Film, optical member, optical device, head mounted display

Abstract

The present invention addresses the problem of providing a film capable of suppressing the occurrence of multiple images when applied to AR glasses. A film according to the present invention includes at least one light-absorbing anisotropic layer, the angle formed by the transmittance center axis of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer being 0-45 DEG, and the maximum height difference of corrugations in a 10 mm * 10 mm region of the film surface being 1.2 [mu] m or less.

Description

Films, optical components, optical devices, head-mounted displays Technical Field

[0001] The present invention relates to a membrane and an optical component comprising the above-described membrane.

[0002] Furthermore, the present invention relates to an optical device comprising the aforementioned optical components and a head-mounted display comprising the aforementioned optical device. Background Technology

[0003] In recent years, head-mounted displays such as AR (Augmented Reality) glasses, which overlay images onto a background, have been put into practical use.

[0004] AR glasses, for example, have an image display element, a light guide plate, and a diffraction element, and have the following structure: the image light emitted by the image display element is diffracted by the diffraction element and incident on the light guide plate, the light guide plate guides the light, and the image light guided by the light is diffracted by the diffraction element to display an image to the visual recognizer.

[0005] In many cases, the light guide plate is transparent, and AR glasses can project images onto the background.

[0006] In this type of AR glasses, external light incident from a specific tilt direction is diffracted by a diffraction element and directed towards the visual observer. This can lead to the visual observer perceiving rainbow irregularities when the external light is reflected in a rainbow pattern. Furthermore, the specific tilt direction refers to a direction perpendicular (or approximately perpendicular) to the slit direction of the diffraction element.

[0007] Depending on the spacing of the diffraction elements, the visually perceptible angle of incidence (the angle of incidence tilted relative to the principal surface of the diffraction element) varies, but the case where external light incident between 40° and 80° relative to the normal of the diffraction element is visually perceptible as a rainbow pattern is particularly problematic.

[0008] For example, in the use of AR glasses, the diffraction element with the slit direction close to the horizontal direction reflects external light incident from the top of the head and is visually perceived as a rainbow pattern.

[0009] As a method for suppressing rainbow patterns, one example is a method of configuring a film to suppress the incidence of external light at the aforementioned angle relative to the normal of the diffraction element. For example, a film with this function, as described in Patent Document 1, in which the absorption axis of the polarizer is perpendicular to the film surface of the polarizer. In the film described above, light inclined in a direction perpendicular to the film surface of the polarizer is less likely to be transmitted.

[0010] Previous technical documents, patent documents, patent document 1: Japanese Patent Application Publication No. 2008-165201 Summary of the Invention

[0011] Technical Problem to be Solved by the Invention The inventors have discovered that when a film is made to suppress rainbow patterns in AR glasses by applying the film described in reference patent document 1, sometimes the image is presented in multiple forms (multiple images are produced).

[0012] In particular, when the light guide plate of the AR glasses and the cover plate of the AR glasses are arranged alternately, and the aforementioned film is arranged on the light guide plate side of the cover plate, the generation of multiple images is observed more significantly.

[0013] Therefore, the objective of this invention is to provide a film that suppresses the generation of multiple images when applied to AR glasses.

[0014] Furthermore, the present invention also aims to provide an optical component, an optical device, and a head-mounted display that includes a film.

[0015] The present invention is a result of in-depth research conducted by the inventors to solve the aforementioned technical problems. Specifically, it was discovered that the above-mentioned problems can be solved through the following configuration.

[0016] [1] A film comprising at least one light-absorbing anisotropic layer, wherein the angle between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer is 0 to 45°, and the maximum height difference of the ripples in a 10 mm × 10 mm area on the surface of the film is less than 1.2 μm.

[0017] [2] The film according to [1] comprises two light-absorbing anisotropic layers and at least one phase difference layer is included between the two light-absorbing anisotropic layers.

[0018] [3] The membrane according to [2] comprises two phase difference layers, wherein the phase difference layers are λ / 2 plates.

[0019] [4] The membrane according to any one of [1] to [3] further comprises a polarizer.

[0020] [5] The membrane according to any one of [1] to [4] further comprises an anti-reflective layer disposed on the outermost side of the membrane.

[0021] [6] The film according to any one of [1] to [5] has a surface reflectance of 1% or less.

[0022] [7] The membrane according to any one of [1] to [6] further comprises one or more layers selected from the group consisting of an adhesive layer with a thickness of 10 μm or less and an adhesive layer with a thickness of 10 μm or less.

[0023] [8] An optical component comprising the film and transparent support described in any one of [1] to [7].

[0024] [9] The optical component according to [8], wherein the transparent support is glass.

[0025]

[10] An optical device comprising the optical component described in [8] and a light guide plate on which diffraction elements are disposed, wherein the optical component and the light guide plate are spaced apart.

[0026]

[11] According to the optical device of

[10] , the transparent support in the optical component is disposed at a position closer to the light guide plate than the film.

[0027]

[12] A head-mounted display comprising the optical device and image display element described in

[10] .

[0028]

[13] A head-mounted display comprising the optical device and image display element described in

[11] .

[0029] Effects of the Invention According to the present invention, a film is provided that suppresses the generation of multiple images when applied to AR glasses.

[0030] Furthermore, according to the present invention, it is also possible to provide an optical component including a film, an optical device, and a head-mounted display. Attached Figure Description

[0031] Figure 1 is a schematic diagram illustrating an example of a first embodiment of the membrane of the present invention.

[0032] Figure 2 is a schematic diagram illustrating an example of a second embodiment of the membrane of the present invention.

[0033] Figure 3 is a cross-sectional schematic diagram showing a portion of the AR glasses of the present invention.

[0034] Figure 4 is a cross-sectional schematic diagram showing a portion of AR glasses when a conventional rainbow-prevention film is applied to the AR glasses. Detailed Implementation

[0035] The present invention will now be described in detail.

[0036] The following constituent elements are sometimes described in light of representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0037] The following explains the meaning of each statement in this specification.

[0038] In this specification, the numerical range indicated by “~” refers to the range encompassed by the values ​​recorded before and after “~” as the lower and upper limits.

[0039] Furthermore, in this specification, parallel and orthogonal refer to the range of parallel ±5° and orthogonal ±5°, respectively, rather than parallel and orthogonal in the strict sense.

[0040] Furthermore, in this specification, for each component, one substance corresponding to that component may be used alone, or two or more substances may be used simultaneously. Here, when two or more substances are used together for each component, the content of that component, unless otherwise stated, refers to the total content of the substances used together.

[0041] Furthermore, in this specification, "(meth)acrylate" is a designation for "acrylate" or "methacrylate", "(meth)acrylic acid" is a designation for "acrylic acid" or "methacrylic acid", and "(meth)acryloyl" is a designation for "acryloyl" or "methacryloyl".

[0042] Furthermore, in this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness-direction retardation at wavelength λ, respectively. Unless otherwise specified, wavelength λ is 550 nm.

[0043] In this invention, Re(λ) and Rth(λ) are values ​​measured at wavelength λ using an AxoScan OPMF-2 (manufactured by Opto Science, Inc.). The values ​​are calculated using the AxoScan input: average refractive index ((nx+ny+nz) / 3) and film thickness (d(μm)).

[0044] Slow axis direction (°) Re (λ) = R0 (λ) Rth (λ) = ((nx+ny) / 2-nz) × d.

[0045] Additionally, although R0(λ) is displayed as a value calculated by AxoScan OPMF-2, it refers to Re(λ).

[0046] In this specification, the transmittance center axis refers to the direction representing the highest transmittance when measuring transmittance by changing the tilt angle (polar angle) and tilt direction (azimuth angle) relative to the normal direction of the light absorption anisotropic layer surface.

[0047] Specifically, the Mueller matrix at a wavelength of 550 nm was measured using an AxoScan OPMF-2 (manufactured by Opto Science, Inc.). More specifically, during the measurement, the azimuth angle at which the transmittance central axis is tilted was first determined. Then, within a surface including the normal direction of the light-absorbing anisotropic layer along that azimuth angle (including the plane orthogonal to the surface of the layer along the transmittance central axis), the angle relative to the normal direction of the light-absorbing anisotropic layer surface was varied by 1°, i.e., the polar angle, from -70° to 70°. The Mueller matrix at a wavelength of 550 nm was measured, and the transmittance of the light-absorbing anisotropic layer was derived. As a result, the direction with the highest transmittance was set as the transmittance central axis.

[0048] In addition, the transmittance central axis refers to the direction of the absorption axis (long axis direction of the molecule) of the dichroic material contained in the light absorption anisotropic layer.

[0049] Furthermore, in this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by ATAGO CO.,LTD.) and a sodium lamp (λ=589nm) as the light source. Moreover, when measuring wavelength dependence, a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO.,LTD.) can be used in combination with an interference filter for measurement.

[0050] Furthermore, values ​​from the polymer handbook (JOHN WILEY & SONS, INC) and various optical film product catalogs can be used. The following are examples of the average refractive index values ​​for major optical films: cellulose acylate (1.48), cyclic olefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0051] Furthermore, the bonding direction of the divalent groups (e.g., -COO-) described in this specification is not particularly limited. For example, if L in XLY is -COO-, the position bonded to the X side is set as... 1. Set the position of bonding with the Y side as... 2, then L could be 1-O-CO- 2, or it could be 1-CO-O- 2.

[0052] <Film> The film of the present invention comprises at least one optical anisotropic absorption layer of the present invention, wherein the angle between the transmittance central axis of the optical anisotropic absorption layer and the normal direction of the optical anisotropic absorption layer is 0 to 45°, and the maximum height difference of the ripples in a 10 mm × 10 mm area on the film surface is less than 1.2 μm. The method for measuring the maximum height difference of the ripples will be described in detail later.

[0053] When the membrane of the present invention is applied to AR glasses, the mechanism for suppressing the generation of multiple images is not yet clear, but the inventors speculate as follows.

[0054] First, the principle behind the multiple images that are expected to occur when applying a rainbow-pattern prevention film to conventional AR glasses is explained using diagrams.

[0055] Figure 4 is a cross-sectional schematic diagram showing a portion of AR glasses when a conventional rainbow-prevention film is applied to AR glasses (head-mounted displays).

[0056] Specifically, the AR glasses 40C shown in Figure 4 include an optical device 30C and an image display element 42 that allows image light L1 to be incident on the optical device.

[0057] The optical device 30C includes a light guide plate 32 and an incident diffraction element 34 and an exit diffraction element 36 disposed on the side of the light guide plate 32 opposite to the image display element 42 side. Furthermore, the optical device 30C includes an optical component 20C formed from a cover glass 22 and a film 10C (a conventional iridescence prevention film). In the optical component 20C, the film 10C is disposed on the side of the light guide plate 32. Additionally, the film 10C is spaced apart from the incident diffraction element 34 and the exit diffraction element 36.

[0058] The position of the incident diffraction element 34 corresponds to the incident position of the image light L1 from the image display element 42. The position of the exit diffraction element 36 corresponds to the exit position of the image light L1 from the light guide plate 32, that is, the observation position of the user observing the image light L1.

[0059] The incident diffraction element 34 causes the image light L1 incident from the image display element 42 onto the light guide plate 32 to diffract within the light guide plate 32. The diffracted image light L1 undergoes total internal reflection within the light guide plate 32 and travels in the in-plane direction of the light guide plate 32. The exit diffraction element 36 causes the light propagating within the light guide plate 32 to diffract towards the user side.

[0060] Through the research of the inventors, it was clarified that in the emission diffraction element 36 of this AR glasses 40C, a portion of the image light L1 is emitted towards the side opposite to the user side (the optical component 20C side) to generate stray light Ls. The stray light Ls travels towards the optical component 20C side, and a portion of it is reflected on the surface of the film 10C.

[0061] In this case, the surface of the film 10C often produces ripples, and stray light Ls is reflected in a direction that is not parallel to the image light L1, and is observed by the user. If stray light Ls is reflected in a direction different from the image light L1, the position of the image generated by stray light Ls is different from the position of the image generated by image light L1, and therefore it is considered that multiple images are generated.

[0062] On the other hand, in the membrane of the present invention, the maximum height difference of the ripples in the 10mm×10mm area on the membrane surface is less than 1.2μm. Therefore, even if stray light Ls is generated, it is easy to be reflected in the same direction as the image light L1. As a result, it is believed that the generation of multiple images is suppressed (refer to Figure 3 described later).

[0063] Hereinafter, the first and second embodiments will be described in detail as representative embodiments of the membrane of the present invention. Furthermore, the membrane of the present invention is not limited to the embodiments described below, and its constituent elements can be appropriately modified.

[0064] [First Embodiment] The first embodiment of the film of the present invention includes two anisotropic light-absorbing layers, and at least one phase retardation layer is included between the two anisotropic light-absorbing layers. In the two anisotropic light-absorbing layers, the angle between the central axis of the transmittance of the anisotropic light-absorbing layer and the normal direction of the anisotropic light-absorbing layer is 0° to 45°. Furthermore, the maximum height difference of the ripples in a 10mm × 10mm region on the film surface is 1.2μm or less.

[0065] Figure 1 shows a schematic diagram illustrating an example of a first embodiment of the membrane of the present invention.

[0066] The film 10A shown in Figure 1 sequentially comprises a first light-absorbing anisotropic layer 12a, a first phase reversal layer 14a, a second phase reversal layer 14b, and a second light-absorbing anisotropic layer 12b. In the first light-absorbing anisotropic layer 12a and the second light-absorbing anisotropic layer 12b shown in Figure 1, the angles formed by the transmittance central axis and the normal directions of the light-absorbing anisotropic layers (the first light-absorbing anisotropic layer 12a and the second light-absorbing anisotropic layer 12b) are both 0° (in Figure 1, the black double arrows corresponding to the first light-absorbing anisotropic layer 12a and the second light-absorbing anisotropic layer 12b). Furthermore, in the configuration shown in Figure 1, the first phase difference layer 14a and the second phase difference layer 14b are λ / 2 plates, and their in-plane slow axis directions are configured such that the angle formed when viewed from the normal direction is 45° (in Figure 1, the hollow double arrows correspond to the first phase difference layer 14a and the second phase difference layer 14b).

[0067] In the film of the first embodiment having the structure shown in FIG1, light incident from the transmissivity central axis direction (the direction of the black arrow in FIG1) of the first light-absorbing anisotropic layer 12a and the second light-absorbing anisotropic layer 12b is transmitted without polarization conversion. On the other hand, in light incident from a direction inclined toward the transmissivity central axis (the direction of the hollow arrow in FIG1), a portion of the component with vibration direction in the in-plane direction of the plane of the transmissivity central axis (hereinafter referred to as "P-polarized light") is absorbed by the first light-absorbing anisotropic layer 12a, while the component with vibration direction orthogonal to the P-polarized light (hereinafter referred to as "S-polarized light") is almost not absorbed by the first light-absorbing anisotropic layer 12a and is transmitted. In this way, if light incident from a direction inclined toward the transmissivity central axis is transmitted through the first light-absorbing anisotropic layer 12a, it becomes light with a large S-polarized light component.

[0068] Additionally, in Figure 1, the direction inclined from the transmittance center axis and the plane of the transmittance center axis are parallel to the in-plane slow axis direction of the first phase difference layer 14a.

[0069] In the light transmitted through the first anisotropic absorption layer 12a, regarding the S-polarized light component, in the manner shown in Figure 1, almost no polarization conversion occurs in the first phase difference layer 14a, but in the second phase difference layer 14b, a polarization conversion occurs, with the vibration direction rotating by approximately 90°, becoming the P-polarized light component. If converted to the P-polarized light component, it is absorbed by the second anisotropic absorption layer 12b.

[0070] As described above, light absorption is the same regardless of the azimuth angle from which the light is incident, as long as the direction is tilted towards the central axis of transmittance. For example, in the case of light incident from a direction 45° off the azimuth angle from the direction of the hollow arrow and tilted towards the central axis of transmittance, the transmitted S-polarized light component undergoes polarization conversion in the first phase difference layer 14a to become the P-polarized light component. On the other hand, almost no polarization conversion occurs in the second phase difference layer 14b, and the P-polarized light component is absorbed by the second light absorption anisotropy layer 12b.

[0071] Therefore, in the configuration shown in Figure 1, light incident from any azimuth angle is absorbed by either the first anisotropic light-absorbing layer 12a or the second anisotropic light-absorbing layer 12b, as long as it is in the direction tilted towards the central axis of transmittance. On the other hand, light incident from the direction of the central axis of transmittance is not absorbed and is transmitted. Therefore, when the configuration shown in Figure 1 is applied to AR glasses, it functions as a filter with high transmittance for light incident from the direction of the central axis of transmittance (e.g., the visual recognition direction) and low transmittance for light incident from the tilted direction. This filter can prevent external light from incident from the tilted direction onto the diffraction elements in the AR glasses, thus suppressing rainbow patterns when applied to AR glasses.

[0072] Furthermore, the above description describes a configuration of two phase retardation layers between two anisotropic light-absorbing layers. However, a single phase retardation layer can be configured between the two anisotropic light-absorbing layers. Even with only one phase retardation layer, light incident from an oblique direction can still be absorbed using the aforementioned principle, functioning as a filter with low transmittance for light incident from an oblique direction.

[0073] Hereinafter, a first embodiment of the membrane of the present invention will be described in detail.

[0074] (Maximum height difference of ripples) As described above, in the first embodiment of the membrane of the present invention, the maximum height difference of ripples in a 10mm×10mm area is less than 1.2μm.

[0075] In this specification, the maximum height difference of the membrane ripples is measured as follows.

[0076] In this specification, a three-dimensional optical profilometer (New View 7200, manufactured by Zygo Corporation) was used to measure the maximum height difference of the ripples. MetroPro ver 9.0.10 Advanced TextureApplication was used as the measurement / analysis software. The analysis conditions were High FFT Filter: Auto, Low FFT Filter: Auto, NoiseFilter Size: 0. In the above analysis, the analysis was performed without using the AUTO function, under the conditions of a High Filter Wavelen of 330 μm and a Low Filter Wavelen of 1020 μm.

[0077] Furthermore, by removing the high-frequency components from the three-dimensional profile obtained through the above analysis, the degree of ripples in the three-dimensional profile can be evaluated. Additionally, the surface obtained by removing the high-frequency components from the three-dimensional profile will be referred to below as a "rippled surface".

[0078] First, a 10mm × 10mm area of ​​the glass surface (manufactured by Corning Incorporated Co., Ltd., EAGLE XG) was initially measured using the aforementioned three-dimensional optical profilometer, acquiring 10 three-dimensional profiles while changing the measurement position. Under the aforementioned analysis software and conditions, corrugated surfaces were obtained from these 10 three-dimensional profiles. The maximum height difference of the corrugated surface at each measurement position (maximum height difference of the corrugation) was calculated, and the arithmetic mean of the maximum height difference of the corrugation at the 10 locations was obtained. The average value of the maximum height difference of the corrugation of this glass was set as Wg (unit: μm).

[0079] Next, the film was bonded to the glass using Opteria (registered trademark) NCF-D692 (15 μm thick, manufactured by LINTEC Corporation). On the film-side surface opposite the glass side, 10 three-dimensional profiles were obtained in the same manner as described above, resulting in corrugated surfaces. The maximum height difference of the corrugations at these 10 locations was then calculated, and the arithmetic mean of the maximum height difference was determined. This average maximum height difference of the corrugations on the glass was denoted as Wf (unit: μm).

[0080] Here, the "maximum height difference of the ripples" of the membrane in this invention refers to the value (unit: μm) of Wf minus Wg.

[0081] From the viewpoint of further suppressing the generation of multiple images when applied to AR glasses, the maximum height difference of the ripple is preferably 1.0 μm or less, more preferably 0.8 μm or less, and even more preferably 0.6 μm or less. There is no particular limitation on the lower limit of the maximum height difference of the ripple, but it is more common to find values ​​above 0.1 μm.

[0082] (Light Absorption Anisotropic Layer) The first embodiment of the film of the present invention includes two light absorption anisotropic layers. Hereinafter, when it is not necessary to distinguish between the two light absorption anisotropic layers, they will sometimes be referred to as "light absorption anisotropic layers".

[0083] In the light-absorbing anisotropic layer, the angle between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer is 0 to 45°, preferably 0° or more and less than 45°, more preferably 0° or more and less than 35°, and even more preferably 0° or more and less than 35°. Furthermore, from the viewpoint of improving light transmittance, the transmittance central axes of the two light-absorbing anisotropic layers are preferably parallel.

[0084] The light-absorbing anisotropic layer preferably contains a dichroic material, more preferably contains a dichroic material and a liquid crystal compound, and even more preferably is a layer that fixes the orientation state of the liquid crystal compound and the dichroic material.

[0085] The following describes the preferred dichroic material and liquid crystal compound contained in the light-absorbing anisotropic layer.

[0086] - Dichroic substances - In this invention, dichroic substances refer to pigments whose absorbance varies with direction. Dichroic substances may or may not exhibit liquid crystal properties.

[0087] There are no particular limitations on dichroic substances. Examples include visible light absorbing substances (dichroic pigments), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet light absorbing substances, infrared light absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (such as quantum rods). Previously known dichroic substances (dichroic pigments) can be used.

[0088] Specifically, examples include paragraphs

[0067] to

[0071] of Japanese Patent Application Publication No. 2013-228706, paragraphs

[0008] to

[0026] of Japanese Patent Application Publication No. 2013-227532, paragraphs

[0008] to

[0015] of Japanese Patent Application Publication No. 2013-209367, paragraphs

[0045] to

[0058] of Japanese Patent Application Publication No. 2013-14883, paragraphs

[0012] to

[0029] of Japanese Patent Application Publication No. 2013-101328, paragraphs

[0009] to

[0017] of Japanese Patent Application Publication No. 2013-37353, and paragraphs

[0051] to

[0065] of Japanese Patent Application Publication No. 2013-37353. Japanese Patent Application Publication No. 2012-63387, paragraphs

[0049] to

[0073] ; Japanese Patent Application Publication No. Hei 11-305036, paragraphs

[0016] to

[0018] ; Japanese Patent Application Publication No. 2001-133630, paragraphs

[0009] to

[0011] ; Japanese Patent Application Publication No. 2011-215337, paragraphs

[0030] to

[0169] ; Japanese Patent Application Publication No. 2010-106242, paragraphs

[0021] to

[0075] ; Japanese Patent Application Publication No. 2010-215846, paragraphs

[0011] to

[0025] ; Japanese Patent Application Publication No. 2011-048311, paragraphs

[0017] to

[0069] ; Japanese Patent Application Publication No. 2011-2 Paragraphs

[0013] to

[0133] of Japanese Patent Application Publication No. 13610, paragraphs

[0074] to

[0246] of Japanese Patent Application Publication No. 2011-237513, paragraphs

[0005] to

[0051] of Japanese Patent Application Publication No. 2016-006502, paragraphs

[0014] to

[0032] of Japanese Patent Application Publication No. 2018-053167, paragraphs

[0014] to

[0033] of Japanese Patent Application Publication No. 2020-11716, paragraphs

[0005] to

[0041] of International Publication No. 2016 / 060173, paragraphs

[0008] to

[0062] of International Publication No. 2016 / 136561, and International Publication No. 2017 / 154835. Paragraphs

[0014] to

[0033] , paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154695, paragraphs

[0013] to

[0037] of International Publication No. 2017 / 195833, paragraphs

[0014] to

[0034] of International Publication No. 2018 / 164252, paragraphs

[0021] to

[0030] of International Publication No. 2018 / 186503, paragraphs

[0043] to

[0063] of International Publication No. 2019 / 189345, paragraphs

[0043] to

[0085] of International Publication No. 2019 / 225468, and paragraphs

[0050] to

[0074] of International Publication No. 2020 / 004106.The contents described in paragraphs

[0015] to

[0038] of International Publication No. 2021 / 044843, etc.

[0089] As a dichroic substance, a dichroic azo dye compound is preferred.

[0090] Dichroic azo dye compounds refer to azo dye compounds whose absorbance varies depending on the direction. Dichroic azo dye compounds may or may not exhibit liquid crystal properties. When a dichroic azo dye compound exhibits liquid crystal properties, it can exhibit either nematic or smectic properties. The preferred temperature range for displaying the liquid crystal phase is room temperature (approximately 20–28°C) to 300°C, and more preferably 50–200°C from the viewpoint of operability and manufacturing suitability.

[0091] In this invention, from the viewpoint of hue adjustment, it is preferable to use at least one pigment compound (first dichroic azo pigment compound) having a maximum absorption wavelength in the wavelength range of 560 to 700 nm and at least one pigment compound (second dichroic azo pigment compound) having a maximum absorption wavelength in the wavelength range of 455 nm or more and less than 560 nm.

[0092] In this invention, three or more dichroic azo pigment compounds may be used simultaneously. For example, from the viewpoint of making the light absorption anisotropic layer close to black, it is preferable to use a first dichroic azo pigment compound, a second dichroic azo pigment compound, and at least one pigment compound (a third dichroic azo pigment compound) that has a maximum absorption wavelength in the range of 380 nm or more and less than 455 nm.

[0093] In this invention, the dichroic azo dye compound preferably has crosslinking groups.

[0094] Examples of crosslinking groups include (meth)acryloyl, epoxy, oxetyl, and styryl, with (meth)acryloyl being preferred.

[0095] The light-absorbing anisotropic layer may contain a cured product (crosslinker) of a dichroic pigment (especially a dichroic pigment compound with crosslinking groups).

[0096] The content of the dichroic substance is not particularly limited, but considering the reason for improving the orientation degree of the formed light absorption anisotropic layer, it is preferably 3% by mass or more, more preferably 8% by mass or more, further preferably 10% by mass or more, and especially preferably 10 to 30% by mass, relative to the total mass of the light absorption anisotropic layer. In addition, when multiple dichroic substances are used, it is preferable that the total amount of the multiple dichroic substances is within the above-mentioned range.

[0097] The light-absorbing anisotropic layer preferably contains a liquid crystal compound. This suppresses the precipitation of dichroic substances and allows the dichroic substances to be oriented with a higher degree of orientation.

[0098] As the liquid crystal compound, either a high-molecular-weight liquid crystal compound or a low-molecular-weight liquid crystal compound can be used. From the viewpoint of improving the orientation degree, a high-molecular-weight liquid crystal compound is preferred. Furthermore, both high-molecular-weight liquid crystal compounds and low-molecular-weight liquid crystal compounds can be used simultaneously as the liquid crystal compound.

[0099] Here, "polymer liquid crystal compound" refers to a liquid crystal compound having repeating units in its chemical structure.

[0100] Furthermore, "low molecular weight liquid crystal compounds" refers to liquid crystal compounds that do not have repeating units in their chemical structure.

[0101] Examples of polymeric liquid crystal compounds include, for example, the thermotropic liquid crystal polymer described in Japanese Patent Application Publication No. 2011-237513 and the polymeric liquid crystal compounds described in paragraphs

[0012] to

[0042] of International Publication No. 2018 / 199096.

[0102] As a low-molecular-weight liquid crystal compound, examples include the liquid crystal compounds described in paragraphs

[0072] to

[0088] of Japanese Patent Application Publication No. 2013-228706, among which, liquid crystal compounds exhibiting smectic properties are preferred.

[0103] From the perspective of increasing the orientation degree of dichroic materials, liquid crystal compounds preferably contain polymeric liquid crystal compounds that include repeating units (hereinafter also simply referred to as "repeating units (1)") represented by the following formula (1).

[0104] [Chemical Formula 1] In the above formula (1), P1 represents the main chain of the repeating unit, L1 represents the single bond or divalent linking group, SP1 represents the spacer group, M1 represents the mesocrystalline group, and T1 represents the terminal group.

[0105] As the main chain of the repeating unit represented by P1, examples include groups represented by the following formulas (P1-A) to (P1-D), among which, from the perspective of the diversity of monomers that can be used as raw materials and ease of handling, groups represented by the following formula (P1-A) are preferred.

[0106] [Chemical Formula 2] In the above formulas (P1-A) to (P1-D), " “” indicates the bonding position with L1 in the above formula (1).

[0107] In the above equations (P1-A) to (P1-D), R 1 R 2 R 3 and R 4 Each of the following can be independently represented: a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The aforementioned alkyl group can be a straight-chain or branched alkyl group, or it can be an alkyl group having a cyclic structure (cycloalkyl). Furthermore, the aforementioned alkyl group preferably has 1 to 5 carbon atoms.

[0108] The group represented by the above formula (P1-A) is preferably a unit of a partial structure of poly(meth)acrylate obtained by polymerization of (meth)acrylate.

[0109] The group represented by the above formula (P1-B) is preferably an ethylene glycol unit formed by ring-opening polymerization of an epoxy group of a compound having an epoxy group.

[0110] The group represented by the above formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of an oxetane compound having an oxetane.

[0111] The group represented by the above formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by polycondensation of a compound having at least one of alkoxysilyl and silanol groups. Here, as a compound having at least one of alkoxysilyl and silanol groups, an example is a compound having the formula SiR. 14 (OR) 15 Compounds containing the group represented by )2-. In the formula, R 14 The meaning of R in (P1-D) 14 The meanings are the same, multiple R 15 Alkyl groups, each independently representing 1 to 10 hydrogen or carbon atoms.

[0112] In the above formula (1), L1 is a single bond or a divalent linking group.

[0113] Examples of divalent linking groups represented by L1 include -C(O)O-, -O-, -S-, and -C(O)NR. 3 -, -SO2- and -NR 3 R 4 -. In the formula, R 3 and R 4 Each can be independently represented by a hydrogen atom or an alkyl group having 1 to 6 carbon atoms that may have substituents.

[0114] When P1 is a group represented by formula (P1-A), from the perspective of increasing the orientation degree of the dichroic material, L1 is preferably a group represented by -C(O)O-.

[0115] When P1 is a group represented by formulas (P1-B) to (P1-D), from the perspective of increasing the orientation degree of dichroic substances, L1 is preferably a single bond.

[0116] In the above formula (1), from the perspective of easy liquid crystal properties or availability of raw materials, the spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of ethylene oxide structure, propylene oxide structure, polysiloxane structure and fluorinated alkylene structure.

[0117] In the above formula (1), the mesocrystalline group represented by M1 refers to the group that represents the main framework of liquid crystal molecules that contribute to the formation of liquid crystals. Liquid crystal molecules exhibit liquid crystal properties as an intermediate state (intermediate phase) between the crystalline state and the isotropic liquid state. There are no particular limitations regarding the mesocrystalline group. For example, one can refer to the description in "Flussige Kristalle in Tabellen II" (VEB Deutsche Verlag fur Grundstoff Industrie, Leipzig, 1984), especially pages 7 to 16, and the description in "Liquid Crystal Handbook Editorial Committee, Liquid Crystal Handbook" (Maruzen, 2000), especially Chapter 3.

[0118] As a mesocrystalline group, it is preferably a group having at least one cyclic structure selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups and alicyclic groups.

[0119] From the perspective of increasing the orientation degree of dichroic substances, the mesocrystalline group preferably has aromatic hydrocarbon groups, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups.

[0120] In the above formula (1), examples of terminal groups represented by T1 include hydrogen atoms, halogen atoms, cyano groups, nitro groups, hydroxyl groups, alkyl groups with 1 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, alkylthio groups with 1 to 10 carbon atoms, alkoxycarbonyloxy groups with 1 to 10 carbon atoms, alkoxycarbonyl groups with 1 to 10 carbon atoms (ROC(O)-: R is alkyl), acyloxy groups with 1 to 10 carbon atoms, acylamino groups with 1 to 10 carbon atoms, alkoxycarbonylamino groups with 1 to 10 carbon atoms, sulfonylamino groups with 1 to 10 carbon atoms, aminosulfonyl groups with 1 to 10 carbon atoms, carbamoyl groups with 1 to 10 carbon atoms, thionyl groups with 1 to 10 carbon atoms, urea groups with 1 to 10 carbon atoms, and groups containing (meth)acryloyloxy groups. As an example of the group containing (meth)acryloyloxy, -LA (L represents a single bond or a linking group. Specific examples of linking groups are the same as L1 and SP1 above. A can be a group represented by (meth)acryloyloxy)

[0121] From the perspective of increasing the orientation degree of dichroic substances, T1 is preferably an alkoxy group with 1 to 10 carbon atoms, more preferably an alkoxy group with 1 to 5 carbon atoms, and even more preferably a methoxy group.

[0122] These terminal groups can be further replaced by these groups or the polymerizable groups described in Japanese Patent Application Publication No. 2010-244038.

[0123] From the perspective of improving the adhesion to adjacent layers and enhancing the cohesiveness of the membrane, T1 is preferably a polymerizable group.

[0124] There are no particular limitations on the polymerizable groups, but preferably polymerizable groups that can undergo free radical polymerization or cationic polymerization.

[0125] As a free radical polymerizable group, commonly known free radical polymerizable groups can be used. Examples of preferred free radical polymerizable groups include acryloyl or methacryloyl. In this case, acryloyl is known to generally have a fast polymerization rate, and from the viewpoint of improving productivity, acryloyl is preferred, but methacryloyl can also be used as a polymerizable group.

[0126] As the cationic polymerizable group, commonly known cationic polymerizable groups can be used, specifically including alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spirocyclic orthoester groups, and ethyleneoxy groups. Among these, alicyclic ether groups or ethyleneoxy groups are preferred, and epoxy groups, oxetyl groups, or ethyleneoxy groups are even more preferred.

[0127] From the perspective of achieving a higher degree of orientation in dichroic materials, the weight-average molecular weight (Mw) of the polymeric liquid crystal compound containing the repeating unit represented by the above formula (1) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. If the Mw of the polymeric liquid crystal compound is within the above range, the processing of the polymeric liquid crystal compound becomes easier.

[0128] In particular, from the perspective of suppressing cracks during coating, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably 10,000 or more, and more preferably 10,000 to 300,000.

[0129] Furthermore, considering the temperature tolerance of orientation, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably less than 10,000, and more preferably 2,000 or more but less than 10,000.

[0130] In this invention, the weight-average molecular weight and number-average molecular weight are values ​​determined by gel permeation chromatography (GPC).

[0131] • Solvent (eluent): N-methylpyrrolidone • Apparatus name: TOSOH HLC-8220GPC • Column: Three TOSOH TSKgelSuperAWM-H (6mm×15cm) columns are connected together • Column temperature: 25℃ • Sample concentration: 0.1% by mass • Flow rate: 0.35ml / min • Calibration curve: The calibration curves obtained using seven samples of TSK standard polystyrene manufactured by TOSOH with Mw=2800000~1050 (Mw / Mn=1.03~1.06) are used as liquid crystal compounds, and liquid crystal compounds with reverse wavelength dispersion are preferred.

[0132] In this specification, "having reverse wavelength dispersion" means that the phase difference film made using the liquid crystal compound satisfies the following relationship (X1) and (X2).

[0133] Re(450) / Re(550)<1 (X1) 1<Re(630) / Re(550) (X2) There are no particular limitations on polymeric liquid crystal compounds with reverse wavelength dispersion, as long as they can form films with reverse wavelength dispersion. For example, compounds represented by general formula (I) as described in Japanese Patent Application Publication No. 2008-297210 (especially the compounds described in paragraphs

[0034] to

[0039] ) and compounds described in Japanese Patent Application Publication No. 2010-084032 are examples. The compounds represented by general formula (1) as described herein (especially the compounds described in paragraphs

[0067] to

[0073] ), the compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2019-73496 (especially the compounds described in paragraphs

[0117] to

[0124] ), and the compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2016-081035 (especially the compounds described in paragraphs

[0043] to

[0055] ).

[0134] There are no particular restrictions on the polymerizable groups, but polymerizable groups capable of free radical polymerization or cationic polymerization are preferred.

[0135] As a free radical polymerizable group, known free radical polymerizable groups can be listed, with acryloyl or methacryloyl being preferred. Acryloyl groups are known to generally polymerize faster, and from the viewpoint of improving productivity, acryloyl groups are preferred, but methacryloyl groups can also be used as polymerizable groups for highly birefringent liquid crystals.

[0136] As cationic polymerizable groups, known cationic polymerizable groups include alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spirocyclic orthoester groups, and ethyleneoxy groups. Among these, alicyclic ether groups or ethyleneoxy groups are preferred, and epoxy groups, oxetyl groups, or ethyleneoxy groups are more preferred.

[0137] As a particularly preferred example of a polymeric group, one can cite a polymeric group represented by any one of the following formulas (P-1) to (P-20).

[0138] [Chemical Formula 3] As a liquid crystal compound, it can exhibit positive wavelength dispersion.

[0139] In this specification, "having positive wavelength dispersion" means that the phase retardation film made using the liquid crystal compound satisfies the following relationship (Y1) and (Y2).

[0140] Re(450) / Re(550)>1(Y1)1>Re(630) / Re(550)(Y2) as a liquid crystal compound, is also preferably positive wavelength dispersive and has two polymerizable groups selected from P 1 and P 2 The group consisting of aromatic rings and alicyclic rings, and the group containing the polymerizable group P. 1 and P 2 The key has more than 3 rings B 1 Polymerizable liquid crystal compounds.

[0141] In addition, polymerizable liquid crystal compounds possess two polymerizable groups P 1 and P 2 They can be the same or different; polymerizable liquid crystal compounds possess three or more rings of B. 1 They can be the same or different.

[0142] The polymerizable group P, which is present in polymerizable liquid crystal compounds 1 and P 2 There are no particular restrictions, but polymerizable groups that can polymerize with free radicals or cationic polymers are preferred.

[0143] As a free radical polymerizable group, known free radical polymerizable groups can be used, with acryloyloxy or methacryloyloxy being preferred examples. It is known that in this case, the polymerization rate of acryloyloxy tends to be faster, and from the viewpoint of improving productivity, acryloyloxy is preferred, but methacryloyloxy can also be used as a polymerizable group in the same way.

[0144] As the cationic polymerizable group, known cationic polymerizable groups can be used. Specifically, examples include alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spirocyclic orthoester groups, and ethyleneoxy groups. Among these, alicyclic ether groups or ethyleneoxy groups are preferred, and epoxy groups, oxetyl groups, or ethyleneoxy groups are more preferred.

[0145] As a particularly preferred example of a polymeric group, one can cite a polymeric group represented by any one of the above formulas (P-1) to (P-20).

[0146] Polymerizable liquid crystal compounds can have three or more polymerizable groups. When a polymerizable liquid crystal compound has three or more polymerizable groups, as a polymerizable group P in addition to the aforementioned polymerizable groups... 1 and P 2 Other polymerizable groups are not particularly limited, including preferred polymerizable groups, such as those that are the same as the polymerizable groups described above that can be polymerized with free radicals or cationic polymers.

[0147] The polymerizable liquid crystal compound preferably has 2 to 4 polymerizable groups, more preferably only having polymerizable groups P. 1 and P 2 Two of them.

[0148] Polymerizable liquid crystal compounds are selected from the group consisting of aromatic rings that may have substituents and alicyclic rings that may have substituents, and are present in connection with the polymerizable group P. 1 and P 2 The bond has more than 3 rings B 1 .

[0149] Among them, ring B 1 "Existing in the polymerizing group P" 1 and P 2 "On the bond" refers to the structure that forms a direct bond to the polymeric group P. 1 and P 2 And a part of what is needed.

[0150] Polymerizable liquid crystal compounds can have properties other than those for directly attaching polymerizable groups P. 1 and P 2 The portion other than the required portion (hereinafter also referred to as "side chain"), but the loop structure that constitutes part of the side chain is not included in loop B. 1 middle.

[0151] As ring B 1 One type is an aromatic ring that can have substituents, for example, an aromatic ring with 5 to 20 ring elements that can have substituents.

[0152] Examples of aromatic rings with 5 to 20 ring elements include aromatic hydrocarbon rings such as benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings; and aromatic heterocycles such as furan rings, pyrrole rings, thiophene rings, pyridine rings, thiazole rings, benzothiazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, and quinazoline rings.

[0153] As ring B 1The aromatic ring in one manner may have substituents, for example, alkyl, alkoxy, alkyl carbonyl, alkoxy carbonyl, alkyl carbonyl oxy, alkyl amino, dialkyl amino, alkyl amide, alkenyl, alkynyl, halogen atom, cyano, nitro, alkyl thiol, and N-alkyl carbamate, etc.

[0154] Preferably, the atom is an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom.

[0155] As an alkyl group, it is preferably a straight-chain, branched, or cyclic alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and cyclohexyl), and even more preferably an alkyl group having 1 to 4 carbon atoms, especially methyl or ethyl.

[0156] As an alkoxy group, an alkoxy group having 1 to 18 carbon atoms is preferred, more preferably an alkoxy group having 1 to 8 carbon atoms (e.g., methoxy, ethoxy, n-butoxy, and methoxyethoxy, etc.), and even more preferably an alkoxy group having 1 to 4 carbon atoms, especially methoxy or ethoxy.

[0157] As an alkoxycarbonyl group, examples of groups bonded to alkyl groups with oxycarbonyl (-O-CO-) as exemplified above can be included, preferably methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl or isopropoxycarbonyl, and more preferably methoxycarbonyl.

[0158] As an alkyl carbonyloxy group, examples of carbonyloxy (-CO-O- group) bonded to an alkyl group as exemplified above can be included, preferably methyl carbonyloxy, ethyl carbonyloxy, n-propyl carbonyloxy or isopropyl carbonyloxy, more preferably methyl carbonyloxy.

[0159] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine or chlorine atoms being preferred.

[0160] As ring B 1 One type of alicyclic ring may have substituents, including divalent alicyclic hydrocarbon groups with 5 to 20 carbon atoms that may have substituents and heterocycles formed by substituting one or more of the -CH2- group constituting the alicyclic hydrocarbon group with 5 to 20 carbon atoms with -O-, -S- or -NH-.

[0161] The alicyclic hydrocarbon group with 5 to 20 carbon atoms is preferably a 5-membered or 6-membered ring. Furthermore, the alicyclic hydrocarbon group can be saturated or unsaturated, but a saturated alicyclic hydrocarbon group is preferred. For example, the description of the divalent alicyclic hydrocarbon group can be found in paragraph

[0078] of Japanese Patent Application Publication No. 2012-021068, which is incorporated herein by reference.

[0162] As ring B1 The alicyclic ring is preferably a cycloalkane ring with 5 to 20 carbon atoms. Examples of cycloalkane rings with 5 to 20 carbon atoms include cyclohexane, cycloheptane, cyclooctane, cyclododecane, and cyclodocosahexane. Among these, cyclohexane is preferred, 1,4-cyclohexene is more preferred, and trans-1,4-cyclohexene is even more preferred.

[0163] As ring B 1 The alicyclic ring can have substituents, including preferred substituents, such as those associated with the aforementioned ring B. 1 The aromatic ring can have the same substituents as the functional groups.

[0164] As ring B 1 The alicyclic structure is preferably free of substituents.

[0165] Polymerizable liquid crystal compounds as cyclic B 1 Preferably, it has at least one aromatic ring that may have a substituent, and more preferably, it has at least one group represented by formula (III) described later.

[0166] Furthermore, polymerizable liquid crystal compounds, as cyclic B... 1 Preferably, it has at least one cyclohexane ring, more preferably at least one 1,4-cyclohexene group, and even more preferably at least one trans-1,4-cyclohexene group.

[0167] That is, polymerizable liquid crystal compounds act as cyclic B 1 Preferably, it has a combination consisting of at least one aromatic ring (more preferably a group represented by formula (III) described later) and at least one cyclohexane ring (more preferably 2 to 4 1,4-cyclohexene groups).

[0168] In polymerizable liquid crystal compounds, there exists a polymerizable group P. 1 and P 2 The bonded ring B 1 There is no particular limitation on the number of elements, but from the viewpoint of the orientation stability of the liquid crystal compound, 3 to 7 is preferred, 4 to 6 is more preferred, and 5 is even more preferred.

[0169] -Other Components- The light-absorbing anisotropic layer may also contain components other than those mentioned above. Examples of other components include vertical alignment agents and leveling agents.

[0170] Boric acid compounds and onium salts can be cited as vertical orientation agents.

[0171] As a boric acid compound, the compound represented by formula (A) is preferred.

[0172] Formula (A) [Chemical Formula 4] In equation (A), R 1 and R 2 Each of these can be independently represented as a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroatom-containing cyclic group.

[0173] R 3 This indicates a substituent containing a (meth)acryloyl group.

[0174] As a specific example of a boric acid compound, one can cite the boric acid compound represented by general formula (I) described in paragraphs

[0023] to

[0032] of Japanese Patent Application Publication No. 2008-225281.

[0175] As an onium salt, the preferred compound is one represented by formula (B).

[0176] Formula (B) [Chemical Formula 5] In formula (B), ring A represents a quaternary ammonium ion composed of a nitrogen-containing heterocycle. X - Indicates anion. L 1 This indicates a divalent linker group. L 2 Indicates a single bond or a divalent linked group. Y 1 The symbol indicates a divalent linking group having a 5- or 6-membered ring as part of the structure. Z indicates a divalent linking group having a 2-20 alkylene group as part of the structure. P 1 and P 2 Each of these represents a monovalent substituent that has a polymerizable alkene unsaturated bond.

[0177] Specific examples of onium salts include those described in paragraphs

[0052] to

[0058] of Japanese Patent Application Publication No. 2012-208397, those described in paragraphs

[0024] to

[0055] of Japanese Patent Application Publication No. 2008-026730, and those described in Japanese Patent Application Publication No. 2002-037777.

[0178] When the light-absorbing anisotropic layer contains a vertical alignment agent, the content of the vertical alignment agent relative to the total mass of the liquid crystal compound is preferably 0.1 to 400% by mass, more preferably 0.5 to 350% by mass.

[0179] Vertical alignment agents can be used alone or in combination of two or more. When using two or more vertical alignment agents, it is preferable that their combined dosage is within the range described above.

[0180] The light-absorbing anisotropic layer may also contain a leveling agent. When the composition for forming the light-absorbing anisotropic layer (light-absorbing anisotropic layer) described later contains a leveling agent, the surface roughness caused by the drying wind applied to the surface of the light-absorbing anisotropic layer is suppressed, thereby further homogenizing the dichroic material.

[0181] The leveling agent is not particularly limited, but is preferably a leveling agent containing fluorine atoms (fluorine-based leveling agent) or a leveling agent containing silicon atoms (silicone-based leveling agent), and more preferably a fluorine-based leveling agent.

[0182] Examples of fluorinated leveling agents include fatty acid esters of polycarboxylic acids in which a portion of the fatty acid is replaced by a fluorinated alkyl group, and polyacrylates with fluorinated substituents.

[0183] Specific examples of leveling agents include the compounds illustrated in paragraphs

[0046] to

[0052] of Japanese Patent Application Publication No. 2004-331812 and the compounds described in paragraphs

[0038] to

[0052] of Japanese Patent Application Publication No. 2008-257205.

[0184] When the light-absorbing anisotropic layer contains a liquid crystal compound and a leveling agent, the content of the leveling agent relative to the total mass of the liquid crystal compound is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass.

[0185] Leveling agents can be used alone or in combination of two or more. When using two or more leveling agents, it is preferable that their combined dosage is within the range mentioned above.

[0186] -Composition for forming anisotropic light absorption layer-The anisotropic light absorption layer is preferably formed using a composition for forming anisotropic light absorption layer comprising a dichroic substance and a liquid crystal compound.

[0187] In addition to dichroic substances and liquid crystal compounds, the composition for forming anisotropic light-absorbing layers preferably includes solvents as described later, and may further include other components mentioned above.

[0188] Examples of dichroic substances included in compositions for forming anisotropic light-absorbing layers include dichroic substances that can be included in anisotropic light-absorbing layers.

[0189] The content of the dichroic substance relative to the total solid content of the composition for forming the light-absorbing anisotropic layer is preferably the same as the content of the dichroic substance relative to the total mass of the light-absorbing anisotropic layer.

[0190] Here, "total solids content in the composition for forming anisotropic light-absorbing layers" refers to components other than solvents. Specific examples of solids content include dichroic substances, liquid crystal compounds, and the other components mentioned above.

[0191] The liquid crystal compound and other components that may be included in the composition for forming the light-absorbing anisotropic layer are the same as those that may be included in the liquid crystal compound and other components in the light-absorbing anisotropic layer.

[0192] Preferably, the content of liquid crystal compound and other components relative to the total solid content of the composition for forming the light absorption anisotropic layer is the same as the content of liquid crystal compound and other components relative to the total mass of the light absorption anisotropic layer.

[0193] From an operational point of view, the composition for forming anisotropic light-absorbing layers preferably contains a solvent.

[0194] Examples of solvents include organic solvents such as ketones, ethers, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, carbon halogens, esters, alcohols, cellosols, cellosol acetates, sulfoxides, amides, and heterocyclic compounds, as well as water.

[0195] These solvents can be used alone or in combination with two or more.

[0196] Among these solvents, organic solvents are preferred, and carbon halogens or ketones are more preferred.

[0197] When the composition for forming anisotropic light-absorbing layers contains a solvent, the solvent content relative to the total mass of the composition for forming anisotropic light-absorbing layers is preferably 80 to 99% by mass, more preferably 83 to 97% by mass, and even more preferably 85 to 95% by mass.

[0198] The composition for forming anisotropic light-absorbing layers may contain a polymerization initiator.

[0199] There are no particular restrictions on the polymerization initiator, but it is preferred to use a photosensitive compound, i.e., a photopolymerization initiator.

[0200] Commercially available products can also be used as photopolymerization initiators, such as Irgacure 184, Irgacure 907, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure OXE-01 and Irgacure OXE-02 manufactured by BASF.

[0201] Polymerization initiators can be used alone or in combination with two or more.

[0202] When the composition for forming anisotropic light-absorbing layers contains a polymerization initiator, the content of the polymerization initiator relative to the total solid content of the composition for forming anisotropic light-absorbing layers is preferably 0.01 to 30% by mass, more preferably 0.1 to 15% by mass.

[0203] - Method for Manufacturing a Light-Absorbing Anisotropic Layer- There are no particular limitations on the method for manufacturing a light-absorbing anisotropic layer. From the viewpoint of achieving a higher degree of orientation of the dichroic material, a method comprising the following steps in sequence (hereinafter also referred to as "this manufacturing method") is preferred: a step of forming a coated film by coating a light-absorbing anisotropic layer composition comprising a dichroic material and a liquid crystal compound onto an alignment film (hereinafter also referred to as "coating film forming step"); and a step of aligning the liquid crystal components contained in the coated film (hereinafter also referred to as "alignment step").

[0204] In addition, the liquid crystal component contains not only the aforementioned liquid crystal compound, but also dichroic substances with liquid crystal properties.

[0205] The following describes each process. The coating film formation process is a process of coating the above-mentioned light absorption anisotropic layer formation composition onto the alignment film to form a coating film.

[0206] By using a light-absorbing anisotropic layer forming composition containing the above-mentioned solvent, or by using a light-absorbing anisotropic layer forming composition that has been molten into a liquid such as a melt by heating, it is easy to coat the light-absorbing anisotropic layer forming composition onto an alignment film.

[0207] Coating methods for compositions used to form anisotropic light-absorbing layers include known methods such as roller coating, gravure printing, spin coating, wire-wound bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray coating, and inkjet coating.

[0208] The alignment film can be any film as long as it is a film in which the liquid crystal component contained in the composition for forming anisotropic light absorption layer is oriented.

[0209] Alignment films can be formed by methods such as friction treatment of the film surface with organic compounds (preferably polymers), oblique evaporation of inorganic compounds, formation of a layer with microgrooves, or accumulation of organic compounds (e.g., ω-trisaccharide, di(octadecyl)methylammonium chloride, methyl stearate) based on the Langmuir-Blodgett process (LB film). Furthermore, alignment films that generate alignment functions by applying an electric field, a magnetic field, or light irradiation are also known. In this invention, from the perspective of ease of control of the pretilt angle of the alignment film, an alignment film formed by friction treatment is preferred; from the perspective of alignment uniformity, a photo-alignment film formed by light irradiation is even more preferred.

[0210] As a photoalignment film, a photoalignment film containing azo dyes or polyvinyl cinnamate is used.

[0211] By irradiating ultraviolet light at an angle to the normal direction of the photo-alignment film, an anisotropy with an angle relative to the normal direction of the photo-alignment film is generated. Based on this, the light-absorbing anisotropic layer is oriented, thereby enabling the dichroic substances in the light-absorbing anisotropic layer to be oriented.

[0212] Furthermore, the liquid crystal layer in which the liquid crystal compound is mixed and aligned can also be used as an alignment film.

[0213] The alignment process is a process of aligning the liquid crystal components (especially dichroic substances) contained in the coating film. It is understood that in the alignment process, the dichroic substance is aligned along the liquid crystal compound that is oriented through the alignment film.

[0214] The orientation process can also include a drying process. This drying process removes components such as solvents from the coated film. The drying process can be performed by placing the coated film at room temperature for a specified time (e.g., natural drying), or by heating and / or air supply.

[0215] The orientation process preferably includes heat treatment. This further orients the dichroic material contained in the coated film, increasing the degree of orientation of the dichroic material.

[0216] From the perspective of manufacturing applicability, the heat treatment is preferably 10 to 250°C, more preferably 25 to 190°C. Furthermore, the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0217] The orientation process may also include a cooling process performed after heat treatment. The cooling process involves cooling the heated coating film to approximately room temperature (20–25°C). This further fixes the orientation of the dichroic substances contained in the coating film, and increases the degree of orientation of the dichroic substances. There are no particular limitations on the cooling method; it can be implemented using known methods.

[0218] Through the above processes, the light absorption anisotropic layer of the present invention can be obtained.

[0219] This manufacturing method may include a step of curing the light-absorbing anisotropic layer after the above-described orientation step (hereinafter also referred to as the "curing step").

[0220] The curing process is carried out, for example, by heating and / or light exposure (exposure). Preferably, the curing process is carried out by light exposure.

[0221] The light source used for curing can be various types of light sources such as infrared, visible light, or ultraviolet light, with ultraviolet light being preferred. Furthermore, ultraviolet light can be irradiated while heating is being performed during curing, or ultraviolet light can be irradiated through a filter that allows only specific wavelengths to pass through.

[0222] Furthermore, exposure can be performed under a nitrogen atmosphere. In the case of curing the light-absorbing anisotropic layer via free radical polymerization, the polymerization hindrance caused by oxygen can be reduced; therefore, exposure under a nitrogen atmosphere is preferred.

[0223] There is no particular limitation on the thickness of the light-absorbing anisotropic layer, but from the viewpoint of achieving better results in this invention, it is preferred to be 0.5 to 7 μm, and more preferably 1.0 to 3 μm.

[0224] (Phase difference layer) The film of the first embodiment of the present invention includes at least one phase difference layer between two light-absorbing anisotropic layers.

[0225] In the film of the first embodiment of the present invention, it is preferable to include two or more phase retardation layers.

[0226] The phase retardation layer is preferably a phase retardation layer having a slow axis in the in-plane direction, and is preferably a λ / 2 plate. In addition, in this specification, a λ / 2 plate refers to a phase retardation layer with an in-plane phase difference of approximately half the wavelength, specifically, a phase retardation layer with an in-plane phase difference Re(550) of 220 to 320 nm at a wavelength of 550 nm.

[0227] The material used to form the retardation layer is not particularly limited, and examples include retardation layers containing liquid crystal compounds and stretched films. Among these, a retardation layer containing a liquid crystal compound is preferred.

[0228] Liquid crystal compounds are generally classified into rod-shaped and disc-shaped types based on their shape. Furthermore, they are categorized into low-molecular-weight and high-molecular-weight types. High-molecular-weight compounds typically refer to those with a degree of polymerization of 100 or higher (Polymer Physics and Phase Transition Dynamics, Masao Doi, p. 2, Iwanami Shoten, 1992). In this invention, any liquid crystal compound can be used, but rod-shaped or disc-shaped liquid crystal compounds (disc-shaped liquid crystal compounds) are preferred. Moreover, liquid crystal compounds with a monomeric or low molecular weight structure and a degree of polymerization of less than 100 are preferred.

[0229] Furthermore, examples of polymerizable groups found in polymerizable liquid crystal compounds include acryloyl, methacryloyl, epoxy, and vinyl groups.

[0230] By polymerizing this polymerizable liquid crystal compound, the orientation of the liquid crystal compound can be fixed. Furthermore, once the liquid crystal compound is fixed through polymerization, it is no longer necessary to exhibit liquid crystal properties.

[0231] As rod-shaped liquid crystal compounds, preferably used compounds include methylimine compounds, azo compounds, cyanobiphenyl compounds, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexane compounds, cyano-substituted phenylpyrimidine compounds, alkoxy-substituted phenylpyrimidine compounds, phenyl dioxane compounds, diphenylacetylene compounds, and alkenylcyclohexylbenzyl nitrile compounds. Regarding the fixation of these rod-shaped liquid crystal compounds, polymerizable groups (similar to those described later for disc-shaped liquid crystals) are introduced into the end structure of the rod-shaped liquid crystal compound, and the polymerization and curing reaction is carried out. As a specific example, Japanese Patent Application Publication No. 2006-209073 describes an example of ultraviolet curing of a polymerizable nematic rod-shaped liquid crystal compound. Furthermore, not only the aforementioned low-molecular-weight liquid crystal compounds can be used, but also high-molecular-weight liquid crystal compounds. The high-molecular-weight liquid crystal compound is a polymer having side chains equivalent to those of the low-molecular-weight liquid crystal compounds described above. Optical compensation sheets using high-molecular-weight liquid crystal compounds are described in Japanese Patent Application Publication No. Hei 5-053016, etc.

[0232] As disc-shaped liquid crystal compounds, they include benzene derivatives described in the research reports of C. Destrade et al., Mol. Cryst., Vol. 71, p. 111 (1981); Truxene derivatives described in the research reports of C. Destrade et al., Mol. Cryst., Vol. 122, p. 141 (1985); Physicslett. A, Vol. 78, p. 82 (1990); Cyclohexane derivatives described in the research reports of B. Kohne et al., Angew. Chem., Vol. 96, p. 70 (1984); and azacrown or phenylacetylene macrocycles described in the research reports of J. M. Lehn et al., J. Chem. Commun., p. 1794 (1985); J. Zhang et al., J. Am. Chem. Soc., Vol. 116, p. 2655 (1994).

[0233] The molecule of the disk-shaped liquid crystal compound also includes a parent core relative to the molecular center, and side chains with radially substituted linear alkyl, alkoxy, or substituted benzoyloxy groups as the parent core, exhibiting liquid crystal properties. The molecule or aggregate of molecules is preferably a compound having rotational symmetry and capable of imparting a certain orientation. The retardation layer formed from the composition containing the disk-shaped liquid crystal compound does not need to exhibit liquid crystal properties in its final state contained within the retardation layer. For example, if a low-molecular-weight disk-shaped liquid crystal molecule having groups that react with heat or light is polymerized to increase its molecular weight, liquid crystal properties will be lost; however, a retardation layer containing such a high-molecular-weight compound can certainly be used in the present invention. Preferred examples of disk-shaped liquid crystal compounds include the compound described in Japanese Patent Application Publication No. 8-050206. Furthermore, the polymerization of disk-shaped liquid crystal molecules is described in Japanese Patent Application Publication No. 8-027284.

[0234] In order to fix the disc-shaped liquid crystal molecule by polymerization, it is necessary to bond the polymerizable group as a substituent to the disc-shaped core of the disc-shaped liquid crystal molecule. The disc-shaped core and the polymerizable group are preferably compounds bonded by a linking group, thereby maintaining the orientation state even during the polymerization reaction. For example, compounds described in paragraphs

[0151] to

[0168] of Japanese Patent Application Publication No. 2000-155216 can be cited.

[0235] In the film of the first embodiment of the present invention, at least one phase retardation layer is preferably a layer formed using a composition containing a disk-shaped liquid crystal compound. When two or more phase retardation layers are included, it is also preferable that at least one phase retardation layer is a layer formed using a composition containing a disk-shaped liquid crystal compound, or that at least one phase retardation layer is a layer formed using a composition containing a rod-shaped liquid crystal compound. Furthermore, when two or more phase retardation layers are included, at least two phase retardation layers can be layers formed using a composition containing a disk-shaped liquid crystal compound.

[0236] In the film of the first embodiment of the present invention, from the perspective of being able to suppress hue changes, it is also preferable that at least one of the phase retardation layers is a layer formed using a composition containing a rod-shaped liquid crystal compound with inverse wavelength dispersion.

[0237] Furthermore, examples of such reverse wavelength dispersive rod-shaped liquid crystal compounds include compounds that are any liquid crystal compounds contained in the aforementioned light absorption anisotropy layer (especially reverse wavelength dispersive polymeric liquid crystal compounds).

[0238] Furthermore, when there are two or more retardation layers, considering the need to improve the light-blocking ability of light incident from an oblique direction and suppress hue changes, it is preferable that at least one retardation layer is formed using a composition containing a rod-shaped liquid crystal compound, and that at least one retardation layer, different from the layer formed using the composition containing the aforementioned rod-shaped liquid crystal compound, is formed using a composition containing a disk-shaped liquid crystal compound. It is also preferable that at least one retardation layer is formed using a composition containing a rod-shaped liquid crystal compound with reverse wavelength dispersion, and that at least one retardation layer, different from the layer formed using the composition containing the aforementioned rod-shaped liquid crystal compound with reverse wavelength dispersion, is formed using a composition containing a disk-shaped liquid crystal compound.

[0239] Furthermore, examples of such rod-shaped liquid crystal compounds and rod-shaped liquid crystal compounds with reverse wavelength dispersion include any liquid crystal compound contained in the aforementioned light absorption anisotropy layer (in particular, polymeric liquid crystal compounds with reverse wavelength dispersion and polymeric liquid crystal compounds with positive wavelength dispersion).

[0240] In the film of the first embodiment of the present invention, when the phase retardation layer is a layer formed using a composition containing a liquid crystal compound, as a component other than the liquid crystal compound contained in the composition, a component other than the dichroic substance contained in the light absorption anisotropy layer described above can be cited.

[0241] Furthermore, as a method for forming the phase difference layer, for example, a method can be described that after forming a desired orientation state using a composition containing a liquid crystal compound, the layer is immobilized by polymerization.

[0242] The polymerization conditions are not particularly limited, but in polymerization using light irradiation, ultraviolet light is preferred. The irradiation dose is preferably 10 mJ / cm². 2 ~50J / cm 2 More preferably 20 mJ / cm 2 ~5J / cm 2 Further preferred is 30 mJ / cm 2 ~3J / cm 2 The preferred value is 50–1000 mJ / cm³. 2 Furthermore, irradiation can be carried out under heating conditions to promote the polymerization reaction.

[0243] The thickness of the phase retardation layer is not particularly limited, but is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and even more preferably 1 to 10 μm.

[0244] In the film of the first embodiment of the present invention, when two phase retardation layers are included, it is preferable that the two phase retardation layers are in direct contact or only through at least one of the adhesive layer, the bonding layer and the alignment film described later, for the reason that the light-shielding property of light incident from the oblique direction is better.

[0245] Here, "via at least one stack" means that in the case of any one of the adhesive layer, the adhesive layer, and the alignment film, only that one stack is passed, but in the case of any two of the adhesive layer, the adhesive layer, and the alignment film (e.g., the adhesive layer and the alignment film), only those two stacks are passed.

[0246] In the configuration shown in FIG1, the angle between the in-plane slow axis direction of the first retardation layer 14a and the in-plane slow axis direction of the second retardation layer 14b is 45°. In the film of the first embodiment of the present invention, when two retardation layers are included, the angle between the in-plane slow axis direction of one retardation layer and the in-plane slow axis direction of the other retardation layer is preferably in the range of 45 ± 10°, more preferably in the range of 45 ± 8°, and even more preferably in the range of 45 ± 5°.

[0247] The phase retardation layer may include phase retardation plates other than the λ / 2 plate (other phase retardation plates). For example, a positive C plate is preferably considered as an other phase retardation plate.

[0248] A positive C plate refers to an optical component whose refractive indices nx, ny, and nz satisfy the following formula (2).

[0249] Equation (2): nz>nx≈ny For example, in the case of including a λ / 2 plate as a phase difference layer, for light incident from an oblique direction, a higher degree of optical compensation can be achieved through the positive C plate.

[0250] (Orientation film) In the first embodiment of the film of the present invention, when the above-mentioned light absorption anisotropic layer and phase difference layer are layers formed using a composition containing a liquid crystal compound, an orientation film may be provided as an adjacent layer.

[0251] Specifically, examples of alignment films include layers of polyvinyl alcohol and polyimide, with or without rubbing treatment; and photoalignment films of polyvinyl cinnamate and azo dyes, with or without polarized light exposure treatment.

[0252] The thickness of the alignment film is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm.

[0253] (Adhesive layer) The first embodiment of the membrane of the present invention may have an adhesive layer.

[0254] The adhesive layer is preferably the same transparent and optically isotropic adhesive used in typical image display devices, typically a pressure-sensitive adhesive.

[0255] In addition to the base material (adhesive), conductive particles, and thermally expanding particles used as needed, the adhesive layer may also contain appropriate additives such as crosslinking agents (e.g., isocyanate-based crosslinking agents, epoxy-based crosslinking agents, etc.), tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.), plasticizers, fillers, anti-aging agents, surfactants, ultraviolet absorbers, light stabilizers, and antioxidants.

[0256] In the case where the first embodiment of the membrane of the present invention includes an adhesive layer, from the viewpoint that the maximum height difference of the corrugations can be made smaller, the thickness of the adhesive layer is preferably 20 μm or less, more preferably 10 μm or less, further preferably 8 μm or less, and especially preferably 5 μm or less. The lower limit of the thickness of the adhesive layer is not particularly limited, for example, it is often 0.1 μm or more.

[0257] From the perspective that the maximum height difference of the corrugations can be made smaller, the energy storage modulus of the adhesive layer is preferably 0.6MPa to 20MPa.

[0258] The storage modulus of the adhesive layer refers to the value measured using a dynamic viscoelasticity measuring device (DVA-200) manufactured by IT Keisoku Seigyo Co., Ltd. at a frequency of 1 Hz and a temperature of 25°C.

[0259] From the viewpoint that the maximum height difference of the ripples can be made smaller, the membrane thickness of the membrane in the first embodiment of the present invention is preferably 50 to 400 μm.

[0260] In a first embodiment of the film of the present invention, the adhesive layer may comprise two or more layers. For example, in the manner shown in FIG1, the adhesive layer may be disposed between the first light-absorbing anisotropic layer 12a and the first phase difference layer 14a, between the first phase difference layer 14a and the second phase difference layer 14b, and between the second phase difference layer 14b and the second light-absorbing anisotropic layer 12b, or it may be disposed between two of the above three layers.

[0261] (Adhesive layer) The membrane of the first embodiment of the present invention may have an adhesive layer.

[0262] The adhesive layer exhibits its adhesive properties through drying and reaction after bonding.

[0263] Polyvinyl alcohol adhesives (PVA adhesives) exhibit adhesive properties upon drying, enabling them to bond materials together.

[0264] Specific examples of curing adhesives that exhibit adhesion through reaction include reactive energy-curing adhesives such as (meth)acrylate adhesives and cationic polymerization-curing adhesives. Furthermore, (meth)acrylate refers to acrylates and / or methacrylates. As curing components in (meth)acrylate adhesives, examples include compounds having (meth)acryloyl groups and compounds having vinyl groups. Furthermore, as cationic polymerization-curing adhesives, compounds having epoxy groups or oxobutyl groups can also be used. Compounds having epoxy groups are not particularly limited as long as they have at least two epoxy groups within the molecule; various commonly known curing epoxy compounds can be used. Preferred epoxy compounds include, for example, compounds having at least two epoxy groups and at least one aromatic ring within the molecule (aromatic epoxy compounds), and compounds having at least two epoxy groups within the molecule, with at least one of them formed between two adjacent carbon atoms constituting an alicyclic ring (alicyclic epoxy compounds).

[0265] From the viewpoint of heat deformation resistance, UV-curable adhesives that are cured by UV irradiation are preferred.

[0266] In the case where the membrane of the first embodiment of the present invention includes an adhesive layer, from the viewpoint that the maximum height difference of the corrugations can be easily reduced, the thickness of the adhesive layer is preferably 20 μm or less, more preferably 10 μm or less, even more preferably 8 μm or less, and particularly preferably 5 μm or less. There is no particular limitation on the lower limit of the thickness of the adhesive layer; for example, it is often 0.1 μm or more.

[0267] In a first embodiment of the membrane of the present invention, two or more adhesive layers may be included. For example, in the manner shown in FIG1, the adhesive layer may be disposed between the first light-absorbing anisotropic layer 12a and the first phase difference layer 14a, between the first phase difference layer 14a and the second phase difference layer 14b, and between the second phase difference layer 14b and the second light-absorbing anisotropic layer 12b, or it may be disposed between two of the above three layers.

[0268] (Anti-reflective layer) The film of the first embodiment of the present invention may include an anti-reflective layer. The anti-reflective layer is preferably disposed on the outermost side of the film of the first embodiment of the present invention.

[0269] There are no particular restrictions on the types of anti-reflective layers. For example, there are known anti-reflective layers that can be made by alternating layers of dielectric layers, high-refractive-index materials and low-refractive-index materials, and moth-eye structures formed on the surface.

[0270] As an anti-reflective layer, an anti-reflective layer with a moth-eye structure on its surface is preferred.

[0271] As a method for providing the anti-reflective layer, for example, a method of attaching the anti-reflective film to the film of the first embodiment of the present invention via an adhesive layer can be cited. The aforementioned anti-reflective film is a film having a known anti-reflective layer.

[0272] The surface reflectance of the membrane in the first embodiment of the present invention is preferably 5.0% or less, more preferably 3.0% or less, even more preferably 1.0% or less, and particularly preferably 0.5% or less. There is no particular limitation on the lower limit of the surface reflectance, but it is generally 0.1% or more.

[0273] The aforementioned surface reflectivity can be achieved, for example, by disposing the aforementioned antireflective layer on one side of the film of the first embodiment of the present invention.

[0274] Surface reflectance is measured using the following method.

[0275] Specifically, a black PET film (trade name "KUKKIRI MIERU", manufactured by TOMOEGAWA CORPORATION) was laminated to the side opposite to the surface on which the reflectance was measured, and the specular reflectance was measured using a spectrophotometer. The spectrophotometer used was an ARV-474 spectrophotometer (manufactured by JASCO Corporation) with the option installed on the V-750. The measurement conditions are as follows.

[0276] • Angle of incidence: 5° • Angle of light received: 5° • Wavelength range: 380~780nm (other layers) The first embodiment of the film of the present invention may have layers other than those described above (other layers).

[0277] Other layers include, for example, protective layers, oxygen barrier layers, ultraviolet absorption layers, and blue light absorption layers.

[0278] (Manufacturing Method) The manufacturing method of the membrane of the first embodiment of the present invention is not particularly limited.

[0279] For example, a method can be described in which a light absorption anisotropic layer (first light absorption anisotropic layer 12a), a phase difference layer (first phase difference layer 14a and second phase difference layer 14b) and a light absorption anisotropic layer (second light absorption anisotropic layer 12b) are formed respectively, and each layer is bonded together with an adhesive layer or a bonding agent layer.

[0280] Regarding the first embodiment of the film of the present invention obtained by bonding with an adhesive layer as described above, it is preferable to further perform heat treatment. By performing heat treatment, air bubbles and the like that may be generated during bonding with the adhesive layer can be removed, and the maximum height difference of the ripples can be easily reduced.

[0281] Furthermore, pressure treatment can be performed simultaneously with the aforementioned heat treatment. By performing pressure treatment, air bubbles and other defects that may occur during bonding with adhesive layers can be easily removed.

[0282] Furthermore, the aforementioned heat treatment can be performed during the bonding process. Also, the aforementioned pressure treatment can be performed simultaneously with the heat treatment during the bonding process.

[0283] Examples of heat treatments mentioned above include autoclave treatment, infrared heating treatment, hot pressing treatment, and hot lamination treatment.

[0284] [Second Embodiment] The second embodiment of the film of the present invention includes a light-absorbing anisotropic layer and a polarizer. The angle between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer is 0 to 45°. In addition, the maximum height difference of the ripples in a 10 mm × 10 mm region on the film surface is 1.2 μm or less.

[0285] Figure 2 shows a schematic diagram illustrating an example of a second embodiment of the membrane of the present invention.

[0286] The film 10B shown in Figure 2 has a light-absorbing anisotropic layer 12 and a polarizer 16. In the light-absorbing anisotropic layer 12 shown in Figure 2, the angle between the transmittance central axis and the normal direction of the light-absorbing anisotropic layer 12 is 0° (corresponding to the black double arrow in the light-absorbing anisotropic layer 12 in Figure 2). Furthermore, in the configuration shown in Figure 2, the polarizer 16 has an absorption axis in a direction orthogonal to the left-right direction of the paper (corresponding to the black double arrow in the polarizer 16 in Figure 2).

[0287] In the film of the second embodiment having the structure shown in FIG2, light incident from the transmissivity central axis direction of the light-absorbing anisotropic layer 12 (the direction of the black arrow in FIG2) is transmitted through the light-absorbing anisotropic layer 12. Of the transmitted light, a portion of the polarized component vibrating in a direction orthogonal to the left-right direction of the paper is absorbed by the polarizer 16, but a portion is transmitted through the polarizer 16.

[0288] On the other hand, for light incident from a direction inclined relative to the central axis of transmittance (the direction of the hollow arrow in Figure 2), a portion of the component with vibrational direction in both its direction and the in-plane direction of the plane of the central axis of transmittance (hereinafter referred to as "P-polarized light") is absorbed by the light-absorbing anisotropic layer 12, while the component with vibrational direction orthogonal to the P-polarized light (hereinafter referred to as "S-polarized light") is almost not absorbed by the light-absorbing anisotropic layer 12 and is transmitted. Thus, light incident from a direction inclined relative to the central axis of transmittance, if the transmitted light absorbs the anisotropic layer 12, becomes light with a predominantly S-polarized component.

[0289] Here, in Figure 2, the direction inclined from the center axis of transmittance and the plane of the center axis of transmittance are orthogonal to the absorption axis direction of the polarizer 16. Regarding the absorption of the S-polarized light component in the light from the anisotropic layer 12 by the transmitted light, in the manner shown in Figure 2, the absorption axis direction of the polarizer 16 is approximately aligned with the vibration direction of the S-polarized light, and therefore it is absorbed by the polarizer 16.

[0290] Therefore, in the configuration shown in Figure 2, light incident from a direction inclined from the transmissivity central axis at a specified azimuth angle is absorbed by the light-absorbing anisotropic layer 12 or the polarizer 16. On the other hand, a portion of the light incident from the transmissivity central axis direction is not absorbed and is transmitted. Therefore, when the configuration shown in Figure 2 is applied to AR glasses, it functions as a filter with high transmissivity for light incident from the transmissivity central axis direction (e.g., the visual recognition direction) and low transmissivity for light incident from the inclined direction. This filter can prevent external light from incident from the inclined direction onto the diffraction elements in the AR glasses, thus suppressing rainbow patterns when applied to AR glasses.

[0291] Furthermore, in the configuration shown in Figure 2, for light incident in a plane parallel to the absorption axis of the polarizer 16 and the central axis of transmittance, and incident from a direction inclined from the central axis of transmittance, the S-polarized component is not absorbed by the polarizer 16 and is transmitted. Therefore, the orientation of the absorption axis of the polarizer 16 can be appropriately adjusted according to the direction of the light to be blocked.

[0292] Hereinafter, a second embodiment of the membrane of the present invention will be described in detail.

[0293] (Maximum height difference of ripples) As described above, in the second embodiment of the membrane of the present invention, the maximum height difference of ripples in a 10mm×10mm area is less than 1.2μm.

[0294] The maximum height difference of the ripples of the membrane of the present invention is the same in both the first embodiment and the preferred embodiment, therefore the description is omitted.

[0295] (Light-absorbing anisotropic layer) A second embodiment of the film of the present invention includes a light-absorbing anisotropic layer. In the light-absorbing anisotropic layer, the angle between the central axis of the transmittance of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer is 0 to 45°.

[0296] The light-absorbing anisotropic layer in the second embodiment of the membrane of the present invention is the same as the light-absorbing anisotropic layer in the first embodiment and its preferred embodiment, therefore, the description is omitted.

[0297] (Polarizer) A second embodiment of the membrane of the present invention includes a polarizer.

[0298] The polarizer is preferably a linear polarizer having an absorption axis in the in-plane direction. As a linear polarizer, known linear polarizers can be used.

[0299] Examples of linear polarizers include, for example, absorptive polarizers containing iodine compounds and reflective polarizers such as wire grids. Furthermore, the polarization axis has the same meaning as the transmission axis.

[0300] As an absorptive polarizer, any of the following can be used: iodine-based polarizers, dye-based polarizers utilizing dichroic dyes, and polyene-based polarizers. Iodine-based and dye-based polarizers are generally manufactured by adsorbing iodine or dichroic dyes onto polyvinyl alcohol and then stretching it.

[0301] Furthermore, a linear polarizer that orients the aforementioned dichroic pigments in the in-plane direction can also be used.

[0302] (Adhesive layer and adhesive layer) A second embodiment of the membrane of the present invention may include at least one of an adhesive layer and an adhesive layer.

[0303] The adhesive layer and the bonding agent layer in the second embodiment of the membrane of the present invention are the same as those in the first embodiment, including the preferred embodiment, and therefore description is omitted.

[0304] (Phase difference layer) A second embodiment of the film of the present invention may include a phase difference layer. In the second embodiment of the film of the present invention, the phase difference layer is preferably disposed between the light absorption anisotropic layer and the polarizer.

[0305] As a phase difference layer, plate B can be preferably exemplified, for example.

[0306] B-plate refers to a biaxial optical component with different refractive indices nx, ny, and nz.

[0307] The Re (in-plane delay) of the B-plate is greater than 80nm and less than 250nm, more preferably greater than 100nm and less than 250nm, and even more preferably greater than 100nm and less than 200nm.

[0308] Furthermore, the Nz coefficient of plate B is preferably greater than 1.5, more preferably 2.0 or more and 10.0 or less, and even more preferably 3.0 or more and 5.0 or less. Additionally, the Nz coefficient is a value calculated by Nz = (nx - nz) / (nx - ny).

[0309] The Rth of plate B is preferably set to a range that takes into account the aforementioned Re and Nz coefficients, specifically, it is preferably greater than 60nm.

[0310] Furthermore, when the direction of the absorber's absorption axis is set to 0°, the azimuth angle of the slow axis of plate B (the angle formed with the absorber's absorption axis) is preferably -10 to 10°, more preferably -5 to 5°, and most preferably 0° (i.e., parallel to the absorber's absorption axis). That is, the angle formed by the slow axis of plate B and the absorber's absorption axis is preferably 10° or less, more preferably 5° or less, and most preferably 0°.

[0311] If the optical characteristics of plate B are within the above range, then when viewed from an inclined direction in a position where the absorption axis of the polarizer is neither horizontal nor vertical within the film surface, the deviation of the absorption axis of the polarizer from the vertical direction can be compensated, and the transmittance in that direction can be reduced.

[0312] In the filter of the present invention, a combination of a positive A plate and a positive C plate can also be suitably exemplified as the phase retardation layer. That is, a laminate formed by stacking a positive A plate and a positive C plate can also be suitably exemplified as the phase retardation layer.

[0313] Here, the positive A plate refers to an optical component whose refractive indices nx, ny, and nz satisfy the following equation (1).

[0314] Equation (1): nx>ny≈nz and positive C plate refers to an optical component whose refractive indices nx, ny and nz satisfy the above equation (2).

[0315] The Re of the laminate of the positive C plate and the positive A plate is preferably greater than 80 nm and less than 250 nm, more preferably 100 to 200 nm, and even more preferably 100 to 150 nm. In addition, since the Re of the positive C plate is approximately 0, the Re of the laminate of the positive C plate and the positive A plate is approximately the same as the Re of the positive A plate, and the slow axis of the laminate of the positive C plate and the positive A plate is approximately the same as the slow axis of the positive A plate.

[0316] Furthermore, the azimuth angle of the slow axis of the positive A plate is preferably 80–100°, more preferably 85–95°, and even more preferably 90° (i.e., perpendicular to the absorption axis of the polarizer). That is, the angle between the slow axis of the positive A plate and the absorption axis of the polarizer is preferably 80–100°, more preferably 85–95°, and even more preferably 90°.

[0317] The Rth of the laminate of positive C plate and positive A plate is preferably less than -60 nm, more preferably -600 to -100 nm, and even more preferably -500 nm to -200 nm. In addition, since positive A plate satisfies Rth≈Re / 2, the Rth of the laminate of positive C plate and positive A plate is the sum of the Rth of positive A plate and positive C plate.

[0318] If the optical characteristics of the positive C plate and the positive A plate are within the above range, then when viewed from an oblique direction in an orientation that is neither horizontal nor vertical to the absorption axis of the polarizer within the film surface, the deviation of the polarizer absorption axis from the vertical direction can be compensated, and the transmittance in that direction can be reduced.

[0319] Furthermore, the wavelength dispersion of Re and Rth of the positive C plate and the positive A plate is preferably inverse dispersion.

[0320] More specifically, the wavelength dependence of the phase difference layer preferably satisfies Re(450nm) < Re(550nm) < Re(650nm) or Rth(450nm) < Rth(550nm) < Rth(650nm).

[0321] (Orientation film) A second embodiment of the film of the present invention may include an orientation film. The orientation film in the second embodiment of the film of the present invention is the same as that in the first embodiment and the preferred embodiment, therefore, the description is omitted.

[0322] (Anti-reflective layer) A second embodiment of the film of the present invention may include an anti-reflective layer. The anti-reflective layer in the second embodiment of the film of the present invention is the same as that in the first embodiment and the preferred embodiment, therefore, the description is omitted.

[0323] Furthermore, the surface reflectance of the membrane in the second embodiment of the present invention is preferably the same as that in the first embodiment, therefore the description is omitted.

[0324] Furthermore, the second embodiment of the membrane of the present invention may have other layers described in the first embodiment of the membrane of the present invention.

[0325] <Optical Components> The optical components of the present invention include the film (first embodiment and second embodiment) of the present invention described above and a transparent support.

[0326] The following describes the possible structures of the transparent support and the optical components of the present invention.

[0327] [Transparent Support] The optical component of the present invention includes a transparent support.

[0328] In the embodiment shown in Figure 3 described later, the transparent support included in the optical component is a cover glass. However, there are no particular limitations as long as the transparent support can support the film of the present invention, and any known transparent support can be used. Furthermore, the transparent support refers to a support with a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more.

[0329] The materials constituting the transparent support can be organic materials such as polymers, or inorganic materials such as glass.

[0330] Examples of polymers constituting transparent supports include, for example, cellulose polymers; acrylic polymers containing acrylate polymers such as polymethyl methacrylate and polymers containing lactone rings; thermoplastic norbornene polymers; polycarbonate polymers; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such as polystyrene and acrylonitrile-styrene copolymers; polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymers; vinyl chloride polymers; amide polymers such as nylon and aromatic polyamides; imide polymers; sulfone polymers; polyethersulfone polymers; polyetheretherketone polymers; polyphenylene sulfide polymers; vinylidene chloride polymers; vinyl alcohol polymers; vinyl butyral polymers; aromatic ester polymers; polyoxymethylene polymers; epoxy polymers; or polymers composed of mixtures of these polymers.

[0331] The glass used to form the transparent support can be any type of glass known in the past.

[0332] From the viewpoint of further suppressing the generation of multiple images when applying optical components to AR glasses, the maximum height difference of the ripples on one side of the film with the transparent support is preferably 0.8 μm or less, more preferably 0.6 μm or less. There is no particular limitation on the lower limit of the maximum height difference of the ripples on one side of the film with the transparent support, but it is generally 0.01 μm or more. The maximum height difference of the ripples in the transparent support can be obtained by the same method as measuring the average value Wg of the maximum height difference of the ripples in the aforementioned film.

[0333] The transparent support may have a protective layer on the surface opposite to the side where the membrane of the present invention is disposed. The protective layer preferably has the following functions: high surface hardness, and prevention of scratches on the surface of the transparent support when other objects come into contact with it.

[0334] There are no particular restrictions on the shape of the transparent support. It can be a long strip or a shape corresponding to the head-mounted display. Furthermore, the transparent support can be flat or have curved surfaces.

[0335] Furthermore, when the transparent support is not planar, the overall shape of the transparent support can be removed when analyzing the maximum height difference of the aforementioned ripples, thereby calculating the maximum height difference of the ripples.

[0336] [Adhesive Layer and Adhesive Layer] The optical component of the present invention may include an adhesive layer or adhesive layer between the transparent support and the film of the present invention described above.

[0337] The adhesive layer and bonding agent layer that the optical component may include are the same as those of the adhesive layer and bonding agent layer of the film of the present invention (first embodiment and second embodiment) described above, so the description is omitted.

[0338] In the case where the membrane of the present invention (the first and second embodiments described above) includes an anti-reflective layer, the anti-reflective layer is preferably disposed on the side opposite to the transparent support side.

[0339] <Optical Device and Head-Mounted Display> The optical device of the present invention includes a light guide plate on which the optical components and diffraction elements of the present invention are disposed on a surface, wherein the optical components and the light guide plate are disposed at intervals.

[0340] Furthermore, the head-mounted display of the present invention includes the optical device and image display element described above.

[0341] Hereinafter, a head-mounted display incorporating the optical device of the present invention will be described with reference to the accompanying drawings.

[0342] Figure 3 is a cross-sectional schematic diagram showing a portion of the AR glasses (the head-mounted display of the present invention).

[0343] Specifically, the AR glasses 40 shown in Figure 3 include an optical device 30 and an image display element 42 that allows image light L1 to be incident on the optical device.

[0344] Optical device 30C includes a light guide plate 32 and an incident diffraction element 34 and an exit diffraction element 36 disposed on the side of the light guide plate 32 opposite to the image display element 42 side. Furthermore, optical device 30 includes an optical component 20 composed of a cover glass 22 and a film 10. In the optical component 20, the film 10 is disposed on the side of the light guide plate 32. Additionally, the film 10 is spaced apart from the incident diffraction element 34 and the exit diffraction element 36.

[0345] The optical device 30 shown in Figure 3 is an optical device of the present invention that includes the film of the present invention.

[0346] The position of the incident diffraction element 34 corresponds to the incident position of the image light L1 from the image display element 42. The position of the exit diffraction element 36 corresponds to the exit position of the image light L1 from the light guide plate 32, that is, the observation position of the user observing the image light L1.

[0347] The incident diffraction element 34 causes the image light L1 incident from the image display element 42 onto the light guide plate 32 to diffract within the light guide plate 32. The diffracted image light L1 undergoes total internal reflection within the light guide plate 32 and travels in the in-plane direction of the light guide plate 32. The exit diffraction element 36 causes the light propagating within the light guide plate 32 to diffract towards the user side.

[0348] In the emitted diffraction element 36 of this AR glasses 40, as described above, sometimes a portion of the image light L1 is emitted towards the side opposite to the user's side (the optical component 20 side), generating stray light Ls. It is believed that even when such stray light Ls is generated, since the maximum height difference of the ripples of the film 10 (the film of the present invention) is below a predetermined value, the stray light Ls is reflected in a direction parallel to the image light L1, thus making it less likely to produce multiple images.

[0349] The light guide plate 32 included in the optical device 30 is not particularly limited, and conventionally known light guide plates used in various AR glasses, backlight units of liquid crystal display devices, and image display devices can be used.

[0350] The incident diffraction element 34 and the emitted diffraction element 36 included in the aforementioned optical device 30 are transmission-type diffraction elements. Through the incident diffraction element 34 and the emitted diffraction element 36, the scenery behind can be visually recognized simultaneously. There are no particular limitations on transmission-type diffraction elements. For example, known diffraction elements used in AR glasses, such as relief diffraction elements, liquid crystal diffraction elements, and volumetric holographic diffraction elements, can be used.

[0351] In addition, at least one of the incident diffraction element 34 and the emitted diffraction element 36 can be a reflection type diffraction element.

[0352] The image display element 42 included in the head-mounted display of the present invention is not particularly limited, and various image display elements, such as known image display elements (displays) used in various image display devices such as AR glasses, can be used.

[0353] As an example of image display element 86, liquid crystal displays, organic electroluminescent displays, DLP (Digital Light Processing), MEMS (Micro-Electro-Mechanical Systems) displays, and micro LED (Light Emitting Diode) displays can be cited. Furthermore, liquid crystal displays include LCOS (Liquid Crystal On Silicon).

[0354] In addition, the image display element 86 can display monochrome images, dual-color images, or color images.

[0355] In the AR glasses 40 shown in Figure 3, in addition to the incident diffraction element 34 and the emitted diffraction element 36, an intermediate diffraction element may also be provided. The intermediate diffraction element has the function of bending the travel direction of the image light L1, which is guided into the light guide plate through the incident diffraction element, toward the direction in which the emitted diffraction element 36 is disposed. As the intermediate diffraction element, the same diffraction element as the aforementioned incident diffraction element 34 and emitted diffraction element 36 can be used.

[0356] Furthermore, in the AR glasses 40 shown in FIG3, the film 10 is disposed on the side of the light guide plate 32 in the optical component 20 included in the optical device 30. However, the film 10 may also be disposed on the side opposite to the light guide plate 32 in the optical component 20 included in the optical device 30. That is, the cover glass 22 (transparent support) in the optical component 20 may be disposed on the side of the light guide plate 32.

[0357] By adopting the structure described above, stray light Ls is less likely to be reflected by the film 10, which can further suppress the generation of multiple images.

[0358] Furthermore, the membrane (membrane 10) of the present invention can suppress rainbow patterns, and therefore rainbow patterns can be suppressed in the head-mounted display (AR glasses 40) of the present invention, which includes the membrane of the present invention.

[0359] In the optical device 30, the optical component 20 is preferably configured to overlap at least with the regions corresponding to the incident diffraction element 34 and the emitted diffraction element 36 disposed on the light guide plate 32.

[0360] By configuring the optical component 20 to overlap with the aforementioned area, external light from the tilted direction is less likely to strike the incident diffraction element 34 and the emitted diffraction element 36, thereby further suppressing the generation of rainbow patterns.

[0361] The present invention will be described in more detail below with reference to the embodiments.

[0362] The materials, quantities, proportions, processing contents, and processing order shown in the following embodiments can be appropriately modified as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as limited by the embodiments shown below.

[0363] <Example 1> The head-mounted display (AR glasses) A1 used in Example 1 was fabricated by obtaining film 1 according to the following steps.

[0364] [Fabrication of anisotropic light absorption layer] Anisotropic light absorption layer was fabricated following the steps below.

[0365] (Formation of Orientation Film) The surface of a 40 μm thick cellulose acylated film (TAC substrate; manufactured by FUJIFILM Corporation, TG40) was saponified with an alkaline solution, and the following orientation film forming composition 1 was coated onto it with a wire rod.

[0366] The coated support was dried with warm air at 60°C for 60 seconds, and then dried with warm air at 100°C for 120 seconds to form an oriented film AL1, thereby obtaining a cellulose acylated film 1 with an oriented film. The thickness of the oriented film AL1 was 1 μm.

[0367] ――――――――――――――――――――――――――――――――Orientation Film Forming Composition 1――――――――――――――――――――――――――――― · Modified polyvinyl alcohol PVA-1 3.80 parts by weight · IRGACURE 2959 0.20 parts by weight · Water 70 parts by weight · Methanol 30 parts by weight ――――――――――――――――――――――――――――――― Modified polyvinyl alcohol PVA-1 [Chemical Formula 6] (Formation of light-absorbing anisotropic layer V1) The following light-absorbing anisotropic layer formation composition P1 was continuously coated onto the obtained cellulose acylated film 1 with an oriented film using a winding bar, and then heated at 120°C for 60 seconds and cooled to room temperature (23°C).

[0368] Next, heat at 85°C for 60 seconds and then cool to room temperature again.

[0369] Then, using an LED light (center wavelength 365nm) at an illuminance of 200mW / cm², 2 Under the irradiation conditions, the film was irradiated from the normal direction for 2 seconds, thereby fabricating a light-absorbing anisotropic layer V1 on the alignment film AL1. The thickness of the light-absorbing anisotropic layer V1 is 2.7 μm.

[0370] ――――――――――――――――――――――――――――――――― Composition P1 for Forming Anisotropic Layers of Light Absorption ――――――――――――――――――――――――――――――― · 0.69 parts by weight of the following dichroic substance D-1 · 0.17 parts by weight of the following dichroic substance D-2 · 1.13 parts by weight of the following dichroic substance D-3 · 8.67 parts by weight of the following polymeric liquid crystal compound P-1 · 1.97 parts by weight of the following liquid crystal compound L-1 · 0.20 parts by weight of IRGACURE OXE-02 (manufactured by BASF) · 0.16 parts by weight of the following alignment agent E-1 · 0.16 parts by weight of the following alignment agent E-2 · 0.16 parts by weight of the following surfactant F-1 0.012 parts by weight · 78.17 parts by weight · 8.69 parts by weight ―――――――――――――――――――――――――――――――― Dichroic substance D-1 [Chemical Formula 7] Dichroic substance D-2 [Chemical Formula 8] Dichroic substance D-3 [Chemical Formula 9] P-1, a polymeric liquid crystal compound [Chemical Formula 10] Liquid crystal compound L-1 [a mixture of the following liquid crystal compounds (RA), (RB) and (RC) in an 84:14:2 (mass ratio)][Chemical Formula 11] Orientation agent E-1 [Chemical Formula 12] Orientation agent E-2 [Chemical Formula 13] Surfactant F-1 (in the following formula, TMS represents trimethylsilyl.) [Chemical Formula 14] (Formation of protective layer H1) A protective layer forming composition B1 is continuously coated onto the obtained light absorption anisotropic layer V1 using a winding bar to form a coated film.

[0371] Next, the support with the coated film was dried with warm air at 60°C for 60 seconds, and then further dried with warm air at 100°C for 120 seconds to form a protective layer H1, thus fabricating an optical film Vf with an anisotropic light absorption layer V1. The thickness of the protective layer was 0.5 μm. Furthermore, the angle between the central axis of the transmittance of the anisotropic light absorption layer V1 and the normal direction of the anisotropic light absorption layer V1 was measured using the above steps, and the result was 0°.

[0372] ― ... Pigment compound G-1 [Chemical Formula 16] [Creation of the Phase Difference Layer] The phase difference layer was created following these steps.

[0373] (Formation of Orientation Film 2) The following orientation film forming composition 2 was continuously coated onto one side of a 40 μm thick cellulose acylate film (TAC substrate; manufactured by FUJIFILM Co., Ltd., TG40) using a #14 wire rod. After coating, it was dried with warm air at 60°C for 60 seconds, and then dried with warm air at 100°C for 120 seconds.

[0374] Composition of the alignment film forming composition 2: 10 parts by weight of the above-mentioned modified polyvinyl alcohol PVA-1, 308 parts by weight of water, 70 parts by weight of methanol, 29 parts by weight of isopropanol, and 0.8 parts by weight of photopolymerization initiator (Irgacure-2959, manufactured by BASF). (Formation of λ / 2 layer) The alignment film 2 prepared above was continuously subjected to friction treatment. At this time, the length direction of the elongated film is parallel to the conveying direction. The angle between the length direction of the film and the rotation axis of the friction roller is set to 90° (the width direction of the film is set to 0° and the length direction of the film is set to 90°. When viewed from the orientation film side, the width direction of the film is used as the reference, and a positive value is used to represent the clockwise direction. Then the rotation axis of the friction roller is 0°).

[0375] A phase retardation layer coating solution containing a disk-shaped liquid crystal compound with the following composition was continuously coated onto the alignment film 2 prepared above using a #5.0 wire rod to form a λ / 2 layer. The film transport speed (V) was set to 26 m / min. To dry the solvent of the coating solution and cure the orientation of the disk-shaped liquid crystal compound, it was heated with warm air at 130°C for 90 seconds, followed by heating with warm air at 100°C for 60 seconds, and then UV irradiated at 80°C to fix the orientation of the liquid crystal compound, thus obtaining an optical film Rf with a λ / 2 layer. The thickness of the λ / 2 layer is 2.2 μm, and the Re at 550 nm is 270 nm. It was confirmed that the average tilt angle of the disk surface of the disk-shaped liquid crystal compound relative to the film surface is 90°, and the disk-shaped liquid crystal compound is perpendicularly aligned to the film surface. Furthermore, if the slow axis angle of the λ / 2 layer is parallel to the rotation axis of the friction roller, and the width direction of the film is set to 0° (and the length direction is set to 90°), then when viewed from the λ / 2 layer side, the slow axis is 0°.

[0376] ― ... Disk-shaped liquid crystal-2 [Chemical Formula 18] Orientation agent-3 for orientation film interface [Chemical formula 19] Orientation agent-4 for orientation film interface [Chemical formula 20] Surfactant F-2 [Chemical Formula 21] [Fabrication of Membrane 1] The side of the optical membrane Vf with the protective layer H1 formed thereon, which has the above-mentioned light absorption anisotropic layer V1, was bonded to the side of the optical membrane Rf with the above-mentioned λ / 2 plate using an adhesive layer (Opteria (registered trademark) NCF-D692 (membrane thickness: 15μm, manufactured by LINTEC Corporation)).

[0377] Furthermore, an optical film Rf having a λ / 2 layer different from the optical film Rf to be bonded was prepared, and the λ / 2 layer side surface was bonded to the λ / 2 layer side surface bonded in the above step using the aforementioned adhesive layer. During the bonding of the λ / 2 layers, the bonding was performed such that the angle between the in-plane slow axis of one λ / 2 layer and the in-plane slow axis of the other λ / 2 layer was 45°.

[0378] Next, an optical film Vf with an anisotropic light absorption layer V1 different from the optical film Vf to be bonded was prepared. The side of the optical film Vf with the protective layer H1 formed was bonded to the cellulose acylate film side of the bonded optical film Rf using the aforementioned adhesive layer. After bonding, the film was further processed in an autoclave (Model: PTU507H, manufactured by HIRAYAMA MFG. CORP.) at 50°C and 5 atmospheres for 30 minutes to obtain film 1. Film 1 consists of optical film Vf, optical film Rf, optical film Rf, and optical film Vf, which are bonded together using the aforementioned adhesive layer (refer to the table below).

[0379] [Determination of the maximum height difference of the corrugations] In the above steps, the maximum height difference of the corrugations of the fabricated membrane 1 was measured.

[0380] In addition, the average value (Wg) of the maximum height difference of the ripples of the glass with film 1 attached is 0.4 μm.

[0381] The measurement results are shown in the table below.

[0382] [Measurement of Surface Reflectivity] In the above steps, the surface reflectivity of the fabricated film 1 was measured.

[0383] In addition, the surface reflectance of the above-mentioned cellulose acylated film is 4.0%.

[0384] [Fabrication of Optical Component O1] The above-described film 1 and glass (manufactured by Corning Incorporated Co., Ltd., EAGLE XG) were bonded together with the same adhesive layer as described above to obtain optical component O1.

[0385] [Manufacturing of Head-Mounted Display A1] The cover glass (right eye side) on one side of the light guide plate equipped with Vuzix Blade 2 SMART GLASSES (manufactured by Vuzix Corporation) was removed. Then, the optical component O1 was arranged at the location where the cover glass was removed, with the film 1 side of the aforementioned optical component O1 being the light guide plate side, thus obtaining the head-mounted display A1.

[0386] <Example 2> A head-mounted display A2 was fabricated by obtaining membrane 2 through the following steps.

[0387] [Fabrication of Polarizer] A polarizer with a thickness of 8 μm and one side of the polarizer exposed was obtained by means of the same method as that described in International Publication No. 2015 / 166991 for a polarizer 02 with a single-sided protective film.

[0388] [Fabrication of Film 2] Film 2 was obtained by bonding the polarizer side of the polarizer to the protective layer H1 on which the optical film Vf having the light absorption anisotropy layer V1 is formed by the adhesive layer described above. In addition, a high-pressure reactor-based processing was performed using the same steps as when obtaining film 1.

[0389] [Fabrication of Head-Mounted Display A2] The film 1 used in the fabrication of the optical component O1 in Example 1 was replaced with the film 2 described above. Otherwise, the optical component O2 was obtained in the same manner as in Example 1, thereby obtaining the head-mounted display A2.

[0390] <Example 3> A head-mounted display A3 was fabricated by obtaining film 3 through the following steps.

[0391] [Fabrication of Antireflective Film] Using a 40 μm thick cellulose acylate film (TAC substrate; manufactured by FUJIFILM Corporation, TG40) as the substrate, an antireflective film with a three-layer structure on its surface was fabricated according to Example 1, Antireflective Film No. 1, in Japanese Patent Application Publication No. 2008-262187. The surface reflectivity of the fabricated antireflective film on the side opposite to the substrate was measured using the above method, and the result was 0.4%.

[0392] [Fabrication of Film 3] Film 3 was obtained by bonding one side of film 1 obtained in Example 1 to the substrate side of the antireflective film using the adhesive layer described above. Furthermore, autoclave-based processing was performed using the same steps as when film 1 was obtained.

[0393] [Fabrication of Head-Mounted Display A3] The film 1 used in the fabrication of the optical component O1 in Example 1 was replaced with the aforementioned film 3. Otherwise, the optical component O3 was obtained in the same manner as in Example 1, thereby obtaining the head-mounted display A2. In addition, when fabricating the optical component O3, one side of the glass was bonded to the side of the film 3 opposite to the anti-reflective film side.

[0394] <Example 4> A head-mounted display A4 was fabricated by obtaining film 4 through the following steps.

[0395] [Fabrication of Membrane 4] The thickness of the adhesive layer (film thickness: 15 μm) used in the fabrication of membrane 1 was changed to 5 μm, and membrane 4 was obtained in the same manner as membrane 1.

[0396] [Fabrication of Head-Mounted Display A4] The film 1 used in the fabrication of the optical component O1 in Example 1 was changed to the film 4 described above, and the thickness of the adhesive layer used for bonding with the glass was changed to 5 μm. Otherwise, the optical component O4 was obtained in the same manner as in Example 1, thereby obtaining the head-mounted display A4.

[0397] <Example 5> A head-mounted display A5 was manufactured using the following steps.

[0398] [Fabrication of Head-Mounted Display A5] In the fabrication of the head-mounted display A1 obtained in Example 1, the optical component O1 was configured such that the glass side of the optical component O1 became the light guide plate side. Otherwise, the head-mounted display A5 was obtained in the same manner as the head-mounted display A1.

[0399] <Example 6> A head-mounted display A6 was fabricated by obtaining film 6 through the following steps.

[0400] [Fabrication of Phase Difference Layer B] Phase difference layer B was fabricated using the following steps.

[0401] (Extrusion Molding) The cyclic olefin resin (ARTON G7810 (manufactured by JSR Corporation)) is dried at 100°C for more than 2 hours, and then melt-extruded at 280°C using a twin-shaft compounding extruder to obtain an unstretched film. In addition, a screen filter, a gear pump, and an impeller filter are sequentially arranged between the extruder and the die, and they are connected by melt piping.

[0402] Melt extrusion is performed from a T-die with a width of 1000 mm and a lip gap of 1 mm, and casting is carried out on three consecutive casting rollers set at 180°C, 175°C and 170°C to obtain an unstretched film.

[0403] (Stretching / Heat Setting) The above-mentioned unstretched film was stretched using the following method.

[0404] For unstretched film, longitudinal stretching was performed under the following conditions while conveying it using an inter-roll longitudinal stretching machine with an aspect ratio (L / W) of 0.2.

[0405] -Conditions- Preheating temperature: 175℃; Stretching temperature: 175℃; Stretching ratio: 90%. The obtained stretched film has a Re at 550nm of 270nm, an Rth of 140nm, and a film thickness of 35μm. The stretched film obtained through the above steps is designated as phase retardation layer B. It is also referred to as "λ / 2 layer B" in the table below.

[0406] [Preparation of Adhesive Layer D] An acrylate polymer was prepared by the following steps to prepare adhesive layer D.

[0407] In a reaction vessel equipped with a cooling pipe, a nitrogen inlet pipe, a thermometer, and a stirring device, 43 parts by mass of butyl acrylate, 55 parts by mass of benzyl acrylate, 3 parts by mass of acrylic acid, 0.3 parts by mass of 2,2'-azobisisobutyronitrile, and ethyl acetate were added together to prepare a reaction solution with a solid content of 30% by mass. The reaction solution was reacted at 60°C for 4 hours under a nitrogen flow to obtain an acrylate polymer solution. The average refractive index of the obtained acrylate polymer was measured using an Abbe refractometer (manufactured by ATAGO CO.,LTD.) at an environment of 23.5–26.5°C, and the result was a refractive index of 1.52.

[0408] Next, using the obtained acrylate polymer, adhesive layer D was prepared according to the following steps. 2 parts by mass of trimethylolpropane toluene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., CORONATE L) and 0.1 parts by mass of 3-glycidoxypropyltrimethoxysilane were added relative to 100 parts by mass of the acrylate polymer solids to obtain a coating solution for forming the adhesive layer. The coating solution for forming the adhesive layer was applied to a release membrane that had been surface-treated with a silicone-based release agent using a die coater, and dried at 150°C for 3 hours to obtain adhesive layer D.

[0409] The adhesive layer D has a film thickness of 15 μm.

[0410] [Fabrication of membrane 6] The adhesive layer (film thickness: 15 μm) used in the fabrication of membrane 3 was changed to adhesive layer D, and the phase difference layer was changed to phase difference layer B. Otherwise, membrane 6 was obtained in the same manner as membrane 3.

[0411] [Fabrication of Head-Mounted Display A6] The film 1 used in the fabrication of the optical component O1 in Example 1 was replaced with the film 6 described above, and the adhesive layer used for bonding with the glass was replaced with a pressure-sensitive adhesive layer D. Otherwise, the optical component O6 was obtained in the same manner as in Example 1, thereby obtaining the head-mounted display A6.

[0412] <Comparative Example 1> The membrane C1 was obtained by following the steps below, and the head-mounted display B1 of Comparative Example 1 was fabricated.

[0413] [Fabrication of Membrane C1] The adhesive layer (membrane thickness: 15 μm) used in the fabrication of membrane 1 was changed to adhesive layer C (SK2057 (membrane thickness: 25 μm, manufactured by Soken Chemical & Engineering Co., Ltd.)). Otherwise, membrane C1 was obtained in the same manner as membrane 1. In addition, the autoclave treatment described above was not performed when obtaining membrane C1.

[0414] [Fabrication of Head-Mounted Display B1] The film 1 used in the fabrication of the optical component O1 in Example 1 was replaced with the film C1 described above, and the adhesive layer used for bonding with the glass was replaced with the adhesive layer C described above. Otherwise, the optical component OC1 was obtained in the same manner as in Example 1, thereby obtaining the head-mounted display B1.

[0415] In addition, the maximum height difference of the ripples and the surface reflectivity of the films obtained in each embodiment and comparative example were measured in the same manner as in Example 1.

[0416] <Evaluation of Multiple Images> Multiple images were evaluated for the head-mounted displays of the various embodiments and comparative examples.

[0417] Specifically, an image was displayed on a head-mounted display, and the visual effect of the image was evaluated according to the following criteria. The evaluation results are shown in the table below. Furthermore, in practical applications, evaluation A, evaluation B, or evaluation C is preferred, evaluation A or evaluation B is more preferred, and evaluation A is even more preferred.

[0418] • A: The image is not displayed in multiple ways, and the image can be clearly identified.

[0419] • B: There is a faintly visible image superimposed at a position slightly offset from the main image, which is slightly noticeable.

[0420] • C: There is a slightly visible image superimposed at a position slightly offset from the main image, which is slightly noticeable.

[0421] • D: The image is visible overlapping the main image at a position offset from it, which is very noticeable.

[0422] <Results> The structure, measurement results and evaluation of the head-mounted displays of each embodiment and comparative example are shown in the table.

[0423] In addition, details regarding the various structures, such as the alignment film, protective layer, and cellulose acylate film, are omitted.

[0424] [Table 1] Based on the results shown in Table 1, it was confirmed that when a film with a maximum height difference of less than 1.2 μm in the ripples of a 10 mm × 10 mm area on the film surface is applied to AR glasses, the generation of multiple images is suppressed (Examples 1-6).

[0425] On the other hand, according to the results shown in Table 1, if the maximum height difference of the above-mentioned ripples exceeds 1.2 μm, the generation of multiple images cannot be suppressed when the film is applied to AR glasses (Comparative Example 1).

[0426] Based on a comparison of Example 1 and Example 3, it was confirmed that when an anti-reflective layer disposed on the outermost side of the film is also included, multiple images are less likely to occur.

[0427] Based on a comparison of Examples 1 and 4, it was confirmed that the adhesive layer and the film have a thickness of 10 μm or less. It was also confirmed that when the film further includes one or more layers selected from the group consisting of adhesive layers with a thickness of 10 μm or less, multiple images are less likely to occur.

[0428] Based on a comparison of Examples 1 and 5, it was confirmed that when the transparent support (glass) in the optical component is positioned closer to the light guide plate than the film, multiple images are less likely to occur.

[0429] Symbol Explanation: 10, 10A, 10B, 10C - film; 12 - light absorption anisotropic layer; 12a - first light absorption anisotropic layer; 12b - second light absorption anisotropic layer; 14a - first phase difference layer; 14b - second phase difference layer; 16 - polarizer; 20, 20C - optical components; 22 - cover glass (transparent support); 30, 30C - optical device; 32 - light guide plate; 34 - incident diffraction element; 36 - emitted diffraction element; 40, 40C - AR glasses (head-mounted display).

Claims

1. A membrane comprising at least one light-absorbing anisotropic layer, wherein the angle between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer is 0 to 45°, and the maximum height difference of the ripples in a 10 mm × 10 mm area on the surface of the membrane is less than 1.2 μm.

2. The film according to claim 1, comprising two light-absorbing anisotropic layers, wherein at least one phase retardation layer is included between the two light-absorbing anisotropic layers.

3. The membrane according to claim 2, comprising two phase retardation layers, wherein the phase retardation layers are λ / 2 plates.

4. The membrane according to claim 1, further comprising a polarizer.

5. The membrane according to any one of claims 1 to 4, further comprising an antireflective layer disposed on the outermost side of the membrane.

6. The film according to any one of claims 1 to 4, wherein the surface reflectance is less than 1%.

7. The membrane according to any one of claims 1 to 4, further comprising one or more layers selected from the group consisting of an adhesive layer with a membrane thickness of 10 μm or less and an adhesive layer with a membrane thickness of 10 μm or less.

8. An optical component comprising the film and transparent support as described in any one of claims 1 to 4.

9. The optical component according to claim 8, wherein, The transparent support is made of glass.

10. An optical device comprising the optical component of claim 8 and a light guide plate with diffraction elements disposed on its surface, the optical component and the light guide plate being spaced apart.

11. The optical device according to claim 10, wherein, The transparent support in the optical component is positioned closer to the light guide plate than the film.

12. A head-mounted display comprising the optical device and image display element of claim 10.

13. A head-mounted display comprising the optical device and image display element of claim 11.

Images