 via a protective film 412, and three color layers of R, G, and B are arranged in a predetermined pattern on the color filter 414. A transparent protective film 415 is coated on the surface of the color filter 414, and a plurality of striped transparent electrodes 416 are formed on the surface of the protective film 415 for each colored layer of the color filter 414 using an ITO film or the like. It is formed so as to cross the transparent electrode 409. An alignment film 417 is formed on the surface of the transparent electrode 416. Note that the alignment film 417 is not rubbed.

  A polarizing plate 405 is disposed on the outer surface of the upper transparent substrate 401, and a retardation plate (¼ wavelength plate) 406 is disposed between the polarizing plate 405 and the transparent substrate 401. Further, a retardation plate (¼ wavelength plate) 408 is disposed behind the transparent substrate 402 below the liquid crystal cell, and a polarizing plate 407 is provided behind the retardation plate (¼ wavelength plate) 408. Has been placed. A backlight having a fluorescent tube 419 that emits white light and a light guide plate 418 having an incident end surface along the fluorescent tube 419 is disposed behind the polarizing plate 407. The light guide plate 418 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. The light guide plate 418 receives light from a fluorescent tube 419 as a light source at the end surface. In the figure, almost uniform light is emitted from the upper surface. As the other backlight, LED (light emitting diode), EL (electroluminescence), or the like can be used.

  In this embodiment, in order to prevent light from leaking from the region between the dots during transmissive display, the black matrix layer 413 that is a light shielding portion formed between the colored layers of the color filter 414 is planarly formed. Almost correspondingly provided. The black matrix layer 413 is formed by depositing a Cr layer or using a photosensitive black resin.

  Here, as shown in FIG. 10 (a), the transmission axes P1 and P2 of the polarizing plate 405 and the polarizing plate 407 are set in the same direction, and the retardation plate with respect to the transmission axes P1 and P2 of these polarizing plates. The directions of the slow axes C1 and C2 of the (¼ wavelength plates) 406 and 408 are set to the direction rotated clockwise by θ = 45 degrees. Further, the rubbing treatment direction R1 of the alignment film 410 on the inner surface of the transparent substrate 401 is also applied in a direction that coincides with the directions of the slow axes C1 and C2 of the phase difference plates (¼ wavelength plates) 406 and 408. ing. The rubbing direction R1 defines the direction in which the major axis of the liquid crystal molecules tilts when an electric field is applied to the liquid crystal layer 403. A negative nematic liquid crystal is used for the liquid crystal layer 403.

  FIG. 10B shows the driving voltage characteristic of the reflectance R in the reflective display according to the present embodiment and the driving voltage characteristic of the transmittance T in the transmissive display. The display state when no electric field is applied is dark (black). When this liquid crystal cell is used, it is not necessary to form the black matrix layer 413.

  Next, with reference to FIG. 9, the reflective display and the transmissive display in the present embodiment configured as described above will be described.

  First, in the case of a reflective display, external light incident on the liquid crystal device from the upper side of the drawing is transmitted through the polarizing plate 405 and the phase difference plate 406, passes through the liquid crystal layer 403, passes through the color filter 414, and passes through the reflective layer 411. And is emitted from the polarizing plate 405 again. At this time, the bright state, the dark state, and the intermediate brightness are controlled by the voltage applied to the liquid crystal layer 403.

  In the case of transmissive display, light from the backlight is converted into predetermined polarized light by the polarizing plate 407 and the retardation plate 408 and is introduced into the liquid crystal layer 403 through the gaps of the reflective layer 411 and passes through the color filter 414 and the liquid crystal layer 403. Thereafter, the light passes through the retardation plate 406. At this time, according to the voltage applied to the liquid crystal layer 403, the state of light transmitted through the polarizing plate 405 (bright state), the state of absorption (dark state), and the intermediate brightness can be controlled.

  According to the configuration of the present embodiment as described above, a color liquid crystal device that can switch and display between a reflective display and a transmissive display that do not have double projection or display blur is realized.

  The reflective layer 411 of the present embodiment uses a metal layer containing Al as a main component, covers the surface with a protective film 412, and forms a color filter 414, a protective film 415, and a transparent electrode 416 thereon. . For this reason, since the Al metal layer does not directly come into contact with the ITO developer or the color filter developer, the Al metal layer is not dissolved by the developer. Furthermore, it is possible to easily handle an Al metal layer that is easily damaged. For example, Al having a thickness of 25 nm to which 1.0% by weight of Nd is added exhibits values of a reflectance of 80% and a transmittance of 10%, and functions sufficiently as the reflective layer 411.

  Further, the reflective layer 411 provided with unevenness can reflect the reflected light at a wide angle, so that a liquid crystal device with a wide viewing angle is realized.

(Fifth embodiment)
A fifth embodiment of a liquid crystal device according to the present invention will be described with reference to FIG. FIG. 11 is a schematic longitudinal sectional view of a fifth embodiment of a liquid crystal device according to the present invention. The fifth embodiment has substantially the same configuration as that of the second embodiment described above, and the structure relating to the reflective layer and its protective film is different. In FIG. 11, the same components as those in FIG. 7 according to the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  That is, in FIG. 11, the reflective layer 617 is formed as an aluminum reflective layer with a thickness of 50 to 300 nm in an island shape or a stripe shape for each dot by vapor deposition (see FIGS. 3 to 6). Note that aluminum is preferably used for the reflective layer 617, but other metals such as chromium can be substituted.

Further, a protective film is not formed on the reflective layer 617 as in the second embodiment, and the insulating layer 616 made of Al ₂ O ₃ (aluminum oxide) is formed by anodizing the reflective layer after vapor deposition. Is formed. Anodization is performed using a solution containing 1 to 10% by weight of ammonium salicylate and 20 to 80% by weight of ethylene glycol under conditions of a formation voltage of 5 to 250 V and a current density of 0.001 to 0.1 mA / cm ^2. Good. When the oxide film thus formed has a thickness of 140 nm or an integral multiple thereof, the occurrence of coloring due to interference can be prevented. A transparent electrode 615 is disposed on the insulating layer 616, and the other configuration is the same as that of the second embodiment shown in FIG.

  As described above, according to the fifth embodiment, the insulating film 616 that is very thin and has high insulating properties can be obtained. In particular, the reflectance can be maintained even after oxidation by forming the reflective layer 617 from aluminum. When the insulating film 616 is formed by oxidation in this way, anodization may be used or thermal oxidation may be used.

(Sixth embodiment)
A sixth embodiment of the liquid crystal device according to the present invention will be described with reference to FIG. FIG. 12 is an enlarged cross-sectional view showing a TFT drive element according to the sixth embodiment of the present invention together with a pixel electrode and the like. In addition, the structure which forms a TFT drive element on the board | substrate in 6th Embodiment, and is connected to the transparent electrode formed on this via the insulating film is applicable to each embodiment of this invention.

In FIG. 12, a gate electrode 722, a gate insulating film 723, an i-Si layer 724, an n ⁺ -Si layer 725, a source electrode 726 and a drain electrode 727 are formed on an interlayer insulating film 721 formed on a transparent substrate 702. A TFT element is provided. The reflective layer 728 made of aluminum is formed on an interlayer insulating film 731 formed on the TFT element, and an insulating layer 729 formed by anodizing the reflective layer after vapor deposition is provided on the reflective layer 728. On the insulating layer 729, a transparent electrode 730 (pixel electrode) made of ITO connected to the drain electrode 727 through a contact hole is formed.

  As described above, according to the sixth embodiment, since electric power is supplied to each transparent electrode (pixel electrode) 730 through the TFT element, crosstalk between the transparent electrodes 730 can be reduced, and a higher-quality image display can be achieved. Is possible. The TFT element configured as described above may be a TFT having any structure such as an LDD structure, an offset structure, and a self-alignment structure. Further, in addition to a single gate structure, a dual gate or a triple gate or more may be used.

(Seventh embodiment)
A seventh embodiment of a liquid crystal device according to the present invention will be described with reference to FIG. FIG. 13 is an enlarged cross-sectional view showing a TFD drive element according to a seventh embodiment of the present invention together with a pixel electrode and the like. The configuration in which the TFD driving element is formed on the substrate in the seventh embodiment and connected to the transparent electrode formed thereon via the insulating film is applicable to each embodiment of the present invention.

  In FIG. 13, a first conductive layer 841 made of tantalum is formed on an interlayer insulating film 821 formed on a substrate 802, and obtained by anodizing tantalum on the first conductive layer 841. An insulating layer 842 is formed. A second conductive layer 843 made of chromium is formed on the insulating layer 842. A reflective layer 844 made of aluminum is formed on the interlayer insulating film 821, and an insulating film 845 obtained by anodizing the reflective layer after vapor deposition is formed on the reflective layer 844. A transparent electrode (pixel electrode) 846 formed on the insulating film 845 is connected to the second conductive layer 843.

  As described above, according to the seventh embodiment, since electric power is supplied to each transparent electrode (pixel electrode) 846 via the TFD element, crosstalk between the transparent electrodes 846 can be reduced, and a higher quality image display can be achieved. Is possible. Instead of the illustrated TFD element, a two-terminal nonlinear element having bidirectional diode characteristics such as a ZnO (zinc oxide) varistor, an MSI (Metal Semi-Insulator) driving element, and an RD (Ring Diode) is provided. Also good.

(Eighth embodiment)
An eighth embodiment of the liquid crystal device according to the present invention will be described with reference to FIG. FIG. 14 is a schematic longitudinal sectional view of an eighth embodiment of the liquid crystal device according to the present invention. The eighth embodiment has substantially the same configuration as the fifth embodiment described above, and the structure relating to the insulating film is different. In FIG. 14, the same components as those in FIG. 11 according to the fifth embodiment are denoted by the same reference numerals, and the description thereof is omitted.

That is, in FIG. 14, the insulating layer provided on the reflective layer 617 arranged at a predetermined interval has a multilayer structure including insulating films 616a and 616b. More specifically, in addition to an oxide film 616a obtained by anodizing a reflective layer 617 made of metal, an insulating film 616b coated with an organic material by spin coating is stacked as an insulating layer. As the insulating film 616b, an SiO ₂ film or the like may be deposited in addition to the organic insulating film. Since the other points are the same as in the fifth embodiment, the description thereof is omitted here.

As described above, according to the eighth embodiment, the insulating property of the insulating film can be improved. In addition, an oxide of aluminum or the like can be used for one insulating film, and an SiO ₂ film or an overcoat film made of an organic material can be used as the other insulating film. When the SiO ₂ film is formed, What is necessary is just to form by vapor deposition, a sputter | spatter, and CVD method, and what is necessary is just to form by spin coat etc. when forming an organic film.

  In each of the embodiments described above, the light from the backlight is transmitted through the gaps of the reflective layers 216, 317, 317 ′, 411 and the like. By forming the opening or the slit, the light from the backlight may be introduced into the liquid crystal layer not only through the gap but also through the opening. In this case, one or a plurality of openings such as squares, rectangles, slits, circles, ellipses and the like may be regularly or irregularly arranged for each pixel. In this case, preferably, the total area of the openings is provided at a ratio of about 10% with respect to the total area of the reflective layer. Such an opening can be easily produced by a photo process / development process / peeling process using a resist. Further, it is possible to open the opening at the same time when the reflective layer is formed, and in this way, it is not necessary to increase the number of manufacturing steps. In any shape, the diameter of the opening is preferably 0.01 μm or more and 20 μm or less, and the opening is formed with an area ratio of 5% or more and 30% or less with respect to the reflective layer. Is preferred.

  The colored layers such as the color filters 213, 313, and 414 used in the first to tenth embodiments described above will be described with reference to FIG. FIG. 15 is a characteristic diagram showing the transmittance of each colored layer such as the color filter 213. In each embodiment, when performing a reflective display, incident light once passes through one of the colored layers such as the color filter 213, then passes through the liquid crystal layer, is reflected by the reflective layer, and passes through the colored layer again. Then released. Therefore, unlike a normal transmissive liquid crystal device, the light passes through the color filter 213 twice, so that the display becomes dark and the contrast is lowered with the normal color filter. Therefore, in each embodiment, as shown in FIG. 19, the color filter 213 is formed so as to be lightly colored so that the minimum transmittance 61 in the visible region of each colored layer of R, G, B is 25 to 50%. ing. The colored layer is lightened by reducing the thickness of the colored layer or reducing the concentration of the pigment or dye mixed in the colored layer. Thus, it is possible to configure so that the brightness of the display is not lowered when performing the reflective display.

  The lightening of the color filter 213 and the like causes lightening of the display because it is transmitted only once through the color filter 213 and the like when performing transmissive display. However, in each embodiment, the light of the backlight is reflected by the reflective layer. Since it is often blocked, it is rather convenient for ensuring the brightness of the display.

(Ninth embodiment)
A ninth embodiment of the present invention will be described with reference to FIG. The ninth embodiment is an embodiment of an electronic apparatus including any one of the first to eighth embodiments described above. That is, the ninth embodiment is applied to various electronic devices that suitably use the liquid crystal device shown in the first to eighth embodiments described above as a display unit of a portable device that requires low power consumption in various environments. Involved. FIG. 16 shows three examples of the electronic apparatus of the present invention.

  FIG. 16A shows a mobile phone, and a display unit 72 is provided in the upper front part of the main body 71. Mobile phones are used in all environments, indoors and outdoors. Although it is often used in automobiles, it is very dark at night. Therefore, it is desirable that the display device used for the mobile phone is a transflective liquid crystal device capable of performing transmissive display using auxiliary light as necessary, mainly reflective display with low power consumption. If the liquid crystal device described in the first to eighth embodiments is used as the display unit 72 of the cellular phone, a cellular phone having a higher contrast ratio than the conventional one can be obtained in both the reflective display and the transmissive display.

  FIG. 16B shows a watch, and a display unit 74 is provided at the center 73 of the main body. An important aspect in watch applications is luxury. If the liquid crystal described in the first to eighth embodiments of the present invention is used as the display section 74 of the watch, it is not only bright and high in contrast, but also has little color change because of less characteristic change due to the wavelength of light. Therefore, a color display with a very high-class feeling can be obtained as compared with a conventional watch.

  FIG. 16C shows a portable information device, in which a display unit 76 is provided on the upper side of the main body 75 and an input unit 77 is provided on the lower side. In many cases, a touch key is provided on the front surface of the display unit 76. Ordinary touch keys have a lot of surface reflection, making it difficult to see the display. Therefore, a transmission type liquid crystal device is often used as a display unit even though it is portable. However, since the transmissive liquid crystal device always uses a backlight, the power consumption is large and the battery life is short. Even in such a case, if the liquid crystal device according to any of the first to eighth embodiments is used as the display unit 76 of the portable information device, the mobile phone can be brightly displayed with a reflective, transflective, or transmissive display. Information equipment can be obtained.

  The liquid crystal device of the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Such a liquid crystal device is also included in the technical scope of the present invention.

It is a schematic longitudinal cross-sectional view which shows schematic structure of 1st Embodiment of the liquid crystal device which concerns on this invention. In the comparative example, a conceptual diagram (FIG. 2A) schematically showing the state of an electric field applied to the liquid crystal layer by a semi-transmissive reflective electrode having a single layer structure, and a laminate on the semi-transmissive reflective layer in the first embodiment. It is the conceptual diagram which showed typically the mode of the electric field applied to a liquid-crystal layer by the made transparent electrode (FIG.2 (b)). It is a top view which shows an example of the reflection layer arrange | positioned with the gap | interval in 1st Embodiment. It is a top view which shows the other example of the reflection layer arrange | positioned with the gap | interval in 1st Embodiment. It is a top view which shows the other example of the reflection layer arrange | positioned with the gap | interval in 1st Embodiment. It is a top view which shows the other example of the reflection layer arrange | positioned with the gap | interval in 1st Embodiment. It is a schematic longitudinal cross-sectional view which shows schematic structure of 2nd Embodiment of the liquid crystal device which concerns on this invention. It is a schematic longitudinal cross-sectional view which shows schematic structure of 3rd Embodiment of the liquid crystal device which concerns on this invention. It is a schematic longitudinal cross-sectional view which shows schematic structure of 4th Embodiment of the liquid crystal device which concerns on this invention. Explanatory drawing (FIG. 10 (a)) which shows the relationship of the rubbing direction of the polarizing plate of 4th Embodiment, a phase difference plate, and a liquid crystal cell, and the drive voltage-reflectance R / transmittance T characteristic of the liquid crystal device at this time are shown. FIG. 10 is a characteristic diagram (FIG. 10B). It is a schematic longitudinal cross-sectional view which shows schematic structure of 5th Embodiment of the liquid crystal device which concerns on this invention. It is sectional drawing which expands and shows the TFT drive element in 6th Embodiment of this invention with a pixel electrode. It is sectional drawing which expands and shows the TFD drive element in 7th Embodiment of this invention with a pixel electrode. It is a schematic longitudinal cross-sectional view which shows schematic structure of 8th Embodiment of the liquid crystal device which concerns on this invention. It is a graph which shows the light transmittance for every colored layer of the color filter in each embodiment. It is a schematic perspective view of the various electronic devices of 9th Embodiment which concerns on this invention.

Explanation of symbols

201, 202, 301, 302, 401, 402 ... transparent substrates 203, 303, 403 ... liquid crystal layers 204, 304, 404 ... sealing materials 205, 208, 305, 308, 405, 407 ... polarizing plates 206, 209, 306, 309, 406, 408 ... retardation plates 207, 307 ... scattering plates 211, 215, 311, 315, 409, 416, 615 ... transparent electrodes 210, 214, 310, 314, 410, 417 ... alignment films 212, 312, 316 412, 415 ... protective films 213, 313, 414 ... color filters 216, 317, 317 ', 411, 617 ... reflective layers 217, 318, 418 ... light guide plates 218, 319, 419 ... fluorescent tubes 413 ... black matrix layer ( Light shielding film)
501 ... Scanning line 502 ... TFD element 601 ... Transparent electrode 603 formed on the inner surface of the upper substrate ... Transparent electrode formed on the inner surface of the lower substrate

Claims (6)

A liquid crystal layer is sandwiched between a pair of first and second substrates. On the surface of the second substrate on the liquid crystal layer side, a wiring and a reflective type are connected to the wiring via an active element. An island-shaped reflective layer used for display and an island-shaped transparent electrode directly formed and overlaid on the reflective layer are provided, and the opposite side of the second substrate to the liquid crystal layer is illuminated A liquid crystal device in which the device is arranged,
The reflective layer is disposed close to an end of the transparent electrode on the side where the active element is disposed, the transparent electrode is formed to have a region overlapping the reflective layer, and the reflective layer includes the reflective layer A liquid crystal device, wherein transmissive display is performed in a region of the transparent electrode that is brought close to an end of the transparent electrode and does not overlap the reflective layer.   The liquid crystal device according to claim 1, wherein the transparent electrode is formed so that an area thereof is larger than an area of the reflective layer.   The liquid crystal layer is a liquid crystal having negative dielectric anisotropy, and an alignment film for vertically aligning the liquid crystal is formed on the surface of the transparent electrode. LCD device.   4. The liquid crystal device according to claim 1, wherein the liquid crystal device is in a dark (black) state when not driven.   A resin having irregularities is formed on the surface of the second substrate on the liquid crystal layer side, and the island-shaped reflective layer is formed on the resin so that irregularities are provided on the surface thereof. The liquid crystal device according to claim 1, wherein the liquid crystal device is a liquid crystal device.   An electronic apparatus comprising the liquid crystal device according to claim 1.

Images