JP2023134316A - Lens part, laminated body, display body, display body production method, and display method - Google Patents

Abstract

To provide a lens part that enables weight reduction and higher definition of VR goggles.SOLUTION: A lens part according to an embodiment of the present invention is used in a display system for displaying an image to a user, the lens part comprising: a reflection part that reflects light representing the image, emitted forward from a display surface of a display element, and passing through a polarizing member and a first λ/4 member, and includes a reflective polarizing member and an absorptive polarizing member disposed in front of the reflective polarizing member; a first lens part that is disposed on an optical path between the display element and the reflection part; a half mirror that is disposed between the display element and the first lens part, transmits light emitted from the display element, and reflects light reflected by the reflection part toward the reflection part; and a second λ/4 member that is disposed on an optical path between the half mirror and the reflection part, wherein an orthogonal transmittance when light is incident on a laminate of the reflective polarizing member and the absorptive polarizing member from the reflective polarizing member side is 0.5% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens part, a laminate, a display body, a method for manufacturing a display body, and a display method.

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 lens section that can realize weight reduction and high definition of VR goggles.

1. The lens unit according to the embodiment of the present invention is a lens unit used in a display system that displays an image to a user, and is a lens unit that emits light forward from a display surface of a display element that represents an image, and includes a polarizing member and a first a reflective part that reflects the light that has passed through the λ/4 member and includes a reflective polarizing member and an absorbing polarizing member disposed in front of the reflective polarizing member; and a reflective part between the display element and the reflective part. A first lens section disposed on the optical path is disposed between the display element and the first lens section, and transmits the light emitted from the display element and transmits the light reflected by the reflection section. a half mirror that reflects the light toward a reflecting section; and a second λ/4 member disposed on an optical path between the half mirror and the reflecting section, the reflective polarizing member and the absorbing polarizing member. The orthogonal transmittance when light is incident on the laminate with the member from the reflective polarizing member side is 0.5% or less.
2. In the lens portion described in 1 above, the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member may be arranged parallel to each other.
3. In the lens section described in 1 or 2 above, the first lens section and the half mirror may be integrated.
4. The lens section according to any one of items 1 to 3 above may include a second lens section disposed in front of the reflecting section.
5. In the lens portion according to any one of 1 to 4 above, 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 angle between the absorption axis of the polarizing member included in the display element and the slow axis of the second λ/4 member may be 40° to 50°.

6. The laminate according to the embodiment of the present invention is used in the reflective section of the lens section described in any one of 1 to 5 above, and includes the reflective polarizing member and the absorbing polarizing member.
7. In the laminate described in 6 above, the reflective polarizing member and the absorbing polarizing member may be laminated with an adhesive layer interposed therebetween.
8. In the laminate described in 6 or 7 above, the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member may be arranged parallel to each other.

9. A display body according to an embodiment of the present invention includes the lens portion described in any one of 1 to 5 above.
10. A method for manufacturing a display body according to an embodiment of the present invention is a method for manufacturing a display body having a lens portion according to any one of items 1 to 5 above.

11. A display method according to an embodiment of the present invention includes a step of causing light representing an image emitted through a polarizing member and a first λ/4 member to pass through a half mirror and a first lens portion; a step of causing the light that has passed through the first lens section to pass through a second λ/4 member; and a step of directing the light that has passed through the second λ/4 member to the half mirror using a reflecting section that includes a reflective polarizing member. a step of allowing the light reflected by the reflecting section and the half mirror to pass through the reflective polarizing member of the reflecting section by the second λ/4 member; transmitting the light that has passed through the polarizing member through an absorptive polarizing member, and making the light enter the laminate of the reflective polarizing member and the absorbing polarizing member from the reflective polarizing member side. The orthogonal transmittance is 0.5% or less.

According to the lens portion 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 cross-sectional view showing an example of a laminate used in a reflective section of the display system shown in FIG. 1. FIG. FIG. 2 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film.

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, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Therefore, for example, "45°" means ±45°.

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, a first lens section 16, a half mirror 18, a first retardation member 20, a second retardation member 22, and a second lens section 24. We are prepared. The reflecting section 14 is arranged at the front of the display element 12 on the display surface 12a side, and can reflect the 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 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 first circularly polarized light emitted from the first λ/4 member 20 passes through the half mirror 18 and the first lens section 16, and is converted into second linearly polarized light by the second λ/4 member 22. . The second linearly polarized light emitted from the second λ/4 member 22 is reflected toward the half mirror 18 without passing through the reflective polarizing member included in the reflecting section 14 . At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing member included in the reflecting section 14 is the same direction as the reflection axis of the reflective polarizing member. Therefore, the second linearly polarized light incident on the reflection section is reflected by the reflective polarizing member.

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, and the second circularly polarized light emitted from the second λ/4 member 22 is converted into second circularly polarized light by the second λ/4 member 22. The light passes through one lens section 16 and is reflected by a half mirror 18. The second 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 third linearly polarized light passes through the reflective polarizing member included in the reflecting section 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member included in the reflecting section 14 is the same direction as the transmission axis of the reflective polarizing member. Therefore, the third linearly polarized light that has entered the reflecting section 14 is transmitted through the reflective polarizing member.

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

For example, 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, or may be arranged substantially perpendicular to each other. The angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first 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 °.

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, 0.75 or more and less than 1, and may be 0.8 or more and 0.95 or less.

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, 0.75 or more and less than 1, and may be 0.8 or more and 0.95 or less.

In addition to the reflective polarizing member, the reflecting section 14 may include an absorbing polarizing member. The absorptive polarizing member may be placed in front of the reflective polarizing member. 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, and the transmission axis of the reflective polarizing member and the transmission axis of the absorptive polarizing member may be arranged substantially parallel to each other. When the reflecting section 14 includes an absorption type polarizing member, the reflecting section 14 may include a laminate having a reflective polarizing member and an absorbing polarizing member.

FIG. 2 is a schematic cross-sectional view showing an example of a laminate used in the reflective section of the display system shown in FIG. The laminate 30 includes a reflective polarizing member 32 and an absorbing polarizing member 34, and the reflective polarizing member 32 and the absorbing polarizing member 34 are laminated with an adhesive layer 36 in between. By using the adhesive layer, the reflective polarizing member 32 and the absorbing polarizing member 34 are fixed, and it is possible to prevent misalignment of the axis arrangement between the reflective axis and the absorption axis (the transmission axis and the transmission axis). Further, it is possible to suppress the adverse effects of an air layer that may be formed between the reflective polarizing member 32 and the absorbing polarizing member 34. The adhesive layer 36 may be formed of an adhesive or a pressure-sensitive adhesive. The thickness of the adhesive layer 36 is, for example, 0.05 μm to 30 μm, preferably 3 μm to 20 μm, and more preferably 5 μm to 15 μm.

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 reflective polarizing member is typically composed of a film having a multilayer structure (sometimes referred to as a reflective polarizing film). In this case, the thickness of the reflective polarizing member is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.

FIG. 3 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. The multilayer structure 32a has layers A having birefringence and layers B having substantially no birefringence alternating. The total number of layers making up the multilayer structure may be between 50 and 1000. For example, the refractive index nx in the x-axis direction of the A layer is larger than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction and the refractive index ny in the y-axis direction of the B layer are substantially the same, The refractive index difference between layer A and layer B is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction can become the reflection axis, and the y-axis direction can become the transmission axis. The refractive index difference between layer A and layer B in the x-axis direction is preferably 0.2 to 0.3.

The layer A is typically made of a material that exhibits birefringence when stretched. Such materials include, for example, naphthalene dicarboxylic acid polyesters (eg, polyethylene naphthalate), polycarbonates, and acrylic resins (eg, polymethyl methacrylate). The B layer is typically made of a material that does not substantially exhibit birefringence even when stretched. Examples of such materials include copolyesters of naphthalene dicarboxylic acid and terephthalic acid. The multilayer structure may be formed by a combination of coextrusion and stretching. For example, after extruding the material constituting layer A and the material constituting layer B, they are multilayered (for example, using a multiplier). The obtained multilayer laminate is then stretched. The x-axis direction in the illustrated example may correspond to the stretching direction.

Commercially available reflective polarizing films include, for example, 3M's product names "DBEF" and "APF" and Nitto Denko's product name "APCF".

The cross transmittance (Tc) of the reflective polarizing member (reflective polarizing film) may be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing member (reflective polarizing film) is, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing member (reflective polarizing film) can be, for example, 92% to 99.99%.

The absorption type polarizing member may typically include a resin film (sometimes referred to as an absorption type polarizing film) containing a dichroic substance. The thickness of the absorption type polarizing film is, for example, 1 μm or more and 20 μm or less, may be 2 μm or more and 15 μm or less, may be 12 μm or less, may be 10 μm or less, or may be 8 μm or less, It may be 5 μm or less.

The above-mentioned absorption type polarizing film may be produced from a single layer resin film, or may be produced using a laminate of two or more layers.

When manufacturing from a single-layer resin film, for example, a hydrophilic polymer film such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, or a partially saponified ethylene/vinyl acetate copolymer film is coated with iodine or dichloromethane. An absorption type polarizing film can be obtained by performing a dyeing treatment with a dichroic substance such as a color dye, a stretching treatment, and the like. Among these, an absorption type polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

The above-mentioned staining with iodine is performed, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing process or may be performed while dyeing. Alternatively, it may be dyed after being stretched. If necessary, the PVA film is subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc.

The laminate produced using the above-mentioned laminate of two or more layers is a laminate of a resin base material and a PVA resin layer (PVA resin film) laminated on the resin base material, or a laminate of a resin base material and a PVA resin layer (PVA resin film) laminated on the resin base material, or Examples include a laminate of a material and a PVA-based resin layer formed by coating on the resin base material. An absorption type polarizing film obtained by using a laminate of a resin base material and a PVA resin layer coated on the resin base material can be obtained by, for example, applying a PVA resin solution to the resin base material, drying it, and applying the resin. Forming a PVA-based resin layer on a base material to obtain a laminate of the resin base material and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer an absorption type polarizing film. can be produced by; In this embodiment, preferably, a polyvinyl alcohol resin layer containing a halide and a polyvinyl alcohol resin is formed on one side of the resin base material. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, the stretching may further include stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in the boric acid aqueous solution, if necessary. In addition, in the present embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being conveyed in the longitudinal direction to shrink by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an in-air auxiliary stretching process, a dyeing process, an underwater stretching process, and a drying shrinkage process in this order. By introducing auxiliary stretching, even when PVA is applied onto a thermoplastic resin, it becomes possible to improve the crystallinity of PVA and achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as deterioration of orientation and dissolution of PVA when it is immersed in water during the subsequent dyeing and stretching processes, resulting in high optical properties. becomes possible to achieve. Furthermore, when the PVA-based resin layer is immersed in a liquid, disturbance in the orientation of polyvinyl alcohol molecules and deterioration of orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. Thereby, the optical properties of an absorption polarizing film obtained through a treatment process performed by immersing the laminate in a liquid, such as dyeing treatment and underwater stretching treatment, can be improved. Furthermore, optical properties can be improved by shrinking the laminate in the width direction by drying shrinkage treatment. The obtained resin base material/absorption type polarizing film laminate may be used as is (that is, the resin base material may be used as a protective layer of the absorption type polarizing film), or the resin base material/absorption type polarizing film laminate may be used as is. Any suitable protective layer depending on the purpose may be laminated on the peeled surface from which the resin base material is peeled off, or on the surface opposite to the peeled surface. Details of the manufacturing method of such an absorption type polarizing film are described in, for example, Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire descriptions of these publications are incorporated herein by reference.

The orthogonal transmittance (Tc) of the absorption type polarizing member (absorption type polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and still more preferably 0.05% or less. be. The single transmittance (Ts) of the absorption type polarizing member (absorption type polarizing film) is, for example, 41.0% to 45.0%, preferably 42.0% or more. The degree of polarization (P) of the absorption type polarizing member (absorption type polarizing film) is, for example, 99.0% to 99.997%, preferably 99.9% or more.

The orthogonal transmittance (Tc) of the reflective portion is preferably 0.5% or less, more preferably 0.1% or less, and still more preferably 0.05% or less. By satisfying such orthogonal transmittance, visibility of afterimages (ghosts) by the user can be suppressed, and excellent display characteristics can be achieved. The single transmittance (Ts) of the reflective portion is preferably 40.0% to 45.0%, more preferably 41.0% or more. The degree of polarization (P) of the reflective portion is preferably 99.0% to 99.997%, more preferably 99.9% or more.

The optical properties of the reflective section may correspond to the optical properties of a reflective polarizing member, or may correspond to the optical properties of a laminate of a reflective polarizing member and an absorbing polarizing member. The optical characteristics of the reflective section described above can be achieved extremely well by combining a reflective polarizing member with an absorbing polarizing member.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples. Note that the thickness is a value measured by the following measuring method.
<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”).

[Example 1-1]
(Preparation of polarizing film 1)
As the thermoplastic resin base material, a long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a water absorption rate of 0.75% and a Tg of about 75° C. was used. 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 free end to 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds 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 final polarizing film was added to a dyeing bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 to 100 parts by weight of water) at a liquid temperature of 30°C. It was immersed for 60 seconds while adjusting the concentration so that the single transmittance (Ts) was 42.0% or more (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 maintained at 90°C, it was brought into contact with a SUS heating roll whose surface temperature was maintained at 75°C for about 2 seconds (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, a 5 μm thick polarizing film 1 (absorption type polarizing film) was formed on the resin base material.

(Preparation of absorption type polarizing film)
A cycloolefin resin film having a thickness of 25 μm was bonded as a protective layer to the surface of the obtained absorption type polarizing film (the surface on the polarizing film 1 side of the laminate) via an ultraviolet curable adhesive. Specifically, the adhesive layer was coated so that the thickness of the cured adhesive layer was approximately 1 μm, and the adhesive layers were bonded together using a roll machine. Thereafter, UV light was irradiated from the cycloolefin resin film side to cure the adhesive. Next, the resin base material was peeled off to obtain an absorption type polarizing film having a structure of cycloolefin resin film/absorption type polarizing film.

(Preparation of film for reflective part)
An absorbing polarizing film is placed on a reflective polarizing film ("APCFG4" manufactured by Nitto Denko Corporation) with an adhesive so that the reflection axis of the reflective polarizing film and the absorption axis of the absorbing polarizing film are arranged parallel to each other. The films were bonded together through a laminate to obtain a film for a reflective section (laminated film).

[Example 1-2 and Example 1-3]
A reflective film was obtained in the same manner as in Example 1-1, except that the dyeing conditions were changed in the production of polarizing film 1.

[Example 1-4]
A reflective part was obtained in the same manner as in Example 1-1 except that the following polarizing film 2 was used instead of polarizing film 1.
(Preparation of polarizing film 2)
A long roll of polyvinyl alcohol (PVA) resin film (manufactured by Kuraray, trade name "PE3000") with a thickness of 30 μm was simultaneously uniaxially stretched in the longitudinal direction so as to be 5.9 times larger in the longitudinal direction using a roll stretching machine. After performing swelling, dyeing, crosslinking, and washing treatments in this order, a drying treatment was finally performed to produce a polarizing film 2 with a thickness of 12 μm.
In the above swelling treatment, the film was stretched 2.2 times while being treated with pure water at 20°C. Next, the dyeing process is carried out in an aqueous solution at 30°C in which the weight ratio of iodine and potassium iodide is 1:7 and the iodine concentration is adjusted so that the single transmittance of the polarizing film obtained is 42.0% or more. While doing so, it was stretched 1.4 times. Next, a two-stage crosslinking treatment was adopted for the crosslinking treatment, and the first crosslinking treatment was performed in an aqueous solution containing boric acid and potassium iodide at 40° C. and stretched to 1.2 times. The boric acid content of the aqueous solution for the first stage crosslinking treatment was 5.0% by weight, and the potassium iodide content was 3.0% by weight. In the second stage of crosslinking treatment, the film was stretched to 1.6 times while being treated in an aqueous solution containing boric acid and potassium iodide at 65°C. The boric acid content of the aqueous solution for the second stage crosslinking treatment was 4.3% by weight, and the potassium iodide content was 5.0% by weight. Next, washing treatment was performed with a potassium iodide aqueous solution at 20°C. The potassium iodide content of the aqueous solution for cleaning treatment was 2.6% by weight. Finally, a polarizing film 2 was obtained by drying at 70° C. for 5 minutes.

[Example 1-5]
A reflective film was obtained in the same manner as in Example 1-4, except that the conditions for the dyeing treatment were changed in the production of polarizing film 2.

[Example 2-1 to Example 2-5]
A film for a reflective section was obtained in the same manner as in Examples 1-1 to 1-5, except that "APCFG5" manufactured by Nitto Denko Corporation was used as the reflective polarizing film.

[Comparative example 1]
As the film for the reflective section, "APCFG4" manufactured by Nitto Denko Corporation was used.

[Comparative example 2]
As the film for the reflective section, "APCFG5" manufactured by Nitto Denko Corporation was used.

The following evaluations were performed for the Examples and Comparative Examples. The evaluation results are summarized in Table 1.
<Evaluation>
・Single transmittance, orthogonal transmittance, and degree of polarization The single transmittance of the absorbing polarizing film (absorbing polarizing film) and the reflective film was measured using an ultraviolet-visible spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "LPF200"). Ts, parallel transmittance Tp and orthogonal transmittance Tc were measured. 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. In addition, in the measurement of the reflective film, light was incident from the reflective polarizing film side.
Furthermore, the degree of polarization P was determined from the obtained Tp and Tc using the following formula.
Polarization degree P (%) = {(Tp-Tc)/(Tp+Tc)} ^1/2 ×100

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

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 30 Laminated body 32 Reflective polarizing member 34 Absorptive polarizing member 36 Adhesive layer

Claims (11)

A lens unit used in a display system that displays images to a user, the lens unit comprising:
A reflective polarizing member is arranged in front of a reflective polarizing member and the reflective polarizing member, and reflects light that is emitted forward from a display surface of a display element that represents an image and has passed through a polarizing member and a first λ/4 member. a reflective section including an absorptive polarizing member;
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 second λ/4 member disposed on the optical path between the half mirror and the reflection section,
When light is incident on the laminate of the reflective polarizing member and the absorbing polarizing member from the reflective polarizing member side, the orthogonal transmittance is 0.5% or less,
lens section. The lens portion according to claim 1, wherein the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member are arranged parallel to each other. The lens section according to claim 1, wherein the first lens section and the half mirror are integrated. The lens section according to claim 1, further comprising a second lens section disposed in front of the reflecting section. 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 lens portion according to claim 1, wherein the angle between the absorption axis of the polarizing member included in the display element and the slow axis of the second λ/4 member is 40° to 50°. Used in the reflective part of the lens part according to any one of claims 1 to 5,
comprising the reflective polarizing member and the absorbing polarizing member,
laminate. The laminate according to claim 6, wherein the reflective polarizing member and the absorptive polarizing member are laminated with an adhesive layer interposed therebetween. The laminate according to claim 6, wherein the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member are arranged parallel to each other. A display body comprising the lens portion according to any one of claims 1 to 5. A method for manufacturing a display body having a lens portion according to any one of claims 1 to 5. A step of passing the light representing the image emitted through the polarizing member and the first λ/4 member through the half mirror and the first lens part;
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 reflective polarizing member of the reflection part by the second λ/4 member;
a step of transmitting the light transmitted through the reflective polarizing member through an absorbing polarizing member,
When light is incident on the laminate of the reflective polarizing member and the absorbing polarizing member from the reflective polarizing member side, the orthogonal transmittance is 0.5% or less,
Display method.

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