TW202401086A - Display system, display method, display body, and method for manufacturing display body - Google Patents

Abstract

The present invention provides a display system that makes it possible to realize VR goggles having higher definition. A display system according to an embodiment of the present invention displays an image for a user, and comprises: a display element having a display surface for emitting, in a forward direction through a polarization member, light representing an image; a reflecting unit that is arranged in front of the display element, includes a reflective polarization member, and reflects the light emitted from the display element; a first lens unit arranged on the optical path between the display element and the reflecting unit; a half mirror that is arranged between display element and the first lens unit, transmits the light emitted from the display element, and reflects, toward the reflecting unit, the light reflected by the reflecting unit; a first [lambda]/4 member arranged on the optical path between the display element and the half mirror; and a second [lambda]/4 member arranged on the optical path between the half mirror and the reflecting unit. When linearly polarized light the polarization direction of which forms an angle of 45 DEG with respect to the slow axis is incident to the first [lambda]/4 member, the ellipticity of transmitted light having a wavelength of 380-700 nm is 0.72 or greater, and when linearly polarized light the polarization direction of which forms an angle of 45 DEG with respect to the slow axis is incident to the second [lambda]/4 member, the ellipticity of transmitted light having a wavelength of 380-700 nm is 0.72 or greater.

Description

Display system, display method, display body and manufacturing method of display body

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

Image display devices represented by liquid crystal display devices and electroluminescence (EL) display devices (such as organic EL display devices) are rapidly gaining popularity. In image display devices, in order to realize image display and improve image display performance, optical members such as polarizing members and phase difference members are generally used (for example, see 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. There are studies on using VR goggles in various situations, so they are expected to be lightweight and highly precise. Weight reduction can be achieved, for example, by thinning the lenses used in VR goggles. On the other hand, it is also desired to develop optical components suitable for display systems using thin lenses. Prior technical literature patent documents

Patent Document 1: Japanese Patent Application Publication No. 2021-103286

The problem to be solved by the invention In view of the above, the main purpose of the present invention is to provide a display system that can realize lightweight and high-definition VR goggles.

means to solve problems [1] According to one aspect of the present invention, there is provided a display system for displaying an image to a user, which includes: a display element having a display surface and emitting light for displaying the image forward through a polarizing member; and a reflective portion configured In front of the above-mentioned display element, and including a reflective polarizing member, the reflective part reflects the light emitted from the above-mentioned display element; the first lens part is arranged on the optical path between the above-mentioned display element and the above-mentioned reflective part; semi-reflection A mirror is arranged between the above-mentioned display element and the above-mentioned first lens part, and the half-reflecting mirror transmits the light emitted from the above-mentioned display element and reflects the light reflected by the above-mentioned reflection part toward the above-mentioned reflection part; 1st λ/ The fourth member is arranged on the optical path between the above-mentioned display element and the above-mentioned half mirror; and the 2nd λ/4 member is arranged on the optical path between the above-mentioned half mirror and the above-mentioned reflecting part; the polarization direction is relative to When linearly polarized light with the slow axis of the above-mentioned 1λ/4 member forming an angle of 45° is incident on the above-mentioned 1λ/4 member, the ellipticity of the transmitted light with a wavelength of 380nm~700nm is 0.72 or more; and the polarization direction is relative to the above-mentioned 2λ/4 member. When linearly polarized light with an angle of 45° formed by the slow axis of the member is incident on the above-mentioned 2λ/4 member, the ellipticity of the transmitted light with a wavelength of 380nm~700nm is 0.72 or above. [2] In the display system of [1] above, when linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the first λ/4 member is incident on the first λ/4 member, the ellipse of the transmitted light with a wavelength of 550 nm The rate may also be 0.9 or more; and when linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the above-mentioned 2λ/4 member is incident on the above-mentioned 2λ/4 member, the ellipticity of the transmitted light with a wavelength of 550 nm may also be 0.9. above. [3] In the display system of [1] or [2] above, when linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the first λ/4 member is incident on the first λ/4 member, the wavelength of the light is 450 nm. The ellipticity of the transmitted light can also be greater than the ellipticity of the transmitted light with a wavelength of 650nm; and when linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the above-mentioned 2λ/4 member is incident on the above-mentioned 2λ/4 member, the wavelength is 450nm. The ellipticity of the transmitted light may also be greater than the ellipticity of the transmitted light with a wavelength of 650 nm. [4] In the display system according to any one of the above [1] to [3], in the wavelength range of 380nm~700nm, the polarization direction forms a linear polarization angle of 45° with respect to the slow axis of the first λ/4 member. When incident on the above-mentioned 1λ/4 member, the proportion of the wavelength region in which the ellipticity of the transmitted light is 0.85 or above can also be above 70%; and in the wavelength region of 380nm~700nm, the polarization direction is relative to the above-mentioned 2λ/4 When linearly polarized light with an angle of 45° formed by the slow axis of the member is incident on the above-mentioned 2λ/4 member, the proportion of the wavelength region in which the ellipticity of the transmitted light is 0.85 or more can also be more than 70%. [5] In the display system according to any one of [1] to [4] above, when linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the first λ/4 member is incident on the first λ/4 member , more than 70% of the wavelength region in which the transmitted light exhibits an ellipticity of 0.85 or more can be in the wavelength region of 380nm~600nm; and linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the 2λ/4 member is incident on the above When the 2λ/4 member is used, more than 70% of the wavelength range in which the transmitted light exhibits an ellipticity of 0.85 or more can be in the wavelength range of 380nm~600nm. [6] In the display system according to any one of [1] to [5] above, the polarization direction of the light emitted through the polarizing member and the reflection axis of the reflective polarizing member may be substantially orthogonal to each other. [7] In the display system according to any one of [1] to [5] above, the polarization direction of the light emitted through the polarizing member and the reflection axis of the reflective polarizing member may be substantially parallel to each other. [8] According to another aspect of the present invention, a display body is provided, which is provided with the display system according to any one of the above [1] to [7]. [9] According to yet another aspect of the present invention, a method of manufacturing a display is provided, which is a method of manufacturing a display having the display system according to any one of the above [1] to [7]. [10] According to another aspect of the present invention, a display method is provided, which has the following steps: making the light emitted through the polarizing member to display an image pass through the first λ/4 member; and making the light passing through the first λ/4 member pass through the semi-reflection process. The process of mirror and the first lens part; the process of causing the light passing through the above-mentioned half-mirror and the above-mentioned first lens part to pass through the 2λ/4 member; the process of causing the light passing through the above-mentioned 2λ/4 member to be reflected by the reflective polarizing member The process of reflecting the light towards the above-mentioned half-reflecting mirror; and the process of allowing the light reflected by the above-mentioned reflecting part and the above-mentioned half-reflecting mirror to transmit the above-mentioned reflecting part through the above-mentioned 2λ/4 member; making the polarization direction relative to the above-mentioned 1λ When linearly polarized light with the slow axis of the /4 member constituting an angle of 45° is incident on the above-mentioned 1λ/4 member, the ellipticity of the transmitted light with a wavelength of 380nm~700nm is 0.72 or more; and the polarization direction is slower than that of the above-mentioned 2λ/4 member. When linearly polarized light with an axis forming an angle of 45° is incident on the above-mentioned 2λ/4 member, the ellipticity of the transmitted light with a wavelength of 380nm~700nm is 0.72 or more.

Invention effect In VR goggles, the image displayed on the monitor will be magnified by the lens and viewed by the viewer. Therefore, slight fluctuations in the characteristics of each component will greatly affect the display characteristics. In this regard, according to the display system according to the embodiment of the present invention, by using structural members having predetermined optical characteristics, it is possible to achieve high definition of VR goggles.

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. In order to explain the drawings more clearly, the width, thickness, shape, etc. of each part may be schematically shown compared to the embodiment. However, this is only an example and is not intended to limit the interpretation of the present invention. In addition, regarding the drawings, the same or equivalent elements may be assigned the same symbols, and repeated explanations may be omitted.

(Definition of terms and symbols) The definitions of terms and symbols in this manual are as follows. (1)Refractive index (nx, ny, nz) "nx" is the refractive index in the direction where the in-plane refractive index reaches the maximum (that is, the slow axis direction), "ny" is the refractive index in the direction that is orthogonal to the slow axis in the plane (that is, the fast axis direction), and " nz" is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane phase difference measured with light of wavelength λnm at 23°C. For example, "Re(550)" is the in-plane phase difference measured using light with a wavelength of 550 nm at 23°C. Re(λ) can be calculated by the formula: Re(λ)=(nx-ny)×d when the thickness of the layer (thin film) is d(nm). (3) Phase difference in thickness direction (Rth) "Rth(λ)" is the phase difference in the thickness direction measured with light of wavelength λnm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction measured at 23°C using light with a wavelength of 550 nm. Rth(λ) can be calculated by the formula: Rth(λ)=(nx-nz)×d when the layer (film) thickness is d(nm). (4)Nz coefficient The Nz coefficient can be found by Nz=Rth/Re. (5)Angle When an angle is mentioned in this specification, unless otherwise mentioned, the angle includes both clockwise and counterclockwise directions relative to the reference direction. So, for example, "45°" means ±45°. In addition, in this specification, "approximately parallel" includes the range of 0°±10°, and is preferably within the range of 0°±5°, more preferably within the range of 0°±3°, and more preferably 0°±1°. within the range. "Approximately orthogonal" includes the range of 90°±10°, preferably within the range of 90°±5°, more preferably within the range of 90°±3°, and more preferably within the range of 90°±1°.

FIG. 1 is a schematic diagram showing the schematic structure of a display system according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing the arrangement and shape of each component of the system 2 . The display system 2 includes a display element 12 , a reflective part 14 including a reflective polarizing member, a first lens part 16 , a half mirror 18 , a first phase difference member 20 , a second phase difference member 22 , and a second lens part 24 . The reflective portion 14 is disposed on the display surface 12 a side of the display element 12 , that is, in front of the display element 12 , and can reflect the light emitted from the display element 12 . The first lens part 16 is arranged on the optical path between the display element 12 and the reflecting part 14 , and the half-reflecting mirror 18 is arranged between the display element 12 and the first lens part 16 . The first phase difference member 20 is arranged on the optical path between the display element 12 and the half mirror 18 , and the second phase difference member 22 is arranged on the optical path between the half mirror 18 and the reflecting part 14 .

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 to be emitted from the display surface 12a passes through, for example, a polarizing member (typically a polarizing film) that may be included in the display element 12 and then is emitted, becoming first linearly polarized light.

The first phase difference member 20 is a λ/4 member that can convert the first linearly polarized light incident on the first phase difference member 20 into the first circularly polarized light (hereinafter, the first phase difference member is sometimes referred to as the 1st λ/4 components). In addition, the first phase difference member 20 can also be provided on the display element 12 to be integrated.

The half mirror 18 transmits the light emitted from the display element 12 and reflects the light reflected by the reflective part 14 toward the reflective part 14 . The half-reflecting mirror 18 is integrally provided on the first lens portion 16 .

The second phase difference member 22 is a λ/4 member that allows the light reflected by the reflective part 14 and the half-reflecting mirror 18 to pass through the reflective part 14 including a reflective polarizing member (hereinafter, the second phase difference member may be referred to as the second phase difference member 22 ). 2λ/4 member). In addition, the second phase difference member 22 may also be provided on the first lens part 16 to be integrated.

The first circularly polarized light emitted from the first λ/4 member 20 passes through the half mirror 18 and the first lens part 16 and is converted into the 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 reflective part 14 . At this time, the polarization direction of the second linearly polarized light of the reflective polarizing member included in the incident reflection part 14 is in the same direction as the reflection axis of the reflective polarizing member. Therefore, the second linearly polarized light incident on the reflective part 14 will be reflected by the reflective polarizing member.

The second linearly polarized light reflected by the reflective part 14 is converted into the 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 semi-reflected by the first lens part 16 Mirror 18 reflects. The circularly polarized light reflected by the half mirror 18 passes through the first lens part 16 and is converted into third linearly polarized light by the 2nd λ/4 member 22 . The third linearly polarized light will transmit through the reflective polarizing member included in the reflective part 14 . At this time, the polarization direction of the third linearly polarized light of the reflective polarizing member included in the incident reflection part 14 is in the same direction as the transmission axis of the reflective polarizing member. Therefore, the third linearly polarized light incident on the reflective portion 14 is transmitted through the reflective polarizing member.

The light transmitted through the transflective part 14 will pass through the second lens part 24 and enter 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 portion 14 may be arranged substantially parallel to each other, or may be arranged substantially orthogonal to each other. The angle formed by the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first phase difference member 20 is, for example, 40° to 50°, 42° to 48°, or about 45°. The angle formed by the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second phase difference member 22 is, for example, 40° to 50°, 42° to 48°, or about 45°.

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

It is preferable that the first phase difference member 20 exhibits reverse dispersion wavelength characteristics in which the phase difference value increases with the wavelength of the measurement light. Re(450)/Re(550) of the first phase difference member 20 is, for example, less than 1, and may be 0.95 or less, or may be less than 0.90, and may be 0.85 or less. Re(450)/Re(550) of the first phase difference member 20 is, for example, 0.75 or more.

In one embodiment, the first phase difference member 20 satisfies all of Re(400)/Re(550)<0.85, Re(650)/Re(550)>1.03, and Re(750)/Re(550)>1.05. The first phase difference member 20 should preferably satisfy at least one selected from the following, more preferably at least two, and more preferably all: 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).

It is preferable that the first phase difference member 20 has a refractive index characteristic showing the relationship nx>ny≧nz. Here "ny=nz" includes not only the case where ny and nz are exactly the same, but also the case where they are substantially the same. Therefore, ny<nz may be satisfied as long as the effect of the present invention is not impaired. The Nz coefficient of the first phase difference member 20 is preferably 0.9~3, more preferably 0.9~2.5, more preferably 0.9~1.5, especially 0.9~1.3.

When linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first phase difference member 20 is incident on the first phase difference member 20, the transmitted light exhibits, for example, 0.72 or more, preferably 0.75 or more in the entire wavelength range of 380 nm to 700 nm. , it is better to show an ellipticity of 0.78 or above. The upper limit of the ellipticity of the transmitted light is 1. In addition, in this specification, the ellipticity of the transmitted light is sometimes referred to as the "ellipticity of the first phase difference member": the linearly polarized light with the polarization direction forming an angle of 45° with respect to the slow axis of the first phase difference member is incident. The transmitted light of the first phase difference member. Therefore, for example, "the ellipticity of the first phase difference member at a wavelength λnm" means the ellipticity of the above-mentioned transmitted light at a wavelength λnm, and "the first phase difference member exhibits an ellipticity of X or more" means the above-mentioned ellipticity of the transmitted light. The ellipticity is above X. The same applies to the second phase difference member described later. By using the above-mentioned first phase difference member having a high ellipticity of transmitted light in a wide wavelength range of visible light, display unevenness, ghosting, etc. can be suppressed.

In the wavelength region of 380 nm to 700 nm, the proportion of the wavelength region in which the first phase difference member 20 exhibits an ellipticity of 0.85 or more is, for example, 70% or more, preferably 75% or more, and more preferably 80% or more. This ratio may be, for example, 100% or less. By using the first phase difference member 20, the effect of suppressing display unevenness, ghosting, etc. can be more appropriately obtained.

In one embodiment, in the wavelength region in which the first phase difference member 20 exhibits an ellipticity of 0.85 or more, the wavelength region of 380 nm to 600 nm accounts for, for example, more than 70%, preferably 71% to 75%, and more preferably 76% to 76%. 80%. Since most of the wavelength range in which the first phase difference member 20 exhibits an ellipticity of 0.85 or more is a wavelength range of 380 nm to 600 nm, the effect of suppressing display unevenness, ghosting, etc. can be more appropriately obtained.

The ellipticity (ellipticity (550)) of the first phase difference member 20 at a wavelength of 550 nm is, for example, 0.9 or more, preferably 0.93 or more, and more preferably 0.95~1. By satisfying the ellipticity (550), reduction in light efficiency can be suppressed.

In one embodiment, the ellipticity (ellipticity (450)) of the first phase difference member 20 at a wavelength of 450 nm is greater than the ellipticity (ellipticity (650)) at a wavelength of 650 nm. Ellipticity (450)/ellipticity (650) is, for example, greater than 1, and is preferably 1.01 to 1.08. By using the first phase difference member 20 with an ellipticity (450) and an ellipticity (650) as described above, short-wavelength light leakage (eg, bluing) can be suppressed.

The ISC value of the first phase difference member 20 is, for example, 50 or less, preferably 40 or less, more preferably 30 or less, and more preferably 20 or less. By satisfying the ISC value of the first phase difference member 20, a display system with excellent visibility can be realized. For example, by satisfying the ISC value, the uniformity of the in-plane phase difference can be improved, and as a result, a display system with excellent display characteristics can be obtained. The ISC value can be an indicator of smoothness or unevenness.

The thickness variation of the first phase difference member 20 is preferably less than 1 μm, more preferably less than 0.8 μm, more preferably less than 0.6 μm, and more preferably less than 0.4 μm. Depending on the thickness variation, for example, the above-mentioned ISC value can be well achieved. Here, the thickness variation can be determined by measuring the thickness of the first portion located within the plane of the phase difference member and opening a predetermined interval in any direction (for example, upward direction, downward direction, left direction, and right direction) from the first portion. Calculate the thickness at the position (such as 5mm~15mm).

The ISC value per unit thickness of the first phase difference member 20 is preferably 1 or less, more preferably 0.7 or less, and more preferably 0.5 or less. The ISC value per unit thickness can be calculated, for example, by dividing the thickness (unit: µm) by the ISC value.

The first phase difference member 20 is formed of any suitable material that can satisfy the above characteristics. The first phase difference member 20 may be, for example, a stretched film of a resin film or a directionally solidified layer of a liquid crystal compound. In addition, the stretched film of the resin film is sometimes called a retardation film.

Examples of the resin contained in the above-mentioned resin film include polycarbonate resin, polyester carbonate resin, polyester resin, polyvinyl acetal resin, polyarylate resin, cyclic olefin resin, and cellulose resin. Resin, polyvinyl alcohol resin, polyamide resin, polyimide resin, polyether resin, polystyrene resin, acrylic resin, etc. These resins can be used individually or in combination (eg blending, copolymerization). When the first retardation member 20 exhibits reverse dispersion wavelength characteristics, a resin film containing polycarbonate resin or polyestercarbonate resin (hereinafter sometimes referred to simply as polycarbonate resin) can be suitably used.

As long as the effects of the present invention can be obtained, any appropriate polycarbonate resin may be used as the polycarbonate resin. For example, the polycarbonate resin includes: a structural unit derived from a fluorine-based dihydroxy compound; a structural unit derived from an isosorbide-based dihydroxy compound; and a structural unit derived from an alicyclic diol, an alicyclic diol, or an alicyclic diol. The structural unit of at least one dihydroxy compound in the group consisting of dimethanol, di, tri or polyethylene glycol, and alkylene glycol or spiroglycerol. The polycarbonate resin preferably contains: a structural unit derived from a fluorine-based dihydroxy compound; a structural unit derived from an isosorbide-based dihydroxy compound; a structural unit derived from an alicyclic dimethanol; and/or derived from Structural units of di, tri or polyethylene glycol; more preferably include: structural units derived from fluorine dihydroxy compounds; structural units derived from isosorbide dihydroxy compounds; and, derived from di, tri or polyethylene glycol. Structural unit of glycol. The polycarbonate resin may also contain structural units derived from other dihydroxy compounds if necessary. In addition, details of a polycarbonate-based resin suitably used for the first retardation member and a method of forming the first retardation member are described in, for example, Japanese Patent Application Laid-Open No. 2014-10291 and Japanese Patent Application Laid-Open No. 2014-26266 Publication No. 2015-212816, Japanese Patent Application Publication No. 2015-212817, and Japanese Patent Application Publication No. 2015-212818, the descriptions of these publications are incorporated into this specification as a reference.

The orientation-solidified layer of the above-mentioned liquid crystal compound is a layer in which the liquid crystal compound is oriented in a predetermined direction within the layer and its orientation state is fixed. In addition, the concept of "directionally hardened layer" includes a directionally hardened layer obtained by hardening a liquid crystal monomer as described later. Taking the first retardation member as an example, it means that the rod-shaped liquid crystal compounds are aligned along the slow axis direction of the first retardation member and are oriented (along the plane). 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 liquid crystal compound can be polymerized after alignment, thereby fixing the alignment state of the liquid crystal compound.

The directionally solidified layer of the above-mentioned liquid crystal compound (liquid crystal directionally solidified layer) can be formed by subjecting the surface of a predetermined base material to an orientation treatment, and applying a coating liquid containing a liquid crystal compound to the surface, so that the liquid crystal compound Orient in the direction corresponding to the above orientation processing, and fix the orientation state. The directional treatment may employ any suitable directional treatment. Specifically, mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment can be cited. Specific examples of mechanical orientation treatment include friction treatment and stretching treatment. Specific examples of physical orientation processing include magnetic field orientation processing and electric field orientation processing. Specific examples of chemical orientation treatment include oblique evaporation and photo-orientation treatment. The processing conditions for various targeted treatments can be any appropriate conditions depending on the purpose.

The orientation of the liquid crystal compound can be carried out by treating the liquid crystal compound at a temperature that can exhibit a liquid crystal phase according to the type of the liquid crystal compound. By performing the temperature treatment, the liquid crystal compound will change into a liquid crystal state, and the liquid crystal compound will be oriented according to the direction of the orientation treatment on the surface of the substrate.

In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned in the above manner. When the liquid crystal compound is polymerizable or cross-linked, the alignment state is fixed by subjecting the liquid crystal compound oriented in the above manner to polymerization treatment or cross-linking treatment.

Any appropriate liquid crystal polymer and/or liquid crystal monomer may be used as the above liquid crystal compound. The liquid crystal polymer and the liquid crystal monomer can each be used alone or in combination. Specific examples of the liquid crystal compound and methods of producing the liquid crystal alignment solidified layer are described in, for example, Japanese Patent Laid-Open No. 2006-163343, Japanese Patent Laid-Open No. 2006-178389, and International Publication No. 2018/123551. This manual refers to the records in these publications as a reference.

The thickness of the first phase difference member 20 is preferably 100 μm or less. Specifically, the thickness of the first phase difference member 20 composed of an extended film of a resin film is, for example, 10µm~100µm, preferably 10µm~70µm, more preferably 10µm~60µm, and more preferably 20µm~50µm. In addition, the thickness of the first phase difference member 20 composed of the liquid crystal alignment solidified layer is, for example, 1µm~10µm, preferably 1µm~8µm, more preferably 1µm~6µm, and more preferably 1µm~4µm.

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

It is preferable that the second phase difference member 22 exhibits reverse dispersion wavelength characteristics in which the phase difference value increases with the wavelength of the measurement light. Re(450)/Re(550) of the second phase difference member 22 is, for example, less than 1, and may be 0.95 or less, or may be less than 0.90, and may be 0.85 or less. Re(450)/Re(550) of the second phase difference member 22 is, for example, 0.75 or more.

In one embodiment, the second phase difference member 22 satisfies all of Re(400)/Re(550)<0.85, Re(650)/Re(550)>1.03, and Re(750)/Re(550)>1.05. The second phase difference member 22 preferably satisfies at least one selected from the following, preferably satisfies at least two, and more preferably satisfies all: 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).

It is preferable that the refractive index characteristic of the second phase difference member 22 exhibits the relationship nx>ny≧nz. Here "ny=nz" includes not only the case where ny and nz are exactly the same, but also the case where they are substantially the same. Therefore, ny<nz may be satisfied as long as the effect of the present invention is not impaired. The Nz coefficient of the second phase difference member 22 is preferably 0.9~3, more preferably 0.9~2.5, more preferably 0.9~1.5, especially 0.9~1.3.

When linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first phase difference member 20 is incident on the second phase difference member 22, the transmitted light exhibits, for example, 0.72 or more, preferably 0.75 or more, in the entire wavelength range of 380 nm to 700 nm. , it is better to show an ellipticity of 0.78 or above. The upper limit of the ellipticity of the transmitted light is 1. By using the second phase difference member 22 having a high ellipticity of transmitted light in a wide wavelength range of visible light, display unevenness, ghosting, etc. can be suppressed.

In the wavelength range of 380 nm to 700 nm, the proportion of the wavelength range in which the second phase difference member 22 exhibits an ellipticity of 0.85 or more is, for example, 70% or more, preferably 75% or more, and more preferably 80% or more. The ratio can also be 100%. By using the second phase difference member 22, the effect of suppressing display unevenness, ghosting, etc. can be more appropriately obtained.

In one embodiment, in the wavelength region in which the second phase difference member 22 exhibits an ellipticity of 0.85 or more, the wavelength region of 380 nm to 600 nm accounts for, for example, more than 70%, preferably 71% to 75%, and more preferably 76% to 76%. 80%. Since most of the wavelength range in which the second phase difference member 22 exhibits an ellipticity of 0.85 or more is a wavelength range of 380 nm to 600 nm, the effect of suppressing display unevenness, ghosting, etc. can be more appropriately obtained.

The ellipticity (550) of the second phase difference member 22 is, for example, 0.9 or more, preferably 0.93 or more, and more preferably 0.95~1. By satisfying the ellipticity (550), reduction in light efficiency can be suppressed.

In one embodiment, the ellipticity (450) of the second phase difference component 22 is greater than the ellipticity (650). Ellipticity (450)/ellipticity (650) is, for example, greater than 1, and is preferably 1.01 to 1.08. By using the second phase difference member 22 , short wavelength light leakage (for example, bluing) can be suppressed.

The ISC value of the second phase difference member 22 is, for example, 50 or less, preferably 40 or less, more preferably 30 or less, and more preferably 20 or less. By satisfying the ISC value of the second phase difference member 22, a display system with excellent visibility can be realized. For example, by satisfying the ISC value, the uniformity of the in-plane phase difference can be improved, and as a result, a display system with excellent display characteristics can be obtained. The ISC value can be an indicator of smoothness or unevenness.

The thickness variation of the second phase difference member 22 is preferably less than 1 μm, more preferably less than 0.8 μm, more preferably less than 0.6 μm, and more preferably less than 0.4 μm. Depending on the thickness variation, for example, the above-mentioned ISC value can be well achieved.

The ISC value per unit thickness of the second phase difference member 22 is preferably 1 or less, more preferably 0.7 or less, and more preferably 0.5 or less.

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

The thickness of the second phase difference member 22 is preferably 100 μm or less. Specifically, the thickness of the second phase difference member 22 made of an extended film of a resin film is, for example, 10µm~100µm, preferably 10µm~70µm, more preferably 10µm~60µm, and more preferably 20µm~50µm. In addition, the thickness of the second phase difference member 22 composed of the liquid crystal alignment solidified layer is, for example, 1µm~10µm, preferably 1µm~8µm, more preferably 1µm~6µm, and more preferably 1µm~4µm.

The absolute value of the difference between the in-plane phase difference (a) of the first phase difference member and the in-plane phase difference (b) of the second phase difference member is, for example, 3.5 nm or less, preferably 3.0 nm or less, more preferably 2.5 nm or less. , more preferably below 2.0nm, especially below 1.5nm, most preferably below 1.0nm. In one embodiment, (a) and (b) are values of Re(590). By satisfying the above relationships in (a) and (b), a display system with excellent display characteristics can be obtained.

It is preferable that the in-plane phase difference (a) of the first phase difference member and the in-plane phase difference (b) of the second phase difference member satisfy the following formula (I). ((a)-(b))/((a)+(b)/2)≦0.02・・・(I) More preferably ((a)-(b))/((a)+(b)/2)≦0.015, more preferably ((a)-(b))/((a)+(b)/2 )≦0.01.

In addition to the reflective polarizing member, the reflective part 14 may also include an absorptive polarizing member. The absorptive polarizing member may be disposed 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 reflective part 14 includes an absorptive polarizing member, the reflective part 14 may include a laminate of a reflective polarizing member and an absorptive polarizing member.

The reflective polarizing member can transmit polarized light parallel to its transmission axis (typically linear polarization) while maintaining its polarized state, and can reflect light in other polarized states. The cross transmittance (Tc) of the reflective polarizing member can be, for example, 0.01%~3%. The single transmittance (Ts) of the reflective polarizing member can be, for example, 43% to 49%, preferably 45% to 47%. The polarization degree (P) of the reflective polarizing member can be, for example, 92% to 99.99%. Reflective polarizing components are typically composed of films with a multi-layer structure (sometimes called reflective polarizing films). Commercially available reflective polarizing films include, for example, the trade names "DBEF" and "APF" manufactured by 3M Company, and the trade name "APCF" manufactured by Nitto Denko Corporation.

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

The above-mentioned absorptive polarizing film can be made of a single-layer resin film or a laminate of two or more layers.

When made from a single-layer resin film, for example, hydrophilic polymer films such as polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene vinyl acetate copolymer-based partially saponified films can be processed. Dyeing treatment, stretching treatment, etc. using dichroic substances such as iodine or dichroic dyes are used to obtain an absorptive polarizing film. Among them, an absorption-type polarizing film obtained by dyeing a PVA-based film with iodine and uniaxially stretching it is preferred.

The above-described dyeing with iodine can be performed, for example, by immersing a PVA-based film in an iodine aqueous solution. The extension ratio of the above-mentioned uniaxial extension is preferably 3 to 7 times. Extending can be done after dyeing or while dyeing. Also, it can be dyed after stretching. If necessary, the PVA film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, etc.

Examples of the laminated body when produced using the above-mentioned two or more laminated bodies include the following laminated bodies: a laminated body of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material; or a resin-based laminated body. A laminate consisting of a material and a PVA-based resin layer coated on the resin base material. An absorption-type polarizing film using a laminate of a resin base material and a PVA-based resin layer coated on the resin base material can be produced, for example, by the following steps: applying a PVA-based resin solution to the resin base material and dry it to form a PVA-based resin layer on the resin base material to obtain a laminated body of the resin base material and the PVA-based resin layer; and stretch and dye the laminated body to form the PVA-based resin layer into an absorbing polarizing film . In this embodiment, it is preferable to form a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin on one side of the resin base material. Stretching typically includes immersing the laminate in a boric acid aqueous solution to stretch. And if necessary, stretching may further include stretching the laminate in the air at a high temperature (for example, above 95° C.) before stretching in a boric acid aqueous solution. Furthermore, in this embodiment, it is preferable to subject the laminated body to a drying and shrinking process in which the laminated body is heated while being conveyed in the longitudinal direction to shrink the laminated body by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes sequentially performing an air-assisted stretching process, a dyeing process, an underwater stretching process, and a drying shrinkage process on the laminate. By introducing auxiliary stretching, the crystallinity of PVA can be improved even when PVA is coated on thermoplastic resin, and high optical properties can be achieved. In addition, by improving the orientation of PVA in advance, it can prevent problems such as reduction in orientation or dissolution of PVA when immersed in water in the subsequent dyeing step or stretching step, thereby achieving high optical properties. In addition, when the PVA-based resin layer is immersed in a liquid, compared with the case where the PVA-based resin layer does not contain halides, the orientation disorder and decrease in orientation of polyvinyl alcohol molecules can be suppressed. Thereby, the optical characteristics of the absorptive polarizing film obtained by immersing the laminate in a liquid, such as dyeing treatment and water stretching treatment, can be improved. In addition, the optical properties can be improved by shrinking the laminate in the width direction through drying and shrinkage treatment. The obtained laminate of the resin base material/absorptive polarizing film can be used directly (that is, the resin base material can be used as a protective layer of the absorptive polarizing film), or the resin can be peeled off from the laminate of the resin base material/absorptive polarizing film. Use any suitable protective layer that meets the purpose on the peeling surface behind the base material or on the area opposite to the peeling surface. Details of the manufacturing method of the absorptive polarizing film are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire description of these publications is cited in this specification as a reference.

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

FIG. 2 is a schematic diagram illustrating the progression of light and the change of polarization state in the following embodiment: in the display system shown in FIG. 1 , the absorption axis of the polarizing member included in the display element 12 and the reflective polarization included in the reflective part 14 The reflection axes of the members 14a are arranged to be substantially orthogonal to each other. Specifically, FIG. 2(a) is a schematic diagram illustrating an example of the travel of light in this embodiment, and FIG. 2(b) is a schematic diagram illustrating polarized light generated when light transmits through each member or is reflected by each member in this embodiment. Schematic diagram of an example of a state change. In FIG. 2 , the solid arrow attached to the display element 12 indicates the direction of the absorption axis of the polarizing member included in the display element 12 . The arrows attached to the first λ/4 member 20 and the second λ/4 member 22 indicate the direction of the slow axis. The solid arrows attached to the reflective polarizing member 14a included in the reflecting part 14 indicate the direction of the reflection axis, and the dotted arrows indicate the direction of the transmission axis of each polarizing member. In this embodiment, the angle formed by the polarization direction of the first linearly polarized light emitted forward through the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14a is substantially parallel. The angle formed by the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first λ/4 member 20 is, for example, 40° to 50°. The slow axis of the first λ/4 member 20 and the slow axis of the second λ/4 member 22 are arranged to be substantially orthogonal to each other.

The light L emitted from the display element 12 in the form of first linearly polarized light through 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 portion 16 (not shown in FIG. 2 ), and is converted by the 2nd λ/4 member 22 into a second straight line whose polarization direction is parallel to the first linearly polarized light. Polarized. 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 reflective part 14. Therefore, the second linearly polarized light incident on the reflective portion 14 is reflected toward the half mirror 18 by the reflective polarizing member 14 a.

The second linearly polarized light reflected by the reflective part 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 direction 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 part 16 and is reflected by the half mirror 18, and is converted into a third circularly polarized light that rotates in the opposite direction to the second circularly polarized light. The third circularly polarized light reflected by the half mirror 18 passes through the first lens part 16 and is converted into the third linearly polarized light by the 2λ/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) with the transmission axis of the reflective polarizing member 14a. Therefore, the third linearly polarized light can transmit the reflective polarizing member 14a. Furthermore, although not shown in the figure, when the reflective part includes an absorptive polarizing member, it is arranged so that its absorption axis is substantially parallel to the reflection axis of the reflective polarizing member 14a, so that the third linearly polarized light of the transmissive reflective polarizing member 14a can be directly transmitted. Absorptive polarizing member. The light transmitted through the transflective part 14 will pass through the second lens part 24 and enter the user's eyes 26 .

In the example shown in FIG. 2 , the arrangement is such that when viewed from the display element 12 side, the slow axes of the first λ/4 member and the second λ/4 member are counterclockwise and counterclockwise with respect to the absorption axis of the polarizing member included in the display element 12 respectively. A predetermined angle is formed in the clockwise direction (for example, 40°~50°), but the same description as above can also be applied when arranging the predetermined angles in the clockwise direction and the counterclockwise direction. In an embodiment in which the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14a are arranged to be substantially orthogonal to each other, the first λ/4 member and the second λ/4 member are arranged so as to slow down each other. The angle formed by the axis is, for example, 83° to 97°, preferably 84° to 96°, more preferably 85° to 95°, more preferably 86° to 94°, and still more preferably 87° to 93°. By satisfying the above relationship between the slow axis of the first λ/4 member and the slow axis of the second λ/4 member, a display system with excellent display characteristics can be obtained.

In the example shown in FIG. 2 , the slow axis of the first λ/4 member 20 and the slow axis of the second λ/4 member 22 are arranged substantially orthogonally to each other, but they may also be arranged substantially parallel as shown in FIG. 3 . For example, the slow axis of the first λ/4 member 20 and the slow axis of the second λ/4 member 22 can be arranged to form a predetermined clockwise or counterclockwise direction with respect to the absorption axis of the polarizing member included in the display element 12 Angle (for example 40°~50°). At this time, unlike the example shown in FIG. 2 , the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14 a included in the reflecting portion 14 may be arranged substantially parallel to each other. Therefore, the angle formed by the polarization direction of the first linearly polarized light emitted forward through the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14 may be substantially orthogonal. In an embodiment in which the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14 are arranged substantially parallel to each other, the first λ/4 member and the second λ/4 member are arranged so that their slow axes are aligned with each other. The constituted angle is, for example, 7° or less, preferably 6° or less, more preferably 5° or less, more preferably 4° or less, and still more preferably 3° or less. By satisfying the above relationship between the slow axis of the first λ/4 member and the slow axis of the second λ/4 member, a display system with excellent display characteristics can be obtained.

As described above, in the display system according to the embodiment of the present invention, the first linearly polarized light emitted from the display element 12 through the polarizing member is transmitted through the first λ/4 member 20 and then is transmitted through the second λ/4 member 22 for a total of three times. Reflective polarizing member 14a. In the display system, the first λ/4 member 20 and the second λ/4 member 22 each use a λ/4 member having an ellipticity equal to or higher than a predetermined value over a wide range of the entire visible light region, thereby suppressing the transmission of light. Hue changes, light leakage, etc. Specifically, by reducing the transmittance difference between wavelengths of light transmitted through the transflective polarizing member 14a, it is possible to suppress hue changes caused by the light emitted from the display element, and as a result, display unevenness can be suppressed. Furthermore, by suppressing polarization collapse over a wide range of the entire visible light region, light leakage from the reflective polarizing member 14a is suppressed. As a result, the light that should be reflected by the reflective polarizing member 14a can be suitably suppressed from appearing as a ghost (so-called ghost). Visible to the user.

Example Hereinafter, the present invention will be specifically described through examples, but the present invention is not limited by these examples. In addition, the test and evaluation methods in the Examples and the like are as follows. In addition, when it is described as "parts", it means "parts by weight" unless otherwise specified, and when it is described as "%", it means "% by weight" unless there is any special explanation.

(1) The thickness of 10 μm or less is measured using a scanning electron microscope (manufactured by JEOL Ltd., product name "JSM-7100F"). Thickness greater than 10µm is measured using a digital micrometer (manufactured by Anritsu Co., Ltd., product name "KC-351C"). (2) In-plane phase difference Re (λ) The phase difference at each wavelength was measured at 23° C. using a Mueller matrix polarizer (manufactured by Axometrics, product name "Axoscan"). (3) Single transmittance and polarization degree of the polarizing film Use a spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "LPF-200") to measure the single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of the polarizing film . These Ts, Tp and Tc are the Y values measured using the 2-degree visual field (C light source) of JIS Z8701 and corrected for visual sensitivity. From the obtained Tp and Tc, the degree of polarization of the polarizing film was calculated using the following formula. Degree of polarization (%) = {(Tp-Tc)/(Tp+Tc)} ^1/2 × 100 (4) Thickness variation Cut the phase difference film into a size of 100mm × 100mm to make a measurement sample. As shown in Figure 4, measure the thickness of a total of five points at the center of the sample and four points 10 mm apart from the center, up, down, left, and right, and take the difference between the maximum value and the minimum value as the thickness variation. (5) ISC value The ISC value of the retardation film was measured using EyeScale-4W manufactured by i-system Co., Ltd. Specifically, according to the specifications of the measurement device, the in-plane unevenness is calculated as the ISC value using the ISC measurement mode of the 3CCD image sensor. FIG. 5 is a diagram for explaining the method of measuring the ISC value, and is a schematic view of the arrangement of a light source, a phase difference film, a screen, and a CCD camera when viewed from above. As shown in Figure 5, the light source L, the phase difference film M and the screen S are arranged in sequence, and the transmitted image projected on the screen S is measured by the CCD camera C. In addition, the retardation film M was attached to an alkali-free glass plate (manufactured by Corning Co., Ltd., 1737), and was measured in a state where the glass plate was positioned on the light source L side. The distance in the X-axis direction from the light source L to the retardation film M is arranged to be 10 to 60 cm. The distance in the X-axis direction from the light source L to the screen S is configured to be 70~130cm. The distance in the Y-axis direction from the CCD camera C to the phase difference film M is arranged to be 3~30cm. The distance in the X-axis direction from the CCD camera C to the screen S is configured to be 70~130cm.

[Production Example 1-1: Preparation of retardation film 1] In a batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and a reflux cooler controlled to 100°C, double [9- (2-phenoxycarbonylethyl)ben-9-yl]methane 29.60 parts by weight (0.046mol), isosorbide (ISB) 29.21 parts by weight (0.200mol), spiroglycerol (SPG) 42.28 parts by weight (0.139mol) ), 63.77 parts by weight (0.298 mol) of diphenyl carbonate (DPC) and 1.19×10 ^-2 parts by weight (6.78×10 ^-5 mol) of calcium acetate monohydrate as a catalyst. After the reactor was replaced with nitrogen under reduced pressure, it was heated with a heat medium, and stirring was started when the internal temperature reached 100°C. The internal temperature was brought to 220°C 40 minutes after the start of the temperature rise, and the pressure was reduced while maintaining the temperature. After reaching 220°C, it was adjusted to 13.3 kPa in 90 minutes. The phenol vapor generated by the polymerization reaction is introduced into a reflux cooler at 100°C, so that a small amount of monomer components contained in the phenol vapor is returned to the reactor, and the uncondensed phenol vapor is introduced into a condenser at 45°C for recovery. After introducing nitrogen into the first reactor and temporarily returning it to atmospheric pressure, the oligomerized reaction liquid in the first reactor is moved to the second reactor. Next, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature was adjusted to 240° C. and the pressure to 0.2 kPa over 50 minutes. Then, polymerization is performed until a predetermined stirring power is reached. At the time point when the predetermined power is reached, nitrogen is introduced into the reactor to restore the pressure, the generated polyester carbonate resin is extruded into water, and the bundles are cut to obtain pellets. The obtained polyester carbonate resin (pellets) was vacuum dried at 80°C for 5 hours, and then used a single-screw extruder (manufactured by Toshiba Machinery Co., Ltd., cylinder set temperature: 250°C) and a T-type die (width 200mm). , set temperature: 250℃), cooling roller (set temperature: 120~130℃) and film forming device of the winding machine to produce a long resin film with a thickness of 130μm. 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. In the above manner, a retardation film 1 with a thickness of 47µm, a Re (590) of 143nm and an Nz coefficient of 1.2 was obtained. Re(450)/Re(550) of the obtained retardation film 1 was 0.856. Table 1 shows that the ISC value and thickness of the retardation film 1 vary.

[Table 1]

[Manufacturing Example 1-2: Preparation of retardation film 2] As the retardation film 2, a commercially available retardation film (manufactured by Kaneka Co., Ltd., product name "ZEONOR #140COP QWP") made of a cycloolefin-based resin film was used. The thickness of the retardation film 2 is 33µm, Re(590) is 140nm, and the Nz coefficient is 1.0. Furthermore, Re(450)/Re(550) of the retardation film 2 is 1.01.

[Manufacture Example 2: Production of Polarizing Film 1] The thermoplastic resin base material is a long amorphous isophthalic acid copolymer polyethylene terephthalate film (thickness: 100µm) with a Tg of about 75°C, and corona is applied to one side of the resin base material. handle. PVA-based resin made by mixing polyvinyl alcohol (degree of polymerization 4200, saponification degree 99.2 mol%) and acetate-acetyl-modified PVA (manufactured by Mitsubishi Chemical Co., trade name "GOHSENX Z410") at a ratio of 9:1 13 parts by weight of potassium iodide was added to 100 parts by weight, and the resultant was dissolved in water to prepare a PVA aqueous solution (coating liquid). The above-mentioned 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 to 2.4 times in the longitudinal direction (long side direction) in an oven at 130°C (air-assisted stretching treatment). Next, the laminated body was immersed in an insolubilization bath (a boric acid aqueous solution in which 4 parts by weight of boric acid was mixed with 100 parts by weight of water) having a liquid temperature of 40°C for 30 seconds (insolubilization treatment). Next, immerse the dye bath (an iodine aqueous solution obtained by mixing iodine and potassium iodide at a weight ratio of 1:7 with respect to 100 parts by weight of water) with a liquid temperature of 30°C for 60 seconds while adjusting the concentration. So that the monomer transmittance (Ts) of the finally obtained absorptive polarizing film becomes a desired value (dyeing process). Next, it was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid to 100 parts by weight of water) with a liquid temperature of 40° C. for 30 seconds (crosslinking treatment) ). Then, the laminate was immersed in a boric acid aqueous solution with a liquid temperature of 70°C (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight), and uniaxially stretched in the longitudinal direction (longitudinal direction) between rollers with different circumferential speeds. In order to make the total extension ratio reach 5.5 times (extension treatment in water). Thereafter, the laminated body was immersed in a cleaning bath (an aqueous solution in which 4 parts by weight of potassium iodide was mixed with 100 parts by weight of water) having a liquid temperature of 20° C. (washing treatment). Thereafter, it was dried in an oven kept at about 90° C. while keeping the contact surface temperature at about 75° C. with a SUS heated roller (drying shrinkage treatment). The shrinkage rate in the width direction of the laminated body due to drying shrinkage treatment is 5.2%. Through the above procedures, an absorptive polarizing film with a thickness of approximately 5µm was formed on the resin substrate. An acrylic resin film ("RV-20", thickness 20µm) as a protective layer was bonded to the surface of the resulting absorptive polarizing film (the side opposite to the resin base material) through a water-based adhesive (thickness after hardening: 0.1µm). ). Next, the resin base material is peeled off. Thereby, the polarizing film 1 having the structure of [acrylic resin film/absorptive polarizing film] is obtained. In addition, the above-mentioned water-based adhesive is a water-based adhesive containing PVA-based resin having an acetyl acetyl group, methylol melamine, and positively charged alumina colloid (average particle size 15 nm). The single transmittance (Ts) of polarizing film 1 is 43.0%, and the polarization degree is 99.989%.

The ellipticity of the retardation film 1 and the retardation film 2 was measured in the following manner. The results are shown in Table 2 and Figure 6. <Measurement method of ellipticity> A retardation film is attached to the absorptive polarizing film side surface of polarizing film 1 through an acrylic adhesive layer (manufactured by Nitto Denko Co., Ltd., thickness 5 µm) to obtain [retardation film/polarizing film] 1] The test sample is composed of. In the measurement sample, the angle formed by the slow axis of the retardation film and the absorption axis of the polarizing film 1 is 45°. Using a Mueller matrix polarizer (manufactured by Axometrics, product name "Axoscan"), light is irradiated from the normal direction to the surface of the polarizing film 1 of the measurement sample at 23°C, and the transmission is measured every 10 nm in the wavelength range of 400 nm to 700 nm. Ellipticity of light. [Table 2]

[Example 1] Four pieces of the retardation film 1 obtained in Production Example 1-1 were laminated, and then the polarizing film 1 obtained in Production Example 2 was laminated to obtain a laminated body. Adjacent films are laminated through an acrylic adhesive layer (manufactured by Nitto Denko Co., Ltd., thickness 5 μm). The four retardation films 1 are λ/4 member 1, λ/4 member 2, λ/4 member 3 and λ/4 member 4 in order from one side and are laminated with the axial relationship shown in Table 3. Then, the polarizing film 1 is laminated on the λ/4 member 4 . In addition, the angles shown in Table 3 are the axial angles of each member based on the absorption axis direction of the absorbing polarizing film of the polarizing film when the laminated body is viewed from the λ/4 member 1 side, "+" indicates the clockwise direction, and "- ” means counterclockwise. [table 3]

[Comparative example 1] A laminated body was obtained in the same manner as in Example 1 except that the retardation film 2 was used as the λ/4 members 1 to 4.

<Evaluation> Using a spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "LPF-200"), the parallel transmittance and initial hue (a ^* value, b ^* value) of the polarizing film 1 were measured, as well as those of Example 1 and Comparative Example 1 Parallel transmittance and parallel hue (a ^* value, b ^* value) of the laminated body. The parallel transmittance is the Y value measured using the 2-degree field of view (C light source) of JIS Z8701 and corrected for visual sensitivity. The initial hue of the polarizing film is the hue of the light that is emitted from the other side after being incident on one side of the polarizing film 1 . The parallel hue of the laminated body is the hue of the light that is emitted from the polarizing film 1 side after the linearly polarized light with the polarization direction orthogonal to the absorption axis of the polarizing film 1 is incident from the λ/4 member 1 side of the laminated body.

Table 4 shows the parallel transmittance and initial hue of the polarizing film 1, and the difference between the parallel transmittance and the parallel hue of the laminated body. In addition, the laminates produced in Examples and Comparative Examples are simple evaluation models of the display system according to the embodiment of the present invention. Specifically, the light incident on the laminated body from the λ/4 member 1 side and emitted from the polarizing film 1 side can be evaluated as follows: In the display system according to the embodiment of the present invention, the light emitted forward from the display element via the polarizing member can be evaluated. After the first linearly polarized light transmits the 1st λ/4 member and the 2nd λ/4 member in sequence, it is reflected by the reflective polarizing member and the half-reflecting mirror and then transmits the 2nd λ/4 member twice, and then transmits the reflective polarizing member. Shoot it forward, and then evaluate it by the light it shoots out. Therefore, the difference between the parallel transmittance of the polarizing film 1 and the parallel transmittance of the laminate (ΔTp = Tp of the laminate - Tp of the polarizing film 1 ) can reflect the degree of reduction in light efficiency in the above display system. In addition, the difference (Δa ^* b ^* ) between the initial hue of the polarizing film 1 and the parallel hue of the laminate can reflect the degree of hue change between the emitted light and the transmitted light in the above display system. [Table 4]

Compared with the light transmitted through the laminated body of Comparative Example 1, the hue change of the light transmitted through the laminated body of Example 1 is more suppressed, and compared with the laminated body of Comparative Example 1, the optical efficiency of the laminated body of Example 1 is Decreases are also more suppressed.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, it may be replaced by a structure that is substantially the same as that shown in the above-mentioned embodiment, a structure that can produce the same effects, or a structure that can achieve the same purpose.

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

2:Display system 12:Display components 12a:Display surface 14: Reflective part 14a: Reflective polarizing component 16: First lens part 18: Half mirror 20: First phase difference member (1st λ/4 member) 22: Second phase difference member (2nd λ/4 member) 24: Second lens unit 26:User's Eyes C:CCD camera L: light source M: Phase difference film S:Screen X, Y: axis

FIG. 1 is a schematic diagram showing the schematic structure of a display system according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an example of light traveling and polarization state changes in an embodiment of the display system shown in FIG. 1 . FIG. 3 is a schematic diagram illustrating an example of light traveling and polarization state changes in one embodiment of the display system shown in FIG. 1 . Figure 4 is a diagram illustrating a method of measuring thickness variation. Fig. 5 is a diagram for explaining the method of measuring the ISC value. FIG. 6 is a graph showing the ellipticity spectrum of the retardation film produced in the production example.

2:Display system

12:Display components

12a:Display surface

14: Reflective part

16: First lens part

18: Half mirror

20: First phase difference member (1st λ/4 member)

22: Second phase difference member (2nd λ/4 member)

24: Second lens unit

26:User's Eyes

Claims (10)

A display system that displays images to users, which has: A display element has a display surface and emits light for displaying images forward through a polarizing member; The reflective part is arranged in front of the display element and includes a reflective polarizing member, and the reflective part reflects the light emitted from the display element; The first lens part is arranged on the optical path between the display element and the reflecting part; A half-reflecting mirror is disposed between the display element and the first lens portion, and the half-reflecting mirror transmits the light emitted from the display element and reflects the light reflected by the reflecting portion toward the reflecting portion; The 1st λ/4 member is arranged on the optical path between the aforementioned display element and the aforementioned half-reflecting mirror; and The 2nd λ/4 member is arranged on the optical path between the half mirror and the reflecting part; When linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first λ/4 member is incident on the first λ/4 member, the ellipticity of the transmitted light with a wavelength of 380nm~700nm is 0.72 or more; and When linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the second λ/4 member is incident on the second λ/4 member, the ellipticity of the transmitted light with a wavelength of 380 nm to 700 nm is 0.72 or more. The display system of claim 1, wherein when linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first λ/4 member is incident on the first λ/4 member, the ellipticity of the transmitted light with a wavelength of 550 nm is 0.9 or more. ;and When linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the second λ/4 member is incident on the second λ/4 member, the ellipticity of the transmitted light with a wavelength of 550 nm is 0.9 or more. The display system of claim 1, wherein when linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first λ/4 member is incident on the first λ/4 member, the ellipticity of the transmitted light with a wavelength of 450 nm is greater than that of a wavelength of 650 nm. the ellipticity of the transmitted light; and When linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the 2λ/4 member is incident on the 2λ/4 member, the ellipticity of the transmitted light with a wavelength of 450 nm is greater than the ellipticity of the transmitted light with a wavelength of 650 nm. Such as the display system of claim 1, wherein in the wavelength range of 380nm~700nm, when linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the first λ/4 member is incident on the first λ/4 member, the transmitted light is The proportion of wavelength areas with ellipticity above 0.85 is above 70%; and In the wavelength range of 380nm to 700nm, when linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the 2λ/4 member is incident on the 2λ/4 member, the ellipticity of the transmitted light is 0.85 or above. The proportion is more than 70%. The display system of claim 1, wherein when linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first λ/4 member is incident on the first λ/4 member, the transmitted light exhibits a wavelength region with an ellipticity of 0.85 or more. More than 70% of them are in the wavelength region of 380nm~600nm; and When linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the 2λ/4 member is incident on the 2λ/4 member, more than 70% of the wavelength range in which the transmitted light exhibits an ellipticity of 0.85 or more is 380nm~600nm. wavelength region. The display system of 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 display system of 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 parallel to each other. A display body having a display system according to any one of claims 1 to 7. A method of manufacturing a display body having a display system according to any one of claims 1 to 7. A display method with the following procedure: The process of causing the light emitted by the polarizing member to display the image to pass through the 1λ/4 member; The process of causing the light passing through the aforementioned 1λ/4 member to pass through the half-reflecting mirror and the first lens part; The process of allowing the light passing through the half-reflecting mirror and the first lens part to pass through the 2λ/4 member; The process of reflecting the light passing through the 2λ/4 member toward the half-reflecting mirror through the reflective part including the reflective polarizing member; and The process of allowing the light reflected by the reflective part and the half-reflecting mirror to transmit through the reflective part through the 2λ/4 member; When linearly polarized light with a polarization direction forming an angle of 45° relative to the slow axis of the first λ/4 member is incident on the first λ/4 member, the ellipticity of the transmitted light with a wavelength of 380nm~700nm is 0.72 or more; and When linearly polarized light with a polarization direction forming an angle of 45° with respect to the slow axis of the second λ/4 member is incident on the second λ/4 member, the ellipticity of the transmitted light with a wavelength of 380 nm to 700 nm is 0.72 or more.

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