KR101216988B1 - Ferroelectric liquid crystal display device and fabrication method the same - Google Patents

Abstract

The present invention relates to a ferroelectric liquid crystal display device and a method of manufacturing the same, which realize a wide viewing angle / high brightness and at the same time reduce power consumption and prevent flicker. The first and the ferroelectric layer, which is composed of the ferroelectric liquid crystal in smectic C ^* phase (Sm C ^* phase) between the second substrate and maintaining the initial alignment of the liquid crystal layer by the hydrogen bonding network; And first and second transparent electrodes formed on opposite surfaces of the first and second substrates to apply a vertical electric field to the ferroelectric liquid crystal layer, and a method of manufacturing the ferroelectric liquid crystal display device.

Spontaneous Polarization, Hydrogen Bond, Ferroelectric Liquid Crystal

Description

Ferroelectric liquid crystal display device and its manufacturing method {FERROELECTRIC LIQUID CRYSTAL DISPLAY DEVICE AND FABRICATION METHOD THE SAME}

1 is a graph showing the light transmittance characteristics with respect to the voltage of the ferroelectric liquid crystal of the V-switching mode.

FIG. 2 is a diagram illustrating a phase transition process of ferroelectric liquid crystal in half V-switching mode. FIG.

3 is a view showing the change of liquid crystal molecule arrangement according to the electric field orientation of the ferroelectric liquid crystal of the half V-switching mode.

4 is a graph showing the light transmittance characteristics with respect to the voltage of the ferroelectric liquid crystal of the half-V switching mode.

FIG. 5 is a diagram showing a ferroelectric liquid crystal in half V-switching mode that reacts with an electric field during field orientation; FIG.

6A and 6B are diagrams showing ferroelectric liquid crystals in a half V-switching mode in response to an external electric field that is not driven during driving;

7A to 7D illustrate a method of manufacturing a ferroelectric liquid crystal display device according to the present invention.

8A to 8E are diagrams illustrating a driving process of ferroelectric liquid crystal molecules according to a positive electric field in a state in which a negative electric field is applied.

9 and 10 are graphs showing the light transmittance characteristics with respect to the voltage of the ferroelectric liquid crystal display device according to the present invention.

11 is a view showing an initial alignment state of the ferroelectric liquid crystal according to the present invention in the state that the electric field is not applied.

12A and 12B illustrate ferroelectric liquid crystals of the present invention reacting with an external electric field. FIG. 12A illustrates ferroelectric liquid crystals reacting with a negative external electric field. FIG. 12B illustrates ferroelectric liquid crystals reacting with a positive external electric field. Figures shown.

** Description of the symbols for the main parts of the drawings **

110: first substrate 120: second substrate

130: liquid crystal molecules of isotropic phase 131: ferroelectric liquid crystal molecules of Smectic C ^* phase

140: a substance capable of hydrogen bonding

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferroelectric liquid crystal display device, and more particularly, to a ferroelectric liquid crystal display device capable of realizing a wide viewing angle / high brightness, low power consumption, and improving flicker.

The liquid crystal display device displays an image by modulating the light incident on the liquid crystal cell by controlling an electric field applied to the liquid crystal cell. The liquid crystal display device uses a twisted nematic mode and an IPS according to the driving method of the liquid crystal molecules. Mode may be classified into In Plane Switching Mode.

The TN mode has a narrow viewing angle because liquid crystal molecules oriented horizontally with the substrate are driven based on a direction substantially perpendicular to the substrate when a voltage is applied to the liquid crystal display panel. When the panel voltage is applied, driving in a plane parallel to the substrate has the advantage that the viewing angle can be improved. However, in the IPS mode, since the common electrode and the pixel electrode exist together on the same substrate for planar driving of liquid crystal molecules, the aperture ratio is low and the luminance is low.

On the other hand, the liquid crystal used in the liquid crystal display device implementing the TN / IPS mode has a disadvantage in that the response speed to the external electric field is slow because it reacts after the induced polarization is generated by the external electric field.

Therefore, in recent years, ferroelectric liquid crystal display devices using ferroelectric liquid crystals to realize wide viewing angles and high luminance and to improve response speed have been studied.

Ferroelectric liquid crystals have a permanent polarization, that is, spontaneous polarization even without an external electric field, so when an external electric field is applied like a magnet-magnet interaction, the ferroelectric liquid crystal rapidly rotates due to the interaction of the external electric field and spontaneous polarization. Compared to the mode liquid crystal, the response speed is several hundred to several thousand times faster. In addition, since the liquid crystal itself has a planar driving characteristic, the ferroelectric liquid crystal can realize a wide viewing angle without the need for a special electrode structure or a compensation film. The ferroelectric liquid crystal is divided into a V-switching mode and a half V-switching mode according to a characteristic of reacting in response to the polarity of an external electric field.

V-switching mode As the temperature is lowered isotropic phase (isotropic) → smectic A phase (Smetic A Phase: S _A) → smectic X ^* phase (Smetic X ^* Phase: Sm X ^*) → ferroelectric crystals (Crystal) Thermodynamic phase transition of the liquid crystal is achieved. Here, in the isotropic phase, the liquid crystal molecules have no orientation and positional order, and the Smetic A phase separates the liquid crystal molecules into a virtual layer, is aligned perpendicular to the virtual layer, and has symmetry above and below. The Smetic X phase is an intermediate state between the Smetic A phase and the crystal state. In the V-switching mode in which the liquid crystal molecules are phase-transformed into the Smetic X phase, the arrangement state is changed in response to the positive external voltage (+ V) and the negative external voltage (-V) as shown in FIG. 1. The light transmittance (T) is increased.

By the way, V-switching mode has high-speed response characteristics and wide viewing angle characteristics. However, since the spontaneous polarization value of the liquid crystal is large, the effective power for driving the liquid crystal cell is large, and due to the characteristics of the material , the applied field direction and its own are applied. Since the spontaneous polarization direction is not uniform as a whole and thus the monostable state is difficult, there is a problem in that the luminance is uneven depending on the polarity of the external electric field.

On the other hand, the half V-switching mode not only has high-speed response characteristics and wide viewing angle characteristics, but also has a small power consumption of 1/100 to 1/200 of the spontaneous polarization value of the liquid crystals of the V-switching mode, and thus, the spontaneous polarization direction Since the monostable state is easy, a uniform luminance can be realized as compared with the V-switching mode.

In the half-v switching mode, as shown in FIG. 2, ferroelectric liquid crystals are injected into a liquid crystal cell parallelly aligned at an initial temperature of an isotropic phase without direction and position order, and when the temperature is lowered to the isotropic phase, the ferroelectric liquid crystal is in a rubbing direction. It becomes a nematic phase (N ^* ) which is orientated in parallel with respect to. A ferroelectric liquid crystal of the nematic phase (N ^*) slowly when applying a sufficient electric field inside the liquid crystal cell, and lower the temperature nematic phase in the (N ^*) is a smectic C ^* phase (Sm C ^*) with the phase transition, while the spontaneous polarization direction of the ferroelectric liquid crystal The cells are arranged in accordance with the electric field direction formed in the cell. As a result, the ferroelectric liquid crystal in the liquid crystal cell, as shown in Fig. 3, when applied in the field orientation of the two molecular alignment direction depending on the orientation of the upper and lower plates when the parallel alignment process is applied and its spontaneous polarization direction This becomes coincident and has an overall uniform alignment state (monostable state) by the electric field direction.

FIG. 4 shows the change of the light transmittance according to the voltage in the half V-switching mode. In particular, FIG.

As shown in the graph, the ferroelectric liquid crystal cell of the half V-switching mode converts the incident light by 90 ° only when the positive voltage (+ V) is applied when the field is aligned by the negative voltage. When the light is transmitted and the negative voltage (-V) is applied, the incident light is almost blocked to maintain the polarization direction of the incident light. At this time, the light transmittance is increased in proportion to the intensity of the positive voltage (+ V), and is maintained at the maximum value when the intensity of the positive voltage (+ V) increases above a predetermined threshold.

On the other hand, although not shown on the graph, when the ferroelectric liquid crystal cell of the half switching mode is oriented by the positive voltage (+ V), the incident light is transmitted only when the negative voltage (-V) is applied and the positive voltage ( When + V) is applied, the incident light is blocked.

FIG. 5 illustrates an arrangement of ferroelectric liquid crystal molecules in the half V-switching mode when a negative electric field (-E) is applied to the ferroelectric liquid crystal cell of the half V-switching mode to perform field alignment. FIGS. 6A and 6B The arrangement of the ferroelectric liquid crystal molecules in the half V-switching mode when the negative external electric field (-E) and the positive external electric field (+ E) is applied is shown.

First, as shown in FIG. 5, when the ferroelectric liquid crystal cell of the half V-switching mode is oriented by the negative external electric field (-E), the direction of the spontaneous polarization P _S of the ferroelectric liquid crystal is negative external. It is oriented uniformly in the direction coinciding with the electric field (-E). After the electric field alignment is performed, as shown in FIG. 6A, when the negative external electric field (-E) is applied to the ferroelectric liquid crystal cell or the external electric field is not applied, the arrangement of the liquid crystal molecules maintains the initial arrangement as it is. The polarization direction is maintained so that the upper plate can not pass through.

However, as shown in FIG. 6B, when the positive external electric field (+ E) is applied, the alignment of the liquid crystal molecules is changed while the direction of the spontaneous polarization (P _S ) coincides with the positive external electric field (+ E). . At this time, the polarization direction of the incident light incident on the liquid crystal layer via the polarizer of the lower plate is changed in the polarization direction of the polarizer of the upper plate by the liquid crystal molecules whose arrangement is changed, and the incident light is transmitted through the polarizer of the upper plate.

As described above, since the ferroelectric liquid crystal cell of the conventional half V-switching mode selectively transmits light according to the polarity applied during the electric field alignment, the flicker phenomenon occurs in which the screen flickers as the polarity of the external voltage changes. there is a problem.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a ferroelectric liquid crystal display device and a method of manufacturing the same, which can realize a wide viewing angle and high brightness, and reduce power consumption.

Another object of the present invention is to provide a ferroelectric liquid crystal display device capable of preventing flicker and realizing uniform luminance, and a method of manufacturing the same.

The present invention made to achieve the above object is the first and second substrate; A ferroelectric liquid crystal layer to the second consists of a first and a ferroelectric liquid crystal layer having a smectic C ^* phase (Sm C ^* phase) between the second substrate and maintaining the initial alignment state by the hydrogen bonding network; And first and second transparent electrodes formed on opposite surfaces of the first and second substrates to apply a vertical electric field to the ferroelectric liquid crystal layer.

In this case, the initial alignment direction of the ferroelectric liquid crystal layer is directed toward the lower end of the virtual cone center where the ferroelectric liquid crystal is reacted to the electric field applied to the first and second electrodes, and the ferroelectric liquid crystal layer is in the initial alignment state. The spontaneous polarization direction and the negative electric field direction are different from each other. That is, the direction of the hydrogen bonding network and the initial alignment direction of the ferroelectric liquid crystal layer is the same, and in the initial alignment state, the spontaneous polarization direction of the ferroelectric liquid crystal layer is parallel to the surface of the first substrate. This is because the ferroelectric liquid crystal layer exhibits light transmittance in a V-switching mode that is symmetric with each other in response to both negative and positive electric fields.

The first substrate may include a gate line and a data line arranged in first and second directions to define a plurality of pixels; And a switching element provided at an intersection of the gate line and the data line to switch each pixel, wherein the second substrate comprises: a black matrix; And a color filter.

In addition, the present invention comprises the steps of preparing a first substrate having a first transparent electrode; Preparing a second substrate having a second transparent electrode; Bonding the first substrate and the second substrate to each other such that the first and second transparent electrodes face each other and have a predetermined space between the first and second substrates; Mixing and injecting an isotropic liquid crystal molecule and a substance capable of hydrogen bonding between the first substrate and the second substrate at a first temperature; Lowering the first temperature to a second temperature, thereby causing the liquid crystal molecules to phase change from an isotropic phase to a nematic phase (N ^* ); The phase change of the second temperature to a third by, and lower the temperature, applying a first electric field to the first and second electrodes, the nematic phase (N ^*) liquid crystal molecules in the smectic C ^* phase (Sm C ^*) of Arranging the liquid crystal molecules of the smectic C ^* phase (Sm C ^* ) such that the spontaneous polarization direction of the smectic C ^* phase (Sm C ^* ) coincides with the direction of the first electric field; And applying a second electric field to the first and second transparent electrodes while lowering the third temperature to the fourth temperature, whereby the spontaneous polarization direction of the liquid crystal molecules of the smectic C ^* phase (Sm C ^* ) is changed to the first temperature. It provides a method of manufacturing a ferroelectric liquid crystal display device comprising the step of driving side by side with respect to the surface of one substrate, the hydrogen-bond network (hydrogen-bond network) by the hydrogen bonding of the hydrogen bondable material. In this case, the hydrogen bonding network is formed along the alignment direction of the liquid crystal molecules of the Smetic C ^* phase, and the first electric field and the second electric field are applied to have opposite polarities.

According to the present invention, the ferroelectric liquid crystal display device exhibits transmission characteristics of V-switching mode using a ferroelectric liquid crystal having a Smetic C ^* phase (Sm C ^* ) by controlling an initial alignment direction using a hydrogen bonding network. Can be provided. That is, the conventional V-switching mode ferroelectric liquid crystal display device uses a liquid crystal molecule having a Smetic X ^* (Sm X ^* ) phase, so that the spontaneous polarization value is large, so the power consumption is high, and the electric field applied when the electric field is aligned due to the characteristics of the material. Since the direction and the spontaneous polarization direction thereof are uneven as a whole, the monostable state is difficult, so there is a problem of uneven brightness. In addition, the ferroelectric liquid crystal display device of the half V-switching mode using the ferroelectric liquid crystal of the conventional Smetic C ^* phase (Sm C ^* ) has a negative external voltage (-V) or a positive voltage depending on the polarity of the electric field applied to the initial electric field orientation. There was a problem that flickering occurred due to blocking of light with respect to the polar external voltage (+ V).

Accordingly, the present invention uses a ferroelectric liquid crystal of Sm C ^* phase (Sm C ^* ), but forms a hydrogen bonding network through a hydrogen bonding material, the direction of forming the hydrogen bonding network in the initial orientation of the liquid crystal molecules By fixing the liquid crystal molecules regardless of the polarity of the external voltage, a ferroelectric liquid crystal display device having a V-switching mode in which the light transmittance increases proportionally as the voltage intensity increases.

Thus, the present invention implements a wide viewing angle and high luminance through the ferroelectric liquid crystal display elements, in particular, smectic C ^* by implementing a ferroelectric liquid crystal display element using a ferroelectric liquid crystal phase (Sm C ^*), to reduce the power consumption, It not only realizes uniform luminance, but also prevents flicker to further improve image quality.

Hereinafter, the ferroelectric liquid crystal display device and a method for manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

7A to 7D illustrate a ferroelectric liquid crystal display device and a method of manufacturing the same according to the present invention.

First, as shown in FIG. 7A, the first and second substrates 110 and 120 are prepared, and the first and second substrates 110 and 120 have a predetermined space between the first and second substrates 110 and 120. After the substrate 120 is bonded, the isotropic ferroelectric liquid crystal 130 and the hydrogen bondable material 140 are mixed and injected at a first temperature between 90 and 110 ° C.

Although not shown in detail with respect to the first and second substrates 110 and 120 in the drawings, first and second transparent electrodes are formed on opposite surfaces of the first and second substrates 110 and 120, respectively. The first and second transparent electrodes drive liquid crystal molecules to control light transmittance.

In addition, the first substrate 110 is a thin film transistor array substrate. The first substrate 110 is formed in a gate line and a data line arranged in first and second directions to define a plurality of pixels, and is formed at an intersection of the gate line and the data line. A switching device for switching each pixel is provided, and the switching device switches a signal applied from the data line to the first transparent electrode.

The second substrate 120 is a color filter substrate, and is provided with a black matrix to prevent light leakage between pixels and a color filter for implementing color, and the second transparent electrode is formed over the entire color filter.

Subsequently, when the first temperature is gradually lowered to the second phase transition temperature between 60 and 110 ° C., the phase transition is made to the ferroelectric liquid crystal of the nematic phase (N ^* ). The formation process of the ferroelectric liquid crystal of the nematic phase (N ^* ) is not shown in the drawing.

And, as shown in Figure 7b, while gradually lowering the ferroelectric liquid crystal of the nematic phase (N ^* ) to a third temperature between 40 ~ 80 ℃, when the first electric field is applied to the first and second transparent electrode , The ferroelectric liquid crystal of the nematic phase (N ^* ) is phase-transformed into the Smetic C ^* phase (Sm C ^* ; 135). At this time, the spontaneous polarization (P _S ) is expressed in the liquid crystal molecules 131 of the ferroelectric liquid crystal 135 during the phase transition to the ferroelectric liquid crystal 135 of the Smetic C ^* phase (Sm C ^* ) and the spontaneous polarization (P The direction of _S ) (indicated by an arrow on the drawing) is directed in a direction coinciding with the direction of the first electric field to be applied. For example, when a negative electric field (-E) in which the direction of the electric field is directed downward is applied, as shown in FIG. 7B, the spontaneous ferroelectric liquid crystal is coincided with the direction of the negative electric field (-E). The direction of polarization P _S is also directed downward. If a positive electric field (+ E) is applied, the spontaneous polarization (P _S ) direction of the ferroelectric liquid crystal molecules will be directed upward, and the polarity of the first electric field is not limited to a specific polarity in the present invention.

Subsequently, as shown in FIG. 7C, when a second electric field having a polarity opposite to the first electric field is applied while decreasing to a fourth temperature between 40 and 60 ° C., hydrogen bonding between materials capable of hydrogen bonding is performed. The ferroelectric liquid crystal molecules 131 of the smectic C ^* phase Sm C ^* are subjected to a driving process of the liquid crystal molecules as shown in FIGS. 8A to 8E according to the intensity of the second electric field. Assuming that the first electric field is negative (-E), the second electric field becomes a positive electric field (+ E).

8A to 8E, the driving state of the ferroelectric liquid crystal molecules 131 of the Smetic C ^* phase Sm C ^* according to the strength of the second electric field will be described.

First, as shown in FIG. 8A, when a negative first electric field (-E) is applied to the inside of the liquid crystal cell in the Smetic C ^* phase (Sm C ^* ), the ferroelectric liquid crystal molecules 131 are spontaneously polarized. (Driven by an arrow on the drawing) is driven to coincide with the direction of the first electric field.

In this state, as shown in FIGS. 8B to 8E, when the positive second electric field (+ E) is applied to the inside of the liquid crystal cell, the ferroelectric liquid crystal molecules 131 are intensified in the second electric field (+ E). in response to a rotation in accordance with a virtual cone in the direction of the spontaneous polarization (P _S) it is changed in a direction parallel to the direction of the positive-polarity second field (+ E). 8B to 8E illustrate driving states of the ferroelectric liquid crystal molecules 131 according to the intensity of the second electric field. In the present invention, as shown in FIG. 8C, the ferroelectric liquid crystal molecules 131 face the lower portion of the center of the cone. Apply an electric field.

That is, according to the intensity of the second field-there is changed the driving state of the ferroelectric liquid crystal molecule, in the present invention, the spontaneous polarization (P _S) orientation of the ferroelectric liquid crystal molecules 131 so as to be parallel to the first substrate 110, the second field Apply. At this time, the hydrogen bonding materials form a hydrogen bonding network along the alignment direction of the ferroelectric liquid crystal molecules (see FIG. 7C). At this time, even if the second electric field is not applied in the state where the hydrogen bond network is formed, the ferroelectric liquid crystal molecules 131 are maintained in the alignment state along the formation direction of the hydrogen bond network by the hydrogen bond network.

Subsequently, when further lowered to the fourth temperature between 40 and 60 ° C., as shown in FIG. 7E, more hydrogen bond networks are formed, and the hydrogen bond networks maintain the initial orientation of the ferroelectric liquid crystal molecules 131. It acts as an alignment film. In the present invention, the first to fourth temperatures may vary depending on the material of the liquid crystal and are not limited to a specific temperature.

That is, in the present invention, the initial alignment state of the ferroelectric liquid crystal molecules is made by using hydrogen bonds, and the initial alignment state of the ferroelectric liquid crystal molecules is made in a desired direction, without using an alignment layer that makes the initial alignment state of the ferroelectric liquid crystal molecules. . At this time, by adjusting the intensity of the second electric field applied to the liquid crystal cell, it is possible to change the initial alignment state. That is, when a hydrogen bonding network is formed along the direction in which the ferroelectric liquid crystal molecules are oriented, and once the hydrogen bonding network is formed, the ferroelectric liquid crystal molecules are oriented along the formation direction of the hydrogen bonding network even though an electric field is not applied, It is possible to maintain the alignment state.

Meanwhile, in the present invention, the initial alignment state of the ferroelectric liquid crystal molecules formed by the hydrogen bonding network (that is, the spontaneous polarization direction (indicated by the arrow) of the ferroelectric liquid crystal molecules 131 is arranged side by side with the first substrate 110). In the polarizer is formed to represent black.

As such, when the initial alignment state of the ferroelectric liquid crystal molecules 131 is toward the lower portion of the cone center, and the spontaneous polarization direction thereof is parallel to the first substrate 110, regardless of the polarity of the external electric field, it is proportional to the intensity of the external electric field. The light transmittance is increased.

In more detail, in the liquid crystal display device using the ferroelectric liquid crystal of the conventional Smatic C ^* phase (Sm C ^* ), since the initial alignment direction of the ferroelectric liquid crystal molecules was determined through the field orientation of the negative or positive polarity, Light transmittance did not appear for the electric field of the applied polarity. On the other hand, in the present invention, the smectic C ^* phase (Sm C ^*) A ferroelectric liquid crystal, but using, smectic C ^* phase (Sm C ^*) to the alignment direction of the ferroelectric liquid crystal molecules aligned by the electric field applied in the process of transformation of the By applying the electric field opposite to the electric field applied in the phase transition process, driving the ferroelectric liquid crystal molecules to a desired position without forming the initial alignment state, and forming a hydrogen bond network having the arrangement of the ferroelectric liquid crystal molecules, Determine the orientation direction. At this time, since the hydrogen bonding network of ferroelectric liquid crystal molecules driven to the desired position is formed, the ferroelectric liquid crystal molecules are maintained in the initial alignment state by the hydrogen bonding network even without an electric field applied.

In the present invention, the initial alignment state is determined at a position at which the ferroelectric liquid crystal molecules can be driven regardless of the polarity of the external electric field.

9 and 10 show the change in light transmittance according to the voltage.

As shown in the graph, the ferroelectric liquid crystal display according to the present invention exhibits the same light transmission characteristics as those of the V-switching mode. That is, when no external voltage is applied (V = 0), the polarization direction of the incident light is maintained as it is, and the incident light is almost blocked. If the external voltage is applied irrespective of the polarity, the incident light is converted by converting the incident light by 90 °. Permeate. The light transmittance increases in proportion to the intensity of the positive voltage (± V), and is maintained at the maximum value when the intensity of the voltage (± V) increases above a predetermined threshold.

11 is a view illustrating an initial alignment direction of ferroelectric liquid crystal molecules when no electric field is applied to the ferroelectric liquid crystal cell according to the present invention, and FIGS. 12A and 12B illustrate a negative external electric field (-E _max ) indicating maximum transmittance and The change in the arrangement of the ferroelectric liquid crystal molecules when a positive external electric field (-E _max ) is applied.

First, as shown in FIG. 11, when no electric field is applied to the ferroelectric liquid crystal cell of the present invention, the direction of the spontaneous polarization (P _S ) of the ferroelectric liquid crystal is made parallel to the bottom surface by a hydrogen bonding network, and the ferroelectric liquid crystal The molecules are oriented towards the bottom of the virtual cone center. 12A and 12B, when a negative external electric field (± E _max ) is applied to the ferroelectric liquid crystal cell, the alignment of the liquid crystal molecules is changed while the spontaneous polarization ( The direction of P _S ) coincides with the external electric field (± E _max ). At this time, the polarization direction of the incident light incident on the liquid crystal layer via the polarizer of the lower plate is changed to the polarization direction of the polarizer of the upper plate by the liquid crystal molecules whose arrangement is changed, and the incident light is transmitted through the polarizer of the upper plate.

As described above, the present invention provides a ferroelectric liquid crystal display device in which the light transmittance with respect to the external voltage of the liquid crystal cell implements the V-switching mode through the ferroelectric liquid crystal of Sm C ^* phase (Sm C ^* ).

The basic concept of the present invention does not determine the orientation of the liquid crystal molecules arranged by the applied electric field in the process of transition to the Smetic C ^* phase (Sm C ^* ) as the initial alignment state, regardless of the polarity of the external voltage Ferroelectricity in which the light transmittance increases in proportion to the voltage intensity by maintaining the driving state through the hydrogen bonding network and making the initial alignment state while driving the liquid crystal molecules at the position to transmit. A liquid crystal display device is implemented.

In particular, the present invention by using a ferroelectric liquid crystal with a wide view angle, and implement a high-luminance, and the smectic C ^* phase (Sm C ^*) through a ferroelectric liquid crystal display element, the old v-power by lowering the spontaneous minute peak compared to the switched-mode In addition to reducing the consumption, the light transmittance is displayed in proportion to the voltage intensity regardless of the polarity of the external voltage, thereby eliminating the flicker phenomenon generated in the existing hub-switching mode, and realizing a uniform brightness overall. .

As described above, according to the present invention, through the ferroelectric liquid crystal of the Smetic C ^* phase (Sm C ^* ) by implementing a ferroelectric liquid crystal display device having a light-transmitting characteristic of the V-switching mode to improve the viewing angle, , Improve the brightness.

In particular, the present invention has the effect of reducing power consumption, preventing flicker, and realizing a uniform brightness as a whole to further improve image quality.

Claims (11)

First and second substrates; The first and the second consists of a ferroelectric liquid crystal in smectic C ^* phase (Sm C ^* phase) between the substrates, the ferroelectric liquid crystal layer to form a hydrogen bond network by a hydrogen bond material; And And first and second transparent electrodes formed on opposite surfaces of the first and second substrates to apply a vertical electric field to the ferroelectric liquid crystal layer. The arrangement state of the ferroelectric liquid crystal layer is changed as a voltage is applied to the first and second transparent electrodes by fixing the direction of forming the hydrogen bonding network of the ferroelectric liquid crystal layer in the initial alignment direction of the liquid crystal molecules, regardless of the polarity of the voltage. And changing the light transmittance passing through the ferroelectric liquid crystal layer to implement an image. The method of claim 1, The initial orientation of the ferroelectric liquid crystal layer is a ferroelectric liquid crystal display device characterized in that toward the lower end of the virtual cone (cone) to draw in response to the electric field applied to the first and second electrodes . 3. The method of claim 2, A ferroelectric liquid crystal display device, characterized in that the spontaneous polarization direction and the negative electric field direction of the ferroelectric liquid crystal layer are different from each other in the initial alignment state. delete The method of claim 1, The spontaneous polarization direction of the ferroelectric liquid crystal layer in the initial alignment state is parallel to the surface of the first substrate, the ferroelectric liquid crystal display device. The method of claim 1, And the ferroelectric liquid crystal layer exhibits light transmittance in a V-switching mode that is symmetrical with respect to a negative and positive electric field. The method of claim 1, Wherein the first substrate comprises: Gate lines and data lines arranged in first and second directions to define a plurality of pixels; And And a switching element provided at an intersection portion of the gate line and the data line to switch each pixel. The method of claim 1, The second substrate, Black matrix; And A ferroelectric liquid crystal display device comprising a color filter. Preparing a first substrate having a first transparent electrode; Preparing a second substrate having a second transparent electrode; Bonding the first substrate and the second substrate to each other such that the first and second transparent electrodes face each other and have a predetermined space between the first and second substrates; Mixing and injecting an isotropic liquid crystal molecule and a substance capable of hydrogen bonding between the first substrate and the second substrate at a first temperature; Lowering the first temperature to a second temperature, thereby causing the liquid crystal molecules to phase change from an isotropic phase to a nematic phase (N ^* ); The phase change of the second temperature to a third by, and lower the temperature, applying a first electric field to the first and second electrodes, the nematic phase (N ^*) liquid crystal molecules in the smectic C ^* phase (Sm C ^*) of Arranging liquid crystal molecules of the smectic C ^* phase (Sm C ^* ) in which the spontaneous polarization (Ps) direction of the smectic C ^* phase (Sm C ^* ) has the same direction as the first electric field; And By applying the second electric field to the first and second electrodes while lowering the third temperature to the fourth temperature, the spontaneous polarization direction of the liquid crystal molecules of the smectic C ^* phase (Sm C ^* ) is changed to the first substrate. A method of manufacturing a ferroelectric liquid crystal display device, the method comprising: driving side by side with respect to a surface of a surface, and forming a hydrogen-bond network by hydrogen bonding of the hydrogen bondable materials. 10. The method of claim 9, The hydrogen bonding network is a method of manufacturing a ferroelectric liquid crystal display device, characterized in that formed along the alignment direction of the liquid crystal molecules. 10. The method of claim 9, A method of manufacturing a ferroelectric liquid crystal display device, characterized in that the polarity of the first electric field and the second electric field are applied oppositely.

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