JPH05103352A - Display device - Google Patents

Abstract

PURPOSE:To display the actual inverted image of each dot of a two-dimensional display on a viewer side of each lens when the viewer seed the dots through the lenses. CONSTITUTION:Small lenses 1a, 1b, and 1c are provided in front of the dots 2a, 2b, and 2c of a two-dimensional display DP in corresponding to the dots 2a, 2b, and 2c and the lengths S1 of optical paths between the lenses 1a, 1b, and 1c and dots 2a, 2b, and 2c are set at a value which is longer than the focal distances (f) of the lenses 1a, 1b, and 1c and equal to or shorter than the double of the focal distance (f). Therefore, when a viewer sees each dot 2a, 2b, and 2c through the lenses 1a, 1b, and 1c, the actual inverted images 2a', 2b', and 2c' of the dots can be displayed on the viewer side of the lenses 1a, 1b, and 1c in an enlarged state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device used in computers, television receivers and the like.

[0002]

2. Description of the Related Art In recent years, three-dimensional images (including stereoscopic images) as seen in computer graphics displays.
There is an increasing need for a technology for displaying the, for example, the document “Image Lab, November 1990, pp. 20-24”.
As disclosed in Japanese Patent Laid-Open No. 2003-242242, a system that actually uses binocular parallax is widely used as a three-dimensional display device. The method using binocular parallax is roughly classified into an eyeglass method and an eyeglass-less method. The method without glasses is
For example, the document “Television Society Journal Vol. 44, No. 5,
Pp. 591-597, 1990 ", it is considered to be used as a television receiver because of its generality.

On the other hand, the spectacle system includes a method using a simple polarizing plate and a color filter for the spectacles, a method having a shutter function in the spectacles, and a method having a two-dimensional display in the spectacles.

In the spectacles method, a method of using a simple polarizing plate is generally used, and a method of projecting two images having different polarizations on a large screen such as IMAX Co., Ltd., or a two-dimensional method such as Sony Tektronix Co., Ltd. There is a method in which a shutter of a polarization filter is provided on the front surface of the display and time-division driving is performed while changing the polarization direction.

Further, in the spectacles system, a spectacle having a two-dimensional display is disclosed in, for example, the document “Image Lab”.
As shown in January 1991, page 29 to page 33 "and the document" Image Lab, January 1991, page 20 to page 23 ", it is also called a head-mounted display (HMD), and has recently been used. It is attracting attention due to research on artificial reality.

[0006]

However, most of the above-mentioned various types of display devices are three-dimensional displays using only binocular parallax,
Since information is displayed stereoscopically using the so-called illusion with only binocular disparity, the eye adjustment mechanism (mechanisms such as focus adjustment) and the vergence mechanism (movement mechanism that gazes at an object) often do not match, Generally, there is a drawback that eye fatigue accumulates when the display is continuously viewed for 20 minutes or more. FIG. 16 is a diagram for explaining this state. For example, two images P1 and P2 are displayed on the screen 210 at a predetermined distance Z, and these two images P1 and P2 are displayed by the human eye. 201,
When binocular vision is performed at 202, the adjustment mechanism of the eyes 201, 202 focuses on the actual distance L1 from the eyes 201, 202 to the screen 210, but the convergence mechanism of the eyes 201, 202 is Towards the image P2, the other eye 20
Since the eyes 201 and 202 are controlled so that 2 is directed to the image P1, the gazing point is the intersection position CLS of these, and in the example of FIG. 16, it is in front of the actual screen. Therefore,
Focusing distance L1 and gazing point CLS distance L2
Therefore, it is considered that eye fatigue is caused by this, and if the screen is continuously viewed for a long time, the larger the difference between L1 and L2, the greater the accumulation of eye fatigue.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a display device capable of displaying a stereoscopic image with less fatigue on the eyes and rich in realism in a simple manner.

[0008]

In order to achieve the above object, a display device according to claim 1 has a minute lens on the front surface of each dot formed of at least one pixel forming a two-dimensional display. It is characterized in that the optical path length between the minute lens and the dot is set to be larger than the focal length of the minute lens and not more than twice the focal length.

The display device according to claim 2 is further characterized in that means for changing the optical path length is provided between the minute lens and the dot.

Further, the display device according to claim 3 is characterized in that means for changing the focal length of the minute lens is further provided.

[0011]

According to the display device of the present invention, a minute lens is provided in front of each dot formed of at least one pixel forming a two-dimensional display. By setting the optical path length to be larger than the focal length of the minute lens and not more than twice the focal length, the real image of dots can be enlarged and displayed in front of the two-dimensional display.

A display device according to a second aspect is the display device according to the first aspect, wherein:
Further, a means for changing the optical path length is provided, whereby the position of the real image of the dots can be changed for the entire screen or for each dot.

According to a third aspect of the present invention, there is provided the display device according to the first aspect, wherein:
Further, means for changing the focal length of the minute lens is provided, and in this case also, the position of the real image can be changed by the above means for the entire screen or for each dot.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a sectional view of a first embodiment of a display device according to the present invention. In the display device shown in FIGS. 1 and 2, dots 2a, 2b, 2c consisting of one pixel are formed on the two-dimensional display DP, and a front glass 3 is provided on the two-dimensional display DP. Furthermore, in this display device, 2
In front of each dot 2a, 2b, 2c of the three-dimensional display DP, minute lenses 1a, 1b, 1c are provided corresponding to each dot 2a, 2b, 2c.

The microlenses 1a, 1b and 1c are lenses having a focal length of f, and the microlenses 1a, 1b and 1c.
The optical path length S1 between c and the dots 2a, 2b, 2c is set to a value larger than the focal length f of the lenses 1a, 1b, 1c and not more than twice the focal length f. By setting in this way, in this embodiment, when the observer looks at each dot 2a, 2b, 2c of the two-dimensional display DP with his / her eyes 5 using the minute lenses 1a, 1b, 1c,
It is intended to display the inverted real images 2a ', 2b', 2c 'of each dot in front of the minute lenses 1a, 1b, 1c.

In such a structure, the microlens 1
a, 1b, 1c are thin lenses, the thickness of the front glass 3 is 0 mm for convenience of calculation, and the minute lenses 1a, 1b, 1c
If the refractive index of the air gap between the front glass 3 and the front glass 3 is "1", the minute lenses 1a, 1b, 1c and the inverted real images 2a ', 2b',
The distance S2 from 2c 'is simply calculated by the microlenses 1a, 1
From the focal length f of b and 1c and the distance S1 between the dots 2a, 2b and 2c and the minute lenses 1a, 1b and 1c, the following formula is obtained.

[0017]

1 / S2 = -1 / f + 1 / S1

Further, the magnifying power β of the inverted real images 2a ', 2b', 2c 'is x'when the distance between the front focus F'of the minute lenses 1a, 1b, 1c and the inverted real images 2a', 2b ', 2c'. , X is the distance between the rear focal point F of the microlenses 1a, 1b, 1c and the dots 2a, 2b, 2c, and is calculated by the following equation.

[0019]

[Equation 2]

Now, for example, the minute lenses 1a, 1b, 1c
Focal length f of 3 mm, the distance S1 between the lens and the dot is 5
mm and the distance S2 between the inverted real image and the lens is 7.5 mm, the magnifying power β becomes 1.5 times according to the equations 1 and 2.

If the distance D between the eye 5 of the observer and the lens is 400 mm, then 392.5 mm from the eye 5 of the observer.
An inverted real image of dots can be seen at a distance of, and the position of the real image can be changed so that the eye gazing point is 7.5 mm before the lens. Therefore, when an image composed of a plurality of these dots is viewed, it is possible to make the image look as if it were in front of the lens surface.

When the optical path length S1 between the lens and the dot is smaller than the focal length f of the minute lens, an erecting virtual image is formed behind the lens and the image cannot be seen in front of the lens. Therefore, in order to show an image in front of the lens, at least the optical path length S1 between the lens and the dot needs to be larger than the focal length f of the lens. However, the optical path length S1 between the lens and the dot is set to the focal length 2
If the magnification is increased up to 2 times, the magnifying power β of the inverted real image becomes 1, and if the optical path length S1 is further increased, the magnifying power β becomes 1.
It becomes less than double, the dots visible on the lens become smaller,
The image deteriorates significantly.

Accordingly, in order to display an image in front of the lens without degrading the image, the optical path length S1 between the lens and the dot is set larger than the focal length f, and the focal length f is 2
It should be set to less than double.

FIG. 3 is a diagram showing an example of a display device in which means for changing the optical path length is further added to the display device having the configuration of FIGS. 1 and 2. In this display device, the means for changing the optical path length is used. The panel PN1 of the two-dimensional display DP and the minute lenses 1a, 1b,
An actuator AT1 that changes the distance Z between the panel PN2 and the panels 1c, ...

In such a structure, the actuator AT
1 the distance Z between the panel PN1 and the panel PN2
And the optical path length is changed to change the position of the visible inverted real image. Figure 4
(A) to (d) are diagrams specifically showing this state,
FIG. 4A shows an inverted real image when the focal length f of the minute lens is 3 mm, the distance S1 between the lens and the dot is 5 mm, and the distance S2 between the inverted real image and the lens is 7.5 mm, for example, the state of 2b '. FIG. In this case, the inverted real image 2b ′ has a magnifying power β of 1.5 times, and is located at a position of 392.5 mm from the observer's eye 5 when the distance D between the observer's eye 5 and the lens is 400 m. You can see this statue.

FIG. 4B shows an inverted real image when the focal length f of the minute lens is 3 mm, the distance S1 between the lens and the dot is 6 mm, and the distance S2 between the inverted real image and the lens is 6 mm.
It is a figure which shows the state of 2b ', for example. In this case, the inverted real image 2b ′ has an enlargement magnification β of 1.0, and when the distance D between the eye 5 of the observer and the lens is 400 m, this image is located at a position 394 mm from the eye 5 of the observer. Can be seen.

Further, FIG. 4C shows an inverted real image when the focal length f of the minute lens is 3 mm, the distance S1 between the lens and the dot is 7.5 mm, and the distance S2 between the inverted real image and the lens is 5 mm. It is a figure which shows the state of 2b '. In this case, the magnifying power β of the inverted real image 2b ′ is 0.667 times,
When the distance D between the eye 5 of the observer and the lens is 400 m, this image can be seen from the eye 5 of the observer at a position of 395 mm.

FIG. 4D shows an inverted real image when the focal length f of the minute lens is 3 mm, the distance S1 between the lens and the dot is 4 mm, and the distance S2 between the inverted real image and the lens is 12 mm, for example, 2b '. It is a figure which shows the state of. In this case, the inverted real image 2b ′ has a magnifying power β of 3 times, and when the distance D between the eye 5 of the observer and the lens is 400 m, the image is seen from the eye 5 of the observer at a position of 388 mm. be able to.

As described above, when the optical path length S1 between the minute lens and the dot is changed within a range larger than the focal length f of the minute lens, the position of the dot seen by the observer, that is, the position of the real image is changed. You can

FIG. 5 is a diagram showing changes in S2 when S1 is changed. As can be seen from Equation 1 and FIG. 5, in practice, the optical path length S1 is larger than the focal length f as described above. Even if the range is changed, the distance S2 between the real image and the lens can be changed only within a range smaller than the focal length f (see ΔS2 in FIG. 5). However, as can be seen from FIG. 5, as the optical path length S1 is brought closer to the focal length f, the distance at which the real image can be seen can be greatly changed closer to the observer.

When the optical path length S1 between the minute lens and the dot is set to a value that is at least twice the focal length f as shown in FIG. 4C, the dot enlargement factor β is as described above. Since it is smaller than 1, the quality of the image formed by these dots deteriorates, which is not preferable.

On the other hand, the apparent magnification m seen from the eye 5 is
Proportional to the angle at which the object is viewed. Therefore, for example, in FIG.
At u, the visual angle of the dot is u, the visual angle of the real image is u ′, and the size of the dot is y, the apparent magnification m is given by the following equation.

[0033]

## EQU00003 ## m = tan (u ') / tan (u) tan (u) = y (D + S1) tan (u') = y * .beta ./ (D-S2)

In this case, as shown in the above example, D
Since (for example, 400 mm) is larger than s1 and s2, the influence of the enlargement magnification β becomes large, and the apparent magnification m
Is 1.55 times larger, and it looks as if there is a dot 7.5 mm in front of the lens. However, since a substance having a diffusing action is not provided on the image plane, what is actually observed by the eye is when one lens is seen by the eye 5 as shown in FIG. It is a portion cut at a visual angle, and unless the distance between the lens and the eye is very small, adjacent lenses do not affect the image seen in the eye.

That is, when the magnifying power β is larger than 1 as shown in FIGS. 4A and 4D, only the dots within the range cut by the visual angle between the lens and the eye can be seen. Although flare light and variations in dots are problems, adjacent dots do not directly affect.

In the above-mentioned example, the distance between the panel PN1 of the two-dimensional display DP and the panel PN2 having the minute lenses 1a, 1b, 1c, ... Is changed by the actuator AT1. Although the total distance (optical path length) between the dots and each microlens was changed, a microactuator that changes the distance between each lens and each dot is provided for each lens. If the distance (optical path length) is changed, it is possible to display a stereoscopic image in which the distance of the real image is changed for each dot by changing the distance of the real image for each dot.

Further, the panel PN1 of the two-dimensional display DP and the panel PN2 having a minute lens are not mechanically moved (that is, without changing the actual distance between the lens and the degree (that is, the lens and the lens). Means for changing the optical path length may also be configured (without changing the actual distance between the dots).

FIG. 6 is a diagram showing an example of the structure of a display device in which a material whose refractive index is changed by applying a voltage is provided in the optical path length. That is, the display device of FIG. 6 further includes the material 23 having an electro-optical effect and the transparent electrodes 24a and 24b on the front glass 3 of the two-dimensional display DP.
And a protective glass 25 are provided.

As a material whose refractive index changes by applying a voltage, a material having an electro-optical effect is known, and examples thereof include an inorganic compound such as LiNbO ₃ and PLZT ceramic, and an organic compound such as liquid crystal and organic polymer. is there.

In such a display device, the electrode 2
By changing the applied voltage between 4a and 24b, the refractive index of the material 23 having the electro-optical effect can be easily and continuously changed. Since the optical path length is the product of the actual distance and the refractive index, it is possible to change the optical path length without changing the actual distance by changing the refractive index of the material 23 having the electro-optical effect. As a result, it is possible to accurately control the optical path length. Moreover, since the optical path length can be changed by the voltage, a simple structure in which electrodes are formed on both ends of a material having an electro-optical effect is sufficient.

Now, for example, a material 23 having an electro-optical effect
A nematic liquid crystal is used as the above, the actual distance between the lens and the dot is 4 mm, and the thickness of the liquid crystal is 2 mm. Further, for convenience of calculation, it is assumed that the thickness of the glass is 0 mm and there is no refraction of light rays in the portion other than the lens.

In this case, when a constant voltage is applied to the electrodes 24a and 24b to change the refractive index n of the liquid crystal to 1.5, the optical path length in the liquid crystal having a thickness of 2 mm is 2 × 1. 5 = 3
mm, and the optical path length S1 between the lens and the dot is 5 mm. FIG. 7A is a diagram showing this state. When the refractive index n of the liquid crystal is 1.5 and the optical path length S1 is 5 mm,
The distance S2 between the inverted real image, for example, 2b 'and the lens, for example, 1b, is 7.5 mm.

If the applied voltage is further changed from this state and the refractive index n of the liquid crystal is set to 1.8, the optical path length in the liquid crystal with a thickness of 2 mm becomes 2 × 1.8 = 3.6 mm, and the lens The optical path length S1 between the dot and the dot is 5.6 mm. Figure 7
(B) is a diagram showing this state, and when the refractive index n of the liquid crystal is 1.8 and the optical path length S1 is 5.6 mm, the distance S2 between the inverted real image 2b 'and the lens 1b is 6.46 mm. Become.

When the refractive index n of the liquid crystal is changed from 1.5 to 1.8 in this way, the distance between the lens and the real image is 1.0.
It can be changed by 4 mm. At this time, the optical path length S1
When is set to a size close to the focal length f, the position of the real image can be largely changed by a change in the optical path length S1 due to a slight change in the refractive index, and the distance of the real image seen from the eye 5 can be greatly changed.

Further, the structure shown in FIG. 6 can be modified into the structure shown in FIG. That is, FIG.
Then, the electrodes 28a and 29a are formed corresponding to the dots 2a, the electrodes 28b and 29b are formed corresponding to the dots 2b, and the electrodes 28c and 29c are formed corresponding to the dots 2c. It is formed for each dot, so that the voltage can be controlled for each dot. In this case, the optical path length can be changed for each dot and the distance of the real image can be changed for each dot in the same manner as when the microactuator described above is provided, and a stereoscopic image can be displayed. Becomes

Although the liquid crystal has been described as an example of the material having the electro-optical effect, the optical path length can be changed and the distance of the real image can be changed in the same manner as the liquid crystal when other electro-optical materials are used. You can At this time, the use of PLZT ceramics or the like has an advantage that it is suitable for increasing the area, as compared with the case of using other crystalline materials.

As described above, by using a material whose refractive index is changed by applying a voltage as a means for changing the optical path length, the structure is simple as compared with the case where an actuator is used, but it is precise and accurate. Control can be performed. In particular, when the optical path length is changed dot by dot, it is preferable to use a material having such an electro-optical effect because it has a simple structure and has good controllability.

The position of the inverted real image can also be changed by changing the focal length f of the minute lens instead of changing the optical path length S1 between the lens and the dot.

FIG. 9 is a diagram showing an example of a display device in which a means for changing the focal length f of a minute lens is further added to the display device having the configuration of FIGS. 1 and 2. In this display device, a plurality of minute devices are used. A panel PN4 having a Natotsu lens and a panel PN5 having a plurality of minute convex lenses are provided as a focus variable optical system, that is, a zoom optical system (two-group zoom of a Noto lens), and the panel PN4, the panel PN5, and the two-dimensional display DP. The distances Z1 and Z2 from the panel PN1 of the actuator AT
It is changed by 2.

In the display device having such a structure,
Panel PN4 and panel PN by actuator AT2
5 is changed by changing the distances Z1 and Z2 between the panel PN1 and the focus variable optical system, that is, the focal length f of the minute lens, and the distance S2 between the inverted real image and the lens is calculated based on the equation 1. Can be changed to change the position of the visible real image.

FIGS. 10 (a) to 10 (c) are views specifically showing this state. In FIG. 10 (a), the distance S1 between the dot and the minute lens is 5 mm, and the focal length f of the minute lens is f.
It is a figure which shows the inverted real image, when 2 is 3 mm, for example, the state of 2b '. In this case, the position S2 of this inverted real image 2b '
Is 7.5 mm, and the enlargement magnification β is 1.5 times.

FIG. 10B is a view showing an inverted real image, for example, a state of 2b 'when the distance S1 between the dot and the minute lens is 5 mm and the focal length f of the minute lens is 2.5 mm. is there. In this case, the position S of this inverted real image 2b '
2 is 6 mm, and the enlargement magnification β is 1.

FIG. 10C is a diagram showing an inverted real image, for example, a state of 2b 'when the distance S1 between the dot and the minute lens is 5 mm and the focal length f of the minute lens is 3.5 mm. is there. In this case, the position S of this inverted real image 2b '
2 is 11.67 mm, and the enlargement magnification β is 2.3 times.

In the above example, the distance between the panel PN1, panel PN4, and panel PN5 of the two-dimensional display DP is changed by the actuator AT2, so that the focal lengths of all the microlenses are changed to be the same. However, by providing a microactuator that changes the focal length of each lens for each lens, and changing the focal length for each lens, the distance of the real image can be changed for each dot. Thus, it is possible to display a stereoscopic image in which the distance of the real image is changed for each dot.

Further, each panel PN1, PN4, PN
It is also possible to configure a means for changing the focal length without mechanically moving 5.

FIG. 11 is a diagram showing a configuration example of a display device in which each minute lens is formed of a material whose refractive index changes by applying a voltage. That is, in the display device of FIG. 11, the minute lenses 22a, 22b, 22c are formed of a material having an electro-optical effect (electro-optical material), and the electrodes 20a are provided between the minute lenses 22a, 22b, 22c. , 20b are arranged.

Examples of the electro-optical material include LiN
The bO ₃ crystal is used, and the minute lenses 22a, 22 are arranged so that an electric field can be applied by the electrodes 20a, 20b along the optical axis.
b and 22c are formed. In this case, the electrodes 20a,
When a high voltage is applied between 20b, the minute lenses 22a, 2a
Reference numerals 2b and 22c serve as electro-optical lenses.

In the display device having such a structure,
By changing the voltage between the electrodes 20a and 20b, the focal lengths of the minute lenses 22a, 22b, and 22c can be changed, and the position of the real image can be changed.
A material having an electro-optical effect can be used as the material whose refractive index is changed by applying a voltage, as described above.

In the display device of FIG. 12, the minute lenses 30a, 30b and 30c are minute liquid crystal lenses 31a, 31b and 31c in which a kind of nematic liquid crystal having a relatively large refractive index is sealed, and the transparent electrodes 32a, 32
b, 32c; 33a, 33b, 33c, and flat glass 34a, 34b, 34c; 35a, 35b, 35c.

Also in the display device having such a configuration, the electrodes 32a, 32b, 32c and the electrodes 33a, 33 are provided.
By applying a voltage between b and 33c, the minute liquid crystal lens 31
By controlling the alignment state of the liquid crystal molecules a, 31b, and 31c, the refractive index of the liquid crystal can be changed, the focal length can be continuously changed, and the position of the real image can be changed.

In addition to this, for example, when a liquid crystal material is enclosed between a circular electrode or an elliptical hole-shaped electrode and a flat plate electrode, and a voltage is applied between the electrodes, the liquid crystal material is not uniform. It is also possible to form a minute lens by aligning liquid crystal molecules with a different electric field distribution and change the applied voltage to change the focal length of the minute lens. Alternatively, the variable focus lens can be configured by a liquid crystal lens having a Fresnel structure.

In the above-described embodiment, as shown in FIG. 1, one minute lens is provided for each dot composed of one pixel forming the two-dimensional display DP. As shown in FIG. 14, one minute lens may be provided for each dot composed of a plurality of pixels, and the present invention can be similarly applied to this case.

That is, in the configuration example of FIG.
A minute lens 1e is provided for each dot 2e consisting of RGB (red), G (green), and B (blue) RGB pixels. At this time, the hue information can be accurately displayed only when there are three RGB pixels.
Compared with the case where a minute lens is provided for each pixel, the performance does not change significantly, and it is easy to create a minute lens as much as the diameter of the lens can be increased.

Further, in the configuration example of FIG. 14, four sets of dots 2f, 2g, 2h, 2i each consisting of 3 pixels of RGB are newly set as one dot, and the minute lens 1f is set for each dot.
Is provided. In this case, although the display accuracy of the information of the thin line or the contour is somewhat lowered, the diameter of the lens can be further increased, and thus it becomes easy to form a minute lens. Further, instead of using four groups as one dot, 3 × 3 = 9 groups can be used as one dot.

In the case of FIGS. 1 and 13, that is, when one dot consists of one pixel or three RGB pixels, 1
Since one dot is one piece of information, there is no problem with the inverted image, but in the case of FIG. 14, that is, one dot is RG.
When the dot is composed of a plurality of B3 pixel sets, it is necessary to display an image in an inverted state at least for each RGB3 pixel in each dot.

Further, in each of the above-mentioned embodiments, FIG.
The display device of FIGS. 6, 7, 8, 11, and 12 does not change the optical path length or the focal length for each dot, and a region wider than the dot, for example, 1 in FIG.
The optical path length over the entire area of dots for one column or one row,
Alternatively, when it is configured to change the focal length, it is suitable for the purpose of giving a gentle three-dimensional effect in a wide area. Specifically, in the case where only three types of changes of the distant view, the middle view, and the near view need to be given, by using these configurations, the optical path length, Alternatively, the focal length can be set to be the same for the distant view, and the optical path length or the focal length can be set to be the same for the near view for all the dots in the near view region.

On the other hand, when these display devices are constructed so that the optical path length or the focal length can be changed for each dot, the optical path length or the focal length can be changed over a fine screen. It is suitable for the application, and in this case, it is possible to obtain a stereoscopic effect for each dot.

However, in any of the above cases, the focal length of the minute lens corresponding to each dot or the lens acting on the entire surface of the two-dimensional display DP, or
Since the refractive index of the layer between these lenses and the dots can be easily set to a predetermined value, by determining the focal length or the refractive index according to the image information to be displayed,
Even when the two-dimensional display DP is used, three-dimensional display is possible, and by applying any of the above display devices to the three-dimensional display device, an image can be displayed at the distance of the gazing point even in the case of stereoscopic vision due to binocular parallax. By forming an image, eye fatigue can be reduced.

FIGS. 15A and 15B are views for explaining this situation. For example, on the two-dimensional screen 210, 2
The two images P1 and P2 are displayed at a predetermined distance Z, and when these two images P1 and P2 are observed, FIG.
FIG. 15A shows a state in which one eye 201 sees the image P2, and FIG. 15B shows a case in which the other eye 202 sees the image P1. The congestion mechanism of the eyes 201 and 202 is shown in FIG.
Since the eyes 201 and 202 are controlled so that the other eye 202 faces toward the image P1, the gazing point is the intersection position CLS between them, and in the example of FIGS. , Which is in front of the actual screen 210. In such a case, the display device according to the present invention is mounted for the left eye and the right eye, respectively, and the display device is controlled according to the image information of the screen 210 to display the screen 2
Since the positions of the ten images P1 and P2 (in this case, the real image positions) can be moved to the position of the gazing point CLS,
As a result, the adjustment mechanism of the eyes 201 and 202 is
The eyes 201, 202 are controlled so as to focus on the distance L2 from the point 1, 202 to the gazing point CLS. As a result, eye congestion and accommodation can be matched, and eye fatigue can be reduced.

Contrary to the above example, the gazing point CLS is the actual distance L1 from the eyes 201, 202 to the screen 210.
When an image at a distance farther than that is displayed on the screen 210, the display device is configured to display a virtual image of the image on the screen 210, and the display device is controlled to display the virtual image at the gazing point. By doing so, it is possible to make eye congestion and adjustment coincide with each other in the same manner, and reduce fatigue.

[0071]

As described above, in the display device according to the first aspect, the optical path length between the minute lens and the dot is larger than the focal length of the minute lens and is twice the focal length. Since it is set as follows, the real image of the dot seen by the observer can be set in front of the two-dimensional display, and at the same time, the real image can be enlarged and displayed.

Further, in the display device according to the second aspect, since the means for changing the optical path length is provided between the minute lens and the dot, the position of the real image of the dot is set on the entire screen or for each dot. Further, when a three-dimensional display is constructed by using this display device, by appropriately changing the optical path length and appropriately changing the image position, eyestrain is reduced and presence is enhanced. It is possible to easily display stereoscopic images.

Further, in the display device according to the third aspect, since the means for changing the focal length of the minute lens is provided, the position of the real image of the dot is set on the entire screen or on the screen.
It can be changed for each dot, and when a three-dimensional display is constructed by using this display device, the focal length is appropriately changed and the image position is appropriately changed, so that eye fatigue is reduced and a sense of reality is reduced. It is possible to easily display a rich stereoscopic image.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of a display device according to the present invention.

FIG. 2 is a cross-sectional view of a first embodiment of a display device according to the present invention.

FIG. 3 is a diagram showing an example of a display device to which means for changing the optical path length is further added.

FIG. 4A to FIG. 4D are diagrams for explaining a state when the optical path length is changed.

FIG. 5 is a diagram showing a relationship between an optical path length and a position of an inverted real image.

FIG. 6 is a diagram showing a configuration example of a display device in which a material whose refractive index is changed by applying a voltage is provided in an optical path.

7 (a) and 7 (b) are diagrams for explaining a state when the voltage is changed to change the optical path length in the configuration of FIG.

FIG. 8 is a diagram showing a modification of the display device of FIG.

FIG. 9 is a diagram showing an example of a display device to which means for changing the focal length of the lens is further added.

FIG. 10A to FIG. 10C are diagrams for explaining the state when the focal length of the lens is changed.

FIG. 11 is a diagram showing a configuration example of a display device in which a minute lens is formed of a material whose refractive index is changed by applying a voltage.

12 is a diagram showing a modification of the display device of FIG.

FIG. 13 is a diagram showing a modified example of the arrangement of dots and minute lenses.

FIG. 14 is a diagram showing a modification of the arrangement of dots and minute lenses.

FIGS. 15 (a) and 15 (b) are views for explaining the principle of matching eye congestion and accommodation according to the present invention.

FIG. 16 is a diagram for explaining a general relationship between eye congestion and accommodation.

[Explanation of symbols]

1a, 1b, 1c, 1e, 1f
Micro lenses 2a, 2b, 2c, 2e, 2f, 2g, 2h, 2i
Dots 2a ', 2b', 2c '
Inverted image 3
Front glass 20a, 20b
Electrodes 22a, 22b, 22c
Micro lens 23
Materials having electro-optic effect 24a, 24b
Electrode 25
Protective glass 27
Electro-optic lens 30a, 30b, 30c
Micro lenses 31a, 31b, 31c
Micro liquid crystal lenses 32a, 32b, 32c, 33a, 33b, 33c
Transparent electrodes 34a, 34b, 34c, 35a, 35b, 35c
Flat lens DP
Two-dimensional display PN1, PN2, PN4, PN5
Panel AT1, AT2
Actuator

Claims (3)

[Claims] 1. A microlens is provided in front of each dot of at least one pixel forming a two-dimensional display, and the optical path length between the microlens and the dot is microlens. The display device is set to be larger than the focal length of, and less than or equal to twice the focal length. 2. The display device according to claim 1, further comprising means for changing an optical path length between the minute lens and the dot. 3. The display device according to claim 1, further comprising means for changing the focal length of the minute lens.