JP2004157568A - Liquid crystal display device and portable electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display having such characteristics that when the display is observed in the direction near the normal direction to the display surface of the display apparatus, the display is observed brighter than that in other viewing angles. <P>SOLUTION: The liquid crystal display 3 is equipped with: an electrode and an alignment layer on the inner face of one substrate 10 of the two substrates 10 and 20 opposing to each other sandwiching a liquid crystal layer 30, successively from the inner face side of the substrate 10, successively formed from the inner face of the substrate 20; a reflector 47 disposed on the outer face side of the substrate 10 of a liquid crystal cell 35b in which the electrode and the aligment layer are provided on the inner surface of the other substrate 20 successively from the substrate 20 side or disposed between the substrate 10 and the electrode 15 formed on the inner face of the substrate; and a retardation plate 27 and a polarizing plate 28 disposed in the outer face side of the substrate 20, successively disposed from the substrate 20. The display is set in such a manner that when the angle between the normal direction P<SB>1</SB>on the display screen 1a of the liquid crystal display 3 and the main observation direction α<SB>1</SB>is 0° to 20°, the reflectance for the light incident to the liquid crystal display 3 and reflected on the reflector 47 shows a peak in the range within 20° from the normal direction P<SB>1</SB>. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a liquid crystal display device and a portable electronic device having a reflector, and has a viewing angle characteristic such that when viewing a display from a direction close to a normal direction to a display surface of the liquid crystal display device, the viewing angle characteristic looks brighter than other viewing angles. The present invention relates to a liquid crystal display device having the same and a portable electronic device provided with a liquid crystal display device having such characteristics in a display portion.

  In general, display modes of a liquid crystal display device include a transflective type having a backlight, a transmissive type, and a reflective type. A reflective liquid crystal display device is a liquid crystal display device that displays without using a backlight using only external light such as sunlight and illumination light, and is, for example, a portable information terminal that is required to be thin, light, and low in power consumption. It is often used for such purposes. The transflective liquid crystal display device operates in the transmission mode by turning on the backlight in an environment where sufficient external light cannot be obtained, and operates in the reflection mode in which the backlight is not turned on when sufficient external light is obtained. It is widely used in portable electronic devices such as mobile phones and notebook personal computers (notebook PCs).

FIG. 12 is a sectional view showing an example of a conventional transflective liquid crystal display device.
In this transflective liquid crystal display device, a liquid crystal for a reflection mode STN (Super-Twisted Nematic) system is provided on a lower retardation plate 73a of a reflection plate 71 having a lower polarization plate 70 and a lower retardation plate 73a. A cell 72, a forward scattering plate 90, an upper retardation plate 73b, and an upper polarizing plate 74 are sequentially stacked from the lower retardation plate 73b side, while a backlight 95 as a light source is provided on the lower surface side of the reflection plate 71. It has a configuration.
The liquid crystal cell 72 includes a lower glass substrate 75, a color filter 76, a lower transparent electrode layer 78, a lower alignment film 79, an upper alignment film 80 opposed to the lower alignment film 79 with a gap, and an upper transparent film. An electrode layer 81 and an upper glass substrate 82 are sequentially stacked from the lower polarizing plate 70 side, and an STN liquid crystal layer 83 is disposed between the lower and upper alignment films 79 and 80. An overcoat layer (not shown) made of silica or acrylic resin is provided between the color filter 76 and the lower transparent electrode layer 78.

The reflection plate 71 is made of an Al film having a mirror-finished surface, and has a hole 71a for transmitting backlight when the backlight 90 is used.
The phase difference plates 73a and 73b are for compensating the phase difference of the light transmitted through the STN liquid crystal to prevent the display from being colored blue or yellow.
The forward scattering plate 90 scatters incident light (external light) that has entered through the upper polarizing plate 74 and the upper retardation plate 73 b toward the liquid crystal cell 72, thereby reflecting the incident light on the surface of the reflecting plate 71. This is provided so that light is reflected not only in the direction of specular reflection but also in the direction near specular reflection.

FIG. 13 shows an example of a conventional transflective liquid crystal display device.
In this reflection type liquid crystal display device, a first retardation plate 173a, a second retardation plate 173b, and a polarizing plate 174 are provided on a liquid crystal cell 172 for a reflection mode STN (Super-Twisted Nematic) system on the upper glass substrate 182 side. , And a backlight 195 as a light source is provided on the lower surface side of the liquid crystal cell 172.
The liquid crystal cell 172 includes a lower glass substrate 175, a reflector 171, an overcoat layer 171c, a color filter 176, an overcoat layer 177a, a lower transparent electrode layer 178, a lower alignment film 179, and a gap with the lower alignment film 179. An upper alignment film 180, a top coat layer 177 b, an upper transparent electrode layer 181, and an upper glass substrate 182, which are opposed to each other, are sequentially laminated.

The reflector 171 has a large number of fine irregularities (recesses 171e... In FIG. 13) formed irregularly adjacently on the reflection surface. As a method for forming the irregularities, for example, a surface of a resin substrate 171a made of a photosensitive resin layer or the like is irradiated with light through a mask pattern, and a number of fine spherical concave portions adjacent to each other are formed by a development process. There is known a method of forming a metal film 171b having irregularities (concave portions 171e...) By depositing or plating aluminum, silver, or the like on the surface of a resin substrate 171a on which a large number of spherical concave portions are formed.
By reducing the thickness of the metal film 171b to about 30 nm, light from the backlight 195 can be transmitted in the transmission mode.
The recesses 171 have a spherical inner surface, an inclination angle distribution in a range of −20 degrees to +20 degrees, and a depth in a range of 0.1 μm to 3 μm. The pitch (distance between centers) between the concave portions is set so as to vary within a range of 5 μm to 50 μm.

By the way, the display performance of the liquid crystal display device is usually (1) resolution, (2) contrast, (3) screen brightness, (4) vividness of colors, (5) wide viewing angle range, and the like. Properties, etc. are required.
In addition, as shown in FIG. 14, a liquid crystal display device incorporated in a device that uses a display surface at an angle, such as a portable information terminal such as a mobile phone or a notebook PC, generally has a normal line to the display surface. It is often seen from a direction close to the direction, specifically, a direction within a range of 10 degrees from the normal direction P. In general, the angle θ between the main observation direction α and the normal direction P when the observer (user) looks at the display surface (screen) often ranges from 0 to 20 degrees.
FIG. 14 is an explanatory diagram illustrating a state in which the display unit 100 including the liquid crystal display device uses a mobile phone provided in the main body 105. 14, P is a normal to the display surface of the display unit 100, Q is incident light, and ω ₀ is an incident angle (for example, 30 degrees). Further, R ₁ is reflected light (specular reflection) when the incident angle ω ₀ is equal to the reflection angle ω, R ₂ is reflected light whose reflection angle ω is smaller than the incident angle ω ₀ , and R ₃ is reflected light whose incident angle ω is the incident angle ω. _The reflected light is greater than _zero .

As can be understood from the figure, the observer's viewpoint Ob usually normal direction P direction of the reflected light R ₂ close to, and more specifically to focus the direction of the range from the normal direction P up to 10 degrees. On the other hand, the reflected lights R ₁ and R ₃ are directed in such a direction as to look up the display surface from below, and are difficult to see. Therefore, considering the convenience of use by the observer, it is desirable to secure a wide viewing angle and at the same time, to increase the reflectance in the direction where the reflection angle is smaller than the regular reflection.
However, in the conventional liquid crystal display device shown in FIG. 12, in the reflection mode, although the range in which the incident light is reflected is wider than that of the liquid crystal display device without the forward scattering plate, most of the incident light is Reflects in the direction of specular reflection and its vicinity (the peak of the reflectance is at the angle of the specular reflection or at an angle near the specular reflection), so the display seen from the direction of the specular reflection and its surroundings looks bright but other directions The display seen from looks dark.
Also, in the conventional liquid crystal display device shown in FIG. 13, most of the incident light is also reflected in the direction of specular reflection and its vicinity (the peak of the reflectance is the angle of the specular reflection or the angle on both sides near the specular reflection). ), The display viewed from the specular reflection and its surrounding direction looks bright, but the display viewed from other directions looks dark.

  Therefore, when the conventional transflective display device looks at the display surface of a mobile phone or the like provided in the display unit, the viewpoint of the observer usually concentrates in a direction close to the normal direction P as described above. When the display is dark, on the other hand, when trying to view a bright display, the display must be viewed from the direction of specular reflection and its surroundings, and as described above, the display surface is looked up from below, making it difficult to see.

The present invention has been made in order to solve the above-described problem, and has a viewing angle characteristic such that when viewing a display from a direction close to a normal direction to a display surface of a liquid crystal display device, the viewing angle characteristic looks brighter than other viewing angles. It is an object to provide a liquid crystal display device having the same.
Another object of the present invention is to provide a portable electronic device such as a portable electronic terminal such as a portable telephone or a notebook PC having a liquid crystal display device having the above-described characteristics in a display portion.

In order to achieve the above object, a liquid crystal display device of the present invention is provided with an electrode and an alignment film on the inner surface side of one of the substrates facing each other with a liquid crystal layer interposed therebetween, in that order from the one substrate side, and the other substrate A reflector is provided between the outer surface side of the one substrate or the one substrate and the electrode provided on the inner surface side of the one substrate of the liquid crystal cell in which an electrode and an alignment film are sequentially provided from the other substrate side on the inner surface side of the liquid crystal cell. A retardation plate and a polarizing plate are sequentially provided on the outer surface side of the other substrate from the other substrate side,
When the angle between the normal direction to the display surface of the liquid crystal display device and the main observation direction is 0 to 20 degrees, the reflectance of incident light incident on the liquid crystal display device with respect to the light reflected by the reflector Has a peak region where the reflectance is high around the specular reflection angle, and this reflectance peak is set to be within 30 degrees from the normal direction (one end of the reflectance peak region is Angle is set between 0 degree and 30 degrees).
According to the liquid crystal display device of the present invention having such a configuration, the amount of reflected light in the range of 30 degrees from the normal to the display surface of the liquid crystal display device increases, so that the amount of reflected light is close to the observer's viewpoint. The distribution of directions is also increased, and a liquid crystal display device with a bright display (screen) can be realized from a practical viewpoint, particularly when the angle between the normal direction and the main observation direction is 0 to 20 degrees.

In the liquid crystal display device of the present invention having the above-described configuration, the peak of the reflectance of the reflected light that is incident on the liquid crystal display device and reflected by the reflector extends within a range of 20 degrees from the normal direction. It is preferable that the setting is made such that one end of the peak region of the reflectance exists between the light receiving angle of 0 degree and 20 degrees.
According to the liquid crystal display device of the present invention having such a configuration, the amount of reflected light in the range from the normal to the display surface of the liquid crystal display device to within 20 degrees is large, and the amount of reflected light is closer to the observer's viewpoint. And the area in which the amount of reflected light is high is widened. Therefore, from a practical viewpoint, particularly when the angle between the normal direction and the main observation direction is 0 to 20 degrees, a liquid crystal of a bright display (screen) is obtained. A display device can be realized.

  As an example of a means for realizing a liquid crystal display device having the above characteristics, as the reflector, a plurality of concave portions having light reflectivity are formed on a metal film formed on a base material or on the surface of the base material. Each of the recesses has an inner surface which forms a part of a spherical surface, an inclination angle distribution is formed in a range of −30 ° to + 30 °, and a depth of the recess is irregularly formed in a range of 0.1 μm to 3 μm. The plurality of recesses can be realized by using a configuration in which the pitch of adjacent recesses is irregularly arranged within a range of 2 μm to 50 μm.

In order to achieve the above object, a liquid crystal display device of the present invention is provided with an electrode and an alignment film on the inner surface side of one of the substrates facing each other with a liquid crystal layer interposed therebetween, in that order from the one substrate side, A liquid crystal cell in which an electrode and an alignment film are sequentially provided from the other substrate side on the inner surface side of the substrate, or a reflector between the outer surface side of the one substrate or the one substrate and the electrode provided on the inner surface side thereof. Provided, a retardation plate and a polarizing plate are sequentially provided on the outer surface side of the other substrate from the other substrate side,
When the angle between the normal direction to the display surface of the liquid crystal display device and the main observation direction is 0 to 20 degrees, the reflectance of incident light incident on the liquid crystal display device with respect to the light reflected by the reflector Is set to be within a range smaller than 30 degrees from the normal direction.
According to the liquid crystal display device of the present invention having such a configuration, the amount of reflected light in a range smaller than 30 degrees from the normal direction to the display surface of the liquid crystal display device increases, so that the amount of reflected light is in a direction closer to the observer's viewpoint. The distribution is high, and a liquid crystal display device with a bright display (screen) can be realized from a practical viewpoint, particularly when the angle between the normal direction and the main observation direction is 0 to 20 degrees.

In the liquid crystal display device of the present invention having the above-described configuration, the peak of the reflectance of the light that is incident on the liquid crystal display device and is reflected by the reflector is within a range of 20 degrees from the normal direction. It is preferable that the setting is made as follows.
According to the liquid crystal display device of the present invention having such a configuration, the amount of reflected light within a range of 20 degrees from the normal to the display surface of the liquid crystal display device increases, and the amount of reflected light is distributed in a direction close to the observer's viewpoint. Therefore, a liquid crystal display device having a bright display (screen) can be obtained from a practical viewpoint, particularly when the angle between the normal direction and the main observation direction is 0 to 20 degrees. realizable.

As a first example of a means for realizing a liquid crystal display device having the above-described characteristics, a metal film formed on a substrate or a plurality of concave portions having light reflectivity are formed on the surface of the substrate as the reflector. Each of these recesses is formed such that the inclination angle (the absolute value of the angle between the tangent plane at any point on the curved surface and the substrate surface) is maximized at one side of the recess, and By using a structure in which the depth is irregularly formed in a range of 0.1 μm to 3 μm, and the plurality of recesses are arranged irregularly in a pitch of adjacent recesses in a range of 2 μm to 50 μm. realizable.
As a second example of a means for realizing a liquid crystal display device having the above characteristics, a metal film formed on a base material or a plurality of concave portions having light reflectivity are formed on the surface of the base material as the reflector. Each of these recesses has the following specific vertical cross-section, each passing through the deepest point of the recess, and the specific vertical cross-section has an inner surface whose first surface extends from one peripheral portion of the recess to the deepest point. A second curve extending from the deepest point of the concave portion to a third curve or straight line, a third curve or a straight line continuing from the second curve to another peripheral portion, following the first curve. Wherein the average value of the absolute value of the inclination angle with respect to the substrate surface of the first curve is made larger than the average value of the absolute value of the inclination angle with respect to the substrate surface of the second curve, and the substrate surface of the third curve The average value of the absolute value of the inclination angle with respect to It can be realized by using a material obtained by the different configurations mean value of the absolute value of the tilt angle and the average value of the absolute value of the inclination angle for the third curve or straight line of the substrate surface to be.
As a third example of a means for realizing a liquid crystal display device having the above-described characteristics, a metal film formed on a base material or a plurality of concave portions having light reflectivity are formed on the surface of the base material as the reflector. Wherein the inner surface of the recess is formed by a continuous surface of a peripheral curved surface that is a part of two spherical surfaces having different radii and a bottom curved surface that is located at a position surrounded by the peripheral curved surface, and forms a peripheral curved surface. Is smaller than the radius of the spherical surface forming the bottom curved surface, and the normals set on the reflector surface from the center of each spherical surface exist on straight lines different from each other.

Further, in the liquid crystal display device of the present invention having one of the above configurations, the reflector has an asymmetrical reflectance distribution with respect to the regular reflection angle of the incident light, and the maximum value of the reflectance is equal to the incident light. It is characterized by having a reflection characteristic in a reflection angle range (light reception angle range) smaller than the regular reflection angle.
According to the liquid crystal display device of the present invention having such a configuration, the amount of reflected light in the light-receiving angle range smaller than the specular reflection angle increases, so that the distribution of the amount of reflected light increases in the direction close to the observer's viewpoint, and from a practical viewpoint, A liquid crystal display device with a bright display (screen) can be realized.
Preferably, the profile of the graph showing the reflectance distribution of the reflector has a step-like shape, and the maximum value of the reflectance exists at the top of the step-like profile. According to the liquid crystal display device provided with a reflector exhibiting such a reflectance distribution, the reflectance in a specific angle range within a reflection angle range (light reception angle range) smaller than the regular reflection angle is further increased, so that the amount of reflected light is reduced. The distribution in the direction close to the observer's viewpoint is increased, and a liquid crystal display device with a bright display (screen) can be realized from a practical viewpoint.
Further, in the liquid crystal display device of the present invention having any one of the above structures, when the reflector comprises a base material and a metal film having a plurality of recesses formed thereon, the thickness of the metal film is set to 8 nm. When the thickness is within the range of about 20 nm, the thickness of the metal film is reduced, and the transmissivity of light from a backlight provided below the reflector can be increased. Can be used as a transflective liquid crystal display device exhibiting excellent characteristics in both cases of transmitting light. Further, when the reflector is made of a substrate having a plurality of concave portions, the thickness of the substrate is reduced by setting the thickness of the substrate within a range of 8 nm to 20 nm, and the lower side of the reflector is formed. The transmissivity of light from the backlight provided in the liquid crystal display device can be enhanced, and in both the case of reflecting light and the case of transmitting light, it can be used as a transflective liquid crystal display device exhibiting excellent characteristics. .

In order to achieve the above object, a portable electronic device of the present invention is characterized in that a liquid crystal display device of the present invention having any one of the above-described configurations is provided in a display unit.
According to the portable electronic device of the present invention having such a configuration, the portable electronic device such as a mobile phone or a notebook PC having excellent visibility of the display surface (screen) in the operation in the reflection mode or in both the reflection mode and the transmission mode. Electronic devices can be obtained.

As described above in detail, according to the liquid crystal display device of the present invention, when the angle between the normal direction to the display surface of the liquid crystal display device and the main observation direction is 0 to 20 degrees, the liquid crystal display device By setting the peak of the reflectance of the reflected light that is incident on the device and reflected by the reflector to be within a range of 30 degrees from the normal direction, preferably, the liquid crystal display device By setting the peak of the reflectance of the incident light reflected by the reflector to fall within a range of 20 degrees from the normal direction, the normal direction to the display surface of the liquid crystal display device is set. When viewing the display from a direction close to the viewing angle, it is possible to have a viewing angle characteristic that looks brighter than other viewing angles.
Further, according to the liquid crystal display device of the present invention, when the angle between the normal direction to the display surface of the liquid crystal display device and the main observation direction is 0 to 20 degrees, the incident light incident on the liquid crystal display device is By setting the peak of the reflectance of the reflected light reflected by the reflector to be within a range smaller than 30 degrees from the normal direction, preferably, the incident light incident on the liquid crystal display device is reflected by the reflected light. The display was observed from a direction close to the normal direction to the display surface of the liquid crystal display device because the peak of the reflectance of the light reflected by the body was set to be within a range of 20 degrees from the normal direction. At this time, it is possible to have a viewing angle characteristic that makes it look brighter than other viewing angles.
Further, according to the portable electronic device of the present invention, since the liquid crystal display device of the present invention having any one of the above-described configurations is provided in the display unit, the operation in the reflection mode or the operation in any of the reflection mode and the transmission mode is performed. Thus, a portable electronic device such as a mobile phone or a notebook PC having excellent visibility of the display surface (screen) can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.
(1st Embodiment)
FIG. 1 is a diagram schematically showing a partial cross-sectional structure including an end of a transflective liquid crystal display device according to a first embodiment of the present invention.
In FIG. 1, a transflective liquid crystal display device 1 according to the present invention includes a first substrate (one substrate) 10 made of transparent glass or the like opposed to a liquid crystal layer 30 and a second substrate (the other substrate). Of the two substrates 10 and 20 with a sealing member 40 provided annularly around the peripheral portions of the two substrates 10 and 20.
On the liquid crystal layer 30 side of the first substrate 10, the reflector 7, the color filter 13 for performing color display, and the reflector 7 are covered and protected, and irregularities due to the reflector 7 and the color filter 13 are formed. An overcoat film 14 for flattening, a transparent electrode layer 15 for driving the liquid crystal layer 30, and an alignment film 16 for controlling the alignment of liquid crystal molecules constituting the liquid crystal layer 30 are formed by lamination. . Further, on the liquid crystal layer 30 side of the second substrate 20, a transparent electrode layer 25, an overcoat film 24, and an alignment film 26 are sequentially laminated.

A liquid crystal cell 35 is constituted by the first substrate 10, the second substrate 20, and the components provided between these substrates.
On the opposite side of the first substrate 10 to the liquid crystal layer 30 side (outer surface side of the first substrate 10), a polarizing plate 18 is provided, and the second substrate 20 is opposite to the liquid crystal layer 30 side (second side). On the outer surface side of the substrate 20), a retardation plate 27 and a polarizing plate 28 are laminated in this order. The outer surface of the polarizing plate 28 is the display surface 1a.
A backlight 5 as a light source for performing transmissive display in the transflective liquid crystal display device 1 is provided outside the polarizing plate 18 of the first substrate 10.

Further, when the the transflective liquid crystal display device 1, the angle theta ₁ between the normal direction P ₁ as the main observation direction alpha ₁ relative to the display surface 1a of the liquid crystal display device 1 is 0 degrees to 20 degrees, peak of the reflectance of the reflected light incident light incident on the liquid crystal cell 35 is reflected by the reflecting body 7, it is set to extend from the normal direction P ₁ to within 30 degrees, preferably, the reflected light peak reflectivity of is set to extend from the normal direction P ₁ to within 20 degrees.

The reflector 7 includes an organic film (base material) 11 and a metal reflection film (metal film) 12 formed on the organic film 11. The organic film 11 is provided in order to give the metal reflective film 12 formed thereon an uneven shape to efficiently scatter reflected light. By providing the metal reflective film 12 with the concavo-convex shape as described above, light incident on the liquid crystal display device 1 can be efficiently reflected, so that a bright display in the reflection mode can be realized.
FIG. 2 is a perspective view showing the reflector 7 including the organic film 11 and the metal reflection film 12 formed thereon. As shown in this figure, on the surface of the organic film 11, a large number of concave portions 12A whose inner surface forms a part of a spherical surface are continuously formed so as to overlap left and right, and a metal reflective film is formed on the surface. 12 are stacked.

The depth of the recess 12A is randomly formed in the range of 0.1 μm to 3 μm, the pitch of the adjacent recesses 12A is randomly arranged in the range of 2 μm to 50 μm, and the inclination angle of the inner surface of the recess 12A is −30 ° to It is set in the range of +30 degrees.
In particular, it is particularly important that the inclination angle distribution of the inner surface of the concave portion 12A is set in a range of −30 degrees to +30 degrees, and that the pitch of the adjacent concave portions 12A is randomly arranged in all directions in the plane. This is because if the pitch of the adjacent concave portions 12A is regular, there is a problem that interference colors of light appear and reflected light is colored. On the other hand, when the inclination angle distribution of the inner surface of the concave portion 12A exceeds the range of −30 degrees to 30 degrees, the diffusion angle of the reflected light is too wide, the reflection intensity is reduced, and a bright display cannot be obtained (the diffusion angle of the reflected light is small). This is because it becomes 36 degrees or more in the air, the reflection intensity peak inside the liquid crystal display device decreases, and the total reflection loss increases.) Change the reflection characteristic to be set in the liquid crystal display device 1 (for example, from reflection characteristic peaks of the reflectance of the reflected light to reach the normal direction P ₁ to within 30 degrees, the reflectance of the reflected light the peak is the reflection characteristics as extending from the normal direction P ₁ to within 20 degrees), as the reflecting body 7 comprises a liquid crystal display device 1, for example, the inclination angle distribution of the recess 12A the inner surface different (However, the inclination angle distribution of the inner surface of the concave portion 12A is within the above range).

If the depth of the concave portion 12A exceeds 3 μm, the top of the convex portion cannot be filled with the flattening film (overcoat film 14) when the concave portion 12A is flattened in a later step, and desired flatness can be obtained. Disappears, causing display unevenness.
If the pitch between the adjacent concave portions 12A is less than 2 μm, there is a restriction on the production of a transfer die used to form the organic film 11, and the processing time becomes extremely long, and a shape that can obtain desired reflection characteristics is formed. There are problems such as inability to generate light and interference light. Further, in practice, when a diamond indenter having a diameter of 5 μm to 100 μm which can be used for manufacturing the transfer die is used, it is desirable that the pitch between the adjacent concave portions 12A is 2 μm to 50 μm.

The organic film (base material) 11 is formed by applying a photosensitive resin liquid such as an acrylic resist on the first substrate 10 by a spin coating method or the like, and then prebaking to form a photosensitive resin layer. A transfer mold having a surface consisting of an uneven surface and a flat surface around the periphery thereof is pressed against the surface of the photosensitive resin layer, and the shape of the uneven surface of the transfer mold is transferred to the surface of the photosensitive resin layer. It was done.
It is preferable to use a metal material having a high reflectance such as Al or Ag for the metal reflection film 12, and these metal materials can be formed into a film by a film forming method such as sputtering or vacuum evaporation.
The thickness of the metal reflection film 12 is preferably in the range of 8 nm to 50 nm (80 ° to 500 °). This is because, when the film thickness is less than 8 nm, the display in the reflection mode becomes dark because the light reflectance of the metal reflection film 12 is too small. This is because the transmissivity of the film 12 is reduced and the display in the transmission mode becomes dark.

  Further, the thickness of the metal reflection film 12 is more preferably in the range of 8 nm to 30 nm (80 ° to 300 °). If the thickness of the metal reflective film 12 is in such a range, the display in the transmission mode can be made brighter, so that the difference in display brightness between the transmission mode and the reflection mode can be reduced. . Therefore, it is possible to improve the visibility of the display when using while switching between the two operation modes. Most preferably, the thickness of the metal reflective film 12 is in the range of 8 nm to 20 nm (80 ° to 200 °). By setting the film thickness in such a range, it is possible to maintain the brightness in the reflection mode and realize particularly excellent brightness in the transmission mode.

  The electrode layer 15 is formed by arranging a large number of strip-shaped planar members made of a transparent conductive film such as ITO (Indium tin oxide). The electrode layers 15 are individually connected to an external drive circuit (not shown) to be connected to a liquid crystal layer. 30 are formed on the overcoat film 14 in order to drive the liquid crystal molecules constituting 30. Similarly, the electrode layer 25 is also formed by arranging a large number of strip-shaped planar members made of a transparent conductive film such as ITO on the substrate 20 and individually connected to an external drive circuit. The electrode layer 15 and the electrode layer 25 are arranged so as to be perpendicular to each other in a plan view, and the liquid crystal display device 1 is of a passive matrix type.

In the transflective liquid crystal display device 1 of the present embodiment, since the reflector 7 having the plurality of recesses 12A having the above-described configuration is provided, the incident light incident on the liquid crystal cell 35 is reflected by the reflector 7. peak of the reflectance of the reflected light are set so as to extend from the normal direction P ₁ to within 30 degrees, when the reflective mode, 30 degrees from the normal direction P ₁ relative to the display surface 1a of the liquid crystal display device 1 , The distribution of the amount of reflected light in the direction closer to the observer's viewpoint Ob ₁ also increases, and from a practical viewpoint, in particular, the normal direction P ₁ and the main observation direction α _1. in the angle theta ₁ is 0 degrees to 20 degrees with, it is possible to realize a liquid crystal display device of bright display (screen).

In particular, the peak of the reflectance of the reflected light incident light incident on the liquid crystal cell 35 is reflected by the reflecting body 7, in the one configured so as to extend from the normal direction P ₁ to within 20 degrees is the reflection mode, the reflected light amount in the range from the normal direction P ₁ relative to the display surface 1a of the liquid crystal display device 1 to within 20 degrees is increased, the amount of reflected light direction distribution close to the observer's viewpoint Ob ₁ And the area where the amount of reflected light is high is widened, so that a bright display (screen) is obtained from a practical viewpoint, particularly when the angle between the normal direction P ₁ and the main observation direction α ₁ is 0 to 20 degrees. A liquid crystal display device can be realized.

In addition, the transflective liquid crystal display device 1 of the present embodiment can obtain a display with sufficient brightness in the reflection mode despite the use of the thin metal reflective film 12. Since the metal reflective film 12 is thin, a particularly bright display can be obtained in the transmission mode. This is because the above-described shape is formed on the surface of the organic film 11. That is, when the metal reflective film 12 is made thinner to increase the translucency, the reflectance itself of the metal reflective film 12 is reduced, but a large number of concave portions 12A whose inner surface forms a part of a spherical surface are continuously formed on the surface of the organic film 11. By maximizing the reflection efficiency of light by the metal reflective film 12 by forming it, a bright display in the transmission mode can be realized without greatly impairing the brightness of the display in the reflection mode. .
If the thickness of the metal reflection film 12 is set to 8 nm to 20 nm, the liquid crystal display device 1 of the present embodiment can realize a particularly bright display in the transmission mode. This is not achieved only by the improvement of the translucency due to the extremely thin metal reflection film 12, but is due to the effect of the shape of the surface of the organic film 11 added. That is, as shown in FIG. 2, since the inner surface of the concave portion 12A formed on the surface of the organic film 11 is spherical, a lens effect acts on light incident on the organic film 11 from the substrate 10 side. By increasing the light from the backlight 5 passing through the display 11, a much brighter display can be obtained.

  In the above embodiment, the case where the liquid crystal display device of the present invention is applied to a passive matrix type transflective liquid crystal display device has been described. However, the present invention is not limited to this. The present invention is also applicable to a liquid crystal display device. In that case, for example, a reflector having a plurality of concave portions having light reflectivity formed on the surface described above may be provided above or below a pixel electrode constituting a pixel.

FIG. 3 shows that the liquid crystal display device 1 according to the first embodiment does not have a backlight, but the display surface 1a has an incident angle of 30 ° (display from one side of a perpendicular (normal) to the display surface 1a). external light is irradiated from the opposite side of the observer's viewpoint Ob ₁ to observation at an angle) between the optical axis of external light illuminated viewing direction alpha (acceptance angle) to the perpendicular position (normal position) (0 °) 2 shows the relationship between the light receiving angle (°) and the brightness (reflectance) when the light is shaken from 60 ° to 60 °. In FIG. 3, solid lines (1) and (2) show the relationship between the light receiving angle and the reflectance of the liquid crystal display device of the first embodiment. The difference between the solid lines (1) and (2) is as follows. The point is that the depth and the like of the concave portion 12a of the reflector 7 are different.
In FIG. 3, as a comparative example, the relationship between the light receiving angle and the reflectance of the conventional liquid crystal display device shown in FIG. 12 or 13 without a backlight is shown by a broken line (3). Was.

As apparent from FIG. 3, in the liquid crystal display device of the comparative example, the peak of the reflectance is at the angle of regular reflection (the light receiving angle is 30 °), and when the light receiving angle is smaller than 20 °, the reflectance is significantly reduced. Therefore, it is considered that a display viewed from the regular reflection direction looks bright, but a display viewed from another direction looks dark.
On the other hand, in the liquid crystal display device 1 of the first embodiment having the characteristic shown by the solid line (1), there is a peak region where the reflectance is particularly high around the light receiving angle of 30 ° (specular reflection angle), In addition, the peak of the reflectance extends within a range of 20 degrees from the normal direction (light receiving angle 0 °) (in other words, one end of the peak region of the reflectance exists between the light receiving angle 0 ° and 20 degrees). Therefore, at a light receiving angle of 20 ° to 0 °, the reflectivity is higher than that of the comparative example. When the display is observed from a direction close to the normal direction, the display looks brighter than that of the comparative example. Conceivable. Further, in the liquid crystal display device 1 according to the first embodiment having the characteristic shown by the solid line (1), the peak of the reflectance extends over a wide range of ± 10 ° at a light receiving angle of 30 °.
Further, in the liquid crystal display device 1 of the first embodiment having the characteristic shown by the solid line (2), there is a peak region where the reflectance is particularly high around the light receiving angle of 30 °. The light receiving angle extends from the linear direction (light receiving angle 0 °) to within 10 degrees (in other words, one end of the reflectance peak region exists between the light receiving angle 0 ° and 10 °). At 10 ° to 0 °, the reflectance is higher than that of the comparative example, and it is considered that the display looks brighter than that of the comparative example when the display is observed from a direction close to the normal direction. Further, in the liquid crystal display device 1 of the first embodiment having the characteristic shown by the solid line (2), the peak of the reflectance extends over a wide range of ± 20 ° at a light receiving angle of 30 °.
Therefore, when the liquid crystal display device of the present embodiment is incorporated into the display unit of a portable electronic device such as a mobile phone or a notebook PC in the liquid crystal display device of the present embodiment having any one of the above-described configurations, the visibility is particularly good. It will be.

(Second embodiment)
In the first embodiment, the case where the reflector 7 for reflecting light incident from the outside is incorporated between the substrate 10 and the substrate 20 is described. However, two reflectors sandwiching a liquid crystal layer are described. A reflector external type in which a reflector is provided outside the substrate can also be used. This configuration is referred to as a second embodiment of the present invention, and will be described below with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and the description is simplified.

FIG. 4 is a diagram showing a partial cross-sectional structure of a transflective liquid crystal display device 2 according to a second embodiment of the present invention.
The transflective liquid crystal display device 2 of the second embodiment differs from the transflective liquid crystal display device 1 of the first embodiment in that an overcoat film is provided between the first substrate 10 and the electrode 15. 14, the color filter 13 and the reflector 7 are not provided, and the reflector 7 similar to that described in the first embodiment is provided between the first substrate 10 and the backlight 5. is there.
A liquid crystal cell 35a is composed of the first substrate 10, the second substrate 20, and the components provided between these substrates.

In the transflective liquid crystal display device 2 of the present embodiment, the angle theta ₁ between the normal direction P ₁ as the main observation direction alpha ₁ for the first embodiment similarly to the display surface 1a of the liquid crystal display device 2 when 0 ° to 20 °, so that the peak of the reflectance of the reflected light incident light entering through the liquid crystal cell 35a is reflected by the reflecting body 7, it extends from the normal direction P ₁ to within 30 degrees is set, preferably, the peak of the reflectance of the reflected light is set so as to extend from the normal direction P ₁ to within 20 degrees.
Although not shown, a color filter layer may be formed between the first substrate 10 and the electrode 15 by printing or the like so that the liquid crystal display device 2 can perform color display. .

In the transflective liquid crystal display device 2 of the present embodiment, since the reflector 7 having the plurality of recesses 12A having the above-described configuration is provided, incident light that has passed through the liquid crystal cell 35a is reflected by the reflector 7. The peak of the reflectance of the reflected light is set so as to be within a range of 30 degrees from the normal direction P ₁ , and in the reflection mode, from the normal direction P ₁ to the display surface 1 a of the liquid crystal display device 2. Since the amount of reflected light in the range up to the range of 30 degrees is large, the distribution of the amount of reflected light in the direction close to the observer's viewpoint Ob ₁ is also high, and in a practical viewpoint, in particular, the normal direction P ₁ and the main observation direction in the angle theta ₁ is 0 degrees to 20 degrees with alpha _1, it can realize a liquid crystal display device of bright display (screen).

In particular, to those incident light entering through the liquid crystal cell 35a is the peak of the reflectance of light reflected by the reflecting body 7, is set to extend from the normal direction P ₁ to within 20 degrees is a, when the reflective mode, the amount of reflected light in the range from the normal direction P ₁ relative to the display surface 1a of the liquid crystal display device 2 to within 20 degrees is increased, the amount of reflected light direction close to the observer's viewpoint Ob ₁ Is high, and the area where the amount of reflected light is high is widened. Therefore, from a practical viewpoint, particularly, when the angle between the normal direction P ₁ and the main observation direction α ₁ is 0 to 20 degrees, a bright display (screen ) Can be realized.
In addition, since the reflector 7 used in the second embodiment can be disposed outside the substrate constituting the liquid crystal cell, the reflector 7 can be mounted in a reflection mode without any problem if it is a transmission type liquid crystal display device. A transflective liquid crystal device capable of performing bright display in any of the transmission modes can be formed.
In the second embodiment, an example in which the present invention is applied to a passive matrix type transflective liquid crystal display device has been described. However, a three terminal type (TFT: thin film transistor) active matrix type and a two terminal type The present invention can be applied to the active matrix type liquid crystal display device without any problem.
In the first and second embodiments, the case where the polarizing plate 18 is provided outside the first substrate 10 has been described. However, the polarizing plate 18 is not provided outside the first substrate 10. In such a case, the optical conditions of each member constituting the liquid crystal display device are adjusted so as to obtain good display characteristics.
In the first and second embodiments, the case where the liquid crystal display device of the present invention is applied to a transflective liquid crystal display device has been described. However, the liquid crystal display device can also be applied to a reflective liquid crystal display device. The backlight 5 may not be provided, and the thickness of the metal reflection film 12 may be greater than 50 nm.

(Third embodiment)
FIG. 5 is a diagram schematically illustrating a partial cross-sectional structure of a reflective liquid crystal display device according to a third embodiment of the present invention.
In FIG. 5, the reflection type liquid crystal display device 3 includes a first substrate (one substrate) 10 made of transparent glass or the like opposed to a liquid crystal layer 30 and a second substrate (the other substrate) 20. Are bonded and integrated by a sealing material provided annularly on the peripheral portions of these two substrates 10 and 20.
On the liquid crystal layer 30 side of the first substrate 10, a reflector 47, a transparent intervening layer 53, a color filter 13 for performing color display, and an overcoat film for flattening irregularities due to the color filter 13 are arranged in this order. A (transparent flattening layer) 14, a transparent electrode layer 15 for driving the liquid crystal layer 30, and an alignment film 16 for controlling the alignment of liquid crystal molecules constituting the liquid crystal layer 30 are formed by lamination. Further, on the liquid crystal layer 30 side of the second substrate 20, a transparent electrode layer 25, an overcoat film 24, and an alignment film 26 are sequentially laminated.

A liquid crystal cell 35b is composed of the first substrate 10, the second substrate 20, and the components provided between these substrates.
On the opposite side of the first substrate 10 to the liquid crystal layer 30 side (outer surface side of the first substrate 10), a polarizing plate 18 is provided, and the second substrate 20 is opposite to the liquid crystal layer 30 side (second side). On the outer surface side of the substrate 20), a retardation plate 27 and a polarizing plate 28 are laminated in this order. The outer surface of the polarizing plate 28 is the display surface 1a.
Further, in the reflective liquid crystal display device 3, when the angle theta ₁ between the normal direction P ₁ as the main observation direction alpha ₁ relative to the display surface 1a of the liquid crystal display device 3 is 0 degrees to 20 degrees, the liquid crystal cell peak of the reflectance of light reflected by the incident light reflector 47 that has entered the 35b is, is set to be from the normal direction P ₁ in the range smaller than 30 degrees, preferably, of the reflected light peak of the reflectance is set to be from the normal direction P ₁ in the range of 20 degrees.

  As shown in FIG. 6, the reflector 47 provided in the reflection type liquid crystal display device 3 has a plurality of concave portions 63a and 63b having a large number of light reflectivities on the surface (reference surface H) of a flat substrate 61 made of, for example, aluminum. , 63c,... (Generally referred to as recesses 63) are formed irregularly adjacent to each other.

These concave portions 63 have a circular concave surface in plan view as shown in a perspective view in FIG. 7 and a sectional view in FIG. 8, and the concave surface has a deepest point indicated by D in FIG. A spoon-shaped aspheric surface deviated in one direction (Y direction) from the center O, and the inclination angle at one side A (the absolute value of the angle formed between the tangent plane P and the substrate surface H at an arbitrary point on the curved surface) ) Is formed so that δ is the maximum, that is, the maximum inclination angle δmax. Therefore, in the concave surface, the inclination angle δb of the side portion B opposite to the side portion A with the center O interposed therebetween is smaller than the inclination angle of the side portion A (maximum inclination angle δmax). In the reflector 47 provided in the present embodiment, each of the maximum inclination angles δmax in the concave portions 63a, 63b, 63c,... Varies irregularly within a range of 2 ° to 90 °. However, many concave portions irregularly vary within the range of the maximum inclination angle δmax of 4 ° to 35 °.

The concave portion 63 has a single minimum point (a point on a curved surface at which the inclination angle becomes zero) D. The distance between the minimum point D and the reference surface H of the base material forms the depth d of the concave portion 63. The depth d is 0.1 μm to 3 μm for the concave portions 63a, 63b, 63c,. It varies irregularly within the range.
In addition, the concave portions 63a, 63b, and 63c are arranged irregularly when the pitch between adjacent concave portions is in the range of 2 μm to 50 μm.

In this embodiment, each recess 63a of the, 63 b, 63c, · · ·, as shown in FIG. 9, the side A having respective concave maximum inclination angle δmax is far from the observer's viewpoint Ob ₁ It is formed so as to be aligned with the direction Y.
Generally, external light enters the concave portion 63 from various directions, and is reflected in various directions on the curved surface of the concave portion 63 in accordance with the inclination angle of the incident point. Therefore, the reflected light is diffused in a wide viewing angle range as a whole. As shown in FIG. 10, for example, when the direction of reflection is tracked by focusing on external light incident from the Oa direction, the reflected light is in the opposite direction to the side A having the maximum inclination angle δmax, that is, the observer side. However, more light tends to be concentrated in the range of W (clear vision range) shown in FIG.
Therefore, if to place perspective Ob ₁ observer within this distinct vision range W, compared with the case of observing from the other direction, so that appear brighter. In other words, the observer's viewpoint Ob ₁ typically direction close to the normal direction P ₁ of the display surface 1a, since more specifically to focus the direction of the range from the normal direction P ₁ to 20 degrees, this range to, by setting so that more light is collected (design), when observed from the direction close to the normal direction P ₁ relative to the display surface 1a of the liquid crystal display device, compared with the case of observing from the other direction, more It looks brighter.
The extent and direction of the clear vision range W can be controlled by adjusting the shape and the arrangement direction of the concave portions 63.

In the reflector 47 of the present embodiment, since each concave portion 63 is formed as an aspheric surface having a single minimum point, the change in the reflection angle of light is smooth, and the reflected light is so strong that it is dazzling at a specific viewing angle. I can't see it.
The maximum inclination angle δmax of each of the recesses 63a, 63b, 63c,... Is in the range of 2 ° to 90 °, and most of them are in the range of 4 ° to 35 °. Thus the light incident on the entire surface of the recess 63 is bright as a whole field of view extensively scattered within a range that does not if wasting the reflected light, among them the particular viewing angle within (from the normal direction P ₁ in the range less than 30 degrees direction, in particular, more light is reflected biased direction) in the range from the normal direction P ₁ to 20 degrees, in (practical viewpoint when observing in this viewing angle in particularly, said normal direction When observed at an angle of 0 to 20 degrees with the main observation direction), the image looks particularly bright.
The depth of the concave portions 63 is irregularly formed in the range of 0.1 μm to 3 μm, and the concave portions 63 are arranged irregularly adjacent to each other. This does not occur, and the peak concentration of the amount of reflected light at a specific viewing angle is reduced, and the change in the amount of reflected light within the field of view is gentle.

As shown in FIG. 9, the direction of the side A having the maximum inclination angle of each of the concave portions 63 a, 63 b, 63 c, and the side of the reflector 47 is far from the viewpoint Ob ₁ of the observer (Y direction). It is attached to become.
In addition, the transparent electrode layer 15 and the transparent electrode layer 25 sandwiching the liquid crystal layer 30 are formed in a stripe shape orthogonal to each other, and constitute a simple matrix type liquid crystal device in which the intersection region becomes a pixel.

In the reflective liquid crystal display device 3 of the present embodiment, when external light enters the display surface 1a, the incident light enters the liquid crystal panel 35b, passes through each layer, reaches the surface of the reflector 47, and The light is reflected at a wide angle by the curved surfaces of the concave portions 63a, 63b, 63c,..., Passes through the respective layers again, and exits from the display surface 1a. When so scattered the outgoing light wide viewing angle range, although the display surface 1a can be observed without reflection of light from a wide viewing angle, which is observed from the opposite side of the viewpoint Ob ₁ direction to the orientation direction Y, in particular, when the angle between the normal direction P ₁ as the main observation direction alpha ₁ is observed at 0 ° to 20 °, the brightness of the screen is maximized.

In the reflection type liquid crystal display device 3 of the present embodiment, since the reflector 47 having the plurality of recesses 63 having the above-described configuration is provided, the incident light incident on the liquid crystal cell 35b is reflected by the reflector 47. peak reflectivity are set so that the normal direction P ₁ in the range smaller than 30 degrees, the reflection mode than 30 degrees from the normal direction P ₁ relative to the display surface 1a of the liquid crystal display device 3 Since the amount of reflected light in a small range increases, the distribution of the amount of reflected light in the direction close to the observer's viewpoint Ob ₁ also increases, and in a practical viewpoint, particularly, the normal direction P ₁ and the main observation direction α _{1 make up.} in the angle theta ₁ is 0 degrees to 20 degrees, it is possible to realize a liquid crystal display device of bright display (screen).

In particular, the peak of the reflectance of the reflected light incident light incident on the liquid crystal cell 35b is reflected by the reflector 47, in the one configured so that the normal direction P ₁ in the range of 20 degrees It is the reflection mode, the reflected light amount in the range from the normal direction P ₁ of 20 degrees relative to the display surface 1a of the liquid crystal display device 3 is increased, the amount of reflected light becomes higher direction of distribution close to the observer's viewpoint Ob ₁ In addition, since a region where the amount of reflected light is high is widened, a liquid crystal display of a bright display (screen) is obtained from a practical viewpoint, particularly, when the angle between the normal direction P ₁ and the main observation direction α ₁ is 0 to 20 degrees. The device can be realized.

In the reflective liquid crystal display device 3 according to the third embodiment shown in FIG. 5, the reflector 47 is formed as a layer different from the electrode layer 15, but the electrode layer 15 itself is formed by the reflector 47. If the electrode layer 15 is formed at the position of the reflector 47 in FIG. 5, the transparent electrode layer can also serve as the reflector, and the layer configuration of the reflection type liquid crystal display device is simplified.
Further, in the third embodiment, the case where the reflector 47 for reflecting the light incident from the outside is incorporated between the substrate 10 and the substrate 20 is described. It is also possible to use a reflector external type in which a reflector is provided outside the substrate.
In the third embodiment, the case where the liquid crystal display device of the present invention is applied to a reflective liquid crystal display device has been described. However, the present invention can also be applied to a transflective liquid crystal display device. Has a thickness in the range of 8 nm to 50 nm (80 ° to 500 °), preferably in the range of 8 nm to 30 nm (80 ° to 300 °), and more preferably in the range of 8 nm to 20 nm (80 ° to 200 °). It is sufficient to provide a backlight for the camera.

In the third embodiment, the case where the present invention is applied to a simple matrix type reflection type liquid crystal display device has been described. However, the same applies to an active matrix type or segment type liquid crystal display device using thin film transistors or thin film diodes. It can be applied to All of these liquid crystal display devices are included in the present invention.
In the first to third embodiments, a case has been described in which one retardation plate is provided between the second substrate 20 and the polarizing plate 28. However, a plurality of retardation plates are provided. Is also good.

FIG. 11 shows a display surface 1a of the reflection type liquid crystal display device 3 of the third embodiment with an angle of incidence of 30 ° (a viewer who observes the display from one side of a perpendicular (normal) to the display surface 1a). irradiating external light at an angle) between the optical axis of external light illuminated from the opposite side of the viewpoint Ob _1, swung from the observation direction α (the acceptance angle) perpendicular position (normal position) (0 °) to 60 ° Shows the relationship between the light receiving angle (°) and the brightness (reflectance). In FIG. 11, solid lines (4), (5), and dot-dash line (6) show the relationship between the light receiving angle and the reflectance of the reflective liquid crystal display device of the third embodiment. The difference between (5) and the one-dot chain line (6) is that the shape and arrangement direction of the concave portions 63 of the reflector 47 are different.
In FIG. 11, as a comparative example, the relationship between the light receiving angle and the reflectance of the conventional liquid crystal display device shown in FIG. 12 or 13 without a backlight is shown by a broken line (3). Was.

As is clear from FIG. 11, in the liquid crystal display device of the comparative example, the peak of the reflectance is at the angle of regular reflection (the light receiving angle is 30 °), and when the light receiving angle is smaller than 20 °, the reflectance is significantly reduced. Therefore, it is considered that a display viewed from the regular reflection direction looks bright, but a display viewed from another direction looks dark.
On the other hand, in the liquid crystal display device 3 of the third embodiment having the characteristic shown by the solid line (4), the peak of the reflectance is within a range smaller than 30 degrees from the normal direction (light receiving angle 0 °), There is a peak region where the reflectance is particularly high around the light receiving angle of about 25 °. At the light receiving angle of 0 ° to 30 °, the reflectivity is higher than that of the comparative example, and the display is performed from a direction close to the normal direction. Is observed, it is considered that the display looks brighter than that of the comparative example. Further, in the liquid crystal display device 3 of the third embodiment having the characteristic shown by the solid line (5), the peak of the reflectance is within a range of 20 degrees from the normal direction (light receiving angle 0 °), and the light receiving angle is about 15 °. There is a peak region with a particularly high reflectance centering on °, showing a higher reflectance than the comparative example at a light receiving angle of 0 ° to 22 °, when viewing the display from a direction close to the normal direction. It is considered that the display looks brighter than that of the comparative example. Further, in the liquid crystal display device 3 of the third embodiment having the characteristic indicated by the dashed line (6), the peak of the reflectance is within a range of about 20 degrees from the normal direction (light receiving angle 0 °), and the light receiving angle is The reflectance around 20 ° is higher than the reflectance at the angle of regular reflection, and at a light receiving angle of 0 ° to 25 °, the reflectance is higher than that of the comparative example. When the display is observed, it is considered that the display looks brighter than that of the comparative example. Further, in the liquid crystal display device 3 of the third embodiment having the characteristics indicated by the solid line (4) or (5) or the dashed line (6), the reflectance distribution is asymmetric with respect to the regular reflection angle of the incident light. And the maximum value of the reflectance is in a reflection angle range (light reception angle range) smaller than the regular reflection angle of the incident light (the light reception angle of 30 ° in this embodiment). In particular, in the liquid crystal display device 3 of the third embodiment having the characteristics indicated by the dashed line (6), the profile of the graph showing the reflectance distribution is stepwise, and the maximum value of the reflectance is 20 ° in the light receiving angle. In the vicinity, the maximum value is present at the top of the step-like profile. However, the comparative example has a reflection characteristic having a reflectance distribution symmetrical with respect to the regular reflection angle of incident light.
Therefore, when the liquid crystal display device of the present embodiment is incorporated into the display unit of a portable electronic device such as a mobile phone or a notebook PC in the liquid crystal display device of the present embodiment having any one of the above-described configurations, the visibility is particularly good. It will be.

(Fourth embodiment)
FIG. 15 is a diagram schematically showing a partial cross-sectional structure of a reflective liquid crystal display device according to a fourth embodiment of the present invention.
The reflection type liquid crystal display device 4 of FIG. 15 differs from the reflection type liquid crystal display device 3 of FIG. 5 in that the configuration of the reflector provided in the liquid crystal cell 35b is different.
The reflector 47 provided in the reflection type liquid crystal display device 4 of the present embodiment includes a plurality of concave portions 163a, 163b, 163c having a large number of light reflectivities on the surface (reference surface) of a flat base material 61 made of, for example, aluminum. ... (generally referred to as recesses 163) are formed irregularly adjacent to each other.

  As shown in the sectional view of FIG. 16, these concave portions 163 have an inner surface shape in a specific vertical section Y of the concave portion 163, a first curve J extending from one peripheral portion S1 of the concave portion to the deepest point D, and the first curve J. A second curve K continuing from the curve J to the third curve or straight line L from the deepest point D of the concave portion, and a third curve or straight line L continuing to the second curve K and reaching another peripheral portion S2 It consists of These first and second curves are connected to each other at the deepest point D where the inclination angle with respect to the substrate surface S is zero.

  The inclination angle of the first curve J with respect to the substrate surface S is steeper than the inclination angle of the second curve K or the third curve or the straight line L, and the deepest point D is shifted from the center O of the recess 3 in the Y direction. It is in. That is, the average value of the absolute value of the inclination angle of the first curve J with respect to the substrate surface S (hereinafter referred to as the average value of the inclination angle of the first curve J) is the inclination angle of the second curve K with respect to the substrate surface S. And the average value of the absolute value of the inclination angle of the third curve or the straight line L with respect to the substrate surface S. The average value of the absolute value of the inclination angle of the second curve K with respect to the substrate surface S (hereinafter referred to as the average value of the inclination angle of the second curve K) and the third curve or the straight line L with respect to the substrate surface S The average value of the absolute value of the inclination angle (hereinafter, the average value of the inclination angle of the third curve or the straight line L) is different from the average value of the inclination angle of the third curve or the straight line L in the present embodiment. The inclination angle of the second curve K is set to be larger than the average value.

In other words, the size of the radius of curvature R ₁ of the first curve J is smaller than the radius of curvature R ₃ of the radius of curvature R ₂ and a third curve or the straight line L of the second curve K, the third curve or the straight line L the size of the radius of curvature R ₃ is smaller than the radius of curvature R ₂ of the second curve K. Incidentally, the third curve or straight line L if the radius of curvature R ₃ ∞, so a straight line.

  The average value of the inclination angles of the first curve J with respect to the substrate surface S in the concave portions 163a, 163b, 163c,... Varies irregularly in the range of 1 ° to 89 °. Also, the average value of the inclination angle of the second curve K with respect to the substrate surface S in the concave portions 163a, 163b, 163c,... Varies irregularly in the range of 0.5 ° to 88 °. Also, the average value of the inclination angle of the third curve or the straight line L with respect to the substrate surface S in the concave portions 163a, 163b, 163c,... Varies irregularly in the range of 0.5 ° to 88 °.

Since the inclination angles of the first curve, the second curve, the third curve or the straight line are all gradually changing, the maximum inclination angle δmax (absolute value) of the first curve J is the maximum inclination angle of the second curve K. It is larger than the angle (absolute value) δb and the maximum inclination angle (absolute value) δc of the third curve or the straight line L. Further, the inclination angle of the deepest point D where the first curve J and the second curve K are in contact with the substrate surface is zero, and the first curve J in which the inclination angle is a negative value and the inclination angle in which the inclination angle is a positive value. Is smoothly continuous with the second curve K, and the second curve K and the third curve or the straight line L whose inclination angle is a positive value are smoothly continued.
In the reflector of this embodiment, the maximum inclination angles δmax of the concave portions 163a, 163b, 163c,... Vary irregularly within a range of 2 to 90 °. However, many concave portions irregularly vary within the range of the maximum inclination angle δmax of 4 ° to 35 °.

  The concave portion 163 has a single minimum point D (a point on a curved surface at which the inclination angle becomes zero). The distance between the minimum point D and the substrate surface S of the substrate forms a depth d of the concave portion 163, and the depth d is 0.1 μm to 3 μm for the concave portions 163a, 163b, 163c,. Vary irregularly within the range. In addition, the concave portions 163a, 163b, and 163c are arranged irregularly when the pitch between adjacent concave portions is in the range of 5 μm to 50 μm.

In the present embodiment, the specific vertical sections Y in the concave portions 163a, 163b, 163c,... Are all in the same direction. Further, each of the first curve J is formed so as to align the observer's viewpoint Ob ₁ in the direction of the far direction Y. Further, each of the second curve K, the third curve also straight line L is formed with the direction of the far direction Y from the observer's viewpoint Ob ₁ so as to be aligned in opposite directions.

In the reflector 147 of the present embodiment, each first curve J is formed so as to be oriented in a single direction, and the average value of the inclination angle of the first curve J is equal to the base value of the second curve K. Since the average value of the inclination angle with respect to the surface S and the average value of the inclination angle of the third curve or the straight line L with respect to the substrate surface S are made larger, the reflection characteristics thereof are shifted from the direction of regular reflection with respect to the substrate surface S. It has become something. In other words, the reflected light with respect to the incident light obliquely from above in the Y direction has a brighter display range shifted in the direction shifted in the normal direction to the substrate surface S than in the direction of the regular reflection.
Further, in the reflector 147 of the present embodiment, the second curve K, the third curve or the straight line L is formed so as to be oriented in the opposite direction to the first curve J, respectively. Since the average value of the inclination angles is larger than the average value of the inclination angles of the second curve K, the overall reflection characteristic in the specific vertical section Y is reflected by the surface around the second curve K. The reflectance in the direction increases, and the reflectance in the direction reflected by the surface around the third curve or the straight line L becomes larger than the magnitude of the reflectance. Therefore, it is possible to obtain reflection characteristics in which reflected light is appropriately concentrated in a specific direction.

FIG. 17 shows a display surface 1a of the reflection type liquid crystal display device 4 of the fourth embodiment, in which the observer observes the display from one side of the perpendicular angle (normal line) on the display surface 1a. irradiating external light at an angle) between the optical axis of external light illuminated from the opposite side of the viewpoint Ob _1, swung from the observation direction α (the acceptance angle) perpendicular position (normal position) (0 °) to 60 ° Shows the relationship between the light receiving angle (°) and the brightness (reflectance). In FIG. 17, a dashed line (7) indicates the relationship between the light receiving angle and the reflectance of the reflective liquid crystal display device of the fourth embodiment.
In FIG. 17, as a comparative example, the relationship between the light receiving angle and the reflectance of the conventional liquid crystal display device shown in FIG. 12 or 13 without a backlight is indicated by a broken line (3). The reflection characteristics of the liquid crystal display device of this comparative example are the same as those described with reference to FIGS.

  In the liquid crystal display device 4 of the fourth embodiment having the characteristic shown by the dashed line (7), the profile of the graph showing the reflectance distribution is stepwise, and the reflection becomes asymmetric with respect to the regular reflection angle of the incident light. In addition, the maximum value of the reflectivity exists near a light receiving angle of 20 ° in a reflection angle range (light receiving angle range) smaller than a regular reflection angle of the incident light (a light receiving angle of 30 ° in this embodiment). The maximum value of the reflectance has a reflection characteristic existing at the top of the step-like profile, and the maximum value of the reflectance is larger than that of the liquid crystal display device of the third embodiment. Further, in the liquid crystal display device 4 of the fourth embodiment, the reflectance near the light receiving angle of about 20 ° is higher than the reflectance at the regular reflection angle, and the light receiving angle is 0 ° to 25 ° in the comparative example. It indicates that the display looks brighter than that of the comparative example when the display is observed from a direction close to the normal direction.

(Fifth embodiment)
Next, a reflective liquid crystal display device according to a fifth embodiment of the present invention will be described.
The reflection type liquid crystal display device of the fifth embodiment differs from the reflection type liquid crystal display device 4 of the fourth embodiment shown in FIG. 15 in that the configuration of the reflector provided in the liquid crystal cell is different.
The difference between the reflector provided in the reflective liquid crystal display device of the present embodiment and the reflector provided in the reflective liquid crystal display device of the fourth embodiment is that the surface (reference surface) of the flat base material 61 is provided. The shape of the concave portion formed in ()) is different.
FIG. 18 is an explanatory view of the concave portion 263 of the reflector 247 provided in the reflective liquid crystal display device of the present embodiment. FIG. 18A is a sectional view of the concave portion 263, and FIG. FIG.

As shown in FIG. 18, the inner surface of each recess 263 is formed of a peripheral curved surface 264a and a bottom curved surface 4b located at a position surrounded by the peripheral curved surface 264a. Peripheral curved surface 264a has a radius center as _{O 1} is part of a spherical surface is _{R 4.} Further, the bottom curved surface 264b has a radius center as _{O 2} is part of a spherical surface is _{R 5.} From O ₁ and O ₂ Metropolitan which is the center of each sphere, normal to the surface of the reflector, each located on separate straight lines L _1, L _2. Each of the specific vertical sections Y in the concave portions 263... Are in the same direction. Moreover, are formed so as to be aligned to each of the root surface 264b is a direction close to the observer's viewpoint Ob ₁ (the direction of the far direction Y from the observer's viewpoint Ob ₁ opposite direction, i.e. left side in FIG. 18). The right side direction in FIG. 18 is the light incident side.

Each of the radii R ₁ and R ₂ has a relationship of R ₁ <R ₂ and changes in a range of 5 μm ≦ R ₁ ≦ 70 μm and 10 μm ≦ R ₂ ≦ 100 μm. Further, in FIG. 2 (a), θ ₄ is at an inclination angle of the peripheral curved surface 264a, it is to vary 4 ° ≦ theta ₄ ≦ 35 ° and -35 ° ≦ theta ₄ ≦ -4 °. Further, theta ₅ is at an inclination angle of the bottom curved surface 264b, it is to vary -17 ° ≦ θ ₅ ≦ 17 °.
Incidentally, the radius _{r 5} of radius _{r 4} and a bottom curved surface 264b of the peripheral curved surface 264a as viewed from the planar direction, each of the _radius, R 4, _{R 5} and the inclination angle theta _4, in which depends on the theta _5.

The depth d of the concave portion 263 takes a random value for each concave portion in the range of 0.1 to 3 μm. If the depth of the concave portion 263 is less than 0.1 μm, the regular reflection becomes too strong.
The pitch of the adjacent concave portions 263 is randomly arranged in a range of 2 μm to 50 μm. This is because if the pitch of the adjacent concave portions 263 has regularity, there is a problem that an interference color of light appears and reflected light is colored. When the pitch of the adjacent concave portions 263 is less than 2 μm, there is a restriction in manufacturing the concave portions of the reflector, and the processing time becomes extremely long.

The relationship between the light receiving angle and the reflectance of the reflective liquid crystal display device of the fifth embodiment was measured in the same manner as in the method of the third embodiment, and as a result, the reflective liquid crystal display device of the fifth embodiment was measured. The relationship between the light receiving angle and the reflectance has the same characteristic as the characteristic shown by the one-dot chain line (6) in FIG.
As described above, in the reflective liquid crystal display device of the present embodiment in which the reflector 247 is provided, the inner peripheral surface of the concave portion 263 has the peripheral curved surface 264a formed by a part of a spherical surface having a small radius. Since a large range of the inclination angle is provided, good reflectance is obtained in a wide reflection angle range of about 15 ° to 45 °. In addition, since the bottom curved surface 264b, which is a part of a spherical surface having a large radius, that is, a curved surface close to a flat surface is unevenly distributed, the ratio of the inner surface providing an inclination angle in a specific range increases. As a result, the reflectance at the reflection angle smaller than the regular reflection angle (the light receiving angle of 30 degrees in the present embodiment) is the highest, and the reflectance in the vicinity is also high with that direction as a peak.
When the light is incident from the left direction in FIG. 18, the reflectance at the reflection angle larger than the incident angle of 30 degrees and the reflection angle of 30 degrees in the target direction becomes the highest, and the direction is set as a peak, and Also has a high reflectance.

FIG. 1 is a diagram illustrating a partial cross-sectional structure of a transflective liquid crystal display device according to a first embodiment of the present invention. FIG. 2 is an enlarged perspective view showing a reflector including an organic film and a metal reflection film provided in the liquid crystal display device of FIG. 1. 4 is a graph showing a relationship between a light receiving angle and a reflectance of the liquid crystal display device of the first embodiment and a liquid crystal display device of a comparative example. FIG. 6 is a diagram illustrating a partial cross-sectional structure of a transflective liquid crystal display device according to a second embodiment of the present invention. FIG. 9 is a diagram illustrating a partial cross-sectional structure of a reflective liquid crystal display device according to a third embodiment of the present invention. FIG. 6 is an enlarged perspective view illustrating a reflector provided in the liquid crystal display device of FIG. 5. FIG. 7 is a perspective view showing one concave portion formed on the surface of the reflector of FIG. 6. Sectional drawing which shows the recessed part of FIG. FIG. 7 is a cross-sectional view showing a part of the reflector in FIG. 6. FIG. 7 is a sectional view showing one concave portion of the reflector in FIG. 6. 9 is a graph showing the relationship between the light receiving angle and the reflectance of the liquid crystal display device of the third embodiment and the liquid crystal display device of the comparative example. FIG. 9 is a cross-sectional view illustrating a schematic configuration of a conventional transflective liquid crystal display device. Sectional drawing which shows the other example of the conventional transflective liquid crystal display device. FIG. 4 is an explanatory diagram of a use state of a transflective liquid crystal display device provided in a mobile phone. FIG. 14 is a diagram illustrating a partial cross-sectional structure of a reflective liquid crystal display device according to a fourth embodiment of the present invention. FIG. 16 is a sectional view showing a concave portion formed on the surface of a reflector provided in the reflective liquid crystal display device of FIG. 15. 13 is a graph showing the relationship between the light receiving angle and the reflectance of the liquid crystal display device of the fourth embodiment and the liquid crystal display device of the comparative example. FIG. 14 is an explanatory diagram of a concave portion of a reflector provided in a reflective liquid crystal display device according to a fifth embodiment of the present invention.

Explanation of reference numerals

1, 2, 3, 4 Liquid crystal display device 1a Display surface 5 Backlight 7, 47, 147, 247 Reflector 10 Substrate (one substrate)
11 Organic film (base material)
12 Metal reflective film (metal film)
12A, 63, 63a, 63b, 63c, 163, 263 recess 13 color filter 14, 24 overcoat film 15, 25 transparent electrode layer (electrode)
16, 26 Alignment film 18, 28 Polarizer 20 Substrate (other substrate)
27 retardation plate 30 liquid crystal layer 35, 35a, 35b liquid crystal cell 40 sealing material 53 transparent intervening layer 61 base material 264a peripheral curved surface 264b bottom curved surface P ₁ normal direction Ob ₁ viewpoint θ ₁ angle α ₁ observation direction

Claims (7)

An electrode and an alignment film are sequentially provided on the inner surface side of one of the substrates facing each other with the liquid crystal layer interposed therebetween from the one substrate side, and an electrode and an alignment film are sequentially provided on the inner surface side of the other substrate from the other substrate side. A reflector is provided between an electrode provided on the outer surface of the one substrate or the one substrate and the inner surface of the one substrate of the liquid crystal cell, and a retardation plate and a polarizing plate are provided on the outer surface of the other substrate. A liquid crystal display device provided in order from the other substrate side,
The reflector has a maximum inclination angle (an absolute value of an angle between a tangent plane at an arbitrary point on the surface of the reflection portion and the surface of the base material) at one side of the reflection portion, and the one side portion of the reflection portion is defined by an observer. When the angle formed between the normal direction to the display surface of the liquid crystal display device and the main observation direction is 0 ° to 20 °, incident light incident on the liquid crystal display device is formed so as to be aligned in a direction far from the viewpoint. A liquid crystal display device, wherein the peak of the reflectance of the light reflected by the reflector is set within a range smaller than 30 degrees from the normal direction.   2. The liquid crystal display device according to claim 1, wherein a peak of a reflectance of light reflected by the reflector when the incident light is incident on the liquid crystal display device is set within a range of 20 degrees from the normal direction. The liquid crystal display device according to the above.   In the reflector, a plurality of concave portions having light reflectivity are formed on a metal film formed on the base material or on the surface of the base material, and each of the concave portions has an inclination angle (an arbitrary shape on a curved surface) at one side of the concave portion. 3. The absolute value of the angle between the tangent plane and the surface of the base material at the point (1) is the largest, and the one side is formed so as to be aligned in a direction far from the viewpoint of the observer. 3. The liquid crystal display device according to 1. 4. The liquid crystal display device according to claim 1, wherein the one side of the recess having the maximum inclination angle has a maximum inclination angle of 4 degrees to 35 degrees. 5.   The depth of the concave portions may be irregularly formed in a range of 0.1 μm to 3 μm, and the plurality of concave portions may be irregularly arranged in a pitch of adjacent concave portions in a range of 2 μm to 50 μm. The liquid crystal display device according to claim 3. The liquid crystal display device according to any one of claims 1 to 5, wherein the thickness of the base material or the metal film of the reflector is 8 nm to 20 nm. A portable electronic device comprising the liquid crystal display device according to any one of claims 1 to 6 provided in a display unit.

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