JP2003202520A - Stereoscopic image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a conventional stereoscopic image display device using a stripe phase optical element is low in the latitude of design. <P>SOLUTION: The stereoscopic image display device is provided with image light generation means 1 to 5 for generating left eye image light and right eye image light, first and second phase optical elements 6, 7 horizontally and alternately forming two kinds of areas 6a, 6b, 7a, 7b, respectively, exerting optical action different in accordance with the phase state of incident light to the incident light and a light separation means 8 for separating two kinds of incident light components whose phase states are mutually different. Both the image light components respectively have two kinds of phase states to be separated by the separation means 8 when passing the first and second phase optical elements 6, 7 in the order of the elements 6, 7, being made incident on the separation means 8, passing the element 7, and then being made incident on the means 8 and both the image light components are elliptically polarized light and the phase difference of these image light components is the odd times of π. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic image display device capable of observing a stereoscopic image, and more particularly to a device suitable for stereoscopic image display in a television, a video, a computer monitor, a game machine and the like.

[0002]

2. Description of the Related Art Conventionally, as a stereoscopic image display device, there are those disclosed in Japanese Patent Nos. 2778543 and 2882393. As an example of the stereoscopic image display device disclosed in these publications, a display device that alternately displays a right-eye image and a left-eye image that have binocular parallax information temporally, and forward and backward in front of the display device. Arranged first and second parabolts in which light-transmitting regions and light-shielding regions are alternately formed in long stripes in a direction parallel to the vertical direction of the display image displayed on the display device. In order to observe only the image for the right eye from the Lux barrier and the observer's right eye and only the image for the left eye from the left eye, in synchronization with the display switching between the image for the right eye and the image for the left eye. , And a moving mechanism that moves at least one of the first parallax barrier and the second parallax barrier in the left-right direction of the display image.

The stereoscopic image display device disclosed in the above publication, for example, displays a right eye image and left eye image having binocular disparity information alternately in time, and a front surface of the display device. And a parallax barrier in which light-transmitting regions and light-shielding regions are alternately formed in long stripes in a direction parallel to the vertical direction of the display image displayed on the display device. Located on the front of the Lux barrier or between the display and the parallax barrier,
Areas that transmit light and areas that shield light are formed alternately in long stripes in a direction parallel to the vertical direction of the display image displayed on the display device, and these areas can be inverted from each other. And an electronic optical shutter array, in the electronic optical shutter array, so that only the image for the right eye is observed from the right eye of the observer and only the image for the left eye is observed from the left eye, the image for the right eye And a region for transmitting the light and a region for blocking the light are switched in synchronization with the display switching of the image for the left eye.

[0004]

However, in the above-mentioned conventional stereoscopic image display device, it is necessary to dispose a linear polarizing plate on the front surface of the display device without fail, or the polarization rotating compound slit for rotating the polarization direction is satisfied. There is a problem that the degree of freedom in designing the device is low, such as the conditions to be limited.

[0005]

In order to solve the above problems, in the stereoscopic image display apparatus of the present invention, the image light for the left eye for entering the left eye of the observer and the light for entering the right eye are provided. Image light generating means for generating image light for the right eye, and first and second regions in which two types of regions that respectively exert different optical effects on the incident light depending on the phase state of the incident light are formed in the left-right direction. Two phase optical elements, and a light separating unit that separates two types of incident light having different phase states from each other, and both image lights generated by the image light generating unit are
When the first phase optical element and the second phase optical element are transmitted through the phase optical elements in this order and then are incident on the light separating means, and when the second phase optical element is transmitted and are incident on the light separating means. It has two kinds of phase states that can be separated by the light separating means. Further, both the image lights are elliptically polarized (or circularly polarized), and the phase difference between these image lights is an odd multiple of π.

Of the image light for the left eye which has entered the light separating means, the light emitted from the light separating means is directed toward the left eye of the observer, and the light separating means of the image light for the right eye is emitted. The light is directed in the direction of the observer's right eye.

Specifically, light transmitted through the first region of the first phase optical element and the first region of the second phase optical element, and the second region and the second region of the first phase optical element. The light passing through the second region of the second phase optical element is directed to one of the left eye direction and the right eye direction of the observer to be emitted from the light separating means, and the first phase Light that is transmitted through the second region of the optical element and the first region of the second phase optical element, and is transmitted through the first region of the first phase optical element and the first region of the second phase optical element. The emitted light is directed to the other of the left eye direction and the right eye direction of the observer and emitted from the light separating means.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Explanation of Principle> First, the principle of the stereoscopic image display device of the present invention will be described with reference to FIG. Note that FIG. 10 shows an optical configuration of the stereoscopic image display device as a plan view.

The stereoscopic image display device can be roughly divided into the following three systems. (A) Image light generation system (B) Stripe phase optical system (C) Light separation system The above-mentioned systems have the following properties.

(A) Image Light Generation System In the image light generation system, the image light R for the right eye for entering the right eye of the observer and the image light L for the left eye for entering the left eye of the observer. And are generated, and these are combined to enter the stripe phase optical system of (B). The two image lights form images having parallax with each other, and both have low directivity and enter the stripe phase optical system of (B) at various angles.

Here, the phases of the two image lights are φ
_It is defined as _R and φ _L. However, the phase here is defined as follows.

When light is considered as a transverse wave and the propagation direction of light is defined as the z-axis direction and arbitrary orthogonal axes in a plane perpendicular to the z-axis direction are defined as the x-axis and the y-axis, the x-component and the y-component of the electric field Functions Ex (x, y, z, t), Ey (x,
y, z, t) is expressed as follows.

Ex (x, y, z, t) = Ax.cos
(Ωt−kz + φx) Ey (x, y, z, t) = Ay · cos (ωt−kz
+ Φy) where t is time, x, y, z are positions in space, and ω is angular frequency of light wave.

At this time, φx and φy represent the phases of these waves, but in the case of light waves, the difference φ between them is generally expressed.
= Φx−φy is called the phase of the light wave. Therefore, also in the present embodiment, the image light R for the right eye according to the above definition.
It is possible to define the phase phi _L of the phase phi _R and the left-eye image light L.

(B) Stripe Phase Optical System The stripe phase optical system is constructed by arranging two stripe phase optical elements so as to overlap each other in the traveling direction of image light.

Each of the stripe phase optical elements is constituted by vertically and vertically (up and down direction: a direction perpendicular to the paper surface of FIG. 10) two kinds of long and narrow regions alternately arranged in the horizontal direction.

The above-mentioned two types of regions are divided by the magnitude of the optical action with respect to the phase of the incident light, that is, the difference in the phase difference given to the light. In FIG. 10, these 2
The area of the type is shown by a shaded area and a white area.

For example, the region A (hatched portion in the figure) of the first stripe phase optical element gives a phase difference of a to the incident light. That is, the phase of the light emitted from the area A is the area A
The phase of the light incident on is advanced by a. Similarly, the region B (white portion in the figure) gives a phase difference of b to the incident light.

On the other hand, also in the second stripe phase optical element, similarly, the region C (white portion in the drawing) gives a phase difference of c to the incident light, and the region D (hatched portion in the drawing). A phase difference of d is given to the incident light.

(C) Light separation system The light emitted from the stripe phase optical system of (B) is mixed and incident on the light separation system. At this time, the light separation system includes an optical element having a property of selectively separating a plurality of lights having mutually different phases according to the phase states thereof, for example, a linear polarization plate.

Here, the linear polarizing plate has a property of transmitting only one of p-polarized light and s-polarized light and absorbing the other,
Since the state of polarization such as polarized light or s-polarized light can be uniquely determined by determining the above-mentioned phase value,
In this case, it can be said that the linear polarization plate is a selective separation element according to the phase state of light.

As described above, the light separation system separates two types of light having a phase difference that is an odd multiple of π. The linear polarizing plate also has a separating function of p-polarized light and s-polarized light, but the phase difference between p-polarized light and s-polarized light is an odd multiple of π.

Next, a method of correctly directing the image light for the right eye and the image light for the left eye to the right eye and the left eye of the observer with the above configuration will be described with reference to FIG. For the purpose of assisting the explanation, the phase difference given to the light in each area is written in each area of the two stripe phase optical elements in FIG.

The respective regions of the two striped phase optical elements are arranged so as to alternately overlap each other when viewed from the observer's direction. A method for accurately determining the horizontal width of each region and the width between stripe phase optical elements will be described later. Here, the principle that the image light roughly proceeds in the right eye direction and the left eye direction will be described.

The light transmitted through the two stripe phase optical elements can be classified into eight lights (1) to (8) depending on the phase state. The expressions on the right side of (1) to (8) in the figure represent the phase of each light.

For example, (1) is the image light for the right eye which passes through the area A of the first stripe phase optical element and the area C of the second stripe phase optical element. The phase of this light before entering the first stripe phase optical element is φ _R.
When this penetrates region A, the phase advances by a and region C
Since the phase further advances by c after passing through, the light (1) after passing through these two regions has a phase of φ _R + a + c.

Similarly, the phases of the other lights (2) to (8) are also represented by the equations shown in the figure.

As can be seen from this figure, the light transmitted through the regions A and C and the regions B and D is directed toward the right eye of the observer,
The light transmitted through the areas A and D and the areas B and C is directed toward the left eye of the observer.

In order to perform stereoscopic display, it is desirable that the image light for the right eye goes in the direction of the right eye and the image light for the left eye goes in the direction of the left eye. Therefore, the light (1), (2), ( 7) and (8) are transmitted through the light separation system (light separation element), and light (3), (4),
(5) and (6) should be blocked by a light separation system (light separation element).

Therefore, the light separating element is required to have a separating action corresponding to the phase difference between the former light and the latter light.

As described above, since the light separating element used is one that separates two kinds of light having a phase difference of an odd multiple of π, the light to be transmitted and the light to be blocked are used. The phase difference must be an odd multiple of π. This relationship is shown in FIG.

Further, since the lights of (1) to (8) are all mixed at the time of entering the light separation element, the lights to be transmitted and the lights to be blocked are equal in phase. That is, the phase difference must be an even multiple of π. This relationship is shown in FIG.

When the conditions satisfying all the relationships shown in FIGS. 12 and 13 are obtained, the conditional expression as shown in FIG. 14 is obtained.

That is, in the stereoscopic image display device of this embodiment, 1) the phase difference between the right-eye image light and the left-eye image light coincides with the phase difference separated by the light separating element (phase difference = π 2) Phase difference between adjacent regions of the first stripe phase optical element is an odd multiple of π 3) Phase difference between adjacent regions of the second stripe phase optical element is an odd multiple of π 4 ) The light separation element transmits the one of the two types of light having different phases and blocks the other (the phase difference is an odd multiple of π), so that the right-eye image light and the left-eye image light are satisfied. The image light for the eye is guided to the right eye and the left eye, respectively.

In order to correctly guide the above two types of image light to the observer's right eye position and left eye position, the structure and arrangement of the first stripe phase optical element and the second stripe phase optical element are geometrically arranged. It is necessary to decide according to the proper design. Such a design will be described in detail in the next embodiment.

(First Embodiment) FIG. 1 is a plan view showing the configuration of a stereoscopic image display apparatus according to the first embodiment of the present invention.

This three-dimensional image display device has the above-mentioned (A).
The display 1 that is the first image display element that constitutes the image light generation system of 1 and the display 2 that is the second image display element that is arranged at a position orthogonal to the display 1. The image input device 9 for the left eye is connected to the display 1, and the image input device 10 for the right eye is connected to the display 2.
Are connected.

In the image light generation system (A), a first phase control system 3 is provided on the display surface side of the display 1. The phase control system 3 is composed of a linear polarizing plate 3a and a λ / 4 plate 3b.

Similarly, on the display surface side of the display 2,
A second phase control system 4 is provided. The second phase control system 4 is also composed of a linear polarizing plate 4a and a λ / 4 plate 4b.

A beam splitter 5 as an image synthesizing system is provided on the front surfaces of the phase control systems 3 and 4 so as to form an angle of 45 degrees with respect to the display surfaces of the displays 1 and 2.

The displays 1 and 2 to the beam splitter 5 are unitized as an image light generation unit G.

On the front surface of the beam splitter 5,
Two striped phase optical elements 6 and 7 forming the striped phase optical system of (B) are provided, and the first striped phase optical element 6 is arranged in order from the beam splitter 5 side.
And the second stripe phase optical element 7 are arranged.

Further, on the front surface of the second stripe phase optical element 7, there is provided a phase adjusting plate 8a constituting the light separation system (C).
And a linear polarization plate 8b.

The stripe phase optical elements 6 and 7 to the linearly polarizing plate 8b are unitized as an image separation unit F.

Next, details and functions of the above-mentioned respective constituent members will be described.

(Regarding Displays 1 and 2) On the display 1, a right-eye image having binocular parallax information is displayed by the right-eye image input device 9, and on the display 2, the left-eye image input device 10 displays the left-eye image. The eye image is displayed.
As the left-eye image input device 9 and the right-eye image input device 10, a VTR, TV camera, PC (personal computer), or the like can be used. 9 and 10 do not have to be separated and may be integrated.

In the present embodiment, the display 1,
For No. 2, the liquid crystal display of the same display size is used, and the brightness and the contrast are adjusted equally.

However, even when the display size of the display is different, it is sufficient to add a magnification changing optical system and correct the display size to be the same.

Further, in this embodiment, the left eye image input device 9 and the right eye image input device 10 use PCs. The image displayed on the display 2 is inverted in the horizontal direction by the beam splitter 5 later. Therefore, the image for the right eye displayed on the display 2 is the original image horizontally inverted by the image input device for the right eye 10. Is displayed.

When using a general VTR or the like, a horizontal inverting circuit may be provided between the VTR and the display.

(Regarding the phase control systems 3 and 4) The linearly polarizing plates 3a and 4a have a property of transmitting only light whose phase is an even multiple of π. Therefore, the phase of light after passing through the linear polarizing plates 3a and 4a may be considered to be zero.

The λ / 4 plates 3b and 4b change the phase of incident light by π.
It has the property of advancing only / 2. As a result, both the right-eye image light and the left-eye image light that have passed through the phase control systems 3 and 4 are in a right-handed circularly polarized state.

(Regarding Beam Splitter 5) The beam splitter 5 combines lights from two different directions into light in one direction. In this embodiment, the beam splitter 5
A semi-transmissive mirror having a reflectance of 50% and a transmittance of 50%, which is manufactured by depositing a dielectric film or a metal film on a glass substrate, is used.

The observer can observe the light of the image light for the right eye that is transmitted through the beam splitter 5 and the light of the image light for the left eye that is reflected by the beam splitter 5.

At this time, only the phase of the image light for the left eye advances by π or −π due to the effect of reflection (since they both show the same phase state, they are defined as “−π advance” here).

(Regarding Stripe Phase Optical Elements 6 and 7) First and Second Stripe Phase Optical Elements 6 and 7
On the basis of the above-mentioned principle, in the stripe shape parallel to the vertical direction of the parallax images displayed on the displays 1 and 2, the regions in which the phase difference given to the incident light differs by an odd multiple of π are alternately formed. Is configured.

In this embodiment, as shown in FIG.
In the striped phase optical element 6, the regions 6a having a phase difference of 2π / 3 given to the incident light and the regions 6b having a phase difference of −π / 3 are alternately formed.

Further, the second stripe phase optical element 7
Is a region 7a where the phase difference given to the incident light is 3π / 4.
And −π / 4 regions 7b are formed alternately.

(Regarding Light Separation System 8) The light separation system 8 is arranged on the viewer side of the second stripe phase optical element 7. The phase adjusting plate 8a is a phase difference plate that gives a phase difference of 1 / 12π to incident light. In addition, the linear polarizing plate 8b
Has a property of transmitting only light having a phase that is an even multiple of π.

FIG. 2 shows the overall structure in which the above-mentioned members are combined.

Next, how the parallax images are separately observed by the left and right eyes of the observer will be described with reference to FIG.
Although the optical path of the left-eye image light is bent due to the reflecting action of the beam splitter 5 in the middle, it is shown as a straight light in FIG. 3 for simplification of description.

In the present embodiment, the respective phase states of the eight kinds of light that have been transmitted through the first and second stripe phase optical elements described in the above principle are calculated as follows.

[0063]

[Equation 1]

Therefore, the light (1), (2), (7),
(8) is a group having a phase that is an even multiple of −1 / 12π + π, and the lights (3), (4), (5), and (6) are 11
This is a group having a phase that is an even multiple of / 12π + π.

Further, the phase adjusting plate 8a gives a phase difference of 1 / 12π to both the lights of the two types of phase groups. As a result, light (1), (2), (7),
(8) is a group having a phase of an even multiple of 0 + π (= an even multiple of π), and the lights (3), (4), (5), and (6) have an even multiple of π + π (an odd multiple of π). It becomes a group with a phase.

At this time, since the linearly polarizing plate 8b has a property of transmitting only light of an even multiple of π, the light (1),
The light of (2), (7) and (8) is transmitted through the linear polarizing plate 8b, and the light of (3), (4), (5) and (6) is blocked by the linear polarizing plate 8b.

Since the first stripe phase optical element 6 and the second stripe phase optical element 7 are arranged in a state where the horizontal positions of the respective regions viewed from the observer side are displaced as shown in the drawing, Of the transmitted light, (1) and (2) go to the observer's right eye, and (7) and (8) go to the observer's left eye. An observer can recognize a stereoscopic image by binocular parallax.

At this time, the distance between the eyes of the observer is E, the observation distance is L0, the stripe width of the first stripe phase optical element 6 is H1, and the stripe width of the second stripe phase optical element 7 is H2. And the distance between the first stripe phase optical element 6 and the second stripe phase optical element 7 is L1, the following relational expression holds from the geometrical relationship shown in FIG.

H1: E = L1: L0 H1: H2 = L1 + L0: L0 From this relational expression, when the average inter-eye distance E is 65 mm, the desired observation distance L0 and the stripe width H1 of the stripe phase optical element which can be manufactured are set. Is set, H2 and L1 are uniquely determined.

Further, the stereoscopic image display device of this embodiment can display a normal 2D image.

In order for an observer to observe a 2D image,
A normal 2D image may be displayed on the display 1, and an image obtained by horizontally inverting the 2D image displayed on the display 1 may be displayed on the display 2.

Further, at this time, of the two units indicated by the dotted line in FIG. 1, the unit F is removed and the unit G is removed.
If only it is possible to see a 2D image that is brighter than the 2D image described above.

In each of the unit F and the unit G, highly accurate alignment of the constituent members is required. However, when the unit F and the unit G are combined, highly accurate alignment is not required. Can be easily removable.

In this embodiment, when the left-eye image light and the right-eye image light respectively enter the first stripe phase optical element 6, they are circularly polarized light having different rotation directions. As a result, even if the above unit F rotates about the optical axis, the separation performance of the left and right image lights and the transmittance of the left and right image lights do not change, so that the stripe phase optical elements 6, 7 are provided.
Will be easier to align.

Further, the unit F can be attached and detached as described above, and the observer can hold the unit F by hand for stereoscopic observation. At this time, the observer tilts the unit F left and right to use. Even if it does, similarly, the separation performance of the left and right image light and the left and right image light transmittance do not deteriorate.

These effects cannot be considered when the left-eye image light and the right-eye information light both enter linearly polarized light into the stripe phase optical elements 6 and 7.

(Second Embodiment) FIG. 4 is a plan view showing the structure of a stereoscopic image display apparatus according to the second embodiment of the present invention. In addition, the components denoted by the same reference numerals as those in the first embodiment have the same functions as those in the first embodiment.

This three-dimensional image display device has the above-mentioned (A).
The projector 11 that is the first display device and the projector 12 that serves as the second display device that configure the image light generation system. The image input device 9 for the left eye is connected to the projector 11, and the image input device 10 for the right eye is connected to the projector 12.

Phase control elements 13 and 14 are arranged on the front surfaces of the projectors 11 and 12, respectively. The projection light from the two projectors 11 and 12 is
The projected image is superimposed on the screen 15.

The screen 15 has a role of an image synthesizing system and has a property of not changing the polarization state of projection light, that is, a polarization state preserving property.

The projectors 11 and 12 to the screen 15 are unitized as an image light generation unit K.

On the observer side surface of the screen 15, the same two stripe phase optical elements 6 and 7 as in the first embodiment and the light separation system 8 are provided.

The stripe phase optical elements 6 and 7 to the linear polarizing plate 8b are unitized as an image separation unit J.

Next, in the present embodiment, how the parallax images are separately observed by the left and right eyes of the observer is shown in FIG.
Will be explained.

The change in the phase state of the light after entering the two stripe phase optical elements 6 and 7, the method of separation, and the like are exactly the same as in the first embodiment. However, in this embodiment, since there is no reflecting member such as the beam splitter 5, the phase state of the projection light differs from the beginning by an odd multiple of π. That is, the phase difference between the lights emitted from the phase control elements 13 and 14 is an odd multiple of π.

In this embodiment, as shown in FIG. 7, the right-eye image light emitted from the phase control element 13 is right-handed circularly polarized light, and the left-eye image light emitted from the phase control element 14 is left-handed. It is set to be circularly polarized. For example, in the phase control elements 13 and 14, the polarization axes of the linear polarization plates 13a and 14a are in the same direction, and 13b is π / 2 with respect to the incident light.
14b is an optical member that gives a phase change of −π / 2 with respect to incident light.

At this time, the stripe phase optical elements 6, 7
The phase states of the eight types of light that pass through are as follows.

[0088]

[Equation 2]

The light separation system 8 is composed of a member (a linear polarization plate corresponds to this) that transmits only light having a phase state that is an even multiple of π. Therefore, as in the first embodiment, 8
Of the types of light, only (1), (2), (7), and (8) are transmitted through the light separation system 8. Of these, (1) and (2) are to the observer's right eye, and (7) , (8) is directed to the left eye of the observer, and the observer can recognize a stereoscopic image by binocular parallax.

Also in this embodiment, when the left-eye image light and the right-eye image light respectively enter the first stripe phase optical element 6, they are circularly polarized lights having different rotation directions.

Although this effect has already been described, the present embodiment has a more specific effect. That is,
In the configuration of the present embodiment, the unit J including the two striped phase optical elements 6 and 7 is removed from the unit K, and the left and right image lights projected on the screen 15 are separated into two polarization states. It is easy to change to a so-called "glasses type stereoscopic image display device" in which "polarizing glasses" with polarizing plates attached to the left and right eyes are put on and left and right image lights are separated and observed. Is.

At this time, if the polarization states of the left and right image lights are linear polarizations whose polarization axes are orthogonal to each other, the observer must always observe the image in an upright state without tilting the neck. That is, when the neck is tilted, the polarization directions of the image light and the polarizing plate attached to the glasses do not match, and the separation performance of the left and right image information deteriorates.

However, if the polarization states of the left and right image lights are circularly polarized lights having different rotation directions as in this embodiment,
Even if the observer tilts his / her head, the separation performance of the left and right image information is not separated.

(Third Embodiment) FIG. 8 is a plan view illustrating the configuration of a stereoscopic image display apparatus according to a third embodiment of the present invention. In addition, the components denoted by the same reference numerals as those in the first embodiment have the same functions as those in the first embodiment.

This stereoscopic image display device has the above-mentioned (A).
There is only one device that displays the image light that constitutes the image light generation system, and the image information for the left eye and the image information for the right eye are switched and displayed at high speed by the time division display method.

The image display unit G'of this embodiment is included in the image display unit G shown in the first embodiment.
One of the displays 1 and 2 and one of the displays 2 and the phase control element 4 and the beam splitter 5 attached thereto are removed, and a high-speed phase modulation element 16 is added. Further, the display 1 is selected such that the image display frame rate is twice or more that of a normal display.

An image input device 9'for displaying left-eye and right-eye image information in a time-division manner is connected to the display 1, and a synchronizing signal for switching between the left and right images output from the image input device 9'is provided. It is supplied to a driving device 17 that drives the high-speed phase modulation element 16.

Further, in this embodiment, the image separation unit F described in the first embodiment is provided on the front surface of the high speed phase modulation element 16.

In this embodiment, how the parallax images are separately observed by the left and right eyes of the observer will be described with reference to FIG.

In this embodiment, the left and right parallax images are displayed in a time-division manner, and the phase states of the light incident on the two stripe phase optical elements 6 and 7 are switched in synchronization with it. The high-speed phase modulator 16 can modulate the phase of incident light at high speed.

In the present embodiment, the high-speed phase modulation element 16 is designed to switch between two phase states in which the phase of the emitted light differs by an odd multiple of π when light of the same phase enters.

Specifically, for example, the high-speed phase modulator 1
As 6, there is used a state in which two states, a state without phase modulation and a state in which the phase is advanced by −π, can be alternately switched at 120 Hz.

The image light displayed on the display 1 is phase-modulated by the linear polarization plate 3a and the λ / 4 plate 3b, and only the clockwise circular polarization component is transmitted and is incident on the high-speed phase modulation element 16.

In this embodiment, the right-eye parallax image is displayed on the display 1 when the high-speed phase modulation element 16 is in the state without phase modulation, and the high-speed phase modulation element 16 changes the phase to −π.
The parallax image for the left eye is displayed on the display 1 in the state of only advancing.

Therefore, the parallax image light for the right eye is right-handed circularly polarized light and the parallax image light for the left eye is left-handed circularly polarized light at the stage of exiting the high-speed phase modulation element 16.
The state of the phase of the light thereafter is exactly the same as that of the first embodiment, and the observer can also observe a stereoscopic image with the configuration of this embodiment.

[0106]

As described above, according to the present invention,
The image light for the left eye and the image light for the right eye are made incident on the light separating means after being transmitted through the first phase optical element and the second phase optical element in this order, and the second phase optical element is It is assumed to have two types of phase states that can be separated by the light separating means when passing through and entering the light separating means. Furthermore, since both image lights are elliptically polarized (or circularly polarized) and the phase difference between these image lights is an odd multiple of π, the image light for the left eye and the image light for the right eye can be surely obtained. Realizing a stereoscopic image display device that can guide a left eye and a right eye of an observer to provide a stereoscopic image that is easy to see and has high resolution, has a high degree of freedom in design, and can be used in a wide variety of usage modes. be able to.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a stereoscopic image display device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the stereoscopic image display device according to the first embodiment.

FIG. 3 is a schematic diagram showing a state of image light in the stereoscopic image display device of the first embodiment.

FIG. 4 is a geometrical explanatory view showing a state of image light in the stereoscopic image display device of the first embodiment.

FIG. 5 is a plan view showing a configuration of a stereoscopic image display device which is a second embodiment of the present invention.

FIG. 6 is a schematic diagram showing a state of image light in the stereoscopic image display device of the second embodiment.

FIG. 7 is a perspective view of the stereoscopic image display device according to the second embodiment.

FIG. 8 is a plan view showing the configuration of a stereoscopic image display device which is a third embodiment of the present invention.

FIG. 9 is a schematic diagram showing a state of image light in the stereoscopic image display device of the third embodiment.

FIG. 10 is a diagram illustrating the principle of the stereoscopic image display device according to each of the above embodiments.

FIG. 11 is a principle explanatory diagram showing a state of image light in the stereoscopic image display device of each of the above-described embodiments.

FIG. 12 is an explanatory diagram showing a phase state of image light in the stereoscopic image display device of each of the embodiments.

FIG. 13 is an explanatory diagram showing a phase state of image light in the stereoscopic image display device of each of the embodiments.

FIG. 14 is a diagram showing a relational expression that should be satisfied in the stereoscopic image display device according to each of the embodiments.

[Explanation of symbols]

1,2 display 3, 4, 13, 14 Phase control element 5 Beam splitter 6,7 Stripe phase optical element 8 Optical separation system 9,10,9 'image input device 11,12 projector 15 screen 16 High-speed phase modulator 17 High-speed phase modulator driving device M observer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideki Morishima             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Akinari Takagi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Yoshihiro Saito             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 2H049 BA02 BA05 BA06 BA07 BB03                       BC22                 2H059 AA23 AA33 AB06                 5C061 AA06 AB12 AB14 AB16 AB17

Claims (10)

[Claims] 1. Image light generating means for generating left-eye image light for entering the observer's left eye and right-eye image light for entering the right eye, and incident light for each incident light. First and second phase optical elements in which two types of regions, which exert different optical effects depending on the phase state of light, are alternately formed in the left-right direction, and light that separates two types of incident light having different phase states from each other. And a separation unit, wherein both image lights generated by the image light generation unit are transmitted through the first phase optical element and the second phase optical element in this order, and then the light separation is performed. Has two kinds of phase states which are incident on the means and are separable by the light separating means when passing through the second phase optical element and entering the light separating means, This is elliptically polarized light Stereoscopic image display apparatus, wherein the difference in phase of the image light is an odd multiple of [pi. 2. The stereoscopic image display device according to claim 1, wherein the two image lights are elliptically polarized lights having different rotation directions from each other. 3. The stereoscopic image display device according to claim 1, wherein the both image lights are circularly polarized light. 4. The difference in the amount of phase change exerted on the light by the two types of regions in the first and second phase optical elements is an odd multiple of π.
The stereoscopic image display device according to any one of 1 to 3. 5. The stereoscopic image display device according to claim 1, wherein the light separating unit has a property of separating two lights having a phase difference of an odd multiple of π. 6. The stereoscopic image according to claim 5, wherein the light separating unit has a property of transmitting one of two lights having a phase difference of an odd multiple of π and blocking the other. Display device. 7. The stereoscopic image display device according to claim 5, wherein the light separating means is a linear polarizing plate. 8. Of the image light for the left eye incident on the light separating means, the light emitted from the light separating means is directed toward the left eye of the observer, and the light of the image light for the right eye is The stereoscopic image display device according to claim 1, wherein the light emitted from the light separating means is directed toward the right eye of the observer. 9. The above-mentioned 2 in the above-mentioned first phase optical element.
Light that passes through the first region of the first type optical region and the first region of the two types of regions of the second phase optical element, and the second region and the second optical region of the first phase optical element. The light transmitted through the second region in the second phase optical element is directed to one of the left eye direction and the right eye direction of the observer and exits from the light separating means, and the first phase optical element Light transmitted through the second region of the element and the first region of the second phase optical element, and the first region of the first phase optical element and the first region of the second phase optical element 9. The stereoscopic image display device according to claim 8, wherein the light passing through is emitted to the other of the left eye direction and the right eye direction of the observer and is emitted from the light separating means. 10. The image light generating means includes a left eye image display means for generating left eye image light, a right eye image display means for generating right eye image light, and a beam splitter. The stereoscopic image display device according to claim 1, wherein