JP2000249974A - Display device and stereoscopic display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stereoscopic display optical system capable of adjusting the position of a virtual image. SOLUTION: A 1st optical system 22 having a positive refractive index and enlarging a picture displayed by a two-dimensional display element 21 as the virtual image and a 2nd optical system 23 for adjusting the position of the virtual image enlarged by the optical system 22 are arranged in an optical path between the element 21 and an eye E. The optical system 22 is fixed, and the element 21 is fixed near the focal plane of the optical system 22, then the optical system 23 is fixed with respect to the optical system 22. In the optical system 23, transparent liquid 31 is stored on the inside of two transparent elastic body films 32 and 33 and an annular body 34 surrounding the peripheries of the films 32 and 33, and either film 33 is deformed by an actuator. The position of the virtual image is adjusted to realize the easy-to-view picture by the optical system 23, and a mechanical] driving mechanism is unnecessitated and the device is made small in size and light in weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying an image displayed by a two-dimensional display element as a virtual image on an observer's eye, and displaying an image with parallax on both eyes of the observer to the observer. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional display device for giving a three-dimensional effect.

[0002]

2. Description of the Related Art Conventionally, various stereoscopic display devices have been researched and developed in the field of virtual reality (virtual space).
As one of such devices, a head mounted device called a head mounted display is known. The head-mounted device is provided with a two-dimensional display element such as a liquid crystal display for displaying an image and an optical system for enlarging the image displayed by the two-dimensional display element for both eyes of the observer. ing. Usually, since the two-dimensional display element is optically fixed to the eyes of the observer, the position of the virtual image observed by the observer is also fixed. On the other hand, a device that can change the position of the virtual image in accordance with the diopter of the observer is also known, but also in this device, the position of the virtual image is fixed while the observer is observing.

A convergence angle is used to display an image with parallax to both eyes and to give the observer a three-dimensional effect, that is, a sense of distance. When an image with parallax is displayed on both eyes, the two eyes perform convergence adjustment to naturally concentrate the line of sight on the image to be observed, but if the line of sight cannot match the position of the virtual image, the observer May be uncomfortable.

[0004] On the other hand, Japanese Patent Application Laid-Open Nos. H8-23069 and H9-297 disclose a technique in which a sight line is made to coincide with the position of a virtual image by adjusting convergence so that a viewer can have a more comfortable stereoscopic effect.
No. 282, O plus E (December 1997) and the like.

FIG. 10 shows an apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 8-23069.
Is observed through the mirror 2, the movable lens 3, and the eye-gaze direction detection unit 4 of the eyeglass type, and the gaze direction is input from the gaze direction detection unit 4 to the image processing unit 5. The image processing means 5 is also capable of transmissive projection conversion of the image, calculates information for convergence adjustment from the line of sight direction, and outputs the information to the control means 6. The control means 6 changes the position of the virtual image V by driving the movable lens 3 based on the distance information of the point of gaze obtained from the input information.

FIG. 11 shows an apparatus disclosed in Japanese Patent Application Laid-Open No. 9-297282.
Observes the image displayed by the two-dimensional display element 11 through the variable focus lens 12. Then, the drive circuit 13 electrically drives the varifocal lens 12, changes the refractive index of the varifocal lens 12, and changes the position of the virtual image V.

FIG. 12 shows a variable focus lens 12 in which a fixed optical element 16 and a variable refractive index substance 17 are sandwiched between two transparent electrodes 14 and 15, and the electrodes 14 and 15 are connected to a drive circuit 13. ing. In order to make the layer of the variable refractive index material 17 thin, that is, to reduce the volume of the variable refractive index material 17,
The fixed optical element 16 has a Fresnel lens shape. When an electric signal is applied to the electrodes 14 and 15 from the drive circuit 13,
The refractive index of the refractive index variable substance 17 changes, and the fixed optical element 1
There is a difference between the index of refraction and a refractive index of 6. Thereby, the refractive index of the varifocal lens 12 changes, and the direction of the outgoing light indicated by the broken line changes in the direction indicated by the solid line.

[0008]

However, the prior art shown in FIG. 10 requires a mechanism for driving the movable lens 3, which results in an increase in size and weight, and particularly in a head-mounted device. In this case, there is a problem that the observer P is uncomfortable. It is also conceivable to use a relatively lightweight liquid crystal display or the like as the display 1 and to move the image itself in the optical axis direction to change the position of the virtual image V. In this case, too, it is necessary to drive the liquid crystal display. Since a mechanism is required, there is a problem that the size and weight are increased, and it is difficult to change the position of the virtual image V at a high speed or correspond to a moving image. Furthermore, since the display 1 and the line-of-sight direction detecting means 4 are separate bodies, there is a problem that the wearing of the line-of-sight direction detecting means 4 is troublesome for the observer P.

On the other hand, in the conventional example shown in FIG. 11, the refractive index variable substance 17 is electrically controlled, so that high-speed driving and weight reduction are possible, but the fixed optical element 16 is formed as a Fresnel lens. Non-lens part 16 of fixed optical element 16
There is a problem that the scattered light or the like generated in a degrades the image quality.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a display device capable of adjusting a virtual image position which can realize high image quality and small size and light weight.

Another object of the present invention is to provide a three-dimensional display device which does not require a spectacle type gaze direction detecting means.

[0012]

According to the present invention, there is provided a display device for displaying an image displayed by a two-dimensional display element as a virtual image on an observer's eye. A first optical system for enlarging an image displayed by the two-dimensional display element and an optical path between the two-dimensional display element and an observer's eye while fixing the element; and the first optical system. And a second optical system for adjusting the position of the virtual image enlarged by the second optical system.

[0013] The stereoscopic display device according to the present invention is a stereoscopic display device for displaying an image having parallax to an observer to give the observer a three-dimensional effect, comprising a two-dimensional display element for displaying the image. A first optical system for enlarging an image displayed by the two-dimensional display element, and a second optical system for adjusting the position of a virtual image enlarged by the first optical system, The first optical system is fixed, the two-dimensional display element is fixed near a focal plane of the first optical system, and the second optical system has a focal length adjusting function.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a configuration diagram of the first embodiment. For example, a pair of two-dimensional display elements 21 respectively corresponding to the left and right eyes E are arranged on a mounting means (not shown) that can be mounted on the head of the observer. In the optical path between the two-dimensional display element 21 and the eye E, a first optical system 22 having a positive refractive index, which enlarges an image displayed by the two-dimensional display element 21 as a virtual image.
And a second optical system 23 for adjusting the position of the virtual image formed by the first optical system 22. The two-dimensional display element 21 is, for example, a liquid crystal display, and the second optical system 23 is a varifocal lens.
In this case, a stereoscopic image can be obtained by displaying an image having parallax on the two two-dimensional display elements 21.

The two two-dimensional display elements 21 are electrically connected to a pair of element driving circuits 24, respectively, and both the second optical systems 23 are electrically connected to a common lens driving circuit 25. The element driving circuit 24 and the lens driving circuit 25 are electrically connected to a control circuit 26, and the driving circuit 2
4 and 25 are controlled synchronously.

FIG. 2 is a configuration diagram of the second optical system 23.
An optically transparent liquid 31 is composed of two opposing elastically transparent elastic films 32, 33 and these elastic films 32, 3.
An actuator 35 is connected to one of the elastic films 33, which is housed in an interior surrounded by an inelastic annular body 34 surrounding the periphery of the elastic member 3. The actuator 35 has stacked piezo elements, has a frequency response up to 300 Hz, and applies a load to the elastic film 33 according to an input signal. Thereby, when the actuator 35 applies a load to one of the elastic films 33, the volume of the liquid 31 is constant as shown in FIG. 3, so that the liquid 31 and the elastic films 32, 33 have a concave lens shape. When deformed, the second optical system 23 generates a negative refractive index.

Since the absolute deformation of the elastic film 33 is very small, the change in the refractive power of the second optical system 23 is small. Therefore, when the conventional variable-refractive-index lens disclosed in Japanese Patent Application Laid-Open No. 9-297282 is used for the second optical system 23, the magnification of the virtual image is reduced.
Therefore, in the first embodiment, the first optical system 22 is fixed, and the two-dimensional display element 21 is connected to the first optical system 22.
, And the position of the virtual image formed by the first optical system 22 can be adjusted by the second optical system 23.

As a result, as shown in FIG. 4, the focal length f1 of the first optical system 22 is fixed, the focal length f2 of the second optical system 23 is variable, and the two-dimensional display element 21 is connected to the first optical system. The two-dimensional display element 21 is located at the front focal plane of the system 22.
Is located at an infinite distance from the first optical system 22 in the direction of the two-dimensional display element 21. Therefore, assuming that the second optical system 23 is in close contact with the first optical system 22, the light flux enters the second optical system 23 as parallel light from the first optical system 22 and is therefore a virtual image. Is the second optical system 23
Is separated from the position by the focal length f2. For example,
Assuming that the focal length f2 of the second optical system 23 changes from 0 to -300 mm, the position of the virtual image is 3 from an infinite distance.
Move to a distance of 00 mm. That is, O to -3.33D
It will change to deopta. The first optical system 2
In practice, the thicknesses of the second and second optical systems 23 need to be considered.

FIG. 5 shows the operation when no refracting power is generated in the second optical system 23. The light beam emitted from the two-dimensional display element 21 is transmitted through the first optical The light becomes focal light, passes through the second optical system 23, and enters the eye E of the observer without changing the angle. Then, the two-dimensional display element 21, the first optical system 22, and the second optical system 23, which form a pair, display an image having parallax to both eyes E. At this time, the virtual image is located at an infinite distance.

FIG. 6 shows the operation when a refractive power is generated in the second optical system 23. The control circuit 26 makes the distance of the image having parallax equal to the position of the virtual image V viewed by the observer. That is, the second optical system 23 via the lens driving circuit 25 is adjusted to adjust the position of the virtual image V to a distance corresponding to the parallax.
Control. Thereby, the light beam emitted from the second optical system 23 enters the observer's eye E at different angles. At this time, the virtual image V is located at a finite distance.

As described above, in the first embodiment, the position of the virtual image V is adjusted to a distance corresponding to the parallax displayed by the two two-dimensional display elements 21, so that the observer does not need to adjust the convergence and feel uncomfortable. Never remember. Further, the second optical system 23 has a configuration in which the transparent liquid 31 is sealed between the transparent elastic films 32 and 33 and the annular body 34 and the elastic films 32 and 33 are continuously deformed. In addition to being able to respond and respond to moving images, high definition images can be provided.

Although the liquid crystal display is used as the two-dimensional display element 21 in the first embodiment, the present invention is not limited to this. Although the first optical system 22 is an afocal lens, the type is not limited as long as the image is enlarged and the transmitted light is afocal. Although the first optical system 22 is an optical system having a positive refractive power, any other optical system having a function of enlarging a virtual image may be used. Furthermore, since the two-dimensional display element 21 is arranged near the focal plane of the first optical system 22, the first optical system 2
The position of the virtual image can be adjusted by the second optical system 23 even if the light flux from the light source 2 is not completely parallel light.

The second optical system 23 has a structure as disclosed in
A variable focus lens disclosed in US Pat.
Or Proc.9th Int.Conf.Solid-State Sensors and Ac
A New Compact and Quick-Re of tuator '97, p55,56,1997
A variable focus lens or the like disclosed in the sponse Dynamic Focusing Lens can be used.

FIG. 7 is a diagram showing the configuration of the second embodiment.
A gaze direction detecting means for detecting the gaze direction of the observer is added to the embodiment. The line-of-sight direction detecting means includes a light source 41 for illuminating the eye E, a dichroic mirror 42 for reflecting a light beam reflected by the light source 41 from the light source E, and an aperture stop 4 for the light beam from the dichroic mirror 42.
3. An imaging lens 44 for forming an image of the eye E on the two-dimensional image sensor 45, and a two-dimensional image sensor 45 for capturing an image of the eye E
It is composed of The light source 41 and the two-dimensional image sensor 45 are electrically connected to a line-of-sight detection circuit
6 is electrically connected to the control circuit 26.

The light source 41 includes a plurality of light sources that emit infrared light, and emits a light beam that is not recognized by an observer toward the eye E. The dichroic mirror 42 has a wavelength selection characteristic, and transmits the wavelength included in the image displayed by the two-dimensional display element 21, but mainly reflects the infrared light from the reflection light source 41 with the eye E. The imaging lens 44 conjugates the eye E and the two-dimensional image sensor 45 and forms an image E ′ of the eye E on the two-dimensional image sensor 45 as shown in FIG.

The image E 'has a pupil portion 51, a white eye portion 52, and a Purkinje image portion 53 which is a reflection image of the cornea. Since the light source 41 has a plurality of light spots, the image E' has a plurality of Purkinje images. P appears. In this embodiment, since the light source 41 is composed of two light sources, two Purkinje images appear. The reflected light amount of the pupil portion 51 is small, and the reflected light amount of the Purkinje image P is large. The line-of-sight detection circuit 46 calculates the positions of the pupil portion 51 and the Purkinje image P from the image E 'obtained by the two-dimensional image sensor 45, and calculates the line-of-sight direction of the observer from the information. Then, the control circuit 26 determines which parallax image the observer is observing according to the line of sight, changes the refractive power of the second optical system 23 according to the parallax, and adjusts the position of the virtual image. I do.

In the second embodiment, the visual line detection circuit 46 detects which parallax image the observer is observing,
Since the refractive index of the second optical system 23 is changed in accordance with the parallax, the angle of convergence of the observer and the position of the virtual image can be matched, and the observer can be given a three-dimensional appearance with less discomfort. In addition, since the optical path for observing the image of the two-dimensional display element 21 and the optical path for detecting the direction of the line of sight are shared by the dichroic mirror 42, the observer is put on the eyeglass-type line-of-sight direction detecting means. In addition to eliminating troublesomeness, the same effects as in the first embodiment can be achieved.

A specific method for detecting the line of sight according to the second embodiment is described in JP-A-1-241511,
It is disclosed in JP-A-5-88074. Further, in the first and second embodiments, the two-dimensional display element is replaced by the first one.
Is arranged such that the virtual image of the two-dimensional display element is formed almost infinitely with respect to the first optical system on the focal plane of the optical system, but the present invention is not limited to this.

FIG. 9 is a block diagram showing the main parts of the third embodiment.
A two-dimensional display element 61, a first optical system 62, a second optical system 63, an element driving circuit 64, a lens driving circuit 65, and a control circuit 66 are arranged, a light source 67 as a line-of-sight direction detecting means, an aperture. An aperture 68, an imaging lens 69, a two-dimensional image sensor 70, and a line-of-sight detection circuit 71 are arranged. The first optical system 62 is a decentered optical system or an observation optical system, and the second optical system 63 is the same as the second optical system 23 of the first and second embodiments.

Here, the two-dimensional display element 61 is arranged so as to be substantially parallel to the surface 62 a of the first optical system 62, and the light beam from the two-dimensional display element 61 is transmitted to the first optical system 6.
After being transmitted through the second surface 62a, the light is totally reflected by the surface 62b, further reflected by the surface 62c, transmitted through the surface 62b, transmitted through the second optical system 63, and enters the eye E of the observer.

In the third embodiment, the two-dimensional display element 61
The image displayed by is formed as a virtual image by the first optical system 62, and the position of the virtual image can be adjusted by driving the second optical system 63, and the same effect as that of the second embodiment can be achieved. .

Incidentally, the first optical system 6 of the third embodiment is described.
For 2, the image observation optical system disclosed in JP-A-8-234137 can be used.

[0033]

As described above, since the display device according to the present invention does not have a Fresnel lens-shaped portion in the second optical system, it does not generate scattered light and can realize high image quality. In addition, since a conventional mechanism for mechanically driving the second optical system is not required, the size and weight can be reduced.

In the stereoscopic display device according to the present invention, since the second optical system has a focal length adjusting function, the conventional eyeglass-type line-of-sight direction detecting means is not required, and the viewer is not bothered.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a configuration diagram of a second optical system.

FIG. 3 is an explanatory diagram of an operation of a second optical system.

FIG. 4 is an operation explanatory view.

FIG. 5 is an operation explanatory view.

FIG. 6 is an operation explanatory view.

FIG. 7 is a configuration diagram of a second embodiment.

FIG. 8 is a diagram showing an image of an eye.

FIG. 9 is a configuration diagram of a main part of a third embodiment.

FIG. 10 is a configuration diagram of a conventional example.

FIG. 11 is a configuration diagram of another conventional example.

FIG. 12 is a side view of a conventional variable focus lens.

[Explanation of symbols]

 21, 61 two-dimensional display element 22, 62 first optical system 23, 63 second optical system 31 liquid 32, 33 elastic film 34 annular body 35 actuator 41, 67 light source 42 dichroic mirror 43, 68 aperture stop 44, 69 Imaging lens 45, 70 Two-dimensional image sensor 46, 71 Eye-gaze detection circuit E Eye V Virtual image

Claims (8)

[Claims] 1. A display device for displaying an image displayed by a two-dimensional display element as a virtual image on an observer's eye, wherein the two-dimensional display element is fixed and the distance between the two-dimensional display element and the observer's eye is increased. A first optical system for enlarging an image displayed by the two-dimensional display element and a second optical system for adjusting a position of a virtual image enlarged by the first optical system are provided on the optical path. A display device, characterized in that: 2. The display device according to claim 1, wherein the first optical system is fixed, and the two-dimensional display element is fixed near a focal plane of the first optical system. 3. The display device according to claim 1, wherein the second optical system has a focal length adjusting function, and has a fixed position with respect to the first optical system. 4. The second optical system comprises a transparent liquid, a transparent member for sealing the liquid, and a mechanism for deforming the transparent member, and the transparent member is deformed by the mechanism to set a focal length. The display device according to claim 1, wherein the display device is adjusted. 5. A three-dimensional display device for displaying an image having parallax to an observer to give the observer a three-dimensional effect, wherein the two-dimensional display element for displaying the image and the two-dimensional display element display the image. A first optical system for enlarging the image, and a second optical system for adjusting the position of the virtual image enlarged by the first optical system, while fixing the first optical system, The three-dimensional display device, wherein the two-dimensional display element is fixed near a focal plane of the first optical system, and the second optical system has a focal length adjusting function. 6. The apparatus according to claim 5, further comprising detecting means for detecting a line of sight of the observer, wherein the focal length adjusting function of the second optical system operates based on information detected by the detecting means. 3D display device. 7. An optical path separating means for separating an optical path for an observer to observe the two-dimensional display element and an optical path for detecting a line of sight of the observer, wherein the two-dimensional display element and an eye of the observer are separated. 6. The stereoscopic display device according to claim 5, further comprising: an illumination unit that is provided in an optical path between the light sources and an illumination unit that illuminates an observer's eye with infrared light in order to detect a line of sight of the observer. 8. The second optical system includes a transparent liquid, a transparent member for sealing the liquid, and a mechanism for deforming the transparent member, and the transparent member is deformed by the mechanism to set a focal length. 6. The display device according to claim 5, wherein the display device is adjusted.