JP2000010117A - Liquid crystal display element and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to display color images sufficient in the brightness of a screen at the time of a reflection type display utilizing external light and to display color images sufficient in brightness and contrast at the time of a transmission type display utilizing the illumination light from an illumination means. SOLUTION: Color filters 10R, 10G, 10B of plural colors are disposed in respective correspondence to other pixel regions A exclusive of the prescribed pixel regions A' existing at a ratio of at least one in each of a prescribed number of the pixel regions. Driving is executed by impressing the voltage meeting image data to the colored pixel regions A corresponding to the color filters and impressing the voltage to put the display of the non-colored pixel regions A' not corresponding to the color filters into a non-colored bright display to the non-colored pixel regions A' at all times at the time of the reflection type display. The driving is executed by impressing the voltage meeting the image data to the colored pixel regions A and impressing the voltage to put the display of the non-colored pixel regions A' into the dark display to the non-colored pixel regions A' at all times at the time of the transmission type display.

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 for displaying a color image and a two-way liquid crystal display device using the same.

[0002]

2. Description of the Related Art There are two types of liquid crystal display devices, one displaying a black-and-white image and the other displaying a color image.
On each inner surface of a pair of transparent substrates opposed to each other with a liquid crystal layer interposed therebetween, a transparent electrode for forming a plurality of pixel regions arranged in a matrix by regions opposed to each other is provided. A plurality of colored films are provided on the inner surface of the side substrate) so as to correspond to all the pixel regions.

There are two types of liquid crystal display devices of this type: an active matrix type and a simple matrix type. For example, an active matrix type liquid crystal display device using a TFT (thin film transistor) as an active element is provided on one substrate. A plurality of pixel electrodes arranged in a matrix, a plurality of TFTs respectively connected to each of the pixel electrodes, and a gate line and a data line for supplying a gate signal and a data signal to these TFTs are formed on the inner surface of the TFT. And a counter electrode facing the plurality of pixel electrodes is provided on the inner surface of the other substrate.

The colored film is generally a color filter of three colors of red, green, and blue. Each color filter of each color has almost all of the light transmitted through each pixel region where the electrodes of both substrates face each other. Is formed in a size corresponding to the entirety of the pixel region.

Further, as the liquid crystal display element, a TN (Twisted Nematic) type in which liquid crystal molecules of a liquid crystal layer are twist-aligned at a predetermined twist angle between both substrates is often used. In the liquid crystal display device of the type, polarizing plates are arranged on the front surface of the front substrate and the rear surface of the rear substrate, respectively, with their transmission axes oriented in predetermined directions.

On the other hand, a liquid crystal display device using the above-mentioned liquid crystal display element performs only a reflective display using external light such as natural light or indoor light, and a liquid crystal display device using illumination light from illumination means generally called a backlight. A two-way type that performs both the reflective display and the transmissive display.

The two-way liquid crystal display device emits illuminating light behind the liquid crystal display element toward the back surface of the liquid crystal display element and emits external light incident from the front of the liquid crystal display element. Illumination means for reflecting the light toward the rear surface of the liquid crystal display element is arranged. As the illumination means, an illumination panel that emits illumination light and a transflective plate is arranged on the front surface is used.

In general, the lighting panel has a light guide plate having at least one end surface as a light incident surface and a front surface as an emission surface of light taken in from the end surface, and a light guide plate opposed to the end surface of the light guide plate. What is called a side light type comprising an arranged light source unit is used, and the transflective plate is disposed on the front surface of the light guide plate.

The sidelight type illumination panel guides light from a light source unit with a light guide plate and emits the light from the front surface. The light from the light source unit is introduced into the light guide plate from an end face thereof, and the light from the light guide plate is reflected by the light guide plate. Is guided by repetition of reflection on the front and back surfaces of the light guide plate, and is emitted from almost the entire front surface of the light guide plate. Further, the transflective plate reflects and transmits incident light at a reflection / transmittance according to its characteristics.

The two-way type liquid crystal display device performs a reflective display utilizing external light when sufficient external light is obtained, and performs the illumination when external light having sufficient brightness is not obtained. The light source unit of the illuminating means is turned on when performing the transmissive display.

That is, in the case of a reflection type display utilizing external light, light incident from the front of the liquid crystal display element and transmitted through the liquid crystal display element and incident on the illumination means is reflected by the semi-transmissive reflection plate. The reflected light is incident on the liquid crystal display element from the back thereof, passes through the liquid crystal display element and is emitted forward, and an image is displayed by the emitted light from each pixel region. Is done.

In the case of a transmissive display utilizing illumination light from the illumination means, illumination light emitted to the front of the illumination panel is transmitted through the semi-transmissive reflector at a transmittance according to its characteristics, The transmitted light is incident on the liquid crystal display element from the back surface, passes through the liquid crystal display element and is emitted forward, and an image is displayed by the emitted light from each pixel region.

Light emitted from each pixel region of the liquid crystal display element is divided into red, green, and blue light corresponding to each pixel electrode.
In the case of a liquid crystal display device using a liquid crystal display element provided with a color filter for colors, red, green and blue colored lights are used, and a full color image is displayed by mixing these colored lights.

[0014]

However, a conventional liquid crystal display device for displaying a color image and a two-way type liquid crystal display device using the same have a problem that when a transmission type display using illumination light from illumination means is used, The intensity of the light emitted from the liquid crystal display element is higher than the brightness of the viewing environment of the display, and a color image with sufficient brightness can be displayed. However, in the case of the reflective display using external light, the display viewing environment is high. In this case, the intensity of the light emitted from the liquid crystal display element becomes extremely low as compared with the brightness of the liquid crystal display device, and the entire screen becomes dark.

This is because, of the light in the visible light band transmitted through the liquid crystal display element, the light of the wavelength component in the transmission wavelength band corresponding to the color of the colored film (for example, three color filters of red, green and blue) is emitted. This is because the light passes through the colored film and becomes colored light, and light of other wavelength components is absorbed by the colored film. Therefore, the intensity of the colored light emitted from the liquid crystal display element is smaller than the intensity of the incident light. Is considerably weaker.

[0016] The two-way liquid crystal display device comprises:
When external light of sufficient brightness cannot be obtained, that is, when the display observation environment is dark, a transmissive display using illumination light from the illuminating means is performed. Since the luminance of the illumination light is much higher than the brightness of the display observation environment, and the light incident from the back of the liquid crystal display element only transmits through the liquid crystal display element toward the front, the light of the colored film Absorption is only once.

On the other hand, in the case of a reflection type display utilizing external light, the incident external light is light having an intensity corresponding to the brightness of the display observation environment, and the light is directed toward the rear of the liquid crystal display element. Since the light passes through the colored film twice in a path that transmits light and in a path that transmits light in the front direction, the amount of absorption by the colored film is large, and the intensity of the colored light emitted to the front of the liquid crystal display element is lower than that of the display observation environment. Extremely weak compared to brightness.

Therefore, the conventional liquid crystal display device for displaying a color image and the two-way type liquid crystal display device using the same have a color image of sufficient brightness when performing a transmissive display using illumination light from illumination means. Can be displayed, but in the case of a reflective display using external light, the entire screen becomes dark.

According to the present invention, a color image with sufficient screen brightness is displayed in a reflection type display using external light, and a brightness is also displayed in a transmission type display using illumination light from illumination means. It is an object of the present invention to provide a liquid crystal display element and a two-way liquid crystal display device capable of displaying a color image having a sufficient contrast.

[0020]

According to the liquid crystal display device of the present invention, a plurality of pixel regions arranged in a matrix by opposing regions are formed on the inner surfaces of a pair of substrates facing each other with a liquid crystal layer interposed therebetween. A plurality of colored films corresponding to other pixel regions except for a predetermined pixel region which is present in at least one ratio for every predetermined number of pixel regions on an inner surface of one of the substrates. Is provided, and a voltage corresponding to image data is applied between electrodes of the colored pixel region corresponding to the colored film, and between the electrodes of the non-colored pixel region not corresponding to the colored film, It is characterized in that the display is driven by applying a voltage at which non-colored bright display or dark display is always applied.

In this liquid crystal display device, the display of the non-colored pixel region, which is present in at least one ratio for every predetermined number of pixel regions, is always a non-colored bright display or dark display, and the colored film is formed by another colored pixel region. The colored pixels which are colored in the same color are displayed, and a color image is displayed by these colored pixels. The display of the non-colored pixel region is performed when the reflective display using external light is performed. And a dark display when performing a transmissive display using illumination light from illumination means disposed behind the liquid crystal display element.

That is, when performing a reflection type display using external light, the liquid crystal display element applies a voltage corresponding to image data between electrodes of a colored pixel area of each pixel area, and applies a voltage to the non-colored pixel area. The display of the pixel region is driven by applying a voltage between the electrodes of the region so that the display of the pixel region becomes a non-colored bright display. In this case, the transmission corresponding to the color is performed by the coloring film from the coloring pixel region. Colored light that has absorbed wavelength components other than the wavelength band is emitted, and uncolored light that is not absorbed by the colored film is emitted from the uncolored pixel region.

Therefore, in the case of a reflective display using external light, the colored light emitted from the colored film pixel region in each pixel region is light with low intensity, but at least for each of a predetermined number of pixel regions. Since non-colored light having sufficiently higher intensity than the colored light is emitted from a predetermined pixel region (non-colored pixel region) existing at one ratio, the brightness of the entire screen is supplemented by the non-colored light, and the brightness of the screen is increased. It is possible to display a color image which is sufficient.

Further, when performing a transmissive display using illumination light from illumination means disposed behind the liquid crystal display element, the liquid crystal display element converts image data between electrodes of a colored pixel area of each pixel area. Corresponding voltage is applied between the electrodes of the non-colored pixel region to apply a voltage that makes the display of the pixel region dark. In this case, the colored film is removed from the colored pixel region. As a result, colored light having wavelength components other than the transmission wavelength band corresponding to the color is absorbed, and almost no light is emitted from the pixel region not corresponding to the colored film.

Therefore, in the case of the transmissive display, the intensity of the colored light emitted from the colored pixel region is sufficiently higher than the brightness of the display observation environment, and there is almost no light leakage from the non-colored pixel region. A color image with sufficient brightness and contrast can be displayed.

Further, in this liquid crystal display element, since at least one pixel region which does not correspond to the color film is present for every predetermined number of pixel regions, a non-colored bright display in the reflective display is performed. Alternatively, a dark image in the case of the transmissive display is almost uniformly distributed over the entire screen, and in any display, the brightness of the screen is almost uniform, and the bright image or the dark image is inconspicuous, and a color image of good image quality is obtained. Can be displayed.

Further, the liquid crystal display device of the present invention emits illumination light behind the liquid crystal display device of the present invention toward the back surface of the liquid crystal display device, and enters the illumination light from the front of the liquid crystal display device. An illumination means for reflecting light toward the back of the liquid crystal display element is provided.

This liquid crystal display device performs reflection type display utilizing external light when external light of sufficient brightness is obtained,
When external light of sufficient brightness cannot be obtained, a transmissive display using illumination light from the illumination means is performed,
According to this liquid crystal display device, since the liquid crystal display element performs the display as described above, when a reflective display using external light is used, a color image with sufficient screen brightness is displayed,
In the case of transmissive display using illumination light from the illumination means, a color image with sufficient brightness and contrast can be displayed.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the liquid crystal display device of the present invention has a plurality of liquid crystal display elements corresponding to other pixel areas except for a predetermined pixel area which is present in at least one ratio for every predetermined number of pixel areas. And a voltage corresponding to image data is applied between electrodes of a pixel region corresponding to the colored film (hereinafter referred to as a colored pixel region), and a pixel region not corresponding to the colored film is provided. (Hereinafter, uncolored pixel area)
By applying a voltage that causes the display of the pixel area to always be a non-colored bright display or dark display between the electrodes, the display is sufficiently bright in the reflective display using external light. In the case of a transmissive display that displays an accurate color image and uses illumination light from illumination means, a color image with sufficient brightness and contrast can be displayed.

Further, in the liquid crystal display device according to the present invention, the illumination light is emitted toward the liquid crystal display element behind the liquid crystal display element and the external light incident from the front of the liquid crystal display element is transmitted to the liquid crystal display element. In the case of a reflective display using external light, a color image with sufficient screen brightness is displayed, and a transmissive display using illuminating light from the illuminating means is provided by arranging the illuminating means that reflects toward the In this case, a color image with sufficient brightness and contrast can be displayed.

The liquid crystal display device of the present invention is not limited to a two-way liquid crystal display device that performs both a reflective display using external light and a transmissive display using illumination light from illumination means. The present invention can be applied to a reflection type liquid crystal display device that performs only reflection type display using external light, and a transmission type liquid crystal display device that performs only transmission type display using illumination light from illumination means.

In the present invention, the area of the colored pixel region of the liquid crystal display element may be substantially equal to the area of the non-colored pixel region. In that case, it is desirable that at least half or more of the predetermined number of pixel regions in which the colored pixel regions are present in at least one ratio be the colored pixel regions. A non-colored bright display in the reflective display or a dark display in the transmissive display is made less conspicuous, and a color image with better image quality can be displayed.

Further, in the present invention, in the liquid crystal display element, one of two adjacent pixel regions is the colored pixel region and the other is the non-colored pixel region, and the area of the non-colored pixel region is the colored pixel region. The area may be set to be smaller than the area of the pixel region. By doing so, the non-colored bright display in the reflective display or the dark display in the transmissive display is made more inconspicuous. A high quality color image can be displayed.

[0034]

1 to 5 show a first embodiment of the present invention. FIG. 1 is a plan view of a part of a liquid crystal display element, and FIG. 2 is a two-way liquid crystal display using the liquid crystal display element. FIG. 2 is a cross-sectional view of the device taken along the line II-II of FIG. 1.

As shown in FIG. 2, the liquid crystal display device of this embodiment has a liquid crystal display element 1 for displaying a color image and an illuminating means provided behind the liquid crystal display element 1 and having a function of reflecting light. 20.

As shown in FIGS. 1 and 2, the liquid crystal display element 1 has a pair of transparent substrates (for example, glass substrates) 2 and 3 opposed to each other with a liquid crystal layer 14 therebetween.
Transparent electrodes 12, 4 forming a plurality of pixel regions A, A 'arranged in a matrix by opposing regions are provided, and a colored film of a plurality of colors having different absorption wavelength bands is provided on the inner surface of one of the substrates. , Eg red, green, blue
The color filters 10R, 10G, and 10B of colors are arranged and provided as described later.

The liquid crystal display element 1 is of an active matrix type using a TFT (thin film transistor) as an active element, and one of its substrates, for example, a transparent electrode 4 provided on the inner surface of a rear substrate 3 has a matrix shape. The transparent electrode 12 provided on the other substrate, that is, the inner surface of the front substrate 2, is a single-film counter electrode facing all of the pixel electrodes 4.

The liquid crystal display element 1 has a so-called grid-type arrangement in which the pixel electrodes 4 are linearly arranged in a row direction (left-right direction of the screen) and a column direction (vertical direction of the screen). belongs to.

That is, on the inner surface of the rear substrate 3 of the liquid crystal display element 1, the pixel electrodes 4, a plurality of TFTs 5 connected to the pixel electrodes 4,
A gate line 6 and a data line 7 for supplying a gate signal and a data signal to the FT 5 are provided, and an alignment film 8 is formed thereon.

In FIG. 1, the TFT 5 and the gate line 6
2 and the data line 7 are shown as an equivalent circuit, and FIG.
Although the TFT 5, the gate line 6, and the data line 7 are omitted in the figure, the TFT 5 has a gate electrode formed on the substrate 3, a gate insulating film covering the gate electrode, and An i-type semiconductor film is formed facing the gate electrode, and a source electrode and a drain electrode are formed on both sides of the i-type semiconductor film via an n-type semiconductor film.

The gate line 6 is wired along one side of each pixel electrode row, and the T
The gate electrode of the FT 5 is formed integrally with the gate line 6 corresponding to the row. The gate insulating film (transparent film) of the TFT 5 is formed over substantially the entire surface of the substrate 3, and the gate line 6 is covered with the gate insulating film except for its terminal.

Further, the data line 7 is wired on the gate insulating film along one side of each pixel electrode column, and the drain electrode of the TFT 5 in each column is
It is connected to the data line 7 corresponding to the column. The data line 7 may be formed integrally with the drain electrode of the TFT 5 in each column, and the TFT 5 is covered with an insulating film, and the data line 7 is wired thereon, and is provided on the insulating film. The contact hole may be connected to the drain electrode of the TFT 5.

The pixel electrodes 4 are formed on the gate insulating film, and these pixel electrodes 4 are connected to the source electrodes of the corresponding TFTs 5 at one side edge.

On the other hand, the front substrate 2 of the liquid crystal display element 1
The light-shielding film 9 corresponding to the region between the adjacent pixel regions and the color filters 10 of the three colors red, green and blue
R, 10G, and 10B are provided. The counter electrode 12 is provided on a transparent protective film (insulating film) 11 provided so as to cover them, and an alignment film 13 is formed thereon. Note that the protective film 11 is formed of the color filters 10R, 1R.
By appropriately selecting the materials of 0G and 10B, it can be omitted.

The light-shielding film 9 is made of, for example, a dark-colored metal film such as chromium. The light-shielding film 9 is formed in all adjacent pixel regions where the pixel electrodes 4 and the opposing electrodes 12 face each other. It is formed in a shape corresponding to the region between and the entirety of the TFT 5. Note that, in FIG.
In order to make it easier to distinguish between them, the light-shielding film is shaded in parallel.

The red, green, and blue color filters 10R, 10G, and 10B are provided in at least one predetermined pixel region (hereinafter referred to as a non-colored pixel region) at a ratio of at least one for each predetermined number of pixel regions. A) Other pixel regions except for A '(hereinafter referred to as colored pixel regions) A are provided respectively. These color filters 10R, 10R
G and 10B are formed in a size corresponding to the entire colored pixel area A.

That is, in this embodiment, as shown in FIG. 1, every third pixel region among a plurality of pixel regions arranged in a row direction and each of a plurality of pixel regions Every third pixel area is connected to a color filter 10.
A non-colored pixel area A 'not corresponding to R, 10G, 10B, and all other pixel areas are color filters 10R, 1R.
The color pixel area A corresponds to 0G and 10B.

In this embodiment, each of the pixel electrodes 4
Are formed in substantially the same size. Therefore, the area of the color pixel region A corresponding to the color filters 10R, 10G, and 10B and the color filters 10R, 10G, 1
The areas of the non-colored pixel areas A ′ that do not correspond to 0B are substantially the same, and at least half or more of the predetermined number of pixel areas are the color filters 10R, 10G, 1
The color pixel area A corresponds to 0B.

FIG. 3 shows the color filters 10R and 10R.
G and 10B are shown, and these color filters 10R, 10G, and 10B correspond to the colored pixel area A of the plurality of pixel areas arranged in a matrix, respectively, and correspond to the red filter 10R and the green color. The filters 10G and the blue filters 10B are provided alternately in the row direction and the column direction, respectively.

Therefore, in this embodiment, when a total of four adjacent pixel regions in two rows and two columns are randomly selected and viewed from among a plurality of pixel regions arranged in a matrix, the four One or two non-colored pixel areas A 'always exist in the pixel area, and the predetermined number (four) of the pixel areas in which the non-colored pixel areas A' are present in at least one ratio. At least half or more (two or more) of the pixel regions are the color filters 10.
The color pixel areas A correspond to R, 10G, and 10B.

The pair of substrates 2 and 3 are joined at their peripheral edges via a frame-shaped sealing material (not shown), and a liquid crystal is formed between the substrates 2 and 3 in a region surrounded by the sealing material. A layer 14 is provided.

The alignment films 13 and 8 provided on the inner surfaces of the pair of substrates 2 and 3 are each subjected to an alignment treatment by rubbing the film surfaces in a predetermined direction.
The alignment direction of the liquid crystal molecules of the liquid crystal layer 14 between the substrates 2 and 3 in the vicinity of the substrates 2 and 3 is regulated by the alignment films 13 and 8, and is aligned in a predetermined alignment state between the substrates 2 and 3. are doing.

Further, polarizing plates 15 and 16 are disposed on the outer surfaces of the pair of substrates 2 and 3, respectively, and these polarizing plates 15 and 16 are arranged so that their transmission axes are directed in predetermined directions. It is provided in.

The liquid crystal display element 1 is of a TN type, and the liquid crystal molecules of the liquid crystal layer 14 are twist-aligned at a twist angle of about 90 ° between the substrates 2 and 3. Polarizing plate 15 on the front side of 15 and 16
Is arranged so that its transmission axis is substantially parallel to or substantially perpendicular to the orientation direction of the liquid crystal molecules in the vicinity of the front-side substrate 2, and the rear-side polarizing plate 16 has its transmission axis set to the front-side polarizing plate. It is provided substantially orthogonal to or substantially parallel to the 15 transmission axes.

In the liquid crystal display element 1, a voltage corresponding to image data is applied between the electrodes 4 and 12 of the colored pixel area A corresponding to the color filters 10R, 10G and 10B, and applied to the color filters 10R, 10G and 10B. The non-colored pixel area A 'is driven by applying a voltage between the electrodes 4 and 12 of the non-colored pixel area A' which makes the non-colored pixel area A 'always display a non-colored bright or dark display.

That is, the liquid crystal display element 1 sequentially applies a gate signal to each gate line 6 with the potential of the counter electrode 12 connected to a reference potential (for example, ground potential) by a drive circuit (not shown), In synchronization with each of the data lines 7, when the colored pixel area A corresponding to the color filters 10R, 10G, and 10B is selected, the potential becomes the potential corresponding to the image data, and the non-colored pixel area A that does not correspond to the color filters 10R, 10G, and 10B. ′, A data signal having a waveform at which a non-colored bright display or dark display can be obtained is applied to the liquid crystal layer 14 of the pixel regions A and A ′ of each row via the TFT 5. Is driven by applying a voltage corresponding to a potential difference between the potential of the pixel electrode 4 to which the voltage is supplied and the potential of the counter electrode 12 (reference potential).

Whether the display of the non-colored pixel area A 'is a non-colored bright display or a dark display is selected depending on whether a reflective display or a transmissive display is to be performed. The non-colored bright display is always performed when the pattern display is performed, and the dark display is always performed when the transmissive display using the illumination light from the illuminating means 20 disposed behind the liquid crystal display element 1 is performed.

The voltage applied between the electrodes 4 and 12 in the non-colored pixel region A 'is a voltage at which the liquid crystal molecules are twist-aligned with respect to the substrates 2 and 3 in a falling state close to the initial pretilt angle (hereinafter referred to as the initial voltage). And a voltage at which the liquid crystal molecules rise and align substantially perpendicularly to the surfaces of the substrates 2 and 3 (hereinafter, referred to as a vertical alignment voltage). In the case of a normally white mode liquid crystal display element in which the transmission axes of the non-colored pixel regions A 'are arranged substantially orthogonal to each other, when the initial alignment voltage is applied between the electrodes 4 and 12 in the non-colored pixel region A', The display of the pixel area A 'becomes a non-colored bright display, and when the vertical alignment voltage is applied between the electrodes 4 and 12, the display of the non-colored pixel area A' becomes almost black and dark.

In the case of a normally black mode liquid crystal display device in which the pair of polarizing plates 15 and 16 are arranged with their transmission axes substantially parallel to each other, the electrodes 4 and 12 in the non-colored pixel region A 'are provided. When the initial alignment voltage is applied during this time, the display of the non-colored pixel area A 'becomes almost black and dark display. When the vertical alignment voltage is applied between the electrodes 4 and 12, The display of the pixel area A 'becomes a non-colored bright display.

Next, the illuminating means 20 disposed behind the liquid crystal display element 1 will be described. The illuminating means 20 used in this embodiment is, as shown in FIG. Transflective plate 22 in front of
Is arranged.

That is, the illumination panel 21 has a light guide plate 21a having at least one end surface as a light incident surface and a front surface as a light exit surface for light taken in from the end surface, and a light guide plate 2a.
1a, and a light source unit (not shown) arranged opposite to the end face of the semi-transmissive reflection plate 22.
It is arranged on the front surface of the light guide plate 21a.

In general, a flat transparent plate made of acrylic resin or the like is used for the light guide plate 21a, and a straight tube fluorescent lamp or a plurality of L
An LED array or the like in which EDs (light emitting diodes) are arranged is used.

The lighting panel 21 guides light from a light source unit (not shown) by the light guide plate 21a and emits the light from the front surface thereof. The light from the light source unit is taken into the light guide plate 21a from an end face thereof. The light is guided by repetition of reflection on the front and back surfaces of the light guide plate 21a as shown by the path indicated by the solid line in FIG. 2, and is emitted from almost the entire front surface of the light guide plate. In addition, the transflective plate 22 reflects and transmits incident light at a reflection / transmittance according to its characteristics.

The illuminating means 20 is disposed behind the liquid crystal display element 1 with the transflective plate 22 provided on the front surface of the illuminating panel 21 facing the rear surface of the liquid crystal display element 1. The liquid crystal display device 1 and the illuminating means 20 constitute a two-way liquid crystal display device.

This two-way liquid crystal display device performs a reflective display using external light when sufficient external light is obtained, and performs the above-described illumination when external light with sufficient brightness is not obtained. The transmissive display using the illumination light from the means 20 is performed, and the light source unit of the illuminating means 20 is turned on when performing the transmissive display.

First, a description will be given of a reflection type display using external light. In this case, external light incident on the liquid crystal display element 1 from the front thereof is applied as shown by a broken line in FIG.
The light passes through the liquid crystal display element 1 and is emitted to the rear surface thereof, and the light is reflected by the semi-transmissive reflection plate 22 on the front surface of the illuminating means 20, and is transmitted again through the liquid crystal display element 1 and emitted to the front surface.

The front substrate 2 of the liquid crystal display element 1
The light-shielding film 9 corresponding to the region between the adjacent pixel regions is provided on the inner surface of the device, so that the region between the adjacent pixel regions is always in a black state.

In the case of this reflection type display, the liquid crystal display element 1
External light that has entered from the front of the pixel region is absorbed by the front-side polarizing plate 15 as light having a polarization component along the absorption axis thereof, and becomes linearly polarized light along the transmission axis of the front-side polarizing plate 15 to form a pixel region. A, A ′.

As described above, the liquid crystal display element 1 has three color filters 10R, 1R of red, green, and blue.
0G and 10B are set to at least one for every predetermined number of pixel regions.
Of the light incident on the liquid crystal display element 1 from the front thereof, except for the non-colored pixel area A ′, which is present at two different ratios. The light incident on A is absorbed by the color filters 10R, 10G, and 10B in the wavelength component of the absorption wavelength band and is colored in any of red, green, and blue, and corresponds to the color filters 10R, 10G, and 10B. Light incident on the non-colored non-colored pixel area A 'is not colored.

As described above, the liquid crystal display element 1 performs the color filters 10R, 10G, and 10B of each pixel region when performing the reflective display using external light.
A voltage corresponding to the image data is applied between the electrodes 4 and 12 of the colored pixel region A corresponding to the color filters 10R and 10R.
The electrodes 4 of the non-colored pixel area A 'that do not correspond to G and 10B
The pixel 12 is driven by applying a voltage which makes the display of the non-colored pixel area A 'non-colored and bright.

For this reason, in the colored pixel area A, the red, red, and blue light passes through the color filters 10R, 10G, and 10B.
The colored light colored in any one of green and blue is applied to the liquid crystal layer 14.
In the process of transmitting the light, the light is rotated according to the orientation state of the liquid crystal molecules which is changed by the voltage applied between the electrodes 4 and 12, and the light is incident on the rear-side polarizing plate 16, among which the rear-side polarizing plate The light of the polarization component along the transmission axis 16 passes through the polarizing plate 16 and is emitted to the back of the liquid crystal display element 1, and the light is reflected by the semi-transmissive reflecting plate 22 on the front of the illuminating means 20, and again The liquid crystal display element 1 is
6, liquid crystal layer, color filters 10R, 10G, 10B,
The light passes through the front-side polarizing plate 15 in this order and is emitted to the front surface.

Therefore, the intensity of the colored light emitted from each colored pixel area A of the liquid crystal display element 1 depends on the voltage applied between the electrodes 4 and 12 of the colored pixel area A (voltage according to image data). A full-color image is displayed by mixing the red, green, and blue colored lights of various intensities emitted from these colored pixel regions A.

However, the light emitted from each of the colored pixel areas A is transmitted twice through the color filters 10R, 10G, and 10B in a path passing through the liquid crystal display element 1 in the back direction and a path passing in the front direction. Light
Compared with the intensity of the incident external light, the color filters 10R,
This is a weakly colored light that has been twice absorbed by 10G and 10B.

On the other hand, the light emitted from the non-colored pixel area A 'is transmitted through the liquid crystal layer 14 and transmitted through the rear polarizer 16 with a high transmittance, and is emitted to the rear surface of the liquid crystal display element 1. The light is reflected by the transflective plate 22 on the front surface of the illuminating means 20, and the liquid crystal display element 1 is again moved to the rear polarizing plate 1
6, the liquid crystal layer and the front-side polarizing plate 15 are transmitted in this order and emitted to the front surface.

Therefore, the intensity of the light emitted from each non-colored pixel area A 'of the liquid crystal display element 1 is always constant, and the emitted light is emitted from the color filters 10R, 10G, 1A.
Non-colored light of sufficient intensity that does not receive any absorption by 0B.

The light emitted from each of the non-colored pixel areas A 'is transmitted by the transflective plate 22 of the illumination means 20.
The light is reflected at a reflectivity according to the characteristics. The reflectivity of the semi-transmissive reflector 22 is considerably lower than that of a normal reflector, but the light is not absorbed twice by the color filters 10R, 10G, and 10B. The intensity of the light is sufficiently high compared to the intensity of the light (colored light) emitted from the colored pixel region A.

That is, when performing the reflective display using external light, the liquid crystal display element 1 has the electrodes 4, 12 of the colored pixel area A corresponding to the color filters 10R, 10G, 10B of each pixel area. A voltage corresponding to the image data is applied between the electrodes 4 and 12 of the non-colored pixel area A 'which does not correspond to the color filters 10R, 10G and 10B. In this case, the color filters 10R, 10G, and 10B are driven from the colored pixel areas A corresponding to the color filters 10R, 10G, and 10B.
As a result, colored light of any one of red, green, and blue colors having a wavelength component other than the transmission wavelength band corresponding to the color is emitted, and the non-colored pixel area A ′ not corresponding to the color filters 10R, 10G, and 10B. From the color filter 10
Non-colored light that is not absorbed by R, 10G, and 10B is emitted.

In the case of the reflection type display, the incident external light is light having an intensity corresponding to the brightness of the display observation environment, and in the colored pixel area A corresponding to the color filters 10R, 10G, 10B, Since the light passes through the color filters 10R, 10G, and 10B twice in a path through which light passes through the liquid crystal display element 1 in the back direction and a path in which the light passes through in the front direction, the color filters 10R, 10G, 1
The light emitted from the colored pixel region A corresponding to the color filters 10R and 10B corresponds to the intensity of the incident external light.
G and 10B are weakly colored lights that have been twice absorbed by the color filters 10R, 10G, and 10B.
The non-colored light emitted from the non-colored pixel area A ′ does not absorb the light by the color filters 10R, 10G, and 10B, and therefore, is the colored light that is the light emitted from the colorized pixel area A. It is light with sufficiently high intensity as compared with.

Therefore, in the case of the reflection type display using external light, the color filters 10R, 10R
The colored light emitted from the colored pixel area A corresponding to G, 10B is light of low intensity, but is a predetermined non-colored pixel area (color filter 10R, 10G) which is present in at least one ratio for every predetermined number of pixel areas. , 10B), a non-colored light having a sufficiently higher intensity than the colored light is emitted from the pixel region A ', and the non-colored light compensates for the brightness of the entire screen, and provides a full-color image with a sufficient screen brightness. Can be displayed.

Next, the transmission type display using the illumination light from the illumination means 20 will be described. In this case, the illumination light from the illumination means 20 is applied to the liquid crystal display as shown by the solid line in FIG. The light enters the element 1 from the back, passes through the liquid crystal display element 1, and exits to the front.

The front substrate 2 of the liquid crystal display element 1
Is provided with a light-shielding film 9 corresponding to the region between the adjacent pixel regions. Therefore, even in the transmission type display, the region between the adjacent pixel regions is always in a black state.

In the case of this transmissive display, the liquid crystal display element 1
Illumination light incident from the rear surface of the pixel region is absorbed by the rear-side polarizing plate 16 as light having a polarization component along the absorption axis thereof, and becomes linearly polarized light along the transmission axis of the rear-side polarizing plate 16. A, A ′.

The illuminating means 20 includes an illuminating panel 21 which guides light from a light source (not shown) by a light guide plate 21a and emits the light from the front surface thereof, and a semi-transmissive reflection plate provided on the front surface of the light guide plate 21a. The semi-transmissive reflector 22 reflects and transmits incident light with a reflection / transmittance according to its characteristics. Therefore, the luminance of the illumination light emitted from the illumination means 20 is controlled by the light source unit. Although the luminance of the light source unit is lower than the luminance of the light, the light emission luminance of the light source unit is set to be sufficiently high. Therefore, illumination light having sufficiently high luminance can be incident on the liquid crystal display element 1.

As described above, when performing the transmissive display using the illumination light from the illumination means 20, the liquid crystal display element 1 corresponds to the color filters 10R, 10G, and 10B of each pixel area. A voltage corresponding to the image data is applied between the electrodes 4 and 12 of the colored pixel region A, and the non-colored pixel region between the electrodes 4 and 12 of the non-colored pixel region A 'which does not correspond to the color filters 10R, 10G and 10B. The display of A 'is driven by applying a voltage that makes the display dark.

For this reason, the color filters 10R, 10G, 1 out of the pixel areas A, A 'of the liquid crystal display element 1
In the colored pixel area A corresponding to 0B, the rear-side polarizing plate 16
Light (linearly polarized light) transmitted through the liquid crystal is rotated in the process of transmitting through the liquid crystal layer 14 in accordance with the orientation state of the liquid crystal molecules which is changed by the voltage applied between the electrodes 4 and 12, and the light is converted into color light. The filters 10 </ b> R, 10 </ b> G, and 10 </ b> B absorb the light of the wavelength component in the absorption wavelength band and color the light in any of red, green, and blue, and of the colored light, along the transmission axis of the front-side polarizing plate 15. The polarized component light is
And exits to the front of the liquid crystal display element 1.

Therefore, the intensity of the colored light emitted from each colored pixel area A of the liquid crystal display element 1 depends on the voltage applied between the electrodes 4 and 12 of the colored pixel area A (voltage according to image data). A full-color image is displayed by mixing the red, green, and blue colored lights of various intensities emitted from these colored pixel regions A.

On the other hand, the voltage applied between the electrodes 4 and 12 in the non-colored pixel area A 'during the transmissive display is a voltage at which the display is always dark, and most of the light transmitted through the liquid crystal layer 14 Is absorbed by the front-side polarizing plate 15. That is,
The display of each non-colored pixel area A ′ in the transmissive display is almost black and dark.

That is, when performing the transmissive display using the illuminating light from the illuminating means 20 disposed behind the liquid crystal display element 1, the liquid crystal display element 1 has the electrodes 4 of the colored pixel area A among the pixel areas. The non-colored pixel area A 'is driven by applying a voltage corresponding to image data between the electrodes 12 and applying a voltage between the electrodes 4 and 12 of the non-colored pixel area A' so that the display of the non-colored pixel area A 'is dark. In this case, colored light of any one of red, green, and blue in which the wavelength components other than the transmission wavelength band corresponding to the color are absorbed from the colored pixel region A by the color filters 10R, 10G, and 10B. And almost no light is emitted from the non-colored pixel area A ′.

In the case of this transmissive display, the luminance of the illumination light is high, and in the colored pixel area A, light incident from the back of the liquid crystal display element 1
Is transmitted only toward the front surface thereof, so that the color filters 10R, 10G, and 10B absorb light only once, so that the intensity of the colored light emitted from the colored pixel region A is sufficiently high.

Therefore, in the case of the transmissive display, the intensity of the colored light emitted from the colored pixel area A is sufficiently higher than the brightness of the display observation environment, and the non-colored pixel area A '
, And a full-color image with sufficient brightness and contrast can be displayed.

The color filters 10R, 10G, 10B provided corresponding to the color pixel areas A are provided.
Is formed in a size corresponding to the entirety of the colored pixel region A as described above, so that non-colored light does not leak from the inside of the colored pixel region A. On the inner surface of the side substrate 2, each pixel region A,
Since the light-shielding film 9 corresponding to the region between A 'is provided, the region between the pixel regions A and A' is always in a black state. There is no reduction in contrast due to leakage of uncolored light from the region between the regions.

Moreover, in the liquid crystal display element 1, since at least one non-colored pixel area A 'which does not correspond to the color filters 10R, 10G, and 10B is present for every predetermined number of pixel areas, the reflective type is used. The non-colored bright display area at the time of display or the dark display area at the time of transmissive display is almost uniformly distributed over the entire screen, and in any display, the brightness of the screen is almost uniform, and the bright display area Alternatively, it is possible to display a full-color image of good image quality in which the dark display area is not conspicuous.

The liquid crystal display element 1 has a color pixel region A corresponding to the color filters 10R, 10G, 10B.
And the area of the non-colored pixel area A 'not corresponding to the color filters 10R, 10G, 10B is substantially the same, but the non-colored pixel area A' not corresponding to the color filters 10R, 10G, 10B is at least one. At least half or more of the predetermined number of pixel regions existing at the same ratio are used as color filters 10R, 10G, 10G.
Since the color pixel area A corresponding to B is used, a non-colored bright display in the reflective display or a dark display in the transmissive display is made less noticeable, and a full-color image with better image quality can be displayed. it can.

The two-way liquid crystal display device is
When external light of sufficient brightness is obtained, reflective display using external light is performed, and when external light of sufficient brightness is not obtained, transmissive display using illumination light from the illumination unit is performed. According to this liquid crystal display device, since the liquid crystal display element 1 performs the above-described display, a full-color image with sufficient screen brightness can be obtained when a reflective display using external light is used. In the case of the transmission type display for displaying and utilizing the illumination light from the illumination means 20, a full-color image with sufficient brightness and contrast can be displayed.

The two-way liquid crystal display device of the embodiment described above has a lighting means 2 in which a transflective plate 22 is provided behind the liquid crystal display element 1 and in front of a sidelight type lighting panel 21.
0, the illuminating means arranged behind the liquid crystal display element 1 is described in, for example, Japanese Patent Application No. 35360/1997.
Theoretically, 100% of the light from the light source unit is emitted and 10% of the incident light from the front is described in the specification and drawings of No. 3.
It may be one that reflects 0%.

When such illumination means is used, the light from the light source can be emitted as illumination light with high efficiency, and the incident light from the front can be reflected with high reflectivity. The light emission luminance of the light source unit is set relatively low as compared with the case where the lighting unit 20 including the transflective plate 22 having a lower reflectance than the reflector is used,
A sufficiently bright transmissive display can be performed with low power consumption, and a reflective display using external light can be further brightened.

Further, as shown in FIG. 3, the liquid crystal display element 1 of the above embodiment has the color filters 10R, 10G, 1G.
0B are provided alternately in the row direction and the column direction in the order of the red filter 10R, the green filter 10G, and the blue filter 10B in correspondence with the colored pixel area A of the plurality of pixel areas arranged in a matrix. However, the color filters 10R, 10G, 10B
May be provided in another arrangement state.

FIG. 4 is a diagram showing the arrangement of color filters of a liquid crystal display device according to a second embodiment of the present invention. In this embodiment, every third pixel region among a plurality of pixel regions arranged in the row direction is shown. Each pixel region and every third pixel region among the plurality of pixel regions arranged in the column direction are connected to the color filter 1.
Non-colored pixel area A 'not corresponding to 0R, 10G, 10B
And all the other pixel regions are set as color filters 10R,
10G and 10B as well as the color pixel area A, and red, green and blue color filters 10R, 10G and 10
B are provided alternately for each pixel region row, and color filters 10R, 10G, and 10B of the same color correspond to all the color pixel regions A in each pixel region in the same column.

In this case, one or two non-colored pixel areas A 'always exist in a total of four adjacent pixel areas in two rows and two columns, and at least one non-colored pixel area A' is provided. At least a half or more (two or more) of the four pixel regions existing in the two ratios are colored pixel regions A corresponding to the color filters 10R, 10G, and 10B.

FIG. 5 is a diagram showing a color filter arrangement state of a liquid crystal display device according to a third embodiment of the present invention. In this embodiment, every third pixel region among a plurality of pixel regions arranged in the row direction is shown. The pixel region and every third pixel region among the plurality of pixel regions arranged in the column direction are
A non-colored pixel area A 'not corresponding to R, 10G, 10B, and all other pixel areas are color filters 10R, 1R.
In addition to the color pixel regions A corresponding to the color pixel regions 0G and 10B,
Red, green, blue color filters 10R, 10G, 10B
Are alternately arranged in the row direction and the column direction, respectively.

In this case, one or two non-colored pixel areas A 'always exist in two or three adjacent pixel areas in the row direction and three or two adjacent pixel areas in the column direction. In addition, at least half (three or more) of the six pixel regions in which the non-colored pixel regions A 'are present in at least one ratio are colored corresponding to the color filters 10R, 10G, and 10B. Pixel area A
Becomes

The liquid crystal display elements 1 of the first to third embodiments are of a so-called grid type in which the pixel electrodes 4 are arranged linearly in the row direction and the column direction, respectively. However, in the liquid crystal display element 1, the pixel electrodes 4 forming the colored pixel area A corresponding to the same color filter are alternately arranged in a row direction and linearly arranged. A so-called delta arrangement (also referred to as a mosaic arrangement) type in which the pixels are alternately shifted in the row direction by 5 pitches may be used.

Further, in the liquid crystal display element 1 of the first embodiment, the area of the colored pixel area A corresponding to the color filters 10R, 10G, 10B and the color filters 10R, 1
The areas of the non-colored pixel regions A 'that do not correspond to 0G and 10B are made substantially the same, and a predetermined number (four in the color filter arrangement state shown in FIGS. 3 and 4 and six in the color filter arrangement state shown in FIG. 6). ), At least half of the pixel regions are color filters 10R, 10G,
The color pixel area A corresponds to 10B,
The non-colored pixel area A ′ may be formed adjacent to each of the colored pixel areas A.

FIG. 6 is a plan view of a part of a liquid crystal display device 1 according to a fourth embodiment of the present invention. In the liquid crystal display device 1 of this embodiment, one of two pixel regions adjacent to each other is provided with a color filter. Colored pixel areas A corresponding to 10R, 10G, and 10B, and the other is a color filter 10R, 10G, 1
The non-colored pixel area A 'does not correspond to 0B.

That is, the liquid crystal display element 1 has a TFT
Is an active matrix type having an active element, and a pair of substrates 2 opposed to each other with a liquid crystal layer interposed therebetween.
3, a plurality of pixel electrodes (hereinafter, referred to as display pixel electrodes) 4a for forming a colored pixel area A corresponding to a color filter of the same color are provided on the inner surface of the rear substrate 3 in the row direction. They are arranged in a straight line, and are arranged in a zigzag manner so as to be alternately shifted left and right (row direction) by about 1.5 pitches for each row in the column direction, and are provided on the lower edges of these display pixel electrodes 4a, respectively. A second pixel electrode (hereinafter, referred to as a dimming pixel electrode) 4b for forming the non-colored pixel region A 'is provided adjacent to the pixel electrode.

The dimming pixel electrode 4b is formed to have a width substantially equal to the width of the display pixel electrode 4a and a vertical width smaller than the vertical width of the display pixel electrode 4a. Therefore, these dimming pixel electrodes 4b,
The area of the non-colored pixel area A ′ on which the opposing electrode (not shown) on the inner surface of the front substrate 2 faces each other is the colored pixel area A where the display pixel electrode 4a and the opposing electrode face each other.
Is set smaller than the area.

The colored pixel area A and the non-colored pixel area A '
Are 7 to 9: 3 to 1 (when the total area of both the colored pixel region A and the non-colored pixel region A ′ is 100%,
The area of the colored pixel area A is preferably 70% to 90%, and the area of the non-colored pixel area A 'is preferably 30% to 10%), and more preferably about 8: 2.

A plurality of TFTs 5 connected to the display pixel electrode 4a and the dimming pixel electrode 4b, respectively, are provided on the inner surface of the rear substrate 3 and the display pixel electrode 4b.
a gate line 6a for supplying a gate signal to the TFT 5 connected to the pixel electrode 4a and a gate line 6b for supplying a gate signal to the TFT 5 connected to the pixel electrode 4b for light control;
A data line 7 for supplying a data signal to these TFTs 5 is provided, and an alignment film (not shown) is formed thereon.

In FIG. 6, the TFT 5, the gate line 6, and the data line 7 are shown in an equivalent circuit.
The TFT 5 has the same configuration as the TFT 5 of the liquid crystal display element 1 of the above-described first embodiment, and is used for displaying each column arranged in a zigzag manner by shifting about 1.5 pitches in each row alternately left and right. The pixel electrodes 3a and the dimming pixel electrodes 4b of each row adjacent to the lower edges of the display pixel electrodes 4a are connected to the display pixel electrode 4a and the dimming pixel electrode 4b shifted to the left. The TFT 5 is provided on the right side of the pixel electrodes 4a and 4b, and the TFT 5 connected to the display pixel electrode 4a and the dimming pixel electrode 4b shifted rightward is located on the left side of the pixel electrodes 4a and 4b. Is provided.

The gate lines 6a and 6b are wired on the rear substrate 3 along one side of each display pixel electrode row and one side of the dimming pixel electrode row. The gate electrodes of the TFTs 5 in the electrode row and the dimming pixel electrode row are connected to the gate lines 6a and 6b corresponding to the row.
Are formed integrally. The gate insulating film (transparent film) of the TFT 5 is formed over substantially the entire surface of the substrate 3, and the gate lines 6a and 6b are covered with the gate insulating film except for the terminal portions.

Further, the data line 7 is provided on the gate insulating film for each pixel electrode column arranged in a zigzag pattern on the TFT connection side of each display pixel electrode 4a and dimming pixel electrode 4b in the column. And the drain electrodes of the TFTs 5 connected to the display pixel electrode 4a and the dimming pixel electrode 4b in each column are connected to the same data line 7 corresponding to the column. Is connected to

The light shielding film 9 is provided on the inner surface of the front substrate 2.
And three color filters 10R, 10G of red, green and blue.
10B, a counter electrode in the form of a single film (not shown) is provided thereon, and an alignment film (not shown) is further formed thereon.

The light shielding film 9 is provided on the display pixel electrode 4a.
The dimming pixel electrode 4b and the counter electrode 12 are formed in a shape corresponding to the entire area between all the pixel areas A and A 'facing each other and the entire TFT 5. In FIG. 6, in order to make it easier to distinguish the light-shielding films 9, the light-shielding film portions are hatched in parallel.

In this embodiment, the color filters 10R, 10G, and 10B are formed in a size corresponding to the entire color pixel area A, and the red, green, and blue color filters 10R, 10G, and 10B are formed. The color filters 10R, 10G, and 10B of the same color correspond to all the colored pixel areas A in the pixel area of the same column (zigzag column) by being alternately arranged for each pixel area row.

The liquid crystal display element 1 is of the TN type, and the liquid crystal molecules of the liquid crystal layer are twist-oriented at a twist angle of about 90 ° between the two substrates 2 and 3. , 3 on the outer surface, a front side polarizing plate and a back side polarizing plate make their transmission axes substantially orthogonal to each other (in a normally white mode) or almost parallel (in a normally black mode). Is provided.

That is, the liquid crystal display element 1 of this embodiment
Is a color pixel area A corresponding to the color filters 10R, 10G, 10B, and a non-color pixel area A 'not corresponding to the color filters 10R, 10G, 10B. The area of the non-colored pixel area A ′ that does not correspond to 10R, 10G, 10B is determined by the color filters 10R, 10G, 1
The area is set smaller than the area of the colored pixel area A corresponding to 0B.

In the liquid crystal display element 1, a gate signal is sequentially applied to each of the gate lines 6a and 6b by a drive circuit (not shown) in a state where the potential of the counter electrode is connected to a reference potential (for example, ground potential). Each data line 7 has a potential corresponding to the image data when the colored pixel area A corresponding to the color filters 10R, 10G, 10B is selected, and the non-colored pixel area A ′ not corresponding to the color filters 10R, 10G, 10B. At the time of selection, by applying a data signal having a waveform that provides a potential for obtaining a non-colored bright display or dark display, the data signal is supplied to the liquid crystal layers of the pixel regions A and A 'of each row via the TFT 5. Of the pixel electrodes 4a and 4b and the potential of the counter electrode (reference potential)
And is driven by applying a voltage corresponding to the potential difference between.

Whether the display of the non-colored pixel area A 'is to be a non-colored bright display or a dark display is selected depending on whether a reflective display or a transmissive display is to be performed. The non-colored bright display is always performed when the pattern display is performed, and the dark display is always performed when the transmissive display using the illumination light from the illumination unit disposed behind the liquid crystal display element 1 is performed.

That is, the liquid crystal display element 1 has a structure in which each pixel region A,
A ′ between the electrodes of the colored pixel region A corresponding to the color filters 10R, 10G, 10B (the display pixel electrode 4a
A voltage corresponding to the image data is applied between the non-colored pixel area A ′ (between the dimming pixel electrode 4b and the counter electrode) that does not correspond to the color filters 10R, 10G, and 10B. ) Is driven by applying a voltage at which the display of the non-colored pixel area A 'becomes a non-colored bright display.

At this time, the color filters 10R, 10R
From the colored pixel area A corresponding to G, 10B, colored light in which wavelength components other than the transmission wavelength band corresponding to the color are absorbed by the color filters 10R, 10G, 10B is emitted, and the color filters 10R, 10G, 10B are emitted. From the non-colored pixel area A 'which does not correspond to the color filter 1
Non-colored light that is not absorbed by 0R, 10G, and 10B is emitted.

In the case of the reflection type display, the incident external light is light having an intensity corresponding to the brightness of the display observation environment, and in the colored pixel area A corresponding to the color filters 10R, 10G, 10B, Is transmitted twice through the color filters 10R, 10G, and 10B in a path that transmits the liquid crystal display element 1 in the rear direction and a path that transmits the liquid crystal display element 1 in the front direction. Compared with the intensity of the external light, the color filters 10R, 10R
G and 10B are weakly colored lights that have been twice absorbed by the color filters 10R, 10G, and 10B.
The non-colored light emitted from the non-colored pixel area A ′ does not absorb the light by the color filters 10R, 10G, and 10B, and therefore, is the colored light that is the light emitted from the colorized pixel area A. It is light with sufficiently high intensity as compared with.

Therefore, in the case of a reflection type display using external light, the color filters 10R and 10R in each pixel region are used.
The colored light emitted from the colored pixel area A corresponding to G, 10B is light with low intensity, but the intensity is sufficiently higher than the colored light from the non-colored pixel area A ′ which is present at a ratio of one for every two pixel areas. Since the non-colored light having high brightness is emitted, the brightness of the entire screen is supplemented by the non-colored light, and a full-color image with sufficient screen brightness can be displayed.

Further, this liquid crystal display element performs color display 10 of each pixel region when performing transmissive display using illumination light from illumination means disposed behind the liquid crystal display element.
A voltage corresponding to image data is applied between the electrodes (between the display pixel electrode 4a and the counter electrode) of the colored pixel area A corresponding to R, 10G, and 10B, and the color filters 10R and 10B are applied.
A voltage is applied between the electrodes of the non-colored pixel area A ′ (between the dimming pixel electrode 4b and the counter electrode) that does not correspond to G and 10B so that the display of the non-colored pixel area A ′ becomes dark. Is done.

At this time, the color filters 10R, 10R
From the colored pixel area A corresponding to G, 10B, colored light in which wavelength components other than the transmission wavelength band corresponding to the color are absorbed by the color filters 10R, 10G, 10B is emitted, and the color filters 10R, 10G, 10B are emitted. Hardly emits light from the non-colored pixel area A 'that does not correspond to

In the case of this transmissive display, the luminance of the illumination light is high and the color filters 10R, 10R
In the colored pixel area A corresponding to G and 10B, light incident from the back of the liquid crystal display element 1 only transmits through the liquid crystal display element 1 toward the front thereof, so that the color filters 10R, 10G, and 10B are used. Light is absorbed only once, so that the color filters 10R, 10R
The intensity of the colored light emitted from the colored pixel area A corresponding to G and 10B is sufficiently high.

Therefore, in the case of the transmissive display, the intensity of the colored light emitted from the colored pixel area A corresponding to the color filters 10R, 10G, 10B is sufficiently higher than the brightness of the display / observation environment. 10R,
It is possible to display a full-color image in which there is almost no light leakage from the non-colored pixel area A ′ that does not correspond to 10G and 10B, and that has sufficient brightness and contrast.

Further, in the liquid crystal display element 1, since the non-colored pixel area A 'is present at a ratio of one for every two pixel areas, the non-colored bright display or the transmissive non-colored display in the reflection type display is performed. The dark display at the time of type display is almost evenly distributed over the entire screen, and even in any display, the brightness of the screen is almost uniform, and the bright display or the dark display is inconspicuous, a full-color image of good image quality is obtained. Can be displayed.

Moreover, in the liquid crystal display element 1 of this embodiment, one of the two pixel regions adjacent to each other is a colored pixel region A corresponding to the color filters 10R, 10G and 10B, and the other is a color filter 10R, 10G and 10B. Since the non-colored pixel region A 'is an uncorresponding non-colored pixel region, and the area of the non-colored pixel region A' is set to be smaller than the area of the colored pixel region A, non-colored bright display or transmission in reflective display is performed. It is possible to display a full-color image with better image quality by making the dark display in the pattern display less noticeable.

Therefore, the liquid crystal display element 1 of this embodiment
Behind, the illuminating light as shown in FIG. 2 is emitted toward the back surface of the liquid crystal display device 1, and the external light incident from the front of the liquid crystal display device 1 is directed toward the back surface of the liquid crystal display device 1. If a two-way liquid crystal display device is constructed by arranging the illuminating means 20 that reflects light, a full-color image with sufficient screen brightness is displayed in the case of a reflective display using external light. In the case of the transmissive display using the illumination light from 20, a full-color image with sufficient brightness and contrast can be displayed.

The liquid crystal display element 1 of the second embodiment
Then, the non-colored pixel area A ′ that does not correspond to the color filters 10R, 10G, and 10B is replaced with the color filters 10R, 1
The non-colored pixel area A ′ is formed adjacent to the lower edge of the colored pixel area A corresponding to 0G and 10B, but is formed adjacent to the upper edge or side edge of the colored pixel area A. The arrangement state of the display pixel electrodes 4a forming the colored pixel region A is not limited to the delta arrangement as shown in FIG. 6, and each display pixel electrode 4a may be arranged in the row direction and the column direction, respectively. A so-called lattice-like arrangement in which linear arrangement is performed may be used.

Further, the liquid crystal display element 1 of the first to fourth embodiments uses a color filter for the colored film, but the colored film is not limited to the color filter. The film may be provided on the inner surface of the rear substrate.

Further, the liquid crystal display element 1 of each of the above embodiments is
Although a full-color image is displayed by mixing colors of red, green, and blue light, the present invention includes three color films (for example, color filters) of magenta, yellow, and cyan. The present invention can also be applied to a liquid crystal display element that displays a multicolor image by mixing colored magenta, yellow, and cyan light.

Further, the present invention is not limited to an active matrix type liquid crystal display element using a TFT as an active element, but also an active matrix type liquid crystal display element using an MIM as an active element, or one direction on the inner surface of one substrate. Are provided in parallel with each other,
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 in a direction intersecting with the scanning electrodes are provided in parallel on the inner surface of the other substrate.

Further, the present invention is not limited to the TN type liquid crystal display device, but also includes an STN type liquid crystal display device having a liquid crystal layer in which liquid crystal molecules are twisted at a twist angle of 180 ° to 270 °, a dynamic scattering device, and the like. The present invention can be applied to an effect type liquid crystal display element, a liquid crystal display element using a ferroelectric or antiferroelectric liquid crystal, or the like.

The liquid crystal display device of the present invention is not limited to a two-way liquid crystal display device that performs both reflective display using external light and transmissive display using illumination light from illumination means. The present invention can be applied to a reflection type liquid crystal display device that performs only reflection type display using external light, and a transmission type liquid crystal display device that performs only transmission type display using illumination light from illumination means.

In this case, for example, when used in a reflection type liquid crystal display device, the display of the non-colored pixel area A 'which does not correspond to the color film (the color filters 10R, 10G, 10B in the above embodiment) is always a bright display. When used in a transmissive liquid crystal display device, the display of the non-colored pixel area A 'that does not correspond to the colored film may be always dark.

[0137]

According to the liquid crystal display device of the present invention, a plurality of colored films are provided in correspondence with the other pixel regions except for the predetermined pixel region which is present in at least one ratio for each predetermined number of pixel regions. A voltage corresponding to the image data is applied between the electrodes of the colored pixel region corresponding to the colored film, and the display of the pixel region is always non-displayed between the electrodes of the non-colored pixel region not corresponding to the colored film. Since it is driven by applying a voltage that causes a bright or dark colored display,
In the case of reflective display using external light, a color image with sufficient screen brightness is displayed. In the case of transmissive display using illumination light from illumination means, a color image with sufficient brightness and contrast is displayed. Can be displayed.

Further, in the liquid crystal display device according to the present invention, the illumination light is emitted toward the liquid crystal display element behind the liquid crystal display element and the external light incident from the front of the liquid crystal display element is transmitted to the liquid crystal display element. In the case of reflective display using external light, a color image with sufficient screen brightness is displayed, and transmission using illumination light from the illumination means is used. In the pattern display, a color image with sufficient brightness and contrast can be displayed.

In the present invention, when the area of the pixel region corresponding to the colored film of the liquid crystal display element is made substantially equal to the area of the pixel region not corresponding to the colored film, the pixel region corresponding to the colored film may be formed. If at least one-half of the predetermined number of pixel regions in which at least one pixel region is present is defined as a pixel region corresponding to the colored film, non-colored bright display or transmission during reflective display is performed. A dark image at the time of pattern display can be made less noticeable, and a color image with better image quality can be displayed.

Further, according to the present invention, in the liquid crystal display element, one of two pixel regions adjacent to each other is a pixel region corresponding to the colored film, and the other is a pixel region not corresponding to the colored film. If the area of the non-corresponding pixel region is set smaller than the area of the pixel region corresponding to the colored film, the non-colored bright display in the reflective display or the dark display in the transmissive display can be more improved. A color image with better image quality can be displayed without being noticeable.

[Brief description of the drawings]

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

FIG. 2 shows a liquid crystal display device using the liquid crystal display element.
Sectional drawing along the II-II line of FIG.

FIG. 3 is a diagram showing a color filter arrangement state of the liquid crystal display element.

FIG. 4 is a diagram showing a color filter arrangement state of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a color filter arrangement state of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 6 is a plan view of a part of a liquid crystal display device according to a fourth embodiment of the present invention.

[Description of Signs] 1 ... Liquid crystal display element 2, 3 ... Substrate 4 ... Pixel electrode 4a ... Display pixel electrode 4b ... Dimming pixel electrode 12 ... Counter electrode A ... Colored pixel area A '... Non-colored pixel area 10R 10G, 10B: Color filter 15, 16: Polarizer 20: Illumination means 21: Illumination panel 22: Semi-transmissive reflector

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H091 FA02Y FA14X FD04 FD24 GA03 GA13 HA07 KA03 LA12 LA13 LA15 LA17 LA18 LA30 2H092 JA26 JA29 JA38 JA42 JB05 JB13 JB23 JB32 JB38 JB54 NA07 NA25 PA04 PA06 PA08 PA09 PA12 QA07 NA16 NA79 NC34 NC66 ND02 ND08 ND14 ND52 ND60 NE06 NE10 NF05 5C094 AA06 AA07 AA08 BA43 CA19 CA24 EA04 ED03 ED11

Claims (6)

[Claims] An electrode for forming a plurality of pixel regions arranged in a matrix by opposing regions is provided on each of inner surfaces of a pair of substrates facing each other with a liquid crystal layer interposed therebetween. On the inner surface, a plurality of color films are provided corresponding to the other pixel regions except for the predetermined pixel region which is present in at least one ratio for every predetermined number of pixel regions, and correspond to the color films. A voltage corresponding to the image data is applied between the electrodes of the colored pixel region, and between the electrodes of the non-colored pixel region that does not correspond to the colored film, the display of the non-colored pixel region is always a non-colored bright display or dark display. A liquid crystal display element which is driven by applying a predetermined voltage. 2. The area of the colored pixel area is substantially the same as the area of the non-colored pixel area, and at least half or more of the predetermined number of pixel areas are the colored pixel areas. The liquid crystal display device according to claim 1, wherein: 3. One of two adjacent pixel regions is the colored pixel region and the other is the non-colored pixel region, and the area of the non-colored pixel region is set to be smaller than the area of the colored pixel region. The liquid crystal display device according to claim 1, wherein: 4. An electrode for forming a plurality of pixel regions arranged in a matrix by regions facing each other is provided on each of inner surfaces of a pair of substrates facing each other with a liquid crystal layer interposed therebetween. On the inner surface, a plurality of color films are provided corresponding to the other pixel regions except for the predetermined pixel region which is present in at least one ratio for every predetermined number of pixel regions, and correspond to the color films. A voltage according to image data is applied between the electrodes of the colored pixel region, and a voltage at which the display of the pixel region is always a non-colored bright display or dark display between the electrodes of the non-colored pixel region not corresponding to the colored film. A liquid crystal display element that is driven by applying an external light, and external light that is disposed behind the liquid crystal display element and emits illumination light toward the back surface of the liquid crystal display element and enters from the front of the liquid crystal display element. And a lighting unit for reflecting the light toward the rear surface of the liquid crystal display element. 5. The liquid crystal according to claim 4, wherein said illuminating means includes a light source unit, and when the light source unit is turned on, a non-colored pixel region of the liquid crystal display element is driven to a dark display. Display device. 6. The illumination means includes a light source unit, wherein when the light source unit is turned on, the non-colored pixel area of the liquid crystal display element is driven to dark display, and when the light source unit is turned off, the non-colored pixel region is turned on. 5. The liquid crystal display device according to claim 4, wherein the pixel region is driven for bright display.