JP2023166841A - Display system, display method, display body, and method for manufacturing display body - Google Patents

Abstract

To provide a display system capable of achieving weight reduction and high definition of a VR goggle.SOLUTION: A display system displays an image to a user. The display system comprises: a display element having a display surface that emits light representing the image forward via a polarization member; a reflection portion that is disposed in front of the display element, includes a reflection type polarization member, and reflects the light emitted from the display element; a first lens portion disposed on an optical path between the display element and the reflection portion; a half mirror that is disposed between the display element and the first lens portion, transmits the light emitted from the display element, and reflects the light reflected by the reflection portion toward the reflection portion; a first λ/4 member disposed on an optical path between the display element and the half mirror; and a second λ/4 member disposed on an optical path between the half mirror and the reflection portion. A slow axis of the first λ/4 member and a slow axis of the second λ/4 member are arranged so as to be substantially parallel to each other.SELECTED DRAWING: Figure 2

Description

The present invention relates to a display system, a display method, a display body, and a method for manufacturing a display body.

Image display devices represented by liquid crystal display devices and electroluminescent (EL) display devices (eg, organic EL display devices) are rapidly becoming popular. In image display devices, optical members such as polarizing members and retardation members are generally used to realize image display and improve image display performance (see, for example, Patent Document 1).

In recent years, new uses for image display devices have been developed. For example, goggles with a display (VR goggles) for realizing Virtual Reality (VR) have begun to be commercialized. Since VR goggles are being considered for use in a variety of situations, it is desired that they be lighter and have higher definition. Weight reduction can be achieved, for example, by making the lenses used in VR goggles thinner. On the other hand, there is also a desire for the development of optical members suitable for display systems using thin lenses.

JP2021-103286A

In view of the above, the main object of the present invention is to provide a display system that can reduce the weight and increase the definition of VR goggles.

According to one aspect of the present invention, the following display systems [1] to [7] are provided.
[1] A display system that displays images to a user,
a display element having a display surface that emits light representing an image forward through a polarizing member;
a reflecting section disposed in front of the display element, including a reflective polarizing member, and reflecting light emitted from the display element;
a first lens section disposed on an optical path between the display element and the reflection section;
a half mirror disposed between the display element and the first lens part, which transmits the light emitted from the display element and reflects the light reflected by the reflection part toward the reflection part;
a first λ/4 member disposed on an optical path between the display element and the half mirror;
a second λ/4 member disposed on the optical path between the half mirror and the reflecting section;
Equipped with
A display system, wherein a slow axis of the first λ/4 member and a slow axis of the second λ/4 member are arranged to be substantially parallel to each other.
[2] The display system according to [1], wherein the polarization direction of the light emitted through the polarizing member and the reflection axis of the reflective polarizing member are substantially orthogonal to each other.
[3] The angle between the absorption axis of the polarizing member included in the display element and the slow axis of the first λ/4 member is 40° to 50°,
The display system according to [1] or [2], wherein the angle between the absorption axis of the polarizing member and the slow axis of the second λ/4 member included in the display element is 40° to 50°. .
[4] The display system according to any one of [1] to [3], wherein the first lens portion and the half mirror are integrated.
[5] The display system according to any one of [1] to [4], including a second lens section disposed in front of the reflecting section.
[6] The display system according to any one of [1] to [5], wherein the reflecting section includes an absorbing polarizing member disposed in front of the reflective polarizing member.
[7] The display system according to [6], wherein the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member are arranged substantially parallel to each other.

According to another aspect of the present invention, the following display methods [8] to [9] are provided.
[8] Passing the light representing the image emitted through the polarizing member through the first λ/4 member;
a step of causing the light that has passed through the first λ/4 member to pass through a half mirror and a first lens portion;
passing the light that has passed through the half mirror and the first lens section through a second λ/4 member;
a step of reflecting the light that has passed through the second λ/4 member toward the half mirror by a reflecting section including a reflective polarizing member;
a step of allowing the light reflected by the reflection part and the half mirror to be transmitted through the reflection part by the second λ/4 member;
The slow axis of the first λ/4 member and the slow axis of the second λ/4 member are arranged so as to be substantially parallel to each other;
Display method.
[9] The display method according to [8], wherein the polarization direction of the light emitted through the polarizing member and the reflection axis of the reflective polarizing member are substantially orthogonal to each other.

According to another aspect of the present invention, there is provided a display body comprising the display system according to any one of [1] to [7] above.
According to yet another aspect of the present invention, there is provided a method for manufacturing a display body comprising the display system according to any one of [1] to [7] above.

According to the display system according to the embodiment of the present invention, it is possible to realize lightweight VR goggles and high definition.

1 is a schematic diagram showing a general configuration of a display system according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the progression and polarization state of light in a display system according to an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. Further, in order to make the explanation more clear, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the embodiment, but this is just an example, and the interpretation of the present invention is It is not limited.

(Definition of terms and symbols)
Definitions of terms and symbols used herein are as follows.
(1) Refractive index (nx, ny, nz)
"nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., slow axis direction), and "ny" is the direction perpendicular to the slow axis in the plane (i.e., fast axis direction) "nz" is the refractive index in the thickness direction.
(2) In-plane phase difference (Re)
"Re(λ)" is an in-plane retardation measured with light having a wavelength of λnm at 23°C. For example, "Re(550)" is an in-plane retardation measured with light having a wavelength of 550 nm at 23°C. Re(λ) is determined by the formula: Re(λ)=(nx−ny)×d, where d (nm) is the thickness of the layer (film).
(3) Phase difference in thickness direction (Rth)
"Rth (λ)" is a retardation in the thickness direction measured with light having a wavelength of λ nm at 23°C. For example, "Rth (550)" is the retardation in the thickness direction measured with light having a wavelength of 550 nm at 23°C. Rth(λ) is determined by the formula: Rth(λ)=(nx−nz)×d, where d (nm) is the thickness of the layer (film).
(4) Nz coefficient The Nz coefficient is determined by Nz=Rth/Re.
(5) Angle When an angle is referred to in this specification, unless otherwise specified, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Therefore, for example, "45°" means ±45°. Moreover, in this specification, "substantially parallel" includes cases where the angle is 0°±5°, preferably 0°±3°, more preferably 0°±1°, and even more preferably 0°±0. 5°, and "substantially perpendicular" includes cases where the angle is 90°±5°, preferably 90°±3°, more preferably 90°±1°, and even more preferably 90°±0.5°. It is.

FIG. 1 is a schematic diagram showing the general configuration of a display system according to one embodiment of the present invention. FIG. 1 schematically shows the arrangement, shape, etc. of each component of the display system 2. As shown in FIG. The display system 2 includes a display element 12, a reflection section 14 including a reflective polarizing member, a first lens section 16, a half mirror 18, a first retardation member 20, a second retardation member 22, and a second retardation member 22. It is equipped with two lens parts 24. The reflecting section 14 is disposed at the front of the display element 12 on the display surface 12a side, and can reflect light emitted from the display element 12. The first lens section 16 is arranged on the optical path between the display element 12 and the reflection section 14, and the half mirror 18 is arranged between the display element 12 and the first lens section 16. The first retardation member 20 is arranged on the optical path between the display element 12 and the half mirror 18, and the second retardation member 22 is arranged on the optical path between the half mirror 18 and the reflection section 14.

The components disposed in front of the half mirror (in the illustrated example, the half mirror 18, the first lens section 16, the second retardation member 22, the reflection section 14, and the second lens section 24) are collectively called a lens section (lens section). 4).

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

The first retardation member 20 is a λ/4 member that can convert the first linearly polarized light incident on the first retardation member 20 into first circularly polarized light (hereinafter, the first retardation member is referred to as the first (sometimes referred to as a λ/4 member). Note that the first retardation member 20 may be provided integrally with the display element 12.

The in-plane retardation Re (550) of the first retardation member 20 is, for example, 100 nm to 190 nm, may be 110 nm to 180 nm, may be 130 nm to 160 nm, or may be 135 nm to 155 nm. .

The first retardation member 20 preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases depending on the wavelength of the measurement light. Re(450)/Re(550) of the first retardation member 20 is, for example, less than 1 and may be 0.95 or less, further less than 0.90, and even 0.85 or less. good. Re(450)/Re(550) of the first retardation member 20 is, for example, 0.75 or more.

In one embodiment, the first retardation member 20 has Re(400)/Re(550)<0.85, Re(650)/Re(550)>1.03, and Re(750)/Re( 550)>1.05. The first retardation member 20 has 0.65<Re(400)/Re(550)<0.80 (preferably 0.7<Re(400)/Re(550)<0.75), 1. 0<Re(650)/Re(550)<1.25 (preferably 1.05<Re(650)/Re(550)<1.20) and 1.05<Re(750)/Re( 550)<1.40 (preferably 1.08<Re(750)/Re(550)<1.36), more preferably at least two. More preferably, all of them are satisfied.

The first retardation member 20 preferably exhibits a refractive index characteristic of nx>ny≧nz. Here, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where ny and nz are substantially equal. Therefore, there may be a case where ny<nz within a range that does not impair the effects of the present invention. The Nz coefficient of the first retardation member 20 is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, particularly preferably 0.9 to 1. It is 3.

The first retardation member 20 is formed of any suitable material that can satisfy the above characteristics. The first retardation member 20 may be, for example, a stretched resin film or an oriented solidified layer of a liquid crystal compound.

The resins contained in the above resin film include polycarbonate resin, polyester carbonate resin, polyester resin, polyvinyl acetal resin, polyarylate resin, cyclic olefin resin, cellulose resin, polyvinyl alcohol resin, and polyamide resin. , polyimide resin, polyether resin, polystyrene resin, acrylic resin, and the like. These resins may be used alone or in combination (for example, blended or copolymerized). When the first retardation member 20 exhibits reverse dispersion wavelength characteristics, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) may be suitably used.

As the polycarbonate resin, any suitable polycarbonate resin can be used as long as the effects of the present invention can be obtained. For example, polycarbonate resins contain structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene-based dihydroxy compounds. a structural unit derived from at least one dihydroxy compound selected from the group consisting of glycol or spiroglycol. Preferably, the polycarbonate resin contains a structural unit derived from a fluorene dihydroxy compound, a structural unit derived from an isosorbide dihydroxy compound, a structural unit derived from an alicyclic dimethanol, and/or a di, tri, or polyethylene glycol. More preferably, it contains a structural unit derived from a fluorene dihydroxy compound, a structural unit derived from an isosorbide dihydroxy compound, and a structural unit derived from di, tri or polyethylene glycol. . The polycarbonate resin may contain structural units derived from other dihydroxy compounds as necessary. Note that details of the polycarbonate-based resin that can be suitably used for the first retardation member and the method for forming the first retardation member can be found, for example, in JP-A No. 2014-10291, JP-A No. 2014-26266, and JP-A No. 2015-2015. It is described in JP-A-212816, JP-A-2015-212817, and JP-A-2015-212818, and the descriptions of these publications are incorporated herein by reference.

The thickness of the first retardation member 20 made of a stretched resin film is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 10 μm to 40 μm, and still more preferably 20 μm to 30 μm.

The liquid crystal compound orientation solidification layer is a layer in which the liquid crystal compound is oriented in a predetermined direction within the layer, and the orientation state is fixed. In addition, the "alignment hardened layer" is a concept that includes an orientation hardened layer obtained by curing a liquid crystal monomer as described below. In the first retardation member, rod-shaped liquid crystal compounds are typically aligned in the slow axis direction of the first retardation member (homogeneous alignment). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably polymerizable. If the liquid crystal compound is polymerizable, the alignment state of the liquid crystal compound can be fixed by aligning the liquid crystal compound and then polymerizing it.

The liquid crystal compound alignment and solidification layer (liquid crystal alignment solidification layer) is produced by subjecting the surface of a predetermined base material to an alignment treatment, applying a coating liquid containing the liquid crystal compound to the surface, and subjecting the liquid crystal compound to the alignment treatment. It can be formed by orienting it in a corresponding direction and fixing the orientation state. Any suitable orientation treatment may be employed as the orientation treatment. Specifically, mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment can be mentioned. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photo alignment treatment. As the treatment conditions for various orientation treatments, any appropriate conditions may be adopted depending on the purpose.

The alignment of the liquid crystal compound is carried out by treatment at a temperature at which it exhibits a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compound assumes a liquid crystal state, and the liquid crystal compound is oriented in accordance with the orientation treatment direction of the substrate surface.

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

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

The thickness of the first retardation member 20 composed of the liquid crystal alignment solidified layer is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.

The half mirror 18 transmits the light emitted from the display element 12 and reflects the light reflected by the reflection section 14 toward the reflection section 14 . The half mirror 18 is provided integrally with the first lens section 16.

The second retardation member 22 is a λ/4 member that can transmit the light reflected by the reflection part 14 and the half mirror 18 through the reflection part 14 including a reflective polarizing member (hereinafter referred to as the second retardation member). (sometimes referred to as the second λ/4 member). Note that the second retardation member 22 may be provided integrally with the first lens portion 16.

The in-plane retardation Re (550) of the second retardation member 22 is, for example, 100 nm to 190 nm, may be 110 nm to 180 nm, may be 130 nm to 160 nm, or may be 135 nm to 155 nm. .

The second retardation member 22 preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases depending on the wavelength of the measurement light. Re(450)/Re(550) of the second retardation member 22 is, for example, less than 1 and may be 0.95 or less, further less than 0.90, and even 0.85 or less. good. Re(450)/Re(550) of the second retardation member 22 is, for example, 0.75 or more.

In one embodiment, the second retardation member 22 has Re(400)/Re(550)<0.85, Re(650)/Re(550)>1.03, and Re(750)/Re( 550)>1.05. The second retardation member 22 has 0.65<Re(400)/Re(550)<0.80 (preferably 0.7<Re(400)/Re(550)<0.75), 1. 0<Re(650)/Re(550)<1.25 (preferably 1.05<Re(650)/Re(550)<1.20) and 1.05<Re(750)/Re( 550)<1.40 (preferably 1.08<Re(750)/Re(550)<1.36), more preferably at least two. More preferably, all of them are satisfied.

The second retardation member 22 preferably exhibits a refractive index characteristic of nx>ny≧nz. Here, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where ny and nz are substantially equal. Therefore, there may be a case where ny<nz within a range that does not impair the effects of the present invention. The Nz coefficient of the second retardation member 22 is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, particularly preferably 0.9 to 1. It is 3.

The second retardation member 22 is formed of any suitable material that can satisfy the above characteristics. The second retardation member 22 may be, for example, a stretched resin film or an oriented solidified layer of a liquid crystal compound. The same explanation as for the first retardation member 20 can be applied to the second retardation member 22 made of a stretched resin film or an oriented solidified layer of a liquid crystal compound. The first retardation member 20 and the second retardation member 22 may have the same configuration (forming material, thickness, optical properties, etc.), or may have different configurations.

The reflective section 14 may include an absorption type polarizing member (typically, an absorption type polarizing film). In this case, the absorptive polarizing member may be placed in front of the reflective polarizing member (on the side closer to the eyes). The reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member may be arranged substantially parallel to each other. For example, the reflective polarizing member and the absorptive polarizing member may be laminated with an adhesive layer interposed therebetween, and the reflective section 14 may include a laminate having the reflective polarizing member and the absorbing polarizing member.

The reflective polarizing member can transmit polarized light parallel to its transmission axis (typically, linearly polarized light) while maintaining its polarized state, and can reflect light in other polarized states. The cross transmittance (Tc) of the reflective polarizing member may be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing member may be, for example, 43% to 49%, preferably 45 to 47%. The degree of polarization (P) of the reflective polarizing member may be, for example, 92% to 99.99%. The reflective polarizing member is typically composed of a film having a multilayer structure (sometimes referred to as a reflective polarizing film). Commercially available reflective polarizing films include, for example, 3M's product names "DBEF" and "APF" and Nitto Denko's product name "APCF". The absorption type polarizing member is typically composed of a resin film (sometimes referred to as an absorption type polarizing film) containing a dichroic substance.

Typically, the slow axis of the first phase difference member 20 and the slow axis of the second phase difference member 22 are arranged substantially parallel to each other. Further, the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member included in the reflecting section 14 may be arranged substantially parallel to each other (in other words, the polarizing member included in the display element 12 (The polarization direction of the light emitted through the reflection part 14 and the reflection axis of the reflective polarizing member included in the reflection part 14 may be substantially orthogonal to each other.) The angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first retardation member 20 is, for example, 40° to 50°, may be 42° to 48°, and is about 45°. It may be °. The angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second retardation member 22 is, for example, 40° to 50°, may be 42° to 48°, and is about 45°. It may be °. By adjusting the axial relationship of each member to such a state, coloring of transmitted light can be suitably suppressed.

Hereinafter, a display system in one embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 2(a) is a schematic diagram illustrating the progression of light in the display system, and FIG. 2(b) is a diagram illustrating the progress of light in the display system as it passes through each member or is reflected by each member. FIG. 3 is a schematic diagram illustrating changes in polarization state. In FIG. 2, the solid arrows attached to the display element 12 indicate the absorption axis direction of the polarizing member included in the display element 12, and the arrows attached to the first retardation member 20 and the second retardation member 22 indicate the direction of the absorption axis of the polarizing member included in the display element 12. The solid-line arrows attached to the reflective polarizing member 14a included in the reflecting section 14 indicate the phase axis direction, and the dotted-line arrows indicate the transmission axis direction of each polarizing member.

Light L emitted as first linearly polarized light from the display element 12 via the polarizing member is converted into first circularly polarized light by the first λ/4 member 20. The first circularly polarized light passes through the half mirror 18 and the first lens part 16 (not shown in FIG. 2), and is then passed through the second λ/4 member 22 to form a second circularly polarized light whose polarization direction is orthogonal to the first linearly polarized light. is converted into linearly polarized light. The polarization direction of the second linearly polarized light is in the same direction (substantially parallel) as the reflection axis of the reflective polarizing member 14a included in the reflection section 14. Therefore, the second linearly polarized light incident on the reflection section 14 is reflected toward the half mirror 18 by the reflective polarizing member 14a.

The second linearly polarized light reflected by the reflection section 14 is converted into second circularly polarized light by the second λ/4 member 22. The rotation direction of the second circularly polarized light is the same as the rotation direction of the first circularly polarized light. The second circularly polarized light emitted from the second λ/4 member 22 passes through the first lens section 16 and is reflected by the half mirror 18, forming a third circle that rotates in the opposite direction to the second circularly polarized light. converted into polarized light. The third circularly polarized light reflected by the half mirror 18 passes through the first lens section 16 and is converted into third linearly polarized light by the second λ/4 member 22. The polarization direction of the third linearly polarized light is orthogonal to the polarization direction of the second linearly polarized light, and is in the same direction (substantially parallel) as the transmission axis of the reflective polarizing member 14a. Therefore, the third linearly polarized light can be transmitted through the reflective polarizing member 14a. Further, although not shown, when the reflective section includes an absorption type polarizing member, the absorption axis thereof is arranged to be approximately parallel to the reflection axis of the reflective polarizing member 14a, so that the light transmitted through the reflective polarizing member 14a is The third linearly polarized light can pass through the absorptive polarizing member as it is.

The light that has passed through the reflection section 14 passes through the second lens section 24 and enters the user's eyes 26 .

In FIG. 2, when viewed from the display element 12 side, the slow axes of the first retardation member 20 and the second retardation member 22 are both counterclockwise relative to the absorption axis of the polarizing member included in the display element 12. However, the same explanation as above can be applied even if these are arranged at an angle of 45° clockwise.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples in any way. In addition, the test and evaluation methods in Examples and the like are as follows. In addition, when it is written as "parts", it means "parts by weight" unless there are special notes, and when it is written as "%", it means "wt%" unless there are special notes.

(1) Thickness The thickness of 10 μm or less was measured using a scanning electron microscope (manufactured by JEOL Ltd., product name “JSM-7100F”). Thickness exceeding 10 μm was measured using a digital micrometer (manufactured by Anritsu Corporation, product name “KC-351C”).
(2) In-plane phase difference Re(λ)
A sample was prepared by cutting out the central part and both ends of the λ/4 member in the width direction into a square having a width of 50 mm and a length of 50 mm, with one side parallel to the width direction of the member. The in-plane retardation of this sample at each wavelength at 23° C. was measured using a Mueller matrix polarimeter (manufactured by Axometrics, product name “Axoscan”).
(3) Single transmittance and polarization degree Measure the single transmittance Ts, parallel transmittance Tp, and cross transmittance Tc of the polarizing film or laminate using a spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "LPF-200") did. These Ts, Tp, and Tc are Y values measured using a 2-degree visual field (C light source) according to JIS Z8701 and subjected to visibility correction. From the obtained Tp and Tc, the degree of polarization of the polarizing film was determined using the following formula.
Degree of polarization (%) = {(Tp-Tc)/(Tp+Tc)} ^1/2 ×100
(4) Hue Light from a light source is incident on the λ/4 member side surface of the laminates produced in Examples and Comparative Examples, and the parallel hue of the light emitted from the polarizing film side surface (a ^* value, b ^* value) was measured using a spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "LPF-200").

[Manufacturing Example 1: Fabrication of λ/4 member]
29.60 weight of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane was added to a batch polymerization apparatus consisting of two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100°C. part (0.046 mol), isosorbide (ISB) 29.21 parts by weight (0.200 mol), spiroglycol (SPG) 42.28 parts by weight (0.139 mol), diphenyl carbonate (DPC) 63.77 parts by weight (0 .298 mol) and 1.19×10 ⁻² parts by weight (6.78×10 ⁻⁵ mol) of calcium acetate monohydrate as a catalyst were charged. After the inside of the reactor was replaced with nitrogen under reduced pressure, it was heated with a heating medium, and when the internal temperature reached 100°C, stirring was started. 40 minutes after the start of temperature rise, the internal temperature was controlled to reach 220°C, and at the same time, pressure reduction was started to maintain this temperature, and the pressure was reduced to 13.3 kPa in 90 minutes after reaching 220°C. Phenol vapor produced as a by-product during the polymerization reaction was led to a reflux condenser at 100°C, a small amount of monomer component contained in the phenol vapor was returned to the reactor, and uncondensed phenol vapor was led to a condenser at 45°C for recovery. After nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Next, temperature increase and pressure reduction in the second reactor were started, and the internal temperature was 240° C. and the pressure was 0.2 kPa in 50 minutes. Thereafter, polymerization was allowed to proceed until a predetermined stirring power was reached. When a predetermined power was reached, nitrogen was introduced into the reactor to restore the pressure, the produced polyester carbonate resin was extruded into water, and the strands were cut to obtain pellets.
After vacuum drying the obtained polyester carbonate resin (pellets) at 80°C for 5 hours, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder temperature setting: 250°C) and a T-die (width 200mm, setting temperature: 250°C) were used. A long resin film with a thickness of 130 μm was produced using a film forming apparatus equipped with a chill roll (temperature setting: 120 to 130° C.), a winder and a winder. The obtained long resin film was stretched in the width direction at a stretching temperature of 140° C. and a stretching ratio of 2.7 times. As a result, a retardation film (λ/4 member) having a thickness of 47 μm, a Re(590) of 143 nm, and an Nz coefficient of 1.2 was obtained. Moreover, Re(450)/Re(550) of the λ/4 member was 0.856.

[Production Example 2: Production of polarizing film]
As the thermoplastic resin base material, a long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of approximately 75° C. was used, and one side of the resin base material was subjected to corona treatment.
Iodine was added to 100 parts by weight of a PVA resin prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, product name "Gosenex Z410") in a ratio of 9:1. A PVA aqueous solution (coating liquid) was prepared by dissolving 13 parts by weight of potassium chloride in water.
The PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate.
The obtained laminate was uniaxially stretched 2.4 times in the vertical direction (longitudinal direction) in an oven at 130° C. (in-air auxiliary stretching treatment).
Next, the laminate was immersed for 30 seconds in an insolubilization bath (boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40° C. (insolubilization treatment).
Next, the finally obtained absorption type polarized light was added to a dyeing bath (an iodine aqueous solution obtained by blending iodine and potassium iodide at a weight ratio of 1:7 to 100 parts by weight of water) at a liquid temperature of 30°C. The membrane was immersed for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the membrane became a desired value (staining treatment).
Next, it was immersed for 30 seconds in a crosslinking bath (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C. (Crosslinking treatment).
Thereafter, while immersing the laminate in a boric acid aqueous solution (boric acid concentration: 4% by weight, potassium iodide concentration: 5% by weight) at a liquid temperature of 70°C, the laminate was completely rolled in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds. Uniaxial stretching was performed so that the stretching ratio was 5.5 times (underwater stretching treatment).
Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (cleaning treatment).
Thereafter, while drying in an oven kept at about 90°C, it was brought into contact with a SUS heating roll whose surface temperature was kept at about 75°C (drying shrinkage treatment). The shrinkage rate of the laminate in the width direction due to the drying shrinkage treatment was 5.2%.
In this way, an absorption type polarizing film with a thickness of about 5 μm was formed on the resin base material.
A cycloolefin resin film (thickness: 25 μm) as a protective layer was bonded to the surface of the obtained absorption polarizing film (the surface opposite to the resin base material) via an ultraviolet curable adhesive. Specifically, the curable adhesive was coated to a total thickness of about 1 μm, and then bonded together using a roll machine. Thereafter, UV light was irradiated from the cycloolefin resin film side to cure the adhesive. Then, the resin base material was peeled off.
As a result, a polarizing film having a structure of cycloolefin resin film/absorption type polarizing film was obtained. The single transmittance (Ts) of the polarizing film was 43.4%, the degree of polarization was 99.993%, the parallel a ^* value was -2.0, and the parallel b ^* value was 6.1.

[Example 1]
On one side of the polarizing film obtained in Production Example 2, the four λ/4 members obtained in Production Example 1 were laminated as λ/4 members 1 to 4 so as to have the axial relationship and lamination configuration shown in Table 1. Body 1 was prepared (The angles shown in Table 1 are angles based on the absorption axis direction of the absorption type polarizing film when viewed from the polarizing film side, "+" is clockwise, and "-" is counterclockwise. (meaning around). Lamination of each member was performed by pasting them together via an acrylic adhesive layer (manufactured by Nitto Denko Corporation, thickness 5 μm).

[Comparative example 1]
A laminate C1 was produced in the same manner as in Example 1, except that the four λ/4 members 1 to 4 were laminated in the axial relationship and laminated configuration shown in Table 1.

Table 2 shows the measurement results of the single transmittance and hue of the laminates obtained in the above Examples and Comparative Examples. Note that the laminates produced in Examples and Comparative Examples are simple evaluation models of display systems according to embodiments of the present invention. Specifically, in the display system according to the embodiment of the present invention, the hue of the light that is incident on the λ/4 member 1 side of the laminate and emitted from the polarizing film side is emitted forward from the display element via the polarizing member. After the linearly polarized light passes through the first retardation member and the second retardation member in this order, it is reflected by the reflection part and the half mirror, thereby transmitting the second retardation member two more times, and then passes through the reflection part. It can be evaluated as the hue of the transmitted light that is emitted forward.

As shown in Table 2, according to the display system according to the embodiment of the present invention, the first λ/4 member and the second λ/4 member are arranged such that their slow axes are parallel to each other. By doing so, coloring of the transmitted light is suppressed more than in a configuration in which the slow axes are arranged orthogonal to each other, and transmitted light with a neutral hue can be obtained.

The present invention is not limited to the above embodiments, and various modifications are possible. For example, it can be replaced with a configuration that is substantially the same as the configuration shown in the above embodiment, a configuration that has the same effect, or a configuration that can achieve the same objective.

The display system according to the embodiment of the present invention can be used for a display body such as VR goggles, for example.

2 Display system 4 Lens section 12 Display element 14 Reflection section 16 First lens section 18 Half mirror 20 First retardation member 22 Second retardation member 24 Second lens section

Claims (11)

A display system for displaying images to a user, the display system comprising:
a display element having a display surface that emits light representing an image forward through a polarizing member;
a reflecting section disposed in front of the display element, including a reflective polarizing member, and reflecting light emitted from the display element;
a first lens section disposed on an optical path between the display element and the reflection section;
a half mirror disposed between the display element and the first lens part, which transmits the light emitted from the display element and reflects the light reflected by the reflection part toward the reflection part;
a first λ/4 member disposed on an optical path between the display element and the half mirror;
a second λ/4 member disposed on the optical path between the half mirror and the reflection section;
Equipped with
A display system, wherein a slow axis of the first λ/4 member and a slow axis of the second λ/4 member are arranged to be substantially parallel to each other. The display system according to claim 1, wherein the polarization direction of the light emitted through the polarizing member and the reflection axis of the reflective polarizing member are substantially orthogonal to each other. The angle between the absorption axis of the polarizing member included in the display element and the slow axis of the first λ/4 member is 40° to 50°,
The display system according to claim 1, wherein the angle between the absorption axis of the polarizing member and the slow axis of the second λ/4 member included in the display element is 40° to 50°. The display system according to claim 1, wherein the first lens portion and the half mirror are integrated. The display system according to claim 1, further comprising a second lens section disposed in front of the reflecting section. The display system according to claim 1, wherein the reflective section includes an absorbing polarizing member disposed in front of the reflective polarizing member. 7. The display system according to claim 6, wherein the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member are arranged substantially parallel to each other. passing the light representing the image emitted through the polarizing member through the first λ/4 member;
a step of causing the light that has passed through the first λ/4 member to pass through a half mirror and a first lens portion;
passing the light that has passed through the half mirror and the first lens section through a second λ/4 member;
reflecting the light that has passed through the second λ/4 member toward the half mirror by a reflecting section including a reflective polarizing member;
a step of allowing the light reflected by the reflection part and the half mirror to pass through the reflection part by the second λ/4 member;
The slow axis of the first λ/4 member and the slow axis of the second λ/4 member are arranged so as to be substantially parallel to each other,
Display method. 9. The display method according to claim 8, wherein the polarization direction of the light emitted through the polarizing member and the reflection axis of the reflective polarizing member are substantially orthogonal to each other. A display body comprising the display system according to any one of claims 1 to 7. A method for manufacturing a display body, comprising the display system according to claim 1.

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