JP6136665B2 - Process for producing pattern retardation film, mask, and roll body of pattern retardation film - Google Patents

Description

  The present invention relates to a pattern retardation film according to a passive three-dimensional image display device.

  In recent years, an image display device that displays a three-dimensional image by a passive method has been provided. Here, FIG. 8 is a schematic diagram showing a passive type image display apparatus using a liquid crystal display panel. The passive type image display device sequentially assigns pixels of the liquid crystal display panel that are continuous in the vertical direction or the horizontal direction (vertical direction in the example of FIG. 8) to the right eye and the left eye, respectively. Driving with the image data for the left eye, thereby displaying the image for the right eye and the image for the left eye simultaneously. In addition, a pattern retardation film is arranged on the panel surface (viewer side) of the liquid crystal display panel so that the light emitted from the right-eye pixel and the left-eye pixel is linearly polarized light having different directions for the right-eye and left-eye. Convert to As a result, in the passive method, glasses equipped with corresponding polarizing filters are worn, and a right-eye image and a left-eye image are selectively provided to the viewer's right and left eyes, respectively, and a three-dimensional image is displayed. To do.

  Therefore, in the pattern retardation film, two types of band-like regions in which the slow axis direction (direction in which the refractive index is maximized) are orthogonal to each other are sequentially formed corresponding to the setting of the pixels in the liquid crystal display panel. Thus, in the passive method, glasses equipped with corresponding polarizing filters are worn, and a right-eye image and a left-eye image are selectively provided to the viewer's right eye and left eye, respectively. Here, as the slow axis direction of the adjacent band-like region, a combination of +45 degrees and −45 degrees, or 0 degrees and +90 degrees with respect to the horizontal direction is usually employed. In the example of FIG. 8, the long side direction of the screen is shown as the horizontal direction in accordance with the name in the normal image display apparatus.

  This passive method can also be applied to an image display device having a slow response speed, and can display three-dimensionally with a simple configuration using a pattern retardation film and circularly polarized glasses. Note that the passive image display apparatus employs a method in which pixels that are continuous in the horizontal direction are sequentially and alternately distributed for the right eye and the left eye, instead of the vertical direction in the example of FIG.

  The pattern phase difference film according to this passive method requires a pattern-like phase difference layer that gives a phase difference to transmitted light corresponding to the allocation of pixels. With respect to this pattern retardation film, Patent Document 1 discloses a method of forming a retardation layer by forming a photo-alignment layer on a glass substrate with controlled orientation regulating force and patterning the alignment of liquid crystals with this photo-alignment layer. Is disclosed. Further, Patent Document 2 discloses a method of forming an alignment layer in which a fine uneven shape is formed on the peripheral side surface of a roll plate by laser irradiation, and the uneven shape is transferred to control the alignment regulating force in a pattern shape. ing. Patent Document 3 proposes a method for evaluating a pattern retardation film.

  Such a pattern retardation film is required to have high quality, and straightness is required as one of quality evaluation standards. Here, the pattern retardation film is arranged on the image display panel with the screen center as a reference, and as shown in FIG. 9, the border D of the band-shaped region for the right eye and the left eye at the center of the screen is centered on the screen. Straightness is defined by the maximum deviation amount ΔL of the boundary D with respect to the virtual straight line set to O (represented by taking the screen upward direction as positive). Note that the virtual straight line of the straightness measurement standard is a straight line connecting the boundaries of both ends of the screen.

  If the straightness varies, the image display device has a small margin when the pattern retardation film is attached to the image display panel, and in a severe case, the crosstalk increases. Here, crosstalk is a phenomenon in which light emitted from the image display panel that should be provided to the viewer's right and left eyes leaks into the opposite left and right eyes. The stereoscopic effect is lost, and the deterioration of the image quality is perceived.

  Such a pattern retardation film can be efficiently mass-produced by continuous treatment of a long transparent film material provided by a roll. However, in such continuous processing of transparent film material, various stresses are applied to the transparent film during the production process to accumulate (hold) strain, and when the cutting process cuts to the screen size, the accumulated stress is released. Is done. As a result, it was found that in the completed pattern retardation film, the straightness deteriorated and the straightness varied.

JP 2005-49865 A JP 2010-152296 A JP 2013-15564 A

  The present invention has been made in view of such a situation. Regarding a pattern retardation film applied to a passive image display device, in production by continuous processing of a long transparent film material provided by a roll. The variation in straightness can be reduced.

  In order to solve the above-mentioned problems, the present inventor has conducted extensive research and, when taking a plurality of pattern retardation films in the width direction of a long transparent film, at least the pattern retardation films at both ends with respect to the film center. In this way, the pattern retardation film according to this line symmetric shape has the idea that the variation in straightness is made positive or negative, and the present invention has been completed.

(1) In the method for producing a pattern retardation film, the substrate is processed sequentially while transporting a substrate with a long transparent film material, and a plurality of pattern retardation films are produced in the width direction of the transparent film material.
An alignment film production step for producing an alignment film on the transparent film material,
On the alignment film, a retardation layer is formed by a right-eye region that gives a phase difference corresponding to right-eye transmitted light and a left-eye region that gives a phase difference corresponding to left-eye transmitted light. A phase difference layer manufacturing process,
The alignment film manufacturing step includes
About the pattern phase difference film produced from the at least both ends of the width direction of the said transparent film material, the said alignment film is produced by a line symmetrical shape with respect to the film center.

  According to (1), with respect to the pattern retardation film produced from at least both end portions, it is possible to match the straightness of the straightness, and to reduce variations in straightness.

(2) In (1),
The alignment film manufacturing step includes
The alignment film is produced in a line-symmetric shape with respect to the center of the film by disposing the alignment film in the dummy region of the pattern retardation film.

  According to (2), variation in straightness can be reduced with a more specific configuration.

(3) In (1) or (2),
The alignment film is a photo-alignment film;
The alignment film manufacturing step includes
A photo-alignment material film production process for producing a photo-alignment material film;
An exposure process for producing the photo-alignment film by subjecting the photo-alignment material film to an exposure process using a mask,
The exposure step includes
The portion of the mask corresponding to at least both ends of the long transparent film material is formed in a line-symmetric shape with respect to the portion corresponding to the film center, and the shape is line-symmetrical with respect to the film center. An alignment film is produced.

  According to (3), when the alignment film is formed using the photo-alignment film, it is possible to reduce variation in straightness with a more specific configuration.

(4) A mask used for exposure processing of an alignment film of a pattern retardation film,
The pattern retardation film is
Produced by taking multiple pieces in the width direction of the substrate with a long transparent film material,
The mask is
At least portions corresponding to both end portions of the transparent film material were formed with slits that transmit light to be subjected to exposure processing due to a line-symmetric shape with respect to the film center of the transparent film material.

  According to (3), when producing an alignment film with a photo-alignment film, the positive and negative straightness of the pattern retardation film produced at least from both ends can be matched. Therefore, variation in straightness can be reduced.

(5) A patterned phase difference film in which an alignment film and a retardation layer are sequentially laminated on a substrate made of a long transparent film material, and a plurality of pattern retardation films are produced in the width direction of the transparent film material. A roll body of
The alignment film is
At least at both ends in the width direction of the transparent film material, the transparent film material was produced in a line symmetrical shape with respect to the film center.

  According to (5), in the pattern retardation film produced from this roll body, the positive / negative of the straightness can be matched with respect to the pattern retardation film produced at least from both ends. Therefore, variation in straightness can be reduced.

  The present invention can reduce variation in straightness in production by continuous processing of a long transparent film material provided by a roll.

It is a figure where it uses for description of the pattern phase difference film which concerns on 1st Embodiment of this invention. It is a flowchart which shows the manufacturing process of the pattern phase difference film of FIG. It is a figure where it uses for description of the exposure process of FIG. It is a figure where it uses for description of the relationship between the base material and mask in a manufacturing process. It is a figure where it uses for description of a deformation | transformation of a pattern phase difference film. It is a figure with which it uses for description of the dispersion | variation in straightness. It is a figure which shows the measurement result of the straightness which concerns on embodiment. It is a figure where it uses for description of the three-dimensional image display by a passive system. It is a figure where it uses for description of the definition of straightness.

[First Embodiment]
FIG. 1 is a view showing a pattern retardation film according to the first embodiment of the present invention. In the image display device according to the first embodiment, the pixels of the liquid crystal display panel that are continuous in the vertical direction (left-right direction in FIG. 1) are alternately displayed in the order of the right-eye pixel and the left-eye pixel. The images are distributed to the left-eye pixels that display the image, and are driven by the image data for the right eye and the left eye, respectively. As a result, the image display device alternately divides the display screen into a band-like region for displaying an image for the right eye and a band-like region for displaying an image for the left eye, so that the image for the right eye and the image for the left eye are divided. Display at the same time. In this image display device, the pattern phase difference film 1 shown in FIG. 1 is disposed on the panel surface of the liquid crystal display panel, and the pattern phase difference film 1 corresponds to light emitted from pixels for the right eye and the left eye, respectively. To give the phase difference. Thereby, this image display apparatus displays a desired three-dimensional image by a passive method.

  In the pattern retardation film 1, for example, an alignment film 3 and a retardation layer 4 are sequentially formed on a substrate 2 made of a transparent film material such as triacetyl cellulose. In the pattern retardation film 1, the retardation layer 4 is formed of a liquid crystal material, and the alignment of the liquid crystal material is patterned by the alignment regulating force of the alignment film 3. The orientation of the liquid crystal molecules is indicated by a long and narrow ellipse in FIG. By this patterning, the pattern phase difference film 1 is formed in a band shape alternately with the right-eye area A and the left-eye area B sequentially with a certain width corresponding to the pixel assignment in the liquid crystal display panel. A phase difference corresponding to each of the light emitted from the right-eye and left-eye pixels is given.

  In the pattern retardation film 1, after a photo-alignment material film made of a photo-alignment material is produced, the alignment film 3 is formed by irradiating the photo-alignment material film with ultraviolet rays by linearly polarized light by a so-called photo-alignment technique. Here, the ultraviolet rays applied to the photo-alignment material film are set so that the direction of polarization is different by 90 degrees between the right-eye region A and the left-eye region B, whereby the liquid crystal material provided in the retardation layer 4 , Liquid crystal molecules are aligned in the corresponding directions in the right-eye region A and the left-eye region B, and a phase difference corresponding to transmitted light is given.

  FIG. 2 is a flowchart showing manufacturing steps of the pattern retardation film 1. In the manufacturing process of the pattern retardation film 1, the base material 2 is provided by a long transparent film material wound up on a roll, and the base material 2 is fed out from the roll to sequentially produce a photo-alignment material film (step SP1- SP2). Here, although various manufacturing methods can be applied to the photo-alignment material film, in this embodiment, a film-forming liquid in which the photo-alignment material is dispersed in a solvent such as benzene is applied by a die and then dried. Is produced. In addition, although various materials to which the photo-alignment technique can be applied can be applied as the photo-alignment material, in this embodiment, the alignment is not changed by ultraviolet irradiation after the alignment, for example, a light dimerization type. Use materials. The light dimerization type material is described in “M. Schadt, K. Schmitt, V. Kozinkov and V. Chigrinov: Jpn. J. Appl. Phys., 31, 2155 (1992)”, “M. Schadt, H. Seiberle and A. Schuster: Nature, 381,212 (1996) ", and the like, for example, already marketed under the trade name" ROP-103 ".

  Subsequently, in this manufacturing process, a photo-alignment film is produced by irradiating ultraviolet rays in the exposure process (step SP3). Subsequently, in this manufacturing process, after the liquid crystal material is applied by a die or the like in the retardation layer manufacturing process, the liquid crystal material is cured by irradiation with ultraviolet rays, and the retardation layer 4 is manufactured (step SP4). Subsequently, in this manufacturing process, after performing an antireflection film manufacturing process or the like as necessary, in the cutting process, the pattern phase difference film 1 is manufactured by cutting out to a desired size (steps SP5 to SP6).

  FIG. 3 shows the details of this exposure process. This manufacturing process is performed by irradiating ultraviolet rays (polarized ultraviolet rays) by linearly polarized light through a mask 16 that shields a portion corresponding to the region A for the right eye or the region B for the left eye, For the left-eye region B or the right-eye region A, the photo-alignment material film is oriented in a desired direction (FIG. 3A). Thereby, this manufacturing process executes the first exposure process. Subsequently, this manufacturing process irradiates the entire surface with ultraviolet light with linearly polarized light whose polarization direction is 90 degrees different from that of the first exposure process, and the unexposed area A for the right eye or the area for the left eye in the first exposure process. For B, the photo-alignment material film is oriented in a desired direction (FIG. 3B). Thus, in this manufacturing process, the alignment film 3 is produced by sequentially exposing the right eye region A and the left eye region B by two exposure processes.

[Improved straightness]
FIG. 4 is a schematic diagram showing the relationship between the substrate 2 and the mask 16 in the manufacturing process of FIGS. In the manufacturing process, a base material 2 made of a long transparent film material is provided by a roll 11, and processing such as exposure is sequentially performed while the base material 2 is pulled out from the roll 11 and conveyed by a roller. Various stresses are applied to the base material 2 made of the transparent film material in this series of processes. As a result, as shown in FIG. 5, when the laminate of the substrate 2, the alignment film 3, and the retardation layer 4 that has undergone this series of steps is cut along a cutting line extending in the width direction, it is schematically shown by a broken line. Thus, the whole is transformed into a so-called barrel shape.

  Thus, when divided in the width direction by the center line O in the width direction, the boundary between the right eye region and the left eye region is formed in an upwardly convex shape on the upper side in FIG. The boundary is produced by a downward convex shape. Thus, when two pattern retardation films are taken in the width direction of the long film material to produce the pattern retardation films 1A and 1B, the same direction is obtained on both sides of the center line O in the width direction (that is, FIG. 5). In this case, the pattern retardation films 1A and 1B are cut in the direction in which the upper sides of the pattern retardation films 1A and 1B are both the upper side when attached to the image display panel). It will take a negative value, and in this case, the linearity will vary significantly.

  In this type of pattern retardation film 1, a so-called dummy area DM is provided in a portion corresponding to the upper portion of the effective image display area, and the vertical direction is defined when the dummy area DM is attached to the image display panel. Is done. Thus, in the case where the pattern retardation films 1A and 1B are cut out in the same direction on both sides of the center line O in the width direction in this way, in FIG. 5, the dummy area DM is located above both the pattern retardation films 1A and 1B. It is a case where it is produced on the side. Note that the dummy area DM is formed by, for example, making the widths of the right-eye area A and the left-eye area B significantly different from the effective image display area.

  FIG. 6 is a chart showing measurement results of straightness when the pattern retardation films 1A and 1B are cut out in the same direction on both sides of the center line O in the width direction. From this measurement result, it can be seen that straightness is distributed positively and negatively in the pattern retardation films 1A and 1B.

  Therefore, in this embodiment, the pattern retardation film at both ends in the width direction of the long transparent film is formed in a line symmetrical shape with respect to the center of the film, whereby the pattern retardation film according to the line symmetrical shape corrects the straightness variation. Alternatively, the variation in straightness is reduced to the negative side (see FIG. 4).

  That is, in this embodiment, the mask 16 is provided with regions 12A and 12B for exposure in which slits S are sequentially arranged in the width direction so as to correspond to the two-pieces in the width direction, and in each of the regions 12A and 12B, the film center A slit shape related to the dummy region DM is formed in a line-symmetric shape with respect to O, whereby the alignment film 3 is formed in a line-symmetric shape with respect to the film center O, and the pattern retardation films 1A and 1B are formed in the film center. It is produced with a line-symmetric shape with respect to O.

  FIG. 7 is a diagram showing the measurement results of straightness of the patterned retardation films 1A and 1B produced in this way. In the measurement result of FIG. 7, the straightness distribution center can be set to the positive side in both of the pattern retardation films 1A and 1B. Thus, in the example of FIG. 6, the straightness 3σ is 0.121 mm. Was reduced to 0.029 mm.

  In this embodiment, after sequentially laminating the alignment film 3 and the retardation layer 4 on the substrate 2 made of a long transparent film in this way, an antireflection film or the like is produced and wound on a roll, whereby a pattern is formed. A roll of retardation film is produced. In this manufacturing process, the roll body of this pattern phase difference film is conveyed to another process, and the laminate body related to the pattern phase difference film is pulled out from this roll body and cut sequentially, thereby producing the pattern phase difference films 1A and 1B. Is done.

  According to the above configuration, for a patterned retardation film produced from at least both ends in the width direction, a long transparent film provided by a roll by producing an alignment film with a line-symmetric shape with respect to the film center. In production by continuous processing of materials, it is possible to reduce variation in straightness.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention can be variously combined or modified with the configuration of the above-described embodiment without departing from the spirit of the present invention. Can do.

  That is, in the above-described embodiment, the case where the light distribution film is manufactured by performing the exposure process on the entire surface after the exposure process using the mask has been described. However, the present invention is not limited to this, and conversely, the entire surface is processed. It can be widely applied to the case where a light distribution film is produced by performing an exposure process using a mask after the exposure process, and further to the case where a light distribution film is produced by repeating the exposure process using the mask. .

  In the above-described embodiment, the case where the alignment film is formed using the photo-alignment film has been described. However, the present invention is not limited to this, and the present invention can be widely applied to the case where the alignment film is formed by forming a rubbing process mark. Can do.

  In the above-described embodiment, the case where two pattern retardation films are taken in the width direction of the base material has been described. However, the present invention is not limited to this, and can be widely applied to the case where three or more pieces are taken. . In addition, in the case of producing by taking three or more images in this way, at least the pattern retardation film at both ends may be axisymmetric with respect to the center of the film. Therefore, the direction may be set according to the straightness of the part.

1, 1A, 1B Pattern retardation film 2 Base material 3 Light distribution film 4 Phase difference layer 11 Roll 16 Mask

Claims (4)

In the manufacturing method of the pattern phase difference film, the substrate is sequentially processed while conveying the base material with the long transparent film material, and the pattern phase difference film is produced by taking a plurality in the width direction of the transparent film material.
An alignment film production step for producing an alignment film on the transparent film material,
On the alignment film, a retardation layer is formed by a right-eye region that gives a phase difference corresponding to right-eye transmitted light and a left-eye region that gives a phase difference corresponding to left-eye transmitted light. A phase difference layer manufacturing process,
In the alignment film manufacturing step ,
For the pattern retardation film produced from at least both ends in the width direction of the transparent film material, the alignment film is produced in a line-symmetric shape with respect to the film center serving as the center in the width direction of the transparent film material ,
In the alignment film, the transparent region is formed so that a region corresponding to a dummy region provided in a portion corresponding to an upper portion of an effective image display region in the usage state of the pattern retardation film is axisymmetric with respect to the film center. The manufacturing method of the pattern phase difference film formed in the both ends of the width direction of a film material . The alignment film is a photo-alignment film;
The alignment film manufacturing step includes
A photo-alignment material film production process for producing a photo-alignment material film;
An exposure process for producing the photo-alignment film by subjecting the photo-alignment material film to an exposure process using a mask,
In the exposure step , the mask is formed in a line-symmetric shape with respect to a portion corresponding to the film center with respect to at least portions corresponding to both ends in the width direction of the transparent film material, The method for producing a patterned phase difference film according to claim 1, wherein the alignment film is formed in a line-symmetric shape. A mask used for exposure processing of an alignment film of a pattern retardation film,
The pattern retardation film is produced by taking a plurality in the width direction of the substrate with a long transparent film material,
The mask transmits light to be subjected to the exposure process by a line-symmetric shape with respect to the film center which is the center in the width direction of the transparent film material, at least at portions corresponding to both ends in the width direction of the transparent film material. A plurality of slits are formed ,
Among the slits, the transparent corresponding to the slit corresponding to the dummy region provided in the portion corresponding to the upper portion of the effective image display region in the usage state of the pattern retardation film is line-symmetrical with respect to the film center. A mask formed at a portion corresponding to both ends of the film material . A roll of patterned phase difference film, in which an alignment film and a phase difference layer are sequentially laminated on a substrate made of a long transparent film material, and a pattern phase difference film is produced by taking a plurality in the width direction of the transparent film material. Because
The alignment film is produced in a line-symmetric shape with respect to the film center serving as the center in the width direction of the transparent film material at least at both ends in the width direction of the transparent film material ,
Dummy areas provided at portions corresponding to the upper part of the effective image display area in the usage state of the pattern retardation film are formed at both ends of the transparent film material so as to be line-symmetrical with respect to the film center. roll of the are patterned retardation film.

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