Manufacturing method of display system and optical film group

Abstract

Provided is a method for manufacturing a display system that displays an image to a user, the display system being provided with: a display element that has a display surface that emits light that displays the image forward via a polarizing member; a reflective polarization member that is disposed in front of the display element and reflects light emitted from the display element; a first lens unit disposed on an optical path between the display element and the reflective polarization member; a half mirror that is disposed between the display element and the first lens unit, transmits the light emitted from the display element, and reflects the light reflected by the reflective polarization member toward the reflective polarization member; a first [lambda] / 4 member disposed on an optical path between the display element and the half mirror; and a second [lambda] / 4 member disposed on an optical path between the half mirror and the reflective polarization member, the method of manufacturing the display system including: preparing a plurality of optical films including the first [lambda] / 4 member, and classifying the optical films into a plurality of groups for each type of optical film having a predetermined in-plane phase difference; preparing a plurality of optical films including the second [lambda] / 4 member, and classifying the optical films into a plurality of groups for each type of optical film having a predetermined in-plane phase difference; and selecting a combination of a group having a suitable in-plane phase difference from among a plurality of groups of optical films including the first [lambda] / 4 member and a plurality of groups of optical films including the second [lambda] / 4 member.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a display system such as goggles with a display and an optical film set. Background Art

[0002] Image display devices, represented by liquid crystal displays and electroluminescent (EL) displays (e.g., organic EL displays), are rapidly gaining popularity. In image display devices, optical components such as polarizing elements and phase shifting elements are generally used to achieve image display and improve image display performance (e.g., see Patent Document 1).

[0003] In recent years, new applications for image display devices have been developed. For example, goggles with displays (VR goggles) for realizing virtual reality (VR) have begun to be commercialized. As VR goggles are being studied for their use in various scenarios, they are increasingly being sought after for their high resolution.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-103286 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] A main object of the present invention is to provide a method for manufacturing a display system such as goggles with a high-definition display and an optical member suitable for manufacturing the display system.

[0009] Solutions to the Problem

[0010] [1] A method for manufacturing a display system according to an embodiment of the present invention is a method for manufacturing a display system for displaying an image to a user, the display system comprising: a display element having a display surface for emitting light displaying an image forward via a polarizing member; a reflective polarizing member disposed in front of the display element for reflecting light emitted from the display element; a first lens portion disposed on an optical path between the display element and the reflective polarizing member; a half mirror disposed between the display element and the first lens portion for transmitting light emitted from the display element and reflecting light reflected from the reflective polarizing member toward the reflective polarizing member; a first λ / 4 component, which is arranged on the optical path between the display element and the half-reflecting mirror; and a second λ / 4 component, which is arranged on the optical path between the half-reflecting mirror and the reflective polarization component, the manufacturing method of the display system comprises: preparing a plurality of optical films including the first λ / 4 component, and classifying the optical films into a plurality of groups according to each optical film having a given in-plane phase difference; preparing a plurality of optical films including the second λ / 4 component, and classifying the optical films into a plurality of groups according to each optical film having a given in-plane phase difference; and selecting a combination of groups with suitable in-plane phase differences from the plurality of groups of optical films including the first λ / 4 component and the plurality of groups of optical films including the second λ / 4 component.

[0011] [2] In the above [1], the deviation of the in-plane retardation between the optical films including the first λ / 4 member in each of the classified groups may be 3 nm or less.

[0012] [3] In the above [1] or [2], the deviation of the in-plane retardation between the optical films including the second λ / 4 member in each of the classified groups may be 3 nm or less.

[0013] [4] In any one of [1] to [3] above, the deviation of the in-plane phase difference in the longitudinal direction of the optical film including the first λ / 4 member may be 3 nm or less.

[0014] [5] In any one of the above [1] to [4], the deviation of the in-plane phase difference in the longitudinal direction of the optical film including the second λ / 4 member may be 3 nm or less.

[0015] [6] In any one of the above [1] to [5], the length of one side of the optical film including the first λ / 4 member may be 1000 mm or less.

[0016] [7] In any one of [1] to [6] above, the length of the optical film including the second λ / 4 member may be 50 m or more and 1000 m or less.

[0017] [8] In any one of [1] to [7] above, the in-plane phase difference of the optical film including the first λ / 4 member may be an average value of the in-plane phase differences measured at the four corners of the optical film including the first λ / 4 member.

[0018] [9] In any one of the above [1] to [8], the in-plane phase difference of the optical film including the above-mentioned second λ / 4 component can be the average value of the in-plane phase difference measured at two or more locations at the front end of the optical film including the above-mentioned second λ / 4 component.

[0019]

[10] In any one of the above [1] to [8], the in-plane phase difference of the optical film including the above-mentioned second λ / 4 component can be the average value of the in-plane phase differences measured at more than two locations at the front end and more than two locations at the end of the optical film including the above-mentioned second λ / 4 component.

[0020]

[11] In any one of the above [1] to

[10] , the above manufacturing method may include: step Ii, preparing a first optical film A1 including the above-mentioned first λ / 4 member; step I-ii, dividing the above-mentioned first optical film A1 to obtain a plurality of first optical films A2 having a given width and a given length; step I-iii, stacking the above-mentioned plurality of first optical films A2 and the above-mentioned polarization member to obtain a plurality of second optical films B1; step I-iv, classifying the above-mentioned plurality of second optical films B1 into a plurality of groups according to each optical film having a given in-plane phase difference; step II-i, preparing a third optical film C1 including the above-mentioned second λ / 4 member; step II-ii, dividing the above-mentioned third optical film C1 to obtain a plurality of third optical films C2 having a given width and a given length; step II-iii, classifying the above-mentioned plurality of third optical films C2 into a plurality of groups according to each optical film having a given in-plane phase difference; and step III, selecting a combination of groups with suitable in-plane phase differences from the plurality of groups of the above-mentioned second optical films B1 and the plurality of groups of the above-mentioned third optical films C2.

[0021]

[12] The optical film group of an embodiment of the present invention is an optical film group comprising a plurality of optical films, wherein the optical film comprises a λ / 4 component and has a given width and a given length, and the difference between the maximum value and the minimum value of the in-plane phase difference between the plurality of optical films is less than 3 nm.

[0022]

[13] In the above

[12] , the length of one side of the optical film may be less than 1000 mm.

[0023] Effects of the Invention

[0024] According to the method for manufacturing a display system according to the embodiment of the present invention, a display system is constructed using a combination of λ / 4 members having mutually suitable in-plane phase differences, and therefore a high-definition display system can be preferably obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram showing a schematic configuration of a display system obtained by a manufacturing method according to an embodiment of the present invention.

[0026] Figure 2 of Figure 2 (a) and 2(b) are schematic cross-sectional views illustrating an example of the structure of the first optical film A1.

[0027] Figure 3 This is a schematic diagram illustrating an example of step I-ii of the method for manufacturing a display system according to one embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram illustrating an example of step I-iii of the method for manufacturing a display system according to one embodiment of the present invention.

[0029] Figure 5 of Figure 5 (a) and 5(b) are schematic cross-sectional views illustrating an example of the structure of the second optical film B1.

[0030] Figure 6 This is a schematic diagram illustrating an example of steps I-iv of the method for manufacturing a display system according to one embodiment of the present invention.

[0031] Figure 7 of Figure 7 (a) and 7(b) are schematic cross-sectional views illustrating an example of the structure of the third optical film C1.

[0032] Figure 8 This is a schematic diagram illustrating an example of step II-ii of the method for manufacturing a display system according to one embodiment of the present invention.

[0033] Figure 9 This is a schematic diagram illustrating an example of step II-iii of the method for manufacturing a display system according to one embodiment of the present invention.

[0034] Figure 10 This is a schematic diagram illustrating an example of step III of the method for manufacturing a display system according to one embodiment of the present invention.

[0035] Figure 11 of Figure 1111( a ) and 11 ( b ) are schematic diagrams illustrating an example of punching of the second optical film sheet B2 and the third optical film sheet C3 , respectively.

[0036] Explanation of symbols

[0037] 2 Display System

[0038] 4 Lens section

[0039] 12 display components

[0040] 14 Reflective polarization component

[0041] 16. First lens unit

[0042] 18 Half Mirror

[0043] 20 first phase difference member

[0044] 22 second phase difference member

[0045] 24 Second lens unit

[0046] 30 First Optical Film

[0047] 34a First λ / 4 member

[0048] 34b First positive C plate

[0049] 40 Second optical film

[0050] 42 polarization components

[0051] 50 Third optical film

[0052] 54a Second λ / 4 member

[0053] 54b Second positive C plate DETAILED DESCRIPTION

[0054] The following describes embodiments of the present invention with reference to the accompanying drawings, but the present invention is not limited to these embodiments. Furthermore, for greater clarity, the drawings sometimes schematically illustrate the width, thickness, shape, etc. of various components, as compared to the embodiments. However, this is merely an example and does not limit the interpretation of the present invention. In this specification, "elongated" refers to an elongated shape that is sufficiently long relative to its width, including, for example, an elongated shape that is at least 10 times, and preferably at least 20 times, its width.

[0055] (Definition of Terms and Symbols)

[0056] The definitions of terms and symbols in this specification are as follows.

[0057] (1) Refractive index (nx, ny, nz)

[0058] "nx" is the refractive index in the direction where the refractive index in the plane reaches a maximum (ie, the slow axis direction), "ny" is the refractive index in the direction orthogonal to the slow axis in the plane (ie, the fast axis direction), and "nz" is the refractive index in the thickness direction.

[0059] (2) In-plane retardation (Re)

[0060] "Re(λ)" is the in-plane retardation measured at 23°C using light of a wavelength of λ nm. For example, "Re(550)" is the in-plane retardation measured at 23°C using light of a wavelength of 550 nm. When the thickness of a layer (film) is d (nm), Re(λ) can be calculated using the formula: Re(λ) = (nx - ny) × d.

[0061] (3) Retardation in the thickness direction (Rth)

[0062] "Rth(λ)" is the retardation in the thickness direction measured at 23°C using light with a wavelength of λ nm. For example, "Rth(550)" is the retardation in the thickness direction measured at 23°C using light with a wavelength of 550 nm. When the thickness of a layer (film) is d (nm), Rth(λ) can be calculated using the formula: Rth(λ) = (nx - nz) × d.

[0063] (4) Nz coefficient

[0064] The Nz coefficient can be calculated by Nz=Rth / Re.

[0065] (5) Angle

[0066] In this specification, when referring to an angle, unless otherwise specified, the angle includes both clockwise and counterclockwise angles relative to a reference direction. Thus, for example, "45°" means ±45°. Furthermore, in this specification, "substantially parallel" includes angles within the range of 0°±10°, for example, 0°±5°, preferably 0°±3°, and more preferably 0°±1°. "Substantially orthogonal" includes angles within the range of 90°±10°, for example, 90°±5°, preferably 90°±3°, and more preferably 90°±1°.

[0067] A. Display system overview

[0068] Figure 1 Schematic diagram showing a schematic configuration of a display system manufactured by a manufacturing method according to an embodiment of the present invention. Figure 1In the figure, the configuration and shape of each component of the display system (2) are schematically shown. The display system (2) comprises a display element (12), a reflective polarization component (14), a first lens portion (16), a half-reflecting mirror (18), a first phase difference component (20), a second phase difference component (22) and a second lens portion (24). The reflective polarization component (14) is arranged on the display surface (12a) side of the display element (12), i.e., in front, and can reflect the light emitted from the display element (12). The first lens portion (16) is arranged on the optical path between the display element (12) and the reflective polarization component (14), and the half-reflecting mirror (18) is arranged between the display element (12) and the first lens portion (16). The first phase difference component (20) is arranged on the optical path between the display element (12) and the half-reflecting mirror (18), and the second phase difference component (22) is arranged on the optical path between the half-reflecting mirror (18) and the reflective polarization component (14). Although not shown, from the perspective of improving visual recognition, an absorptive polarizing element may be arranged between the reflective polarizing element (14) and the second lens unit (24). In this case, the reflection axis of the reflective polarizing element (14) and the absorption axis of the absorptive polarizing element may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing element (14) and the transmission axis of the absorptive polarizing element may be arranged substantially parallel to each other.

[0069] The components arranged in front of the half-mirror (in the illustrated example, the half-mirror (18), the first lens unit (16), the second phase difference component (22), the reflective polarization component (14) and the second lens unit (24)) are sometimes collectively referred to as a lens unit (lens unit (4)).

[0070] The display element (12) is, for example, a liquid crystal display or an organic EL display, and has a display surface (12a) for displaying an image. Light emitted from the display surface (12a) passes through a polarizing member (representatively, a polarizing film) that may be included in the display element (12) and then is emitted as first linearly polarized light.

[0071] The first phase difference member (20) includes a first λ / 4 member capable of converting first linearly polarized light incident on the first phase difference member (20) into first circularly polarized light. When the first phase difference member does not include any member other than the first λ / 4 member, the first phase difference member may be equivalent to the first λ / 4 member. The first phase difference member (20) may be provided integrally with the display element (12).

[0072] The half mirror (18) transmits light emitted from the display element (12) and reflects light reflected by the reflective polarizing member (14) toward the reflective polarizing member (14). The half mirror (18) is integrally provided with the first lens portion (16).

[0073] The second phase difference member (22) includes a second λ / 4 member capable of transmitting light reflected by the reflective polarization member (14) and the half mirror (18) through the reflective polarization member (14). When the second phase difference member does not include any member other than the second λ / 4 member, the second phase difference member may be equivalent to the second λ / 4 member. The second phase difference member (22) may be integrally provided with the first lens portion (16).

[0074] The first circularly polarized light emitted from the first λ / 4 component included in the first phase difference component (20) passes through the half-mirror (18) and the first lens unit (16), and is converted into the second linearly polarized light by the second λ / 4 component included in the second phase difference component (22). The second linearly polarized light emitted from the second λ / 4 component does not pass through the reflective polarization component (14) but is reflected toward the half-mirror (18). At this time, the polarization direction of the second linearly polarized light incident on the reflective polarization component (14) is the same direction as the reflection axis of the reflective polarization component (14). Therefore, the second linearly polarized light incident on the reflective polarization component (14) is reflected by the reflective polarization component (14).

[0075] The second linear polarized light reflected by the reflective polarizing component (14) is converted into a second circular polarized light by the second λ / 4 component included in the second phase difference component (22). The second circular polarized light emitted from the second λ / 4 component passes through the first lens unit (16) and is reflected by the half-reflecting mirror (18). The second circular polarized light reflected by the half-reflecting mirror (18) passes through the first lens unit (16) and is converted into a third linear polarized light by the second λ / 4 component included in the second phase difference component (22). The third linear polarized light passes through the reflective polarizing component (14). At this time, the polarization direction of the third linear polarized light incident on the reflective polarizing component (14) is the same direction as the transmission axis of the reflective polarizing component (14). Therefore, the third linear polarized light incident on the reflective polarizing component (14) passes through the reflective polarizing component (14).

[0076] The light transmitted through the reflective polarizing component (14) passes through the second lens portion (24) and then enters the user's eyes (26).

[0077] The reflective polarizing component (14) can allow polarized light (representatively linear polarized light) parallel to its transmission axis to pass through while maintaining its polarization state, while reflecting light of other polarization states. The orthogonal transmittance (Tc) of the reflective polarizing component can be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing component can be, for example, 43% to 49%, and can preferably be 45% to 47%. The polarization degree (P) of the reflective polarizing component can be, for example, 92% to 99.99%. The reflective polarizing component is composed of, for example, a film having a multilayer structure (sometimes referred to as a reflective polarizing film). Commercially available products of reflective polarizing films include, for example, the trade names "DBEF" and "APF" manufactured by 3M and the trade name "APCF" manufactured by Nitto Denko Corporation.

[0078] For example, the absorption axis of the polarization component included in the display element (12) and the reflection axis of the reflective polarization component (14) can be arranged approximately parallel to each other, or approximately orthogonally to each other. The angle formed by the absorption axis of the polarization component included in the display element (12) and the slow axis of the first λ / 4 component included in the first phase difference component (20) is, for example, 40° to 50°, 42° to 48°, or approximately 45°. The angle formed by the absorption axis of the polarization component included in the display element (12) and the slow axis of the second λ / 4 component included in the second phase difference component (22) is, for example, 40° to 50°, 42° to 48°, or approximately 45°. The first λ / 4 component and the second λ / 4 component are preferably arranged in a manner such that the slow axis directions are approximately parallel to each other or approximately orthogonal to each other.

[0079] The in-plane retardation Re(550) of the first λ / 4 element is, for example, 100 nm to 190 nm, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ / 4 element preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases with the wavelength of the measurement light. The Re(450) / Re(550) ratio of the first λ / 4 element is, for example, 0.75 or greater and less than 1, or 0.8 or greater and 0.95 or less.

[0080] The in-plane retardation Re(550) of the second λ / 4 element is, for example, 100 nm to 190 nm, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The second λ / 4 element preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases with the wavelength of the measurement light. The Re(450) / Re(550) ratio of the second λ / 4 element is, for example, 0.75 or greater and less than 1, or 0.8 or greater and 0.95 or less.

[0081] As described above, in the display system (2), linearly polarized light emitted forward from the display surface (12a) of the display element (12) passes through the first λ / 4 element and the second λ / 4 element in sequence, is reflected by the reflective polarizing element (14) and re-reflected by the half mirror (18), and then passes through the second λ / 4 element twice. After passing through the reflective polarizing element (14), it is emitted forward and is visually recognized by the viewer. Therefore, if the in-plane phase difference of the first λ / 4 element or the second λ / 4 element is greatly offset, the following problems may occur: polarization is destroyed and light leakage occurs, and light to be reflected and light to be visually recognized is mixed and visually recognized (as a result, a blurred image is visually recognized). In contrast, in order to prevent this problem and realize high-definition image display, it is desirable that the in-plane phase differences of the first λ / 4 element and the second λ / 4 element are substantially the same.

[0082] B. Display System Manufacturing Method

[0083] B-1. Overview of Display System Manufacturing Method

[0084] A manufacturing method of a display system according to an embodiment of the present invention includes: preparing a plurality of optical films including the above-mentioned first λ / 4 component, and classifying the optical films into a plurality of groups according to each optical film having a given in-plane phase difference; preparing a plurality of optical films including the above-mentioned second λ / 4 component, and classifying the optical films into a plurality of groups according to each optical film having a given in-plane phase difference; and selecting a combination of groups with suitable in-plane phase differences from the plurality of groups of optical films including the above-mentioned first λ / 4 component and the plurality of groups of optical films including the above-mentioned second λ / 4 component.

[0085] Representatively, the manufacturing method of the display system of an embodiment of the present invention further includes: arranging an optical film sheet containing a first λ / 4 component and an optical film sheet containing a second λ / 4 component, respectively obtained from the group of optical films containing a first λ / 4 component and the group of optical films containing a first λ / 4 component of the above-selected combination, at a given position of the above-mentioned display system.

[0086] According to the manufacturing method of the display system of an embodiment of the present invention, as a constituent component of the display system (2) described in item A, that is, an optical film including a first λ / 4 component and a second λ / 4 component, an optical film having a suitable in-plane phase difference with good precision can be effectively prepared, thereby easily and effectively obtaining a display system in which the in-plane phase difference of the first λ / 4 component and the second λ / 4 component is roughly consistent.

[0087] In one embodiment, the deviation of the in-plane phase difference between the optical films including the first λ / 4 member in each of the classified groups is, for example, 3 nm or less, or 2 nm or less, preferably 1 nm or more and 1.5 nm or less, and more preferably 1 nm or more and 1.3 nm or less.

[0088] In one embodiment, the deviation of the in-plane phase difference between the optical films including the second λ / 4 member in each of the classified groups is, for example, 3 nm or less, or 2 nm or less, preferably 1 nm or more and 1.5 nm or less, and more preferably 1 nm or more and 1.3 nm or less.

[0089] In one embodiment, the deviation of the in-plane retardation in the longitudinal direction of the optical film including the first λ / 4 member is, for example, 3 nm or less, or preferably 1.5 nm or less.

[0090] In one embodiment, the deviation of the in-plane retardation in the longitudinal direction of the optical film including the second λ / 4 member is, for example, 3 nm or less, or preferably 1.5 nm or less.

[0091] In one embodiment, the optical film comprising the first λ / 4 member has a predetermined length and width. The length of the optical film is, for example, 50 m to 1000 m, 50 m to 300 m, or 100 m to 150 m. Furthermore, the width of the optical film is, for example, 60 mm to 500 mm, 100 mm to 400 mm, or 100 mm to 300 mm. Alternatively, the optical film may be in the form of a single sheet, with a side length of, for example, 1000 mm or less.

[0092] In one embodiment, the optical film including the second λ / 4 member has a predetermined length and width. For example, the length of the optical film is 50 m to 1000 m, 50 m to 300 m, or 100 m to 150 m. Furthermore, the width of the optical film is 40 mm to 200 mm, 45 mm to 150 mm, or 50 mm to 120 mm.

[0093] In one embodiment, the in-plane retardation of the optical film including the first λ / 4 member is an average value of the in-plane retardations measured at four corners of the optical film.

[0094] In one embodiment, the in-plane retardation of the optical film including the second λ / 4 member is an average value of in-plane retardations measured at two or more locations at the front end of the optical film.

[0095] In one embodiment, the in-plane retardation of the optical film including the second λ / 4 member is an average value of in-plane retardations measured at two or more locations at the front end and two or more locations at the rear end of the optical film.

[0096] Hereinafter, a method for manufacturing a display system according to an embodiment of the present invention will be described in detail.

[0097] B-2. Method for Manufacturing a Display System According to One Embodiment of the Present Invention

[0098] In one embodiment, a method for manufacturing a display system according to an embodiment of the present invention includes: step Ii, preparing a first optical film A1 including the above-mentioned first λ / 4 component; step I-ii, dividing the above-mentioned first optical film A1 to obtain a plurality of first optical films A2 having a given width and a given length; step I-iii, stacking the above-mentioned plurality of first optical films A2 and the above-mentioned polarization component to obtain a plurality of second optical films B1; step I-iv, classifying the above-mentioned plurality of second optical films B1 into a plurality of groups according to each optical film having a given in-plane phase difference; step II-i, preparing a third optical film C1 including the above-mentioned second λ / 4 component; step II-ii, dividing the above-mentioned third optical film C1 to obtain a plurality of third optical films C2 having a given width and a given length; step II-iii, classifying the above-mentioned plurality of third optical films C2 into a plurality of groups according to each optical film having a given in-plane phase difference; and step III, selecting a combination of groups with suitable in-plane phase differences from the plurality of groups of the above-mentioned second optical films B1 and the plurality of groups of the above-mentioned third optical films C2.

[0099] Representatively, the manufacturing method of the display system of the above embodiment includes step IV: after step III, the second optical film piece B2 and the third optical film piece C3 obtained from the above selected combination of the second optical film group B1 and the third optical film group C2 are arranged at a given position of the above display system.

[0100] B-2-1. Step Ii

[0101] In step Ii, a first optical film A1 including a first λ / 4 member is prepared. Figure 2 (a) and 2(b) are schematic cross-sectional views illustrating an example of the structure of the first optical film A1.

[0102] Figure 2The first optical film A1 (30a) shown in (a) includes an adhesive layer (32), a first λ / 4 member (34a), and a first protective member (36) in this order. According to the configuration of the first optical film A1 (30a), the first phase difference member (20) in the display system (2) is composed of the first λ / 4 member (34a). The first λ / 4 member (34a) and the first protective member (36) are typically bonded together via an adhesive layer such as an adhesive layer or an adhesive layer.

[0103] Figure 2 The first optical film A1 (30a') shown in (b) includes, in sequence, an adhesive layer (32), a first λ / 4 component (34a), a component whose refractive index characteristics can show the relationship of nz>nx=ny (the so-called positive C plate, hereinafter also referred to as "the first positive C plate") (34b) and a first protective component (36). According to the structure of the first optical film A1 (30a'), the first phase difference component (20) in the display system (2) includes a first λ / 4 component (34a) and a first positive C plate (34b). In other words, the first phase difference component (20) has a stacked structure of a first λ / 4 component (34a) and a second positive C plate (34b). Different from the example shown in the figure, in the first phase difference component (20), the first λ / 4 component (34a) is located closer to the first protective component (36) than the positive C plate (34b). Typically, the first positive C plate (34b), the first λ / 4 member (34a), and the first protective member (36) are bonded together via adhesive layers such as adhesive layers and pressure-sensitive adhesive layers.

[0104] The surfaces of the adhesive layers (32) of the first optical films A1 (30a) and (30a') are protected by release liners (38).

[0105] The first optical film A1 is preferably in the form of a long strip. In one embodiment, the first optical film A1 can be produced by stacking components formed into a long strip in a roll-to-roll manner and winding them into a roll. Here, "roll-to-roll" means that the rolls are conveyed while being laminated so that their length directions are aligned.

[0106] The length of the first optical film A1 is, for example, 100 m to 2000 m, or preferably 500 m to 1000 m.

[0107] The width of the first optical film A1 is, for example, 500 mm or more and 1500 mm or less, preferably 900 mm or more and 1200 mm or less. As described later in step IV, the second optical film sheet B2 can be obtained by punching the second optical film B1. The width of the first optical film A1 is, for example, 10 times or more, preferably 15 times or more and 25 times or less, and more preferably 15 times or more and 20 times or less of the punched width of the second optical film sheet B2.

[0108] [First λ / 4 member]

[0109] As described in Section A for the first λ / 4 member, the in-plane retardation Re(550) of the first λ / 4 member (34a) is, for example, 100 nm to 190 nm, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ / 4 member preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases with the wavelength of the measurement light. The Re(450) / Re(550) ratio of the first λ / 4 member is, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0110] The refractive index characteristics of the first λ / 4 member preferably exhibit the relationship nx > ny ≥ nz. Here, "ny = nz" encompasses not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Therefore, ny < nz may be acceptable without impairing the effects of the present invention. The Nz coefficient of the λ / 4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0111] In one embodiment, the first λ / 4 member is a stretched film of a resin film, for example, a stretched film obtained by stretching a long resin film in the width direction.

[0112] Examples of the resin contained in the resin film include polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, and acrylic resins. These resins can be used alone or in combination. Examples of methods for combining the resins include blending and copolymerization. When the first λ / 4 component exhibits reverse dispersion wavelength characteristics, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes referred to as a polycarbonate resin) can be suitably used.

[0113] As the above-mentioned polycarbonate resin, any appropriate polycarbonate resin can be used. For example, the polycarbonate resin contains structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from alicyclic diols, alicyclic dimethanols, di-, tri- or polyethylene glycols, and alkylene glycols or spirodiols. Preferably, the polycarbonate resin contains structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, structural units derived from alicyclic dimethanols and / or structural units derived from di-, tri- or polyethylene glycols; more preferably, it contains structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from di-, tri- or polyethylene glycols. The polycarbonate resin may also contain structural units derived from other dihydroxy compounds as needed. It should be noted that details of the polycarbonate resin that can be suitably used for the first λ / 4 member and the method for forming the first λ / 4 member are described in, for example, Japanese Patent Application Publication No. 2014-10291, Japanese Patent Application Publication No. 2014-26266, Japanese Patent Application Publication No. 2015-212816, Japanese Patent Application Publication No. 2015-212817, and Japanese Patent Application Publication No. 2015-212818, and the descriptions of these publications are incorporated into this specification by reference.

[0114] The thickness of the first λ / 4 member, which is a stretched film of a resin film, is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, and more preferably 20 μm to 60 μm.

[0115] In another embodiment, the first λ / 4 component is an orientation fixing layer of a liquid crystal compound. The orientation fixing layer of a liquid crystal compound is a layer in which the liquid crystal compound is oriented in a given direction within the layer and its orientation state is fixed. It should be noted that the "orientation fixing layer" is a concept that includes an orientation solidification layer obtained by solidifying a liquid crystal monomer as described later. In the first λ / 4 component, representatively, the rod-shaped liquid crystal compound is oriented in a state of being arranged along the slow axis direction of the first λ / 4 component (parallel orientation (homogeneous alignment)). Examples of the rod-shaped liquid crystal compound include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably capable of polymerization. If the liquid crystal compound is capable of polymerization, the orientation state of the liquid crystal compound can be fixed by polymerizing it after orienting the liquid crystal compound.

[0116] The orientation fixing layer (liquid crystal orientation fixing layer) of the above-mentioned liquid crystal compound can be formed by the following method: an orientation treatment is applied to the surface of a given substrate, a coating liquid containing a liquid crystal compound is applied to the surface, and the liquid crystal compound is oriented along the direction corresponding to the above-mentioned orientation treatment to fix the orientation state. As an orientation treatment, any appropriate orientation treatment can be adopted. Specifically, mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment can be mentioned. As a specific example of a mechanical orientation treatment, friction treatment and stretching treatment can be mentioned. As a specific example of a physical orientation treatment, magnetic field orientation treatment and electric field orientation treatment can be mentioned. As a specific example of a chemical orientation treatment, inclined evaporation method and optical orientation treatment can be mentioned. The processing conditions of various orientation treatments can adopt any appropriate conditions according to the purpose.

[0117] The liquid crystal compound can be aligned by treating it at a temperature that exhibits a liquid crystal phase, depending on the type of the liquid crystal compound. By treating it at this temperature, the liquid crystal compound assumes a liquid crystal state and is aligned in the alignment treatment direction on the substrate surface.

[0118] In one embodiment, the alignment state is fixed by cooling the aligned liquid crystal compound as described above. If the liquid crystal compound is polymerizable or cross-linkable, the alignment state can be fixed by subjecting the aligned liquid crystal compound to a polymerization treatment or a cross-linking treatment as described above.

[0119] As the liquid crystal compound, any appropriate liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer can be used alone or in combination. Specific examples of liquid crystal compounds and methods for preparing liquid crystal alignment fixing layers are described, for example, in Japanese Patent Application Publication No. 2006-163343, Japanese Patent Application Publication No. 2006-178389, and International Publication No. 2018 / 123551. The contents of these publications are incorporated herein by reference.

[0120] The thickness of the first λ / 4 member composed of the liquid crystal alignment solidified layer is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.

[0121] [First positive C plate]

[0122] The thickness-direction retardation Rth(550) of the first positive C plate (34b) is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, further preferably -90 nm to -200 nm, and particularly preferably -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane retardation Re(550) of the first positive C plate is, for example, less than 10 nm.

[0123] The first positive C plate can be formed of any appropriate material, but the first positive C plate is preferably composed of a film containing a liquid crystal material fixed in a homeotropic orientation. The liquid crystal material (liquid crystal compound) capable of homeotropic orientation can be a liquid crystal monomer or a liquid crystal polymer. As specific examples of such a liquid crystal compound and a method for forming the first positive C plate, the liquid crystal compound and the method for forming the phase difference layer described in

[0020] to

[0028] of Japanese Patent Application Laid-Open No. 2002-333642 can be cited. In this case, the thickness of the first positive C plate is preferably 0.5 μm to 5 μm.

[0124] [First protective member]

[0125] Typically, the first protective member (36) includes a substrate. The substrate can be composed of any appropriate film. Examples of the material constituting the main component of the film constituting the substrate include cellulose resins such as triacetyl cellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyethersulfones, polysulfones, polystyrenes, cycloolefins such as polynorbornene, polyolefins, (meth) acrylic acid, acetates, and the like. The thickness of the substrate is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 35 μm.

[0126] The first protective member preferably comprises a substrate and a surface treatment layer formed on the substrate. The first protective member having the surface treatment layer can be configured so that the surface treatment layer is located on the front side. The surface treatment layer can have any appropriate function. For example, from the perspective of improving visual recognition, the surface treatment layer preferably has an anti-reflection function. In addition, the surface treatment layer may include a hard coating layer. The thickness of the surface treatment layer is preferably 1 μm to 20 μm, more preferably 2 μm to 15 μm, and even more preferably 3 μm to 10 μm.

[0127] [Adhesive layer]

[0128] The adhesive constituting the adhesive layer (32) typically contains a (meth)acrylic polymer, a urethane polymer, a silicone polymer, or a rubber polymer as a base polymer. The adhesive is preferably a (meth)acrylic adhesive containing a (meth)acrylic polymer as a main component. The thickness of the adhesive layer is, for example, 3 μm or more, 5 μm or more, 10 μm or more, or 12 μm or more, and for example, 100 μm or less or 80 μm or less.

[0129] [Release liner]

[0130] The release liner (38) typically comprises a substrate and a release treatment layer (e.g., a silicone treatment layer) provided on the adhesive layer (32) side of the substrate. The substrate is formed of, for example, a resin such as a polyolefin resin, a polyester resin, a (meth) acrylic resin, a polyamide resin, a polyimide resin, a polyvinyl chloride resin, a polyvinylidene chloride resin, a cellulose resin, a polystyrene resin, or a polycarbonate resin.

[0131] B-2-2. Step I-ii

[0132] In step I-ii, the first optical film A1 is divided to obtain a plurality of first optical films A2 having a given width and a given length. Figure 3 As shown, by slitting the first optical film A1 (30a) along the length direction and along the width direction, and / or punching it into a given size, a plurality of first optical films A2 (30b) having a given width and a given length are obtained. Slitting along the width direction may also not be performed. The deviation of the in-plane phase difference of the first optical film A2 in the width direction is typically smaller than that of the first optical film A1.

[0133] The first optical film A2 can have any shape according to the purpose.

[0134] In one embodiment, the first optical film A2 is in the form of an elongated strip. The length of the first optical film A2 in the form of an elongated strip can be, for example, more than 50m and less than 1000m, more than 50m and less than 300m, or more than 100m and less than 150m. The first optical film A2 in the form of an elongated strip can be wound into a roll. The width of the first optical film A2 in the form of an elongated strip can be, for example, more than 60mm and less than 500mm, preferably more than 100mm and less than 400mm, more preferably more than 100mm and less than 300mm. The width of the first optical film A2 in the form of an elongated strip can be, for example, more than 2 times and less than 20 times the width of the punching of the second optical film sheet B2, preferably more than 3 times and less than 10 times. By being divided into narrower widths like this, the deviation of the in-plane phase difference in the length direction and width direction of the first optical film A2 can be reduced.

[0135] In another embodiment, the first optical film A2 is in a monolithic form. The length of one side of the monolithic first optical film A2 is, for example, less than 1000 mm, less than 800 mm, or less than 500 mm. Specifically, the first optical film A2 may be in a generally rectangular shape with a size of 500 mm to 350 mm × 450 mm to 300 mm, 400 mm to 250 mm × 350 mm to 200 mm, or 250 mm to 150 mm × 200 mm to 100 mm. In the case where the first λ / 4 member has a slow axis in the width direction or the length direction, the first optical film A2 having a slow axis in a direction inclined relative to the side direction can be effectively obtained by obliquely punching the first optical film A1.

[0136] The deviation of the in-plane phase difference (e.g., Re(590)) in the length direction (long side direction in the case of a rectangular shape) of the first optical film A2 is, for example, less than 3 nm, preferably less than 1.5 nm. The deviation of the in-plane phase difference (e.g., Re(590)) in the width direction (short side direction in the case of a rectangular shape) of the first optical film A2 is, for example, less than 3 nm, preferably less than 1.5 nm. The deviation of the in-plane phase difference in the length direction can be measured at any position (e.g., the center of the width direction) in the width direction of the optical film over a given length (e.g., more than 50 m, or the full length) in the length direction, and is obtained as the difference between its maximum and minimum values. The deviation of the in-plane phase difference in the width direction can be measured at any position (e.g., the center of the width direction) in the width direction of the optical film at a given interval (e.g., about 30 mm to about 350 mm intervals) in the width direction of a plurality of locations, and is obtained as the difference between its maximum and minimum values.

[0137] In the embodiment where the first optical film A1 is divided by slits, the number of divisions of the film based on the slits along the longitudinal direction (meaning the number of divisions of the first optical film A1 in the width direction) is, for example, 2 or more and 20 or less, or, for example, 3 or more and 10 or less.

[0138] B-2-3. Step I-iii

[0139] In process I-iii, if Figure 4 As shown, a plurality of first optical films A2 (30b) and a plurality of polarizing components (42) are stacked to obtain a plurality of second optical films B1 (40a). The polarizing component (42) is a polarizing component included in the display element (12) in the display system (2). Preferably, the first optical film A2 is stacked with the polarizing component with an adhesive layer. Typically, the second optical film B1 has the same size as the first optical film A2.

[0140] Figure 5(a) and 5 (b) are schematic cross-sectional views illustrating an example of the structure of the second optical film B1. The second optical films B1 (40a) and (40a') respectively have a structure in which a polarizing component (42) and an adhesive layer (44) are sequentially stacked on the adhesive layer (32) surface of the second optical film A2 (30b) and (30b') from which the release liner has been peeled off. Here, the polarizing component is configured so that the absorption axis direction and the slow axis direction of the first optical film A2 (more specifically, the slow axis direction of the first λ / 4 component (34a)) are, for example, 40° to 50°, preferably 42° to 48°, and more preferably about 45°. In addition, although not shown in the figure, the surface of the adhesive layer (44) is preferably protected by a release liner.

[0141] The polarizing element (42) is typically an absorbing polarizing element comprising a resin film containing a dichroic substance (sometimes referred to as an absorbing polarizing film). The thickness of the absorbing polarizing film is, for example, 1 μm to 20 μm, 2 μm to 15 μm, 12 μm to 10 μm, 8 μm to 8 μm, or 5 μm to 5 μm. A protective layer may be provided on one or both sides of the absorbing polarizing film.

[0142] The absorption-type polarizing film may be produced from a single-layer resin film or a laminate of two or more layers.

[0143] When produced from a single-layer resin film, for example, a hydrophilic polymer film such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, or a partially saponified ethylene-vinyl acetate copolymer film can be subjected to dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and stretching treatment to obtain an absorption-type polarizing film. Among them, an absorption-type polarizing film obtained by dyeing a PVA film with iodine and then uniaxially stretching the film is preferred.

[0144] The iodine-based dyeing can be performed, for example, by immersing the PVA film in an aqueous iodine solution. The uniaxial stretching preferably has a stretch ratio of 3 to 7 times. Stretching can be performed after dyeing or while dyeing. Alternatively, dyeing can be performed after stretching. The PVA film can be subjected to swelling treatment, crosslinking treatment, cleaning treatment, drying treatment, and the like as needed.

[0145] As a laminate produced using the above-mentioned two or more layers, there can be mentioned a laminate of a resin substrate and a PVA-type resin layer (PVA-type resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-type resin layer formed by coating the resin substrate. The absorption-type polarizing film obtained by using a laminate of a resin substrate and a PVA-type resin layer formed by coating the resin substrate can be produced by the following method: for example, a PVA-type resin solution is applied to a resin substrate, dried to form a PVA-type resin layer on the resin substrate, and a laminate of the resin substrate and the PVA-type resin layer is obtained; the laminate is stretched and dyed to make the PVA-type resin layer into an absorption-type polarizing film. In this embodiment, it is preferred to form a polyvinyl alcohol-type resin layer containing a halide and a polyvinyl alcohol-type resin on one side of the resin substrate. Stretching typically includes immersing the laminate in a boric acid aqueous solution for stretching. In addition, stretching can further include stretching the laminate in a gas atmosphere at a high temperature (for example, above 95°C) before stretching in a boric acid aqueous solution as needed. Furthermore, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate shrinks by more than 2% in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment includes sequentially subjecting the laminate to an auxiliary stretching treatment in a gas atmosphere, a dyeing treatment, an aqueous solution stretching treatment, and a drying shrinkage treatment. By introducing the auxiliary stretching, the crystallinity of the PVA can be improved even when PVA is coated on a thermoplastic resin, enabling high optical properties to be achieved. Furthermore, by simultaneously improving the orientation of the PVA in advance, it is possible to prevent problems such as a decrease in orientation and dissolution of the PVA during subsequent dyeing and stretching steps when immersed in water, thereby enabling high optical properties to be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, the orientation disorder and decrease in orientation of the polyvinyl alcohol molecules can be suppressed compared to a case where the PVA-based resin layer does not contain a halide. Thus, the optical properties of the absorption-type polarizing film obtained by immersing the laminate in a liquid through treatment steps such as dyeing and aqueous solution stretching can be improved. Furthermore, the laminate is shrunk in the width direction by drying and shrinking treatment, thereby improving the optical properties. The obtained laminate of resin substrate / absorption type polarizing film can be used directly (that is, the resin substrate can be used as a protective layer of absorption type polarizing film), or the resin substrate can be peeled off from the laminate of resin substrate / absorption type polarizing film and used by laminating any appropriate protective layer corresponding to the purpose on the peeling surface or on the side opposite to the peeling surface. The details of the manufacturing method of such absorption type polarizing film are described in, for example, Japanese Patent Publication No. 2012-73580 and Japanese Patent No. 6470455. The records of these publications as a whole are incorporated into this specification as a reference.

[0146] The cross transmittance (Tc) of the absorbing polarizing element (absorbing polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single transmittance (Ts) of the absorbing polarizing element (absorbing polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or greater. The degree of polarization (P) of the absorbing polarizing element (absorbing polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or greater.

[0147] Regarding the adhesive layer (44), the same description as that of the adhesive layer (32) described in Section B-2-1 can be applied.

[0148] B-2-4. Step I-iv

[0149] In steps I-iv, if Figure 6 As shown, the second optical film B1 (40a) is classified into a plurality of groups (in the example shown, two groups, Group A and Group B) according to each optical film having a given in-plane phase difference. Specifically, the in-plane phase difference (for example, Re (590)) is measured for each of the plurality of second optical films B1, and the optical films are classified into a plurality of groups according to each optical film having a given in-plane phase difference. The number of the classified groups is not particularly limited, and from the perspective of balancing the high precision of the display system with the production efficiency, it is, for example, 2 or more and 4 or less, preferably 2 or 3. In addition, the number of the second optical films B1 that include the first optical film A2 from the same first optical film A1 and are classified into the same group is, for example, 50 or more and 250 or less, and for example, 80 or more and 200 or less.

[0150] The in-plane phase difference of the second optical film B1 (substantially the in-plane phase difference of the first λ / 4 component) can be measured, for example, at the front end and / or end in the longitudinal direction, or at two or more locations (e.g., two locations). Specifically, it can be measured at two or more locations within 500 mm from the front end and / or end (e.g., multiple locations separated by a given interval in the width direction). For an optical film having a small deviation in the in-plane phase difference in the longitudinal direction, even if it has a length of more than 50 m, its overall in-plane phase difference can be roughly grasped by measuring at the front end and / or end. In one embodiment, as in Figure 6 As indicated by the “×” mark in the upper left section of the second optical film B1 (40a), the in-plane phase difference is measured at the four corners of the second optical film B1 (for example, at a position 5 mm to 50 mm away from the corner), and the average value of these measured values ​​can be used as the in-plane phase difference of the second optical film B1.

[0151] In one embodiment, with a given in-plane phase difference (e.g., Re(590)) as a reference value, the above classification is typically performed with a classification width of 3 nm or less, for example, 2 nm or less, preferably 1 nm or more and 1.5 nm or less, and more preferably 1 nm or more and 1.3 nm or less. As a specific example, when Re(590) of 146 nm is used as a reference value and classification is performed with a classification width of 2 nm (classification width of ±1 nm), the materials can be sequentially classified into, for example, a group having Re(590) of 145 nm or more and less than 147 nm, a group having Re(590) of 143 nm or more and less than 145 nm, a group having Re(590) of 147 nm or more and less than 149 nm, a group having Re(590) of 141 nm or more and less than 143 nm, a group having Re(590) of 149 nm or more and less than 151 nm, and the like.

[0152] In another embodiment, the above classification can be performed as follows: the classification is performed in order of a given classification width, starting from the maximum or minimum measured value of the in-plane retardation (e.g., Re(590)). The classification width of the in-plane retardation (e.g., Re(590)) can typically be 3 nm or less, for example, 2 nm or less, preferably 1 nm or more and 1.5 nm or less, and more preferably 1 nm or more and 1.3 nm or less.

[0153] In another embodiment, the above classification can be performed by using one or more reference values ​​(in-plane retardation) to perform divisions. For example, a given in-plane retardation (e.g., Re(590)) can be used as a reference value to classify the images into two groups, above and below the reference value. A first reference value and a second reference value can be set to classify the images into three groups, one below the first reference value, one above the first reference value and below the second reference value, and one above the second reference value.

[0154] The deviation of the in-plane retardation between the second optical films B1 in each group after the above classification (the difference between the maximum and minimum in-plane retardation of the second optical films B1 contained in the group) is less than the deviation of the in-plane retardation between all the second optical films B1 before classification, and can be, for example, approximately half or less. The deviation of the in-plane retardation between the second optical films B1 in each group can be, for example, 3 nm or less. The deviation of the in-plane retardation between the second optical films B1 in each group can correspond to the above classification width, for example, 2 nm or less, preferably 1.5 nm or less, and more preferably 1 nm or more and 1.3 nm or less.

[0155] B-2-5. Step II-i

[0156] In step II-i, a third optical film C1 including a second λ / 4 member is prepared. Figure 7(a) and 7(b) are schematic cross-sectional views illustrating an example of the structure of the third optical film C1.

[0157] Figure 7 The first optical film C1 (50a) shown in (a) sequentially includes an adhesive layer (52), a second λ / 4 component (54a), and a second protective component (56). According to the configuration of the third optical film C1 (50a), the second phase difference component (22) in the display system (2) is composed of the second λ / 4 component (54a).

[0158] Figure 7 The third optical film C1 (50a') shown in (b) sequentially includes an adhesive layer (52), a second λ / 4 member (54a), a second positive C plate (54b), and a second protective member (56). According to the configuration of the third optical film C1 (50a'), the second phase difference member (22) in the display system (2) includes the second λ / 4 member (54a) and the second positive C plate (54b). In other words, the second phase difference member (22) has a laminated structure of the second λ / 4 member (54a) and the second positive C plate (54b).

[0159] The surfaces of the adhesive layers ( 52 ) of the third optical films C1 ( 50 a ) and ( 50 a ′) shown in the figures are protected by release liners ( 58 ).

[0160] The same descriptions as those for the first λ / 4 member (34a), first positive C plate (34b), first protective member (36), adhesive layer (32) and release liner (38) described in item B-2-1 apply to the second λ / 4 member (54a), second positive C plate (54b), second protective member (56), adhesive layer (52) and release liner (58), respectively.

[0161] The third optical film C1 is preferably in a long strip shape. In one embodiment, the third optical film C1 can be produced by laminating members formed in a long strip shape in a roll-to-roll manner and winding the layers into a roll shape.

[0162] The length of the third optical film C1 is, for example, 100 m to 2000 m, or preferably 500 m to 1000 m.

[0163] The width of the third optical film C1 is, for example, 500 mm or more and 1500 mm or less, preferably 900 mm or more and 1200 mm or less. As described later in step IV, the third optical film sheet C3 can be obtained by punching the third optical film C2. The width of the third optical film C1 is, for example, 10 times or more, preferably 15 times or more and 25 times or less, and more preferably 15 times or more and 20 times or less of the punched width of the third optical film sheet C3.

[0164] B-2-6. Step II-ii

[0165] In step II-ii, the third optical film C1 is divided to obtain a plurality of third optical films C2 having a given width and a given length. Figure 8 As shown, the third optical film C1 (50a) formed into a long strip is slit along the length direction to obtain a plurality of third optical films C2 (50b). Not only can the slits be made along the length direction, but also along the width direction. Thus, a plurality of third optical films C2 (50b) having a given width and a given length can be obtained. As needed, the third optical film C2 can be wound into a roll. The deviation of the in-plane phase difference of the third optical film C2 in the width direction is typically smaller than that of the third optical film C1.

[0166] The length of the third optical film C2 is, for example, 50 m or more and 1000 m or less, for example, 50 m or more and 300 m or less, or for example, 100 m or more and 150 m or less.

[0167] The width of the third optical film C2 is, for example, 40 mm to 200 mm, or 45 mm to 150 mm, or 50 mm to 120 mm. In one embodiment, the width of the third optical film C2 is, for example, 1.1 to 3.0 times the width of the third optical film sheet C3, preferably 1.2 to 2.0 times, and more preferably 1.2 to 1.5 times. By dividing the third optical film C2 into narrower widths in this manner, the deviation of the in-plane phase difference in the longitudinal and width directions of the third optical film C2 can be reduced.

[0168] The deviation of the in-plane retardation (e.g., Re(590)) in the length direction of the third optical film C2 is, for example, 3 nm or less, preferably 1.5 nm or less. The deviation of the in-plane retardation (e.g., Re(590)) in the width direction of the third optical film C2 is, for example, 3 nm or less, preferably 1.5 nm or less.

[0169] In one embodiment, the number of film divisions by the slits along the longitudinal direction (meaning the number of divisions of the third optical film C1 in the width direction) is, for example, 6 or more, preferably 10 or more and 25 or less, and preferably 15 or more and 20 or less.

[0170] B-2-7. Step II-iii

[0171] In step II-iii, if Figure 9As shown, a plurality of third optical films C2 (50b) are classified into a plurality of groups (in the example shown, two groups, Group C and Group D) according to each optical film having a given in-plane phase difference. Specifically, the in-plane phase difference (for example, Re (590)) is measured for each of the plurality of third optical films C2, and the plurality of groups are classified according to each optical film having a given in-plane phase difference. The number of the classified groups is not particularly limited, and from the perspective of balancing the high precision of the display system with the production efficiency, it is, for example, 2 or more and 4 or less, preferably 2 or 3. In one embodiment, the number of groups of the second optical film B1 obtained in step I-iv is the same as the number of groups of the third optical film C2 obtained in step II-iii.

[0172] The in-plane phase difference of the third optical film C2 (substantially the in-plane phase difference of the second λ / 4 member) is measured, for example, at the front end and / or the end of the third optical film C2, respectively, at two or more locations (for example, two locations). For an optical film having a small deviation in the in-plane phase difference in the length direction, even when the film has a length of more than 50 m, the overall in-plane phase difference can be roughly grasped by measuring at the front end and / or the end. In one embodiment, as in Figure 9 As indicated by the "×" mark in the third optical film C2 (50b) on the uppermost section on the left side, the in-plane phase difference is measured at more than two locations in the width direction of the front end of the film (for example, at more than two locations within a distance of 500 mm from the front end (for example, multiple locations separated by given intervals in the width direction)). If necessary, it can be measured at more than two locations in the width direction of the end (for example, at more than two locations within a distance of 500 mm from the end (for example, multiple locations separated by given intervals in the width direction)). Thus, the in-plane phase difference is measured, for example, at the four corners of the third optical film C2. The average value of these measurements can be used as the in-plane phase difference of the third optical film C2.

[0173] Alternatively, the in-plane retardation can be measured, for example, on the third optical film C1 before slitting (or slitting). In this case, the in-plane retardation can be measured as follows: the third optical film C1 before slitting is divided along the lines intended for slitting, and the in-plane retardation of the portion corresponding to the leading end and / or trailing end of the division is measured in the same manner as described above, and this is used as the in-plane retardation of the third optical film C2 corresponding to the division obtained after slitting.

[0174] As the above-mentioned classification method, the same method as the classification method in step I-iv can be cited. In one embodiment, the classification method in step I-iv is the same as the classification method in step II-iii. In this case, the same reference value and the same classification width can be applied. This makes it easier to match the in-plane retardation of the second optical film B1 group with the in-plane retardation of the third optical film C2 group.

[0175] The deviation of the in-plane retardation between the third optical films C2 in each group after classification is smaller than the deviation of the in-plane retardation between all the third optical films C2 before classification, and can be, for example, approximately half or less. The deviation of the in-plane retardation between the third optical films C2 in each group can be, for example, 3 nm or less. The deviation of the in-plane retardation between the third optical films C2 in each group can correspond to the above-mentioned classification width, for example, 2 nm or less, preferably 1.5 nm or less, and more preferably 1 nm or more and 1.3 nm or less.

[0176] B-2-8. Step III

[0177] In step III, a combination of groups having a suitable in-plane retardation is selected from the plurality of groups of the second optical film B1 and the plurality of groups of the third optical film C2. Specifically, groups having a smaller difference in in-plane retardation are combined. For example, the average in-plane retardation of the optical films in the group or a reference value for in-plane retardation used for classification can be used as the in-plane retardation of each group, and a combination of groups having a difference of less than a predetermined value (e.g., less than 3 nm, preferably less than 1.5 nm) can be selected.

[0178] Below, refer to Figure 10A specific example of step III is described. In the following case, a combination of group A with a reference value (Re(590)) of 145 nm and group C with a reference value (Re(590)) of 144 nm, and a combination of group B with a reference value (Re(590)) of 148 nm and group D with a reference value (Re(590)) of 147 nm are selected. In the case where, in step I-iv, the second optical film B1 (40a) is classified into group A with Re(590) = 145 nm as the reference value and a classification width of 3 nm (143.5 nm ≤ Re(590) < 146.5 nm) and group C with Re(590) = 148 nm as the reference value and a classification width of 3 nm (143.5 nm ≤ Re(590) < 147.5 nm). The two groups are group B, which is classified with 148nm as the reference value and a classification width of 3nm (146.5nm≤Re(590)<149.5nm). In process II-iii, the third optical film C2(50b) is classified into group C, which is classified with Re(590)=144nm as the reference value and a classification width of 3nm (142.5nm≤Re(590)<145.5nm), and group D, which is classified with Re(590)=147nm as the reference value and a classification width of 3nm (145.5nm≤Re(590)<148.5nm).

[0179] B-2-9. Step IV

[0180] In step IV, the second optical film sheet B2 and the third optical film sheet C3 obtained from the combination of the second optical film group B1 and the third optical film group C2 selected in step III are arranged at predetermined positions of the display system (2). For example, the second optical film sheet B2 is bonded to a desired optical component (e.g., a liquid crystal cell, an organic EL panel, etc.) via an adhesive layer (44) so ​​that the polarizing component (42) is included in the display element (12), and the third optical film sheet C3 is bonded to the front side of the first lens unit (16) via an adhesive layer (52).

[0181] The second optical film B2 and the third optical film C3 can each have any suitable shape. In one embodiment, the second optical film B2 is substantially rectangular. In one embodiment, the third optical film C3 is substantially circular. In this specification, the substantially circular shape includes a circle or an ellipse, and further includes a shape that is visually recognized as being close to a circle or an ellipse.

[0182] like Figure 11As shown in (a), the second optical film piece B2 (40b) can be typically obtained by punching the second optical film B1 (40a) into a given shape (in the figure, X1 represents the width of the second optical film B1 (40a) and X2 represents the punched width of the second optical film piece B2 (40b)). The number of second optical film pieces B2 obtained from one second optical film B1, for example, one single-piece second optical film B1, can be, for example, more than 10 and less than 100, or more than 15 and less than 50.

[0183] like Figure 11 As shown in (b), the third optical film piece C3 (50c) can be typically obtained by punching the third optical film C2 (50b) into a given shape (in the figure, X3 represents the width of the third optical film C2 (50b) and X4 represents the punched width of the third optical film piece C3 (50c)). In one embodiment, one or two third optical film pieces C3 are punched out in the width direction of the third optical film C2, and preferably one third optical film piece C3 is punched out. The number of third optical film pieces C3 obtained from one third optical film C2 is, for example, 800 or more and 6000 or less, and is also, for example, 1000 or more and 3000 or less.

[0184] As described above, the groups of combinations selected in step III have in-plane phase differences that are suitable for each other. Furthermore, the in-plane phase differences of the second optical films B1 in the selected groups are similar to each other, and in each second optical film B1, the deviation of the in-plane phase difference in the length direction and the width direction is small. Similarly, the in-plane phase differences of the third optical films C2 in the selected groups are similar to each other, and in each third optical film C2, the deviation of the in-plane phase difference in the length direction and the width direction is also small. Therefore, the deviation of the in-plane phase difference of the second optical film sheet B2 and the third optical film sheet C3 obtained from the group of the second optical film B1 and the group of the third optical film C2 of the above-mentioned selected combination is small (in other words, the uniformity of the in-plane phase difference is high), and they have in-plane phase differences that are suitable for each other. Therefore, by arranging these optical film sheets at a given position of the display system (2), a display system (2) capable of displaying high-definition images can be easily and efficiently obtained.

[0185] B-3. ​​Modification

[0186] In the embodiment described in Section B-2, the classification of optical films including a first λ / 4 member was based on the in-plane retardation of the optical film including the first λ / 4 member and the polarizing member. However, classification can also be based on the in-plane retardation of an optical film including a first λ / 4 member and not including a polarizing member. In this case, after classification, the optical film including the first λ / 4 member and not including a polarizing member can be laminated with the polarizing member. This lamination can be performed before or after the optical film sheet is punched out. Alternatively, the optical film including the first λ / 4 member and the polarizing member can be separately incorporated into the display system.

[0187] Furthermore, for example, if the first optical film A2 is a single sheet, it is not necessary to measure the in-plane retardation of the entire film. For example, for a single sheet of the first optical film A2 punched out from the first optical film A1, the first optical films A2 punched out from the same region along the longitudinal direction can be considered to have substantially the same in-plane retardation, and the in-plane retardation of one sheet or the average of the in-plane retardations of several sheets selected from these sheets can be applied to the entire sheet. The same applies when measuring the in-plane retardation of the second optical film B1 obtained using such a first optical film A2.

[0188] C. Optical film set

[0189] The optical film set according to an embodiment of the present invention is composed of a plurality of optical films. The optical films include a λ / 4 member and have a predetermined width and a predetermined length. The optical films may further include a polarizing member.

[0190] The difference between the maximum and minimum values ​​of the in-plane phase difference (for example, Re (590)) between the above-mentioned multiple optical films constituting the optical film group is, for example, less than 3 nm, preferably less than 2 nm, more preferably less than 1.5 nm, and further preferably less than 1.3 nm, for example, more than 1 nm.

[0191] That is, the optical film set according to the embodiment of the present invention is composed of optical films having high uniformity of in-plane retardation.

[0192] In one embodiment, the optical film included in the optical film set is in the form of a long strip. The length of the long strip of optical film is, for example, 50 m or more and 1000 m or less, preferably 50 m or more and 3000 m or less, and more preferably 100 m or more and 150 m or less. The width of the long strip of optical film is, for example, 900 mm or more and 1500 mm or less, preferably 1000 mm or more and 1300 mm or less.

[0193] In another embodiment, the optical film included in the optical film assembly is in a monolithic form. The length of a side of the monolithic first optical film A2 is, for example, 1000 mm or less, 800 mm or less, or 500 mm or less. Specifically, the first optical film A2 may be in a generally rectangular shape with dimensions of 500 mm to 350 mm, 450 mm to 300 mm, 400 mm to 250 mm, 350 mm to 200 mm, or 250 mm to 150 mm, 200 mm to 100 mm.

[0194] In one embodiment, the optical films included in the optical film set are produced by dividing an optical film produced in a large area from a single optical film. In this embodiment, the number of optical films included in the optical film set is, for example, 50 or more and 250 or less, or, for example, 80 or more and 200 or less.

[0195] Examples of the optical film set include a set of the second optical film B1 obtained through step Ii to step I-iv described in section B. The specific description thereof is as described above.

[0196] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configuration shown in the above-described embodiment may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiment, a configuration that exhibits the same function and effect, or a configuration that achieves the same purpose.

[0197] Industrial Applicability

[0198] The method for manufacturing a display system according to the embodiment of the present invention can be suitably used for manufacturing a display body such as VR goggles, for example.

Claims

1. A method for manufacturing a display system, wherein the display system is a display system that displays images to a user, The display system comprises: A display element having a display surface for emitting light displaying an image forward via a polarizing member; a reflective polarizing member disposed in front of the display element and reflecting light emitted from the display element; a first lens portion disposed on an optical path between the display element and the reflective polarizing member; a half mirror disposed between the display element and the first lens portion, transmitting light emitted from the display element and reflecting light reflected from the reflective polarizing element toward the reflective polarizing element; a first λ / 4 element disposed on an optical path between the display element and the half mirror; as well as a second λ / 4 element disposed on the optical path between the half mirror and the reflective polarization element; The manufacturing method of the display system comprises: preparing a plurality of optical films including the first λ / 4 member, and classifying the optical films into a plurality of groups each having a given in-plane phase difference; preparing a plurality of optical films including the second λ / 4 member, and classifying the optical films into a plurality of groups each having a given in-plane phase difference; and A combination of groups having an appropriate in-plane phase difference is selected from a plurality of groups of optical films including the first λ / 4 member and a plurality of groups of optical films including the second λ / 4 member.

2. The manufacturing method according to claim 1, wherein The variation in in-plane retardation between the optical films including the first λ / 4 member in each of the classified groups is 3 nm or less.

3. The manufacturing method according to claim 1, wherein The variation in in-plane retardation between the optical films including the second λ / 4 member in each of the classified groups is 3 nm or less.

4. The manufacturing method according to claim 1, wherein The optical film including the first λ / 4 member has a deviation in in-plane retardation in the longitudinal direction of 3 nm or less.

5. The manufacturing method according to claim 1, wherein The optical film including the second λ / 4 member has a deviation in in-plane retardation in the longitudinal direction of 3 nm or less.

6. The manufacturing method according to claim 1, wherein The length of one side of the optical film including the first λ / 4 member is 1000 mm or less.

7. The manufacturing method according to claim 1, wherein: The length of the optical film including the second λ / 4 member is 50 m to 1000 m.

8. The manufacturing method according to claim 1, wherein: The in-plane retardation of the optical film including the first λ / 4 member is an average value of in-plane retardations measured at four corners of the optical film including the first λ / 4 member.

9. The manufacturing method according to claim 1, wherein: The in-plane retardation of the optical film including the second λ / 4 member is an average value of in-plane retardations measured at two or more locations at the front end of the optical film including the second λ / 4 member.

10. The manufacturing method according to claim 1, wherein: The in-plane retardation of the optical film including the second λ / 4 member is an average value of in-plane retardations measured at two or more locations at the front end and two or more locations at the rear end of the optical film including the second λ / 4 member.

11. The manufacturing method according to claim 1, comprising: Step Ii, preparing a first optical film A1 including the first λ / 4 member; Step I-ii, dividing the first optical film A1 to obtain a plurality of first optical films A2 having a given width and a given length; Step I-iii, laminating the plurality of first optical films A2 and the polarizing member to obtain a plurality of second optical films B1; Step I-iv, classifying the plurality of second optical films B1 into a plurality of groups according to each optical film having a given in-plane phase difference; Step II-i, preparing a third optical film C1 including the second λ / 4 member; Step II-ii, dividing the third optical film C1 to obtain a plurality of third optical films C2 having a given width and a given length; Step II-iii, classifying the plurality of third optical films C2 into a plurality of groups according to each optical film having a given in-plane phase difference; as well as In step III, a combination of groups having a suitable in-plane retardation is selected from the plurality of groups of the second optical films B1 and the plurality of groups of the third optical films C2.

12. An optical film assembly comprising a plurality of optical films, wherein: The optical film includes a λ / 4 member and has a given width and a given length, The difference between the maximum value and the minimum value of the in-plane retardation among the plurality of optical films is 3 nm or less.

13. The optical film assembly according to claim 12, wherein: The length of one side of the optical film is 1000 mm or less.

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