JPH1172779A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display of a color image with enough brightness by forming a colorless light-transmitting region which does not correspond to the color filter in each pixel region, arranging color filters for the respective colors in the horizontal direction of the screen and shifting the dividing position of the color filter of each color in the vertical direction of the screen. SOLUTION: A red filter 15R is divided in the center position in the longitudinal direction of a pixel region A into upper and lower parts, while a green filter 15G is divided at the position shifted to the upper edge of the region A from the dividing position of the filter 15R. A blue filter 15B is divided in the position shifted to the lower edge of the region A from the dividing position of the filter 15R. The area not corresponding to the color filters 15R, 15G, 15B in the region A, namely, the edge part and a region between divided filters are formed as a colorless light-transmitting region (a) which transmits light without coloring when the light enters through the front face, is reflected by a scattering reflecting plate on the back surface and outgoes through the front face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display device.

[0002]

2. Description of the Related Art There are two types of liquid crystal display devices: a transmissive type which displays by using light from a backlight, and a reflective type which displays by using external light such as natural light or indoor illumination light. On the other hand, the reflection type liquid crystal display device has a reflection member on the rear surface side for reflecting external light incident from the front surface of the display device and emitting the light to the front surface side.

In general, a liquid crystal display device has a TN (Twisted Nematic) in which liquid crystal molecules of the liquid crystal layer are twist-aligned at a predetermined twist angle between both substrates.
In the TN method, polarizing plates are arranged on the outer surface of the one substrate and the outer surface of the other substrate, respectively, with their transmission axes directed in a predetermined direction.

There are various types of liquid crystal display elements such as an active matrix type and a simple matrix type. For example, an active matrix type liquid crystal display element has a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween. A plurality of pixel electrodes arranged in the vertical and horizontal directions of the screen and a plurality of active elements respectively connected to the pixel electrodes are provided on an inner surface of one of the substrates, and the plurality of active elements are respectively provided on the inner surface of the other substrate. At least one pixel electrode facing
One counter electrode is provided, and a plurality of pixel regions in which the plurality of pixel electrodes and the counter electrode face each other are arranged in the vertical and horizontal directions of the screen.

Further, there are a liquid crystal display element for displaying a black and white image and a liquid crystal display element. A color liquid crystal display element for displaying a multicolor image such as a full-color image has a pair of substrates. A plurality of color filters formed in a size that covers the entire pixel region are provided on the inner surface of any one of the substrates in such a manner that the color filters of the respective colors correspond to the respective pixel regions.

In this color liquid crystal display device, for example,
A color filter of three colors of red, green, and blue is provided corresponding to each pixel region, and by selectively displaying red, green, and blue pixels in these pixel regions, a full-color image is displayed by additive color mixture. There is something.

[0007] Of the above color liquid crystal display elements, those using a striped color filter have pixel regions for displaying pixels of the same color arranged in the vertical direction of the screen, and are different in the horizontal direction of the screen. It has a configuration in which pixel areas for displaying color pixels are alternately arranged and arranged,
Therefore, the color filters are provided such that color filters of the same color are arranged in the vertical direction of the screen, and color filters of different colors are alternately arranged in the horizontal direction of the screen.

[0008]

However, in the conventional liquid crystal display device having the color filters of the respective colors corresponding to the respective pixel regions as described above, the color filters of the respective colors corresponding to the respective pixel regions are provided in the respective pixel regions. Since it is formed to have a size that covers the whole, all of the light transmitted through the pixel region is incident on the color filter, the light in the absorption wavelength range is absorbed by the color filter, and the light in the other wavelength range in the visible light range is absorbed. Since only light passes through the color filter and becomes light colored in the color of the color filter, the intensity of the outgoing colored light becomes extremely weak with respect to the intensity of the incident light, and thus there is a problem that a bright screen cannot be obtained. I have.

This problem can be alleviated to some extent by increasing the brightness of the backlight in the case of a transmissive liquid crystal display element, but it is reduced in the case of a reflective liquid crystal display element which displays by using external light. , Light incident from the front side,
Since the light passes through the color filter twice before being reflected by the reflection member on the rear surface side and exiting to the front side, the attenuation of light is large and the screen becomes considerably dark.

In addition, the reflection type liquid crystal display element is usually designed so that more external light enters from above the screen (a direction inclined to the upper edge side of the screen to some extent with respect to the direction perpendicular to the screen).
The screen is used with the screen facing the brightest direction of the surrounding brightness, but the external light is not only from the top of the screen but also the left and right sides of the screen (the right edge of the screen relative to the direction perpendicular to the screen). And a direction inclined to the left edge side).

FIG. 7 shows an example of incidence of external light when the reflective liquid crystal display device is used indoors. The liquid crystal display device shown in the figure is a display of a notebook computer.

As shown in the example of FIG. 7, the reflection type liquid crystal display element is used with its screen directed to an illumination light source (ceiling fluorescent light in the figure) above the place of use. Therefore, the most external light incident on the liquid crystal display element is the light from the illumination light source located above the place of use, that is, the incident light from the upper direction of the screen, but the light from other illumination light sources and the room Since the light reflected by the wall also enters the liquid crystal display element, external light also enters from the left and right directions of the screen.

As described above, since the external light is incident not only from the upper direction of the screen but also from the left and right directions, if the incident light from these directions can be efficiently emitted to the front side, the screen becomes brighter. be able to.

However, since external light incident from the upper direction or the horizontal direction of the screen is incident at various incident angles (angles with respect to the direction perpendicular to the screen), light incident at a relatively small incident angle is Light that is transmitted through the same pixel region as the transmitted pixel region and is emitted, and light that is incident at a large incident angle is transmitted and emitted through a pixel region different from the pixel region that was transmitted at the time of incidence. Since the display of the liquid crystal display element is observed from the front direction of the screen, the display observer's eyes (see FIG. 7) display the screen of the light reflected by the reflection member and emitted to the front side. Light emitted in the front direction can be seen.

In the conventional liquid crystal display device, since the color filters of the respective colors corresponding to the respective pixel regions are formed so as to cover the entire pixel region, the light enters from the front side and is reflected by the reflection member to be reflected by the reflection member. Of the light emitted to the side, all of the light transmitted through different pixel regions at the time of incidence and at the time of emission are all color filters corresponding to the pixel region transmitted at the time of incidence, and the color filter corresponding to the pixel region transmitted at the time of emission. By this, light in the absorption wavelength range of each color filter is absorbed.

This phenomenon occurs irrespective of the incident direction of external light. Light incident from the upper side of the screen passes through two pixel regions arranged in the vertical direction of the screen, and corresponds to the two pixel regions corresponding to these pixel regions. The light in each absorption wavelength range is absorbed by the two color filters, and the light incident from the left and right directions of the screen passes through two pixel areas arranged in the left and right directions of the screen, and corresponds to the two pixel areas. The light in each absorption wavelength range is absorbed by one color filter.

On the other hand, in the color liquid crystal display device using the striped color filters, as described above, the color filters of the respective colors are arranged in the vertical direction of the screen, and the color filters of the respective colors are arranged in the horizontal direction of the screen. The filters are provided alternately.

Therefore, even if the light incident from the upper direction of the screen passes through two pixel regions arranged in the vertical direction of the screen, the light is transmitted twice by the same color filter corresponding to these pixel regions. Although there is a decrease in the brightness of the emitted light due to the light absorption of the color filter, the light is emitted as light colored in the color of the color filter.

However, when incident light from the left and right directions of the screen passes through two pixel regions arranged in the left and right directions of the screen,
Since the light is absorbed by a color filter corresponding to one pixel region and a color filter having a different color corresponding to the other pixel region, light in a different wavelength range is absorbed. I will.

That is, for example, when the color filter corresponding to the one pixel region is a red filter and the color filter corresponding to the other pixel region is a green filter, first, the red filter is used to cover the green and blue wavelength ranges. The light is absorbed, and then the light in the red wavelength range is absorbed by the green filter, so that there is almost no emitted light.

For this reason, in the conventional reflective type color liquid crystal display device, the utilization efficiency of light incident from the upper side of the screen is moderate, but the utilization efficiency of light incident from the left and right directions of the screen is extremely poor. , Could not brighten the screen.

According to the present invention, as a reflection type liquid crystal display device having a color filter, a color image with a sufficiently bright screen can be obtained by efficiently using both the incident light from the upper direction and the incident light from the left and right directions. The purpose is to provide something that can be displayed.

[0023]

According to the present invention, a plurality of first substrates provided on an inner surface of one of a pair of front and rear substrates which are provided with a reflection member on a rear surface thereof and opposed to each other with a liquid crystal layer interposed therebetween are provided. A plurality of pixel regions in which electrodes and at least one second electrode provided on the inner surface of the other substrate oppose each other are arranged in the horizontal direction and the vertical direction of the screen, and any one of the pair of substrates is used. A reflection type liquid crystal display in which a plurality of color filters are provided on the inner surface of the substrate, and the color filters of the respective colors correspond to the respective pixel regions, and color filters of different colors are alternately arranged in the left-right direction of the screen. In the device, a color filter of each color corresponding to each of the pixel regions is divided into a plurality of portions in the vertical direction of the screen, and a region which does not correspond to the color filter in each of the pixel regions. Is a non-colored light emission area that transmits light that is incident from the front side and is reflected by the reflection member and emitted toward the front side without coloring, and a color filter of each color arranged in the horizontal direction of the screen. The division position is shifted in the vertical direction of the screen for each color filter having a different color.

According to the liquid crystal display device of the present invention, the color filters of the respective colors corresponding to the respective pixel regions are divided into a plurality of parts in the vertical direction of the screen, and the regions not corresponding to the color filters in the respective pixel regions are located on the front surface. Because it is an uncolored light emitting area that transmits the light that is incident from the side and is reflected by the reflective member on the rear surface side and emitted to the front side without coloring, it is included in the light incident from the top and left and right directions of the screen. Looking at light that is incident at a relatively small angle of incidence and passes through the same pixel region as the pixel region that was transmitted at the time of incidence, and exits,
Of the light incident on each pixel area, reflected by the reflection member on the rear surface side, and emitted to the front side, only the light transmitted through the area corresponding to the color filter is the light in the absorption wavelength range by the color filter. Is absorbed and emitted as colored light, and the light transmitted through the uncolored light emission region that does not correspond to the color filter in the pixel region has a high emission rate as uncolored light without being absorbed by the color filter. Emit.

When light is incident at a large incident angle and transmitted through a pixel region different from the pixel region transmitted at the time of the incident light, light incident from above the screen is also incident from the left and right directions of the screen. The light transmitted through the region corresponding to the color filter of the pixel region is also absorbed by the color filter in the absorption wavelength region and becomes colored light. The transmitted light is transmitted at a high transmittance without being absorbed by the color filter.

Therefore, of the light transmitted through the different pixel areas at the time of incidence and the time of emission, both the color filter corresponding to the pixel area transmitted at the time of incidence and the color filter corresponding to the pixel area transmitted at the time of emission are used. The light in the absorption wavelength range of each color filter is absorbed only by the light that passes through both the color filter corresponding region of one pixel region and the color filter corresponding region of the other pixel region. The light transmitted through the color filter corresponding area of the area and the uncolored light emission area of the other pixel area becomes colored light in which the light in the absorption wavelength range is absorbed by the color filter corresponding to the one pixel area. And emit
Light transmitted through the uncolored light emission areas of both pixel areas is emitted at a high emission rate as uncolored light without being absorbed by the color filter.

Moreover, according to this liquid crystal display element, the division positions of the color filters of each color arranged in the horizontal direction of the screen are
Since each color filter having a different color is shifted in the vertical direction of the screen, light incident from the left and right directions of the screen is a pixel region corresponding to the different color filters arranged in the horizontal direction of the screen. Even if the light is transmitted through one of the pixel areas and is transmitted through the other pixel area, the light is different in color between the color filter corresponding to the one pixel area and the color corresponding to the other pixel area. The probability of passing through both the color filters is low, and therefore, the absorption of light by the color filters having different colors can be reduced, and the light incident from the left and right directions of the screen can be emitted more efficiently.

The display of the liquid crystal display element is observed from the front direction of the screen. In the liquid crystal display element, from each pixel area, the colored light by the color filter and the high-brightness light which is not absorbed by the color filter. The uncolored light is emitted, and a high-luminance color pixel is displayed by the uncolored light and the colored light.

Therefore, the liquid crystal display device of the present invention
Although it is a reflective display element provided with a color filter, it is possible to display a color image with a sufficiently bright screen by efficiently using both the incident light from the upper direction and the incident light from the left and right directions.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the liquid crystal display device of the present invention divides a color filter of each color corresponding to each pixel region into a plurality of parts in the vertical direction of the screen, and applies the color filters in the respective pixel regions to each other. The uncolored light emitting area is defined as an uncorresponding area, and the division positions of the color filters of each color arranged in the horizontal direction of the screen are shifted in the vertical direction of the screen for each color filter having a different color, so that the area from the top of the screen is reduced. The system can efficiently use both incident light and incident light from the left and right directions to display a color image with a sufficiently bright screen.

In the liquid crystal display device according to the present invention, it is preferable that the horizontal width of the color filter along the horizontal direction of the screen is smaller than the horizontal width of the pixel region. Since the region on the side of the filter is the uncolored light emission region, the light passes through one of the pixel regions corresponding to the different color filters arranged in the horizontal direction on the screen and is incident. Since the light transmitted through and emitted from the other pixel region passes through both the color filter corresponding to the one pixel region and the color filter having a different color corresponding to the other pixel region, the probability is further reduced. The light absorption by the color filters having different colors can be further reduced, and the utilization efficiency of light incident from the left and right directions of the screen can be further improved.

Further, in the liquid crystal display device of the present invention, a region between adjacent pixel regions is a bright display region in which light incident from the front side is reflected by the reflection member and emitted to the front side. Desirably, in this way, the portion between the pixel regions can be brightened, and the screen can be further brightened.

[0033]

1 to 6 show one embodiment of the present invention. FIG. 1 is a front view of a part of a liquid crystal display element, and FIG.
FIG. 2 is a sectional view taken along line II-II of FIG. The liquid crystal display element of this embodiment is of an active matrix type using a TFT (thin film transistor) as an active element, and a pair of front and rear substrates (a transparent substrate made of glass or the like) facing each other with a liquid crystal layer LC interposed therebetween. Among them, a plurality of transparent pixel electrodes 3 are provided on the inner surface of the rear substrate 2 so as to be arranged in the horizontal direction (horizontal direction in FIG. 1) and the vertical direction (vertical direction in FIG. 1) of the screen. Active elements (hereinafter, referred to as TFTs) 4 corresponding to these pixel electrodes 3 are provided.

In FIG. 1, the electrode (R) is a pixel electrode for displaying a red pixel, the electrode (G) is a pixel electrode for displaying a green pixel, and the electrode (B) is a blue pixel. Pixel electrode for red,
Pixel electrodes 3 for displaying green and blue pixels are arranged alternately and linearly, and in the vertical direction of the screen, pixel electrodes 3 for displaying pixels of the same color are arranged linearly. I have.

The TFT 4 is formed on the rear substrate 2, a gate electrode 5, a gate insulating film 6 covering the gate electrode 5, and formed on the gate insulating film 6 so as to face the gate electrode 5. And a source electrode 8 and a drain electrode 9 formed on both sides of the i-type semiconductor film 7 via an n-type semiconductor film (not shown).

On the rear substrate 2, a gate line 10 for supplying a gate signal to the TFT 4 in each row is wired along one side of each pixel electrode row along the horizontal direction of the screen. The gate electrode 5 of the TFT 4 in each row is formed integrally with the gate line 10 corresponding to the row.

The gate insulating film (transparent film) 6 of the TFT 4 is formed over substantially the entire surface of the substrate 2, and the gate line 10 is covered with the gate insulating film 6 except for its terminal. .

A data line 11 for supplying a data signal to each TFT 4 in each column is provided on the gate insulating film 6 along one side of each pixel electrode column along the vertical direction of the screen. The drain electrodes 9 of the TFTs 4 in each column are respectively connected to the data lines 1 corresponding to the column.
Connected to one.

In this embodiment, the data line 11 is wired on the gate insulating film 6, and the drain electrodes 9 of the TFTs 4 in each column are connected to the data line 1 corresponding to the column.
1, but the data line 11 is
The TFT 4 may be covered with an insulating film and wired thereon, and may be connected to the drain electrode 9 of the TFT 4 at a contact hole provided in the insulating film.

The pixel electrode 3 is formed on the gate insulating film 6, and the pixel electrode 3 is connected to the source electrode 9 of the corresponding TFT 4 at one side edge.

Further, on the rear substrate 2, a compensation capacitor forming electrode (hereinafter, referred to as a pixel electrode 3) facing each pixel electrode row with the gate insulating film 6 interposed therebetween corresponding to each pixel electrode row. 12 is provided.
The capacitance forming electrode 12, the pixel electrode 3, and the gate insulating film 6 between them constitute a compensation capacitor (storage capacitor) for compensating the fluctuation of the potential of the pixel electrode 3 during the non-selection period.
Are formed.

The pixel electrode 3 is a vertically long rectangular electrode having a slightly larger vertical width than its horizontal width. The capacitance forming electrode 12 is located on the opposite side of the pixel electrode 3 from the TFT connection side. The gate line 10 is formed in parallel with the gate line 10 so as to face a portion slightly offset from the edge to the inside of the pixel electrode.

The gate line 10 and the capacitance forming electrode 12
Is formed of a metal film having a low resistance and a high light reflectance (for example, an aluminum alloy), and the data line 11 is also formed of a metal film having a low resistance and a high reflectance.

The gate line 10 and the capacitance forming electrode 12 are formed to increase the dielectric strength between the pixel electrode 3 formed on the gate insulating film 6 and the data line 11.
Although its surface is anodized and not shown in the figure, these gate lines 10 and capacitance forming electrodes 1 are not shown.
2 is covered with a transparent oxide film generated by anodic oxidation.

Further, a transparent overcoat insulating film 13 is provided on the inner surface of the rear substrate 2 so as to cover the TFT 4, the data line 11, and the periphery of the pixel electrode 3, and an alignment film 14 is formed thereon. Is formed.

On the other hand, on the inner surface of the front substrate 1, there are provided three color filters 15R, 15G, and 15B of red, green, and blue, which correspond to the respective pixel areas A, which will be described later. On a transparent protective film (insulating film) 16 formed so as to cover 15R, 15G, 15B, a pixel region A is formed by a portion facing the plurality of pixel electrodes 3 and a portion facing the pixel electrodes 3 respectively. At least one transparent counter electrode 17 is provided, on which an alignment film 18 is formed.

The front substrate 1 and the rear substrate 2 are
Liquid crystal is filled in a region between the two substrates 1 and 2 surrounded by the sealing material, which is joined via a frame-shaped sealing material (not shown).

The alignment films 14 and 18 provided on the inner surfaces of the pair of substrates 1 and 2 are each subjected to an alignment process by rubbing the film surfaces in a predetermined direction. The alignment direction of the liquid crystal molecules of the liquid crystal layer LC in the vicinity of the respective substrates 1 and 2 is regulated by the alignment film 14 of the rear substrate 2 and the alignment film 18 of the front substrate 1. Twist angle (eg, approximately 9
0 °).

Further, polarizing plates 21 and 22 are disposed on the outer surfaces of the pair of substrates 1 and 2, respectively, and these polarizing plates 21 and 22 are arranged so that their transmission axes are directed in predetermined directions. In the liquid crystal display element, a display in a state where an electric field is not applied to the liquid crystal layer LC (a state in which liquid crystal molecules are aligned in an initial twist alignment state) is a bright display. A so-called normally white mode display, in which the liquid crystal molecules rise and align with respect to the substrates 1 and 2 by application of an electric field to the liquid crystal layer LC, thereby lowering the light emission rate and darkening the display. For example, when the twist angle of the liquid crystal molecules is approximately 90 °, the polarizing plates 21 and 22 are provided with their transmission axes substantially orthogonal to each other.

Further, behind the rear polarizing plate 22,
A scattering reflector 23 is arranged as a reflecting member for reflecting light that has entered the liquid crystal display element from the front side and transmitted through the liquid crystal layer LC.

In the liquid crystal display device of this embodiment,
The three color filters 15R, 15G, 15B of red, green, and blue provided on the inner surface of the front substrate 1 are formed in the following sizes and shapes. FIG. 3 is a shape diagram of the color filters 15R, 15G, and 15B.

As shown in FIGS. 1 and 3, the red, green, and blue color filters 15R, 15G, and 15B are composed of the pixel electrodes 3 provided on the rear substrate 2 and the counter electrodes provided on the front substrate 1. 18 correspond to the pixel regions A (regions having the same outer shape as the pixel electrode 3) facing each other, and red, green, and blue color filters 15R, 15R in the horizontal direction of the screen.
G and 15B are alternately arranged, and color filters of the same color are arranged in the vertical direction of the screen.

The color filters 15R, 15G,
15B is divided into a plurality of parts (two divisions in this embodiment) in the vertical direction of the screen, and these division filters are provided at intervals above and below.

The color filters 15R, 15R of each color
G and 15B each make the horizontal width of each of the divided filters along the horizontal direction of the screen smaller than the horizontal width of the pixel area A, and the length from the upper edge of the upper divided filter to the lower edge of the lower divided filter. Is smaller than the horizontal width of the pixel area A. Therefore, the total area of the upper and lower divided filters of the color filters 15R, 15G, and 15B of each color is smaller than the area of the pixel area A.

The color filters 15 for the respective colors are used.
R, 15G and 15B respectively correspond to each pixel area A.
The color filters 15R, 15G, and 15B of the respective colors arranged in the horizontal direction of the screen are provided corresponding to the center of the pixel area A in the horizontal width direction. , Are formed so as to be shifted in the vertical direction of the screen.

That is, in this embodiment, as shown in FIGS. 1 and 3, the red filter 15R is vertically divided at a position corresponding to the center of the pixel area A in the vertical width direction.
The green filter 15G is vertically divided at a position shifted in the upper edge direction of the pixel area A with respect to the division position of the red filter 15R, and the blue filter 15B is divided into the red filter 1R.
It is vertically divided at a position shifted in the lower edge direction of the pixel area A with respect to the division position of 5R.

Areas that do not correspond to the color filters 15R, 15G, and 15B in each of the pixel areas A, that is, areas that correspond between the peripheral edge of the pixel area A and the upper and lower divided filters are incident from the front side. In addition, an uncolored light emitting area a that transmits, without coloring, the light that is reflected by the scattering reflection plate 23 on the rear surface side and emitted to the front side without being colored.

It should be noted that, of the light incident on each pixel area A from the front side, the light incident on the compensation capacitance section is blocked by the capacitance forming electrode 12 and does not enter the reflection plate 23. Because it is formed of a metal film with high reflectivity,
The light incident on the compensation capacitance portion is reflected by the capacitance forming electrode 12.

This liquid crystal display element performs a display in a normally white mode as described above, and the region between adjacent pixel regions A, that is, the liquid crystal molecules are always aligned in the initial twist alignment state. The electric field non-applied area in the state of being turned is a bright display area W in which light incident from the front side is reflected by the scattering reflector 23 or the gate line 10, the data line 11, and the capacitance forming electrode 12 and emitted to the front side. ing.

That is, the gate lines 10 and the data lines 11 provided on the inner surface of the rear substrate 2 pass through the bright display region W, and the capacitance forming electrodes 12 also cross the bright display region W. Therefore, of the light that has entered the bright display region W from the front side, the light that has entered the portion where the gate line 10 and the data line 11 and the capacitance forming electrode 12 pass does not enter the reflector 23, but the gate line 10 In addition, since the data line 11 and the capacitance forming electrode 12 are formed of a metal film having a high reflectance, light incident on these portions is also reflected.

This liquid crystal display element performs reflection type display using external light, and light incident from the front side is
The light passes through the front polarizer 21 to become linearly polarized light, and the light sequentially passes through the liquid crystal layer LC and the rear polarizer 22 to be scattered / reflected 23 or the gate line 10 and the data line 11.
Is reflected by the capacitor forming electrode 12 and the rear polarizer 2
2, the liquid crystal layer LC, and the front polarizer 21 sequentially pass through and exit to the front side.

Then, of the light incident on each pixel area A from the front side, the color filters 15R, 15 composed of upper and lower divided filters provided corresponding to the pixel area A are provided.
The light incident on G, 15B is absorbed by this color filter in the absorption wavelength range and is colored to the color of the color filter, and the colored light is reflected and emitted to the front side. The intensity of the colored outgoing light changes according to the rising alignment state of the liquid crystal molecules according to the applied electric field of each pixel region A.

Further, of the light incident on each pixel area A, an area corresponding to a portion between the peripheral portion in the pixel area A and the upper and lower divided filters, that is, the color filters 15R,
Light that has entered the uncolored light emission area a that does not correspond to 15G and 15B is reflected as uncolored light (white light) without passing through the color filter, and is emitted to the front side. The intensity of the uncolored emitted light also changes according to the rising alignment state of the liquid crystal molecules according to the applied electric field in each pixel region A.

Further, the light incident on the bright display area W between the adjacent pixel areas A is reflected as uncolored light (white light) and emitted to the front side. The uncolored light emitted from the bright display area W is always high intensity light because the liquid crystal molecules in the bright display area W are always in the initial twist alignment state.

Incidentally, the reflection type liquid crystal display element is usually designed so that more external light enters from the upper direction of the screen (the direction inclined to the upper edge side of the screen to some extent with respect to the direction perpendicular to the screen).
The screen is used by directing the screen in the brightest direction of the ambient brightness. The external light is not only from the top of the screen but also from the left and right of the screen, as in the example of external light incidence shown in FIG. The light is also incident from a direction (a direction inclined to the right and left edges of the screen with respect to the direction perpendicular to the screen).

Since the incident angle of external light incident from the upper direction or the horizontal direction of the screen (the angle with respect to the direction perpendicular to the screen) is various, the light incident at a relatively small incident angle is
The light transmitted through the same pixel region as the pixel region A transmitted at the time of incidence and exits, and the light incident at a large incident angle passes through the pixel region A different from the pixel region A transmitted at the time of incidence and exits.

Therefore, of the light incident from the upper direction and the horizontal direction of the screen, light incident at a relatively small angle of incidence and transmitted through the same pixel area as the pixel area transmitted at the time of incidence, is considered as follows. In the liquid crystal display device, the color filters 15R, 15G,
A region 15B having a total area smaller than the area of the pixel region A, and a region that does not correspond to the color filter in each pixel region A enters from the front side and is reflected by the scattering reflector 23 on the rear side and emitted to the front side. Is a non-colored light emission area a that transmits light without coloring, and in all the pixel areas A, light enters from the upper direction or the left / right direction of the screen and the reflection plate 2
Of the light that is reflected by 3 and emitted to the front side, only the light that passes through the regions corresponding to the color filters 15R, 15G, and 15B is absorbed by the color filter in the absorption wavelength range and is colored light. And the light is emitted, and the pixel area A
The light transmitted through the uncolored light emission area a that does not correspond to the color filter in the inside emits the uncolored light at a high emission rate without being absorbed by the color filter.

When light is incident at a large incident angle and transmitted through a pixel area A different from the pixel area A transmitted at the time of the incident light, the light incident from the upper side of the screen is also in the horizontal direction of the screen. Incident on the pixel region A, the light transmitted through the regions corresponding to the color filters 15R, 15G, and 15B of the pixel region A is absorbed by the color filter in the absorption wavelength range, and becomes colored light. Light transmitted through the uncolored light emission area a is transmitted at a high transmittance without being absorbed by the color filter.

Therefore, of the light transmitted through the different pixel areas at the time of incidence and the time of emission, the pixel area A transmitted at the time of incidence
The light in the absorption wavelength range of each color filter is absorbed by both the color filter corresponding to the pixel region A and the color filter corresponding to the pixel region A that is transmitted at the time of emission. And only the light that passes through both the color filter corresponding region of the other pixel region A and the color filter corresponding region of one pixel region A, and transmits the uncolored light emitting region a of the other pixel region A. The emitted light is emitted as colored light in which the light in the absorption wavelength range is absorbed by the color filter corresponding to one of the pixel areas A, and is transmitted through the uncolored light emitting areas a of both the pixel areas A. The light is emitted at a high emission rate without being colored by the color filter without being absorbed.

Therefore, according to this liquid crystal display device,
Compared to conventional liquid crystal display devices, in which color filters for each color corresponding to each pixel area are formed to cover the entire pixel area, the efficiency of both incident light from the top and left and right of the screen is higher. Good emission can be achieved.

Further, in the liquid crystal display device of the above embodiment,
Color filters 15R, 1 of each color arranged in the horizontal direction of the screen
Since the division positions of 5G and 15B are shifted in the vertical direction of the screen for each color filter having a different color,
Light incident from the left and right directions of the screen is transmitted through one pixel area A of the pixel areas corresponding to different color filters arranged in the left and right direction of the screen, and is incident on the other pixel area A. Is low, the probability that the light passes through both the color filter corresponding to the one pixel region A and the color filter having a different color corresponding to the other pixel region A is low. Light absorption by the color filters 15R, 15G and 15B having different colors can be reduced.

That is, the transmission path of light incident from the left and right directions of the screen in the liquid crystal display element will be described with respect to light incident along each of the light incident lines x1 to x5 shown by chain lines in FIG. become.

FIG. 4 is a sectional view showing a transmission path of light incident along the light incident line x1, and FIG. 5 is a sectional view showing a transmission path of light incident along the light incident line x3. In FIGS. 4 and 5, hatching indicating a cross section is omitted to make the figures easy to see, and among the electrodes, color filters, insulating films, and the like provided on the inner surfaces of the substrates 1 and 2, the rear substrate 2 is formed. Only the pixel electrodes 3 provided and the color filters 15R, 15G, 15B provided on the front substrate 1 are shown. The reflection member disposed on the rear surface side of the liquid crystal display element is the scattering reflection plate 23. In FIGS. 4 and 5, of the light reflected by the scattering reflection plate 23, the front direction of the screen (display Only the reflected light traveling in the observation direction of FIG.

First, the transmission path shown in FIG. 4 will be described. In the liquid crystal display device of the above embodiment, the red, green and blue color filters 15R, 15G and 15B are replaced with the red filter as shown in FIG. The division position of the green filter 15R corresponds to the center of the pixel region A in the vertical width direction.
The division position of G is shifted toward the upper edge of the pixel region A, and the division position of the blue filter 15B is shifted toward the lower edge of the pixel region A. However, on the cross section along the light incident line x1 shown in FIG.
That is, on the cross section along the line passing near the upper edge of each pixel area A arranged in the horizontal direction of the screen, all the pixel areas A arranged in the horizontal direction of the screen have the color filters 15R, 15G, 15
B is supported.

For this reason, on the cross section along the light incident line x1, as shown in FIG. 4, light is incident at various incident angles from the left and right directions (left direction in the figure) of the screen and is reflected by the scattering reflector 23 and the like. Out of the light emitted to the front side through the color filter corresponding area of one pixel area A arranged in the left-right direction of the screen and entering, and transmitted and emitted through the color filter corresponding area of the other pixel area A L1 is absorbed by the color filter corresponding to the one pixel region A and the color filter having a different color corresponding to the other pixel region A, and the emitted light is hardly obtained.

That is, for example, as shown in FIG.
When the color filter corresponding to one pixel region A through which 1 transmits is a red filter 15R, and the color filter corresponding to the other pixel region A is a green filter 15G, first, the green color and the blue wavelength are determined by the red filter 15R. The light in the red band is absorbed by the green filter 15G, and the light in the red wavelength band is absorbed by the green filter 15G.

However, in the liquid crystal display device of the above embodiment,
Since the width of the color filters 15R, 15G, and 15B is smaller than the width of the pixel area A, and the area on the side of the color filter in the pixel area A is the uncolored light emission area a, the transmitted light is transmitted to one pixel area. The probability of passing through both the color filter corresponding to A and the color filter corresponding to the other pixel region A is lower than that of a conventional liquid crystal display element in which the color filter is formed to have a size that covers the entire pixel region.

Therefore, in the liquid crystal display element of the above embodiment, light is transmitted through the color filter corresponding area in one pixel area A and enters, and transmitted and emitted through the color filter corresponding area in the other pixel area A. Outgoing light cannot be obtained.

In the transmission path shown in FIG. 4, light incident on the liquid crystal display element at a relatively small incident angle passes through the same pixel area A as the pixel area A transmitted at the time of incidence, and exits. The light L2 passing through the color filter corresponding region of the pixel region A is absorbed by the color filters 15R, 15G, and 15B corresponding to the pixel region, and the light colored in the color of the color filter. And emit.

Next, the transmission path shown in FIG. 5 will be described. In the liquid crystal display element of the above embodiment, the red, green and blue color filters 15R, 15R,
Since 15G and 15B are provided in the above positional relationship, on the cross section along the light incident line x3 shown in FIG. 3, that is, on the cross section along the line passing through the division position of the red filter 15R, the horizontal direction of the screen is obtained. Only the pixel area A for displaying green and blue pixels among the pixel areas arranged corresponds to the color filters (green and blue filters) 15G and 15B, and is a pixel area for displaying red pixels. A does not correspond to a color filter.

For this reason, on the cross section along the light incident line x3, as shown in FIG. 5, light is incident at various incident angles from the horizontal direction (left direction in the figure) of the screen, and is reflected by the scattering reflector 23 and the like. Out of the light emitted to the front side, the light incident at a large incident angle passes through the two pixel areas arranged in the horizontal direction of the screen, but the color filter of the pixel area A for displaying the green pixels among them. The light L3 passing through the corresponding region is absorbed by the green filter 15G in the absorption wavelength range, and the light (not shown) passing through the color filter corresponding region of the pixel region A for displaying a blue pixel is converted into a blue filter. Only the light in the absorption wavelength range is absorbed by 15B.

Accordingly, on the cross section along the light incident line x3, light passing through both the color filter corresponding regions of the pixel region A for displaying green pixels and the pixel region A for displaying blue pixels. Can hardly obtain the output light of
Light transmitted through a pixel region A for displaying red pixels and a pixel region A for displaying green pixels, and a pixel region A for displaying blue pixels and a pixel region A for displaying red pixels. When any light transmitted through the pixel region A passes through the color filter corresponding region of one of the two pixel regions A through which the light passes, the color filter 15G corresponding to the pixel region A or Only the light in the absorption wavelength range is absorbed by 15B.

That is, like the light L3 shown in FIG. 5, the pixel region A for displaying a red pixel is transmitted through the pixel region A, and the pixel region A for displaying a green pixel corresponds to a color filter. The light that is transmitted and emitted through the region passes through the pixel region A for displaying the red pixel without being absorbed by the color filter at the time of incidence, and absorbs the light in the absorption wavelength range by the green filter 15G at the time of emission. The light is then emitted as green colored light.

Further, for example, the light that passes through the color filter corresponding region of the pixel region A for displaying the blue pixel and enters, and the light that passes through and exits the pixel region A for displaying the red pixel is: At the time of incidence, the light in the absorption wavelength range is absorbed by the blue filter 15G to become blue-colored light, and at the time of emission, the light passes through the pixel area A for displaying the red pixel without being absorbed by the color filter. The light is emitted as blue colored light.

In the transmission path shown in FIG.
Light incident on the liquid crystal display element at a relatively small angle of incidence passes through the same pixel area as the pixel area A transmitted at the time of incidence, and exits. Of the light, light passing through the color filter corresponding area of the pixel area A L4 absorbs light in the absorption wavelength range by the color filters 15R, 15G, and 15B corresponding to the pixel region, and emits light colored in the color filter.

The light incident lines x1 to x5 shown in FIG.
Although the transmission path of light incident along the light incident lines x2, x4, and x5 is not shown, a cross section along a light incident line x2, that is, a line along a line passing through the division position of the green filter 15G is shown. In the above, outgoing light of light passing through the color filter corresponding regions of both pixel regions of light transmitted through the two pixel regions A for displaying red and blue pixels is simply not obtained. On the cross-section along the line x4, that is, on the cross-section along the line passing through the division position of the blue filter 15B, both pixel regions of the light transmitted through the two pixel regions A for displaying the red and green pixels are displayed. However, only the emission light of the light passing through the region corresponding to the color filter cannot be obtained.

However, on the cross section along the light incident line x5, that is, on the cross section along the line passing near the lower edge of each pixel area A, as in the transmission path shown in FIG. The light that passes through the color filter corresponding region of one pixel region A and enters and is transmitted through the color filter corresponding region of the other pixel region A and exits, and the color filter corresponding to the one pixel region A Is absorbed by a color filter of a different color corresponding to the other pixel region A, and almost no emitted light is obtained.

As described above, the liquid crystal display element of the above embodiment is provided with the color filters 15 of each color arranged in the horizontal direction of the screen.
Since the division positions of R, 15G, and 15B are shifted in the vertical direction of the screen for each of the color filters having different colors, light incident from the horizontal direction of the screen is one of the pixel regions arranged in the horizontal direction of the screen. To reduce the probability of passing through both the color filter corresponding to A and the color filter of a different color corresponding to the other pixel area A, and to reduce the absorption of light by the color filters 15R, 15G, and 15B of different colors. Therefore, light incident from the left and right directions of the screen can be emitted more efficiently.

In the liquid crystal display device of the above embodiment, the color filters 15R, 15G and 15B of the respective colors are arranged in the vertical direction of the screen, and the color filters of the respective colors are alternately arranged in the horizontal direction of the screen. Even if light incident from the upper side of the screen passes through two pixel regions A arranged in the vertical direction of the screen, the light is transmitted in the same color corresponding to these pixel regions A, respectively. Although there is a decrease in the brightness of the emitted light due to the twice light absorption in the filter,
The light is emitted as light colored in the color of the color filter.

In this embodiment, the areas above and below the color filters in the pixel area A are also the uncolored light emitting areas a.
Therefore, the probability that light incident from the upper side of the screen passes through both the color filter corresponding to one pixel region A and the color filter corresponding to the other pixel region A arranged in the vertical direction of the screen is the color filter. Is lower than that of a conventional liquid crystal display element formed so as to cover the entire pixel region, and therefore, light incident from the upper direction of the screen can be emitted more efficiently than the conventional liquid crystal display element. .

The display of the liquid crystal display element is observed from the front of the screen. In the liquid crystal display element, the color filters 15R, 15G, 15B
, And high-luminance uncolored light that is not absorbed by the color filter is emitted, and a high-luminance color pixel is displayed by the non-colored light and the colored light.

The color pixels include red, green, and blue colored light, which is light emitted from regions corresponding to the color filters 15R, 15G, and 15B in each pixel region A, and the pixel region A. Are displayed with high-luminance uncolored light (white light) emitted from the uncolored light emission area a at the periphery of the pixel.
It looks as one color pixel colored R, 15G, 15B.

Therefore, the liquid crystal display device is a reflection type display device provided with a color filter. However, the incident light from the upper direction of the screen and the incident light from the left and right directions are efficiently used, and the screen is sufficiently displayed. A bright color image can be displayed.

Further, in the liquid crystal display device of the above embodiment, the area between the adjacent pixel areas A is changed so that the light incident from the front side is reflected by the reflection plate 23 on the rear side or the gate line 10 on the inner surface of the rear substrate 2. And a bright display area W which is reflected by the data line 11 and the capacitance forming electrode 12 and emitted to the front side. Since the bright display area W emits high-color uncolored light, a portion between the pixel areas A is provided. And the screen can be further brightened.

In the above embodiment, the width of each color filter 15R, 15G, 15B is smaller than the width of the pixel area A.
15G and 15B may be formed to have substantially the same width as the horizontal width of the pixel region A.

However, the color filters 15R, 15R
It is desirable that the horizontal width of G and 15B be smaller than the horizontal width of pixel region A. In this case, as in the above-described embodiment, the region on the side of the color filter in pixel region A emits uncolored light. Since it is the area a, one of the pixel areas corresponding to the different color filters arranged in the horizontal direction of the screen and corresponding to the color filter is transmitted through one of the pixel areas A, and is transmitted through the other pixel area A. Since the probability that the emitted light passes through both the color filter corresponding to the one pixel region A and the color filter having a different color corresponding to the other pixel region A is further reduced, the color filters having different colors are used. Light absorption can be further reduced, and the utilization efficiency of light incident from the left and right directions of the screen can be further improved.

The liquid crystal display device of the above embodiment is of a so-called lattice type in which the pixel regions A are linearly arranged in the horizontal and vertical directions of the screen. Are arranged in a straight line by alternately arranging pixel regions A for displaying pixels of different colors in the horizontal direction of the screen, and connecting the pixel regions for displaying pixels of the same color in the vertical direction of the screen with each other. The present invention can also be applied to a so-called mosaic array type liquid crystal display element which is arranged in a zigzag manner by being alternately shifted in the left-right direction.

FIG. 6 shows another embodiment of the present invention, in which a color filter 1 of each color corresponding to each pixel area A is shown.
5R, 15G, and 15B are shape diagrams. In this embodiment,
This is intended for the mosaic arrangement type liquid crystal display element.

That is, the liquid crystal display device of this embodiment is
In the horizontal direction of the screen, pixel regions A for displaying pixels of each color of red, green, and blue are alternately arranged and linearly arranged. In the vertical direction of the screen, pixels for displaying pixels of the same color The areas are arranged in a zigzag manner with the areas being alternately shifted by about 1.5 pitches in the horizontal direction of the screen.

In this embodiment, the color filters 15R, 15G, 15G of the respective colors corresponding to the respective pixel regions are also provided.
B is divided into a plurality of portions in the vertical direction of the screen, and a region not corresponding to the color filter in each pixel region A is colored with light that enters from the front side, is reflected by the reflection member on the rear side, and exits to the front side. In addition to the non-colored light emitting area a that transmits light, the division positions of the color filters 15R, 15G, and 15B of each color arranged in the horizontal direction of the screen are shifted in the vertical direction of the screen for each color filter having a different color. .

Therefore, also in the liquid crystal display device of this embodiment, it is possible to efficiently use both the incident light from the upper direction of the screen and the incident light from the left and right directions, and to display a color image with a sufficiently bright screen.

In the mosaic array type liquid crystal display device of this embodiment, as shown in FIG.
Color filters 15R, 15G, 15 of each color corresponding to
B has a width equal to or less than the interval between the two color filters corresponding to the pixel regions A adjacent to each other in the horizontal direction of the screen.
15G and 15B are provided in the space between the two color filters corresponding to the pixel areas A adjacent to each other in one row so as to correspond to the color filters corresponding to the pixel areas A in the upper and lower rows. desirable.

In this way, even in the case of a mosaic array type liquid crystal display element, when incident light from above the screen passes through two pixel regions arranged in the vertical direction of the screen, the light is transmitted to one side. Since light in different wavelength ranges is hardly absorbed by the color filter corresponding to the pixel region and the color filter having a different color corresponding to the other pixel region, incident light from the upper direction of the screen can be efficiently removed. It can be emitted.

In each of the above-described embodiments, the color filters 15R, 15G, and 15B for each color are vertically divided into two parts. However, the number of divisions of the color filters may be arbitrary. The probability that light incident from the left and right direction of the screen passes through both the color filters corresponding to one pixel region A and the color filters of different colors corresponding to the other pixel region A, which are arranged in the left and right direction of the screen, will be described. Color filters 15R and 15R having different colors.
G, 15B can further reduce the absorption of light, and can more efficiently emit light incident from the left and right directions of the screen.

The liquid crystal display device of each of the above embodiments is
Although the present invention includes red, green, and blue color filters, the present invention performs multi-color display by subtractive color mixing, with three color filters of magenta, yellow, and cyan corresponding to respective pixel regions. It can also be applied to liquid crystal display elements.

Further, the liquid crystal display element of the above embodiment has the color filters 15R, 15G, 15B on the inner surface of the front substrate 2.
, But the color filters 15R, 15R
G and 15B may be provided on the inner surface of the rear substrate 2.

In the liquid crystal display device of the above embodiment, a reflection member made of a scattering reflection plate 23 is disposed behind the rear polarizing plate 22. It may be provided on the inner surface, and in that case, the polarizing plate may be only one polarizing plate 21 on the front side.

Further, the present invention is not limited to the active matrix type, and a plurality of scanning electrodes extending in one direction are provided on an inner surface of one substrate in parallel with each other, and a plurality of scanning electrodes are provided on an inner surface of the other substrate in a direction intersecting the scanning electrodes. The present invention can also be applied to a simple matrix type liquid crystal display device or the like in which a plurality of signal electrodes extending along the same are provided in parallel with each other.

[0109]

According to the liquid crystal display device of the present invention, the color filters of the respective colors corresponding to the respective pixel regions are divided into a plurality of portions in the vertical direction of the screen, and the regions in the respective pixel regions which do not correspond to the color filters are not colored. With the emission area,
Since the division position of the color filters of each color arranged in the horizontal direction of the screen is shifted in the vertical direction of the screen for each color filter of a different color, it is a reflective display element equipped with color filters. A sufficiently bright color image can be displayed on the screen by efficiently using both the incident light from the direction and the incident light from the left and right directions.

In the liquid crystal display device according to the present invention, if the horizontal width of the color filter along the horizontal direction of the screen is smaller than the horizontal width of the pixel region, the region of the pixel region on the side of the color filter is the same as that of the color filter. Since it becomes a colored light emission area, one of the pixel areas corresponding to different color filters arranged in the horizontal direction of the screen corresponding to different color filters is transmitted and incident, and transmitted through the other pixel area. Since the probability that the emitted light passes through both the color filter corresponding to the one pixel region and the color filter having a different color corresponding to the other pixel region is further reduced, the light emitted by the color filters having different colors is reduced. Less absorption,
The utilization efficiency of light incident from the left and right directions of the screen can be further improved.

Further, in the liquid crystal display device of the present invention, if a region between adjacent pixel regions is a bright display region in which light incident from the front side is reflected by the reflection member and emitted to the front side, The portion between the pixel regions can be brightened, and the screen can be further brightened.

[Brief description of the drawings]

FIG. 1 is a front view of a part of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a shape diagram of a color filter of each color corresponding to each pixel region in the liquid crystal display element.

FIG. 4 is a sectional view showing a transmission path of light incident along the light incident line x1 shown in FIG. 3;

FIG. 5 is a sectional view showing a transmission path of light incident along a light incident line x3 shown in FIG. 3;

FIG. 6 is a view showing a shape of a color filter of each color corresponding to each pixel region, showing another embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of incidence of external light on a liquid crystal display element.

[Explanation of symbols]

 Reference numerals 1, 2, substrate 3, pixel electrode 4, TFT (active element) 10, gate line 11, data line 12, compensation capacitance forming electrode 15R, 15G, 15B, color filter 17, counter electrode 21, 22, polarizing plate 23, etc. Scattering reflector (reflection member) A: Pixel area a: Uncolored light emission area W: Bright display area

Claims (3)

[Claims] A plurality of first electrodes provided on an inner surface of one of a pair of front and rear substrates facing each other with a liquid crystal layer interposed therebetween and a reflective member provided on a rear surface side; A plurality of pixel regions in which at least one provided second electrode is opposed to each other are arranged in the left-right direction and the up-down direction of the screen, and a plurality of colors are formed on an inner surface of any one of the pair of substrates. In a reflection type liquid crystal display element in which color filters of the respective colors correspond to the respective pixel regions and color filters of different colors are alternately arranged in the left and right direction of the screen, A corresponding color filter of each color is divided into a plurality of parts in the vertical direction of the screen, and a region in each of the pixel regions, which does not correspond to the color filter, is incident from the front side and the color filter is formed. The uncolored light emission area for transmitting the light reflected by the light-emitting member and emitted to the front side without coloring, and the color filter of each color arranged in the horizontal direction on the screen is divided into different colors. A liquid crystal display device wherein each filter is shifted in the vertical direction of the screen. 2. The liquid crystal display device according to claim 1, wherein the horizontal width of the color filter along the horizontal direction of the screen is smaller than the horizontal width of the pixel region. 3. A bright display area between adjacent pixel areas is a bright display area in which light incident from the front side is reflected by the reflection member and emitted to the front side.
Or the liquid crystal display device according to claim 2.