Stereoscopic display device and circularly polarized light glasses

Abstract

A stereoscopic display device (100) includes a first image display section (110) that outputs first image light (151) of linearly polarized light, a second image display section (120) that outputs second image light (152) of linearly polarized light, a first phase difference plate (112) that modulates the first image light (151) output from the first image display section (110) to convert it into first elliptically polarized light, a second phase difference plate (122) that modulates the second image light (152) output from the second image display section (120) to convert it into second elliptically polarized light that rotates in the same direction as the first elliptically polarized light, and a half mirror (130) that transmits the first elliptically polarized light to make it first circularly polarized light that rotates in the same direction as the first elliptically polarized light, and reflects the second elliptically polarized light to make it second circularly polarized light that rotates in the opposite direction to the second elliptically polarized light.

Description

Technical Field

[0001] This invention relates to stereoscopic display devices and circularly polarized glasses. Background Technology

[0002] Stereoscopic display devices capable of displaying images that appear to be three-dimensional are known. For example, Patent Document 1 discloses a stereoscopic display device comprising two displays, a circularly polarizing filter, and a half-mirror. This stereoscopic display device uses a circularly polarizing filter to convert image light transmitted from the two displays into circularly polarized light, and uses the half-mirror to superimpose them, thereby displaying an image that appears to be three-dimensional. An observer wearing circularly polarized glasses can perceive the displayed image as a three-dimensional image.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-42261 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the stereoscopic display device disclosed in Patent Document 1, the polarization state sometimes breaks down as the image light passes through a circularly polarized filter and a semi-transparent mirror until it reaches the observer. As a result, when an observer wearing circularly polarized glasses observes a stereoscopic image using the stereoscopic display device disclosed in Patent Document 1, crosstalk occurs, where the left eye sees the image light that should be seen by the right eye, and the right eye sees the image light that should be seen by the left eye.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a stereoscopic display device and circularly polarized glasses with less crosstalk.

[0009] Methods for solving problems

[0010] To achieve the above objectives, [1] the stereoscopic display device of the present invention comprises: a first image display unit that outputs linearly polarized first image light; a second image display unit that outputs linearly polarized second image light; a first phase difference plate that modulates the first image light output from the first image display unit to convert it into first elliptically polarized light; a second phase difference plate that modulates the second image light output from the second image display unit to convert it into second elliptically polarized light rotating in the same direction as the rotation direction of the first elliptically polarized light; and a semi-transparent mirror that transmits the first elliptically polarized light and makes the first elliptically polarized light become first circularly polarized light rotating in the same direction as the rotation direction of the first elliptically polarized light, and reflects the second elliptically polarized light. The light is vibrated and the aforementioned second elliptically polarized light is transformed into second circularly polarized light that rotates in the opposite direction to the rotation direction of the aforementioned second elliptically polarized light. The aforementioned first image display unit and the aforementioned second image display unit are configured such that the image display surfaces of the first image display unit and the image display surfaces of the second image display unit form a predetermined angle. The aforementioned semi-transparent mirror is configured in the region where the first image light and the aforementioned second image light intersect, such that the angle formed by the image display surface of the first image display unit and the surface of the semi-transparent mirror facing the aforementioned first image display unit is equal to the angle formed by the image display surface of the aforementioned second image display unit and the surface of the semi-transparent mirror facing the aforementioned second image display unit.

[0011] In addition, [2] the aforementioned first phase difference plate and the aforementioned second phase difference plate may have a structure in which an alignment layer and a liquid crystal layer are sequentially stacked on the substrate and the aforementioned substrate.

[0012] Alternatively, [3] could be that the delay value of the first phase difference plate is 136nm to 165nm, and the delay value of the second phase difference plate is 72nm to 114nm.

[0013] In addition, [4] the aforementioned semi-transparent and semi-reflective mirror may have a substrate and a chromium layer stacked on the substrate.

[0014] In addition, [5] circularly polarized glasses, which are circularly polarized glasses used together with any one of the stereoscopic display devices described in [1] to [4], wherein the lens constituting the aforementioned circularly polarized glasses has a structure in which a polarizing plate and a λ / 4 phase difference film are stacked.

[0015] Invention Effects

[0016] According to the present invention, a stereoscopic display device and circularly polarized glasses with less crosstalk can be provided. Attached Figure Description

[0017] [ Figure 1 [This is a schematic diagram of the stereoscopic display device according to the embodiment.]

[0018] [ Figure 2 This diagram illustrates the relationship between the slow axis of the phase retardation plate and the transmission axis of the polarizing plate.

[0019] [ Figure 3 ] is used for Figure 1 A schematic diagram illustrating the transmission and reflection states of the first and second image lights in the semi-transparent mirror.

[0020] [ Figure 4 [ ] is a diagram illustrating the structure of the right and left eye lenses in circularly polarized glasses.

[0021] [ Figure 5 ] is used for Figure 1 A schematic diagram illustrating the function of the stereoscopic display device in displaying stereoscopic images. Detailed Implementation

[0022] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "implementations") will be described in detail. These embodiments are illustrative of the present invention and are not intended to limit the invention to the following. The present invention can be implemented with appropriate modifications within its scope.

[0023] See below. Figure 1 , Figure 2 The configuration of the stereoscopic display device 100 according to the embodiment will be described.

[0024] like Figure 1 As shown, the stereoscopic display device 100 includes: a control unit 90, a first image display unit 110, a second image display unit 120, a first phase difference plate 112, a second phase difference plate 122, and a semi-transparent mirror 130.

[0025] The control unit 90 is connected to the first image display unit 110 and the second image display unit 120. Based on image data provided externally, it provides image data of the right parallax image of the displayed object to the first image display unit 110 and image data of the left parallax image of the displayed object to the second image display unit 120. It should be noted that the right parallax image and the left parallax image are images obtained from viewing the displayed object from a right-hand viewpoint and a left-hand viewpoint, respectively.

[0026] The first image display unit 110 and the second image display unit 120 display parallax images of the display objects on the image display surface 114 and the image display surface 124, respectively, based on the image data provided by the control unit 90. Hereinafter, the light emitted from the image display surface 114 and the image display surface 124 and containing the displayed image will be referred to as the first image light 151 and the second image light 152.

[0027] Image display surface 114 and image display surface 124 are respectively provided with polarizing plate 116 and polarizing plate 126. Figure 1 (Not shown in the figure). The transmission axes of polarizing plate 116 and polarizing plate 126 are parallel to the vertical direction when the first image display unit 110 and the second image display unit 120 are erected vertically.

[0028] The first image display unit 110 and the second image display unit 120 are each composed of a liquid crystal display panel, an organic EL (Electro-Luminescence) panel with a polarizing plate, and other display devices.

[0029] The first retardation plate 112 and the second retardation plate 122 each have an alignment layer formed on a substrate and a liquid crystal layer formed on the alignment layer. The substrate is in the shape of a film or a plate. From a productivity point of view, the thickness of the substrate is 0.01 to 10 mm. The material constituting the substrate is not particularly limited as long as it has high transparency, low birefringence, and excellent optical properties. Examples include cyclic olefin polymers (COP), cyclic olefin copolymers (COC), triacetyl cellulose (TAC) polymers, and glass. From the viewpoint of dimensional stability, glass is preferred. The material constituting the alignment layer can be a known photo-alignment compound. Examples of photo-alignment compounds include photodecomposition type, photodimerization type, and photoisomerization type compounds. From the viewpoint of controlling the orientation of the liquid crystal molecules constituting the liquid crystal layer, the thickness of the alignment layer is 0.001 to 10 μm. The material constituting the liquid crystal layer is not particularly limited as long as it is a liquid crystal polymer that can be cured by ultraviolet light or heat. As a preferred liquid crystal polymer, a linear liquid crystal polymer is preferred from the viewpoint of modulating the polarization states of the first image light 151 and the second image light 152. By aligning a portion of the liquid crystal molecules of this linear liquid crystal polymer parallel to the principal plane (XY plane direction) of the glass plate, the polarization state of the image light can be efficiently modulated. From the viewpoint of effectively modulating the polarization state, the thickness of the liquid crystal layer is 0.1 to 20 μm. The retardation value of the retardation plate can be adjusted by changing the thickness of the alignment layer and the thickness of the liquid crystal layer.

[0030] The first retardation plate 112 and the second retardation plate 122 can be either retardation plates having an alignment layer and a liquid crystal layer, or retardation plates formed by stretching a polycarbonate film. In this case, the retardation value of the retardation plate can be adjusted by adjusting the degree of stretching of the polycarbonate film.

[0031] 130mm semi-transparent mirror Figure 1As shown in circle 1, the mirror 136 comprises a substrate 135 and a semi-transparent mirror layer 136 formed on the substrate 135. The semi-transparent mirror 136 has the function of transmitting part of the incident light and reflecting part of it. From the viewpoint of dimensional stability, the material constituting the substrate 135 is preferably glass. From the viewpoint of productivity, the thickness of the substrate 135 is 0.01 to 10 mm. From the viewpoint of durability, the material constituting the semi-transparent mirror layer 136 is a metal such as gold, silver, aluminum, or chromium, preferably chromium. From the viewpoint of ensuring sufficient reflection of the incident light, the thickness of the semi-transparent mirror layer 136 is 0.5 nm to 50 nm. The semi-transparent mirror layer 136 can be obtained, for example, by vapor deposition of metal onto the surface of the substrate 135.

[0032] The semi-transparent and semi-reflective mirror layer 136 can also be composed of a dielectric multilayer film, which is formed by alternately stacking multiple layers of high-refractive-index dielectric films composed of SiO, Ta2O5, TiO2, Y2O3, ZnSe, ZnS, ZrO2, etc. and low-refractive-index dielectric films composed of Al2O3, CaF2, MgF2, MgO, SiO2, Si2O3, etc.

[0033] Next, the optical configuration of each part constituting the stereoscopic display device 100 will be described.

[0034] The first image display unit 110 and the second image display unit 120 are arranged such that the image display surface 114 and the image display surface 124 form an angle γ. From the viewpoint that more image light emitted from the first image display unit 110 and the second image display unit 120 reaches the observer 170 via the semi-transparent mirror 130, the angle γ is 85° to 100°, preferably 90° to 100°. From the viewpoint of miniaturizing the stereoscopic display device 100, the angle γ is more preferably 90°.

[0035] A translucent mirror 130 is disposed in the region where the first image light 151 and the second image light 152 emitted from the first image display unit 110 and the second image display unit 120 intersect. The translucent mirror 130 may be disposed such that either the surface 131 of the substrate 135 or the surface 133 of the translucent mirror layer 136 faces the observer 170. From the viewpoint of suppressing the brightness of the first image light 151 emitted from the first image display unit 110, it is preferable that the surface 133 of the translucent mirror layer 136 faces the observer 170.

[0036] The positional relationship between the semi-transparent mirror 130, the first image display unit 110, and the second image display unit 120 is expressed by the formula α = β = γ / 2. Angle α is the angle formed by the image display surface 114 and the semi-transparent mirror 130. Angle β is the angle formed by the image display surface 124 and the semi-transparent mirror 130. Angles α and β are set to be equal. However, the statement that angles α and β are equal does not mean that they are geometrically identical, but rather that they are equal to a degree that results in nearly identical optical effects. Therefore, a deviation of approximately ±10° for both angles α and β is within the acceptable range. Figure 1 The angle γ shown is 90°, and the angles α and β are each 45°.

[0037] A first phase retardation plate 112 is mounted on the image display surface 114. From the viewpoint of protecting the liquid crystal layer constituting the first phase retardation plate 112, the surface of the liquid crystal layer constituting the first phase retardation plate 112 is preferably mounted facing the image display surface 114. A second phase retardation plate 122 is disposed on the image display surface 124. From the viewpoint of protecting the liquid crystal layer constituting the second phase retardation plate 122, the surface of the liquid crystal layer constituting the second phase retardation plate 122 is preferably mounted facing the image display surface 124.

[0038] use Figure 2 The relationship between the slow axis of the retardation plate and the transmission axis of the polarizing plate disposed on the image display surface will be explained. The first retardation plate 112 is mounted such that its slow axis 113 is tilted clockwise by 40° to 50°, or ideally by 45°, relative to the transmission axis 117 of the polarizing plate 116 disposed on the first image display unit 110. The second retardation plate 122 is configured such that its slow axis 123 is tilted clockwise by 40° to 50°, or ideally by 45°, relative to the transmission axis 127 of the polarizing plate 126 disposed on the second image display unit 120.

[0039] Methods for fixing the first phase retardation plate 112 to the image display surface 114 include: fixing the outer periphery of the first phase retardation plate 112 to the outer periphery of the first image display unit 110 using a clamp or adhesive; applying a liquid adhesive to the surface of the image display surface 114 and placing the first phase retardation plate 112 thereon for fixing; attaching an adhesive sheet or bonding sheet to the surface of the image display surface 114 and placing the first phase retardation plate 112 thereon for fixing; and so on. From the viewpoints of transparency, weather resistance, and lightfastness, the material constituting the liquid adhesive, adhesive sheet, or bonding sheet is preferably an acrylic resin composition. Methods for fixing the second phase retardation plate 122 to the image display surface 124 can be the same as those for fixing the first phase retardation plate 112 to the image display surface 114.

[0040] Next, use Figure 3 The transmission and reflection states of the first image light 151 and the second image light 152 will be explained. The first image light 151 is emitted from the first image display unit 110, passes through the first phase retardation plate 112, and, as shown in circle 2, is incident from surface 131 onto the substrate 135 constituting the semi-transparent mirror 130, and exits from surface 133 after passing through the semi-transparent mirror layer 136. Then, the first image light 151 reaches the observer 170 via circularly polarized glasses 160. Because the first image light 151 passes through the semi-transparent mirror 130, its brightness is attenuated compared to before it passed through.

[0041] The second image light 152 is emitted from the second image display unit 120, passes through the second phase retardation plate 122, and is reflected at the surface 133 of the semi-transparent mirror layer 136 as shown in circle 2, before reaching the observer 170 via the circularly polarized glasses 160. Because the second image light 152 is reflected at the surface 133 of the semi-transparent mirror layer 136, its brightness is attenuated compared to before reflection.

[0042] The brightness of the first image light 151 after passing through the semi-transparent mirror 130 may be lower or higher than the brightness of the second image light 152 reflected from the surface 133 of the semi-transparent mirror layer 136 due to differences in the material constituting the semi-transparent mirror layer 136. In this case, it is preferable to adjust the brightness of the first image light 151 emitted from the first image display unit 110 and the brightness of the second image light 152 emitted from the second image display unit 120 in a manner that allows the observer 170 to perceive that the brightness of the first image light 151 and the brightness of the second image light 152 are approximately equal.

[0043] Next, use Figure 4 The structure and function of the circularly polarized glasses 160 used with the stereoscopic display device 100 will be described. The circularly polarized glasses 160 have a right eye lens 161 and a left eye lens 162.

[0044] The right eye lens 161 has a structure comprising a polarizing plate 182 and a λ / 4 retardation film 180 stacked on top of each other. The right eye lens 161 is mounted on the circularly polarized glasses 160 with the polarizing plate 182 positioned on the observer's side. As viewed from the observer's 170, the slow axis 181 of the λ / 4 retardation film 180 is tilted 45° clockwise relative to the vertical direction. The polarizing plate 182 is arranged with its absorption axis vertical and its transmission axis 183 horizontal (orthogonal to the vertical direction).

[0045] The left eye lens 162 has a configuration comprising a polarizing plate 186 and a λ / 4 retardation film 184 stacked together. The left eye lens 162 is mounted on the circularly polarized glasses 160 with the polarizing plate 186 positioned on the observer's side. From the observer's perspective, the slow axis 185 of the λ / 4 retardation film 184 is orthogonal to the slow axis 181 of the λ / 4 retardation film 180. That is, from the observer's perspective, the slow axis 185 is tilted counterclockwise by 45° relative to the vertical direction. The polarizing plate 186 is configured such that its absorption axis is vertical and its transmission axis 187 is horizontal (orthogonal to the vertical direction).

[0046] Next, use Figure 5 The operation of the stereoscopic display device 100 in displaying an image that appears to be stereoscopic is explained.

[0047] It should be noted that, in the following description of the operation, the polarization state of the first image light 151 and the second image light 152 is expected to be based on the wavelength at which the observer 170 has the highest sensitivity, for example, around 550 nm, which is the green wavelength in the approximate center of the visible light region. However, it is not limited to this and other wavelengths may also be used as the reference.

[0048] The first image light 151 emitted from the image display surface 114 passes through the polarizing plate 116 disposed on the image display surface 114. Figure 5 (Not shown in the diagram), thus becoming linearly polarized light vibrating in the same direction as its transmission axis 117. If this linearly polarized light passes through the first phase difference plate 112, the phase delay of the polarization component on the slow axis 113 of the first phase difference plate 112 is modulated into right-handed elliptically polarized light with its long axis orthogonal to the transmission axis 117 of the polarizing plate 116. The ratio of the size of the long axis to the short axis of this elliptically polarized light is 1.5:1. If this elliptically polarized light passes through the semi-transparent mirror 130, the angle of incidence is approximately 45°, therefore the intensity ratio of the s-polarization component to the p-polarization component of the elliptically polarized light is close to 1.0, becoming right-handed circularly polarized light.

[0049] The second image light 152, which has just been emitted from the image display surface 124, passes through the polarizing plate 126 disposed on the image display surface 124. Figure 5 (Not shown in the figure), thus becoming linearly polarized light vibrating in the same direction as its transmission axis 127. If this linearly polarized light passes through the second phase difference plate 122, the phase delay of the polarization component on the slow axis 123 of the second phase difference plate 122 is modulated into right-handed elliptically polarized light with its long axis parallel to the transmission axis 127 of the polarizing plate 126. The ratio of the size of the long axis to the short axis of this elliptically polarized light is 2.6:1. If this elliptically polarized light is reflected at the semi-transparent mirror layer 136 of the semi-transparent mirror 130, the rotation direction of the elliptically polarized light is reversed. Furthermore, since the incident angle is approximately 45°, and at the same time the intensity ratio of the s-polarization component to the p-polarization component is close to 1.0, it becomes left-handed circularly polarized light.

[0050] If right-handed circularly polarized light 151 passes through the λ / 4 phase retardation film 180 of the right-eye lens 161, the phase shift of the right-handed circularly polarized light 151 is modulated into linearly polarized light with a horizontal vibration direction. The transmission axis 183 of the polarizing plate 182 is also almost horizontal, so the linearly polarized light 151 passes through the polarizing plate 182 and reaches the right eye 171. On the other hand, if left-handed circularly polarized light 152 passes through the λ / 4 phase retardation film 180 of the right-eye lens 161, the phase shift of the circularly polarized light 152 is modulated into linearly polarized light with a vertical vibration direction. Since the transmission axis 183 of the polarizing plate 182 is horizontal and the absorption axis is vertical, the linearly polarized light 152 is absorbed by the polarizing plate 182 and cannot reach the right eye 171. Therefore, the observer 170 can only perceive the first image light 151 with their right eye 171.

[0051] If left-handed circularly polarized light 152 passes through the λ / 4 phase retardation film 184 of the left-eye lens 162, the phase shift of the left-handed circularly polarized light 152 is modulated into linearly polarized light with a horizontal vibration direction. The transmission axis 187 of the polarizing plate 186 is also almost horizontal, so the linearly polarized light 152 passes through the polarizing plate 186 and reaches the left eye 172. On the other hand, if right-handed circularly polarized light 151 passes through the λ / 4 phase retardation film 184 of the left-eye lens 162, the phase shift of the circularly polarized light 151 is modulated into linearly polarized light with a vertical vibration direction. Since the transmission axis 187 of the polarizing plate 186 is horizontal and the absorption axis is vertical, the linearly polarized light 151 is absorbed by the polarizing plate 186 and cannot reach the left eye 172. Therefore, the observer 170 can only perceive the second image light 152 with the left eye 172.

[0052] The first image light 151 contains a right parallax image of the displayed object, and the second image light 152 contains a left parallax image of the displayed object. The observer 170 synthesizes the left and right parallax images in their brain and recognizes them as a stereoscopic image.

[0053] The stereoscopic display device 100 and the circularly polarized glasses 160 have been described above as embodiments. The arrangement angles of the polarizing plate, the phase difference plate, and the semi-transparent mirror can be appropriately changed. In addition, the configuration of each part can be changed to achieve the same function.

[0054] For example, in the above embodiment, the first image light 151 is modulated into right-handed circularly polarized light, and the second image light 152 is modulated into left-handed circularly polarized light. However, it is also possible to modulate the first image light 151 into left-handed circularly polarized light and the second image light 152 into right-handed circularly polarized light. In this case, the right eye lens 161 of the circularly polarized glasses 160 transmits left-handed circularly polarized light, and the left eye lens 162 transmits right-handed circularly polarized light.

[0055] Furthermore, the arrangement of each polarizing plate and phase retardation plate can be appropriately changed. For example, as long as circularly polarized light in the same direction as the rotation direction of elliptically polarized light (the first rotation direction) can be generated through the semi-transparent mirror 130, the optical arrangement of the polarizing plate 116 and the first phase retardation plate 112 can be arbitrarily set. Similarly, as long as circularly polarized light in the opposite direction to the first rotation direction can be generated through the semi-transparent mirror 130, the optical arrangement of the polarizing plate 126 and the second phase retardation plate 122 can be arbitrarily set. The optical arrangement of the phase retardation films 180 and 184 of the right eye lens 161 and left eye lens 162 constituting the circularly polarized glasses 160, and the polarizing plates 182 and 186, is also the same.

[0056] Furthermore, the delay values ​​of the first retardation plate 112 and the second retardation plate 122 can be appropriately adjusted according to the optical characteristics of other components. For example, if the semi-transparent mirror layer 136 constituting the semi-transparent mirror 130 is composed of a chromium layer, the delay value of the first retardation plate 112 is preferably in the range of 136 nm to 165 nm from the viewpoint of suppressing crosstalk to 2.0% or less, and more preferably in the range of 136 nm to 156 nm from the viewpoint of suppressing crosstalk to 1.0% or less. The delay value of the second retardation plate 122 is preferably in the range of 72 nm to 114 nm from the viewpoint of suppressing crosstalk to 2.0% or less, and more preferably in the range of 82 nm to 103 nm from the viewpoint of suppressing crosstalk to 1.0% or less.

[0057] Example

[0058] The present invention will be further described in detail with reference to the following embodiments and comparative examples, but the present invention is not limited to any of the following embodiments.

[0059] Specifically, the following substances were used as the apparatus and materials in the embodiments and comparative examples.

[0060] (1) Liquid crystal display (LCD)

[0061] As the image display unit, a liquid crystal display (LCD) is used. For the LCD, a 32-inch (screen size, screen width (long side) 70.71cm, screen height (short side) 39.83cm), IPS (In-Plane Switching) type LCD is used, and the transmission axis of the polarizing plate provided on the surface of the LCD is parallel to the short side of the LCD.

[0062] (2) Semi-transparent and semi-reflective mirror

[0063] For the semi-transparent and semi-reflective mirror 130, a semi-transparent and semi-reflective mirror with chromium deposited on the surface of a 2.7 mm thick soda-lime glass substrate has a transmittance of 33% and a reflectance of 24%.

[0064] (3) Phase difference plate

[0065] For the retardation plate, an alignment layer and a liquid crystal layer are sequentially stacked on a glass substrate. A retardation plate with a retardation value of 72 nm is fabricated as follows.

[0066] <Phase retardation plate (72nm delay)>

[0067] A dimerizing polymer (ROLIC, ROP-212) was coated onto a 32-inch glass substrate (width (long side) 70.71 cm, height (short side) 39.83 cm) with a thickness of 0.7 mm, to achieve a dried thickness of 0.1 μm. After the coated polymer dried, its surface was irradiated with a specified amount of ultraviolet light until the cumulative light intensity reached 150 mJ / cm². 2 Thus, an alignment layer is obtained. The irradiated ultraviolet light is linearly polarized ultraviolet B (UVB 280nm~320nm). When viewed from the coated surface, the angle of the vibration direction of this linearly polarized light is 45° counterclockwise relative to the short side of the glass substrate.

[0068] Next, rod-shaped liquid crystal polymer (MERCK, RMS03-013C) is coated on the alignment layer to achieve a dried thickness of 0.40 μm. Then, the substrate is irradiated with ultraviolet A light (UVA 320 nm–400 nm) until the cumulative light intensity reaches 1200 mJ / cm². 2 Until then, a liquid crystal layer is obtained.

[0069] The delay value of the obtained phase difference plate was measured.

[0070] Here, the delay value refers to the phase difference between the fast and slow axes. Light with a wavelength of 590 nm is irradiated onto a phase retardation plate, and the delay value is measured using a phase difference measuring device (KOBRA-CCD, manufactured by Oji Measurement Machinery Co., Ltd.). The measurement is performed at three points: the center and both ends of the phase retardation plate, and the average value (X) is calculated. Then, this average value (X) is substituted into the following mathematical formula (1) to calculate the delay value (Y) at 550 nm.

[0071] Y = 1.03 × X···(1)

[0072] The delay value at X...590nm

[0073] The delay value at Y···550nm

[0074] Viewed from the liquid crystal layer side, the angle of the slow axis of the retardation plate is 45° counterclockwise relative to the short side of the glass substrate. Furthermore, the retardation value at 550nm is 72nm.

[0075] <Phase retardation plate (delay value 82nm)>

[0076] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.45 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0077] <Phase retardation plate (delay value 89nm)>

[0078] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.49 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0079] <Phase retardation plate (delay value 103nm)>

[0080] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.56 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0081] <Phase retardation plate (125nm delay)>

[0082] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.71 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0083] <Phase retardation plate (144nm delay)>

[0084] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.79 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0085] <Phase retardation plate (155nm delay)>

[0086] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.85 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0087] <Phase retardation plate (165nm delay)>

[0088] Except for coating rod-shaped liquid crystal polymers on the alignment layer to make the dried liquid crystal layer 0.90 μm thick, the fabrication is carried out using the same steps as the fabrication of the retardation plate (72 nm delay value).

[0089] (4) Circularly polarized glasses

[0090] Use circularly polarized 3D glasses (made by MeCan Imaging Inc., right eye lens CP125R, left eye lens CP125L).

[0091] The fabrication of the apparatus, evaluation methods, and measurement methods in the examples and comparative examples are described below.

[0092] <Fabrication of Stereoscopic Display Device 100>

[0093] The stereoscopic display device 100 is obtained by preparing and assembling a liquid crystal display with a phase difference plate fixed thereon and a transflective mirror 130, which will be described later.

[0094] (Fabrication of a liquid crystal display with a fixed phase retardation plate)

[0095] A liquid crystal display (LCD) with a fixed retardation plate is fabricated as follows. First, the retardation plate is placed on the LCD with the surface of the liquid crystal layer constituting the retardation plate aligned with the image display surface of the LCD. Next, the periphery of the image display surface is fixed to the periphery of the retardation plate using a fixing tool. Viewed from the glass surface of the glass substrate constituting the retardation plate, the slow axis of the retardation plate is 45° clockwise relative to the direction of vibration of the linearly polarized light emitted from the LCD. Another LCD with a fixed retardation plate is prepared in the same manner. The first LCD is designated as the first image display unit 110, and the retardation plate fixed to it is designated as the first retardation plate 112. A retardation plate (retardation value 144nm) is used for the first retardation plate 112. The second LCD is designated as the second image display unit 120, and the retardation plate fixed to it is designated as the second retardation plate 122. A retardation plate (retardation value 82nm) is obtained for the second retardation plate 122.

[0096] (Setting of the first image display unit 110 (liquid crystal display) and the second image display unit 120 (liquid crystal display))

[0097] The second image display unit 120 is mounted on the floor with its image display surface 124 facing vertically upward. Next, the first image display unit 110 is aligned with one long side of the first image display unit 110, which is vertically erected, and with one long side of the second image display unit 120 aligned. That is, the first image display unit 110 and the second image display unit 120 are mounted such that the angle formed by the image display surface 114 of the first image display unit 110 and the image display surface 124 of the second image display unit 120 is perpendicular.

[0098] (130mm semi-transparent mirror configuration)

[0099] A transflective mirror 130 is positioned at the intersection of the first image light 151 and the second image light 152. The chromium-plated surface (transflective mirror layer 136) of the transflective mirror 130 faces the observer. Furthermore, the transflective mirror 130 is positioned such that the angle between the image display surface 124 and the surface 133 of the transflective mirror layer 136 is 45°, and the angle between the image display surface 114 and the surface 131 of the substrate 135 (glass substrate) is also 45°.

[0100] <Measurement of Crosstalk>

[0101] (1) Measurement conditions

[0102] In a darkroom with a luminance of 100 lux or less, the stereoscopic display device 100 and the luminance meter are positioned such that the distance from the surface of the first phase retardation plate 112 of the stereoscopic display device 100 to the surface of the lens of the luminance meter (KONICA MINOLTA CA-2000, using a wide-angle lens) is 600 mm. The points for measuring luminance are set at the center of the image display surface 114 and the center of the image display surface 124.

[0103] (2) Measurement method

[0104] The right eye lens 161 and the left eye lens 162 constituting the circularly polarized glasses 160 are respectively placed in front of the lens of the luminance meter, and the light transmittance of the right eye, the light blockage of the right eye, the light transmittance of the left eye, and the light blockage of the left eye are measured as follows.

[0105] (2-1) Light transmittance of the right eye

[0106] When a white image (255 / 255 grayscale) is displayed on image display surface 114 and a black image (0 / 255 grayscale) is displayed on image display surface 124, the brightness of the image light transmitted through the right eye lens 161 is measured using a luminance meter.

[0107] (2-2) Brightness of light blocking on the right eye

[0108] When a black image (0 / 255 grayscale) is displayed on image display surface 114 and a white image (255 / 255 grayscale) is displayed on image display surface 124, the brightness of the image light transmitted through the right eye lens 161 is measured using a luminance meter.

[0109] (2-3) Light transmittance of the left eye

[0110] When a black image (0 / 255 grayscale) is displayed on image display surface 114 and a white image (255 / 255 grayscale) is displayed on image display surface 124, the brightness of the image light transmitted through the left eye lens 162 is measured using a luminance meter.

[0111] (2-4) Brightness of light blocking on the left eye

[0112] When a white image (255 / 255 grayscale) is displayed on image display surface 114 and a black image (0 / 255 grayscale) is displayed on image display surface 124, the brightness of the image light transmitted through the left eye lens 162 is measured using a luminance meter.

[0113] (3) Evaluation methods

[0114] The transmittance of the right eye (cd / m²) obtained by the measurement method in (2) 2 ), right eye shading brightness (cd / m 2 ), left eye transmittance (cd / m 2 ), and the light shading brightness of the left eye (cd / m²) 2 Substitute the mathematical formulas (2) and (3) to calculate the crosstalk rate of the right eye and the crosstalk rate of the left eye.

[0115] Right eye crosstalk rate (%) = (right eye shading brightness / right eye light transmission brightness) × 100···(2)

[0116] Left eye crosstalk rate (%) = (left eye shading brightness / left eye light transmission brightness) × 100···(3)

[0117] The average crosstalk rate of the right eye and the left eye is calculated using mathematical formula (4).

[0118] Crosstalk rate (%) = (Right eye crosstalk rate + Left eye crosstalk rate) / 2···(4)

[0119] <Example 1>

[0120] The stereoscopic display device 100 is manufactured according to the "Manufacturing of Stereoscopic Display Device 100". For the first phase retardation plate 112, a phase retardation plate with a delay value of 144nm is used, and for the second phase retardation plate 122, a phase retardation plate with a delay value of 82nm is used.

[0121] <Example 2>

[0122] For the second retardation plate 122, a retardation plate with a delay value of 89 nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0123] <Example 3>

[0124] For the first phase retardation plate 112, a phase retardation plate with a delay value of 155 nm is used, and for the second phase retardation plate 122, a phase retardation plate with a delay value of 103 nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0125] <Example 4>

[0126] For the second retardation plate 122, a retardation plate with a delay value of 72nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0127] <Example 5>

[0128] For the first phase retardation plate 112, a phase retardation plate with a delay value of 165 nm is used, and for the second phase retardation plate 122, a phase retardation plate with a delay value of 103 nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0129] <Comparative Example 1>

[0130] For the first phase retardation plate 112, a phase retardation plate with a delay value of 125 nm is used; for the second phase retardation plate 122, a phase retardation plate with a delay value of 125 nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0131] <Comparative Example 2>

[0132] For the first phase retardation plate 112, a phase retardation plate with a delay value of 155 nm is used, and for the second phase retardation plate 122, a phase retardation plate with a delay value of 125 nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0133] <Comparative Example 3>

[0134] For the first phase retardation plate 112, a phase retardation plate with a delay value of 165 nm is used, and for the second phase retardation plate 122, a phase retardation plate with a delay value of 125 nm is used. Otherwise, the stereoscopic display device 100 is manufactured in the same manner as in Embodiment 1.

[0135] [Table 1]

[0136]

[0137] It was confirmed that the crosstalk rate of the stereoscopic display device 100 of the embodiment is 2.0% or less, which is a stereoscopic display device with less ghosting and image blurring. On the other hand, it was confirmed that the crosstalk rate of the stereoscopic display device 100 of the comparative example is 3.8% or more, which is a device with strong ghosting and image blurring.

[0138] Various embodiments and modifications can be implemented with respect to this invention without departing from its broad spirit and scope. Furthermore, the embodiments described above are illustrative and do not limit the scope of the invention. That is, the scope of the invention is defined by the claims, not the embodiments. Moreover, various modifications implemented within the scope of the claims and their equivalents are considered to be within the scope of this invention.

[0139] This application is based on Japanese Patent Application No. 2020-104922, filed on June 17, 2020. The entire description, claims, and drawings of Japanese Patent Application No. 2020-104922 are incorporated herein by reference.

[0140] Explanation of reference numerals in the attached figures

[0141] 90 Control Department

[0142] 100 stereoscopic display devices

[0143] 110 First Image Display Unit

[0144] 120 Second Image Display Unit

[0145] 114, 124 image display surfaces

[0146] 112 First phase difference plate,

[0147] 122 Second phase difference plate,

[0148] 113, 123 slow axis

[0149] 116, 126, 182, 186 polarizing plate,

[0150] 117, 127, 183, 187 transmission axes

[0151] 130 semi-transparent mirror,

[0152] 131, 133 surfaces

[0153] 135 substrate,

[0154] 136 semi-transparent and semi-reflective mirror layer

[0155] 151 First image light, right-handed elliptically polarized light, right-handed circularly polarized light

[0156] 152 Second image light, right-handed elliptically polarized light, left-handed circularly polarized light

[0157] 160 circularly polarized glasses

[0158] 161 Right eye lens,

[0159] 162 Left eye lens,

[0160] 180, 184λ / 4 phase retardation films

[0161] 181, 185 slow axis

[0162] 170 observers

[0163] 171 Right eye,

[0164] 172 Left eye.

Claims

1. A stereoscopic display device, which includes: The first image display unit outputs linearly polarized first image light; The second image display unit outputs linearly polarized second image light; A first phase difference plate modulates the first image light output from the first image display unit and converts it into first elliptically polarized light; The second phase difference plate modulates the second image light output from the second image display unit and converts it into second elliptically polarized light that rotates in the same direction as the first elliptically polarized light. A semi-transparent, semi-reflective mirror transmits the first elliptically polarized light and transforms it into first circularly polarized light rotating in the same direction as the first elliptically polarized light, and reflects the second elliptically polarized light and transforms it into second circularly polarized light rotating in the opposite direction to the second elliptically polarized light. The first image display unit and the second image display unit are configured such that the image display surfaces of the first image display unit and the image display surfaces of the second image display unit form a predetermined angle. The semi-transparent mirror is configured in the region where the first image light and the second image light intersect, such that the angle formed between the image display surface of the first image display unit and the surface of the semi-transparent mirror facing the first image display unit is equal to the angle formed between the image display surface of the second image display unit and the surface of the semi-transparent mirror facing the second image display unit. The first phase décor plate is mounted on the polarizing plate with its slow axis tilted clockwise by 40° to 50° relative to the transmission axis of the polarizing plate disposed on the image display surface of the image displayed in the first image display unit. The second phase retardation plate is disposed on the polarizing plate such that its slow axis is tilted clockwise by 40° to 50° relative to the transmission axis of the polarizing plate disposed on the image display surface of the displayed image in the second image display unit. The delay value of the first phase retardation plate at 550nm is 136nm~165nm, and the delay value of the second phase retardation plate is 72nm~114nm. The semi-transparent and semi-reflective mirror has a substrate and a semi-transparent and semi-reflective mirror layer formed on the substrate. The material constituting the semi-transparent and semi-reflective mirror layer is chromium, and the thickness of the semi-transparent and semi-reflective mirror layer is 0.5nm~50nm.

2. The stereoscopic display device as described in claim 1, wherein, The first phase retardation plate and the second phase retardation plate have a substrate and an alignment layer and a liquid crystal layer are sequentially stacked on the substrate.

3. The stereoscopic display device as described in claim 1 or 2, wherein, The crosstalk rate of the stereoscopic display device is less than 2.0%.

4. The stereoscopic display device as described in claim 1 or 2, wherein, The brightness of the first image light after passing through the semi-transparent mirror is equal to the brightness of the second image light after being reflected by the semi-transparent mirror.

5. Circularly polarized glasses, which are used with the stereoscopic display device according to any one of claims 1 to 4, wherein the lens constituting the circularly polarized glasses has a configuration in which a polarizing plate and a λ / 4 phase difference film are stacked.

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