JP2008191219A - Method and device of manufacturing alignment layer, and optical element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and highly precisely align a liquid crystal material when an alignment layer is manufactured, used for an optical element and the like used as a birefringence correcting element of an optical disk in an optical pickup and coming in contact with a surface layer of a liquid crystal to align the liquid crystal in a prescribed direction. <P>SOLUTION: When a resin layer 7 containing a photoreactive functional group aligned in a light incident direction is layered on a substrate 3 and a point light source 4 is turned on to align the photoreactive functional group, a portion of the resin layer except a direct under part of the point light source 4 and an outer peripheral side is irradiated with oblique light by using a light shielding member 5 having a ring-shaped aperture 5a and the outer peripheral side of the resin layer is irradiated with nearly parallel light by using a ring-shaped mirror 6. When thus formed alignment layer is brought into contact with a liquid crystal layer to align the liquid crystal, the liquid crystal can be radially extended nearly from an optical axis as a base point, can fall in a face direction in the vicinity of the optical axis and can be raised in a thickness direction as separated from the optical axis and the liquid crystal can be easily and highly accurately aligned so that birefringent anisotropy is canceled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an alignment film manufacturing method and apparatus used for an optical element of an optical pickup and the like, and an optical element using the same.

  In general, in an optical system of an optical disk, linearly polarized light emitted from a light source passes through a beam splitter, passes through a quarter-wave plate, becomes circularly polarized light, and then is collected by a condenser lens. Irradiated onto the optical disk, the reflected light traces the incident optical path in the reverse direction, passes through the quarter-wave plate, becomes linearly polarized light rotated 90 degrees from the incident light, and is reflected in a direction different from the incident optical path by the polarizing beam splitter The light is received by the light receiver.

In that system, incident light enters the optical disk as condensed light, and the incident angle increases toward the outer side away from the optical axis. If the optical disk has unnecessary birefringence anisotropy, the birefringence increases toward the outer side. Thus, the light incident as circularly polarized light becomes elliptically polarized light after reflection. This not only reduces the amount of light but also increases the size of the spot light, thereby reducing the resolution. Therefore, a birefringence correction element in which the phase of light advances toward the outside so as to cancel such birefringence anisotropy is interposed between the quarter-wave plate and the optical disk. The structure and function of such an optical pickup is described in detail in Patent Document 1 and the like.
JP 2005-332435 A

  In the above-described prior art, the birefringence correction function is realized by aligning the liquid crystal, and the alignment is realized by selective rubbing, selection of the liquid crystal material, and adjustment of the voltage applied to the liquid crystal. Therefore, when a lithography process such as a mask rubbing method is used, man-hours are required, and there is a problem in that it is expensive at the time of mass production, and there are restrictions on the shape to which rubbing can be applied, and it cannot be made completely radial or concentric.

  An object of the present invention is to provide a method and apparatus for producing an alignment film capable of distributing light with a uniaxial refractive index anisotropy with high accuracy and an optical element using the same.

  The alignment film manufacturing method of the present invention is an alignment film manufacturing method in which a material having a uniaxial refractive index anisotropy is brought into contact with the refractive index anisotropic layer to align the material. And a step of laminating a resin layer containing a compound having a photoreactive functional group on the substrate, and a step of irradiating the resin layer with light at an axially symmetric incident angle.

  The alignment film manufacturing apparatus according to the present invention is an alignment film manufacturing apparatus that contacts a refractive index anisotropic layer containing a material having uniaxial refractive index anisotropy to align the material, and the incident direction of light. A substrate on which a resin layer containing a compound having a photoreactive functional group oriented to the substrate is laminated; a light source disposed on the center of the resin layer to irradiate light to the resin layer; and light from the light source to the resin layer Is irradiated with an incident angle that is axially symmetric, and includes at least one of a mirror, a light shielding member, and a convex lens.

  According to the above configuration, the surface layer of the refractive index anisotropy layer is used for an optical element used as a birefringence correction element of an optical disc in an optical pickup and includes a material having uniaxial refractive index anisotropy such as liquid crystal. In preparing an alignment film for contacting and orienting the material in a predetermined direction (giving a pretilt angle), a resin containing a compound having a photoreactive functional group that is oriented in the incident direction of light is used. After laminating a layer on a substrate such as glass, quartz, or plastic by any method such as spin coating, casting, or screen printing, the resin layer is irradiated with light at an axially symmetric incident angle, and the photoreaction is performed. Orient the functional groups. The photoreactive functional group has at least one double bond selected from an N═N bond and a C═C bond, and causes a reaction upon irradiation with light. A polymer, a condensation polymer, an addition polymer, or the like can be used.

  Further, as the light irradiation method as described above, a light source is disposed on the center of the resin layer, and the light from the light source is transmitted to the resin layer using at least one of a mirror, a light shielding member, and a convex lens. Irradiating at an axially symmetric incident angle. Preferably, the axisymmetric incident angle has different portions depending on the distance from the axis.

  For example, by irradiating the resin layer with light from a point light source through a light shielding member having a ring-shaped opening, the light from the point light source is reflected by a ring-shaped mirror and irradiated onto the resin layer. In the resin layer, light is incident near the outer periphery by a ring-shaped mirror in a substantially vertical direction (deep incident angle), and light is incident obliquely (shallow incident angle) from the point light source on the inner peripheral side. And the vicinity of the optical axis can be shielded. Alternatively, oblique light is generated by using a light source disposed on the outer side of the disk-shaped second resin layer, and a part of the light is reflected by a mirror in the direction of the resin layer. It can be realized by generating substantially vertical light and rotating the disk-shaped resin layer around the center position of the ring, or rotating the light source and the mirror around the disk-shaped resin layer. it can. Note that the step of irradiating light at the axis-symmetric incident angle and the step of irradiating oblique light except near the optical axis may be performed simultaneously or in the reverse order. Furthermore, a concave mirror is provided on the side opposite to the substrate with respect to the point light source, and a convex lens is provided as necessary, and the resin layer is arranged so as to be shifted from the focal point of the mirror or convex lens. In the layer, light can be incident obliquely (shallow incident angle) near the outer periphery, and can be incident substantially perpendicular (deep incident angle) on the inner periphery.

  Therefore, when such an alignment film is brought into contact with a refractive index anisotropic layer containing a material having a uniaxial refractive index anisotropy to orient the material (giving a pretilt angle), the material is roughly It extends radially from the optical axis, falls in the plane direction near the optical axis, and can stand up in the thickness direction as it is farther from the optical axis. In this way, a material having uniaxial refractive index anisotropy can be easily and accurately aligned, and when the alignment film is used for the birefringence correction element, it is more than the optical axis side of the passing light beam. The phase on the outer peripheral side advances, and the optical element that can cancel the influence of the birefringence of the optical disk and improve the resolution can be realized.

  Moreover, the optical element of the present invention has an alignment film produced by the above-described manufacturing method on at least one opposing surface side of a pair of substrates, and the material having the uniaxial refractive index anisotropy is a liquid crystal. The liquid crystal is used as a birefringence correction element of an optical disk, and by applying an electric field with a ring-shaped electrode, the liquid crystal axis is erected in the thickness direction as it goes outward in the plane direction, It is characterized by being fixed by the resin solidified in that state.

  According to the above configuration, the liquid crystal is used as the material having the uniaxial refractive index anisotropy, and in the optical element used as the birefringence correction element of the optical disc in the optical pickup, the alignment film is used, and the ring-shaped By applying an electric field with an electrode, preferably a solid electrode on the light emission side, and an annular side electrode on the incident side, the liquid crystal axis stands in the plane direction at the center and in the thickness direction as it goes outward. I can let you. Then, the optical element is completed by realizing the resin with a photo-curable resin and solidifying the resin in such a state, and removing the electrode as necessary.

  Therefore, the phase of the light beam on the outer peripheral side rather than the optical axis side advances, and the influence of the birefringence of the optical disc can be canceled, and an optical element that can improve the resolution can be realized.

  As described above, the method and apparatus for producing an alignment film of the present invention is used for an optical element used as a birefringence correction element of an optical disk in an optical pickup, and is made of a material having a uniaxial refractive index anisotropy such as liquid crystal. A photoreactive functional group that orients in the direction of incidence of light when producing an orientation film for orienting the material in a predetermined direction (giving a pretilt angle) in contact with the surface layer of the refractive index anisotropic layer After using a resin containing a compound and laminating a layer of the resin on the substrate, the photoreactive functional group is oriented by irradiating light at an axially symmetric incident angle.

  Therefore, when such an alignment film is brought into contact with a refractive index anisotropic layer containing a material having a uniaxial refractive index anisotropy and the material is oriented, the material is roughly based on the optical axis. A material that extends radially and tilts in the plane direction near the optical axis and can stand up in the thickness direction away from the optical axis, and easily and accurately orients a material having uniaxial refractive index anisotropy. be able to.

  In addition, as described above, the optical element of the present invention uses a liquid crystal as the material having the uniaxial refractive index anisotropy, and the optical element used as a birefringence correction element of an optical disk in an optical pickup includes the alignment film. And applying an electric field with a ring-shaped electrode, preferably a solid electrode on the light emitting side, and an incident side with the ring-shaped electrode, the liquid crystal axis in the plane direction at the central portion, outward Then, the optical element can be erected in the thickness direction. In this state, the resin is solidified, and the electrode is removed as necessary to complete the optical element.

  Therefore, the phase of the light beam on the outer peripheral side rather than the optical axis side advances, the influence of the birefringence of the optical disc can be canceled, and an optical element that can improve the resolution can be realized.

[Embodiment 1]
FIG. 1 is a cross-sectional view for explaining an alignment film manufacturing apparatus 1 and a manufacturing method according to a first embodiment of the present invention. The manufacturing apparatus 1 includes a base 2, a disk-shaped substrate 3 mounted on the base 2, a point light source 4 disposed on the center of the substrate 3, the point light source 4 and the substrate 3. A light shielding member 5 having a ring-shaped opening 5a, and a mirror 6 formed in a ring shape having a larger diameter than the light shielding member 5 and arranged to surround the point light source 4 And is configured symmetrically with respect to the optical axis 8. The substrate 3 is made of glass, quartz, plastic, etc., and is detachable from the base 2, and in the removed state, a resin that becomes an alignment film by any method such as spin coating, casting, and screen printing. Layer 7 is laminated.

  Thereafter, after setting the substrate 3 on the base 2, the point light source 4 is turned on to irradiate the resin layer 7 with light, and the photoreactive functional groups of the resin layer 7 are oriented. Here, as shown in FIG. 2, the light shielding member 5 has the ring-shaped opening 5a as described above. Therefore, as shown in FIG. 1, the light from the point light source 4 is shielded by the first light shielding plate 5b on the inner peripheral side immediately below the point light source 4 (near the optical axis 8), and near the outer periphery of the base 2. Only the area between them is shielded by the second light-shielding plate 5 c and irradiated to the resin layer 7 side, and light is incident on the resin layer 7 obliquely.

  On the other hand, the mirror 6 shown in FIG. 3 is formed in a ring shape having a diameter larger than that of the light shielding member 5 as apparent from the light shielding member 5 shown in FIG. It is arranged so as to surround. The height of the substrate 3 (resin layer 7) is substantially the same as that of the point light source 4 and the light from the point light source 4 is reflected to the substrate 3 side as ring-shaped substantially parallel light. It is installed at an angle according to the height.

  With this configuration, light is incident on the resin layer 7 in a substantially vertical direction (deep incident angle) near the outer peripheral portion by the ring-shaped mirror 6, and the inner peripheral side is obliquely (shallow incident) from the point light source 4. Light can be incident on the corner), and the vicinity of the optical axis 8 can be shielded. As a result, as shown in FIG. 4, the photoreactive functional group 7a extends radially from the optical axis 8 as a starting point, falls in the plane direction in the vicinity of the optical axis 8, and becomes thicker as the distance from the optical axis 8 increases. You can stand up in the direction. 4A is a plan view of the resin layer 7 after light irradiation, and FIG. 4B is a cross-sectional view. Thus, the photoreactive functional group 7a can be oriented easily and with high accuracy.

  In the above description, a single point light source 4 is used to generate ring-shaped oblique light by the light shielding member 5 and ring-shaped substantially parallel light is generated by the mirror 6 and simultaneously irradiated. Alternatively, a ring-shaped light source may be used in place of 6, and irradiation may be performed individually. In that case, either one may be irradiated first and the other may be irradiated later.

[Embodiment 2]
FIG. 5 is a cross-sectional view for explaining an alignment film manufacturing apparatus 11 and a manufacturing method according to the second embodiment of the present invention. This manufacturing apparatus 11 is similar to the above-described manufacturing apparatus 1, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. It should be noted that in this manufacturing apparatus 11, a prism 12 is provided immediately below the point light source 4, and the light shielding corresponding to the first light shielding plate 5 b of the light shielding member 5 is provided on the outer periphery of the prism 12. The first light-shielding plate 15b of the member 15 is fitted, and the second light-shielding plate 5c described above is formed in the chamfered portion of the prism 12 formed in a shape in which the top of the pentagon is chamfered in the section in the direction of the axis 8. The second light-shielding plate 15c corresponding to is attached. Then, the light from the point light source 4 enters from the bottom of the pentagon, exits from the inclined surface and enters the resin layer 7 obliquely, and the light directly below the point light source 4 is shielded by the first light shielding plate 15b. In the vicinity of the outer periphery of the base 2, the light is shielded by the second light shielding plate 15 c.

  With this configuration, the height of the light shielding member 5 and the point light source 4 that determines the angle of oblique light incident on the resin layer 7 can be easily adjusted, and the incident angle can be controlled with high accuracy. Or when the size of the resin layer 7, that is, the alignment film is different, can be easily handled.

[Embodiment 3]
6 and 7 are a sectional view and a plan view for explaining an alignment film manufacturing apparatus 21 and a manufacturing method according to the third embodiment of the present invention. This manufacturing apparatus 21 is similar to the manufacturing apparatus 1 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. It should be noted that in this manufacturing apparatus 21, the light shielding member 5 is not provided, and instead, a light source 24 and a mirror 25 arranged on the outer side of the turntable 22 corresponding to the base 2 are used. The oblique light in the slit shape is generated in an intermediate region excluding the inner peripheral side and the outer peripheral side of the turntable 22, and a part of the light is further directed toward the resin layer 7 by a mirror 26 disposed on the outer periphery of the turntable 22. The substantially parallel light is generated by reflection, and the turntable 22 and thus the substrate 3 and the resin layer 7 are rotated by the motor 23 using the axis that coincides with the optical axis 8 as the rotation axis 28. Irradiating the substantially parallel light and oblique light in a ring shape.

  Even if comprised in this way, the photoreactive functional group 7a can be orientated simply and with high precision. Further, when the light shielding members 5, 15, the prism 12, and the mirror 6 described above are inclined with respect to the optical axis 8, the light irradiation is performed eccentrically (untargeted) with respect to the resin layer 7. By performing light irradiation while rotating by the turntable 22, uniform (target) light irradiation can be performed. Although not shown, in order to support the light shielding member 5 and the prism 12 on the resin layer 7, a stay crossing the point light source 4 to the irradiation region of the resin layer 7 is required. On the other hand, by arranging the light source 24, the mirror 25, and the mirror on the outer side of the turntable 22, as shown in FIG. 7, a structure that suppresses the generation of shadows by the support member 28 that supports them is provided. be able to. Further, even if shadowing occurs, by performing light irradiation while rotating, uneven irradiation can be suppressed, and the support member 28 is strengthened (thickened, etc.), and the irradiation position accuracy is improved. It can also be increased.

  The photoreactive functional group is used when light is irradiated from the center side of the optical axis 8 as in the manufacturing apparatuses 1 and 11 and when light is irradiated from the outer side as in the manufacturing apparatus 21. The orientation direction of 7a becomes a reverse phase especially on the outer peripheral side of the resin layer 7. However, the photoreactive functional group 7a having a very small length does not cause a large difference in the light transmission effect of the liquid crystal aligned as described later. Instead of rotating the substrate 3 and the resin layer 7 side, the turntable 22 is used as the base 2 described above, and the light source 24, the mirror 25, and the mirror are arranged on the annular rail laid around the base 2. The trolley | bogie which mounts 26 may circulate, and you may make it perform light irradiation.

[Embodiment 4]
FIG. 8 is a cross-sectional view for explaining an alignment film manufacturing apparatus 31 and a manufacturing method according to the fourth embodiment of the present invention. The manufacturing apparatus 31 is similar to the manufacturing apparatus 1 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. It should be noted that in this manufacturing apparatus 31, a ring-shaped light shielding member 35 is interposed between the point light source 4 and the resin layer 37, and a mirror 36 is provided on the opposite side of the point light source 4 from the substrate 3. In accordance with these, the resin layer 37 is made of a resin containing a negative photoreactive functional group oriented in a direction crossing the light incident direction.

  The mirror 36 has a parabolic cross section at the optical axis 8, and the light reflected by the mirror 36 is once condensed at the focal point 34 and then dispersed, and near the optical axis 8 it is vertical (deep incident angle). ) At an angle close to the optical axis 8 and can be incident obliquely (shallow incident angle) away from the optical axis 8, and direct light from the point light source 4 can be narrowed only to the vicinity of the optical axis 8 by the light shielding member 5. By configuring in this way, the negative photoreactive functional group extends substantially radially from the optical axis 8 as in the photoreactive functional group 7a shown in FIG. It can be tilted in the plane direction near 8 and can be raised in the thickness direction as the distance from the optical axis 8 increases.

  The mirror 36 may have any shape that is symmetric with respect to the optical axis 8 and that does not cause an extreme difference in brightness in the region to be irradiated on the resin layer 37. The shape and the area (size) of the resin layer 37 are not particularly limited. ) And the like, the arrangement position of the resin layer 37 may be adjusted as appropriate. For example, in the manufacturing apparatus 31a shown in FIG. 9, the mirror 36a has a shape in which the cross section at the optical axis 8 is cut off from one focal point 34a side of the ellipse, and the point light source 4 is disposed on the other focal point side. A resin layer 37 is disposed on the near side (point light source 4) side of one focal point 34a, that is, on the front pin position. Also in this case, the photoreactive functional groups in the resin layer 37 are aligned in the opposite phase as compared with the manufacturing apparatus 31 shown in FIG. 8, but there is no great difference in the light transmission effect of the liquid crystal.

  In the manufacturing apparatus 31b shown in FIG. 10, the same mirror 36a is used, and the resin layer 37 is arranged on the rear side (opposite to the point light source 4) from the position of one focal point 34a, that is, at the rear pin position.

  Furthermore, in the manufacturing apparatus 41 shown in FIG. 11, the point light source 4 is disposed at the focal position of the mirror 46, and parallel light is emitted from the mirror 46 toward the resin layer 37, and the parallel light is collected by the convex lens 43. The resin layer 37 is disposed on the rear side (opposite to the point light source 4) of the convex lens 43, that is, on the rear pin position. Similarly, in the manufacturing apparatus 41a shown in FIG. 12, the convex lens 43 is used for the mirror 46, and the resin layer 37 is arranged on the front side (point light source 4) side of the focal point 44 position of the mirror 46, that is, the front pin position. ing. In the case of the manufacturing apparatus 41 in which the resin layer 37 is disposed at the rear pin position, a zoom lens is used instead of the convex lens 43, and a diaphragm 45 is provided, and the numerical aperture is changed by changing the focal length with a constant diaphragm diameter. Can be made. That is, the incident angle of light on the outer peripheral side of the resin layer 37 can be changed.

  Thus, in the present invention, the optical axis 8 substantially coincides with the center position in the surface direction of the resin layers 7 and 37, and the focal point is located on the optical axis 8 away from the surface of the resin layers 7 and 37. In addition, the non-polarized condensed light or dispersed light may be irradiated through the ring-shaped light shielding member 35.

[Embodiment 5]
13 and 14 are schematic cross-sectional views for explaining a manufacturing process of the optical element 50 according to the fifth embodiment of the present invention. This optical element 50 is an alignment film produced by irradiating the resin layers 7 and 37 with the manufacturing apparatuses 1, 11, 21, 31, 31a, 31b, 41 and 41a shown in FIGS. 51 and 52 are used as follows. The optical element 50 is mounted on an optical pickup as shown in Patent Document 1 and used as a birefringence correction element for the optical disc.

  It should be noted that this optical element 50 has the alignment films 51 and 52 on the facing surfaces of the pair of substrates 53 and 54, respectively, and a photo-curing resin 55 containing liquid crystal and an appropriate liquid crystal between them. The spacer (not shown) is filled and the outer peripheral portion is hermetically sealed by the seal member 56, and then the photo-curing resin 55 is cured as described below.

  That is, as shown in FIG. 13, dummy substrates 59 and 60 on which electrodes 57 and 58 are formed are laminated on the outer surface side (the side opposite to the alignment films 51 and 52) of the substrates 53 and 54, respectively. A voltage is applied from the power source 61 between the electrodes 57 and 58, and the photocurable resin 55 is irradiated with ultraviolet rays and solidified while an electric field is generated between the electrodes 57 and 58. At least one of the dummy substrate 59 and the electrode 57 and the dummy substrate 60 and the electrode 58 is transparent to the ultraviolet rays, and the ultraviolet irradiation is performed from the transparent substrate side. Further, the substrates 53 and 54 are transparent to the irradiation light to the optical disc. Instead of the photocurable resin 55, a thermosetting resin may be used.

  One of the electrodes 57 and 58 (57 in FIGS. 13 and 14) is a ring-shaped electrode formed facing the outer peripheral edge of the substrates 53 and 54, and the other of the electrodes 57 and 58 (FIGS. 13 and 14). Then 58) is a solid electrode. The power supply 61 applies alternating current for a predetermined period to activate the liquid crystal, and then applies direct current for a predetermined time during the photocuring and before the photocuring. By applying a voltage between the electrodes 57 and 58 having the above-described shape, an electric field as indicated by reference numeral 62 in FIG. 15 is generated. The electric field is strong on the peripheral side of the optical element 50 facing the electrodes 57 and 58 and weak on the central side.

  Therefore, first, the alignment films 51 and 52 manufactured as described above are brought into contact with the photo-curing resin 55 including the liquid crystal molecules 55a which are materials having uniaxial refractive index anisotropy. 16, the liquid crystal molecules 55 a extend radially from the optical axis 8 as a base point, fall in the plane direction near the optical axis 8, and concentrically incline as the distance from the optical axis 8 increases. The liquid crystal molecules 55a can be aligned even more strongly by applying the electric field 62 as described above.

  In this state, a direct current is applied to stop the movement of the liquid crystal molecules 55a, and after being cured by irradiating the ultraviolet rays, the dummy substrates 59 and 60 are removed together with the electrodes 57 and 58 as shown in FIGS. The optical element 50 is completed. In such an optical element 50, the substrate 53 side on which the ring-shaped electrode 57 is formed is used as the light incident side on the light source side, and the substrate 54 side on which the solid electrode 58 is formed is used as the light emitting side on the optical disc side. Thus, it is possible to advance the phase of the light beam on the outer peripheral side rather than the optical axis side. In this way, the liquid crystal molecules 55a can be aligned easily and with high precision. By using this optical element 50 for an optical pickup, the phase of the light beam passing therethrough is advanced on the outer peripheral side rather than the optical axis side, and the optical disk The influence of birefringence can be canceled and the resolution can be improved. For example, a configuration with high correction accuracy can be manufactured at a low cost as compared with a mask rubbing method in which a radial shape is formed on an alignment film by rubbing or lithography as disclosed in JP-A-6-324337.

  The resin layers 7 and 37 are made of a resin containing a compound having a photoreactive functional group oriented in the light incident direction, and the photoreactive functional group is at least selected from N = N bond and C = C bond. There are materials that contain a photoisomerization structural unit that has one double bond and reacts when irradiated with non-polarized light. As the resin containing this, a vinyl polymer, a condensation polymer, an addition polymer, or the like is used. be able to. A material including such a photoisomer reaction structural unit that is aligned in the light incident direction and an alignment method are described in detail in JP-A-11-95223. And it is desirable to stabilize the alignment by heating after the non-polarized light irradiation. In such a case, if a liquid crystal thermal polymerization initiator is added to the material containing the photoisomerization structural unit or the resin layers 7 and 37 containing the photoisomerization structural unit, it can be stabilized for a longer period of time.

  In addition to irradiating the material containing the photoisomerization structural unit with non-polarized light, a method of applying a resin film of a low molecular azo dye derivative and irradiating with ultraviolet rays may be used. Even in this case, the liquid crystal thermal polymerization initiator is put in the low molecular azo dye or a resin film containing the low molecular weight azo dye and heated after irradiation with ultraviolet rays, so that it can be stabilized for a longer period of time. As another method, as described in the conventional example of Japanese Patent Laid-Open No. 2000-284288, the same effect can be obtained by a method of irradiating a polyimide laser with a polarized laser.

  Note that the optical element 50 does not necessarily have to be solidified, and as shown by the optical element 70 in FIG. 17, a configuration in which electrodes 57 and 57 and a power source 72 for constantly applying an alternating electric field are provided. If so, the same birefringence correction effect can be obtained without solidification. In that case, the solid electrode 58 is formed of a transparent electrode such as ITO. Further, the electrode 58 is not necessarily a solid electrode, and may be ring-shaped like the electrode 57. In that case, an electric field is generated between a portion where the electrodes 57 and 58 are formed and a portion where the electrodes 57 and 58 are not formed. Since the change becomes steep, the change in the alignment direction of the liquid crystal molecules 55a described above becomes steep.

  The alignment films 51 and 52 produced by the manufacturing apparatuses 1, 11, 21, 31, 31a, 31b, 41, and 41a are not limited to the optical element 50, but are used in, for example, the liquid crystal display device, for example, the above-mentioned Japanese Patent Laid-Open No. 6-324337. In this case, a liquid crystal device having a wide viewing angle can be realized.

It is sectional drawing for demonstrating the manufacturing apparatus and manufacturing method of the alignment film which concern on the 1st Embodiment of this invention. It is a top view for demonstrating the shape of the light-shielding member in the said manufacturing apparatus. It is a top view for demonstrating the shape of the mirror in the said manufacturing apparatus. It is a figure which shows typically the orientation state of the photoreactive functional group in the resin layer after light irradiation. It is sectional drawing for demonstrating the manufacturing apparatus and manufacturing method of the alignment film which concern on the 2nd Embodiment of this invention. It is a side view for demonstrating the manufacturing apparatus and manufacturing method of the alignment film which concern on the 3rd Embodiment of this invention. It is a top view for demonstrating the manufacturing apparatus and manufacturing method of the alignment film which concern on the 3rd Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing apparatus and manufacturing method of the alignment film which concern on the 4th Embodiment of this invention. It is sectional drawing for demonstrating the other example of the manufacturing apparatus and manufacturing method of the alignment film which concerns on the 4th Embodiment of this invention. It is sectional drawing for demonstrating the further another example of the manufacturing apparatus and manufacturing method of the alignment film which concerns on the 4th Embodiment of this invention. It is sectional drawing for demonstrating the other example of the manufacturing apparatus and manufacturing method of the alignment film which concerns on the 4th Embodiment of this invention. It is sectional drawing for demonstrating the further another example of the manufacturing apparatus and manufacturing method of the alignment film which concerns on the 4th Embodiment of this invention. It is typical sectional drawing for demonstrating the manufacturing process of the optical element which concerns on the 5th Embodiment of this invention. It is typical sectional drawing for demonstrating the manufacturing process of the optical element which concerns on the 5th Embodiment of this invention. It is typical sectional drawing for demonstrating the orientation direction of the liquid crystal molecule in the optical element shown in FIG. 13 and FIG. It is typical sectional drawing for demonstrating the orientation direction of the liquid crystal molecule in the optical element shown in FIG. 13 and FIG. It is typical sectional drawing of the other example of the optical element which concerns on the 5th Embodiment of this invention.

Explanation of symbols

1, 11, 21, 31, 31a, 31b, 41, 41a Manufacturing apparatus 2 Base 3 Substrate 4 Point light source 5, 15, 35 Light shielding member 6, 26 Mirror 8 Optical axis 7, 37 Resin layer 7a Photoreactive functional group 12 Prism 22 Turntable 23 Motor 24 Light source 25, 36, 36 a, 46 Mirror 28 Rotating shaft 34, 34 a, 44 Focus 43 Convex lens 45 Aperture 50 Optical element 51, 52 Alignment film 53, 54 Substrate 55 Photocurable resin 55 a Liquid crystal molecule 56 Seal Members 57 and 58 Electrodes 59 and 60 Dummy substrate 61 Power supply

Claims (8)

In the method for producing an alignment film in which the material is aligned in contact with a refractive index anisotropic layer including a material having uniaxial refractive index anisotropy,
Laminating a resin layer containing a compound having a photoreactive functional group oriented in a light incident direction on a substrate;
Irradiating the resin layer with light at an axially symmetric incident angle.   The alignment film manufacturing method according to claim 1, wherein the axially symmetric incident angle has a portion that varies depending on a distance from the axis.   The alignment film produced by the manufacturing method according to claim 1 or 2 is provided on at least one opposing surface side of a pair of substrates, and the material having the uniaxial refractive index anisotropy is a liquid crystal, Used as a birefringence correction element, by applying an electric field with a ring-shaped electrode, the axis of the liquid crystal is erected in the plane direction in the center portion and in the thickness direction as it goes outward, and in that state An optical element which is fixed by a solidified resin. In an apparatus for manufacturing an alignment film that contacts a refractive index anisotropic layer including a material having uniaxial refractive index anisotropy and aligns the material,
A substrate on which a resin layer containing a compound having a photoreactive functional group oriented in the light incident direction is laminated;
A light source disposed on the center of the resin layer for irradiating the resin layer with light;
An apparatus for producing an alignment film, wherein the resin layer is irradiated with light from the light source at an axially symmetric incident angle and includes at least one of a mirror, a light shielding member, and a convex lens.   5. The alignment film manufacturing apparatus according to claim 4, wherein the mirror is provided on the opposite side of the substrate from the light source and has a concave shape.   The alignment film according to claim 4, further comprising a turntable that irradiates light from the light source to the resin layer at an axis-symmetric incident angle by rotating the substrate about the axis. Manufacturing equipment.   The mirror has an elliptical cross section in the optical axis direction, the light source is a point light source, and is disposed at one focal point of the ellipse, and the resin layer laminated on the substrate is disposed offset from the other focal point. 6. The apparatus for producing an alignment film according to claim 5, wherein   The mirror has a cross section in the optical axis direction formed in a semicircular arc shape, the light source is a point light source, and is disposed at the focal point of the arc, and the light from the point light source is reflected by the parallel light by the mirror. 6. The alignment film manufacturing apparatus according to claim 5, wherein the parallel light is condensed through a convex lens, and the resin layer laminated on the substrate is arranged so as to be shifted from a focal point of the convex lens.

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