Method for managing optical laminate and method for manufacturing display system

Abstract

The present invention is a method for managing a first optical laminate including a first λ / 4 member and a second optical laminate including a second λ / 4 member, said management method comprising: (i) classifying a plurality of the first optical laminate into Na groups having mutually different average values of in-plane phase difference (Here, the Na groups include a 1a group, a 2a group, and a 3a group in the stated order when arranged in order of size of said average value, the maximum value of the in-plane phase difference of the first optical laminates in the 2a group is smaller than the maximum value of the in-plane phase difference of the first optical laminates in the 1a group, and the minimum value of the in-plane phase difference of the first optical laminates in the 2a group is larger than the minimum value of the in-plane phase difference of the first optical laminates in the 3a group.); (ii) classifying a plurality of the second optical laminate into Nb groups having mutually different average values of in-plane phase difference (Here, the Nb groups include a 1b group, a 2b group, and a 3b group in the stated order when arranged in order of size of said average value, the maximum value of the in-plane phase difference of the second optical laminates in the 2b group is smaller than the maximum value of the in-plane phase difference of the second optical laminates in the 1b group, and the minimum value of the in-plane phase difference of the second optical laminates in the 2b group is larger than the minimum value of the in-plane phase difference of the second optical laminates in the 3b group.); (iii) matching a combination A of the 1a group and the 1b group and a combination B of the 3a group and the 3b group on the basis of the average value of the in-plane phase difference; and (iv) distributing the first optical laminates included in the 2a group and the second optical laminates included in the 2b group to the combination A and / or the combination B so that the difference between the number of the first optical laminates and the number of the second optical laminates in the combination A and / or the combination B is reduced.

Description

Method for managing optical laminate and method for manufacturing display system

[0001] The present invention relates to a method for managing an optical stack and a method for manufacturing a display system.

[0002] Image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices), are rapidly becoming popular. In image display devices, optical components such as polarizing components and phase difference components are generally used to realize image display and improve image display performance (see, for example, Patent Document 1).

[0003] In recent years, new applications of image display devices have been developed. For example, goggles with displays (VR goggles) for realizing virtual reality (VR) have begun to be commercialized. Since the use of VR goggles in various situations is being considered, there is a demand for high-definition images.

[0004] Japanese Patent Application Laid-Open No. 2021-103286

[0005] In view of the above, a primary object of the present invention is to provide a manufacturing method for a display system such as high-definition VR goggles.

[0006] [1] According to one aspect of the present invention, there is provided a method for managing a first optical laminate including a first λ / 4 member and a second optical laminate including a second λ / 4 member, the method comprising: (i) classifying a plurality of the first optical laminates into Na groups having mutually different average values ​​of in-plane retardation (wherein the Na groups include a 1a group, a 2a group, and a 3a group which are consecutive in this order when sorted in descending order of the average value, and the maximum value of the in-plane retardation of the first optical laminate in the 2a group is smaller than the maximum value of the in-plane retardation of the first optical laminate in the 1a group, and the minimum value of the in-plane retardation of the first optical laminate in the 2a group is larger than the minimum value of the in-plane retardation of the first optical laminate in the 3a group); (ii) classifying a plurality of the second optical laminates into Nb groups having different average values ​​of in-plane retardation (here, the Nb groups include a 1b group, a 2b group, and a 3b group which are consecutive in this order when sorted in descending order of the average value, and the maximum value of the in-plane retardation of the second optical laminate in the 2b group is smaller than the maximum value of the in-plane retardation of the second optical laminate in the 1b group, and the minimum value of the in-plane retardation of the second optical laminate in the 2b group is larger than the minimum value of the in-plane retardation of the second optical laminate in the 3b group); (iii) matching a combination A of the 1a group and the 1b group and a combination B of the 3a group and the 3b group based on the average value of the in-plane retardation; and (iv) allocating the first optical stacks included in the group 2a and the second optical stacks included in the group 2b to the combination A and / or the combination B such that a difference between the number of the first optical stacks and the number of the second optical stacks in the combination A and / or the combination B is small. [2] In the management method described in [1] above, a variation in in-plane retardation of the first optical stacks in each of the Na groups may be 0.1 nm to 10 nm, and / or a variation in in-plane retardation of the second optical stacks in each of the Nb groups may be 0.1 nm to 10 nm.[3] In the management method according to the above [1] or [2], the maximum value of the in-plane retardation of the first optical laminate in the 2a group may be greater than the minimum value of the in-plane retardation of the first optical laminate in the 1a group, and / or the maximum value of the in-plane retardation of the second optical laminate in the 2b group may be greater than the minimum value of the in-plane retardation of the second optical laminate in the 1b group. [4] In the management method according to any one of the above [1] to [3], the maximum value of the in-plane retardation of the first optical laminate in the 2a group may be equal to or less than the average value of the in-plane retardation of the first optical laminate in the 1a group, and / or the maximum value of the in-plane retardation of the second optical laminate in the 2b group may be equal to or less than the average value of the in-plane retardation of the second optical laminate in the 1b group. [5] In the management method according to any one of [1] to [4] above, the minimum value of the in-plane retardation of the first optical laminate in the 2a group may be smaller than the maximum value of the in-plane retardation of the first optical laminate in the 3a group, and / or the minimum value of the in-plane retardation of the second optical laminate in the 2b group may be smaller than the maximum value of the in-plane retardation of the second optical laminate in the 3b group. [6] In the management method according to any one of [1] to [5] above, the minimum value of the in-plane retardation of the first optical laminate in the 2a group may be equal to or greater than the average value of the in-plane retardation of the first optical laminate in the 3a group, and / or the minimum value of the in-plane retardation of the second optical laminate in the 2b group may be equal to or greater than the average value of the in-plane retardation of the second optical laminate in the 3b group. [7] In the management method according to any one of [1] to [6] above, the number of the first optical laminates included in the group 2a may be 50% or more of the total number of the first optical laminates included in the group 1a and the group 3a, and / or the number of the second optical laminates included in the group 2b may be 50% or more of the total number of the second optical laminates included in the group 1b and the group 3b. [8] In the management method according to any one of [1] to [7] above, Na may be an integer of 3 to 10, and / or Nb may be an integer of 3 to 10.[9] In the management method according to any one of [1] to [8] above, the variation in in-plane retardation among the plurality of first optical laminates before the classification may be 1.0 nm to 20 nm, and / or the variation in in-plane retardation among the plurality of second optical laminates before the classification may be 1.0 nm to 20 nm.

[10] According to another aspect of the present invention, there is provided a manufacturing method for a display system that displays an image to a user, the display system comprising: a display element having a display surface that emits light representing an image forward via a polarizing element; a reflective polarizing element that is arranged in front of the display element and reflects the light emitted from the display element; a first lens unit that is arranged on an optical path between the display element and the reflective polarizing element; a half mirror that is arranged between the display element and the first lens unit and transmits the light emitted from the display element and reflects the light reflected by the reflective polarizing element toward the reflective polarizing element; a first λ / 4 element that is arranged on the optical path between the display element and the half mirror; and a second λ / 4 element that is arranged on the optical path between the half mirror and the reflective polarizing element; the manufacturing method includes manufacturing the display system using the first optical stack and the second optical stack that are assigned to the same combination by the management method of any one of [1] to [9] above.

[0007] According to the method for managing an optical laminate and the method for manufacturing a display system according to the embodiment of the present invention, display systems such as high-definition VR goggles can be manufactured efficiently.

[0008] 1 is a schematic diagram illustrating an overall configuration of a display system according to one embodiment of the present invention. FIG. 1 is a schematic diagram illustrating an example of variations in in-plane retardation of a first optical laminate in groups 1a, 2a, and 3a. FIGS. 1(a) to 1(c) are schematic diagrams illustrating an example of variations in in-plane retardation of a first optical laminate in groups 1a, 2a, and 3a, respectively. FIG. 1 is a schematic diagram illustrating an example of variations in in-plane retardation of a second optical laminate in groups 1b, 2b, and 3b. FIG. 1 is a schematic diagram illustrating an example of step iii. FIG. 1 is a schematic diagram illustrating an example of step iv. FIG. 1 is a schematic diagram illustrating an example of step iv. FIG. 1 is a schematic cross-sectional view illustrating an example of the configuration of a first optical laminate. FIG. 1 is a schematic cross-sectional view illustrating an example of the configuration of a second optical laminate.

[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. In order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than in the embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0010] (Definition of Terms and Symbols) The definitions of terms and symbols used 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 in-plane direction perpendicular to the slow axis (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-Plane Retardation (Re) "Re(λ)" is the in-plane retardation measured with light having a wavelength of λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured with light having a wavelength of 550 nm at 23°C. Re(λ) is calculated by the formula: Re(λ) = (nx - ny) × d, where d (nm) is the thickness of the layer (film). (3) Thickness Direction Retardation (Rth) "Rth(λ)" is the retardation in the thickness direction measured with light having a wavelength of λ nm at 23°C. For example, "Rth(550)" is the retardation in the thickness direction measured with light having a wavelength of 550 nm at 23°C. Rth(λ) is calculated by 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 by Nz = Rth / Re. (5) Angle When an angle is referred to in this specification, unless otherwise specified, the angle includes both clockwise and counterclockwise angles with respect to the reference direction. Therefore, for example, "45°" means ±45°. Furthermore, in this specification, "substantially parallel" includes a range of 0° ±10°, preferably within a range of 0° ±5°. "Substantially perpendicular" includes a range of 90° ±10°, preferably within a range of 90° ±5°.

[0011] A. Display System FIG. 1 is a schematic diagram showing the overall configuration of a display system according to one embodiment of the present invention. FIG. 1 schematically illustrates the arrangement and shape of each component of a display system 2. The display system 2 includes a display element 12, a reflective polarizing member 14, a first lens unit 16, a half mirror 18, a first phase difference member 20, a second phase difference member 22, and a second lens unit 24. The reflective polarizing member 14 is disposed in front of the display surface 12a of the display element 12 and can reflect light emitted from the display element 12. The first lens unit 16 is disposed on the optical path between the display element 12 and the reflective polarizing member 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first phase difference member 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second phase difference member 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing member 14.

[0012] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12 a for displaying an image. The light emitted from the display surface 12 a passes through, for example, a polarizing member (typically, a polarizing film) that may be included in the display element 12, and is converted into first linearly polarized light.

[0013] The first phase difference member 20 includes a first λ / 4 member that can convert 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 correspond to the first λ / 4 member. The first phase difference member 20 may be provided integrally with the display element 12.

[0014] The half mirror 18 transmits the light emitted from the display element 12 and reflects the light reflected by the reflective polarizing member 14 back toward the reflective polarizing member 14. The half mirror 18 is provided integrally with the first lens portion 16.

[0015] 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. When the second phase difference member does not include any member 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.

[0016] The first circularly polarized light emitted from the first λ / 4 element included in the first phase difference element 20 passes through the half mirror 18 and the first lens portion 16, and is converted into the second linearly polarized light by the second λ / 4 element included in the second phase difference element 22. The second linearly polarized light emitted from the second λ / 4 element is reflected toward the half mirror 18 without passing through the reflective polarizing element 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing element 14 is the same as the reflection axis of the reflective polarizing element 14. Therefore, the second linearly polarized light incident on the reflective polarizing element 14 is reflected by the reflective polarizing element 14.

[0017] The second linearly polarized light reflected by the reflective polarizing element 14 is converted into second circularly polarized light by the second λ / 4 element included in the second phase difference element 22, and the second circularly polarized light output from the second λ / 4 element passes through the first lens unit 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 unit 16 and is converted into third linearly polarized light by the second λ / 4 element included in the second phase difference element 22. The third linearly polarized light is transmitted through the reflective polarizing element 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing element 14 is the same as the transmission axis of the reflective polarizing element 14. Therefore, the third linearly polarized light incident on the reflective polarizing element 14 is transmitted through the reflective polarizing element 14.

[0018] The light transmitted through the reflective polarizing member 14 passes through the second lens portion 24 and enters the user's eye 26 .

[0019] Although not shown, the display system 2 may include an absorptive polarizing member (typically, an absorptive polarizing film) in front of the reflective polarizing member 14. The reflection axis of the reflective polarizing member 14 and the absorption axis of the absorptive polarizing member may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing member and the transmission axis of the absorptive polarizing member may be arranged substantially parallel to each other. This allows the third linearly polarized light that has passed through the reflective polarizing member 14 to pass directly through the absorptive polarizing member.

[0020] For example, the absorption axis of the polarizing member that can be included in the display element 12 and the reflection axis of the reflective polarizing member 14 may be disposed approximately parallel to each other or approximately perpendicular to each other. The angle formed between the absorption axis of the polarizing member that can be included in the display element 12 and the slow axis of the first λ / 4 member included in the first retardation member 20 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°. The angle formed between the absorption axis of the polarizing member that can be included in the display element 12 and the slow axis of the second λ / 4 member included in the second retardation member 22 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°.

[0021] The in-plane retardation Re(550) of the first λ / 4 component is, for example, 100 nm to 190 nm, or may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ / 4 component preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the first λ / 4 component may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0022] The in-plane retardation Re(550) of the second λ / 4 component is, for example, 100 nm to 190 nm, or may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The second λ / 4 component preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the second λ / 4 component may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0023] The reflective polarizing element can transmit light polarized parallel to its transmission axis (typically, linearly polarized light) while maintaining its polarization state, and reflect light polarized in other states. The orthogonal transmittance (Tc) of the reflective polarizing element can be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing element can be, for example, 43% to 49%, preferably 45% to 47%. The polarization degree (P) of the reflective polarizing element can be, for example, 92% to 99.99%. The reflective polarizing element is typically composed of a film having a multilayer structure (sometimes referred to as a reflective polarizing film). Commercially available reflective polarizing films include, for example, "DBEF" and "APF" manufactured by 3M, and "APCF" manufactured by Nitto Denko Corporation.

[0024] The crossed transmittance, single transmittance, and degree of polarization can be measured, for example, using an ultraviolet-visible spectrophotometer. The degree of polarization P can be calculated from the obtained Tp and Tc by measuring the single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc using an ultraviolet-visible spectrophotometer, using the following formula: Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z 8701 and corrected for visibility. Degree of polarization P (%) = {(Tp - Tc) / (Tp + Tc)} １／２ ×100

[0025] 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 this order, then passes through the second λ / 4 member twice more by being reflected by the reflective polarizing member 14 and then reflected again by the half mirror 18, and then passes through the reflective polarizing member 14 and emits forward, whereby it is viewed by a viewer. Therefore, if there is a large difference between the in-plane phase difference of the first λ / 4 member and the in-plane phase difference of the second λ / 4 member, the polarization may be disrupted, causing light leakage, and the light that should be reflected may be perceived as mixed with the light that should be perceived (resulting in a blurred image). To prevent such problems and display high-definition images, it is desirable that the in-plane phase differences of the first λ / 4 member and the second λ / 4 member be at the same level.

[0026] B. Method for Managing Optical Stacks According to another aspect of the present invention, there is provided a method for managing optical stacks that can be used in the display system described in Section A. The method for managing optical stacks according to an embodiment of the present invention is a method for managing a first optical stack including the first λ / 4 member and a second optical stack including the second λ / 4 member, the method comprising: (i) classifying a plurality of the first optical stacks into Na groups having different average values ​​of in-plane retardation (wherein the Na groups include a 1a group, a 2a group, and a 3a group that are consecutive in this order when sorted in order of the magnitude of the average value, and the maximum value of the in-plane retardation of the first optical stack in the 2a group is smaller than the maximum value of the in-plane retardation of the first optical stack in the 1a group, and the minimum value of the in-plane retardation of the first optical stack in the 2a group is greater than the minimum value of the in-plane retardation of the first optical stack in the 3a group); (ii) classifying a plurality of the second optical laminates into Nb groups having different average values ​​of in-plane retardation (here, the Nb groups include a 1b group, a 2b group, and a 3b group which are consecutive in this order when sorted in descending order of the average value, and the maximum value of the in-plane retardation of the second optical laminate in the 2b group is smaller than the maximum value of the in-plane retardation of the second optical laminate in the 1b group, and the minimum value of the in-plane retardation of the second optical laminate in the 2b group is larger than the minimum value of the in-plane retardation of the second optical laminate in the 3b group); (iii) matching a combination A of the 1a group and the 1b group and a combination B of the 3a group and the 3b group based on the average value of the in-plane retardation; and (iv) allocating the first optical laminate included in the group 2a and the second optical laminate included in the group 2b to the combination A and / or the combination B so that the difference between the number of the first optical laminate and the number of the second optical laminate in the combination A and / or the combination B is small. According to the method for managing optical laminates, it is possible to create a combination of a first optical laminate and a second optical laminate in which the in-plane retardation of the first λ / 4 member and the second λ / 4 member are at the same level.Furthermore, by creating two or more such combinations and preparing an optical laminate having an in-plane retardation at an intermediate level between these combinations, it is possible to suppress the generation of surplus materials in each combination. In this method for managing optical laminates, a display system is manufactured using the first optical laminate and the second optical laminate that belong to the same combination, thereby improving manufacturing efficiency and productivity.

[0027] In the above-described method for managing an optical stack, the in-plane retardation of the first optical stack and the in-plane retardation of the second optical stack may correspond to the in-plane retardation of the first λ / 4 member and the second λ / 4 member, respectively. The optical stack to be managed may be an optical stack piece having a shape (such as a substantially rectangular or circular shape) that is applicable to a display system, or may be a large-sized optical stack (mother sheet or roll) before being punched or cut into such optical stack pieces. In one embodiment, the optical stack to be managed is a large-sized optical stack before being punched or cut into optical stack pieces.

[0028] In the above-mentioned method for managing an optical laminate, the wavelength for measuring the in-plane retardation is not particularly limited. For example, Re(590) can be used as the in-plane retardation. The in-plane retardation of the optical laminate may be the in-plane retardation at any one position in the plane of the optical laminate, but it is preferable to use the average value of the in-plane retardations at multiple positions in the plane.

[0029] In the method for managing optical laminates, a plurality of first optical laminates are classified into Na groups each having a different average value of in-plane retardation, and a plurality of second optical laminates are classified into Nb groups each having a different average value of in-plane retardation. The number of optical laminates included in each of the Na groups and the Nb groups can be 100 to 10,000, for example, 100 to 1,000, or for example, 1,000 to 10,000.

[0030] When Na groups are arranged in descending order of the average value of the in-plane retardation of the first optical laminate in each group, the difference in average value between the preceding and succeeding groups is, for example, 0.5 nm to 2.0 nm, preferably 1.0 nm to 1.5 nm. It is preferable that the difference in average value is substantially constant. In one embodiment, the first optical laminate is classified so that the average value of the in-plane retardation in each group is approximately equally spaced. When Nb groups are arranged in descending order of the average value of the in-plane retardation of the second optical laminate in each group, the difference in average value between the preceding and succeeding groups is, for example, 0.5 nm to 2.0 nm, preferably 1.0 nm to 1.5 nm. It is preferable that the difference in average value is substantially constant. In one embodiment, the second optical laminate is classified so that the average value of the in-plane retardation in each group is approximately equally spaced.

[0031] The variation in in-plane retardation (the difference between the maximum and minimum values ​​of in-plane retardation) across the entire plurality of first optical laminates before classification may be, for example, 1.0 nm or more, 3.0 nm or more, or 5.0 nm or more, and may be, for example, 20 nm or less, or 18 nm or less. The variation in in-plane retardation (the difference between the maximum and minimum values ​​of in-plane retardation) across the entire plurality of second optical laminates before classification may be, for example, 1.0 nm or more, 3.0 nm or more, or 5.0 nm or more, and may be, for example, 20 nm or less, or 18 nm or less.

[0032] The number of groups (Na, Nb) and the variation in in-plane retardation of the first optical laminate or the second optical laminate in each group (the difference between the maximum and minimum in-plane retardation) can be appropriately set according to the variation in in-plane retardation of the entire first optical laminate or the entire second optical laminate before classification. For example, the variation in in-plane retardation of the first optical laminate or the second optical laminate in each group can be, for example, 0.1 nm to 10 nm. Furthermore, Na and Nb can each be an integer of, for example, 3 to 10, preferably 3 to 7, more preferably 3 to 5. Na and Nb may be the same or different. Preferably, Na and Nb are the same number.

[0033] Hereinafter, each step will be specifically described using an embodiment in which Na and Nb are 3 as an example.

[0034] B-1. Step i Figure 2 is a schematic diagram illustrating an example of the variation in the in-plane retardation of the first optical laminate in the 1a group, the 2a group, and the 3a group. The arrows for each group indicate the variation in the in-plane retardation of the first optical laminate in that group, with the upper end indicating the maximum value of the in-plane retardation of the first optical laminate in that group and the lower end indicating the minimum value of the in-plane retardation of the first optical laminate in that group. The same applies to Figures 3 to 8 below.

[0035] In the illustrated embodiment, the first optical laminates are classified into groups 1a, 2a, and 3a, which have different average values ​​of in-plane retardation. The average value of the in-plane retardation of the first optical laminates in each group is the largest in group 1a, the second largest in group 2a, and the smallest in group 3a.

[0036] 2, the maximum value of the in-plane retardation of the first optical laminate in the 2a group is smaller than the maximum value of the in-plane retardation of the first optical laminate in the 1a group, and the minimum value of the in-plane retardation of the first optical laminate in the 2a group is larger than the minimum value of the in-plane retardation of the first optical laminate in the 3a group. That is, in terms of the variation in in-plane retardation, the 2a group is positioned between the 1a group and the 3a group.

[0037] The variation in the in-plane retardation of the first optical laminate in each group (the difference between the upper and lower ends of the arrow in each group) is, for example, 0.1 nm to 10 nm, and may be 1 nm to 7 nm or 3 nm to 5 nm.

[0038] The maximum value of the in-plane retardation of the first optical laminate in the 2a group is preferably equal to or greater than the minimum value of the in-plane retardation of the first optical laminate in the 1a group, and more preferably greater than the minimum value of the in-plane retardation of the first optical laminate in the 1a group. In one embodiment, the maximum value of the in-plane retardation of the first optical laminate in the 2a group is greater than the minimum value of the in-plane retardation of the first optical laminate in the 1a group and is equal to or less than the average value. When the 1a group and the 2a group have such overlapping in-plane retardation variations, the effects of the present invention can be more suitably obtained.

[0039] The minimum value of the in-plane retardation of the first optical laminate in the 2a group is preferably equal to or less than the maximum value of the in-plane retardation of the first optical laminate in the 3a group, and more preferably equal to or less than the maximum value of the in-plane retardation of the first optical laminate in the 3a group. In one embodiment, the minimum value of the in-plane retardation of the first optical laminate in the 2a group is smaller than the maximum value of the in-plane retardation of the first optical laminate in the 3a group and equal to or greater than the average value. When the 2a group and the 3a group have such overlapping in-plane retardation variations, the effects of the present invention can be more suitably obtained.

[0040] In one embodiment, the number of first optical laminates included in group 2a is 50% or more, preferably 50% to 80%, and more preferably 60% to 80% of the total number of first optical laminates included in groups 1a and 3a. By setting the number of first optical laminates included in group 2a at the above ratio, the effects of the present invention can be more suitably obtained.

[0041] The classification method for the 1a group, the 2a group, and the 3a group is not limited to the illustrated example. For example, Figures 3(a) to 3(c) are schematic diagrams illustrating another example of the variation in the in-plane retardation of the first optical laminate in the 1a group, the 2a group, and the 3a group, respectively. As shown in Figure 3(a) or (b), the variation in the in-plane retardation of the first optical laminate in the 2a group may overlap with only one of the variations in the 1a group and the 3a group. Also, as shown in Figure 3(c), the 1a group, the 2a group, and the 3a group can be classified so that the variation in the in-plane retardation of the first optical laminate in each group does not overlap.

[0042] B-2. Step ii Figure 4 is a schematic diagram illustrating an example of the variation in the in-plane retardation of the second optical laminate in the 1b group, the 2b group, and the 3b group. In the illustrated example, a plurality of second optical laminates are classified into the 1b group, the 2b group, and the 3b group, which have different average values ​​of the in-plane retardation. The average value of the in-plane retardation of the second optical laminate in each group is the largest in the 1b group, the second largest in the 2b group, and the smallest in the 3b group.

[0043] As a classification method, a method similar to the classification method for the first optical laminate can be adopted. Specifically, as shown in Figure 4, the maximum value of the in-plane retardation of the second optical laminate in the 2b group is smaller than the maximum value of the in-plane retardation of the second optical laminate in the 1b group, and the minimum value of the in-plane retardation of the second optical laminate in the 2b group is larger than the minimum value of the in-plane retardation of the second optical laminate in the 3b group. That is, with respect to the variation in in-plane retardation, the 2b group is positioned intermediate between the 1b group and the 3b group.

[0044] The variation in the in-plane retardation of the second optical laminate in each group is, for example, 0.1 nm to 10 nm, and may be 1 nm to 7 nm or 3 nm to 5 nm.

[0045] The maximum value of the in-plane retardation of the second optical laminate in the 2b group is preferably equal to or greater than the minimum value of the in-plane retardation of the second optical laminate in the 1b group, and more preferably greater than the minimum value of the in-plane retardation of the second optical laminate in the 1b group. In one embodiment, the maximum value of the in-plane retardation of the second optical laminate in the 2b group is greater than the minimum value of the in-plane retardation of the second optical laminate in the 1b group and is equal to or less than the average value. When the 1b group and the 2b group have such overlapping in-plane retardation variations, the effects of the present invention can be more suitably obtained.

[0046] The minimum value of the in-plane retardation of the second optical laminate in the 2b group is preferably equal to or less than the maximum value of the in-plane retardation of the second optical laminate in the 3b group, and more preferably equal to or less than the maximum value of the in-plane retardation of the second optical laminate in the 3b group. In one embodiment, the minimum value of the in-plane retardation of the second optical laminate in the 2b group is smaller than the maximum value of the in-plane retardation of the second optical laminate in the 3b group and equal to or greater than the average value. When the 2b group and the 3b group have such overlapping in-plane retardation variations, the effects of the present invention can be more suitably obtained.

[0047] In one embodiment, the number of second optical laminates included in group 2b is 50% or more, preferably 50% to 80%, and more preferably 60% to 80% of the total number of second optical laminates included in groups 1b and 3b. By setting the number of second optical laminates included in group 2b at the above ratio, the effects of the present invention can be more suitably obtained.

[0048] The classification method of the 1b group, the 2b group, and the 3b group is not limited to the illustrated example.For example, as in the example shown in FIG. 3(a) or (b), the variation of the in-plane retardation of the second optical laminate in the 2b group may overlap with only one of the variations of the 1b group and the 3b group.In addition, as in the example shown in FIG. 3(c), the 1b group, the 2b group, and the 3b group can also be classified so that the variation of the in-plane retardation of the second optical laminate in each group does not overlap.

[0049] B-3. ​​Step iii Next, based on the average value of the in-plane retardation in each group, as shown in FIG. 5, from each group classified in steps i and ii, a combination A of group 1a and group 1b, and a combination B of group 3a and group 3b are matched. Group 1a includes an optical laminate having a relatively large in-plane retardation among the entire first optical laminate before classification, and group 1b includes an optical laminate having a relatively large in-plane retardation among the entire second optical laminate before classification. Furthermore, group 3a includes an optical laminate having a relatively small in-plane retardation among the entire first optical laminate before classification, and group 3b includes an optical laminate having a relatively small in-plane retardation among the entire second optical laminate before classification. Therefore, by matching in this way, it is possible to suitably combine a first optical laminate and a second optical laminate having the same level of in-plane retardation of the first λ / 4 member and the second λ / 4 member. Furthermore, as will be described in detail in step iv, by matching in this manner, Group 2a and Group 2b can be used in combination A and combination B in common.

[0050] In the matched 1a group and 1b group, the difference in the average value of the in-plane retardation of the optical laminate in both groups may be, for example, 1.0 nm or less, or, for example, 0.5 nm or less. Similarly, in the matched 3a group and 3b group, the difference in the average value of the in-plane retardation of the optical laminate in both groups may be, for example, 1.0 nm or less, or, for example, 0.5 nm or less.

[0051] B-4. Step iv: Next, the first optical stack included in group 2a and the second optical stack included in group 2b are assigned to combination A and / or combination B so that the difference between the number of first optical stacks and the number of second optical stacks in combination A and / or combination B is small. When manufacturing a display system using the first optical stack and the second optical stack included in the two groups combined as described above, if the numbers of optical stacks included in these groups are different, the optical stack with the larger number will have no paired optical stack and will be surplus. Therefore, by replenishing the first optical stack and / or the second optical stack from group 2a and / or group 2b so that the surplus of any optical stack in each combination is reduced, it is possible to suitably prevent the occurrence of surplus optical stacks when manufacturing a display system. Furthermore, in the display system obtained thereby, it is possible to prevent a large deviation in the in-plane retardation of the first λ / 4 component and the second λ / 4 component, resulting in a high-definition display system.

[0052] An example of step iv is shown in Figure 6. In the example shown in Figure 6, a total of 200 first optical laminates are classified into group 1a (65), group 2a (65), and group 3a (70), and a total of 200 second optical laminates are classified into group 1b (75), group 2b (65), and group 3b (60). In this case, in combination A, group 1a has 10 fewer optical laminates than group 1b, and in combination B, group 3a has 10 more optical laminates than group 3b. Therefore, by allocating 35 and 30 optical laminates from group 2a to combination A and combination B, respectively, and allocating 25 and 40 optical laminates from group 2b to combination A and combination B, respectively, it is possible to obtain exactly 100 pairs of first optical laminates and second optical laminates in each of combinations A and B. Needless to say, the number of optical laminates allocated from Group 2a and Group 2b to Combination A and Combination B is not limited as long as the number of surplus optical laminates in each combination is small.

[0053] B-5. Modifications The above has described an embodiment in which Na and Nb are 3, but as mentioned above, the present invention is not limited to the above embodiment, and in three or more groups having different average values ​​of in-plane retardation, any three consecutive groups in order of magnitude of the average value can be the 1a group and 1b group, the 2a group and 2b group, and the 3a group and 3b group. Steps i to iv can be performed. For example, when Na and Nb are odd numbers, the 2n-1 group, the 2n group, and the 2n+1 group in order of magnitude of the average value of the in-plane retardation can be managed in the same manner as above as the first group (1a group, 1b group), the second group (2a group, 2b group), and the third group (3a group, 3b group), respectively (n is an integer of 1 or more, for example, 1 to 4). Furthermore, for example, when Na and Nb are even numbers, the 2n-1 group, the 2n group, and the 2n+1 group consecutive in order of the magnitude of the average value of the in-plane retardation can be managed in the same manner as above as the first group (group 1a, group 1b), the second group (group 2a, group 2b), and the third group (group 3a, group 3b), respectively, and for the last groups (groups 6a and 6b when Na = Nb = 6), the last groups can be combined with each other, or incorporated into the previous group, etc.

[0054] FIG. 7 is a schematic diagram illustrating an example of step iv when Na and Nb are 4. As shown in FIG. 7, when Na and Nb are 4, in addition to groups 1a to 3a and groups 1b to 3b, groups 4a to 4b, which have a smaller average in-plane retardation value than group 3a, and groups 4b to 4b, which have a smaller average in-plane retardation value than group 3b, can be set. The maximum in-plane retardation values ​​of the optical laminates in groups 4a and 4b are each smaller than the maximum in-plane retardation values ​​of the optical laminates in groups 3a and 3b. In this case, the optical laminates included in groups 2a and 2b are assigned to combination A and / or combination B so that the number of surplus optical laminates in combination A and combination B is reduced, and the optical laminates included in groups 4a and 4b can be incorporated into combination B. Also, unlike the illustrated example, a combination C of groups 4a and 4b may be set.

[0055] 8 is a schematic diagram illustrating an example of step iv when Na and Nb are 5. As shown in FIG. 8, when Na and Nb are 5, in addition to groups 1a to 4a and groups 1b to 4b, groups 5a and 5b may be set, each having a smaller average in-plane retardation than groups 4a and 4b. The maximum in-plane retardation of the optical stacks in groups 5a and 5b is smaller than the maximum in-plane retardation of the optical stacks in groups 4a and 4b. In this case, in addition to combination A and combination B, combination C of groups 5a and 5b is matched, and the optical stacks in groups 2a and 2b are assigned to combination A and / or combination B, and the optical stacks in groups 4a and 4b are assigned to combination B and / or combination C, so that the number of surplus optical stacks in each combination is reduced.

[0056] B-6. First Optical Laminate FIG. 9 is a schematic cross-sectional view showing an example of the configuration of a first optical laminate. The first optical laminate 100 includes a polarizing member 10 and a first phase difference member 20, in this order. The polarizing member 10 and the first phase difference member 20 are laminated via an adhesive layer (e.g., a pressure-sensitive adhesive layer). The first optical laminate 100 further includes a first protective member 31 disposed on the side of the first phase difference member 20 opposite to the side on which the polarizing member 10 is disposed. The first protective member 31 is laminated to the first phase difference member 20 via an adhesive layer (e.g., a pressure-sensitive adhesive layer). The first optical laminate 100 also includes a first pressure-sensitive adhesive layer 41 disposed on the side of the polarizing member 10 opposite to the side on which the first phase difference member 20 is disposed. A release liner 51 is temporarily attached to the surface of the first pressure-sensitive adhesive layer 41. The polarizing member 10 is a polarizing member that can be included in a display element 12. After the first release liner 51 is peeled off, the first optical laminate can be integrated with the display element 12 by the first pressure-sensitive adhesive layer 41 .

[0057] In the example shown in FIG. 9 , the first phase difference member 20 includes, in addition to a first λ / 4 member 20a, a member (hereinafter also referred to as a "first positive C plate") 20b whose refractive index characteristics satisfy the relationship nz > nx = ny. The first phase difference member 20 has a laminated structure of the first λ / 4 member 20a and the first positive C plate 20b. The use of the first positive C plate 20b can prevent light leakage (e.g., light leakage in oblique directions). As shown in the example, in the first phase difference member 20, the first λ / 4 member 20a is preferably located closer to the polarizing member 10 than the first positive C plate 20b. The first λ / 4 member 20a and the first positive C plate 20b are typically laminated via an adhesive layer (e.g., an adhesive layer).

[0058] B-6-1. Polarizing Member The polarizing member 10 is typically an absorptive polarizing member. The absorptive polarizing member may typically include a resin film (sometimes referred to as an absorptive polarizing film) containing a dichroic material. The thickness of the absorptive polarizing film is, for example, 1 μm or more and 20 μm or less, and may 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.

[0059] The absorptive polarizing film may be made from a single layer of resin film or may be made from a laminate of two or more layers.

[0060] When the absorptive polarizing film is produced from a single-layer resin film, for example, an absorptive polarizing film can be obtained by subjecting a hydrophilic polymer film such as a polyvinyl alcohol (PVA)-based film, a partially formalized PVA-based film, or a partially saponified ethylene-vinyl acetate copolymer-based film to a dyeing treatment with iodine or a dichroic substance such as a dichroic dye, a stretching treatment, etc. Among these, an absorptive polarizing film obtained by dyeing a PVA-based film with iodine and uniaxially stretching it is preferred.

[0061] The dyeing with iodine is carried out, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment or while dyeing. Alternatively, the PVA-based film may be dyed after stretching. If necessary, the PVA-based film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like.

[0062] Examples of laminates produced using the two or more layer laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, and a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate. An absorptive polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying the solution to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer, and then stretching and dyeing the laminate to convert the PVA-based resin layer into an absorptive polarizing film. In this embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. The stretching typically involves immersing the laminate in an aqueous boric acid solution to stretch it. Furthermore, the stretching may further include in-air stretching of the laminate at a high temperature (e.g., 95°C or higher) before stretching in the boric acid aqueous solution, as necessary. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being transported in the longitudinal direction, thereby shrinking the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an auxiliary in-air stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment, in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of the PVA, even when the PVA is coated on a thermoplastic resin, thereby achieving high optical properties. Furthermore, by simultaneously increasing the orientation of the PVA in advance, problems such as a decrease in orientation or dissolution of the PVA when immersed in water in the subsequent dyeing or stretching steps can be prevented, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disordering of the polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. This can improve the optical properties of the absorptive polarizing film obtained through treatment steps in which the laminate is immersed in a liquid, such as a dyeing treatment and an underwater stretching treatment.Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through a drying shrinkage treatment.The obtained resin substrate / absorptive polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorptive polarizing film), or any suitable protective layer may be laminated depending on the purpose on the surface obtained by peeling the resin substrate from the resin substrate / absorptive polarizing film laminate or on the surface opposite to the peeled surface. Details of such methods for producing an absorptive polarizing film are described in, for example, JP-A-2012-73580 and Japanese Patent No. 6,470,455. The entire disclosures of these publications are incorporated herein by reference.

[0063] The crossed transmittance (Tc) of the absorptive polarizing element (absorptive 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 absorptive polarizing element (absorptive polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The polarization degree (P) of the absorptive polarizing element (absorptive polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0064] B-6-2. First λ / 4 Member The first λ / 4 member 20a preferably exhibits the refractive index characteristic relationship nx>ny≧nz. Here, "ny=nz" does not only refer to the case where ny and nz are completely equal, but also encompasses the case where they are substantially equal. Therefore, ny<nz may be satisfied within a range that does not impair the effects of the present invention. The Nz coefficient of the first 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. The Re(550), wavelength dispersion characteristics, and axial relationship with the polarizing member 10 of the first λ / 4 member are as described in Section A.

[0065] The first λ / 4 member may be made of any suitable material that satisfies the above-mentioned characteristics, and may be, for example, a stretched resin film or an oriented and solidified layer of a liquid crystal compound.

[0066] Examples of resins contained in the resin film include polycarbonate-based resins, polyester carbonate-based resins, polyester-based resins, polyvinyl acetal-based resins, polyarylate-based resins, cyclic olefin-based resins, cellulose-based resins, polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polystyrene-based resins, and acrylic-based resins. These resins may be used alone or in combination. Examples of methods for combining include blending and copolymerization. When the first λ / 4 member exhibits reverse dispersion wavelength characteristics, a resin film containing a polycarbonate-based resin or a polyester carbonate-based resin (hereinafter sometimes simply referred to as a polycarbonate-based resin) can be suitably used.

[0067] Any suitable polycarbonate resin can be used as the polycarbonate resin. For example, the polycarbonate resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene glycols or spiroglycols. Preferably, the polycarbonate resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, structural units derived from an alicyclic dimethanol and / or structural units derived from di-, tri-, or polyethylene glycol; more preferably, it contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from di-, tri-, or polyethylene glycol. The polycarbonate resin may contain structural units derived from other dihydroxy compounds as needed. Details of polycarbonate-based resins that can be suitably used for the first λ / 4 member and methods for forming the first λ / 4 member are described, for example, in JP 2014-10291 A, JP 2014-26266 A, JP 2015-212816 A, JP 2015-212817 A, and JP 2015-212818 A, and the descriptions in these publications are incorporated herein by reference.

[0068] The thickness of the first λ / 4 member made of 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.

[0069] The above-mentioned liquid crystal compound alignment solidified layer is a layer in which the liquid crystal compound is aligned in a predetermined direction within the layer and the alignment state is fixed. The term "alignment solidified layer" encompasses an alignment solidified layer obtained by curing a liquid crystal monomer, as described below. In the first λ / 4 member, typically, rod-shaped liquid crystal compounds are aligned in the slow axis direction of the first λ / 4 member (homogeneous alignment). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably polymerizable. If the liquid crystal compound is polymerizable, the alignment state of the liquid crystal compound can be fixed by aligning the liquid crystal compound and then polymerizing it.

[0070] The alignment and solidification layer of the liquid crystal compound (liquid crystal alignment and solidification layer) can be formed by performing an alignment treatment on the surface of a predetermined substrate, applying a coating liquid containing a liquid crystal compound to the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment, and fixing the alignment state. Any appropriate alignment treatment can be used as the alignment treatment. Specific examples include mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photoalignment treatment. Any appropriate treatment conditions can be used for the various alignment treatments depending on the purpose.

[0071] The alignment of liquid crystal compounds is achieved by treating them at a temperature at which they exhibit a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compounds assume a liquid crystal state and are aligned in accordance with the alignment treatment direction on the substrate surface.

[0072] In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is polymerizable or crosslinkable, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment.

[0073] Any suitable liquid crystal polymer and / or liquid crystal monomer can be used as the liquid crystal compound. The liquid crystal polymer and the liquid crystal monomer can be used alone or in combination. Specific examples of liquid crystal compounds and methods for producing a liquid crystal alignment solidified layer are described in, for example, JP 2006-163343 A, JP 2006-178389 A, and WO 2018 / 123551 A. The descriptions in these publications are incorporated herein by reference.

[0074] The thickness of the first λ / 4 member formed 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.

[0075] B-6-3. First Positive C Plate The thickness direction retardation Rth(550) of the first positive C plate 20b is preferably −50 nm to −300 nm, more preferably −70 nm to −250 nm, even more preferably −90 nm to −200 nm, and particularly preferably −100 nm to −180 nm. Here, "nx = ny" encompasses 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.

[0076] The first positive C plate can be formed from any suitable material, but is preferably composed of a film containing a liquid crystal material fixed in homeotropic alignment. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned 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 include the liquid crystal compounds and methods for forming the retardation layer described in paragraphs

[0020] to

[0028] of JP 2002-333642 A. In this case, the thickness of the first positive C plate is preferably 0.5 μm to 5 μm.

[0077] B-6-4. First Protective Member The first protective member 31 typically includes a substrate. The thickness of the substrate is preferably 5 μm to 80 μm, more preferably 10 μm to 50 μm, and even more preferably 15 μm to 40 μm. The substrate can be composed of any appropriate film. Examples of materials that form the main component of the film constituting the substrate include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, cycloolefin-based resins such as polynorbornene, polyolefin-based, (meth)acrylic, and acetate-based resins. Here, (meth)acrylic refers to acrylic and / or methacrylic.

[0078] The first protective member preferably has a substrate and a surface treatment layer formed on the substrate. The first protective member having the surface treatment layer can be arranged so that the surface treatment layer is located on the front side. Specifically, the surface treatment layer can be located on the outermost surface of the optical laminate. The surface treatment layer can have any appropriate function. For example, from the viewpoint of improving visibility, the surface treatment layer preferably has an anti-reflection function. The thickness of the surface treatment layer is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm.

[0079] B-6-5. First Pressure-Sensitive Adhesive Layer The first pressure-sensitive adhesive layer 41 can be composed of any appropriate pressure-sensitive adhesive. Specific examples include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyester pressure-sensitive adhesives, urethane pressure-sensitive adhesives, epoxy pressure-sensitive adhesives, and polyether pressure-sensitive adhesives. By adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the pressure-sensitive adhesive, as well as the amount of cross-linking agent, reaction temperature, reaction time, etc., a pressure-sensitive adhesive having desired properties according to the intended purpose can be prepared. The base resin of the pressure-sensitive adhesive may be used alone or in combination of two or more types. An acrylic resin is preferably used as the base resin. Specifically, the first pressure-sensitive adhesive layer is preferably composed of an acrylic pressure-sensitive adhesive.

[0080] The thickness of the first pressure-sensitive adhesive layer is, for example, 1 μm or more, preferably 3 μm or more, and for example, 50 μm or less, preferably 30 μm or less.

[0081] B-6-6. First Release Liner For example, a flexible plastic film can be used as the first release liner 51. Examples of such plastic films include polyethylene terephthalate film, polyethylene film, polypropylene film, and polyester film. The surface of the release liner is preferably coated with a release agent. Specific examples of release agents include silicone-based release agents, fluorine-based release agents, and long-chain alkyl acrylate-based release agents. The thickness of the release liner (including the thickness of the release agent layer) is, for example, 3 μm or more and, for example, 200 μm or less.

[0082] B-7. Second Optical Laminate FIG. 10 is a schematic cross-sectional view showing an example of the configuration of a second optical laminate. The second optical laminate 200 includes a second phase difference member 22 and a second protective member 32. The second protective member 32 is laminated to the second phase difference member 22 via an adhesive layer (e.g., a pressure-sensitive adhesive layer). The second optical laminate 200 further includes a second pressure-sensitive adhesive layer 42 disposed on the side of the second phase difference member 22 opposite to the side on which the second protective member 32 is disposed. A second release liner 52 is temporarily attached to the surface of the second pressure-sensitive adhesive layer 42. After the second release liner 52 is peeled off, the second optical laminate 200 can be integrated with the first lens unit 16 by the second pressure-sensitive adhesive layer 42.

[0083] In the example shown in FIG. 10 , the second phase difference member 22 includes, in addition to a second λ / 4 member 22a, a member (hereinafter also referred to as a "second positive C plate") 22b whose refractive index characteristics satisfy the relationship nz > nx = ny. The second phase difference member 22 has a laminated structure of the second λ / 4 member 22a and the second positive C plate 22b. The use of the second positive C plate 22b can prevent light leakage (e.g., light leakage in oblique directions). As shown in the example, in the second phase difference member 22, the second λ / 4 member 22a is preferably located closer to the second protective member 32 than the second positive C plate 22b. The second λ / 4 member 22a and the second positive C plate 22b are typically laminated via an adhesive layer (e.g., an adhesive layer).

[0084] The same descriptions can be applied to the second λ / 4 member 22a, the second positive C plate 22b, the second protective member 32, the second adhesive layer 42, and the second release liner 52 as to the first λ / 4 member 20a, the first positive C plate 20b, the first protective member 31, the first adhesive layer 41, and the first release liner 51, respectively.

[0085] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations shown in the above-described embodiment can be replaced with configurations that are substantially the same as those shown in the above-described embodiment, that have the same effects, or that can achieve the same purpose.

[0086] The method for managing an optical laminate according to an embodiment of the present invention can be suitably used in the manufacture of display systems such as VR goggles, for example.

[0087] 2 Display system, 12 Display element, 14 Reflective polarizing member, 16 First lens portion, 18 Half mirror, 20 First phase difference member, 22 Second phase difference member, 24 Second lens portion

Claims

1. A method for managing a first optical laminate including a first λ / 4 member and a second optical laminate including a second λ / 4 member, comprising: (i) classifying a plurality of the first optical laminates into Na groups having mutually different average values ​​of in-plane retardation (wherein the Na groups include Group 1a, Group 2a, and Group 3a which are consecutive in this order when sorted in order of magnitude of the average value, and the maximum value of the in-plane retardation of the first optical laminate in Group 2a is smaller than the maximum value of the in-plane retardation of the first optical laminate in Group 1a, and the minimum value of the in-plane retardation of the first optical laminate in Group 2a is larger than the minimum value of the in-plane retardation of the first optical laminate in Group 3a); (ii) classifying a plurality of the second optical laminates into Nb groups having different average values ​​of in-plane retardation (here, the Nb groups include a 1b group, a 2b group, and a 3b group which are consecutive in this order when arranged in order of the magnitude of the average value, the maximum value of the in-plane retardation of the second optical laminate in the 2b group is smaller than the maximum value of the in-plane retardation of the second optical laminate in the 1b group, and the minimum value of the in-plane retardation of the second optical laminate in the 2b group is larger than the minimum value of the in-plane retardation of the second optical laminate in the 3b group); (iii) matching a combination A of the 1a group and the 1b group, and a combination B of the 3a group and the 3b group based on the average value of the in-plane retardation; and (iv) allocating a first optical laminate included in the group 2a and a second optical laminate included in the group 2b to the combination A and / or the combination B so that a difference between the number of the first optical laminates and the number of the second optical laminates in the combination A and / or the combination B is small; 2. The management method according to claim 1, wherein the variation in in-plane retardation of the first optical stack in each of the Na groups is 0.1 nm to 10 nm, and / or the variation in in-plane retardation of the second optical stack in each of the Nb groups is 0.1 nm to 10 nm.

3. The management method described in claim 1, wherein the maximum value of the in-plane retardation of the first optical laminate in the 2a group is greater than the minimum value of the in-plane retardation of the first optical laminate in the 1a group, and / or the maximum value of the in-plane retardation of the second optical laminate in the 2b group is greater than the minimum value of the in-plane retardation of the second optical laminate in the 1b group.

4. The management method described in claim 1, wherein the maximum value of the in-plane retardation of the first optical laminate in the 2a group is equal to or less than the average value of the in-plane retardation of the first optical laminate in the 1a group, and / or the maximum value of the in-plane retardation of the second optical laminate in the 2b group is equal to or less than the average value of the in-plane retardation of the second optical laminate in the 1b group.

5. The management method described in claim 1, wherein the minimum value of the in-plane retardation of the first optical laminate in the 2a group is smaller than the maximum value of the in-plane retardation of the first optical laminate in the 3a group, and / or the minimum value of the in-plane retardation of the second optical laminate in the 2b group is smaller than the maximum value of the in-plane retardation of the second optical laminate in the 3b group.

6. The management method described in claim 1, wherein the minimum value of the in-plane retardation of the first optical laminate in the 2a group is equal to or greater than the average value of the in-plane retardation of the first optical laminate in the 3a group, and / or the minimum value of the in-plane retardation of the second optical laminate in the 2b group is equal to or greater than the average value of the in-plane retardation of the second optical laminate in the 3b group.

7. The management method described in claim 1, wherein the number of the first optical laminates included in the group 2a is 50% or more of the total number of the first optical laminates included in the groups 1a and 3a, and / or the number of the second optical laminates included in the group 2b is 50% or more of the total number of the second optical laminates included in the groups 1b and 3b.

8. The management method according to claim 1, wherein Na is an integer from 3 to 10, and / or Nb is an integer from 3 to 10.

9. The management method according to claim 1, wherein the variation in in-plane retardation in the plurality of first optical laminates before the classification is 1.0 nm to 20 nm, and / or the variation in in-plane retardation in the plurality of second optical laminates before the classification is 1.0 nm to 20 nm.

10. A manufacturing method for a display system that displays an image to a user, comprising: a display element having a display surface that emits light representing an image forward via a polarizing element; a reflective polarizing element arranged in front of the display element and reflecting the light emitted from the display element; a first lens unit arranged on an optical path between the display element and the reflective polarizing element; a half mirror arranged between the display element and the first lens unit, which transmits the light emitted from the display element and reflects the light reflected by the reflective polarizing element toward the reflective polarizing element; a first λ / 4 element arranged on the optical path between the display element and the half mirror; and a second λ / 4 element arranged on the optical path between the half mirror and the reflective polarizing element; the manufacturing method comprising: manufacturing the display system using the first optical stack and the second optical stack that are assigned to the same combination by a management method of any one of claims 1 to 9.

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