JP3756481B2 - 3D display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional display device that suppresses contradiction between physiological factors of stereoscopic vision and can display a three-dimensional stereoscopic image without using glasses, and in particular, has a simple configuration and is compact. The present invention relates to a three-dimensional display device.
[0002]
[Prior art]
The present inventors have proposed a three-dimensional display device capable of suppressing a contradiction between physiological factors of stereoscopic vision and displaying a three-dimensional stereoscopic image of a color image without using glasses (for example, (See patent literature).
[0003]
The prior art document information related to the invention of the present application includes the following.
[Patent Literature]
Japanese Patent No. 3022558
[Non-patent literature]
"Liquid Crystal / Fundamentals", "Liquid Crystal / Applications" (Okano, Kobayashi, Ed.)
[0004]
FIG. 8 is a diagram showing a schematic configuration of a three-dimensional display device which is the basis of the present invention, and is the three-dimensional display device shown as FIG. 1 in the above-mentioned patent document.
The three-dimensional display device shown in FIG. 2 sets a plurality of display surfaces, for example, display surfaces (101, 102) (the display surface 101 is closer to the viewer 100 than the display surface 102) on the front surface of the viewer 100. In order to display a plurality of two-dimensional images on the display surfaces (101, 102), an optical system 103 is constructed using a two-dimensional display device and various optical elements.
Hereinafter, the display principle of the three-dimensional display device, which is the basis of the present invention, will be described with reference to FIGS.
As shown in FIG. 9, an image (hereinafter referred to as a “2D image”) of a three-dimensional object 104 desired to be presented to the viewer 100, projected from the viewing direction of both eyes of the viewer 100 onto the display surface (101, 102). Is generated) (105, 106).
As a method for generating the 2D image, for example, a method using a two-dimensional image obtained by photographing the object 104 with a camera from the line-of-sight direction, a method of combining from a plurality of two-dimensional images taken from different directions, or a computer graphic There are various methods such as a synthesis technique based on the above and a method using modeling.
[0005]
Then, as shown in FIG. 8, the 2D image (105, 106) is seen from one point on the line connecting the right eye and the left eye of the observer 100 on both the display surface 101 and the display surface 102, respectively. Display to overlap.
This can be achieved, for example, by controlling the arrangement of the center position and the center of gravity position of each 2D image (105, 106) and the enlargement / reduction of each image.
The important point of the three-dimensional display device that is the basis of the present invention is that the luminance of each of the 2D images (105, 106) is constant as viewed from the observer 100 on the device having the above-described configuration. It is to change corresponding to the depth position of the three-dimensional object 104.
An example of how to change is described below. Here, since it is a black and white drawing, the higher luminance is shown darkly in the following drawings for easy understanding.
For example, when the three-dimensional object 104 is on the display surface 101, as shown in FIG. 10, the luminance of the 2D image 105 above it is made equal to the luminance of the three-dimensional object 104 and 2D on the display surface 102 is displayed. The luminance of the converted image 106 is zero.
[0006]
Next, for example, when the three-dimensional object 104 is slightly away from the viewer 100 and is slightly closer to the display surface 102 than the display surface 101, the brightness of the 2D image 105 is increased as shown in FIG. Slightly lower the brightness of the 2D image 106 slightly.
Furthermore, for example, when the three-dimensional object 104 is further away from the observer 100 and is further away from the display surface 101 toward the display surface 102, the brightness of the 2D image 105 is further increased as shown in FIG. The brightness of the 2D image 106 is further increased.
Finally, for example, when the three-dimensional object 104 is on the display surface 102, the luminance of the 2D image 106 on the display surface 102 is made equal to the luminance of the three-dimensional object 104, as shown in FIG. The brightness of the 2D image 105 is zero.
By displaying in this way, even if a 2D image (105, 106) is displayed due to the physiological or psychological factors or illusion of the observer (person) 100, the observer 100 is as if It feels as if the three-dimensional object 104 is located in the middle of the display surfaces (101, 102).
That is, for example, when a 2D image (105, 106) having substantially equal luminance is displayed on the display surface (101, 102), the three-dimensional object 104 is located near the middle of the depth position of the display surface (101, 102). It feels like there is.
[0007]
[Problems to be solved by the invention]
As the above-described two-dimensional display device for displaying a two-dimensional image on the display surface, for example, a CRT, a liquid crystal display, an LED display, an EL display, a plasma display, an FED display, a projection display, a line drawing display, or the like is used. As the optical element, for example, a lens, a total reflection mirror, a partial reflection mirror, a curved mirror, a prism, a polarization element, a wave plate, or the like is used.
For this reason, the three-dimensional display device described above has a problem that the configuration becomes complicated as described in the third and subsequent embodiments of the above-mentioned patent document.
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to suppress contradiction among physiological factors of stereoscopic vision and to perform three-dimensional without using glasses. An object of the present invention is to provide a compact three-dimensional display device that can display a stereoscopic image, has a simple configuration, and is compact.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.
[0008]
[Means for Solving the Problems]
  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
  That is, the present invention changes the focal length of the varifocal lens device in n stages when n is an integer equal to or larger than 2, the display device, the varifocal lens device provided on the viewer side of the display device. First means and a focal length of the variable focus lens deviceIs changed to the kth (where k is an integer of 1 to n) focal length,Among the n display surfaces at different depth positions as viewed from the observerkthAnd a second means for causing the display device to display a two-dimensional image obtained by projecting the display target object from the line of sight of the observer. MeansIn synchronization with the n-stage change in the focal length of the variable focus lens deviceDisplay on the display devicenThe brightness of the two-dimensional image is changed independently for each of the n two-dimensional images, and the varifocal lens device includes a first microlens array and forms a reduced inverted real image of the original image. The reduction inversion imaged by the first lens set includes a lens set, a variable focus microlens array that changes the focal length in n steps based on the first means, and a second microlens array. A second lens set that forms a magnified erect real image of a real image, the magnified erect real image and the original image on the plane are the same size, and the variable focus microlens array is: It is arranged at the focal position of the second microlens array.
[0009]
Further, the present invention is provided on the viewer side of the display device and the display device, and switches the polarization direction of the two-dimensional image incident from the display device between the first polarization direction and the second polarization direction. A polarization switching device, a polarization type bifocal lens device provided on the observer side of the polarization switching device, and a polarization direction of a two-dimensional image incident from the display device in the polarization switching device to the first polarization direction When switching, one two-dimensional image of the two-dimensional images obtained by projecting the display target object from the viewing direction of the observer is displayed on two display surfaces at different depth positions as viewed from the observer. Different depth positions as viewed from the observer when the polarization direction of the two-dimensional image incident from the display device is switched to the second polarization direction in the polarization switching device. It is in A three-dimensional display device comprising, on one display surface, means for causing the display device to display the other two-dimensional image among the two-dimensional images obtained by projecting the display target object from the viewing direction of the observer, The means changes the brightness of the two-dimensional image displayed on the display device independently for each of the two two-dimensional images, and the polarized bifocal lens device includes a first microlens array, and the original image A first type of lens that forms a reduced inverted real image and a polarization type bifocal having different focal lengths when the incident light is in the first polarization direction and in the second polarization direction. A second lens set that includes a microlens array and a second microlens array, and forms an enlarged upright real image of the reduced inverted real image formed by the first lens set; Magnified upright real image and element on the plane It is the same size and the image, and the polarization type bifocal microlens array, characterized in that it is arranged at the focal position of the second microlens array.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.
[Embodiment 1]
FIG. 1 is a diagram showing a schematic configuration of the three-dimensional display device according to Embodiment 1 of the present invention.
As shown in the figure, the three-dimensional display device of this embodiment includes a self-luminous two-dimensional display device (hereinafter simply referred to as a self-luminous display device) 201 and an observer side of the self-luminous display device 201. And a variable focal length lens device 135 disposed in the.
As the self-luminous display device 201, for example, a CRT, a liquid crystal display, an LED display, an EL display, a plasma display, an FED display, a projection display, a line drawing display, or the like is used.
When n is an integer greater than or equal to 2 (n ≧ 2), the variable focus lens device 135 can change the focal length in n stages. In the following description, the case where n is 2 will be described. To do.
[0011]
In the present embodiment, the focal length of the varifocal lens device 135 is changed in two stages in a time-sharing manner, and a two-dimensional image displayed on the self-luminous display device 201 is converted into an imaging surface 1021 and an imaging surface 1022. To form an image.
When the two-dimensional image displayed on the self-luminous display device 201 is imaged on the imaging surface 1021, the self-luminous display device 201 displays the 2D image 105 described with reference to FIG. When the two-dimensional image displayed on the self-luminous display device 201 is imaged on the imaging surface 1022, the self-luminous display device 201 displays the 2D image 106 described with reference to FIG. The luminance of the 2D image (105, 106) is changed as described with reference to FIGS.
By performing this operation within the afterimage time of human eyes, the three-dimensional display device of the present embodiment is optically equivalent to the three-dimensional display device shown in FIG.
In FIG. 2, reference numeral 111 denotes a display surface made up of a two-dimensional image formed on the image formation surface 1021, and 112 denotes a display surface made up of a two-dimensional image formed on the image formation surface 1022.
Therefore, the three-dimensional display device of the present embodiment can display a three-dimensional stereoscopic image based on the display principle of the three-dimensional display device that is the basis of the present invention described above.
[0012]
[Configuration of Variable-Focus Lens Device 135 of First Embodiment]
Hereinafter, the variable focus lens device 135 that is a feature of the present embodiment will be described.
FIG. 3 is a diagram showing a schematic configuration of the variable focus lens device 135 according to the embodiment of the present invention.
As shown in the figure, the variable focus lens device 135 of the present embodiment includes a first microlens array (L₀) Including a first lens set 20 and a variable focus microlens array (L₁) And the second microlens array (L₂) Including the second lens set 21.
In the variable focus lens device 135 of the present embodiment, the first lens set 20 reduces the original image 10 on the plane to form a reduced inverted real image 11, and the reduced inverted real image 11 is the second inverted real image 11. A magnified erect real image 12 of the original image 10 on the plane is formed by enlarging with the lens set 21.
Here, the first microlens array (L₀) Is the focal length f₀, Second microlens array (L₂) Is the focal length f₂It is.
When m is a positive number of 1 or more, the reduction magnification of the original image 10 in the first lens set 20 is (1 / m), and the enlargement magnification of the reduced inverted real image 11 in the second lens set 21. Is m. That is, when viewed from the reduced inverted real image 11, the magnification of the first lens set 20 and the magnification of the second lens set 21 are made to coincide with each other, and the size of the enlarged upright real image 12 is set to the original image on the plane. Same as 10 size.
Here, each lens of the microlens array mainly contributes to the image formation of the portion of the original image corresponding to the diameter of each lens, and the original image 10 and the real image 12 have the same size. Only the image at the joint of the lens can be reduced.
[0013]
This variable focus micro lens array (L₁For example, a variable focus microlens array using a dual frequency liquid crystal is used.
The variable focus micro lens array (L₁) And the second microlens array (L₂) To the second microlens array (L₂) Focal length. That is, the variable focus micro lens array (L₁) To the second microlens array (L₂) At the focal position.
According to the variable focus lens device 135 of the present embodiment, the variable focus microlens array (L₁) Is changed, the distance between the second lens set 21 and the imaging position of the erect real image 12 of the original image 10 can be moved.
Normally, when the imaging position moves, the size of the image also changes, but the variable focus microlens array (L₁) To the second microlens array (L₂) Can be moved without changing the size.
Thus, according to the variable focus lens device 135 of the present embodiment, the imaging position of the erect real image 12 of the original image 10 is varied without changing the size of the erect real image 12 of the original image 10. It becomes possible.
[0014]
Further, in the variable focus lens device 135 of the present embodiment, a concave lens type variable focus microlens array (L₁) And convex lens type micro lens array (L₂), The focal length (F) of the second lens set 21 becomes the second lens set 21 as a microlens array (L₂) Only (ie, the second microlens array (L₂) Focal length f₂) Longer than
Therefore, as shown in FIG. 4, the distance (O) between the second lens set 21 and the imaging position of the erecting real image 12 of the original image is set to the original image 10 and the first lens set 20 on the plane. It becomes possible to make it longer than the distance (R) between.
Therefore, in the three-dimensional display device of this embodiment, the interval between the self-luminous display device 201 shown in FIG. 1 and the variable focus lens device 135 can be shortened.
Furthermore, in the three-dimensional display device according to the present embodiment, only one self-luminous display device 201 and the variable focus lens device 135 are arranged. Therefore, in the three-dimensional display device according to the present embodiment, FIG. Compared to the conventional three-dimensional display device shown in FIG. 1, the configuration can be simplified and the configuration can be made compact.
[0015]
  In the variable focus lens device 135 described above, the first microlens array (L₀), Variable focus micro lens array (L₁) And the second microlens array (L₂) Is arranged at a position where the size of the enlarged upright real image 12 is the same as the size of the original image 10 on the plane.
  In the variable focus lens device 135 described above, the first microlens array (L₀), Variable focus micro lens array (L₁) Or second microlens array (L₂It is also possible to use a Fresnel lens array or a hologram lens array.
  Further, by making the aberration of the first lens group 20 and the aberration of the second lens group 21 as close as possible, it is possible to obtain an enlarged erecting real image 12 with less color shift and distortion.
  In the above description, the case in which the focal length of the variable focus lens device 135 is changed in two stages has been described. However, the focal length of the variable focus lens apparatus 135 can be changed in two or more n stages.
  In this case, the focal length of the variable focus lens device 135Is changed to the kth (where k is an integer of 1 to n) focal length,Among the n display surfaces at different depth positions as viewed from the observerkthThe display target object is projected from the viewing direction of the observer onto the display surface of2DThe image is displayed on the self-luminous display device 201.Then, the luminance of the n number of 2D images displayed on the display device 201 is changed as described with reference to FIGS.
[0016]
Furthermore, in the above description, for example, the depth position of the entire three-dimensional object is changed in two steps in the time division of the focal length of the variable focus lens device 135, and the 2D image displayed on the self-luminous display device 201 is displayed. The method and apparatus for expressing the images on the imaging plane 1021 and the imaging plane 1022 have been mainly described. However, as described in the above-described patent document, the three-dimensional display apparatus according to the present embodiment is It can also be used as a method and apparatus for expressing the depth of the original object itself.
Similarly, the three-dimensional display device according to the present embodiment can be used when the three-dimensional object itself moves as described in the aforementioned patent document.
When the 2D image moves three-dimensionally, it is possible to reproduce the moving image in the transparent self-luminous display device as in the case of a normal two-dimensional display device with respect to the movement of the observer in the horizontal and vertical directions, Regarding the movement in the depth direction, as described in the above-mentioned patent document, the 2D image displayed on the self-luminous display device 201 by changing the focal length of the variable focus lens device 135 in two stages in a time division manner is used. When imaging on the imaging surface 1021 and the imaging surface 1022, a moving image of a three-dimensional image is expressed by temporally changing the luminance of the 2D image displayed on the self-luminous display device 201. be able to.
[0017]
[Embodiment 2]
FIG. 5 is a diagram showing a schematic configuration of the three-dimensional display device according to Embodiment 2 of the present invention.
As shown in the figure, the three-dimensional display device of the present embodiment is arranged on the observer side of the self-luminous display device 201 and the self-luminous display device 201 and is incident from the self-luminous display device 201. A polarization switching device 150 that switches a polarization direction of a two-dimensional image between a first polarization direction and a second polarization direction, and a polarization type bifocal lens device 136 provided on the observer side of the polarization switching device 150 are provided.
As the self-luminous display device 201, for example, a CRT, a liquid crystal display, an LED display, an EL display, a plasma display, an FED display, a projection display, a line drawing display, or the like is used.
The polarized bifocal lens device 136 is a lens having different focal lengths when the incident light is in the first polarization direction and when the incident light is in the second polarization direction.
[0018]
In the present embodiment, the polarization switching device 150 switches the polarization direction of the two-dimensional image output from the polarization switching device 150 between the first polarization direction and the second polarization direction in a time division manner.
In addition, the polarizing bifocal lens device 136 has different focal lengths when the incident light is in the first polarization direction and when the incident light is in the second polarization direction. In the embodiment, the two-dimensional image displayed on the self-luminous display device 201 can be imaged on the imaging plane 1021 and the imaging plane 1022 by time division.
When the two-dimensional image displayed on the self-luminous display device 201 is imaged on the imaging surface 1021, the self-luminous display device 201 displays the 2D image 105 described with reference to FIG. When the two-dimensional image displayed on the self-luminous display device 201 is imaged on the imaging surface 1022, the self-luminous display device 201 displays the 2D image 106 described with reference to FIG. The luminance of the 2D image (105, 106) is changed as described with reference to FIGS.
By performing this operation within the afterimage time of human eyes, the three-dimensional display device of the present embodiment is optically equivalent to the three-dimensional display device shown in FIG.
Therefore, the three-dimensional display device of the present embodiment can display a three-dimensional stereoscopic image based on the display principle of the three-dimensional display device that is the basis of the present invention described above.
[0019]
[Configuration of Polarization Type Bifocal Lens Device 136 According to Embodiment 2]
Hereinafter, the polarization type bifocal lens device 136 which is a feature of the present embodiment will be described.
FIG. 6 is a diagram showing a schematic configuration of the polarization type bifocal lens device 136 according to the embodiment of the present invention.
As shown in the figure, the polarization type bifocal lens device 136 of the present embodiment includes a first microlens array (L₀) Including a first lens set 20 and a polarized bifocal microlens array (L₃) And the second microlens array (L₂) Including the second lens set 21.
In the polarization type bifocal lens device 136 of the present embodiment, the first lens set 20 reduces the original image 10 on the plane to form a reduced inverted real image 11, and the reduced inverted real image 11 is converted into the first inverted inverted real image 11. A magnified erecting real image 12 of the original image 10 on the plane is formed by enlarging with the second lens set 21.
When m is a positive number of 1 or more, the reduction magnification of the original image 10 in the first lens set 20 is (1 / m), and the enlargement magnification of the reduced inverted real image 11 in the second lens set 21. Is m. That is, when viewed from the reduced inverted real image 11, the magnification of the first lens set 20 and the magnification of the second lens set 21 are made to coincide with each other, and the size of the enlarged upright real image 12 is set to the original image on the plane. Same as 10 size.
[0020]
Here, each lens of the microlens array mainly contributes to the image formation of the portion of the original image corresponding to the diameter of each lens, and the original image 10 and the real image 12 have the same size. Only the image at the joint of the lens can be reduced.
In addition, a polarized bifocal microlens array (L₃) And the second microlens array (L₂) To the second microlens array (L₂) Focal length. That is, a polarized bifocal microlens array (L₃) To the second microlens array (L₂) At the focal position.
According to the polarization type bifocal lens device 136 of the present embodiment, by changing the polarization direction of the light incident on the polarization type bifocal lens device 136, the second lens set 21 and the erect real image of the original image 10. The distance between the 12 imaging positions can be moved.
Normally, when the imaging position moves, the size of the image also changes, but the polarization type bifocal microlens array (L₃) To the second microlens array (L₂) Can be moved without changing the size.
As described above, also in the polarization type bifocal lens device 136 according to the present embodiment, the imaging position of the erecting real image 12 of the original image 10 can be changed without changing the size of the erecting real image 12 of the original image 10. It becomes possible.
[0021]
FIG. 7 shows a polarization type bifocal microlens array (L₃It is a figure which shows an example. 7 shows a polarization type bifocal microlens array (L₃) Shows individual microlenses.
As shown in FIGS. 7A and 7B, a polarization type bifocal microlens array (L₃Each of the microlenses includes a fixed focus lens 301 and a birefringent region 302.
Here, the fixed focus lens 301 is, for example, a glass or plastic convex lens shown in FIG. 7B, a glass or plastic concave lens shown in FIG. 7A, or a glass or plastic convex lens, The lens system is configured by a combination of a concave lens and a prism, or a mirror system by a combination of a convex lens, a concave lens, and a prism made of glass or plastic.
In addition, the birefringent region 302 is formed of a medium having birefringent properties made of, for example, liquid crystal or PLZT.
[0022]
Here, the refractive index of the fixed focus lens 301 is n1, and the refractive indexes of the birefringent region 302 in the first polarization direction and the second polarization direction of incident light are n21 and n22, respectively.
For example, when light is incident from the birefringent region 302, the light travels while feeling the refractive indexes n21 and n22 according to the polarization direction of the incident light, and then comes into contact with the fixed focus lens 301 having the refractive index n1.
Therefore, the emitted light is imaged at different positions according to the polarization state of the incident light. That is, a polarization type bifocal microlens array (L₃).
On the other hand, even when the light is incident from the fixed focus lens 301 side, the image is separated and formed on the two image planes by the refractive index corresponding to the intrinsic polarization direction.
Here, as shown in FIG. 7, when the birefringent region 302 is a liquid crystal, an in-plane uniform separation can be obtained for light incident from the birefringent region 302 side by adding an alignment film 303. .
[0023]
Further, the polarization type bifocal microlens array (L₃In this case, even when the fixed focus lens 301 is not provided, the same effect can be obtained when one or both surfaces of the birefringent region 302 have a lens shape or a prism shape as shown in FIG.
Furthermore, as a medium having birefringence, the liquid crystal is useful because of its large refractive index anisotropy, and as its type, in addition to the usual nematic liquid crystal, for example, polymer dispersed liquid crystal, holographic polymer dispersed Type liquid crystal, polymer liquid crystal, smectic liquid crystal, ferroelectric liquid crystal, and polymer stabilized ferroelectric liquid crystal.
Furthermore, it is clear that birefringence can be obtained by forming the main axis of the polymer material in alignment with other than the liquid crystal.
As the polarization switching device 150 of the present embodiment, for example, a device using a medium (for example, liquid crystal or PLZT) whose birefringence can be changed by an electric field or voltage is well known. Many types of apparatuses using liquid crystals are described in, for example, “Liquid Crystal / Fundamentals”, “Liquid Crystal / Applications” (Okano, Kobayashi, edited by Baifukan).
[0024]
As described above, also in the three-dimensional display device of the present embodiment, the interval between the self-luminous display device 201 shown in FIG. 1 and the polarizing bifocal lens device 136 can be shortened.
Furthermore, in the 3D display device of the present embodiment, only one self-luminous display device 201 and a polarization type bifocal lens device 136 are arranged. Therefore, in the 3D display device of the present embodiment, Compared to the conventional three-dimensional display device shown in FIG. 8, the configuration can be simplified and the configuration can be made compact.
In the polarization type bifocal lens device 136 described above, the first microlens array (L₀), Polarized bifocal microlens array (L₃) And the second microlens array (L₂) Is arranged at a position where the size of the enlarged upright real image 12 is the same as the size of the original image 10 on the plane.
In the polarization type bifocal lens device 136 described above, the first microlens array (L₀), Polarized bifocal microlens array (L₃) Or second microlens array (L₂It is also possible to use a Fresnel lens array or a hologram lens array.
Further, by making the aberration of the first lens group 20 and the aberration of the second lens group 21 as close as possible, it is possible to obtain an enlarged erecting real image 12 with less color shift and distortion.
[0025]
Further, in the above description, for example, the depth position of the entire three-dimensional object is changed to 2D displayed on the self-luminous display device 201 by changing the focal length of the polarization type bifocal lens device 136 in two stages in a time division manner. The method and apparatus for expressing an image by forming the image on the imaging plane 1021 and the imaging plane 1022 have been mainly described. However, the three-dimensional display apparatus according to the present embodiment is as described in the above-described patent document. It can also be used as a method and apparatus for expressing the depth of a three-dimensional object itself.
Similarly, the three-dimensional display device according to the present embodiment can be used when the three-dimensional object itself moves as described in the aforementioned patent document.
When the 2D image moves three-dimensionally, it is possible to reproduce the moving image in the transparent self-luminous display device as in the case of a normal two-dimensional display device with respect to the movement of the observer in the horizontal and vertical directions, Regarding the movement in the depth direction, as described in the above-mentioned patent document, the focal length of the polarization type bifocal lens device 136 is changed in two stages in a time-division manner and displayed in the self-luminous display device 201. When an image is formed on the image formation surface 1021 and the image formation surface 1022, the luminance of the 2D image displayed on the self-luminous display device 201 is temporally changed, so that a moving image of the three-dimensional image can be obtained. Can be expressed.
Note that the display surface of the two-dimensional image in each of the above-described embodiments is not necessarily a flat surface in view of the gist of the present invention, and is a spherical surface, an elliptical surface, a quadric surface, or another complicated curved surface. It is clear that a similar effect can be obtained.
Although the invention made by the present inventor has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Of course.
[0026]
【The invention's effect】
The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the present invention, it is possible to suppress a contradiction between physiological factors of stereoscopic vision, display a three-dimensional stereoscopic image of a color image without using glasses, have a simple configuration, and be compact. A three-dimensional display device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a three-dimensional display device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a three-dimensional display device that is optically equivalent to the three-dimensional display device according to the first embodiment of the present invention;
FIG. 3 is a diagram showing a schematic configuration of a variable focus lens apparatus according to Embodiment 1 of the present invention.
FIG. 4 is a schematic diagram for explaining the operation of the variable focus lens apparatus according to Embodiment 1 of the present invention;
FIG. 5 is a diagram showing a schematic configuration of a three-dimensional display device according to a second embodiment of the present invention.
FIG. 6 is a diagram showing a schematic configuration of a polarizing bifocal lens device according to a second embodiment of the present invention.
FIG. 7 is a diagram for explaining a schematic configuration of a polarization type bifocal microlens array according to a second embodiment of the present invention.
FIG. 8 is a diagram showing a schematic configuration of a three-dimensional display device which is the basis of the present invention.
FIG. 9 is a diagram for explaining a method of generating a 2D image to be displayed on each display surface in the three-dimensional display device that is the basis of the present invention.
FIG. 10 is a diagram for explaining a display principle of a conventional three-dimensional display device.
FIG. 11 is a diagram for explaining the display principle of the three-dimensional display device which is the basis of the present invention.
FIG. 12 is a diagram for explaining the display principle of the three-dimensional display device that is the basis of the present invention.
FIG. 13 is a diagram for explaining the display principle of the three-dimensional display device that is the basis of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Original image on a plane, 11 ... Inverted real image, 12 ... Erect real image, 20, 21 ... Lens group, 100 ... Observer, 101, 102, 111, 112 ... Display surface, 103 ... Optical system, 104 ... Tertiary Original object, 105, 106 ... 2D image, 135 ... Variable focus lens device, 136 ... Polarization type bifocal lens device, 150 ... Polarization switching device, 201 ... Self-luminous two-dimensional display device, 301 ... Fixed focus lens, 302 ... birefringence region, 303 ... orientation film, 1021, 1022 ... imaging plane, L₀, L₂... Microlens array, L₁... Variable focus micro lens array, L₃... Polarized bifocal microlens array.

Claims (5)

A display device;
A variable focus lens device provided on the viewer side of the display device;
a first means for changing the focal length of the varifocal lens device in n stages when n is an integer of 2 or more;
When the focal length of the varifocal lens device is changed to the kth (where k is an integer not smaller than 1 and not larger than n) focal length, among n display surfaces at different depth positions as viewed from the observer And a second means for causing the display device to display a two-dimensional image obtained by projecting the display target object from the viewing direction of the observer with respect to the kth display surface,
Said second means, said variable n stages of change in the focal length of the focusing lens unit in synchronism with the n to be displayed on the display device brightness of the two-dimensional image, independently for each n-number of two-dimensional image Change to
The varifocal lens device includes a first lens group that includes a first microlens array and forms a reduced inverted real image of the original image;
A variable focus microlens array that changes the focal length in n steps based on the first means, and a second microlens array, and an enlargement correction of the reduced inverted real image formed by the first lens set A second lens set for forming a real image,
The enlarged erect real image and the original image on the plane have the same size, and the variable focus microlens array is arranged at a focal position of the second microlens array. Original display device. The three-dimensional display device according to claim 1, wherein the variable focus microlens array is a variable focus microlens array using a dual frequency liquid crystal. 3. The three-dimensional display device according to claim 1, wherein the first or second microlens array and the variable focus microlens array are a Fresnel lens array or a diffractive lens array. . A display device;
A polarization switching device that is provided on the viewer side of the display device and switches a polarization direction of a two-dimensional image incident from the display device between a first polarization direction and a second polarization direction;
A polarized bifocal lens device provided on the observer side of the polarization switching device;
In the polarization switching device, when the polarization direction of the two-dimensional image incident from the display device is switched to the first polarization direction, two display surfaces at different depth positions as viewed from the observer are displayed. One of the two-dimensional images obtained by projecting the display target object from the viewing direction of the observer is displayed on the display device, or the two-dimensional image incident on the polarization switching device from the display device. When the polarization direction is switched to the second polarization direction, the display target object is projected from the viewing direction of the observer onto two display surfaces at different depth positions as seen from the observer. Means for displaying the other two-dimensional image in the two-dimensional image on the display device,
The means changes the brightness of the two-dimensional image displayed on the display device independently for each of the two two-dimensional images,
The polarized bifocal lens device includes a first lens group that includes a first microlens array and forms a reduced inverted real image of an original image;
A polarizing bifocal microlens array having different focal lengths when the incident light is in the first polarization direction and the second polarization direction, and a second microlens array, A second lens set that forms an enlarged upright real image of the reduced inverted real image formed by the first lens set;
The enlarged upright real image and the original image on the plane have the same size, and the polarizing bifocal microlens array is disposed at a focal position of the second microlens array. 3D display device. The three-dimensional display device according to claim 4, wherein the first or second microlens array and the polarization type bifocal microlens array are a Fresnel lens array or a diffractive lens array.

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