JP6925787B2 - Liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal display element.

As a driving method of the liquid crystal display element, there are a method such as TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal) and the like.
Of these, the IPS method changes the orientation direction of the liquid crystal molecules by applying an electric field in the direction parallel to the substrate surface (horizontal direction) to the liquid crystal molecules filled between the two substrates, and displays the display. Is going. Such an IPS liquid crystal display element has excellent visual characteristics and is applied to a wide range of devices such as mobile phones and televisions.

In the existing liquid crystal display element, the orientation direction of the liquid crystal molecules is forced so that the liquid crystal molecules are arranged along a predetermined direction in a state where no electric field is applied.

As a method of forcing the orientation direction of the liquid crystal molecules, a method of forming an alignment film made of polyimide or the like on a substrate and rubbing the surface of the alignment film in a predetermined direction with a cloth such as rayon or cotton (rubbing method) or polarized ultraviolet rays. A method (photoalignment method) for generating anisotropy on the surface of the polyimide film by irradiating the polyimide film with light is adopted. By these treatments, the liquid crystal molecules are strongly bound to the surface of the substrate and oriented in a certain direction.

On the other hand, a method has also been proposed in which the orientation direction of the liquid crystal molecules is directed to an arbitrary direction by an external field (electric field, magnetic field, etc.) and the state is maintained (memorized). In order to realize such an operation, it is necessary to eliminate the orientation forcing force (anchoring) on the substrate surface. Patent Document 1 (Japanese Unexamined Patent Publication No. 2014-215421) has been proposed as a related technique for a configuration that weakens anchoring in this way. In the configuration disclosed in Patent Document 1, a polymer brush is formed on a flattened substrate, and in a liquid crystal cell in which a liquid crystal is sandwiched between the substrates, Tg (glass transition temperature) of a coexistence portion between the polymer brush and the liquid crystal is formed. ), And by heating to a temperature at which the shape of the coexisting part can be freely changed, a zero-plane anchoring state is realized.

In the existing liquid crystal display element, when the application of the electric field is stopped, the liquid crystal molecules in the liquid crystal layer recover the orientation of the liquid crystal molecules displaced by the electric field to the original orientation state, that is, the orientation state when no voltage is applied.
At this time, in the configuration in which the liquid crystal molecules are oriented in a certain direction by applying a strong binding force to the liquid crystal molecules by the alignment film formed by the rubbing method or the photoalignment method, when the application of the electric field is stopped, the liquid crystal molecules are released. , The orientation of the liquid crystal molecules displaced by the strong binding force of the alignment film quickly returns to the original orientation state.
On the other hand, in the configuration described in Patent Document 1, since the binding force by the alignment film is weak, it takes time to restore the orientation of the liquid crystal molecules to the original orientation state. From such a background, high display responsiveness is desired.

In the present invention, a light source that emits light, a first substrate on which a first alignment film is formed, and a second alignment film that is arranged so as to face each other with a space between the first alignment film are formed. A liquid crystal layer arranged between the first alignment film and the second alignment film, and transmitting or blocking the light by driving liquid crystal molecules, and the first alignment film. The liquid crystal display is provided on either one of the above-mentioned substrate and the above-mentioned second substrate, and includes the first substrate and a driving electrode layer for applying an electric field in a direction along the second substrate to the liquid crystal molecule. The layer maintains a state in which the liquid crystal molecules are oriented in a preset initial orientation direction on the second alignment film side in a state where the electric field is applied, and on the first alignment film side, the layer is said. The orientation direction of the liquid crystal molecules changes from the initial orientation direction to the direction corresponding to the electric field in the plane parallel to the surface of the second substrate, and the liquid crystal molecules are not applied to the liquid crystal layer by the electric field. Provided is a liquid crystal display element to which a chiral agent for restoring the initial orientation direction in the above state is added.

In the liquid crystal layer, the liquid crystal molecules may be spirally arranged from the second alignment film side toward the first alignment film side in a state where the electric field is not applied.

In the chiral agent, the initial orientation direction of the liquid crystal molecules on the first alignment film side is 90 ° with respect to the initial orientation direction of the liquid crystal molecules on the second alignment film side in a state where the electric field is not applied. It may be added so as to be twisted.

An orientation treatment direction for constraining the orientation direction of the liquid crystal molecules in the first alignment film to the initial orientation direction, and an orientation treatment direction for constraining the orientation direction of the liquid crystal molecules in the second alignment film. However, they may be orthogonal to each other.

The first alignment film may have a binding force that constrains the orientation direction of the liquid crystal molecules in the initial alignment direction when an electric field is applied, which is smaller than that of the second alignment film.

The orientation direction of the liquid crystal molecules in the vicinity of the first alignment film when no electric field is applied may be determined by the twisting force of the chiral agent.

A first polarizing plate provided on the first substrate side and a second polarizing plate provided on the second substrate side are further provided, and the transmission axis direction of the first polarizing plate and the said Even if the transmission axis direction of the second polarizing plate is parallel to each other and the transmission axis direction of the first polarizing plate is parallel or orthogonal to the initial orientation direction of the second alignment film. good.

A first polarizing plate provided on the first substrate side and a second polarizing plate provided on the second substrate side are further provided, and the transmission axis direction of the first polarizing plate and the said The transmission axis directions of the second polarizing plate may be orthogonal to each other, and the transmission axis direction of the first polarizing plate may be parallel or orthogonal to the initial orientation direction of the second alignment film. ..

With the electric field applied, the displacement angle of the liquid crystal molecules in the orientation direction with respect to the state in which the liquid crystal layer is oriented in the initial orientation direction from the second alignment film side toward the first alignment film side. May be gradually increased.

The initial stage of the liquid crystal molecule due to the electric field generated by applying a predetermined voltage between the liquid crystal molecule located on the first alignment film side and the liquid crystal molecule located on the second alignment film side. The difference in the displacement angle in the orientation direction with respect to the state oriented in the orientation direction may be 0 ° or more and 90 ° or less.

As the first alignment film, a polymer brush may be formed on the first substrate.

The driving electrode layer is composed of a plurality of electrode wires arranged on the first substrate or the second substrate surface, and the orientation direction of the liquid crystal molecules on the second substrate side when the electric field is not applied. However, the electrode lines may be parallel or orthogonal to each other in the continuous direction.

The driving electrode layer is composed of a plurality of electrode wires arranged on the first substrate or the second substrate surface, and the orientation direction of the liquid crystal molecules on the second substrate side when the electric field is not applied. However, the electrode wire may be inclined with respect to the continuous direction.

The dielectric anisotropy of the liquid crystal molecule may be negative.

The dielectric anisotropy of the liquid crystal molecule may be positive.

According to the present invention, the following effects can be obtained.

That is, it is possible to realize higher transmittance and higher display responsiveness while driving the liquid crystal molecules at a low voltage.

It is sectional drawing which shows the schematic structure of the liquid crystal display shown as the 1st Embodiment of this invention. In the liquid crystal panel of the liquid crystal display shown as the first embodiment, a liquid crystal having a positive dielectric anisotropy is used, and the distribution in the orientation direction of the liquid crystal molecules in a state where an electric field is applied is shown. In the liquid crystal panel of the liquid crystal display shown as the first embodiment, a liquid crystal having a positive dielectric anisotropy is used, and the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied are used. It is a figure which shows the relationship. In the liquid crystal panel of the liquid crystal display shown as the first embodiment, a liquid crystal having a positive dielectric anisotropy is used, and it is a figure which shows the relationship between the electrode wire and the orientation direction of a liquid crystal molecule in a state where an electric field is applied. It is sectional drawing which shows the example of the polymer brush formed on the substrate as a weak anchoring alignment film. In the liquid crystal panel of the liquid crystal display shown as the second embodiment, a liquid crystal having a positive dielectric anisotropy is used, and the relationship between the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied. It is a figure which shows. In the liquid crystal panel of the liquid crystal display shown as the second embodiment, a liquid crystal having a positive dielectric anisotropy is used, and the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are used. It is a figure which shows another example of a relationship. In the liquid crystal panel of the liquid crystal display shown as the third embodiment, a liquid crystal having a positive dielectric anisotropy is used, and the relationship between the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied. It is a figure which shows. In the liquid crystal panel of the liquid crystal display shown as the third embodiment, a liquid crystal having a positive dielectric anisotropy is used, and the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are used. It is a figure which shows another example of a relationship. It is sectional drawing which shows the schematic structure of the liquid crystal display shown as the 4th Embodiment of this invention. In the liquid crystal panel of the liquid crystal display shown as the fourth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and the distribution in the orientation direction of the liquid crystal molecules in a state where an electric field is applied is shown. In the liquid crystal panel of the liquid crystal display shown as the fourth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied are used. It is a figure which shows the relationship. In the liquid crystal panel of the liquid crystal display shown as the fourth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and it is a figure which shows the relationship between the electrode wire and the orientation direction of a liquid crystal molecule in a state where an electric field is applied. In the liquid crystal panel of the liquid crystal display shown as the fifth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and the relationship between the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied. It is a figure which shows. In the liquid crystal panel of the liquid crystal display shown as the fifth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are used. It is a figure which shows another example of a relationship. In the liquid crystal panel of the liquid crystal display shown as the sixth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and the relationship between the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied. It is a figure which shows. In the liquid crystal panel of the liquid crystal display shown as the sixth embodiment, a liquid crystal having a negative dielectric anisotropy is used, and the electrode wire and the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are used. It is a figure which shows another example of a relationship. It is sectional drawing which shows the schematic structure of the liquid crystal display shown as the 7th Embodiment of this invention in the state (a) in the state where the electric field is not applied, and (b) in the state where the electric field is applied. The liquid crystal display shown as the eighth embodiment of the present invention is a cross-sectional view showing a schematic configuration of (a) in a state where an electric field is not applied and (b) in a state where an electric field is applied. 9A is a cross-sectional view showing a schematic configuration of the liquid crystal display shown as the 9th embodiment of the present invention in a state where an electric field is not applied and in a state where an electric field is applied. The liquid crystal display shown as the tenth embodiment of the present invention is a cross-sectional view showing a schematic configuration of (a) in a state where an electric field is not applied and (b) in a state where an electric field is applied. The liquid crystal display shown as the eleventh embodiment of the present invention is a cross-sectional view showing a schematic configuration of (a) in a state where an electric field is not applied and (b) in a state where an electric field is applied. The liquid crystal display shown as the twelfth embodiment of the present invention is a cross-sectional view showing a schematic configuration of (a) in a state where an electric field is not applied and (b) in a state where an electric field is applied. The liquid crystal display shown as the thirteenth embodiment of the present invention is a cross-sectional view showing a schematic configuration of (a) in a state where an electric field is not applied and (b) in a state where an electric field is applied. The liquid crystal display shown as the 14th embodiment of the present invention is a cross-sectional view showing a schematic configuration of (a) in a state where an electric field is not applied and (b) in a state where an electric field is applied. This is an experimental result regarding the relationship between the angle formed by the two polarizing plates in the transmission axis direction and the transmittance. This is an experimental result regarding the relationship between the angle formed by the two polarizing plates in the transmission axis direction and the transmittance. It is an experimental result about voltage and transmittance in 1st Example. It is an experimental result about voltage and transmittance in 1st comparative example. It is an experimental result about voltage and response speed in 1st Example. It is an experimental result about voltage and response speed in 1st comparative example. It is explanatory drawing of the 2nd Example and the 2nd Comparative Example used in the response speed experiment. It is explanatory drawing of the 3rd Example and the 3rd Comparative Example used in the response speed experiment. It is explanatory drawing of the 4th Example and the 4th Comparative Example used in the response speed experiment. This is the experimental result of the response speed experiment.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.

Liquid crystals include a positive type having a positive dielectric anisotropy and a negative type having a negative dielectric anisotropy. The positive liquid crystal has a large dielectric property in the long axis direction of the liquid crystal molecule and a small dielectric property in the direction orthogonal to the long axis direction. The negative type has a small dielectric property in the long axis direction and a large dielectric property in the direction orthogonal to the long axis direction. In this embodiment, an example using a positive liquid crystal display will be described.
Further, as the alignment film for controlling the orientation direction of the liquid crystal molecules, a strong anchoring alignment film having a strong force to restrain the orientation direction of the liquid crystal molecules and a weak anchoring alignment film having a weak force to restrain the orientation direction of the liquid crystal molecules. And there is. The present invention targets a one-sided weak anchoring type in which a strong anchoring alignment film is used for one of the alignment films facing each other and a weak anchoring alignment film is used for the other.

FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal display shown as the first embodiment of the present invention. FIG. 2 is a diagram showing the distribution of the orientation direction of liquid crystal molecules in a state where an electric field is applied by using a liquid crystal having a positive dielectric anisotropy in the liquid crystal panel of the liquid crystal display shown in the first embodiment. FIG. 3 shows the liquid crystal panel of the liquid crystal display shown in the first embodiment, in which a liquid crystal having a positive dielectric anisotropy is used, and the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied are shown. It is a figure which shows the relationship with the orientation direction. FIG. 4 shows the relationship between the electrode wire and the orientation direction of the liquid crystal molecule in a state where a liquid crystal having a positive dielectric anisotropy is used in the liquid crystal panel of the liquid crystal display shown as the first embodiment and an electric field is applied. It is a figure.
As shown in FIGS. 1 and 2, the liquid crystal display 10 includes a liquid crystal panel (liquid crystal display element) 11 and a backlight unit 12 that provides light to the liquid crystal panel 11.

The backlight unit 12 uniformly irradiates the light input from the light source (not shown) provided on the back surface of the liquid crystal panel 11 from the back surface 11r side to the front surface 11f side of the liquid crystal panel 11. The backlight unit 12 propagates, for example, light input from a light source (not shown) provided at one end thereof in a direction parallel to the surface 11f of the liquid crystal panel 11, and propagates the propagated light to the liquid crystal panel. A so-called edge light type that irradiates from the back surface 11r side to the front surface 11f side of 11 can be used. Further, the backlight unit 12 is a so-called direct type that irradiates the light input from the light source provided on the back surface 11r side of the liquid crystal panel 11 from the back surface 11r side to the front surface 11f side of the liquid crystal panel 11. You can also do it.

The liquid crystal panel 11 includes a substrate (second substrate) 13A, a substrate (first substrate) 13B, a polarizing plate (second polarizing plate) 14A, a polarizing plate (first polarizing plate) 14B, and a driving electrode layer. A strong anchoring alignment film (second alignment film) 16, a weak anchoring alignment film (first alignment film) 17, and a liquid crystal layer 18 are provided.

The substrates 13A and 13B are each made of a substrate such as glass or resin, and are arranged in parallel with each other at predetermined intervals.

The polarizing plate 14A is provided on the substrate 13A arranged on the backlight unit 12 side, on the side facing the backlight unit 12 or on the side opposite to the backlight unit 12.
The polarizing plate 14B is provided on the substrate 13B arranged on the side separated from the backlight unit 12 on the side opposite to the backlight unit 12 or on the side facing the backlight unit 12.
These polarizing plates 14A and 14B are arranged so that their transmission axis directions are parallel to each other. For example, the transmission axis direction of one polarizing plate 14A and the transmission axis direction of the other polarizing plate 14B are set to the direction X along the substrate 13B.

The drive electrode layer 15 is provided on either one of the substrates 13A and 13B. In this embodiment, the drive electrode layer 15 is provided on the substrate 13A on the backlight unit 12 side on the side separated from the backlight unit 12.
The drive electrode layer 15 is formed by arranging a plurality of electrode wires 20A in parallel along the surface of the substrate 13A. Here, as shown in FIG. 3, each electrode wire 20A is formed linearly so that its major axis direction extends along the direction Y in a plane parallel to, for example, the surface of the substrate 13A. In the drive electrode layer 15, such electrode wires 20A are arranged side by side at regular intervals along the direction X orthogonal to the direction Y in a plane parallel to the surface of the substrate 13A.

As shown in FIGS. 2 and 4, in such a drive electrode layer 15, when a preset voltage is applied to each electrode line 20A of the drive electrode layer 15, they are located between the electrode lines 20A adjacent to each other. An electric field E in the direction X connecting the electrode wires 20A adjacent to each other, that is, in the direction X parallel to the substrate 13B is generated in this embodiment.

The strong anchoring alignment film 16 is provided on either one of the substrates 13A and 13B. In this embodiment, the strong anchoring alignment film 16 is formed on the substrate 13A on the backlight unit 12 side on the side separated from the backlight unit 12. The strong anchoring alignment film 16 makes the liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincide with a predetermined orientation direction (direction X in FIG. 1) in a plane whose long axis direction is parallel to the surfaces of the substrates 13A and 13B. The initial orientation direction is set so that.

The weak anchoring alignment film 17 is provided on either one of the substrates 13A and 13B. In this embodiment, the weak anchoring alignment film 17 is formed on the side of the substrate 13B on the side separated from the backlight unit 12 on the side facing the backlight unit 12.
The weak anchoring alignment film 17 is the initial orientation direction of the liquid crystal molecule Lp of the liquid crystal layer 18 in the strong anchoring alignment film 16 in a plane whose major axis direction is parallel to the surfaces of the substrates 13A and 13B (in FIG. 1). The initial orientation direction is set so as to substantially match the direction (direction Y in FIG. 1) orthogonal to the direction X).

The liquid crystal layer 18 is formed by filling a large number of liquid crystal molecules Lp between the strong anchoring alignment film 16 and the weak anchoring alignment film 17. The liquid crystal layer 18 is driven by changing the orientation direction of the liquid crystal molecules Lp by an electric field E generated by applying a voltage to each of the electrode wires 20A constituting the drive electrode layer 15. By changing the orientation of the liquid crystal molecules Lp in this way, the liquid crystal layer 18 partially transmits or blocks the light supplied from the backlight unit 12 to generate a display image.

Further, when the application of the electric field E is released to the liquid crystal layer 18, the direction of the liquid crystal molecules Lp whose orientation direction is changed by the electric field E applied by the drive electrode layer 15 is the initial direction in which the electric field E is not applied. A chiral agent (optically active substance) is added to impart a restoring force for returning to the state.
Due to the addition of this chiral agent, in the liquid crystal layer 18, the liquid crystal on the strong anchoring alignment film 16 side is directed from the strong anchoring alignment film 16 side toward the weak anchoring alignment film 17 side in a state where the electric field E is not applied. The amount of displacement of the liquid crystal molecule Lp in the orientation direction with respect to the orientation direction in the major axis direction of the molecule Lp gradually increases, resulting in a spirally twisted orientation state. Specifically, when the electric field E is not applied, the liquid crystal molecules Lp of the liquid crystal layer 18 are in a 90 ° twisted orientation state from the strong anchoring alignment film 16 side toward the weak anchoring alignment film 17 side. As such, it is preferable to add a chiral agent.

Here, the strong anchoring alignment film 16 and the weak anchoring alignment film 17 have different orientation binding forces that constrain the orientation direction of the liquid crystal molecules Lp.
That is, as shown in FIG. 2, in the strong anchoring alignment film 16, even if a voltage is applied to generate an electric field E, the liquid crystal molecules Lp on the strong anchoring alignment film 16 side in the liquid crystal layer 18 have a long axis thereof. The initial orientation state is maintained in which the direction is substantially the same as the orientation processing direction (direction X) of the strong anchoring alignment film 16 in the plane along the surfaces of the substrates 13A and 13B.
On the other hand, in the weak anchoring alignment film 17, when the applied voltage becomes equal to or higher than the threshold voltage when the electric field E is generated by applying the voltage, the weak anchoring alignment film 17 side of the liquid crystal layer 18 The liquid crystal molecule Lp is released from the twist elastic force applied by the chiral agent to maintain the spirally twisted orientation state and the restraint of the weak anchoring alignment film 17. The orientation direction of the liquid crystal molecules Lp changes from the initial orientation direction (direction Y in FIG. 2) in a plane parallel to the surfaces of the substrates 13A and 13B according to the magnitude of the applied voltage.

As described above, when the electric field E is applied to the liquid crystal molecules Lp of the liquid crystal layer 18, the liquid crystal molecules Lp are oriented by the strong anchoring alignment film 16 on the strong anchoring alignment film 16 side of the liquid crystal layer 18 ( While the orientation direction is maintained while receiving the binding force), on the weak anchoring alignment film 17 side, the twist elastic force due to the chiral agent and the orientation forcing force (binding force) due to the weak anchoring alignment film 17 The orientation direction of the liquid crystal molecule Lp changes.

As a result, in the liquid crystal layer 18, the displacement amount of the liquid crystal molecules Lp with respect to the initial orientation direction when the electric field E equal to or higher than the threshold value is applied between the strong anchoring alignment film 16 side and the weak anchoring alignment film 17 side. Is different. Specifically, as the magnitude of the applied electric field E increases, the amount of displacement of the liquid crystal molecule Lp in the vicinity of the weak anchoring alignment film 17 in the orientation direction with respect to the initial orientation direction gradually increases. As a result, in the initial orientation state, the liquid crystal molecules Lp are twisted spirally from the strong anchoring alignment film 16 side toward the weak anchoring alignment film 17 side, whereas the liquid crystal on the weak anchoring alignment film 17 side The twist angle in the orientation direction with respect to the initial orientation state of the molecule Lp becomes smaller. When the electric field strength reaches a certain value, the liquid crystal molecules Lp near the weak anchoring alignment film 17 are oriented in a direction parallel to the direction of the electric field E. That is, the orientation direction becomes uniform from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 side along the direction parallel to the direction of the electric field E (direction X in FIG. 2).

By the way, the orientation state of the liquid crystal layer 18 when no voltage is applied is the same as the orientation state of the liquid crystal when no voltage is applied in the TN method. Therefore, the optical design of the liquid crystal panel 11 is performed so as to satisfy ΔnP >> λ (Δn is the refractive anisotropy of the liquid crystal, P is the helical pitch of the liquid crystal, λ is the wavelength of light), that is, the Morgan condition (Mougain Condition). For example, it is possible to generate a diversion ability effect on the liquid crystal layer 18.

Further, the following Gooch-Tarry equation (1) is known as an equation for giving the light transmittance T in the TN type liquid crystal panel.

Here, u = dΔn / λ · π / θ, d is the cell gap (thickness of the liquid crystal layer 18), θ is the twist angle of the liquid crystal molecule Lp, and in the present embodiment, the strong anchor when no voltage is applied. It corresponds to the difference in the orientation direction angle between the liquid crystal molecules on the ring alignment film 16 side and the liquid crystal molecules on the weak anchoring alignment film 17 side. In this embodiment, θ = π / 2, so u = 2dΔn / λ.

In the liquid crystal panel 11, a positive type liquid crystal molecule Lp is used, and the polarizing plate 14A and the polarizing plate 14B are arranged in parallel Nicols whose transmission axis directions are parallel to each other, and the transmission axis direction of the polarizing plate 14A is the electric field E. Is set so as to coincide with the orientation processing direction (direction X in FIG. 1) with respect to the strong anchoring alignment film 16 for regulating the orientation direction of the liquid crystal molecule Lp in the non-applied state.
As shown in FIG. 1, in the state where the electric field E is not applied, the liquid crystal molecule Lp has an initial orientation state on the strong anchoring alignment film 16 side as described above, and a strong anchor in the long axis direction of the liquid crystal molecule Lp. It follows the orientation processing direction of the ring alignment film 16 (direction X in FIG. 1). On the other hand, on the weak anchoring alignment film 17 side, the long axis direction of the liquid crystal molecules Lp is along the orientation processing direction of the weak anchoring alignment film 17 (direction Y in FIG. 1). If the restrictive force of the weak anchoring alignment film 17 is close to zero, the initial orientation direction cannot be memorized even if the weak anchoring alignment film 17 is subjected to the alignment treatment. Even in that case, the amount of the chiral agent is adjusted so that the liquid crystal molecules Lp of the liquid crystal layer 18 are twisted by 90 ° from the strong anchoring alignment film 16 side toward the weak anchoring alignment film 17 side, so that the weak anchoring is weak. On the ring alignment film 17 side, the long axis direction of the liquid crystal molecules Lp is along a direction (direction Y in FIG. 1) orthogonal to the alignment processing direction of the strong anchoring alignment film 16. At this time, by designing the optical conditions of the liquid crystal panel 11 so as to satisfy the Morgan condition and the equation (1) takes the minimum value, the linearly polarized light incident on the liquid crystal layer 18 remains polarized. The polarizing surface is rotated by 90 ° (optical rotation) and emitted from the liquid crystal panel 11. At this time, since the polarization direction of the light emitted from the liquid crystal panel 11 and the transmission axis direction of the polarizing plate 14B are orthogonal to each other, most of the light emitted from the liquid crystal panel 11 is absorbed by the polarizing plate 14B and emitted from the liquid crystal panel 11. The amount of light can be minimized. Thereby, the contrast ratio in this embodiment can be maximized. Here, in general, when the cell gap d becomes large, the response speed decreases. Therefore, in the optical design of the liquid crystal panel, the so-called first minimum condition is selected from a plurality of conditions in which the equation (1) takes the minimum value. It is preferable to do so.

On the other hand, as shown in FIG. 2, when the electric field E is applied, the liquid crystal molecules Lp are oriented in the major axis direction on the strong anchoring alignment film 16 side as described above. The initial orientation state along (direction X in FIG. 2) is maintained. On the other hand, on the weak anchoring alignment film 17 side, the orientation direction of the liquid crystal molecules Lp began to change in the plane parallel to the substrate 13B by applying an electric field E equal to or higher than the threshold value, and the electric field strength reached a certain value. Occasionally, the long axis direction of the liquid crystal molecule Lp is along the direction parallel to the electric field E, that is, the direction X parallel to the substrate 13B. As a result, the liquid crystal molecules Lp are uniformly oriented in the orientation processing direction (direction X in FIG. 2) with respect to the strong anchoring alignment film 16, so that the linearly polarized light incident on the liquid crystal layer 18 maintains the polarized state and the plane of polarization. As it is, it emits light from the liquid crystal panel 11. At this time, since the polarization direction of the linearly polarized light incident on the liquid crystal layer 18 (direction X in FIG. 2) and the transmission axis direction of the polarizing plate 14B (direction X in FIG. 2) are the same, the direction is from the backlight unit 12 side. Most of the light can pass through the polarizing plate 14B.

Further, when the application of the electric field E is stopped from the state in which the electric field E is applied, the liquid crystal molecules Lp of the liquid crystal layer 18 are oriented in the orientation direction of the liquid crystal molecules Lp due to the restoring force (elastic force) applied by the chiral agent. It returns to the spiral initial orientation state as shown in 1. Here, on the strong anchoring alignment film 16 side, the long axis direction of the liquid crystal molecules Lp is maintained along the orientation processing direction (direction X in FIG. 1) of the strong anchoring alignment film 16. On the other hand, on the weak anchoring alignment film 17 side of the liquid crystal layer 18, the major axis direction of the liquid crystal molecules Lp is the orientation processing direction of the weak anchoring alignment film 17 due to the restoring force (elastic force) applied by the chiral agent. The orientation direction is displaced along (direction Y in FIG. 2). As a result, the amount of displacement of the orientation angle in the long axis direction gradually increases from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 side, and the liquid crystal molecule Lp returns to a spirally twisted state.

As described above, in the liquid crystal panel 11 of the present embodiment, the positive type liquid crystal molecule Lp is used, the polarizing plate 14A and the polarizing plate 14B are arranged in parallel Nicol, and the transmission axis direction of the polarizing plate 14A is the electric field E. It is set so as to coincide with the orientation processing direction with respect to the strong anchoring alignment film 16 for regulating the orientation direction of the liquid crystal molecule Lp in the non-applied state (direction X in FIG. 1). The liquid crystal molecules Lp of the liquid crystal layer 18 are in an initial orientation state twisted spirally from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 side by adding a chiral agent.
In such a configuration, when the electric field E is not applied, as shown in FIG. 1, the light passing through the polarizing plate 14A from the backlight unit 12 side is spiral in the orientation direction of the liquid crystal molecules Lp in the liquid crystal layer 18. The plane of polarization changes along the distribution and is absorbed by the polarizing plate 14B on the opposite side.
Further, as shown in FIG. 2, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, as the magnitude of the applied electric field E increases, the initial stage of the liquid crystal molecules Lp near the weak anchoring alignment film 17 The amount of displacement in the orientation direction with respect to the orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Lp of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction X in FIG. 2) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14A from the backlight unit 12 side passes through the polarizing plate 14B on the opposite side.
That is, the liquid crystal panel 11 employs an IPS drive method in which the liquid crystal molecules Lp are displaced in the plane along the surfaces of the substrates 13A and 13B as the liquid crystal drive method, while the optical rotation is used to turn on the light. Perform off control.

By the way, the strong anchoring alignment film 16 as described above is formed, for example, as follows. First, an alignment film made of polyimide or the like is formed on the substrate 13A. Then, a roller wrapped with a cloth made of rayon or cotton is rotated while keeping the rotation speed and the distance between the roller and the substrate 13A constant, and the surface of the alignment film is rubbed in a predetermined direction (rubbing method). Alternatively, the surface of the alignment film made of polyimide is irradiated with polarized ultraviolet rays to generate anisotropy (photoalignment method). The strong anchoring alignment film 16 whose orientation direction is set by the rubbing method, the photoalignment method, or the like imparts a stronger orientation forcing force to the liquid crystal molecule Lp than the weak anchoring alignment film 17.

As the weak anchoring alignment film 17, for example, one formed by a polymer brush can be used. The polymer brush is formed by a graft polymer chain having one end fixed to the surface of the substrate 13B and the other end extending in a direction away from the surface of the substrate 13B. Such a graft polymer chain may be generated by extending from the substrate 13B side, or a polymer chain having a predetermined length in advance may be attached to the substrate 13B. The initial orientation direction of the weak anchoring alignment film 17 may be determined by a known method such as a rubbing method.

一般式（１）において、ＸはＨ又はＣＨ_３であり、ｍは正の整数であって、ポリマーブラシのＴｇ（ガラス転移温度）が−５℃以下であるものである。 A specific example of the polymer brush is shown below.
The polymer brush is represented by, for example, the following general formula (1).

In the general formula (1), X is H or CH ₃ , m is a positive integer, and the Tg (glass transition temperature) of the polymer brush is −5 ° C. or lower.

FIG. 5 is a cross-sectional view showing an example of a polymer brush formed on a substrate as a weak anchoring alignment film.
As shown in FIG. 5, the liquid crystal molecule Lp permeates the surface layer portion of the polymer brush 2 formed on the substrate 13B, and the surface layer portion of the polymer brush 2 in contact with the liquid crystal molecule Lp is swollen (FIG. 5). Inside, the swollen state is not shown).

In the present specification, the portion of the polymer brush 2 in which the liquid crystal molecule Lp has penetrated is represented as the coexistence portion 4, and the portion of the polymer brush 2 in which the liquid crystal molecule Lp has not penetrated is represented as the polymer brush layer 3. In FIG. 5, from the viewpoint of facilitating the understanding of the present invention, the coexisting portion 4 and the polymer brush layer 3 are clearly distinguished, but in reality, the boundary between the coexisting portion 4 and the polymer brush layer 3 is defined. It is difficult to distinguish.

By using the polymer brush 2 as described above, the Tg (glass transition temperature) of the coexisting portion 4 becomes considerably lower than the room temperature, so that the shape of the coexisting portion 4 can be freely changed at room temperature. .. Therefore, the state of the coexisting part 4 changes at the interface between the coexisting part 4 and the liquid crystal molecule Lp, and while forcing the liquid crystal molecule Lp to be oriented horizontally with respect to the substrate 13B, the orientation forcing force is applied in any direction in the plane. (Zero-plane anchoring state) can be realized.

Since the Tg of the coexisting part 4 differs depending on the type of the polymer brush 2 and the liquid crystal molecule Lp used, it cannot be uniquely defined, but it is generally lower than the Tg of the polymer brush 2 alone. Further, the Tg of the coexisting portion 4 also changes depending on the degree of penetration of the liquid crystal molecules Lp into the polymer brush 2 (that is, the ratio of the polymer brush 2 to the liquid crystal molecules Lp). Specifically, in the coexistence portion 4, the coexistence portion 4 on the liquid crystal molecule Lp side having a large proportion of the liquid crystal molecule Lp has a low Tg, and the coexistence portion 4 on the polymer brush layer 3 side having a small proportion of the liquid crystal molecule Lp has a high Tg. Become.

However, the polymer brush 2 is represented by the above general formula (1). In the general formula (1), X is H or CH ₃ , m is a positive integer, and the Tg of the polymer brush is −5 ° C. By using the following, the Tg of the coexisting part 4 can be set to a temperature sufficiently lower than the room temperature, so that the liquid crystal molecules Lp are forced to be oriented in a plane horizontal to the surface of the substrate 13B at the room temperature. At the same time, it is possible to realize a state in which there is no orientation forcing force in any direction in the plane (zero-plane anchoring state).

The surface of the substrate 13B may be flattened if necessary. The flattening treatment is not particularly limited, and can be performed by using a method known in the art. An example of the flattening treatment is a method of forming a flattening film on the surface of the substrate 13B. For example, a UV-curable transparent resin or the like may be applied to the surface of the substrate 13B and UV-cured.

Examples of the substrate 13B include an array substrate and a counter substrate.
An example of an array substrate is an active matrix array substrate. In this active matrix array substrate, gate wiring and source wiring are generally arranged in a matrix on a glass substrate, and active elements such as a thin film transistor (TFT) are formed at the intersections thereof. The pixel electrode is connected to this active element.

Further, as an example of the opposed substrate, a color filter substrate can be mentioned. In this color filter substrate, generally, a black matrix is formed on a glass substrate to prevent unnecessary light leakage, and then R (red), G (green), and B (blue) colored layers are formed. A pattern is formed and a protective film is formed as needed. When these substrates 13B are used, a transparent resin may be applied to the surface of the substrate 13B and cured to form a flattening film.

The polymer brush 2 formed on the substrate 13B is represented by the above general formula (1). In the general formula (1), X is H or CH ₃ , m is a positive integer, and the polymer brush. Tg of -5 ° C or lower can be used. Here, the polymer brush 2 preferably has a structure in which a large number of graft polymer chains are densely extended in a direction perpendicular to the surface of the substrate 13B.

Generally, a graft polymer chain having one end fixed to the surface of the substrate 13B has a crimped structure like a thread when the graft density is low, but the polymer brush 2 has a high graft density, so that the graft polymer is adjacent to the graft polymer chain. Due to the interaction of the chains (three-dimensional repulsion), it has a structure that extends in the direction perpendicular to the surface of the substrate 13B.

As used herein, the term "high density" means the density of graft polymer chains that are dense enough to cause steric repulsion between adjacent graft polymer chains, and generally 0.1 strands / nm ² or more, preferably 0. .1 to 1.2 lines / nm ² density. Further, in the present specification, the “density of graft polymer chains” means the number of graft polymer chains formed on the surface of the substrate 13B per ^{unit area (nm 2).}
The polymer brush 2 may be provided with a large number of graft polymer chains having a density lower than the "high density" shown above.

The polymer brush 2 forms a layer of the polymer brush 2 on the surface of the substrate 13B. The thickness of the layer of the polymer brush 2 is not particularly limited, but is generally several tens of nm, specifically 1 nm or more and less than 100 nm, preferably 10 nm to 80 nm. Further, the layer of the polymer brush 2 has a size exclusion effect, and a substance having a certain size cannot pass through the layer of the polymer brush 2. Therefore, even if the thickness of the layer of the polymer brush 2 is reduced, it is possible to prevent impurities from entering the liquid crystal molecules Lp from the base.

The method for forming the polymer brush 2 is not particularly limited, and a method known in the art can be used. Specifically, the polymer brush 2 can be formed by subjecting a radically polymerizable monomer to living radical polymerization. Here, in the present specification, "living radical polymerization" means that the chain transfer reaction and the termination reaction do not substantially occur in the radical polymerization reaction, and the chain growth end remains active even after the radically polymerizable monomer has completely reacted. It means a polymerization reaction that is retained.

In this polymerization reaction, the polymerization activity is maintained at the end of the produced polymer even after the completion of the polymerization reaction, and the polymerization reaction can be restarted by adding a radically polymerizable monomer. Further, in living radical polymerization, a polymer having an arbitrary average molecular weight can be synthesized by adjusting the concentration ratio of the radically polymerizable monomer and the polymerization initiator, and the molecular weight distribution of the produced polymer is extremely narrow. There is a feature of.

A typical example of living radical polymerization is atom transfer radical polymerization (ATRP). For example, in the presence of a polymerization initiator, atom transfer living radical polymerization of a radically polymerizable monomer is carried out using a copper halide / ligand complex. A radically polymerizable monomer is added to a growth radical that grows reversibly by extracting a polymer terminal halogen by a copper halide / ligand complex, and the molecular weight distribution proceeds by reversible activation / inactivation at a sufficient frequency. Is regulated.

The radically polymerizable monomer used for living radical polymerization has an unsaturated bond capable of performing radical polymerization in the presence of an organic radical, and is, for example, t-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and the like. Methacrylate monomers such as nonyl methacrylate, lauryl methacrylate, n-octyl methacrylate; acrylate monomers such as t-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, benzyl acrylate, lauryl acrylate, n-octyl acrylate; styrene, Styrene derivatives (eg, o-, m-, p-methoxystyrene, o-, m-, pt-butoxystyrene, o-, m-, p-chloromethylstyrene, etc.), vinyl esters (eg, acetate) Vinyl, vinyl propionate, vinyl benzoate, vinyl acetate, etc.), vinyl ketones (eg, vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, etc.), N-vinyl compounds (eg, N-vinylpyrrolidone, N-vinyl, etc.) Pyrrole, N-vinylcarbazole, N-vinylindole, etc.), (meth) acrylic acid derivatives (eg, acrylonitrile, metaacrylonitrile, acrylamide, isopropylacrylamide, methacrylicamide, etc.), vinyl halides (eg, vinyl chloride, vinylidene chloride, etc.) , Tetrachloroethylene, hexachloroprene, vinyl fluoride, etc.) and other vinyl monomers. These various radically polymerizable monomers may be used alone or in combination of two or more.

The polymerization initiator is not particularly limited, and those generally known for living radical polymerization can be used. Examples of polymerization initiators are p-chloromethylstyrene, α-dichloroxylene, α, α-dichloroxylene, α, α-dibromoxylene, hexax (α-bromomethyl) benzene, benzyl chloride, benzyl bromide, 1- Benzyl halides such as bromo-1-phenylethane, 1-chloro-1-phenylethane; propyl-2-bromopropionate, methyl-2-chloropropionate, ethyl-2-chloropropionate, methyl- Α-halogenated carboxylic acids such as 2-bromopropionate, ethyl-2-bromoisobutyrate (EBIB); tosil halides such as p-toluenesulfonyl chloride (TsCl); tetrachloromethane, tribromo Alkyl halides such as methane, 1-vinylethyl chloride, 1-vinylethyl bromide; halogen derivatives of phosphate esters such as dimethylphosphate chloride can be mentioned. These various polymerization initiators may be used alone or in combination of two or more.

The copper halide that gives the copper halide / ligand complex is not particularly limited, and those generally known for living radical polymerization can be used. Examples of copper halide include CuBr, CuCl, CuI and the like. These various types of copper halides may be used alone or in combination of two or more.

The ligand compound that gives the copper halide / ligand complex is not particularly limited, and those generally known for living radical polymerization can be used. Examples of ligand compounds include triphenylphosphine, 4,4'-dinonyl-2,2'-dipyridine (dNbipy), N, N, N', N'N "-pentamethyldiethylenetriamine, 1,1,4. , 7, 10, 10-Hexamethyltriethylenetetraamine and the like. These various ligand compounds may be used alone or in combination of two or more.

The amounts of the radically polymerizable monomer, the polymerization initiator, the copper halide and the ligand compound may be appropriately adjusted according to the type of the raw material used, but in general, the radically polymerizable monomer is used with respect to 1 mol of the polymerization initiator. Is 5 to 10,000 mol, preferably 50 to 5,000 mol, copper halide is 0.1 to 100 mol, preferably 0.5 to 100 mol, and the ligand compound is 0.2 to 200 mol, preferably 1.0 to 200 mol. be.

Living radical polymerization is usually carried out without a solvent, but a solvent generally used in living radical polymerization may be used. Examples of the solvent that can be used include benzene, toluene, N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), acetone, chloroform, carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, trifluoromethylbenzene and the like. Organic solvents: water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol and other aqueous solvents. These various solvents may be used alone or in combination of two or more. The amount of the solvent may be appropriately adjusted according to the type of the raw material used, but generally, the amount of the solvent is 0.01 to 100 mL, preferably 0.05 to 10 mL with respect to 1 g of the radically polymerizable monomer. be.

Living radical polymerization can be carried out by immersing the substrate 13B in the polymer brush forming solution containing the above raw materials, or by applying the polymer brush forming solution containing the above raw materials to the substrate 13B and heating. The heating conditions are not particularly limited and may be appropriately adjusted according to the raw materials to be used, but generally, the heating temperature is 60 to 150 ° C. and the heating time is 0.1 to 10 hours. This polymerization reaction is generally carried out at normal pressure, but may be pressurized or depressurized. If necessary, the substrate 13B may be washed before the polymer brush 2 is formed.

The molecular weight of the polymer brush 2 formed by living radical polymerization can be adjusted depending on the reaction temperature, reaction time, type and amount of raw materials used, but generally, the number average molecular weight is preferably 500 to 1,000,000. Can form 1,000 to 500,000 polymer brushes 2. Further, the molecular weight distribution (Mw / Mn) of the polymer brush 2 can be controlled between 1.05 and 1.60.

The polymer brush 2 may be formed on the surface of the substrate 13B via an immobilization film, if necessary, from the viewpoint of enhancing the adhesiveness between the substrate 13B and the polymer brush 2. The immobilized film is not particularly limited as long as it has excellent adhesion to the substrate 13B and the polymer brush 2, and a film generally known for living radical polymerization can be used. Examples of the immobilized film include a film formed from an alkoxysilane compound represented by the following general formula (2).

In the general formula (2), R ¹ is independently an alkyl group of C1 to C3, preferably a methyl group or an ethyl group, R ² is independently a methyl group or an ethyl group, and X is a halogen atom. , Preferably Br, and n is an integer of 3 to 10, more preferably an integer of 4 to 8.

It is preferable that the polymer brush 2 is covalently bonded to the immobilized membrane. If the immobilization film and the polymer brush 2 are connected by a covalent bond having a strong bonding force, the peeling of the polymer brush 2 can be sufficiently prevented. As a result, the possibility that the characteristics of the liquid crystal panel 11 are deteriorated is reduced, and the reliability of the liquid crystal panel 11 is improved.

The method for forming the immobilized film is not particularly limited, and may be appropriately set according to the material to be used. For example, the immobilized film can be formed by immersing the substrate 13B in the immobilized film forming solution, or by applying the above-mentioned immobilized film forming solution to the substrate 13B and then drying it. Here, in order to form the immobilization film on the predetermined portion, masking may be applied to the portion on which the immobilization film is not formed. Further, the substrate 13B may be washed before forming the immobilization film, if necessary.

The method of injecting a liquid crystal material containing liquid crystal molecules Lp and a chiral agent between the substrate 13A and the substrate 13B on which the polymer brush 2 is formed is not particularly limited, and is a vacuum injection method utilizing a capillary phenomenon or liquid crystal dropping. A known method such as an injection method (ODF: One Drop Filling) can be used. For example, when the vacuum injection method utilizing the capillary phenomenon is used, it may be carried out as follows.

First, the electrode layer 15 is formed on one of the substrates 13A by a known method. On the other substrate 13B, a spacer is formed by a known method such as photolithography, and then an immobilization film (if necessary) and a polymer brush 2 are formed. Here, if necessary, a flattening film or the like may be formed on the substrate 13B (other than the spacer portion) to flatten the substrate 13B, and an immobilization film (if necessary) and a polymer brush 2 may be formed on the flattening film. ..

Next, after washing and drying one substrate 13A, a sealing material is applied, and the sealing material is superposed on the other substrate 13B, and the sealing material is cured and adhered by heating or UV irradiation. Here, it is necessary to open an injection port for injecting a liquid crystal material containing a liquid crystal molecule Lp and a chiral agent in a part of the sealing material. Next, a liquid crystal material containing liquid crystal molecules Lp and a chiral agent is injected between the substrates 13A and 13B from the injection port by a vacuum injection method, and then the injection port is sealed.

The liquid crystal molecule Lp used in the present invention is not particularly limited, and those known in the art can be used. Among them, as the liquid crystal molecule Lp, it is preferable that the NI point (phase transition temperature from the N phase to the I phase) of the liquid crystal molecule Lp is higher than the Tg of the coexisting portion 4.

The chiral agent is not particularly limited, and those known in the art can be used.

As described above, according to the liquid crystal panel 11, the back light unit 12, the substrate 13B on which the weak anchoring alignment film 17 is formed, and the weak anchoring alignment film 17 are arranged so as to face each other with a gap. A liquid crystal display that is arranged between the substrate 13A on which the strong anchoring alignment film 16 is formed and the weak anchoring alignment film 17 and the strong anchoring alignment film 16 and transmits or blocks light by driving the liquid crystal molecule Lp. A layer 18 and a drive electrode layer 15 provided on either one of the substrate 13A and the substrate 13B and applying an electric field E to the liquid crystal molecule Lp are provided, and the liquid crystal molecule Lp is not applied to the liquid crystal layer 18. A chiral agent that restores the initial orientation state in the above state is added.
In this way, the liquid crystal molecule Lp whose orientation direction is displaced by the electric field E generated in the drive electrode layer 15 is returned to the initial orientation state by the restoring force applied by the chiral agent, whereby the liquid crystal molecule Lp is driven at high speed. It becomes possible to change. This makes it possible to improve the display responsiveness of the liquid crystal panel 11. Further, in order to return the liquid crystal molecule Lp to the initial state, it is not necessary to separately provide an electrode or the like, and a simple configuration can be made while suppressing power consumption.

Further, the weak anchoring alignment film 17 has a smaller binding force that constrains the orientation direction of the liquid crystal molecules Lp when an electric field E is applied than the strong anchoring alignment film 16.
Then, with the electric field E applied, as the magnitude of the applied electric field E increases, the amount of displacement of the liquid crystal molecules Lp in the vicinity of the weak anchoring alignment film 17 with respect to the initial orientation state gradually increases.
As a result, if a predetermined voltage sufficient to change the orientation direction of the liquid crystal molecules Lp on the weak anchoring alignment film 17 side is applied, the liquid crystal layer 18 of the liquid crystal panel 11 can be driven and displayed. Therefore, the liquid crystal molecule Lp can be driven with a low voltage.
Further, according to the above configuration, in the state where the electric field E is not applied, the light changes along the orientation of the liquid crystal molecules Lp, almost all the light is absorbed by the polarizing plate 14B, and the transmittance becomes almost zero. .. On the other hand, when an electric field E of a certain value or more is applied, the liquid crystal layer 18 is uniformly oriented in a direction parallel to the electric field direction, and almost all the light incident on the liquid crystal panel 11 is transmitted through the polarizing plate 14B. It is possible to display a display having a high transmittance and a high contrast ratio.

[Second Embodiment]
Next, a second embodiment of the liquid crystal display element according to the present invention will be described. In the second embodiment described below, the same components as those in the first embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted. In this second embodiment, the arrangement of the electrode wires 20B in the drive electrode layer 15 is different from that in the first embodiment.
FIG. 6 shows the orientation of the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in the liquid crystal panel of the liquid crystal display shown as the second embodiment, using a liquid crystal having a positive dielectric anisotropy and no electric field applied. It is a figure which shows the relationship with a direction. FIG. 7 shows the liquid crystal panel of the liquid crystal display shown in the second embodiment, in which a liquid crystal having a positive dielectric anisotropy is used, and the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are shown. It is a figure which shows another example of the relationship with the orientation direction.

As shown in FIG. 6, in the second embodiment, the drive electrode layer 15 is formed by arranging a plurality of electrode wires 20B in parallel along the surface of the substrate 13A. Here, each electrode wire 20B is formed so that its major axis direction is inclined with respect to the direction Y along the substrate 13A, for example. The drive electrode layer 15 is formed by arranging such electrode wires 20B side by side at regular intervals along the direction X orthogonal to the direction Y along the substrate 13A.

As shown in FIG. 1, in the liquid crystal layer 18, in a state where the electric field E is not applied, the positive type liquid crystal molecules Lp are transferred from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 by adding a chiral agent. The initial orientation is twisted in a spiral toward the side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Lp are oriented along the orientation treatment direction (direction X) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 6, on the weak anchoring alignment film 17 side, positive type liquid crystal molecules are formed between the electrode lines 20B and 20B adjacent to each other in the drive electrode layer 15 in a state where the electric field E is not applied. Lp is oriented along the orientation treatment direction (direction Y) on the weak anchoring alignment film 17 side.

In the liquid crystal layer 18, the positive liquid crystal molecule Lp has a strong anchoring alignment film 16 on the long axis direction of the strong anchoring alignment film 16 even when an electric field E is applied. Maintain the initial orientation along X). On the other hand, as shown in FIG. 7, on the weak anchoring alignment film 17 side, the orientation angle of the liquid crystal molecules Lp is displaced in the plane parallel to the substrate 13B due to the applied electric field E, and the electric field strength becomes a certain constant value. When it reaches, its long axis direction follows the direction parallel to the electric field E, that is, the direction orthogonal to the electrode line 20B.

Also in the liquid crystal panel 11 of the present embodiment provided with such a drive electrode layer 15, when the application of the electric field E is released, the liquid crystal molecules Lp whose orientation direction is displaced by the electric field E generated by the drive electrode layer 15 are released. By returning to the spiral initial orientation state by the restoring force applied by the chiral agent, it is possible to speed up the driving of the liquid crystal molecule Lp. This makes it possible to improve the display responsiveness of the liquid crystal panel 11. Further, in the present embodiment, when the orientation direction of the liquid crystal molecule Lp on the weak anchoring alignment film 17 side is parallel to the electric field E, the orientation direction of the liquid crystal molecule Lp and the transmission axis direction of the polarizing plate 14B completely match. Therefore, the maximum transmittance is slightly lower than that of the configuration shown in the first embodiment, but it is possible to realize a higher maximum transmittance than that of the conventional IPS type liquid crystal panel.

[Third Embodiment]
Next, a third embodiment of the liquid crystal display element according to the present invention will be described. In the third embodiment described below, the same reference numerals are given in the drawings to the configurations common to the first and second embodiments, and the description thereof will be omitted. In this third embodiment, the arrangement of the electrode wire 20C in the drive electrode layer 15 is different from that of the first and second embodiments.
FIG. 8 shows the orientation of the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in the liquid crystal panel of the liquid crystal display shown as the third embodiment, using a liquid crystal having a positive dielectric anisotropy and not applying an electric field. It is a figure which shows the relationship with a direction. FIG. 9 shows the liquid crystal panel of the liquid crystal display shown in the third embodiment, in which a liquid crystal having a positive dielectric anisotropy is used, and the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are shown. It is a figure which shows another example of the relationship with the orientation direction.

As shown in FIG. 8, in the third embodiment, the drive electrode layer 15 is formed by arranging a plurality of electrode wires 20C in parallel along the surface of the substrate 13A. Here, each electrode wire 20C has a first inclined portion 20a inclined by a predetermined angle α with respect to the direction Y along the substrate 13A and a second inclined portion 20C inclined by a predetermined angle −α with respect to the direction Y in each pixel. The portions 20b form a continuous "dogleg" shape in the direction Y, which is the long axis direction. The drive electrode layer 15 is formed by arranging such electrode wires 20C side by side at regular intervals along the direction X orthogonal to the direction Y along the substrate 13A.

In such a driving electrode layer 15, in a state where an electric field E is not applied between the electrode wires 20C and 20C adjacent to each other, the positive liquid crystal molecule Lp is oriented in the strong anchoring alignment film 16 (direction). It is oriented along X).

As shown in FIG. 1, in the liquid crystal layer 18, in a state where the electric field E is not applied, the positive type liquid crystal molecules Lp are transferred from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 by adding a chiral agent. The initial orientation is twisted in a spiral toward the side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Lp are oriented along the orientation treatment direction (direction X) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 8, on the weak anchoring alignment film 17 side, positive type liquid crystal molecules are formed between the electrode lines 20B and 20B adjacent to each other in the driving electrode layer 15 in a state where the electric field E is not applied. Lp is oriented along the orientation treatment direction (direction Y) on the weak anchoring alignment film 17 side.

In the liquid crystal layer 18, the positive liquid crystal molecule Lp has a strong anchoring alignment film 16 on the long axis direction of the strong anchoring alignment film 16 even when an electric field E is applied. Maintain the initial orientation along X). On the other hand, as shown in FIG. 9, on the weak anchoring alignment film 17 side, the orientation angle of the liquid crystal molecules Lp is displaced in the plane parallel to the substrate 13B due to the applied electric field E, and the strength of the electric field E is constant. When the value is reached, the major axis direction is oriented so as to be orthogonal to the first inclined portion 20a and the second inclined portion 20b. Specifically, when the electric field E is applied, the liquid crystal molecule Lp is orthogonal to the first inclined portion 20a between the first inclined portions 20a and 20a, and the liquid crystal molecule Lp is formed between the second inclined portions 20b and 20b. It is orthogonal to the second inclined portion 20b.
Here, in the drive electrode layer 15, the electrode wire 20C is bent in a dogleg shape at each pixel. Therefore, when the electric field E is applied, the liquid crystal molecules Lp inclined by the angle α and the liquid crystal molecules Lp inclined by the angle −α coexist with respect to the direction X to form an image. As a result, image deterioration when the liquid crystal panel 11 is viewed from an oblique direction inclined with respect to the panel surface can be suppressed.

Also in the liquid crystal panel 11 of the present embodiment provided with such a drive electrode layer 15, when the application of the electric field E is released, the liquid crystal molecules Lp whose orientation direction is displaced by the electric field E generated by the drive electrode layer 15 are released. By returning to the spiral initial orientation state by the restoring force applied by the chiral agent, it is possible to speed up the driving of the liquid crystal molecule Lp. This makes it possible to improve the display responsiveness of the liquid crystal panel 11. Further, in the present embodiment, when the orientation direction of the liquid crystal molecule Lp on the weak anchoring alignment film 17 side is parallel to the electric field E, the orientation direction of the liquid crystal molecule Lp and the transmission axis direction of the polarizing plate 14B completely match. Therefore, the maximum transmittance is slightly lower than that of the configuration shown in the first embodiment, but it is possible to realize a higher maximum transmittance than that of the conventional IPS type liquid crystal panel.

[Fourth Embodiment]
Next, a fourth embodiment of the liquid crystal display element according to the present invention will be described. In the fourth embodiment described below, the same reference numerals are given in the drawings to the configurations common to the first to third embodiments, and the description thereof will be omitted. In this fourth embodiment, the same driving electrode layer 15 as in the first embodiment is provided, and the negative type liquid crystal molecule Ln is driven.
FIG. 10 is a cross-sectional view showing a schematic configuration of a liquid crystal display shown as a fourth embodiment of the present invention. FIG. 11 is a diagram showing the distribution of the orientation direction of liquid crystal molecules in a state where an electric field is applied by using a liquid crystal having a negative dielectric anisotropy in the liquid crystal panel of the liquid crystal display shown in the fourth embodiment. FIG. 12 shows the liquid crystal panel of the liquid crystal display shown in the fourth embodiment, in which a liquid crystal having a negative dielectric anisotropy is used, and the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in a state where no electric field is applied are shown. It is a figure which shows the relationship with the orientation direction. FIG. 13 shows the relationship between the electrode wire and the orientation direction of the liquid crystal molecule in a state where an electric field is applied by using a liquid crystal having a negative dielectric anisotropy in the liquid crystal panel of the liquid crystal display shown in the fourth embodiment. It is a figure.

As shown in FIGS. 10 and 11, in this embodiment, the polarizing plate 14A and the polarizing plate 14B are arranged in parallel Nicols, and the transmission axis directions of the polarizing plate 14A and the polarizing plate 14B are set to be along the direction Y, respectively. ing.

The drive electrode layer 15 is formed by arranging a plurality of electrode wires 20A in parallel along the surface of the substrate 13A. As shown in FIGS. 12 and 13, each electrode wire 20A is formed linearly so that its major axis direction extends along the direction Y in a plane parallel to the surface of the substrate 13A, for example. In the drive electrode layer 15, such electrode wires 20A are arranged side by side at regular intervals along the direction X orthogonal to the direction Y in a plane parallel to the surface of the substrate 13A.

The liquid crystal molecule Ln of the liquid crystal layer 18 has a negative dielectric anisotropy, a small dielectric property in the long axis direction, and a large negative type in the direction orthogonal to the long axis direction.
As shown in FIG. 10, when a negative type liquid crystal molecule Ln is used, the orientation processing direction of the strong anchoring alignment film 16 for regulating the orientation direction of the liquid crystal molecule Ln in a state where the electric field E is not applied is set for each electrode. The direction is parallel to the long axis direction of the line 20A (direction Y in FIG. 10). Further, the orientation processing direction of the weak anchoring alignment film 17 is set to be a direction orthogonal to the orientation processing direction of the strong anchoring alignment film 16 (direction X in FIG. 10).
Further, in the liquid crystal layer 18, the liquid crystal molecules Ln are spirally oriented (initially oriented state) from the strong anchoring alignment film 16 side toward the weak anchoring alignment film 17 side in a state where the electric field E is not applied. A chiral agent that imparts a restoring force that restores the spiral initial orientation state when the application of the electric field E is released is added.

As a result, as shown in FIG. 10, the negative type liquid crystal molecule Ln of the liquid crystal layer 18 is oriented in the major axis direction of the strong anchoring alignment film 16 on the strong anchoring alignment film 16 side (FIG. 10). In 10, the orientation is substantially aligned with the direction Y). On the other hand, on the weak anchoring alignment film 17 side, the major axis direction thereof is oriented so as to be substantially aligned with the orientation processing direction (direction X in FIG. 10) of the weak anchoring alignment film 17.
Then, in the liquid crystal display 10 of this embodiment, in the state where the electric field E is not applied, the polarization plane of the light passing through the polarizing plate 14A from the backlight unit 12 side changes along the distribution in the orientation direction of the liquid crystal molecules Ln. However, almost all the light is absorbed by the polarizing plate 14B on the opposite side.

As shown in FIG. 11, the negative type liquid crystal molecule Ln is subjected to the orientation treatment of the strong anchoring alignment film 16 in the major axis direction on the strong anchoring alignment film 16 side as described above even when the electric field E is applied. The initial orientation state (direction Y) along the direction is maintained. On the other hand, as shown in FIGS. 11 and 13, on the weak anchoring alignment film 17 side, the orientation angle of the liquid crystal molecule Ln is displaced in the plane parallel to the substrate 13B due to the applied electric field E, and there is an electric field strength. When a certain value is reached, the long axis direction is along the direction orthogonal to the electric field E, that is, along the direction Y parallel to the substrate 13B. In this way, in the state where the electric field E is applied, as the magnitude of the applied electric field E increases, the amount of displacement of the liquid crystal molecules Ln near the weak anchoring alignment film 17 in the orientation direction with respect to the initial orientation state gradually increases. Further, when an electric field of a certain value or more is applied, the orientation direction (direction Y) of the liquid crystal molecules Ln on the weak anchoring alignment film 17 side becomes a direction orthogonal to the electric field E, and weak anchoring is performed from the strong anchoring alignment film 16 side. The orientation direction of the liquid crystal molecules Ln of the liquid crystal layer 18 becomes uniform toward the alignment film 17 side. As a result, the light from the backlight unit 12 side passes through the liquid crystal panel 11.

Further, when the application of the electric field E is stopped from the state in which the electric field E is applied, the orientation direction of the liquid crystal molecules Ln of the liquid crystal molecule Ln of the liquid crystal layer 18 is shown in FIG. 10 due to the restoring force applied by the chiral agent. It returns to the spiral initial orientation state. That is, on the strong anchoring alignment film 16 side, the long axis direction of the liquid crystal molecules Ln is maintained along the orientation processing direction (direction Y in FIG. 10) of the strong anchoring alignment film 16. On the other hand, on the weak anchoring alignment film 17 side of the liquid crystal layer 18, the orientation direction is such that the long axis direction of the liquid crystal molecules Ln is along the alignment processing direction of the weak anchoring alignment film 17 (direction X in FIG. 10). Displace. As a result, the displacement amount of the orientation angle in the long axis direction gradually increases from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 side, and the liquid crystal molecule Ln is in the initial orientation state twisted in a spiral shape. return.

Also in the liquid crystal panel 11 of the present embodiment including the drive electrode layer 15, the liquid crystal molecules Ln whose orientation direction is displaced by the electric field E generated by the drive electrode layer 15 are initially displaced by the restoring force applied by the chiral agent. By restoring the oriented state, it is possible to speed up the driving of the liquid crystal molecule Ln. This makes it possible to improve the display responsiveness of the liquid crystal panel 11. Further, in order to return the liquid crystal molecule Ln to the initial state, it is not necessary to separately provide an electrode or the like, and a simple configuration can be made while suppressing power consumption.

[Fifth Embodiment]
Next, a fifth embodiment of the liquid crystal display element according to the present invention will be described. In the fifth embodiment described below, the same reference numerals are given in the drawings to the configurations common to the first to fourth embodiments, and the description thereof will be omitted. In the fifth embodiment, the same driving electrode layer 15 as in the second embodiment is provided, and the negative type liquid crystal molecule Ln is driven.
FIG. 14 shows the orientation of the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in the liquid crystal panel of the liquid crystal display shown as the fifth embodiment, using a liquid crystal having a negative dielectric anisotropy and not applying an electric field. It is a figure which shows the relationship with a direction. FIG. 15 shows the liquid crystal panel of the liquid crystal display shown in the fifth embodiment, in which a liquid crystal having a negative dielectric anisotropy is used, and the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are shown. It is a figure which shows another example of the relationship with the orientation direction.

In this embodiment, the transmission axis directions of one of the polarizing plates 14A and the polarizing plate 14B are set to follow the direction Y, respectively, as in the fourth embodiment.

As shown in FIG. 14, the drive electrode layer 15 is formed by arranging a plurality of electrode wires 20B side by side along the surface of the substrate 13A. Each electrode wire 20B is formed so that its major axis direction is inclined with respect to the direction Y along the substrate 13A, for example. The drive electrode layer 15 is formed by arranging such electrode wires 20B side by side at regular intervals along the direction X orthogonal to the direction Y along the substrate 13A.

As shown in FIG. 10, in the liquid crystal layer 18, in a state where the electric field E is not applied, the liquid crystal molecules Ln are directed from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 side by adding a chiral agent. The initial orientation is twisted in a spiral shape. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Ln are oriented along the orientation treatment direction (direction Y) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 14, on the weak anchoring alignment film 17 side, negative type liquid crystal molecules are formed between the electrode lines 20B and 20B adjacent to each other in the driving electrode layer 15 in a state where the electric field E is not applied. Ln is oriented along the orientation treatment direction (direction X) on the weak anchoring alignment film 17 side.

In the liquid crystal layer 18, even if an electric field E is applied to the negative type liquid crystal molecule Ln, the long axis direction of the liquid crystal molecule Ln is the orientation processing direction (direction) of the strong anchoring alignment film 16 on the strong anchoring alignment film 16 side. The initial orientation state along Y) is maintained. On the other hand, as shown in FIG. 15, on the weak anchoring alignment film 17 side, the orientation angle of the liquid crystal molecules Ln is displaced in the plane parallel to the substrate 13B due to the applied electric field E, and the electric field strength has a certain constant value. When it reaches, the major axis direction is along the direction orthogonal to the electric field E, that is, the direction parallel to the electrode line 20B.

Also in the liquid crystal panel 11 of the present embodiment including the drive electrode layer 15, the liquid crystal molecules Ln whose orientation direction is displaced by the electric field E generated by the drive electrode layer 15 are initially displaced by the restoring force applied by the chiral agent. By restoring the oriented state, it is possible to speed up the driving of the liquid crystal molecule Ln. This makes it possible to improve the display responsiveness of the liquid crystal panel 11. Further, in order to return the liquid crystal molecule Ln to the initial state, it is not necessary to separately provide an electrode or the like, and a simple configuration can be made while suppressing power consumption. Further, in the present embodiment, when the orientation direction of the liquid crystal molecule Ln on the weak anchoring alignment film 17 side is perpendicular to the electric field E, the orientation direction of the liquid crystal molecule Ln and the transmission axis direction of the polarizing plate 14B completely match. Therefore, the maximum transmittance is slightly lower than that of the configuration shown in the fourth embodiment, but it is possible to realize a higher maximum transmittance than that of the conventional IPS type liquid crystal panel.

[Sixth Embodiment]
Next, a sixth embodiment of the liquid crystal display element according to the present invention will be described. In the sixth embodiment described below, the same reference numerals are given in the drawings to the configurations common to the first to fifth embodiments, and the description thereof will be omitted. In the sixth embodiment, the same driving electrode layer 15 as in the third embodiment is provided, and the negative type liquid crystal molecule Ln is driven.
FIG. 16 shows the orientation of the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in the liquid crystal panel of the liquid crystal display shown as the sixth embodiment, using a liquid crystal having a negative dielectric anisotropy and not applying an electric field. It is a figure which shows the relationship with a direction. FIG. 17 shows the liquid crystal panel of the liquid crystal display shown in the sixth embodiment, in which a liquid crystal having a negative dielectric anisotropy is used, and the electrode wire and the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is applied are shown. It is a figure which shows another example of the relationship with the orientation direction.

In this embodiment, the transmission axis directions of one of the polarizing plates 14A and the polarizing plate 14B are set to follow the direction Y, respectively, as in the fourth embodiment.

As shown in FIG. 16, the drive electrode layer 15 is formed by arranging a plurality of electrode wires 20C in parallel along the surface of the substrate 13A. Each electrode wire 20C has a first inclined portion 20a inclined by a predetermined angle α with respect to the direction Y along the substrate 13A and a second inclined portion 20b inclined by a predetermined angle −α with respect to the direction Y in each pixel. However, a continuous "dogleg" shape is formed in the direction Y, which is the long axis direction. The drive electrode layer 15 is formed by arranging such electrode wires 20C side by side at regular intervals along the direction X orthogonal to the direction Y along the substrate 13A.

As shown in FIG. 10, in the liquid crystal layer 18, in a state where the electric field E is not applied, the liquid crystal molecules Ln are directed from the strong anchoring alignment film 16 side to the weak anchoring alignment film 17 side by adding a chiral agent. Therefore, the initial orientation is twisted in a spiral shape. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Ln are oriented along the orientation treatment direction (direction Y) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 16, on the weak anchoring alignment film 17 side, negative type liquid crystal molecules are formed between the electrode lines 20B and 20B adjacent to each other in the driving electrode layer 15 in a state where the electric field E is not applied. Ln is oriented along the orientation treatment direction (direction X) on the weak anchoring alignment film 17 side.

In the liquid crystal layer 18, even if an electric field E is applied to the negative type liquid crystal molecule Ln, the long axis direction of the liquid crystal molecule Ln is the orientation processing direction (direction) of the strong anchoring alignment film 16 on the strong anchoring alignment film 16 side. The initial orientation state along Y) is maintained. On the other hand, as shown in FIG. 17, on the weak anchoring alignment film 17 side, the orientation angle of the liquid crystal molecules Ln is displaced in the plane parallel to the substrate 13B due to the applied electric field E, and the electric field strength becomes a certain value. When it reaches, it is oriented so that its major axis direction is parallel to the first inclined portion 20a and the second inclined portion 20b. Specifically, when the electric field E is applied, the liquid crystal molecule Ln is parallel to the first inclined portion 20a between the first inclined portions 20a and 20a, and the liquid crystal molecule Ln is generated between the second inclined portions 20b and 20b. It is parallel to the second inclined portion 20b.
Here, in the drive electrode layer 15, the electrode wire 20C is bent in a dogleg shape at each pixel. Therefore, when the electric field E is applied, the liquid crystal molecules Ln inclined at two different angles are mixed to form an image. As a result, image deterioration when the liquid crystal panel 11 is viewed from an oblique direction inclined with respect to the panel surface can be suppressed.

Also in the liquid crystal panel 11 of the present embodiment including the drive electrode layer 15, the liquid crystal molecules Ln whose orientation direction is displaced by the electric field E generated by the drive electrode layer 15 are initially displaced by the restoring force applied by the chiral agent. By restoring the oriented state, it is possible to speed up the driving of the liquid crystal molecule Ln. This makes it possible to improve the display responsiveness of the liquid crystal panel 11. Further, in order to return the liquid crystal molecule Ln to the initial state, it is not necessary to separately provide an electrode or the like, and a simple configuration can be made while suppressing power consumption.
Further, in the present embodiment, when the orientation direction of the liquid crystal molecule Ln on the weak anchoring alignment film 17 side is perpendicular to the electric field E, the orientation direction of the liquid crystal molecule Ln and the transmission axis direction of the polarizing plate 14B completely match. Therefore, the maximum transmittance is slightly lower than that of the configuration shown in the fourth embodiment, but it is possible to realize a higher maximum transmittance than that of the conventional IPS type liquid crystal panel.

[7th Embodiment]
Next, a seventh embodiment of the liquid crystal display element according to the present invention will be described. In the seventh embodiment described below, the same reference numerals are given in the drawings to the configurations common to each of the above embodiments, and the description thereof will be omitted. In the seventh embodiment, the transmission axis direction of the polarizing plate 14B is different from that of the first embodiment.
FIG. 18 is a cross-sectional view showing a schematic configuration of the liquid crystal display shown as the seventh embodiment, (a) in a state where an electric field is not applied, and (b) in a state where an electric field is applied. In FIGS. 18A and 18B, the directions indicating the transmission axis direction and the orientation direction of each member are on the right side of the polarizing plates 14A and 14B, the strong anchoring alignment film 16, and the weak anchoring alignment film 17. Is illustrated. The same applies to FIGS. 19 to 25 described later. In the first embodiment, the transmission axis direction of the polarizing plate 14B is the direction X, but in the seventh embodiment, the direction Y is set. As a result, the polarizing plates 14A and 14B are arranged so that their transmission axis directions are perpendicular to each other, that is, cross Nicols.

In such a configuration, when the electric field E is not applied, as shown in FIG. 18A, the light passing through the polarizing plate 14A from the backlight unit 12 side is the positive type liquid crystal molecule Lp in the liquid crystal layer 18. Since the plane of polarization changes along the spiral distribution in the orientation direction of, the polarizing plate 14B on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14A is transmitted.
Further, as shown in FIG. 18B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of the Lp in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Lp of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction X in FIG. 18) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14A from the backlight unit 12 side reaches the polarizing plate 14B with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14B is orthogonal to the polarizing plate 14A, the light is absorbed by the polarizing plate 14B.

When the application of the electric field E is stopped from the state where the electric field E is applied, the orientation direction of the liquid crystal molecule Lp is spiral as shown in FIG. 18A due to the restoring force (elastic force) applied by the chiral agent. The light that has passed through the polarizing plate 14A passes through the polarizing plate 14B on the opposite side in order to return to the initial orientation state of the above.
By arranging the polarizing plates 14A and 14B so as to form a cross Nicol in this way, the display becomes dark when the voltage is not applied and becomes bright when the voltage is applied, as described in the first to sixth embodiments. Unlike the normally black type liquid crystal panel 11, the liquid crystal panel 11 can be configured as a so-called normally white type in which the display is bright when no voltage is applied and the display is dark when a voltage is applied.

In the liquid crystal panel 11 as described in the first embodiment, one of the alignment films is the weak anchoring alignment film 17, and the liquid crystal on the weak anchoring alignment film 17 side in the state where the electric field E is not applied. The orientation direction of the molecules with respect to the liquid crystal molecules on the strong anchoring alignment film 16 side is basically maintained to be twisted by 90 ° due to the twist elastic force of the chiral agent that tries to maintain the spirally twisted orientation state. Has been done. However, since this twist elastic force is subtly affected by the temperature, it is not always 90 ° and fluctuates subtly.
Here, while the human eye is sensitive to changes in the brightness of black, it tends to be difficult to recognize even if a bright color becomes slightly darker. That is, in the case of the dark normally black type liquid crystal panel 11 when the electric field E is not applied, for example, the brightness of the black color output to the liquid crystal panel 11 differs slightly depending on the day, so that it is visible to the human eye. Although the change in brightness is easily recognized, in the case of the normally white type liquid crystal panel 11 which is bright when the electric field E is not applied, the change in brightness is difficult to be recognized by the human eye. This makes it possible to provide a normally white type liquid crystal panel 11 that looks more natural to the human eye than the normally black type liquid crystal panel 11 shown in the first embodiment.
Needless to say, the seventh embodiment has the same effect as the first embodiment.

[8th Embodiment]
Next, an eighth embodiment of the liquid crystal display element according to the present invention will be described. In the eighth embodiment described below, the same reference numerals are given in the drawings to the configurations common to each of the above embodiments, and the description thereof will be omitted. In the eighth embodiment, the transmission axis direction of the polarizing plate 14B is different from that of the fourth embodiment.
19A and 19B are cross-sectional views showing a schematic configuration of the liquid crystal display shown as the eighth embodiment, in which FIG. 19A is a state in which an electric field is not applied, and FIG. 19B is a state in which an electric field is applied. In the fourth embodiment, the transmission axis direction of the polarizing plate 14B is the direction Y, but in the seventh embodiment, the direction X is set. As a result, the polarizing plates 14A and 14B are arranged so that their transmission axis directions are perpendicular to each other, that is, cross Nicols.

In such a configuration, when the electric field E is not applied, as shown in FIG. 19A, the light passing through the polarizing plate 14A from the backlight unit 12 side is the negative type liquid crystal molecule Ln in the liquid crystal layer 18. Since the plane of polarization changes along the spiral distribution in the orientation direction of, the polarizing plate 14B on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14A is transmitted.
Further, as shown in FIG. 19B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of Ln in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Ln of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction Y in FIG. 19) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14A from the backlight unit 12 side reaches the polarizing plate 14B with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14B is orthogonal to the polarizing plate 14A, the light is absorbed by the polarizing plate 14B.

When the application of the electric field E is stopped from the state where the electric field E is applied, the orientation direction of the liquid crystal molecule Ln is spiral as shown in FIG. 19A due to the restoring force (elastic force) applied by the chiral agent. The light that has passed through the polarizing plate 14A passes through the polarizing plate 14B on the opposite side in order to return to the initial orientation state of the above.

As described above, in the eighth embodiment, the normal white type is configured as in the seventh embodiment.
Further, the electric field E is actually generated substantially radially from the electrode wire 20 as shown in FIG. Since the liquid crystal is displaced along the electric field E, in the case of a positive type liquid crystal having a large dielectric property in the long axis direction of the liquid crystal molecule, it is displaced so as to be tilted in the vertical direction, especially at a position away from the electrode wire 20. It tends to be. On the other hand, in the case of a negative type liquid crystal, since the dielectric property is small in the major axis direction and large in the direction orthogonal to the major axis direction, the liquid crystal is centered in the major axis direction even at a position away from the electrode line 20. It is displaced so as to rotate about the line, and as a result, it is difficult to be displaced so as to be tilted in the vertical direction.
The above effects are synergistic, and the eighth embodiment using a negative liquid crystal display makes it possible to provide a liquid crystal panel 11 that is more naturally reflected by the human eye than the seventh embodiment.
Needless to say, the eighth embodiment has the same effect as the fourth embodiment.

[9th Embodiment]
Next, a ninth embodiment of the liquid crystal display element according to the present invention will be described. In the ninth embodiment described below, the same reference numerals are given in the drawings to the configurations common to each of the above embodiments, and the description thereof will be omitted. In this ninth embodiment, the positions of the strong anchoring alignment film 16 and the weak anchoring alignment film 17 are interchanged with those of the first embodiment.
20A and 20B are cross-sectional views showing a schematic configuration of the liquid crystal display shown as the ninth embodiment, in which FIG. 20A is a state in which an electric field is not applied, and FIG. 20B is a state in which an electric field is applied. In the ninth embodiment, the substrate (first substrate) 13B is located on the backlight 12 side, and the substrate (second substrate) 13A is located on the side away from the backlight unit 12.

The polarizing plate (first polarizing plate) 14B is provided on the side of the substrate 13B arranged on the backlight unit 12 side facing the backlight unit 12.
The polarizing plate (second polarizing plate) 14A is provided on the side opposite to the backlight unit 12 in the substrate 13A arranged on the side separated from the backlight unit 12.
These polarizing plates 14A and 14B are arranged so that their transmission axis directions are orthogonal to each other. For example, the transmission axis direction of one polarizing plate 14B is set to the direction Y, and the transmission axis direction of the other polarizing plate 14A is set to the direction X, respectively.

The drive electrode layer 15 is provided on the opposite side of the backlight unit 12 in the substrate 13B on the backlight unit 12 side.

The strong anchoring alignment film (second alignment film) 16 is formed on the side of the substrate 13A on the side separated from the backlight unit 12 on the side facing the backlight unit 12. The initial orientation direction of the strong anchoring alignment film 16 is set so that the long axis direction of the positive liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincides with the direction X.
The weak anchoring alignment film (first alignment film) 17 is formed on the substrate 13B on the backlight unit 12 side on the opposite side of the backlight unit 12. The initial orientation direction of the weak anchoring alignment film 17 is set so that the long axis direction of the liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincides with the direction Y.

As shown in FIG. 20A, in the liquid crystal layer 18, in a state where the electric field E is not applied, the positive type liquid crystal molecules Lp are weakly anchored from the strong anchoring alignment film 16 side by adding a chiral agent. The initial orientation state is twisted spirally toward the alignment film 17 side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Lp are oriented along the orientation treatment direction (direction X) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 20A, on the weak anchoring alignment film 17 side, the positive type is formed in the driving electrode layer 15 between the electrode wires 20 and 20 adjacent to each other in a state where the electric field E is not applied. The liquid crystal molecule Lp of No. 1 is oriented along the orientation treatment direction (direction Y) on the weak anchoring alignment film 17 side.

In such a configuration, when the electric field E is not applied, as shown in FIG. 20A, the light passing through the polarizing plate 14B from the backlight unit 12 side is guided into the liquid crystal layer 18, and further, the liquid crystal display. Since the plane of polarization changes along the spiral distribution in the orientation direction of the liquid crystal molecules Lp in the layer 18, the polarizing plate 14A on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14B is transmitted.
Further, as shown in FIG. 20B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of the Lp in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Lp of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction X in FIG. 20) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14B from the backlight unit 12 side reaches the polarizing plate 14A with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14A is orthogonal to the polarizing plate 14B, the light is absorbed by the polarizing plate 14A.

When the application of the electric field E is stopped from the state where the electric field E is applied, the orientation direction of the liquid crystal molecule Lp is spiral as shown in FIG. 20 (a) due to the restoring force (elastic force) applied by the chiral agent. The light that has passed through the polarizing plate 14B passes through the polarizing plate 14A on the opposite side in order to return to the initial orientation state of the above.

As described above, in the ninth embodiment, it is configured as a normally white type as in the seventh and eighth embodiments.
Further, as described with reference to FIG. 18B, the electric field E is generated substantially radially from the electrode wire 20. Therefore, the electric field E acts so as to rise closer to the electrode wire 20 in parallel with the substrate 13B and to rise in the vertical direction as the distance from the electrode wire 20 increases. Here, in the ninth embodiment, the weak anchoring alignment film 17 in which the orientation direction of the liquid crystal molecule Lp is displaced is formed on the electrode wire 20 side. Therefore, as compared with the case where the weak anchoring alignment film 17 is formed at a position away from the electrode wire 20, the liquid crystal molecule Lp is less likely to be displaced so as to be tilted in the vertical direction.
The above effects are synergistic, and it is possible to provide a liquid crystal panel 11 that is more naturally reflected by the human eye than in the first and seventh embodiments.
Needless to say, the ninth embodiment has the same effect as the first and seventh embodiments.

[10th Embodiment]
Next, a tenth embodiment of the liquid crystal display element according to the present invention will be described. In the tenth embodiment described below, the same reference numerals are given in the drawings to the configurations common to each of the above embodiments, and the description thereof will be omitted. In the tenth embodiment, the positions of the strong anchoring alignment film 16 and the weak anchoring alignment film 17 are interchanged with respect to the fourth embodiment, as in the ninth embodiment.
21A and 21B are cross-sectional views showing schematic configurations of the liquid crystal display shown as the tenth embodiment, in which FIG. 21A is a state in which an electric field is not applied, and FIG. 21B is a state in which an electric field is applied. In the tenth embodiment, the substrate (first substrate) 13B is located on the backlight 12 side, and the substrate (second substrate) 13A is located on the side separated from the backlight unit 12.

Polarizing plate (first polarizing plate) 14B, polarizing plate (second polarizing plate) 14A, driving electrode layer 15, strong anchoring alignment film (second alignment film) 16, weak anchoring alignment film (first alignment film) The alignment film) 17 is provided in the same manner as in the ninth embodiment.
The polarizing plates 14A and 14B are arranged so that their transmission axis directions are orthogonal to each other. Here, unlike the ninth embodiment, the transmission axis direction of one polarizing plate 14B is set to the direction X, and the transmission axis direction of the other polarizing plate 14A is set to the direction Y, respectively.
Unlike the ninth embodiment, the strong anchoring alignment film 16 and the weak anchoring alignment film 17 substantially coincide with the negative type liquid crystal molecules Ln of the liquid crystal layer 18 in the major axis directions Y and X, respectively. The initial orientation direction is set so as to allow.

As shown in FIG. 21 (a), in the liquid crystal layer 18, in a state where the electric field E is not applied, the negative type liquid crystal molecules Ln are weakly anchored from the strong anchoring alignment film 16 side by adding a chiral agent. The initial orientation state is twisted spirally toward the alignment film 17 side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Ln are oriented along the orientation treatment direction (direction Y) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 21A, on the weak anchoring alignment film 17 side, the negative type is formed in the driving electrode layer 15 between the electrode wires 20 and 20 adjacent to each other in a state where the electric field E is not applied. The liquid crystal molecule Ln of No. 1 is oriented along the orientation treatment direction (direction X) on the weak anchoring alignment film 17 side.

In such a configuration, when the electric field E is not applied, as shown in FIG. 21A, the light passing through the polarizing plate 14B from the backlight unit 12 side is guided into the liquid crystal layer 18, and further, the liquid crystal display. Since the plane of polarization changes along the spiral distribution in the orientation direction of the liquid crystal molecules Ln in the layer 18, the polarizing plate 14A on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14B is transmitted.
Further, as shown in FIG. 21B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of Ln in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Ln of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction Y in FIG. 21) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14B from the backlight unit 12 side reaches the polarizing plate 14A with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14A is orthogonal to the polarizing plate 14B, the light is absorbed by the polarizing plate 14A.

When the application of the electric field E is stopped from the state in which the electric field E is applied, the liquid crystal molecules Ln of the liquid crystal layer 18 are oriented in the orientation direction of the liquid crystal molecules Ln due to the restoring force (elastic force) applied by the chiral agent (FIG. 21). In order to return to the spiral initial orientation state as shown in a), the light that has passed through the polarizing plate 14B passes through the polarizing plate 14A on the opposite side.

As described above, in the tenth embodiment, it is configured as a normally white type as in the seventh to ninth embodiments.
Further, since the weak anchoring alignment film 17 in which the orientation direction of the liquid crystal molecule Ln is displaced is formed on the electrode line 20 side and the liquid crystal molecule Ln is a negative type, each of the eighth and ninth embodiments described above. As described above, the liquid crystal molecules Ln are less likely to be displaced so as to be tilted in the vertical direction.
The above effects are synergistic, and it is possible to provide a liquid crystal panel 11 that is more naturally reflected by the human eye than the seventh to ninth embodiments.
Needless to say, the tenth embodiment has the same effect as the fourth embodiment.

[11th Embodiment]
Next, the eleventh embodiment of the liquid crystal display element according to the present invention will be described. In the eleventh embodiment described below, the same reference numerals are given in the drawings to the configurations common to the above-described embodiments, and the description thereof will be omitted. The eleventh embodiment has a structure in which the liquid crystal panel 11 of the seventh embodiment is inverted in the vertical direction.
FIG. 22 is a cross-sectional view showing a schematic configuration of the liquid crystal display shown as the eleventh embodiment, in which (a) is a state in which an electric field is not applied and (b) is a state in which an electric field is applied. In the eleventh embodiment, the substrate (first substrate) 13B is located on the backlight 12 side, and the substrate (second substrate) 13A is located on the side away from the backlight unit 12.

The polarizing plate (first polarizing plate) 14B is provided on the side of the substrate 13B arranged on the backlight unit 12 side facing the backlight unit 12.
The polarizing plate (second polarizing plate) 14A is provided on the side opposite to the backlight unit 12 in the substrate 13A arranged on the side separated from the backlight unit 12.
These polarizing plates 14A and 14B are arranged so that their transmission axis directions are orthogonal to each other. For example, the transmission axis direction of one polarizing plate 14B is set to the direction Y, and the transmission axis direction of the other polarizing plate 14A is set to the direction X, respectively.

The drive electrode layer 15 is provided on the side of the substrate 13A on the side separated from the backlight unit 12 on the side facing the backlight unit 12.

The strong anchoring alignment film (second alignment film) 16 is formed on the side of the substrate 13A on the side separated from the backlight unit 12 on the side facing the backlight unit 12. The initial orientation direction of the strong anchoring alignment film 16 is set so that the long axis direction of the positive liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincides with the direction X.
The weak anchoring alignment film (first alignment film) 17 is formed on the substrate 13B on the backlight unit 12 side on the opposite side to the backlight unit 12. The initial orientation direction of the weak anchoring alignment film 17 is set so that the long axis direction of the liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincides with the direction Y.

As shown in FIG. 22A, in the liquid crystal layer 18, in a state where the electric field E is not applied, the positive type liquid crystal molecules Lp are weakly anchored from the strong anchoring alignment film 16 side by adding a chiral agent. The initial orientation state is twisted spirally toward the alignment film 17 side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Lp are oriented along the orientation treatment direction (direction X) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 22A, on the weak anchoring alignment film 17 side, the positive type is formed in the driving electrode layer 15 between the electrode wires 20 and 20 adjacent to each other in a state where the electric field E is not applied. The liquid crystal molecule Lp of No. 1 is oriented along the orientation treatment direction (direction Y) on the weak anchoring alignment film 17 side.

In such a configuration, when the electric field E is not applied, as shown in FIG. 22A, the light passing through the polarizing plate 14B from the backlight unit 12 side is the orientation direction of the liquid crystal molecules Lp in the liquid crystal layer 18. Since the plane of polarization changes along the spiral distribution of the above, the polarizing plate 14A on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14B is transmitted.
Further, as shown in FIG. 22B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of the Lp in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Lp of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction X in FIG. 22) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14B from the backlight unit 12 side reaches the polarizing plate 14A with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14A is orthogonal to the polarizing plate 14B, the light is absorbed by the polarizing plate 14A.

When the application of the electric field E is stopped from the state where the electric field E is applied, the orientation direction of the liquid crystal molecule Lp is spiral as shown in FIG. 22 (a) due to the restoring force (elastic force) applied by the chiral agent. The light that has passed through the polarizing plate 14B passes through the polarizing plate 14A on the opposite side in order to return to the initial orientation state of the above.

Needless to say, the eleventh embodiment has the same effect as the seventh embodiment.

[12th Embodiment]
Next, a twelfth embodiment of the liquid crystal display element according to the present invention will be described. In the twelfth embodiment described below, the same reference numerals are given in the drawings to the configurations common to the above-described embodiments, and the description thereof will be omitted. The twelfth embodiment has a structure in which the liquid crystal panel 11 of the eighth embodiment is inverted in the vertical direction.
FIG. 23 is a cross-sectional view showing a schematic configuration of the liquid crystal display shown as the twelfth embodiment, (a) in a state where an electric field is not applied, and (b) in a state where an electric field is applied. In the twelfth embodiment, the substrate (first substrate) 13B is located on the backlight 12 side, and the substrate (second substrate) 13A is located on the side separated from the backlight unit 12.

Polarizing plate (first polarizing plate) 14B, polarizing plate (second polarizing plate) 14A, driving electrode layer 15, strong anchoring alignment film (second alignment film) 16, weak anchoring alignment film (first alignment film) The alignment film) 17 is provided in the same manner as in the eleventh embodiment.
The polarizing plates 14A and 14B are arranged so that their transmission axis directions are orthogonal to each other. Here, unlike the eleventh embodiment, the transmission axis direction of one polarizing plate 14B is set to the direction X, and the transmission axis direction of the other polarizing plate 14A is set to the direction Y, respectively.
Unlike the eleventh embodiment, the strong anchoring alignment film 16 and the weak anchoring alignment film 17 substantially coincide with the negative type liquid crystal molecules Ln of the liquid crystal layer 18 in the major axis directions Y and X, respectively. The initial orientation direction is set so as to allow.

As shown in FIG. 23A, in the liquid crystal layer 18, in a state where the electric field E is not applied, the negative type liquid crystal molecules Ln are weakly anchored from the strong anchoring alignment film 16 side by adding a chiral agent. The initial orientation state is twisted spirally toward the alignment film 17 side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Ln are oriented along the orientation treatment direction (direction Y) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 23A, on the weak anchoring alignment film 17 side, the negative type is formed in the driving electrode layer 15 between the electrode wires 20 and 20 adjacent to each other in a state where the electric field E is not applied. The liquid crystal molecule Ln of No. 1 is oriented along the orientation treatment direction (direction X) on the weak anchoring alignment film 17 side.

In such a configuration, when the electric field E is not applied, as shown in FIG. 23A, the light passing through the polarizing plate 14B from the backlight unit 12 side is guided into the liquid crystal layer 18, and further, the liquid crystal display. Since the plane of polarization changes along the spiral distribution in the orientation direction of the liquid crystal molecules Ln in the layer 18, the polarizing plate 14A on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14B is transmitted.
Further, as shown in FIG. 23B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of Ln in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Ln of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction Y in FIG. 23) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14B from the backlight unit 12 side reaches the polarizing plate 14A with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14A is orthogonal to the polarizing plate 14B, the light is absorbed by the polarizing plate 14A.

When the application of the electric field E is stopped from the state where the electric field E is applied, the orientation direction of the liquid crystal molecule Ln is spiral as shown in FIG. 23 (a) due to the restoring force (elastic force) applied by the chiral agent. The light that has passed through the polarizing plate 14B passes through the polarizing plate 14A on the opposite side in order to return to the initial orientation state of the above.

Needless to say, the twelfth embodiment has the same effect as the eighth embodiment.

[13th Embodiment]
Next, a thirteenth embodiment of the liquid crystal display element according to the present invention will be described. In the thirteenth embodiment described below, the same reference numerals are given in the drawings to the configurations common to each of the above embodiments, and the description thereof will be omitted. The thirteenth embodiment has a structure in which the liquid crystal panel 11 of the ninth embodiment is inverted in the vertical direction.
FIG. 24 is a cross-sectional view showing a schematic configuration of the liquid crystal display shown as the thirteenth embodiment, (a) in a state where an electric field is not applied, and (b) in a state where an electric field is applied. In the thirteenth embodiment, the substrate (first substrate) 13B is located on the side separated from the backlight 12, and the substrate (second substrate) 13A is located on the backlight unit 12 side.

The polarizing plate (second polarizing plate) 14A is provided on the side of the substrate 13A arranged on the backlight unit 12 side facing the backlight unit 12.
The polarizing plate (first polarizing plate) 14B is provided on the side opposite to the backlight unit 12 in the substrate 13B arranged on the side separated from the backlight unit 12.
These polarizing plates 14A and 14B are arranged so that their transmission axis directions are orthogonal to each other. For example, the transmission axis direction of one polarizing plate 14B is set to the direction Y, and the transmission axis direction of the other polarizing plate 14A is set to the direction X, respectively.

The drive electrode layer 15 is provided on the side of the substrate 13B on the side separated from the backlight unit 12 on the side facing the backlight unit 12.

The strong anchoring alignment film (second alignment film) 16 is formed on the substrate 13A on the backlight unit 12 side on the opposite side to the backlight unit 12. The initial orientation direction of the strong anchoring alignment film 16 is set so that the long axis direction of the positive liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincides with the direction X.
The weak anchoring alignment film (first alignment film) 17 is formed on the side of the substrate 13B on the side separated from the backlight unit 12 on the side facing the backlight unit 12. The initial orientation direction of the weak anchoring alignment film 17 is set so that the long axis direction of the liquid crystal molecules Lp of the liquid crystal layer 18 substantially coincides with the direction Y.

As shown in FIG. 24A, in the liquid crystal layer 18, in a state where the electric field E is not applied, the positive type liquid crystal molecules Lp are weakly anchored from the strong anchoring alignment film 16 side by adding a chiral agent. The initial orientation state is twisted spirally toward the alignment film 17 side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Lp are oriented along the orientation treatment direction (direction X) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 24A, on the weak anchoring alignment film 17 side, the positive type is formed in the driving electrode layer 15 between the electrode wires 20 and 20 adjacent to each other in a state where the electric field E is not applied. The liquid crystal molecule Lp of No. 1 is oriented along the orientation treatment direction (direction Y) on the weak anchoring alignment film 17 side.

In such a configuration, when the electric field E is not applied, as shown in FIG. 24A, the light passing through the polarizing plate 14A from the backlight unit 12 side is the orientation direction of the liquid crystal molecules Lp in the liquid crystal layer 18. Since the plane of polarization changes along the spiral distribution of the above, the polarizing plate 14B on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14A is transmitted.
Further, as shown in FIG. 24B, when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of the Lp in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Lp of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction X in FIG. 24) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14A from the backlight unit 12 side reaches the polarizing plate 14B with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14B is orthogonal to the polarizing plate 14A, the light is absorbed by the polarizing plate 14B.

When the application of the electric field E is stopped from the state where the electric field E is applied, the orientation direction of the liquid crystal molecule Lp is spiral as shown in FIG. 24 (a) due to the restoring force (elastic force) applied by the chiral agent. The light that has passed through the polarizing plate 14A passes through the polarizing plate 14B on the opposite side in order to return to the initial orientation state of the above.

Needless to say, the thirteenth embodiment has the same effect as the ninth embodiment.

[14th Embodiment]
Next, a fourteenth embodiment of the liquid crystal display element according to the present invention will be described. In the fourteenth embodiment described below, the same reference numerals are given in the drawings to the configurations common to each of the above embodiments, and the description thereof will be omitted. The 14th embodiment has a structure in which the liquid crystal panel 11 of the 10th embodiment is inverted in the vertical direction.
FIG. 25 is a cross-sectional view showing a schematic configuration of the liquid crystal display shown as the 14th embodiment, (a) in a state where an electric field is not applied, and (b) in a state where an electric field is applied. In the 14th embodiment, the substrate (second substrate) 13A is located on the backlight 12 side, and the substrate (first substrate) 13B is located on the side separated from the backlight unit 12.

Polarizing plate (first polarizing plate) 14B, polarizing plate (second polarizing plate) 14A, driving electrode layer 15, strong anchoring alignment film (second alignment film) 16, weak anchoring alignment film (first alignment film) The alignment film) 17 is provided in the same manner as in the thirteenth embodiment.
The polarizing plates 14A and 14B are arranged so that their transmission axis directions are orthogonal to each other. Here, unlike the thirteenth embodiment, the transmission axis direction of one polarizing plate 14B is set to the direction X, and the transmission axis direction of the other polarizing plate 14A is set to the direction Y, respectively.
Unlike the thirteenth embodiment, the strong anchoring alignment film 16 and the weak anchoring alignment film 17 substantially coincide with the negative type liquid crystal molecules Ln of the liquid crystal layer 18 in the major axis directions Y and X, respectively. The initial orientation direction is set so as to allow.

As shown in FIG. 25 (a), in the liquid crystal layer 18, in a state where the electric field E is not applied, the negative type liquid crystal molecules Ln are weakly anchored from the strong anchoring alignment film 16 side by adding a chiral agent. The initial orientation state is twisted spirally toward the alignment film 17 side. In this state, on the strong anchoring alignment film 16 side, the liquid crystal molecules Ln are oriented along the orientation treatment direction (direction Y) of the strong anchoring alignment film 16. On the other hand, as shown in FIG. 25 (a), on the weak anchoring alignment film 17 side, the negative type is applied between the electrode wires 20 and 20 adjacent to each other in the drive electrode layer 15 in a state where the electric field E is not applied. The liquid crystal molecule Ln of No. 1 is oriented along the orientation treatment direction (direction X) on the weak anchoring alignment film 17 side.

In such a configuration, when the electric field E is not applied, as shown in FIG. 25 (a), the light passing through the polarizing plate 14A from the backlight unit 12 side is guided into the liquid crystal layer 18, and further, the liquid crystal display. Since the plane of polarization changes along the spiral distribution in the orientation direction of the liquid crystal molecules Ln in the layer 18, the polarizing plate 14B on the opposite side whose transmission axis direction is orthogonal to the polarizing plate 14A is transmitted.
Further, as shown in FIG. 25 (b), when a predetermined electric field E equal to or larger than the threshold value is applied to the liquid crystal panel 11, the liquid crystal molecules in the vicinity of the weak anchoring alignment film 17 increase as the magnitude of the applied electric field E increases. The amount of displacement of Ln in the orientation direction with respect to the initial orientation direction gradually increases. When the intensity of the applied electric field E reaches a certain value, the liquid crystal molecules Ln of the liquid crystal layer 18 are in a uniformly oriented state along the orientation processing direction (direction Y in FIG. 25) in the strong anchoring alignment film 16. Transfer to. As a result, the light that has passed through the polarizing plate 14A from the backlight unit 12 side reaches the polarizing plate 14B with the polarization plane unchanged. Here, since the transmission axis direction of the polarizing plate 14B is orthogonal to the polarizing plate 14A, the light is absorbed by the polarizing plate 14B.

When the application of the electric field E is stopped from the state in which the electric field E is applied, the liquid crystal molecules Ln of the liquid crystal layer 18 are oriented in the orientation direction of the liquid crystal molecules Ln due to the restoring force (elastic force) applied by the chiral agent (FIG. 25). In order to return to the spiral initial orientation state as shown in a), the light that has passed through the polarizing plate 14A passes through the polarizing plate 14B on the opposite side.

Needless to say, the 14th embodiment has the same effect as the 10th embodiment.

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto.

[First Example]
In the first embodiment, a liquid crystal panel was manufactured based on the configuration of the seventh embodiment described with reference to FIG. More specifically, the substrate 13A on which a comb-shaped electrode wire 20 (thickness: about 55 nm, electrode width L / distance between electrodes S = 4 μm / 10 μm) made of indium tin oxide (ITO) is formed (this implementation). The electrode substrate in the example) and the substrate 13B (opposing substrate in the present embodiment) were laminated so as to face each other, and a liquid crystal panel 11 was manufactured in which the gaps were filled with liquid crystal.

A PHMA brush was polymerized as an alignment film on the facing substrate of the liquid crystal panel 11. PHMA brush polymerization was carried out by surface-initiated ATRP.
More specifically, first, after ultrasonically cleaning the substrate by 15 minutes with acetone and chloroform, nitrogen gas is dried sprayed with, was followed UV-O ₃ treatment for 15 minutes. At this stage, the region where the polymer brush is not formed, that is, the portion to which the sealing material is attached when the electrode substrate and the facing substrate are later bonded to each other, is protected by masking tape.

Next, a solution prepared by mixing 0.05 g of 2-bromo-2-methyl-N- (3- (triethoxysilyl) propyl) propanamide (BPA), 4.7 g of ethanol, and 0.25 g of aqueous ammonia was prepared. , The starting material was prepared and immersed in this solution overnight with the opposing substrate shielded from light, and the starting material was fixed to the surface of the opposing substrate. Then, the opposing substrate was ultrasonically cleaned with acetone for 10 minutes and dried by spraying nitrogen gas. The PHMA brush is a polymerization solution (monomer: hexyl methacrylate (HMA) / 29.74 g / 174.7 mmol) in which a facing substrate on which BPA is immobilized is freeze-deaerated, and a starting material: ethyl-2-bromoisobuty is used. Rate (EBIB) / 68.7 mg / 0.35 mmol, catalyst: copper bromide (CuBr) / 152.2 mg / 1.06 mmol, ligand: N, N, N', N'', N''-pentamethyldiethylenetriamine It was formed by immersing in (PMDETA) /243.8 mg / 1.41 mmol, solvent: anisole / 29.97 g / 277 mmol), heating at 70 ° C. for 7 hours, and polymerizing.

As a result of measuring the free polymer in the same batch by gel permeation chromatography, the molecular weight and the molecular weight distribution of the polymerized PHMA brush were estimated to be Mn = 88,900 and Mw / Mn = 1.74, respectively. The film thickness h of the PHMA brush was determined to be 18.0 nm based on the X-ray reflectance measurement (Ultima IV manufactured by Rigaku Corporation). Also, the graft density σ of the PHMA brush is σ = ρhNA / M (ρ: bulk) under the assumption that the density of the polymer brush is equal to the polymer density of the bulk ( ^{using 1.00 g / cm 3 as the density of PHMA).} It was estimated ^{to be 0.12 chains / nm 2} from the relational expression of polymer density, h: film thickness of polymer brush, NA: number of avocadro, M: molecular weight of polymer brush).

A photospacer having a height of 6 μm was formed on the electrode substrate side of the liquid crystal panel 11, and then a polyimide (JALS-16470 manufactured by JSR Corporation) was formed as an alignment film. The surface of the polyimide alignment film was subjected to a rubbing treatment.
The rubbing treatment was performed so that when the electrode substrate and the opposing substrate were bonded together, the angle between the rubbing direction of the electrode substrate and the comb tooth electrode was 90 °.

The electrode substrate and the opposing substrate were bonded to each other via a sealing material, and a seal hardening treatment was performed at 120 ° C. for 2 hours in a nitrogen atmosphere while pressurizing to prepare an empty cell. Then, by the vacuum injection method, nematic liquid crystal (JNC Corporation, JC-5051LA, positive type, nematic / isotropic transition temperature: NI point 112.7 ° C., refractive index anisotropy: Δn = 0.081, chiral After injecting (pitch 24 μm) into an empty cell, the injection port was sealed with a UV curable sealing material. In the liquid crystal panel 11, as shown in FIG. 18, the substrate 13A (electrode substrate) is arranged on the lower side, that is, the backlight unit 12 side, and the substrate 13B (opposing substrate) is arranged on the upper side.

Next, the policy for determining the height of the photo spacer will be described. When no electric field is applied to the liquid crystal panel 11, the orientation of the liquid crystal near the polyimide interface is fixed in the rubbing direction, and the liquid crystal at the PHMA brush interface is oriented in a direction twisted 90 degrees from the rubbing direction due to the effect of the chiral agent. The orientation state of the liquid crystal in this case is the same as the orientation state when no voltage is applied to the TN type liquid crystal display, and in order to maximize the transmission T when the voltage is applied to the liquid crystal panel, the above equation (1) is used. The condition that takes the maximum value, that is, u = 2Δnd / λ (Δn: liquid crystal dielectric anisotropy, d: cell gap, λ: wavelength of light) is √3, that is, the cell thickness that satisfies the first minimum condition. It is necessary to obtain a certain 6 μm. Therefore, 6 μm was selected as the height of the photo spacer.
At this time, the twist pitch P of the liquid crystal is 4d (24 μm), which satisfies the Morgan condition. Therefore, the linearly polarized light incident parallel to or perpendicular to the optical axis of the liquid crystal panel keeps the linearly polarized state. It is expected that the plane of polarization will rotate and exhibit optical rotation.
Further, when an electric field is applied to the liquid crystal panel, the liquid crystal at the PHMA brush interface rotates in a direction parallel to the electric field, so that it is assumed that the liquid crystal is homogenically oriented from the electrode substrate to the opposing substrate. At this time, the linearly polarized light incident parallel to or perpendicular to the optical axis of the liquid crystal panel is transmitted while maintaining the linearly polarized state. Therefore, when the polarizing plates 14A and 14B are arranged on the cross Nicol, the two polarizing plates cannot pass through the polarizing plates, so that the liquid crystal panel can be configured as a normally white type.

[Observation with a polarizing microscope]
The liquid crystal panel of the first embodiment manufactured as described above was observed with a polarizing microscope. As the polarizing microscope, BX50P manufactured by Olympus Corporation was used. In the polarizing microscope, it was confirmed that the liquid crystal was uniformly spirally oriented from the electrode substrate to the opposing substrate in the state where no electric field was applied.

Next, the first embodiment was annealed at 120 ° C. for 10 minutes to prepare an experimental body. The polarizing plate 14A was attached to the substrate 13A (electrode substrate) located on the lower side of this experimental body. A polarizing plate 14B is rotatably attached to the substrate 13B (opposing substrate) located on the upper side in a horizontal plane, and the polarizing plate 14B is rotated to form the angle and transparency of the two polarizing plates 14A and 14B in the transmission axis direction. The relationship between the light states was observed. More specifically, as an experimental body, one manufactured so that the height of the photo spacer was 6.1 μm, the twist angle of the orientation state of the liquid crystal molecules was 91 °, and Δnd was 488 μm was used.

FIG. 26 is the result of the above observation. The horizontal axis is the angle formed by the two polarizing plates 14A and 14B in the transmission axis direction, and the vertical axis is the amount of transmitted light.
When the angle between the transmission axis directions is around 90 °, which is the twist angle of the orientation state of the liquid crystal molecules, the amount of transmitted light is the largest. That is, linearly polarized light incident parallel to or perpendicular to the optical axis of the liquid crystal panel causes the plane of polarization to rotate to exhibit optical rotation, and as a result, polarized light located on the upper side and whose transmission axis direction is orthogonal to the polarizing plate 14A. It was observed to pass through the plate 14B.
On the contrary, when the transmission axis directions of the two polarizing plates 14A and 14B are parallel to each other, that is, when the angles between the transmission axis directions are around 0 ° and 180 °, the amount of transmitted light is the smallest. That is, linearly polarized light incident parallel to or perpendicular to the optical axis of the liquid crystal panel causes the plane of polarization to rotate to exhibit optical rotation, and as a result, polarized light located on the upper side and whose transmission axis direction is parallel to the polarizing plate 14A. It was observed that it was absorbed by the plate 14B.

27 (a) shows a state in which the upper and lower polarizing plates 14A and 14B are not provided, and FIG. 27 (b) shows a state in which the upper and lower polarizing plates 14A and 14B are provided and the angle between these transmission axis directions is 0 °. (C) is a photograph of the observation result in a state where the angle between the transmission axis directions is 90 °. It can be confirmed that FIG. 27 (c) transmits light and is displayed brightly in the same manner as in FIG. 27 (a).

[First Comparative Example]
Next, the relationship between the applied voltage, the transmittance, and the response speed was observed with respect to the first embodiment. For this measurement, an LCD-5200 manufactured by Otsuka Electronics Co., Ltd. was used. A first comparative example was produced as a comparison target in this observation. In the first comparative example, in the structure of the thirteenth embodiment shown as FIG. 24, the chiral agent is not added to the liquid crystal layer 18, and the transmission axis direction of each polarizing plate and the orientation direction of each alignment film Those provided so as to be orthogonal to the direction shown in FIG. 24 were used. That is, in the first comparative example, when no voltage is applied, the liquid crystal molecules Lp are oriented in parallel with each other because the chiral agent is not contained, and the two polarizing plates are oriented in the transmission axis direction. Since they are provided so as to be orthogonal to each other, the display becomes dark when no voltage is applied, and the display is configured as a normally black type. When a voltage is applied, the liquid crystal molecules Lp are oriented as shown in FIG. 24A and are displayed brightly.

[Observation of the relationship between applied voltage and transmittance]
First, the experimental results regarding the relationship between the applied voltage and the transmittance will be described. Prior to this experiment, each of the substrate 13A (electrode substrate) and the substrate 13B (opposing substrate) had the same form as the liquid crystal panel shown in FIG. 18A with respect to the first embodiment. Polarizing plates 14A and 14B were attached. Here, in the polarizing plates 14A and 14B, the transmission axis directions are orthogonal to each other, and the rubbing direction of the surface of the polyimide alignment film provided on the electrode substrate coincides with the transmission axis direction of the polarizing plate 14A located on the lower side. Adjusted to do. Regarding the first cited example, two polarizing plates were attached so as to have the same shape as the liquid crystal panel shown in FIG. 24 (b).

28 and 29 show the experimental results regarding voltage and transmittance in the first embodiment and the first comparative example, respectively. The horizontal axis of FIGS. 28 (a) and 29 (a) shows the voltage (V), and the vertical axis shows the transmittance (%). 28 (a) and 29 (a) show the relationship between the voltage and the transmittance under six kinds of atmospheric temperatures of -15 to 85 ° C.
FIG. 28B shows the values of V0, V50, V90, T0, and V90 / V10 at each temperature shown on the horizontal axis. The same applies to FIG. 29 (b), but some indicators are different from those of FIG. 28 (b). Of the above indexes, V indicates a voltage and T indicates a transmittance. The numbers after V and T indicate the transmittance values in FIGS. 28 (a) and 29 (a), which are normalized to values from 0 to 100. That is, V0 indicates the voltage value when the transmittance becomes the minimum value, that is, when it is displayed in the darkest value. V50 indicates a voltage value when the transmittance takes a value of (maximum value-minimum value) × 0.5. V100 indicates the voltage value when the transmittance becomes the maximum value, that is, when it is displayed brightest. T0 and T100 shown in FIG. 29B indicate the minimum value and the maximum value of the transmittance, respectively. The same applies to other indicators.
V90 / V10 represents the steepness of the displacement of the transmittance. As can be seen from FIGS. 28 (a) and 29 (a), in the vicinity of the portion where the transmittance shows the minimum value and the maximum value, the slope is gentler than that of the other portions, and the inclination is gentle with respect to the change in voltage. The transmittance is relatively gently displaced. That is, the value of V90 / V10 is used as the steepness in order to remove the noise caused by these gently displaced portions and extract only the portions having the same transmittance tendency between them.

The first embodiment is a normally white type liquid crystal panel. Also in FIG. 28 showing the experimental results of the first embodiment, the transmittance increases when no voltage is applied, and the transmittance decreases as the voltage increases.
The first comparative example is a normally black type liquid crystal panel. Also in FIG. 29 showing the experimental results of the first comparative example, the transmittance is low when no voltage is applied, and the transmittance is increased when a voltage is applied.
Further, according to T100 of FIG. 29 (b), in the first comparative example, the maximum value of the transmittance is approximately 14.00 or less, particularly at 45 ° C. or lower where the temperature can be the indoor temperature. On the other hand, according to FIG. 28A, the maximum value of the transmittance is larger than 14.00 at all temperatures. That is, it was confirmed that the first embodiment had a higher transmittance than the liquid crystal panel that did not use the chiral agent, which was the first comparative example.

[Observation of the relationship between the applied voltage and the response speed when the voltage is off]
Next, the experimental results regarding the relationship between the applied voltage and the response speed when the voltage is off will be described. 30 and 31 show the experimental results regarding the voltage and the response speed in the first embodiment and the first comparative example, respectively. The horizontal axis of FIGS. 30 and 31 indicates the voltage (V), and the vertical axis indicates the response speed (msec) when the voltage is applied.
Both the graph 30a in FIG. 30 and the graph 31a in FIG. 31 show the response speed when the liquid crystal panel changes from a dark state to a bright state. Further, both the graph 30b in FIG. 30 and the graph 31b in FIG. 31 show the response speed when the liquid crystal panel changes from a bright state to a dark state.

Using these graphs, in each of the first embodiment and the first cited example, the response speed when the voltage is off, that is, the voltage is once applied, the voltage is not applied, and the liquid crystal molecules are subjected to the electric field E. The time required to get rid of the influence of the above and return to the orientation of the liquid crystal molecules in the state where no voltage is applied is compared.
In the first embodiment, since the liquid crystal panel is a normally white type, the graph showing the response speed when the voltage changes from the applied state to the non-applied state shows that the liquid crystal panel changes from a dark state to a bright state at this time. Therefore, it is a graph 30a.
In the first comparative example, since it is a normally black type liquid crystal panel, the graph showing the response speed when the voltage changes from the applied state to the non-applied state shows that the liquid crystal panel changes from a bright state to a dark state at this time. Therefore, it is a graph 31b.
That is, here, the graph 30a and the graph 31b are compared.

In the graph 30a, the response speed is about 150 msec at the highest, whereas in the graph 31b, the response speed exceeds 600 msec. That is, in the first embodiment corresponding to the graph 30a, due to the action of the chiral agent, the voltage is once applied, the voltage is not applied, and the liquid crystal molecules are removed from the influence of the electric field E, and the voltage is not applied. It was confirmed that the time required to return to the orientation of the liquid crystal molecules in the state was reduced.

[Comparison of response speeds in other examples]
Next, the response speeds are compared using the other examples and cited examples shown in FIGS. 32 to 34.
FIG. 32A is an explanatory diagram of the second embodiment. The second embodiment is a liquid crystal panel based on the configuration of the ninth embodiment described with reference to FIG. 20. That is, a zero anchoring alignment film and electrodes are formed on the substrate on the backlight unit side, a strong anchoring alignment film is formed on the other substrate, and the liquid crystal layer contains a positive chiral agent.
Further, FIG. 32 (b) is an explanatory diagram of the second comparative example. In the second comparative example, as compared with the second embodiment, no chiral agent was added to the liquid crystal layer, and the transmission axis direction of each polarizing plate and the orientation direction of each alignment film were different from those of the second embodiment. Is a liquid crystal panel provided so as to be orthogonal to each other.

FIG. 33A is an explanatory diagram of the third embodiment. The third embodiment is a liquid crystal panel based on the configuration of the tenth embodiment described with reference to FIG. 21. That is, a zero anchoring alignment film and electrodes are formed on the substrate on the backlight unit side, a strong anchoring alignment film is formed on the other substrate, and the liquid crystal layer contains a negative chiral agent.
Further, FIG. 33 (b) is an explanatory diagram of the third comparative example. In the third comparative example, as compared with the third embodiment, no chiral agent was added to the liquid crystal layer, and the transmission axis direction of each polarizing plate and the orientation direction of each alignment film were the same as those of the third embodiment. Is a liquid crystal panel provided so as to be orthogonal to each other.

FIG. 34A is an explanatory diagram of the fourth embodiment. The fourth embodiment is a liquid crystal panel based on the configuration of the eighth embodiment described with reference to FIG. That is, a strong anchoring alignment film and electrodes are formed on the substrate on the backlight unit side, a zero anchoring alignment film is formed on the other substrate, and the liquid crystal layer contains a negative chiral agent.
Further, FIG. 34 (b) is an explanatory diagram of the fourth comparative example. In the fourth comparative example, as compared with the fourth embodiment, no chiral agent was added to the liquid crystal layer, and the transmission axis direction of each polarizing plate and the orientation direction of each alignment film were the same as those of the fourth embodiment. Is a liquid crystal panel provided so as to be orthogonal to each other.

A polarizing plate is attached to each embodiment so as to be a normally white type. Further, for each comparative example, a polarizing plate is attached so as to be a normally black type.

FIG. 35 shows the response speed comparison results of the second to fourth examples and the second to fourth comparative examples.
The item of "response speed (ON)" is the time in which the transmittance is darkened to about 10% of the transmittance when the voltage is not applied in the second to fourth embodiments. Further, in the second to fourth comparative examples, it is the time required for the transmittance to reach 90% of the maximum transmittance by applying a voltage so as to maximize the transmittance.
The item of "response speed (off)" is, in the second to fourth embodiments, the time from the voltage application operation until the voltage application is stopped and the transmittance returns to the initial transmittance. Further, in the second to fourth comparative examples, it is the time from applying the voltage so as to maximize the transmittance, and then stopping the application of the voltage until the transmittance reaches 10% of the maximum value.

The response speeds (off) of the second example and the second comparative example, the third example and the third comparative example, and the fourth example and the fourth comparative example having substantially the same structure were compared. ..
In each comparison, it was confirmed that in the examples, the speed was increased by 70% or more as compared with the comparative examples.

Although the preferred embodiments of the present invention have been described in detail above, various modifications and equal embodiments are possible from now on by a person having ordinary knowledge in the art.
Therefore, the scope of rights of the present invention is not limited to this, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the claims are also included in the present invention.

For example, in the above embodiment, specific forming methods for each of the strong anchoring alignment film 16 and the weak anchoring alignment film 17 have been illustrated, but the present invention is not limited to this. That is, if the strong anchoring alignment film 16 and the weak anchoring alignment film 17 have different orientation forcing forces for correcting the orientation directions of the liquid crystal molecules Lp and Ln when the electric field E is applied, the strong anchoring is performed. The alignment film 16 and the weak anchoring alignment film 17 may be formed by any other method or material, respectively.

Further, there are some chiral agents that induce a left-handed spiral and a right-handed spiral, and either of them may be used.

Further, in the first to sixth embodiments, the strong anchoring alignment film 16 is arranged on the backlight unit 12 side, and the weak anchoring alignment film 17 is arranged on the side away from the backlight unit 12. Not exclusively. As in the ninth to twelfth embodiments, the strong anchoring alignment film 16 may be arranged on the side separated from the backlight unit 12, and the weak anchoring alignment film 17 may be arranged on the backlight unit 12 side.

The drive electrode layer 15 is not limited to the backlight unit 12 side, and may be arranged on the opposite side as in the above 11th to 14th embodiments.

Further, in the first to sixth embodiments, the polarizing plate 14A and the polarizing plate 14B are arranged in parallel Nicols, and the transmission axis direction of the polarizing plate 14A is the orientation direction of the liquid crystal molecule L in a state where the electric field E is not applied. Although an example is shown in which the orientation treatment direction with respect to the strong anchoring alignment film 16 for regulating the above is the same as the orientation treatment direction of the polarizing plate 14A, the orientation of the liquid crystal molecule L in the state where the electric field E is not applied in the transmission axis direction of the polarizing plate 14A is shown. It may be orthogonal to the orientation processing direction with respect to the strong anchoring alignment film 16 for regulating the direction.

Further, in the first to sixth embodiments, the so-called normally black type liquid crystal panel 11 in which the display becomes dark when the voltage is not applied and becomes bright when the voltage is applied has been described, but the present invention is not limited to this. As in the 7th to 14th embodiments, the liquid crystal panel 11 may have a so-called normally white type structure in which the display is bright when the voltage is not applied and the display is dark when the voltage is applied.

2 Polymer brush 3 Polymer brush layer 4 Coexistence part 7 Geometric uneven structure 10 Liquid crystal display 11 Liquid crystal panel (liquid crystal display element)
11f Front surface 11r Back surface 12 Backlight unit 13A Substrate (second substrate)
13B board (first board)
14A polarizing plate (second polarizing plate)
14B polarizing plate (first polarizing plate)
15 Drive electrode layer 16 Strong anchoring alignment film (second alignment film)
17 Weak anchoring alignment film (first alignment film)
18 Liquid crystal layer 20 Electrode line 20a First inclined portion 20b Second inclined portion 21 Electrode line E Electric field L Liquid crystal molecule

Claims (14)

A light source that emits light and
The first substrate on which the first alignment film was formed and
A second substrate on which a second alignment film is formed, which is arranged so as to face the first alignment film at intervals.
A liquid crystal layer arranged between the first alignment film and the second alignment film and transmitting or blocking the light by driving liquid crystal molecules.
A drive electrode layer provided on either one of the first substrate and the second substrate and applying an electric field in a direction along the first substrate and the second substrate to the liquid crystal molecules is provided. ,
The liquid crystal layer is
In the state where the electric field is applied, the liquid crystal molecules are maintained in a state of being oriented in the preset initial orientation direction on the second alignment film side, and on the first alignment film side, the liquid crystal molecules of the liquid crystal molecules are maintained. The orientation direction changes from the initial orientation direction to the direction corresponding to the electric field in the plane parallel to the surface of the second substrate, and at the same time.
A chiral agent that restores the liquid crystal molecules to the initial orientation direction in a state where the electric field is not applied is added to the liquid crystal layer.
The second alignment film is arranged between the liquid crystal layer and the driving electrode layer.
The initial orientation direction of the second alignment film is parallel to the surface of the second substrate.
The initial orientation direction of the first alignment film is parallel to the surface of the first substrate and orthogonal to the initial orientation direction of the second alignment film.
The first alignment film has a smaller binding force that constrains the orientation direction of the liquid crystal molecules in the initial orientation direction when an electric field is applied than the second alignment film.
The first alignment film contains a polymer brush represented by the formula (1).
X is H or CH ₃ , m is a positive integer, and the glass transition temperature of the polymer brush is −5 ° C. or lower.
Further comprising an immobilization film between the first substrate and the first alignment film,
The immobilized membrane contains an alkoxysilane compound represented by the formula (2) and contains.
A liquid crystal display element ^{in which R 1} is selected from the alkyl groups C1 to C3, R ² is selected from the methyl group and the ethyl group, X is a halogen atom, and n is an integer of 3 to 10.

The liquid crystal layer according to claim 1, wherein the liquid crystal molecules are spirally arranged from the second alignment film side toward the first alignment film side in a state where the electric field is not applied. Liquid crystal display element. In the chiral agent, the initial orientation direction of the liquid crystal molecules on the first alignment film side is 90 ° with respect to the initial orientation direction of the liquid crystal molecules on the second alignment film side in a state where the electric field is not applied. The liquid crystal display element according to claim 1 or 2, which is added so as to twist. An orientation treatment direction for constraining the orientation direction of the liquid crystal molecules in the first alignment film to the initial orientation direction, and an orientation treatment direction for constraining the orientation direction of the liquid crystal molecules in the second alignment film. However, the liquid crystal display element according to any one of claims 1 to 3, wherein the liquid crystal display elements are orthogonal to each other. The liquid crystal display element according to any one of claims 1 to 3, wherein the orientation direction of the liquid crystal molecules in the vicinity of the first alignment film in a state where an electric field is not applied is determined by the twisting force of the chiral agent. .. The first polarizing plate provided on the first substrate side and
A second polarizing plate provided on the second substrate side is further provided.
The transmission axis direction of the first polarizing plate and the transmission axis direction of the second polarizing plate are parallel to each other, and the transmission axis direction of the first polarizing plate is the initial orientation in the second alignment film. The liquid crystal display element according to any one of claims 1 to 5 , which is parallel or orthogonal to the direction. The first polarizing plate provided on the first substrate side and
A second polarizing plate provided on the second substrate side is further provided.
The transmission axis direction of the first polarizing plate and the transmission axis direction of the second polarizing plate are orthogonal to each other, and the transmission axis direction of the first polarizing plate is the initial orientation direction of the second alignment film. The liquid crystal display element according to any one of claims 1 to 5 , which is parallel or orthogonal to the liquid crystal display element. With the electric field applied, the displacement angle of the liquid crystal molecule in the orientation direction with respect to the state in which the liquid crystal layer is oriented in the initial orientation direction from the second alignment film side toward the first alignment film side. The liquid crystal display element according to any one of claims 1 to 7 , wherein the amount of liquid crystal display element gradually increases. The initial stage of the liquid crystal molecule due to the electric field generated by applying a predetermined voltage between the liquid crystal molecule located on the first alignment film side and the liquid crystal molecule located on the second alignment film side. The liquid crystal display element according to claim 8 , wherein the difference in the displacement angle in the orientation direction with respect to the state oriented in the orientation direction is 0 ° or more and 90 ° or less. The liquid crystal display element according to any one of claims 1 to 9 , wherein a polymer brush is formed on the first substrate as the first alignment film. The drive electrode layer comprises a plurality of electrode wires arranged on the first substrate or the second substrate surface.
The invention according to any one of claims 1 to 10 , wherein the orientation direction of the liquid crystal molecules on the second substrate side is parallel or orthogonal to the continuous direction of the electrode lines when the electric field is not applied. Liquid crystal display element. The drive electrode layer comprises a plurality of electrode wires arranged on the first substrate or the second substrate surface.
The method according to any one of claims 1 to 10 , wherein the orientation direction of the liquid crystal molecules on the second substrate side is inclined with respect to the direction in which the electrode lines are continuous when the electric field is not applied. Liquid crystal display element. The liquid crystal display element according to any one of claims 1 to 12 , wherein the dielectric anisotropy of the liquid crystal molecule is negative. The liquid crystal display element according to any one of claims 1 to 12 , wherein the dielectric anisotropy of the liquid crystal molecule is positive.

Images