WO1983001719A1

WO1983001719A1 - Stereoscopic television device totally bidimensionally compatible, without alteration of the colours, applicable to s.e.c.a.m standards

Info

Publication number: WO1983001719A1
Application number: PCT/FR1982/000182
Authority: WO
Inventors: Raymond Charles Corviole
Original assignee: Raymond Charles Corviole
Priority date: 1981-11-09
Filing date: 1982-11-08
Publication date: 1983-05-11
Also published as: FR2516334A1; EP0093129A1; FR2516334B1

Abstract

A first camera (a) supplies bidimensionally the broadcast according to S.E.C.A.M standards (m). The crominance subcarrier, modulated in frequency is also modulated in amplitude by the red signal of a second synchronized camera (b) providing for the left vision of the stereoscopic couple. A circuit adaptable to a colour receiver allows the normal bidimensional or stereoscopic reception (n). An original filter device restores the relief vision without alteration of the colours (p). The latter device is applicable to movies, projections of slides and relief printings.

Description

Embossed television process fully compatible in two dimensions, without color alteration, applicable to the S.E.C.A.M.

It is recognized that the impression of relief is satisfied with health when it is given by a stereoscopic process. The problems raised for the application of this process on television are:

1) Compatibility with existing equipment, possibly use of additive material, easily adaptable and economical.

2) Possibility of simultaneously transmitting in 2d (2-dimensional image) and in 3d (relief image).

3) Obtain a sufficient definition for the 2nd view of the stereoscopic couple. 4) Transmit the additional signal (s) without widening the frequency spectrum occupied by the transmitter. 5) When the differentiation of left and right views is based on the decomposition of colors or light, obtain a correct reproduction of the colors of the raised image. 6) Being able to adjust the base and stereoscopic convergence. Incidentally, we can consider the non-imperative conditions:

7) Possibility of retransmitting existing stereoscopic films.

8) To be able to record the programs in relief on video recorders.

No known systems meet all of these conditions. They are either closed chain or used in different SECAM standards, and they deeply alter the colors.

The present invention relates to a chain allowing the retransmission of relief images fulfilling the first 6 conditions. This chain is not incompatible with the 7 ° and 8 ° conditions, but these would require a deeper transformation of the equipment of tele cinema and video recorders if we want to keep the compatibility 2d - 3d. However, it allows recording 3 d broadcasts by viewers without modifying existing video recorders.

The invention includes: I. - An Orise element of compound view: a) A normal three-color camera sending to the matrixing the 3 chrominance signals for the frequency modulation of the subcarrier = 4300 Me according to SECAM standards, thus as the luminance signal, to allow transmission and reception in 2 dimensions by all viewers.

Ib) A second camera for the left shot of the stereoscopic couple. It is synchronized with the same signals used by the first camera. It only sends a signal corresponding to red to the transmitter to modulate the amplitude of the subcarrier. le) The two cameras can be paired according to figure (I). The sliding of the two central mirrors makes it possible to adjust the basic width of the stereo stereos. The pivoting of a side mirror allows the adjustment of the convergence. This system does not allow very small bases to be obtained. The arrangement according to figure (2) with a single semi-silver mirror makes it possible to adjust the base from = 0 mm by sliding a camera, thus authorizing micro and macro shooting »The pivoting of the mirror allows the adjustment of the convergence. These settings can be manual or synchronized with the lenses or Zoom. We can thus maintain convergence on the main plane or other planes to obtain the effects of window or off-screen projection. The 2nd camera can be of the trichrome type, of which we will only use the red signal or a monochrome camera in which case we will add a red filter with narrow band or passing only λ> 600nm. Id) An electronic viewfinder adding the green and blue signals from the 1st camera and the red signal from the 2nd camera allows you to check the setting of the convergence at the same time as the development of objectives. The convergence of the cameras will generally be centered on the main plane, which will make it possible, on reception, to benefit from the 2d luminance signal for the two stereoscopic views at the level of this plane. The relief is very well perceived when a view of the couple is blurred. The lack of luminance of the left lane on the secondary planes will therefore not be harmful; the red chrominance signal would be sufficient, even if there was only a mediocre definition le) A matrixing allows the FM modulation of the subcarrier with the differential signals EB-EY, EV-EY; ER-EY (DB, DV, DR) for 2 d transmission and AM modulation of the subcarrier, with the ER3d signal. Alternatively, the AM modulation may be ER3d-EY2d + Cte (ER3d = Chrominance red 3d, EY2d = luminance 2d), (see diagram fig.3).

As a variant, the modulation may relate only to one channel, in particular the blue, the amplitude of which is at the maximum at = 50% after anti-bell shaping, with the advantage of a greater margin for AM over-modulation and a reduction in the risk of moving frame in reception N. and B. On the main plane, the reds 2d and 3d have the same instantaneous chrominance and the maximum amplitude of the subcarrier is = 30% for the red before 3d over-aodulation. If, for example, the 3D overmodulation is 50% maximum, the DB channel of the subcarrier will be modulated at most by ≤45% for red, 35% for white, <52% for yellow.

On the secondary planes, the maximum amplitude will be 76%, but only in transition zones between yellow of the main plan and red of the secondary planes, that is to say very exceptional cases in nature. As a variant, the amplitude of the anti-bell shape of the two differential channels DB2d and DR2d could be reduced within the limit where the signals could always be equalized by the clo circuits bells of the color receivers, before limitation by clipping, and, where the transmitted energy will be sufficient for all the national network, (fig.4) By optimization, one can determine the value of the overmodulation and the anticloche shaping by taking account in addition to the parameters that were used to develop the current anticloche shape, the following parameters:

On the main plane: graduation of red. On the secondary planes: the extreme amplitudes mentioned above only occur over very short line lengths and possibly only one line out of two.

For all shots: that the parasitic modulation is approximately 0.5 V / 5 V at the output of the receiver bell amplifier.

As a variant, an accentuation of the red signal ER3d or DR3d can be planned and calculated during the optimization (fig.5) 2- A circuit to be added to the SECAM receiver (fig.6) comprising: 2a) A power outlet and of signals necessary for its operation as well as the subcarrier received before clipping, after bell circuit or before for the case where the amplifier and the limiter are an integrated circuit, or in order to make the adjustment of the assembly more independent. 2b) Optionally, a VCR socket for three-dimensional recording. 2c) A bell circuit if that of the receiver is not used. 2d) AM detection of the subcarrier by diode bridge making it possible to obtain a definition twice that obtained by a single diode. The definition of a 67 cm screen is of the order of I, I binds for PIL tubes and 1.3 Me for tubes with shadow mask. These definitions are in harmony with the definition of the detected signal. Alternatively, and in depending on the variant adopted on transmission, the signal can be ER 3d or ER3d - EY2d + cte. 2e - An amplifier of the ER3d signal, looped by a damped comparator allows to obtain an ER3d signal of a constant ratio with the ER2d signal, ratio which can be adjusted manually.

The adjustable damping takes into account the maximum distance at 2 homologous points in the right and left views. Alternatively, the loopback can adjust the gain of the amplifier, by comparing the integrated ER3d and ER2d signals on 0 <t ≤ 64 μs or t = 128 μ s. The integration time can be limited by oscillating circuit, or by the erasure signals or by the signals of the delayed channel switch of the chroma stage.

As a variant, the signals ER3d and ER2d can be differential signals ER3d - EY2d + Cte and ER2d - EY2d 2f - In the event that the over-modulation only concerns one channel, a delay line of 64 μs with its channel balancing amplifier direct / delayed. Optionally, a flip-flop to escape parasites from the unused channel. (see diagram fig.7) 2g - A contactor, permutator, returns according to the diagram of the receiver, the 3d signals to replace the 2d signals, either towards the matrixing, or towards the tube. If the matrixing normally provides ER, EV, EB chroma signals to the tube, it will simply exchange the ER signals.

If the matrixing provides differential signals several cases are possible:

- either ER3d - EY2 + cte is supplied by the transmitter: it exchanges the differential signals taking account of the constant.

- ER3d is supplied by the transmitter. A differential signal is reconstructed before exchange: ER3d - EY2d Amorti + Cte for exchange. The signal EY 2d taken from the video is amortized over time to enjoy the definition of luminance on the red canon. The damping is adjustable so that the difference EY2d - EY2d damping does not cause a fan tome image on the secondary planes which is greater than the limit admitted by the visual cortex without fatigue, ie 5 to 8%.

Alternatively, one can matrix the signal ER2d-EY2d + EY2d to compare it to ER3d. The ER3d signal obtained (regulated) will be reinjected into the tube to replace the signal

ER2d - EY2d and we will replace the luminance signal EY of the red cannon by a constant signal. (see diagram of the assembly fig. 7). 3.- A device intended to decode the raised image of the screen without altering the colors.

3.I - The restitution of colors by filtering glasses, red and cian, is not faithful for the following causes: a) The decrease in brightness due to filtering and the separation of colors for each eye causes dilation of the pupils. This expansion is a function of the wavelength of the filtered light and is variable from one spectator to another. b) The significant emission of UV from the receiver screen reduces the dilation of the pupil on the cian side compared to that on the red side. c) The light rays, more or less modulated and not identical for the two eyes, pass around the glasses, irregularly reducing the dilation of the pupils, which disturbs as in (a) "the exact restitution of colors by the visual cortex, and decreases the brightness of the reconstituted image d) The more or less directing and different eye from one spectator to another, causes a dominant color of the filter which is assigned to it é) An eye can present a difference a temporary visual disturbance 3.2.- The device used makes it possible to obtain images correctly colored for all spectators who do not have excessive visual disturbances. It is a pair of glasses with a skirt obscuring stray light to compensate for the defect (c). This skirt possibly has a shape that does not interfere with the wearing of medical glasses (I). Fig.8 It has 2 fixed filters:

- a red on the left side (2) allowed only the rays λ> 600nm to be passed, - a right hand side (3) allowing only the rays with low density of 47Q <λ <535 nm and of the order of 440 to pass 580 high density, pu beyond 700nm and stopping UV as much as possible Correction filters, degraded continuously or discreetly, can move in front of or behind the fixed filters, either by translation (fig8) or by rotation (fig. 9) allowing adjustment of the brightness and filtering of fixed filters at the discretion of the spectators. Various devices, not described, can be used for moving and locating the position of these filters.

In order to maintain the maximum brightness, the correction filter for red (4) is gray, blue or green, or a mixture of these colors.

For the cian, we use 2 degraded filters, one magenta (5), the other yellow (6).

These three filters are graduated in subtractive values from 0.

For reasons of economy and ease of implementation, the quality of the filters may be less pure than that suggested above, but to the detriment of the brightness of the image, and moreover, an imbalance of the brightness will cause. some eye strain.

The skirt can also be removed if the spectator is located in an area free of stray light rays. 4.- The accompanying drawings describe the essential points of the invention.

Fig.I - Shooting mounting diagram. a) three-color camera b) camera for 2nd red view c) 2 mirrors sliding along arrow for adjusting the stereo base d) fixed mirror e) pivoting mirror for adjusting the convergence.

Fig. 2 - Shooting mounting variant. a) trichrome camera b) camera for 2nd red view sliding along arrow for setting the stereo base. c) semi-silver, pivoting glass for adjusting the convergence. d) red filter if camera b is of type N. and B. Fig. 3 - Simplified diagram of the emission

Alternatively, the 3d differential matrix can be omitted.

The variant where the A.M. modulation relates only to the blue channel has not been shown. Fig. 4 - G-raphic modulation of A.M. of the Blue DB2d differential channel by an ER3d overmodulation of 50%. a) anti-bell curve of DB2d of S.E.C.A.M standard b) overmodulation limit for the main plane c) overmodulation limit for transients between main and secondary plane. Fig. 5 - ER3d channel pre-emphasis graph. d) unaccented stress curve f;

(f '[chrominance R3dJ = cte> 0) e, f, g, h - examples of pre-accentuated curves Fig. 6 - 2d / 3d reception diagram (Variant) k) Subcarrier socket variant. Fig. 7 - Diagram of electronic decoder.

Variant relating to over-modulation on a track. Fig. 8 - Optical decoder with rectilinear corrective filters For a better understanding, the winding, tracking, and displacement devices of the corrective filters have not been represented 1.- Skirt

2.- Fixed filter red 3.- Fixed filter cian

4.- Corrective filter 5.- Magenta corrective filter 6.- Yellow corrective filter Fig.9 - Optical decoder with pivoting corrective filters. Identical remarks to fig. 8.

Fig. 10 - Diagram of the television channel. a) three-color camera. b) 2nd camera for 2nd red view m) transmitter n) circuit adaptable to receiver p) optical decoder

Claims

CLAIMS. I.- Television device allowing the simultaneous transmission of programs in 2 dimensions (2d) and in relief (3d) characterized by a stereoscopic shooting device composed of 2 cameras and a mirror system, a device electronics ensuring the over-modulation of the SECAM composite signal subcarrier by the signal from the 2nd camera, a device adaptable to the color receiver comprising a subcarrier socket before clipping, a detection, a regulating amplifier, a switch replacing the 2d signal supplying the trichromatic tube with a 3d signal during the relief vision, a filtering device allowing the optical decoding of the 3 d image composed of an adjustable filtering system and a screen blocking the stray light rays, this latter device being able to be used for applications other than relief TV.

2.- Device according to claim I characterized in that it comprises, inter alia, a camera (a) providing the three-dimensional signals in 2 dimensions, a 2nd camera (b) providing a signal corresponding to the red of the 2nd view stereoscopic, synchronized with the 1st camera, a mirror system (c) ensuring the optical connection, the pivoting of the mirror ensuring the adjustment of the convergence and the sliding of the 2nd camera ensuring the adjustment of the stereoscopic base, these two movements can be synchronized with the development of objectives.

3.- Device according to claim I characterized in that The device for modulating the composite sub-carrier according to the SECAM standard added to the AM modulation in anti-bell form of the sub-carrier (a) AM modulation (b and c) from the ER3d signal from the 2nd camera; the latter signal can be pre-emphasized and the anticlock modulation (a) be reduced in amplitude. As a variant, the signal ER3d could be a differential signal ER3d-EY2d + cte 4.- Device according to claim 3 characterized in that the signal ER3d modulates the subcarrier only the space of time where it is modulated in FM by signal

EB2d or EB2d - EY2d from the 1st tri-color camera. In this case, the electronic decoding device attached to the receiver will contain a 64 μs delay line with its delayed channel / direct channel amplifier-equalizer and a channel permutator synchronized by a signal from the receiver.

5.- Device according to claim I characterized in that it comprises a socket of the sub-carrier by a connector adaptable to the color receiver between the bell circuit and the clipper, followed by an A.M. detection of the signal

ER3d or ER3d - EY2d + cte; this detection will be carried out by a diode bridge doubling the definition; alternatively, the subcarrier may be taken before _. receiver bell circuit and the device will contain its own bell circuit.

6.- Device according to claim I characterized in that the amplifier-regulator device possibly ensuring the de-emphasis of the signal E3d is of variable gain controlled by a loop comparing its output signal ER3d or ER3d - EY2d + cte with the signal ER2d- EY2d given by the final amplifier of the chrominance plate of the receiver, with possible adjustment of the ratio and the damping between the 2 signals "

7.- Device according to the claim which is characterized in that the amplifier-regulator device has a damping of its loop produced by comparison between the signals ER2d and ER3d integrated over a time of 0 <t <64 μs or t = 128 μs. This integration time can be provided either by an oscillating circuit, or by a signal from the chrominance delayed channel permutator or by the line erasure signal from the receiver.

8.- Device according to claim I characterized in that the optical decoding device of the 3d image of the screen of the three-color tube is a pair of filter glasses, comprising a screen in the form of a skirt (I) obscuring the light rays parasites capable of modifying the dilation of the spectator's pupils and of such shape that it will not harm the wearing of medical glasses.

9.- Device according to claim I characterized in that the device is a pair of filter glasses having 2 fixed filters: red left side (2) and right side cian (3), and three correction filters degraded continuously or discreetly, . can move in front of or behind the fixed filters, either by translation or by rotation: one of a color other than red (4) for the brightness correction of the fixed red filter, one of magenta color (5) and one of yellow color (6) for the cian fixed filter.

Correction filters will be graduated. They can be protected or manipulated using any technology.

10.- Device according to claim I characterized in that the optical decoding device can be produced on a three-color separation basis of different colors of red and cian, by observing the same complementary rules and can be used for stereoscopic vision of cinematographic or slide projections, photographic prints, reproductions using various printing methods.