Stereoscopic apparatus having liquid crystal filter viewer

Claim 2

A stereoscopic apparatus comprising: a stereopair reproducing means for displaying right-eyed and left-eyed pictures of stereopairs alternately on its screen at short alternate time intervals; a synchronizing signal generator associated with said stereopair reproducing means and generating synchronizing signals in synchronism with alternation of said right-eyed and left-eyed pictures; at least one viewer device comprising a pair of liquid crystal filters, each of said filters being adapted to cover the right and left eyes of an observer, respectively, each filter having at least one layer of liquid crystal held in the form of a film and at least one set of transparent electrodes, the transparency of said liquid crystal filters being dependent upon the electric field intensity generated by said electrodes; and at least one viewer controller receiving said synchronizing signals generated by said synchronizing signal generator and controlling the power applied to said electrodes to thereby vary the electric field and the transparency of said liquid crystal filters such that a pair of said liquid crystal filters covering the right and the left eyes respectively of an observer alternately exchange transparency and translucency in synchronism with each other and in synchronism with alternation of said right-eyed and left-eyed pictures being displayed by said stereopair reproducing means.

Claim 3

Apparatus as claimed in claim 1 wherein said synchronizing signals are coupled to said at least one viewer controller by means of wires connecting said synchronizing signal generator to saId at least one viewer controller.

Claim 4

Apparatus as claimed in claim 1 wherein said synchronizing signal generator includes a radio transmitter and said viewer controllers include a radio receiver, said synchronizing signals being coupled to said at least one viewer controller by means of radio.

Claim 5

Apparatus as claimed in claim 1 wherein said synchronizing signal generator generates synchronizing signals having identical code formats in synchronism with alternation of said right-eyed and left-eyed pictures.

Claim 6

Apparatus as claimed in claim 1 wherein said synchronizing signal generator generates a synchronizing signal for exclusive one of the right and left eyes, corresponding to disappearance of the opposite eye picture and persisting until the other eye picture disappears.

Claim 7

Apparatus as claimed in claim 1 wherein said viewer controller is at least partially appendant to said stereopair reproducing means.

Claim 8

Apparatus as claimed in claim 6 wherein said viewer controller is integrated with said synchronizing signal generator.

Claim 9

Apparatus as claimed in claim 1 wherein said synchronizing signal generator generates two types of synchronizing signals alternately, signal for the right eye being coupled to the left eye filter and corresponding to disappearance of the left-eyed pictures, and signal for the left eye being coupled to the right eye filter and corresponding to disappearance of the right-eyed pictures.

Claim 10

Apparatus as claimed in claim 8 wherein said synchronizing signal for the right eye persists until the right-eyed picture disappears and said synchronizing signal for the left eye persists until the left-eyed picture disappears.

Claim 11

Apparatus as claimed in claim 1 wherein said stereopair reproducing means includes a film-type motion picture projector and projection screen, and said synchronizing signal generator generates said synchronizing signals in synchronism with the movement of each picture frame of the film.

Claim 12

Apparatus as claimed in claim 10 wherein said synchronizing signal generator includes a recorded tape player, the recorded tape having pulses recorded thereon for synchronizing the sound with the movement of each picture of the associated film.

Claim 13

Apparatus as claimed in claim 1 wherein said stereopair reproducing means includes a screen on which pictures are reproduced by means of at least one light spot varying its brightness and scanning the screen.

Claim 14

Apparatus as claimed in claim 12 wherein said stereopair reproducing means is a television receiver, and wherein said synchronizing signal generator generates synchronizing signals each time said light spot completes scanning one field.

Claim 15

Apparatus as claimed in claim 12 wherein said stereopair reproducing means is a television receiver, and wherein said synchronizing signal generator generates synchronizing signals each time said light spot completes scanning one frame.

Claim 16

Apparatus as claimed in claim 12 wherein said stereopair reproducing means comprises: an amplitude separation circuit for separating scanning signals from video signals; a differentiation circuit coupled to said scanning signals and altering the scanning signal into pulses of the same and the opposite polarities with respect to said scanning signal; a horizontal deflection control circuit triggered by said altered pulses having the same polarity of said scanning signals; a pulse selection circuit; a vertical deflection control circuit triggered by signals delivered by the pulse selection circuit; and means for producing one or more light spots to scan a picture screen, and being controlled by the horizontal and the vertical deflection control circuits; the pulse selection circuit comprising a pulse discrimination circuit which includes a timing limit switch means, a pulse counting circuit and a lock circuit, the timing limit switch means having a least upper bound of time h where H/2 <h<H - (h1 - h2) and H - (h2 + h3), H is repetition rate of horizontal synchronizing pulses, h1 is width of horizontal synchronizing pulses, h2 is width of equalizing pulses, and h3 is H/2 less by width of vertical synchronizing pulses; said discrimination circuit receiving pulses altered from said differentiation circuit and of opposite polarity to said scanning signals, and passing only the pulses which arrive at smaller intervals the h, to said pulse counting circuit, the pulse counting circuit comprising two pulse counters, the first counter counting up to the same number of the equalizing pulses prior to the vertical synchronizing pulses and the second counter counting up to one more number than the first counter, at least one of said counters being reset to the initial state of counting upon each detection by the pulse discrimination circuit of time intervals in excess of the least upper bound h, said lock circuit locking said two counters upon attainment of full count by said first counter and by said second counter, alternately, and said lock circuit unlocking said counters upon receipt by said pulse discrimination circuit of at least one pulse corresponding to horizontal synchronizing pulses, and said pulse selection circuit delivering a vertical deflection signal to the vertical deflection control circuit upon attainment of full count by said first and said second counters alternately.

Claim 17

Apparatus as claimed in claim 15 wherein scanning signals are aligned for the first field of (2n - 1)th frame, for the second field of (2n - 1)th frame, for the first field of (2n)th frame and for the second field of (2n)th frame, said scanning signals being generated in sequence and cyclically, the scanning signals for each field having the sequence of a plurality of equalizing pulses, a plurality of vertical synchronizing pulses, a plurality of equalizing pulses and plurality of horizontal synchronizing pulses in order, all the vertical synchronizing pulses for the (2n - 1)th frame having identical configuration, and the vertical synchronizing pulses for the (2n)th frame being same in the total number as of the vertical synchronizing pulses for the (2n - 1)th frame, all except the first pulse of a sequence having identical or proximate configuration to the equalizing pulse and said first pulse having identical configuration as of the vertical synchronizing pulses for the (2n - 1)th frame; the horizontal synchronizing pulses are aligned at constant time intervals; and the equalizing pulses and the vertical synchronizing pulses are aligned at one half of the time intervals of the horizontal synchronizing pulses, the (2n - 1)th frames carrying right-eyed pictures and the (2n)th frames carrying left-eyed pictures of stereopairs.

Claim 18

Apparatus as claimed in claim 15 including an integration circuit coupled to and integrating said scanning signals for discriminating said (2n - 1)th frames and said (2n)th frames according to the level of integrated signals of said vertical synchronizing pulses.

Claim 19

Apparatus as claimed in claim 1 wherein each liquid crystal filter of said at least one viewer device further includes at least one pair of transparent plates; and said at least one layer of liquid crystal being held in the form of film between said pair of transparent plates, the transparency of said liquid crystal film being dependent on the electric field intensity; said at least one set of transparent electrodes being so arranged to effectively change the electric field intensity to control transparency of said liquid crystal film of the filter.

Claim 20

Apparatus as claimed in claim 18 wherein two or more of said filters are laminated in one piece and a pair of the same pieces form said viewer.

Claim 21

Apparatus as claimed in claim 18 wherein each plate of said pair of transparent plates of said liquid crystal filter has a surface in contact with said liquid crystal film, said contacting surface being coated with electrically conductive and transparent material to form said set of transparent electrodes.

Claim 22

Apparatus as claimed in claim 20 wherein at least one of the electrically conductive coatings on said pair of transparent plates is uniformly semi-reflective.

Claim 23

Apparatus as claimed in claim 18 wherein one plate of said pair of transparent plates of said liquid crystal filter has a surface in contact with said liquid crystal film, said contacting surface having electrically conductive and transparent parallel lines thereon, every other line being connected to a first terminal and the remaining lines being connected to a second terminal, thereby forming said set of electrodes; and wherein the other plate of said pair of transparent plates has a surface in contact with said liquid crystal fil said contacting surface of the other plate uniformly coated with electrically conductive and transparent material and being connected to a third terminal.

Claim 24

Apparatus as claimed in claim 22 wherein the surface of said paired transparent plates, being in contact with the liquid crystal film and being uniformly coated with said electrically conductive material, is semi-reflective.

Claim 25

Apparatus as claimed in claim 18 wherein at least one plate of said pair of transparent plates of said liquid crystal filter has a surface in contact with said liquid crystal film, said contacting surface having electrically conductive and transparent parallel lines thereon, every other line being connected to one terminal and the remaining lines being connected to another terminal, thereby forming said set of electrodes.

Claim 26

Apparatus as claimed in claim 24 wherein both plates of said pair of transparent plates have surfaces provided with said set of transparent parallel line electrodes, said pair of plates being arranged at such an orientation that the parallel lines of the electrodes on said two plates are at right angles relative to each other.

Claim 27

Apparatus as claimed in claim 24 wherein one surface of said paired transparent plates which is in contact with said liquid crystal film and which is not provided with electrically conductive parallel lines, is semi-reflective.

Claim 28

Apparatus as claimed in claim 1 wherein said viewer controller comprises a switching circuit for connecting and disconnecting said electrodes of said liquid crystal filters with a power source responsive to said synchronizing signals such that the filter covering the right eye and the other filter covering the left eye of an observer alternately exchange transparency and translucency in synchronism with each other according to the synchronizing signals transmitted from said synchronizing signal generator.

Claim 29

Apparatus as claimed in claim 27 wherein said power source is a direct current source.

Claim 30

Apparatus as claimed in claim 27 wherein said power source is an alternating current source.

Claim 31

Apparatus as claimed in claim 27 wherein said switching circuit includes means for short-circuiting said electrodes of said liquid crystal filters after disconnection thereof from said power source to expedite returning said filters to transparency as soon as they are disconnected from said power source.

Claim 32

Apparatus as claimed in claim 27 wherein said switching circuit includes means for connecting said electrodes of said liquid crystal filters to an alternating current source of sufficiently high frequency to exert a quenching effect upon the associated liquid crystal film as soon as they are disconnected from said power source.

Claim 33

Apparatus as claimed in claim 27 wherein said synchronizing signals comprise two types of alternately generated synchronizing signals, and said viewer controller, further includes a signal discrimination circuit for discriminating said two types of synchronizing signals.

Claim 34

Apparatus as claimed In claim 27 wherein said switching circuit is a transfer relay.

Claim 35

Apparatus as claimed in claim 27 wherein said switching circuit includes means for applying an alternating electric field of sufficiently high frequency across said liquid crystal films of the liquid crystal filters to exert a quenching effect upon them as soon as said sets of electrodes are disconnected from said power source.

Claim 36

Apparatus as claimed in claim 34 wherein said alternating electric field of sufficiently high frequency is continuously imposed across said liquid crystal films to exert a latent quenching effect upon them at such an intensity so that the electric field applied across said sets of electrodes is not prevented from rendering the associated liquid crystal films translucent.

Claim 37

Apparatus as claimed in claim 27 wherein said switching circuit includes a flip-flop circuit, and further including a one-shot pulse generator for delivery of a one shot pulse to said switching circuit at a desired time.

Claim 38

Apparatus as claimed in claim 36 and wherein said switching circuit is a quaternary counting circuit comprised of two interconnected flip-flop circuits.

Claim 39

Apparatus as claimed in claim 36 wherein said stereopair reproducing means is a television receiver, and wherein said synchronizing signal generator generates synchronizing signals each time said light spot completes scanning one field, said synchronizing signal comprising the vertical synchronizing signal which is used to trigger the vertical deflection circuit for said television receiver, said vertical synchronizing signal being tapped out of said television receiver and transmitted to said viewer controller.