JPH11231318A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the brightness and the whiteness of a liquid crystal display device with respect to a promising reflection liquid crystal display device which uses an external light source to reduce the power consumption of the liquid crystal display device. SOLUTION: With respect to the liquid crystal; display device consisting of upper and lower substrates 1 and 11 facing each other with a prescribed gap between them and liquid crystal 16 enclosed between them, the upper substrate 1 is arranged on the observer side, and at least a diffusion plate 20 is provided on the lower substrate 11 or on the lower face side of the lower substrate 11, and a lower polarizing plate 22 is provided on the lower face side of the diffusion plate 20, and further, at least either a semitransparent reflection plate 25a or a reflection plate 25b is provided. The white diffusion plate 22 doesn't have any phase difference and doesn't have any transmittance difference for each wavelength in the visible light area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device in which a signal electrode on an upper substrate is bonded to a counter electrode on a lower substrate with a predetermined gap therebetween, a liquid crystal is sealed, and a predetermined signal is applied to each electrode. When the external environment where the liquid crystal display device is used is bright when the display is performed by utilizing the optical change of the liquid crystal display device, and the reflection type liquid crystal display device is used by the reflection plate or the semi-transmissive reflection plate, and the external environment is dark. The present invention relates to a transflective (semi-reflective) liquid crystal display device used as a transmissive type.

[0002]

2. Description of the Related Art In recent years, the display capacity of a liquid crystal display device using a liquid crystal panel has been steadily increasing. The structure of the liquid crystal display device includes a passive matrix type in which a display electrode of a liquid crystal pixel is directly connected to a signal electrode provided on an upper substrate, and an active matrix type in which a switching element is provided between the signal electrode and the display electrode. Further, a counter electrode is provided via a liquid crystal so as to face the display electrode on the upper substrate, a plurality of signal electrodes and a plurality of counter electrodes are arranged in a matrix, and the signal electrode and the data electrode connected to the counter electrode are arranged. It has a structure in which a predetermined signal is applied from an external circuit.

[0005] The means of using multiplex driving in a liquid crystal display device having a simple matrix configuration (passive matrix type) causes a decrease in contrast or a reduction in response speed as time division is increased, so that about 200 scanning lines are required. If it does, it will be difficult to obtain sufficient contrast.

Therefore, in order to eliminate such a defect, an active matrix liquid crystal display panel in which switching elements are provided in individual pixels has been adopted.

The active matrix liquid crystal display panel is roughly classified into a three-terminal switching element using a thin film transistor and a two-terminal switching element using a non-linear resistance element. Of these, the structure and manufacturing method are simple and relatively low-temperature
Two-terminal switching elements are excellent.

[0006] As this two-terminal switching element,
Diode type, varistor type, TFD type and the like have been developed.

[0007] Among them, the TFD type has a feature that the structure is particularly simple and the manufacturing process is short.

Further, since the liquid crystal display device is not a self-luminous display device, an external light source is used to perform display by utilizing a change in external light by an optical change of the liquid crystal. Therefore, the positional relationship between the observer, the liquid crystal display device, and the light source is roughly classified into two types. The first is a so-called reflection type liquid crystal display device in which the external light source (main light source) and the observer are on the same plane with respect to the liquid crystal display device, and the second is the arrangement of the observer-liquid crystal display device-light source unit. , A so-called transmission type liquid crystal display device. For the purpose of reducing power consumption, which is an advantage of a liquid crystal display device, a reflection type liquid crystal display device that does not require a light source and uses an external light source around the liquid crystal display device is effective.

Further, when the use environment of the liquid crystal display device is bright, the liquid crystal display device is a reflection type liquid crystal display device using an external light source. When the use environment is dark, the light source section of the liquid crystal display device is turned on. There is a transflective (reflective) liquid crystal display device used as a transmissive liquid crystal display device. Since a transflective liquid crystal display device is basically used as a reflective liquid crystal display device, power consumption can be reduced as compared with a transmissive liquid crystal display device. Therefore, a reflective liquid crystal display device, or
The transflective liquid crystal display device is a display mode that is extremely important for application to portable information devices.

A conventional example of a transflective liquid crystal display device having a two-terminal switching element as a switching element between a signal electrode and a display electrode will be described below with reference to the drawings.

FIG. 13 is a plan view showing the configuration of a conventional transflective liquid crystal display device using a two-terminal switching element. FIG. 14 is a sectional view showing a section taken along line AA in the plan view of FIG. Hereinafter, FIG.
The prior art will be described with reference to FIGS. 3 and 14 alternately.

On a lower substrate 11 made of a transparent substrate, a wiring electrode 17 made of a tantalum (Ta) film and a lower electrode 4 formed integrally with the wiring electrode 17 are provided. On the wiring electrode 17 and the lower electrode 4, tantalum oxide (Ta2 O5
) Is provided.

Further, an upper electrode 6 overlapping the nonlinear resistance layer 15 on the lower electrode 4 and a display electrode 9 integrally formed with the upper electrode 6 are provided by an indium tin oxide (ITO) film. The upper electrode 6, the nonlinear resistance layer 15, and the lower electrode 4
Thus, the two-terminal switching element 5 is configured.

When the lower substrate 11 described above is used as a liquid crystal display device, the upper substrate 1 made of a transparent substrate is provided so as to face the lower substrate 11. On the upper substrate 1, a signal electrode 2 made of an indium tin oxide (ITO) film made of a transparent conductive film so as to face the display electrode 9.
Having. Further, a data electrode (not shown) for applying a signal of an external circuit is connected to the signal electrode 2.

Further, alignment films 3 and 13 are provided on the upper substrate 1 and the lower substrate 11 as processing layers for regularly aligning molecules of the liquid crystal 16, respectively. Further, the upper substrate 1 and the lower substrate 11 are opposed to each other with a predetermined gap by a spacer (not shown), and a liquid crystal 16 is sealed between the upper substrate 1 and the lower substrate 11.

Further, a first polarizing plate 21 is provided on the upper surface of the upper substrate 1, and a second polarizing plate 2 is provided on the lower surface of the lower substrate 11.
2 Further, a semi-transmissive reflection plate 2 made of a thin film metal
5a, and further includes an electroluminescent (EL) element as the light source unit 31. Since the liquid crystal 16 does not emit light by itself, when the external environment (external light source: not shown) is bright, display is performed by using the reflection characteristics of the semi-transmissive reflector 25a. An electroluminescent (EL) element 31 is turned on to perform display using the transmissivity of the semi-transmissive reflector 25a.

[0017]

Here, in the conventional liquid crystal display device, although the contrast ratio is good, the brightness,
In particular, there is no whiteness, and the display performance is not sufficient. This is largely due to coloring that occurs because the transmittance of the polarizing plate is not uniform in the visible light region. Further, when a color filter is provided, the brightness is further reduced.

Further, in the case where irregularities are provided on the reflecting plate,
Since the control of the surface shape and the improvement of the reflectance are required, the formation of the reflector becomes complicated. Further, in a white diffuser having a specific polarization, the alignment of the diffusion direction and the polarization direction having directivity due to the surface shape occurs, and it becomes necessary to prepare a diffusion plate depending on the polarization direction of the liquid crystal display device. Versatility deteriorates.

One of the optical axes is a transmission polarization axis, and the orthogonal optical axis is a diffusion plate between the lower substrate and the reflection type deflection plate in the case of a reflection type deflection plate having a reflection polarization axis. Although there is a configuration to provide, the absorption layer is required on the lower side of the reflective deflecting plate, the case where an external light source is used, and the case where the light source section below the reflective deflecting plate is used are the same. When driving is performed, the white display unit when using an external light source is used, and when using a light source unit, an image that becomes a black display unit is inverted in brightness.

An object of the present invention is to solve the above-mentioned problems and to provide a structure for achieving a translucent liquid crystal display device having a bright and white tint.

[0021]

In order to achieve the above object, the liquid crystal display of the present invention employs the following configuration.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate and at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval. The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. Having a polarizing plate, a diffusion plate that scatters straight light, a polarizing plate, and a semi-transmissive reflector are arranged in this order on the lower side of the lower substrate, and further, a light source unit is provided below the semi-transmissive reflector. It is characterized by.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate, has at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval; The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. It has a polarizing plate, and on the lower side of the lower substrate, a diffusion plate, a polarizing plate, a light guide plate, and a reflecting plate that scatter straight light are arranged in this order, and further,
A light source unit facing a part of the light guide plate.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate and at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval, The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. It has a polarizing plate, a diffusion plate for scattering straight light, a polarizing plate, and a light source section below the lower substrate, and the light source section further includes at least a fluorescent tube and a reflecting plate.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate and at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval, The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. It has a polarizing plate, a diffusion plate and a polarizing plate that scatter straight light on the lower side of the lower substrate, and a light source unit that includes an upper electrode made of a transparent conductive film, a light emitting layer, and a lower electrode. The lower electrode is a reflection electrode that also serves as a reflection plate.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate and at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval; The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. It has a polarizing plate, and has a diffusion plate, a polarizing plate, and a light source portion that scatter straight light on the lower side of the lower substrate, and further, the light source portion has at least an upper electrode, a light emitting layer, and a lower electrode. The light emitting layer is an organic electroluminescent layer.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate and at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval. The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. It has a polarizing plate, and has a diffusion plate, a polarizing plate, and a light source unit which scatter straight light on the lower side of the lower substrate, and further, the light source unit has at least an upper electrode and a light emitting layer made of a transparent conductive film. A lower electrode, wherein the light emitting layer is an organic electroluminescent layer, and the lower electrode is a reflective electrode made of a silver film.

The liquid crystal display device of the present invention has at least a signal electrode on an upper substrate and at least a counter electrode on a lower substrate, and opposes the upper substrate and the lower substrate at a predetermined interval. The signal electrode and the counter electrode face each other to form a pixel portion, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and the upper substrate is disposed above the upper substrate. It has a polarizing plate, and has a diffusion plate, a polarizing plate, a semi-transmissive reflecting plate, and a light source section on the lower side of the lower substrate, which further scatters straight light, and the light source section has an upper electrode made of a transparent conductive film. And a light emitting layer and a lower electrode.

The liquid crystal display of the present invention is characterized in that a lens film for limiting the viewing angle is provided between the polarizing plate and the light source or between the transflective plate and the light source.

The liquid crystal display device according to the present invention is characterized in that the diffusion plate has substantially the same transmittance for visible light. <Action>

On the lower side of the lower substrate constituting the liquid crystal display device,
A diffusion plate, a polarizing plate, a transflective plate, and a light source unit are arranged. As described above, the coloring of the reflection plate can be converted by the scattering properties and the color of the diffusion plate. That is, the light from the upper substrate side is partially scattered and reflected by the diffusion plate and emitted to the observer side on the upper substrate side. Further, the light transmitted through the diffuser and the polarizer is reflected by the reflector and scattered again by the diffuser, corrects the coloring of the polarizer, and is emitted toward the observer. In particular, by using a white diffuser having substantially the same transmission and scattering characteristics in the visible light region as the diffuser, the coloring of the polarizing plate is corrected to white.

Further, by making the front or back surface of the light source section provided below the semi-transmissive reflector have reflective characteristics, the light transmitted through the semi-transmissive reflector can be effectively emitted to the observer side. it can. Further, by providing a light source unit including a transparent conductive film, a light emitting layer, and a reflective electrode on the back surface of the diffusion plate and the polarizing plate, the reflection characteristics and light emission of the light emitting layer when an external light source is used, that is, of the light source unit, Brightness at the time of lighting can be improved.

In addition, an external light source is provided by guiding light to the back surface of a diffusion plate via a light guide plate without providing a light emitting portion directly below the lower substrate, and further providing a reflection plate below the light guide plate. In the case of using the light emitting device, it is possible to ensure good reflection characteristics and brightness by using a diffusion plate, a polarizing plate, a light guide plate, and a reflection plate. further,
When the light emitting unit is turned on, a bright display can be performed by the light guide plate, the reflection plate, and the diffusion plate. In addition, since the scattering property of the light guide plate can be sufficiently achieved by the diffusion plate as compared with the related art, the transmittance and the uniformity of the light guide can be improved.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> The structure of a liquid crystal display device in the best mode for carrying out the liquid crystal display device of the present invention will be described below with reference to the drawings.

The structure of the liquid crystal display device according to the first embodiment of the present invention will be described below with reference to FIGS. In the first embodiment of the present invention, an application example to a passive matrix type liquid crystal display device in which a signal electrode and a counter electrode are provided without using a switching element will be described. FIG. 1 is a plan view enlarging a part of the liquid crystal display device according to the first embodiment of the present invention. FIG. 2 is a sectional view showing a section taken along line BB of the plan view of FIG. Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 and 2 alternately.

A signal electrode 2 made of an indium tin oxide film is provided on an upper substrate 1 made of a glass substrate. The signal electrode 2 has a stripe shape to serve also as the display electrode 9.

When the upper substrate 1 is used for a liquid crystal display device, a lower substrate 11 made of a glass substrate facing the upper substrate 1 is provided. On the lower substrate 11, a counter electrode 12 made of an indium tin oxide (ITO) film is provided so as to face the display electrode 9 provided on the upper substrate 1.
Further, the counter electrode 12 is connected to a data electrode (not shown) for applying a signal of an external circuit.

Further, the upper substrate 1 and the lower substrate 11 have alignment films 3 and 13 as processing layers for regularly arranging the molecules of the liquid crystal 16, respectively. Further, the upper substrate 1 and the lower substrate 11 are opposed to each other with a predetermined gap dimension by a spacer (not shown), fixed by a seal portion (not shown), and the liquid crystal 16 is placed between the upper substrate 1 and the lower substrate 11. Is enclosed. Further, a so-called reflection type liquid crystal display device in which the upper substrate 1 is arranged in the direction of the observer and the external light source 30 is arranged on the same side as the observer. Further, an upper polarizing plate 21 is provided on an upper surface (upper side) of the upper substrate 1, and a lower polarizing plate 22 is provided on a lower surface (lower side) of the lower substrate 11.

Further, in the first embodiment, a diffusion plate 20 for scattering linear light is provided between the lower substrate 11 and the lower polarizing plate 22. This diffusion plate 20 kneads acrylic resin with polystyrene beads of 1 μm and 3 μm,
It is formed by processing into a thin film. Further, a transflective plate 25a is provided on the lower surface (lower side) of the lower polarizing plate 22, and the light source unit 3 is provided on the lower surface of the transflective plate 25a.
One.

In the liquid crystal display device, in the external environment, that is, when the external light source 30 is bright, the light from the external light source 30 is transmitted to the upper polarizing plate 21, the upper substrate 1, the signal electrode 2, the liquid crystal 13, the counter electrode 1
2, transmitting through the lower substrate 11, the diffusion plate 20, and the lower polarizing plate 22,
The display is performed by utilizing the reflection of the transflective plate 25a and the surface of the light source unit 31. In this case, since the transmittance of the lower polarizing plate 22 is colored in the visible light region, in the conventional example in which the diffusion plate 20 is not used, the display is colored and white display cannot be performed. However, between the lower substrate 11 and the lower polarizer 22 shown in the present embodiment, the diffusion plate 20, particularly the transmittance in the visible light region,
By using a white diffuser with almost the same reflectance,
Coloring of the lower polarizing plate 22 and coloring of the upper polarizing plate 23 can be prevented.

When the external light source 30 is dark, the liquid crystal 13 generally does not emit light, so that illumination (light source) is required. In the present embodiment, a light source unit composed of an electroluminescent (EL) element is arranged on the lower surface of the transflective plate 25a. Therefore, even when the external environment is dark, the light from the light source unit is transmitted through the transflective plate 25a,
The light passes through the lower polarizing plate 22 and is diffused by the diffusion plate 20 to a predetermined scattering angle.
The white light is reflected by the surface of the light source unit 31 and the light is scattered on the surface side of the lower substrate 11, so that the white light is emitted to the lower substrate 11. Therefore, bright and white display is possible.

Next, the characteristics of the white diffusion plate 20 will be described. FIG. 3 is a diagram showing the relationship between the reflectance of the liquid crystal display device according to the first embodiment and the characteristics of the applied voltage (V). The vertical axis is the reflectance, and the horizontal axis is the voltage applied to the liquid crystal. A characteristic utilizing an embodiment of the present invention is shown by curve X. For comparison, the characteristic of the conventional example is shown by a curve Y. Compared with the conventional example, the reflectance is first improved by surface reflection and diffuse reflection of the diffusion plate 20. Furthermore, by making the transflective plate 25a a mirror surface and making the diffusing plate 20 have diffusivity, it is possible to improve the reflection characteristics of the transflective plate 25a. As described above, by using the present invention, the reflectance can be increased as compared with the conventional example regardless of the voltage applied to the liquid crystal 13. It is very effective especially when used as a reflection type liquid crystal display device in which reflection characteristics are important.

FIG. 4 is a diagram showing the wavelength dependence of the reflectance of the liquid crystal display device according to the first embodiment. The vertical axis is the reflectance, and the horizontal axis is the wavelength (unit: nm). A curve L is a graph showing characteristics of the present invention, and a curve M is a graph showing a conventional example. Hereinafter, the difference between the case where the diffusion plate 20 of the present invention is used and the conventional characteristics using the alternation of FIGS. 3 and 4 will be described. Curve X in FIG. 3 shows the characteristics of the present embodiment,
A curve Y is a diagram showing characteristics when the structure shown in the conventional example is used. The curve Y has sufficient contrast, but lacks brightness, has wavelength dependence as shown by the curve M in FIG. 4, and has a white display ranging from green to blue. Therefore, the display is not dark and white. On the other hand, the characteristic of the present embodiment using the diffusion plate 20 is that the contrast slightly decreases as shown by the curve X in FIG. 3 and the curve L in FIG. The improvement and the improvement in whiteness are clearly improved. In the case of a liquid crystal display device,
Brightness and whiteness are prioritized over contrast, and since the contrast is 5: 1, the recognizability of a newspaper is as good as that of a newspaper. Therefore, it can be said that a decrease in contrast by the diffusion plate 20 has a smaller effect than an improvement in brightness and whiteness.

When the light source unit 31 is turned on, the light from the light source unit 31 can be displayed by the lower polarizing plate 22, the liquid crystal 13, and the upper polarizing plate 21 in the same manner as in the case where the light is used as a reflection type. Become. That is, the light of the light source unit 31 has a predetermined scattering angle by the diffusion plate 20,
0 on the light source unit 31 side and the scattering on the lower substrate 11 side,
The color of the lower polarizing plate 22 can be whitened and emitted to the observer side. In the case of using a reflection type polarizing plate made by Sumitomo 3M, which is similar to the configuration of the present invention, the phenomenon that the brightness is inverted between the reflection and transmission displays occurs. In both displays, the bright display is a bright display, and the dark display can be a dark display. Therefore, the present invention is also very effective because it is possible to prevent the color change of the reflection type and the transmission type display by the color display.

Further, the polarizing plate to be used can be the same as the conventional one, and the contrast can be improved and the cost can be reduced. In addition, the transmittance of the upper polarizing plate 21 and that of the lower polarizing plate 22 should preferably be the same in the visible light region as much as possible, so that the effects of the present invention can be more effective.

Further, the diffusing plate 20 does not need optical phase difference and polarization, but only needs scattering and high transmittance by beads having a plurality of particle diameters. Therefore, since it is not necessary to carry out a stretching treatment in a specific direction or to include a substance having optical anisotropy, it can be easily produced at low cost.

<Second Embodiment> Next, a second embodiment of the present invention will be described.
The configuration of the liquid crystal display device according to the embodiment will be described with reference to FIG. The second embodiment of the present invention relates to a structure having a cold cathode tube and a reflecting mirror in a light source unit, a light guide plate on a lower surface of a lower substrate, and a reflector plate on a lower surface of the light guide plate. Things. FIG. 5 is a cross-sectional view of a portion corresponding to line BB of the liquid crystal display device according to the first embodiment of the present invention. Hereinafter, a second embodiment of the present invention will be described with reference to FIG.

The second embodiment has substantially the same structure as the first embodiment, and the same components are described using the same symbols. First, a signal electrode 2 and an alignment film 3 are provided on the upper substrate 1, and a counter electrode 12 and an alignment film 13 are provided on a lower substrate 11 facing the upper substrate 1. Upper substrate 1
The lower substrate 11 is hermetically sealed by a seal portion 8 and a sealing portion (not shown), and a liquid crystal 16 is sealed therein.

Further, the lower substrate 1 is provided on the lower surface of the lower substrate 11.
1 and a diffusion plate 20 and a lower polarizing plate 22 facing each other with a slight gap. The difference between the second embodiment and the first embodiment is that the light source unit is disposed between the reflection plate 25b and the lower polarizing plate 22, and the light source unit is provided around the lower substrate 11, that is, the seal. A configuration including a cold cathode tube 32 provided in the vicinity of the unit 8, a reflecting mirror 33, a light guide plate 19 facing the lower surface of the lower substrate 11, and a reflector 25 b arranged on the lower surface of the light guide plate 19 is adopted. The light guide plate is made of a transparent acrylic resin or an epoxy resin, and has good transmittance. Furthermore, since there is no phase difference, even if a light guide plate is provided between the lower polarizing plate 22 and the reflecting plate 25b, display quality is rarely reduced.

Further, unlike the first embodiment, the reflecting plate 25b is different from the first embodiment in that the light source portion facing the lower substrate 11 is transparent.
Since the reflecting plate can be provided on the lower surface of the light source unit, the reflecting plate 25b can give priority to the reflectance. Further, even when the light source unit is turned on, bright display is possible because there is no loss of light due to the transflective plate.

That is, when used as a reflection type, the light loss of the light guide plate 19 is small, and
Can give priority to the reflectance, and display bright and white. Further, particularly in the case of transmission, the transflective plate 25 is used.
Bright display is possible by the light guide plate 19 and the reflection plate 25b which have good transmittance as compared with the case of FIG.

<Third Embodiment> Next, a third embodiment of the present invention will be described.
The configuration of the liquid crystal display device according to the embodiment will be described with reference to FIG. In the third embodiment of the present invention, the light source unit includes a cold cathode tube and a reflecting mirror, and the cold cathode tube is disposed on the lower surface of the lower polarizing plate. Further, a reflection plate is provided on the lower surface of the cold cathode tube. FIG. 6 is a cross-sectional view of a portion corresponding to line BB of the liquid crystal display device according to the first embodiment of the present invention. Hereinafter, a third embodiment of the present invention will be described with reference to FIG.

The third embodiment has substantially the same structure as the first embodiment, and the same components are described using the same symbols. First, a signal electrode 2 and an alignment film 3 are provided on the upper substrate 1, and a counter electrode 12 and an alignment film 13 are provided on a lower substrate 11 facing the upper substrate 1. Upper substrate 1
The lower substrate 11 is hermetically sealed by a sealing portion and a sealing portion (not shown), and a liquid crystal 16 is sealed therein.

Further, on the lower surface of the lower substrate 11, the lower substrate 1
1 and a diffusion plate 20 and a lower polarizing plate 22 facing each other with a slight gap. The difference between the third embodiment and the first embodiment is that the light source unit is disposed between the reflector 25b and the lower polarizing plate 22, and the light source unit is provided on the lower surface of the lower polarizing plate 22. The point is that a configuration including a cathode tube 32 and a reflection plate 25b arranged on the lower surface of the cold cathode tube 32 is adopted. The diameter of the cold-cathode tube 32 is 1 mm, and the diffusion plate 20 is used to prevent the cold-cathode tube 32 from being a shadow in the case of a reflective or transmissive display.

In the third embodiment, similarly to the second embodiment, the reflecting plate 25b is different from the first embodiment in that the light source is transparent and the reflecting plate 25b is located on the lower surface of the light source. Therefore, the reflection plate 25b can give priority to the reflectance. Further, even when the light source unit is turned on, bright display is possible because there is no loss of light due to the transflective plate.

That is, in the case of using as a reflection type, only the portion of the cold cathode tube 32 is slightly shaded, and the other portions can use light from an external light source very effectively. In the case of the transmission type, only the uniformity of light emission of the cold cathode tube 32 needs to be considered. The influence of the reflection type and transmission type cold cathode tubes 32 can be considerably improved by the diffusion plate 20 provided on the upper surface of the lower polarizing plate 22.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described.
The configuration of the liquid crystal display device according to the embodiment will be described with reference to FIG. In the fourth embodiment of the present invention, the light source unit has an organic electroluminescent (EL) layer. A transparent conductive film is provided on the lower substrate side of the organic electroluminescent (EL) layer, and a lower electrode serving also as a reflector is provided on the opposite surface. FIG. 7 is a cross-sectional view of a portion corresponding to line BB of the liquid crystal display device according to the first embodiment of the present invention. Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.

The fourth embodiment has substantially the same structure as the first embodiment, and the same components are described using the same symbols. First, a signal electrode 2 and an alignment film 3 are provided on the upper substrate 1, and a counter electrode 12 and an alignment film 13 are provided on a lower substrate 11 facing the upper substrate 1. Upper substrate 1
The lower substrate 11 is hermetically sealed by a sealing portion and a sealing portion (not shown), and a liquid crystal 16 is sealed therein.

Further, on the lower surface of the lower substrate 11, the lower substrate 1
1 and a diffusion plate 20 and a lower polarizing plate 22 bonded to each other. The feature of the fourth embodiment resides in that an organic electroluminescent (EL) layer 38 is used as a light source unit. The organic electroluminescent (EL) 38 has high transmittance and further functions as a surface light source. Therefore, it can be used for the arrangement facing the lower polarizing plate 22.

The light source section includes a protective layer 36 made of polyethyl terephthalate (PET) and an upper electrode 37 made of an indium tin oxide film (ITO film) from the lower polarizing plate 22 side.
And a lower electrode 39 made of a silver film and a substrate 40 made of PET. The organic electroluminescent (EL) layer 38
It is formed by a vapor deposition method. The upper and lower PET films are sealed by a seal portion (not shown) to prevent air and humidity from entering the silver film and the organic electroluminescent (EL) 38.

In the fourth embodiment, the light emitting layer (electroluminescent (EL) layer 38) of the light source section can be made transparent. In addition, electroluminescent (E
L) Layer 38 has electroluminescent (E)
L) An electrode is necessary to allow a current to flow through the layer 38, and the lower electrode 39 is an electrode having reflective characteristics and can be used as a reflector in order to extract light emission effectively. The upper electrode 37 is a transparent electrode in order to effectively emit light emitted from the electroluminescent (EL) layer 38 and reflected light from the lower electrode 39.

When used as a reflection type, the diffusion plate 2
Light transmitted through the organic electroluminescent (E)
L) The light is transmitted through the layer 38, reflected by the lower electrode 39, emitted again to the observer side, and displayed. The diffusion plate 20 allows the electroluminescent (EL) 398 to be colored and the electrodes 37,
39 shapes can be shielded.

In the case of transmission, complete whitening by the diffusion plate 20 depends on the emission wavelength of the organic electroluminescent (EL) layer 38, but by selecting a material for the emission layer, , Can be considerably whitened. Further, even if the lower electrode 29 has a flat structure, the diffusion plate 20 can provide good display quality regardless of the position of the liquid crystal display device with respect to the observer.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described.
The configuration of the liquid crystal display device according to the embodiment will be described with reference to FIG. The fifth embodiment of the present invention is characterized in that the light source section has a cold cathode tube, and the cold cathode tube is arranged on the lower surface of the lower polarizing plate. Further, a reflection plate is provided on the lower surface of the cold cathode tube. Further, a diffusion plate is provided between the upper polarizing plate and the upper substrate in order to prevent the shadow of the cold cathode tube. Furthermore, we strengthen reflection on light source part and prevent visibility of cold cathode fluorescent lamp,
Further, a lens film is provided between the lower polarizing plate and the cold cathode tube in order to enhance the directivity of light when the light source unit is turned on. FIG. 8 is a cross-sectional view of a portion corresponding to line BB of the liquid crystal display device according to the first embodiment of the present invention. Less than,
A fifth embodiment of the present invention will be described with reference to FIG.

The fifth embodiment has substantially the same structure as the first embodiment, and the same components are described using the same symbols. First, a signal electrode 2 and an alignment film 3 are provided on the upper substrate 1, and a counter electrode 12 and an alignment film 13 are provided on a lower substrate 11 facing the upper substrate 1. Upper substrate 1
The lower substrate 11 is hermetically sealed by a sealing portion and a sealing portion (not shown), and a liquid crystal 16 is sealed therein.

Further, on the lower surface of the lower substrate 11, the lower substrate 1
1 and a diffusion plate 20 and a lower polarizing plate 22 facing each other with a slight gap. The light source unit is disposed between the reflection plate 25b and the lower polarizing plate 22.
A lens film 27 and a cold cathode tube 32 provided on the lower surface of
A configuration including a reflection plate 25b disposed on the lower surface of the cold cathode tube 32 is employed. The diameter of the cold-cathode tube 32 is 1 mm, and furthermore, it is possible that the light is not shadowed in the case of the reflection type or the transmission type display due to the scattering effect of the diffusion plate 20 and the surface reflection effect of the lens film 27. Very little.

Since the light source portion facing the lower substrate 11 is transmissive, the reflection plate 25b can be used as the lower surface of the light source portion, so that the reflectance of the reflection plate 25b can be prioritized.
Further, even when the light source unit is turned on, bright display is possible because there is no loss of light due to the transflective plate.

Further, an upper diffusion plate 26 is disposed between the upper polarizing plate 21 and the upper substrate 1. The upper diffusion plate 26 has an effect of preventing a change in display quality due to a positional relationship between the liquid crystal display device and an observer, and at the same time, making it difficult to recognize the shadow of the cold cathode tube 32 of the light source unit. Further, compared to the case where the diffusion plate 26 is provided on the upper polarizing plate 21, it is possible to prevent a decrease in contrast ratio due to reflection on the surface of the diffusion plate 26.

<Sixth Embodiment> Next, a sixth embodiment of the present invention will be described.
The configuration of the liquid crystal display device according to the embodiment will be described with reference to FIG. According to the ninth embodiment of the present invention, the light source section is provided with an electroluminescent (EL) which is a flat light source.
It has an element 31. Further, the lower substrate 1 is used as the diffusion plate 20.
1 adopts a structure having irregularities on the back surface. FIG. 9 is a cross-sectional view of a portion corresponding to line BB of the liquid crystal display device according to the first embodiment of the present invention. Hereinafter, a sixth embodiment of the present invention will be described with reference to FIG.

The sixth embodiment has substantially the same structure as the first embodiment, and the same components are described using the same symbols. First, a signal electrode 2 and an alignment film 3 are provided on the upper substrate 1, and a counter electrode 12 and an alignment film 13 are provided on a lower substrate 11 facing the upper substrate 1. Upper substrate 1
The lower substrate 11 is hermetically sealed by a sealing portion and a sealing portion (not shown), and a liquid crystal 16 is sealed therein.

Further, the surface on the lower surface side of the lower substrate 11 has irregularities in the shape of a quadratic curve. As a method for forming the irregularities, diamond powder or tungsten carbide (WC) powder is sprayed by a fine nozzle at a high pressure to roughen the substrate, further etched by hydrofluoric acid, and further rubbed by cleaning the glass surface with a sponge. It was formed by this.
Due to the unevenness formed on the lower surface of the lower substrate 11, the diffusion plate 2
Set to 0.

Further, the lower polarizing plate 2 is provided on the lower surface of the lower substrate 11.
2, a transflective plate 25a, and an inorganic electroluminescent (EL) element 31 as a light source unit. The inorganic electroluminescent (EL) element 31 is
, A PET film, a transparent conductive film, an inorganic electroluminescent (EL) layer made of zinc sulfide (ZnS) having manganese (Mn) as an emission center, an insulating film, a carbon electrode, and a protective layer.

By employing the above structure, the distance between the liquid crystal layer 16 and the transflective plate 25a can be reduced, and double images or blurring of images can be prevented.

<Seventh Embodiment> Next, a seventh embodiment of the present invention will be described.
The configuration of the liquid crystal display device according to the embodiment will be described with reference to FIG. In a tenth embodiment of the present invention,
Electroluminescent (E) which is a flat light source
L) It has the element 31. Further, a structure having unevenness on the upper surface of the lower substrate 11 is adopted as the diffusion plate 20. In addition, a two-terminal switching element is provided as a switching element on the upper substrate. FIG. 10 is a cross-sectional view of a portion corresponding to line BB of an active matrix liquid crystal display device. Hereinafter, a seventh embodiment of the present invention will be described with reference to FIG.

The seventh embodiment is characterized in that a two-terminal switching element is provided on the upper substrate 1, irregularities are provided on the upper surface of the lower substrate 11, and a diffusion plate 20 is provided. Further, the structure in which the upper surface of the lower substrate 11 is provided with irregularities and the protective film 14 is provided for flattening and controlling the refractive index is employed, so that the characteristics of the two-terminal switching element are stabilized and the influence on the base during the manufacturing process is reduced. For this purpose, a switching element 5 is provided on the upper substrate 1. Further, in order to prevent coloring due to a difference in refractive index between the substrate and the transparent conductive film, a display electrode 9 which can be used even with a higher resistance than the wiring electrode (counter electrode) 12 is provided on the upper substrate 1.

First, on the upper substrate 1, a wiring electrode 17 made of a tantalum (Ta) film and a lower electrode 4 formed integrally with the wiring electrode 17 are provided. A non-linear resistance layer 15 made of tantalum oxide (Ta2 O5) is provided on the wiring electrode 17 and the lower electrode 4.

Further, the upper electrode 6 overlapping with the non-linear resistance layer 15 on the lower electrode 4 and the display electrode 9 having an integral structure with the upper electrode 6 are made of indium tin oxide having a thickness of 10 nm to 50 nm. (ITO) film. In terms of visibility, in particular, 10 nanometers (n
m) to 30 nanometers (nm) are very effective. If the thickness is 10 nanometers (nm) or less, the etching property and the film thickness variation during formation are large, and there is a problem in controllability. The upper electrode 6, the nonlinear resistance layer 15, and the lower electrode 4 form a two-terminal switching element 5.

The alignment film 3 is provided on the upper substrate 1 in order to arrange the liquid crystal 16 regularly. A counter electrode 12 and an alignment film 13 are formed on a lower substrate 11 facing the upper substrate 1.
And The upper substrate 1 and the lower substrate 11 are sealed by a seal portion and a sealing portion (not shown), and a liquid crystal 16 is sealed therein.

Further, the upper surface of the lower substrate 11 has irregularities in the shape of a quadratic curve. In the same manner as in the sixth embodiment, the irregularities are formed by spraying diamond powder or tungsten carbide powder with a high-pressure micro nozzle to roughen the substrate, and further performing etching with hydrofluoric acid.
Further, it was formed by rubbing the glass surface with a sponge and performing cleaning. The diffusion plate 20 is formed by the unevenness formed on the upper surface of the lower substrate 11. Further, in order to prevent disconnection of the counter electrode 12 due to the unevenness or decrease in the orientation of the alignment film 13, a protective layer 14 for flattening is provided. The protective layer 14 is made of tantalum oxide (T) having a large refractive index in order to improve scattering due to unevenness on the upper surface of the lower substrate 11.
a2O5) film and silicon oxide (SiO2) with small refractive index
A structure in which films are stacked is adopted. The tantalum oxide film is
Since the stress is large and a thick film is difficult, a silicon oxide film that can be formed by a printing method is employed.

Further, the lower polarizing plate 2 is provided on the lower surface of the lower substrate 11.
2, a transflective plate 25a and an electroluminescent (EL) element 31 as a light source unit. Further, for effective use of light, each component is bonded with an adhesive (not shown) to prevent reflection between the air layer and each component. The inorganic electroluminescent (EL) element 31 is composed of an inorganic electroluminescent (EL) element composed of a PET film, a transparent conductive film, and zinc sulfide (ZnS) having manganese (Mn) as a light emission center from the surface side of the lower substrate 11. (E
L) A layer, an insulating film, a carbon electrode, and a protective layer.

By employing the above structure, the distance between the liquid crystal layer 16 and the transflective plate 25a can be reduced, and double images or blurring of images can be prevented.

Further, by forming the display electrode 9 used for the switching element from a thin transparent conductive film, coloring and a decrease in transmittance due to a difference in refractive index between the upper substrate 1, the transparent conductive film and the alignment film 3 are greatly reduced. Can be smaller. Furthermore, the counter electrode 1 is formed by the unevenness provided on the lower substrate 11 (upper surface) and the protective film 14.
A bright white background can be displayed without disconnection of 2.

<Eighth Embodiment> Next, the structure of a diffusion plate used in the liquid crystal display device of the present invention will be described with reference to the drawings. FIG. 11 is a cross-sectional view in which a part of the diffusion plate 20 is enlarged. An embodiment of the diffusion plate 20 will be described below with reference to FIG.

The diffusion plate 20 has polystyrene beads 41
Is dispersed in an acrylic monomer to form a film having a thickness of 30 micrometers on the polarizing plate 22 by a printing method, and the monomer is polymerized by ultraviolet rays to form a film. On the lower surface of the polarizing plate 22, a semi-transmissive reflection plate 25a in which an aluminum (Al) film is formed at 30 nanometers (nm) is formed by a vacuum evaporation method. The aluminum film is covered with an aluminum oxide film. In this embodiment, the transmittance of the reflector is controlled by the thickness and crystallinity of the aluminum film.
The diffusion plate 20 having the above structure has a substantially uniform transmittance in the visible light region, and has a large transmittance. Also, the degree of diffusion (haze) can be relatively large.

Next, the behavior of light rays from the upper surface of the diffusion plate 20 will be described with reference to FIG. The light beam 45 is incident on the diffusion plate 20.
At a predetermined angle. Due to the difference in the refractive index between the acrylic resin 42 of the diffusion plate 20 and the beads 41, the light 4
5 repeats refraction and reflection, reaches the lower polarizing plate 22, is polarized, and reaches the transflective plate 25a. Transflective plate 25
According to a, light is reflected 80% and transmitted 20%. The reflected light beam passes through the lower polarizing plate 22, is refracted again by the diffusion plate 20, and is emitted to the upper surface. As described above, the polarized light of the lower polarizing plate 22 can be transmitted to the upper surface, and at the same time,
The color tone of the lower polarizing plate 22 can be whitened.

Further, the light beam 46 enters the diffusion plate 20 and is reflected on the upper surface side by refraction with the beads 41.
For this reason, the lower polarizer 22 does not show the polarization property, but the color tone does not change at the same time. As described above, by the light beam represented by the light beam 45, the polarization of the lower polarizer 22 is transmitted to the upper surface side, and by the light beam represented by the light beam 46, the reflection component from the diffusion plate 20 is used. Brightness and whiteness background display becomes possible.

When the light source unit is turned on, as shown by a light ray 48, the light passes through the transflective plate 25 a and the lower polarizer 22 from the lower surface side of the transflective plate 25 a, and is scattered and reflected by the diffuser 20. Are repeatedly transmitted and emitted to the upper surface. Therefore, the light beam 48 has a scattering property on the upper surface of the diffusion plate 20 and is further whitened.

<Ninth Embodiment> Next, another structure of the diffusion plate used in the liquid crystal display device of the present invention will be described with reference to the drawings. FIG. 12 is a cross-sectional view in which a part of the diffusion plate 20 is enlarged. An embodiment of the diffusion plate 20 will be described below with reference to FIG.

The diffusion plate 20 has polystyrene beads 41
Is dispersed in melamine resin, processed into a film shape, and adhered on the lower polarizing plate 22 with an adhesive, and a minute opening 50 is formed on the lower surface of the lower polarizing plate 22 by etching a metal foil, and An embossed transflective plate 25a having a silver-plated surface is used. In this embodiment, the transmittance of the reflector is controlled by the ratio of the area of the emboss. Diffusion plate 20 having the above structure
Has a substantially uniform transmittance in the visible light region, and has a high transmittance. Also, the degree of diffusion can be relatively large.

Next, the behavior of light rays from the upper surface of the diffusion plate 20 will be described with reference to FIG. The light beam 45 is incident on the diffusion plate 20.
At a predetermined angle. Due to the difference in the refractive index between the acrylic resin 42 of the diffusion plate 20 and the beads 41, the light beam repeats refraction and reflection, reaches the lower polarizing plate 22, is polarized, and reaches the transflective plate 25a. Transflective reflector 25a
Light reflection and transmission occur depending on whether the light is incident on the embossed portion or the metal portion. The light beam 45 is reflected by the metal portion, passes through the lower polarizer 22 again, repeats refraction again by the diffusion plate 20, and is emitted to the upper surface. As described above, the polarization of the lower polarizing plate 22 can be transmitted to the upper surface, and at the same time, the color tone of the lower polarizing plate 22 can be whitened.

Further, the light beam 46 enters the diffusion plate 20 and is reflected on the upper surface side by refraction with the beads 41.
For this reason, the lower polarizer 22 does not show the polarization property, but the color tone does not change at the same time. The light beam 49 is refracted and reflected in the same manner as the light beam 45, and the transflective plate 25a
, But reaches the embossed portion, so that it is transmitted downward without being reflected. Since the external light source enters the transflective plate 25a at various incident angles, the diameter of the opening of the embossed portion 50, the thickness of the transflective plate 25a, and the embossed portion 50
, The reflection characteristics when an external light source is used can be varied. In the case of transmission, since a flat light source is used and the light ray 48 which is relatively close to parallel light is used, brightness can be ensured.

In the above embodiment, an example in which a color filter is not used has been described. However, the blue, red, and green colors are provided on the upper surface of the lower substrate 11, for example, between the lower substrate 11 and the counter electrode 12. This can be achieved by providing filters in a delta arrangement or an oblique mosaic arrangement corresponding to each pixel portion, and further providing a flattening film.

In the embodiment, the description has been made using a passive matrix type liquid crystal display device which does not use a switching element, except for the seventh embodiment.
Even when a switching element is used, the effect of the embodiment of the present invention is of course effective. Further, similarly to the two-terminal switching element, the present invention is also effective in the case of a three-terminal switching element.

[0094]

As is apparent from the above description, the diffusion plate 2
0 is a lower substrate 11 and a lower polarizing plate 22 that constitute a liquid crystal display device.
In the liquid crystal display device that performs display using an external light source on the observer side by reflecting between a part of the light rays from the external light source of the diffusion plate 20 and transmit most other light rays, By reaching the reflection plates 25a and 25b, compared with a liquid crystal display device not using the diffusion plate 20,
It is possible to obtain a bright and white liquid crystal display device.

Furthermore, by using a combination of resin and beads for the structure of the diffusion plate 20, utilizing the difference in the refractive index between the resin and the beads and the shape of the beads, the transmittance in the visible region can be made substantially constant. At the same time, it is possible to have both diffusivity and reflection characteristics.

By using a plurality of types of diameters of beads included in the diffusion plate 20, the scattering can be controlled, and the diffusion plate 20 having directivity can be formed. further,
By changing the transmittance, reflection characteristics, and scattering characteristics of the diffusion plate 20 in and around the pixel portion, it is possible to provide a liquid crystal display device that is bright and has excellent white balance without lowering the contrast of the liquid crystal display device.

By utilizing the light source unit provided on the lower surface side of the diffusion plate 20 and the fluorescent pigment of the absorbing layer, the luminous efficiency of the auxiliary light source can be improved when the auxiliary light source is turned on, and a bright display can be achieved.

Further, by providing a color printing layer on the back surface of the diffusion plate 20, a satin-like display becomes possible due to the color of the color ink layer and the scattering property of the diffusion plate.

Further, by providing a color filter on the diffusion plate 20, the brightness of the diffusion plate 20 can be secured while maintaining the saturation of the color filter.

By employing a scattering type liquid crystal layer for the diffusion plate, it is easy to change the degree of scattering. Further, by applying a voltage to the scattering type liquid crystal layer, it is possible to turn on the external environment or turn on the auxiliary light source. This makes it possible to change the degree of scattering of the white diffuser plate, and display bright and with good visibility.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a planar structure of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a cross-sectional structure of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a reflectance and an applied voltage of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating the wavelength dependence of the reflectance of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a cross-sectional structure of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a cross-sectional structure of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating a cross-sectional structure of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 8 is a diagram illustrating a cross-sectional structure of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 9 is a diagram illustrating a cross-sectional structure of a liquid crystal display device according to a sixth embodiment of the present invention.

FIG. 10 is a diagram illustrating a cross-sectional structure of a liquid crystal display device according to a seventh embodiment of the present invention.

FIG. 11 is a diagram illustrating a cross-sectional structure of a white diffusion plate according to an eighth embodiment of the present invention.

FIG. 12 is a diagram illustrating a cross-sectional structure of a white diffusion plate according to a ninth embodiment of the present invention.

FIG. 13 is a diagram showing a planar structure of a liquid crystal display device in a conventional example.

FIG. 14 is a diagram showing a cross-sectional structure of a liquid crystal display device in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper substrate 2 Signal electrode 3 Alignment film 4 Lower electrode 5 Switching element 6 Upper electrode 7 Pixel part 8 Seal part 9 Display electrode 11 Lower substrate 12 Counter electrode 13 Alignment film 16 Liquid crystal 20 Diffusion plate 21 Upper polarizing plate 22 Lower polarizing plate 25a Transflective reflector 25b Reflector 27 Lens film 31 Light source 33 Reflector 38 Organic electroluminescent (EL) layer 41 Bead

Claims (10)

[Claims] An upper substrate has at least a signal electrode, and a lower substrate has at least a counter electrode. The upper substrate and the lower substrate face each other at a predetermined interval, and the signal electrode and the counter electrode Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, A liquid crystal display comprising a diffusion plate, a polarizing plate, and a semi-transmissive reflector arranged in this order on the lower side of the lower substrate, and a light source unit below the semi-transmissive reflector. apparatus. An upper substrate having at least a signal electrode and a lower substrate having at least a counter electrode, wherein the upper substrate and the lower substrate face each other at a predetermined interval, and a signal electrode and a counter electrode are provided. Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, A liquid crystal display, comprising: a diffusion plate that scatters straight light, a polarizing plate, a light guide plate, and a reflection plate arranged under the lower substrate in this order, and further includes a light source unit facing a part of the light guide plate. apparatus. 3. An upper substrate having at least a signal electrode, and a lower substrate having at least a counter electrode. The upper substrate and the lower substrate are opposed at a predetermined interval, and the signal electrode and the counter electrode are Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, A liquid crystal display device having a diffusion plate, a polarizing plate, and a light source unit for scattering straight light on a lower side of a lower substrate, and the light source unit further includes at least a fluorescent tube and a reflection plate. 4. An upper substrate having at least a signal electrode, and a lower substrate having at least a counter electrode, wherein the upper substrate and the lower substrate face each other at a predetermined interval, and the signal electrode and the counter electrode Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, On the lower side of the lower substrate, there is a diffusion plate, a polarizing plate, and a light source unit that scatters straight light, and further, the light source unit has at least an upper electrode, a light emitting layer, and a lower electrode, and the lower electrode is A liquid crystal display device, which is a reflection electrode that also serves as a reflection plate. 5. At least a signal electrode is provided on an upper substrate, and at least a counter electrode is provided on a lower substrate. The upper substrate and the lower substrate face each other at a predetermined interval, and the signal electrode and the counter electrode are connected to each other. Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, On the lower side of the lower substrate, there is provided a diffuser, a polarizing plate, and a light source unit that scatter straight light, the light source unit has at least an upper electrode, a light emitting layer, and a lower electrode, and the light emitting layer is an organic material. A liquid crystal display device comprising an electroluminescent layer. 6. An upper substrate having at least a signal electrode and a lower substrate having at least a counter electrode. The upper substrate and the lower substrate are opposed to each other at a predetermined interval. Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, On the lower side of the lower substrate, there is provided a diffusion plate, a polarizing plate, and a light source unit that scatters straight light, and further, the light source unit has at least an upper electrode made of a transparent conductive film, a light emitting layer, and a lower electrode. The liquid crystal display device, wherein the light emitting layer is an organic electroluminescent layer, and the lower electrode is a reflective electrode made of a silver film. 7. An upper substrate having at least a signal electrode and a lower substrate having at least a counter electrode. The upper substrate and the lower substrate are opposed at a predetermined interval, and the signal electrode and the counter electrode are Constituting a pixel portion facing each other, comprising a liquid crystal sealed between the upper substrate and the lower substrate, the upper substrate is disposed on the viewer side, and a polarizing plate is provided on the upper substrate, On the lower side of the lower substrate, a diffuser, a polarizing plate, a semi-transmissive reflector, and a light source unit which scatter straight light are arranged in this order, and further, the light source unit is
A liquid crystal display device comprising at least an upper electrode made of a transparent conductive film, a light emitting layer, and a lower electrode. 8. The method according to claim 1, wherein a lens film for limiting a viewing angle is provided between the polarizing plate and the light source unit or between the transflective plate and the light source unit. The liquid crystal display device as described in the above. 9. The liquid crystal display device according to claim 1, wherein the diffusion plate has substantially the same transmittance for visible light. 10. The liquid crystal display device according to claim 1, wherein the diffusion plate has no phase difference.