JPH0695121A - Oriented film for liquid crystal display device and its production - Google Patents

Abstract

PURPOSE:To provide the structure with which the large-area oriented films are easily obtainable and the process for production. CONSTITUTION:Fine rugged parts of an aligned state are formed on the liquid crystal 20 side of the oriented film 19. The oriented film 19 is divided to plural regions. The rugged parts are exactly aligned to each of these divided regions. Non-aligned regions where the rugged parts of the divided regions on both sides of boundary parts 19a of the divided regions are not aligned are formed in these boundary parts. The non-aligned regions are disposed in the non-display area of the liquid crystal 20. Then, the non-aligned regions of the rugged parts are disposed in the non-display area of the liquid crystal 20 according to such constitution and, therefore, the generation of a disturbance in the display occurring in the non-alignment is obviated. Since the exact formation of the fine rugged parts in the aligned state in each of the divided regions is merely necessitated, the oriented film 19 obviating the generation of the disturbance in the display even with the large-area oriented film 19 is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment film for a liquid crystal display device adapted to a large area and an improvement in a method for producing the alignment film.

[0002]

2. Description of the Related Art FIG. 9 is a cross-sectional view showing one structural example of a liquid crystal display substrate previously proposed by the present inventors. The substrate 41 includes a substrate main body 42 and an alignment film 43 having a thickness of several hundred angstroms and coated on the upper surface of the substrate main body 42.
It consists of and. The substrate body 42 includes a substrate portion 44 made of transparent glass or the like and a transparent electrode 45 laminated on the upper surface thereof. The alignment film 43 is made of a polymer resin film such as polyimide, and has a large number of fine irregularities 43a formed on its surface.

The present inventors have previously proposed a transfer method using a press device 47 having the structure shown in FIG. 10 as a method for forming the alignment film 43 having the uneven portion 43a. The pressing device 47 includes a pedestal 48 and an upper plate 49 which is vertically provided above the pedestal 48. The pedestal 48 is for installing the substrate main body 42, and the substrate main body 42 installed on the pedestal 48.
A smooth polymer resin film 50 before the uneven portion is formed is formed on the upper surface of the. The upper plate 49 is for moving up and down by a moving mechanism (not shown) to apply pressure to the polymer resin film 50, and the lower surface thereof has a recess 51.
Is formed, and a stamper (grating type) 52 is attached in the recess 51. Further, a protruding stopper 53 is formed in the peripheral portion of the recess 51, and the stopper 53 comes into contact with the upper surface of the pedestal 48 to stop the lowering of the upper plate 49. It should be noted that the lower surface of the stamper 52 is provided with an uneven portion 52a for forming an uneven portion 43a to be formed on the upper surface of the alignment film 43.

In order to manufacture the substrate 41 shown in FIG. 9 by using the pressing device 47 having the above-mentioned structure, first, the substrate body 42 having the polymer resin film 50 made of polyimide or the like is placed on the pedestal 48, and then the substrate body 42 is placed. The upper plate 49 is lowered.
Then, since the stamper 52 is pressed against the upper surface of the polymer resin film 50, the uneven portion 52a on the lower surface of the stamper 52 is pressed.
Is transferred onto the upper surface of the polymer resin film 50 to obtain the alignment film 43 having the uneven portions 43a shown in FIG. Further, when the stopper 53 of the upper plate 49 comes into contact with the upper surface of the pedestal 48, the lowering of the upper plate 49 is stopped, the entrance of the stamper 52 into the polymer resin film 50 is stopped, and the uneven portion 43a having a predetermined depth is raised. It is generated on the upper surface of the molecular resin film 50.

[0005]

However, as shown in FIG.
When the alignment film 43 is formed by using the pressing device 47 shown in FIG. 1, there is a problem that the following inconvenience occurs. First, when the stamper 52 is viewed from the bottom surface, it has a quadrilateral shape as shown in FIG. 11, and innumerable minute uneven portions 52a are formed on the bottom surface. The size of the uneven portion 52a of the stamper 52 is currently formed to an extremely fine size of about 1 μm, and the shape of each uneven portion 52a is precisely formed. The size of the obtained stamper 52 is the largest at 60 mm square, and a stamper 52 larger than this cannot be obtained. However, as is well known, the screen area of the liquid crystal display device is being increased year by year, and therefore, the size of the alignment film that can be formed by the above-mentioned transfer method using the stamper 52 having the above-mentioned size is not suitable for the liquid crystal display device. The situation is becoming unable to cope with large screens.

Therefore, the inventors of the present invention have, for example, stamper 5
When manufacturing the alignment film 55 shown in FIG. 12, which is larger than 2, the alignment film 55 is considered to be divided into a plurality of regions, and the stamper 52 is pressed in each divided region to obtain the large alignment film 55. That is, as shown in FIG.
When manufacturing an alignment film 55 which is four times as large as
Border part 5 that divides into 4 areas and divides into 4 areas
The alignment film 15 can be obtained by sequentially pressing the stamper 52 for each region along the lines 6 and 56. Note that FIG.
The size of the concave portion 51 of the pressing device 47 shown in FIG. 0 can be adapted for manufacturing a large alignment film 55 by forming it larger than the conventional size in accordance with the size of the alignment film 55.

By the way, when the alignment film 55 is formed using the stamper 52, at the boundary portions 56, 56,
If the position of the stamper 52 is not accurately aligned, there is a problem that adjacent concave and convex portions overlap each other at the boundary portions 56, 56, or a gap portion in which the concave and convex portions are not transferred is formed, resulting in a mismatched portion. However, it is extremely difficult to strictly control the accuracy when the stamper 52 is laterally moved and positioned. For example, the positioning accuracy is set to be smaller than the size of the uneven portion 52a having a size of about 1 μm. Has a difficult problem. In addition, there is a problem in that, in particular, in the portion where the boundary portions 56, 56 intersect, an uneven portion of the uneven portion due to a positioning error occurs. If the uneven portion is not accurately formed as described above, the alignment of the liquid crystal molecules corresponding to this portion is disturbed, the liquid crystal is not aligned in a prescribed manner, and the display is disturbed.

The present invention has been made in view of the above circumstances, and an alignment film having a larger area than that of a stamper can be formed by a transfer method using a stamper having a constant size, and further adversely affects the display. An object of the present invention is to provide an alignment film having a structure that does not exist and a method for manufacturing the alignment film.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 is provided in a liquid crystal display device in which a liquid crystal is sealed between substrates which are arranged opposite to each other. In the alignment film formed on the surface, fine alignment irregularities are formed on the liquid crystal side surface of the alignment film, the alignment film is divided into a plurality of regions, and The concavo-convex portion is accurately aligned, and a non-conforming area where the concavo-convex portions of the divided areas on both sides of the divided area are misaligned is formed at the boundary portion of the divided area, and the non-conforming area is arranged in the non-display area of the liquid crystal display device. It has been done.

In order to solve the above-mentioned problems, the invention according to claim 2 is the alignment film for a liquid crystal display device according to claim 1, wherein the substrate is provided with an electrode for aligning liquid crystals,
The electrode has a matrix structure of a plurality of electrode lines formed on one substrate and a plurality of electrode lines formed on the other substrate, and the mismatched region is formed on the electrode lines of one substrate and the other substrate. It is formed in a portion excluding the intersection with the electrode wire.

According to a third aspect of the present invention, in order to solve the above problems, in the alignment film for a liquid crystal display device according to the first aspect, the substrate is provided with a circuit for aligning the liquid crystal,
The circuit is an active matrix circuit including scan electrode lines, signal electrode lines, switch elements, and pixel electrodes formed on a substrate, wherein the mismatched region is formed in a portion excluding the pixel electrodes. Is.

In order to solve the above-mentioned problems, the invention as set forth in claim 4 is provided in a liquid crystal display device in which liquid crystal is sealed between opposed substrates, and an alignment formed on the liquid crystal side surface of the substrate. A method for producing a film, which comprises pressing a stamper having fine irregularities against a resin film formed on a substrate to form an alignment film having fine irregularities, which is used for non-display of a liquid crystal display device. The resin film is divided into a plurality of regions via the boundary portions so that the boundary portions are located in the areas, and the stamper is pressed in each region to form an alignment film having uneven portions on the entire surface of the resin film. .

In order to solve the above-mentioned problems, a thermosetting resin film is used as a resin film formed on a substrate, and a region where a stamper is pressed is heated to a temperature higher than the curing temperature of the thermosetting resin. In addition, the uneven portion is formed by maintaining the region where the uneven shape is not formed at a temperature not higher than the curing temperature of the thermosetting resin.

[0014]

[Function] The alignment film is divided into a plurality of regions, uneven portions are formed in each divided region, and the boundary portion of the divided regions is a mismatched region of the uneven portions. Since it is in the display area, the display is not affected even if the alignment disorder of the liquid crystal occurs due to the mismatching of the concave and convex portions. Therefore, even in the case of a large-area alignment film, it is sufficient to precisely form fine uneven portions in each divided region in an aligned state, and it is necessary to form a continuous uneven portion with a large area and no boundary. It becomes easier to form the uneven portion. As a non-display area suitable as a mismatch area, specifically, in a simple matrix circuit, a portion other than a portion sandwiched by a plurality of electrode lines on one substrate and a plurality of electrode lines on the other substrate is excluded. is there. Further, in the active matrix circuit, specifically, a non-display area suitable as a mismatch area is a portion excluding the pixel electrode.

Further, according to the above-mentioned structure, when the uneven portion is transferred onto the alignment film by the stamper to manufacture the stamper, the size of the stamper is limited, and an alignment film larger than the maximum size stamper to be obtained is required. Even if it is necessary to manufacture it, the alignment film can be appropriately divided into areas and the uneven portions can be transferred, so that a large-area alignment film can be easily obtained by a transfer method using a stamper smaller than that. .

On the other hand, if the resin film for forming the alignment film is divided into regions and the stamper is pressed in each divided region to sequentially form the uneven portions, the mismatched portions of the uneven portions are concentrated at the boundary of the divided regions. It is possible to form the concave and convex portions in a completely aligned state except the boundary portion. Then, by setting the unmatched portion of the uneven portion to the non-display area of the liquid crystal, the display disorder due to the unmatched portion does not occur.

Although the effect of the present invention can be obtained by using a thermoplastic resin as the resin film for forming the alignment film,
A thermosetting resin is used to divide the resin film into regions, and the divided regions are sequentially heated to a temperature not lower than the curing temperature of the thermosetting resin, and the stamper is pressed in order to form uneven portions, thus ensuring accurate size without disturbance. And an uneven portion having a shape are formed. Furthermore, when pressing the stamper sequentially for each divided area of the resin film,
By setting the area where the uneven shape is not formed below the curing temperature of the thermosetting resin, the stamper will not affect the area kept below the curing temperature even if the stamper is pressed against the adjacent area. Accurate size and shape of irregularities can be obtained.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of an equivalent circuit of an active matrix liquid crystal display device using thin film transistors as switching elements. 1, a large number of scanning electrode lines G1, G2, ..., Gn and a large number of signal electrode lines S1, S2 ,.
Each scan electrode line G is connected to the scan circuit 1 and each signal electrode line S is connected to the signal supply circuit 2. A transistor 3 is provided in the vicinity of the intersection of each line. The part 4 and the liquid crystal element 5 are connected to form a circuit. 1, the scanning electrode lines G1, G2, ..., Gn and the signal electrode lines S1, S2 ,. It has become.

2 and 3A are provided with scan electrode lines G and signal electrode lines S in the active matrix liquid crystal display device shown in the equivalent circuit of FIG. 1, and further with an alignment film according to the present invention. 2 is a view showing a main part of a structural example of the active matrix substrate. In the active matrix substrate shown in FIGS. 2 and 3A, the scanning electrode lines G and the signal electrode lines S are arranged in a matrix pattern on the transparent substrate 6 made of glass or the like at their intersecting portions with an insulating layer interposed therebetween. ing. Further, the thin film transistor 3 is provided near the intersection of the scanning electrode line G and the signal electrode line S.

The thin film transistor 3 shown in FIGS. 2 and 3 (a) has the most general structure, and the gate insulating film 9 shown in FIG. A semiconductor layer 10 made of amorphous silicon (a-Si) is provided on the gate insulating film 9, and a drain electrode 11 and a source electrode 12 made of a conductor such as aluminum are further provided on the semiconductor layer 10. Has been done. The drain electrode 11 is connected to the pixel electrode 15 via a contact hole 14 formed in the gate insulating layer 9. Then, a leveling layer 17 is formed on each of the layers, an alignment film 19 is formed above the leveling layer 17, a liquid crystal 20 is provided above the leveling layer 17, and an alignment film 21 and an electrode layer 22 are provided above the liquid crystal 20 and are transparent. The substrate 23 is provided to form a liquid crystal display device.

Then, a boundary portion 19a is formed in a part of the alignment film 19 located above one particular scanning electrode line G of the liquid crystal display device, and an alignment film located above one particular signal electrode line S. Boundary portions 19 a are provided in a part of each 19. In addition, the alignment film 2 above the alignment film 19
1, the boundary portion 21a is formed at a position corresponding to the boundary portion 19a. The boundary portions 19a, 21a
Is an inconsistent portion of fine irregularities formed on the surfaces of the alignment films 19 and 21. That is, the surface of the alignment films 19 and 21 has a width of 1 μm in order to control the alignment of liquid crystal molecules.
Fine irregularities are formed in an aligned state, but the boundary portions 19a and 21a are portions where the aligned state of the irregularities is disturbed. The positions of the boundary portions 19a and 21a are shown by the alternate long and short dash lines in FIGS. The boundary portion 19
For example, when the entire alignment film 19 is viewed as a rectangular shape as shown in FIG. 6A, a is formed so as to be divided into four, and the boundary portion 19a is the scanning signal line of the liquid crystal display device as described above. It is located on G and on the signal electrode line S, in other words, in the non-display area.

The non-display area will be described below.
In the liquid crystal display device having the above structure, when the pixel electrode 15 applies an electric field to the molecules of the liquid crystal 20, the alignment of the liquid crystal molecules can be controlled. Therefore, the area above the pixel electrode 15 is the display area, and the other area is the non-display area. Therefore, the boundary portions 19a, 21a
Are formed in a part of the non-display area. Since the boundary portions 19a and 21a are the non-matching portions of the concave and convex portions of the alignment films 19 and 21, there is a possibility that the alignment property of the liquid crystal molecules may be disturbed, but the boundary portions 19a and 21a correspond to the non-display portion. Since it is provided as an option, it does not adversely affect the actual display.

In the current active matrix liquid crystal display device, the scanning electrode line G or the signal electrode line S is used.
Has a width of about 7 μm, and the distance between the pixel electrode 15 and each electrode line is about 10 μm, the boundary portions 19a and 21a can be easily arranged by utilizing these spaces. In this case, in the conventional method, it was necessary to align the stamper with an error of about 1 μm in accordance with the dimension of the uneven portion to transfer the uneven portion. The allowable limit is greatly expanded. For example, assuming that the width of the electrode lines is 7 μm and the distance to the adjacent pixel electrodes 15 is 10 μm, the total is 2
Since the permissible limit is about 7 μm and the permissible limit is remarkably widened, the stamper can be easily positioned when the alignment film is manufactured by the transfer method as described later.

Incidentally, FIG. 3B shows another example of the active matrix liquid crystal display device, and the present invention can be applied to the structure of this example. The structure of this example is almost the same as that of the active matrix liquid crystal display device shown in FIG. 3A, except that the second pixel electrode 15 ′ is provided on the leveling layer 17 and the gate insulating film is provided. 9 is provided with a connection electrode 16 penetrating the leveling layer 17, and the connection electrode 16 connects the second pixel electrode 15 ′ and the pixel electrode 15. Also in the structure of this example, the boundary portion 19'a is provided in the same portion as that of the structure shown in FIG. 3A so that the object can be achieved.

FIG. 5 is a view for explaining an embodiment in which the alignment film according to the present invention is applied to a simple matrix type liquid crystal display device. In the simple matrix liquid crystal display device, a plurality of electrode lines 26 are aligned and formed on the substrate 25 as shown by the hatched area in the lower right of FIG. A plurality of electrode lines 28 are aligned and formed in a matrix with respect to the electrode lines 26 as indicated by a diagonally downward-sloping area, and a double-hatched portion of FIG. The display area 29 is provided, liquid crystal is provided between the substrate 25 and the substrate 27, and display is performed in a portion corresponding to the display area 29. Therefore, in the case of the alignment film applied to this simple matrix liquid crystal display device, the object can be achieved by arranging the boundary portion 19a ′ so as to avoid the display area 29. Specifically, the adjacent specific electrode wire 2
The boundary portion 19a ′ is arranged so as to pass between the electrodes 6 and 26 and between the adjacent specific electrode lines 28 and 28.

In a normal simple matrix type liquid crystal display device, the space between the electrode lines is 10 to 30 μm.
Since a space of about m is available, the boundary portion 19a 'can be arranged with a sufficient margin by using this space. In this case, the position error when pressing the stamper is allowed within the range of this space, and since it does not affect the display, the stamper is aligned and pressed against the resin film to form the uneven portion as described later. The work when transferring and forming the alignment film becomes easy.

Next, a method of manufacturing the alignment film 19 having the uneven portion will be described. In order to manufacture the alignment film by carrying out the method of the present invention, a press device having the same structure as the press device 47 shown in FIG. 10 is used, the stamper 52 is attached to the upper plate 49 of this press device, and the pedestal 48 is mounted. Board 4 on top
Install 2 and perform. However, it is assumed that a moving mechanism is provided so that the upper plate 49 can be moved left and right, and that the press device 47 that is improved so that the stamper 52 can be moved left and right is used. Further, the alignment film to be manufactured is composed of the stamper 52.
Since it is several times larger than the above, the recess 51 for accommodating the stamper 52 is formed to be larger accordingly.

First, suppose that the alignment film 19 is the stamper 52 4
A description will be given of one having a double size and using a thermoplastic resin as the alignment film. First, FIG. 6 (a)
As shown in FIG. 4, a rectangular transparent substrate coated with a thermoplastic resin film such as polyether sulfone (3600P manufactured by Mitsui Toatsu Co., Ltd.) is prepared, and this is formed into four regions having the same shape as the stamper 52. Boundary 19 at R1, R2, R3, R4
Divide into 4 via a. The boundary portion 19a is
When the manufactured alignment film is incorporated into a liquid crystal display device,
In the case of the active matrix substrate as described in the previous embodiment, the positioning is performed so as to correspond to the non-display area, such as above the scanning electrode lines G and the signal electrode lines S.

Next, in the region of the resin film, the upper left region R1 is heated to a temperature higher than the glass transition point of the resin film by 10 ° C. or more, more preferably 20 ° C. or more, and the temperature of the other region is set to the glass. The temperature is maintained at a temperature not higher than the transition point, more preferably not lower than 20 ° C. Specifically, the substrate coated with the resin film is heated region by region with a heater, infrared ray, or laser beam from the back side to heat the required region R1 to a temperature higher than the glass transition point by 10 ° C. or more. , The other regions R2 to R4 are not heated or are actively cooled to adjust the temperature. At this time, the heating region can be accurately controlled by using an optical means such as infrared rays or laser beams. Then, the region R1
Then, align the stamper 52 and
Is pressed to form an uneven portion on the surface. Stamper 5
The area where 2 is pressed is indicated by the diagonal lines in FIG. As described above, the resin film in the heated region R1 is the stamper 52.
It is easily deformed by pressing and the uneven portion is transferred.
By heating the region R1 to a temperature higher than the glass transition point by 10 ° C. or more, the transfer of the uneven portion can be easily performed. It should be noted that the heating temperature of the region R1 is set to 1 above the glass transition point.
If the temperature is lower than 0 ° C. higher, the transfer of the uneven portion may not be performed smoothly and the depth of the uneven portion on the alignment film may become shallow, which is not preferable.

Next, the heating of the region R1 is stopped and cooled to a temperature lower than the glass transition point, more preferably 20 ° C. or more, and then the region R2 is heated to 10 ° C. lower than the glass transition point. It is heated to a higher temperature. By this operation, the uneven portion of the region R1 where the stamper 52 was previously pressed is completely solidified. Then, as shown in FIG.
The stamper 52 is pressed against 2 to form an uneven portion on the surface of the region R2. At this time, the boundary portion 19 between the region R1 and the region R2
In the case of a, it is preferable to adjust the position of the stamper 52 so that the stamper 52 is pressed against the stamper 52 in a predetermined width.

Subsequently, similarly, each region R3, R4 is sequentially heated and the stamper 52 is sequentially pressed against each region, thereby
Concavo-convex portions can be formed in all of the two regions R1 to R4, and finally the alignment film 19 shown in FIG. 6 (d) having concavo-convex portions on the entire surface can be obtained. When the stamper 52 is pressed, the stamper 5 is pressed at the boundary portion 19a of each area.
It is preferable to press 2 in duplicate. Further, in a region where the stamper 52 is not pressed or a region where the stamper 52 has already been pressed, the temperature must be kept lower than the glass transition point, more preferably 20 ° C. or more, and the stamper 52 pressed to another region. Since the resin layer may be deformed in the portion exceeding the boundary portion 19a due to the influence of the resin flow due to the pressure, the temperature is kept at a temperature lower than the glass transition point, more preferably 20 ° C. or lower. Accordingly, even if the stamper 52 is pressed in a specific area, the influence of the stamper 52 on other adjacent areas can be prevented.

In the above method, the stamper 52 is pushed twice or more at the boundary portion 19a, so that the uneven portion becomes an unaligned portion. However, if the mismatched portion is located at a position corresponding to the non-display area as in the structure described above with reference to FIGS. 1 to 5, the mismatched portion does not adversely affect the display. By the way, although the example in which the alignment film 19 is divided into four has been described in the above-described embodiment, the number of divided regions may be any number of two or more, and it is not necessary that all divided regions have the same shape. Further, a plurality of stampers of the same size may be used for each area and the stampers may be selectively used and pressed.

Next, as the alignment film, a film using a thermosetting resin will be described. Similar to the above embodiment, first, as shown in FIG. 7A, a rectangular transparent substrate coated with a thermosetting resin film such as polyimide (San Ever made by Nissan Kagaku Co., Ltd.) was prepared. A boundary portion 19a is formed in four regions R1, R2, R3, and R4 having the same shape as the stamper 52.
Divide into 4 through. It should be noted that this boundary portion 19a is formed between the scanning electrode line G and the signal electrode line S when the manufactured alignment film is incorporated in a liquid crystal display device and in the case of an active matrix substrate as described in the previous embodiment. Position it so as to correspond to the non-display area, such as above.

Of the resin film area, the upper left area R1
Then, align the stamper 52 and
Press. After that, the region R1 is heated to a temperature higher than the curing temperature of the resin film, and the temperature of the other regions is maintained at 20 ° C. or more, preferably 30 ° C. or more lower than the curing temperature. Specifically, the substrate coated with the resin film is heated region by region from the back side with an infrared heater or a laser beam to heat the required region R1 to a temperature higher than the curing temperature and the other regions R2. The temperature of R4 is controlled by not heating it or actively cooling it.

The area where the stamper 52 is pressed is shown in FIG.
It is indicated by the diagonal line in (b). Since the resin heating film in the region R1 is heated and hardened by pressing the stamper 52 in a state of having a film surface shape corresponding to the surface shape of the stamper, it is uneven by heating to a temperature higher than the hardening temperature. It is easy to transfer parts. It should be noted that if the heating temperature of the region R1 is set lower than the curing temperature, the transfer of the uneven portion may not be performed smoothly and the shape of the uneven portion on the alignment film may collapse, which is not preferable.

Next, as shown in FIG. 7C, the stamper 52 is pressed against the region R2 to form an uneven portion on the surface of the region R2. At this time, the boundary portion 19a between the region R1 and the region R2
In the above, it is preferable to adjust the position of the stamper 52 so as to press the stamper 52 with a predetermined width in the non-display area.

Subsequently, similarly, by sequentially pressing the stamper 52 to the respective regions R3 and R4, the concavo-convex portion can be formed in all of the four regions R1 to R4, and finally the concavo-convex portion is formed on the entire surface. The alignment film 19 shown in (d) can be obtained. When the stamper 52 is pressed, it is preferable to press the stamper 52 at a predetermined width in the non-display area at the boundary portion 19a of each area. Also, in the area where the uneven shape is not yet formed,
If the temperature is not lower than the curing temperature by 20 ° C. or higher, more preferably 30 ° C. or higher, the film may be cured before transfer and the shape cannot be transferred. More preferably, it is maintained at a temperature lower than 30 ° C. As a result, the stamper 52
It is possible to prevent the influence of this region from affecting other adjacent regions even if is pressed.

In the above method, since the stamper 52 is pushed at the boundary portion 19a with a gap of a predetermined width, the concavo-convex portion becomes a disordered portion. However, if the mismatched portion is located at a position corresponding to the non-display area as in the structure described above with reference to FIGS. 1 to 5,
This mismatched portion does not adversely affect the display. By the way, although the example in which the alignment film 19 is divided into four has been described in the above-described embodiment, the number of divided regions may be any number of two or more, and it is not necessary that all divided regions have the same shape. Further, a plurality of stampers of the same size may be used for each area and the stampers may be selectively used and pressed.

Next, another example using a thermosetting resin as the alignment film will be described. Similar to the above example, first, as shown in FIG. 7 (a), a rectangular transparent substrate coated with a thermosetting resin film such as polyimide (Semicofine manufactured by Toray Industries, Inc.) was prepared, This is divided into four regions R1, R2, R3 and R4 having the same shape as the stamper 52 at the boundary portion 19a.
Divide into 4 through. It should be noted that this boundary portion 19a is formed between the scanning electrode line G and the signal electrode line S when the manufactured alignment film is incorporated in a liquid crystal display device and in the case of an active matrix substrate as described in the previous embodiment. Position it so as to correspond to the non-display area, such as above.

Next, of the region of the resin film, the upper left region R1 is heated to a temperature higher by 5 ° C. or more than the glass transition point of the resin film, and the temperature of other regions is set at the glass transition point or lower, more preferably. Hold at a temperature lower than 20 ° C. Specifically, the substrate coated with the resin film is heated region by region from the back side with an infrared heater or a laser beam to heat the required region R1 to a temperature higher than the glass transition point by 5 ° C. or more, The other regions R2 to R4 are temperature-controlled by not heating them or by actively cooling them.
Subsequently, the stamper 52 is aligned with the region R1 and the stamper 52 is pressed to form an uneven portion on the surface thereof. The area where the stamper 52 is pressed is shown by the diagonal lines in FIG. As described above, the resin film in the heated region R1 is easily deformed by pressing the stamper 52, and the uneven portion is transferred. Here, by heating the region R1 to a temperature higher than the glass transition point by 5 ° C. or more, transfer of the uneven portion can be facilitated. If the heating temperature of the region R1 is set to be lower than the temperature higher by 5 ° C. than the glass transition point, the uneven portion may not be transferred smoothly and the uneven portion on the alignment film may have a shallow depth. Not preferable.

Next, the heating of the region R1 is stopped and cooled to a temperature lower than the glass transition point, more preferably 20 ° C. or more, and then the region R2 is heated to 5 ° C. below the glass transition point. It is heated to a higher temperature. By this operation, the uneven portion of the region R1 where the stamper 52 was previously pressed is completely solidified. Then, as shown in FIG. 7C, the region R2
Then, the stamper 52 is pressed against the surface to form an uneven portion on the surface of the region R2. At this time, the boundary portion 19 between the region R1 and the region R2
In the case of a, it is preferable to adjust the position of the stamper 52 so as to press the stamper 52 at a predetermined width in the non-display area.

Subsequently, similarly, the respective regions R3 and R4 are sequentially heated, and the stamper 52 is sequentially pressed against each of the regions, thereby 4
Irregularities can be formed in all of the two regions R1 to R4, and finally the alignment film 19 shown in FIG. 7D having irregularities on the entire surface can be obtained. When the stamper 52 is pressed, it is preferable to press the stamper 52 at a predetermined width in the non-display area at the boundary portion 19a of each area. Further, in a region where the stamper 52 is not pressed or a region where the stamper has already been pressed, unless the temperature is lower than the glass transition point, the boundary is affected by the resin flow due to the pressure of the stamper 52 pressed to another region. Since the resin layer may be deformed in a portion exceeding the portion 19a, the temperature is kept lower than the glass transition point, more preferably 20 ° C. or more. Accordingly, even if the stamper 52 is pressed in a specific area, the influence of the stamper 52 on other adjacent areas can be prevented.

In the above method, since the stamper 52 is pushed at the boundary portion 19a with a gap of a predetermined width, the concavo-convex portion becomes a misaligned portion. However, if the mismatched portion is located at a position corresponding to the non-display area as in the structure described above with reference to FIGS. 1 to 5,
This mismatched portion does not adversely affect the display. By the way, although the example in which the alignment film 19 is divided into four has been described in the above-described embodiment, the number of divided regions may be any number of two or more, and it is not necessary that all divided regions have the same shape. Further, a plurality of stampers of the same size may be used for each area and the stampers may be selectively used and pressed.

Next, an example in which a UV curable resin is used as the thermosetting resin formed on the substrate will be described with reference to FIG. First, as shown in FIG. 7A, a rectangular substrate coated with a UV resin film (UV curable resin) such as TB-3052 manufactured by ThreeBond is prepared, and this is prepared in the same manner as in the case of the previous example. The stamper 52 is divided into four regions R1, R2, R3, and R4 having the same shape through a boundary portion 19a. It should be noted that this boundary portion 19a is formed between the scanning electrode line G and the signal electrode line S when the manufactured alignment film is incorporated in a liquid crystal display element and in the case of an active matrix substrate as described in the previous embodiment. Positioning should be performed so as to correspond to a non-display area such as above.

Next, of the region of the UV resin film, other regions R2 to R4 except the upper left region R1 are covered with a mask, the stamper 52 is aligned with the region R1 and the stamper 52 is pressed against the surface. A concave-convex portion is formed on the surface and ultraviolet rays are applied only to the region R1 to cure the UV resin layer. The area to which the stamper 52 is pressed is shown by hatching in FIG. Note that the back surface side of the substrate on which the UV resin film is formed may be covered with a mask having a desired shape, and ultraviolet rays may be irradiated from the back surface side. Then, the irradiation of the ultraviolet rays to the region R1 is stopped, and then the region R1 is covered with a mask.
The mask is removed, the stamper 52 is pressed against the region R2, and only the region R2 is irradiated with ultraviolet rays. And FIG.
As shown in (c), the stamper 52 is pressed against the region R2 to form an uneven portion on the surface. At this time, the regions R1 and R2
At the boundary between the stamper 52 and the predetermined width,
Stamper 52 to be pressed so that they do not overlap
It is preferable to adjust the position. Subsequently, similarly, the stamper 52 is sequentially pressed against each of the regions R3 and R4, and ultraviolet rays are irradiated, and a portion not irradiated with ultraviolet rays is covered with a mask to obtain an alignment film 19 shown in FIG. 7D. By performing the above operation, the concavo-convex portion can be transferred to all four regions, and the large-area alignment film 19 having the concavo-convex portion on the entire surface can be formed.

Next, an example of another method for obtaining the alignment film of the present invention will be described. FIG. 8A shows a stamper 30 used in this example. In order to manufacture an alignment film larger than the stamper 30 using this stamper 30, first, the conventional method described above with reference to FIGS. 9 and 10 is performed to form a plurality of stampers 31 having the same size as the stamper 30. (Fig. 8 (b)
4) in the case shown in FIG. Next, these stampers 3
A large stamper 32 as shown in FIG. 8 (d), in which four pieces of No. 1 are connected and the shape is transferred from the connected large mold, is manufactured. Then, by pressing the large stamper 32 against the resin film having the size shown in FIG. 8D, the alignment film 19 ′ having a shape larger than that of the stamper 30 can be obtained by one pressing operation. And this alignment film 1
Also in 9 ′, a boundary portion 19 a ″ of the unmatched portion of the uneven portion is generated in the portion corresponding to the boundary portion of the stampers 31, 31, but this boundary portion 19 ″ is similar to the case of the example described above. An alignment film 19 'that is larger than the stamper 30 and does not affect the display by being positioned in the non-display area
Can be obtained.

[0047]

As described above, according to the present invention, the alignment film is divided into a plurality of regions, and fine concave and convex portions aligned in each divided region are formed. Since the non-matching area is formed and the non-matching area is arranged in the non-display area of the liquid crystal, even if the liquid crystal alignment disorder occurs due to the mismatch of the concavo-convex portion, the actual display is not disturbed.
Further, according to the structure of the present invention, since it is sufficient to form fine uneven portions in alignment in each divided region of the alignment film accurately, it is possible to form an alignment film that does not disturb display even in a large-area alignment film. You will be able to obtain a film. Further, when the structure according to the present invention is adopted, when the uneven portion of the alignment film is transferred and manufactured by the stamper, the size of the stamper is limited, and the orientation is larger than that of the maximum size stamper to be obtained. Even if it is necessary to manufacture a film, it is sufficient to divide the alignment film into regions and form the uneven portions, so that a large-area alignment film can be easily obtained with a stamper having a smaller area. it can.

On the other hand, as the non-display area, specifically, in a liquid crystal display device having a simple matrix circuit, it is to be a portion excluding a portion sandwiched between an electrode line of one substrate and an electrode line of the other substrate. You can Further, specifically, the non-display area can be a portion excluding the pixel electrode in a liquid crystal display device including an active matrix circuit.

On the other hand, according to the method of the present invention, the resin film for forming the alignment film is divided into regions, and the stamper is pressed in each divided region to sequentially form the uneven portions, thereby dividing the unmatched portions of the uneven portions. It can be formed concentrated on the boundary portion of the region, whereby the uneven portion other than the boundary portion can be precisely formed into an accurate shape without disturbance. Therefore, there is an effect that a large-area alignment film that does not cause display disorder can be manufactured with a stamper smaller than the alignment film.

Further, a thermosetting resin is used as a resin film for forming the alignment film, the resin film is divided into regions, each divided region is heated to a temperature not lower than the curing temperature of the thermosetting resin, and a stamper is pressed to form unevenness. By forming the portion, the uneven portion can be surely transferred to the thermosetting resin film, and the uneven portion having an accurate size and shape without disturbance can be formed. Further, by keeping the area where the uneven shape is not yet formed in the divided area of the resin film below the curing temperature of the thermosetting resin, even if the stamper is pressed to a specific area, it is kept below the surrounding curing temperature. Since the shape of the area does not change, the uneven portion of the already formed specific divided area is not deformed by pressing the stamper against another area adjacent to it.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an equivalent circuit of a substrate for an active matrix liquid crystal display device.

FIG. 2 is a plan view showing a structural example of a main part of a substrate for an active matrix liquid crystal display device provided with an alignment film according to the present invention.

FIG. 3 (a) is a plan view showing one structural example of an active matrix liquid crystal display device provided with an alignment film according to the present invention, and FIG. 3 (b) is provided with an alignment film according to the present invention. It is a top view which shows the other structural example of an active matrix liquid crystal display device.

FIG. 4 is a plan view showing one structural example of a substrate for an active matrix liquid crystal display device provided with an alignment film according to the present invention.

FIG. 5 is a plan view showing one structural example of a simple matrix liquid crystal substrate provided with an alignment film according to the present invention.

FIG. 6 is a view for explaining an example of the method of the present invention, and FIG. 6 (a) is a plan view showing a region division state of an alignment film,
6B is a plan view for explaining a state where the stamper is pressed to the first area, and FIG. 6C is a plan view for explaining a state where the stamper is pressed to the second area. (D)
[Fig. 3] is a plan view showing the obtained alignment film.

FIG. 7 is a view for explaining another example of the method of the present invention, FIG. 7 (a) is a plan view showing a region division state of the alignment film, and FIG. 7 (b) shows a stamper as a first example. FIG. 7C is a plan view for explaining a state in which the stamper is pressed against the area.
7 is a plan view for explaining a state in which it is pressed to the area of FIG.
(D) is a plan view showing the obtained alignment film.

8A and 8B are views for explaining another example of the present invention, FIG. 8A is a plan view showing a stamper, and FIG. 8B is a plan view showing a state in which a plurality of stampers are duplicated. Figure 8 (c)
FIG. 8A is a plan view for explaining a state in which a stamper is formed by using a plurality of stampers, and FIG. 8D is a plan view of the obtained alignment film.

FIG. 9 is a cross-sectional view showing one structural example of a substrate provided with a conventional alignment film.

FIG. 10 is a cross-sectional view showing an example of a pressing device including a stamper and a substrate.

FIG. 11 is a bottom view showing a conventional stamper.

FIG. 12 is a plan view showing a large-area alignment film.

[Explanation of symbols]

G, scan electrode line, S,
Signal electrode line, 3, thin film transistor,
6, 23, substrate, 9, gate insulating film,
10, semiconductor layer, 12,
Source electrode, 15, pixel electrode,
19, 21, alignment film, 19a, 21a, boundary part, 20, liquid crystal, 25, 27,
Substrate, 26, 28, electrode wire, 29,
Display area, R1, R2, R3, R4, area, 41, substrate, 42,
Substrate body, 43, alignment film,
44, substrate portion, 45, substrate, 43a, uneven portion, 47,
Press machine, 48, pedestal, 49,
Upper plate, 50, polymer resin film, 51, recess, 5
2, stamper, 53, stopper, 55, alignment film, 56,
Border,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Kurokawa 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd.

Claims (5)

[Claims] 1. An alignment film formed on a liquid crystal side surface of a substrate, which is provided in a liquid crystal display device in which liquid crystal is sealed between opposed substrates, wherein the liquid crystal side surface of the alignment film comprises: Fine alignment concave and convex portions are formed, and the alignment film is divided into a plurality of regions, and the concave and convex portions are accurately aligned in each of these divided regions. An alignment film for a liquid crystal display device, characterized in that a non-matching region is formed in which uneven portions of the region are mismatched, and the non-matching region is arranged in a non-display area of the liquid crystal display device. 2. The alignment film for a liquid crystal display device according to claim 1, wherein the substrate is provided with electrodes for aligning liquid crystals, and the electrodes are a plurality of electrode lines formed on one substrate and the other substrate. And a plurality of electrode lines formed in a matrix structure, wherein the non-matching region is formed in a portion excluding an intersection of the electrode line of one substrate and the electrode line of the other substrate. Alignment film for liquid crystal display device. 3. The alignment film for a liquid crystal display device according to claim 1, wherein the substrate is provided with a circuit for aligning liquid crystal, and the circuit is formed on the substrate by scanning electrode lines, signal electrode lines and switches. An alignment film for a liquid crystal display device, which is an active matrix circuit including an element and a pixel electrode, wherein the unmatched region is formed in a portion excluding the pixel electrode. 4. A method for manufacturing an alignment film formed on a liquid crystal side surface of a substrate, which is provided in a liquid crystal display device in which liquid crystal is sealed between opposed substrates, wherein a fine uneven portion is provided. A stamper is pressed against a resin film formed on a substrate to form an alignment film having fine irregularities. The resin film is formed so that the boundary portion is located in a non-display area of a liquid crystal display device. A method for manufacturing an alignment film for a liquid crystal display device, which comprises dividing the film into a plurality of regions via a portion and pressing a stamper in each region to form an alignment film having a concavo-convex portion on the entire surface of the resin film. 5. A thermosetting resin film is used as a resin film formed on a substrate, and a region where a stamper is pressed is heated to a temperature equal to or higher than a curing temperature of the thermosetting resin, and a region where an uneven shape is not formed is formed. The uneven portion is formed by maintaining the temperature below the curing temperature of the thermosetting resin.
A method for producing an alignment film for a liquid crystal display device as described above.