KR20050092882A - Stereoscopic image display apparatus - Google Patents

Abstract

The present invention relates to a time-division stereoscopic image display device.

According to an aspect of the present invention, there is provided a stereoscopic image display device including: a display device configured to alternately display a left eye image and a right eye image for a period of at least two divisions of a field scanning period of an image signal; Polarization signal generating means for generating optical signals each having different polarization characteristics from the optical signal generated by the light source alternately for at least two divisions of the field scanning period of the image signal, and synchronizing with the display period of the left and right images. ; And an optical system for projecting the optical signal generated by the polarization signal generating means to the display means.

In the stereoscopic image display device according to the present invention, an optical signal incident on a reflective display device displaying a left eye image and a right eye image according to a time division stereoscopic image display method is synchronized with a switching cycle of the left eye image and the right eye image, so as to generate a first polarization characteristic or a first image. By having two polarization characteristics, it is possible to enjoy a stereoscopic image by using general polarized glasses.

Description

Stereoscopic image display apparatus

The present invention relates to a time-division stereoscopic image display device, and more particularly, an optical signal incident on a reflective display device displaying a left eye image and a right eye image, in synchronization with a replacement cycle of the left eye image and the right eye image, to provide a first polarization characteristic. Alternatively, the present invention relates to a method for allowing a stereoscopic image to be enjoyed using general polarized glasses by having a second polarization characteristic and a device suitable therefor.

In general, stereoscopic image (stereoscope) is made by the principle of stereo vision through the human eyes, the binocular parallax that appears because the two eyes are about 65mm apart is the most important factor of the stereoscopic sense. .

The stereoscopic image display includes a display using glasses and a non-glasses type display, and a display without glasses is used to obtain a stereoscopic image by separating left and right images without using glasses.

In the spectacle method, the polarization directions of the left and right parallax images are displayed on the direct view display or the projector in a time-division manner, and the stereoscopic images are viewed using polarized glasses or liquid crystal shutter glasses. In the polarizing glasses method, a method of providing a large area liquid crystal shutter in front of a display device has been proposed.

For example, there is a parallax barrier method and a lenticular method.

In the parallax barrier method, images to be viewed by both the left and right eyes are alternately printed or photographed in a vertical pattern in units of pixels, and viewed using an extremely thin vertical grid, that is, a barrier. In this way, the vertical pattern image to enter the left eye and the vertical pattern image to enter the right eye are distributed by the barrier so that images of different view points are shown to the left eye and the right eye, so that the image is viewed as a stereoscopic image.

The time division stereoscopic image display method writes left and right images into a field memory as a normal 60 Hz, 2: 1 interlaced signal, and reads these signals as a double speed 120 Hz, 4: 1 interlaced signal. Thereafter, the left and right images are alternately displayed every 1/120 sec and displayed on the screen, and the liquid crystal shutter or the liquid crystal shutter glasses arranged on the front of the screen are synchronized with this.

The conventional time-division stereoscopic image display method has three advantages such as displaying a stereoscopic image on a single display, displaying a high-quality stereoscopic image, having high compatibility with current TV systems, and easily realizing a system at low cost. On the other hand, there is a disadvantage that flicker occurs at 30 Hz.

In addition, the conventional time-division stereoscopic image display method has a disadvantage in that the price of the display device is increased because liquid crystal shutters having a large area must be installed in front of the display device or using liquid crystal shutter glasses.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a stereoscopic image display apparatus that can watch a stereoscopic image using general polarized glasses, which is inexpensive, and generates a stereoscopic image with low flicker. do.

A stereoscopic image display device according to the present invention for achieving the above object

A display device for alternately displaying a left eye image and a right eye image for a period of at least two divisions of a field scanning period of an image signal;

Polarization signal generating means for generating optical signals each having different polarization characteristics from the optical signal generated by the light source alternately for at least two divisions of the field scanning period of the image signal, and synchronizing with the display period of the left and right images. ; And

An optical system for projecting the optical signal generated by the polarization signal generating means to the display means,

By viewing the optical signals reflected from the display device through polarizing glasses having different polarization characteristics from left and right, it is possible to watch a stereoscopic image.

Here, it is preferable that the polarization signal generating means generates linearly polarized signals or circularly polarized signals having different polarization characteristics.

The polarization signal generating means may cause an optical signal incident on a display device that alternately displays a left eye image and a right eye image to have a first polarization characteristic or a second polarization characteristic in synchronization with a switching cycle of the left eye image and the right eye image.

A color wheel in which at least two polarizing filters having different polarization characteristics are alternately disposed; And

Preferably, the display device includes a motor that rotates the color wheel in synchronization with a period for displaying left and right images.

The display apparatus alternately displays three primary color images obtained by color-separating the left eye image and three primary color images obtained by color-separating the right eye image for a period of six divisions of the field scanning period of the image signal.

The color wheel includes three polarizing filters having polarization characteristics for the left eye image and having different color characteristics and three polarization filters having different polarization characteristics for the right eye image and having different color characteristics. Preferably, the display device is arranged in order of displaying three primary colors obtained by color separation of a left eye image and three primary colors obtained by color separation of a right eye image.

Here, the display device is preferably a DMD.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 shows a configuration of a preferred embodiment of a stereoscopic image display device according to the present invention, and shows an example of expressing color by a single plate type, that is, one reflective display device.

Referring to FIG. 1, a beam emitted from the light source 102 is collected by the first capacitor lens 104 and incident on the color wheel 106. The light source 102 is a lamp for producing white light, such as a metal halide lamp or the like.

As described below with reference to FIGS. 2 and 3, the color wheel 106 has different polarization characteristics so as to obtain an optical signal having a specific polarization characteristic and color light from the optical signal generated from the light source 102. Branches have red (R), green (G), and blue (B) tricolor filters arranged at equal proportions.

The beam passing through the color wheel 106 is incident to the display device 110 via the second capacitor lens 108.

The optical signal reflected by the display device 110 is magnified through the projection lens 112 and projected onto the screen 114.

In the apparatus shown in Fig. 1, the color wheel 106 is fixed to a drive shaft of a drive motor (not shown) and rotates in accordance with the rotation of the drive shaft.

FIG. 2 shows an embodiment of the color wheel shown in FIG. 1.

Although the color wheel 106 shown in FIG. 2 is divided into six parts, the color wheel 106 may be divided into a multiple of two or a multiple of six, depending on the driving characteristics of the display apparatus 110.

For example, when using three display devices for each of the R, G, and B images, that is, in the case of a three-plate type, a first polarization filter having a first polarization characteristic for the left eye image and a first polarization filter for the right eye image Only the second polarization filter having the bipolarization characteristic is necessary.

In the case of a single plate type, as shown in FIG. 1, R, G, and B three-color polarization colors having first polarization characteristics for the left eye image and R, G and B three-color polarization colors having second polarization characteristics for the right eye image. Filters are needed.

Here, the first polarization characteristic for the left eye image is a linear polarization characteristic of 0 degrees or a clockwise rotation, and the second polarization characteristic for the right eye image is a linear polarization characteristic of 90 degrees or a counterclockwise rotation. .

The color wheel 106 shown in FIG. 2 is a polarized color filter 202 having a 0 degree linear polarization characteristic for a left eye R image-> a polarized color filter 204 having a 90 degree linear polarization characteristic for a right eye R image-> a left eye Polarization color filter 206 having a 0 degree linear polarization characteristic for the G-image polarizing color filter having a 90 degree linear polarization characteristic for the right eye G image 208 polarizing color having a 0 degree linear polarization characteristic for the left eye B image The filter 210 has a structure in which polarized color filters are arranged in the order of a polarized color filter 212 having a 90 degree linear polarization characteristic for a right eye B image.

In the apparatus shown in FIG. 1, the optical signal generated by the light source 102 is preferably focused to be focused on the color wheel 106. The reason is that in order for the optical signal obtained by the color wheel 106 to have uniform polarization characteristics, it is preferable that the incident area (or the area of the light spot) of the optical signal incident on the color wheel 106 is minimized.

In addition, as shown using arrows in FIG. 2, polarized color filters having polarization characteristics of 0 degrees have uniform polarization characteristics in the circumferential direction, and polarized color filters having polarization characteristics of 90 degrees are uniform in radial direction. It has a polarization characteristic.

According to the arrangement of the polarization color filters, the display apparatus 110 may include a left eye R image-> right eye R image-> left eye G image-> right eye G image-> left eye B image-> as shown at the bottom of FIG. 2. The right eye B image is displayed in order.

When the vertical frequency of the image signal is 60 Hz, the color wheel 106 is rotated at a period of 60 Hz.

Figure 3 shows another example of the color wheel shown in FIG.

The color wheel 106 shown in FIG. 3 is a polarized color filter 302 having a 0 degree linear polarization characteristic for the left eye R image-> a polarized color filter 304 having a 90 degree linear polarization characteristic for the right eye G image Polarized color filter 306 having a 0 degree linear polarization characteristic for image B-> right polarized color filter having a 90 degree linear polarization characteristic for R image 308-> Polarized color having a 0 degree linear polarization characteristic for left eye G image The filter 310 has a structure in which polarized color filters are arranged in order of a polarized color filter 312 having a 90 degree linear polarization characteristic for a right eye B image.

According to the arrangement of the polarization color filters, the display apparatus 110 is shown in the lower left R image-> right eye G image-> left eye B image-> right eye R image-> left eye G image-> The right eye B image is displayed in order.

In the case of the device shown in Figure 1 because the frequency of the polarized and color-specific image signal is six times higher than the vertical frequency of the image signal generation of flicker is suppressed.

On the other hand, although the example using the linear polarization filter in the example of Figures 2 and 3 has been presented, it should be noted that it is also possible to use a circular polarization filter. When the circularly polarized filter is used, an optical signal rotating clockwise or an optical signal rotating counterclockwise is obtained.

When the circularly polarized signal is used, a range in which a stereoscopic image can be recognized, that is, a range in which the user can obtain a stereoscopic image that can be recognized while moving the observation point, is wider than using the linear polarized signal.

In the apparatus shown in FIG. 1, the display apparatus is preferably a digital micromirror device (DMD). DMD is a projection display device using semiconductors that control light developed by Texas Instruments (TI).

In general, the DMD includes a plurality of micromirrors installed to be driven by an electrostatic force, and converts the reflection path of the incident light by varying the angle of reflection according to the inclination of the micromirror.

The DMD is applied to a projection television, a scanner, a copier, a facsimile, and the like. In particular, a DMD used in a projection television is a two-dimensional array of micromirrors corresponding to the number of pixels, and each micromirror is an image signal for each pixel, that is, The image is generated by driving independently in accordance with the pixel value.

Each micromirror of the DMD is not inclined or inclined at a predetermined angle according to the pixel value of the corresponding pixel, so that the beam corresponding to each pixel is reflected at an appropriate angle to the projection lens 112 and the projection lens 112 The enlarged beam is caused to form on the screen 114.

DMD is basically useful for reflecting or non-reflecting an incident optical signal, since it does not use polarization characteristics like a liquid crystal device, and thus does not change the polarization characteristics of an optical signal generated from a color wheel.

The stereoscopic image display device according to the present invention simply implements a stereoscopic image by improving the structure of an illumination system, especially a color wheel, in a conventional projection type image display device. In addition, the polarization signal generating means in the summary of the present invention is characterized in that the optical signal incident on the display device for alternately displaying the left eye image and the right eye image is synchronized with the switching period of the left eye image and the right eye image in accordance with the first polarization characteristic or the second. It should be noted that the polarizing property may have a structure other than a color wheel in which a plurality of polarizing color filters are arranged in an annular shape on a rotating disc.

For example, a plurality of polarization color filters are arranged on a flat plate that moves in the vertical or horizontal direction, and a polarization signal generating means having a structure that controls the movement of the flat plate in synchronization with the switching period of the left eye image and the right eye image is sufficiently considered. Can be.

As described above, in the stereoscopic image display apparatus according to the present invention, an optical signal incident on a reflective display device displaying a left eye image and a right eye image according to a time-division stereoscopic image display method is synchronized with a first switching cycle of the left eye image and the right eye image. By having a polarization characteristic or a second polarization characteristic, it has the effect of being able to enjoy a stereoscopic image using a general polarizing glasses.

The stereoscopic image display device according to the present invention has an effect of realizing a stereoscopic image by changing the structure of an illumination system in a conventional projection type image display device.

In addition, the stereoscopic image display device according to the present invention has the effect of color separation of the left eye image and the right eye image into three primary colors, and display them sequentially to suppress the generation of flicker.

1 shows a configuration of a preferred embodiment of a stereoscopic image display device according to the present invention.

FIG. 2 shows an embodiment of the color wheel shown in FIG. 1.

FIG. 3 shows another embodiment of the color wheel shown in FIG. 1.

Claims (5)

A display device for alternately displaying a left eye image and a right eye image for a period of at least two divisions of a field scanning period of an image signal; Polarization signal generating means for generating optical signals each having different polarization characteristics from the optical signal generated by the light source alternately for at least two divisions of the field scanning period of the image signal, and synchronizing with the display period of the left and right images. ; And An optical system for projecting the optical signal generated by the polarization signal generating means to the display means, And viewing the optical signals reflected by the display apparatus through polarizing glasses having different polarization characteristics from right to left. The stereoscopic image display device of claim 1, wherein the polarization signal generating means generates linearly or circularly polarized signals having different polarization characteristics. The method of claim 2, wherein the polarization signal generating means A color wheel in which at least two polarizing filters having different polarization characteristics are alternately disposed; And And a motor for rotating the color wheel in synchronization with a period for displaying the left and right images by the display apparatus. The method of claim 3, The display device alternately displays three primary color images obtained by color separation of a left eye image and three primary color images obtained by color separation of a right eye image for a period obtained by dividing a field scanning period of a video signal by six divisions, The color wheel includes three polarizing filters having polarization characteristics for the left eye image and having different color characteristics and three polarization filters having different polarization characteristics for the right eye image and having different color characteristics. And displaying the three primary colors obtained by color separation of the left eye image and the three primary colors obtained by color separation of the right eye image. The stereoscopic image display device of claim 1, wherein the display device is a digital micromirror device (DMD).