JP2749798B2 - Projection type stereoscopic video playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a projection type stereoscopic video reproducing apparatus that reproduces a stereoscopic video with a sense of depth by projecting different types of projection light on a screen and displaying a left-eye video and a right-eye video on the screen, respectively.

[0002]

2. Description of the Related Art Conventionally, an apparatus for reproducing a stereoscopic image having a sense of depth from a left-eye video signal and a right-eye video signal has different polarization states as described in Japanese Utility Model Application Laid-Open No. 63-56889. The left-eye image and the right-eye image are projected on a reflective screen, and the projected light reflected by the screen is viewed using polarized glasses.

As described in Japanese Patent Application Laid-Open No. 62-285595, a left-eye image and a right-eye image are alternately reproduced on a display in a time-series manner using a time-division shutter.
The stereoscopic image is reproduced using polarized glasses so that the left-eye image is incident only on the left eye and the right-eye image is incident only on the right eye.

[0004]

In the above-mentioned prior art, a device for projecting a left-eye image and a right-eye image on a reflection type screen to reproduce a stereoscopic image, respectively, is used to reproduce an original stereoscopic image. However, if the user wants to switch the operation to reproduce a non-stereoscopic image, there is a problem that the screen brightness cannot be sufficiently obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and accordingly, an object of the present invention is to provide a screen having a sufficient luminance even when reproducing a non-stereoscopic image instead of an original stereoscopic image. It is an object of the present invention to provide a projection type stereoscopic video reproducing device which can be obtained.

[0006]

In order to achieve the above object, according to the present invention, when reproducing a non-stereoscopic image, a left-eye video signal and a right-eye video signal are added to a left-eye signal circuit and a right-eye signal circuit. Instead of transmitting the same video signal, the left-eye polarization filter is removed from the front of the left-eye projection optical system, and the right-eye polarization filter is removed from the front of the right-eye projection optical system.

[0007]

According to the present invention, the projection screen for the left eye and the projection light for the right eye are projected from the back of the transmission screen using the transmission screen to display the left-eye image and the right-eye image, respectively. Video can be played. When reproducing non-stereoscopic video instead of original stereoscopic video, the same video signal is transmitted to the left-eye signal circuit and the right-eye signal circuit instead of the left-eye video signal and the right-eye video signal, respectively. The projection light from the left-eye projection optical system and the projection light from the right-eye projection optical system have the same image content. Therefore, the luminance on the screen is the luminance due to the projection light from the left-eye projection optical system and the luminance due to the right-eye projection optical system. It is the sum of the luminances due to the projection light from the system.

Further, a left-eye polarizing filter having a transmittance of about several tens% is removed from the front of the left-eye projection optical system, and a right-eye polarizing filter having the same transmittance of about several tens% is removed from the front of the right-eye projection optical system. Thereby, the screen brightness can be increased several times or more.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 are explanatory diagrams showing the configuration of a projection type stereoscopic video reproducing apparatus as one embodiment of the present invention. FIG. 1 shows a state when reproducing a stereoscopic video, and FIG. Each state at the time of reproduction is shown. FIG. 3 shows FIG.
2 is a plan view showing the projector unit in FIG. 2, and FIG. 4 is a front view of the projector unit.

First, the operation of the present embodiment for reproducing a stereoscopic video will be described with reference to FIG.

In FIG. 1, for example, a signal source 1 converts a left-eye video signal (hereinafter, referred to as a left-eye signal) L and a right-eye video signal (hereinafter, referred to as a right-eye signal) R as different pit trains. This is a stereoscopic video disc player that reproduces a left-eye signal L and a right-eye signal R from optical disks recorded spirally in parallel.

The left-eye signal L and the right-eye signal R output from the signal source 1 are supplied to input terminals 2 and 2 ', respectively.
The left-eye signal L supplied to the input terminal 2 is amplified by the signal circuit 4 to a predetermined signal level, and each projection tube (CRT) for red (R), green (G), and blue (B) colors is used. ) 5R, 5
G and 5B are driven. The left-eye projection light 11 emitted from the fluorescent screens of the projection tubes 5R, 5G, 5B
R, 6G, and 6B project the image on the transmission screen 13 and form an enlarged television image on the transmission screen 13.

On the other hand, the right-eye video signal R supplied to the terminal 2 'is input to the signal circuit 4' via the contacts 3A and 3C of the switch 3, and is amplified to a predetermined signal level. Projection tubes 5R ', 5G', 5 for green and blue
B 'is driven. The right-eye projection light 11 ′ emitted from the projection tubes 5 R ′, 5 G ′, 5 B ′
R ′, 6G ′, and 6B ′ project an image on the transmissive screen 13 and form an enlarged television image on the transmissive screen 13.

The mirror 12 is a plane mirror that bends the optical path of the projection lights 11, 11 'in order to reduce the external dimensions of the device.

The projector 7 includes a left-eye projection tube 5R,
5G, 5B and a projection lens 6R, 6G, 6B, a right-eye projection tube 5R ', 5G', 5B 'and a projection lens 6
R ′, 6G ′, and 6B ′ are arranged vertically. Also, as shown in FIGS. 3 and 4, the projection lenses 6R, 6R
A polarizing filter 8 is provided on the front surface of the projection lens 6 and the projection lens 6B.
On the front surfaces of R ', 6G', and 6B ', polarizing filters 8' are respectively attached to support frames 9. Since the support frame 9 is fixed to the rotatable shaft 10, the support frame 9 can rotate around the shaft 10.

The polarizing filter 8 polarizes the projection light 11 for the left eye, and the polarization filter 8 'polarizes the projection light 11' for the right eye. A linear polarizing plate is used for each.
The polarizing filter 8 has an azimuth of +45 on the plane of polarization of the linear polarizing plate.
And the azimuth of the polarization plane of the linear polarizing plate is set to −45 °, so that the polarization planes of the linear polarizing plates are orthogonal to each other.

Here, the polarization plane of the linear polarizer is
When linearly polarized light is incident on the linearly polarized light plate, when the plane of polarization of the linearly polarized light and the electric vibration plane of the incident linearly polarized light (the plane of polarization of the linearly polarized light) coincide with each other, This is the surface that maximizes the transmittance. In FIG. 4, the polarization plane of the linear polarizer is indicated by an arrow.

Therefore, the polarization plane of the left-eye projection light 11 polarized through the polarization filter 8 and the polarization filter 8 '
And the polarization plane of the right-eye projection light 11 ′
They will differ from each other by 90 °.

Thereafter, the projection light 11 for the left eye and the polarization filter 8 ′ thus polarized by the polarization filter 8.
The right-eye projection light 11 ′ polarized by the optical path is bent by the mirror 12 as described above, and
An image for the left eye and an image for the right eye are formed on the transmission screen 13 supported by the camera.

On the transmissive screen 13, time-sequential left-eye images and right-eye images that are successive in time series are simultaneously projected in parallel, and these images are formed by setting the azimuth of the polarization plane of the polarizing plate to + 45 °, When viewed using the −45 ° polarized glasses 16, the left-eye image and the right-eye image can be viewed independently. That is, the left-eye projection light 11 transmitted through the transmission screen 13 is transmitted without being absorbed by the left-eye polarizing plate and reaches the left eye because the left-eye polarizing plate of the polarizing glasses 16 has the same polarization plane. Yes, polarized glasses 16
Since the polarization plane differs from the right-eye polarizing plate by 90 °,
It is absorbed and blocked by the right-eye polarizing plate and does not reach the right eye.

On the other hand, the right-eye projection light 11 ′ is transmitted without being absorbed by the right-eye polarizing plate and reaches the right eye because the right-hand polarizing plate of the polarizing glasses 16 has the same polarization plane. Since the polarization plane of the polarizing glasses 16 is different from that of the left-eye polarizing plate by 90 °, the light is absorbed and absorbed by the left-eye polarizing plate.
It is shut off and does not reach the left eye. Therefore, since the left-eye image is incident on the left eye and the right-eye image is incident on the right eye, it is possible to reproduce a stereoscopic image having a sense of depth due to binocular parallax.

Next, the operation of the present embodiment for reproducing a non-stereoscopic video will be described with reference to FIG. FIG.
, The signal source 1 is, for example, a video tape player as a television signal source for non-stereoscopic video. Signal source 1
The output non-stereoscopic video signal is supplied to the input terminal 2.

The mode switch 14 is used to select between switching between stereoscopic video reproduction and non-stereoscopic video reproduction. When reproducing non-stereoscopic video, the mode switch 14 is switched to a non-stereoscopic video reproduction side. Then, the contacts 3B and 3C of the switch 3 conduct, and the support frame 9 of the polarizing filters 8 and 8 ′ rotates about the axis 10 to rotate the polarizing filters 8, 8 ′.
8 'is operated so as to be removed from the front surfaces of the projection lenses 6R, 6G, 6B and the projection lenses 6R', 6G ', 6B'.

On the other hand, the non-stereoscopic video signal supplied to the input terminal 2 is supplied to the signal circuit 4 and the contact 3 of the switch 3.
B, 3C to the signal circuit 4 ', so that the projection tubes 5R, 5G, 5B and the projection tubes 5R', 5G ', 5B' are the same non-stereoscopic video signal. Driven by Therefore, the projection lens 6
R, 6G, 6B and the projection lenses 6R ', 6G', 6B 'project the projection light 18, 18' of the same video content onto the transmission screen 13, so that the transmission screen 1
The luminance on 3 is the sum of the luminance by the projection light 18 and the luminance by the projection light 18 '.

When a non-stereoscopic image is being reproduced, FIG.
It is not necessary to use the polarized glasses 16 shown in FIG. Now,
As described above, in this embodiment, the support frame 9 holding the polarization filters 8, 8 'is removed from the front surfaces of the projection lenses 6R, 6G, 6B and the projection lenses 6R', 6G ', 6B'. The projection light 18,
18 'is not absorbed. Therefore, assuming that a linear polarizing plate having a transmittance of about 41% (for example, G1220DU manufactured by Nitto Denko Corporation) is used as the polarizing filters 8, 8 ', the polarizing filters 8, 8' are used as the projection lenses 6R, 6 '.
G, 6B and the brightness of the transmissive screen 13 is about 2.
It is possible to improve four times.

In the present embodiment, the azimuths of the polarization planes of the linear polarizing plates in the polarization filters 8 and 8 'are set to + 45 ° and -45 °, respectively. However, the present invention is not limited to this. For example, the azimuth angles of the polarization plane of the linear polarizer may be set to be relatively 90 °, such as 0 ° and 90 °, between the polarizing filter 8 and the polarizing filter 8 ′.

In this embodiment, the polarization filters 8 and
Although a linear polarizing plate is used as 8 ', a circular polarizing plate may be used instead. That is, for example, by using a left-handed circularly polarizing plate as the left-eye polarizing filter 8 and a right-handed circularly polarizing plate as the right-eye polarizing filter 8 ', a stereoscopic image can be similarly reproduced.

FIGS. 5 and 6 are explanatory diagrams showing the configuration of a projection type stereoscopic video reproducing apparatus as another embodiment of the present invention.
FIG. 5 shows a state when a stereoscopic video is reproduced, and FIG. 6 shows a state when a non-stereoscopic video is reproduced. In addition,
5 and 6, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals.

In FIG. 5 and FIG. 6, the signal source 1 is, for example, an optical disk on which a left-eye signal L and a right-eye signal R, which are stereoscopic video signals, or an optical disk on which a non-stereoscopic video signal is recorded. , A video disc player for reproducing video signals.

First, the operation of the present embodiment for reproducing a stereoscopic video will be described with reference to FIG. In FIG. 5, a signal source 1 reproduces a video signal from an optical disc on which a left-eye signal L and a right-eye signal R, which are stereoscopic video signals, are recorded. The reproduced left-eye signal L and right-eye signal are reproduced. R is alternately switched in a time-division manner, and is supplied from the signal source 1 to the projector 7 as one time-division signal.

The projector 7 includes three projection tubes 5R, 5G, 5B for red, green, and blue, and three projection lenses 6R, 6G, 6B. It is fixed to. Also, the projector 7
Projection tubes 5R, 5G, 5B and projection lenses 6R, 6G, 6
B, the polarization filter 8 and the polarization axis converter 2
3R, 23G, and 23B are arranged and held by the support frame 9. Note that the support frame 9 is fixed to a rotatable shaft 10 and can rotate around the shaft 10.

In the polarizing filter 8, the azimuth of the polarization plane of the linear polarizing plate is set in the + 45 ° direction.
The azimuth angle of the plane of polarization of the linearly polarized light transmitted through the polarizing filter 8 is + 45 °. Also, the polarization axis converter 23
R, 23G, 23B is twisted nematic liquid crystal or PLZT (L ead L anthanum Z irconate T intana
te; a transparent ferroelectric material made of a metal element of Pb, La, Zr, Ti) or the like is used to convert the azimuth of the plane of polarization of linearly polarized light transmitted through the polarizing filter 8.

That is, the polarization axis converters 23R, 23G,
When the control voltage is not applied to 23B, the incident linearly polarized light is emitted without changing the azimuth of its polarization plane at + 45 °. On the other hand, the polarization axis converters 23R, 23G, 23
When the control voltage is applied to B, the incident linearly polarized light is emitted with its polarization plane rotated and its azimuth changed by about 90 ° to −45 °. Therefore, by switching between the left-eye signal L and the right-eye signal R in the signal source 1 in synchronization with the switching operation of the azimuth of the polarization plane in the polarization axis converters 23R, 23G, and 23B,
From the polarization axis converters 23R, 23G, and 23B, the left-eye projection light and the right-eye projection light are emitted alternately in a time-division manner, and the azimuths of the respective polarization planes are different from each other by 90 °.

Then, the polarization axis converters 23R, 23G, 2
The projection light emitted from the 3B is projected on a reflective screen 33 made of, for example, an aluminum film, which is installed on a wall 31, and a left-eye image and a right-eye image are alternately formed on the reflective screen 33 in a time-division manner. I do.

The viewer has an azimuth of +4 on the plane of polarization of the polarizing plate.
The image projected on the reflective screen 33 is viewed using the polarizing glasses 16 set at 5 ° and −45 °. Then
Since the polarization plane of the left-eye polarizing plate of the polarizing glasses 16 is set to coincide with the polarization plane of the left-eye projection light, the left-eye projection light enters the left eye without being absorbed by the left-eye polarization plate. . On the other hand, since the left-eye projection light and the polarization plane of the right-eye polarizing plate of the polarizing glasses 16 have different azimuth angles by 90 °, the left-eye projection light is absorbed and cut off by the right-eye polarizing plate, so that it enters the right eye. I will not do it. Similarly, the right eye projection light enters only the right eye and does not enter the left eye.

After all, the left-eye image and the right-eye image which are time-divided and alternately projected enter only the left eye and the right eye, respectively, so that a stereoscopic image having a sense of depth can be reproduced by binocular parallax.

Next, the operation of the present embodiment for reproducing a non-stereoscopic video will be described with reference to FIG. FIG.
, The signal source 1 reproduces a video signal from an optical disc on which a non-stereoscopic video signal is recorded, and the reproduced non-stereoscopic video signal (normal video signal) is continuously output from the signal source 1. Is supplied to the projector 7.

The projector 7 is provided with a mode discriminating circuit (not shown), which discriminates whether the supplied video signal is a video signal of a stereoscopic video or a video signal of a non-stereoscopic video.

If the supplied video signal is a non-stereoscopic video signal, the mode discriminating circuit outputs a control signal, and the support frame to which the polarization axis converters 23R, 23G, 23B and the polarization filter 8 are fixed. 9 is rotated around a shaft 10 to move the entire support frame 9 upward. With this control, when a video signal of a non-stereoscopic video is input to the projector 7, the video signal is input from the front of the projection lenses 6 </ b> R, 6 </ b> G, and 6 </ b> B.
The projection tubes 5R and 5R are moved so that the polarization axis converters 23R, 23G and 23B and the polarization filters are removed.
The projection light emitted from G and 5B is not absorbed by the polarization filter 8 and the polarization axis converters 23R, 23G and 23B, and a bright image can be obtained on the reflection type screen 33.

That is, for example, in this embodiment, it is assumed that a polarization filter having a transmittance of 41% is used as the polarization filter 8 and a polarization axis converter having a transmittance of 70% is used as the polarization axis converters 23R, 23G, and 23B. , The polarization filter 8 and the polarization axis converters 23R, 23G, and 23B are not removed from the projection lenses 6R, 6G, and 6B.
It is possible to increase the screen brightness about 3.7 times.

In the present embodiment, the azimuth of the polarization plane of the linear polarizing plate in the polarization filter 8 is set to + 45 °, but it is not limited to this. In this embodiment, a linear polarizing plate is used as the polarizing filter 8, but a circular polarizing plate may be used instead.

FIGS. 7 and 8 are explanatory views showing the configuration of a projection type stereoscopic video reproducing apparatus as another embodiment of the present invention.
FIG. 7 shows a state when a stereoscopic video is reproduced, and FIG. 8 shows a state when a non-stereoscopic video is reproduced. Also,
FIG. 9 is a front view showing the projector section in FIGS. 7 to 9, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals.

The present embodiment is different from the embodiments of FIGS. 1 and 2 in that, first, a phase plate 17 is arranged on the back surface of a transmissive screen 13, and And three polarizing filters 8R, 8G, 8B having different azimuthal angles of the polarization planes of the linear polarizers in one-to-one correspondence with the projection lenses 6R, 6G, 6B.
G ′, 6B ′, one-to-one, and three polarizing filters 8R ′, 8 having different azimuthal angles of the polarization planes of the linear polarizers.
G ′ and 8B ′ are respectively arranged.

In the present embodiment, the operation when reproducing a non-stereoscopic video is the same as that of the embodiment of FIG. 2, and a description thereof will be omitted. Also, the operation at the time of reproducing the stereoscopic video is basically the same as that of the embodiment of FIG.
Only parts different from the embodiment of FIG. 2 will be described below.

In general, a transmissive screen in a rear projection type video reproducing apparatus is often configured by combining two lenticular screens made of plastics and a Fresnel screen made of plastics. In addition, the lenticular screen is produced by extruding a resin plate such as polymethyl methacrylate resin, and the Fresnel screen is produced by hot-pressing the resin plate.

As described above, in the case of a screen formed by extruding a resin plate of polymethyl methacrylate resin or the like or by hot press molding, stress distortion during molding tends to remain on the resin plate, causing birefringence. In particular, in the case of the above-mentioned Fresnel screen, stress-strain during molding tends to remain in the peripheral portion, and birefringence occurs. Therefore, when the left-eye projection light 11 and right-eye projection light 11 ′ that have become linearly polarized light pass through the periphery of the Fresnel screen, the plane of polarization cannot be maintained due to the birefringence, and the light becomes elliptically polarized light. Would. Thus, the left-eye projection light 11 and the right-eye projection light 1
When 1 ′ is elliptically polarized light, there is a problem that a reproduced ghost appears as a ghost that appears double.

Therefore, in the embodiment of FIG. 1 described above, such a problem is dealt with by restricting the molding conditions (annealing the screen after molding).
On the other hand, in the present embodiment, this is dealt with by providing the phase plate 17.

That is, in this embodiment, as the transmission screen 13, a lenticular screen made by extruding a resin plate such as polymethyl methacrylate resin and a Fresnel screen made by hot press molding are also used. In particular, the Fresnel screen has a birefringence in its peripheral portion.

On the other hand, the phase plate 17 is an optically birefringent body made of a transparent plastic film (for example, a thin film of oxidized cellulose). When linearly polarized light is incident, two orthogonal polarization components, that is, an ordinary ray and The light is split into extraordinary rays (both are linearly polarized light) and emitted. The relative phase difference (retardance) between the emitted ordinary ray and the extraordinary ray is determined by the phase plate 1
7 can be controlled by the stress strain.

FIG. 10 is a characteristic diagram showing the relationship between the retardance δ of the transmission screen and the phase plate in FIG. 9 and the distance r of the transmitted projection light from the optical axis. In FIG. 10, a broken line indicates the transmission screen 13 and a solid line indicates the phase plate 17. The distance r is 0 at the position of the optical axis of the transmitted projection light (that is, the center of the screen surface of the transmission screen 13 and the center of the plate surface of the phase plate 17).

Since the transmissive screen 13 has a large stress strain at the periphery when the above-described Fresnel screen is formed, as shown in FIG. 10, the retardance gradually increases from the center to the periphery of the screen surface. It shows the property of increasing.

On the other hand, as shown in FIG.
The retardation of the transmissive screen 13 has a sign opposite to that of the retardation, and the retardation gradually increases from the center to the periphery of the plate surface.

Therefore, the polarization filters 8R, 8G, 8
The left-eye projection light 11 and the right-eye projection light 11 ′ that have become linearly polarized light that has emitted B, 8R ′, 8G ′, and 8B ′
When transmitted through 7, the light becomes elliptically polarized light due to its birefringence.
When the elliptically polarized left-eye projection light 11 and right-eye projection light 11 ′ emitted from the phase plate 17 enter the transmission screen 13, the retardance of the phase plate 17 and the retardance of the transmission screen 13 are changed. Because the signs are opposite,
The phase difference is canceled, and the left-eye projection light 11 and the right-eye projection light 11 ′ that have become linearly polarized light are emitted from the transmission screen 13.

Therefore, when the polarizing glasses 16 are used, the left-eye image and the right-eye image can be separated, and a stereoscopic image having a sense of depth without a ghost can be reproduced. By the way, in the embodiment of FIG. 1, when the left eye image and the right eye image projected on the transmission screen 13 are viewed using the polarizing glasses 16, the left eye projection light transmitted through the transmission screen 13. 11 is different from the right-eye polarizing plate of the polarizing glasses 16 in polarization plane by 90 °, is absorbed and cut off by the right-eye polarizing plate, does not reach the right eye, and conversely, the right-eye projection light 11 is Since the polarization plane of the polarizing glasses 16 is different from that of the polarizing plate for the left eye by 90 °, the light is absorbed and blocked by the polarizing plate for the left eye and does not reach the left eye.

However, actually, the left-eye projection light 1
1 and the right-eye projection light 11 ′ are respectively different from the polarizing plate of the polarizing glasses 16 even if the polarization plane is different by 90 °.
Not all light is absorbed and blocked by the polarizing plate. That is, of the light included in the left-eye projection light 11 and the right-eye projection light 11 ′, depending on the wavelength, the light may be partially transmitted without being absorbed or blocked by the polarizing plate.

This is because the angle between the polarizing plane of the polarizing plate and the polarizing plane of the light, at which all the light is absorbed and blocked by the polarizing plate, is
This is because it is not constant at 90 ° and slightly varies depending on the difference in the wavelength of light.

Therefore, in this embodiment, as described above,
Left-eye projection light 1 emitted from projection lenses 6R, 6G, 6B
Among them, red light is polarized by the polarization filter 8R, green light is polarized by the polarization filter 8G, and blue light is polarized by the polarization filter 8B, and the projection lenses 6R ', 6G', Out of the left-eye projection light 11 ′ that has emitted 6B ′, the red light is emitted by the polarizing filter 8R ′, the green light is emitted by the polarizing filter 8G ′, and the blue light is emitted by the polarizing filter 8R.
The light was polarized by B ′.

Then, of the left-eye projection light 11 transmitted through the transmissive screen 13, red light, green light, and blue light are all absorbed and cut off to the maximum by the right-eye polarizing plate of the polarizing glasses 16. In addition, the azimuth of the polarization plane of the linear polarizing plate in each of the polarization filters 8R, 8G, and 8B is adjusted so as to have a polarization plane, and the right-eye projection light 1 is adjusted.
1 ′, each of the polarizing filters 8 is formed such that the red light, the green light, and the blue light have a polarization plane such that the left eye polarizing plate of the polarizing glasses 16 absorbs and blocks the light to the maximum.
The azimuths of the polarization planes of the linear polarizers at R ′, 8G ′, and 8B ′ were respectively adjusted.

As a result, when the left-eye image and the right-eye image projected on the transmissive screen 13 are viewed using the polarizing glasses 16, the left-eye projection light 11 transmitted through the transmissive screen 13 is reflected by the polarizing glasses 16. Most of the light is absorbed and cut off by the right-eye polarizing plate, and does not reach the right eye. Conversely, most of the right-eye projection light 11 is absorbed and cut off by the left-eye polarizing plate of the polarizing glasses 16. Will not reach the left eye.

[0060]

According to the present invention, a left-eye image and a right-eye image are displayed by using a transmission screen and projecting left-eye projection light and right-eye projection light from the back of the transmission screen. Thus, a stereoscopic video can be reproduced. However, even when a non-stereoscopic video is reproduced, a sufficient luminance of the screen can be obtained and a bright screen can be viewed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration (a state at the time of stereoscopic video reproduction) of a projection type stereoscopic video reproduction device as one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration (a state at the time of non-stereoscopic video reproduction) of a projection type stereoscopic video reproducing device as one embodiment of the present invention.

FIG. 3 is a plan view showing a projector unit in FIGS. 1 and 2.

FIG. 4 is a front view showing the projector unit in FIGS. 1 and 2.

FIG. 5 is an explanatory diagram showing a configuration (a state at the time of stereoscopic video reproduction) of a projection type stereoscopic video reproduction device as another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a configuration (a state at the time of non-stereoscopic video reproduction) of a projection type stereoscopic video reproducing device as another embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a configuration (a state at the time of reproducing a stereoscopic video) of a projection type stereoscopic video reproducing device as another embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a configuration (a state during non-stereoscopic video reproduction) of a projection stereoscopic video reproducing device as another embodiment of the present invention.

FIG. 9 is a front view showing the projector unit in FIGS. 7 and 8;

FIG. 10 is a characteristic diagram showing the relationship between the retardance δ of the transmission screen and the phase plate in FIGS. 7 and 8, and the distance r of the transmitted projection light from the optical axis.

[Explanation of symbols]

1 ... signal source, 3 ... switch, 4,4 '... signal circuit, 5
R, 5G, 5B, 5R ', 5G', 5B '... projection tube, 6
R, 6G, 6B, 6R ', 6G', 6B '... projection lens, 8, 8', 8R, 8G, 8B, 8R ', 8G', 8
B ′: polarizing filter, 9: support frame, 10: axis, 11: left-eye projection light, 11 ′: right-eye projection light, 13: transmissive screen, 16: polarizing glasses, 17: phase plate, 23R, 2
3G, 23B: polarization axis converter; 33: reflective screen.

Claims (5)

(57) [Claims] 1. A first signal circuit for transmitting a left-eye video signal for obtaining a left-eye video, a second signal circuit for transmitting a right-eye video signal for obtaining a right-eye video, and A red projection tube, a green projection tube, which receives the left-eye video signal and emits red, green, and blue projection lights, respectively.
A red primary tube, a green primary tube, and a blue primary tube for receiving the transmitted right-eye video signal and emitting red, green, and blue projection light, respectively. A three-primary-color projection tube group for the right eye, comprising at least a projection tube for the right eye; a screen; , A left-eye projection optical system group including at least a green projection optical system and a blue projection optical system, and the red, green, and blue projection lights emitted from the right-eye three primary color projection tube group are respectively enlarged and projected on the screen. Red projection optics,
A right-eye projection optical system group including at least a green projection optical system and a blue projection optical system, and a red, green, and red light from the left-eye projection optical system group are arranged in front of the left-eye projection optical system group.
A left-eye polarizing filter that polarizes the blue projection light, and a front surface of the right-eye projection optical system group, which polarizes the red, green, and blue projection lights from the left-eye projection optical system group, respectively. A right-eye polarizing filter, and the left-eye image is projected on the screen by the red, green, and blue projection light projected by the left-eye projection optical system group, by the right-eye projection optical system group. The right-eye image is displayed by the projected red, green, and blue projection lights, respectively. In the projection type stereoscopic video reproduction device capable of reproducing a stereoscopic video, when reproducing a non-stereoscopic video, Means for transmitting the same video signal to the first and second signal circuits in place of the left-eye video signal and the right-eye video signal, respectively; Optical filter,
Means for detaching the right-eye polarizing filter from the front of the right-eye projection optical system group, respectively. 2. A stereoscopic video signal for obtaining a left-eye video and a right-eye video in a time-division manner is inputted, and red, green,
A three primary color projection tube group comprising at least a red projection tube, a green projection tube, and a blue projection tube for emitting blue projection light, respectively;
A projection optical system for red, a projection optical system for green, and a projection optical system for enlarging and projecting the red, green, and blue projection lights emitted from the three primary color projection tube groups onto the screen, respectively;
A projection optical system group comprising at least a blue projection optical system,
A polarizing filter disposed on a front surface of the projection optical system group to polarize the red, green, and blue projection lights from the projection optical system group; and a red, green, and blue polarization filter polarized by the polarization filter. A polarization axis converter group including at least a red polarization axis converter, a green polarization axis converter, and a blue polarization axis converter that convert the azimuth of the polarization plane of the projection light in synchronization with the input control signal; By displaying the left-eye image and the right-eye image in a time-division manner on the screen by the red, green, and blue projection lights projected by the projection optical system group, respectively, In the projection type stereoscopic video reproducing apparatus capable of reproducing stereoscopic video, when reproducing non-stereoscopic video, a non-stereoscopic video signal is input to the three primary color projection tube group instead of the stereoscopic video signal. And a means for detaching the polarizing filter and the polarization axis converter group from the front of the projection optical system group, respectively. 3. The projection type stereoscopic video reproducing apparatus according to claim 1, wherein the switching between the reproduction of the stereoscopic video and the reproduction of the non-stereoscopic video is performed according to switching of a switch means, or the video is reproduced. A projection type stereoscopic video reproducing apparatus characterized in that a specific signal superimposed on a signal is detected, decoded, and performed in accordance with the result of the decoding. 4. The projection type stereoscopic video reproducing apparatus according to claim 1, wherein said polarizing filter is constituted by at least a red polarizing filter, a green polarizing filter, and a blue polarizing filter. The red polarization filter, the green polarization filter, and the blue polarization filter are each formed of a linear polarizer or a circular polarizer, and are arranged so that the azimuths of the respective polarization planes do not coincide with each other. Projection stereoscopic video playback device. 5. The projection type stereoscopic video reproducing apparatus according to claim 1, wherein information of a left-eye video signal and information of a right-eye video signal are respectively arranged on a transparent resin plate in parallel as a pit row. From an optical disk that is spirally recorded
The stereoscopic video is reproduced by using the left-eye video signal and the right-eye video signal obtained from an optical disc reproducing apparatus that can simultaneously read the left-eye video signal and the right-eye video signal using two different wavelengths of light. A projection type stereoscopic video reproducing apparatus characterized by the above-mentioned.