JP2002221691A - Stereoscopic image display method and stereoscopic image display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereoscopic image display method which enables an observer to well observe stereoscopic images without fatiguing when the observer observes the stereoscopic images by utilizing a super-multinocular stereoscopic display and a stereoscopic image display device using the same. SOLUTION: A luminance distribution having the minimum area in a string of the luminance distributions indicating the same object at a ray focal plane in the stereoscopic image display method of focusing the adjustment of the observer's eyes to the intersection point position of the rays with each other by making the plural rays incident on the observer's pupils is defined as the minimum object and the set of the rays radiated from the minimum object is defined as an object ray flux. The display device in the method described above is so installed that the distance L from the observer's pupils to the simultaneous intersection point position of the object ray fluxes, the distance 1 from the observer's pupils to a position where the diameter of the object ray fluxes is minimum, the spacing d of the farthest object ray fluxes with each other on the pupil surface among the object ray fluxes and the diameter ϕof the diameter when the object ray fluxes are made incident on the pupils are adequate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional image display method and a three-dimensional image display device using the same, and more particularly, to reduce the burden on the eyes of an observer when observing a three-dimensional image, and to maintain a natural condition without fatigue. TECHNICAL FIELD The present invention relates to a stereoscopic image display method that can be observed at a high speed and a stereoscopic image display device using the same.

[0002]

2. Description of the Related Art Conventionally, various methods have been tried as a method of reproducing a three-dimensional image (three-dimensional object, three-dimensional object).

[0003] Among these methods, a method of causing a viewer to perform stereoscopic vision using binocular parallax (for example, a polarized glasses method or a lenticular method) is widely used.

However, in these methods, since inconsistency occurs between stereoscopic recognition by the accommodation function of the eyes and stereoscopic recognition by binocular parallax, the observer often feels tired and uncomfortable. Therefore, several methods of three-dimensional image reproduction satisfying other three-dimensional recognition functions of the eye without relying only on binocular parallax have been attempted.

Proceedings of "3D Image Conference 2000", pp95-98, "3D Image Reproduction by Ray Reproduction Method"
Discloses a new stereoscopic display method for expressing a 3D image (stereoscopic image) using intersections of light rays. In this method, as shown in FIG.
tion) 281, Light beam deflection 2
82, Emission point array 283-3
A three-dimensional image is represented by forming intersections of light rays using two means. The light beam generating means 281 forms a parallel light beam having a small diameter, and the light beam deflecting means 282 converts the parallel light beams into three beams.
A ray intersection is formed by intersecting at an arbitrary position in the dimensional space. All the points where the light beam is deflected are arranged at a high density as a light beam emission point sequence 283. According to the above document, if two or more rays forming the intersection point are simultaneously incident on the pupil 285 of the observer 284, the focus adjustment of the observer's eye is guided to the vicinity of the stereoscopic image and the stereoscopic image is adjusted. It is said that fatigue and discomfort of the observer are reduced.

[0006]

In the above-mentioned prior art, when the intersection of light rays cannot be recognized as one bright point,
An image on the fundus of the observer is formed in the same number as the number of light beams, and the adjustment (focus adjustment) of the observer's eyes is focused on the position where the light beam diameter is the smallest. In such a situation, the observer does not lead the focus adjustment of the eye to the vicinity where the stereoscopic image is formed, and the stereoscopic recognition by the eye adjustment function is performed similarly to the conventional stereoscopic image display method by the binocular parallax method. There is a contradiction between this and stereoscopic recognition by binocular parallax. For this reason, a defect that the observer feels tired or uncomfortable occurs. Therefore, it is necessary to determine in advance the conditions for guiding the adjustment of the observer's eyes to the vicinity of the position where the stereoscopic image is correctly formed.

Japanese Patent Application No. 2000-70289 discloses a technique for obtaining such conditions by a geometrical optics method. This is because the state of the image formed on the fundus by multiple light rays incident on the observer's monocular (pupil) is compared and examined by geometrical optics analysis, and the adjustment of the observer's eye is easily guided to the ray intersection position. We are looking for a certain condition. In the geometric analysis at this time, when judging the state of blurring of the fundus image, the analysis is performed at the minimum unit = pixel level constituting the image.

In practice, the degree of overlap between the fundus images of the individual pixels does not significantly affect the judgment of the human visual recognition system, and the observer of a continuous image composed of a plurality of pixels is not affected. The degree of overlap between images in the fundus often affects depth perception.

The present invention provides a stereoscopic image display method and a stereoscopic image display method using the supermultiple stereoscopic display, which enable the observer to observe the stereoscopic image well without fatigue when observing the stereoscopic image. An image display device is provided.

[0010]

According to a first aspect of the present invention, there is provided a stereoscopic image display method, wherein a plurality of light beams are made incident on an observer's pupil, and the eye of the observer is adjusted at the intersection of the light beams. In a three-dimensional image display method for focusing, when one of a series of luminance distributions representing the same object on a ray focal plane has a minimum area, a minimum object is obtained, and a set of light rays emitted from the minimum object is an object light flux. , The distance from the observer's pupil to the intersection point of the object light fluxes is L, the distance from the observer's pupil to the position where the diameter of the object light flux is minimum is l, the pupil of the object light flux When the distance between the object beam bundles farthest on the plane is d and the diameter of the object beam bundle when entering the pupil is φ, the distance between the distance L and the distance l It is characterized by setting the magnitude relationship between d and the diameter phi.

According to a third aspect of the present invention, there is provided a three-dimensional image display method in which a plurality of light beams are made incident on an observer's pupil, and adjustment of the observer's eye is focused on the intersection of the light beams. , The smallest object in a series of brightness distributions representing the same object on the ray focal plane is the smallest object, and the set of rays emitted from the smallest object is the object ray bundle. Ω, the number of object light fluxes incident on the pupil is n, the distance between the object light fluxes farthest on the pupil plane among the n object light fluxes is d, and the distance between the object light fluxes entering the pupil of the object light flux is d. Φ is the diameter, l is the distance from the observer's pupil to the position where the diameter of the object light beam is minimum, and l is the distance from the observer's pupil to the intersection of the object light beams. Is L and the angular resolution ρ of the observer's eye is:

[0012]

(Equation 5)

When L> l,

[0014]

(Equation 6)

The three-dimensional image to be reproduced is selected so as to satisfy the following.

According to a third aspect of the present invention, in the second aspect, the resolution of the stereoscopic image is suppressed so that the size Ω of the minimum object satisfies the conditional expression when an image to be displayed is generated. I have.

According to a fourth aspect of the present invention, in the second aspect, the maximum spatial frequency of the image to be displayed is detected, and the size Ω of at least the area where the minimum object size Ω does not satisfy the conditional expression is detected. An image is displayed after performing image processing for lowering the spatial frequency to a level that satisfies the conditional expression.

According to a fifth aspect of the present invention, there is provided a three-dimensional image display method in which a plurality of light beams are made incident on an observer's pupil, and adjustment of the observer's eye is focused on an intersection of the light beams. Wherein the light beam has a diffusion characteristic only in the vertical direction, or a cross section of the light beam at the pupil position of the observer is horizontally short and vertically long, and the light beam focal plane When the smallest object in the series of luminance distributions representing the same object at is the smallest object, and the set of rays emitted from the smallest object is the object ray bundle, the horizontal width of the smallest object is Ω _h , the number of n _h of the horizontal component of the object light beam incident on the pupil, the horizontal distance of the most distant object light beams having on the pupil plane of the n objects ray bundle d,該O The horizontal width phi _h when entering the pupil of the object light beam, the distance l from the observer's pupil to a position where the diameter of the object light beam is minimized, the observer's pupil between the object light beams Assuming that the distance to the intersection point is L and the angle subdivision function of the observer's eye is ρ,

[0019]

(Equation 7)

When L> l,

[0021]

(Equation 8)

A feature is that a stereoscopic image to be reproduced is selected so as to satisfy the following.

[0023] The invention of claim 6 is the invention of claim 5, when generating the image to be displayed, that the horizontal width Omega _h of the minimum object to suppress the resolution of the stereoscopic image so as to satisfy the condition Features.

The invention of claim 7 is the invention of claim 5 detects the maximum spatial frequency of the image to be displayed, the area horizontal width Omega _h of at least the minimum object does not satisfy the conditional expression width to a level where Omega _h satisfies the condition is characterized by displaying an image after performing image processing to reduce the spatial frequency.

According to an eighth aspect of the present invention, in any one of the second to seventh aspects, the distance d between the most distant object light beams among the plurality of object light beams in each of the conditional expressions is determined by an observer. It is characterized by satisfying the conditional expression replaced with the pupil diameter d _p .

According to a ninth aspect of the present invention, there is provided a three-dimensional image display apparatus wherein a three-dimensional image is observed using the three-dimensional image display method according to any one of the first to eighth aspects.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a stereoscopic image display method according to the present invention and a stereoscopic image display device using the same (stereoscopic display device)
A technical field to which the present invention is applicable will be described.

The three-dimensional image display device of the present invention can be applied to a three-dimensional display device of a type that expresses the depth of a three-dimensional image at the intersection of a plurality of light rays incident on a single eye of an observer. First, the principle of stereoscopic vision for this type of stereoscopic display device will be described.

Many conventional stereoscopic display devices express stereoscopic images using binocular parallax. This is because when a human observes a three-dimensional object with both eyes, there is a parallax between the retinal image of the right eye and the retinal image of the left eye. The principle is that stereoscopic recognition becomes possible if two images having the following are independently presented to the left and right eyes.

FIG. 1 is an explanatory diagram of the principle of the three-dimensional recognition. FIG. 1 shows a state in which the depth of a point 1 on a solid (object) 2 is recognized using binocular parallax. Reference numeral 3 denotes an image display surface, on which a solid 2 is displayed. When the point 1R is displayed on the image display surface 3 and is presented only to the right eye ER, and the point 1L is displayed on the image display surface 3 and is presented only to the left eye EL, the convergence of the eye becomes point 1 And the human visual recognition system uses a straight line connecting the point 1R and the right eye ER, and a point 1L and the left eye EL
Can be three-dimensionally recognized at the intersection of the straight lines connecting.

However, at this time, the adjustment of the lens of the eye is point 1
However, there is a divergence between accommodation and convergence of the eye. It is said that if this deviation is large, an unreasonable load is imposed on the visual recognition system, which may cause fatigue and discomfort.

On the other hand, various types of stereoscopic display devices of the type which expresses stereoscopic vision by the intersection of a plurality of light rays incident on a single eye (pupil) as shown in the conventional examples have appeared.

FIG. 2 is an explanatory diagram of the principle of the three-dimensional recognition. FIG. 2 shows a state in which the depth of the point 1 on the three-dimensional object 2 similar to that of FIG. 1 is recognized using the parallax in the monocular 5.

Reference numeral 3 'does not need to be an image display surface, and can be considered as a light beam focal plane where light beams representing a three-dimensional object are the thinnest. (Because the diameter of the light beam is the smallest at the light beam focal plane, and the light appears to diverge therefrom, the light beam cross section at the light source surface is referred to herein as the "light source.") In order to generate parallax in the monocular 5, a plurality of light rays need to be independently incident on different positions of the crystalline lens (pupil) 4 of the eye at different angles as shown.

In FIG. 2, the position 4L of the pupil (lens) 4 of the eye,
Light rays incident on the two positions of 4R are separated from each other and intersect at point 1.

In such a situation, the human visual recognition system recognizes the intersection 1 of the two light beams as the divergence point of the light beam, adjusts the crystalline lens 4 so that the eye 1 is in focus, and adjusts the fundus 5.
There is a possibility that an image point 1E is formed at a.

However, the human visual recognition system does not always recognize the intersection 1 of the light beam as the divergence point of the light beam. Even in the same situation, there is a possibility that the focus is on the light beam focal plane 3 'as shown in FIG. 3 and two independent image points 3EL and 3ER are formed on the fundus 5a. (Here, for convenience, the state of FIG. 2 is referred to as an intersection focus state, and the state of FIG. 3 is referred to as a light source focus state.) In a stereoscopic display device of a type in which parallax is generated within a single eye, the intersection focus state is more than the light source focus state. Is preferentially generated.

Japanese Patent Application No. 2000-7 proposed together by the present inventors.
In Japanese Patent No. 0289, in this type of three-dimensional display device, a condition for preferentially generating an intersection focus state is obtained by a geometric optics method. However, at this time, with respect to the image forming state on the fundus of the observer, the image forming state at the level of each pixel serving as a light source of a single light ray is analyzed. In practice, the degree of overlap between the fundus images of a series of images composed of a plurality of pixels has a greater effect on the depth perception of the observer than the state of image formation and the degree of overlap of individual pixels.

This will be described with reference to FIGS.

First, the aforementioned Japanese Patent Application No. 2000-70289.
The image forming state of the fundus image at the pixel level, which is also analyzed in FIG.

FIG. 4 shows a geometrical optical relationship including the eye lens 4 when the eye is focused on the light source of the light beam, that is, the pixel. In FIG. 4, three rays form an intersection. However, since the focus of the eye is not at the intersection of the rays but at the pixel, images of three light sources (pixels) are formed on the fundus. FIG. 5 shows an image diagram of the fundus image at this time. FIG. 5 is characterized in that the fundus images of the three pixels are separated from each other and are in focus, so that the areas of the images are all small.

FIG. 6 shows a geometrical optical relationship including the eye lens 4 when the eye is in focus at the intermediate position B between the pixel and the ray intersection. In FIG. 6 as well, images of three light sources (pixels) are formed on the fundus, and the images are partially overlapped. In addition, since the focus of the eye is slightly shifted from the pixel position, the image of each pixel includes blur. An image diagram of the fundus image at this time is as shown in FIG. FIG. 7 is characterized in that the fundus images of three pixels partially overlap each other and the focus is slightly blurred, so that the area of each image is slightly larger than in FIG.

FIG. 8 shows a geometrical optical relationship including the eye lens 4 when the eye is focused on the position of the ray intersection. In this figure, although the images of the three light sources (pixels) are completely overlapped on the fundus, they are blurred because the eye is out of focus from the pixel position. An image diagram of the fundus image at this time is as shown in FIG. FIG. 9 shows a state in which the fundus images of the three pixels overlap with one another and the focus is out of focus. The area of the image of each pixel is larger than that of FIG.
The feature is that the sum of the image areas of all the pixels is smaller than that in FIG.

In Japanese Patent Application No. 2000-70289, the condition that the sum of the areas including the blur of the fundus image of each pixel is minimized,
In addition, a condition that the fundus images of the respective pixels do not separate as shown in FIG. 5 but overlap at least as shown in FIG. 7 is derived, and the condition is such that the eye is more easily focused on the ray intersection.

Next, a description will be given of how conditions change when a fundus image forming state is similarly considered for a series of images formed of a plurality of pixels and representing the same object.

First, as shown in FIG. 10, a series of images (having a luminance distribution) constituted by a plurality of pixels P and representing the same object is defined as an object O.

FIG. 4 shows an example in which the eye is focused on a pixel.
, Three different objects O1, O
Pixels P1, P2, and P3 at the upper left corners of the pixels 2 and O3 are imaged separately from each other as shown in FIG.
However, paying attention to each object, the three objects overlap each other and form an image. In such a state, the observer should recognize that the objects O <b> 1 to O <b> 3 are connected based on the degree of overlap between the objects, without being conscious of separation of the individual pixels.

On the other hand, the separation between pixels is further increased, and the objects may be separated and recognized as shown in FIG. In this case, the observer's visual recognition system recognizes the objects O1 to O3 as being "away".
It can be seen from the figure that the condition is much looser than the condition of separation / non-separation between pixels.

Therefore, when determining the condition that makes it easy to focus on the ray intersection, it is more practical to analyze the connected image composed of a plurality of pixels to obtain the condition than to analyze at the pixel level. Conditions can be determined. In the present invention, based on such a concept, a condition that makes it easy to focus on the ray intersection is obtained.

Next, an analysis procedure for a series of images which are constituted by a plurality of pixels as described above and represent the same object will be described below.

First, a series of images composed of a plurality of pixels and representing the same object is called an object, and a set of a plurality of rays emitted from the object is called an object ray bundle. Furthermore, in this analysis, objects with the smallest size (objects with an area) among objects of various sizes (objects closest to the pixel size)
Is called the minimum object, and this is analyzed.
This is because it is considered that, if the condition that makes it easy to focus on the object light beam intersection in the minimum object is satisfied, even an object having a larger size can be easily focused on the object light beam intersection. The size Ω of the smallest object in an image is
It can be obtained as the reciprocal of the maximum spatial frequency υ of the image.

Ω = 1 / υ In the case of a three-dimensional display device of a type in which the depth of a solid is represented by the intersection of a plurality of light rays incident on a single eye (pupil), the intersection of the object light flux bundle is particularly reduced to reduce the amount of information. Is often limited only to the horizontal direction. Therefore the minimum vertical size of the object is not related at all to the derivation of the condition when, may be derived conditions by focusing only in the horizontal direction length Omega _h minimum objects in an image.

In the following description for deriving the condition, the geometric analysis which has been conventionally performed at the pixel level is performed at the minimum object level. That is, the geometric analysis that has been conventionally performed on a single ray and pixel is applied to the object ray bundle and the smallest object. In the following description, “object” means a minimum object unless otherwise specified.

FIG. 13 is a geometrical optics model simulating a single eye observing a reproduced image of a stereoscopic display device of a type in which the depth is expressed by the intersection of a plurality of object light beams entering the single eye (pupil). . It is assumed that the eye lens and the fundus are separated by s', and that the eye is in focus at a position conjugated with the fundus, which is separated by s from the eye lens 4 (the crystalline lens). When three different object light beams enter the single eye, light emitted from the three objects enters different positions of the lens 4 of the eye and reaches the fundus. The object image at this time is blurred. Further, if the interval between the three object light beams is sufficiently small, the three object images are regarded as one connected image, and are recognized as one blurred image. The overall amount of blur is determined by the amount of blur of each object image and the amount of separation between object images. Therefore, the amount of blur of the object image and the amount of separation between the object images are calculated, and the overall amount of blur is calculated.

When the distance s between the focus positions of the eyes is changed, the overall blur amount also changes, but the value of the distance s at which the overall blur amount is minimum is extremely important.
This is because if there is a distance s at which the overall blur amount is minimized, it is considered that the lens accommodation of the eye is guided to that position. If a condition can be derived such that the value of the distance s always coincides with the position of the intersection of the object ray bundle, a stereoscopic display device effective for reducing the load on the visual recognition system can be configured.

Whether or not a plurality of object images formed on the fundus are connected and recognized as one is determined by the blur amount of each object image and the number of object light fluxes incident on a single eye (the number of parallaxes in a single eye). Depends on. Therefore, the number of object ray bundles to be incident on a single eye from the condition that the object images are connected and recognized (the required number of intraocular disparities)
Can be requested.

First, it is determined from the total blur amount at the fundus. FIG. 14 is a geometrical optical model for deriving the blur amount of the object image. The parameters used for the calculation are as follows.

S: distance from the eye lens to the focus position of the eye s ': distance from the eye lens to the fundus l: distance from the eye lens to the object l': distance from the eye lens to a position conjugate with the object position Ω : The size of the object φ: The diameter of the object light beam incident on the eye lens h: The maximum angle of view from the object The distance between the main object light beams δ: The diameter of the circle of confusion of the edge of the object image When the above parameters are used , The blur amount σ = h + δ of the object image is obtained.

Confusion circle diameter of edge of object image

[0060]

(Equation 9)

From the paraxial relationship

[0062]

(Equation 10)

Therefore, by deleting l ′ from the above equation,

[0064]

[Equation 11]

Maximum angle of view from object Distance between main object ray bundles

[0066]

(Equation 12)

Therefore,

[0068]

(Equation 13)

Next, the separation amount of the object image is obtained. FIG. 15 is a geometrical optical model for deriving the amount of separation of an object image. The parameters used for the calculation are as follows.

L: distance from the eye lens to the object light beam intersection point L ': distance from the eye lens to the position conjugate to the object light beam intersection point D: distance between objects (parallax) D': focus position of the eye D: distance between object light fluxes incident on the eye lens d ′: separation amount of the image center at the fundus, where d ′ is the farthest 2 of the plurality of object light fluxes incident on the eye This is the amount of separation between the images by the book object light beam.

[0071]

[Equation 14]

FIG. 16 shows the relationship between the parameters.
become that way. Summarizing the above

[0073]

(Equation 15)

Is obtained.

From the above equation, the overall blur amount Σ _{s = L} when the eye is focused on the stereoscopic image is

[0076]

(Equation 16)

The total blur amount Σ _{S = l} when the eye is in focus on the object is

[0078]

[Equation 17]

It can be seen that

In the present embodiment, the magnitude relationship between the distance d and the diameter φ is set according to the magnitude relationship between the distance L and the distance l.

The above equation (1) is developed by dividing the case according to the magnitude relation of s, l, and L, and the change of the blur amount に 対 す る with respect to the change of s is graphed as follows.

[If l> L]

[0083]

(Equation 18)

FIG. 17 shows a graph in which Σ is plotted on the vertical axis and s is plotted on the horizontal axis based on the above equation.

From the graph, it can be seen that when d> φ, ｓ has the minimum value at s = L, and when d <φ, s = 1 and Σ has the minimum value.

Since the visual recognition system is considered to adjust the crystalline lens so as to minimize the spread of the image on the fundus, the position where Σ takes the minimum value can be regarded as the position of the observer's adjustment. In other words, in order for the observer's adjustment to easily match the object ray intersection, it is necessary that Σ take a minimum value with s = L,
It can be seen from the above graph that d> φ is a condition to be satisfied. (If s = 1, the observer adjusts to the object itself.) Therefore, if l> L,

[0087]

[Equation 19]

The stereoscopic image to be reproduced is selected so as to satisfy the above condition.

[When l <L] When Σ is obtained in the same manner as when l> L,

[0090]

(Equation 20)

FIG. 18 shows a graph in which Σ is the vertical axis and s is the horizontal axis based on the above equation. From the graph, d> φ
When s = 1, Σ takes the minimum value, and when d <φ, s = L
It can be seen that Σ takes the minimum value.

Since the visual recognition system is considered to adjust the crystalline lens so as to minimize the spread of the image on the fundus, the position where Σ takes the minimum value can be regarded as the position of the observer's adjustment. In other words, in order for the observer's adjustment to easily match the object ray intersection, it is necessary that Σ take a minimum value with s = L,
It can be seen from the graph that d <φ is a condition to be satisfied.

Then, if l <L,

[0094]

(Equation 21)

The stereoscopic image to be reproduced is selected so as to satisfy the following condition.

Next, the condition of the multiplier n of the object light beam entering the pupil is determined. FIG. 19 also shows an image at the fundus. As can be seen, when an image is formed by n object light beams within the maximum image separation amount d ′, the distance between the images is

[0097]

(Equation 22)

Is represented by ε is the eye resolution ρ (unit is ra
If d is less than d), all the images appear to be connected, so that an image formed by a plurality of object light beams is recognized as one blur, and a three-dimensional image reproduction by the object light beam reproduction method is easily established. Then, when the condition of n satisfying ε <ρ is obtained,

[0099]

(Equation 23)

By substituting d′ σ and solving for n−1,

[0101]

(Equation 24)

When the above equation is verified in the range of L <s <l or l <s <L, Therefore, in the above range, the right side has the maximum value when s = 1. (Although the range of s exists infinitely, it seems practically sufficient to consider only the above range.) Therefore, the condition that n must satisfy in order for the retinal image to be recognized as one blur is

[0103]

(Equation 25)

Is obtained.

However, since the number of rays incident on the observer's monocular is generally determined in advance by the specifications of the apparatus, conversely,
(2) The condition of the size Ω to be satisfied by the minimum object can be derived by using n in the equation as a constant. The conditional expression for that is

[0106]

(Equation 26)

Is obtained. In this case, it is desirable to select and display a stereoscopic image in which the size of the smallest object in the image satisfies the expression (3). For example, (A-1) the resolution of the stereoscopic image is suppressed in advance when the image is generated, and only the solid having a low spatial frequency is displayed. (A-2) The maximum spatial frequency of the image to be displayed is detected. For an area that is not satisfied, display is performed by performing processing such as performing image processing for lowering the spatial frequency to a level that satisfies Expression (3) and then displaying.

When a stereoscopic image display device is actually constructed, the parallax information in the vertical direction is removed due to a reduction in the amount of information or a problem in the device configuration, and a stereoscopic image is reproduced only with the parallax in the horizontal direction. I often do it.

In this case, in order to secure the observation area in the vertical direction, the object light beam incident on the pupil should be light that spreads in the vertical direction as shown in FIG. 21 or it has directivity in the horizontal direction and diffuses only in the vertical direction. It is desirable that the object light beam has light characteristics.

The above conditional expression is obtained assuming that the cross section of the object light beam at the pupil position is rotationally symmetric as shown in FIG. 20, but in the case of FIG. the minimum diameter Omega bundles of rays, the horizontal width phi _h of each object light beam, if the conditional expression is replaced by the horizontal minimum diameter Omega _h object light beam, similarly focus object light beam intersection side of the eye It is possible to derive conditions that are suitable for

That is, the horizontal width of the smallest object is Ω.
_h , the number of horizontal components of the object ray bundle incident on the pupil is n _h , the horizontal distance between the object ray bundles farthest on the pupil plane among the n object ray bundles is d, The horizontal width at the time of incidence on the pupil is φ _h , the distance from the observer's pupil to the position where the diameter of the object light beam becomes minimum is l, and the distance from the observer's pupil to the intersection of the object light beams is When the distance is L and the angle subdivision ρ of the observer's eye is

[0112]

[Equation 27]

When L> l,

[0114]

[Equation 28]

That is, a stereoscopic image to be reproduced is selected so as to satisfy the following.

Next, an example of the configuration of a stereoscopic display device to which the above conditions are applied will be described.

(Structure Example 1) In Japanese Patent Application No. 9-368961, the same super-multi-view area display as in the prior art is realized by using liquid crystal shutter glasses. FIG. 22 is a block diagram showing the configuration of the present invention. In the figure, reference numeral 100 denotes stereoscopic spectacles as image separation means, reference numeral 200 denotes a monitor as display means for switching and displaying parallax images at a high speed, and reference numeral 200a corresponds to a light beam focal plane (luminance distribution forming plane). A controller 300 controls switching of parallax images and a slit opening of the stereoscopic observation glasses 100, and also has an interface function with a video source.

The controller 300 is a monitor driving circuit 3
01, a glasses driving circuit 302 for slitting the stereoscopic observation glasses 100, a synchronization circuit 303 for synchronizing parallax image information displayed on the monitor 200 and slit formation of the stereoscopic glasses.
have.

FIG. 23 is a perspective view of an essential part of the stereoscopic observation glasses. In the figure, 101L and 101R are observation frames as observation means that can be observed by an observer through an aperture, and 102L and 10R.
Reference numerals 2R, 103L, and 103R denote light blocking portions in the observation frame 101 that block light, 104R and 104L denote slits through which light can pass, and TS denotes the width of the slit 104.

The slit 104 is scanned (scanned) in the horizontal direction at a high speed, and a parallax image corresponding to the position of the slit is displayed on the monitor 200 in synchronization. Slit 104
If the width TS is sufficiently smaller than the pupil of the observer, a plurality of object beam powers will be incident at intervals smaller than the pupil of the observer, and a three-dimensional image can be expressed at the intersection of the object beam bundle Becomes

When the present invention is applied to the above-mentioned Japanese Patent Application No. 9-368961, the horizontal width Ω _h of the minimum object is derived from the equation (3) based on the multiplier of the object ray incident on the monocular of the observer. Can also. For example, l = 600m
m, L = 300 mm, d _p = 4 mm, horizontal width Ω _h of the smallest object = 1.5 mm, and eye resolution ρ is 1 ′ (=
2.9 * 10 ^-4 rad), and when the number of object light rays entering the monocular is limited to two, n = 2 is obtained by applying the equation (3) to only the horizontal component and Ω _h > 3.83. Is obtained, the stereoscopic image is selected so that the horizontal width of the smallest object in the image to be displayed is about 3.9 mm or more. Specifically, (a-1) an image is generated in which the horizontal width of the minimum object is 3.9 mm or more by suppressing the resolution of the stereoscopic image at the time of image generation in advance, and (a-2) an image to be displayed. Of the maximum spatial frequency of the minimum object, and in a region where the horizontal width of the minimum object is 3.9 mm or less, image processing for lowering the spatial frequency to a level of 3.9 mm or more is performed and then displayed. Display.

(Structural Example 2) In Japanese Patent Application Laid-Open No. H11-174377, a stereoscopic display device that expresses a stereoscopic depth at the intersection of a plurality of light beams incident on a single eye without using special glasses or a device mounted on the head. Has been realized.

FIG. 24 is a schematic diagram of a three-dimensional image reproducing apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 11-174377. In the figure, reference numeral 501 denotes an image display, on which an image 507 is displayed. In the figure, reference numeral 502 denotes a convex lens (lens system).
Reference numeral 503 denotes an opening forming unit, which can electronically switch the transmittance at an arbitrary position to form an optical opening 504. The image display 501 and the aperture forming unit 503 are driven and controlled by an image controller 505 and an aperture controller 506, respectively. The two control devices 505 and 506 are connected by signal lines and can synchronize with each other.
The opening 504 moves at high speed over the entire area of the opening forming means 503 at a constant period T.

A method of reproducing a three-dimensional image at the intersection of a plurality of light beams using the above-described device will be described with reference to FIG. A corresponding image is selected and displayed on the image display 501 in synchronization with the position of the opening 504. The selection of an image is performed as follows. When reproducing the three-dimensional image 1, the intensity distribution of the image 501 serving as a light source of the light may be controlled so that the light emitted from the opening 504 always passes through the three-dimensional image 1. For example, when the opening 504 is located at the position of the opening 504a in the figure, the three-dimensional image 1
The reverse ray tracing is performed on the light passing through the aperture 504 in consideration of the refraction of the convex lens 502, and it is determined that luminance should be given to the pixel 501a. That is, when the opening position is the opening 504a, luminance is given to the pixel 501a. Even when the opening 504 is moved and is located at the position of the opening 504b in the drawing, luminance can be similarly given to the pixel 501b, and a light ray passing through the three-dimensional image 1 can be generated. If these actions are repeated at high speed for all aperture positions, the observer can perceive the stereoscopic image 1 as if the light multiplication is diverging. Of course, when the three-dimensional image is not a point image but a plurality of point images, it is only necessary to give luminance to a plurality of pixels so as to simultaneously generate a plurality of light beams.

The above-mentioned Japanese Patent Application Laid-Open No. H11-174377 also discloses an embodiment in which the light beam deflection in the vertical direction is omitted in order to reduce the amount of information. FIG. 26 is a schematic view of the embodiment. As the opening 504, a rectangular slit long in the vertical direction as shown in the figure is employed. in this case,
Since the aperture is moved only in the horizontal direction, the light beam is also deflected only in the horizontal direction. FIG. 27 is a side view of the above configuration. The vertical component of the image 507 forms an aerial image at the position 507 ′ in the figure by the convex lens 502, and the observer observes this aerial image.

When the present invention is applied to the above-mentioned Japanese Patent Application Laid-Open No. H11-174377, the condition of the minimum object size for guiding the adjustment of the observer's eye to the position of the object light beam intersection can be obtained. In particular, if the power of the object ray incident on the observer's monocular is limited to a certain value or less due to the configuration of the device, derive the minimum object size Ω _h from Equation (3) based on the number. Can also. For example, l = 600 mm, L = 300 mm, d _p = 4 mm,
Ω _h = 1 mm, and the resolution ρ of the eye is 1 ′ (= 2.9 * 10 ⁻⁴ ra
d) and the multiplier of the object ray entering the monocular is 3
If it is limited to a book, by substituting n = 3 into equation (3) and applying only to the horizontal component, Ω _h > 1.83 is obtained. A stereoscopic image is selected to be 1.8 mm or more. Specifically, (c-1) an image is generated such that the horizontal width of the minimum object is 1.8 mm or more by suppressing the resolution of the stereoscopic image in advance when generating the image.
(C-2) detecting the maximum spatial frequency of the image to be displayed,
For an area where the horizontal width of the smallest object is 1.8 mm or less, the image is displayed after performing image processing for lowering the spatial frequency to a level of 1.8 mm or more and then displaying.

[0127]

According to the present invention, a stereoscopic image display method and a stereoscopic image display method capable of satisfactorily observing a stereoscopic image without fatigue when observing the stereoscopic image using super multi-view stereoscopic display. And a stereoscopic image display device using the same can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of stereoscopic recognition according to the present invention.

FIG. 2 is a diagram illustrating the principle of stereoscopic recognition according to the present invention.

FIG. 3 is a diagram illustrating the principle of stereoscopic recognition according to the present invention.

FIG. 4 is an explanatory diagram of a reproduced image of the stereoscopic display device according to the present invention.

5 is an explanatory diagram of a fundus image of a pixel in FIG. 4;

FIG. 6 is an explanatory diagram of a reproduced image of the stereoscopic display device according to the present invention.

FIG. 7 is an explanatory diagram of a fundus image of a pixel in FIG. 6;

FIG. 8 is an explanatory diagram of a reproduced image of the stereoscopic display device according to the present invention.

9 is an explanatory diagram of a fundus image of a pixel in FIG.

FIG. 10 is an explanatory diagram of a pixel and an object according to the present invention.

FIG. 11 is an explanatory diagram of a pixel and an object according to the present invention.

FIG. 12 is an explanatory diagram of a pixel and an object according to the present invention.

FIG. 13 is an explanatory diagram of a reproduced image of the stereoscopic display device according to the present invention.

FIG. 14 is an explanatory diagram of blurring of a light source image in super multi-view stereoscopic vision according to the present invention.

FIG. 15 is an explanatory diagram of blurring of a light source image in super multi-view stereoscopic vision according to the present invention.

FIG. 16 is an explanatory diagram of blurring of a light source image in super-multi-view stereoscopic vision according to the present invention.

FIG. 17 is an explanatory diagram of a relationship between a blur amount and a distance S in the super-multi-view stereoscopic vision according to the present invention.

FIG. 18 is an explanatory diagram of a relationship between a blur amount and a distance S in the super-multi-view stereoscopic vision according to the present invention.

FIG. 19 is an explanatory diagram of a fundus in super-multi-view stereoscopic vision according to the present invention.

FIG. 20 is an explanatory diagram at a pupil position in super-multi-view stereoscopic vision according to the present invention.

FIG. 21 is an explanatory diagram at a pupil position in super-multi-view stereoscopic vision according to the present invention.

FIG. 22 is a configuration block diagram of a super multi-view stereoscopic vision according to the present invention.

FIG. 23 is a perspective view of a main part when the stereoscopic image display device of the present invention is applied to glasses.

FIG. 24 is a schematic view of a main part of a conventional stereoscopic image reproducing apparatus.

FIG. 25 is an explanatory view of a part of FIG. 24;

FIG. 26 is a schematic view of a main part of a conventional stereoscopic image reproducing apparatus.

FIG. 27 is a side view of FIG. 26;

FIG. 28 is a diagram illustrating the principle of a conventional super multi-view stereoscopic vision.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Object point 2 Object (solid) 3 Image display surface 4 Pupil 5 Monocular 100 Image separation means 200 Monitor 300 Controller 301 Monitor drive circuit 302 Eyeglass drive circuit 303 Synchronous circuit 101L, 101R Observation frame 102L, 102R Light shield 103L, 103R Light shield Part 104L, 104R Slit TS Slit width

Claims (9)

[Claims] 1. A stereoscopic image display method in which a plurality of light beams are made incident on an observer's pupil and an eye of the observer is focused on an intersection of the light beams, wherein the same object is represented on a light beam focal plane. When the object having the smallest area in the continuous luminance distribution is the minimum object and the set of light rays emitted from the minimum object is the object light flux, from the observer's pupil to the intersection of the object light fluxes L, the distance from the observer's pupil to the position where the diameter of the object light beam becomes the minimum is l, and the distance between the object light beams that are farthest on the pupil plane among the object light beams is d. When the diameter of the object ray bundle incident on the pupil is φ, the magnitude relationship between the interval d and the diameter φ is set according to the magnitude relationship between the distance L and the distance l. How to Display. 2. A stereoscopic image display method in which a plurality of light beams are made incident on an observer's pupil and the adjustment of the observer's eye is focused on an intersection point between the light beams. The object with the smallest area in the connected luminance distribution is the smallest object,
When the set of rays emitted from the smallest object is an object ray bundle, the size of the smallest object is Ω, the number of the object ray bundles incident on the pupil is n, and the n The distance between the object beam bundles farthest from each other is d, the diameter of the object beam bundle when it enters the pupil is φ, and the distance from the observer's pupil to the position where the diameter of the object beam bundle is the minimum is l. When the distance from the observer's pupil to the intersection of the object light fluxes is L and the angular resolution ρ of the observer's eye is: L> L In the case of L> l, A three-dimensional image to be reproduced is selected so as to satisfy the following. 3. The stereoscopic image display method according to claim 2, wherein when generating an image to be displayed, the resolution of the stereoscopic image is suppressed so that the size Ω of the minimum object satisfies the conditional expression. 4. A maximum spatial frequency of an image to be displayed is detected, and at least a region where the size Ω of the minimum object does not satisfy the conditional expression is reduced to a level at which the size Ω satisfies the conditional expression. 3. An image is displayed after performing image processing for lowering image quality.
3D image display method. 5. A three-dimensional image display method in which a plurality of light beams are made incident on an observer's pupil and the adjustment of the eyes of the observer is focused on the intersection of the light beams. Or a state in which the cross section of the light ray at the pupil position of the observer has a shape that is short in the horizontal direction and long in the vertical direction, and a series of luminance distributions representing the same object in the light ray focal plane. When the object with the smallest area is the smallest object and the set of rays emitted from the smallest object is the object ray bundle, the horizontal width of the smallest object is Ω _h , and the horizontal component of the object ray bundle incident on the pupil Is the number n _h , and the horizontal distance between the object beam bundles farthest on the pupil plane among the n object beam bundles is d,
The horizontal width of the object light beam when entering the pupil is φ _h , the distance from the observer's pupil to the position where the diameter of the object light beam is minimized is l, Where L is the distance to the position of the intersection, and ρ is the angle division function of the observer's eye. In the case of L> l, A three-dimensional image to be reproduced is selected so as to satisfy the following. 6. A time of generation of the image to be displayed, the stereoscopic image display method according to claim 5 in which the horizontal width Omega _h of the minimum object which comprises suppressing the resolution of the stereoscopic image so as to satisfy the condition . 7. A maximum spatial frequency of an image to be displayed is detected, and at least a horizontal width Ω of the minimum object is detected.
_h until the level width Omega _h is the region that does not satisfy the condition satisfies the condition, the three-dimensional image display according to claim 5, characterized in that to display an image after performing image processing to reduce the spatial frequency Method. 8. A conditional expression in which in each of the conditional expressions, a distance d between object beam bundles farthest among the plurality of object light bundles is replaced with a pupil diameter d _p of an observer. The stereoscopic image display method according to any one of claims 2 to 7. 9. A three-dimensional image display apparatus, wherein a three-dimensional image is observed using the three-dimensional image display method according to claim 1.