JP2000292784A - Liquid crystal display device using reflective color filters - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device using a reflection type color filter which prevents light reflected by a color filter due to external light and generates light when receiving light when a TFT is formed in a liquid crystal layer cell. This prevents erroneous operation of the TFT due to electricity generated. A quarter wavelength layer (22) is provided outside a liquid crystal layer (20).
And a color filter 2 composed of a cholesteric liquid crystal layer
A liquid crystal display device 10 comprising, in this order, a light-absorbing dichroic circularly polarizing layer 30.

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 using a reflection type color filter.

[0002]

2. Description of the Related Art In a transmission type color liquid crystal display device, a backlight is illuminated from behind a liquid crystal layer, and light transmitted through the liquid crystal layer passes through a color filter and is emitted from the surface of the liquid crystal panel to perform color display. ing.

As such a liquid crystal display device, for example, a cholesteric liquid crystal layer in which a cholesteric liquid crystal for a color filter is dispersed between two glass substrates as disclosed in Japanese Patent Application Laid-Open No. 9-318807 is disclosed. / 4
In some cases, a wave plate is disposed on the light incident side of the liquid crystal layer.

[0004]

As described above, in a liquid crystal display device having a configuration in which the cholesteric liquid crystal layer and the quarter-wave plate are arranged on the light incident side of the liquid crystal layer, external light incident from the surface of the liquid crystal panel is not affected. Since the light is reflected on the surface of the cholesteric liquid crystal layer and emitted from the surface of the liquid crystal panel, the visibility of the liquid crystal display is deteriorated, the contrast is lowered, and the display quality is insufficient.

Further, when a TFT (thin film transistor) is formed on the liquid crystal layer, there is a problem that the TFT may malfunction due to electricity generated at the time of receiving light.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to prevent reflected light from a color filter due to external light and to generate light at the time of receiving light when a TFT is formed in a liquid crystal layer. It is an object of the present invention to provide a liquid crystal display device using a reflection type color filter which prevents a malfunction of a TFT due to electricity.

Further, a light absorbing type dichroic circularly polarizing plate is used on the surface visible from the outside, and the retardation value of the liquid crystal layer, the optical rotation, or the director of the liquid crystal is adjusted in accordance with the dichroic circularly polarizing plate. The change of the
It is an object of the present invention to provide a liquid crystal display device using a reflection type color filter having a good contrast while preventing a significant decrease in contrast and a decrease in visibility due to external light without lowering light use efficiency. .

[0008]

According to a first aspect of the present invention, there is provided:
And the light emitted from the light source,
It comprises a linearly polarized light separating layer that transmits one linearly polarized light component and reflects a linearly polarized light component in a direction orthogonal to the linearly polarized light component, and a liquid crystal and an electrode that applies an electric field to the liquid crystal. The optical rotation of the light is changed, whereby the linearly polarized light transmitted through the linearly polarized light separating layer and incident thereon,
A liquid crystal layer having a function of shifting the polarization plane at the time of emission from the liquid crystal or transmitting without being shifted, and disposed on the opposite side of the linear polarization separation layer with respect to this liquid crystal layer, and a straight line incident from the liquid crystal layer. A 1/4 wavelength layer that shifts the phase of polarized light by π / 2 and transmits as circularly polarized light; and a cholesteric liquid crystal layer disposed on the opposite side of the liquid crystal layer with respect to the 1/4 wavelength layer. A color filter that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component of the circularly polarized light incident from the 波長 wavelength layer; A light absorption type dichroic circularly polarizing layer disposed on the opposite side of the / 4 wavelength layer, transmitting the right or left circularly polarized light component transmitted through the color filter, and absorbing the other circularly polarized light component; And characterized by having It is intended to achieve the above object by the liquid crystal display device using a reflection type color filter that.

According to a second aspect of the present invention, a light source,
Among the light emitted from this light source, one of the linearly polarized light components is transmitted, and the linearly polarized light component in a direction orthogonal to the one is absorbed.
A liquid crystal and an electrode for applying an electric field to the liquid crystal; and applying an electric field to the liquid crystal to change the optical rotation of the liquid crystal, thereby transmitting the light through the dichroic linear polarizing layer. A liquid crystal layer having a function of shifting the plane of polarization of the linearly polarized light incident upon exit from the liquid crystal at the time of emission from the liquid crystal, or having a function of transmitting the light without being shifted, and an opposite of the dichroic linear polarizing layer to the liquid crystal layer. And a quarter-wave layer that shifts the phase of the linearly polarized light incident from the liquid crystal layer by π / 2 and transmits the circularly polarized light, and the opposite side of the liquid crystal layer with respect to the quarter-wave layer. The cholesteric liquid crystal layer is disposed, and transmits one circularly polarized light component in the right or left optical rotation direction among the circularly polarized light incident from the quarter wavelength layer,
A color filter that reflects the other circularly polarized light component; and a color filter that is disposed on the opposite side of the quarter wavelength layer with respect to the color filter and transmits the right or left circularly polarized light component that has passed through the color filter. And a light-absorbing dichroic circularly polarizing layer that absorbs the other circularly polarized light component.

According to a third aspect of the present invention, a light source includes:
It comprises a linearly polarized light separating layer that transmits one linearly polarized light component of the light emitted from the light source and reflects a linearly polarized light component in a direction orthogonal to the linearly polarized light component, a liquid crystal, and an electrode that applies an electric field to the liquid crystal. A liquid crystal layer having the function of applying an electric field to the liquid crystal to rotate the liquid crystal in a plane while keeping the retardation value constant, and to shift the phase of the incident linearly polarized light substantially by 0 to π and transmit the light. A 波長 wavelength layer that is disposed on the opposite side of the linearly polarized light separating layer with respect to the liquid crystal layer and shifts the phase of linearly polarized light incident from the liquid crystal layer by π / 2 and transmits as circularly polarized light; The cholesteric liquid crystal layer is disposed on the opposite side of the liquid crystal layer with respect to the quarter wavelength layer, and of the circularly polarized light incident from the quarter wavelength layer,
A color filter that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component,
A light absorption type that is disposed on the opposite side of the quarter-wave layer with respect to this color filter, transmits the right or left circularly polarized light component transmitted through the color filter, and absorbs the other circularly polarized light component. The above object is achieved by a liquid crystal display device using a reflective color filter, comprising: a dichroic circularly polarizing layer.

According to a fourth aspect of the present invention, a light source includes:
Among the light emitted from this light source, one of the linearly polarized light components is transmitted, and the linearly polarized light component in a direction orthogonal to the one is absorbed.
It comprises a chromatic linearly polarizing layer, a liquid crystal and an electrode for applying an electric field to the liquid crystal, and by applying an electric field to the liquid crystal,
A liquid crystal layer having a function of rotating the liquid crystal in the plane while the retardation value is kept constant and transmitting the incident linearly polarized light by shifting the phase by substantially 0 to π; A 波長 wavelength layer that is disposed on the opposite side of the chromatic linear polarization layer and that shifts the phase of linearly polarized light incident from the liquid crystal layer by π / 2 and transmits as circularly polarized light; Consisting of a cholesteric liquid crystal layer disposed on the opposite side of the liquid crystal layer, of the circularly polarized light incident from the liquid crystal layer, transmits one circularly polarized light component in the right or left optical rotation direction,
A color filter that reflects the other circularly polarized light component; and a color filter that is disposed on the opposite side of the quarter wavelength layer with respect to the color filter and transmits the right or left circularly polarized light component that has passed through the color filter. And a light-absorbing dichroic circularly polarizing layer that absorbs the other circularly polarized light component.

According to a fifth aspect of the present invention, a light source,
Of the light emitted from this light source, a linearly polarized light separating layer that transmits one linearly polarized light component and reflects a linearly polarized light component in a direction orthogonal to the linearly polarized light component;
A liquid crystal having a retardation value that shifts by .pi. / 2 and an electrode that applies an electric field to the liquid crystal. The phase of transmitted light is substantially shifted by -.pi./2 to .pi. / 2 to the right or left. A liquid crystal layer having the function of circularly polarized light in the direction of optical rotation, and a cholesteric liquid crystal layer disposed on the opposite side of the linearly polarized light separation layer with respect to the liquid crystal layer, of the circularly polarized light incident from the liquid crystal layer A color filter that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component, and is disposed on the opposite side of the liquid crystal layer with respect to this color filter, and the color filter is A light-absorbing dichroic circularly polarizing layer that transmits the transmitted right or left circularly polarized light component and absorbs the other circularly polarized light component. LCD The shown device is intended to achieve the above object.

According to a sixth aspect of the present invention, a light source includes:
Among the light emitted from this light source, one of the linearly polarized light components is transmitted, and the linearly polarized light component in a direction orthogonal to the one is absorbed.
The phase of the transmitted light is substantially -π /
A liquid crystal having a retardation value for shifting by 2 to π / 2 and an electrode for applying an electric field to the liquid crystal, wherein the phase of transmitted light is substantially shifted by -π / 2 to π / 2;
A liquid crystal layer having a function of producing circularly polarized light in the right or left optical rotation direction; and a cholesteric liquid crystal layer disposed on the opposite side of the dichroic linearly polarizing layer with respect to the liquid crystal layer. A color filter that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component, and is disposed on the opposite side of the liquid crystal layer with respect to this color filter. And a light absorption type 2 that transmits the right or left circularly polarized light component transmitted through the color filter and absorbs the other circularly polarized light component.
The above object is achieved by a liquid crystal display device using a reflective color filter, comprising a chromatic circularly polarizing layer.

Further, a dichroic linearly polarizing layer that transmits one linearly polarized light component and absorbs a linearly polarized light component in a direction orthogonal to the linearly polarized light component may be provided on the liquid crystal layer side of the linearly polarized light separating layer. .

Further, the linearly polarized light separating layer has a planar multilayer structure in which three or more birefringent films are laminated, and has a vibration direction perpendicular to each other in the plane of each layer.
Of the two lights, the difference in refractive index between layers adjacent in the thickness direction with respect to one light may be different from the difference in refractive index between layers adjacent in the thickness direction with respect to the other light.

The linearly polarized light separating layer comprises a retardation layer having a retardation value for substantially shifting the phase of transmitted light by π / 2, and an optical rotation selecting layer made of a cholesteric liquid crystal layer. The circularly polarized light transmitted through the liquid crystal layer may be converted to linearly polarized light.

The dichroic circularly polarizing layer may be formed by attaching a １ ／ wavelength layer to one of both surfaces of the dichroic linearly polarizing layer or one of the surfaces on the liquid crystal layer side or directly forming the same. .

Further, in the liquid crystal layer, the liquid crystal is sandwiched between two substrates, and the electrodes are formed on one of the electrodes.
A mode in which the direction of an electric field when a voltage is applied to the electrode has a portion substantially parallel to the substrate surface, and the direction of liquid crystal molecules of most of the liquid crystal rotates while being substantially parallel to the substrate surface. It may be.

In the present invention, a color filter composed of a linearly polarized light separating layer or a dichroic linearly polarized light layer, a quarter wavelength layer, a cholesteric liquid crystal layer, a combination of a dichroic circularly polarized light layer and a liquid crystal layer is used to control external light. The TFT generated by the light generated when receiving light when the TFT is formed in the liquid crystal layer cell while preventing the reflected light from the color filter.
To prevent malfunction.

Further, in the present invention, a dichroic circularly polarizing plate of a light absorption type is used on the surface visible from the outside, and the retardation value of the liquid crystal layer, the optical rotation, Alternatively, a change in the director of the liquid crystal is selected, thereby preventing a significant decrease in contrast and visibility due to external light without lowering the light use efficiency, and obtaining a color display with good contrast. You can also.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, a liquid crystal display device 10 using a reflection type color filter according to a first embodiment of the present invention has a light source 12 for emitting unpolarized light, Among the incident light, the linearly polarized light separating layer 14 that transmits one linearly polarized light component and reflects the linearly polarized light component in a direction orthogonal to the linearly polarized light component, the liquid crystal 26, and the electrodes 28A and 28B ( 2), an electric field is applied to the liquid crystal 26 to change the optical rotation of the liquid crystal to light, whereby the linearly polarized light transmitted through the linearly polarized light separating layer 14 and incident on the liquid crystal 26 A liquid crystal layer 20 having a function of shifting the polarization plane at the time of emission or transmitting without being shifted, and disposed on the opposite side of the linear polarization separation layer 14 with respect to the liquid crystal layer 20, and Linear deviation And a cholesteric liquid crystal layer disposed on the opposite side of the liquid crystal layer 20 with respect to the quarter wavelength layer 22 and transmitting a circularly polarized light by shifting the phase by π / 2. A color filter 24 that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component of the circularly polarized light incident from the liquid crystal layer 20; A light-absorbing dichroic filter which is disposed on the opposite side of the quarter wavelength layer 22 and transmits the right or left circularly polarized light component transmitted through the color filter 24 and absorbs the other circularly polarized light component. And a circularly polarizing layer 30.

In FIG. 1, symbols R and L (see FIG. 3) indicate right-handed circularly polarized light and left-handed circularly polarized light, respectively. Also, "←
“→” and “•” indicate electric field vibration vectors of linearly polarized light, respectively, “← →” indicates an in-plane direction of the paper, and “•” indicates a direction perpendicular to the paper.

The light source 12 is a transparent thin-film white surface light source made of thin-film electroluminescence or the like sandwiched between transparent resin sheets having transparent electrodes, and has a rear side (lower side in FIG. 1) on its rear side. For example, a reflection layer 12A made of a metal thin film is disposed.

The reflection layer 12A emits light from the light source 12 and is reflected by the linearly polarized light separation layer 14, for example,
The linearly polarized light component of “•” is reflected again in the direction of the linearly polarized light separation layer 14, and at this time, the phase of the linearly polarized light component is inverted, or the state is unpolarized, and the light can pass through the linearly polarized light separation layer 14. As a linearly polarized light component, the light utilization factor is improved.

The linearly polarized light separating layer 14 has a planar multilayer structure formed by laminating three or more films having birefringence. Of the two lights having vibration directions perpendicular to each other in the plane of each layer. Alternatively, the difference in refractive index between layers adjacent in the thickness direction for one light may be different from the difference in refractive index between layers adjacent in the thickness direction for the other light.

The film having birefringence as described above is, for example, as disclosed in JP-A-3-75705, etc., such as a polycarbonate resin, a polyester resin, a polyvinyl alcohol resin, and a cellulose acetate. A material exhibiting in-plane birefringence (refractive index anisotropy) such as a system resin can be obtained by a method such as stretching.

For example, adjacent birefringent layers (films)
Has a refractive index of substantially n for a light beam oscillating in the X-axis direction.
x, and the refractive index difference Δnx (= | nx−nx |) between adjacent layers in the X-axis direction is substantially zero.

On the other hand, for example, among the three birefringent layers, the refractive indices of the first layer and the third layer with respect to the light vibrating in the Y-axis direction are both ny1, and the refraction of the second layer in the same direction is ny1. Assuming that the refractive index is ny2 (≠ ny1), the refractive index Δny between adjacent layers in the Y-axis direction is not substantially zero.

The reflection of light oscillating in the direction in which the refractive index difference is large (Y-axis direction) is greater than the reflection of light oscillating in the direction of small refractive index difference (X-axis direction). Light transmission is greater than light transmission in the Y-axis direction.

Therefore, even if the linearly polarized light separating layer 14 has a planar multilayer structure, the refractive index of the light oscillating in the X-axis direction is substantially the same. Only a slight surface reflection occurs at two points, the surface and the exit surface.

On the other hand, for the light oscillating in the Y-axis direction, the refractive index in the planar multilayer structure is different between the respective layers. Surface (interface) reflection occurs between the layers, and the greater the number of birefringent layers, the greater the number of times of reflection of light vibrating in the Y-axis direction.

The linearly polarized light separating layer 14 comprises a retardation layer having a retardation value for shifting the phase of transmitted light substantially by π / 2, and an optical rotation selecting layer comprising a cholesteric liquid crystal layer. By converting circularly polarized light transmitted through the cholesteric liquid crystal layer into linearly polarized light,
Transmit the linearly polarized light component of `` ← → '' which is the one light,
You may make it reflect the linearly polarized light component of "." Which is the other light.

The liquid crystal layer 20 is shown in more detail in FIG.
As shown in FIG. 2A, the liquid crystal 26 sandwiched between two substrates 32A and 32B is disposed on the lower surface of the upper substrate 32A and the upper surface of the lower substrate 32B in FIG. 2A. , And the pair of pixel electrodes 28A and 28B sandwiching the liquid crystal 26 in the thickness direction.

The liquid crystal 26 in the liquid crystal layer 20 is TN
(Twisted Nematic) type, and the pixel electrode 28A,
An electric field is applied from the liquid crystal 28B to change the optical rotation of the liquid crystal, thereby having a function of shifting the polarization direction of the linearly polarized light that is transmitted through the linearly polarized light separating layer 14 and exits from the liquid crystal 26. Has been adjusted.

This adjustment can be performed using various known liquid crystals in consideration of the liquid crystal layer material, the alignment film material, and the cell configuration.

As shown in FIG. 2B, the liquid crystal layer 20 includes the first quarter wavelength layer 22 and the color filter 2.
4 may be disposed integrally between the substrate 32A and the pixel electrode 28A.

The quarter-wavelength layer 22 is a phase plate made of a polymer material such as polyimide using crystal or optical glass as its substrate, and converts incident linearly polarized light into circularly polarized light or vice versa. It has the action to do.

The color filter 24 is composed of, for example, a cholesteric liquid crystal layer as disclosed in JP-A-9-318807.

FIGS. 1 to 17 show one pixel of the liquid crystal layer and each part corresponding thereto. As shown in the drawing, the color filter 24 has R, G, and B regions for each pixel, and each region transmits only light in each wavelength region and transmits light in other wavelength regions. It is made to reflect.

The light absorbing type dichroic circularly polarizing layer 30
Is a polaroid that transmits polarized light in the direction of the transmission axis and absorbs most of the polarized light in the direction perpendicular to the transmission axis.
A λ / 4 retardation layer on one or both sides of a dichroic linear polarizing layer made of a dichroic polarizing material with respect to its light absorption axis;
It is constituted by a method such as laminating such that the fast axis or the slow axis forms an angle of 45 degrees. For one side, 1 /
The 4λ retardation layer is provided on the liquid crystal layer 20 side of the dichroic linear polarizing layer.

In the liquid crystal display device 10, the light source 12
Is transmitted through the linearly polarized light separating layer 14, and the linearly polarized light component of “•” in the direction orthogonal to this is reflected.

When the reflected linearly polarized light component is reflected by the reflection layer 12A on the back surface of the light source 12, it is converted into a linearly polarized light component of “← →”, or a light diffusing plate or the like disposed in the optical path. A non-polarized state occurs due to (not shown), the light passes through the linearly polarized light separating layer 14 and reaches the liquid crystal layer 20.

The pixel electrode 2 is applied to the liquid crystal 26 in the liquid crystal layer 20.
By applying a voltage from 8A and 28B, the twisted state of the liquid crystal changes, and as a result, the linearly polarized light passing through the liquid crystal layer 20 becomes “•” when the polarization direction at the time of emission is shifted by π / 2 at the maximum. When the shift is zero, the light is emitted from the liquid crystal layer 20 as linearly polarized light “← →”, and is incident on the １ ／ wavelength layer 22.

The linearly polarized light “← →” incident on the 波長 wavelength layer 22 is a right-handed circularly polarized light indicated by a symbol R in FIG.
The linearly polarized light of “•” becomes left-handed circularly polarized light indicated by L in FIG.

If the direction of the transmitted rotatory light of the cholesteric liquid crystal layer constituting the color filter 24 is coincident with the right-handed circularly polarized light or the left-handed circularly polarized light, in this case, the right-handed circularly polarized light R can be obtained. R is transmitted through the color filter 24 and, in the case of left-handed circularly polarized light L, is reflected by the color filter 24 as shown in FIG.

Here, if the direction of optical rotation passing through the dichroic circularly polarizing layer 30 is made to correspond to the color filter 24 as right-handed circularly polarized light R, the right-handed circularly polarized light R transmitted through the color filter 24 becomes Transmitted through the dichroic circularly polarizing layer 30,
As shown in FIG. 1, the display becomes bright, and in the case of the left-handed circularly polarized light L, the display becomes dark as shown in FIG.

Accordingly, the amount of light transmitted through the dichroic circularly polarizing layer 30 increases in inverse proportion to the magnitude of the optical rotation in the liquid crystal 26, thereby enabling gradation display.

The dichroic circularly polarizing layer 30 is of a light absorption type, and external light (non-polarized light) is supplied to the dichroic circularly polarizing layer 3.
Even if it is incident on the surface of 0, 50% of it is absorbed,
Even when a TFT is formed on the liquid crystal layer side, a malfunction of the TFT due to electricity generated at the time of light reception can be suppressed by reducing the amount of received light. Further, the remaining 50% (right-handed circularly polarized light R) is transmitted, and this also transmits through the color filter 24, so that there is almost no reflection component returning to the liquid crystal panel surface, and the reduction of the screen contrast in the liquid crystal display device 10 is prevented. It can be greatly suppressed.

Here, the linearly polarized light separating layer 14 converts the linearly polarized light component of "."
There is a case where reflection cannot be performed by 00%. Accordingly, the unpolarized linearly polarized light component passes through the liquid crystal layer 20 and the 波長 wavelength layer 22 and reaches the color filter 24 as left-handed circularly polarized light, is reflected there, and is again reflected by the ４ wavelength layer 22 and the liquid crystal. After passing through the layer 20, it may reach the linearly polarized light separation layer 14 as linearly polarized light of “•” and be reflected again there.

As a result, the linearly polarized light of “•” may cause multiple reflections between the color filter 24 and the linearly polarized light separating layer 14, which may lower the contrast of the screen.

On the other hand, in FIGS. 1 and 3,
As shown by the two-dot chain line, a dichroic linear polarizing layer 36 that transmits the linearly polarized light component of “← →” and absorbs the linearly polarized light component of “•” in the direction perpendicular to the line is provided.

In this way, of the unpolarized light from the light source 12, the linearly polarized light component “•” transmitted through the liquid crystal layer 20 and the linearly polarized light separating layer 14 is absorbed by the dichroic linearly polarized light layer 36. As described above, the linearly polarized light separating layer 14
Since no multiple reflection occurs between the image and the color filter 24, it is possible to prevent a decrease in the contrast of the screen due to the multiple reflection.

That is, the dichroic linear polarizing layer 36 transmits the polarized light in the transmission axis direction and the linearly polarized light component of “← →”, and converts almost all of the linearly polarized light component of “•” in the direction orthogonal to the transmission axis. It absorbs and is made of a dichroic polarizing material such as Polaroid (trade name).

Next, a liquid crystal display device 40 using a reflection type color filter according to a second embodiment of the present invention shown in FIGS. 4 and 5 will be described.

The liquid crystal display device 40 has a dichroic linearly polarized light having the same configuration as the dichroic linearly polarizing layer 36 instead of the linearly polarized light separating layer 14 in the liquid crystal display device 10 according to the first embodiment of the present invention. The layer 42 is provided. The other configuration is the same as that of the liquid crystal display device 10 according to the first example of the above-described embodiment, and the description will be omitted by using the same reference numerals for the same portions. The same applies to the liquid crystal display devices of the third and subsequent examples of the embodiment.

Therefore, in the liquid crystal display device 40, the unpolarized light from the light source 12 is transmitted to the dichroic linear polarizing layer 42.
The transmission of one of the linearly polarized light components of “← →” is the same as in the liquid crystal display device 10, but the linearly polarized light component of “•” in the direction orthogonal to this is absorbed without being reflected. Is reflected by the reflective layer 12A,
It is not converted to a linearly polarized light component of “← →”. Only light in the back direction from the light source 12 is reflected by the reflective layer 12A and returned to the dichroic linearly polarizing layer 42.

“← →” transmitted through the dichroic linear polarizing layer 42
Is incident on the liquid crystal layer 20, and thereafter, the bright display (see FIG. 4) and the dark display (see FIG. 5) are performed in the same process as in the liquid crystal display device 10 according to the first example of the embodiment. Do.

Next, a liquid crystal display device 50 using a reflection type color filter according to a third embodiment of the present invention shown in FIGS. 6 to 10 will be described.

In the liquid crystal display device 50, the liquid crystal layer 20 in the liquid crystal display device 10 according to the first example of the embodiment is replaced with a liquid crystal layer 52 having another configuration.

As shown in FIG. 7, the liquid crystal layer 52 includes an IPS type liquid crystal 54 and pixel electrodes 56A and 56B for applying an electric field to the liquid crystal 54.
When an electric field is applied to the liquid crystal 4 and the retardation value is kept constant, the liquid crystal is rotated in the plane, and the direction of the director D is changed.
It has a function of transmitting by shifting by π.

Further, the structure of the liquid crystal layer 52 is shown in FIG.
This will be described in detail with reference to FIGS.

As shown in FIG. 7A, the liquid crystal layer 52 includes the liquid crystal layer 5 sandwiched between two substrates 58A and 58B.
7 and the pixel electrode 56 disposed on the upper surface of the lower substrate 58A in FIG.
A, 56B, and the pixel electrodes 56A, 56B.
The direction of the electric field when a voltage is applied from the circuit 59 during B is
A mode in which the direction of the director D of most of the liquid crystal molecules in the liquid crystal 54 is substantially parallel to the substrate surface and rotates while being substantially parallel to the substrate surface (typically, IPS (In Plain Switchin).
g) Called mode. ).

As shown in FIG. 7B, the liquid crystal layer 52 includes the first quarter wavelength layer 22 and the color filter 2.
4 may be disposed between the substrate 58B and the liquid crystal 54 and integrally therewith.

Further, the direction of the director D in the liquid crystal 54 will be described in detail. As shown in FIG. 8, in a state where an electric field is applied between the pixel electrodes 56A and 56B, the direction of the director D of the liquid crystal moves in a direction substantially perpendicular to the paper surface, and is shown in FIG. As described above, when no electric field is applied between the pixel electrodes 56A and 56B, the director D of the liquid crystal is made to move in a direction substantially parallel to the paper surface.

FIG. 8 shows a case where the dielectric anisotropy Δε is positive for the liquid crystal, but when the dielectric anisotropy Δε is negative,
In the state where no electric field is applied between the pixel electrodes 56A and 56B, the direction of the director D of the liquid crystal is substantially parallel to the paper surface, and in the state where the electric field is applied between the pixel electrodes 56A and 56B. The liquid crystal director D is adapted to move in a direction substantially perpendicular to the plane of the paper.

Here, the liquid crystal 54 is adjusted so as to have a retardation value that substantially shifts the phase of transmitted light by π, and regardless of whether or not an electric field is applied between the pixel electrodes 56A and 56B. The retardation values are almost the same. This adjustment can be performed with various known liquid crystals, for example, a nematic (Nn) liquid crystal by controlling the birefringence and thickness of the liquid crystal. The direction of the director D of the liquid crystal is substantially parallel to the substrates 58A and 58B.

Note that “substantially” in the above “substantially shift by 0 to π” and “substantially parallel to the substrates 58A and 58B” is, for example, a pretilt angle of a liquid crystal,
It is meant to include a case where the ideal state slightly deviates due to various disturbances or the like.

The above-mentioned “substantially shifts by 0 to π”
Is to substantially change the phase of the liquid crystal 54 itself, or to provide a phase difference layer different from the liquid crystal layer 52 adjacent to one and / or the other of the liquid crystal layer 52 so that the liquid crystal 54 and the phase difference layer Means that the phase of light passing therethrough is substantially shifted by 0 to π.

When the phase of the linearly polarized light is shifted by π / 2 by the 波長 wavelength layer 22, the light becomes circularly polarized light.

The shift will be described with reference to the Poincare sphere shown in FIG.

The Poincare sphere is used to describe the polarization and to examine how the shape of the polarization changes when the phase changes. In FIG.
The upper and lower poles of the sphere represent left-handed circularly polarized light and right-handed circularly polarized light, respectively. Points on the equator represent linearly polarized light, and the other points represent elliptically polarized light, respectively.

Further, an arbitrary point H on the equator indicates horizontal polarization, and a point V on the equator opposite to the diameter passing through the point H indicates vertical polarization. Polarizations perpendicular to each other will be represented by points at one end of a diameter, and generally assume that the radius of the sphere is 1, but may be proportional to the intensity of the light beam.

An arbitrary point P on the surface of a Poincare sphere having a unit radius is represented by a longitude 2λ and a latitude 2ω. However, -180 ° <2λ <180 °, -90 ° <
2ω <90 °.

The longitude is positive when measured clockwise from point H, and the latitude is positive when measured downward from the equator, that is, when measured toward the pole representing right circularly polarized light. Therefore, the coordinates of the point P in FIG. 10 are positive.

An arbitrary point P represents perfect elliptically polarized light having an azimuthal angle λ of an ellipse and an ellipticity of tan | ω |. Further, whether the point P is counterclockwise or clockwise is determined depending on whether the point P is in the upper hemisphere or the lower hemisphere. In summary, the following equations (1) and (2) hold for the cross-sectional view of the elliptically polarized light represented by the point P.

Α = λ (1)

B / a = tan | ω | (2)

The direction of polarization is clockwise if 2ω is positive, and counterclockwise if 2ω is negative. Thus, each point on the Poincare sphere represents a different polarization shape. That is, one polarization shape can be represented by one point on the Poincare sphere.

Therefore, for example, if the counterclockwise perfect circularly polarized light at the point of the upper pole of the Poincare sphere is shifted in the positive direction by π / 2 at the azimuth λ = 0, the point H on the equator in the Poincare sphere becomes To reach. That is, the circularly polarized light becomes horizontal linearly polarized light by being shifted by π / 2. Similarly, π in the positive direction
When shifted, it arrives at the lower pole and becomes clockwise perfect circularly polarized light.

When the clockwise perfect circularly polarized light at the lower pole position of the Poincare sphere is shifted by π / 2 at the azimuth λ = 0, it reaches the point V on the equator and becomes a vertical linearly polarized light. Then, the light reaches the upper pole and becomes a completely counterclockwise circularly polarized light. When the shift amount is not π / 2 or π, the light is elliptically polarized light.

In the example shown in FIG. 7, the change in the director D of the liquid crystal changes the linear polarization axis of the linearly polarized light incident on the liquid crystal layer 52. This changes the azimuth λ direction on the sphere of Poincare, That is, a change in the longitude direction occurs.

As shown in FIG. 8, the director D of the liquid crystal in the liquid crystal 54 has the pixel electrodes 56A,
6B, the direction of the director D of the liquid crystal moves in a direction substantially perpendicular to the paper surface according to the applied voltage, and as shown in FIG.
When no electric field is applied between A and 56B, it is set to move in a direction substantially parallel to the paper surface.

In the liquid crystal display device 50, the light source 12
The non-polarized light from the light source passes through the linearly polarized light separating layer 14 in the same manner as in the liquid crystal display device 10, and only the linearly polarized light component “← →” reaches the liquid crystal layer 52.

The retardation of the liquid crystal in the liquid crystal 54 remains constant irrespective of whether an electric field is applied between the pixel electrodes 56A and 56B, and the director D of the liquid crystal is controlled by the pixel electrode 56A. , 56B does not change in a state where no electric field is applied, and the direction of the director D of the liquid crystal is substantially parallel to the paper surface. 1 as it is
The light enters the ４ wavelength layer 22.

In a state where an electric field is applied between the pixel electrodes 56A and 56B, the direction of the director D of the liquid crystal moves in a direction substantially perpendicular to the plane of the drawing according to the applied voltage. The linearly polarized light component of ← → becomes a linearly polarized light component of “•” according to the applied voltage,
2 is incident.

The linearly polarized light “← →” incident on the quarter-wavelength layer 22 is right-handed circularly polarized light indicated by R, and the linearly polarized light “•” is left-handed circularly polarized light indicated by L. Becomes 1
The light is emitted from the 波長 wavelength layer 22.

Thereafter, bright display (see FIG. 6) and dark display (see FIG. 11) are performed in the same process as in the liquid crystal display device 10 according to the first example of the embodiment.

In the liquid crystal display device 50, as in the liquid crystal display device 10 described above, the linearly polarized light separating layer 1 is formed.
4 may not be able to reflect 100% of the linearly polarized light component of “•” in the unpolarized light from the light source 12. In this case,
As shown in FIGS. 6 and 11, a dichroic linear polarizing layer 36 similar to that described above is disposed to prevent the occurrence of multiple reflection between the linearly polarized light separating layer 14 and the color filter 24.

Next, a liquid crystal display device 60 using a reflection type color filter according to a fourth embodiment of the present invention shown in FIGS. 12 and 13 will be described.

The liquid crystal display device 60 is different from the liquid crystal display device 50 according to the third embodiment in that a dichroic linear polarization layer 42 is provided instead of the linear polarization separation layer 14. Other configurations are the same as those of the liquid crystal display devices 10 and 50 according to the first and third examples of the above-described embodiment. Therefore, the description will be omitted by using the same reference numerals for the same portions.

The dichroic linear polarizing layer 42 has the same configuration as that of the liquid crystal display device 40 according to the second example of the above embodiment.

Therefore, in this liquid crystal display device 60, the unpolarized light from the light source 12 is
Is different from the liquid crystal display device 50 only in that the linearly polarized component of “•” is absorbed without being reflected, and after the linearly polarized component of “← →” is transmitted and enters the liquid crystal layer 52. Is a bright display in the same process as in the liquid crystal display device 50 according to the third example of the embodiment (FIG. 12).
(See FIG. 13) and dark display (see FIG. 13).

Next, a liquid crystal display device 70 using a reflection type color filter according to a fifth embodiment of the present invention shown in FIGS. 14 and 15 will be described.

This liquid crystal display device 70 has a configuration in which the liquid crystal layer 20 of the liquid crystal display device 10 according to the first embodiment of the above-described embodiment is replaced with a liquid crystal layer 72 of another configuration, and the quarter wavelength layer 22 is omitted. It is.

The liquid crystal layer 72 has the same structure as the liquid crystal layer 20 shown in FIG. 2, and includes a liquid crystal sandwiched between two substrates, a lower surface of an upper substrate, and an upper surface of a lower substrate. And a pair of pixel electrodes (both not shown) sandwiching the liquid crystal in the thickness direction.

The liquid crystal in the liquid crystal layer 72 substantially shifts the phase of the linearly polarized light that passes through the linearly polarized light separating layer 14 and is incident. 2. It is set to -π / 2 when a voltage is applied. That is, the retardation value of the liquid crystal is changed in accordance with the applied amount of the voltage, whereby -π / 2
It is adjusted to have the effect of shifting by π / 2.

This adjustment can be performed with various known liquid crystals by controlling the birefringence and thickness of the liquid crystal layer.

Such a liquid crystal is ECB (Electrikally
Controlled Briefringence (DAP) is known as the Deformation of vertical Aligned Ph
ases) mode, HAN (Hybrid Aligned Nematic) mode, STN (Super Twisted Nematic) mode, S
BE (Super Twisted Briefringence Effect) SS
FLC (Surface Stabilized Ferroelectric Liquid
Crystal) mode, OCB (Opticcally Compensated)
Beud mode, VAN (Vertically-aligned nemati)
c) There are modes and so on.

The OCB mode usually has a structure in which a bend-aligned liquid crystal layer and a biaxial retardation plate are sandwiched between light absorption type dichroic linear polarizers whose light absorption axes are orthogonal to each other. Refers to only the bend-aligned liquid crystal layer.

The VAN mode usually refers to a configuration in which a VAN array cell vertically sandwiching an Nn (nematic) liquid crystal is sandwiched between light-absorbing dichroic linear polarizers whose light absorption axes are orthogonal to each other. In the present invention, it refers to only the liquid crystal layer of the VAN alignment.

The same applies to other modes.

The expression ECB is often used as a color display system utilizing birefringence, but in the present invention, it is used as a mode in which the value of the birefringence of the liquid crystal changes. .

The term “substantially shift by −π / 2 to π / 2” means that the phase of the liquid crystal itself is substantially changed, or a phase difference layer different from the liquid crystal layer 72 is formed by a liquid crystal layer. 72 formed on both sides or one side, and the phase of light transmitted therethrough due to the interaction between the liquid crystal and the retardation layer is substantially -π / 2 to
This means shifting by π / 2.

For example, the retardation value of the liquid crystal itself is changed from 0 to π, and the interaction with a retardation layer provided separately on both sides or one side of the liquid crystal and having a retardation value of substantially π / 2. , The phase of light passing therethrough is substantially shifted by -π / 2 to π / 2.

The interaction means the fast axis or slow axis of the retardation layer whose retardation value is substantially π / 2 with respect to the fast axis or slow axis when the retardation value of the liquid crystal shows π. The effect that occurs when the phase axes are orthogonalized, etc.
For example, 0-π / 2 = -π / 2, π-π / 2 = π / 2,
It can be calculated as follows.

Needless to say, the use of a liquid crystal layer having a function of shifting the phase substantially by -π / 2 to π / 2 also falls within the scope of the present invention.

The shift will be described with reference to the Poincare sphere shown in FIG.

For example, when the horizontal linearly polarized light at point H on the equator in the Poincare sphere is shifted in the positive direction by π / 2 at the azimuth λ = 0, it arrives at the lower pole of the Poincare sphere and completes clockwise. When circularly polarized light is shifted in the negative direction by π / 2, the light arrives at the upper pole of the Poincare sphere and becomes counterclockwise completely circularly polarized light. When the shift amount is not π / 2 or π, the light is elliptically polarized light.

In the liquid crystal display device 70, the light source 12
The non-polarized light from the light passes through the linearly polarized light separating layer 14 in the same manner as in the liquid crystal display device 10, and only the linearly polarized light component “← →” reaches the liquid crystal layer 72.

The retardation of the liquid crystal in the liquid crystal layer does not change when no electric field is applied between the pixel electrodes, and the incident “← →” linearly polarized light component is −π /
When the electric field is applied to the color filter 24 after being shifted by two to become right-handed circularly polarized light R and the electric field is applied, the incident linearly polarized light component of “← →” is π / The light is shifted by 2 and becomes the left-handed circularly polarized light L and enters the color filter 24.

As described above, the color filter 24
If the direction of the transmitted optical rotation of the cholesteric liquid crystal layer is made to match one of right-handed circularly polarized light and left-handed circularly polarized light, for example, right-handed circularly polarized light R, the right-handed circularly polarized light R passes through the color filter 24. , Left-handed circularly polarized light L is reflected by the color filter 24 as shown in FIG.

Thereafter, bright display (see FIG. 14) and dark display (see FIG. 15) are performed in the same process as in the liquid crystal display device 10 according to the first example of the embodiment.

In the liquid crystal display device 70, as in the liquid crystal display device 10, the linearly polarized light separating layer 1 is formed.
4 may not be able to reflect 100% of the linearly polarized light component of “•” in the unpolarized light from the light source 12. In this case,
As shown in FIGS. 14 and 15, a dichroic linear polarizing layer 36 similar to the above is disposed, and a linearly polarized light separating layer 14 is provided.
The occurrence of multiple reflection with the color filter 24 is prevented.

Next, a liquid crystal display device 80 using a reflective color filter according to a sixth embodiment of the present invention shown in FIGS. 16 and 17 will be described.

The liquid crystal display device 80 is different from the liquid crystal display device 70 according to the fifth embodiment in that a dichroic linearly polarizing layer 42 is provided instead of the linearly polarized light separating layer 14. The other configurations are the same as those of the liquid crystal display devices 10 and 70 according to the first and fifth examples of the above-described embodiment.

The dichroic linear polarizing layer 42 has the same structure as the liquid crystal display devices 40 and 60 according to the second and fourth examples of the above embodiment.

Therefore, in the liquid crystal display device 80, the unpolarized light from the light source 12 is applied to the dichroic linear polarizing layer 42.
Is different from the liquid crystal display device 70 only in that the linearly polarized light component of “•” is absorbed without being reflected, and after the linearly polarized light component of “← →” is transmitted and enters the liquid crystal layer 72. Is a bright display in the same process as in the liquid crystal display device 70 according to the fifth example of the embodiment (FIG. 17).
(See FIG. 18) and dark display (see FIG. 18).

In the above embodiment, the light source 12 is a transparent thin-film white light source made of thin-film electroluminescence and the like sandwiched between transparent resin sheets having transparent electrodes. However, the present invention is not limited to this, and the light source light incident from the side end surface of the light guide plate is emitted from one surface of the light guide plate. And so on. In this case, a reflection layer made of a metal thin film or the like is provided on the other surface of the light guide plate, but white PET (polyethylene terephthalate) may be used.

In the reflective liquid crystal display device 10, the pixel becomes brightest when no voltage is applied to the liquid crystal layer 20, and black is displayed when the voltage is applied. However, the present invention is not limited to this, and can be naturally applied to a “normally black mode” in which black display is performed when no voltage is applied to the liquid crystal layer.

[0121]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device 10 shown in FIG. A 波長 wavelength layer 22, a color filter 24 composed of a cholesteric liquid crystal layer, and a light absorption type dichroic circularly polarizing layer 26 are laminated to form an electric field.
By changing the optical rotation of the liquid crystal, it is possible to prevent reflected light from the color filter due to external light, to prevent malfunction of the TFT due to electricity generated at the time of receiving light, and to further improve the contrast. There was no decrease and the light use efficiency could be improved.

When the liquid crystal display device 40 shown in FIG. 4 is constituted by using the dichroic linearly polarizing layer 42, the unpolarized light from the light source 12
The liquid crystal display device 10 shown in FIG. 1 is lighter than that of the liquid crystal display device 10 shown in FIG. The brightness of the screen during display was slightly reduced, but the other effects were the same.

The liquid crystal display device 50 shown in FIG.
The liquid crystal layer 52 is formed using a liquid crystal layer 52 including an S-type liquid crystal 54, an electric field is applied to the liquid crystal 54, and the liquid crystal is rotated in a plane while the retardation value of the liquid crystal 54 is kept constant. When the phase was substantially shifted by π or transmitted without being shifted, the same operation and effect as those of the liquid crystal display device 10 shown in FIG. 1 were obtained.

The liquid crystal display device 60 shown in FIG.
When the chromatic linear polarization layer 42 was provided, the screen brightness during bright display was slightly reduced as compared with the liquid crystal display device 50, but the other effects were the same.

The liquid crystal display device 70 shown in FIG. 14 is different from the liquid crystal display device 10 shown in FIG.
When the liquid crystal layer 72 is replaced with the liquid crystal layer 72 containing the liquid crystal, and the quarter wavelength layer 22 is omitted, an electric field is applied to the liquid crystal layer 72 to change the retardation of the liquid crystal. As in the embodiment of the display device 10, it is possible to prevent the reflected light from the color filter due to external light, to prevent the TFT from malfunctioning at the time of receiving light, and to improve the light use efficiency without significantly lowering the contrast. Was completed.

The liquid crystal display device 80 shown in FIG. 16 is provided with a dichroic linear polarizing layer 42 instead of the linearly polarized light separating layer 14 in the liquid crystal display device 70. The brightness of the screen at the time of bright display is slightly reduced, but other effects are the same.

[0127]

According to the present invention, since the liquid crystal display device using the reflection type color filter is constructed as described above, it is possible to prevent the light reflected by the color filter due to the external light and to form the TFT of the liquid crystal layer. However, there is an excellent effect that malfunction of the TFT due to electricity generated at the time of light reception can be prevented.

Further, in a liquid crystal display device using a reflection type color filter, the light use efficiency can be greatly improved, there is no significant decrease in contrast caused by external light, and the optical rotation of the liquid crystal layer is utilized. The display has an excellent effect that a display state with good contrast can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an exploded main part of a liquid crystal display device using a reflective color filter according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view showing an enlarged liquid crystal layer in the liquid crystal display device.

FIG. 2B is an enlarged cross-sectional view showing another configuration of the liquid crystal layer.

FIG. 3 is a schematic cross-sectional view showing a dark display state of the liquid crystal display device.

FIG. 4 is a schematic cross-sectional view similar to FIG. 1, showing a liquid crystal display device according to a second embodiment of the present invention in a bright display state;

FIG. 5 is a schematic sectional view showing a state of the dark display.

FIG. 6 is a schematic sectional view similar to FIG. 1, showing a third example of the embodiment of the present invention in a brightly displayed state;

FIG. 7A is a schematic cross-sectional view showing an enlarged liquid crystal layer in the third example.

FIG. 7B is an enlarged sectional view showing another configuration of the liquid crystal layer.

FIG. 8 is a schematic cross-sectional view showing a direction of a director of a liquid crystal in the liquid crystal layer when an electric field is not applied.

FIG. 9 is a schematic sectional view showing directions of directors of the liquid crystal when an electric field is applied to the liquid crystal layer.

FIG. 10 is a diagram showing a Poincare sphere for describing changes in the polarization state of light rays.

FIG. 11 is a schematic sectional view similar to FIG. 3, showing the third example in a dark display state;

FIG. 12 is a schematic sectional view similar to FIG. 1, showing a fourth example of the embodiment of the present invention in a brightly displayed state;

FIG. 13 is a schematic sectional view showing a state of the dark display.

FIG. 14 is a schematic sectional view similar to FIG. 1, showing a fifth example of the embodiment of the present invention in a brightly displayed state;

FIG. 15 is a schematic sectional view showing the state of the dark display.

FIG. 16 is a schematic sectional view similar to FIG. 1, showing a sixth example of the embodiment of the present invention in a brightly displayed state;

FIG. 17 is a schematic sectional view showing a state of dark display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 12 ... Light source 14 ... Linear polarization separation layer 20, 52, 72 ... Liquid crystal layer 22 ... 1/4 wavelength layer 24 ... Color filter 26, 54 ... Liquid crystal 28A, 28B, 56A, 56B ... Pixel electrode 30 ... Dichroic circularly polarizing layers 36, 42 ... dichroic linearly polarizing layers

Claims (11)

[Claims] 1. A light source, a linearly polarized light separating layer that transmits one linearly polarized light component of light emitted from the light source and reflects a linearly polarized light component in a direction orthogonal to the light, a liquid crystal, and an electric field applied to the liquid crystal. And applying an electric field to the liquid crystal to change the optical rotation of the liquid crystal, thereby causing the linearly polarized light transmitted through the linearly polarized light separating layer to be incident upon exiting from the liquid crystal. A liquid crystal layer having a function of shifting the polarization plane or transmitting the light without being shifted; and a liquid crystal layer disposed on the opposite side of the linearly polarized light separating layer with respect to the liquid crystal layer, and having a phase of π / It comprises a quarter-wave layer that transmits two circularly polarized light beams shifted by two, and a cholesteric liquid crystal layer disposed on the opposite side of the liquid crystal layer with respect to the quarter-wave layer. Out of the circularly polarized light A color filter that transmits one circularly polarized light component in the left optical rotation direction and reflects the other circularly polarized light component, and is disposed on the opposite side of the quarter wavelength layer with respect to this color filter, A light-absorbing dichroic circularly polarizing layer that transmits the transmitted right or left circularly polarized light component in the optical rotation direction and absorbs the other circularly polarized light component;
A liquid crystal display device using a reflective color filter, comprising: 2. A light source, a dichroic linearly polarizing layer that transmits one linearly polarized light component of the light emitted from the light source and absorbs a linearly polarized light component in a direction orthogonal to the light source, a liquid crystal, and the liquid crystal. An electrode for applying an electric field to the liquid crystal to change the optical rotation of the liquid crystal by applying an electric field, whereby the linearly polarized light transmitted through the dichroic linearly polarized light layer, Shift the plane of polarization at the time of emission, or
A liquid crystal layer having a function of transmitting light without being shifted; and a liquid crystal layer which is disposed on the opposite side of the dichroic linear polarizing layer with respect to the liquid crystal layer and shifts the phase of linearly polarized light incident from the liquid crystal layer by π / 2 to circularly polarized light. A quarter-wave layer that transmits light,
The cholesteric liquid crystal layer is disposed on the opposite side of the liquid crystal layer with respect to the four-wavelength layer, and one of the right and left optical rotation directions of the circularly polarized light incident from the quarter-wavelength layer. A color filter that transmits light and reflects the other circularly polarized light component, and a circularly polarized light in the right or left optical rotation direction that is disposed on the opposite side of the 波長 wavelength layer with respect to the color filter and transmitted through the color filter. A liquid crystal display device using a reflection type color filter, comprising: a light absorption type dichroic circularly polarizing layer that transmits a component and absorbs the other circularly polarized component. 3. A light source, a linearly polarized light separating layer that transmits one linearly polarized light component of the light emitted from the light source and reflects a linearly polarized light component in a direction orthogonal to the light source, a liquid crystal, and an electric field applied to the liquid crystal. By applying an electric field to the liquid crystal, the liquid crystal is rotated in the plane while the retardation value is constant, and the phase of the incident linearly polarized light is substantially shifted by 0 to π. A liquid crystal layer having a transmitting function,
A quarter-wavelength layer disposed on the opposite side of the linearly polarized light separating layer with respect to the liquid crystal layer and transmitting the circularly polarized light by shifting the phase of linearly polarized light incident from the liquid crystal layer by π / 2;
A cholesteric liquid crystal layer disposed on the opposite side of the liquid crystal layer with respect to the 波長 wavelength layer, and of the circularly polarized light incident from the 波長 wavelength layer, one of the right and left optical rotation directions. A color filter that transmits the light component and reflects the other circularly polarized light component; and a right or left optical rotation direction circle that is disposed on the opposite side of the quarter-wave layer with respect to the color filter and transmits the color filter. A liquid crystal display device using a reflection type color filter, comprising: a light absorbing dichroic circularly polarizing layer that transmits a polarized light component and absorbs the other circularly polarized light component. 4. A light source, a dichroic linear polarizing layer that transmits one linearly polarized light component of light emitted from the light source and absorbs a linearly polarized light component in a direction orthogonal to the light, a liquid crystal, and the liquid crystal. When an electric field is applied to the liquid crystal, the liquid crystal rotates in the plane while the retardation value is kept constant, and the phase of the incident linearly polarized light is substantially 0 to π. A liquid crystal layer having a function of shifting and transmitting the light; and a liquid crystal layer disposed on the opposite side of the dichroic linear polarizing layer with respect to the liquid crystal layer.
A 波長 wavelength layer that is shifted by two and transmitted as circularly polarized light,
A cholesteric liquid crystal layer disposed on the opposite side of the liquid crystal layer with respect to the quarter wavelength layer, and one of the right and left optical rotation directions of the circularly polarized light incident from the liquid crystal layer. A color filter that transmits light and reflects the other circularly polarized light component, and a circularly polarized light in the right or left optical rotation direction that is disposed on the opposite side of the 波長 wavelength layer with respect to the color filter and transmitted through the color filter. A liquid crystal display device using a reflection type color filter, comprising: a light absorption type dichroic circularly polarizing layer that transmits a component and absorbs the other circularly polarized component. 5. A light source, a linearly polarized light separating layer that transmits one linearly polarized light component of the light emitted from the light source and reflects a linearly polarized light component in a direction orthogonal to the light, and a phase of the transmitted light. A retardation substantially shifted from -π / 2 to π / 2.
A liquid crystal having a liquid crystal phase value and an electrode for applying an electric field to the liquid crystal.
A cholesteric liquid crystal layer disposed on the opposite side of the linearly polarized light separating layer with respect to the liquid crystal layer; Among the circularly polarized light incident from the liquid crystal layer, a color filter that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component; And a light-absorbing dichroic circularly polarizing layer that transmits a circularly polarized light component in the right or left optical rotation direction that has passed through the color filter and absorbs the other circularly polarized light component. A liquid crystal display device using a reflection type color filter. 6. A light source, a dichroic linearly polarizing layer that transmits one linearly polarized light component of the light emitted from the light source and absorbs a linearly polarized light component in a direction orthogonal to the linearly polarized light component, A liquid crystal having a retardation value for shifting the phase substantially from -π / 2 to π / 2 and an electrode for applying an electric field to the liquid crystal are included, and the phase of transmitted light is substantially -π /
A liquid crystal layer having a function of shifting by 2 to π / 2 into circularly polarized light in the right or left optical rotation direction; A color filter that transmits one circularly polarized light component in the right or left optical rotation direction and reflects the other circularly polarized light component of the circularly polarized light incident from the liquid crystal layer, A light-absorbing dichroic circularly polarizing layer that is disposed on the opposite side of the liquid crystal layer, transmits the right or left circularly polarized light component transmitted through the color filter, and absorbs the other circularly polarized light component, A liquid crystal display device using a reflective color filter, comprising: 7. The dichroic light according to claim 1, wherein one of the linearly polarized light components is transmitted to the liquid crystal layer side of the linearly polarized light separating layer and the linearly polarized light component in a direction orthogonal to the one is absorbed. A liquid crystal display device using a reflective color filter, comprising a linear polarizing layer. 8. The linearly polarized light separating layer according to claim 1, wherein said linearly polarized light separating layer has a planar multilayer structure in which three or more birefringent films are laminated. Of the two lights having vibration directions perpendicular to each other, the difference in the refractive index between the layers adjacent to each other in the thickness direction for one light and the difference in the refractive index between the layers adjacent in the thickness direction to the other light A liquid crystal display device using a reflective color filter. 9. The method according to claim 1, wherein the phase of light passing through said linearly polarized light separating layer is substantially π /
A retardation layer having a retardation value for shifting by two,
A liquid crystal display device using a reflection type color filter, comprising: an optical rotation selecting layer formed of a cholesteric liquid crystal layer; and converting circularly polarized light transmitted through the cholesteric liquid crystal layer into linearly polarized light. 10. The dichroic circularly polarizing layer according to claim 1, wherein a 波長 wavelength layer is attached to both sides of the dichroic linearly polarizing layer or one of the two sides of the liquid crystal layer. Alternatively, a liquid crystal display device using a reflective color filter, which is formed directly. 11. The liquid crystal layer according to claim 3, wherein the liquid crystal layer has the liquid crystal sandwiched between two substrates, the electrode is formed on one of the electrodes, and an electric field direction when a voltage is applied to the electrode. Has a portion substantially parallel to the substrate surface,
A liquid crystal display device using a reflective color filter, wherein the liquid crystal display device is in a mode in which most liquid crystal molecules in the liquid crystal rotate in a direction substantially parallel to the substrate surface.