JP2005099635A - Liquid crystal display device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which a reflective region and a transmissive region are completely distinguished from each other and further variation of reflection characteristics in the reflective region and that of transmission characteristics in the transmissive region are little and a method for manufacturing the same. <P>SOLUTION: The liquid crystal display device is constructed by disposing a backlight means BL on a liquid crystal display panel LP wherein a metal reflection film 17 and a transparent insulating resin film 16 straddling at least a display pixel region 6 are adhered to and formed on a substrate 2 placed on the rear face side of the liquid crystal panel LP and further a color filter 18 is adhered to and formed on a region corresponding to the display pixel region. Also the transparent insulating resin film 16 is formed by using the metal reflection film 17 as a photomask. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a metal reflective film in which a backlight is disposed on the back side of a liquid crystal panel, light from the backlight is transmitted to the liquid crystal panel, and external light from the display surface side of the liquid crystal panel is disposed in the liquid crystal panel. The present invention relates to a liquid crystal display device that can be reflected by a light source and a method for manufacturing the same.

  Usually, the liquid crystal display device is displayed in a matrix, and a first transparent electrode group (for example, a segment side transparent electrode group) formed on a first substrate and a second transparent electrode group (for example, a group of transparent electrodes formed on a second substrate) , A common-side transparent electrode group) was used so as to be orthogonal to each other.

  Such a liquid crystal display panel has a light transmission mode, a reflection mode, and a semi-transmission mode combining both modes from the viewpoint of light transmission / reflection.

  As a display method of the liquid crystal display panel, there are a color display in which a color filter is formed in each pixel region and a monochrome display liquid crystal display device in which no color filter is used.

  Further, the liquid crystal display driving method includes a simple matrix driving method and an active driving method in which a switching element such as a thin film transistor is provided in one pixel and one pixel.

From the viewpoint of light transmission / reflection described above, the reflective liquid crystal display device in the reflection mode has a metal reflective film disposed on the inner surface or the outer surface of the back side substrate of the liquid crystal display panel. Then, light incident from the liquid crystal display surface side is reflected by the metal reflection film through the liquid crystal layer, and is emitted from the liquid crystal display surface side again. For example, a film having an uneven surface is formed on the inner surface of the back-side substrate, and this metal reflective layer is scattered and reflected by this surface. In addition, a light reflecting film or the like is attached to the outer surface of the back side substrate via a polarizing film or a retardation film. This reflection type liquid crystal display device eliminates the need for backlight means and effectively uses ambient light.
On the other hand, the transmissive liquid crystal display device that is in the transmissive mode does not use a metal reflection film, and the backlight means is disposed outside the back substrate. The backlight means emits light that does not cause luminance unevenness over the display area, and includes, for example, a light source and a light guide plate for uniformly guiding light to the display area. The light emitted from the backlight means is incident on the liquid crystal display panel, passes through the liquid crystal layer, and is emitted toward the liquid crystal display surface. This transmissive liquid crystal display device has the advantage that it can be used even in a dark surrounding.

There has been a transflective liquid crystal display device that uses light incident from the display surface side and has a function of transmitting light to the back side of the back side substrate using backlight means.
In this semi-transmissive liquid crystal display device, a semi-transmissive film that transmits incident light on the back surface side and reflects light incident from the liquid crystal display surface side is used on the inner surface side of the rear substrate. (See Japanese Patent Application Laid-Open No. 8-292413.)

  A liquid crystal display panel using such a semi-transmissive film is often used for a color display liquid crystal display panel using a color filter. The driving method is applied to active matrix driving and normal simple matrix driving. (Refer to patent document 2 Unexamined-Japanese-Patent No. 7-318929).

  As such a semi-transmissive film, a semi-transmissive film having a half mirror action in which transmissive films having different refractive indexes are laminated may be considered. However, the reflectance (reflection characteristics) of incident light from the display surface side and the back surface side are considered. It is very difficult to form a semi-transmissive film that satisfies both the transmittance (transmission characteristics) of incident light.

  As a semi-transparent film that simplifies this, a semi-transparent film is also proposed in which light-transmitting holes through which incident light from the back side of the substrate can be transmitted are scattered on a metal reflective film having excellent reflection characteristics. . (Refer patent document 3 patent 2878231).

  FIG. 5 is a main cross-sectional view of a liquid crystal display panel portion of a liquid crystal display device capable of color display using a conventional semi-transmissive film.

  The liquid crystal display panel of the liquid crystal display device includes a first substrate (for example, a segment side substrate) 1 positioned on the liquid crystal display surface side, a second substrate (for example, a common side substrate) 2 positioned on the back side, The liquid crystal layer 3 is sandwiched between a first substrate 1 and a second substrate 2.

  A plurality of transparent electrodes extending in the first direction (in the depth direction of the paper surface in FIG. 5) are formed on the inner surface of the substrate 1 on the liquid crystal layer 3 side located on the upper surface, thereby constituting the segment transparent electrode 4. . In addition, a plurality of transparent electrodes extending in a direction orthogonal to the first direction are formed on the inner surface of the common substrate 2 on the liquid crystal layer 3 side, and these constitute a common transparent electrode group 5. Then, the segment transparent electrode group 4 and the common transparent electrode group 5 form a display pixel region 6 that is opposed to and intersects with each other through the liquid crystal layer 3, and a portion where the display pixels are arranged vertically and horizontally is called a display unit. .

  At least an alignment film 7 is formed on the segment transparent electrode group 4 of the segment side substrate 1 in the display area.

  At least an alignment film 8 is formed in the display area on the common transparent electrode group 5 of the common substrate 2.

  A phase difference plate 9 and a polarizing plate 10 are formed on the outer surface side of the segment side substrate 1, and a phase difference plate 11 and a polarizing plate 12 are also formed on the outer surface side of the common side substrate 2.

  In addition, the segment side substrate 1 and the common side substrate 2 are formed with a frame-shaped seal member (not shown in FIG. 5) that is particularly similar to the outer peripheral shape of the common side substrate 2.

  In the transflective liquid crystal display device, backlight means (not shown in FIG. 5) is arranged outside the common side substrate 2 which is the back side substrate.

  In the transflective liquid crystal display device of FIG. 5, a transflective film 50, a color filter 54, and a smooth transparent insulation are provided on the surface of the common substrate 2 that is the back substrate, that is, between the substrate surface and the common transparent electrode group 5. A film 20 was formed.

Conventionally, the semi-transmissive film 50 includes an insulating film 51 and a metal reflective film 52. Then, the transmission through hole 53 is formed so that the insulating film 51 and the metal reflection film 52 are removed near the center of one display pixel region.

Further, the color filter 54 is formed so as to cover the metal thin film 52 and the transmission through hole 53 in one display pixel region. (Patent Document 4 Japanese Patent Laid-Open No. 2001-166289)
In the transflective liquid crystal display device, the number of passes through the color filter 54 in the display in the reflection mode is two, and the number of passes through the color filter 54 in the display in the transmissive mode is one. For this reason, due to the difference in the number of times of passing through the color filter 54, the color purity of the light in the transmission mode has been reduced.

Therefore, the transmission through-hole 53 that is a region through which light in the transmission mode passes and the metal reflective film 52 that is a region in which light in the reflection mode is reflected are displaced in the thickness direction. As a result, the thickness of the color filter 54 is reduced. The transmission through hole 53 is thick, and the metal reflection film 52 is thin. As this means, an insulating film 51 formed immediately below the metal reflection film 52 is used.
JP-A-8-292413 JP-A-7-318929 JP 2001-166289 A JP 2001-166289 A

  Further, in the transflective color liquid crystal display device disclosed in Patent Document 3, a region constituting one display pixel, for example, one of R (red), G (green), and B (blue) of the color filter 54 is used. In the display pixel area of one dye, a reflection area (metal reflection film 52) and a transmission area (transmission through hole 53) are provided.

  However, in the conventional liquid crystal display device, the insulating film 51 and the metal reflective layer 52 constituting the semi-transmissive film 50 are formed in separate steps. Moreover, when viewed from the cross section, the metal reflective film 52 is formed only in one display pixel, and a plurality of metal reflective films 52 are independently formed.

  In such a structure, it is difficult to deposit the metal reflection layer 52 on the insulating film 51 so as to be completely overlapped in one display pixel region.

  The semi-transmissive film 50 is formed by independently forming an insulating film 51 on the substrate 2, and then depositing and forming a metal thin film such as aluminum to be the metal reflective film 52 including the insulating film 51, and The metal reflective film 52 is formed by patterning the metal thin film using the lithography technique. At this time, it is difficult to accurately form the photoresist formed on the metal thin film and used for forming the metal reflective film 52 on the insulating film 51.

  As a result, a part of the metal reflection layer 52 exists in the transmission through-hole 53 while being a transmission region that is the transmission through-hole 53, or a metal reflection film while being a reflection region on the insulating film 51. 52 is not formed, and a part of the surface of the insulating film 51 is exposed.

  As a result, it has become a cause of variation in reflectance, variation in reflection chromaticity, variation in transmittance, and variation in transmission chromaticity.

  The present invention has been devised in view of the above-mentioned problems, and its purpose is to make the reflection positions and the reflection chromaticity variations by making the formation positions of the metal reflection film and the insulating film completely coincide. It is an object of the present invention to provide a liquid crystal display device having no variation in transmittance and no variation in transmission chromaticity.

  It is another object of the present invention to provide a method of manufacturing a liquid crystal display device that can completely match the formation positions of the metal reflective film and the resin layer.

The present invention includes a rectangular first substrate formed by sequentially laminating a first transparent electrode group composed of a plurality of transparent electrodes extending in a first direction and an alignment film;
A rectangular second substrate formed by sequentially stacking a second transparent electrode group composed of a plurality of transparent electrodes extending in a second direction orthogonal to the first direction and an alignment film;
The first and second transparent electrode groups are opposed to each other so as to form display pixels orthogonal to each other, and are bonded together by a substantially rectangular sealing member, and the sealing member is filled with liquid crystal and the second substrate A liquid crystal display device in which a backlight means is disposed on the back side main surface of
A metal reflective film and a transparent insulating resin film are formed on the second substrate so as to straddle at least the display pixel region, and a part of the adjacent transparent insulating resin film is straddled. A color filter is deposited on the pixel region of the second substrate, a smoothing transparent insulating film is formed on the color filter and the transparent insulating resin film, and a second transparent electrode group is formed on the smoothing transparent insulating film. Are sequentially formed.

  The transparent insulating resin film is mixed with light scattering particles.

A rectangular first substrate formed by sequentially laminating a first transparent electrode group composed of a plurality of transparent electrodes extending in a first direction and an alignment film;
A second substrate formed by sequentially laminating a second transparent electrode group composed of a plurality of transparent electrodes extending in a second direction orthogonal to the first direction and an alignment film;
The first and second transparent electrode groups are opposed to each other so as to form display pixels orthogonal to each other, and bonded together with a substantially rectangular seal member, and the seal member is filled with liquid crystal and the second substrate A method of manufacturing a liquid crystal display device in which backlight means is arranged on the back side main surface,
The second substrate is
A first step of depositing an independent metal reflective film on the second substrate with at least the display pixel region in between;
A second step of depositing and forming a positive-type photocurable transparent resin film to be a transparent insulating resin film on the metal reflective film;
A third step of performing an exposure process from the metal reflective film side to photodecompose the transparent resin film, and developing the transparent resin film from the transparent resin film side to form a transparent insulating resin film;
A fourth step of depositing and forming a color filter corresponding to the pixel region so as to straddle the plurality of transparent insulating resin films;
A fifth step of forming a smoothing transparent insulating film on the color filter and a second transparent electrode group on the smoothing transparent insulating film;
It is formed through this, It is a manufacturing method of the liquid crystal display device characterized by the above-mentioned.

  In the present invention, a metal reflection film and a transparent insulating resin film formed between display pixel regions are formed. Since the metal reflective film and the transparent insulating resin film have the same shape, the reflective area where the metal reflective film and the transparent insulating resin film overlap and the transmission where the metal reflective film and the transparent insulating resin film are not formed are provided. Although the region can be completely distinguished from the transmissive region, the metal reflective film does not extend.

  As a result, when color filters are formed in the transmissive region and the reflective region, it is possible to completely control the thickness of the color filter in the transmissive region and the thickness of the color filter in the reflective region. Since there is no variation in reflectivity and there is no metal reflective layer present in the transmissive region, there is no chromaticity variation in the reflective region, no chromaticity variation in the transmissive region, and there is a metal reflective layer in the transmissive region. Since it does not exist, there is no variation in transmittance and a liquid crystal display device without variations in transmission chromaticity is obtained.

  In addition, since the transparent insulating resin film superimposed on the upper surface of the metal reflecting film is subjected to exposure processing, development processing and patterning using the independent metal reflecting film as a mask, the metal reflecting film and the transparent insulating resin film are completely formed. It becomes the same shape.

  Accordingly, as described above, a liquid crystal display device that is free from variations in reflectance and reflection chromaticity in the reflection region and also has no variation in transmittance and transmission chromaticity in the transmission region can be easily manufactured. Can do.

  In the present invention, a transmissive region is formed at the center of a region to be a display pixel region, and a reflective region is provided around the transmissive region. That is, a metal reflection film and a transparent insulating resin film, which are reflection areas, are formed around each display pixel area. A metal reflective film and a transparent insulating resin film are formed so as to straddle adjacent pixel regions. That is, one independent metal reflective film and transparent insulating resin film are formed across two pixel regions, and the shape of the metal reflective film and transparent insulating resin film is the shape of each pixel region. Since the processed shape can be increased as compared with the case where it is independently formed inside, the manufacturing method becomes very simple.

  The liquid crystal display device of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of the liquid crystal display device of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a cross-sectional view of the main part. Note that the liquid crystal display device of the present invention is intended for a transflective liquid crystal display panel capable of color display, and its driving will be described by a normal simple matrix driving method.

The liquid crystal display device includes a liquid crystal display panel LP and backlight means BL disposed on the back surface side (the surface side opposite to the liquid crystal display surface).

  The liquid crystal display panel LP used in the liquid crystal display device of the present invention is formed by sequentially laminating a first transparent electrode group composed of a plurality of transparent electrodes extending in one direction, for example, a segment side terminal group 4 and an alignment film 7. A rectangular first substrate, for example, a segment-side substrate 1, a second transparent electrode group (common transparent electrode group 5) composed of a plurality of transparent electrodes extending in the other direction orthogonal to the one direction, and an alignment film 8 A second substrate formed by sequentially stacking, for example, the common substrate 2 is bonded by a seal member 14 so that the two transparent electrode groups 4 and 5 are opposed to each other so as to be orthogonal to each other. The liquid crystal layer 3 is filled in. For example, the segment side substrate 1 is disposed on the liquid crystal display surface side, and the common side substrate 2 is disposed on the back side, for example, and the backlight means BL is disposed outside the common side substrate 1.

Then, an intersection region between the segment transparent electrode group 4 and the common transparent electrode group 5 is a display pixel region 6 with the liquid crystal layer 3 interposed therebetween. When this color filter is used, an aggregate of three display pixel regions 6 (filter regions for the respective dyes of R (red), G (green), and B (blue)) is a pixel 6 ′ on the viewing angle. It becomes.
Then, on the inner surface side of the common substrate 2 of the liquid crystal display panel LP, between the substrate surface and the transparent electrode group 5, a semi-transmissive film that defines a reflective region and a transmissive region is formed on the semi-transmissive film. The applied color filter and a smooth film deposited on the color filter are arranged.

The segment side substrate 1 is a substrate located on the liquid crystal display surface side, for example, and is made of acrylic resin, polycarbonate resin, epoxy resin, glass, etc., and has a rectangular shape. The segment-side substrate 1 includes the above-described display region and a circuit wiring region in which the first and second wiring patterns 20 and 21 are routed in a region surrounded by the seal member 7 in plan view. And a circuit wiring region in which the segment side terminal group 23 and the common side terminal group 24 are formed.

  In the display region on the inner surface side of the liquid crystal layer 3 of the substrate 1, transparent electrodes extending in the vertical direction in FIG. 1 and in the left-right direction in FIG. 2 are formed to constitute a segment transparent electrode group 4.

  For the transparent electrode, for example, a transparent electrode material such as indium oxide / tin (ITO) is deposited by a thin film technique, and then formed into a predetermined pattern by photolithography.

  A first wiring pattern 20 connected to the segment transparent electrode group 4 is formed on the upper surface of the segment side substrate 1. One end of the first wiring pattern 20 is connected to or integrated with one end of each transparent electrode constituting the segment transparent electrode group 4. Further, the other end extends to one end portion of the segment side substrate 1 and the lower end portion of FIG.

  Further, on the segment side substrate 1, the second wiring pattern 21 is connected to the common transparent electrode group 5 of the common side substrate 1 in the region between the display region and the seal member 14. One end extends to the lower end of FIG.

  An alignment film 7 is formed on the segment transparent electrode group 4 of the segment side substrate 1.

  The alignment film 7 is made of a resin material or an inorganic material and is subjected to an alignment process so as to define the twist angle of the liquid crystal molecules of the liquid crystal layer 3. When the alignment film 7 is a resin material, it is rubbed in a predetermined alignment direction. When the alignment film 7 is an inorganic material, physical alignment processing is performed by oblique deposition or the like during the thin film formation process.

  The first wiring patterns 20 and 21 are formed of ITO, which is the same material as the transparent electrodes constituting the segment transparent electrode group 4, or a metal material such as aluminum, aluminum alloy, silver, or gold is formed on the ITO film. A laminated multilayer structure may be used, or a metal layer formed of a metal material such as aluminum, an aluminum alloy, silver, or gold may be used.

  A retardation plate 9 and a polarizing plate 10 are deposited on the display area on the outer surface side of the segment side substrate 1.

Common side substrate The common side substrate 2 is made of acrylic resin, polycarbonate resin, epoxy resin, glass or the like, and has a rectangular shape. In the dimensions of the common side substrate 2, the horizontal dimension is substantially the same width as the segment side substrate 1, and the vertical dimension is substantially shorter than the segment side substrate 1.

  In the display area of the common substrate 2, a semi-transmissive film 15 that functions also in the reflection mode and the transmission mode is formed. A color filter 18 is formed on the semipermeable membrane 15. Further, a smoothing transparent insulating film 20 is formed on the color filter 18, and a plurality of transparent electrodes are formed on the smoothing transparent insulating film 20. This transparent electrode extends, for example, in a direction orthogonal to the segment transparent electrode group 4 and constitutes the common transparent electrode group 5. An alignment film 8 is formed on the common transparent electrode group 5 to be in contact with the liquid crystal layer 3.

  One end of the common transparent electrode group 5 extends to the area other than the display area and reaches the seal portion 14. One end of the common transparent electrode group 5 is connected to one end of the second wiring pattern 21 through the seal portion 14. Specifically, the conductive particles 13 are mixed in the seal portion 14, and the common transparent electrode group 5 and the second wiring pattern 21 are connected via the conductive particles 13.

  The transparent electrodes constituting the common transparent electrode group 5 are formed by depositing a transparent electrode material such as ITO by a thin film technique and then forming a predetermined pattern by photolithography. It is not necessary to use a transparent material in an area other than the display area, and a metal material such as aluminum, aluminum alloy, silver, or gold is laminated on the ITO film like the wiring pattern 20 of the segment side substrate 1. A multilayer structure may be used, or a metal layer formed of a metal material such as aluminum, an aluminum alloy, silver, or gold may be used.

  A retardation plate 11 and a polarizing plate 12 are formed on the display area on the outer surface side of the common substrate 2.

  In the display pixel region 6 formed by intersecting the segment transparent electrode group 4 and the common transparent electrode group 5 in the display region portion, a semi-transmissive film 15 for distinguishing between the reflective region and the transmissive region is formed. The semi-transmissive film 15 includes a metal reflective film 17 and a transparent insulating resin film 16 formed on the metal reflective film 17, and a through-hole 19 for passage is formed in the semi-transmissive film 15. ing.

  In the present invention, the metal reflection film 17 and the transparent insulating resin film 16 are formed so that their shapes are completely coincident with each other. The transmissive through hole 19 is formed at the center of each display pixel region 6. That is, each display pixel region 6 in the cross-sectional view shown in FIG. 3 has a semi-transmissive film 15 formed in the peripheral portion thereof. The semi-transmissive film 15 is formed across the interval between one display pixel region 6 and the adjacent display pixel region 6, and further across the adjacent display pixel region 6. That is, the metal reflection film 17 and the transparent insulating resin film 16 formed on the upper surface of the metal reflection film 17 are formed across the display pixel regions 6 adjacent to each other. In this manner, by forming over two adjacent display pixel areas, processing is performed as compared with the insulating film 51 and the metal reflection film 52 independently formed in the display pixel area as in the past. Since the shape of the object becomes large, the processing accuracy is improved.

  In the semi-transmissive film 15 having such a configuration, a region where the transparent insulating resin film 16 having the same planar shape as the metal reflective film 17 is formed on the metal reflective film 17 is a reflective region, and the metal reflective film The transmission through hole 19 in which the layer 17 and the transparent insulating resin film 16 are not formed becomes a transmission region.

  In addition, a color filter 18 is formed in the semi-transmissive film 15 corresponding to each display pixel region 6. In the color filter 18, an R (red) filter, a G (green) filter, and a B (blue) filter are formed independently for each pixel region. In FIG. 3, three types of filters are independently formed. However, a black light shielding filter may be interposed at the boundary portion, that is, the boundary portion of each display pixel 6.

In addition , a switching transistor as a switching unit may be provided in each display pixel region 6.

The seal member seal member 14 contains a seal resin as a main component and further contains conductive particles 13.

The sealing member 14 including the conductive particles 13 exhibits anisotropic conductive characteristics. Such a seal member 7 has two functions.

  One is for bonding the segment side substrate 1 and the common side substrate 2 to seal the liquid crystal layer 3 therein. The seal member 14 is formed in a frame shape in the outer peripheral region of the common side substrate 2 in accordance with the shape of the common side substrate 2 which is a substantially small substrate. Thus, by forming along the outer peripheral region of the common side substrate 2, it is not necessary to form a wiring pattern outside the seal member 14 in the lateral direction, which can contribute to downsizing of the liquid crystal display device. .

  The second function is to connect one end of the common transparent electrode group 5 of the common side substrate 2 to one end of the second wiring pattern 21 of the segment side substrate 1. The function is that the common transparent electrode group 5 is a part of the seal member 7 extending to the formation region of the seal member 7 and is formed on the segment side substrate 1 side, and the second wiring pattern in which one end is located in this portion. 21 is connected. That is, one end of the common transparent electrode group 5 formed on the common side substrate and one end of the second wiring pattern 21 formed on the segment side substrate 1 are made to correspond completely one-to-one, and there is an interval between adjacent patterns. It is important to specify the particle size and content of the conductive particles 13 so that conduction in the thickness direction is possible at the same time without short-circuiting in the planar direction.

The liquid crystal layer 3 is made of a liquid crystal material such as a twisted nematic liquid crystal or a cholesteric liquid crystal, and is formed by injecting a liquid crystal material into a region surrounded by the segment side substrate 1, the common side substrate 2 and the seal member 7. . A spacer material (not shown) for controlling the thickness of the liquid crystal layer 3 is mixed in the liquid crystal layer 3. This spacer material can be uniformly dispersed in the liquid crystal layer 3 as a result by spraying uniformly on at least the display area before and after applying the seal member 14 on one substrate.

  The liquid crystal molecules of the liquid crystal layer 3 have a liquid crystal material, its thickness, and a tilt angle and a twist angle defined by the alignment treatment of the alignment films 7 and 8 described above. The twist angle when an electric field for displaying on the liquid crystal layer 3 is not applied is, for example, 270 °. When a predetermined electric field is applied, the twist is eliminated, and the liquid crystal molecules are aligned in the thickness direction of the substrate, for example. To do.

The light passing through the liquid crystal layer 3 is blocked or allowed to pass through the polarizing plate and the retardation plates 9, 10, 11, and 12, and the display ON− A predetermined display is created in the entire display area by performing OFF control.

Backlight means The backlight means BL is disposed outside the liquid crystal display panel LP. The backlight BL includes a light guide plate 25 and a light source 26.

Reflective region and transmissive region A semi-transmissive film 15 that defines the reflective region and the transmissive region is formed in the display region of the common substrate 2. For example, the reflection region includes a metal reflection film 17 and a transparent insulating resin film 16, and light incident from the liquid crystal display screen side passes through the liquid crystal layer 3, the color filter 18, and the transparent insulating resin film 16 to reflect the metal. The light is reflected by the film 17 and further emitted from the liquid crystal display screen side through the transparent insulating resin film 16, the color filter 18, and the liquid crystal layer 3.

Further, the transmission region is a transmission through hole 19 of the semi-permeable membrane 15. The transmission through-hole 19 guides light emitted from the backlight means BL arranged on the back side of the liquid crystal display panel LP, and passes through the color filter 18 region having a thickness larger than that of the color filter 18 formed in the reflection region portion. Then, the light is emitted from the liquid crystal display screen side through the liquid crystal layer 3.

  The surface of the color filter 18 formed on the reflection region and the transmission region is substantially flattened. That is, in terms of the thickness of the color filter 18, the thickness of the color filter 18 is thinner than the transmission region by the thickness of the reflection region. Note that the thickness of the metal reflective film 17 and the transparent insulating resin film 16 is equal to the thickness of the color filter 18 deposited on the metal reflective film 17 and the thickness of the color filter 18 in the transmissive area. It is about twice the thickness of the filter 18.

  In the display pixel region, that is, in each of the R (red), G (green), and B (blue) regions of the color filter 18, the central portion of the display pixel region 6 is a transmissive region, and the display pixel The area around the area is a reflection area. The reflection area of one display pixel area 6 is connected to the reflection area of the adjacent display pixel area 6 in common. That is, a reflective region is formed between the display pixel regions.

Structure of Reflection Area In this reflection area, a metal reflection film 17 and a transparent insulating resin film 16 having the same shape as the metal reflection film 17 are deposited on the common side substrate 2. That is, the metal reflection film 17 and the transparent insulating resin film 16 are in a completely matched shape.

As a result, the transparent insulating resin film 16 having a predetermined thickness is formed on the reflective region in accordance with the shape of the metal reflective film 17. At the same time, a part of the metal reflection film 17 does not extend into the transmission through hole 19 which is a transmission region.

  As a result, the reflection characteristics are completely uniform in the reflection region, and the transmittance does not vary from the predetermined value in the transmission region. Further, the light reflected by the metal reflection film 17 passes through the color filter 18 before reaching the metal reflection film 17 and after being reflected twice. On the other hand, it does not pass through the color filter 18 once in the transmission region. However, since the thickness of the color filter 18 is about twice as thick in the transmissive region, there is no chromaticity variation in the reflective region and the transmissive region as a result. Variations are also eliminated.

  Therefore, by completely matching the formation positions of the metal reflection film 17 and the transparent insulating resin film 16, a liquid crystal display device having no reflectance variation, reflection chromaticity variation, transmittance variation, and transmission chromaticity variation is provided. Become.

It is another object of the present invention to provide a method for manufacturing a common side substrate, and a method for manufacturing a liquid crystal display device capable of completely matching the formation positions of the metal reflection film and the insulating film. The manufacturing method will be described in detail with reference to FIG. FIG. 4 shows only the main process.

  First, a substrate 40 to be the common side substrate 1 is prepared. This glass substrate is a large substrate that can be obtained in large numbers.

  Next, as shown in FIG. 4A, the metal reflection film 17 is formed in the display area of the substrate 40. Specifically, examples of the metal thin film that becomes the metal reflection film 17 on the substrate 40 include an aluminum alloy such as aluminum and AlNd, or a silver alloy such as silver, AgPd, AgPdCu, and AgCuAu. The thickness of the metal thin film is, for example, 0.05 to 0.5 μm. Then, the metal thin film is etched into a predetermined shape by a photolithography technique to form an independent metal reflection film 17. The metal reflection film 17 is formed at a position straddling the adjacent display pixel region 6.

Next, as shown in FIG. 4B, a transparent resin film 41 to be the transparent insulating resin film 16 is formed on the independent metal reflection film 17. The transparent resin film 41 is an acrylic organic resin material containing a light scattering member such as an inorganic filler of SiO ₂ or TiO ₂ and includes a positive-type curable material. The transparent resin film 41 has a thickness of about 0.5 to 3.0 μm.

  Next, as shown in FIG. 4C, an exposure process (250 mj (i line)) is performed from the back side of the substrate 40. By this exposure process, the metal reflective film 17 becomes a mask for the exposure process, and a part of the transparent resin film 41, that is, the transparent resin film 41 present in the space between the adjacent metal reflective films 17 is exposed. A solubilized portion 42 is formed.

Next, as shown in FIG. 4D, the solubilized portion 42 of the transparent resin film 41 is developed from the transparent resin film 41 side. As a result, a transmission region is formed on the substrate 40 at a gap between the reflective region composed of the metal reflective film 17 and the transparent insulating resin film 16 and the adjacent metal reflective film 17.

  As described above, since the transparent resin film 41 is developed using the metal reflection film 17 as a photomask, the metal reflection film 17 and the transparent insulating resin film 16 can be formed in the same shape, and the inside of the transmission through-hole 19 can be formed. In addition, no part of the metal reflection film 17 remains.

As another manufacturing method in the steps of FIGS. 4 (a) to 4 (d), a metal thin film is formed on the entire surface of a glass substrate, a negative photosensitive transparent resin is applied, and a negative photosensitive is obtained by exposure and development. There is a method in which a transparent insulating resin film 16 is formed by patterning a conductive resin, and a metal film exposed by patterning the resin is etched using an etching solution in which phosphoric acid, nitric acid, and acetic acid are mixed to form a metal reflective film 17.

  Next, as shown in FIG. 4E, a color filter 18 corresponding to the display pixel region 6 is formed. The color filter 18 is a pigment dispersion method, that is, a photosensitive resist previously prepared by pigments (red, green, and blue) is applied so as to straddle the adjacent transparent insulating resin films 16 to display pixel regions 6. It is formed by a photolithography technique so as to correspond to the above. Thereby, for example, one color filter out of three colors can be formed. By repeating this a total of three times, a color filter 18 made of RGB is formed. If necessary, a black shading filter may be formed in the space between the display pixel regions 6.

  Next, as shown in FIG. 4F, a smoothing transparent insulating film 20 made of an acrylic resin is formed on the color filter 18.

Thereafter, as shown in FIG. 4G, the common transparent electrode group 5 made of ITO is formed on the smoothing transparent insulating film 20.

On the common transparent electrode group 5, an alignment film made of polyimide resin rubbed in a certain direction is sequentially laminated. An insulating film made of resin, SiO ₂ or the like may be interposed between the transparent electrode group and the alignment film.

  Further, with respect to the other substrate, the segment side substrate 1, a plurality of segment transparent electrode groups 4 made of ITO arranged in stripes in parallel and an alignment film 7 made of polyimide resin rubbed in a certain direction are sequentially laminated on the inner surface of the substrate 1. Has been.

  Then, the seal portion 14 is formed on either of the segment side substrate 1 and the common side substrate 2 having such a configuration, and at the same time, spacers are dispersed, for example, from chiral nematic liquid crystal twisted at an angle of 200 ° to 260 °. It sticks together by the sealing member 14 through the liquid crystal material which becomes.

  Further, a phase difference plate 9 made of polycarbonate or the like and an iodine polarizing plate 10 are sequentially formed outside the segment side substrate 1. Further, a phase difference plate 11 made of polycarbonate or the like and an iodine polarizing plate 12 are sequentially formed outside the common side substrate 2. About these arrangement | positioning, it carries out by apply | coating the adhesive material which consists of an acryl-type material.

  Then, on the back side (the surface opposite to the liquid crystal display surface) side of the common side substrate 2, the backlight unit BL including the light source 26 and the light guide plate 15 is disposed.

  In the manufacturing method described above, when forming the metal reflective film 17 and the metal transparent insulating resin film 16 that distinguish between the reflective area and the transmissive area and control the film thickness of the color filter 18, the metal reflective film 17 constituting the metal reflective film 17 is formed. Since the transparent insulating resin film 16 is formed by developing with the photomask as a photomask, not only can the process be shortened, but the transparent insulating resin film 16 can be simply formed on the metal reflecting film 17 in the same shape as the metal reflecting film 17. Can be formed. At the same time, the transmission through hole 19 can be reliably formed.

  In addition, since the metal reflection film 17 and the transparent insulating resin film 16 that define the reflection area are formed across the adjacent display pixel area 6, the reflection area positioned around the display pixel area 6 is As a result, the shape becomes large and processing becomes easy, and the accuracy of patterning during etching and development is improved.

  As in the present invention, a liquid crystal display device using a common substrate 2 in which a transparent insulating resin film 16 is formed as a photomask using a metal reflective film defining a reflective region, a conventional insulating film 51 and a metal reflective film 52, And a liquid crystal display device using a common substrate formed in separate steps, transmittance in the transmissive region, transmissive color (R, G, B), transmissive color purity (ΔS), reflectance in the reflective region The variation in reflection color (R, G, B) and reflection color purity (ΔS) was examined.

  In addition, the width of the reflection region appearing in the cross-sectional view and the transmission region (the width of the slit between the metal reflection films were set to 15 μm, respectively.

  In the conventional liquid crystal display device, a displacement between the insulating film 51 and the metal reflection film 52 for controlling the film thickness of the color filter 54, that is, a displacement of the slit between the metal reflection films 52 occurs. The amount of positional deviation varies in the range of ˜5 μm.

  As a result, variation in transmittance, transmission color (R, G, B), transmission color purity (ΔS), reflectance, reflection color (R, G, B), and reflection color purity (ΔS) of the liquid crystal display device. For example, the transmittance varies in the range of 1.94% to 2.07%, and the transmission color purity ΔS varies in the range of 20.5 to 25.3 and 23.4%. The rate varies in the range of 28.7% to 29.4%, and the reflected color purity ΔS varies in the range of 13.9 to 15.1.

  On the other hand, in the liquid crystal display device of the present invention, since the displacement between the insulating film defining the reflective region and the metal reflective film does not occur at all, the transmittance and transmission color (R, G, B) of the liquid crystal display device , Transmission color purity (ΔS), reflectance, reflection color (R, G, B), and reflection color purity (ΔS) do not vary.

It is a top view of the liquid crystal display device of this invention. It is sectional drawing of the AA line of FIG. It is an expanded sectional view of the principal part of this invention. (A)-(g) is sectional drawing of the principal part process of the manufacturing method of the liquid crystal display device of this invention. It is sectional drawing of the principal part of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Segment side substrate 2 ... Common side substrate 3 ... Liquid crystal layer 4 ... Segment transparent electrode group 5 ... Common transparent electrode group 6 ... Display pixel area 14 ... Seal part 15 ..Transparent film 16 ..Transparent insulating resin film 17 ..Metal reflection film 18 ..Color filter 19 ..Transmission through-hole

Claims (4)

A rectangular first substrate formed by sequentially laminating a first transparent electrode group composed of a plurality of transparent electrodes extending in a first direction and an alignment film;
A rectangular second substrate formed by sequentially stacking a second transparent electrode group composed of a plurality of transparent electrodes extending in a second direction orthogonal to the first direction and an alignment film;
The first and second transparent electrode groups are opposed to each other so as to form display pixels orthogonal to each other, and are bonded together by a substantially rectangular sealing member, and the sealing member is filled with liquid crystal and the second substrate A liquid crystal display device in which a backlight means is disposed on the back side main surface of
A metal reflective film and a transparent insulating resin film are formed on the second substrate so as to straddle at least the display pixel region, and a part of the adjacent transparent insulating resin film is straddled. A color filter is deposited on the pixel region of the second substrate, a smoothing transparent insulating film is formed on the color filter and the transparent insulating resin film, and a second transparent electrode group is formed on the smoothing transparent insulating film. Are sequentially formed.   The liquid crystal display device according to claim 1, wherein the transparent insulating resin film is mixed with light scattering particles. A rectangular first substrate formed by sequentially laminating a first transparent electrode group composed of a plurality of transparent electrodes extending in a first direction and an alignment film;
A second substrate formed by sequentially laminating a second transparent electrode group composed of a plurality of transparent electrodes extending in a second direction orthogonal to the first direction and an alignment film;
The first and second transparent electrode groups are opposed to each other so as to form display pixels orthogonal to each other, and bonded together with a substantially rectangular seal member, and the seal member is filled with liquid crystal and the second substrate A method of manufacturing a liquid crystal display device in which backlight means is arranged on the back side main surface,
The second substrate is
A first step of depositing an independent metal reflective film on the second substrate with at least the display pixel region in between;
A second step of depositing and forming a positive-type photocurable transparent resin film to be an insulating transparent resin film on the metal reflective film;
A third step in which the transparent resin film is exposed from the metal reflective film side to photodecompose, and the transparent resin film is developed from the transparent resin film side;
A fourth step of depositing and forming a color filter corresponding to the pixel region so as to straddle the plurality of transparent resin films;
A fifth step of forming a transparent insulating film for smoothing on the color filter, and a second transparent electrode group on the transparent insulating film for smoothing;
A method of manufacturing a liquid crystal display device, wherein   4. The method of manufacturing a transflective liquid crystal display device according to claim 3, wherein the transparent resin film is mixed with light scattering particles.

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