JPH06317793A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To make the brightness of display very high by coloring transmitted light without using a color filter and making the transmissivity of the light high. CONSTITUTION:This device is provided with a ferroelectric liquid crystal cell 30 obtained by sealing ferroelectric liquid crystal 38 between a pair of transparent substrates 31 and 32 on which transparent electrodes 33 and 34 are formed, a polarizing plate 40 and a reflector 41. The polarizing plate 40 is arranged on the front surface side of the cell 30, the reflector 41 is arranged on the rear side of the cell 30, and the transmission axis of the polarizing plate 40 is made nearly parallel with the oriented direction of liquid crystal molecules at the time of orienting the ferroelectric liquid crystal 38 in the cell 30 in either stable state of 1st and 2nd stable states.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As a liquid crystal display device, there is a color liquid crystal display device which can obtain a colored display. FIG. 3 is a cross-sectional view of a conventional color liquid crystal display device. This liquid crystal display device includes a liquid crystal cell 10 having a color filter and a liquid crystal cell 1.
It is composed of a pair of polarizing plates 21 and 22 which are arranged with 0 interposed therebetween.

The liquid crystal cell 10 has transparent electrodes 13 and 14
And a pair of upper and lower transparent substrates 11 and 12 on which the alignment films 15 and 16 are formed are bonded to each other via a frame-shaped sealing material 18, and are surrounded by the sealing material 18 between the two substrates 11 and 12. A liquid crystal 19 is sealed in a closed region. One substrate of the liquid crystal cell 10, for example, the lower substrate 12 in the figure,
A color filter 17 for coloring the transmitted light is provided.

The color filter 17 is provided on the substrate 12
The transparent electrode 14 on the substrate 12 side is formed on a protective film (not shown) that covers the color filter 17. Further, as the liquid crystal cell 10,
In general, the liquid crystal molecules between the substrates 11 and 12 are almost 9
A TN (twisted nematic) type having a twist orientation at a twist angle of 0 ° is used.

The pair of polarizing plates 21 and 22 are arranged such that their transmission axes are substantially parallel to each other, and the transmission axes of these polarizing plates 21 and 22 are liquid crystal on one substrate side of the liquid crystal cell 10. It is almost parallel to the molecular orientation direction.

There are two types of liquid crystal display devices, a transmissive type and a reflective type in which a reflecting plate is arranged on the back surface.
A color liquid crystal display device equipped with a color filter is generally
It is of a transmissive type as shown in FIG.

In the color liquid crystal display device, a light source (not shown) is arranged on the back surface side thereof, and both substrates 1 of the liquid crystal cell 10 are arranged.
The display is driven by applying a voltage between the electrodes 13 and 14 of Nos. 1 and 12, and the light from the light source is linearly polarized by the polarizing plate 22 on the incident side (the lower side in FIG. 3) to the liquid crystal cell 10. Incident.

The linearly polarized light that has entered the liquid crystal cell 10 passes through the color filter 17 and the liquid crystal layer, and the liquid crystal cell 1
0 is emitted, but in that case, light having a wavelength other than the wavelength band corresponding to the color of the color filter 17 is absorbed by the color filter 17, so that the light emitted from the liquid crystal cell 10 is colored in the color of the color filter 17. Become light.

Further, when no voltage is applied between the electrodes 13 and 14 of the liquid crystal cell 10, that is, when the liquid crystal molecules are twist-aligned, the light passing through the liquid crystal cell 10 is the liquid crystal 1.
The linearly polarized light that has been emitted from the liquid crystal cell 10 at this time is linearly polarized in a direction substantially orthogonal to the linearly polarized light that has entered the liquid crystal cell 10 when it has finished passing through the liquid crystal layer due to the polarization effect of 9. It is absorbed by the polarizing plate 21 (upper side in FIG. 3), and the display is in a dark (black) state.

On the other hand, when a voltage is applied between the electrodes 13 and 14 of the liquid crystal cell 10, the liquid crystal molecules are vertically aligned with respect to the surfaces of the substrates 11 and 12, and the polarization effect of the liquid crystal 19 is almost eliminated. The linearly polarized light entering 10 exits the liquid crystal cell 10 as it is. Then, at this time, the linearly polarized light emitted from the liquid crystal cell 10 is transmitted through the emission side polarization plate 21, and the display becomes a bright display of the color colored by the color filter 17.

[0011]

However, since the above-mentioned conventional color liquid crystal display device colors the transmitted light by using the color filter 17, it has a problem that the light transmittance is low and therefore the display is dark. There is.

This is due to the absorption of light by the color filter 17. Since the color filter 17 also absorbs light in the wavelength band corresponding to the color with a considerably high absorption rate, coloring through the color filter 17 is performed. The light becomes light in which the amount of light is significantly reduced compared to the light in the wavelength band before entering the color filter 17, and the display becomes dark.

Although the color liquid crystal display device shown in FIG. 3 is of a transmissive type, if a reflection plate is arranged on the back surface of this color liquid crystal display device to form a reflection type device, light is incident from the front side of the device. Since the light reflected by the reflecting plate on the back surface and emitted to the front surface side passes through the color filter 17 twice and the light amount is doubly reduced, the display is considerably darkened and becomes almost unusable as a display device.

It is an object of the present invention to provide a color liquid crystal display device capable of coloring transmitted light without using a color filter to increase the light transmittance and sufficiently increase the display brightness. It is a thing.

[0015]

A color liquid crystal display device of the present invention comprises a ferroelectric liquid crystal cell in which a ferroelectric liquid crystal is sealed between a pair of transparent substrates having transparent electrodes formed thereon, and one polarizing plate. A reflecting plate, the polarizing plate is arranged on the front surface side of the liquid crystal cell, the reflecting plate is arranged on the rear surface side of the liquid crystal cell, and the transmission axis of the polarizing plate is defined by the ferroelectricity of the liquid crystal cell. It is characterized in that the liquid crystal is oriented substantially parallel to the alignment direction of the liquid crystal molecules when the liquid crystal is aligned in either one of the first and second stable states.

In the present invention, the first ferroelectric liquid crystal described above is used.
It is desirable that the angle formed by the orientation direction of the liquid crystal molecules in the stable state of 1 and the orientation direction of the liquid crystal molecules in the second stable state is approximately 45 °.

[0017]

This color liquid crystal display device is of a reflection type in which light incident from the front surface side is reflected by the reflection plate on the rear surface side and displayed. The incident light from the front surface side is reflected by the polarizing plate and the liquid crystal cell. The light passes through the liquid crystal cell and the polarizing plate and is emitted again.

In this color liquid crystal display device, the liquid crystal cell has two stable states (bistability) in the alignment state of the liquid crystal molecules, and the alignment state of the liquid crystal molecules is the first depending on the polarity of the applied voltage. A ferroelectric liquid crystal cell using a ferroelectric liquid crystal that changes between a stable state and a second stable state is used, and the transmission axis of the polarizing plate is such that the ferroelectric liquid crystal of the liquid crystal cell has the first and second stable states. Since the liquid crystal molecules are aligned substantially parallel to one of the two stable states, the liquid crystal molecules are almost parallel to the transmission axis of the polarizing plate when a voltage of one polarity is applied to the liquid crystal cell. When a voltage of opposite polarity is applied, the liquid crystal molecules are oriented obliquely with respect to the transmission axis of the polarizing plate.

Then, a voltage of one polarity is applied to the liquid crystal cell to orient the liquid crystal molecules in a direction substantially parallel to the transmission axis of the polarizing plate. The incident linearly polarized light passes through the liquid crystal cell in its polarization state, is reflected by the reflection plate, and passes through the liquid crystal cell without changing the polarization state when passing through the liquid crystal cell again.
Therefore, at this time, the light which passes through the liquid crystal cell twice and is incident on the polarizing plate again is the same linearly polarized light as when it is incident from the outside through the polarizing plate, and the re-incident light on the polarizing plate is With such linearly polarized light, all the wavelength light thereof passes through the polarizing plate and is emitted, so that the emitted light is uncolored light at this time.

When a voltage of opposite polarity is applied to the liquid crystal cell to orient the liquid crystal molecules obliquely with respect to the transmission axis of the polarizing plate, at this time, a straight line incident on the liquid crystal cell through the polarizing plate is introduced. While the polarized light passes through the liquid crystal cell, it is polarized by the liquid crystal to become elliptically polarized light. The polarized state is further changed in the process of being reflected by the reflector and passing through the liquid crystal cell again. Therefore, at this time, the light that passes through the liquid crystal cell twice and is incident on the polarizing plate again is non-linearly polarized light that has been subjected to the polarization effect of two times by the liquid crystal, and the re-incident light on the polarizing plate is non-linearly polarized light. If so, only the wavelength light of the polarization component that passes through the polarizing plate out of the light passes through the polarizing plate and is emitted, so that the emitted light becomes colored light at this time.

That is, this color liquid crystal display device colors the transmitted light without using a color filter like the conventional liquid crystal display device, and therefore the amount of the colored light is the amount of the light incident on the display device. Since it is almost the same as the amount of light in the wavelength band that becomes the colored light, it is possible to increase the light transmittance and sufficiently increase the brightness of the display.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view of a color liquid crystal display device. This color liquid crystal display device includes one ferroelectric liquid crystal cell 30, one polarizing plate 40, and one reflecting plate 41.
The polarizing plate 40 is arranged on the front surface side of the liquid crystal cell 30, and the reflection plate 41 is arranged on the rear surface side of the liquid crystal cell 30.

The ferroelectric liquid crystal cell 30 has a transparent electrode 3
A pair of upper and lower transparent substrates 31 and 32, on which the alignment films 35 and 36 are formed, are bonded to each other via a frame-shaped sealing material 37, and the sealing material 37 between the substrates 31 and 32 is joined. Ferroelectric liquid crystal 38 having a smectic layer structure is enclosed in a region surrounded by, and alignment films 35 and 36 on both substrates 31 and 32 regulate the direction of the normal line of the smectic layer structure. Orientation treatment has been performed.

The ferroelectric liquid crystal 38 has two stable states (bistability) in the alignment state of its molecules, and the alignment states of the liquid crystal molecules are the first stable state and the second stable state depending on the polarity of the applied voltage. Changes to a stable state of.

That is, both substrates 31, 3 of the liquid crystal cell 30
When a voltage having one polarity and an absolute value which is equal to or higher than the threshold voltage of the liquid crystal 38 is applied between the two electrodes 33 and 34, liquid crystal molecules are regulated by the alignment films 35 and 36, and the normal direction of the smectic layer structure. First tilted almost uniformly in one direction with respect to
Is aligned in a stable state, and the alignment state is maintained even after the voltage application is stopped. Further, when a voltage having an opposite polarity and an absolute value equal to or higher than the threshold voltage of the liquid crystal 38 is applied between the electrodes 33 and 34, the liquid crystal molecules are substantially uniform in the opposite direction to the normal direction of the smectic layer structure. It is oriented in the second stable state inclining to, and the oriented state is maintained even after the voltage application is stopped.

The polarizing plate 40 has its transmission axis
The ferroelectric liquid crystal 38 of the liquid crystal cell 30 is arranged substantially parallel to the alignment direction of the liquid crystal molecules when the ferroelectric liquid crystal 38 is aligned in one of the first and second stable states. Is bonded to the outer surface of a front surface side substrate (upper substrate in the figure) 31 of the liquid crystal cell 30, and the reflection plate 41 is bonded to the outer surface of a back surface side substrate (lower substrate in the figure) 32 of the liquid crystal cell 30.

FIG. 2 is a plan view showing the alignment direction of the liquid crystal molecules of the liquid crystal cell 30 and the transmission axis of the polarizing plate 40. Figure 2
In the above, 30a and 30b are liquid crystal molecule alignment directions of the liquid crystal cell 30, 30a is a liquid crystal molecule alignment direction in the first stable state, and 30b is a liquid crystal molecule alignment direction in the second stable state.

These two liquid crystal molecule orientation directions 30a, 30
The angle formed by b is the sum of the tilt angle of the first liquid crystal molecule alignment direction 30a and the tilt angle of the second liquid crystal molecule alignment direction 30b with respect to the normal direction of the smectic layer structure. Is θ, the angle formed by these orientation directions 30a and 30b is 2θ. Then, in this embodiment, the angle 2θ is set to approximately 45 °,
The material of the ferroelectric liquid crystal 38 is selected.

Further, in FIG. 2, reference numeral 40a denotes a polarizing plate 40.
In this embodiment, the transmission axis 40a of the polarizing plate 40 is the first axis of the ferroelectric liquid crystal 38 of the liquid crystal cell 30.
The alignment direction 30a of the liquid crystal molecules when aligned in the stable state is substantially parallel.

This color liquid crystal display device is of a reflection type in which light incident from the front surface side (natural light or light from an illumination light source) is reflected by the back surface side reflection plate 41 and displayed. Incident light is generated by the polarizing plate 40 and the liquid crystal cell 30.
The liquid crystal cell 30 is again reflected by the reflection plate 41 and passes through the liquid crystal cell 30.
And goes out through the polarizing plate 41. In addition, this color liquid crystal display device includes electrodes 3 of both substrates 31 and 32 of the liquid crystal cell 30.
A display is driven by applying a voltage between 3 and 34.

In this color liquid crystal display device, the liquid crystal cell 30 has two stable states in the alignment state of the liquid crystal molecules, and the alignment states of the liquid crystal molecules are the first stable state and the first stable state according to the polarity of the applied voltage. A ferroelectric liquid crystal cell using a ferroelectric liquid crystal 38 that changes to a stable state of 2, and a transmission axis 40a of a polarizing plate 40 arranged on the surface side thereof is used as the liquid crystal cell 3
Since the ferroelectric liquid crystal 38 of 0 is substantially parallel to the liquid crystal molecule alignment direction 30a when aligned in the first stable state,
When a voltage of one polarity is applied to the liquid crystal cell 30, the liquid crystal molecules are aligned in a direction substantially parallel to the transmission axis 40a of the polarizing plate 40, and when a voltage of the opposite polarity is applied, the liquid crystal molecules are polarized.
Is oriented in an oblique direction with respect to the transmission axis 40a.

The deviation angle between the liquid crystal molecule alignment direction 30b and the transmission axis 40a of the polarizing plate 40 when a voltage of opposite polarity is applied to the liquid crystal cell 30 is determined by the first and second liquid crystal molecule alignments of the liquid crystal cell 30. It is the same as the angle 2θ formed by the directions 30a and 30b, and in this embodiment, 2θ = 45 °.

Then, a voltage of one polarity is applied to the liquid crystal cell 30 to orient the liquid crystal molecules in a direction 30a substantially parallel to the transmission axis 40a of the polarizing plate 40. At this time, the polarizing plate 40 is externally applied. The linearly polarized light passing through the liquid crystal cell 30 passes through the liquid crystal cell 30 in its polarization state, is reflected by the reflection plate 41, and passes through the liquid crystal cell 30 without changing the polarization state when passing through the liquid crystal cell 30 again. To do.

Therefore, at this time, the light that passes through the liquid crystal cell 30 twice and is incident on the polarizing plate 40 again is the same linearly polarized light as when it is incident from the outside through the polarizing plate 40.
If the re-incident light on the polarizing plate 40 is such linearly polarized light, all the wavelength light thereof passes through the polarizing plate 40 and is emitted, so that the emitted light is uncolored light at this time.

When a voltage of opposite polarity is applied to the liquid crystal cell 30 to orient the liquid crystal molecules in the direction 30b obliquely intersecting the transmission axis 40a of the polarizing plate 40, the polarizing plate 40 is then moved. The linearly polarized light that has passed through the liquid crystal cell 30 is polarized by the liquid crystal 39 in the process of passing through the liquid crystal cell 30, and its polarization state changes.

That is, the ferroelectric liquid crystal cell 30 is
In the state where the liquid crystal molecules are aligned in the first stable state and in the state where the liquid crystal molecules are aligned in the second stable state, a retardation plate having a slow axis in the alignment directions 30a and 30b of the liquid crystal molecules Therefore, in the first stable state, that is, in the state where the liquid crystal molecules are aligned in the direction 30a parallel to the transmission axis 40a of the polarizing plate 40, the linearly polarized light incident through the polarizing plate 40 causes the polarization action of the liquid crystal 38. Liquid crystal cell 30 without receiving
The second stable state, that is, the direction 30 in which the liquid crystal molecules obliquely intersect the transmission axis 40a of the polarizing plate 40.
In the state of being aligned in b, the linearly polarized light that has entered through the polarizing plate 40 is subjected to the polarization effect of the liquid crystal 38 to become elliptically polarized light,
In the process of being reflected by the reflecting plate 41 and passing through the liquid crystal cell 30 again, its polarization state further changes.

Therefore, the liquid crystal 38 of the liquid crystal cell 30 is changed to the second liquid crystal.
The light that has passed through the liquid crystal cell twice and is incident on the polarizing plate 40 again when it is aligned in the stable state is non-linearly polarized light that has been polarized by the liquid crystal 38 twice and is re-incident on the polarizing plate 40. If the light is non-linearly polarized light, only the light having the wavelength of the polarization component that passes through the polarizing plate 40 passes through the polarizing plate 40 and is emitted, so that the emitted light becomes colored light at this time.

The color of this colored light is the product Δnd of the refractive index anisotropy Δn of the liquid crystal 38 of the liquid crystal cell 30 and the liquid crystal layer thickness d.
And the deviation angle between the liquid crystal molecule alignment direction 30b and the transmission axis 40a of the polarizing plate 40 when the liquid crystal 38 is aligned in the second stable state.

As described above, the color liquid crystal display device is
Unlike conventional color liquid crystal display devices, the transmitted light is colored without using a color filter. Therefore, the amount of colored light is the amount of light in the wavelength band that is pre-colored light of the light that enters the display device. Since it is almost the same as the amount, the light transmittance can be increased and the display brightness can be sufficiently increased.

That is, in the conventional color liquid crystal display device, the light amount of the colored light passing through the color filter is considerably reduced as compared with the light amount of the wavelength band which becomes the colored light of the light incident on the display device. In the color liquid crystal display device,
Such a decrease in light amount hardly occurs. For this reason,
The color liquid crystal display device is of a reflective type, but its display brightness is sufficient.

The brightness of the display in the above color liquid crystal display device will be described. When a voltage of one polarity is applied to the liquid crystal cell 30, the liquid crystal 38 is aligned in the first stable state, that is, the liquid crystal molecules are polarized. The intensity I of the uncolored light emitted from the display device when oriented in the direction 30a parallel to the transmission axis 40a of 40 is expressed by the following equation (1).

I = 1/2 (1) This light intensity I is 1/2 of the intensity of all wavelength light (visible light) incident on the display device, and this light intensity I is in the visible light band. The uncolored light is high-intensity white light because it is uniform in all wavelength light.

When a voltage of opposite polarity is applied to the liquid crystal cell 30 to orient the liquid crystal 38 in the second stable state,
That is, when the liquid crystal molecules are aligned in the direction 30b obliquely intersecting the transmission axis 40a of the polarizing plate 40, the intensity I of the colored light emitted from the display device is as follows. The deviation angle from the transmission axis 40a is 2θ =
If it is 45 ° (2θ = π / 4), it is expressed by the following equation (2).

[0044]

[Equation 1]

The value of the light intensity I obtained by the equation (2) is
In white display, that is, the light intensity (I = 1/2) when the emitted light is uncolored light is somewhat lower, but most of the wavelength light of the polarization component that passes through the polarizing plate 40 is the emitted light. Therefore, the brightness is sufficiently high, and therefore, a much brighter colored display can be obtained as compared with the conventional color liquid crystal display device using the color filter.

Next, the display color of the color liquid crystal display device will be described. The display color of this color liquid crystal display device is obtained by applying a voltage of one polarity to the liquid crystal cell 30 and the liquid crystal 3.
8 is oriented in the first stable state, that is, when the emitted light is uncolored light, the display is "white", and the liquid crystal cell 3
When a voltage of reverse polarity is applied to 0 to orient the liquid crystal 38 in the second stable state, that is, when the emitted light becomes colored light, display is performed by refraction of the liquid crystal 38 of the liquid crystal cell 30 as described above. The product of the anisotropy Δn and the liquid crystal layer thickness d, Δn · d, and the liquid crystal 3
8 is determined by the angle of deviation between the liquid crystal molecule alignment direction 30b and the transmission axis 40a of the polarizing plate 40 when 8 is aligned in the second stable state.

In the following [Table 1], the deviation angle between the liquid crystal molecule alignment direction 30b and the transmission axis 40a of the polarizing plate 40 in the second stable state of the liquid crystal cell 30 is 2θ = 45 °, and Δn of the liquid crystal cell 30 is set. -Display colors of four types of color liquid crystal display devices with different values of d are shown. In Table 1, -E and + E are applied voltages to the liquid crystal cell 30, and here, the liquid crystal molecule alignment state when a negative voltage -E is applied is defined as the first stable state, and The liquid crystal molecule alignment state when the voltage + E is applied is the second stable state.

[0048]

[Table 1]

As shown in [Table 1], the display color of the color liquid crystal display device is the liquid crystal when the negative voltage −E is applied to the liquid crystal cell 30 to align the liquid crystal 38 in the first stable state. It is always “white” regardless of the value of Δn · d of the cell 30, and when a positive voltage + E is applied to the liquid crystal cell 30 to align the liquid crystal 38 to the second stable state, the Δ of the liquid crystal cell 30 is changed.
The value of n · d is Δn · d = 225 nm and Δn · d = 4
In the case of 50 nm, it is “blue”, in the case of Δn · d = 550 nm, it is “green”, and in the case of Δn · d = 620 nm, it is “red”.

Further, the color liquid crystal display device is composed of only three elements, one ferroelectric liquid crystal cell 30, one polarizing plate 40, and one reflecting plate 41. It has a simple structure and can be obtained at low cost.

In the above embodiment, the shift angle between the transmission axis 40a of the polarizing plate 40 and the liquid crystal molecule alignment direction 30b in the second stable state of the liquid crystal cell 30 is 45 °, but this shift angle is 45 °. Not limited to °, it can be selected arbitrarily. However, in order to sufficiently obtain the above-mentioned coloring effect, it is desirable that the shift angle is approximately 45 ° (for example, 45 ± 5 °).

Further, in the above embodiment, the transmission axis 40a of the polarizing plate 40 is connected to the ferroelectric liquid crystal 38 of the liquid crystal cell 30 as the first axis.
The alignment axis 30a of the liquid crystal molecules when aligned in the stable state is substantially parallel to the alignment axis 30a.
The ferroelectric liquid crystal 38 of the liquid crystal cell 30 may be made substantially parallel to the liquid crystal molecule orientation direction 30b when the liquid crystal cell 30 is oriented in the second stable state. In that case, the liquid crystal 38 of the liquid crystal cell 30 is placed in the second stable state. When oriented, the emitted light becomes uncolored light,
The emitted light becomes colored light when the liquid crystal 38 is oriented in the first stable state.

[0053]

The color liquid crystal display device of the present invention comprises a ferroelectric liquid crystal cell in which a ferroelectric liquid crystal is sealed between a pair of transparent substrates having transparent electrodes, one polarizing plate, and a reflecting plate. The polarizing plate is disposed on the front surface side of the liquid crystal cell, the reflector is disposed on the rear surface side of the liquid crystal cell, and the transmission axis of the polarizing plate is set to the first ferroelectric liquid crystal of the liquid crystal cell. And the second stable state, the liquid crystal molecules are aligned substantially parallel to one of the stable states, so that the transmitted light is colored without using a color filter to improve the light transmittance. The display brightness can be made sufficiently high.

[Brief description of drawings]

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

FIG. 2 shows a ferroelectric liquid crystal cell 2 according to an embodiment of the present invention.
FIG. 3 is a plan view showing two liquid crystal molecule alignment directions and a transmission axis of a polarizing plate.

FIG. 3 is a sectional view of a conventional color liquid crystal display device.

[Explanation of symbols]

30 ... Ferroelectric liquid crystal cell 30a ... Liquid crystal molecule alignment direction in the first stable state, 3
0b ... Alignment direction of liquid crystal molecules in second stable state 31, 32 ... Transparent substrate 33, 34 ... Transparent electrode 35, 36 ... Alignment film 38 ... Ferroelectric liquid crystal 40 ... Polarizing plate 40a ... Transmission axis 41 ... Reflector

Claims (2)

[Claims] 1. A liquid crystal cell comprising a ferroelectric liquid crystal cell in which a ferroelectric liquid crystal is sealed between a pair of transparent substrates having transparent electrodes, a polarizing plate, and a reflector. Is arranged on the front surface side of the liquid crystal cell, the reflection plate is arranged on the back surface side of the liquid crystal cell, and the transmission axis of the polarizing plate is set to one of the first and second stable states of the ferroelectric liquid crystal of the liquid crystal cell. A color liquid crystal display device, wherein the liquid crystal molecules are oriented substantially parallel to one of the stable states. 2. The angle formed by the liquid crystal molecule alignment direction in the first stable state of the ferroelectric liquid crystal and the liquid crystal molecule alignment direction in the second stable state is approximately 45 °. The described color liquid crystal display device.