WO2014073676A1

WO2014073676A1 - Patterned-film production device and production method

Info

Publication number: WO2014073676A1
Application number: PCT/JP2013/080376
Authority: WO
Inventors: 英章香川; 和宏沖
Original assignee: 富士フイルム株式会社
Priority date: 2012-11-12
Filing date: 2013-11-11
Publication date: 2014-05-15
Also published as: JP2014095845A

Abstract

Provided are a patterned-film production device and method, with which a patterned film having a striped pattern exhibiting highly precise individual line width and highly precise spacing between each line can be efficiently produced. This production device produces a patterned phase-difference film. A light exposure device provided to the production device irradiates, with illumination light from a light source unit, via a mask unit, a film being continuously conveyed. The mask unit is provided with a first mask and a second mask which are disposed with a distance (D) therebetween. A plurality of slits arranged in the width direction of the film are formed respectively in the first mask and the second mask. The first mask and the second mask are assembled such that the respective slits thereof completely overlap each other in the light path of the illumination light.

Description

Pattern film manufacturing apparatus and manufacturing method

The present invention relates to a manufacturing apparatus and a manufacturing method of a pattern film having a stripe pattern that requires high accuracy in individual line widths and intervals between lines.

There is known a method of forming a stripe pattern extending in the film transport direction by continuously exposing a film having a photosensitive film formed on the surface while exposing through a mask plate. For example, a mask plate known from Japanese Patent Application Laid-Open No. 9-274323 and International Publication No. 2010/090429 A2 has a light transmission slit that is elongated in the film transport direction on one side of a transparent glass substrate. And a mask layer arranged at a constant pitch. The mask plate is disposed as close as possible so that the mask layer does not contact the surface of the film, and the surface of the film is exposed to a stripe pattern by a so-called proximity method.

A pattern phase difference film (Film Patterned Retarder: hereinafter referred to as FPR) known from International Publication No. 2010/090429 A2 is used as an optical filter of a stereoscopic image display device using polarization glasses having different circular polarization directions on the left and right sides. . This pattern retardation film has a stripe pattern in which first and second retardation regions having a line width of 250 to 700 μm are alternately arranged horizontally. In the first phase difference region and the second phase difference region, rod-like liquid crystal layers oriented so that their optical axes are orthogonal to each other are formed. The line widths of the first phase difference area and the second phase difference area are matched with the pixel pitch constituting the horizontal line of the display screen of the stereoscopic image display device with high accuracy. A stereoscopic image is observed by observing the display light whose polarization direction is modulated for each horizontal pixel line through the corresponding first and second phase difference regions and polarizing glasses.

In the International Publication No. 2010/090429 A2, two types of mask plates are used in which the slit and the light-shielding part are exchanged in the width direction when the FPR is manufactured. These mask plates are arranged in the film transport direction, and ultraviolet rays having different polarization directions are sequentially irradiated through the respective mask plates while transporting the film. As a result, the polymer layer of the film becomes a film for expressing stripe-like orientation characteristics corresponding to the polarization direction of the irradiated ultraviolet rays. On the film thus obtained, a liquid crystal layer (phase layer) containing rod-shaped liquid crystals (nematic liquid crystals) is formed, and the rod-shaped liquid crystals are aligned corresponding to the respective regions of the above-described film, so that the optical axes are orthogonal to each other. An FPR in which stripe-like first and second phase difference regions are alternately arranged is obtained. Also in this International Publication No. 2010/090429 A2, exposure is performed by a proximity method using a mask plate in which a plurality of slits are formed at the time of ultraviolet irradiation.

In the FPR manufacturing method described in International Publication No. 2010/090429 A2, pattern exposure must be performed at two locations on the film conveyance path using two types of ultraviolet rays having different polarization directions. Here, an attempt has been made to more efficiently manufacture an FPR using a film whose orientation characteristics can be varied depending on whether or not illumination light such as ultraviolet rays is irradiated. In this manufacturing method, an exposure region and a non-exposure region corresponding to the first and second retardation regions can be obtained by performing a single exposure with a stripe pattern on the film. However, it is necessary to perform high-accuracy exposure by a proximity method using a mask plate. In manufacturing this FPR, a mask plate is used in which slits elongated in the film transport direction are arranged at a constant pitch in the film width direction.

In order to increase the accuracy of the exposure pattern when the film being conveyed is exposed by the proximity method, it is preferable that the illumination light directed from the light source to the mask plate is made parallel light. When the illumination light is incident obliquely with respect to the width direction of the film and passes through the slit, depending on the direction of inclination of the illumination light, it is blocked by the edge of the slit and the line width of the stripe pattern becomes narrow, or illumination that has passed through the slit diagonally The light enters the area that should be shielded, and the width of the shading band becomes narrow.

In this way, the boundary between the exposure area and the non-exposure area becomes an intermediate exposure area (hereinafter referred to as a blur area), which is an exposure amount at an intermediate level. A non-oriented region that is not oriented in any direction. Thus, if the line width of the non-oriented region generated at the boundary between the first and second retardation regions is sufficiently narrow, there is no practical problem because it is hidden by the black matrix of the liquid crystal color filter. When it gets thick, it becomes a big problem.

In addition, when illuminating the film that is continuously transported with illumination light, the irradiation time is limited depending on the transport speed, so it is necessary to arrange a plurality of light sources in the width direction of the film so that a sufficient amount of light can be obtained. It is normal. Furthermore, as described above, a light source device that combines a light source close to a point light source and a reflector having a parabolic surface as a reflecting surface so as to obtain illumination light close to parallel light toward the mask plate is used. They are also arranged in the direction.

However, even if a plurality of light source devices that combine a light source close to a point light source and a reflector having a parabolic reflecting surface are arranged in the width direction of the film, the illumination light from one light source device is made to be completely parallel light. It is extremely difficult. For this reason, for example, when a plurality of slits arranged in parallel are passed, the exposure amount becomes an intermediate level at the boundary between the exposure region and the non-exposure region, resulting in a loss of pattern exposure accuracy. Further, in the region on the film where the illumination light from adjacent light source devices overlaps and reaches the mask plate, a blur region is formed at the boundary between the exposure region and the non-exposure region, and the range in which the blur region is generated is likely to be widened.

To alleviate this problem, increase the number of light source devices arranged in the width direction of the film, and use a light source that can be considered as a point light source, and install a parabolic mirror or collimator lens processed with high precision. It can be handled by combining them. However, both cause a significant increase in equipment costs.

The present invention provides a pattern film that can efficiently produce a pattern film having a stripe pattern that requires high accuracy in the individual line widths and the spacing between the lines without incurring high costs in the pattern exposure part. An object is to provide a manufacturing apparatus and a manufacturing method.

The pattern film manufacturing apparatus of the present invention includes a transport mechanism unit, a light source device, a first mask, a second mask, and an optical property imparting unit. A conveyance mechanism part conveys continuously the film which formed the reaction film which reacts with the light of a specific wavelength on the surface. The light source device emits light of the specific wavelength in a non-parallel manner. The first mask is disposed between the light source device and the film. The first mask has a first mask pattern in which a plurality of first slits whose longitudinal directions coincide with the film transport direction are arranged at a constant pitch in the width direction of the film. The first mask allows light out of the light emitted from the light source device to pass through the film, the light shaped into a plurality of lines by the plurality of first slits. The second mask is disposed between the first mask and the light source device. The second mask has a second mask pattern in which a plurality of second slits whose longitudinal directions coincide with the film transport direction are arranged at a constant pitch in the width direction of the film. The second mask blocks light emitted from the light source device and passing through the first slit and obliquely entering between the light shielding portion between the first slits and the reaction film. The optical property imparting unit imparts a function having different optical transmission characteristics to the exposed region and the non-exposed region of the reaction film that are pattern-exposed through the first and second masks.

It is preferable that the first mask and the second mask are formed of a light shielding film provided on the surface of a transparent quartz glass mask base material on which each slit pattern through which the light passes is formed. The light shielding film is preferably formed of a heat resistant inorganic material.

The pattern film manufacturing apparatus preferably includes a backup roller. A part of the film is wound around the backup roller, and the back surface of the film is supported by the outer peripheral surface. The light that has passed through the first and second masks is irradiated onto the surface of the film supported by the backup roller.

The optical property imparting section is preferably a liquid crystal layer forming section that forms a liquid crystal layer by applying a coating liquid containing liquid crystal to the reaction film that has been pattern-exposed through the first and second masks.

The pattern film manufacturing method of the present invention includes a transport step and an irradiation step. In the transport step, a film having a reaction film that reacts with light of a specific wavelength formed on the surface thereof is transported continuously. In the irradiation step, the light having the specific wavelength emitted from the light source device is continuously transported after being shaped into a line through a pair of masks formed with a narrow slit in the film width direction at a constant pitch in the film transport direction. Irradiate the surface of the film inside.

In the irradiation step, it is preferable that the surface of the film whose back surface is supported by being wound around a backup roller is irradiated with light having the specific wavelength shaped in a line shape.

It is preferable that the manufacturing method of a pattern film includes the photoreactive film formation step which forms the said reaction film on the surface of a film before the said conveyance step. It is preferable to perform a rubbing treatment on the surface of the film before or after the irradiation step. It is preferable to have a liquid crystal layer forming step of forming a liquid crystal layer by applying a coating liquid containing liquid crystal on the surface of the film after performing both the irradiation step and the rubbing treatment.

While using illumination light emitted in a non-parallel manner from the light source device, the second mask masks light having a tilt in the width direction of the film that greatly enters the portion to be shielded by the first mask. This is advantageous in narrowing the region irradiated to the portion to be shielded and making the line width uniform.

It is explanatory drawing which shows the structure of the manufacturing apparatus of a pattern phase difference film. It is explanatory drawing which shows a pattern phase difference film. It is explanatory drawing which shows the arrangement | sequence of each lamp | ramp of a lamp array. It is a perspective view which shows the structure of each mask board. It is explanatory drawing which shows the incident state of the light ray to each mask board and a film. It is explanatory drawing which shows the structure of the manufacturing apparatus of the pattern phase difference film which provided the rubbing process part in front of the exposure apparatus.

In FIG. 1, a manufacturing apparatus 10 that implements the present invention processes a supplied film 18 to manufacture a pattern retardation film (hereinafter referred to as FPR) 19. The manufacturing apparatus 10 includes a transport mechanism unit 12, a reaction film forming unit 14, an exposure device 15, a rubbing processing unit 16, a liquid crystal layer forming unit 17, and the like. The film 18 is transparent and flexible, and is drawn from, for example, a film roll (not shown) and supplied to the manufacturing apparatus 10. The film 18 is continuously conveyed at a constant speed by the conveyance mechanism unit 12.

In the FPR 19 manufactured by the manufacturing apparatus 10, as shown in FIG. 2, the first retardation region 21 and the second retardation region 22 are alternately arranged in the width direction of the long film 18. The first retardation region 21 and the second retardation region 22 extend in a stripe shape in the direction in which the film 18 is conveyed at the time of manufacture. In the first and second phase difference regions 21 and 22, the optical axes, for example, the slow axes are orthogonal to each other as indicated by arrows A1 and A2 in the drawing. These first and second retardation regions 21 and 22 exhibit retardation characteristics by changing the alignment direction of the liquid crystal layer formed on the surface of the film 18. Reference numeral 23 denotes a non-oriented region formed at each boundary portion between the first and second retardation regions 21 and 22 and extends in the transport direction of the film 18 when the FPR 19 is manufactured.

The first retardation region 21 is formed with a width W1, and the second retardation region 22 is formed with a width W2. The arrangement pitch in the width direction of the first and second phase difference regions 21 and 22 is P1. The arrangement pitch P1 is “width W1”. The width W2 is smaller than the width W1 by “the width Wa × 2 of the non-oriented region 23” and is “width W1−width Wa × 2”. The width W1 can be selected from various values, but is usually set to 300 to 700 μm. The width Wa of the non-oriented region 23 is preferably uniform and small, but is 15 μm or less. In FIG. 2, the width of the non-oriented region 23 is exaggerated with respect to the width of each of the phase difference regions 21 and 22.

In the reaction film forming unit 14, a coating liquid containing a photoacid generator is applied to the surface of the film 18, and further subjected to a drying process to form a reaction film 24 (see FIG. 5) having a constant film thickness. The photoacid generator is decomposed by irradiation with ultraviolet rays to generate an acid. The reaction film 24 reacts to light of a specific wavelength, in this example, ultraviolet light, by this photoacid generator. However, a curing agent or a photoacid generator that cures in response to light of a specific wavelength other than ultraviolet light may be used for the reaction film. Further, regarding the formation of the reaction film 24, a technique such as spraying other than coating may be used. The film 18 on which the reaction film 24 is formed is sent from the reaction film forming unit 14 to the exposure device 15.

The exposure device 15 irradiates the film 18 being continuously conveyed with illumination light with a striped exposure pattern corresponding to the pattern of the first and second retardation regions 21 and 22 to be formed. As illumination light, light corresponding to the type of photochemical reaction of the reaction film 24 is used, and in this example, ultraviolet light is used. Of the reaction film 24 formed on the surface of the film 18, for example, a striped pattern exposure is performed in which a portion that becomes the first retardation region 21 is a linear exposure region, and the other portion is a non-exposure region. Is called.

The exposure apparatus 15 includes a backup roller 27, a light source unit 28, a mask unit 31, and a mask holder 32 that holds the mask unit 31. The backup roller 27 is wound around the film 18 and supports the back side of the film 18 with the peripheral surface 27a. The backup roller 27 is rotatable and rotates following the conveyance of the film 18. The backup roller 27 may be rotated by a motor or the like in synchronization with the conveyance of the film 18.

The light source unit 28 includes a light source device array 33 in which a plurality of light source devices 30 are arranged at a pitch P2 in the width direction of the film 18 as shown in FIG. Each of the light source devices 30 includes an ultraviolet lamp 30a that emits ultraviolet light as illumination light, and an illumination optical system (not shown) that includes a reflector 30b that reflects the illumination light emitted from the ultraviolet lamp 30a toward the backup roller 27. Have. The illumination optical system is a well-known one that increases the utilization efficiency of the illumination light from the ultraviolet lamp 30a. For example, if the reflecting surface of the reflector 30b is shaped like a parabolic mirror, the illumination light parallel to the backup roller 27 is parallel. The degree can be kept high. However, in general, the ultraviolet lamp 30a is not regarded as a point light source, and illumination light radiated at a radiation angle of 7 to 8 ° or more even if a parabolic mirror is incorporated in each of the light source devices 30 to increase parallelism. It is normal to become. Accordingly, the illumination light is irradiated toward the backup roller 27 while being optically non-parallel.

The illuminance on the film 18 by illumination from the light source unit 28 is preferably, for example, 200 mW / cm ² or more, and more preferably 500 mW / cm ² or more. In order to increase the use efficiency of illumination light and increase the accuracy of pattern exposure, it is necessary to suppress the radiation angle of illumination light emitted from each light source device 30 to 10 ° or less in at least the width direction of the film 18. desirable. In order to keep the radiation angle small, a lens may be used instead of or in addition to the reflector 30b described above.

The mask holder 32 holds the mask unit 31 in which the first mask plate 41 and the second mask plate 42 are overlapped, and positions the mask unit 31 so that the first mask plate 41 is close to the film 18. The first mask plate 41 shapes the illumination light from the light source unit 28 into a striped exposure pattern corresponding to the first and second phase difference regions 21 and 22 and passes it through the film 18 to be exposed by the proximity method. I do. The second mask plate 42 positioned between the first mask plate 41 and the light source unit 28 is used for the purpose of uniformly limiting the width Wa of the non-oriented region 23 shown in FIG. 2 as narrowly as possible. .

As shown in FIG. 4, the first mask plate 41 is formed by vapor-depositing a first mask 41a made of an inorganic material having excellent heat resistance and light shielding properties such as chromium on the surface of a transparent mask base material 41b. It is. The first mask plate 41 is arranged so that the first mask 41a faces the surface of the film 18 with an interval of 300 μm. The mask base material 41b is preferably made of a material that satisfies each condition of high spectral transmittance with respect to illumination light, high heat resistance, and low thermal expansion coefficient. For example, quartz glass. Among quartz glasses, ozoneless quartz glass, synthetic quartz glass, and natural quartz glass, which are excellent in ultraviolet transmittance and stable to heat from an ultraviolet light source, are preferable.

The first mask 41a has a pattern in which a large number of slits 41s having an opening width Ws1 and a length L are arranged at a pitch P3 in the width direction of the film 18, and the light shielding width Ws2 between adjacent slits 41s is also the same as the opening width Ws1. It is. The second mask plate 42 is configured similarly to the first mask plate 41. The second mask plate 42 is used with the second mask 42 a facing the light source unit 28. The opening width Ws1, the light shielding width Ws2, and the pitch P3 of the slits 42s constituting the pattern of the second mask 42a are also made the same as the first mask plate 41. In addition, in order to avoid complication of a figure, the number of

slits

41s and 42s is shown few.

The arrangement pitch P3 of the slit 41s is twice the arrangement pitch P1 of the first and second phase difference regions 21 and 22 shown in FIG. 2, and the opening width Ws1 of the slit 41s is equal to the width W1 of the first phase difference region 21. It is the same. The light shielding width Ws2 between the slits is also set to be the same as the width W1 of the first phase difference region 21. Accordingly, the width W2 of the second phase difference region 22 corresponding to this should be equal to the width W1, but actually the width W2 of the second phase difference region 22 is “the width Wa × 2 of the non-oriented region 23”. It gets smaller by the minute.

The length L of the slit 41s takes into consideration the photosensitivity of the photoacid generator contained in the reaction film 24 that undergoes chemical reaction upon exposure, the transport speed of the film 18, the intensity of ultraviolet rays emitted from the light source unit 28, and the like. For example, the length L can be set to 20 mm. If the length L is too long, the surface of the film 18 that is curved and supported by the backup roller 27 is separated from the first mask 41a at both ends of the slit 41s, and the illumination light that has passed through the slit 41s is likely to spread in the width direction. Therefore, it is preferable to consider the outer diameter of the backup roller 27 in advance. If the length L is shortened too much, the exposure time is shortened. Therefore, it is necessary to consider the intensity of illumination light from the light source unit 28, the conveyance speed of the film 18, and the like.

As shown in FIG. 5, the first and

second mask plates

41 and 42 described above are brought into close contact with the surfaces opposite to the surfaces on which the first and

second masks

41a and 42a are formed, so that the mask unit 31 is attached. It is configured and held by a mask holder 32. The surfaces of the

masks

41 a and 42 a are aligned in parallel with each other, and are arranged so as to cross the optical path between the light source unit 28 and the film 18 vertically. Then, the first mask 41a and the second mask 42a are separated by a distance D that is the sum of the thicknesses of the

mask base materials

41b and 42b. In this example, since the thickness of the

mask base materials

41b and 42b is 3000 μm, the distance D is 6000 μm.

As shown in FIG. 5, the first and

second mask plates

41 and 42 are combined so that the

slits

41s and 42s formed in the

respective masks

41a and 42a completely overlap in the optical path of the illumination light. Therefore, the light beam L0 radiated from the light source unit 28 substantially in parallel, passing through the vicinity of the edge of the slit 41a of the first mask plate 41 and perpendicularly incident on the reaction film 24 on the surface of the film 18 is reflected on the second mask plate 42. Similarly, when passing through the slit 42s, it passes through the vicinity of the edge.

Of the light rays L1 to L3 included in the illumination light emitted from the light source unit 28 with a radiation angle θ of 7 to 8 ° or more, the light ray L1 whose radiation angle θ does not exceed 10 ° is the first of the light rays L0. 1 through the slit 41 s of the mask 41 a to reach the reaction film 24 and give an intermediate level exposure, which causes a blur region 46. If the radiation angle θ is within a small range, the blur region 46 is Narrow. Further, like the light beam L2, a light beam that travels toward the slit 41s of the first mask 41a at a radiation angle θ exceeding 10 ° is blocked by the second mask 42a, and the width of the blurred region 46 is not increased. The light beam L3 that reaches the reaction film 24 through the

slits

41s and 42s at different positions in the first mask 41a and the second mask 42a is irradiated on the exposure region corresponding to the first phase difference region 21, which is inconvenient. Absent.

By changing the distance D, it is possible to adjust the angle of the light beam allowed to reach the reaction film 24 through each slit 41s of the first mask 41a. If the interval D is increased, the radiation angle θ of the illumination light allowed to enter the slit 41s of the corresponding first mask 41a through the slit 42s of the second mask 42a can be further reduced. If the distance D is too large, the illumination light having a large radiation angle θ passes through the slit 42 s at a specific position of the second mask 42 a, but not the slit 41 s of the first mask 41 a immediately below it in FIG. 5. It is preferable not to make it too large because there is a risk of passing through the vicinity of the edge of the slit 41s adjacent to the slit 41s and entering the light shielding area immediately below the slits. In addition, the light shielding area immediately below the adjacent slits 41s is an area between the slits 41s and the reaction film 24.

Note that the

slits

41 s and 42 s formed in the first and

second mask plates

41 and 42 so that the width W 2 of the second retardation region 22 in FIG. 2 is the same as the width W 1 of the first retardation region 21. The opening width Ws1 (see FIG. 4) may be narrowed from both sides, and the light shielding width Ws2 (see FIG. 4) may be made larger than the opening width Ws1 by the width Wa of the non-oriented region.

The film 18 after the exposure processing by the exposure device 15 is conveyed to the rubbing processing unit 16. The rubbing processing unit 16 is provided with a rubbing roller, a driving mechanism thereof, and the like, and performs an alignment process on the reaction film 24 after pattern exposure. The rubbing processing unit 16 performs a rubbing process on the reaction film 24 on the film 18 in a rubbing direction of 45 ° with respect to the conveying direction of the film 18 by a rubbing roller. The film 18 after the rubbing treatment is sent to the liquid crystal layer forming unit 17.

The liquid crystal layer forming unit 17 forms on the reaction film 24 a liquid crystal layer that exhibits retardation characteristics corresponding to the first and second retardation regions 21 and 22. In the liquid crystal layer forming unit 17, a coating liquid containing a vertical alignment agent, a discotic liquid crystal, and the like is applied to the surface of the reaction film 24 after the rubbing process. In the liquid crystal layer forming unit 17, processing such as heat aging and cooling is further performed, and further, the reaction film 24 is cured by irradiation of ultraviolet rays to perform alignment state fixing processing and the like. By these processes, liquid crystal layers having different optical transmission characteristics are formed in the exposed region and the non-exposed region of the reaction film 24 exposed in a stripe pattern through the first mask 41a and the second mask 42a, and as a result. The liquid crystal layer forming unit 17 functions as an optical property providing unit.

The above-described vertical alignment agent has the function of vertically raising the discotic liquid crystal with respect to the surface of the reaction film 24 and the function of aligning the discotic liquid crystal in a direction perpendicular to the rubbing direction. Due to the pattern exposure process in the exposure apparatus 15, acid is generated in the exposure region of the reaction film 24, and the discotic liquid crystal is erected vertically, but the discotic liquid crystal is oriented in a direction perpendicular to the rubbing direction. The action of aligning the liquid crystal is lost. For this reason, the discotic liquid crystal in the exposure region stands upright and is oriented in the rubbing direction.

Further, the action of the vertical alignment agent is still preserved in the non-exposed region of the reaction film 24. For this reason, in the liquid crystal layer in contact with the interface with the non-exposed region of the reaction film 24, the discotic liquid crystal stands vertically and has an orientation posture orthogonal to the rubbing direction. As a result, on the reaction film 24 formed on the surface of the film 18, a fixed width line is formed by the discotic liquid crystal layer in a posture that is erected and oriented in the rubbing direction, and a disc that is erected and orthogonal to the rubbing direction. Lines of a certain width by the tick liquid crystal layer are alternately arranged. Thus, a striped pattern of the first retardation region 21 and the second retardation region 22 whose slow axes are orthogonal to each other is obtained on the film 18.

Next, the operation of the above configuration will be described. The film 18 is continuously transported at a constant speed by the transport mechanism 12. The reaction film 24 is sequentially applied and dried by the reaction film forming unit 14 on the surface of the film 18 being conveyed. The film 18 having the reaction film 24 on the surface is sent to the exposure device 15.

In the exposure device 15, the film 18 is pattern-exposed with illumination light from the light source unit 28 while being supported by the backup roller 27. Illumination light from the light source unit 28 is applied to the reaction film 24 on the film 18 in a striped exposure pattern by the first mask plate 41 and the second mask plate 42. The

slits

41 s and 42 s provided in the first and

second mask plates

41 and 42 are elongated in the transport direction of the film 18 and arranged at a constant pitch P3 in the width direction of the film 18.

As the film 18 is transported, the position of the film 18 exposed with the illumination light continuously moves. Thereby, the exposure area | region by irradiation of illumination light extends in the shape of a line in the conveyance direction according to conveyance of the film 18. FIG. Further, a non-exposure region is formed between the exposure region and the exposure region, and as a result, the entire length of the film 18 is exposed with a striped exposure pattern.

Although the illumination light from the light source unit 28 is made to approach parallel light with respect to the width direction of the film 18, it is still inevitable that light having an angle in the width direction is included. However, in the exposure apparatus 15, in addition to the first mask plate 41 that is close to the film 18 and contributes to the proximity exposure, the second mask disposed at a distance D from the first mask plate 41 to the light source unit 28 side. Since the plate 42 is used, a light beam having a large inclination such as the light beam L2 shown in FIG. 5 is blocked by the second mask 42a and does not enter the slit 41s of the first mask 41a. Therefore, the blurred region 46 becomes narrow.

By performing pattern exposure on the reaction film 24 as described above, the photoacid generator is decomposed in the exposed region to generate acid, and no acid is generated in the non-exposed region. In the blurred area 46 exposed at the intermediate level, acid is generated according to the exposure amount, but the amount of acid generated is small because the exposure amount is small.

The film 18 after the pattern exposure processing is rubbed in a predetermined rubbing direction by the rubbing processing section 16 and then sent to the liquid crystal layer forming section 17. By the rubbing treatment, the reaction film 24 functions as a so-called alignment film that aligns the liquid crystal of the liquid crystal layer applied by the liquid crystal layer forming unit 17 in a predetermined direction. Then, a liquid crystal layer is formed on the reaction film 24 by the liquid crystal layer forming unit 17, and is heated and matured and cooled. Thus, on the film 18, a line-shaped liquid crystal layer in which vertically extending discotic liquid crystals are aligned in the rubbing direction in correspondence with an exposure pattern in which line-shaped exposed areas and non-exposed areas are alternately arranged at a constant width. As a result, a stripe-like pattern is obtained in which vertically extending discotic liquid crystals are alternately arranged with a constant width in a line-like liquid crystal layer oriented perpendicular to the rubbing direction.

These liquid crystal layers become a first retardation region 21 and a second retardation region 22 whose slow axes are orthogonal to each other. In the blurred region 46, since the amount of the generated acid is small, the discotic liquid crystal is not aligned in a specific direction with respect to the rubbing direction, and becomes the non-oriented region 23. Thereafter, the curing process of the reaction film 24 is performed by irradiation of ultraviolet rays, and the alignment state of the liquid crystal layer is fixed together with this to obtain FPR19.

In the above embodiment, the rubbing process is performed after the exposure by the exposure apparatus 15. However, as shown in FIG. 6, a rubbing processing unit 16 may be provided on the upstream side of the exposure device 15 in the transport direction of the film 18, and the rubbing processing may be performed before exposure.

FPR19 was manufactured with the manufacturing apparatus 10. Each of the

mask plates

41 and 42 used in the exposure apparatus 15 has first and second chromium formed on one surface of each of the first and second

mask base materials

41b and 42b made of ozoneless quartz glass having a thickness of 3000 μm by sputtering.

Masks

41a and 42a are formed.

The mask unit 31 was made with the surfaces of the first and

second mask plates

41 and 42 opposite to the mask being in close contact with each other. The mask unit 31 was held by a mask holder 32 and arranged to face the backup roller 27. The width Ws1 of the slit 41s and the interval Ws2 between the slits are both 530 μm wide. In addition, the distance D obtained by combining the thicknesses of the

mask base materials

41b and 42b at this time was 6000 μm. The mask unit 31 was disposed with a gap of 300 μm between the first mask 41 a and the surface of the film 18.

The long film 18 subjected to the saponification treatment was continuously guided to the production apparatus 10, and the FPR 19 was continuously produced as follows. In this production, a film 18 made of cellulose acetate was first prepared.

<Preparation of film 18>
In order to produce the film 18, the cellulose acetate solution A and the additive solution B were prepared, respectively. The composition of the cellulose acetate solution A is shown below. The following components of the cellulose acetate solution A were put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution A.

Composition of Cellulose Acetate Solution A Cellulose acetate with a substitution degree of 2.86 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Methylene chloride (first component of the solvent) 300 parts by mass Methanol (second component of the solvent) 54 parts by mass 1-butanol 11 parts by mass

Additive solution B was prepared using another mixing tank. The composition of the additive solution B is shown below. Each of the following components of additive solution B was put into a mixing tank and stirred while heating to dissolve each component to prepare additive solution B. In addition, the following “Re reducing agent” means a retardation reducing agent.

Composition of additive solution B The following compound B1 (Re reducing agent) 40 parts by mass The following compound B2 (wavelength dispersion controlling agent) 4 parts by mass Methylene chloride (first component of solvent) 80 parts by mass Methanol (second component of solvent) 20 Parts by mass

<< Preparation of film 18 made of cellulose acetate >>
40 parts by mass of additive solution B was added to 477 parts by mass of cellulose acetate solution A, and the mixture was sufficiently stirred to prepare a dope. The dope was supplied to a casting die (not shown), and the dope was discharged from the casting port of the casting die onto the peripheral surface of the rotating drum cooled to 0 ° C. The cast film formed by casting on the peripheral surface of the drum by this outflow was peeled off from the drum in a state where the solvent content was 70% by mass. The cast film, that is, the wet film peeled off, was guided to a pin tenter (a pin tenter described in FIG. 3 of JP-A-4-1009). Both ends in the width direction of the wet film are fixed with a plurality of pins of a pin tenter, and the stretching ratio in the width direction (direction perpendicular to the longitudinal direction of the wet film) is 3% with a solvent content of 3 to 5% by mass. The wet film was dried while changing its width. Thereafter, the wet film was guided to a heat treatment apparatus in which a plurality of rollers were arranged along the conveyance path of the wet film. The wet film was further dried by transporting the inside of the heat treatment apparatus with a roller to obtain a film 18 having a thickness of 60 μm. This film 18 did not contain an ultraviolet absorber, Re (measurement wavelength was 550 nm) was 0 nm, and Rth (measurement wavelength was 550 nm) was 12.3 nm.

<< Alkaline saponification treatment >>
The obtained film 18 was passed while contacting a dielectric heating roller having a temperature of 60 ° C., and the surface temperature of the film 18 was raised to 40 ° C. Then, the alkali solution of the composition shown below was apply | coated to the single side | surface of the film 18 by the coating amount of 14 ml / m < ² > using the bar coater. The film 18 coated with the alkaline solution was heated to 110 ° C. and conveyed for 10 seconds under a steam far-infrared heater manufactured by Noritake Co., Limited. Subsequently, pure water was applied at a coating amount of 3 ml / m ² using the same bar coater. The washing process was then repeated 3 times. The washing process consists of washing with a fountain coater and draining with an air knife. After this washing step, the film 18 was dried by being conveyed through a drying zone at 70 ° C. for 10 seconds to obtain an alkali saponified film 18.

Composition of alkaline solution Potassium hydroxide 4.7 parts by weight Water 15.8 parts by weight Isopropanol 63.7 parts by weight Surfactant (SF-1: C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₂₀ H) 1.0 Parts by weight propylene glycol 14.8 parts by weight

<Manufacture of FPR19>
The film 18 subjected to the saponification treatment as described above was sent to the reaction film forming unit 14, and the coating solution for forming the reaction film 24 was continuously applied to the surface of the film 18 subjected to the saponification treatment. The coating solution has the following composition. The application was performed with a # 8 wire bar. The coating liquid applied on the film 18 was dried with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds, thereby forming a reaction film 24.

Composition of coating solution for forming reaction film 24 3.9 parts by mass of polymer material for forming reaction film 24 (PVA103, Kuraray Co., Ltd. polyvinyl alcohol)
Photoacid generator (S-2) 0.1 part by weight Methanol 36 parts by weight Water 60 parts by weight

Next, the film 18 was irradiated with ultraviolet rays from the light source unit 28 through the mask unit 31. From the light source unit 28, two air-cooled mercury lamps (made by HOYA Co., Ltd .: UL750) having an illuminance of 200 mW / cm ² on the film 18 in the UV-A region at room temperature air are used as the ultraviolet lamps 30a. The interval P2 between the ultraviolet lamps 30a was set to 60 mm, and the ultraviolet rays were irradiated so as to be 50 mJ / cm ² . The region for the first retardation region was formed by decomposing the photoacid generator of the reaction film 24 by ultraviolet irradiation to generate an acidic compound.

The parallelism of the illumination light output from the light source unit 28 (in the width direction of the film 18) was 10 °. Since the interval Ws2 between the slits is 530 μm and the interval D between the

masks

41a and 42a is 6000 μm, the mask unit 31 satisfies the conditional expression “0 ° <tan ⁻¹ (Ws2 / D) ≦ θ”.

Thereafter, the rubbing treatment unit 16 performed rubbing treatment on the film 18. In the rubbing treatment, rubbing was performed in one direction at 500 rpm while maintaining a 45 ° angle in the transport direction. Thus, a film 18 in which the reaction film 24 was oriented in one direction was obtained. The thickness of the reaction film 24 was 0.5 μm.

After the rubbing treatment, the following liquid crystal layer coating solution was applied by the liquid crystal layer forming unit 17 at a coating amount of 4 ml / m ² using a bar coater. Next, after aging at a film surface temperature of 110 ° C. for 2 minutes, the film was cooled to 80 ° C., and was irradiated with ultraviolet rays at 50 mJ / cm ² using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) of 200 mW / cm ^{2 in} the air. Irradiation fixed the orientation state. Thus, the first and second phase difference regions 21 and 22 whose slow axes are orthogonal to each other are FPR19 arranged in the width direction. In each of the phase difference regions 21 and 22, the discotic liquid crystal is vertically aligned, but the slow axis of the first phase difference region 21 irradiated with ultraviolet rays is parallel to the rubbing direction, and the second non-irradiated second phase is also present. The slow axis of the phase difference region 22 was orthogonal to the rubbing direction. The film thickness of the liquid crystal layer was 0.9 μm.

Composition of coating liquid for optically anisotropic layer Discotic liquid crystal E-1 100 parts by mass Alignment film interface alignment agent (II-1) 3.0 parts by mass Air interface alignment agent (P-1) 0.4 part by mass Photopolymerization 3.0 parts by weight of initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals)
Sensitizer (Kayacure-DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 part by weight Methyl ethyl ketone 400 parts by weight

Even in the region where the illumination lights from the adjacent lamps of the light source unit 28 of the FPR 19 created as described above overlap, a wide non-orientation region 23 that causes a practical problem does not occur, and a failure area where it is distributed There was no. The width Wa of the non-oriented region 23 was sufficiently thin as 8 μm at the maximum.

The pattern film manufacturing apparatus and method of the present invention have been described above according to the illustrated embodiment and specific examples. However, if it is a pattern film manufacturing apparatus or manufacturing method that uses a non-parallel illumination light from a light source unit and performs a patterned pattern exposure in a proximity manner through two mask plates that are combined to face each other, exposure is possible. It is not limited to forming a liquid crystal layer in which the directions of the slow axes are orthogonal to each other in the region and the non-exposed region. For example, by using a photo-curable film as the reaction layer and performing stripe pattern exposure, a stripe pattern in which cured portions and uncured portions are alternately arranged in a line can be obtained. After removing the uncured portion, after forming a color filter layer or light shielding layer having specific optical transmission characteristics as a whole and then removing the cured portion, striped color filter layer or light shielding It is also possible to manufacture a pattern film in which layers and stripe-shaped threading regions are alternately arranged.

Claims

A transport mechanism for continuously transporting a film having a reaction film that reacts to light of a specific wavelength on the surface;
A light source device that emits light of the specific wavelength in a non-parallel manner;
A plurality of first slits arranged between the light source device and the film and having the longitudinal direction coincided with the transport direction of the film have a first mask pattern arranged at a constant pitch in the width direction of the film. And a first mask for passing light shaped from the light source device shaped into a plurality of lines by the plurality of first slits to the film,
A second mask arranged between the first mask and the light source device, wherein a plurality of second slits whose longitudinal directions coincide with the film transport direction are arranged at a constant pitch in the width direction of the film. A second mask having a pattern and blocking light that is radiated from the light source device and obliquely enters between the light shielding portion between the first slits and the reaction film through the first slit;
An optical property imparting unit that imparts a function of different optical transmission properties to the exposed region and the non-exposed region of the reaction film that are pattern-exposed through the first and second masks;
An apparatus for producing a pattern film, comprising:
The first mask and the second mask are provided on the surface of a transparent quartz glass mask base material, and are formed of a light shielding film in which each slit pattern through which the light passes is formed. The pattern film manufacturing apparatus according to claim 1.
3. The pattern film manufacturing apparatus according to claim 2, wherein the light-shielding film is formed of a heat-resistant inorganic material.
A portion of the film is wound around and includes a backup roller that supports the back surface of the film on the outer peripheral surface, and light that has passed through the first and second masks is applied to the surface of the film supported by the backup roller. 4. The pattern film manufacturing apparatus according to claim 1, wherein the pattern film manufacturing apparatus is irradiated.
The optical property imparting section is a liquid crystal layer forming section that forms a liquid crystal layer by applying a coating liquid containing liquid crystal to the reaction film that has been pattern-exposed through the first and second masks. Item 5. A pattern film manufacturing apparatus according to Item 4.
A transport step for continuously transporting a film having a reaction film that reacts with light of a specific wavelength formed on the surface;
The film being continuously conveyed after the light of the specific wavelength radiated from the light source device is shaped into a line through a pair of masks formed with a narrow slit in the film width direction at a constant pitch in the film conveyance direction. An irradiation step for irradiating the surface of
A process for producing a patterned film, comprising:
7. The pattern film according to claim 6, wherein, in the irradiation step, the surface of the film whose back surface is supported by being wound around a backup roller is irradiated with the light having the specific wavelength shaped in a line shape. Manufacturing method.
The method for producing a patterned film according to claim 6 or 7, further comprising a photoreactive film forming step of forming the reactive film on the surface of the film before the transporting step.
The pattern film manufacturing method according to claim 8, wherein a rubbing treatment is performed on the surface of the film before or after the irradiation step.
10. A liquid crystal layer forming step of forming a liquid crystal layer by applying a coating liquid containing liquid crystal on the surface of the film after performing both the irradiation step and the rubbing treatment. Manufacturing method of pattern film.