Method for manufacturing a display system and a group of optical films

Abstract

The present invention provides a method for manufacturing a display system and optical components. [Solution] A method for manufacturing a display system that displays an image to a user, comprising: preparing a plurality of optical films including a first λ / 4 member and classifying them into a plurality of groups according to the predetermined in-plane phase difference; preparing a plurality of optical films including a second λ / 4 member and classifying them into a plurality of groups according to the predetermined in-plane phase difference; and selecting a combination of groups from the plurality of groups of optical films including the first λ / 4 member and the plurality of groups of optical films including the second λ / 4 member that have a suitable in-plane phase difference.

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 group.

Background Art

[0002] Image display devices represented by liquid crystal display devices and electroluminescence (EL) display devices (for example, organic EL display devices) have been rapidly spreading. In image display devices, in order to realize image display and improve the performance of image display, generally, optical members such as polarizing members and retardation members are used (for example, see Patent Document 1).

[0003] In recent years, new applications of image display devices have been developed. For example, goggles with a display (VR goggles) for realizing Virtual Reality (VR) have begun to be commercialized. Since VR goggles are being considered for use in various scenarios, higher definition is desired.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The main object of the present invention is to provide a method for manufacturing a display system such as high-definition goggles with a display and an optical member suitable for manufacturing the display system.

Means for Solving the Problems

[0006] [1] The method for manufacturing a display system according to an embodiment of the present invention is a display element having a display surface that emits light representing an image forward through a polarizing member, A reflective polarizing member is positioned in front of the above-mentioned display element and reflects the light emitted from the above-mentioned display element, A first lens portion is arranged in the optical path between the above-mentioned display element and the above-mentioned reflective polarizing member, A half-mirror is positioned between the display element and the first lens portion, which transmits light emitted from the display element and reflects the light reflected by the reflective polarizing member back towards the reflective polarizing member. A first λ / 4 member is arranged in the optical path between the above-mentioned display element and the above-mentioned half-mirror, A second λ / 4 member is positioned in the optical path between the above half mirror and the above reflective polarizing member, A method for manufacturing a display system that displays an image to a user, comprising: Prepare multiple optical films containing the above-mentioned first λ / 4 member, and classify them into multiple groups according to the predetermined in-plane phase difference. Prepare multiple optical films containing the above-mentioned second λ / 4 member, and classify them into multiple groups according to the predetermined in-plane phase difference, and Select a combination of groups from which the in-plane phase difference is suitable from a plurality of groups of optical films containing the first λ / 4 member and a plurality of groups of optical films containing the second λ / 4 member. Includes. [2] In the above [1], the variation in in-plane phase difference between optical films including the first λ / 4 member in each group after the above classification may be 3 nm or less. [3] In the above [1] or [2], the variation in in-plane phase difference between optical films including the second λ / 4 member in each group after the above classification may be 3 nm or less. [4] In any of the above [1] to [3], the variation in 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. [5] In any of the above [1] to [4], the variation in 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. [6] In any 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. [7] In any of the above [1] to [6], the length of the optical film including the second λ / 4 member may be 50m or more and 1000m or less. [8] In any of [1] to [7] above, the in-plane phase difference of the optical film including the first λ / 4 member may be the average value of the in-plane phase differences measured at the four corners of the optical film including the first λ / 4 member. [9] In any of the above [1] to [8], the in-plane phase difference of the optical film including the second λ / 4 member may be the average value of the in-plane phase differences measured at two or more locations at the leading edge of the optical film including the second λ / 4 member.

[10] In any of the above [1] to [8], the in-plane phase difference of the optical film including the second λ / 4 member may be the average value of the in-plane phase differences measured at two or more locations at the leading edge and two or more locations at the trailing edge of the optical film including the second λ / 4 member.

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

[10] , the above manufacturing method is: Step Ii is to prepare a first optical film A1 including the first λ / 4 member described above, Step I-ii involves dividing the above-mentioned first optical film A1 to obtain a plurality of first optical films A2 having a predetermined width and predetermined length, Step I-iii involves laminating the above-mentioned multiple first optical films A2 and the above-mentioned polarizing members to obtain a plurality of second optical films B1, Steps I-iv: Classifying the above-mentioned multiple second optical films B1 into multiple groups according to those having a predetermined in-plane phase difference, Step II-i involves preparing a third optical film C1 containing the second λ / 4 member described above, Step II-ii involves dividing the above-mentioned third optical film C1 to obtain a plurality of third optical films C2 having a predetermined width and predetermined length, Step II-iii involves classifying the above-mentioned multiple third optical films C2 into multiple groups according to those having a predetermined in-plane phase difference, Step III involves selecting a combination of groups from the above-mentioned multiple groups of the second optical film B1 and the above-mentioned multiple groups of the third optical film C2 that have a suitable in-plane phase difference. It may include.

[12] The group of optical films according to embodiments of the present invention are: An optical film group comprising multiple optical films, wherein each optical film includes a λ / 4 member and has a predetermined width and predetermined length, and the difference between the maximum and minimum in-plane phase differences between the multiple optical films is 3 nm or less.

[13] In the above

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

[0007] According to the manufacturing method of the display system according to the embodiment of the present invention, the display system is constructed using a combination of λ / 4 members having compatible in-plane phase differences, thus enabling high-resolution displays. A suitable display system can be obtained. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the general configuration of a display system obtained by the manufacturing method according to an embodiment of the present invention. [Figure 2] Figures 2(a) and 2(b) are schematic cross-sectional views illustrating an example of the configuration of the first optical film A1, respectively. [Figure 3] This is a schematic diagram illustrating an example of steps I-ii of the manufacturing method for a display system according to one embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating an example of steps I-iii in the manufacturing method of a display system according to one embodiment of the present invention. [Figure 5] Figures 5(a) and 5(b) are schematic cross-sectional views illustrating an example of the configuration of the second optical film B1, respectively. [Figure 6] This is a schematic diagram illustrating an example of steps I-iv of the manufacturing method of a display system according to one embodiment of the present invention. [Figure 7] Figs. 7(a) and 7(b) are schematic cross-sectional views each illustrating an example of the configuration of the third optical film C1. [Figure 8] FIG. 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. [Figure 9] FIG. 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. [Figure 10] FIG. 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. [Figure 11] Figs. 11(a) and 11(b) are schematic diagrams each illustrating an example of the punching of the second optical film piece B2 and the third optical film piece C3.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. Also, for the sake of clearer explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the embodiments, but this is merely an example and does not limit the interpretation of the present invention. In this specification, the term "elongated shape" means an elongated shape in which the length is sufficiently long with respect to the width, for example, an elongated shape in which the length is 10 times or more, preferably 20 times or more, the width.

[0010] (Definitions of Terms and Symbols) The definitions of the terms and symbols in this specification are as follows. (1) Refractive Index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-Plane Phase Difference (Re) "Re(λ)" is the in-plane phase difference measured with light of wavelength λnm at 23°C. For example, "Re(550)" is the in-plane phase difference measured with light of wavelength 550nm at 23°C. Re(λ) can be calculated using the formula: Re(λ) = (nx - ny) × d, where d (nm) is the thickness of the layer (film). (3) Phase difference in the thickness direction (Rth) "Rth(λ)" is the phase difference in the thickness direction measured with light of wavelength λnm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction measured with light of wavelength 550nm at 23°C. Rth(λ) can be calculated using the formula: Rth(λ) = (nx - nz) × d, where d (nm) is the thickness of the layer (film). (4) Nz coefficient The Nz coefficient is calculated using the formula Nz = Rth / Re. (5)Angle In this specification, when an angle is mentioned, unless otherwise specified, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. For example, "45°" means ±45°. Also in this specification, "approximately parallel" includes the case where the angle is 0°±10°, for example, within the range of 0°±5°, preferably 0°±3°, and more preferably 0°±1°, and "approximately orthogonal" includes the case where the angle is 90°±10°, for example, within the range of 90°±5°, preferably 90°±3°, and more preferably 90°±1°.

[0011] A. Overview of the display system Figure 1 is a schematic diagram showing the general configuration of a display system manufactured by the manufacturing method according to an embodiment of the present invention. Figure 1 schematically illustrates the arrangement and shape of each component of the display system (2). The display system (2) comprises a display element (12), a reflective polarizing member (14), a first lens section (16), a half mirror (18), a first phase difference member (20), a second phase difference member (22), and a second lens section (24). The reflective polarizing member (14) is positioned in front of the display element (12) on the display surface (12a) side and can reflect light emitted from the display element (12). The first lens section (16) is positioned in the optical path between the display element (12) and the reflective polarizing member (14), and the half mirror (18) is positioned between the display element (12) and the first lens section (16). The first phase difference member (20) is positioned in the optical path between the display element (12) and the half mirror (18), and the second phase difference member (22) is positioned in the optical path between the half mirror (18) and the reflective polarizing member (14). Although not shown, an absorbing polarizing member may be positioned between the reflective polarizing member (14) and the second lens portion (24) from the viewpoint of improving visibility. In this case, the reflection axis of the reflective polarizing member (14) and the absorption axis of the absorbing polarizing member may be positioned substantially parallel to each other, and the transmission axis of the reflective polarizing member (14) and the transmission axis of the absorbing polarizing member may be positioned substantially parallel to each other.

[0012] The components positioned in front of the half-mirror (in the illustrated example, the half-mirror (18), the first lens section (16), the second phase difference member (22), the reflective polarizing member (14), and the second lens section (24)) are sometimes collectively referred to as the lens section (lens section (4)).

[0013] 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 (typically a polarizing film) that may be included in the display element (12), and is emitted as first linearly polarized light.

[0014] The first phase difference member (20) includes a first λ / 4 member capable of converting a first linearly polarized light incident on the first phase difference member (20) into a first circularly polarized light. If the first phase difference member does not include any members other than the first λ / 4 member, the first phase difference member may correspond to the first λ / 4 member. The first phase difference member (20) may be provided integrally with the display element (12).

[0015] The half mirror (18) transmits light emitted from the display element (12) and reflects the light reflected by the reflective polarizing member (14) back towards the reflective polarizing member (14). The half mirror (18) is integrally provided with the first lens portion (16).

[0016] The second phase difference member (22) includes a second λ / 4 member that can transmit light reflected by the reflective polarizing member (14) and the half mirror (18) through the reflective polarizing member (14). If the second phase difference member does not include any members other than the second λ / 4 member, the second phase difference member may correspond to the second λ / 4 member. The second phase difference member (22) may be provided integrally with the first lens portion (16).

[0017] The first circularly polarized light emitted from the first λ / 4 member contained in the first phase difference member (20) passes through the half mirror (18) and the first lens portion (16), and is converted into a second linearly polarized light by the second λ / 4 member contained in the second phase difference member (22). The second linearly polarized light emitted from the second λ / 4 member is reflected towards the half mirror (18) without passing through the reflective polarizing member (14). At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing member (14) is in the same direction as the reflection axis of the reflective polarizing member (14). Therefore, the second linearly polarized light incident on the reflective polarizing member (14) is reflected by the reflective polarizing member (14).

[0018] The second linearly polarized light reflected by the reflective polarizing member (14) is converted into a second circularly polarized light by the second λ / 4 member contained in the second phase difference member (22), and the second circularly polarized light emitted from the second λ / 4 member passes through the first lens portion (16) and is reflected by the half mirror (18). The second circularly polarized light reflected by the half mirror (18) passes through the first lens portion (16) and is converted into a third linearly polarized light by the second λ / 4 member contained in the second phase difference member (22). The third linearly polarized light is transmitted through the reflective polarizing member (14). At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member (14) is in the same direction as the transmission axis of the reflective polarizing member (14). Therefore, the third linearly polarized light incident on the reflective polarizing member (14) is transmitted through the reflective polarizing member (14).

[0019] Light that has passed through the reflective polarizing member (14) passes through the second lens section (24) and enters the user's eye (26).

[0020] The reflective polarizing member (14) transmits polarized light parallel to its transmission axis (typically linearly polarized light) while maintaining its polarization state, and reflects light in other polarization states. The orthogonal transmittance (Tc) of the reflective polarizing member may be, for example, 0.01% to 3%. The single-element transmittance (Ts) of the reflective polarizing member may be, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing member may be, for example, 92% to 99.99%. The reflective polarizing member is composed of, for example, a multilayer film (sometimes referred to as a reflective polarizing film). Examples of commercially available reflective polarizing films include the product names "DBEF" and "APF" from 3M, and "APCF" from Nitto Denko.

[0021] For example, the absorption axis of the polarizing member included in the display element (12) and the reflection axis of the reflective polarizing member (14) may be arranged substantially parallel to each other or substantially perpendicular to each other. The angle between the absorption axis of the polarizing member included in the display element (12) and the slow axis of the first λ / 4 member included in the first phase difference member (20) is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. The angle between the absorption axis of the polarizing member included in the display element (12) and the slow axis of the second λ / 4 member included in the second phase difference member (22) is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. Preferably, the first λ / 4 member and the second λ / 4 member are arranged so that their slow axis directions are substantially parallel or substantially perpendicular to each other.

[0022] The in-plane phase difference Re(550) of the first λ / 4 member is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. Preferably, the first λ / 4 member exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the first λ / 4 member is, for example, 0.75 or more and less than 1, but may also be 0.8 or more and 0.95 or less.

[0023] The in-plane phase difference Re(550) of the second λ / 4 member is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. Preferably, the second λ / 4 member exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the second λ / 4 member is, for example, 0.75 or more and less than 1, but may also be 0.8 or more and 0.95 or less.

[0024] 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 member and the second λ / 4 member in that order, then passes through the second λ / 4 member two more times due to reflection by the reflective polarizing member (14) and re-reflection by the half mirror (18), and then passes through the reflective polarizing member (14) and is emitted forward, making it visible to the viewer. Therefore, if the in-plane phase difference between the first λ / 4 member or the second λ / 4 member is large, the polarization will be disrupted and light leakage will occur, and the light that should be reflected will be mixed with the light that should be visible and seen (resulting in a blurred image being seen). To prevent this problem and achieve high-definition image display, it is desirable that the in-plane phase differences between the first λ / 4 member and the second λ / 4 member be approximately the same.

[0025] B. Manufacturing method of the display system B-1. Outline of the manufacturing method of the display system The method for manufacturing a display system according to an embodiment of the present invention is: Prepare multiple optical films containing the above-mentioned first λ / 4 member, and classify them into multiple groups according to the predetermined in-plane phase difference. Prepare multiple optical films containing the above-mentioned second λ / 4 member, and classify them into multiple groups according to the predetermined in-plane phase difference, and Select a combination of groups from which the in-plane phase difference is suitable from a plurality of groups of optical films containing the first λ / 4 member and a plurality of groups of optical films containing the second λ / 4 member. Includes. Typically, a method for manufacturing a display system according to an embodiment of the present invention further includes arranging an optical film piece containing a first λ / 4 member and an optical film piece containing a second λ / 4 member, obtained from the group of optical films containing the first λ / 4 member and the group of optical films containing the first λ / 4 member respectively, at a predetermined position in the display system. According to the method for manufacturing a display system according to an embodiment of the present invention, optical film pieces having precisely matched in-plane phase differences can be efficiently prepared as the first λ / 4 member and the second λ / 4 member, which are components of the display system (2) described in Section A. As a result, a display system in which the in-plane phase differences of the first λ / 4 member and the second λ / 4 member substantially coincide can be easily and efficiently obtained. In one embodiment, the variation in in-plane phase difference between optical films containing the first λ / 4 member in each of the above-classified groups is, for example, 3 nm or less, or for example, 2 nm or less, preferably 1 nm to 1.5 nm, and more preferably 1 nm to 1.3 nm. In one embodiment, the variation in in-plane phase difference between optical films containing the second λ / 4 member in each of the above-classified groups is, for example, 3 nm or less, or for example, 2 nm or less, preferably 1 nm to 1.5 nm, and more preferably 1 nm to 1.3 nm. In one embodiment, the variation in the in-plane phase difference in the longitudinal direction of the optical film including the first λ / 4 member is, for example, 3 nm or less, preferably 1.5 nm or less. In one embodiment, the variation in the in-plane phase difference in the longitudinal direction of the optical film including the second λ / 4 member is, for example, 3 nm or less, preferably 1.5 nm or less. In one embodiment, the optical film including 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. 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, and the length of one side may be, for example, 1000 mm or less. In one embodiment, the optical film including the second λ / 4 member has a predetermined length and width. The length of the optical film is, for example, 50m to 1000m, 50m to 300m, or 100m to 150m. The width of the optical film is, for example, 40mm to 200mm, 45mm to 150mm, or 50mm to 120mm. In one embodiment, the in-plane phase difference of an optical film including the first λ / 4 member is the average value of the in-plane phase differences measured at the four corners of the optical film. In one embodiment, the in-plane phase difference of the optical film including the second λ / 4 member is the average value of the in-plane phase differences measured at two or more locations at the leading edge of the optical film. In one embodiment, the in-plane phase difference of the optical film including the second λ / 4 member is the average value of the in-plane phase differences measured at two or more locations at the leading edge and two or more locations at the trailing edge of the optical film. The following describes in detail a method for manufacturing a display system according to one embodiment of the present invention.

[0026] B-2. Method for manufacturing a display system according to one embodiment of the present invention In one embodiment, the method for manufacturing a display system according to an embodiment of the present invention is: Step Ii is to prepare a first optical film A1 including the first λ / 4 member described above, Step I-ii involves dividing the above-mentioned first optical film A1 to obtain a plurality of first optical films A2 having a predetermined width and predetermined length, Step I-iii involves laminating the above-mentioned multiple first optical films A2 and the above-mentioned polarizing members to obtain a plurality of second optical films B1, Steps I-iv: Classifying the above-mentioned multiple second optical films B1 into multiple groups according to those having a predetermined in-plane phase difference, Step II-i involves preparing a third optical film C1 containing the second λ / 4 member described above, Step II-ii involves dividing the above-mentioned third optical film C1 to obtain a plurality of third optical films C2 having a predetermined width and predetermined length, Step II-iii involves classifying the above-mentioned multiple third optical films C2 into multiple groups according to those having a predetermined in-plane phase difference, Step III involves selecting a combination of groups from the above-mentioned multiple groups of the second optical film B1 and the above-mentioned multiple groups of the third optical film C2 that have a suitable in-plane phase difference. Includes. Typically, the method for manufacturing the display system according to the above embodiment includes, after step III, step IV, in which the second optical film pieces B2 and third optical film pieces C3 obtained from the selected combination of second optical film B1 and third optical film C2, respectively, are placed in predetermined positions on the display system.

[0027] B-2-1. Process II In step Ii, a first optical film A1 containing a first λ / 4 member is prepared. Figures 2(a) and 2(b) are schematic cross-sectional views illustrating an example of the configuration of the first optical film A1, respectively. The first optical film A1(30a) shown in Figure 2(a) includes, in this order, an adhesive layer (32), a first λ / 4 member (34a), and a first protective member (36). According to the configuration of the first optical film A1(30a), the first phase difference member (20) in the display system (2) consists 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 a tack layer. The first optical film A1(30a') shown in Figure 2(b) includes, in this order, an adhesive layer (32), a first λ / 4 member (34a), a member whose refractive index characteristics can be expressed in the relationship nz>nx=ny (a so-called positive C plate, hereinafter also referred to as the "first positive C plate") (34b), and a first protective member (36). According to the configuration of the first optical film A1(30a'), the first phase difference member (20) in the display system (2) includes the first λ / 4 member (34a) and the first positive C plate (34b). In other words, the first phase difference member (20) has a laminated structure of the first λ / 4 member (34a) and the first positive C plate (34b). Unlike the illustrated example, in the first phase difference member (20), the first λ / 4 member (34a) may be located on the first protective member (36) side of the positive C plate (34b). The first positive C plate (34b), the first λ / 4 member (34a), and the first protective member (36) are typically bonded together via adhesive layers such as an adhesive layer or a tack layer. Both Daiichi Optical Film A1 (30a) and (30a') have the adhesive layer (32) surface protected by a release liner (38).

[0028] The first optical film A1 is preferably elongated. In one embodiment, the first optical film A1 may be manufactured by laminating elongated components using a roll-to-roll method and then wound into a roll. Here, "roll-to-roll" refers to laminating rolls of film together while transporting them, aligning their elongated directions. The length of the first optical film A1 is, for example, 100m to 2000m, preferably 500m to 1000m. 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 will be described later with respect to Step IV, the second optical film piece B2 is obtained by punching out the second optical film B1, and the width of the first optical film A1 is, for example, 10 times or more the punching width of the second optical film piece B2, preferably 15 times or more and 25 times or less, and more preferably 15 times or more and 20 times or less.

[0029] [First λ / 4 member] As described for the first λ / 4 member in Item A, the in-plane retardation Re(550) of the first λ / 4 member (34a) is, for example, 100 nm to 190 nm, may be 110 nm to 180 nm, may be 130 nm to 160 nm, or may be 135 nm to 155 nm. The first λ / 4 member preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. Re(450) / Re(550) of the first λ / 4 member is, for example, 0.75 or more and less than 1, and may be 0.8 or more and 0.95 or less.

[0030] The first λ / 4 member preferably exhibits a refractive index characteristic showing a relationship of nx > ny ≧ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within a range not impairing the effects of the present invention, ny < nz may occur. The Nz coefficient of the λ / 4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, still more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0031] In one embodiment, the first λ / 4 member is a stretched film of a resin film. For example, it is a stretched film in which a long resin film is stretched in the width direction.

[0032] Examples of resins included in the above-mentioned 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 may be used individually or in combination. Methods of combination include blending and copolymerization. When the first λ / 4 member exhibits inverse dispersion wavelength characteristics, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) can be suitably used.

[0033] Any suitable polycarbonate resin can be used as the above-mentioned polycarbonate resin. For example, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanol, di, tri, or polyethylene glycol, and alkylene glycol or spiroglycol. Preferably, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, structural units derived from alicyclic dimethanol, and / or structural units derived from di, tri, or polyethylene glycol; more preferably, it includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from di, tri, or polyethylene glycol. The polycarbonate resin may optionally include structural units derived from other dihydroxy compounds. Further details regarding polycarbonate resins suitably used for the first λ / 4 member and methods for forming the first λ / 4 member are described, for example, in Japanese Patent Publication Nos. 2014-10291, 2014-26266, 2015-212816, 2015-212817, and 2015-212818, and the descriptions in these publications are incorporated herein by reference.

[0034] The thickness of the first λ / 4 member, which is a stretched resin film, is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, and more preferably 20 μm to 60 μm.

[0035] In another embodiment, the first λ / 4 member is an orientation-solidified layer of liquid crystal compounds. The orientation-solidified layer of liquid crystal compounds is a layer in which the liquid crystal compounds are oriented in a predetermined direction within the layer, and this orientation state is fixed. Note that the term "orientation-solidified layer" is a concept that includes orientation-cured layers obtained by curing liquid crystal monomers, as described later. In the first λ / 4 member, typically, rod-shaped liquid crystal compounds are oriented in a state aligned along the slow axis direction of the first λ / 4 member (homogenous orientation). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. Preferably, the liquid crystal compounds are polymerizable. If the liquid crystal compounds are polymerizable, the orientation state of the liquid crystal compounds can be fixed by polymerizing them after orientation.

[0036] The above-mentioned oriented solidified layer of liquid crystal compound (liquid crystal oriented solidified layer) can be formed by applying an orientation treatment to the surface of a predetermined substrate, coating the surface with a coating liquid containing the liquid crystal compound to orient the liquid crystal compound in the direction corresponding to the orientation treatment, and fixing the orientation state. Any appropriate orientation treatment can be used as the orientation treatment. Specifically, these include mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment. Specific examples of mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of physical orientation treatment include magnetic field orientation treatment and electric field orientation treatment. Specific examples of chemical orientation treatment include oblique deposition and photo-orientation treatment. Any appropriate conditions can be adopted for each orientation treatment depending on the purpose.

[0037] The orientation of liquid crystal compounds is achieved by treating them at a temperature that exhibits the liquid crystal phase, depending on the type of liquid crystal compound. This temperature treatment causes the liquid crystal compound to enter a liquid crystal state, and it then orients according to the orientation treatment direction on the substrate surface.

[0038] In one embodiment, the orientation state is fixed by cooling the liquid crystal compound oriented as described above. If the liquid crystal compound is polymerizable or crosslinkable, the orientation state is fixed by subjecting the liquid crystal compound oriented as described above to a polymerization treatment or a crosslinking treatment.

[0039] As the above-mentioned liquid crystal compound, any suitable liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer may be used individually or in combination. Specific examples of liquid crystal compounds and methods for producing liquid crystal alignment solidified layers are described, for example, in Japanese Patent Publication No. 2006-163343, Japanese Patent Publication No. 2006-178389, and International Publication No. 2018 / 123551. The descriptions in these publications are incorporated herein by reference.

[0040] The thickness of the first λ / 4 member, which is composed of a liquid crystal alignment solidification 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.

[0041] [First positive C plate] The phase difference Rth(550) in the thickness direction of the first positive C plate (34b) is preferably -50nm to -300nm, more preferably -70nm to -250nm, even more preferably -90nm to -200nm, and particularly preferably -100nm to -180nm. Here, "nx=ny" includes not only the case where nx and ny are exactly equal, but also the case where nx and ny are substantially equal. The in-plane phase difference Re(550) of the first positive C plate is, for example, less than 10nm.

[0042] The first positive C plate can be formed from any suitable material, but preferably it is composed of a film containing a liquid crystal material fixed in a homeotropic orientation. The liquid crystal material (liquid crystal compound) that can be homeotropically oriented may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of such liquid crystal compounds and methods for forming the first positive C plate are those described in paragraphs

[0020] to

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

[0043] [First protective component] The above-mentioned first protective member (36) typically includes a base material. The base material can be composed of any suitable film. Examples of materials that make up the main component of the film constituting the base material include cellulosic resins such as triacetylcellulose (TAC), polyester, polyvinyl alcohol, polycarbonate, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, cycloolefins such as polynorbornene, polyolefins, (meth)acrylic, acetate, and other resins. The thickness of the base material is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 35 μm.

[0044] 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 may be positioned such that the surface treatment layer is located on the front side. The surface treatment layer may have any suitable function. For example, the surface treatment layer preferably has an anti-reflective function from the viewpoint of improving visibility. The surface treatment layer may also include a hard coat 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.

[0045] [Adhesive layer] The adhesive constituting the above adhesive layer (32) typically contains a (meth)acrylic polymer, a urethane polymer, a silicone polymer, or a rubber polymer as a base polymer. Preferably, the adhesive is a (meth)acrylic adhesive containing a (meth)acrylic polymer as the 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.

[0046] [Removable Liner] The release liner (38) typically comprises a base material and a release treatment layer (e.g., a silicone treatment layer) provided on the adhesive layer (32) side of the base material. The base material is formed from a resin such as a polyolefin resin, polyester resin, (meth)acrylic resin, polyamide resin, polyimide resin, polyvinyl chloride resin, polyvinylidene chloride resin, cellulose resin, polystyrene resin, or polycarbonate resin.

[0047] B-2-2. Process I-ii In step I-ii, the first optical film A1 is divided to obtain a plurality of first optical films A2 having a predetermined width and predetermined length. Specifically, as shown in Figure 3, the first optical film A1 (30a) is slit along the longitudinal direction and along the width direction, and / or punched out to a predetermined size to obtain a plurality of first optical films A2 (30b) having a predetermined width and predetermined length. Slitting along the width direction is not required. Typically, the variation in in-plane phase difference in the width direction of the first optical film A2 is smaller than that of the first optical film A1.

[0048] The first optical film A2 may have any shape depending on the purpose. In one embodiment, the first optical film A2 is elongated. The length of the elongated first optical film A2 may be, for example, 50m to 1000m, 50m to 300m, or 100m to 150m. The elongated first optical film A2 may be wound into a roll. The width of the elongated first optical film A2 is, for example, 60mm to 500mm, preferably 100mm to 400mm, and more preferably 100mm to 300mm. The width of the elongated first optical film A2 is, for example, 2 to 20 times, preferably 3 to 10 times, the punched width of the second optical film piece B2. By dividing it into relatively narrow widths in this way, the variation in in-plane phase difference in the longitudinal and width directions of the first optical film A2 can be reduced.

[0049] In another embodiment, the first optical film A2 is sheet-like. The sheet-like first optical film A2 has a side length of, for example, 1000 mm or less, but may be 800 mm or less, or 500 mm or less. Specifically, the first optical film A2 may be roughly rectangular in size, such as 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. When the first λ / 4 member has a slow axis in the width direction or length direction, the first optical film A2 having a slow axis oblique to the side direction can be efficiently obtained by punching the first optical film A1 obliquely.

[0050] The variation in the in-plane phase difference (e.g., Re(590)) of the first optical film A2 in the longitudinal direction (long side direction in the case of a rectangular shape) is, for example, 3 nm or less, preferably 1.5 nm or less. The variation in the in-plane phase difference (e.g., Re(590)) of the first optical film A2 in the width direction is, for example, 3 nm or less, preferably 1.5 nm or less. The variation in the in-plane phase difference in the longitudinal direction can be determined by measuring the in-plane phase difference over a predetermined length (e.g., 50 m or more, and may be the entire length) in the longitudinal direction at an arbitrary position in the width direction of the elongated optical film (e.g., the center in the width direction) and calculating the difference between the maximum and minimum values. The variation in the in-plane phase difference in the width direction can be determined by measuring the in-plane phase difference at multiple locations in the width direction at predetermined intervals (e.g., intervals of about 30 mm to about 350 mm) in the longitudinal direction of the elongated optical film and calculating the difference between the maximum and minimum values.

[0051] In an embodiment in which the first optical film A1 is divided by slits, the number of divisions of the film by slits along the longitudinal direction (meaning how many parts the first optical film A1 is divided into in the width direction) is, for example, 2 to 20, or for example, 3 to 10.

[0052] B-2-3. Process I-iii In step I-iii, as shown in Figure 4, multiple first optical films A2 (30b) and multiple polarizing members (42) are laminated to obtain multiple second optical films B1 (40a). The polarizing members (42) are polarizing members included in the display element (12) in the display system (2). Preferably, the first optical film A2 and the polarizing member with an adhesive layer are laminated. Typically, the second optical film B1 is the same size as the first optical film A2.

[0053] Figures 5(a) and 5(b) are schematic cross-sectional views illustrating an example of the configuration of the second optical film B1, respectively. The second optical films B1 (40a) and (40a') have a configuration in which a polarizing member (42) and an adhesive layer (44) are laminated in this order 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 absorption axis direction of the polarizing member and the slow phase axis direction of the first optical film A2 (more specifically, the slow phase axis direction of the first λ / 4 member (34a)) are arranged to be, for example, 40° to 50°, preferably 42° to 48°, and more preferably about 45°. Although not shown, the surface of the adhesive layer (44) is preferably protected by a release liner.

[0054] The polarizing member (42) described above is typically an absorbing polarizing member that includes 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 or more and 20 μm or less, but may also be 2 μm or more and 15 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, or 5 μm or less. A protective layer may be provided on one or both sides of the absorbing polarizing film.

[0055] The above-mentioned absorption polarizing film may be made from a single layer of resin film, or it may be made using a laminate of two or more layers.

[0056] When manufactured from a single layer of resin film, for example, an absorption polarizing film can be obtained by subjecting 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, to dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and stretching treatment. Among these, an absorption polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

[0057] The above iodine staining is carried out, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio for the above uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the staining treatment, or during the staining process. Alternatively, staining may be performed after stretching. If necessary, the PVA-based film may be subjected to swelling, crosslinking, washing, drying, etc.

[0058] When using the above-mentioned laminate of two or more layers, examples of laminates include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate. An absorption polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate can be produced, for example, by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and obtaining a laminate of a resin substrate and a PVA-based resin layer; or by stretching and dyeing the laminate to make the PVA-based resin layer an absorption polarizing film. In this embodiment, preferably, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching may, if necessary, further include air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment includes applying an air-assisted stretching treatment, a dyeing treatment, a water-based stretching treatment, and a drying shrinkage treatment to the laminate in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated on a thermoplastic resin, making it possible to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as a decrease in the orientation of PVA and dissolution when immersed in water in the subsequent dyeing and stretching processes, making it possible to achieve high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain halides. As a result, the optical properties of the absorption polarizing film obtained through processing steps in which the laminate is immersed in a liquid, such as dyeing and water-based stretching, can be improved. Furthermore, by shrinking the laminate in the width direction through a drying shrinkage treatment, the optical properties can be improved.The resulting resin substrate / absorbent polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorbent polarizing film), or an appropriate protective layer may be laminated on the peeled surface obtained by removing the resin substrate from the resin substrate / absorbent polarizing film laminate, or on the surface opposite to the peeled surface, depending on the purpose. Details of such a method for manufacturing an absorbent polarizing film are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0059] The orthogonal transmittance (Tc) of the absorbing polarizing member (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-layer transmittance (Ts) of the absorbing polarizing member (absorbing polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The degree of polarization (P) of the absorbing polarizing member (absorbing polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0060] The same explanation as for the adhesive layer (32) described in Section B-2-1 can be applied to the adhesive layer (44).

[0061] B-2-4. Process I-iv In steps I-iv, as shown in Figure 6, the second optical film B1 (40a) is classified into multiple groups (in the illustrated example, two groups, group A and group B) based on whether it has a predetermined in-plane phase difference. Specifically, for each of the multiple second optical films B1, the in-plane phase difference (e.g., Re(590)) is measured, and it is classified into multiple groups based on whether it has a predetermined in-plane phase difference. The number of groups to be classified is not particularly limited, but from the viewpoint of balancing the high resolution of the display system with production efficiency, it is, for example, 2 to 4, and preferably 2 or 3. In addition, the number of second optical films B1 that include the first optical film A2 derived from the same first optical film A1 and are classified into the same group is, for example, 50 to 250, or for example, 80 to 200.

[0062] The in-plane phase difference of the second optical film B1 (substantially, the in-plane phase difference of the first λ / 4 plate) is measured at two or more locations (e.g., two locations) at the leading and / or trailing ends in the longitudinal direction. Specifically, it can be measured at two or more locations within 500 mm of the leading and / or trailing ends (e.g., multiple locations separated by predetermined intervals in the width direction). For long optical films with small variations in the in-plane phase difference in the longitudinal direction, the overall in-plane phase difference can be roughly determined by measurements at the leading and / or trailing ends, even if the length is 50 m or more. In one embodiment, the in-plane phase difference is measured at the four corners of the second optical film B1 (e.g., 5 mm to 50 mm from the corners), as indicated by the "×" marks in the upper left of Figure 6, and the average of these measurements can be taken as the in-plane phase difference of the second optical film B1.

[0063] In one embodiment, the above classification is performed with a predetermined in-plane phase difference (e.g., Re(590)) as the reference value, typically with a classification width of 3 nm or less, for example, 2 nm or less, preferably 1 nm to 1.5 nm, and more preferably 1 nm to 1.3 nm. As a specific example, when classifying with a classification width of 2 nm (±1 nm) using a Re(590) of 146 nm as the reference value, for example, the data can be sequentially classified into groups such as: 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 so on.

[0064] In another embodiment, the above classification is performed by classifying the in-plane phase difference (e.g., Re(590)) in order from the largest to the smallest measurement, within a predetermined classification range. The classification range for the in-plane phase difference (e.g., Re(590)) can typically be 3 nm or less, for example, 2 nm or less, preferably 1 nm to 1.5 nm, and more preferably 1 nm to 1.3 nm.

[0065] In yet another embodiment, the above classification is performed by dividing by one or more reference values ​​(in-plane phase difference). For example, a predetermined in-plane phase difference (e.g., Re(590)) can be used as a reference value, and the data can be classified into two groups above and below this reference value. Alternatively, a first reference value and a second reference value can be established, and the data can be classified into three groups: less than the first reference value, between the first and second reference values, and greater than the second reference value.

[0066] The variation in in-plane phase difference between the second optical films B1 in each group after the above classification (the difference between the maximum and minimum values ​​of the in-plane phase difference of the second optical films B1 included in the group) is smaller than the variation in in-plane phase difference between all the second optical films B1 before classification, and may be, for example, about half or less. The variation in in-plane phase difference between the second optical films B1 in each group may be, for example, 3 nm or less. The variation in in-plane phase difference between the second optical films B1 in each group may correspond to the above classification range, for example, 2 nm or less, preferably 1.5 nm or less, and more preferably 1 nm to 1.3 nm.

[0067] B-2-5. Process II-i In step II-i, a third optical film C1 containing a second λ / 4 member is prepared. Figures 7(a) and 7(b) are schematic cross-sectional views illustrating an example of the configuration of the third optical film C1, respectively. The third optical film C1(50a) shown in Figure 7(a) includes an adhesive layer (52), a second λ / 4 member (54a), and a second protective member (56) in that order. According to the configuration of the third optical film C1(50a), the second phase difference member (22) in the display system (2) consists of the second λ / 4 member (54a). The elongated optical film (50a') shown in Figure 7(b) includes, in this order, 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 a second λ / 4 member (54a) and a second positive C plate (54b). In other words, the second phase difference member (22) has a laminated structure of a second λ / 4 member (54a) and a second positive C plate (54b). In the illustrated example, the third optical films C1(50a) and (50a') both have the adhesive layer (52) surface protected by a release liner (58).

[0068] The same description as that given for the first λ / 4 member (34a), the first positive C plate (34b), the first protective member (36), the adhesive layer (32), and the release liner (38) in Section B-2-1 applies to the second λ / 4 member (54a), the second positive C plate (54b), the second protective member (56), the adhesive layer (32), and the release liner (38), respectively.

[0069] The third optical film C1 is preferably elongated. In one embodiment, the third optical film C1 may be manufactured by laminating elongated members in a roll-to-roll manner and then wound into a roll. The length of the third optical film C1 is, for example, 100m to 2000m, preferably 500m to 1000m. The width of the third optical film C1 is, for example, 500 mm to 1500 mm, preferably 900 mm to 1200 mm. As will be described later with respect to step IV, the third optical film piece C3 is obtained by punching out the third optical film C2, but the width of the third optical film C1 is, for example, 10 times or more the punching width of the third optical film piece C3, preferably 15 times to 25 times, and more preferably 15 times to 20 times.

[0070] B-2-6. Process II-ii In step II-ii, the third optical film C1 is divided to obtain a plurality of third optical films C2 having a predetermined width and predetermined length. For example, as shown in Figure 8, the elongated third optical film C1 (50a) is slit along the length direction to obtain a plurality of third optical films C2 (50b). Slitting can be performed not only in the length direction but also in the width direction. This makes it possible to obtain a plurality of third optical films C2 (50b) having a predetermined width and predetermined length. If necessary, the third optical film C2 may be wound into a roll. Typically, the variation in in-plane phase difference in the width direction of the third optical film C2 is smaller than that of the third optical film C1.

[0071] The length of the third optical film C2 is, for example, 50m to 1000m, or 50m to 300m, or 100m to 150m.

[0072] The width of the third optical film C2 is, for example, 40 mm to 200 mm, or for example, 45 mm to 150 mm, or for example, 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, preferably 1.2 to 2.0 times, and more preferably 1.2 to 1.5 times, the punched width of the third optical film piece C3. By dividing it into relatively narrow widths in this way, the variation in in-plane phase difference in the longitudinal and width directions of the third optical film C2 can be reduced.

[0073] The variation in the in-plane phase difference (e.g., Re(590)) in the longitudinal direction of the third optical film C2 is, for example, 3 nm or less, preferably 1.5 nm or less. The variation in the in-plane phase difference (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.

[0074] In one embodiment, the number of divisions of the film by slits along the longitudinal direction (meaning how many divisions the third optical film C1 is made into in the width direction) is, for example, 6 or more, preferably 10 to 25, and preferably 15 to 20.

[0075] B-2-7. Process II-iii In step II-iii, as shown in Figure 9, the multiple third optical films C2(50b) are classified into multiple groups (in the illustrated example, two groups, group C and group D) based on whether they have a predetermined in-plane phase difference. Specifically, for each of the multiple third optical films C2, the in-plane phase difference (e.g., Re(590)) is measured, and they are classified into multiple groups based on whether they have a predetermined in-plane phase difference. The number of groups to be classified is not particularly limited, but from the viewpoint of balancing the high resolution of the display system with production efficiency, it is, for example, 2 to 4, and preferably 2 or 3. In one embodiment, the number of groups of the second optical film B1 obtained in step I-iv and the number of groups of the third optical film C2 obtained in step II-iii are the same.

[0076] The in-plane phase difference of the third optical film C2 (substantially, the in-plane phase difference of the second λ / 4 plate) is measured at two or more locations (e.g., two locations) at the leading and / or trailing ends of the third optical film C2. For long optical films with small variations in the in-plane phase difference in the longitudinal direction, the overall in-plane phase difference can be roughly determined by measurements at the leading and / or trailing ends, even if the film has a length of 50 m or more. In one embodiment, the in-plane phase difference is measured at two or more locations in the width direction of the leading end of the film (e.g., two or more locations within 500 mm of the leading end (e.g., multiple locations spaced at predetermined intervals in the width direction)), as indicated by the "×" marks in the upper left third optical film C2 (50b) of Figure 9, and may also be measured at two or more locations in the width direction of the trailing end (e.g., two or more locations within 500 mm of the trailing end (e.g., multiple locations spaced at predetermined intervals in the width direction)) as needed. Therefore, the in-plane phase difference is measured, for example, at the four corners of the third optical film C2. The average of these measurements can be taken as the in-plane phase difference of the third optical film C2.

[0077] For example, the in-plane phase difference measurement is performed on the third optical film C1 before slitting. In this case, the third optical film C1 before slitting is divided along the line to be slit, and the in-plane phase difference at the leading and / or trailing points of the division is measured in the same manner as above. This can then be used as the in-plane phase difference of the third optical film C2 corresponding to the division obtained after slitting.

[0078] The above classification method is the same as the classification method in steps I-iv. In one embodiment, the classification method in steps I-iv and the classification method in steps II-iii are the same, and the same reference values ​​and the same classification range can be applied. This makes it easier to match the in-plane phase difference of the group of second optical film B1 with the in-plane phase difference of the group of third optical film C2.

[0079] The variation in in-plane phase difference between third optical films C2 in each group after classification is smaller than the variation in in-plane phase difference between all third optical films C2 before classification, and may be approximately half or less. The variation in in-plane phase difference between third optical films C2 in each group may be, for example, 3 nm or less. The variation in in-plane phase difference between third optical films C2 in each group may correspond to the above classification range, for example, 2 nm or less, preferably 1.5 nm or less, and more preferably 1 nm to 1.3 nm.

[0080] B-2-8. Process III In step III, a combination of groups with suitable in-plane phase differences is selected from multiple groups of the second optical film B1 and multiple groups of the third optical film C2. Specifically, groups with small differences in in-plane phase differences are combined. For example, the average value of the in-plane phase differences of the optical films within a group, or the reference value of the in-plane phase difference applied during classification, can be used as the in-plane phase difference for each group, and a combination of groups whose difference is less than or equal to a predetermined value (e.g., 3 nm or less, preferably 1.5 nm or less) can be selected.

[0081] The following is a specific example of process III, referring to Figure 10. In processes I-iv, the second optical film B1 (40a) is classified into two groups: Group A, which is classified with a classification range of 3 nm (143.5 nm ≤ Re(590) < 146.5 nm) with Re(590) = 145 nm as the reference value, and Group B, which is classified with a classification range of 3 nm (146.5 nm ≤ Re(590) < 149.5 nm) with Re(590) = 148 nm as the reference value. In process II-iii, the third optical film C2 (50b) is classified with a classification range of 3 nm (142.5 nm) with Re(590) = 144 nm as the reference value. When data is classified into two groups, Group C, which is classified by m ≤ Re(590) < 145.5 nm, and Group D, which is classified with a classification range of 3 nm (145.5 nm ≤ Re(590) < 148.5 nm) with Re(590) = 147 nm as the reference value, the following combinations are selected: Group A, where the reference value (Re(590)) is 145 nm, and Group C, where the reference value (Re(590)) is 144 nm; and Group B, where the reference value (Re(590)) is 148 nm, and Group D, where the reference value (Re(590)) is 147 nm.

[0082] B-2-9. Process IV In step IV, the second optical film pieces B2 and third optical film pieces C3, respectively, obtained from the group of second optical films B1 and the group of third optical films C2 selected in step III, are placed in predetermined positions on the display system (2). For example, the second optical film piece 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 member (42) is included in the display element (12), and the third optical film piece C3 is bonded to the front side of the first lens portion (16) via an adhesive layer (52).

[0083] The second optical film piece B2 and the third optical film piece C3 can each have any suitable shape. In one embodiment, the second optical film piece B2 is substantially rectangular. In one embodiment, the third optical film piece C3 is substantially circular. In this specification, substantially circular includes circular or elliptical shapes, and further includes shapes that appear to be nearly circular or elliptical.

[0084] As shown in Figure 11(a), the second optical film piece B2(40b) is typically obtained by punching out the second optical film B1(40a) into a predetermined shape (in the figure, X1 represents the width of the second optical film B1(40a), and X2 represents the punching 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 sheet of second optical film B1, may be, for example, 10 to 100, or for example, 15 to 50.

[0085] As shown in Figure 11(b), a third optical film piece C3(50c) is typically obtained by punching out a third optical film C2(50b) into a predetermined shape (in the figure, X3 represents the width of the third optical film C2(50b), and X4 represents the punching 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, preferably one third optical film piece C3. The number of third optical film pieces C3 obtained from one third optical film C2 is, for example, 800 to 6000, or for example, 1000 to 3000.

[0086] As described above, the group of combinations selected in step III has compatible in-plane phase differences. Furthermore, the second optical films B1 within the selected group have similar in-plane phase differences, and the variation in in-plane phase differences in the longitudinal and width directions is small for each individual second optical film B1. Similarly, the third optical films C2 within the selected group have similar in-plane phase differences, and the variation in in-plane phase differences in the longitudinal and width directions is small for each individual third optical film C2. Therefore, the second optical film pieces B2 and third optical film pieces C3 obtained from the selected group of second optical films B1 and third optical films C2, respectively, all have small variations in in-plane phase differences (in other words, high uniformity of in-plane phase differences) and have compatible in-plane phase differences. Therefore, by arranging these optical film pieces in predetermined positions in the display system (2), a display system (2) capable of displaying high-definition images can be easily and efficiently produced.

[0087] B-3. ​​Variations In the embodiment described in Section B-2, the classification of optical films including the first λ / 4 member is performed based on the in-plane phase difference of the optical film including the first λ / 4 member and the polarizing member. However, the classification may also be performed based on the in-plane phase difference of optical films including the first λ / 4 member but not including the polarizing member. In this case, the optical film including the first λ / 4 member but not including the polarizing member and the polarizing member can be laminated after classification, and this lamination can be performed before or after punching out the optical film piece. Alternatively, the optical film piece including the first λ / 4 member and the polarizing member may be attached to the display system separately. Furthermore, for example, if the first optical film A2 is in the form of a single sheet, it is not necessary to measure the in-plane phase difference for all of the films. For example, for a single sheet of first optical film A2 punched out from the first optical film A1, those punched out from the same region along the longitudinal direction can be considered to have substantially the same in-plane phase difference, and the in-plane phase difference of one arbitrarily selected sheet or the average of the in-plane phase differences of several sheets can be applied to the whole. The same applies when measuring the in-plane phase difference of the second optical film B1 obtained using such first optical film A2.

[0088] C. Optical Film Group The optical film group according to embodiments of the present invention is composed of a plurality of optical films. The optical film includes a λ / 4 member and has a predetermined width and a predetermined length. The optical film may further include a polarizing member. The difference between the maximum and minimum values ​​of the in-plane phase difference (e.g., Re(590)) between the plurality of optical films constituting the optical film group is, for example, 3 nm or less, preferably 2 nm or less, more preferably 1.5 nm or less, even more preferably 1.3 nm or less, and for example, 1 nm or more. In other words, the optical film group according to the embodiment of the present invention is composed of optical films with high uniformity of in-plane phase difference.

[0089] In one embodiment, the optical film included in the optical film group is elongated. The length of the elongated optical film is, for example, 50m to 1000m, preferably 50m to 3000m, and more preferably 100m to 150m. The width of the elongated optical film is, for example, 900mm to 1500mm, preferably 1000mm to 1300mm.

[0090] In another embodiment, the optical films included in the optical film group are sheet-like. The sheet-like first optical film A2 has a side length of, for example, 1000 mm or less, but may be 800 mm or less, or 500 mm or less. Specifically, the first optical film A2 may be roughly rectangular in size, such as 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.

[0091] In one embodiment, the optical films included in the optical film group are produced by dividing an optical film made in a large area, and thus originate from a single optical film. In this embodiment, the number of optical films included in the optical film group is, for example, 50 to 250, or for example, 80 to 200.

[0092] The above-mentioned group of optical films includes the second optical film B1 obtained in steps Ii to I-iv described in section B, and its specific description is as stated above.

[0093] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the configurations shown in the embodiments above can be replaced with configurations that are substantially the same, configurations that produce the same effects, or configurations that can achieve the same purpose. [Industrial applicability]

[0094] A method for manufacturing a display system according to an embodiment of the present invention can be suitably used, for example, in the manufacture of a display device such as VR goggles. [Explanation of Symbols]

[0095] 2 Display system, 4 Lens section, 12 Display element, 14 Reflective polarizing member, 16 First lens section, 18 Half mirror, 20 First phase difference member, 22 Second phase difference member, 24 Second lens section, 30 First optical film, 34a First λ / 4 member, 34b First positive C plate, 40 Second optical film, 42 Polarizing member, 50 Third optical film, 54a Second λ / 4 member, 54b Second positive C plate

Claims

1. A display element having a display surface that emits light representing an image forward via a polarizing member, A reflective polarizing member is positioned in front of the display element and reflects light emitted from the display element, A first lens portion is arranged in the optical path between the display element and the reflective polarizing member, A half-mirror is disposed between the display element and the first lens portion, which transmits light emitted from the display element and reflects the light reflected by the reflective polarizing member toward the reflective polarizing member, A first λ / 4 member is positioned in the optical path between the display element and the half mirror, A second λ / 4 member is positioned in the optical path between the half mirror and the reflective polarizing member, A method for manufacturing a display system that displays an image to a user, comprising: Step I-i for preparing the first optical film A1 including the first λ / 4 member, Step I-ii involves dividing the first optical film A1 to obtain a plurality of first optical films A2 having a predetermined width and predetermined length, Step I-iii involves laminating the plurality of first optical films A2 and the polarizing members to obtain a plurality of second optical films B1, Steps I-iv: Classifying the plurality of second optical films B1 into a plurality of groups according to those having a predetermined in-plane phase difference, Step II-i involves preparing a third optical film C1 including the second λ / 4 member, Step II-ii involves dividing the third optical film C1 to obtain a plurality of third optical films C2 having a predetermined width and predetermined length, Step II-iii classifies the plurality of third optical films C2 into a plurality of groups according to those having a predetermined in-plane phase difference, Step III: Select a combination of groups from a plurality of groups of the second optical film B1 and a plurality of groups of the third optical film C2 that have a suitable in-plane phase difference. A manufacturing method that includes this.

2. The manufacturing method according to claim 1, wherein the variation in in-plane phase difference between the second optical films B1 in each of the groups after classification is 3 nm or less.

3. The manufacturing method according to claim 1, wherein the variation in in-plane phase difference between the third optical films C2 in each of the groups after classification is 3 nm or less.

4. The manufacturing method according to claim 1, wherein the variation in the in-plane phase difference in the longitudinal direction of the first optical film A2 is 3 nm or less.

5. The manufacturing method according to claim 1, wherein the variation in the in-plane phase difference in the longitudinal direction of the third optical film C2 is 3 nm or less.

6. The manufacturing method according to claim 1, wherein the length of one side of the first optical film A2 is 1000 mm or less.

7. The manufacturing method according to claim 1, wherein the length of the third optical film C2 is 50 m or more and 1000 m or less.

8. The manufacturing method according to claim 1, wherein the in-plane phase difference of the second optical film B1 is the average value of the in-plane phase differences measured at the four corners of the second optical film B1.

9. The manufacturing method according to claim 1, wherein the in-plane phase difference of the third optical film C2 is the average value of the in-plane phase differences measured at two or more locations at the leading edge of the third optical film C2.

10. The manufacturing method according to claim 1, wherein the in-plane phase difference of the third optical film C2 is the average value of the in-plane phase differences measured at two or more locations at the leading edge and two or more locations at the trailing edge of the third optical film C2.

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