SYSTEM FOR THREE-DIMENSIONAL VIEWING OF STEREOSCOPIC PROJECTIONS

Abstract: A system for three-dimensional viewing of stereoscopic projections, comprising a group of devices, Fig. 1 (2, 3, 4) that permits alternating projection of the right and left images of pairs of stereoscopic films or diapositives, or alternating display of the odd-numbered line fields corresponding to the left images and the even-numbered line fields of the right images of the stereoscopic programs received from television transmitters, so that, on the projection screens or television sets, one image is shown at a time, that is, one left-handed one, one right-handed one, and so on, in a certain frequency of images or fields per second, permitting the viewer or televiewer using eyeglasses with alternating shutters, Fig. 4 (3-8) synchronized with the projection devices or television sets to see with the left eye only the left images or odd-numbered line fields, and with the right eye the right images or even-numbered line fields, of stereoscopic pairs, at the same frequency of images or fields per second projected or transmitted resulting in the impression of three-dimensional images, although the images are projected or displayed on an essentially two-dimensional surface.

Description: DESCRIPTION "SYSTEM FOR THREE-DIMENSIONAL VIEWING OF STEREOSCOPIC PROJECTIONS". The methods currently in use simultane- ously project through polarizing filters the images of stereo¬ scopic slide pairs, which are also viewed simultaneously through eyeglasses with polarizing filters which permit each separate eye to observe only the image intended for it. This invention refers to five devices interconnected in such a manner as to permit three-dimensio¬ nal viewing of film or diapositive stereoscopic pairs suitab¬ ly projected, as well as of stereoscopic pair images of films, diaposi ti ves , video-tapes and live program takes, on tele¬ vision receivers also suitably transmitted and received. This system for three-dimensional viewing of stereoscopic projec¬ tions, though not doing away with the use of special eye¬ glasses, to the contrary of those currently in use does not employ polarizing filters, which therefore makes it possible for spectators not only to observe the images clearly and in perfect color on any screen but also to use the sa es kind of eyeglasses for the movies, television and slide project¬ ion, in the event the respective program is three-dimensio¬ nal . The five devices referred to above are: Alternative Synchronizing Shutter; Alternating Field Circuit; Vertical Synchronism Pick-up Circuit, Alternate Shutter Eyeglasses and Alternate Field Plates. Figure 1 is a simplified drawing of a stereoscopic diapositive or film projector, showing the two -ξ^TS-E OM objectives (1) and the Synchronizing Alternating Synchronize (2) which, like those commonly used in filming or film proje tion units, are free to rotate around their shaft (3) to a suitable position and open up alternatively one objective or 5 the other at a particular frequency so that the two images are never projected at the same time. The electric impulses for operating th Alternating Shutter Eyeglasses in synchronism with the pro¬ jector shutter, may be obtained from a luminous source in 10. the projector which, through the shutter itself (2) excites one or two LDR's at the frequency of the images projected. The later, in turn, control a low powered transmission unit with one or two channels, operating in the 27 MHz band which, as a remote control device, operates in the eyeglass receive 15 that is synchronized to the same frequency. Figure 2 contains a schemati csi pl if i ed view of the studio of a television station, adapted for broadcasting of three-dimensional programs. Connected to the cutting table (1) are the stereoscopic film or slide pro 20 jectors (2), the stereoscopic video-tape units (3) and the TV cameras for stereoscopic takes (4). The program selected or, rather, the signals from the selected pair of units, go to the Field Alternating Circuit (5). The latter, like an electronic switch, selects the odd numbered lines of the 25 fields in the left-hand machine and the fields with even numbered lines in the right-hand machine to be transmitted alternatively, so that the pictures are composed of stereo- scopi c fields . Figure 3 depicts an ordinary television 0 unit (1) to which has been adapted a Vertical Synchronism Pick-up Circuit (2) purpose of which is to pick up the verti cal synchronism signal of the television so as to control a one or two-channel low power transmitter operating in the 27 MHz band. The latter, like a remote control unit, acts on 35 the Alternative Shutter Eyeglasses unit, figure 4, which are tuned to the same frequency, to supply the electric impulses to the electric magnets of the Alternating Field Plates, Figure 5. Figure 4 shows the Alternating Shutter Eyeglasses. The latter will be seen to consist of an ordi¬ nary frame (1) and, instead of the lenses, or together with the latter, an opaque plate (2) with two rectangular slots (3) at the viewing point of the eyes; on this plate, and at each shorter side of the slots, are set the holders for the bearings (4) of the ends of the shafts (5) of the two shutters (6). These shutters are in the form of small rectangular tubes, with the ends of the shafts set in the centers of the shorter sides (5); also attached to the shutters are two small straight permanent magnets (7), parallel to the smaller faces, whose neutral ends coincide with the align¬ ment of the axes of rotation and alignment of the lines of force in the gaps of the electric magnets (8), and are at¬ tached to the plate (2) alongside the slots (3). The North- South directions of these small magnets (7) form angles which are slightly larger or smaller than 90- to the lines of force of the gaps of the electric magnets, dependent on whether the shutters (6) are open or closed. Attached to the plate (2) and in suitable position are the dampers (9) which restrict the rotary movement of the shutters (6) in both directions. A lid (10) shaped like the plate (2) and with the slots (11) in the same corresponding positions, covers the group of components. The windings of each electric magnet are connected in series or in parallel so as to form at each electro-magnet (8) one North and one South Pole, when traversed by a direct current. The terminals of the groups of windings of the electric magnets are connected with the receiver of the synchron zing signals. The latter, whether assembled separate from the eyeglasses or in the empty spaces of the latter, supply the electric impulses to open and close the shutters alternately, in synchronism with the devices transmitting the synchronizing signals of the stereoscopic film or slide projectors and stereoscopic television units. Figure 5 shows the device termed the Field Alternative Plate set, to be mounted at the front >of the television unit (1), close to the luminescent screen (2). It consists of two plates (3) of about the same size as the screen of the cinescopes; each one has a number of equidistant horizontal slots (4) equal to the number of field lines received. Mounted one in front* of the other and by means of lugs (5), they fit into the guides (6) of a supporting device (7). This support (7) is a rectangular molding which, as already noted, has guides (6) at the shorter sides in which the lugs slide; the upper - portion holds the springs (8) which,"by means of traction, keep the two plates (3) supported on the upper dampers (9);the lower portion is fitted with bottom dampers (9) and the electro¬ magnets (10) close to the lower edges of the two plates(3). To these edges, close to the poles of the electro-magnets, the anchors (11) of the latter are attached. The system operates as follows: in the event stereoscopic diapositives or films are projected, each stereoscopic pair is projected in such a manner that the right and-left diapositives are projected alternately by means of the Synchronizing Alternating Shutter, (2) shown in figure 1 , at a certain frequency of images per second. The spectator, using the Alternating Shutter Eye-glasses, figure 4, and receiving, through his own set, the synchronism signa of the projection transmitter, sees, also alternately, the right image with the right eye only and the left image with the left eye only, in view of the action of the shutters on the glasses, which open and close at the appropiate times, thus producing a perfect three-dimensional effect. In case of television, the system is applied in simillar manner: the two cameras, (4) of figure 2 which pick up the scene, are arranged so as to supply stereo copic images, i.e., two images pick up from different angles in line with the technique adopted in stereoscopy. Stereoscopic images may also be obtained with stereoscopic fil es and dia¬ positives, (2) in figure 2, and stereoscopic video-tapes, (3) in figure 2. Only the fields of even lines in each pictures, of the right-hand image, and the fields of odd numbered lines of each frame of the left image are transmitted alternatively through the Field Alternating Circuit, (5) in figure 2, at the particular field per second frequency adopted, so that each frame is composed of a pair of stereoscopic fields, i .e., a field of odd lines from one machine and a field of even lines from the other. The televiewer, using the Alternating Shutter Eyeglasses, figure 4, who receives via his receiving set the synchronising signals of the transmitter of the Vertical Synchronism Pick-up Circuit, (2) of Figure 3, sees, also alternately, the odd-numbered line fields only with the left eye and the even-numbered fields only with the right eye as a result of the action of the eyeglass shutters which open and close at the appropriate moments causing the concept of three-dimensions of the image to be. a perfect one. Of course, for this effect to be obtained, the luminescence of one field on the cinescope screen must not persist until the commencement -of the ensuing field. It is therefore necessary to alter the proportion or composition of the fluorescent material used to make " existing cinescopes, or if the same ones are to be used, then use must be made of the Alternating Field Plates, figure 5. These, when fitted to the front of the television set, function as follows: When in a state of repose, the two plates, (3) of figure 5, remain supported by the dampers, (9) of figure 5, at the top, so that the slots of one do not coincide with those of the other, i.e., the television screen, (2) of figure 5, remains fully covered. When in operation, the impulses obtained through the Vertical Synchronism Pick-up Circuit, (2) in figure 3, are alternately passed to one or other electro-magnet, (10) of figure 5, dependent on whether the field received is even - or odd - numbered and dependent on whether the signal transmitted to the eyeglasses is right - or left-handed, so that one of the plates, (3) in figure 5, the one at the back, for ins¬ tance, is moved downwards to a distance corresponding to that separating two consecutive even or odd line, leaving exposed to view only the odd line field. When the follow¬ ing impulse excites the other electro-magnet, (10) of figure 5, the front plate moves down the same distance as that corresponding to the distance between *two consecutive even or odd lines, at the same time that the rear plate rises to the resting position under the action of the springs, (8) in figure 5. Hence only the even line field remains uncovered. A new impulse moves the rear plate down at the same time that the forward plate rises to " the rest position under the effect of the respective springs and the odd line field becomes uncovered. This sequence is repeated time after time in synchronism with the fields received and with the eyeglass shutters, so that the odd line field is always exposed when the sweeping starts in this field, and when the left eyeglass shutter opens, or ' , on the other hand, when the even line field is exposed, with the commencement of the sweep in this field, with opening of the right eyeglass shutters-.

Claims: CLAIMS 1. "System for three-dimensional view¬ ing of stereoscopic projections", characterized by the fact that, through an Alternative Synchronizing Shutter, alternating projection is effected of the images of stereoscopic pairs, at the same time that transmission is effected by electro¬ magnetic means of synchronism signals for the alternating shutters of eyeglasses that permit viewers to see the image of the left diapositive of the stereoscopic pair with the left eye only and the image of the right diapositive of the same pair with the right eye only. ' 2. "System for three-dimensional view¬ ing of stereoscopic projections", characterized by transmitting, via a television station, only the odd-numbered line fields of the frames obtained by one of two cameras, arranged for stereoscopic takes, or of one of the two machines for project¬ ing films, diapositives or video-tapes, provided the latter are equipped respectively with one of the stereoscopic tapes, diapositive of the stereoscopic pair or stereoscopic video- tape, alternatively with the even-numbered line fields of the frames obtained by the other camera or the other machines • for projecting films, diapositives or video-tapes, provided the latter are equipped respectively with another stereoscopic tape or another diapositive of stereoscopic pair or another stereoscopic video-tape, so as to view by the televiewer arrangement in a television set, by the left eye of the spectator, only the odd-numbered line fields of the frames taken by the machines of the transmitter which effect the left take or are fitted with diapositives or recordings of the left of stereoscopic pairs, with the right eye of the spectator viewing only the even-numbered line fields of the frames obtained by the machines of the transmitter which effect the right take or are fitted with the devices or right recordings of the said stereoscopic pairs, through alternat¬ ing shutters on the eyeglasses synchronized with the vertica synchronism signals of the television set, the latter being obtained and transmitted by an electronic circuit fitted to the television set itself. 3. "System for three-dimensional view ing' of stereoscopic projections", characterized by an eyeglas frame which instead of lenses or together with them possesse two mutually synchronized shutters arranged so that when one closes the other opens, alternatively, so that at no time ar both open at the same time, they being controlled by electro magnets excited by electric impulses derived from a receiver which in turn receives them from the devices transmitting the synchronized signals from projectors or stereoscopic films or stereoscopic diapositives or stereoscopic televisio un ts . 4. "System for three-dimensional view ing of stereoscopic projections", characterized by having two plates for size and shape approximately equal to the screens of the cinescopes, each having a number of horizontal mutually equidistant slots equal to the number of lines of the field received by the television set. Mounted one in front of the other, and by means of lugs, they fit into guides arranged on the shorter sides of a rectangular support in th form of a molding or frame. The said support is also fitted in the upper portion with springs whose tractive effect maintains the two plates supported on dampers also attached to the upper portion. The lower portion is fitted with dampers and electro-magnets close to the lower edges of the two pl-ates; and on these edges, close to the poles of the electro-magnets, the anchors for the latter are fitted. O

Inventors: MENSCH W
Applicants: MENSCH W
Application year: 1979
Main classification: H04N9
IPC codes: H04N13