JPWO2008114813A1 - Image display device and panel manufacturing method - Google Patents

Abstract

When a planar image is viewed through a conventional lenticular lens, only a part of the planar image corresponding to the viewing direction is viewed, which has a problem that the resolution is significantly deteriorated. A first panel having an image plane, having a concave lens array on one side, and a second panel having a convex lens array on one side, are arranged in the order of the image plane, the first panel, and the second panel. The convex lens and the concave lens are opposed to each other, and the first panel and the second panel are arranged at a predetermined interval to display a stereoscopic image, and the first panel and the second panel are brought into contact with or close to each other. To display a flat image. Thereby, the image display apparatus which can switch a planar image and a stereo image can be provided.

Description

  The present invention relates to an image display device capable of switching between a planar image and a stereoscopic image.

  There are two types of stereoscopic image display devices that require glasses and those that do not. A stereoscopic image display device using a lenticular lens is known as a method that does not require glasses. FIG. 34 is a perspective view of a lenticular lens. In FIG. 34, reference numeral 3401 denotes a plurality of cylindrical lenses arranged in parallel.

  FIG. 35 is a cross-sectional view of a stereoscopic image display device using a lenticular lens. In FIG. 35, 3501 is a lenticular lens, 3502 is an image display unit, and 3503 is a transparent panel. Examples of the image display portion 3502 include a liquid crystal layer, a plasma discharge portion, and an organic EL layer. FIG. 35 shows a structure in which a lenticular lens 3501 is bonded to a general display including an image display unit 3502 and a transparent panel 3503. A multi-viewpoint image is displayed on the image display unit 3502, and the image is recognized three-dimensionally by being viewed with the left and right eyes through the lenticular lens 3501. If both the lenticular lens 3501 and the transparent panel 3503 are made of general glass or resin, their refractive index is about 1.5. In that case, the lenticular lens 3501 and the transparent panel 3503 are considered to be optically integrated.

  One method for capturing a multi-viewpoint image is to capture an image of the subject from many directions. FIG. 36 is a configuration diagram for capturing a multi-viewpoint image. In FIG. 36, a subject 3601 is imaged using five cameras 3602 to 3606. The plurality of captured images have parallax with each other. FIG. 36 shows an example in which five cameras are used.

  FIG. 37 shows a method for creating a multi-viewpoint image. In FIG. 37, reference numerals 3702 to 3706 denote images taken by the cameras 3602 to 3606 in FIG. These captured images are divided into strip images and combined into one as shown in FIG. 37 to obtain a multi-viewpoint image 3701. In the example of five viewpoints as shown in FIG. 36 and FIG. 37, each strip image is compressed to 1/5 in the horizontal direction and synthesized into 3701.

  38 and 39 are diagrams showing the principle of stereoscopic viewing using a lenticular lens. 38 and 39, 3801 is a cylindrical lens, and 3802 is an image plane. In FIGS. 38 and 39, the lenticular lens (3501 in FIG. 35) and the transparent panel (3503 in FIG. 35) are handled integrally. An image 3803 displayed on the image plane 3802 is a portion corresponding to one cylindrical lens of the multi-viewpoint image 3701 in FIG. In the example of FIGS. 38 and 39, the multi-viewpoint image 3803 is shown only on the image plane corresponding to one cylindrical lens. Actually, a multi-viewpoint image is displayed on an image plane corresponding to all cylindrical lenses. The light emitted from each point on the image plane becomes substantially parallel light by the cylindrical lens and enters the right eye or the left eye. In the positions of the right eye 3804 and the left eye 3805 as shown in FIG. 38, the substantially blind light 3806 is incident on the right eye 3804, the substantially parallel light 3807 is incident on the left eye 3805, and the right eye and the left eye are mutually connected. A stereoscopic image is recognized by looking at an image with parallax.

  When the position of the right eye 3804 and the left eye 3805 is changed as shown in FIG. 39 by moving the head position, substantially parallel light 3808 is incident on the right eye 3804 and substantially parallel to the left eye 3805. Light 3809 enters to recognize the image three-dimensionally. Moving the head changes the three-dimensional direction, and things that could not be seen in FIG. 38 can be seen in FIG. 39, increasing the sense of reality. Such a multi-view image and a stereoscopic image using a lenticular lens have been reported in recent academic conferences (see, for example, Non-Patent Document 1).

  In the lenticular lens as shown in FIGS. 38 and 39, light emitted from different points on the image plane becomes substantially parallel light in different directions, and a stereoscopic image is recognized by viewing different images with the right eye and the left eye. The principle of such substantially parallel light will be described analytically with reference to FIG.

  In FIG. 40, 4001 is a cylindrical lens, and 4002 is an image plane. Also in FIG. 40, the lenticular lens (3501 in FIG. 35) and the transparent panel (3503 in FIG. 35) are handled integrally. In FIG. 40, a spherical lens is used, and the spherical radius of the lens is R. Let T be the distance from the image plane 4002 to the top of the lens, n be the refractive index of the lens medium, and W be the width of one cylindrical lens. Let δ be the distance from the lens center line 4003 passing through the top of the lens to the point of interest on the image plane. The light coming out of this image plane point and reaching the point P on the lens surface is refracted on the lens surface and emitted from the cylindrical lens 4001 with an angle β.

The distance X of the point P from the lens center line 4003 is expressed by (Equation 1), and the angle θ of the light ray from the point of interest on the image plane toward the point P is obtained by (Equation 2). Further, the incident angle α to the lens surface is obtained by (Equation 3), and the emission angle β is obtained by (Equation 4) from the law of refraction on the lens surface.
(Equation 1) X = R · sinφ
(Formula 2) tan θ = (δ−X) / (T−R + R · cos φ)
(Equation 3) α = θ + φ
(Expression 4) sin (φ + β) = n · sin α

  If a point on the image plane (distance δ from the lens center line 4003) and a refraction point P (distance X from the lens center line 4003) are given, then φ, θ in order from (Equation 1) to (Equation 4). , Α, β are obtained, and the direction of the light emitted from the cylindrical lens 4001 is obtained.

  Ideally, light emitted from different points on the image plane 4002 is emitted from the cylindrical lens 4001 as parallel light having different emission angles. FIG. 41 shows the ideal behavior. The horizontal axis represents the position (X) where light emitted from a point on the image plane enters the lens surface, and the vertical axis represents the emission angle (β) from the cylindrical lens. As a point on the image plane (distance δ from the lens center line 4003), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light emitted from a point on the image plane corresponding to the adjacent cylindrical lens. For example, light emitted from a point on the image plane (δ = W / 4) becomes parallel light having a constant emission angle regardless of the position on the lens surface. In other words, if the lenticular lens is viewed from the emission angle, only the image of the point (δ = W / 4) is viewed. In this way, the fact that light emitted from a point on the image surface becomes parallel light with a constant emission angle regardless of the incident position on the lens surface is referred to as a lenticular effect. In reality, such an ideal outgoing light cannot be obtained, and a realistic case will be described below.

First, consider paraxial approximation with a small ray angle. In this paraxial approximation, (Equation 1) through (Equation 4) are expressed as (Equation 5) through (Equation 8), respectively.
(Equation 5) X = Rφ
(Equation 6) θ = (δ−X) / T
(Equation 7) α = θ + φ
(Equation 8) φ + β = nα

From these (Equation 5) to (Equation 8), the exit angle β in paraxial approximation is expressed by (Equation 9). The lenticular lens effect, that is, the condition that light emitted from a point on the image plane (distance δ from the lens center line 4003) becomes substantially parallel light with a constant emission angle is that β does not depend on θ. This is the case. The emission angle β at that time is given by (Equation 11). When T is given by (Equation 10), the light emitted from the image plane becomes parallel light, so that T corresponds to the focal length of the spherical lens with radius R.
(Equation 9) β = (n−1) (δ / R) − [(n−1) (T / R) −n] θ
(Equation 10) T = Rn / (n-1)
(Equation 11) β = (n−1) (δ / R)

When the lens medium is general glass or resin, the refractive index n is about 1.5, the distance T from the image surface to the top of the cylindrical lens is (Equation 12), and the emission angle β of substantially parallel light is ( (13) This means that the focal length of a spherical lens made of a medium having a refractive index of about 1.5 is three times the spherical radius.
(Equation 12) T = 3R
(Equation 13) β = δ / (2R)

  Next, a general case is simulated using (Equation 1) to (Equation 4). As an example, in FIG. 40, R = 1, T = 3, n = 1.5, and W = 1.5. These conditions satisfy (Equation 10). FIG. 42 shows the result of the simulation. The horizontal axis represents the position (X) where light emitted from a point on the image surface enters the lens surface, and the vertical axis represents the exit angle (β) emitted from the cylindrical lens. As a point on the image plane (distance δ from the lens center line 4003), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light emitted from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. Most of the light emitted from the lens center (δ = 0) on the image plane is emitted from the cylindrical lens as substantially parallel light having an angle β = 0, and the light in the peripheral portion becomes a slightly focused light. When light coming from a point on the image plane (δ = W / 4) at a distance W / 4 from the lens center line is incident on the lens plane range (−0.75 to +0.5), the angle β = 0. When the light is emitted from the cylindrical lens as approximately parallel light having 19 radians and enters the range (+0.5 to +0.75) of the lens surface, the light becomes non-parallel light. Further, when the light emitted from the point (δ = W / 2) on the image plane corresponding to the boundary between the adjacent cylindrical lenses is incident on the lens surface range (−0.75 to +0.3), the angle β = When the light is emitted from the cylindrical lens as substantially parallel light having 0.37 radians and enters the range (+0.3 to +0.6) of the lens surface, the light becomes non-parallel light. When the light enters the lens surface range (+0.6 or more) from the boundary point (δ = W / 2), the light is not emitted from the cylindrical lens due to total reflection. Comparing FIG. 41 and FIG. 42, most of the light is relatively close to the ideal, but there is also light that is not ideal. The effect on the image of rays that deviate from this ideal must be considered.

  In order to recognize a high-quality stereoscopic image, it is important that only an image near one point on the image plane is visible when the lenticular lens is viewed from one direction. If light from many points appears to be mixed, a plurality of images are mixed and the image quality deteriorates. A case where the lenticular lens is viewed from an angle of 0.19 radians will be described with reference to FIG. In FIG. 43, the same components as those of FIG. Reference numeral 4004 denotes an eye having an angle of 0.19 radians. In FIG. 43, the eye 4004 is drawn so as to be near the lenticular lens, but it is actually far in the direction of the arrow. As can be seen from FIG. 42, most of the light emitted from the point (δ = W / 4) on the image plane is substantially parallel light having an emission angle of 0.19 radians. These are lights in a region surrounded by the light ray 4005 (solid line) and the light ray 4006 (solid line) in FIG. 43, and this substantially parallel light can be seen from the eye 4004. Light such as a ray 4007 (wave line) emitted from a point (δ = W / 4) on the image plane has an emission angle larger than 0.19 radians and cannot be seen by the eye 4004.

  Next, the case where the lenticular lens is viewed from an angle of 0.37 radians will be described with reference to FIG. 44, the same components as those in FIGS. 40 and 43 are denoted by the same reference numerals, and description thereof is omitted. The eye 4004 is far away at an angle of 0.37 radians (arrow direction). As can be seen from FIG. 42, most of the light emitted from the point (δ = W / 2) on the image plane is substantially parallel light having an emission angle of 0.37 radians. These are lights in a region surrounded by the light ray 4008 (solid line) and the light ray 4009 (solid line) in FIG. 44, and this substantially parallel light can be seen from the eye 4004. On the other hand, part of the light from other points on the image plane also has an exit angle of 0.37 radians. For example, light ray 4010 (dashed line) exits from a point where δ = W / 4 and is emitted with an exit angle of 0.37 radians. The light ray 4010 is generated in a very narrow range as compared with the region surrounded by the light ray 4008 and the light ray 4009, and the amount of light is small. That is, when the lenticular lens is viewed from an angle of 0.37 radians, only the image near the point where δ = W / 2 is seen.

  42, when the change in the emission angle β is large with respect to the horizontal axis (incidence position X on the lens surface), that is, when the gradient of the curve representing the emission angle is large, the light ray 4007 (dashed line) in FIG. And, as seen from a specific emission angle, like a light ray 4010 (wave line) in FIG. 44, the amount of light is small, and there is no problem in image quality degradation.

  Images from many viewpoints are displayed on the image plane corresponding to one cylindrical lens. Of these multi-viewpoint images, the adjacent images are images taken by the adjacent cameras in FIG. 36, and have a strong correlation with each other. However, the image near the boundary between adjacent cylindrical lenses is, for example, an image captured by the cameras 3602 and 3606 in FIG. 36, and the correlation is low. If they are mixed, the image quality deteriorates.

  Accordingly, the light having a relatively high intensity out of the light exiting from the boundary point (δ = W / 2) between adjacent cylindrical lenses and emitted from the cylindrical lens, and the smallest exit angle determines the viewing angle of the stereoscopic image. It will be a thing. The viewing angle in the case of FIG. 42 is ± 0.37 radians (± 21 degrees). The larger the viewing angle, the more stable the stereoscopic image can be obtained.

  As shown in FIG. 42, light emitted from the image plane corresponding to the adjacent cylindrical lens (δ> W / 2) is also mostly parallel light, but as the point on the image plane moves away from the lens center line, as shown in FIG. The ratio of non-parallel light increases. The light emitted from the image plane corresponding to these adjacent cylindrical lenses is outside the viewing angle and does not affect the stereoscopic image within the viewing angle.

  As described above, a stereoscopic image can be recognized using a lenticular lens. However, when the planar image is viewed through the lenticular lens, only a part of the planar image corresponding to the viewing direction is viewed, and the resolution is significantly degraded. In particular, small characters may become unreadable. Thus, an image display device that can switch between a planar image and a stereoscopic image has been proposed (see, for example, Patent Document 1).

  FIG. 45 is a cross-sectional view of a conventional image display device capable of switching between a planar image and a stereoscopic image. In FIG. 45, 4501 is an array of convex cylindrical lenses, 4502 is an array of concave cylindrical lenses, 4503 is an image display unit, and 4504 is a transparent panel. FIG. 45 shows a structure in which an array 4501 of convex cylindrical lenses is bonded to a general display including an image display unit 4503 and a transparent panel 4504. The convex cylindrical lens and the concave cylindrical lens are arranged so as to face each other.

  FIG. 46 is a cross-sectional view of a panel when a stereoscopic image is displayed using a conventional image display device, and FIG. 47 is a cross-sectional view of the panel when a flat image is displayed using a conventional image display device. FIG. If the convex cylindrical lens 4501, the concave cylindrical lens 4502 and the transparent panel 4504 in FIG. 45 are made of general glass or resin, their refractive indexes are almost the same. In that case, 4501 and 4504 can be handled optically as one. 46 and 47, 4601 is an integrated convex cylindrical lens, 4602 is a concave cylindrical lens, and 4603 is an image plane.

  In FIG. 46, the convex cylindrical lens panel 4601 and the concave cylindrical lens panel 4602 are arranged with an appropriate interval. A multi-viewpoint image is displayed on the image plane 4603. Light emitted from a point on the image plane 4603 is emitted from the convex cylindrical lens panel 4601 as focused light and is incident on the concave cylindrical lens panel 4602. The light becomes substantially parallel light by the concave cylindrical lens panel 4602 and is further emitted from the concave cylindrical lens panel 4602 as substantially parallel light. A stereoscopic image can be recognized as in the conventional lenticular lens shown in FIGS.

  In FIG. 47, a convex cylindrical lens panel 4601 and a concave cylindrical lens panel 4602 are disposed in close contact with each other. A general plane image is displayed on the image plane 4603. Light emitted from a point on the image plane 4603 passes through the convex cylindrical lens panel 4601 and the concave cylindrical lens panel 4602 with almost no change in the traveling direction thereof, and is emitted from the concave cylindrical lens panel 4602 as emitted light. The convex cylindrical lens panel 4601 and the concave cylindrical lens panel 4602 behave like a single transparent plate to recognize a general planar image.

  The distance between the convex cylindrical lens panel and the concave cylindrical lens panel that allows a good stereoscopic image to be recognized will be analytically described with reference to FIG. In FIG. 48, the same components as those in FIGS. 46 and 47 are denoted by the same reference numerals. Let T be the distance from the image plane 4603 to the top of the convex cylindrical lens. In FIG. 48, a spherical cylindrical lens is used, and its spherical radius is R. The distance between the convex cylindrical lens panel 4601 and the concave cylindrical lens panel 4602 is D, and the width of one cylindrical lens is W. Further, the refractive index of the medium of the convex cylindrical lens panel 4601 and the concave cylindrical lens panel 4602 is n. Let P1 be the point at which light emitted from a point on the image plane 4603 at a distance δ from the lens center line 4604 is incident on the surface of the convex cylindrical lens, and P2 will be the point at which the light is incident on the surface of the concave cylindrical lens.

The distance X1 of the point P1 from the lens center line 4604 is expressed by (Expression 14), and the angle θ of the light ray from the point of interest on the image plane toward the point P1 is determined by (Expression 15). Further, the incident angle α to the convex cylindrical lens surface is obtained by (Equation 16), and the angle β is obtained by (Equation 17) from the law of refraction. A distance X2 from the lens center line 4604 of the incident point P2 to the concave cylindrical lens is expressed by (Expression 18). (Equation 19) represents the relationship of angles, and the angle χ is obtained from (Equation 20) from the law of refraction. The emission angle ν is obtained by (Equation 21) from the law of refraction in the plane. Further, (Equation 18) is rewritten as (Equation 22).
(Expression 14) X1 = R · sinφ
(Equation 15) tan θ = (δ−X1) / (T−R + R · cos φ)
(Equation 16) α = φ + θ
(Equation 17) sin β = n · sin α
(Expression 18) X2 = R · sinφ = R · sinφ
-(D-R.cos.phi. + R.cos.phi.). Tan (.beta .-. Phi.)
(Equation 19) φ−β + γ−ψ = 0
(Equation 20) sinγ = n · sin (ψ + χ)
(Expression 21) sinν = n · sinχ
(Equation 22) R · sin (ψ + β−φ) = R · sin β−D · sin (β−φ)

  If a point on the image plane (distance δ from the lens center line 4604) and a refraction point P1 (distance X1 from the lens center line 4604) of the convex cylindrical lens surface are given, (Equation 14) to (Equation 17), (Equation 22) ) And (Equation 19) to (Equation 21), φ, θ, α, β, ψ, γ, χ, and ν are obtained in order, and the direction of light emitted from the concave cylindrical lens panel 4602 is obtained.

First, consider paraxial approximation with a small ray angle. In this paraxial approximation, (Equation 14) to (Equation 17), (Equation 22), and (Equation 19) to (Equation 21) are expressed as (Equation 23) to (Equation 30), respectively.
(Equation 23) X1 = Rφ
(Equation 24) θ = (δ−X1) / T
(Equation 25) α = φ + θ
(Equation 26) β = nα
(Expression 27) R (ψ + β−φ) = Rβ−D (β−φ)
(Equation 28) φ−β + γ−ψ = 0
(Equation 29) γ = n (ψ + χ)
(Equation 30) ν = nχ

From these (Equation 23) to (Equation 30), the paraxial approximate emission angle ν is expressed by (Equation 31). The condition that the lenticular lens effect, that is, the light emitted from a point on the image plane (distance δ from the lens center line 4604) takes substantially parallel light with a constant emission angle is that ν does not depend on θ, which is Is the case. The emission angle at that time is (Expression 33).
(Expression 31) ν = (n−1) ² (D / R) (δ / R)
-[(D / R) (n-1) {(n-1) (T / R) -n} -n] θ
(Equation 32) D = nR / [(n-1) {(n-1) (T / R) -n}]
(Expression 33) ν = (n−1) ² (D / R) (δ / R)

When the lens medium is general glass or resin, the refractive index n is about 1.5, the distance T from the image plane to the convex cylindrical lens head, the convex cylindrical lens panel 4601 and the concave cylindrical lens panel. The distance D of 4602 satisfies the relational expression (Equation 34), and light emitted from a point on the image plane (distance δ from the lens center line 4604) is emitted as substantially parallel light from the concave cylindrical lens panel 4602, and its angle ν is (Expression 35)
(Equation 34) D = 6R / [(T / R) -3]
(Expression 35) ν = δD / (4R ² )

  Next, a general case is simulated using (Equation 14) to (Equation 17), (Equation 22), and (Equation 19) to (Equation 21). As an example, in FIG. 48, R = 1, T = 9, D = 1, n = 1.5, and W = 1.5. These conditions satisfy (Expression 32). FIG. 49 shows the result of the simulation. The horizontal axis represents the position (X1) where light emitted from a point on the image surface enters the convex cylindrical lens surface, and the vertical axis represents the emission angle (ν) from the concave cylindrical lens panel. As the points on the image plane (distance δ from the lens center line 4604), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. Light that reaches the center of the convex cylindrical surface from a point on the image plane is emitted as substantially parallel light from the concave cylindrical lens panel, but light that reaches the periphery of the convex cylindrical lens becomes non-parallel light. The same applies to the light (δ> W / 2) from the image plane corresponding to the adjacent cylindrical lens. This result is similar to that of a conventional lenticular lens. In FIG. 49, the curve representing the non-parallel light portion has a large change in the emission angle ν with respect to the horizontal axis (incident position X1 on the lens surface). That is, when the convex cylindrical lens array and the concave cylindrical lens array are viewed from a certain direction, the intensity of the non-parallel light is small and almost parallel light is viewed.

  Images from many viewpoints are displayed on the image plane corresponding to one cylindrical lens. Among these multi-viewpoint images, adjacent images have a strong correlation with each other, and even if they are mixed, it does not pose a big problem for image quality degradation. However, the image near the boundary between adjacent cylindrical lenses has a low correlation, and when they are mixed, the image quality deteriorates. Accordingly, the light exiting from the boundary point (δ = W / 2) between adjacent cylindrical lenses and exiting from the concave cylindrical lens panel has a relatively high intensity, and the smallest exit angle has the viewing angle of the stereoscopic image. It will be decided. The viewing angle in the case of FIG. 49 is approximately ± 0.19 radians (± 11 degrees). This viewing angle (± 11 degrees) is too small to enjoy a stereoscopic image.

  A method of increasing the viewing angle is to reduce T while satisfying (Expression 32) with the same cylindrical lens width W. For example, if T = 5, the viewing angle becomes larger than ± 0.3 radians. However, D = 3 from (Equation 32). That is, the distance between the convex cylindrical lens panel and the concave cylindrical lens panel is three times the spherical radius (R). Since a spherical lens is used in FIG. 48, the focal length of the spherical lens is three times the spherical radius, as shown in (Equation 12). That is, the distance between the convex cylindrical lens panel and the concave cylindrical lens panel is the extent of the focal length of these lenses. The conventional image display device (Patent Document 1) claims that T = 5 and D = 3 are preferable.

However, such T = 5 and D = 3 have the following drawbacks. As shown in FIG. 50, light from the image plane corresponding to the adjacent convex cylindrical lens is mixed as substantially parallel light having the same emission angle. Much of the light from different image planes will enter the eye, degrading the quality of the stereoscopic image. Therefore, the conventional image display device as shown in FIG. 45 requires a large value of about T = 9, and the viewing angle is about ± 0.19 radians (± 11 degrees).
JP 2006-243732 A Proceedings of 3D image conference 2005 (July 7-8, 2005, Tokyo)

  In an image display device that can switch between a conventional planar image and a stereoscopic image, the viewing angle of the stereoscopic image is narrow, and the quality of the stereoscopic image deteriorates if the eye position is moved a little.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an image display device capable of switching between a planar image and a stereoscopic image having a wide viewing angle. In addition, a method for manufacturing a panel used in such a display device is provided.

  In order to solve the above-described conventional problems, an image display device according to the present invention includes a first panel having an image surface, having an array of concave lenses on one side, and a second panel having an array of convex lenses on one side. A three-dimensional image in which the convex lens and the concave lens face each other, and the first panel and the second panel are arranged at a predetermined interval. And displaying the planar image by arranging the first panel and the second panel in contact or close to each other. Thus, it is possible to provide an image display device that can switch between a planar image and a stereoscopic image and can improve the resolution of the planar image.

  Alternatively, the image display device of the present invention has a second panel having an image surface, having an array of convex lenses on one side, and having a first panel having an array of concave lenses on one side. Two panels and a first panel are arranged in this order, the convex lens and the concave lens face each other, the second panel and the first panel are arranged at a predetermined interval to display a stereoscopic image, and the second panel And the first panel are arranged in contact with each other or close to each other to display a planar image, and the predetermined interval is not more than twice the radius of curvature in the vicinity of the lens center line of the convex lens and the concave lens. Thus, it is possible to provide an image display device that can switch between a planar image and a stereoscopic image and can improve the resolution of the planar image.

  It is preferable that the concave lens and the convex lens are aspherical lenses. Even if a spherical lens is used, a planar image and a stereoscopic image can be switched. However, by using an aspherical lens, the viewing angle of the stereoscopic image can be increased.

  In the aspheric lens, it is preferable that the radius of curvature of each point on the lens surface gradually increases from the center of the lens toward the periphery.

  Alternatively, it is preferable that the shape of the aspheric lens is approximated by an ellipse, a hyperbola, a quadratic even function, or a combination function thereof.

  In the image display device of the present invention, the first panel has a configuration in which an array of concave lenses having a refractive index n2 is formed on a first transparent plate having a refractive index n1, and the second panel has a refractive index n1. This is a configuration in which an array of convex lenses having a refractive index n2 is formed on the second transparent plate, and n2> n1. By this, the refractive index of a lens part can be enlarged and the viewing angle of a stereo image can be enlarged more.

  It is preferable that the convex lens array or the concave lens array is made of a resin in which fine particles are dispersed. Thereby, an image display apparatus having a large viewing angle can be provided at low cost.

  It is preferable that the fine particles contain one or more dielectrics selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, and aluminum oxide.

  In the image display device of the present invention, a stopper is provided on at least one of the first panel and the second panel. As a result, the concave lens surface and the convex lens surface can be brought close to each other with a stable minute gap, and a stable flat image can be provided.

  In the image display device of the present invention, a conductive transparent thin film is formed on at least one surface of the concave lens array or the convex lens array. As a result, it is possible to prevent static electricity from being accumulated when the concave lens surface and the convex lens surface are separated or brought close to each other, and to switch between a stereoscopic image and a planar image stably.

  The panel manufacturing method of the present invention has a transparent plate having a convex lens array formed on one side, supplies an ultraviolet curable resin to the boundary of each lens of the convex lens array, and cures the ultraviolet curable resin by irradiating ultraviolet rays. Features. By this, a stopper can be formed and the panel used for the image display apparatus which can switch a planar image and a stereo image can be manufactured.

  In the panel manufacturing method of the present invention, a transparent plate and a mold having a concave lens array shape or a convex lens array shape are opposed to each other, an ultraviolet curable resin is held between the transparent plate and the mold, and ultraviolet rays are irradiated. The ultraviolet curable resin is cured. This makes it possible to manufacture a panel of an image display device that displays a stereoscopic image with a large viewing angle by increasing the refractive index of the lens portion.

  According to the image display device of the present invention, it is possible to provide an image display device that can stably switch between a high-resolution planar image and a stereoscopic image with a wide viewing angle.

  Further, according to the panel manufacturing method of the present invention, it is possible to manufacture a panel constituting an image display device capable of stably switching between a high-resolution planar image and a wide-angle stereoscopic image.

Sectional drawing of the image display apparatus of this invention. Sectional drawing of the panel in the case of displaying a stereo image in the image display apparatus of this invention. Sectional drawing of the panel in the case of displaying the plane image in the image display apparatus of this invention. The figure explaining analytically the principle of the three-dimensional image display in the image display apparatus of this invention. The simulation result in Embodiment 1 of this invention. Explanatory drawing of the light which emerges from the point ((delta) = W / 4) of the image surface in Embodiment 1 of this invention. Explanatory drawing of the light emitted from the point ((delta) = W / 2) of the image surface in Embodiment 1 of this invention. Explanatory drawing of the leak light in Embodiment 1 of this invention. Explanatory drawing of the aspherical lens shape in the image evaluation apparatus of this invention. Sectional drawing of the panel which used high refractive index resin only for the lens part in the image evaluation apparatus of this invention. The figure explaining analytically the principle of the three-dimensional image display in the image evaluation apparatus of this invention. The simulation result at the time of using the elliptical lens and polycarbonate resin in Embodiment 2 of this invention. The simulation result at the time of using the hyperbolic lens and polycarbonate resin in Embodiment 3 of this invention. Explanatory drawing of the light which emerges from the point ((delta) = W / 4) of the image surface in Embodiment 3 of this invention. Explanatory drawing of the light emitted from the point ((delta) = W / 2) of the image surface in Embodiment 3 of this invention. The simulation result at the time of using the 4th order even function lens and polycarbonate resin in Embodiment 4 of this invention. The figure which compares the shape of a spherical lens, an elliptical lens, a hyperbolic lens, and a quartic even function lens in Embodiment 1 thru | or 4 of this invention. The simulation result at the time of using the 4th order even function lens and high refractive index resin in Embodiment 5 of this invention. Sectional drawing of the panel which used high refractive index resin only for the lens part in Embodiment 6 of this invention. The simulation result at the time of using the 4th order even function lens and high refractive index resin in Embodiment 6 of this invention. Panel sectional drawing in the case of displaying a plane image in Embodiment 7 of this invention. The block diagram of the stopper in Embodiment 8 of this invention. Explanatory drawing of the manufacturing method of the stopper in Embodiment 9 of this invention. The block diagram of the electroconductive transparent thin film in Embodiment 10 of this invention. Sectional drawing of the panel which shows the specific example in Embodiment 11 of this invention. The pixel arrangement | sequence figure which shows the specific example in Embodiment 11 of this invention. The simulation result in Embodiment 12 of this invention. Sectional drawing of the panel in Embodiment 12 of this invention. The figure which shows the relationship between the position of the eye in the case of appreciating a stereo image, and a light ray. The figure which shows the relationship between the position of the eye and light rays in the case of appreciating a stereo image in Embodiment 13 of this invention. The block diagram of the image display apparatus in Embodiment 14 of this invention. The perspective view of the fly-eye lens in Embodiment 15 of this invention. Explanatory drawing of the manufacturing method of the 1st panel which uses high refractive index resin only for the lens part in Embodiment 16 of this invention. The perspective view of a lenticular lens. Sectional drawing of the image display apparatus using a lenticular lens. The figure which shows the imaging method of a multiview image. The figure which shows the preparation method of a multiview image. The principle figure of the stereoscopic vision with respect to the position of the right and left eyes using a lenticular lens. The principle figure of the stereoscopic vision with respect to the changed position of the right and left eyes using a lenticular lens. An analytical explanatory diagram of a spherical lenticular lens. The figure which shows the angle of an ideal emitted light. Simulation result of spherical lenticular lens. Explanatory drawing of the light ray emitted from the point ((delta) = W / 4) of an image surface at the time of using a spherical lenticular lens. Explanatory drawing of the light ray which comes out from the point ((delta) = W / 2) of an image surface at the time of using a spherical lenticular lens. Sectional drawing of the conventional image display apparatus. Sectional drawing of the panel in the case of displaying a stereo image in the conventional image display apparatus. Sectional drawing of the panel in the case of displaying the planar image in the conventional image display apparatus. The figure explaining analytically the principle of the stereoscopic image display in the conventional image display apparatus. The simulation result in the conventional image display apparatus. Explanatory drawing of the substantially parallel leak light in the conventional image display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Concave cylindrical lens panel 102 Convex cylindrical lens panel 103 Image display part 104 Transparent panel 201 Concave cylindrical lens panel 202 Convex cylindrical lens panel 203 Image surface 204 Lens centerline 205 Substantially parallel light 206 Substantially parallel light 207 Non-parallel light 208 Non-parallel light 209 Eye 210 Substantially parallel light with low intensity 211 Substantially parallel light with low intensity 212 Substantially parallel light 213 Substantially parallel light 214 Leakage light 215 Leakage light 901 Spherical lens 902 Aspherical lens 903 Lens center line 1001 Transparent plate 1002 Transparent plate 1003 Image plane 1004 Lens center line 1005 High refractive index resin lens portion 1006 High refractive index resin lens portion 1401 Concave cylindrical lens panel 1402 Convex cylindrical lens panel 1403 Image plane 1 04 lens center line 1405 substantially parallel light 1406 substantially parallel light 1407 non-parallel light 1410 light for determining the viewing angle 1701 spherical lens 1702 elliptic lens 1703 hyperbolic lens 1704 fourth-order even function lens 1901 transparent plate 1902 transparent plate 1903 image plane 1904 lens center Line 1905 High refractive index resin lens portion 1906 High refractive index resin lens portion 2201 Concave cylindrical lens panel 2202 Convex cylindrical lens panel 2203 Stopper 2204 Ultraviolet lamp 2205 Ultraviolet 2401 Concave cylindrical lens panel 2402 Convex cylindrical lens panel 2403 Conductive thin film 3101 Image display device 3102 Display unit for switching between stereoscopic image and planar image 3103 Display surface for displaying planar image 3201 Single lens 3202 Lens 3301 Transparent plate 3302 High refractive index resin 3303 Mold 3304 Ultraviolet lamp 3305 Ultraviolet 3401 Cylindrical lens 3501 Lenticular lens 3502 Image display unit 3503 Transparent panel 3601 Subject 3602 Camera 3603 Camera 3604 Camera 3605 Camera 3606 Camera 3701 Composite multi-viewpoint image 3702 Image taken by 3602 3703 Image taken by camera 3603 3704 Image taken by camera 3604 3705 Image taken by camera 3605 3706 Image taken by camera 3606 3801 Cylindrical lens 3802 Image plane 3803 Multi-viewpoint image 3804 Right eye 3805 Left eye 3806 Substantially parallel light 3807 Substantially parallel light 3808 Substantially parallel light 3809 Substantially parallel light 4001 Cylindrical lens 4002 Image surface 4003 Lens center line 4004 Eye 4005 Substantially parallel light 4006 Substantially parallel light 4007 Non-parallel light 4008 Substantially parallel light 4009 Substantially parallel light 4010 Light with low intensity 4501 Convex cylindrical lens panel 4502 Concave cylindrical lens panel 4503 Image display Part 4504 Transparent panel 4601 Convex cylindrical lens panel 4602 Concave cylindrical lens panel 4603 Image plane 4604 Lens center line

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)

  FIG. 1 is a cross-sectional view of an image display device capable of switching between a planar image and a stereoscopic image according to the present invention. In FIG. 1, 101 is an array of concave cylindrical lenses, 102 is an array of convex cylindrical lenses, 103 is an image display unit, and 104 is a transparent panel. FIG. 1 shows a structure in which an array 101 of concave cylindrical lenses is bonded to a general display including an image display unit 103 and a transparent panel 104. The concave cylindrical lens and the convex cylindrical lens are arranged to face each other.

  FIG. 2 is a cross-sectional view of a panel when a stereoscopic image is displayed using the image display device of the present invention, and FIG. 3 is a cross-sectional view of the panel when a flat image is displayed using the image display device of the present invention. FIG. If the concave cylindrical lens 101, the convex cylindrical lens 102, and the transparent panel 104 of FIG. 1 are made of general glass or resin, their refractive indexes are approximately the same. In that case, 101 and 104 can be handled optically as one. 2 and 3, 201 is an integrated concave cylindrical lens, 202 is a convex cylindrical lens, and 203 is an image plane.

  In FIG. 2, the concave cylindrical lens panel 201 and the convex cylindrical lens panel 202 are arranged with an appropriate interval. A multi-viewpoint image is displayed on the image plane 203. Light emitted from a point on the image plane 203 is emitted from the concave cylindrical lens panel 201 as divergent light and enters the convex cylindrical lens panel 202. The light becomes substantially parallel light by the convex cylindrical lens panel 202 and is further emitted from the convex cylindrical lens panel 202 as substantially parallel light. A stereoscopic image can be recognized in the same manner as in the conventional lenticular lens shown in FIGS. 38, 39, and 45.

  In FIG. 3, the concave cylindrical lens panel 201 and the convex cylindrical lens panel 202 are arranged in close contact or very close to each other. A general plane image is displayed on the image plane 203. The light emitted from the point on the image plane 203 passes through the concave cylindrical lens panel 201 and the convex cylindrical lens panel 202 with almost no change in the traveling direction thereof, and is emitted from the convex cylindrical lens panel 202 as emitted light. The concave cylindrical lens panel 201 and the convex cylindrical lens panel 202 are combined to behave like a single transparent plate, and a general planar image can be recognized.

  A distance between the concave cylindrical lens panel and the convex cylindrical lens panel to determine a good stereoscopic image can be analytically described with reference to FIG. 4, the same reference numerals are used for the same components as those in FIGS. 2 and 3. Let T be the distance from the image plane 203 to the bottom of the concave cylindrical lens. In FIG. 4, a spherical cylindrical lens is used, and its spherical radius is R. The distance between the concave cylindrical lens panel 201 and the convex cylindrical lens panel 202 is D, and the width of one cylindrical lens is W. Further, the refractive index of the medium of the concave cylindrical lens panel 201 and the convex cylindrical lens panel 202 is n. Let P1 be the point at which light emitted from a point on the image plane 203 at a distance δ from the lens center line 204 is incident on the concave cylindrical lens surface, and P2 be the point at which the light is incident on the convex cylindrical lens surface.

The distance X1 of the point P1 from the lens center line 204 is represented by (Equation 36), and the angle θ of the light ray from the point of interest on the image plane toward the point P1 is obtained by (Equation 37). Further, the incident angle α to the concave cylindrical lens surface is obtained by (Equation 38), and the angle β is obtained by (Equation 39) from the law of refraction. The distance X2 from the lens center line 204 of the incident point P2 to the convex cylindrical lens is expressed by (Equation 40). (Equation 41) represents the relationship of angles, and the angle χ is obtained by (Equation 42) from the law of refraction. From the law of refraction in the plane, the exit angle ν is determined by (Equation 43). Also, (Equation 40) can be rewritten as (Equation 44).
(Equation 36) X1 = R · sinφ
Tan θ = (δ−X1) / (T + R−R · cos φ)
(Equation 38) α = φ−θ
(Equation 39) sin β = n · sin α
(Equation 40) X2 = R · sinφ = R · sinφ
− (D + R · cos φ−R · cos φ) · tan (φ−β)
(Equation 41) β−φ + ψ−γ = 0
(Formula 42) sinγ = n · sin (ψ−χ)
(Expression 43) sinν = n · sinχ
(Equation 44) R · sin (φ−φ + β) = R · sin β−D · sin (φ−β)

  Given a point on the image plane (distance δ from the lens center line 204) and a refraction point P1 (distance X1 from the lens center line 204) of the convex cylindrical lens surface, (Equation 36) through (Equation 39), (Equation 44) ) And (Equation 41) to (Equation 43), φ, θ, α, β, ψ, γ, χ, and ν are obtained in order, and the direction of the light emitted from the convex cylindrical lens panel 202 is obtained.

First, consider paraxial approximation with a small ray angle. In this paraxial approximation, (Equation 36) through (Equation 39), (Equation 44), and (Equation 41) through (Equation 43) are expressed as (Equation 45) through (Equation 52), respectively.
(Equation 45) X1 = Rφ
(Equation 46) θ = (δ−X1) / T
(Equation 47) α = φ−θ
(Equation 48) β = nα
(Equation 49) R (ψ−φ + β) = Rβ−D (φ−β)
(Equation 50) β−φ + ψ−γ = 0
(Equation 51) γ = n (ψ−χ)
(Equation 52) ν = nχ

From these (Equation 45) to (Equation 52), the paraxial approximate emission angle ν is expressed by (Equation 53). The condition that the lenticular lens effect, that is, the light emitted from a point on the image plane (distance δ from the lens center line) becomes substantially parallel light with a constant emission angle is that ν does not depend on θ, which is Is the case. The emission angle at that time is given by (Expression 55).
(Formula 53) ν = (n−1) ² (D / R) (δ / R)
− [(N−1) {(n−1) (T / R) + n} (D / R) −n] θ
(Formula 54) D = nR / [(n-1) {(n-1) (T / R) + n}]
(Expression 55) ν = (n−1) ² (D / R) (δ / R)

When the lens medium is general glass or resin, the refractive index n is about 1.5, the distance T from the image surface to the bottom of the concave cylindrical lens, and the distance between the concave cylindrical lens panel 201 and the convex cylindrical lens panel 202. D satisfies the relational expression of (Equation 56), and light emitted from a point on the image plane (distance δ from the lens center line) is emitted from the convex cylindrical lens panel 202 as substantially parallel light, and its angle ν is expressed by (Equation 57). It becomes.
(Equation 56) D = 6R / [(T / R) +3]
(Expression 57) ν = δD / (4R ² )

  Next, a general case is simulated using (Equation 36) to (Equation 39), (Equation 44), and (Equation 41) to (Equation 43). For example, in FIG. 4, R = 1, T = 1, D = 1.5, n = 1.5, and W = 1.5. These conditions satisfy (Equation 54). FIG. 5 shows the result of the simulation. The horizontal axis represents the position (X1) where light emitted from a point on the image surface enters the concave cylindrical lens surface, and the vertical axis represents the emission angle (ν) from the convex cylindrical lens panel. As a point on the image plane (distance δ from the lens center line 204), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. The light flux from each point on the image plane toward the concave cylindrical lens is emitted from the central portion of the light flux as approximately parallel light from the convex cylindrical lens panel, but the light in the peripheral portion of each light flux It becomes non-parallel light. As for the light beam from the point (δ> W / 2) on the image plane corresponding to the adjacent cylindrical lens, the light at each central portion becomes substantially parallel light, but the light at each peripheral portion becomes non-parallel light.

  These non-parallel lights have a large change in the emission angle ν with respect to the horizontal axis (incident position X1 on the lens surface), and the amount of light when viewed from a specific emission angle is small. That is, when the convex cylindrical lens panel and the concave cylindrical lens panel are viewed from one direction, the intensity of these non-parallel lights is small and almost parallel lights are seen.

  As an example, light emitted from a point on the image plane (distance W / 4 from the lens center line 204) will be described with reference to FIG. In FIG. 6, the same components as those in FIGS. The light at the center of the light beam, that is, the light surrounded by the light ray 205 (solid line) and the light ray 206 (solid line) is emitted from the convex cylindrical lens panel 202 as substantially parallel light having an angle of 0.14 radians. Light in the peripheral portion of the light beam, such as light ray 207 (wave line) and light ray 208 (wave line), is emitted as non-parallel light from the convex cylindrical lens panel 202.

  Next, an image when the concave cylindrical lens panel and the convex cylindrical lens panel are viewed from an angle of 0.14 radians will be described with reference to FIG. In FIG. 7, the same components as those in FIG. Reference numeral 209 denotes an eye having an angle of 0.14 radians. In FIG. 7, the eye 209 is drawn so as to be near the panel, but is actually far in the direction of the arrow. As can be seen from FIG. 5, most of the light from the point on the image plane (distance W / 4 from the lens center line 204) has an emission angle of 0.14 radians. These are the light in the area surrounded by the light ray 205 (solid line) and the light ray 206 (solid line) in FIGS. On the other hand, among the light emitted from the points on the lens center line 204, a light ray 210 (wave line) passing through the periphery of the concave cylindrical lens is also emitted with an angle of 0.14 radians, and the distance from the lens center line 204 is W. Of the light emitted from the point on the image plane of / 2, the light ray 211 (wavy line) is also emitted with an angle of 0.14 radians. The light ray 210 and the light ray 211 are generated in a very narrow range as compared with the substantially parallel light surrounded by the light ray 205 and the light ray 206, the light amount is small, and there is no big problem in the deterioration of image quality. That is, when the concave cylindrical lens panel and the convex cylindrical lens panel are viewed from the direction of an angle of 0.14 radians, only the image near the point of δ = W / 4 is almost viewed.

  Images from many viewpoints are displayed on the image plane corresponding to one cylindrical lens. Among these multi-viewpoint images, adjacent images have a strong correlation with each other, and even if they are mixed, it does not pose a big problem for image quality degradation. However, the image near the boundary between adjacent cylindrical lenses has a low correlation, and when they are mixed, the image quality deteriorates. Accordingly, among the light emitted from the boundary point (δ = W / 2) between adjacent cylindrical lenses and emitted from the convex cylindrical lens panel, the light having a relatively high intensity and the smallest emission angle has the viewing angle of the stereoscopic image. It will be decided. The viewing angle in the case of FIG. 5 is approximately ± 0.28 radians (± 16 degrees).

  In Embodiment 1 of this invention, the space | interval of a concave cylindrical lens panel and a convex cylindrical lens panel is comparatively large. Therefore, when paying attention to one convex cylindrical lens, the light emitted from the point on the image plane corresponding to the adjacent cylindrical lens is refracted by the lens surface of the adjacent concave cylindrical lens and leaks to the focused convex cylindrical lens. Come. FIG. 8 shows the state of light leakage.

  In FIG. 8, the same components as those in FIGS. In the light ray 212 (solid line) and the light ray 213 (solid line), light emitted from a point (δ = W / 2) on the image plane corresponding to the boundary between adjacent cylindrical lenses is emitted from the convex cylindrical lens panel 202 as substantially parallel light. To do. A light ray 214 (dashed line) exits from a point (δ = W / 2) on the image plane corresponding to the boundary between adjacent cylindrical lenses, and refracts and leaks at the lens surface of the adjacent concave cylindrical lens. However, the emission angle of the light ray 214 from the convex cylindrical lens panel is larger than the emission angles of the light ray 212 and the light ray 213 and is outside the viewing angle. The light ray 215 (wave line) exits from a point (δ = 3W / 4) on the image plane corresponding to the adjacent cylindrical lens and is refracted and leaks from the lens surface of the adjacent concave cylindrical lens. Again, the emission angle of the light ray 215 is larger than the emission angles of the light ray 212 and the light ray 213 and is outside the viewing angle.

As described above, in the first embodiment of the present invention, there is light that exits from a point on the image surface corresponding to the adjacent cylindrical lens and is refracted and leaks at the adjacent concave cylindrical lens surface. It is emitted outside the viewing angle and does not affect the image within the viewing angle. It can be seen that a stereoscopic image having a larger viewing angle than the conventional example can be provided.
(Expansion of viewing angle)

  The viewing angle of Embodiment 1 of the present invention is ± 0.28 radians (± 16 degrees). The first method for enlarging the viewing angle is to increase the width W of the cylindrical lens. However, if the cylindrical lens shape is spherical, increasing the lens width W increases the curved surface gradient around the lens, greatly changes the angle of the light beam refracted on the lens surface, and the emitted light is not substantially parallel light. Therefore, the effect of increasing the lens width does not appear in the spherical lens.

  Therefore, an aspherical surface is used for the lens shape. FIG. 9 is a diagram for explaining a cylindrical lens shape. In FIG. 9, reference numeral 901 (dashed line) denotes a spherical lens shape, 902 denotes an aspheric lens shape, and 903 denotes a lens center line. The characteristics of the aspheric lens shape 902 will be described. Near the lens center line 903, paraxial approximation needs to be satisfied, and the shape 902 can approximate a spherical surface. FIG. 9 shows a case where the radius of curvature at the lens center line of the spherical lens 901 and the aspherical lens 902 is the same, the center of the curved surface is O1, and the radius of curvature is an interval R1 between Q1 and O1. As the distance from the lens center line 903 increases, the gradient of the lens shape 902 becomes smaller than the gradient of the spherical lens shape 901. That is, the radius of curvature of the lens shape increases as the distance from the lens center line 903 increases. The center of the curved surface near the point Q2 is O2, and the radius of curvature is an interval R2 between Q2 and O2. The center of the curved surface near the point Q3 is O3, and the radius of curvature is an interval R3 between Q3 and O3. The curvature radius R2 near the point O2 is larger than the curvature radius R1 near the point O1, and the curvature radius R3 near the point O3 is larger than the curvature radius R2 near the point O2.

  The second method of enlarging the viewing angle is to increase the refractive index n of the medium of the concave cylindrical lens panel and the convex cylindrical lens panel. This can be understood from (Equation 55) of the first embodiment.

  Some high refractive index glasses have a refractive index greater than 1.8. However, a process such as molding is used for manufacturing the panel. Glass molding is expensive, and the glass may break. A resin having a low production cost and a high refractive index is desired. As such a resin, a “nanocomposite resin” in which fine particles having a high refractive index are dispersed is used. An ultraviolet curable resin is used as the base material resin, and fine particles of a dielectric such as titanium oxide, zirconium oxide, zinc oxide, or aluminum oxide having a diameter of 10 nanometers or less are used as the fine particles. A resin having a refractive index of about 1.7 can be synthesized by dispersing one kind or two or more kinds of dielectric fine particles.

  However, if fine particles are mixed in the resin, the transmittance decreases due to scattering by the fine particles. Therefore, when such a nanocomposite resin is used, the smallest possible resin thickness is desired. FIG. 10 shows a configuration in which a high refractive index resin is used only for the cylindrical lens portion. In FIG. 10, 1001 and 1002 are transparent plates such as polycarbonate resin, and 1003 is an image plane. Reference numeral 1004 denotes a lens center line, and reference numerals 1005 and 1006 denote lens portions made of a high refractive index resin such as a nanocomposite resin. By reducing the thickness of the nanocomposite resin, the transmittance can be prevented from decreasing, and the refractive index of the lens portion can be increased to obtain a stable stereoscopic image having a large viewing angle.

  The method for enlarging the first and second viewing angles is analyzed with reference to FIG. In FIG. 11, the same components as those in FIG. The refractive indexes of the transparent plate 1001 and the transparent plate 1002 are n1, and the refractive indexes of the high refractive index resin lens portions 1005 and 1006 are n2. The space between the concave cylindrical lens and the convex cylindrical lens is air, and the refractive index is n = 1. The thickness of the transparent plate 1001 is C, and the thickness from the boundary between the transparent plate and the high refractive index resin lens portion 1005 to the bottom of the concave cylindrical lens is H. In the first embodiment, the transparent plate and the lens portion have the same medium, and T = C + H. The distance between the concave cylindrical lens and the convex cylindrical lens is D, the width of one cylindrical lens is W, and the radius of curvature near the lens center line 1004 is R.

  P1 is a point at which light emitted from a point on the image plane 1003 at a distance δ from the lens center line 1004 enters the boundary between the transparent plate 1001 and the high refractive index resin lens unit 1005, and the light enters the surface of the concave cylindrical lens. Let the point be P2. Next, let P3 be a point where light refracted on the surface of the concave cylindrical lens is incident on the surface of the convex cylindrical lens, and let P4 be a point where the light is incident on the boundary between the high refractive index resin lens part 1006 and the transparent plate 1002. Thereafter, the light is emitted from the surface of the transparent plate 1002.

  Although FIG. 11 shows an example in which the image surface 1003 side is a concave cylindrical lens, even if the image surface 1003 side is a convex cylindrical lens, it can be analyzed using FIG. In this case, the thickness from the boundary between the transparent plate and the high refractive index resin lens portion to the top of the convex cylindrical lens is H. Whether the image surface side is a concave cylindrical lens or a convex cylindrical lens, the lens shape on the image surface 1003 side is represented by F (X), and the facing lens shape is represented by F (X) + D. By appropriately setting this function F (X), a concave cylindrical lens or a convex cylindrical lens can be represented, and the shape of a spherical lens or an aspherical lens can also be represented.

The angle θ of the light ray from the point on the image plane to the point P1 (Q, C) is obtained by (Equation 58), and the angle α refracted and emitted at the point P1 is obtained by (Equation 59). The light ray emitted from the point P1 is expressed by (Equation 60), and the X coordinate (X2) of the point P2 is obtained by solving the equation (Equation 61). The gradient of the lens curved surface at the point P2 is a differential coefficient of the function F (X) and is obtained by (Equation 62). The incident angle β to the lens curved surface [F (X)] is obtained by (Equation 63), and the exit angle γ is obtained by (Equation 64) from the law of refraction. A light ray traveling from the point P2 to the point P3 is expressed by (Equation 65). The X coordinate (X3) of the point P3 is obtained by solving the equation (Equation 66). The gradient of the lens curved surface at the point P3 is a differential coefficient of the function [F (X) + D] and is obtained by (Equation 67). The incident angle φ to the lens curved surface [F (X) + D] is obtained by (Equation 68), and the emission angle ψ is obtained by (Equation 69) from the law of refraction. The incident angle ξ to the point P4 is obtained by (Equation 70), and the exit angle ζ is obtained by (Equation 71) from the law of refraction. The exit angle ν from the panel is obtained by (Equation 72).
(Equation 58) tan θ = (δ−Q) / C
(Formula 59) n2 · sin α = n1 · sin θ
(Equation 60) YC =-(XQ) · cot α
(Equation 61) C− (X−Q) · cot α = F (X)
Tan κ = dF (X) / dX (X = X2)
(Equation 63) β = κ−α
(Expression 64) sin γ = n 2 · sin β
(Equation 65) YF (X2) =-(X-X2) .cot (κ-γ)
(Equation 66) F (X2)-(X-X2) .cot (κ-γ) = G (X)
(Equation 67) tanτ = dG (X) / dX (X = X3)
(Equation 68) φ = τ− (κ−γ)
(Equation 69) n2 · sinψ = sinφ
(Equation 70) ξ = τ−ψ
(Equation 71) n1 · sinζ = n2 · sinξ
(Expression 72) sinν = n1 · sinζ

  If a point on the image plane (distance δ from the lens center line 1004) and a refraction point P1 (distance X1 from the lens center line 1004) at the boundary between the transparent plate 1001 and the high refractive index resin lens portion 1005 are given, (Equation 58) From (Equation 72), θ, α, κ, β, γ, τ, φ, ψ, ξ, ζ, and ν are obtained in order, and the direction of the light emitted from the transparent plate 1002 is obtained.

First, consider paraxial approximation with a small angle. The function F (X) representing the lens shape is approximated by (Equation 73). Further, in the vicinity of the lens center line 1004, the lens shape is well approximated to a spherical surface, so the curvature is (1 / R), and the differential coefficient [dF (X) / dX] representing the gradient is expressed by (Equation 74). Is done. Here, σ has a value of (+1) or (−1) depending on the sign of the gradient. When the image surface 1003 side is a concave cylindrical lens as in the first embodiment, the gradient near the lens center line is positive and σ = + 1. When the image surface 1003 side is a convex cylindrical lens, the gradient near the lens center line is negative and σ = −1.
(Expression 73) F (X) = C + H
(Expression 74) dF (X) / dX = σ (X / R)

Using these, in the paraxial approximation, (Equation 58) through (Equation 72) are approximated as (Equation 75) through (Equation 89), respectively.
(Equation 75) θ = (δ−Q) / C
(Equation 76) n2 · α = n1 · θ
(Equation 77) YC =-(XQ) / α
(Formula 78) C- (X2-Q) / α = C + H
(Equation 79) κ = (σ / R) · (X2)
(Equation 80) β = κ−α
(Equation 81) γ = n2 · β
(Equation 82) Y− (C + H) = − (X−X2) / (κ−γ)
(Expression 83) C + H− (X3−X2) / (κ−γ) = C + H + D
(Equation 84) τ = (σ / R) · (X3)
(Equation 85) φ = τ− (κ−γ)
(Equation 86) n2 · ψ = φ
(Equation 87) ξ = τ−ψ
(Equation 88) n1 · ζ = n2 · ξ
(Equation 89) ν = n1 · ζ

The lenticular lens effect, that is, the condition that light emitted from a point on the image plane (distance δ from the lens center line 1003) becomes substantially parallel light with a constant emission angle is that ν does not depend on θ. At least, the paraxial approximation needs to satisfy the lenticular effect well. In this case, the distance D between the two lens surfaces is given by (Equation 90) and (Equation 91).
(Equation 90) D = n1, n2, R / Δ
(Equation 91) Δ = (n2-1) [(n2-1) (n1 · H + n2 · C) / R
+ Σ · n1 · n2]

As in the conventional example (Patent Document 1), in a configuration in which the side close to the image surface is a convex cylindrical lens and the light emission side is a concave cylindrical lens, n1 = n2 = n, C + H = T, and σ = −1. (Equation 90) and (Equation 91) are the same as (Equation 32). Further, as in the first embodiment, in the configuration in which the side close to the image surface is a concave cylindrical lens and the light emission side is a convex cylindrical lens, n1 = n2 = n, C + H = T, and σ = + 1, ) And (Equation 91) are the same as (Equation 54).
(Embodiment 2)

Embodiment 2 of the present invention is a case where the aspherical lens shape is an ellipse and can be approximated well. The elliptic function is expressed by (Equation 92), and m is a coefficient that specifies the shape of the ellipse.
(Equation 92) F (X) = C + H + (mR) − [(mR) ² −m · X ² ] ^1/2

  In the second embodiment, the transparent plate and the lens unit are integrated, and polycarbonate resin is used. In FIG. 11, it is assumed that n1 = n2 = 1.57, R = 1, m = 3, C = 3, H = 0, D = 0.84, and W = 2.6. These values satisfy the conditions (Equation 90) and (Equation 91). FIG. 12 shows the result of simulation using (Formula 58) to (Formula 72). (Equation 61) and (Equation 66) are quadratic equations of X, and a solution can be obtained algebraically. The horizontal axis is the position (X1) where the light emitted from the point on the image plane enters the virtual boundary surface between the transparent plate and the lens unit, and the vertical axis is the angle (ν) emitted from the convex cylindrical lens panel. As the points on the image plane (distance δ from the lens center line 1004), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. The light behavior is similar to FIG. 5, but the viewing angle is ± 0.35 radians (± 20 degrees). In Embodiment 2, by making the lens shape an ellipse, the width W of the cylindrical lens can be made larger than the spherical surface, and the viewing angle can be enlarged. However, the ellipse is a closed curve like the spherical surface, and if the width W is made too large, the gradient around the lens will increase as with the spherical surface, the angle of the light beam refracted on the lens surface will change greatly, and the emitted light will be substantially parallel light. Disappear. Therefore, the elliptical shape has a limit on the effect of increasing the lens width.

In Embodiment 1 of the present invention, when paying attention to one convex cylindrical lens, the light emitted from the point of the image surface corresponding to the adjacent cylindrical lens is refracted by the lens surface of the adjacent concave cylindrical lens, and attention is paid. Leak into the convex cylindrical lens. In the second embodiment of the present invention, light leaks, but the leaked light is outside the viewing angle as in the first embodiment.
(Embodiment 3)

Embodiment 3 of the present invention is a case where the aspherical lens shape can be approximated by a hyperbola. The hyperbolic function is expressed by (Equation 93), and m is a coefficient that specifies the shape of the hyperbola.
(Equation 93) F (X) = C + H− (mR) + [(mR) ² + m · X ² ] ^1/2

  In the third embodiment, the transparent plate and the lens unit are integrated and polycarbonate resin is used. In FIG. 11, n1 = n2 = 1.57, R = 1, m = 3, C = 3, H = 0, D = 0.84, and W = 4.5. These values satisfy the conditions (Equation 90) and (Equation 91). FIG. 13 shows the result of simulation using (Formula 58) to (Formula 72). (Equation 61) and (Equation 66) are quadratic equations of X, and a solution can be obtained algebraically. The horizontal axis is the position (X1) where the light emitted from the point on the image plane enters the virtual boundary surface between the transparent plate and the lens unit, and the vertical axis is the angle (ν) emitted from the convex cylindrical lens panel. As the points on the image plane (distance δ from the lens center line 1004), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be seen from FIG. Of the light beam traveling from the lens center line (δ = 0) of the image plane to the concave cylindrical lens, when entering the range (−0.3 to +0.3) of the lens surface, it is substantially parallel light having an angle ν = 0. When the light is emitted from the convex cylindrical lens panel and enters the lens surface outside the range (−0.3 to +0.3), the light becomes non-parallel light. The light emitted from a point on the image plane (δ = W / 4) at a distance W / 4 from the lens center line is approximately at an angle ν = 0.0 when entering the lens surface range (+0.2 to +0.9). When the light is emitted from the convex cylindrical lens panel as substantially parallel light having 27 and enters the lens surface in the range (0 to +0.2), the light becomes non-parallel light. However, the angle at which light emitted from a point on the image plane (δ = W / 2) near the boundary between adjacent cylindrical lenses changes from the convex cylindrical lens panel depending on the incident position of the lens surface. When entering the lens surface range (+0.3 to +0.5), the exit angle changes abruptly. When entering the lens surface range (+0.5 to +1.5), the exit angle is v = It changes gradually from 0.59 to ν = 0.42.

  The light emitted from a point (δ = W / 4) on the image plane will be described with reference to FIG. In FIG. 14, reference numeral 1401 denotes a panel made of an array of concave cylindrical lenses, 1402 a panel made of an array of convex cylindrical lenses, 1403 an image plane, and 1404 a lens center line. Of the light emitted from the point (δ = W / 4) on the image plane, the range surrounded by the light beam 1405 (solid line) and the light beam 1406 (solid line) is substantially parallel light having an angle of 0.27 radians from the convex cylindrical lens panel 1402. Is emitted. However, the light incident in the vicinity of the lens center line 1404 becomes non-parallel light, and the emission angle changes rapidly. FIG. 14 shows a light beam 1407 (dashed line). In FIG. 13, the non-parallel light has a large change in the emission angle (ν) with respect to the horizontal axis (X1), and the amount of light is small, which does not cause a problem in image quality degradation.

  Next, the light emitted from the boundary point (δ = W / 2) between adjacent cylindrical lenses will be described with reference to FIG. In FIG. 15, the same components as those in FIG. The light incident on the lens surface range (+0.6 to +1.5) has an emission angle of ν = 0.59 radians to ν as shown by a ray 1408 (solid line), a ray 1409 (solid line), and a ray 1410 (solid line). = Slowly changes to 0.42 radians. However, the emission angle of light incident on the lens surface range (+0.3 to +0.5) changes abruptly. FIG. 15 shows a light ray 1411 (dashed line) as an example.

  Images from many viewpoints are displayed on the image plane corresponding to one cylindrical lens. Of these multi-viewpoint images, the adjacent images are images taken by the adjacent cameras in FIG. 36, and have a strong correlation with each other. However, the image near the boundary between adjacent cylindrical lenses is, for example, an image captured by the cameras 3602 and 3606 in FIG. 36, and the correlation is low. Therefore, the smallest exit angle of the light exiting from the boundary between adjacent cylindrical lenses and exiting from the convex cylindrical lens panel with a relatively high intensity determines the viewing angle. The light ray 1411 (broken line) in FIG. The viewing angle is determined by the light ray 1410 (solid line), and the viewing angle is ± 0.42 radians (± 24 degrees). It can be seen that the viewing angle can be expanded by making the lens shape an aspherical surface.

In Embodiment 1 of the present invention, when attention is paid to one convex cylindrical lens, the light emitted from a point on the image surface corresponding to the adjacent cylindrical lens is refracted by the lens surface of the adjacent concave cylindrical lens, and attention is paid. Leak into the convex cylindrical lens. However, in the combination of the hyperbolic lens shapes C and D as in the third embodiment of the present invention, light leakage like the light rays 214 and 215 in FIG. 8 hardly occurs.
(Embodiment 4)

  In the second embodiment, the lens shape is an ellipse and the emitted light is substantially parallel light, but there is a limit to the expansion of the viewing angle. In addition, when the lens shape is a hyperbola, the viewing angle can be enlarged, but the emitted light is slightly divergent. Although a stereoscopic view is possible even with divergent light as shown in FIG. 15, it is still better to be closer to parallel light. Therefore, a quartic even function is conceivable as the lens shape between the ellipse and the hyperbola.

Embodiment 4 of the present invention is a case where the aspheric lens shape can be approximated by a quaternary even function. The fourth-order even function is expressed by (Equation 94), and (ρW) is the X coordinate of the inflection point of the fourth-order even function.
(Equation 94) F (X) =-[1 / {12R (ρW) ² }] · X ⁴
+ [1 / (2R)] · X ²

  In the fourth embodiment, the transparent plate and the lens unit are integrated, and polycarbonate resin is used. In FIG. 11, n1 = n2 = 1.57, R = 1, ρ = 1.5, C = 3, H = 0, D = 0.84, and W = 4.5. These values satisfy the conditions (Equation 90) and (Equation 91). FIG. 16 shows the result of simulation using (Formula 58) to (Formula 72). (Equation 61) and (Equation 66) are X quaternary equations, and a solution can be obtained algebraically using the Ferrari solution. The horizontal axis is the position (X1) where the light emitted from the point on the image plane enters the virtual boundary surface between the transparent plate and the lens unit, and the vertical axis is the angle (ν) emitted from the convex cylindrical lens panel. As the points on the image plane (distance δ from the lens center line 1004), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. The behavior of the light is similar when the lens shape is a quartic even function (FIG. 16) and the case of a hyperbola (FIG. 15), but the quaternary even function lens emits more parallel light than the hyperbolic lens. close. The viewing angle can be expanded to ± 0.52 radians (± 30 degrees).

  In the fourth embodiment of the present invention, as in the third embodiment, the light emitted from the point on the image plane corresponding to the adjacent cylindrical lens is refracted by the lens surface of the adjacent concave cylindrical lens, and the convex cylindrical lens of interest is focused. Little light leaks into the lens.

  In the first to fourth embodiments, the case where the lens shape can be well approximated to a spherical surface, an ellipse, a hyperbola, and a quartic even function has been described. FIG. 17 is a diagram comparing these shapes. In FIG. 17, 1701 is the spherical surface of the first embodiment, 1702 is the ellipse of the second embodiment, 1703 is the hyperbola of the third embodiment, and 1704 is the fourth-order even function of the fourth embodiment. In the first embodiment, T = 1, and in the second to fourth embodiments, C = 3 (H = 0). The radius of the curved surface in the vicinity of each lens center line is the same and R = 1. It can be seen that the quaternary even function 1704 is intermediate between the ellipse 1702 and the hyperbola 1703, and the lens width can be increased similarly to the hyperbola.

In the second to fourth embodiments, the case where the lens shape can be well approximated to an ellipse, a hyperbola, and a quartic even function has been described, but the present invention is not limited thereto. For example, a combination of an ellipse and a hyperbola, or a combination of a hyperbola and a quartic even function may be used. Other aspherical lens shapes may be used as long as the viewing angle is large and the range in which substantially parallel light is obtained can be increased.
(Embodiment 5)

  Embodiment 5 of the present invention uses a high refractive index resin only for the lens portion. Further, the shape of the aspherical lens can be well approximated by a fourth order even function as in the fourth embodiment. The fourth order even function is expressed by (Equation 94).

  In Embodiment 5, a polycarbonate resin is used for the transparent plate, and a nanocomposite resin having a refractive index of 1.7 is used for the lens portion. In FIG. 11, n1 = 1.57, n2 = 1.7, R = 1, ρ = 1.5, C = 3, H = 0, D = 0.84, and W = 4.5. These values satisfy the conditions (Equation 90) and (Equation 91). FIG. 18 shows the result of simulation using (Formula 58) to (Formula 72). (Equation 61) and (Equation 66) are X quaternary equations, and a solution can be obtained algebraically using the Ferrari solution. The horizontal axis represents the position (X1) where light emitted from a point on the image plane enters the boundary surface between the transparent plate and the lens portion, and the vertical axis represents the angle (ν) emitted from the convex cylindrical lens panel. As the points on the image plane (distance δ from the lens center line 1004), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. In the fourth and fifth embodiments, the lens shape can be approximated by a quartic even function, and the behavior of light is very similar. However, since the high refractive index resin is used only for the lens portion, the viewing angle can be enlarged, and becomes ± 0.58 radians (± 33 degrees).

In the fifth embodiment of the present invention, as in the third and fourth embodiments, the light emitted from the point on the image plane corresponding to the adjacent cylindrical lens is refracted by the lens surface of the adjacent concave cylindrical lens, and attention is paid. There is almost no light leaking into the convex cylindrical lens.
(Embodiment 6)

  In an image display device (Patent Document 1) that can switch between a stereoscopic image and a planar image of a conventional example, the panel closer to the image plane is a convex cylindrical lens panel, and the light emission side is a concave cylindrical lens panel. In this conventional example, the distance between the panel of the convex cylindrical lens and the panel of the concave cylindrical lens (D in FIG. 48) is the extent of the focal length of these lenses. In this case, as shown in FIG. 50, the light emitted from the point on the image plane corresponding to the adjacent convex cylindrical lens is refracted by the lens surface of the adjacent convex cylindrical lens, and the focused concave cylindrical lens is obtained. Leaks. The leaked light is mixed as substantially parallel light having the same emission angle, and the image quality is deteriorated.

  FIG. 19 shows a general configuration of the configuration of the convex cylindrical lens panel closer to the image plane and the light emission side of the concave cylindrical lens panel. In FIG. 19, 1901 and 1902 are transparent plates such as polycarbonate resin, and 1903 is an image plane. Reference numeral 1904 denotes a lens center line, and reference numerals 1905 and 1906 denote lens portions made of a high refractive index resin such as a nanocomposite resin. The configuration as shown in FIG. 19 can also be analyzed using FIG. However, the function representing the lens shape in FIG. 11 is upside down from the first to fifth embodiments.

  If the distance between the panel of the convex cylindrical lens and the panel of the concave cylindrical lens is reduced, and an aspherical surface is used as the lens shape, it will come out of the point of the image surface corresponding to the adjacent convex cylindrical lens, and the adjacent convex cylindrical lens The light that is refracted on the lens surface and leaks to the concave cylindrical lens of interest is reduced, and the viewing angle can be increased.

Embodiment 6 of the present invention is a case where the aspherical lens shape can be approximated well by a quartic even function in the configuration of FIG. The quaternary even function in this case is upside down from the quaternary even function of the fourth embodiment, and is represented by (Equation 95). Here, (ρW) is an inflection point of the fourth order even function.
(Equation 95) F (X) = [1 / {12R (ρW) ² }] · X ⁴
-[1 / (2R)] · X ²

  In the sixth embodiment, the transparent plate and the lens unit are integrated, and polycarbonate resin is used. In FIG. 11, n1 = n2 = 1.57, R = 1, ρ = 1.5, C = 6.23, H = 0.77, D = 1.1, W = 2.5, σ = −1 And Here, H is the distance from the boundary between the transparent plate 1001 and the lens unit 1005 in FIG. 11 to the top of the lens. These values satisfy the conditions (Equation 90) and (Equation 91). FIG. 20 shows the result of simulation using (Formula 58) to (Formula 72). (Equation 61) and (Equation 66) are X quaternary equations, and a solution can be obtained algebraically using the Ferrari solution. The horizontal axis represents the position (X1) where light emitted from a point on the image plane enters the boundary surface between the transparent plate and the lens unit, and the vertical axis represents the angle (ν) emitted from the convex cylindrical lens panel. As the points on the image plane (distance δ from the lens center line 1004), five cases of 0, W / 4, W / 2, 3W / 4, and W are shown. δ = 3W / 4 and δ = W are light from a point on the image plane corresponding to the adjacent cylindrical lens.

  The following can be understood from FIG. The light incident on the central portion of the convex cylindrical lens from the point on the image plane is almost parallel light, but the light incident on the peripheral portion of the lens becomes divergent light. The lenticular lens effect can be satisfied approximately. By making the lens shape a fourth order even function, the lens width W can be increased and the viewing angle can be expanded to ± 0.45 radians (± 26 degrees).

  In Embodiment 6 of the present invention, D can be reduced to 1.1. Light emitted from a point on the image plane corresponding to the adjacent convex cylindrical lens is refracted by the adjacent convex cylindrical lens surface and slightly leaks to the concave cylindrical lens of interest. However, if the lenses are viewed from a certain angle, the intensity of the leaked light is small. That is, it is important that the distance (D) between the convex cylindrical lens panel and the concave cylindrical lens panel is small, and is at least twice the radius of curvature (R) near the lens center line.

  In the sixth embodiment, the case where the lens shape can be approximated by a quaternary even function has been described, but the lens shape is not limited thereto. The lens shape may be an ellipse, a hyperbola, a quartic even function, or a combination thereof. If W can be increased and D can be decreased, that is, if the viewing angle is large and the leakage light can be decreased, other aspherical lens shapes may be used.

Even in the configuration as shown in FIG. 19, a detailed example is not shown here, but if a high refractive index resin such as a nanocomposite resin is used only for the lens portion, the viewing angle can be further increased.
(Embodiment 7)

  In displaying a planar image, as shown in FIG. 3, the concave cylindrical lens panel and the convex cylindrical lens panel are brought into contact with each other. If a planar image is displayed on the image plane 203, the combined concave cylindrical lens panel and convex cylindrical lens panel behave like a single transparent plate and are recognized as a planar image.

  Generally, a concave cylindrical lens panel and a convex cylindrical lens panel are manufactured by a method such as molding, and it cannot be expected that they are completely adhered. The concave cylindrical lens panel and the convex cylindrical lens panel are in partial contact with each other, and the other portions are in close proximity with a slight gap therebetween.

  However, it is not necessary that the concave cylindrical lens panel and the convex cylindrical lens panel are completely brought into close contact with each other. If the concave cylindrical lens panel and the convex cylindrical lens panel are arranged with a slight gap as shown in FIG. 21, the light emitted from the image plane 203 is refracted on the concave cylindrical lens surface or the convex cylindrical lens surface, but the concave cylindrical lens. The gap between the panel and the convex cylindrical lens panel is small, and the traveling direction of the light beam hardly changes. Therefore, when a planar image is displayed on the image surface 203, the combined concave cylindrical lens panel and convex cylindrical lens panel optically behave like a single transparent plate and are recognized as a planar image.

FIG. 21 shows the case where the image surface side is a concave cylindrical lens, but the same applies to the case where the image surface side is a convex cylindrical lens.
(Embodiment 8)

  The concave cylindrical lens and the convex cylindrical lens are in close contact or close to each other in the case of planar image display, and are separated with a predetermined interval in the case of stereoscopic image display, so that static electricity is generated by repeated contact and separation. Failure often occurs.

  FIG. 22 shows a case where the concave cylindrical lens panel and the convex cylindrical lens panel are proximately provided with a small gap. In FIG. 22, 2201 is a concave cylindrical lens, and 2202 is a convex cylindrical lens. In order to stably bring them into close proximity, a stopper is provided on at least one of the concave cylindrical lens 2201 and the convex cylindrical lens 2202. In FIG. 22, a stopper 2203 is provided at a boundary portion between adjacent convex cylindrical lenses. When the concave cylindrical lens 2201 and the convex cylindrical lens 2202 are brought close to each other, the stopper 2203 is prevented from being in contact with each other, and is stably provided with a small gap.

  In FIG. 22, the stopper 2203 is provided at the boundary between adjacent convex cylindrical lenses, but this is not restrictive. Other structures may be used as long as the concave cylindrical lens and the convex cylindrical lens can be stably disposed with a small gap.

FIG. 22 shows the case where the image surface side is a concave cylindrical lens, but the same applies to the case where the image surface side is a convex cylindrical lens.
(Embodiment 9)

A method for manufacturing the stopper of FIG. 22 will be described with reference to FIG. In FIG. 23, the same reference numerals are used for the same components as in FIG. Reference numeral 2202 denotes a convex cylindrical lens panel, 2203 denotes a stopper made of an ultraviolet curable resin, 2204 denotes an ultraviolet lamp, and 2205 denotes ultraviolet light. A small amount of uncured ultraviolet effect resin is dropped from the lens side of the convex cylindrical lens panel 2202. The resin liquid collects in a valley portion at the boundary between adjacent convex cylindrical lenses. When the ultraviolet ray 2205 is irradiated, the ultraviolet curable resin 2203 is cured and becomes a stopper.
(Embodiment 10)

  If the concave cylindrical lens panel and the convex cylindrical lens panel are placed close to each other and separated from each other by a predetermined distance, static electricity may be generated even if they are not brought into contact with each other. The concave cylindrical lens panel and the convex cylindrical lens The proximity and separation of the panels cannot be stabilized.

  Therefore, a conductive transparent thin film is provided on the surface of one or both of the concave cylindrical lens and the convex cylindrical lens. The conductive transparent thin film prevents static electricity from being accumulated, and the concave cylindrical lens panel and the convex cylindrical lens panel can be brought into contact or close to each other, or can be stably separated with a predetermined interval. FIG. 24 shows an example in which a conductive transparent thin film is provided on the concave cylindrical lens surface and the convex cylindrical lens surface. In FIG. 24, 2401 is a concave cylindrical lens panel, 2402 is a convex cylindrical lens panel, and 2403 is a conductive transparent thin film. It is also effective to provide a conductive transparent thin film on either the convex cylindrical lens surface or the concave cylindrical lens surface.

  FIG. 24 shows the case where the image surface side is a concave cylindrical lens, but the same applies to the case where the image surface side is a convex cylindrical lens.

As this conductive transparent thin film, ITO (Indium Tin Oxide) which is a transparent electrode of a liquid crystal display can be used.
(Embodiment 11)

  A specific example using the panel structure of Embodiment 3 or Embodiment 4 of the present invention will be described. As the image display unit, a 14-inch SXGA liquid crystal display having a vertical length of 1050 pixels and a horizontal length of 1400 pixels is used. Each pixel has a vertical size of 0.12 mm and a horizontal size of 0.16 mm, and each pixel has a configuration in which three vertically long issuing units emitting red (R), green (G), and blue (B) are arranged. . The convex cylindrical lens panel is provided with the stopper shown in FIG. 22, and an ITO thin film is formed on the surface of the convex cylindrical lens and the surface of the concave cylindrical lens. In the case of planar image display, the convex cylindrical lens panel is brought close to the concave cylindrical lens panel, and in the case of stereoscopic image display, the convex cylindrical lens panel and the concave cylindrical lens panel are separated by a predetermined distance (D).

  The thickness of the concave cylindrical lens panel from the image plane to the bottom of the lens is C = 0.98 mm (H = 0), the radius of curvature near the lens center line is R = 0.33 mm, and the concave cylindrical lens panel for stereoscopic image display The distance between the convex cylindrical lens panels is D = 0.27 mm, and the width of one cylindrical lens is W = 1.47 mm. The refractive index of the polycarbonate resin of the lens medium is n = 1.57. The thickness of the concave cylindrical lens panel is about 1 mm. However, in the case of stereoscopic image display, the convex cylindrical lens panel is moved, so that the thickness of the convex cylindrical lens panel is set to 1 mm or more in consideration of rigidity and stability. This 14-inch liquid crystal display has a configuration in which 155 cylindrical lenses are arranged side by side.

  FIG. 25 is a cross-sectional view of the concave cylindrical lens panel and the convex cylindrical lens panel. In FIG. 25, reference numeral 2501 denotes a concave cylindrical lens panel, 2502 denotes a convex cylindrical lens panel, and 2503 denotes an image plane. The relative sizes are illustrated based on the above-described numerical values. Although 2504 is a stopper, a conductive transparent thin film (ITO) is not shown.

FIG. 26 shows a pixel configuration of the display. In FIG. 26, reference numeral 2601 denotes a red issuer, 2602 denotes a green issuer, and 2603 denotes a blue issuer. The three issuers 2601 to 2603 constitute one set to constitute one pixel. One cylindrical lens is arranged for nine pixel columns. Reference numeral 2604 schematically shows the cylindrical lens. In this embodiment, too many viewpoint images cannot be displayed. A three-viewpoint stereoscopic image display is suitable by displaying one strip image by combining three pixel columns.
Embodiment 12

  Images from many viewpoints are displayed on the image plane. Adjacent images on the image plane corresponding to one cylindrical lens have a strong correlation with each other, and even if mixed, it does not pose a big problem for image quality degradation. However, the image near the boundary between adjacent cylindrical lenses has a low correlation, and when they are mixed, the image quality deteriorates. Therefore, the smallest exit angle of the light exiting from the boundary between adjacent cylindrical lenses and exiting from the convex cylindrical lens with relatively high intensity determines the viewing angle.

  For example, the light ray 1411 (broken line) in FIG. 15 has a small amount of light and is not a problem, but the light ray 1410 (solid line) having a relatively large amount of light determines the viewing angle. In FIG. 13 where the lens shape can be approximated by a hyperbola, the viewing angle is ± 0.42 radians (± 24 degrees), and in FIG. 16 where the lens shape can be approximated by a quaternary even function, the viewing angle is ± 0.52 radians (± 30 degrees). It is.

  When displaying a stereoscopic image, if an image is not displayed near the boundary between adjacent cylindrical lenses, an image having a low correlation can be prevented from being mixed and the viewing angle can be increased. This will be described using a panel structure in which the lens shape of Embodiment 3 can be approximated by a hyperbola. FIG. 27 shows the simulation results with n = 1.57, R = 1, C = m = 3, D = 0.84, and W = 4.5. Reference numeral 2701 represents light emitted from a point on the image plane of δ = 0.4 W from the lens center line, and 2702 represents light emitted from a point on the image plane of δ = 0.6 W. δ = 0.6 W is a point on the image plane of the adjacent cylindrical lens. The light emitted from these two points is not mixed, the maximum emission angle from δ = 0.4 W is about 0.49 radians, and the viewing angle is ± 0.49 radians (± 28 degrees). The viewing angle when an image is displayed near the boundary between adjacent cylindrical lenses is ± 0.42 radians (± 24 degrees) as described above, and the viewing angle can be expanded by not displaying the image at the boundary. I understand.

  FIG. 28 is a cross-sectional view of a concave cylindrical lens panel and a convex cylindrical lens panel in Embodiment 12 of the present invention. In FIG. 28, 2801 is a concave cylindrical lens panel, 2802 is a convex cylindrical lens panel, 2803 is an image plane, and 2804 is a stopper. A conductive thin film (ITO) is not shown. Reference numeral 2805 denotes a displayed image, which displays an image only in an 80% portion of the image surface 2803, and does not display an image near the boundary between adjacent cylindrical lenses.

  In flat display, the concave cylindrical lens panel and the convex cylindrical lens panel are brought close to each other, and an image is displayed on the entire image surface 2803.

FIG. 28 shows the case where the image surface side is a concave cylindrical lens, but the same applies to the case where the image surface side is a convex cylindrical lens.
(Embodiment 13)

  FIG. 29 is a diagram illustrating the relationship between the eye position and the light rays when viewing the image display apparatus. In FIG. 29, 2901 is a concave cylindrical lens panel, 2902 is a convex cylindrical lens panel, and 2903 is an image plane. In general, viewing is performed from the center of the image display apparatus, and 2904 is the position of the eye. FIG. 29 shows only the center, the left end, and the right end of the image display device, 2905 is an image at the center, 2906 is an image at the left end, and 2907 is an image at the right end. With the eye 2904, an image near the lens center line is viewed at the center, an image on the left side of the lens center line is viewed at the left end, and an image on the right side of the lens center line is viewed at the right end. Therefore, if the position of the eyes moves a little, there is a high possibility that the image on either the left or right end will be out of the viewing angle.

  Therefore, an image is displayed centering on the outer peripheral side of the cylindrical lens center line from the center of the image display device to the outer peripheral side. This is shown in FIG. In FIG. 30, the same components as those of FIG. Reference numeral 2908 denotes the position of the left end image, and 2909 denotes the position of the right end image. All of the central portion 2905, the left end 2908, and the right end 2909 are such that light rays from the central portion of the image are incident on the eye, and even if the eye position is slightly moved, it does not deviate from the viewing angle.

FIG. 30 shows the case where the image surface side is a concave cylindrical lens, but the same applies to the case where the image surface side is a convex cylindrical lens.
(Embodiment 14)

  When displaying a two-dimensional image, small characters with high resolution can be read. However, when displaying a three-dimensional image, the resolution is low and it is difficult to read small characters. However, I want to display small characters such as subtitles in 3D movies in foreign languages. Therefore, a part that always displays a planar image is provided in a part of the image display device, and the other part is configured to be able to switch between the stereoscopic image and the planar image in any of Embodiments 1 to 13 of the present invention. .

FIG. 31 shows an example in which a portion that always displays a planar image is installed at the bottom of the screen. In FIG. 31, 3101 is an image display device, 3102 is a part capable of switching between a stereoscopic image and a planar image, and 3103 is a part which always displays a planar image. 3103 displays subtitles and the like.
(Embodiment 15)

  In Embodiments 1 to 14 of the present invention, a cylindrical lens is used as the lens, but the same can be achieved by using a “fly eye lens” in which single lenses are arranged in a matrix in the vertical and horizontal directions. If the “fly eye lens” is used, the left and right eyes can recognize a stereoscopic image even if the image device is rotated 90 degrees.

Such a “fly eye lens” panel is shown in FIG. In FIG. 32, 3201 is a single convex lens, 3202 is an array of single convex lenses. Prepare an array of single-concave lenses of the opposite shape to this single-convex lens, and move the single-convex lens array panel or single-concave lens array panel by moving the single-convex lens array panel and the single-concave lens array panel together. It is possible to switch between stereoscopic display and flat display.
(Embodiment 16)

  A method for manufacturing a concave lens array panel in which only the lens portion is made of a high refractive index resin as shown in FIGS. 10 and 19 will be described with reference to FIG. 33, reference numeral 3301 denotes a transparent plate, and 3302 denotes a nanocomposite resin in which fine particles having a high refractive index are dispersed in an ultraviolet curable resin. Reference numeral 3303 denotes a mold in which a lens array is formed. 3304 is an ultraviolet lamp, and 3305 is an ultraviolet ray. An array of cylindrical lenses or single lenses is formed on the mold.

  The transparent plate 3301 and the mold 3303 are made to face each other, and the nanocomposite resin 3302 is inserted between them, and the ultraviolet composite 3305 is irradiated from the transparent plate 3301 side to cure the nanocomposite resin, and 3301 and 3302 are integrated. A panel on which a concave lens array is formed is produced. The panel on which the convex lens array is formed is also produced in the same manner as in FIG.

  Embodiments 1 to 16 disclosed above are merely examples of the present invention, and the present invention is not construed as being limited by these embodiments. The scope of the present invention is defined not only by the above-described embodiments but also by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

The image display device of the present invention has a function of switching between a stereoscopic image and a planar image, and the stereoscopic image has a wide viewing angle and is useful as a stereoscopic television. It can also be applied to applications such as mobile devices, personal computer monitors, and game consoles.

Claims (18)

A first panel having an image plane, having a concave lens array on one side, and a second panel having a convex lens array on one side, are arranged in this order: image plane, first panel, second panel. The convex lens and the concave lens face each other, the first panel and the second panel are arranged at a predetermined interval to display a stereoscopic image, and the first panel and the second panel are brought into contact or close to each other. An image display device characterized in that a flat image is displayed by arranging them. It has an image plane, has a second panel with an array of convex lenses on one side, has a first panel with an array of concave lenses on one side, and arranges the image plane, the second panel, and the first panel in this order. The convex lens and the concave lens are opposed to each other, the second panel and the first panel are arranged at a predetermined interval to display a stereoscopic image, and the second panel and the first panel are brought into contact with or close to each other. The image display apparatus is characterized in that a planar image is displayed and the predetermined interval is not more than twice a radius of curvature in the vicinity of the lens center line of the convex lens and the concave lens. The image display apparatus according to claim 1, wherein the concave lens and the convex lens are spherical lenses. The image display device according to claim 1, wherein the concave lens and the convex lens are aspherical lenses. The image display apparatus according to claim 4, wherein the aspheric lens has a radius of curvature of each point on each lens surface that gradually increases from the center to the periphery of the lens. The image display apparatus according to claim 4, wherein the shape of the aspheric lens is approximated by an ellipse, a hyperbola, a quadratic even function, or a combination function thereof. The first panel has a configuration in which an array of concave lenses with a refractive index n2 is formed on a first transparent plate with a refractive index n1, and the second panel has a refractive index on a second transparent plate with a refractive index n1. 3. The image display device according to claim 1, wherein an array of n2 convex lenses is formed, and n2> n1. 8. The image display device according to claim 7, wherein the array of convex lenses or the array of concave lenses is made of a resin in which fine particles are dispersed. 9. The image display device according to claim 8, wherein the fine particles contain one or more dielectrics selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, and aluminum oxide. The image display device according to claim 1, wherein a stopper is provided on at least one of the first panel and the second panel. 3. The image display device according to claim 1, wherein a conductive transparent thin film is formed on at least one surface of the concave lens array or the convex lens array. The image display device according to claim 1, wherein no image is displayed on an image plane corresponding to a boundary between the adjacent concave lenses or a boundary between the adjacent convex lenses. 3. The image display device according to claim 1, wherein an outer peripheral portion of the first panel or the second panel displays an image centering on an outer peripheral side from a center of each lens. An image display device comprising a part for switching between a stereoscopic image and a planar image and a part for always displaying a planar image. The image display apparatus according to claim 1, wherein the concave lens and the convex lens are cylindrical lenses. The image display apparatus according to claim 1, wherein the concave lens and the convex lens are single lenses. A panel manufacturing method comprising: a panel having a convex lens array formed on one side thereof; an ultraviolet curable resin is supplied to a boundary of each lens of the convex lens array; and the ultraviolet curable resin is cured by irradiating ultraviolet rays. A transparent plate and a mold having a concave lens array shape or a convex lens array shape are opposed to each other, an ultraviolet curable resin is held between the transparent plate and the mold, and ultraviolet rays are irradiated to cure the ultraviolet curable resin. A panel manufacturing method characterized by the above.

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