Display apparatus of stereoscopic image via circular polarization

The present invention relates to a display apparatus of the stereoscopic image via the circular polarization which comprises first and second image display devices arranged mutually perpendicular for displaying images respectively corresponding to left and right eyes; first and second polarizer plates respectively provided in the front of the first and second image display devices; a half-mirror provided between the first and second image display devices; and a glass window having a quarter-wave plate attached thereto for being opposed to the first image display device in parallel. The invention realizes a stereoscopic image in a circular polarization mode so as to reduce crosstalk due to the phase difference caused by observer's turning head and the difference of reflectivity and transmissivity of the half-mirror thereby improving appreciated image qualities.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter detailed invention will be made about an embodiment of the invention in reference to the accompanying drawings. FIG. 4 shows a display apparatus of stereoscopic image via circular polarization of the invention. Referring to FIG. 4, a display apparatus 400 of stereoscopic image via circular polarization is comprised of the first liquid crystal panel 410 having a liquid crystal 411 , linear polarizer plates 412 and 413 attached to both sides of the liquid crystal 411 and a back light device arranged in the rear of the linear polarizer plate 413 as the rear one of the linear polarizer plates 412 and 413 ; the second liquid crystal panel 420 arranged perpendicular to the first liquid crystal panel 410 and having a liquid crystal 421 , linear polarizer plates 422 and 423 attached to both sides of the liquid crystal 421 and a back light device arranged in the rear of the linear polarizer plate 423 as the rear one of the linear polarizer plates 422 and 423 ; the first and second polarizer plates 430 and 440 respectively arranged in the front of the first and second liquid crystal panels 410 and 420 ; a half-mirror 450 arranged between the first and second liquid crystal panels 410 and 420 at an inclination of 45°; and a glass window 460 having a quarter-wave plate 461 attached thereto as opposed in parallel to the first liquid crystal panel. The first and second liquid crystal panels 410 and 420 are arranged perpendicular from each other, and the half-mirror 450 is arranged therebetween for combining images from the panels 410 and 420 . Therefore, the half-mirror causes the first and second panels to be looked as if overlapped in the position of the first liquid crystal panel to the eyes of the observer. On the top surface of the first and second liquid panels are attached with the polarizer panels which have vertical (or horizontal) and horizontal (or vertical) polarizing axial directions. Meanwhile, the quarter-wave plate 461 is arranged in the glass window 460 to which the images come out from the first and second panels at the same time. An observer wears the circular polarizing glasses so that left and right eyes respectively sense the images of the first and second panels separated from each other. Each of the first and second panels is configured such that the linear polarizer plates are attached to the both sides of the liquid crystal and the image displayed in the liquid crystal panel can be watched via the back light device similar to the related art. In this case, the polarizing direction of an output light is inclined for 45° (or −45°) in respect to horizontal directions of the polarizer plates attached to an output-side of the first and second panels. In this case, as mentioned in the related art, when the light transmits or is reflected from the half-mirror as inclined for 45° (or −45°), elliptic polarization takes place to incur the crosstalk. Therefore, on the first liquid crystal panel 410 is installed with the first polarizer plate 430 with the vertical polarizing in the axial direction, and on the second liquid crystal panel 420 is installed with the second polarizer plate 440 with the horizontal polarizing in the axial direction. The first and second polarizer plates respectively permit a horizontally or vertically directed polarization component to transmit or be reflected from the half-mirror 450 so that the polarizing directions are maintained without elliptic polarization. Further, the quarter-wave 416 is attached to the surface of the glass window 460 to which all of the images come out from the first and second liquid crystal panels. FIG. 5 shows an optical axial direction of a quarter-wave plate in the display apparatus of the stereoscopic image via circular polarization of the invention. Referring to FIG. 5 , (a) of FIG. 5 shows lights radiating from a quarter-wave plate 520 attached to a glass window 510 , and the optical axis (axis with the fastest propagating speed of the lights) of the quarter-wave plate is inclined for 45° in respect to horizon as in (b) of FIG. 5 . Therefore, the image of the first liquid crystal panel 410 of FIG. 4 has the polarizing direction which is vertically directed by the first polarizer plate 430 so as to be inclined in respect to the optical axis of the quarter-wave plate. Thus, the vertically directed image light, which transmitted the first polarizer plate 430 , can be divided into two mutually crossing linear polarization components with the same magnitude of amplitude and phase, in which the two mutually crossing linear polarization components have a phase difference of &pgr;/2 when coming out of the quarter-waver plate 461 thereby forming a left circularly polarized light due to this phase difference. Further, the image of the second liquid crystal panel 420 has the polarizing direction which is horizontally directed by the second polarizer plate 440 so as to be inclined for −45° in respect to the optical axis of the quarter-wave plate. Therefore, the horizontally directed image light, which transmitted the second polarizer plate 440 , can be divided into two mutually crossing linear polarization components with the same magnitude of amplitude and phase, in which the two mutually crossing linear polarization components have a phase difference of &pgr;/2 when coming out of the quarter-waver plate 461 and thus form a right circularly polarized light. FIG. 6 shows polarizing directions in circular polarizing glasses in use for the display apparatus of the stereoscopic image via the circular polarization of the invention. Therefore, the observer can respectively sense the separated images in the first and second panels in the left and right eyes and synthesize the images in the brain to sense solidity when wearing the circular polarizing glasses as shown in FIG. 6 . Due to such circular polarization, the images in the first and second panels are separated and transmitted to the both eyes even when the observer inclines the head. According to the invention as described hereinbefore, the liquid panels, the vertical/horizontal polarizer plates, the display apparatus of stereoscopic image via circular polarization can realize the stereoscopic image in a circular polarization mode by employing the liquid crystal panel, the vertical/horizontal polarizer plates, the half-mirror and the quarter-wave frequency plate to reduce crosstalk due to the phase difference caused by observer's turning head and the difference of reflectivity and transmissivity of the half-mirror thereby improving appreciated image qualities.