JP2003202519A - Stereoscopic image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein there is possibility to cause cross-talking in a conventional stereoscopic image display device. <P>SOLUTION: The stereoscopic image display device is provided with an image display means 1 for alternately displaying right and left parallax images in time division, first and second polarizing elements 2, 4 alternately having first and second polarization action areas (a), (b) whose action to polarization is respectively fixed in the right and left direction, a polarization conversion element 3 capable of switching first and second states whose action to polarization is mutually different and converting the polarization direction of image light from almost the whole display surface of the image display means 1, and a polarization conversion control means 11 for switching the state of the element 3 so as to be synchronized with the display switching of parallax images in the means 1. The element 3 is divided into a plurality of polarization conversion parts 3a to 3d so that respective parts 3a to 3d are independently switched to the first and second states by the control means 11. <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.

These stereoscopic image display devices allow an observer to observe a stereoscopic image without wearing so-called 3D glasses.

[0005]

As described above, in the conventional stereoscopic image display apparatus, the parallax barrier is vibrated in the horizontal direction in synchronization with the display switching of the left and right parallax images, and the parallax image display switching is performed. Turn on / off voltage on each vertical stripe area of electronic shutter array to synchronize
By turning it off and changing the polarization state of the image light, the left and right parallax images are alternately observed by the left and right eyes of the observer.

However, since the display device is generally configured to sequentially draw images by point scanning or line scanning, the parallax image is being scanned in the display device, the parallax barrier is being moved, or the electronic shutter array is being switched. There is a possibility that so-called crosstalk, which is a phenomenon in which left and right parallax images are partially mixed in the middle, occurs.

The applicant of the present invention has found that the number of members such as actuators, which is a problem in the structure of vibrating the parallax barrier in the horizontal direction, and the difficulty of controlling the movement amount, and the electrode structure when the electronic shutter is used, In order to eliminate the complication of the electric circuit, image display means for alternately displaying left and right parallax images in a time division manner, and first and second polarization action regions in which the action on polarization is fixed are alternated in the left and right direction. The first and second polarizing elements included in the first and second polarization elements can be switched to the first and second states having different effects on the polarized light, and the polarized light for converting the polarization direction of the image light from substantially the entire display surface of the image display unit. A stereoscopic image display device having a conversion element and polarization conversion control means for switching the state of the polarization conversion element so as to be synchronized with display switching of parallax images on the image display means. It is draft.

However, even in the stereoscopic image display device proposed by the present applicant, a higher performance stereoscopic image is obtained by reducing crosstalk during the switching of the display image in the image display means or the switching of the state of the polarization conversion element. It can be an image display device.

[0009]

In order to solve the above-mentioned problems, a stereoscopic image display device of the present invention has an image display means for alternately displaying left and right parallax images in a time-division manner and a fixed action on polarization. It is possible to switch between the first and second polarizing elements having the first and second polarized action regions alternately arranged in the left and right direction and the first and second states in which the actions on the polarized light are different from each other, and the image display means is provided. A polarization conversion element for converting the polarization direction of the image light from substantially the entire display surface of,
A polarization conversion control means for switching the state of the polarization conversion element in synchronism with the display switching of the parallax image in the image display means, wherein the polarization conversion element is divided into a plurality of polarization conversion sections, and a plurality of polarization conversion control means are provided. The polarization converters are independently switched to the first and second states.

As a result, it becomes possible to sequentially change the states of the plurality of polarization conversion units as the parallax image of the image display means is switched (the image is rewritten by dot or line scanning). It is possible to prevent crosstalk from occurring in only a part of the stereoscopic image. Therefore, the first invention of the present application is effective in reducing crosstalk as compared with the conventional one in which crosstalk occurs in the entire stereoscopic image.

Specifically, for example, in the first state, each of the polarization converters is emitted from the image display means, passes through the first polarization action region of the first polarization element, and is transmitted to the second polarization. The light incident on the first polarization action region of the element and the light transmitted through the second polarization action region of the first polarization element and incident on the second polarization action region of the second polarization element are The polarization element is set to a polarization state in which the light is transmitted to the observer side, and the other light is set to a polarization state in which the second polarization element is not transmitted to the viewer side. In the second state, the light is emitted from the image display means, and Of the first polarization element of the first polarization element and the light that has passed through the second polarization element of the first polarization element of the second polarization element
Through the polarization action region of the first polarization element of the second polarization element
Light incident on the polarization action region of the second polarization element is made into a polarization state in which the second polarization element transmits to the observer side, and other light is transmitted to the second polarization element.
The polarization element is set to a polarization state that does not transmit to the observer side, and the first state and the second state can be switched for each polarization conversion unit.

Further, the stereoscopic image display device of the second invention of the present application is capable of displaying an image by receiving a backlight from the illumination means, and image display means for displaying left and right parallax images alternately in a time division manner, Switchable between first and second polarization elements having first and second polarization action regions, which have fixed actions on polarization, alternately in the left-right direction, and first and second states, which have different actions on polarization. A polarization conversion element for converting the polarization direction of the image light from substantially the entire display surface of the image display means, and a polarization conversion control means for switching the state of the polarization conversion element in synchronization with the display switching of the parallax image on the image display means. And an illumination control means for turning on the illumination means at a predetermined timing with respect to the operations of the image display means and the polarization conversion control means.

Thus, for example, the entire one of the parallax images is displayed on the image display means, and the illumination means can be turned on at a predetermined timing when the switching of the state of the polarization conversion element is completed. Become. Therefore, the second invention of the present application is effective in reducing crosstalk due to backlight illumination of the image display unit during switching (rewriting) of parallax images or switching of states of the polarization conversion elements.

The stereoscopic image display device according to the third invention of the present application is capable of displaying an image by receiving a backlight from the illumination means, and image display means for alternately displaying left and right parallax images in a time division manner, Switchable between first and second polarization elements having first and second polarization action regions, which have fixed actions on polarization, alternately in the left-right direction, and first and second states, which have different actions on polarization. A polarization conversion element for converting the polarization direction of the image light from substantially the entire display surface of the image display means, and a polarization conversion control means for switching the state of the polarization conversion element in synchronization with the display switching of the parallax image on the image display means. And a lighting control means for controlling the lighting means, the polarization conversion element is divided into a plurality of polarization conversion units, a plurality of lighting means are provided, Switching independently plurality of states of polarization conversion unit by the light conversion control means, so as to control independently the plurality of illumination means by the illumination control unit.

Thus, for example, among the plurality of illumination means, the illumination means provided for the portion where the display of the parallax image on the image display means is being switched or the portion corresponding to the polarization conversion portion is turned off. Is possible. Therefore, the third invention of the present application is effective in reducing crosstalk and displaying a stereoscopic image with high brightness.

Further, the stereoscopic image display device according to the fourth invention of the present application comprises an image display means for displaying an image according to an image source signal, and first and second polarization action regions in which the action on polarization is fixed. First having alternating left and right
And a second polarization element, and a polarization conversion element capable of switching between first and second states having mutually different effects on polarization and converting the polarization direction of the image light from substantially the entire display surface of the image display means, Polarization conversion control means for switching the states of the polarization conversion elements in synchronization with display switching of parallax images in the image display means, and a signal (three-dimensional image signal) for displaying left and right parallax images as image source signals are input. When the signal (2D image signal) for displaying the image without parallax is input alternately, the parallax images on the left and right are displayed alternately on the image display means. And display control means for displaying.

Thus, not only a parallax image for three-dimensional display but also a normal two-dimensional image can be favorably displayed, and a stereoscopic image display device capable of automatically switching the display of the parallax image and the two-dimensional image is realized. It becomes possible.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Description of Principle) FIG. 1 is a perspective view showing the basic structure of a stereoscopic image display device of the present invention. Less than,
The principle of stereoscopic image display in the following embodiment will be described with reference to this drawing.

On a display 1 such as a CRT which is an image display means, parallax images (left eye image and right eye image) for two viewpoints corresponding to the positions of the left and right eyes of an observer are alternately displayed in a time division manner. To be done.

As the display 1, a display having a sufficiently fast image rewriting performance such that flicker is not noticeable even when the left and right parallax images are alternately displayed in a time division manner, for example, an image rewriting performance at 120 Hz is possible. Good.

On the front surface of the display 1, a first polarization element 2, a polarization conversion element 3 and a second polarization element 4 are arranged. As shown in detail in FIG. 2, the first and second polarizing elements 2 and 4 have vertical (extending in the vertical direction) stripes and their optical axes (directions of transmitted polarized light) are orthogonal to each other.
It is configured by alternately arranging polarizing plates (polarizing action areas a and b) of different types in the horizontal (left and right) directions. The polarization action regions a and b are both fixed in polarization action (the polarization action does not change as in the polarization conversion element 3 described later).

The polarization conversion element 3 includes a liquid crystal layer such as FLC whose state changes at a sufficiently high speed by switching the applied voltage.
It is sandwiched between the transparent electrode and the cover glass, and the phase of the polarization component in the predetermined direction is determined by the anisotropy of the refractive index and the thickness of the liquid crystal layer with respect to the phase of the polarization component in the direction orthogonal to the predetermined direction. It is possible to switch between a state of delaying by a given value and a state of not providing a phase difference. In this embodiment, as the polarization conversion element 3, a polarization conversion element having a retarded phase difference of π is used.

The state switching of the polarization conversion element 3 is performed in synchronization with the display switching of the left and right parallax images on the display 1. For example, the vertical synchronizing signal of the image signal output from the display 1 can be used as the switching signal of the polarization conversion element 3. In this case, the switching signal is sent from the electric circuit 5 which produces the switching signal from the vertical synchronizing signal to the polarization conversion element.

FIG. 3 is an explanatory view of the principle when the polarization conversion element 3 is composed of FLC (ferroelectric liquid crystal). In FLC, it is known that the liquid crystal has two stable states, and the director of the stable first state liquid crystal is direct1 and the stable second state director is direct2. θ is the angle formed by the two directors.

The FLC has an optical axis in the director direction and the direction orthogonal thereto. In FLC, the angle θ between the directors differs depending on the material, and the refractive index difference Δn in the biaxial direction differs, but the angle θ between the directors is currently 20.
A material having a refractive index difference Δn of about 0.1 is known.

When a phase conversion element is made of a material having a refractive index difference Δn = 0.1, a phase difference of π can be obtained by using a liquid crystal layer having a thickness five times the central wavelength of image light used. .

In FIG. 3, when the linearly polarized light ρ1 whose polarization direction is inclined by the angle α with respect to the director direct1, is transmitted through this polarization conversion element, the FLC is directed by the director direct1.
In the case of the state, the light is converted into linearly polarized light ρ2 having the polarization direction in the direction opposite to the director direct1 by the angle α.

On the other hand, when the FLC is the director direct2 in the second state, when the linearly polarized light ρ1 passes through the polarization conversion element, it is converted into the linearly polarized light ρ3 inclined by α-θ with respect to the director direct2. .

The inclination between the linearly polarized light ρ3 and the director direct1 is θ- (α-θ) = 2 · θ-α, and the angle formed by the polarized light of the linearly polarized light ρ2 and ρ3 is 2 · θ-α + α = 2.・ Θ. In addition, the angle formed by the linearly polarized light after transmission is 2 of the angle θ formed between the directors regardless of the polarization direction of the incident light.
Doubled.

If a FLC material is selected so that θ = 45 °, then the lights emitted in the first and second states of the FLC can be made into linearly polarized lights which are orthogonal to each other regardless of the polarization direction of the incident light. it can.

In this embodiment, the angle formed between the directors is θ = 45 °, and the center wavelength of the image light is, for example, 6 °.
The thickness of the liquid crystal layer is set so as to give a phase difference π with respect to 00 nm, and one direction of the two directors is shown in FIG.
It is assumed that they coincide with the optical axes in the vertical direction of the polarizing elements 2 and 4 indicated by.

The function of each component in this embodiment is
This will be described with reference to FIGS. 4 and 5 which are plan views of the stereoscopic image display device according to the present embodiment. The same components as those in FIG. 1 are designated by the same reference numerals as those in FIG.

FIG. 4 is an explanatory diagram when the director of the polarization conversion element 3 is in the vertical direction and the polarization direction is not changed for vertical and horizontal linearly polarized light. The display 1 displays the right eye image. At this time, the image light is randomly polarized.

Next, the image light is incident on the first polarizing element 2, and if the vertical stripe-shaped region incident at that time is the region a, only the linearly polarized light component in the horizontal direction, and if the region b is the vertical component, the vertical light component is vertical. Only the linearly polarized light component of the direction is transmitted.

The image light transmitted through the first polarizing element 2 is transmitted through the polarization display element 3, but in the state shown in FIG. 4, even if the image light is transmitted through the polarization display element 3, the image light is divided into orthogonal polarization components. The phase difference is not given, and the image light has the same polarization distribution as that at the time of passing through the first polarizing element 2.

Next, when the image light is incident on the second polarizing element 4, the second of the image light transmitted through the region a by the first polarizing element 2 and being linearly polarized in the horizontal direction. Polarizing element 4
Only the image light incident on the region a of the above is transmitted through the second polarizing element 4, and the image light incident on the region b of the second polarizing element 4 is absorbed.

Similarly, the second polarization of the image light transmitted through the region b by the first polarization element 2 and being linearly polarized light in the vertical direction.
Only the image light incident on the area b of the polarizing element 7 is transmitted through the second polarizing element 4, and the image light incident on the area a of the second polarizing element is absorbed.

When the horizontal pitches of the vertical stripe regions a and b of the first and second polarizing elements 2 and 4 are properly determined, the image light reaches only the right eye position of the observer and the left eye position. Can be reached.

FIG. 5 shows that the director is 45 degrees from the vertical direction.
FIG. 6 is an explanatory diagram in a state in which the linearly polarized light that is inclined by ° and is converted into linearly polarized light that is orthogonal to each of the vertical and horizontal directions. The display 1 displays a left eye image. At this time, the image light is randomly polarized.

Next, the image light is incident on the first polarizing element 2, and if the vertical stripe-shaped region incident at that time is the region a, only the linearly polarized light component in the horizontal direction is generated, and if the region b is the vertical polarized component, the image light is vertically generated. Only the linearly polarized light component of the direction is transmitted.

The image light transmitted through the first polarizing element 2 is given a phase difference π when passing through the polarization display element 3, and the image light is a straight line orthogonal to the time when the image light passes through the first polarizing element 2. It has a polarization distribution with only polarization components.

Next, when the image light is incident on the second polarizing element 4, the first polarizing element 2 transmits the region a and further the polarization converting element 3 to form a linearly polarized light in the vertical direction. Of the existing image light, only the image light incident on the region b of the second polarizing element 4 passes through the second polarizing element 4, and the image light incident on the region a of the second polarizing element is absorbed.

Similarly, in the image light which is transmitted through the region b by the first polarization element 2 and further transmitted through the polarization conversion element 3 and is linearly polarized in the horizontal direction, the region a of the second polarization element is obtained. Only the image light that is incident on the second polarization element 4 passes through the second polarization element 4.
The image light incident on the area b of the polarizing element is absorbed. As a result, the image light reaches only the left eye position of the observer and does not reach the right eye position.

In this embodiment, the polarization conversion element 3 is controlled so as not to give a phase difference to the polarization component orthogonal to the transmitted light during 1/120 seconds when the display 1 displays the right eye image, 1/1 displays the left-eye image 1/1
During 20 seconds, the polarization conversion element 3 is controlled to give a phase difference π to the polarization component orthogonal to the transmitted light,
This process is repeated every 20 seconds.

Therefore, the observer repeats the observation of the right-eye image only with the right eye and the observation of the left-eye image only with the left eye at a high speed every 1/120 second, whereby the stereoscopic image is reproduced. The image can be observed.

It should be noted that in each 1/120 second period, the image light from all the pixels on the screen of the display 1 reaches either the left or right eye of the observer, which is a generally known stereoscopic image display method. Unlike the method using a parallax barrier or a lenticular, the state in which some of the pixels of the image display device are not visually recognized by either the left or right eye of the observer does not occur.

Here, in each of the embodiments in the present specification, the polarization conversion element that changes the polarization of the image light in synchronization with the switching of the parallax images to be displayed is basically the entire screen as described above. It is an element that gives different phase differences to the image light from the.

However, in some of the embodiments described below, this polarization conversion element is divided into a plurality of polarization conversion sections, and the polarization conversion state can be switched for each polarization conversion section.

As will be described later in detail, in each of the embodiments in the present specification, a so-called double barrier is formed by polarized light, and the left and right parallax images are displayed on a display or the like in synchronization with switching of the double barrier by time division. The display element is used for switching and display is separated on the observation surface. Thereby, the parallax image by all the pixels of the image display element is displayed to the observer to visually recognize the stereoscopic image.

(First Embodiment) In the first embodiment, in the three-dimensional image display optical device having the structure described in the section of the principle description, the polarization conversion element is divided into a plurality of polarization conversion sections, and this polarization conversion element is further divided. A method for synchronizing the display with the image display will be described.

A general image display means such as a CRT or LCD scans from the top to the bottom of the display screen. A scanning method such as a CRT is called a dot sequential scanning method, and a scanning method such as an LCD is called a line sequential scanning method.

In the present embodiment, a dot-sequential or line-sequential scanning type display such as a CRT or a plasma display is used. (1) Configuration of Stereoscopic Image Display Device of First Embodiment FIG. 6 is a configuration diagram of the stereoscopic image display device of the present embodiment.
Reference numeral 3-1 in the figure is a polarization conversion element for switching the polarization state by an electric signal. The polarization conversion element 3-1 can be switched to a binary state by taking a predetermined time. The right parallax image is displayed on the one side of the binary, and the left parallax image is displayed on the other side. Further, the polarization conversion element 3-1 is different from the polarization conversion element 3 described in FIG. 1 in that it is divided into a plurality of polarization conversion sections as described later.

An image display drive unit 9 drives the display 1 so that the display 1 alternately displays a parallax image for the right eye and a parallax image for the left eye.

Reference numeral 6 denotes a slack polarization conversion element driving section for switching the polarization conversion state of each polarization conversion section of the polarization conversion element 3-1 which is divided.

Reference numeral 7 is a sync signal generator for generating a sync signal necessary for driving the polarization conversion element 3-1 from the display video signal.

Reference numeral 8 denotes a video signal generation unit for generating a video source signal for displaying as a parallax image, which is composed of a computer, a stereoscopic television stereoscopic image display device, or the like, and displays parallax images for the right eye and the left eye. There is no particular limitation as long as the source signals are generated alternately.

(2) Description of Polarization Conversion Element 3-1 and Polarization Conversion Element Drive Unit 6 FIG. 7 is a detailed explanatory view illustrating the driving of the polarization conversion element 3-1. In the figure, reference numerals 3-1a to 3-1d denote polarization conversion units obtained by dividing the polarization conversion element into a predetermined number, and the polarization conversion states can be independently switched for each polarization conversion unit.

Reference numerals 10a to 10d denote the plurality of polarization conversion units 3-1a to 3-1a provided in the polarization conversion element drive unit 6 described above.
A driving element for applying a voltage to 3-1d, which includes a transistor or the like. Reference numeral 11 is also the polarization conversion element driving unit 6
This is a polarization conversion control circuit that is provided inside and controls switching of the polarization conversion states of the polarization conversion units 3-1a to 3-1d based on a synchronization signal, and is composed of a logic circuit, a microcomputer, and the like.

A synchronization adjustment circuit may be provided for adjusting the switching timing of the polarization conversion state of each polarization conversion unit with respect to the display timing of the parallax image.

(3) Synchronization between polarization converters 3-1a to 3-1d and image display (No. 1) FIG. 8 is for explaining synchronization between polarization converters 3-1a to 3-1d and image display. FIG. Note that FIG. 8 illustrates a process in which the image for the left eye is switched to the image for the right eye.

In the state (a), the image for the right eye is displayed on almost the entire display screen. All polarization converters 3-1a-3
-1d is also controlled to the right-eye parallax polarization conversion state (simply described as a polarization state in the drawing) R corresponding to the display image.

States (b) to (d) show states in which the display image is being rewritten by scanning from above. During this period, the polarization conversion states of the polarization conversion units 3-1a to 3-1d are sequentially switched according to the scanning from above.

The state (e) shows a state in which the image for the left eye is completely rewritten and the entire image for the left eye is displayed. When the image for the left eye is switched to the image for the right eye, the relationship between the parallax image and the polarization conversion state shown in FIG. 8 may be reversed.

(4) Synchronization between the polarization converters 3-1a to 3-1d and the image display (part 2) FIG. 9 is a diagram showing a state between the state (b) and the state (c) of FIG. Is. Since the display image is scanned from top to bottom, the state shown in FIG. 9 occurs.

Further, the polarization converters 3-1a to 3-1d require a predetermined time for their response. From this, in the state shown in FIG. 9, the polarization conversion elements (polarization conversion units 3-1a to 3-1) are
In consideration of the response time of d), switching control of the polarization conversion state in the polarization conversion unit is performed before scanning the image. Figure 9
Then, the polarization conversion unit 3-1b switches the polarization conversion state prior to scanning the image.

FIG. 10 shows an example in which the polarization conversion state switching control in the polarization conversion unit is performed prior to scanning of an image when a response speed slower than that of the polarization conversion element 3 used in FIG. 9 is used. Is shown. In this case,
Considering the response time of the polarization conversion element, which is slower than
The switching of the polarization conversion states of the plurality of polarization conversion units is performed prior to the scanning of the image. In FIG. 10, the polarization conversion states of the polarization conversion units 3-1b and 3-1c are switched in advance.

(5) Area where crosstalk occurs In the case of FIG. 9, crosstalk occurs in the polarization conversion section 3-1b. The place where the crosstalk occurs depends on the timing of switching the image display and the polarization conversion state of the polarization conversion unit. The maximum crosstalk generation region is the region of the polarization conversion unit 3-1b.

In the case of FIG. 10, the polarization conversion section 3-1.
The maximum crosstalk occurs in b and 3-1c.

As described above, in the present embodiment, crosstalk occurs not in the entire display screen but in a part of the screen. Then, this crosstalk region moves along with scanning (rewriting) of the image and switching of the polarization conversion unit. Therefore, as the number of divisions of the polarization conversion unit is made smaller, the crosstalk becomes less conspicuous.

(6) When the rewriting scanning of the display image is horizontal In FIGS. 6 to 10, the rewriting cutting scanning of the image is sequentially performed from the top to the bottom, which is common in a television monitor or a computer monitor. is there. However, in order to change the aspect ratio of the display monitor from horizontally long to vertically long, the image display portion of the monitor is rotated by 90 °, and the image is converted and displayed so as to have a normal upside-down direction. In this case, the rewriting / cutting scan of the image is sequentially performed in the horizontal direction.

FIG. 11 is an explanatory diagram in the case where the image rewriting / cutting scanning is performed in the horizontal direction. The difference from the case of vertical scanning is the same as in the case of image rewriting, that is, the polarization conversion element 3
-1 is also horizontally divided into a plurality of polarization conversion units, and the polarization conversion state switching control is performed in synchronization with the rewriting of the image display as described above.

(7) Features and effects of the first embodiment In this embodiment, the polarization conversion element is configured by being divided into a plurality of polarization conversion sections, and each polarization conversion section is synchronized with the rewriting scanning of the parallax image display. By independently controlling the switching of the polarization conversion state of, it is possible to display a stereoscopic image with reduced crosstalk. In this device, the polarizing element 2,
Since crosstalk also occurs due to reflection of optical members such as 4 and polarization conversion elements 3 and 3-1, synchronous control of the above-mentioned polarization conversion units 3a to 3d and 3-1a to 3-1d and image display is performed. However, there is some crosstalk.

However, the above-mentioned polarization converters 3a to 3d,
Since crosstalk is reliably reduced by performing synchronous control between 3-1a to 3-1d and image display, stereoscopic image display with less crosstalk can be performed.

Further, in this embodiment, for simplicity of explanation,
Although the number of divisions of the polarization conversion elements 3 and 3-1 is set to 4, it is clear that it is more effective to subdivide the polarization conversion elements 3 and 3-1.

(Second Embodiment) In the second embodiment, a configuration will be described in which a display device including a transmissive spatial modulation element such as a liquid crystal display and a backlight is used as image display means, and the backlight is turned on and controlled. .

(1) Description of Configuration of Stereoscopic Image Display Device FIG. 12 is a configuration diagram of the stereoscopic image display device of the second embodiment. Differences from the first embodiment will be described. The polarization conversion element 3-2 used in the second embodiment is not divided as in the first embodiment, and has a single structure as described in the above principle.

Reference numeral 21 in the figure is a liquid crystal display, which is composed of a transmissive spatial modulation element 21d and a backlight 21b which is an illumination light source. Reference numeral 22 denotes a synchronization signal generator, which generates a synchronization signal for controlling the lighting of the backlight 21b in addition to the synchronization signal for driving the polarization conversion element 3-2.

Reference numeral 23 denotes a backlight driving section, which drives the backlight 21b to turn on. When the backlight 21b is composed of a fluorescent tube, so-called inverter driving, which is driven at high voltage and high frequency, is performed.

FIG. 13 is a detailed explanatory diagram of the liquid crystal display 21. Reference numeral 24 is a display panel which is a spatial modulation element capable of controlling liquid crystal with an electric signal, 25 is a drain driver,
Reference numeral 26 is a gate driver, and 27 is a fluorescent tube as the backlight 21b.

In FIG. 13, one fluorescent tube is formed, but a plurality of fluorescent tubes may be provided as long as lighting control can be performed simultaneously.

(2) Description of Backlight Lighting Control FIG. 14 is a timing chart for explaining the backlight lighting control in this embodiment. This timing chart shows how the right parallax display frame and the left parallax display frame are alternately and repeatedly controlled.

(A) in the figure shows the image writing timing of the display panel 24. The display panel 24 is TF
With the T structure, the display image can be held for about one frame once the signal is written. In this embodiment, the image writing time is shorter than the predetermined one frame time.

(B) in the figure shows the polarization conversion state of the polarization conversion element 3-2. The polarization conversion element 3-2 is alternately controlled to the right parallax polarization state and the left parallax change state. . (C) in the figure shows turning on and off of the fluorescent tube 27.

(3) Features and effects of the second embodiment As shown in the timing chart of FIG. 14, in this embodiment, image writing (rewriting) on the liquid crystal display 21 (display panel 24) is completed, and polarization Conversion element 3
The backlight (fluorescent tube 27) 21b is turned on only at a predetermined timing while the switching of the polarization conversion state is completed. By performing such control, during the image rewriting period on the liquid crystal display 21, the polarization conversion element 3-2
It is possible to reduce crosstalk during the switching period of the polarization conversion state in.

(Third Embodiment) In the second embodiment described above, the stereoscopic image display device with less crosstalk is configured by controlling the lighting of the backlight. However, the lighting of the backlight is controlled for each frame display. , The displayed image may be dark. In order to solve this problem, a very high-intensity backlight is necessary.

Therefore, in the third embodiment, the polarization conversion element 3-1 is divided and controlled in the same manner as in the first embodiment, and a plurality of backlight light sources are provided and independently controlled, whereby the above problem can be solved. It is a thing.

(1) Description of Configuration of Stereoscopic Image Display Device FIG. 15 is an explanatory diagram of a liquid crystal display used in the stereoscopic image display device of this embodiment. The polarization conversion element 3-1 is
Similar to the first embodiment, it is divided into a plurality of polarization conversion units 3-1a to 3-1d, and switching of the polarization conversion state is controlled for each polarization conversion unit.

Reference numerals 24a to 24d in the figure denote the display panel 24.
The regions corresponding to the polarization conversion units 3-1a to 3-1d are shown above. The screen region 24a is the polarization conversion unit 3-1a, the screen region 24b is the polarization conversion unit 3-1b, and the screen region 24c is the polarized light. In the conversion unit 3-1c, the screen area 24d has a polarization conversion unit 3-1.
Corresponds to d.

A plurality of backlights 31a to 31d are provided corresponding to the number of polarization conversion units 3-1a to 3-1d, and each of them is individually controlled to be turned on and off.

The backlight 31a is the screen area 24a of the display panel 24, and the backlight 31b is the screen area 24b.
The backlight 31c illuminates the screen area 24c, and the backlight 31d illuminates the screen area 24d.

The other structure of the liquid crystal display and the structure of the polarization conversion element and its drive circuit are the same as in the first embodiment.

(2) Description of Control of Liquid Crystal Display 21 and Polarization Conversion Element 3-1 FIG. 16 is a timing chart for explaining backlight lighting, parallax image rewriting, and polarization conversion element switching control in this embodiment. .

Although this timing chart describes one frame, the right parallax display frame and the left parallax display frame are alternately and repeatedly controlled.

(A) in the figure shows the timing of writing an image on the display panel 24. Further, (b) in the figure shows the polarization conversion state in the polarization conversion units 3-1a to 3-1d, and the right parallax polarization (conversion) state and the left parallax polarization (conversion) state are displayed according to the display image on the display panel 24. ) The state is controlled so as to switch alternately. (C) in the figure shows turning on and off of the backlights 31a to 31d.

An illumination synchronization adjustment circuit for adjusting the backlight on / off timing with respect to the parallax image display switching timing may be provided.

(3) Features and effects of the third embodiment As shown in the timing chart of FIG. 16, in the present embodiment, the polarization conversion unit corresponding to the image scanning (displaying) portion in the liquid crystal display (display panel 24). The switching of the polarization conversion state and the turning off of the backlight are controlled in synchronization. That is, the backlight is turned off while the image is being rewritten in the liquid crystal display and the polarization conversion state is being switched in the polarization conversion unit. On the other hand, image scanning (display)
Turn on the other backlight that does not correspond to the part.

By performing such control, it is possible to reduce the occurrence of crosstalk from the scanning portion of the image where the crosstalk is originally likely to occur and the polarization conversion state switching portion of the polarization conversion portion, and a stereoscopic image with a bright display brightness is obtained. A display device can be provided.

(Fourth Embodiment) A computer environment or a video source for a two-dimensional image such as a television signal is much more popular than a three-dimensional video source. Therefore, it is desirable that the stereoscopic image display device can display the video source of the two-dimensional image.

In addition, a two-dimensional image and a three-dimensional image may be mixed on one screen of the stereoscopic image display device. In this case, since it can be easily realized by displaying an image having no parallax in the two-dimensional display area, an image in which a two-dimensional image and a three-dimensional image are mixed is also included in the three-dimensional image here.

In the fourth embodiment, in addition to the stereoscopic image display,
A general device configuration capable of displaying a two-dimensional image will be described.

(1) Description of Video Source When a television system such as the NTSC system is used for the stereoscopic image display device described in the above description, NT
Since the SC system television signal is an interlaced system, there is a field sequential system in which one of the right parallax image and the left parallax image is assigned to the even field and the other is assigned to the odd field.

However, the field sequential system of the television signal is not preferable as a video source of the stereoscopic image display device because the display frequency of each parallax image becomes half and flicker becomes conspicuous and the resolution also becomes half.

Further, in the non-interlace system, a frame sequential system in which the right parallax image frame and the left parallax image frame are alternately displayed is used. The frame sequential method is
The graphics circuit for stereoscopic display is mounted on the computer to display images at double speed to improve flicker.

(2) Description of Configuration of Stereoscopic Image Display Device FIG. 17 is a configuration diagram of the stereoscopic image display device of this embodiment. The stereoscopic image display system may be any of the first to third embodiments, but FIG. 17 shows the same system as the stereoscopic image display system of the first embodiment.

Here, the difference from the first embodiment will be described. Reference numeral 40 in the figure switches the connection to the 2D video signal generation unit 43 if the video source signal input from the outside is two-dimensional, and to the 3D video signal generation unit 42 if the video source signal is three-dimensional.
It is a D / 3D switching unit.

Reference numeral 41 is a 2D / 3D judging section for judging whether the video source signal is two-dimensional or three-dimensional.

A frame memory 44 is used for accumulating a 2D video signal.

(2) Description of Video Source Signal and 2D / 3D Judgment Unit 41 Video source signals mainly include television signals and computer signals. A typical television signal is
There are NTSC, PAL, etc., and a synchronization signal and a video signal are specified. Therefore, by analyzing the signal pattern, it can be determined that the signal is a television signal, that is, a two-dimensional signal.

There are several types of video signals for computers, but the frame frequency is set so that humans do not feel flicker. Therefore, if the frequency of the synchronization signal is detected, it is determined whether the signal is a normal two-dimensional signal. You can Also, 2
In the case of a computer stereoscopic image display device in which two-dimensional signals and three-dimensional signals are mixed, an interface for discriminating between two-dimensional signals and three-dimensional signals may be provided.

Further, it is possible for the observer to selectively set the two-dimensional display and the three-dimensional display by the setting switch.

(3) Description of 2D video signal generator 43 When displaying a two-dimensional video by this display method, the display 1 needs to be driven at double speed. Since normal speed two-dimensional display signals cannot drive at double speed, two-dimensional display is possible by storing one image in the frame memory 44 and continuously outputting at double speed.

(4) Features and effects of the fourth embodiment: As described above, the 2D / 3D determination unit 41, the 2D / 3D switching unit 40, the 2D video signal generation unit 43, and the frame memory 4
By adding 3, it is possible to realize a stereoscopic image display device capable of displaying an existing 2D video source and automatically switching between 2D display and 3D display.

[0113]

As described above, according to the first invention of the present application, the polarization conversion element is divided, and control is performed in synchronization with the display switching of the parallax image for each divided polarization conversion unit. It is possible to display a stereoscopic image with less image.

Further, according to the second aspect of the present invention, since the backlight lighting control can be performed at a predetermined timing with respect to the display switching of the parallax image and the state switching operation of the polarization conversion element, the switching of the parallax image is performed. Crosstalk due to backlight illumination of the image display means can be reduced during (rewriting) or during switching of the state of the polarization conversion element.

Further, according to the third invention of the present application, among the plurality of illuminating means, it is provided for a portion where the display of the parallax image on the image display means is being switched or a portion corresponding to the polarization conversion portion. Since the illumination means can be turned off, crosstalk can be reduced and a stereoscopic image with bright brightness can be displayed.

Furthermore, according to the fourth invention of the present application, not only a parallax image for three-dimensional display but also a normal two-dimensional image can be favorably displayed, and display switching between the parallax image and the two-dimensional image is automatically performed. It is possible to realize a stereoscopic image display device that can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic configuration of a stereoscopic image display device of the present invention.

FIG. 2 is a front view showing a configuration of a polarizing element used in the stereoscopic image display device.

FIG. 3 is an explanatory view of the principle when the polarization conversion element used in the stereoscopic image display device is configured by FLC.

FIG. 4 is a plan view of the stereoscopic image display device.

FIG. 5 is a plan view of the stereoscopic image display device.

FIG. 6 is a configuration diagram of a stereoscopic image display device according to the first embodiment of the present invention.

FIG. 7 is a detailed explanatory diagram of a polarization conversion element driving unit used in the first embodiment.

FIG. 8 is an explanatory diagram relating to synchronization between the polarization conversion element used in the first embodiment and a display image.

FIG. 9 is an explanatory diagram relating to synchronization between the polarization conversion element used in the first embodiment and a display image.

FIG. 10 is an explanatory diagram relating to synchronization between the polarization conversion element used in the first embodiment and a display image.

FIG. 11 is an explanatory diagram regarding synchronization of a polarization conversion element and a display image in a modified example of the first embodiment (when the image scanning direction is the horizontal direction).

FIG. 12 is a configuration diagram of a stereoscopic image display device according to a second embodiment of the present invention.

FIG. 13 is a detailed view of a liquid crystal display used in the second embodiment.

FIG. 14 is an operation timing chart in the second embodiment.

FIG. 15 is an explanatory diagram of a liquid crystal display and a polarization conversion element in a stereoscopic image display device according to a third embodiment of the present invention.

FIG. 16 is an operation timing chart in the third embodiment.

FIG. 17 is a configuration diagram of a stereoscopic image display device (stereoscopic image display device capable of 2D display) according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 display 2 First polarizing element 3,3-1,3-2 Polarization conversion element 3a to 3d, 3-1a to 3-1d polarization converter 4 Second polarizing element 5 electric circuits 10a-10d drive element 21 LCD display 24 display panel 27, 31a to 31d Backlight (fluorescent tube)

Claims (14)

[Claims] 1. An image display unit for alternately displaying left and right parallax images in a time division manner, and first and second units each having a fixed action on polarized light.
Of the first and second polarizing elements alternately having the polarization action regions in the left and right direction, and the first and second states in which the actions on the polarization are different from each other. A polarization conversion element for converting the polarization direction of the image light, and a polarization conversion control means for switching the state of the polarization conversion element so as to be synchronized with the display switching of the parallax image in the image display means, wherein the polarization conversion element is The stereoscopic image display device is divided into a plurality of polarization conversion units, and the polarization conversion control unit independently switches the plurality of polarization conversion units to the first and second states, respectively. 2. The stereoscopic image display device according to claim 1, wherein in the polarization conversion element, the plurality of polarization conversion units are sequentially arranged in a switching direction of a parallax image of the image display unit. 3. The stereoscopic device according to claim 1, further comprising a synchronization adjusting unit that adjusts a switching timing of a state of each of the polarization conversion units by the control unit with respect to a display timing of the parallax image by the image display unit. Image display device. 4. The stereoscopic device according to claim 3, wherein the polarization conversion control unit controls the plurality of polarization conversion units so as to precede the display timing of the parallax image by the image display unit. Image display device. 5. Each of the polarization conversion units, in the first state, is emitted from the image display unit, passes through a first polarization action region of the first polarization element, and is transmitted to the second polarization element. In the first polarizing element and the second polarizing element in the second polarizing element after passing through the second polarizing element in the first polarizing element.
And the light incident on the polarization action region of the second polarization element in a polarization state that transmits to the observer side, and other light in a polarization state that does not transmit the second polarization element to the observer side, In the second state, the light emitted from the image display means, transmitted through the second polarization action region of the first polarization element, and incident on the first polarization action region of the second polarization element, The first polarization action region of the first polarization element transmits the first polarization action region to transmit the first polarization element of the second polarization element.
Light incident on the polarization action region of the second polarization element is set to a polarization state in which the second polarization element is transmitted to the viewer side, and other light is set to a polarization state in which the second polarization element is not transmitted to the viewer side. The stereoscopic image display device according to claim 1, characterized in that. 6. The first and second polarizing elements have the function of changing the phase of light transmitted through at least one of the first and second polarizing elements.
A first optical axis direction in which the first and second polarization action regions are common to each other, and a second optical axis direction orthogonal to the first optical axis direction.
Optical polarization direction of the first and second polarization elements, the first polarization action region in the first and second polarization elements is a polarization component in the second optical axis direction with respect to a polarization component in the first optical axis direction. And the phase difference given to the first
And the second polarization action region of the second polarizing element has a phase difference of about π with respect to the polarization component in the second optical axis direction with respect to the polarization component in the first optical axis direction. The stereoscopic image display device according to claim 5. 7. Each polarization conversion unit has a state in which a phase difference is imparted to a polarization component in a specific direction with respect to a polarization component in a direction orthogonal to the specific direction, and a polarization component is divided into two polarization components in directions orthogonal to each other. The stereoscopic image display device according to claim 1, wherein the stereoscopic image display device is switched to a state in which no phase difference is applied. 8. An image display unit capable of displaying an image by receiving a backlight from an illuminating unit and alternately displaying left and right parallax images in a time division manner, and a first and a first unit each having a fixed action on polarized light. Two
Of the first and second polarizing elements alternately having the polarization action regions in the left and right direction, and the first and second states in which the actions on the polarization are different from each other. Polarization conversion element for converting the polarization direction of the image light, polarization conversion control means for switching the state of the polarization conversion element so as to be synchronized with display switching of the parallax image in the image display means, the image display means and the polarization conversion A stereoscopic image display device, comprising: illumination control means for turning on the illumination means at a predetermined timing with respect to the operation of the control means. 9. The illumination control means controls the illumination means at a predetermined timing when one of the parallax images is displayed on the image display means and the state of the polarization conversion element is completely switched. The stereoscopic image display device according to claim 8, which is turned on. 10. An image display device capable of displaying an image by receiving a backlight from an illuminating device, alternately displaying left and right parallax images in a time-division manner, and first and first fixed operation for polarized light. Two
Of the first and second polarizing elements alternately having the polarization action regions in the left and right direction, and the first and second states in which the actions on the polarization are different from each other. Polarization conversion element for converting the polarization direction of the image light, polarization conversion control means for switching the state of the polarization conversion element so as to be synchronized with display switching of the parallax image in the image display means, and illumination control for controlling the illumination means. Means, the polarization conversion element is divided into a plurality of polarization conversion unit, a plurality of the illumination unit is provided, the polarization conversion control unit, the state of the plurality of polarization conversion unit, respectively. The three-dimensional image display device, wherein the lighting control means controls the plurality of lighting means independently of each other. 11. An illumination synchronization adjustment means is provided for adjusting the timing of turning on and off the plurality of illumination means by the illumination control means with respect to the display switching timing of the parallax image in the image display means.
The stereoscopic image display device described in 1. 12. The illumination control means is provided for a portion of the plurality of illumination means in which parallax image display on the image display means is being switched or a portion corresponding to the polarization conversion section. The stereoscopic image display device according to claim 10, wherein the illumination means is turned off. 13. An image display unit for displaying an image according to an image source signal, and first and second units each having a fixed action on polarized light.
Of the first and second polarizing elements alternately having the polarization action regions in the left and right directions, and the first and second states in which the actions on the polarization are different from each other. A polarization conversion element that converts the polarization direction of the image light, a polarization conversion control unit that switches the state of the polarization conversion element so as to synchronize with the display switching of the parallax image in the image display unit, and a left and right parallax image as an image source signal. When the signal for displaying is inputted, the left and right parallax images are alternately displayed on the image display means, and when the signal for displaying the image having no parallax is inputted, the image having no parallax A three-dimensional image display device comprising: a display control unit configured to continuously display a plurality of times. 14. The display control means stores the image source signal in a frame memory when the image source signal is a signal for displaying an image having no parallax, and the image display means is based on the stored signal. The image having no parallax is continuously displayed on the screen a plurality of times.
The stereoscopic image display device according to item 3.