Image display device

Abstract

To provide an image display device with high light utilization efficiency.SOLUTION: An image display device includes a display, a first reflective polarizer, and a second reflective polarizer. The first and second reflective polarizers include a first region transmitting first deflection and reflecting second deflection and a second region transmitting the second deflection and reflecting the first deflection and are divided into the first region and the second region by a line passing through an optical axis. The shapes of the first region and the second region are symmetrical about a point across the optical axis. The display is divided into a first display region emitting the first deflection and a second display region emitting the second deflection by a line going through the optical axis. The shapes of the first display region and the second display region are symmetrical about a point across the optical axis. A focal point of the fist reflective polarizer is positioned on the opposite side of the first reflective polarizer with respect to the second reflective polarizer, and a focal point of the second reflective polarizer is positioned between the first reflective polarizer and the second reflective polarizer. The first display region of the display, the first region of the first reflective polarizer, and the second region of the second reflective polarizer overlap when seen from the optical axis direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image display device. [Background technology]

[0002] Virtual reality display devices such as head mounted displays (HMDs) including AR (Augmented Reality) glasses, VR (Virtual Reality) glasses, and MR (Mixed Reality) glasses overlay virtual images and various information on the scene you are actually viewing. These are image display devices that allow you to feel as if you are immersed in a virtual world by wearing a dedicated headset on your head and viewing the images displayed through the lenses.

[0003] As a virtual reality display device, an image display device has been proposed that has a display and two partially reflective elements, and has an optical unit known as a pancake lens or folded optical system, which reduces the overall thickness of the headset by redirecting the light emitted from the display back and forth between the two partially reflective elements.

[0004] For example, Patent Document 1 describes an optical device including a first polarizer configured to polarize incident light into light of a first circular polarization state, a second polarizer configured to transmit light of the second circular polarization state and reflect light of the first circular polarization state, where light reflected by the second polarizer is in the first circular polarization state, and a partial reflector disposed between the first polarizer and the second polarizer, configured to transmit light from the first polarizer and reflect light from the second polarizer, where the light reflected by the partial reflector has a different polarization state from the light from the second polarizer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-532393 Summary of the Invention [Problem to be solved by the invention]

[0006] In an image display device having a conventional folding optical system as described above, a partial reflector (half mirror) transmits a portion of the light emitted from the display, and the transmitted light is reflected by a reflective polarizer and reflected again by the partial reflector (half mirror), while its polarization direction is converted to polarized light that transmits through the reflective polarizer, and the light transmits through the reflective polarizer and is emitted from the image display device.

[0007] As described above, conventional image display devices require the use of a so-called half mirror to convert the polarization state of light from the polarized light reflected by the reflective polarizer to the polarized light that is transmitted. However, the light must pass through the half mirror twice (transmitted and reflected), and the amount of light is roughly halved each time. This causes a problem in that the light utilization efficiency of the amount of image light emitted by the display is low at approximately 25%.

[0008] An object of the present invention is to solve such problems in the prior art and to provide an image display device with high light utilization efficiency. [Means for solving the problem]

[0009] In order to solve this problem, the present invention has the following configuration. [1] A liquid crystal display comprising a display, a first reflective polarizer, and a second reflective polarizer, in that order; The first reflective polarizer and the second reflective polarizer are arranged such that an optical axis of the first reflective polarizer and an optical axis of the second reflective polarizer coincide with each other; the first reflective polarizer has a first region that transmits light of a first polarization and reflects light of a second polarization orthogonal to the first polarization, and a second region that transmits light of the second polarization and reflects the first polarization; the first reflective polarizer is divided into a first region and a second region by a line passing through an optical axis of the first reflective polarizer, and the shape of the first region and the shape of the second region are point-symmetric with respect to the optical axis of the first reflective polarizer; the second reflective polarizer has a first region that transmits the first polarized light and reflects the second polarized light, and a second region that transmits the second polarized light and reflects the first polarized light; the second reflective polarizer is divided into a first region and a second region by a line passing through the optical axis of the first reflective polarizer, and the shapes of the first region and the second region are point-symmetric with respect to the optical axis of the first reflective polarizer; the display is divided by a line passing through the optical axis of the first reflective polarizer into a first display region that outputs a first polarized light and a second display region that outputs a second polarized light, and the shapes of the first display region and the second display region are point-symmetric with respect to the optical axis of the first reflective polarizer; a focal point of the first reflective polarizer is located on an opposite side of the first reflective polarizer with respect to the second reflective polarizer; the focal point of the second reflective polarizer is located between the first reflective polarizer and the second reflective polarizer; An image display device, in which a first display region of the display, a first region of the first reflective polarizer, and a second region of the second reflective polarizer overlap when viewed from the optical axis direction of the first reflective polarizer. [2] The image display device according to [1], wherein the first reflective polarizer and the second reflective polarizer are reflective circular polarizers. [3] A display includes an image display element, a linear polarizer, and a patterned retardation layer in this order; The patterned retardation layer is a λ / 4 plate, The image display device according to [2], wherein the pattern of the patterned retardation layer corresponds to the first display area and the second display area. [4] The image display element is a self-luminous display element; The image display device according to [3], wherein the linear polarizer is a reflective linear polarizer. [5] A display comprising an image display element and a patterned circular polarizer in this order; The image display device according to [2], wherein a pattern of the patterned circular polarizer corresponds to the first display area and the second display area. [6] The image display element is a self-luminous display element; The image display device according to [5], wherein the patterned circular polarizing plate is a reflective circular polarizer. [7] The image display device according to [1], wherein the first reflective polarizer and the second reflective polarizer are reflective linear polarizers. [8] A display comprising, in order, an image display element and a patterned linear polarizer; The image display device according to [7], wherein the pattern of the patterned linear polarizer corresponds to the first display region and the second display region. [9] The image display element is a self-luminous display element; The image display device according to [8], wherein the patterned linear polarizing plate is a reflective linear polarizer. Effect of the Invention

[0010] According to the present invention, it is possible to provide an image display device with high light utilization efficiency. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram conceptually illustrating an example of an image display device of the present invention. [Diagram 2] FIG. 2 is a diagram conceptually showing a patterned retardation layer included in the image display device shown in FIG. [Diagram 3] 2 is a diagram conceptually illustrating a first reflective polarizer included in the image display device shown in FIG. [Figure 4] 2 is a diagram conceptually illustrating a second reflective polarizer included in the image display device shown in FIG. [Diagram 5] FIG. 13 is a diagram conceptually illustrating another example of an image display device of the present invention. [Figure 6] FIG. 6 is a diagram conceptually showing a patterned circular polarizing plate included in the image display device shown in FIG. [Figure 7] FIG. 13 is a diagram conceptually illustrating another example of an image display device of the present invention. [Figure 8] FIG. 8 is a diagram conceptually illustrating a patterned linear polarizer included in the image display device shown in FIG. [Figure 9]8 is a diagram conceptually illustrating a first reflective polarizer included in the image display device shown in FIG. 7. [Figure 10] 8 is a diagram conceptually illustrating a second reflective polarizer included in the image display device shown in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image display device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

[0013] The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0014] In addition, the drawings shown below are all conceptual diagrams for explaining the present invention, and therefore the shape, size, thickness, and positional relationship of each member, such as spacing, in each drawing do not necessarily match the actual objects.

[0015] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0016] In this specification, unless otherwise specified, angles such as "45°", "parallel", "perpendicular" or "orthogonal" mean that the difference from the exact angle is within a range of less than 5 degrees. The difference from the exact angle is preferably less than 3 degrees, and more preferably less than 1 degree.

[0017] In this specification, the terms "same", "match", and the like include a generally accepted margin of error in the relevant technical field.

[0018] In this specification, "(meth)acrylate" is used to mean "either one or both of acrylate and methacrylate."

[0019] In this specification, visible light is electromagnetic light with wavelengths visible to the human eye, in the wavelength range of 380 to 780 nm, while non-visible light is light with wavelengths below 380 nm and above 780 nm.

[0020] [Image display device] The image display device of the present invention comprises: a display, a first reflective polarizer, and a second reflective polarizer, in that order; The first reflective polarizer and the second reflective polarizer are arranged such that an optical axis of the first reflective polarizer and an optical axis of the second reflective polarizer coincide with each other; the first reflective polarizer has a first region that transmits light of a first polarization and reflects light of a second polarization orthogonal to the first polarization, and a second region that transmits light of the second polarization and reflects the first polarization; the first reflective polarizer is divided into a first region and a second region by a line passing through an optical axis of the first reflective polarizer, and the shape of the first region and the shape of the second region are point-symmetric with respect to the optical axis of the first reflective polarizer; the second reflective polarizer has a first region that transmits the first polarized light and reflects the second polarized light, and a second region that transmits the second polarized light and reflects the first polarized light; the second reflective polarizer is divided into a first region and a second region by a line passing through the optical axis of the first reflective polarizer, and the shapes of the first region and the second region are point-symmetric with respect to the optical axis of the first reflective polarizer; the display is divided by a line passing through the optical axis of the first reflective polarizer into a first display region that outputs a first polarized light and a second display region that outputs a second polarized light, and the shapes of the first display region and the second display region are point-symmetric with respect to the optical axis of the first reflective polarizer; a focal point of the first reflective polarizer is located on an opposite side of the first reflective polarizer with respect to the second reflective polarizer; the focal point of the second reflective polarizer is located between the first reflective polarizer and the second reflective polarizer; The image display device has a first display region of the display, a first region of the first reflective polarizer, and a second region of the second reflective polarizer, which overlap when viewed from the optical axis direction of the first reflective polarizer.

[0021] FIG. 1 conceptually shows an example of an image display device of the present invention.

[0022] An image display device (virtual reality display device) 200a shown in FIG. 1 includes a display 201a, a first reflective polarizer 211, and a second reflective polarizer 213, in this order.

[0023] <Display> The display is divided by a line passing through the optical axis of the first reflective polarizer into a first display area that emits a first polarized light and a second display area that emits a second polarized light, and the shapes of the first display area and the second display area are point-symmetric with respect to the optical axis of the first reflective polarizer.

[0024] 1, the display 201a includes, in this order, an image display element 202, a linear polarizer 206, and a patterned retardation layer 208. The patterned retardation layer 208 side of the display 201a is an output surface from which image light is output, and a first reflective polarizer 211 and a second reflective polarizer 213 are disposed on the patterned retardation layer 208 side.

[0025] A known display element can be used as the image display element 202. Examples of the image display element 202 include a liquid crystal display element (LCD (Liquid Crystal Display)), an organic electroluminescence display element (OLED (Organic Light Emitting Diode)), a CRT (cathode-ray tube), a plasma display element, electronic paper, an LED (Light Emitting Diode) display element, a micro LED display element, DLP (Digital Light Processing), and a MEMS (Micro-Electro-Mechanical Systems) display element. In the present invention, the liquid crystal display element includes LCOS (Liquid Crystal On Silicon) and the like. The image display element 202 may also be a transparent display capable of transmitting light.

[0026] The image display element 202 may be one that displays a monochrome image, one that displays a two-color image, or one that displays a color image.

[0027] Furthermore, the light emitted by the image display element 202 may be unpolarized, linearly polarized, or circularly polarized.

[0028] On the display surface side of the image display element 202, a linear polarizer 206 and a patterned retardation layer 208 are disposed in this order.

[0029] There is no limitation on the linear polarizer 206. Thus, the linear polarizer 206 may be a reflective linear polarizer or an absorptive linear polarizer, and various known linear polarizers can be used, such as an iodine-based polarizer, a dye-based polarizer using a dichroic dye, a polyene-based polarizer, a wire grid polarizer, and a film obtained by stretching a dielectric multilayer film as described in JP2011-053705A and the like.

[0030] The patterned retardation layer 208 is a λ / 4 plate, and regions with different directions of the slow axis are formed in a predetermined pattern. Fig. 2 shows a conceptual diagram of the patterned retardation layer 208. Fig. 2 is a diagram of the patterned retardation layer 208 as viewed from the optical axis direction (the left-right direction in Fig. 1). Note that the optical axis is the optical axis of the first reflective polarizer 211. The optical axis of the first reflective polarizer 211 will be described in detail later.

[0031] As shown in Fig. 2, the patterned retardation layer 208 has a first slow axis region 208a and a second slow axis region 208b in the plane. In the first slow axis region 208a, the slow axis is arranged so that the angle between the slow axis and the transmission axis of the linear polarizer 206 is 45°. In addition, in the second slow axis region 208b, the slow axis is arranged so that the angle between the slow axis and the transmission axis of the linear polarizer 206 is -45°. That is, the direction of the slow axis in the first slow axis region 208a is perpendicular to the direction of the slow axis in the second slow axis region 208b.

[0032] Moreover, the shape of the first slow axis region 208a and the shape of the second slow axis region 208b are point-symmetric with respect to the optical axis O of the first reflective polarizer 211 when viewed from the optical axis O direction. In the example shown in Fig. 2, the patterned retardation layer 208 has a rectangular region in the upper half thereof which is the first slow axis region 208a and a rectangular region in the lower half which is the second slow axis region 208b.

[0033] In such a display 201a, when the image display element 202 emits image light, the image light is converted into linearly polarized light by the linear polarizer 206, and the linearly polarized light is converted into circularly polarized light by the patterned retardation layer 208. At this time, the patterned retardation layer 208 converts the light into polarized light that is orthogonal to each other in the first slow axis region 208a and the second slow axis region 208b. For example, the first slow axis region 208a converts linearly polarized light into right-handed circularly polarized light, and the second slow axis region 208b converts linearly polarized light into left-handed circularly polarized light. Note that the first slow axis region 208a may convert linearly polarized light into left-handed circularly polarized light, and the second slow axis region 208b may convert linearly polarized light into right-handed circularly polarized light.

[0034] Here, mutually orthogonal polarized light refers to polarized light that is located at antipodes on the Poincaré sphere. Examples of such polarized light include mutually orthogonal linear polarized light, and right-handed circularly polarized light (right circular polarization) and left-handed circularly polarized light (left circular polarization).

[0035] Therefore, the display 201a emits a first polarized light (e.g., right-handed circularly polarized light) from a first display region corresponding to the first slow axis region 208a, and emits a second polarized light (e.g., left-handed circularly polarized light) that is perpendicular to the first polarized light from a second display region corresponding to the second slow axis region 208b.

[0036] Since the first slow axis region 208a of the patterned retardation layer 208 corresponds to the first display region of the display 201a, and the second slow axis region 208b corresponds to the second display region, the display 201a is divided by a line passing through the optical axis O of the first reflective polarizer 211 into a first display region that emits a first polarized light and a second display region that emits a second polarized light, and when viewed from the direction of the optical axis O, the shapes of the first display region and the second display region are point-symmetric with respect to the optical axis of the first reflective polarizer 211.

[0037] <1st reflective polarizer> The first reflective polarizer 211 has a first region 211a that transmits a first polarized light and reflects a second polarized light that is perpendicular to the first polarized light, and a second region 211b that transmits the second polarized light and reflects the first polarized light. The first reflective polarizer 211 is divided into the first region 211a and the second region 211b by a line passing through the optical axis O of the first reflective polarizer 211. When viewed from the direction of the optical axis O, the shapes of the first region 211a and the second region 211b are point-symmetric with respect to the optical axis O of the first reflective polarizer 211.

[0038] Fig. 3 is a conceptual diagram of the first reflective polarizer 211. Fig. 3 is a diagram of the first reflective polarizer 211 as viewed from the optical axis direction (the left-right direction in Fig. 1).

[0039] 3, the first reflective polarizer 211 has a first region 211a and a second region 211b in its plane. The first region 211a and the second region 211b are divided by a line passing through the optical axis O of the first reflective polarizer 211.

[0040] In the example shown in FIG. 1 and FIG. 3, the first reflective polarizer 211 is a reflective circular polarizer that transmits right-handed or left-handed circularly polarized light and reflects circularly polarized light with the opposite rotation direction to the transmitted circularly polarized light. In the illustrated example, right-handed circularly polarized light is the first polarization, and left-handed circularly polarized light is the second polarization. In this case, the first region 211a transmits right-handed circularly polarized light, which is the first polarization, and reflects left-handed circularly polarized light, which is the second polarization, and the second region 211b transmits left-handed circularly polarized light (second polarization) and reflects right-handed circularly polarized light (first polarization). In FIG. 3, the region that transmits right-handed circularly polarized light is marked with "R," and the region that transmits left-handed circularly polarized light is marked with "L." This is also the case in FIG. 4 and FIG. 6.

[0041] When viewed from the optical axis O direction, the first reflective polarizer 211 has a shape of the first region 211a and a shape of the second region 211b that are point-symmetric with respect to the optical axis O of the first reflective polarizer 211. In the example shown in Fig. 3, the first reflective polarizer 211 has a circular shape in a plan view viewed from the optical axis O direction, with the upper half semicircular region being the first region 211a and the lower half semicircular region being the second region 211b.

[0042] The first region 211a and the second region 211b of the first reflective polarizer 211 are arranged to overlap with the first display region and the second display region of the display 201a, respectively, when viewed from the optical axis O direction of the first reflective polarizer 211. That is, when viewed from the optical axis O direction of the first reflective polarizer 211, the first region 211a of the first reflective polarizer 211 is arranged to overlap with the first display region of the display 201a but not overlap with the second display region. Moreover, the second region 211b is arranged to overlap with the second display region of the display 201a but not overlap with the first display region.

[0043] Desirably, when viewed from the optical axis O direction of the first reflective polarizer 211, the first region 211a of the first reflective polarizer 211 covers the entire surface of the first display region of the display 201a, and the second region 211b covers the entire surface of the second display region of the display 201a.

[0044] 1, the first reflective polarizer 211 has a curved shape so as to focus the reflected polarized light at a predetermined focal point P1. That is, the first reflective polarizer 211 acts as a concave mirror. The first reflective polarizer 211 is disposed with its concave side facing away from the display 201a, that is, facing the second reflective polarizer 213 side. Therefore, the first reflective polarizer 211 reflects and focuses the polarized light incident from the second reflective polarizer 213 side.

[0045] In the present invention, the optical axis of the first reflective polarizer 211 is the optical axis of the first reflective polarizer as a concave mirror.

[0046] Furthermore, the focal point P1 of the first reflective polarizer 211 as a concave mirror is disposed to be located on the opposite side of the first reflective polarizer 211 with respect to the second reflective polarizer 213. In other words, the focal point P1 of the first reflective polarizer 211 is located farther from the first reflective polarizer 211 than the second reflective polarizer 213. As a result, the polarized light reflected by the first reflective polarizer 211 passes through the second reflective polarizer 213 and is output as image light from the image display device 200a, and becomes visible to the user. This point will be described in detail later.

[0047] <Second reflective polarizer> The second reflective polarizer 213 has a first region 213a that transmits the first polarized light and reflects the second polarized light, and a second region 213b that transmits the second polarized light and reflects the first polarized light. The second reflective polarizer 213 is divided into the first region 213a and the second region 213b by a line passing through the optical axis O of the first reflective polarizer 211. When viewed from the direction of the optical axis O, the shapes of the first region 213a and the second region 213b are point-symmetric with respect to the optical axis O of the first reflective polarizer 211.

[0048] Fig. 4 is a conceptual diagram of the second reflective polarizer 213. Fig. 4 is a diagram of the second reflective polarizer 213 as viewed from the optical axis direction (the left-right direction in Fig. 1).

[0049] 4, the second reflective polarizer 213 has a first region 213a and a second region 213b in its plane. The first region 213a and the second region 213b are divided by a line passing through the optical axis O of the first reflective polarizer 211.

[0050] 1 and 4, the second reflective polarizer 213 is a reflective circular polarizer, with right-handed circularly polarized light as the first polarization and left-handed circularly polarized light as the second polarization. In this case, the first region 213a transmits right-handed circularly polarized light as the first polarization and reflects left-handed circularly polarized light as the second polarization, and the second region 213b transmits left-handed circularly polarized light (second polarization) and reflects right-handed circularly polarized light (first polarization).

[0051] In the second reflective polarizer 213, the shape of the first region 213a and the shape of the second region 213b are point-symmetric with respect to the optical axis O of the first reflective polarizer 211 when viewed from the optical axis O direction. In the example shown in Fig. 4, the second reflective polarizer 213 has a circular shape in a plan view viewed from the optical axis O direction, with the semicircular region in the upper half being the second region 213b and the semicircular region in the lower half being the first region 213a.

[0052] The first region 213a and the second region 213b of the second reflective polarizer 213 are arranged to overlap with the second display region and the first display region of the display 201a, respectively, when viewed from the optical axis O direction of the first reflective polarizer 211. That is, when viewed from the optical axis O direction of the first reflective polarizer 211, the first region 213a of the second reflective polarizer 213 is arranged to overlap with the second display region of the display 201a but not overlap with the first display region. Moreover, the second region 213b is arranged to overlap with the first display region of the display 201a but not overlap with the second display region.

[0053] Desirably, when viewed from the optical axis O direction of the first reflective polarizer 211, the first region 213a of the second reflective polarizer 213 covers the entire surface of the second display region of the display 201a, and the second region 213b covers the entire surface of the first display region of the display 201a.

[0054] That is, in the image display device 200a, when viewed from the optical axis O direction of the first reflective polarizer 211, the first display area of ​​the display 201a, the first area 211a of the first reflective polarizer 211, and the second area 213b of the second reflective polarizer 213 overlap, and the second display area of ​​the display 201a, the second area 211b of the first reflective polarizer 211, and the first area 213a of the second reflective polarizer 213 overlap.

[0055] 1, the second reflective polarizer 213 has a curved shape so as to focus the reflected polarized light at a predetermined focal point P2. That is, the second reflective polarizer 213 acts as a concave mirror. The second reflective polarizer 213 is disposed with its concave side facing the display 201a, that is, facing the first reflective polarizer 211 side. Therefore, the second reflective polarizer 213 reflects and focuses the polarized light incident from the first reflective polarizer 211 side.

[0056] The second reflective polarizer 213 is disposed such that the optical axis of the second reflective polarizer 213 as a concave mirror coincides with the optical axis O of the first reflective polarizer 211 .

[0057] Further, the focal point P2 of the second reflective polarizer 213 as a concave mirror is disposed to be located between the first reflective polarizer 211 and the second reflective polarizer 213. That is, the focal point P2 of the second reflective polarizer 213 is located closer to the second reflective polarizer 213 than the first reflective polarizer 211. As a result, the polarized light reflected by the second reflective polarizer 213 is reflected by the first reflective polarizer 211. This will be described in detail later.

[0058] <Function of image display device> The image display device 200a shown in FIG. 1 will now be described. The display 201a emits image light. At this time, right-handed circularly polarized light (indicated by a thick solid line in FIG. 1) is emitted from a first display region corresponding to the first slow axis region 208a of the patterned retardation layer 208, and left-handed circularly polarized light (indicated by a thick dashed line in FIG. 1) is emitted from a second display region corresponding to the second slow axis region 208b.

[0059] The right-handed circularly polarized light emitted from the first display region of the display 201a is incident on the first region 211a of the first reflective polarizer 211. Because the first region 211a of the first reflective polarizer 211 is an area that transmits right-handed circularly polarized light, almost all of the incident right-handed circularly polarized light is transmitted through the first reflective polarizer 211 and is incident on the second region 213b of the second reflective polarizer 213. Because the second region 213b of the second reflective polarizer 213 is an area that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light, almost all of the incident right-handed circularly polarized light is reflected towards the first reflective polarizer 211.

[0060] The second reflective polarizer 213 has a curved shape and acts as a concave mirror, and its focal point P2 is closer than that of the first reflective polarizer 211, so that the right-handed circularly polarized light reflected by the second region 213b of the second reflective polarizer 213 passes through the focal point P2 and enters the second region 211b of the first reflective polarizer 211.

[0061] Since the second region 211b of the first reflective polarizer 211 is an area that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light, almost all of the right-handed circularly polarized light that enters the second region 211b of the first reflective polarizer 211 is reflected toward the second reflective polarizer 213.

[0062] The first reflective polarizer 211 has a curved shape and acts as a concave mirror, but its focal point P1 is located farther away than the second reflective polarizer 213, so that almost all of the right-handed circularly polarized light reflected by the second region 211b of the first reflective polarizer 211 enters the first region 213a of the second reflective polarizer 213 before passing through the focal point P1.

[0063] Since the first region 213a of the second reflective polarizer 213 is a region that transmits right-handed circularly polarized light, almost all of the right-handed circularly polarized light that enters the first region 213a of the second reflective polarizer 213 is transmitted through the second reflective polarizer 213.

[0064] Furthermore, the left-handed circularly polarized light emitted from the second display region of the display 201a is incident on the second region 211b of the first reflective polarizer 211. Because the second region 211b of the first reflective polarizer 211 is an area that transmits left-handed circularly polarized light, almost all of the incident left-handed circularly polarized light is transmitted through the first reflective polarizer 211 and incident on the first region 213a of the second reflective polarizer 213. Because the first region 213a of the second reflective polarizer 213 is an area that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, almost all of the incident left-handed circularly polarized light is reflected towards the first reflective polarizer 211.

[0065] The second reflective polarizer 213 has a curved shape and acts as a concave mirror, and its focal point P2 is closer than that of the first reflective polarizer 211, so that almost all of the left-handed circularly polarized light reflected by the first region 213a of the second reflective polarizer 213 passes through the focal point P2 and enters the first region 211a of the first reflective polarizer 211.

[0066] Since the first region 211a of the first reflective polarizer 211 is an area that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, almost all of the left-handed circularly polarized light that enters the first region 211a of the first reflective polarizer 211 is reflected toward the second reflective polarizer 213.

[0067] The first reflective polarizer 211 has a curved shape and acts as a concave mirror, but its focal point P1 is located farther away than the second reflective polarizer 213, so that almost all of the left-handed circularly polarized light reflected by the first region 211a of the first reflective polarizer 211 enters the second region 213b of the second reflective polarizer 213 before passing through the focal point P1.

[0068] Since the second region 213b of the second reflective polarizer 213 is a region that transmits left-handed circularly polarized light, almost all of the left-handed circularly polarized light that enters the second region 213b of the second reflective polarizer 213 is transmitted through the second reflective polarizer 213.

[0069] As a result, the right-handed circularly polarized light and the left-handed circularly polarized light emitted from the display 201a are reflected once by the second reflective polarizer 213 and the first reflective polarizer 211, respectively, and are emitted as image light from the image display device 200a. At this time, since the light emitted from the display 201a is made to travel back and forth between the two reflective polarizers, the overall thickness of the image display device 200a can be made thin.

[0070] As described above, in a conventional image display device equipped with a folding optical system having a reflective polarizer and a half mirror, light must pass through the half mirror twice (transmission and reflection), and the amount of light is roughly halved each time. This causes a problem in that the light utilization efficiency of the amount of image light emitted by the display becomes low at approximately 25%.

[0071] In contrast, the image display device 200a of the present invention, with the above-mentioned configuration, can transmit or reflect the first polarized light (right-handed circularly polarized light) emitted from the first display region of the display 201a and the second polarized light (left-handed circularly polarized light) emitted from the second display region of the display 201a without any loss in the amount of light when they are transmitted or reflected by the first reflective polarizer 211 and the second reflective polarizer 213, respectively, so that almost 100% of the polarized light emitted from the display 201a can be emitted from the image display device 200a. In other words, the light utilization efficiency can be made almost 100%.

[0072] In the above example, the first polarized light is right-handed circularly polarized light and the second polarized light is left-handed circularly polarized light, but the present invention is not limited thereto, and the first polarized light may be left-handed circularly polarized light and the second polarized light may be right-handed circularly polarized light. In this case, the first display region of the display 201a may emit left-handed circularly polarized light, the second display region may emit right-handed circularly polarized light, the first region 211a of the first reflective polarizer 211 may transmit left-handed circularly polarized light and reflect right-handed circularly polarized light, the second region 211b may transmit right-handed circularly polarized light and reflect left-handed circularly polarized light, the first region 211a of the second reflective polarizer 213 may transmit left-handed circularly polarized light and reflect right-handed circularly polarized light, and the second region 211b may transmit right-handed circularly polarized light and reflect left-handed circularly polarized light.

[0073] Furthermore, there are no particular limitations on the distance between the display 201a and the first reflective polarizer 211, and the distance between the first reflective polarizer 211 and the second reflective polarizer 213, and these may be set appropriately depending on the performance, size, etc. required for the image display device.

[0074] Furthermore, there is no particular limitation on the focal length of the first reflective polarizer 211 as a concave mirror and the focal length of the second reflective polarizer 213 as a concave mirror, and these may be set appropriately depending on the performance, size, etc. required of the image display device.

[0075] In addition, as in the example shown in FIG. 1, when the display 201a has an image display element 202, a linear polarizer 206, and a patterned retardation layer 208, the image display element 202 is preferably a self-luminous display element such as an OLED, a plasma display element, or a micro LED display element, and the linear polarizer 206 is preferably a reflective linear polarizer.

[0076] Since the self-luminous display element emits unpolarized light, when the linear polarizer 206 is an absorptive linear polarizer, the polarized light component (about half of the amount of light) that does not pass through the linear polarizer 206 is absorbed by the linear polarizer 206. In contrast, when a reflective linear polarizer is used as the linear polarizer 206, the polarized light component that does not pass through the linear polarizer 206 is reflected back to the image display element 202 and is reflected again by the surface of the image display element 202, etc. During this reflection, the polarization state is destroyed, and a part of the light that is incident on the linear polarizer 206 again passes through the linear polarizer 206, thereby improving the brightness of the light emitted from the display 201a.

[0077] In the example shown in FIG. 1, the display 201a of the image display device 200a includes the image display element 202, the linear polarizer 206, and the patterned retardation layer 208, but the present invention is not limited to this.

[0078] FIG. 5 shows a conceptual diagram of another example of the image display device of the present invention. Image display device 200b shown in Fig. 5 has display 201b, first reflective polarizer 211, and second reflective polarizer 213 in this order. Image display device 200b shown in Fig. 5 has the same configuration as image display device 200a shown in Fig. 1 except that display 201a is replaced with display 201b, so the same components are given the same reference numerals and differences will be mainly described. Also, image display device 200b shown in Fig. 5 will be described assuming that the first polarized light is right-handed circularly polarized light and the second polarized light is left-handed circularly polarized light, but the first polarized light may be left-handed circularly polarized light and the second polarized light may be right-handed circularly polarized light.

[0079] A display 201b included in an image display device 200b shown in FIG.

[0080] The image display element 202 has a similar configuration to the image display element 202 of the display 201a, and therefore a description thereof will be omitted.

[0081] The patterned circular polarizer 204 is a circular polarizer that transmits right-handed or left-handed circularly polarized light and blocks circularly polarized light with a rotation direction opposite to that of the transmitted circularly polarized light, and regions with different rotation directions of the transmitted circularly polarized light are formed in a predetermined pattern. Figure 6 shows a conceptual diagram of the patterned circular polarizer 204. Figure 6 is a diagram of the patterned circular polarizer 204 as viewed from the optical axis O direction (the left-right direction in Figure 5).

[0082] 6, the patterned circular polarizer 204 has right-handed circularly polarized light transmission region 204a and left-handed circularly polarized light transmission region 204b in its plane. The right-handed circularly polarized light transmission region 204a is a region that transmits right-handed circularly polarized light (first polarization) and blocks left-handed circularly polarized light (second polarization), and the left-handed circularly polarized light transmission region 204b is a region that transmits left-handed circularly polarized light (second polarization) and blocks right-handed circularly polarized light (first polarization). In other words, the polarized light transmitted by the right-handed circularly polarized light transmission region 204a and the polarized light transmitted by the left-handed circularly polarized light transmission region 204b are orthogonal to each other.

[0083] When viewed from the direction of the optical axis O, the shapes of the right-handed circularly polarized light transmission region 204a and the left-handed circularly polarized light transmission region 204b are point-symmetric with respect to the optical axis O of the first reflective polarizer 211. In the example shown in Fig. 6, the rectangular region in the upper half of the patterned circular polarizer 204 is the right-handed circularly polarized light transmission region 204a, and the rectangular region in the lower half is the left-handed circularly polarized light transmission region 204b.

[0084] In such a display 201b, when image display element 202 emits image light, the image light is converted into circularly polarized light by patterned circular polarizer 204. At that time, patterned circular polarizer 204 converts the light into polarized light that is orthogonal to each other in right-handed circularly polarized light transmission region 204a and left-handed circularly polarized light transmission region 204b. Right-handed circularly polarized light transmission region 204a converts the light emitted by image display element 202 into right-handed circularly polarized light, and left-handed circularly polarized light transmission region 204b converts the light emitted by image display element 202 into left-handed circularly polarized light.

[0085] Therefore, display 201b emits a first polarized light (right-handed circularly polarized light) from a first display region corresponding to right-handed circularly polarized light transmission region 204a, and emits a second polarized light (left-handed circularly polarized light) that is perpendicular to the first polarized light from a second display region corresponding to left-handed circularly polarized light transmission region 204b.

[0086] Since the right-hand circularly polarized light transmission region 204a of the patterned circular polarizer 204 corresponds to the first display region of the display 201b, and the left-hand circularly polarized light transmission region 204b corresponds to the second display region, the display 201b is divided by a line passing through the optical axis O of the first reflective polarizer 211 into a first display region that emits the first polarized light and a second display region that emits the second polarized light. When viewed from the direction of the optical axis O, the shapes of the first display region and the second display region are point-symmetric with respect to the optical axis of the first reflective polarizer 211.

[0087] Furthermore, in the image display device 200b, when viewed from the optical axis O direction of the first reflective polarizer 211, the first display area of ​​the display 201b, the first area 211a of the first reflective polarizer 211, and the second area 213b of the second reflective polarizer 213 overlap, and the second display area of ​​the display 201b, the second area 211b of the first reflective polarizer 211, and the first area 213a of the second reflective polarizer 213 overlap.

[0088] In the image display device 200b having such a display 201b, the display 201b emits a first polarized light (right-handed circularly polarized light) from the first display region and emits a second polarized light (left-handed circularly polarized light) from the second display region, similar to the display 201a. In the image display device 200b, the first reflective polarizer 211 and the second reflective element 213 exert the same effect on the first polarized light and the second polarized light emitted from the display 201b as the first reflective polarizer 211 and the second reflective element 213 of the image display device 200a. Therefore, in the image display device 200b, the first polarized light (right-handed circularly polarized light) emitted from the first display region of the display 201b and the second polarized light (left-handed circularly polarized light) emitted from the second display region can be transmitted or reflected without loss of light amount when transmitted or reflected by the first reflective polarizer 211 and the second reflective polarizer 213, respectively, so that almost 100% of the polarized light emitted from the display 201b can be emitted from the image display device 200b. In other words, the light utilization efficiency can be made almost 100%.

[0089] Furthermore, in the case where the display 201b has an image display element 202 and a patterned circular polarizer 204 as in the example shown in FIG. 5, the image display element 202 is preferably a self-luminous display element such as an OLED, a plasma display element, or a micro LED display element, and the patterned circular polarizer 204 is preferably a reflective circular polarizer.

[0090] By using a reflective circular polarizer as patterned circular polarizer 204, the polarized components that do not pass through patterned circular polarizer 204 are reflected back to image display element 202 and are reflected again by the surface of image display element 202. During this reflection, the polarization state is destroyed and a part of the light that is again incident on patterned circular polarizer 204 passes through patterned circular polarizer 204, thereby improving the brightness of the light emitted from display 201b.

[0091] In the examples shown in FIGS. 1 and 5, the first reflective polarizer 211 and the second reflective polarizer 213 are reflective circular polarizers, and the display emits circularly polarized light, but this is not limiting.

[0092] FIG. 7 shows a conceptual diagram of another example of an image display device of the present invention.

[0093] An image display device (virtual reality display device) 200c shown in FIG. 7 includes a display 201c, a first reflective polarizer 212, and a second reflective polarizer 214, in this order.

[0094] 7, display 201c includes, in this order, image display element 202 and patterned linear polarizer 207. The patterned linear polarizer 207 side of display 201c is an output surface from which image light is output, and a first reflective polarizer 212 and a second reflective polarizer 214 are disposed on the patterned linear polarizer 207 side.

[0095] The image display element 202 has a similar configuration to the image display element 202 of the display 201a, and therefore a description thereof will be omitted.

[0096] A patterned linear polarizer 207 is disposed on the display surface side of the image display element 202 .

[0097] Patterned linear polarizer 207 is a linear polarizer that transmits one of orthogonal linearly polarized lights and blocks the other, and regions whose transmission axis directions are orthogonal to each other are formed in a predetermined pattern. Figure 8 shows a conceptual diagram of patterned linear polarizer 207. Figure 8 shows patterned linear polarizer 207 as viewed from the optical axis direction (left and right direction in Figure 7).

[0098] 8, patterned linear polarizer 207 has first polarization transmission region 207a and second polarization transmission region 207b in its plane. As an example, first polarization transmission region 207a has a transmission axis in the left-right direction as indicated by the arrow in the figure. Second polarization transmission region 207b has a transmission axis in the up-down direction as indicated by the arrow in the figure. In other words, the direction of the transmission axis in first polarization transmission region 207a is perpendicular to the direction of the transmission axis in second polarization transmission region 207b.

[0099] Furthermore, the shape of first polarization transmission region 207a and the shape of second polarization transmission region 207b are point-symmetric with respect to the optical axis O of first reflective polarizer 212 when viewed from the direction of the optical axis O. In the example shown in Fig. 8, the rectangular region in the upper half of patterned linear polarizer 207 is first polarization transmission region 207a, and the rectangular region in the lower half is second polarization transmission region 207b.

[0100] In such a display 201c, when image display element 202 emits image light, the image light is converted into linearly polarized light by patterned linear polarizer 207. At that time, patterned linear polarizer 207 converts the light into polarized light that is orthogonal to each other in first polarization transmission region 207a and second polarization transmission region 207b. First polarization transmission region 207a converts the light emitted by image display element 202 into linearly polarized light in the left-right direction in FIG. 8 (direction perpendicular to the paper surface in FIG. 7), and second polarization transmission region 207b converts the light emitted by image display element 202 into linearly polarized light in the up-down direction in FIG. 8. In the above example, the first polarized light transmitting region 207a has a transmission axis in the left-right direction in FIG. 8, and the second polarized light transmitting region 207b has a transmission axis in the up-down direction in FIG. 8; however, this is not limited to this, and as long as the transmission axis of the first polarized light transmitting region 207a and the transmission axis of the second polarized light transmitting region 207b are perpendicular to each other, the directions of the transmission axis of the first polarized light transmitting region 207a and the transmission axis of the second polarized light transmitting region 207b can be any direction.

[0101] Therefore, display 201c emits a first polarized light (for example, linearly polarized light perpendicular to the paper surface in FIG. 7) from a first display region corresponding to first polarization transmission region 207a, and emits a second polarized light orthogonal to the first polarized light (for example, linearly polarized light vertically in FIG. 7) from a second display region corresponding to second polarization transmission region 207b. Note that in the following description, the linearly polarized light perpendicular to the paper surface in FIG. 7 that is emitted from the first display region is also referred to as "linearly polarized light in the horizontal direction," and the linearly polarized light vertically in FIG. 7 that is emitted from the second display region is also referred to as "linearly polarized light in the vertical direction."

[0102] Since the first polarization transmission region 207a of the patterned linear polarizer 207 corresponds to the first display region of the display 201c, and the second polarization transmission region 207b corresponds to the second display region, the display 201c is divided by a line passing through the optical axis O of the first reflective polarizer 212 into a first display region that emits the first polarized light and a second display region that emits the second polarized light. When viewed from the direction of the optical axis O, the shapes of the first display region and the second display region are point-symmetric with respect to the optical axis of the first reflective polarizer 212.

[0103] The first reflective polarizer 212 has a first region 212a that transmits a first polarized light and reflects a second polarized light that is perpendicular to the first polarized light, and a second region 212b that transmits the second polarized light and reflects the first polarized light. The first reflective polarizer 212 is divided into the first region 212a and the second region 212b by a line passing through the optical axis O of the first reflective polarizer 212. When viewed from the direction of the optical axis O, the shapes of the first region 212a and the second region 212b are point-symmetric with respect to the optical axis O of the first reflective polarizer 212.

[0104] Fig. 9 is a conceptual diagram of the first reflective polarizer 212. Fig. 9 is a diagram of the first reflective polarizer 212 as viewed from the optical axis direction (the left-right direction in Fig. 1).

[0105] 9, the first reflective polarizer 212 has a first region 212a and a second region 212b in its plane. The first region 212a and the second region 212b are divided by a line passing through the optical axis O of the first reflective polarizer 212.

[0106] 7 and 9, the first reflective polarizer 212 is a reflective linear polarizer that transmits linearly polarized light in the left-right direction or linearly polarized light in the up-down direction and reflects linearly polarized light in a direction perpendicular to the transmitted linearly polarized light. In the illustrated example, the linearly polarized light in the left-right direction is the first polarized light, and the linearly polarized light in the up-down direction is the second polarized light. In this case, the first region 212a transmits linearly polarized light in the left-right direction, which is the first polarized light, and reflects linearly polarized light in the up-down direction, which is the second polarized light, and the second region 212b transmits linearly polarized light in the up-down direction (second polarized light) and reflects linearly polarized light in the left-right direction (first polarized light).

[0107] Furthermore, when the first reflective polarizer 212 is viewed from the optical axis O direction, the shape of the first region 212a and the shape of the second region 212b are point-symmetric with respect to the optical axis O of the first reflective polarizer 212. In the example shown in Fig. 9, the first reflective polarizer 212 has a circular shape in a plan view viewed from the optical axis O direction, with the upper half semicircular region being the first region 212a and the lower half semicircular region being the second region 212b.

[0108] The first region 212a and the second region 212b of the first reflective polarizer 212 are arranged to overlap with the first display region and the second display region of the display 201c, respectively, when viewed from the optical axis O direction of the first reflective polarizer 212. That is, when viewed from the optical axis O direction of the first reflective polarizer 212, the first region 212a of the first reflective polarizer 212 is arranged to overlap with the first display region of the display 201c but not overlap with the second display region. Moreover, the second region 212b is arranged to overlap with the second display region of the display 201c but not overlap with the first display region.

[0109] Desirably, when viewed from the optical axis O direction of the first reflective polarizer 212, the first region 212a of the first reflective polarizer 212 covers the entire surface of the first display region of the display 201c, and the second region 212b covers the entire surface of the second display region of the display 201c.

[0110] 7, the first reflective polarizer 212 has a curved shape so as to focus the reflected polarized light at a predetermined focal point P1. That is, the first reflective polarizer 212 acts as a concave mirror. The first reflective polarizer 212 is disposed with its concave side facing away from the display 201c, that is, facing the second reflective polarizer 214 side. Therefore, the first reflective polarizer 212 reflects and focuses the polarized light incident from the second reflective polarizer 214 side.

[0111] Further, the focal point P1 of the first reflective polarizer 212 as a concave mirror is disposed to be located on the opposite side of the first reflective polarizer 212 with respect to the second reflective polarizer 214. In other words, the focal point P1 of the first reflective polarizer 212 is located farther away than the second reflective polarizer 214. As a result, the polarized light reflected by the first reflective polarizer 212 is transmitted through the second reflective polarizer 214 and is output as image light from the image display device 200c, and becomes visible to the user.

[0112] The second reflective polarizer 214 has a first region 214a that transmits a first polarized light and reflects a second polarized light, and a second region 214b that transmits the second polarized light and reflects the first polarized light. The second reflective polarizer 214 is divided into the first region 214a and the second region 214b by a line passing through the optical axis O of the first reflective polarizer 212. When viewed from the direction of the optical axis O, the shapes of the first region 214a and the second region 214b are point-symmetric with respect to the optical axis O of the first reflective polarizer 212.

[0113] Fig. 10 is a conceptual diagram of the second reflective polarizer 214. Fig. 4 is a diagram of the second reflective polarizer 214 as viewed from the optical axis direction (the left-right direction in Fig. 7).

[0114] 10, the second reflective polarizer 214 has a first region 214a and a second region 214b in its plane. The first region 214a and the second region 214b are divided by a line passing through the optical axis O of the first reflective polarizer 212.

[0115] 7 and 10, the second reflective polarizer 214 is a reflective linear polarizer, with horizontally linearly polarized light being the first polarization and vertically linearly polarized light being the second polarization. In this case, the first region 214a transmits horizontally linearly polarized light, which is the first polarization, and reflects vertically linearly polarized light, which is the second polarization, and the second region 214b transmits vertically linearly polarized light (second polarization) and reflects horizontally linearly polarized light (first polarization).

[0116] In addition, when viewed from the optical axis O direction, the shape of the first region 214a and the shape of the second region 214b of the second reflective polarizer 214 are point-symmetric with respect to the optical axis O of the first reflective polarizer 212. In the example shown in Fig. 10, the second reflective polarizer 214 has a circular shape in a plan view viewed from the optical axis O direction, with the semicircular region in the upper half being the second region 214b and the semicircular region in the lower half being the first region 214a.

[0117] The first region 214a and the second region 214b of the second reflective polarizer 214 are arranged to overlap with the second display region and the first display region of the display 201c, respectively, when viewed from the optical axis O direction of the first reflective polarizer 212. That is, when viewed from the optical axis O direction of the first reflective polarizer 212, the first region 214a of the second reflective polarizer 214 is arranged to overlap with the second display region of the display 201c but not overlap with the first display region. Also, the second region 214b is arranged to overlap with the first display region of the display 201c but not overlap with the second display region.

[0118] Desirably, when viewed from the optical axis O direction of the first reflective polarizer 212, the first region 214a of the second reflective polarizer 214 covers the entire surface of the second display region of the display 201c, and the second region 214b covers the entire surface of the first display region of the display 201c.

[0119] That is, in the image display device 200c, when viewed from the optical axis O direction of the first reflective polarizer 212, the first display area of ​​the display 201c, the first area 212a of the first reflective polarizer 212, and the second area 214b of the second reflective polarizer 214 overlap, and the second display area of ​​the display 201c, the second area 212b of the first reflective polarizer 212, and the first area 214a of the second reflective polarizer 214 overlap.

[0120] 7, the second reflective polarizer 214 has a curved shape so as to focus the reflected polarized light at a predetermined focal point P2. That is, the second reflective polarizer 214 acts as a concave mirror. The second reflective polarizer 214 is disposed with its concave side facing the display 201c, that is, facing the first reflective polarizer 212 side. Therefore, the second reflective polarizer 214 reflects and focuses the polarized light incident from the first reflective polarizer 212 side.

[0121] The second reflective polarizer 214 is disposed such that the optical axis of the second reflective polarizer 214 as a concave mirror coincides with the optical axis O of the first reflective polarizer 212 .

[0122] Further, the focal point P2 of the second reflective polarizer 214 as a concave mirror is disposed to be located between the first reflective polarizer 212 and the second reflective polarizer 214. That is, the focal point P2 of the second reflective polarizer 214 is located closer than the first reflective polarizer 212. As a result, the polarized light reflected by the second reflective polarizer 214 is reflected by the first reflective polarizer 212.

[0123] The image display device 200c shown in FIG. 7 will now be described. Display 201c emits image light. At this time, horizontally linearly polarized light (indicated by a thick solid line in FIG. 7) is emitted from a first display region corresponding to first polarization transmission region 207a of patterned linear polarizer 207, and vertically linearly polarized light (indicated by a thick dashed line in FIG. 1) is emitted from a second display region corresponding to second polarization transmission region 207b.

[0124] The linearly polarized light in the left-right direction emitted from the first display region of the display 201c is incident on the first region 212a of the first reflective polarizer 212. Because the first region 212a of the first reflective polarizer 212 is an area that transmits linearly polarized light in the left-right direction, almost all of the incident linearly polarized light in the left-right direction is transmitted through the first reflective polarizer 212 and is incident on the second region 214b of the second reflective polarizer 214. Because the second region 214b of the second reflective polarizer 214 is an area that transmits linearly polarized light in the up-down direction and reflects linearly polarized light in the left-right direction, almost all of the incident linearly polarized light in the left-right direction is reflected towards the first reflective polarizer 212.

[0125] The second reflective polarizer 214 has a curved shape and acts as a concave mirror, and its focal point P2 is located closer than the first reflective polarizer 212, so that the left-right linearly polarized light reflected by the second region 214b of the second reflective polarizer 214 passes through the focal point P2 and enters the second region 212b of the first reflective polarizer 212.

[0126] Since the second region 212b of the first reflective polarizer 212 is an area that transmits vertical linearly polarized light and reflects horizontal linearly polarized light, almost all of the horizontal linearly polarized light incident on the second region 212b of the first reflective polarizer 212 is reflected toward the second reflective polarizer 214.

[0127] The first reflective polarizer 212 has a curved shape and acts as a concave mirror, but its focal point P1 is located farther away than the second reflective polarizer 214, so that almost all of the left-right linearly polarized light reflected by the second region 212b of the first reflective polarizer 212 enters the first region 214a of the second reflective polarizer 214 before passing through the focal point P1.

[0128] Since the first region 214a of the second reflective polarizer 214 is an area that transmits left-right linearly polarized light, almost all of the left-right linearly polarized light that enters the first region 214a of the second reflective polarizer 214 is transmitted through the second reflective polarizer 214.

[0129] Furthermore, vertical linearly polarized light emitted from the second display region of the display 201c is incident on the second region 212b of the first reflective polarizer 212. Because the second region 212b of the first reflective polarizer 212 is an area that transmits vertical linearly polarized light, almost all of the incident vertical linearly polarized light is transmitted through the first reflective polarizer 212 and incident on the first region 214a of the second reflective polarizer 214. Because the first region 214a of the second reflective polarizer 214 is an area that transmits horizontal linearly polarized light and reflects vertical linearly polarized light, almost all of the incident vertical linearly polarized light is reflected towards the first reflective polarizer 212.

[0130] The second reflective polarizer 214 has a curved shape and acts as a concave mirror, and its focal point P2 is located closer than the first reflective polarizer 212, so that almost all of the vertical linearly polarized light reflected by the first region 214a of the second reflective polarizer 214 passes through the focal point P2 and enters the first region 212a of the first reflective polarizer 212.

[0131] Since the first region 212a of the first reflective polarizer 212 is an area that transmits linearly polarized light in the left-right direction and reflects linearly polarized light in the up-down direction, almost all of the linearly polarized light in the up-down direction that is incident on the first region 212a of the first reflective polarizer 212 is reflected toward the second reflective polarizer 214.

[0132] The first reflective polarizer 212 has a curved shape and acts as a concave mirror, but its focal point P1 is located farther away than the second reflective polarizer 214, so that almost all of the vertical linearly polarized light reflected by the first region 212a of the first reflective polarizer 212 enters the second region 214b of the second reflective polarizer 214 before passing through the focal point P1.

[0133] Since the second region 214b of the second reflective polarizer 214 is a region that transmits vertical linearly polarized light, almost all of the vertical linearly polarized light that enters the second region 214b of the second reflective polarizer 214 is transmitted through the second reflective polarizer 214.

[0134] As a result, the left-right linearly polarized light and the up-down linearly polarized light emitted from the display 201c are reflected once by the second reflective polarizer 214 and the first reflective polarizer 212, respectively, and are emitted as image light from the image display device 200c. At this time, since the light emitted from the display 201c is made to travel back and forth between the two reflective polarizers, the overall thickness of the image display device 200c can be made thin.

[0135] Furthermore, with the above-mentioned configuration, the image display device 200c can transmit or reflect the first polarized light (linearly polarized light in the horizontal direction) emitted from the first display region of the display 201c and the second polarized light (linearly polarized light in the vertical direction) emitted from the second display region of the display 201c without any loss in the amount of light when they are transmitted or reflected by the first reflective polarizer 212 and the second reflective polarizer 214, respectively, so that almost 100% of the polarized light emitted from the display 201c can be emitted from the image display device 200c. In other words, the light utilization efficiency can be made almost 100%.

[0136] Here, in the case where the display 201c has an image display element 202 and a patterned linear polarizer 207 as in the example shown in FIG. 7, the image display element 202 is preferably a self-luminous display element such as an OLED, a plasma display element, or a micro LED display element, and the patterned linear polarizer 207 is preferably a reflective linear polarizer.

[0137] By using a reflective linear polarizer as patterned linear polarizer 207, the polarized light component that does not pass through patterned linear polarizer 207 is reflected back to image display element 202 and is reflected again by the surface or the like of image display element 202. During this reflection, the polarization state is destroyed, and a part of the light that is again incident on patterned linear polarizer 207 passes through patterned linear polarizer 207, thereby improving the luminance of the light emitted from display 201c.

[0138] The components of the image display device of the present invention will be described below.

[0139] <<Reflective polarizer>> (Reflective circular polarizer) A reflective circular polarizer transmits right-handed or left-handed circularly polarized light and reflects circularly polarized light that has the opposite rotation direction to the transmitted circularly polarized light.

[0140] An example of a reflective circular polarizer is a reflective circular polarizer having a cholesteric liquid crystal layer. The cholesteric liquid crystal layer is a liquid crystal phase formed by fixing a cholesterically oriented liquid crystal phase (cholesteric liquid crystal phase).

[0141] As is well known, a cholesteric liquid crystal layer has a helical structure in which liquid crystal compounds are spirally rotated and stacked, and the liquid crystal compounds are stacked in a spiral shape for one rotation (360° rotation) to form one helical period (helical period), and the layer has a structure in which multiple periods of helically rotating liquid crystal compounds are stacked.

[0142] A cholesteric liquid crystal layer reflects right-handed or left-handed circularly polarized light in a specific wavelength range and transmits other light, depending on the length of the helical period and the direction of rotation (sense) of the helix of the liquid crystal compound.

[0143] Therefore, when the image display device displays a color image, the reflective circular polarizer may have multiple cholesteric liquid crystal layers, such as a cholesteric liquid crystal layer having a central wavelength that selectively reflects red light, a cholesteric liquid crystal layer having a central wavelength that selectively reflects green light, and a cholesteric liquid crystal layer having a central wavelength that selectively reflects blue light.

[0144] When the reflective circular polarizer has a cholesteric liquid crystal layer, it may have a support and an alignment film for aligning the liquid crystal compound in the cholesteric liquid crystal layer.

[0145] The thickness of the reflective circular polarizer may be appropriately adjusted depending on the type of the reflective circular polarizer, etc., so that the polarized light to be reflected can be sufficiently reflected and the polarized light to be transmitted can be sufficiently transmitted.

[0146] Here, the first reflective polarizer 211 and the second reflective polarizer 213, and the reflective circular polarizer as the patterned circular polarizer 204, have a region that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, and a region that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light. As described above, whether the reflective circular polarizer reflects right-handed or left-handed circularly polarized light is determined according to the sense of rotation of the helix caused by the liquid crystal compound. Therefore, the first reflective polarizer 211 and the second reflective polarizer 213, and the reflective circular polarizer as the patterned circular polarizer 204 have regions in which the directions of rotation of the helix caused by the liquid crystal compound are different from each other.

[0147] (Method of forming a cholesteric liquid crystal layer) The cholesteric liquid crystal layer can be formed by fixing a cholesteric liquid crystal phase in a layer form.

[0148] The structure in which the cholesteric liquid crystal phase is fixed may be any structure in which the orientation of the liquid crystal compound in the cholesteric liquid crystal phase is maintained, and typically, a structure in which a polymerizable liquid crystal compound is brought into a cholesteric liquid crystal phase orientation state, and then polymerized and hardened by ultraviolet light irradiation, heating, etc. to form a layer with no fluidity, and at the same time, changed to a state in which the orientation form is not changed by an external field or external force, is preferred.

[0149] In the structure in which the cholesteric liquid crystal phase is fixed, it is sufficient that the optical properties of the cholesteric liquid crystal phase are maintained, and the liquid crystal compound in the cholesteric liquid crystal layer does not need to exhibit liquid crystallinity. For example, the polymerizable liquid crystal compound may be polymerized by a curing reaction and lose its liquid crystallinity.

[0150] An example of a material used to form a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase is a liquid crystal composition containing a liquid crystal compound, which is preferably a polymerizable liquid crystal compound.

[0151] The liquid crystal composition used to form the cholesteric liquid crystal layer may further contain a surfactant and a chiral agent.

[0152] --Polymerizable liquid crystal compound-- The polymerizable liquid crystal compound may be a rod-shaped liquid crystal compound or a discotic liquid crystal compound.

[0153] Examples of rod-shaped polymerizable liquid crystal compounds that form cholesteric liquid crystal phase include rod-shaped nematic liquid crystal compounds.As rod-shaped nematic liquid crystal compounds, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexane carboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles are preferably used.Not only low molecular weight liquid crystal compounds, but also high molecular weight liquid crystal compounds can be used.

[0154] The polymerizable liquid crystal compound is obtained by introducing a polymerizable group into a liquid crystal compound. Examples of the polymerizable group include an unsaturated polymerizable group, an epoxy group, and an aziridinyl group, and an unsaturated polymerizable group is preferable, and an ethylenically unsaturated polymerizable group is more preferable. The polymerizable group can be introduced into the molecule of the liquid crystal compound by various methods. The number of polymerizable groups that the polymerizable liquid crystal compound has is preferably 1 to 6, more preferably 1 to 3.

[0155] Examples of the polymerizable liquid crystal compound include compounds described in Makromol.Chem., Vol. 190, p. 2255 (1989), Advanced Materials, Vol. 5, p. 107 (1993), U.S. Pat. No. 4,683,327, U.S. Pat. No. 5,622,648, U.S. Pat. No. 5,770,107, International Publication No. 95 / 22586, International Publication No. 95 / 24455, International Publication No. 97 / 00600, International Publication No. 98 / 23580, International Publication No. 98 / 52905, JP-A-1-272551, JP-A-6-016616, JP-A-7-110469, JP-A-11-080081, and JP-A-2001-328973. Two or more polymerizable liquid crystal compounds may be used in combination. The alignment temperature can be lowered by using two or more kinds of polymerizable liquid crystal compounds in combination.

[0156] As other polymerizable liquid crystal compounds, a cyclic organopolysiloxane compound having a cholesteric phase as disclosed in JP-A-57-165480 can be used. As the above-mentioned polymer liquid crystal compounds, a polymer having a mesogen group exhibiting liquid crystal property introduced into the main chain, the side chain, or both the main chain and the side chain, a polymer cholesteric liquid crystal having a cholesteryl group introduced into the side chain, a liquid crystal polymer as disclosed in JP-A-9-133810, and a liquid crystal polymer as disclosed in JP-A-11-293252 can be used.

[0157] --Discoid Liquid Crystal Compounds-- As the discotic liquid crystal compound, for example, those described in JP-A-2007-108732 and JP-A-2010-244038 can be preferably used.

[0158] Furthermore, the amount of the polymerizable liquid crystal compound added in the liquid crystal composition is preferably 75 to 99.9 mass %, more preferably 80 to 99 mass %, and even more preferably 85 to 90 mass %, based on the solid content mass (mass excluding the solvent) of the liquid crystal composition.

[0159] --Surfactant-- The liquid crystal composition used in forming the cholesteric liquid crystal layer may contain a surfactant.

[0160] The surfactant is preferably a compound that can function as an alignment control agent that contributes to the alignment of the cholesteric liquid crystal phase stably or quickly. Examples of the surfactant include silicone surfactants and fluorine surfactants, and fluorine surfactants are preferred.

[0161] Specific examples of surfactants include the compounds described in paragraphs

[0082] to

[0090] of JP 2014-119605 A, the compounds described in paragraphs

[0031] to

[0034] of JP 2012-203237 A, the compounds exemplified in paragraphs

[0092] and

[0093] of JP 2005-099248 A, the compounds exemplified in paragraphs

[0076] to

[0078] and paragraphs

[0082] to

[0085] of JP 2002-129162 A, and the fluorine (meth)acrylate polymers described in paragraphs

[0018] to

[0043] of JP 2007-272185 A, etc.

[0162] The surfactant may be used alone or in combination of two or more kinds.

[0163] As the fluorine-based surfactant, the compounds described in paragraphs

[0082] to

[0090] of JP2014-119605A are preferred.

[0164] The amount of the surfactant added in the liquid crystal composition is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and further preferably 0.02 to 1% by mass, based on the total mass of the liquid crystal compound.

[0165] --Chiral agents (optically active compounds)-- Chiral agents have the function of inducing a helical structure in the cholesteric liquid crystal phase. Chiral agents can be selected according to the purpose, since the twist direction or helical period of the helix induced varies depending on the compound.

[0166] The chiral agent is not particularly limited, and known compounds (for example, those described in Liquid Crystal Device Handbook, Chapter 3, Section 4-3, Chiral Agents for TN (twisted nematic) and STN (Super Twisted Nematic), p. 199, edited by the 142nd Committee of the Japan Society for the Promotion of Science, 1989), isosorbide, and isomannide derivatives can be used.

[0167] Although the chiral agent generally contains an asymmetric carbon atom, an axially asymmetric compound or a planarly asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent. Examples of the axially asymmetric compound or the planarly asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof. The chiral agent may have a polymerizable group. When both the chiral agent and the liquid crystal compound have a polymerizable group, a polymer having a repeating unit derived from the polymerizable liquid crystal compound and a repeating unit derived from the chiral agent can be formed by a polymerization reaction between the polymerizable chiral agent and the polymerizable liquid crystal compound. In this embodiment, the polymerizable group of the polymerizable chiral agent is preferably the same type of group as the polymerizable group of the polymerizable liquid crystal compound. Therefore, the polymerizable group of the chiral agent is also preferably an unsaturated polymerizable group, an epoxy group, or an aziridinyl group, more preferably an unsaturated polymerizable group, and even more preferably an ethylenically unsaturated polymerizable group.

[0168] The chiral agent may also be a liquid crystal compound.

[0169] When the chiral agent has a photoisomerizable group, it is preferable because a pattern of a desired reflection wavelength corresponding to the emission wavelength can be formed by irradiating a photomask with actinic rays or the like after coating and alignment. As the photoisomerizable group, an isomerization site of a compound exhibiting photochromic properties, an azo group, an azoxy group, or a cinnamoyl group is preferable. Specific compounds that can be used include those described in JP-A-2002-080478, JP-A-2002-080851, JP-A-2002-179668, JP-A-2002-179669, JP-A-2002-179670, JP-A-2002-179681, JP-A-2002-179682, JP-A-2002-338575, JP-A-2002-338668, JP-A-2003-313189, and JP-A-2003-313292.

[0170] The content of the chiral dopant in the liquid crystal composition is preferably 0.01 to 200 mol %, more preferably 1 to 30 mol %, based on the molar amount of the liquid crystal compound.

[0171] --Polymerization initiator-- When the liquid crystal composition contains a polymerizable compound, it preferably contains a polymerization initiator. In an embodiment in which the polymerization reaction is caused to proceed by irradiation with ultraviolet light, the polymerization initiator used is preferably a photopolymerization initiator capable of initiating the polymerization reaction by irradiation with ultraviolet light.

[0172] Examples of the photopolymerization initiator include α-carbonyl compounds (described in U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (described in U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (described in U.S. Pat. No. 2,722,512), polynuclear quinone compounds (described in U.S. Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketones (described in U.S. Pat. No. 3,549,367), acridine and phenazine compounds (described in JP-A-60-105,667 and U.S. Pat. No. 4,239,850), and oxadiazole compounds (described in U.S. Pat. No. 4,212,970).

[0173] The content of the photopolymerization initiator in the liquid crystal composition is preferably 0.1 to 20% by mass, and more preferably 0.5 to 12% by mass, based on the content of the liquid crystal compound.

[0174] --Crosslinking agent-- The liquid crystal composition may contain a crosslinking agent in order to improve the film strength and durability after curing. As the crosslinking agent, those which are cured by ultraviolet light, heat, moisture, etc. can be suitably used.

[0175] The crosslinking agent is not particularly limited and can be appropriately selected according to the purpose. For example, polyfunctional acrylate compounds such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; epoxy compounds such as glycidyl (meth)acrylate and ethylene glycol diglycidyl ether; aziridine compounds such as 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] and 4,4-bis(ethyleneiminocarbonylamino)diphenylmethane; isocyanate compounds such as hexamethylene diisocyanate and biuret type isocyanate; polyoxazoline compounds having an oxazoline group in the side chain; and alkoxysilane compounds such as vinyltrimethoxysilane and N-(2-aminoethyl)3-aminopropyltrimethoxysilane. In addition, a known catalyst can be used according to the reactivity of the crosslinking agent, which can improve productivity in addition to improving film strength and durability. These may be used alone or in combination of two or more.

[0176] The content of the crosslinking agent is preferably 3 to 20% by mass, more preferably 5 to 15% by mass, based on the solid content by mass of the liquid crystal composition. When the content of the crosslinking agent is within the above range, the effect of improving the crosslinking density is easily obtained, and the stability of the cholesteric liquid crystal phase is further improved.

[0177] --Other additives-- If necessary, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, metal oxide fine particles, etc. may be added to the liquid crystal composition within a range that does not deteriorate the optical performance, etc.

[0178] The liquid crystal composition is preferably used in the form of a liquid when forming a cholesteric liquid crystal layer.

[0179] The liquid crystal composition may contain a solvent. The solvent is not limited and can be appropriately selected depending on the purpose, but an organic solvent is preferable.

[0180] The organic solvent is not limited and can be appropriately selected according to the purpose, and examples thereof include ketones, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, and ethers. These may be used alone or in combination of two or more. Among these, ketones are preferred when considering the burden on the environment.

[0181] When forming a cholesteric liquid crystal layer, it is preferable to apply a liquid crystal composition to the surface on which the cholesteric liquid crystal layer is to be formed, align the liquid crystal compound in a cholesteric liquid crystal phase state, and then harden the liquid crystal compound to form a cholesteric liquid crystal layer.

[0182] That is, when forming a cholesteric liquid crystal layer on an alignment film, it is preferable to apply a liquid crystal composition to the alignment film, align the liquid crystal compound in a cholesteric liquid crystal phase state, and then harden the liquid crystal compound to form a cholesteric liquid crystal layer in which the cholesteric liquid crystal phase is fixed.

[0183] The liquid crystal composition can be applied by any known method capable of uniformly applying a liquid to a sheet-like material, such as printing methods including ink-jet printing and scroll printing, as well as spin coating, bar coating and spray coating.

[0184] The applied liquid crystal composition is dried and / or heated as necessary, and then cured to form a cholesteric liquid crystal layer. In this drying and / or heating process, the liquid crystal compound in the liquid crystal composition may be aligned in a cholesteric liquid crystal phase. When heating is performed, the heating temperature is preferably 200° C. or less, more preferably 130° C. or less.

[0185] The aligned liquid crystal compound is further polymerized as necessary. The polymerization may be either thermal polymerization or photopolymerization by light irradiation, but photopolymerization is preferred. The light irradiation is preferably performed using ultraviolet light. The irradiation energy is 20 mJ / cm. 2 ~50J / cm 2 is preferable, and 50 to 1500 mJ / cm 2In order to promote the photopolymerization reaction, the light irradiation may be performed under heating conditions or in a nitrogen atmosphere. The wavelength of the ultraviolet light to be irradiated is preferably 250 to 430 nm.

[0186] Here, in the case of a configuration having an area that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, and an area that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light, such as the first reflective polarizer 211 and the second reflective polarizer 213, and the reflective circular polarizer as the patterned circular polarizer 204, the polarizer can be produced by forming a cholesteric liquid crystal layer that is an area that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, and an area that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light, and then aligning and adhering each area on a support.

[0187] Alternatively, a liquid crystal composition that will become a cholesteric liquid crystal layer that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, and a liquid crystal composition that will become a cholesteric liquid crystal layer that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light may be prepared, and the liquid crystal composition that will become the cholesteric liquid crystal layer that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light may be applied to a partial region of the support and cured to form a cholesteric liquid crystal layer that transmits right-handed circularly polarized light and reflects left-handed circularly polarized light, and the liquid crystal composition that will become the cholesteric liquid crystal layer that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light may be applied to another partial region of the support and cured to form a cholesteric liquid crystal layer that transmits left-handed circularly polarized light and reflects right-handed circularly polarized light, thereby producing a reflective circular polarizer having regions that transmit polarized light that is orthogonal to each other.

[0188] Alternatively, a liquid crystal composition may contain two chiral agents having opposite helical twisting powers (HTP), one of which changes its helical twisting power when irradiated with light. After application of the liquid crystal composition, before curing, or during curing, light of a wavelength that changes the HTP of the chiral agent may be irradiated in different doses for each region, thereby forming a cholesteric liquid crystal layer having regions that transmit polarized light that is perpendicular to each other.

[0189] There is no particular limitation on the method for changing the amount of light irradiation for each region, and methods that can be used include irradiating light through a mask, changing the irradiation time for each region, or changing the irradiation intensity for each region.

[0190] Furthermore, the reflective circular polarizers serving as the first reflective polarizer 211 and the second reflective polarizer 213 have the function of a concave mirror. In order to impart the function of a concave mirror to a reflective circular polarizer, the reflective circular polarizer itself may be formed into a concave shape.

[0191] There is no particular limitation on the method for forming the reflective circular polarizer into a concave shape. For example, the reflective circular polarizer prepared as described above may be molded into a curved surface by vacuum molding or the like. Alternatively, the reflective circular polarizer prepared as described above may be attached to a lens-shaped support to form a concave shape.

[0192] (Reflective linear polarizer) A reflective linear polarizer transmits one of two linearly polarized lights that are orthogonal to each other and reflects the other light.

[0193] Examples of the reflective linear polarizer include a film obtained by stretching a dielectric multilayer film as described in JP 2011-053705 A and a wire grid polarizer as described in JP 2015-028656 A. Commercially available reflective linear polarizers can also be used. Commercially available reflective linear polarizers include a reflective polarizer (product name APF) manufactured by 3M and a wire grid polarizer (product name WGF) manufactured by AGC.

[0194] Here, in the case of a configuration having two types of regions that transmit linearly polarized light perpendicular to each other, such as the first reflective polarizer 212 and the second reflective polarizer 214, and the reflective linear polarizer as the patterned linear polarizer 207, the above-mentioned reflective linear polarizers can be prepared by arranging and adhering them on a support so that their transmission axes are perpendicular to each other.

[0195] Furthermore, the reflective linear polarizers serving as the first reflective polarizer 212 and the second reflective polarizer 214 have the function of a concave mirror. In order to impart the reflective linear polarizer with the function of a concave mirror, the reflective linear polarizer itself may be formed into a concave shape. The method for forming the reflective linear polarizer into a concave shape is the same as that for the reflective circular polarizer described above.

[0196] <<Patterned Retardation Layer>> The patterned retardation layer 208 is a λ / 4 plate, in which regions having different directions of the slow axis are formed in a predetermined pattern.

[0197] In addition, there is no limitation on the retardation layer. As the retardation layer, various known retardation layers can be used, such as a stretched polycarbonate film, a stretched norbornene-based polymer film, a transparent film containing and oriented with inorganic particles having birefringence such as strontium carbonate, a thin film obtained by obliquely depositing an inorganic dielectric on a support, a film in which a polymerizable liquid crystal compound is uniaxially aligned and oriented, and a film in which a liquid crystal compound is uniaxially aligned and oriented and oriented, etc.

[0198] Here, the patterned retardation layer 208 has regions in which the directions of the slow axes are perpendicular to each other. Such a patterned retardation layer 208 can be produced by adhering the above-mentioned retardation layers on a support so that the slow axes are aligned perpendicular to each other.

[0199] Alternatively, the patterned retardation layer 208 may be produced by a known method such as the method described in JP-A-2012-008170 and the method described in JP-A-2012-032661. In addition, the patterned retardation layer may be a commercially available product.

[0200] In the above example, the first reflective polarizer and the second reflective polarizer are divided into two parts, each having one first region that transmits the first polarized light and one second region that transmits the second polarized light, but the present invention is not limited to this. The first reflective polarizer and the second reflective polarizer may each have multiple regions, as long as the shapes of the first region and the second region are point-symmetric with respect to the optical axis. In this case, the sizes of the regions may be different.

[0201] In this case, the display may be configured to have multiple first display regions that emit the first polarized light and multiple second display regions that emit the second polarized light, corresponding to the first and second regions of the first and second reflective polarizers.

[0202] The image display device of the present invention has been described in detail above, but the present invention is not limited to the above-mentioned examples, and various improvements and modifications may be made without departing from the gist of the present invention. [Explanation of symbols]

[0203] 200a, 200b, 200c image display device 201a, 201b, 201c Display 202 Image display element 204 Patterned circular polarizer 204a Right circularly polarized light transmission area 204b Left circularly polarized light transmission area 206 Linear Polarizer 207 Patterned Linear Polarizer 207a 1st polarized light transmission area 207b 2nd polarized light transmission area 208 Patterned retardation layer 208a 1st slow axis region 208b 2nd slow axis region 211, 212 1st reflective polarizer 211a, 212a 1st area 211b, 212b 2nd area 213, 214 Second reflective polarizer 213a, 214a 1st area 213b, 214b Second area

Claims

1. a display, a first reflective polarizer, and a second reflective polarizer, in that order; The first reflective polarizer and the second reflective polarizer are arranged such that an optical axis of the first reflective polarizer and an optical axis of the second reflective polarizer coincide with each other; the first reflective polarizer has a first region that transmits a first polarized light and reflects a second polarized light that is orthogonal to the first polarized light, and a second region that transmits the second polarized light and reflects the first polarized light; the first reflective polarizer is divided into the first region and the second region by a line passing through an optical axis of the first reflective polarizer, and a shape of the first region and a shape of the second region are point-symmetric with respect to the optical axis of the first reflective polarizer, the second reflective polarizer has a first region that transmits the first polarized light and reflects the second polarized light, and a second region that transmits the second polarized light and reflects the first polarized light, the second reflective polarizer is divided into the first region and the second region by a line passing through an optical axis of the first reflective polarizer, and a shape of the first region and a shape of the second region are point-symmetric with respect to the optical axis of the first reflective polarizer, the display is divided by a line passing through an optical axis of the first reflective polarizer into a first display area that outputs the first polarized light and a second display area that outputs the second polarized light, and a shape of the first display area and a shape of the second display area are point-symmetric with respect to the optical axis of the first reflective polarizer, a focal point of the first reflective polarizer is located on an opposite side of the first reflective polarizer with respect to the second reflective polarizer; a focal point of the second reflective polarizer is located between the first reflective polarizer and the second reflective polarizer; An image display device, wherein when viewed from the optical axis direction of the first reflective polarizer, the first display area of ​​the display, the first area of ​​the first reflective polarizer, and the second area of ​​the second reflective polarizer overlap.

2. The image display device according to claim 1 , wherein the first reflective polarizer and the second reflective polarizer are reflective circular polarizers.

3. The display includes an image display element, a linear polarizer, and a patterned retardation layer in this order; The patterned retardation layer is a λ / 4 plate, The image display device according to claim 2 , wherein a pattern of the patterned retardation layer corresponds to the first display area and the second display area.

4. the image display element is a self-luminous display element, The image display device according to claim 3 , wherein the linear polarizer is a reflective linear polarizer.

5. the display comprises, in this order, an image display element and a patterned circular polarizer; The image display device according to claim 2 , wherein a pattern of the patterned circular polarizer corresponds to the first display area and the second display area.

6. the image display element is a self-luminous display element, The image display device according to claim 5 , wherein the patterned circular polarizer is a reflective circular polarizer.

7. The image display device according to claim 1 , wherein the first reflective polarizer and the second reflective polarizer are reflective linear polarizers.

8. the display comprises, in this order, an image display element and a patterned linear polarizer; The image display device according to claim 7 , wherein a pattern of the patterned linear polarizer corresponds to the first display area and the second display area.

9. the image display element is a self-luminous display element, The image display device according to claim 8 , wherein the patterned linear polarizer is a reflective linear polarizer.

Images