JP6600129B2 - Image display device - Google Patents

Description

  The present invention relates to a laminate of electrode films used for touch panels, electromagnetic wave shields, and the like, an image display device using the laminate of electrode films, and the like.

  Conventionally, some image display devices detect user operations using a touch panel. Here, the touch panel is configured such that an electrode film made of a transparent film material on which an electrode for detecting a user operation is formed is arranged on the panel surface of the image display panel, and a user operation is detected by detecting a change in capacitance or the like by the electrode. To detect. In the touch panel, it is difficult to visually recognize this electrode, and deterioration of the visibility of the display screen due to the provision of the touch panel is prevented.

  The touch panel employs a configuration in which this type of electrode is made of a transparent electrode material made of ITO (Indium Tin Oxide) so that the electrode is difficult to visually recognize. Moreover, in the touch panel, a method of forming an electrode with a fine width using a metal material such as copper or aluminum instead of ITO is employed (Patent Document 1). Patent Document 2 proposes a device that makes it difficult to visually recognize this type of electrode by providing a low reflection layer. Further, Patent Document 3 proposes a device that makes it difficult to visually recognize this type of electrode by creating a mesh shape and by devising a cross-sectional shape of each part related to the mesh shape. Thus, when an electrode is made of a metal material and further an electrode is made of a mesh shape, the resistance of the electrode can be reduced, so that a user operation can be detected at a high response speed.

  In Patent Documents 4 and 5, when an electronic viewfinder using a flat display is used instead of an optical viewfinder in a video camera or the like, an optical low-pass filter using a diffraction grating is arranged on the front surface of the flat display. Is disclosed.

  By the way, it has been found that in the conventional touch panel, the electrode may be visually recognized by the user. Accordingly, it is desired that the touch panel is made more difficult to visually recognize in the touch panel.

JP 2010-257350 A JP 2013-235315 A JP 2014-16944 A JP 63-114475 A JP 05-227456 A

  The present invention has been made in view of such a situation, and an object of the present invention is to make the electrodes more difficult to visually recognize as compared with the related art for electrodes used in touch panels and the like.

  The present inventor has intensively studied to solve the above-mentioned problems, and devised that a diffraction grating is laminated on a film material provided with an electrode, and the electrode is difficult to visually recognize due to the function of the optical low-pass filter of the diffraction grating. The present invention has been completed.

(1) an electrode film having electrodes formed on a transparent substrate;
And a diffraction grating laminated on the electrode film.

  According to (1), the visibility of the electrode can be reduced by the function of the optical low-pass filter of the diffraction grating, and as a result, the electrode can be made more difficult to see compared to the conventional case.

(2) In (1),
The electrode is an electrode used for detecting a user operation on the touch panel.

  According to (2), when applied to a touch panel, the electrode according to the touch panel can be made more difficult to visually recognize as compared with the related art.

(3) In (1) or (2),
The diffraction grating is
It is a one-dimensional diffraction grating having a periodic structure in a repeating direction of the electrodes.

  According to (3), the spatial frequency component related to the electrode can be efficiently suppressed, and the electrode can be made more difficult to visually recognize as compared with the conventional case.

(4) In (1) or (2),
The diffraction grating is
It is a two-dimensional diffraction grating.

  According to (4), when one set of electrodes is arranged so that the extending directions are orthogonal, the spatial frequency component related to the electrodes is efficiently suppressed, making it difficult to visually recognize the electrodes as compared with the conventional case. It can be.

(5) In (4),
The diffraction grating is
It is a laminate of one-dimensional diffraction gratings.

  According to (5), a two-dimensional diffraction grating can be easily configured by stacking one-dimensional diffraction gratings.

  (6) An image display device in which the laminate of electrode films according to any one of (1), (2), (3), (4), and (5) is disposed on the panel surface of an image display panel.

  According to (6), in an image display device or the like equipped with a touch panel, it is possible to make the electrodes provided on the electrode film more difficult to see compared to the conventional case.

  Regarding the laminate of electrode films used for a touch panel or the like, the electrodes can be made more difficult to visually recognize.

It is a figure which shows the image display apparatus which concerns on 1st Embodiment of this invention. It is a figure where it uses for description of the function of a diffraction grating. It is a figure where it uses for description of the diffraction grating applied to the image display apparatus of FIG. It is a figure where it uses for description of the manufacturing process of the diffraction grating of FIG. It is a figure which shows the diffraction grating applied to the image display apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the diffraction grating applied to the image display apparatus which concerns on 3rd Embodiment of this invention.

[First Embodiment]
[Laminated body of image display device and electrode film]
FIG. 1 is a diagram showing an image display apparatus according to the first embodiment of the present invention. The image display device 1 is an image display device provided with a touch panel, and an electrode film laminate 3 for a touch panel is disposed on the panel surface (viewer side surface) of the image display panel 2. Here, the image display panel 2 is a liquid crystal display panel, and a backlight device 6 is disposed on the back surface. The image display panel 2 is provided with linearly polarizing plates 7A and 7B on the entrance surface and the exit surface of the liquid crystal cell 5, respectively, and the liquid crystal cell 5 sandwiches the liquid crystal with a transparent member such as a glass plate on which a transparent electrode is disposed. Configured. Further, the backlight device 6 can widely apply various configurations such as a so-called side edge type and a direct-light type. In addition, it can replace with a liquid crystal display panel and can apply various structures, such as an image display panel by organic EL, a plasma display, to the image display panel 2 widely.

  The electrode film laminate 3 is configured by disposing the diffraction grating 10 and the touch panel sensor film 9 on both surfaces of the cover glass 14 with the adhesive layers 11 and 12 respectively, and the touch panel sensor film 9 is connected to the image display panel 2 side. It is arranged to become. The cover glass 14 may be omitted and the diffraction grating 10 may be directly laminated on the touch panel sensor film 9. Moreover, you may make it arrange | position the diffraction grating 10 and the sensor film 9 for touchscreens on the image display panel 2 side of the cover glass 14, or the other side. Further, a hard coat layer, an antireflection layer or the like may be appropriately disposed on the outermost surface.

  Here, the sensor film 9 for the touch panel is a film material (hereinafter referred to as an electrode film) in which an electrode is produced on the transparent base material 15, has a thin line shape extending in the X direction and the Y direction, and this extending direction. The electrodes 9X and 9Y, each of which is formed by repeatedly forming a thin line-shaped portion in a direction perpendicular to each other, are held so as to face each other with a certain distance therebetween. The image display device 1 sequentially scans the electrodes 9X and 9Y by a signal processing circuit for a touch panel (not shown), and detects an operation by a user based on a change in capacitance between the electrodes. It should be noted that the electrodes 9X and 9Y may be formed in a mesh shape at portions extending in the X direction and the Y direction, respectively.

  The sensor film 9 for a touch panel is configured by forming electrodes 9X and 9Y on one surface and the other surface of a base material 15 made of a transparent film, respectively. Here, a transparent film such as a PET film or TAC (triacetyl cellulose) can be applied to the substrate 15.

  For the electrodes 9X and 9Y, a metal material such as silver, copper, gold, or aluminum is preferably used. The electrodes 9X and 9Y may be a single metal or alloy, or may be formed by binding metal particles with a binder. The electrodes 9X and 9Y are subjected to rust prevention treatment on the metal surface as necessary. The electrodes 9X and 9Y may be made of a transparent electrode material such as ITO. In this case, a configuration is adopted in which a dummy electrode that is not used for detection of any user operation is provided to make it difficult to visually recognize the electrodes 9X and 9Y. May be.

  The electrodes 9X and 9Y can be manufactured by photolithography (etching), pattern printing, transfer, self-assembly, and the like. Here, in the case of producing by photolithography, a metal layer is produced on the base material 15 by lamination, vapor deposition, sputtering or the like, and this metal layer is produced by etching. As a method of producing by pattern printing, a method of printing a conductive ink in the shape of an electrode pattern, a method of printing a material having a catalytic function of electroless plating on the shape of an electrode, and then electrolessly plating a conductive metal, Examples include a method of printing an electroless plating catalyst and a material forming an adduct and then adding the catalyst to perform electroless plating treatment. Examples of the conductive ink include silver paste, copper paste, and conductive polymer. Examples of the material having a catalytic function include ink containing catalyst particles such as palladium and particles having catalyst particles supported on the surface. Examples of the material forming the adduct with the catalyst include ink containing silver, a conductive polymer, an adsorbing material, and the like. Examples of the metal forming the electroless plating layer include conductive metals such as copper, nickel, and silver. Although any method can be applied as the pattern printing method depending on the required pattern accuracy, screen printing, intaglio offset printing, a method of transferring from the intaglio using a UV curing primer, or the like is preferably used. Although various adhesives and pressure-sensitive adhesives such as an ultraviolet curable resin and a thermosetting resin agent can be widely applied to the adhesive layer 11, an ultraviolet curable resin should be applied from the viewpoint of reducing the overall thickness. Is preferred.

  In addition, you may make it the sensor film 9 for touchscreens laminate | stack the transparent base material formed by producing the electrodes 9X and 9Y, respectively. Alternatively, a transparent substrate formed by preparing electrodes 9X and 9Y, respectively, may be prepared, and the electrode 9X or 9Y prepared on one substrate may be transferred to the other substrate.

  Various glass plates that are applied to this type of image display device can be applied to the cover glass 14.

〔Diffraction grating〕
In the image display device 1, the diffraction grating 10 is arranged on the cover glass 14, and the function of an optical low-pass filter by the diffraction grating 10 makes it difficult to visually recognize the electrodes 9X and 9Y. FIG. 2 is a cross-sectional view and a perspective view schematically showing a configuration related to the diffraction grating. In FIG. 2, for easy understanding, the diffraction grating 10 is shown by a transparent member in which concave grooves having a rectangular cross section are formed at a constant pitch P <b> 2. Therefore, the diffraction grating 10 shown in FIG. 2 is a diffraction grating having a periodic structure with different optical optical path lengths due to changes in thickness, and is a transmission type diffraction grating. In the diffraction grating 10, due to this repeated periodic structure, the spatial frequency component of the transmitted light is suppressed on the high frequency side in this repeated direction, and as a result, functions as an optical low-pass filter. Thus, in this embodiment, the amount of the diffraction grating 10 is arranged, and the function of the optical low-pass filter of the diffraction grating 10 makes it difficult to visually recognize the electrodes 9X and 9Y and improves the image quality.

  Here, when the electrodes 9X and 9Y that are arranged on the panel surface of the image display panel and constitute the touch panel cannot be visually recognized as in this embodiment, the spatial frequency components of the electrodes 9X and 9Y are sufficiently obtained by this optical low-pass filter. Therefore, it is necessary to set the repetition pitch P2 and the like in the diffraction grating. For this purpose, it is desirable that the pitch P2 be sufficiently larger than the pitch and line width of the electrodes 9X and 9Y. However, when the pitch P2 is sufficiently increased as described above, the resolution of the image displayed by the image display panel 2 also decreases in the repetition direction of the diffraction grating 10, and the image becomes blurred. Thus, in the image display device 1, the pitch P2 is sufficiently increased so that the electrodes 9X and 9Y cannot be visually recognized within a range in which a decrease in the resolution of the display image by the image display panel 2 cannot be perceived. More specifically, in the portable image display device to which the touch panel is applied, the pixel pitch is about 200 μm, the line widths of the electrodes 9X and 9Y are about 2 μm, and the pitch P1 is 50 to 100 μm. Is set to be equal to or smaller than the pixel pitch of the image display panel and equal to or larger than 1/10 pixel pitch, for example, about 200 μm.

  The diffraction grating 10 functions as an optical low-pass filter with respect to the repetition direction, so that the repetition direction X of the electrode 9X on the most surface side is the same as that of the diffraction grating 10 as shown in FIG. The electrode 9X can be prevented from being visually recognized efficiently by setting the repetition direction. However, when the repetition direction X of the electrode 9X is set to be the repetition direction of the diffraction grating 10 as described above, interference fringes (moire) may occur due to the periodicity of the two repetition structures. Accordingly, it is desirable that the repeating direction X of the electrode 9X and the repeating direction of the diffraction grating 10 intersect each other at an angle of 2 degrees or more, preferably 5 degrees or more, more preferably 10 degrees or more.

  In addition, it is desired that not only the outermost layer electrode 9X but also the lower layer electrode 9Y be invisible. In this lower layer electrode 9Y, the extending direction is orthogonal to the electrode 9X. Further, the repetition direction X of the electrode 9X and the repetition direction of the diffraction grating 10 are arranged so as to intersect at an angle of 45 degrees, and the spatial frequency component related to the repetition direction of the diffraction grating 10 is suppressed for both the electrodes 9X and 9Y. However, the electrodes 9X and 9Y may be difficult to see.

  FIG. 3 is a perspective view showing a specific configuration of the diffraction grating 10 according to this embodiment. In the diffraction grating 10, an orientation layer 23 and a retardation layer 24 are sequentially provided on one surface of a base material 22 made of a transparent film such as TAC (triacetyl cellulose), acrylic, and cycloolefin polymer. The diffraction grating 10 is disposed so that the retardation layer 24 is on the cover glass 14 side, and is held on the cover glass 14 by the adhesive layer 12. However, from the viewpoint of making the electrodes 9X and 9Y more difficult to visually recognize, it is desirable to dispose the retardation layer 24 away from the electrodes 9X and 9Y by arranging the base material 22 on the cover glass 14 side.

  In the diffraction grating 10, the retardation layer 24 is formed of a liquid crystal material that is solidified (cured) while maintaining the refractive index anisotropy, and the alignment of the liquid crystal material is patterned by the alignment regulating force of the alignment layer 23. In FIG. 3, the orientation of the liquid crystal molecules is exaggerated by an elongated ellipse. By this patterning, the diffraction grating 10 is produced with the first and second strip regions A and B having different slow axis directions alternately corresponding to the repetitive structure described above with reference to FIG. A periodic structure is formed by regions A and B having different directions. Here, the periodic structure having different slow axis directions is a periodic structure of a region having a different refractive index corresponding to the polarization plane of the transmitted light, and thus has a different optical optical path length as described above with reference to FIG. The structure has been fabricated, thereby functioning as a diffraction grating.

  In this embodiment, the slow axis directions of the first and second belt-like regions A and B are set to be orthogonal. The light emitted from the first and second belt-like regions A and B is produced with a thickness that forms a phase difference of ½ wavelength. Thereby, in this embodiment, the diffraction grating 10 is efficiently functioned as an optical low-pass filter so that the electrodes 9X and 9Y cannot be visually recognized.

  In this way, when the slow axis directions of the first and second belt-like regions A and B are set to be orthogonal to each other, the light is transmitted through the output surface side linearly polarizing plate 7A provided in the image display panel 2. The slow axis direction of the belt-like regions A and B with respect to the axis may be set any number of times. The reason is that since the slow axis directions of the strip regions A and B are orthogonal, the diffraction grating 10 has a repeated periodic structure with different refractive indexes due to the strip regions A and B regardless of the incident polarized light. This is because. This is one of the characteristics of the present invention. If one of the liquid crystals in the band-like regions A and B is horizontally aligned and the other one is vertically aligned, polarization dependence appears in this diffraction grating. The slow axis directions of the belt-like regions A and B must be set to a predetermined angle, so that the occurrence of interference fringes (moire) due to periodicity due to the repetitive structure of the electrodes 9X and 9Y and the diffraction grating described above is suppressed. For this reason, the angle at which the electrode and the repeating direction of the diffraction grating intersect cannot be freely set.

  If the electrodes 9X and 9Y cannot be visually recognized while avoiding image quality deterioration sufficiently practically, the slow axis directions of the first and second strip regions A and B are other than 90 degrees. You may make it cross | intersect according to an angle, and you may make it set the phase difference in the emitted light of 1st and 2nd strip | belt-shaped area | regions A and B to phase differences other than 1/2 wavelength.

  In the diffraction grating 10, after the photo-alignment material layer is made of the photo-alignment material, the photo-alignment material layer is irradiated with ultraviolet rays by linearly polarized light, and thereby the alignment layer 23 is formed by applying the photo-alignment technique. . Here, the ultraviolet light applied to the photo-alignment material layer is set so that the direction of polarization differs between the first and second regions A and B by, for example, 90 degrees so as to correspond to the retardation layer 24. With respect to the liquid crystal material provided in the retardation layer 24, liquid crystal molecules are aligned in the corresponding directions in the first and second regions A and B, and the slow axis direction is set. 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).

  In this way, instead of a photo-alignment material whose orientation does not change by irradiation with ultraviolet rays, a photo-alignment material whose orientation direction changes according to the polarization direction of the irradiated ultraviolet rays every time it is irradiated with ultraviolet rays is used. You may make it apply. Moreover, it may replace with the orientation layer by photo-alignment, and may produce an orientation layer by a rubbing process, and may transfer the fine line-shaped uneven | corrugated shape produced by the rubbing process, and may produce an orientation layer. Further, the alignment layer may be omitted by constituting the retardation layer with a liquid crystal polymer that is aligned and cured in the polarization direction of the ultraviolet rays by irradiation with ultraviolet rays by linearly polarized light.

  The retardation layer 24 contains a polymerizable liquid crystal composition. This polymerizable liquid crystal composition can contain an antiblocking agent and the like in addition to a liquid crystal compound exhibiting liquid crystallinity and having a polymerizable functional group in the molecule (hereinafter also referred to as “rod-like compound”).

  The rod-shaped compound has a refractive index anisotropy, and has a function of imparting a desired phase difference by arranging regularly by the alignment regulating force of the alignment layer 23. Examples of the rod-like compound include materials exhibiting a liquid crystal phase such as a nematic phase and a smectic phase, but the nematic phase is easier to arrange regularly than liquid crystal compounds exhibiting other liquid crystal phases. It is more preferable to use the rod-shaped compound shown.

  Specific examples of the rod-shaped compound used in the present embodiment include compounds represented by the following formulas (1) to (16).

〔Manufacturing process〕
FIG. 4 is a flowchart showing the manufacturing process of the laminate 3. The manufacturing process of the laminated body 3 produces the laminated body 3 by processing the base material 22 by a long transparent film material sequentially by the manufacturing process shown in this FIG. Here, in this manufacturing process, the base material 22 is provided by a long transparent film material wound up on a roll, and in the alignment layer creating process SP2, the coating liquid related to the photo-alignment film is applied by a die or the like, and then dried. And cured, thereby producing a photo-alignment material layer. Subsequently, in this alignment layer creating step SP2, the alignment layer 23 is formed on the substrate by irradiating ultraviolet rays in the exposure step. Here, in the exposure step, the first belt-shaped region or the region corresponding to the second belt-shaped region is selectively exposed by irradiation with ultraviolet light using linearly polarized light using a mask, and then linearly polarized light whose polarization directions are orthogonal to each other. This is performed by irradiating the entire surface with ultraviolet rays.

  Subsequently, in the manufacturing step SP3 of the retardation layer, the liquid crystal material coating liquid is applied and dried with a die or the like, and then the liquid crystal material is cured by irradiation with ultraviolet rays, whereby the retardation layer is manufactured. As a result, the diffraction grating 10 is produced in the shape of a long film. Next, in the manufacturing process, the diffraction grating 10 having the long film shape is cut into a desired size in the cutting process SP4.

  In this manufacturing process, in the subsequent bonding process SP5, the diffraction grating 10 is bonded to the sensor film 9 for the touch panel and the cover glass 14 produced in a separate process, whereby the laminate 3 of electrode films is manufactured.

  According to this embodiment, by stacking the diffraction grating on the touch panel sensor film, it is possible to make it difficult to visually recognize the electrodes provided on the touch panel sensor film as compared with the conventional case.

[Second Embodiment]
FIG. 5 is an exploded perspective view showing a diffraction grating according to the second embodiment of the present invention in comparison with FIG. This embodiment has the same configuration as that of the first embodiment except that the diffraction grating 30 shown in FIG. This diffraction grating 30 uses the above-described diffraction grating 10 (10A and 10B) with reference to FIG. 3 using an ultraviolet curable resin or the like so that the extending directions of the first and second strip regions A and B are orthogonal to each other. A two-dimensional optical low-pass filter having a two-dimensional periodic structure of regions having different slow axis directions is formed by stacking the diffraction gratings 10A and 10B. In FIG. 5, the two diffraction gratings 10 relating to this stack are shown with different symbols. Instead of the configuration in which the diffraction gratings 10A and 10B are laminated together with the base materials 22A and 22B, only the phase difference layer 24B or 24A of the other diffraction grating is transferred to one diffraction grating 10A or 10B to form a two-dimensional diffraction grating. You may make it produce. In this case, the retardation layer 24B or 24A may be transferred integrally with the alignment layer 23B or 23A.

  Here, in the two diffraction gratings 10A and 10B, the same configuration may be laminated, and the first and second regions A and B may be laminated with different region widths and pitches. May be. When the region width and pitch of the first and second regions A and B are made different in this way, the characteristics of the optical low-pass filter are made different in the two-dimensional direction related to the repeating direction of the diffraction grating 30. Can do.

  The image display apparatus according to this embodiment is arranged so that the repetitive directions related to the diffraction grating 30 are the horizontal direction and the vertical direction of the image display panel 2. By applying the two-dimensional diffraction grating in this way, even when the resolution of the image display panel is impaired by the diffraction grating, the degradation of the resolution can be expressed equally in each direction. It is possible to prevent the perception of image quality degradation due to resolution degradation. This further suppresses the spatial frequency component related to the electrode, making it difficult to visually recognize the electrode. Moreover, since the spatial frequency component concerning an electrode can be suppressed about each direction, an electrode can be made much more difficult to visually recognize.

  In addition, instead of the arrangement in which the repetitive direction related to the diffraction grating 30 is in the horizontal direction and the vertical direction of the image display panel 2 in this way, the image display panel 2 may be arranged so as to have an inclination of, for example, 45 degrees obliquely. You may make it arrange | position by inclination. In the arrangement in which the repetitive directions related to the diffraction grating 30 are the horizontal direction and the vertical direction of the image display panel 2, as described above, the region widths and pitches of the first and second regions A and B are different. Thus, the horizontal and vertical characteristics of the display screen can be adjusted by making the spatial frequency characteristics related to the repetition direction different.

  In this embodiment, by disposing a two-dimensional diffraction grating, it is possible to make the electrode invisible further than in the first embodiment.

  In addition, this two-dimensional diffraction grating can be produced efficiently because it can be manufactured by stacking one-dimensional diffraction gratings. That is, in the one-dimensional diffraction grating, as described above with reference to FIG. 2, a retardation layer can be produced by repeating a band-like region, and in this case, a long substrate provided by a roll is conveyed. On the other hand, an alignment film of each diffraction grating to be used for lamination can be produced by continuous exposure processing using a mask in which slits extending in the carrying direction are repeatedly produced in a direction perpendicular to the extending direction.

  On the other hand, when producing a two-dimensional diffraction grating with one retardation layer, it is necessary to perform region setting in the retardation layer in a checkered pattern (see the third embodiment). Therefore, when producing an alignment film while transporting a long substrate, the exposure apparatus has a special and complicated configuration. Thereby, in this embodiment, a two-dimensional diffraction grating can be easily produced.

[Third Embodiment]
FIG. 6 is a diagram showing a diffraction grating applied to an image display apparatus according to the third embodiment of the present invention. This embodiment has the same configuration as that of the second embodiment except that the diffraction grating 40 shown in FIG. 6 is used instead of the diffraction grating 30.

  Here, in the diffraction grating 40, the first and second regions A and B are formed in a rectangular shape when viewed from the front, and are arranged in a checkered pattern, thereby producing a two-dimensional diffraction grating by one retardation layer 24. Then, a two-dimensional optical low-pass filter is produced. In the diffraction grating 40, the alignment layer 23 is produced so as to exhibit the alignment regulating force patterned in a checkered pattern so as to correspond to the checkered pattern setting of the regions A and B.

  Even if the diffraction grating is configured by setting the checkered pattern region as in this embodiment, the same effect as in the second embodiment can be obtained.

[Fourth Embodiment]
In this embodiment, instead of the repetitive structure with different regions in the slow axis direction described above with respect to the first to third embodiments, the diffraction grating is manufactured with the repetitive structure with different thicknesses described above with reference to FIG.

  In addition, in such diffraction gratings having different thicknesses, the first and second regions having different thicknesses are formed as base materials by, for example, a molding process using a molding die having a corresponding uneven shape. It is possible to fabricate a diffraction grating by repeatedly fabricating the surface.

  Even if the diffraction grating is configured by a repeating structure of portions having different thicknesses as in this embodiment, the same effects as those of the first to third embodiments can be obtained.

[Fifth Embodiment]
In this embodiment, instead of the repetitive structure with different regions in the slow axis direction described above for the first to third embodiments, a periodic structure with different optical optical path lengths is produced by a repetitive structure with regions having different refractive indexes. To produce a diffraction grating.

  Note that such a diffraction grating is manufactured by, for example, partially doping impurities in a transparent member by a technique such as thermal diffusion, and manufacturing portions having different refractive indexes corresponding to the first and second regions. Can do.

  Even if a diffraction grating having a periodic structure with a different optical optical path length is applied by a repeating structure of regions having different refractive indexes as in this embodiment, the same effects as those of the above-described embodiment can be obtained.

[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 it is applied to an image display device including a touch panel to make it difficult to visually recognize an electrode related to the touch panel is described, but the present invention is not limited to this, and the panel surface of the image display panel is used. The present invention can be widely applied to configurations in which various electrodes are arranged.

  Specifically, in this type of image display device, when electromagnetic shielding material is arranged on the panel surface of the image display panel to reduce unnecessary radiation, the electromagnetic shielding material is difficult to visually recognize like the touch panel sensor film. An electrode for shielding is produced by fine lines in a mesh shape or mesh shape. In such a configuration, it is possible to make the electrode more difficult to visually recognize by forming a laminated body of electrode films by a laminated body of an electromagnetic sealing material and a diffraction grating.

  In addition, in this type of image display device, when an antenna is configured by arranging a film material on which an antenna is printed on the panel surface of the image display panel, the film material, like the sensor film for a touch panel, is difficult to visually recognize. The antenna is printed with fine lines in a mesh shape. In such a configuration, the electrode material can be made more difficult to see by laminating the film material on which the antenna is printed and the diffraction grating to form a laminate of electrode films.

  In the above-described embodiment, the case where the diffraction grating is configured by the periodic structure of the regions having different slow axis directions, the periodic structure of the portions having different thicknesses, and the periodic structure of the portions having different refractive indexes has been described. However, the present invention is not limited to this, and a diffraction grating may be manufactured by a combination of these structures.

  In the first to third embodiments described above, the case where the base material, the alignment layer, and the retardation layer are integrally laminated on the sensor film for a touch panel that is an electrode film is described, but the present invention is not limited thereto. In the diffraction gratings according to the first to third embodiments, the retardation layer is a part that functions as a diffraction grating, so that only the retardation layer is laminated on the electrode film to form a laminate of electrode films. You may make it comprise. In this case, the alignment film may be laminated together with the retardation layer.

  In the above-described embodiment, the case of arranging on the panel surface of the image display panel has been described. However, the present invention is not limited to this, and can be widely applied to the case where the image display panel is arranged in each part other than the image display panel.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 2 Image display panel 3 Laminated body 5 Liquid crystal cell 6 Backlight apparatus 7A, 7B Linear polarizing plate 9 Sensor film for touch panels 9X, 9Y Electrode 10, 10A, 10B, 30, 40 Diffraction grating 11, 12 Adhesive layer 14 Cover glass 15, 22, 22A, 22B Base material 23, 23A, 23B Alignment layer 24, 24A, 24B Retardation layer

Claims (5)

An electrode film having electrodes formed on a transparent substrate;
A diffraction grating laminated on the electrode film;
An image display device in which a laminate of electrode films provided with an image display panel is disposed on the panel surface,
The electrode has a thin line shape extending in a first direction and a second direction orthogonal to the first direction, and a thin line portion is repeatedly formed in a direction orthogonal to the extension direction,
The repetition pitch of the electrodes is 50-100 μm,
The pitch of the diffraction grating is larger than the repetition pitch of the electrodes, and is 1/10 times or more and 1 time or less of the pixel pitch of the image display panel,
An image display device in which the electrode repeat direction and the diffraction grating repeat direction intersect each other at an angle of 2 degrees or more. The diffraction grating is composed of a retardation layer formed of a liquid crystal material cured in a state in which the refractive index anisotropy is maintained,
The image display apparatus according to claim 1 . The diffraction grating is
The image display device according to claim 1, wherein the image display device is a one-dimensional diffraction grating having a periodic structure in a repeating direction of the electrodes. The diffraction grating is
The image display device according to claim 1, wherein the image display device is a two-dimensional diffraction grating. The diffraction grating is
The image display device according to claim 4, wherein the image display device is a laminated body of one-dimensional diffraction gratings.

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