JP2003107244A - Liquid crystal polymer film and method for producing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a liquid crystal display device having a reflective polarizing plate on the incident side,
Provided is a liquid crystal polymer film which can perform bright and high-contrast display. A plurality of groove-shaped recesses are formed on one surface in parallel with each other, and one of the two wall surfaces facing each other of the groove-shaped recesses is formed on an inclined surface. The optically anisotropic transparent film 3 has a plurality of groove-shaped recesses 4 in which optically anisotropic refractive index in a direction parallel to the longitudinal direction of the groove-shaped recesses 4 is provided. Is provided with a liquid crystal polymer layer 5 having a refractive index larger than the refractive index of the liquid crystal polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal polymer film for improving the display quality of a liquid crystal display device having a reflective polarizing plate on the incident side and a method for manufacturing the same.

[0002]

2. Description of the Related Art A liquid crystal display device includes a pair of transparent substrates,
The liquid crystal element, which is provided with a liquid crystal layer that controls the polarization state of transmitted light according to an electric field applied between transparent electrodes provided on the inner surfaces of these substrates, sandwiches the incident light into linearly polarized light to form the liquid crystal. A polarizer for entering the device,
An analyzer for controlling transmission of light transmitted through the liquid crystal element according to its polarization state to obtain image light is arranged.

The polarizer disposed on the incident side of the liquid crystal element is an absorption polarizing plate having an absorption axis and a transmission axis in directions substantially orthogonal to each other, or a reflection axis and a transmission axis in directions substantially orthogonal to each other. A reflective polarizing plate having the above is used, and an absorption polarizing plate is generally used as an analyzer arranged on the emission side of the liquid crystal element.

[0004]

However, since the absorption polarizing plate transmits the light of the polarization component along the transmission axis of the incident light and absorbs the light of the polarization component along the absorption axis, it has a polarization degree of Is high, but the light transmittance is low.

Therefore, in the liquid crystal display device having the absorption polarizing plate on the incident side, the intensity of the linearly polarized light transmitted through the absorption polarizing plate is low and a bright display cannot be obtained.

On the other hand, the reflection polarizing plate transmits the light of the polarization component along the transmission axis of the incident light and reflects the light of the polarization component along the reflection axis. Since it is low, there is a light leakage that the light of the polarized component along the reflection axis is also transmitted to some extent.

Therefore, in the liquid crystal display device having the reflection polarizing plate on the incident side, the linearly polarized light which passes through the reflection polarizing plate and is incident on the liquid crystal element includes the leakage of the polarization component along the reflection axis. Since the light has a low degree of polarization, the display brightness is brighter than that of a liquid crystal display device in which the absorption polarizing plate is arranged on the incident surface of a liquid crystal element, but a display with good contrast cannot be obtained.

By the way, the reflection polarizing plate transmits the light of the polarization component along the transmission axis of the incident light and reflects the light of the polarization component along the reflection axis, so that it is reflected by the reflection polarizing plate. If the reflected light can be made incident on the reflective polarizing plate again by changing its polarization state, the intensity of the linearly polarized light that passes through the reflective polarizing plate and is incident on the liquid crystal element is further increased and the degree of polarization is sufficient. In addition, it is possible to make the liquid crystal display device having the reflection polarizing plate disposed on the incident side display bright and good contrast.

For that purpose, for example, a phase plate is arranged on the incident side of the reflective polarizing plate, and the light reflected by the reflective polarizing plate and incident on the phase plate is internally reflected by the phase plate, and It suffices to change the polarization state of light according to the phase difference of the phase plate and make it enter the reflection polarizing plate again.

However, by simply disposing the phase plate on the incident side of the reflective polarizing plate, most of the light reflected by the reflective polarizing plate will not be internally reflected by the phase plate, and this phase plate will not be reflected. Since the light is transmitted, there is almost no effect of changing the polarization state of the light reflected by the reflective polarizing plate and making it enter the reflective polarizing plate again.

According to the present invention, for light having two orthogonal polarization components, light of one polarization component is transmitted without being refracted, and light of the other polarization component is refracted at an emission angle larger than the incident angle. An object of the present invention is to provide a liquid crystal polymer film which is made transparent.

Further, according to the present invention, by interposing the reflective polarizing plate disposed on the incident side of the liquid crystal element and the phase plate disposed on the incident side of the reflective polarizing plate, the above The light reflected by the reflective polarizing plate is efficiently internally reflected by the phase plate, and the light whose polarization state is changed by the phase difference of the phase plate is transmitted through the reflective polarizing plate to be incident on the liquid crystal element. An object of the present invention is to provide a liquid crystal polymer film capable of causing a liquid crystal display device having a reflective polarizing plate on its side to perform bright display with good contrast, and a method for producing the liquid crystal polymer film.

[0013]

A liquid crystal polymer film of the present invention has a plurality of groove-shaped recesses formed on one surface thereof in parallel with each other, and at least one of two wall surfaces of the groove-shaped recesses facing each other. An optically isotropic transparent film whose wall surface is formed into an inclined surface and an optically anisotropic, groove-shaped recess provided in the plurality of groove-shaped recesses of the transparent film. And a liquid crystal polymer layer having a refractive index in a direction substantially parallel to the direction larger than that of the transparent film.

This liquid crystal polymer film allows light of a polarized component having an oscillating surface in a direction orthogonal to the lengthwise direction of the groove-like recess to pass without refraction, and one surface side provided with the liquid crystal polymer layer. Of the light incident from the, the light of the polarization component having a vibrating surface along the length direction of the groove-like recess,
By the interface between the liquid crystal polymer layer and the wall surface of the groove-shaped recess of the transparent film, the liquid crystal polymer layer is refracted in the direction in which the angle with respect to the normal line of the other surface of the transparent film increases, and is emitted to the other surface side of the transparent film. .

Therefore, the liquid crystal polymer film is
Between the reflective polarizing plate disposed on the incident side of the liquid crystal element and the phase plate disposed on the incident side of the reflective polarizing plate, one surface provided with the liquid crystal polymer layer is opposed to the reflective polarizing plate, The other surface of the transparent film is opposed to the phase plate, and the lengthwise direction of the plurality of groove-shaped recesses of the transparent film is made substantially parallel to the reflection axis of the reflection polarizing plate so as to be incident. Of the light, the light reflected by the reflective polarizing plate is efficiently internally reflected by the phase plate, and the light whose polarization state is changed by the phase difference of the phase plate is transmitted through the reflective polarizing plate and incident on the liquid crystal element. Therefore, the intensity of linearly polarized light that passes through the reflective polarizing plate and enters the liquid crystal element is increased, and the degree of polarization is also sufficient, so that the liquid crystal display device having the reflective polarizing plate on the incident side is bright and Ko It is possible to perform a good display of trust.

Further, in the method for producing a liquid crystal polymer film of the present invention, a plurality of groove-shaped recesses are formed in parallel on one surface, and at least one of the two wall surfaces of the groove-shaped recesses facing each other is formed. Polymer liquid crystal is filled in the plurality of groove-shaped recesses of the optically isotropic transparent film having the wall surface formed on the inclined surface, and the liquid crystal molecules are aligned in the lengthwise direction of the groove-shaped recesses with a molecular long axis. By orienting so as to align, the optically transparent anisotropic refractive index in the plurality of groove-shaped recesses of the transparent film in a direction substantially parallel to the lengthwise direction of the groove-shaped recesses is transparent. The present invention is characterized in that a liquid crystal polymer layer having a refractive index larger than that of the film is formed. According to this production method, the liquid crystal polymer film can be produced.

In the method for producing a liquid crystal polymer film of the present invention, in the liquid crystal polymer layer, the wall surfaces of the plurality of groove-shaped recesses of the transparent film are subjected to an alignment treatment along the length direction of the groove-shaped recesses. After that, it is preferable that the plurality of groove-shaped recesses be filled with a polymer liquid crystal to align the liquid crystal molecules in the direction of the alignment treatment, and then the polymer liquid crystal is polymerized.

In this case, the polymer liquid crystal filled in the plurality of groove-shaped recesses of the transparent film is heated to a temperature exhibiting an isotropic phase, and then gradually cooled to return to the nematic phase, whereby It is further preferable that the liquid crystal molecules of the molecular liquid crystal are aligned in the direction of the alignment treatment applied to the wall surface of the groove-shaped recess.

Further, in the method for producing a liquid crystal polymer film according to the present invention, the liquid crystal polymer layer is formed by filling a plurality of groove-shaped concave portions of the transparent film with a polymerized thermosoftening polymer liquid crystal, and The plate material is adhered to the outer surface of the molecular liquid crystal, and the plate material with respect to the transparent film is warmed to a temperature just before the polymer liquid crystal is softened to a state in which liquid crystal molecules can freely move, and The liquid crystal molecules of the polymer liquid crystal may be aligned in the shift direction of the plate material by shifting in one direction along the direction.

[0020]

1 is a side view showing an embodiment of a liquid crystal polymer film of the present invention.

The liquid crystal polymer film 1 of this example is
As shown in FIG. 1, a base film 2, a plurality of groove-shaped recesses 4 formed on one surface of the base film 2 in parallel with each other, and a transparent film 3 laminated on the base film 2; The liquid crystal polymer layer 5 is provided in each of the plurality of groove-shaped recesses 4.

The transparent film 3 is made of an optically isotropic transparent resin such as an acrylic resin, and the surface of the transparent film 3 facing the base film 2 is formed into a flat surface and the opposite side. A plurality of groove-shaped recesses 4 having a length over the entire width of the transparent film 3 are formed continuously over the entire surface of the transparent film 3 in the groove width direction.

The base film 2 is made of TAC.
The transparent film 3 is made of an optically isotropic transparent resin such as (triacetyl cellulose), and the transparent film 3 has the other surface (flat surface) adhered to the base film 2 so that it is on the base film 2. Are stacked on.

A plurality of groove-shaped recesses 4 formed on one surface of the transparent film 3 are respectively opposed to each other 2
At least one of the two wall surfaces 4a and 4b is
It is formed as an inclined surface that is inclined in a direction away from the normal line h toward one surface of the transparent film 3 with respect to the normal line h of the other surface of the transparent film 3 (a surface facing the base film 2). In this embodiment, one wall surface (wall surface on the right side in FIG. 1) 4a of the groove-shaped recess 4 is formed at an angle with respect to the normal line h of the other surface of the transparent film 3. θ1 is an inclined surface of 40 to 60 degrees, and the other wall surface (wall surface on the left side in FIG. 1) 4b is a surface having an acute angle of 0 to 10 degrees with respect to the normal line h.

That is, the plurality of groove-shaped recesses 4 have a shape in which one wall surface 4a is formed as an inclined surface and the other wall surface 4b is formed as a steep angle surface. One surface of No. 3 is an uneven surface having a sawtooth cross section.

Although the plurality of groove-shaped recesses 4 are greatly exaggerated in the drawing, the plurality of groove-shaped recesses 4 are 2
It is formed with an extremely small pitch of about 5 μm to 50 μm.

On the other hand, in the liquid crystal polymer layer 5 provided in each of the plurality of groove-shaped recesses 4 of the transparent film 3, the liquid crystal molecules are aligned so that the major axes of the molecules are aligned in the lengthwise direction of the groove-shaped recesses 4. It is made of polymer liquid crystal.

The liquid crystal polymer layer 5 is optically anisotropic because the liquid crystal molecules of the polymer liquid crystal are oriented so that the major axes of the molecules are aligned in the lengthwise direction of the groove-shaped recess 4. The refractive index in the direction along the alignment direction of the liquid crystal molecules is higher than the refractive index in the direction orthogonal to the alignment direction of the liquid crystal molecules.

The refractive index of the liquid crystal polymer layer 5 in the direction along the alignment direction of the liquid crystal molecules, that is, in the direction substantially parallel to the lengthwise direction of the groove-shaped recess 4 of the transparent film 3, is the transparent film 3. Which is larger than the refractive index of the liquid crystal molecules and is orthogonal to the alignment direction of the liquid crystal molecules, that is, the transparent film 3
The refractive index in the direction substantially orthogonal to the lengthwise direction of the groove-shaped recess 4 is the same as the refractive index of the transparent film 3.

The liquid crystal polymer layer 5 is flush with the open edges of the groove-shaped recesses 4 in the plurality of groove-shaped recesses 4 of the transparent film 3, and the outer surfaces of these liquid crystal polymer layers 5 are flush with each other. , The other surface of the transparent film 3 (flat surface)
It is filled so that it becomes a flat surface parallel to.

Next, a method for producing the liquid crystal polymer film 1 will be described. 2 and 3 show a first embodiment of the method for producing a liquid crystal polymer film of the present invention,
FIG. 2 is a side view of the step of producing a laminate of the base film 2 and the transparent film 3, and FIG. 3 is a side view of the step of forming the liquid crystal polymer layer 5 in the plurality of groove-shaped recesses 4 of the transparent film 3. is there.

The manufacturing method of this embodiment is a method of forming the liquid crystal polymer layer 5 by using a photopolymerizable polymer liquid crystal, and after manufacturing a laminate of the base film 2 and the transparent film 3, A plurality of groove-shaped recesses 4 in the transparent film 3
The inside is filled with a photopolymerizable polymer liquid crystal 5a, and the photopolymerizable polymer liquid crystal 5a is polymerized in a state in which liquid crystal molecules are aligned so that the long axes of the molecules are aligned in the longitudinal direction of the groove-shaped recess 4. Thus, the liquid crystal polymer layer 5 is formed.

First, the production of a laminate of the base film 2 and the transparent film 3 will be described. This laminate is formed to a depth corresponding to the thickness of the transparent film 3 as shown in FIG. And a die 6 having a recessed portion on the bottom surface in which sawtooth-shaped surfaces having a shape corresponding to the plurality of groove-shaped recesses 4 formed on one surface of the transparent film 3 are formed.
A photopolymerizable polymer material (for example, an acrylic resin material) 4a is poured into the inside, and a base film 2 having an adhesive treatment on one surface (the surface facing the transparent film 3) is superposed thereon and flattened. Manufactured by a method of forming the transparent film 3 by pressing the above to flatten the upper surface of the polymer material 4a, and then irradiating ultraviolet rays from above the base film 2 to polymerize the polymer material 4a. To do.

Next, the formation of the liquid crystal polymer layer 5 provided in each of the plurality of groove-shaped recesses 4 provided on one surface of the transparent film 3 will be described. The liquid crystal polymer layer 5 is formed by the following procedure. To form.

First, as shown in FIG. 3A, a supporting material 7 such as a glass plate is optically glued to the outer surface of the base film 2 which is adhered to the other surface (flat surface) of the transparent film 3. Wall surfaces 4 of the plurality of groove-shaped recesses 4 of the transparent film 3 in a state in which the laminated body of the base film 2 and the transparent film 3 is reinforced by the support material 7 by being attached with 8 or the like.
The a and 4b are subjected to an alignment treatment along the longitudinal direction of the groove-shaped recess 4.

In this alignment treatment, a horizontal aligning agent (not shown) is applied to the wall surfaces 4a and 4b of the plurality of groove-shaped recesses 4 of the transparent film 3 by a spin coating method and dried, and then the aligning agent The film surface is rubbed several times in the same direction along the lengthwise direction of the groove-shaped recess 4 with a rubbing cloth having fine fur.

The application of the aligning agent by the spin coating method allows the aligning agent to be applied to the wall surfaces 4a and 4b of the plurality of groove-shaped recesses 4 of the transparent film 3 in a uniform film thickness over the entire surfaces thereof. In addition, it is preferable that the laminated body reinforced by the support material 7 is fixed on the spinner in such a manner that the lengthwise directions of the plurality of groove-shaped recesses 4 of the transparent film 3 are aligned with the radial direction of the spinner.

Further, it is preferable to use a γ-butyrolactone solution of soluble polyimide which can be applied in a temperature range in which the transparent film 3 is not deformed as the aligning agent. In this case, the spinner is rotated at a rotation speed of 2500 rpm. After being rotated for about 30 seconds at about 80 ° C. after coating on the wall surfaces 4a, 4b of the plurality of groove-shaped recesses 4 of the transparent film 3.
It may be dried in the oven for about 1 hour.

Next, as shown in FIG. 3B, a liquid photopolymerizable polymer liquid crystal 5a is dropped on the transparent film 3,
The polymer liquid crystal 5a is filled in the plurality of groove-shaped recesses 4 of the transparent film 3 such that the outer surface thereof is flush with the open edge of the groove-shaped recess 4.

The photopolymerizable polymer liquid crystal 5a may be a liquid crystal which is liquid at room temperature or a liquid which is dissolved in a solvent such as cyclopentanone.

The filling of the polymer liquid crystals 5a dropped on the transparent film 3 into the plurality of groove-shaped recesses 4 is performed by allowing the polymer liquid crystals 5a to uniformly spread over the entire area of the groove-shaped recesses 4 by natural flow. By doing.

When the polymer liquid crystals 5a dissolved in a solvent are filled in the plurality of groove-shaped recesses 4, the solution is concentrated by an evaporator to increase the viscosity and dropped on the transparent film 3. The polymer liquid crystal 5a is shown in FIG.
It is also possible to push and smooth with a rod 9 indicated by an imaginary line (two-dot chain line) and fill the entire area of the plurality of groove-shaped recesses 4 of the transparent film 3 so as to be flush with the open edge thereof. In that case, the rod 9 is preferably made of a metal that does not contaminate the liquid crystal, for example, stainless steel. The moving direction of the rod 9 may be arbitrary.

As described above, when the liquid crystalline polymer liquid crystal 5a is filled in the plurality of groove-shaped recesses 4 of the transparent film 3, the liquid crystal molecules of the polymer liquid crystal 5a are wall surfaces 4a and 4b of the groove-shaped recess 4. The orientation is performed so that the long axes of the molecules are aligned in the direction of the orientation treatment performed on the substrate, that is, in the lengthwise direction of the groove-shaped recess 4.

Next, as shown in FIG. 3C, the polymer liquid crystal 5 filled in the plurality of groove-shaped recesses 4 of the transparent film 3 is filled.
On a, an orientation-treated film 10 made of a TAC film or the like having one surface rubbed several times in the same direction,
The orientation processing direction (rubbing direction) is the opposite direction (parallel and opposite direction) to the orientation processing direction applied to the wall surfaces 4a and 4b of the groove-shaped recess 4 along the length direction of the groove-shaped recess 4. And a transparent plate 11 such as a glass plate is provided on the orientation-treated film 10 so that the outer peripheral portion of the orientation-treated surface is in contact with the outer surface of the polymer liquid crystal 5a. The orientation-treated film 10 is formed by stacking them in a state of protruding to the periphery, and lightly pressing the outer peripheral portion of the transparent plate 11 with a frame-shaped pressing jig 12.
Is pressed against the upper surface of the polymer liquid crystal 5a.

When the polymer liquid crystal 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3 is dissolved in a solvent, the polymer liquid crystal 5a is heated in a vacuum oven heated to the evaporation temperature of the solvent. The solvent is removed, and then the alignment treatment film 10 is stacked on the polymer liquid crystal 5a.

Next, the polymer liquid crystal 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3 is heated in an oven (not shown) at a temperature at which the polymer liquid crystal 5a exhibits an isotropic phase (nematic-isolation). The polymer liquid crystal 5a is returned to the nematic phase by heating to a temperature above the tropic phase transition temperature) and then gradually cooling.

As described above, the polymer liquid crystal 5a is heated to once transition to the isotropic phase, and then gradually cooled to return to the nematic phase, whereby the polymer liquid crystal 5 is formed.
In the process of a returning from the isotropic phase to the nematic phase, the liquid crystal molecules are converted into
Realignment is performed along the alignment treatment direction and the alignment treatment direction of the alignment treatment film 10, and most of the liquid crystal molecules of the polymer liquid crystal 5a are aligned with their long axes aligned in the longitudinal direction of the groove-shaped recess 4. It becomes a state.

Next, by irradiating ultraviolet rays from the outer surface side of the transparent plate 11, the photopolymerizable polymer liquid crystals 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3 are polymerized to form a liquid crystal polymer. After forming the layer 5, the transparent plate 11 and the orientation-treated film 10 are removed, and the supporting material 7 is peeled off to complete the liquid crystal polymer film 1 shown in FIG.

As described above, in the method for manufacturing the liquid crystal polymer film 1 of the above-mentioned embodiment, the plurality of groove-shaped recesses 4 are formed in parallel on one surface, and the two wall surfaces 4 of the groove-shaped recess 4 are formed.
In the plurality of groove-shaped concave portions 4 of the optically isotropic transparent film 3 in which one wall surface 4a of a and 4b is formed as an inclined surface and the other wall surface 4b is formed of a steep angle surface. The photopolymerizable polymer liquid crystal 5a is filled in the
By aligning the liquid crystal molecules of a in the longitudinal direction of the groove-shaped recess 4 so that the long axes of the molecules are aligned, the transparent film 3
Liquid crystal which is optically anisotropic in the plurality of groove-shaped recesses 4 and has a refractive index in a direction substantially parallel to the longitudinal direction of the groove-shaped recesses 4 is larger than that of the transparent film 3. The polymer layer 5 is formed, and according to this manufacturing method, the liquid crystal polymer film 1 shown in FIG. 1 can be manufactured.

Further, in the manufacturing method of this embodiment,
The liquid crystal polymer layer 5 is subjected to an alignment treatment on the wall surfaces 4a, 4b of the plurality of groove-shaped recesses 4 of the transparent film 3 along the lengthwise direction of the groove-shaped recesses 4, and then the plurality of groove-shaped recesses 4 are formed.
Polymer liquid crystal 5a is filled therein, and the liquid crystal molecules are aligned in the direction of the alignment treatment.
Since it is formed by polymerizing, the liquid crystal molecules of the polymer liquid crystal 5a are oriented so that the long axes of the molecules are aligned in the lengthwise direction of the groove-shaped recess 4 and are optically anisotropic.
Further, it is possible to form the liquid crystal polymer layer 5 whose refractive index in the direction substantially parallel to the lengthwise direction of the groove-shaped recess 4 is larger than that of the transparent film 3.

Moreover, in the manufacturing method of the above-described embodiment, the orientation-treated film 10 in which the orientation treatment is applied in one direction on the polymer liquid crystal 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3. With the orientation treatment direction facing the direction opposite to the orientation treatment direction applied to the wall surfaces 4a, 4b of the groove-shaped recess 4, and the polymer liquid crystal 5a is heated to a temperature exhibiting an isotropic phase in that state. The polymer liquid crystal 5a is then cooled by slowly cooling it back to the nematic phase.
Most of the liquid crystal molecules of the polymer liquid crystal 5a are realigned in the alignment treatment direction of the wall surfaces 4a and 4b of the groove-shaped recess 4 and the alignment-treated film 10 in the groove-shaped recess 4. By aligning in the length direction, the liquid crystal polymer layer 5 having a better alignment state can be formed.

In the manufacturing method of the above embodiment, the polymer liquid crystal 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3 with the alignment treatment film 10 stacked thereon is used. 5a is heated to a temperature showing an isotropic phase and then slowly cooled to return to a nematic phase. The realignment treatment is performed by stacking the alignment treatment film 10 on the polymer liquid crystal 5a. You may do without.

In that case, when the polymer liquid crystal 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3 is dissolved in a solvent, the step of evaporating and removing the solvent, The treatment of heating the polymer liquid crystal 5a to a temperature exhibiting an isotropic phase may be continuously performed.

Further, in the manufacturing method of the above-mentioned embodiment, the polymer liquid crystal 5a filled in the plurality of groove-shaped recesses 4 of the transparent film 3 is heated to a temperature exhibiting an isotropic phase and then gradually cooled to a nematic phase. However, as described above, when the liquid crystalline polymer liquid crystals 5a are filled in the plurality of groove-shaped concave portions 4 of the transparent film 3, the liquid crystal molecules of the polymeric liquid crystal molecules 5a become Groove-shaped recess 4
The reorientation treatment is not always necessary because the molecules are oriented so that the long axes of the molecules are aligned in the orientation direction of the wall surfaces 4a and 4b (the lengthwise direction of the groove-shaped recess 4).

FIG. 4 is a perspective view of a step of forming a liquid crystal polymer layer 5 in a plurality of groove-shaped recesses 4 of the transparent film 3 showing a second embodiment of the method for producing a liquid crystal polymer film of the present invention.

The manufacturing method of this embodiment is a method of forming the liquid crystal polymer layer 5 using a polymerized thermosoftening polymer liquid crystal, and is the same as the manufacturing method of the first embodiment described above. After the laminated body of the base film 2 and the transparent film 3 is prepared, the plurality of groove-shaped recesses 4 of the transparent film 3 are filled with the softening polymer liquid crystal 5b, and the liquid crystal molecules are filled in the length of the groove-shaped recesses 4. The liquid crystal polymer layer 5 is formed by orienting so that the long axes of the molecules are aligned with each other.

In the manufacturing method of the first embodiment, the wall surfaces 4a and 4b of the plurality of groove-shaped recesses 4 of the transparent film 3 are subjected to the orientation treatment, but in the manufacturing method of this embodiment,
Wall surfaces 4a, 4 of the plurality of groove-shaped recesses 4 of the transparent film 3
It is not necessary to subject b to orientation treatment.

The formation of the liquid crystal polymer layer 5 by the manufacturing method of this embodiment will be described. In this embodiment,
The polymerized thermo-softening polymer liquid crystal 5b is dissolved in a small amount of solvent such as toluene or xylene to have fluidity,
The thermosoftening polymer liquid crystal 5b is dropped on the transparent film 3 and is evenly pressed by the rod 9 shown by a virtual line in FIG.
The entire area of the plurality of groove-shaped recesses 4 of the transparent film 3 is filled so as to be flush with the open edges.

Next, the solvent is removed in a vacuum oven heated to the evaporation temperature of the solvent in which the polymer liquid crystal 5b is dissolved, and then the temperature is slightly lower than the softening temperature of the thermosoftening polymer liquid crystal 5b. On a hot plate (not shown),
While warming the polymer liquid crystal 5b to a temperature just before the liquid crystal molecules are softened to a freely movable state, the polymer liquid crystal 5b is further heated to the temperature shown in FIG.
As shown in FIG. 5, a transparent plate material 13 made of a glass plate or a resin film is placed, and the plate material 13 is attached to the polymer liquid crystal 5
Adhere to the outer surface of b.

The polymerized thermo-softening polymer liquid crystal 5b is preferably completely solid at room temperature and has physical properties such that the liquid crystal molecules start to soften at a temperature of a little less than 80 ° C. Since the temperature immediately before the thermosoftening polymer liquid crystal 5b having such physical properties starts to soften is about 70 ° C., the polymer liquid crystal 5b can freely move without deforming the transparent film 3. It can be warmed to the temperature just before softening.

Next, as shown in FIG. 4B, while maintaining the state where the polymer liquid crystal 5b is warmed to the above temperature (the temperature just before the liquid crystal molecules are softened to the freely movable state), The plate material 1 adhered to the upper surface of the polymer liquid crystal 5b
3 is slightly shifted in one direction along the lengthwise direction of the groove-shaped recess 4 with respect to the transparent film 3, and shearing force is applied to the liquid crystal molecules of the polymer liquid crystal 5b in the groove-shaped recesses 4. As a result, the polymer liquid crystal is aligned in the displacement direction of the plate member 13 to form the liquid crystal polymer layer 5 in which the liquid crystal molecules are aligned so that their long axes are aligned in the lengthwise direction of the groove-shaped recess 4.

After that, the temperature is lowered to room temperature by slow cooling or forced cooling, and the polymer liquid crystal 5 of the liquid crystal polymer layer 5 is cooled.
b is made completely solid, the plate material 13 is peeled off, and further the support material 7 attached to the outer surface of the base film 2 is peeled off to obtain the liquid crystal polymer film 1 shown in FIG.
To complete.

As described above, according to the manufacturing method of this embodiment, after filling the plurality of groove-shaped recesses 4 of the transparent film 3 with the polymerized thermosoftening polymer liquid crystal 5b, the outer surface of the polymer liquid crystal 5b is filled. The plate material 13 is closely attached to the polymer liquid crystal 5
By shifting b in one direction along the length direction of the groove-shaped recess 4 with respect to the transparent film 3 while warming b to a temperature immediately before softening to a state where liquid crystal molecules can freely move, The liquid crystal molecules of the polymer liquid crystal 5b are aligned in the displacement direction of the plate material 13 to form the liquid crystal polymer layer 5. According to this manufacturing method, the polymerized polymer liquid crystal 5b is used to form the liquid crystal polymer. The layer 5 can be formed.

In the manufacturing method of this embodiment, the thermosoftening polymer liquid crystal 5b filled in the plurality of groove-shaped recesses 4 of the transparent film 3 is heated to a temperature immediately before it is softened so that liquid crystal molecules can freely move. While the plate material 13 is placed on the polymer liquid crystal 5b while being warmed, the plate material 13 is brought into close contact with the outer surface of the polymer liquid crystal 5b. The plate material 13 is a photocurable adhesive on the outer surface of the polymer liquid crystal 5b. It may be adhered by adhering by means such as, and in that case, after adhering the plate material 13 to the outer surface of the polymer liquid crystal 5b, the liquid crystal molecules are warmed to a temperature just before softening to a freely movable state, In this state, the plate material 13 is displaced in one direction along the lengthwise direction of the groove-shaped recess 4 with respect to the transparent film 3 so that the liquid crystal molecules of the polymer liquid crystal 5b are aligned in the displacement direction of the plate material 13. Let It may be formed of the liquid crystal polymer layer 5. Also in this case, the plate material 13 is peeled off after the liquid crystal polymer layer 5 is formed.

The liquid crystal polymer film 1 has a plurality of groove-shaped recesses 4 formed on one surface in parallel with each other, and one wall surface 4a of the two wall surfaces 4a, 4b of the groove-shaped recesses 4 facing each other. Is formed on the inclined surface, and the other wall surface 4
b is an optically isotropic transparent film 3 formed on a surface with a steep angle, and the optically anisotropic and groove-shaped transparent films 3 are provided in a plurality of groove-shaped recesses 4 of the transparent film 3. One surface provided with the liquid crystal polymer layer 5 because the liquid crystal polymer layer 5 has a refractive index in a direction substantially parallel to the lengthwise direction of the concave portion 4 is larger than that of the transparent film 3. Of the light incident from the side, the light of the polarized component having the vibrating surface along the length direction of the groove-shaped recess 4 is converted into the liquid crystal polymer layer 5 and the wall surface 4a of the groove-shaped recess 4 of the transparent film 3,
By the interface with 4b, the light is refracted in the direction in which the angle of the other surface of the transparent film 3 with respect to the normal line h increases, and the light is emitted to the other surface side of the transparent film 3.

The refractive index in the direction orthogonal to the alignment direction of the liquid crystal molecules of the liquid crystal polymer layer 5, that is, in the direction substantially orthogonal to the longitudinal direction of the groove-shaped recess 4 of the transparent film 3, is the transparent film. Since it has the same refractive index as that of 3, the light of the polarized component having the vibrating surface along the direction orthogonal to the lengthwise direction of the groove-shaped recess 4 is transmitted with almost no refraction.

The other surface of the transparent film 3 is adhered onto the base film 2, but since the base film 2 is optically isotropic like the transparent film 3, The light emitted to the other surface side of the transparent film 3 passes through the base film 2 with almost no refraction and is emitted to the outside of the base film 2.

Therefore, the liquid crystal polymer film 1
Between the reflective polarizing plate disposed on the incident side of the liquid crystal element and the phase plate disposed on the incident side of the reflective polarizing plate, one surface on which the liquid crystal polymer layer 5 is provided is used as the reflective polarizing plate. The other surface of the transparent film 3 (the outer surface of the base film 2) is opposed to the phase plate, and the lengthwise direction of the plurality of groove-shaped recesses 4 of the transparent film 3 is set to the reflection axis of the reflection polarizing plate. The light reflected by the reflective polarizing plate among the incident light is efficiently internally reflected by the phase plate by changing the polarization state by the phase difference of the phase plate by interposing the phase plate substantially parallel to Light can be transmitted through the reflective polarizing plate and incident on a liquid crystal element,
Therefore, the intensity of the linearly polarized light that passes through the reflective polarizing plate and enters the liquid crystal element is increased, and the degree of polarization is also sufficient, so that a liquid crystal display device having a reflective polarizing plate on the incident side can display a bright and good contrast. Can be done.

FIG. 5 is a side view showing an example of a liquid crystal display device provided with the liquid crystal polymer film 1. This liquid crystal display device is a reflection type device that utilizes external light, which is the light of the environment in which the liquid crystal display device is used. It is a liquid crystal display device, and a liquid crystal element 20 and a reflective polarizing plate (hereinafter referred to as front reflective polarizing plate) 21 arranged as a polarizer on the front side which is the incident surface of the liquid crystal element 20.
A phase plate 22 arranged on the front side (incident side) thereof, the liquid crystal polymer film 1 arranged between the reflection polarizing plate 21 and the phase plate 22, and a rear side of the liquid crystal element 20. A reflective polarizing plate (hereinafter referred to as a rear reflective polarizing plate) 23 arranged as a reflecting means that also serves as a photon, an absorption film 24 arranged behind the reflective polarizing plate 23, the liquid crystal element 20, and the reflected polarized light. The diffusion layer 25 is disposed between the plate 23 and the plate 23.

The liquid crystal element 20 is of an active matrix type or a simple matrix type,
Although its structure is not shown, a liquid crystal layer for controlling the polarization state of transmitted light according to an electric field applied between transparent electrodes provided on the inner surfaces of the pair of transparent substrates is provided between the pair of transparent substrates. Is.

Further, both the front-side reflection polarizing plate 21 and the back-side reflection polarizing plate 23 have a reflection axis and a transmission axis in directions orthogonal to each other, and among the two polarization components of incident light which are orthogonal to each other, A polarized light component having a vibration plane along the transmission axis (hereinafter referred to as a polarization component along the transmission axis) is transmitted, and a polarization component having a vibration plane along the reflection axis (hereinafter, referred to as a reflection axis (Referred to as a polarization component), which reflects the light.
3 are arranged so that their reflection axis and transmission axis are oriented in a predetermined direction.

Further, the absorption film 24 arranged behind the rear reflection polarizing plate 23 is made of a black film, and is diffused between the liquid crystal element 20 and the rear reflection polarizing plate 23. The layer 25 is composed of a transparent resin film having a roughened surface or a transparent resin layer in which scattering particles are dispersed.

On the other hand, the phase plate 22 arranged on the front side of the front side reflection polarizing plate 23 is made of a λ / 4 phase difference film which gives a phase difference of ¼ wavelength between the ordinary ray and the extraordinary ray of the transmitted light. Has become.

6 and 7 show the front side reflection polarizing plate 2
1 is an enlarged view and a perspective view of a part of the liquid crystal polymer film 1 disposed between the front reflection polarizing plate 21 and the phase plate 22;
2, the slow axis 22a is approximately 45 ° with respect to both the reflection axis 21s and the transmission axis 21p of the front side reflection polarizing plate 21.
Are crossed at an angle of.

The liquid crystal polymer film 1 is
One of the surfaces provided with the liquid crystal polymer layer 5 faces the front-side reflective polarizing plate 21, the other surface of the transparent film 3 (the outer surface of the base film 2) faces the phase plate 22, and the transparent The lengthwise direction of the plurality of groove-shaped recesses 4 of the film 3 is defined by the reflection axis 2 of the front side reflection polarizing plate 21.
It is interposed between the front reflective polarizing plate 21 and the phase plate 22 in a direction substantially parallel to 1 s.

The reflection type liquid crystal display device which displays by utilizing external light is bright external light in the direction inclined to the upper edge side (right side in FIGS. 5 to 7) of the screen with respect to the normal line of the screen. Is usually used in such a direction that the light is obtained, so that the brightest external light enters from a direction inclined toward the upper edge direction of the screen with respect to the normal line of the screen.

Therefore, in this liquid crystal display device, as shown in FIG. 7, the reflection axis 21s of the front side reflection polarizing plate 21 is incident from the normal line of the screen and the incident direction of the brightest external light. The liquid crystal polymer film 1 is disposed so that the transmission axis 21p is substantially parallel to the incident azimuth plane A including the optical path of light and the transmission axis 21p is substantially parallel to the incident azimuth plane A. The lengthwise direction of the plurality of groove-shaped recesses 4 is made substantially orthogonal to the incident azimuth plane A, and the two wall surfaces 4a and 4b of the groove-shaped recesses 4 facing each other are formed on the inclined surfaces. One wall surface 4a
Are arranged toward the upper edge side of the screen, which is the direction of incidence of the brightest external light.

In this liquid crystal display device, external light incident from the front side, which is the viewing side of the display, is incident on the liquid crystal element 20 as linearly polarized light along the transmission axis 21p of the front reflective polarizing plate 21, and at the same time, this liquid crystal element is used. Of the light transmitted through 20 and emitted to the rear side, light having a polarization component along the reflection axis of the rear reflective polarizing plate 23 is reflected by the rear reflective polarizing plate 23 and emitted to the front side, An image is displayed by transmitting light having a polarization component along the transmission axis of the rear reflective polarizing plate 23 through the rear reflective polarizing plate 23 and absorbing it by the absorbing film 24.

That is, the external light incident on the liquid crystal display device from the front side thereof passes through the phase plate 22 as shown by the arrow in FIGS. 6 and 7, and further, the liquid crystal polymer film. 1 through which the front side reflective polarizing plate 21 is transmitted.
Incident on.

Since the outside light is non-polarized light and its polarization state does not change even if it passes through the phase plate 22 and the liquid crystal polymer film 1, the light incident on the front side reflection polarizing plate 21 is non-polarized. It is polarized light.

Of the light incident on the front reflection polarizing plate 21, the light p of the polarization component along the transmission axis 21p of the front reflection polarizing plate 21 is transmitted through the front reflection polarizing plate 21 and the liquid crystal element. It is incident on 20.

On the other hand, of the light that has passed through the phase plate 22 and the liquid crystal polymer film 1 from the front side and is incident on the front reflection polarization plate 21, the reflection axis 21 of the front reflection polarization plate 21 is included.
The light s of the polarization component along s is reflected by the front side reflection polarizing plate 21.
Is reflected by.

The light s reflected by the front reflective polarizing plate 21 is incident on the liquid crystal polymer film 1 from the rear side thereof, and the wall surfaces 4 of the plurality of groove-shaped recesses 4 of the transparent film 3 are made.
The interface between a and 4b and the liquid crystal polymer layer 5 is refracted in a direction in which the angle with respect to the normal line of the other surface of the transparent film 3 becomes large, and is emitted to the front side of the liquid crystal polymer film 1, and the phase plate 22 Is incident from the rear side.

That is, the liquid crystal polymer film 1
Is arranged such that the lengthwise direction of the plurality of groove-shaped recesses 4 of the transparent film 3 is substantially parallel to the reflection axis 21s of the front-side reflection polarizing plate 21, and thus the front-side reflection polarizing plate 21.
The light that is reflected by the liquid crystal polymer film 1 and enters the liquid crystal polymer film 1 from the rear side (one surface side where the liquid crystal polymer layer 5 is provided) is the light s of the polarization component along the reflection axis 21s of the front side reflection polarizing plate 21. Is.

The liquid crystal polymer film 1 is
As described above, among the light incident from the one surface side where the liquid crystal polymer layer 5 is provided, the light of the polarization component having the vibrating surface along the length direction of the groove-shaped recess 4 of the transparent film 3 is The transparent film is refracted by an interface between the liquid crystal polymer layer 5 and the wall surfaces 4a, 4b of the groove-shaped recess 4 of the transparent film 3 in a direction in which an angle with respect to a normal line h of the other surface of the transparent film 3 increases. 3, the light s reflected by the front-side reflection polarization plate 21 is emitted to the other surface side of the transparent film 3, and the liquid crystal polymer film 1 increases the angle with respect to the normal line of the other surface of the transparent film 3. The light is refracted into and enters the phase plate 22 from the rear side.

Therefore, most of the light incident on the phase plate 22 from the rear side is internally reflected by the front surface of the phase plate 22 (total reflection at the interface between the front surface of the phase plate 22 and the air as the outside air), The light whose polarization state is changed by the phase difference while reciprocating through the phase plate 22 is transmitted to the phase plate 22.
The light is emitted to the rear side, passes through the liquid crystal polymer film 1 again, and is incident on the front reflective polarizing plate 21.

Since the phase plate 22 is made of a λ / 4 retardation film, the light reflected by the reflective polarizing plate 21 and incident on the phase plate 22 from the rear side (reflection of the front reflective polarizing plate 21). The light s of the polarized component along the axis 21s is reciprocated in the phase plate 22, and is given a phase difference of ½ wavelength between the ordinary light and the extraordinary light due to the phase difference of the phase plate 22. Light rotated by 90 degrees with respect to the light reflected by the front reflective polarizing plate 21 (light having a polarization component along the reflective axis 21s of the front reflective polarizing plate 21), that is, the transmission axis 21p of the reflective polarizing plate 21. The light p of the polarized component is emitted to the rear side of the phase plate 22.

The liquid crystal polymer film 1 is
As described above, since the light of the polarized component having the vibrating surface along the direction orthogonal to the lengthwise direction of the groove-shaped recess 4 of the transparent film 3 is transmitted with almost no refraction, the reflective polarizing plate 21. The light p, which is the polarized component along the transmission axis 21p and is emitted to the rear side of the phase plate 22, passes through the liquid crystal polymer film 1 with almost no refraction and enters the liquid crystal element.

As described above, in this liquid crystal display device, of the external light incident from the front side, the light p of the polarization component along the transmission axis 21p of the front side reflection polarization plate 21 is reflected.
While being incident on the liquid crystal element 20, most of the light (polarized component light along the reflection axis 21s of the front reflection polarizing plate 21) s reflected by the front reflection polarizing plate 21 is transmitted to the phase plate 22. Is reflected on the inner surface of the front reflection polarizing plate 21 and is changed into light p of a polarization component along the transmission axis 21p of the front reflection polarizing plate 21.
Therefore, linearly polarized light having a high intensity and a sufficient degree of polarization can be made incident on the liquid crystal element 20.

The light (light having a polarization component along the transmission axis 21p of the front reflection polarizing plate 21) p that has passed through the front reflection polarizing plate 21 and is incident on the liquid crystal element 20 is the liquid crystal of the liquid crystal element 20. In the process of passing through the layer, the polarization state is changed by receiving the birefringence effect according to the alignment state of the liquid crystal molecules, the light is emitted to the rear side of the liquid crystal element 20, and is diffused by the diffusion layer 25 to be the rear reflection polarized light. It is incident on the plate 23.

Of the light incident on the rear reflective polarizing plate 23, the light having the polarization component along the reflection axis of the rear reflective polarizing plate 23 is reflected by the rear reflective polarizing plate 23, and The reflected light reflects the diffusion layer 25, the liquid crystal element 20, the front reflection polarizing plate 21, the liquid crystal polymer film 1, and the phase plate 2.
2 and the light is emitted to the front side, and the rear side reflection polarizing plate 23
The light of the polarization component along the transmission axis of (1) is transmitted through the rear reflection polarization plate 23 and is absorbed by the absorption film 24.

As described above, in this liquid crystal display device, the liquid crystal polymer film 1 is provided with the reflective polarizing plate 21 disposed on the incident side of the liquid crystal element 20 and the phase plate 22 disposed on the incident side of the reflective polarizing plate 21. Between the liquid crystal polymer layer 5
One surface provided with is opposed to the reflective polarizing plate 21, the other surface of the transparent film 3 is opposed to the phase plate 22, and the lengthwise direction of the plurality of groove-shaped recesses 4 of the transparent film 3 is provided. Is the reflection axis 21s of the reflection polarizing plate 21.
The light reflected by the reflective polarizing plate 21 of the incident light is
The light internally reflected efficiently by the phase plate 22 and the light whose polarization state is changed by the phase difference of the phase plate 22 can be transmitted through the reflective polarizing plate 21 and incident on the liquid crystal element 20. It is possible to increase the intensity of the linearly polarized light that passes through the plate 21 and is incident on the liquid crystal element, and to make the degree of polarization sufficient, so that a bright display with good contrast can be displayed.

The pitch of the plurality of groove-shaped recesses 4 of the transparent film 3 of the liquid crystal polymer film 1 is about 25 μm to 50 μm as described above, and the liquid crystal element 20
Since it is sufficiently smaller than the pixel pitch (about 100 μm to 200 μm), even if the liquid crystal display device is provided with the liquid crystal polymer film 1, the brightness of light emitted from each pixel of the liquid crystal element 20 is made uniform, It is possible to obtain a good display without uneven brightness.

The liquid crystal display device has the liquid crystal element 20.
A reflection polarizing plate 23 is provided on the rear side as a reflection means also serving as an analyzer.
The liquid crystal polymer film 1 has a reflective polarizing plate as a polarizer on the front side of the liquid crystal element and an absorption film 24 on the rear side thereof as an analyzer. A reflective liquid crystal having a structure in which an absorption polarizing plate (a polarizing plate that absorbs light having a polarization component along the absorption axis and transmits light having a polarization component along the transmission axis) is arranged, and a reflecting plate is arranged on the rear side thereof. It can also be used for a display device.

Further, the liquid crystal polymer film 1 is
The rear surface of the liquid crystal element is used as an incident surface, a reflective polarizing plate is provided as a polarizer on the rear side of the liquid crystal element, a surface light source is arranged on the rear side thereof, and a reflective polarizing plate is arranged as an analyzer on the front side of the liquid crystal element. Type liquid crystal display device, and in that case, a phase plate is disposed on the rear side (incident side) of the reflective polarizing plate disposed on the rear side of the liquid crystal element, and The liquid crystal polymer film 1 between the phase plates
Should be placed.

Further, in the liquid crystal polymer film 1 of the above-mentioned embodiment, the liquid crystal polymer layer 5 is placed in each of the plurality of groove-shaped recesses 4 of the transparent film 3, and the outer surface thereof is the groove-shaped recess 4.
However, the liquid crystal polymer layer 5 is thicker than the groove-shaped recess 4 so that the outer surface portions of the adjacent liquid crystal polymer layers 5 are continuous with each other. You may form.

Further, in the liquid crystal polymer film 1 of the above-mentioned embodiment, one wall surface 4a of the plurality of groove-shaped recesses 4 of the transparent film 3 is an inclined surface, and the other wall surface 4b is a steep angle surface. However, the plurality of groove-shaped recesses 4 of the transparent film 3 have two wall surfaces 4a and 4b facing each other.
Both may be formed into an inclined surface.

The refractive index in the direction orthogonal to the alignment direction of the liquid crystal molecules of the liquid crystal polymer layer 5, that is, in the direction substantially orthogonal to the lengthwise direction of the groove-shaped recess 4 of the transparent film 3, is not necessarily the transparent one. The liquid crystal polymer film 1 of the present invention is not limited to the liquid crystal display device and may be used as an optical film that refracts incident light and emits it. Can be used.

[0099]

According to the liquid crystal polymer film of the present invention, a plurality of groove-shaped recesses are formed in parallel with each other on one surface, and at least one of the two wall surfaces facing each other of these groove-shaped recesses is inclined. An optically isotropic transparent film formed on the surface, and optically anisotropic provided in the plurality of groove-shaped recesses of the transparent film, and substantially in the longitudinal direction of the groove-shaped recesses. Since it is composed of a liquid crystal polymer layer whose refractive index in a direction parallel to is larger than that of the transparent film, light of a polarized component having a vibrating surface in a direction orthogonal to the lengthwise direction of the groove-shaped recess is Pass through without refracting,
Of the light incident from one surface side on which the liquid crystal polymer layer is provided, the polarized component light having an oscillating surface along the length direction of the groove-shaped recess is converted into the groove of the liquid crystal polymer layer and the transparent film. By the interface with the wall surface of the concave portion, the light can be refracted in a direction in which the angle with respect to the normal line of the other surface of the transparent film increases, and the light can be emitted to the other surface side of the transparent film.

Therefore, this liquid crystal polymer film is
Between the reflective polarizing plate disposed on the incident side of the liquid crystal element and the phase plate disposed on the incident side of the reflective polarizing plate, one surface provided with the liquid crystal polymer layer is opposed to the reflective polarizing plate, The other surface of the transparent film is opposed to the phase plate, and the lengthwise direction of the plurality of groove-shaped recesses of the transparent film is made substantially parallel to the reflection axis of the reflection polarizing plate so as to be incident. Of the light, the light reflected by the reflective polarizing plate is efficiently internally reflected by the phase plate, and the light whose polarization state is changed by the phase difference of the phase plate is transmitted through the reflective polarizing plate to enter the liquid crystal element. Therefore, the intensity of linearly polarized light that passes through the reflective polarizing plate and enters the liquid crystal element is increased, and the degree of polarization is also sufficient, so that the liquid crystal display device having the reflective polarizing plate on the incident side is bright. It is possible to perform good display contrast.

Further, in the method for producing a liquid crystal polymer film of the present invention, a plurality of groove-shaped recesses are formed in parallel on one surface, and at least one of the two wall surfaces of the groove-shaped recesses facing each other is formed. Polymer liquid crystal is filled in the plurality of groove-shaped recesses of an optically isotropic transparent film having a wall surface formed on an inclined surface, and liquid crystal molecules of the polymer liquid crystal are arranged in the lengthwise direction of the groove-shaped recess. By orienting so that the molecular long axes are aligned, refraction in the plurality of groove-shaped recesses of the transparent film is optically anisotropic and in a direction substantially parallel to the length direction of the groove-shaped recesses. To form a liquid crystal polymer layer whose index is higher than the refractive index of the transparent film,
According to this manufacturing method, the liquid crystal polymer film can be manufactured.

In the method for producing a liquid crystal polymer film of the present invention, the transparent film is provided with a plurality of groove-shaped recesses on the wall surfaces thereof.
After performing an alignment treatment along the lengthwise direction of the groove-shaped recesses, polymer liquid crystals are filled in the groove-shaped recesses to align the liquid crystal molecules in the direction of the alignment treatment, and then the polymer. It is preferable to form the liquid crystal by polymerizing it, and by doing so, the liquid crystal molecules of the polymer liquid crystal are aligned so that the long axes of the molecules are aligned in the longitudinal direction of the groove-like recess, It is possible to form a liquid crystal polymer layer which is anisotropic and has a refractive index in a direction substantially parallel to the lengthwise direction of the groove-shaped recesses larger than that of the transparent film.

In this case, the polymer liquid crystal filled in the plurality of groove-shaped recesses of the transparent film is heated to a temperature exhibiting an isotropic phase, and then gradually cooled to return to the nematic phase. It is more preferable that the liquid crystal molecules of (1) are aligned in the direction of the alignment treatment applied to the wall surface of the groove-like recess, and by doing so, most of the liquid crystal molecules of the polymer liquid crystal are extended in the length of the groove-like recess. The liquid crystal polymer layer can be formed in a better alignment state by aligning in the vertical direction.

Further, in the method for producing a liquid crystal polymer film according to the present invention, the liquid crystal polymer layer is prepared by filling a plurality of groove-shaped concave portions of a transparent film with a polymerized thermosoftening polymer liquid crystal, and then polymerizing the polymer. A plate material is adhered to the outer surface of the liquid crystal, and the plate material is heated to a temperature immediately before the liquid crystal molecule is softened to a state in which the liquid crystal molecules can freely move. It may be formed by aligning the liquid crystal molecules of the polymer liquid crystal in the shift direction of the plate material by displacing the liquid crystal molecules in one direction along the same direction. A polymer layer can be formed.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a liquid crystal polymer film of the present invention.

FIG. 2 is a side view of a step of producing a laminate of a base film and a transparent film, showing a first embodiment of the method for producing a liquid crystal polymer film of the present invention.

FIG. 3 is a side view of a step of forming a liquid crystal polymer layer in a plurality of groove-shaped recesses of a transparent film, which shows the manufacturing method of the first embodiment.

FIG. 4 is a perspective view of a step of forming a liquid crystal polymer layer in a plurality of groove-shaped recesses 4 of a transparent film, showing a second embodiment of the method for producing a liquid crystal polymer film of the present invention.

FIG. 5 is a side view showing an example of a liquid crystal display device including the liquid crystal polymer film of the present invention.

FIG. 6 is an enlarged view of a reflective polarizing plate and a phase plate arranged on the front side of a liquid crystal element of the liquid crystal display device, and a part of a liquid crystal polymer film interposed therebetween.

FIG. 7 is a perspective view of the reflective polarizing plate, a phase plate, and a liquid crystal polymer film.

[Explanation of symbols]

1 ... Liquid crystal polymer film 2 ... Base film 3 ... Transparent film 4 ... Groove-shaped recess 4a, 4b ... Wall surface 5 ... Liquid crystal polymer layer 5a ... Photopolymerizable polymer liquid crystal 5b ... Softening polymer liquid crystal 10 ... Orientation-treated film 13 ... Plate material

Continued front page    F-term (reference) 2H049 BA05 BA06 BA12 BA42 BA43                       BA47 BB03 BB49 BB62 BC01                       BC05 BC22                 2H088 EA47 MA06                 2H091 FA07X FA15X FD06 LA03                       LA17                 4F100 AK25 AK80B AT00A BA02                       BA03 BA21 DD05A EJ42B                       EJ50B GB41 JN01A JN18B                       JN30 JN30A JN30B

Claims (5)

[Claims] 1. An optical system in which a plurality of groove-shaped recesses are formed in parallel with each other on one surface, and at least one of the two wall surfaces of these groove-shaped recesses facing each other is formed as an inclined surface. Isotropic transparent film, provided in the plurality of groove-shaped recesses of the transparent film, optically anisotropic, the refractive index in a direction substantially parallel to the lengthwise direction of the groove-shaped recess A liquid crystal polymer film comprising a liquid crystal polymer layer having a refractive index higher than that of the transparent film. 2. An optical system in which a plurality of groove-shaped recesses are formed in parallel with each other on one surface, and at least one of the two wall surfaces of these groove-shaped recesses facing each other is formed as an inclined surface. By filling a polymer liquid crystal in the plurality of groove-shaped recesses of the isotropic transparent film, by orienting the liquid crystal molecules of the polymer liquid crystal so that the long axes of the molecules are aligned in the length direction of the groove-shaped recess. In the plurality of groove-shaped recesses of the transparent film, the refractive index in a direction that is optically anisotropic and is substantially parallel to the lengthwise direction of the groove-shaped recesses is larger than the refractive index of the transparent film. A method for producing a liquid crystal polymer film, which comprises forming a liquid crystal polymer layer. 3. A liquid crystal polymer layer, wherein a wall surface of a plurality of groove-shaped recesses of a transparent film is subjected to an alignment treatment along the lengthwise direction of the groove-shaped recesses, and then a polymer liquid crystal is placed in the groove-shaped recesses. 3. The method for producing a liquid crystal polymer film according to claim 2, wherein the liquid crystal molecules are aligned by filling the liquid crystal molecules in the direction of the alignment treatment, and then the polymer liquid crystal is polymerized. 4. A polymer liquid crystal filled in a plurality of groove-shaped recesses of a transparent film is heated to a temperature exhibiting an isotropic phase, and then gradually cooled to return to a nematic phase, whereby the polymer liquid crystal The method for producing a liquid crystal polymer film according to claim 3, wherein the liquid crystal molecules are aligned in the direction of the alignment treatment applied to the wall surface of the groove-shaped recess. 5. The liquid crystal polymer layer comprises: filling a plurality of groove-shaped recesses of a transparent film with a polymerized thermosoftening polymer liquid crystal, and then adhering a plate material to the outer surface of the polymer liquid crystal, By shifting the plate material with respect to the transparent film in a state where the liquid crystal is warmed to a temperature immediately before softening so that the liquid crystal molecules can freely move, the polymer is shifted in one direction along the lengthwise direction of the groove-like recessed portion. The method for producing a liquid crystal polymer film according to claim 2, wherein the liquid crystal molecules of liquid crystal are formed by orienting them in the shifting direction of the plate material.