2D/3D compatible polarized color TV system

A 2D/3D compatible polarized TV system is described which comprises a 3 color TV camera with pairs of adjacent 3D right and left images in each color. The image pairs are scanned to derive pairs of 3D image signals. These 3D signals are presented as 3 color pixels alternately polarized orthogonally. The display may be viewed without glasses to see a 2D color image with either the right or left images suppressed; or with polarized viewers to see a color 3D image. A method of manufacturing orthogonally oriented polarized color pixels is described utilizing inorganic polarizing dipoles electrostatically aligned in a fusible transparent coating.

FIELD OF THE INVENTION 
This invention comprises a 2D/3D compatible polarized color cathode ray 
tube (CRT) system, including a video camera, a polarizing display device, 
and polarized viewers which will display 2D or 3D color video images. 
BACKGROUND 
In an earlier U.S. Patent.sup.1, I disclosed a polarizing electrooptic 
screen employing a suspension of dipolar particles, which is placed over a 
standard CRT. These dipoles are oriented alternately in the X and Y 
directions to distinguish two orthogonally polarized stereo images, which 
are viewed through polarized viewers (eyeglasses) to produce a 3D image. 
The inventors Alvin and Mortimer Marks describe a 3D TV system.sup.2, 
utilizing a 3D TV camera with a dichroic beam splitter in which the right 
and left stereo images are carried on the standard color signals. The 
intermixed stereo images on the CRT are separated by color filters mounted 
in the viewers. The presentation of different color images at the 
observer's eyes produces a good stereo image; however, the color imbalance 
causes visual fatigue and discomfort. Accordingly, the inventors sought to 
overcome this problem by employing polarizers over the color pixels, 
enabling the viewer to wear standard polarized viewers to separate the 
images. While this is an improvement, it did not entirely solve the 
problem, because the CRT images still had color imbalance, although the 
surroundings appeared normal. 
An advantage of this system is that it is compatible with the 3D motion 
picture standards used in producing and exhibiting modern 3D film filmed 
in the format employed in the Marks 3Dipex Converter; that is, 2 images, 
right and left, one over the other with a narrow black bar between them, 
and with a width/height ratio exceeding 2. 
A further advantage of this system is that the 3D color CRT is inherently, 
automatically 2D/3D compatible without additional circuitry or switches; 
that is, if a 3D-color signal is transmitted, the CRT of this invention 
will display 3D color polarized images when seen through polarized 
viewers; if a (2D) flat color image is transmitted, the CRT of this 
invention will display a flat color image in the usual manner without 
viewers. All of the information is processed at the television 
broadcasting facility using the 3D-TV color camera and associated circuits 
of this invention; and, displayed on the color-polarized CRT of this 
invention. 
SUMMARY 
This invention utilizes a 3D converter for optically placing right and left 
images one over the other, in each of three 3 color vidicon tubes to 
produce 3 pairs of R,B,G, colored 3D image pairs. The pairs are scanned 
and signals transmitted to a 3D Display screen comprising 3 color pixels, 
adjacent color pixels being polarized orthogonally. In each row pixels of 
the same color and polarization direction repeat every sixth pixel; and 
successive rows of pixels of the same color and polarization direction are 
offset by 11/2 the center to center distance between adjacent pixels. This 
pattern intersperses the right and left images. If only one of the pairs 
of images is transmitted the screen may be viewed without polarized 
glasses to see a 2D image; if a pair of 3D color images is transmitted, 
presented and viewed with polarized glasses, a 3D image is seen. A method 
of producing 3D colored pixels is described, in which polarizing dipoles 
are suspended in a fusible coating, and adjacent pixels are oriented 
orthogonally by a local electric field while the coating is fluid at an 
elevated temperature.

DESCRIPTION OF THE FIGURES 
The same inventors disclose a 3D optical converter known as the 3Depix.RTM. 
Camera Converter which enables two images taken horizontally, separated by 
the interocular distance, to be placed one over the other at an aperture 
or gate..sup.3,4,5 
In FIG. 1, there is shown a 3Depix.RTM. Converter 10, an object 11 being 
photographed, an imaging lens 12 which provides right and left images 13 
and 14, shown in FIG. 2, one over the other at the gate 15. An RBG (red, 
blue and green) prism 16 splits the image into the corresponding colors 
and images them upon the three Vidicon tubes 17, 18 and 19 which provide 
the red, blue and green video signal components respectively. Single or 
dual electron guns may be used. In the preferred configuration shown, 
there are two electron guns, which impinge on pixels 20 and 21 at 
positions X,Y.sub.1 and X,Y.sub.2 on areas 13 and 14 respectively as shown 
in FIG. 2; in which Y.sub.1 =Y.sub.2. Thus the two images 13 and 14 are 
simultaneously scanned by dual electron beams (not shown) which impinge on 
the pixels 20 and 21 in each of the color tubes 17, 18 and 19. 
Blanking pulses from a pulse generator 23 are provided to the dual electron 
guns of tubes 17, 18, and 19 causing the selection of the upper and lower 
images at different time intervals. The pulse generator 23 controls the 
alternate presentation of the color and stereo images to the special 3D TV 
CRT 28. The signal train contains the red, blue and green images and 
alternates the right and left stereo image signals. 
Referring to FIG. 1, the control of the color/polarized pixels is 
established by an enabling pulse circuit 23, which has 6 pulse train 
outputs 71-76 inclusive; 71, 72 respectively to the control terminals of 
the right and left dual electron guns 81 and 82 of the red tube 17, 73-74 
respectively to the control terminals of the right and left dual electron 
guns 83 and 84 of the blue tube 18 and 75-76 respectively to the control 
terminals of the right and left electron guns 85 and 86 of the green tube 
19. 
As shown in FIG. 2, in the 3 color tubes 17,18 and 19 the right electron 
guns 81, 83 and 85 impinge respectively, on the R,B,G right image areas 
13,13',13"; and, left electron guns 82,84 and 86 impinge on the R,B,G left 
image areas 14,14',14". Each pulse train comprises an enabling pulse for 
an impinging electron beam to actuate each sixth pixel followed by a pulse 
of opposite polarity to suppress the electron beam for the pixels between 
the activated pixels. The pulse trains establish the color/polarized pixel 
matrix on the CRT tube face of this invention, as shown in FIG. 3. Table 1 
shows the pulse trains and their corresponding color and polarization 
directions for right and left stereo images. 
TABLE 1 
Showing enabling pulse trains for actuating the k pixels corresponding to 
R,B,G pixels, and the corresponding polarizing directions for right and 
left stereo images for the even j, j+2, j+4, lines. The odd interlace 
lines are shifted1/2pixel to make the pattern shown in FIG. 3. 
__________________________________________________________________________ 
DESCRIPTION 
POLARIZED STEREO 
PULSE 
PIXEL No. (+ON/-OFF) 
COLOR 
DIRECTION 
IMAGE TRAIN k k + 1 
k + 2 
k + 3 
k + 4 
k + 5 
k + 6 
k 
k 
__________________________________________________________________________ 
+ 8 
R -- R 71 + 
- 
B .vertline. 
L 73 + 
- 
G -- R 75 + 
- 
R .vertline. 
L 72 + 
- 
B -- R 74 + 
- 
G .vertline. 
L 76 + 
- 
__________________________________________________________________________ 
These signals are transmitted by a transmission line 24 which may be, for 
example, a coaxial conductor, or video microwave link. These signals are 
received by the standard color CRT receiving circuitry 25. 
A switch 27 at the video 3D color camera controls the blanking pulses from 
pulse generator 23 to select either a flat image or a 3D image. To obtain 
a 2D image from the same video camera, the 3D control pulses from 23 are 
cut off and a 2D control voltage is substituted which allows only the 
right or left image to appear in the usual manner. Since the polarizing 
elements are colorless, the right or left image which appears on the CRT 
color TV screen may be viewed without the glasses in the normal manner, 
but then only a (2D) flat image will appear. 
Returning to FIGS. 1 and 2, in the Depix Converter 10, the lower image 14 
is transmitted over the prism deflector 30, utilizing the mirror 
deflectors 31 and 32 so that the optical axis 33 of the left image and the 
optical axis 34 of the right image are in the same horizontal plane and 
the images 13 and 14 of the object 11 are free of parallax. The deflector 
35 deflects the right image to the prism deflector 30, which directs the 
right image via lens 12 to the area 13 at the aperture 9. A horizontal 
black bar 36 separates the images 13 and 14 in the same format now 
conventional on film used to project 3D in the Motion Picture art. The 
prism deflector 30 is angularly adjustable to converge the axes 33 and 34 
at any suitable distance z from a reference plane 37. Lenses 38 and 39 
image the object 11 via lens 12 onto the 3 color video tube apertures, 
respectively 9, 9', 9" for the R,B,G tubes. 
A 3D TV CRT employing polarizing elements according to this invention is 
described: 
Referring now to FIG. 3, there is shown the j, j+1, and j+2 lines, pixels 
k, k+1, k+2 and k+3 are located on the j and j+2 lines. The interlaced 
lines j+1 and j+3 pixels are at K+0.5, K+1.5, K+2.5 etc. The pixel 
elements on each line are alternately polarized orthogonally; for example, 
oriented as shown at 0.degree. and 90.degree.. This configuration provides 
the most intimate intermixture of the right and left orthogonally 
polarized stereo images. 
FIG. 4 shows a magnified sectional view of the polarized and color phosphor 
elements. A section of the tube face 48 is shown, the inner surface 49 
being coated with a thin layer 50 of polarizing material oriented as 
shown. The layer thickness of 50 maybe, for example, 5 to 10 .mu.m. In 
this example, polarizing elements 53 and 55 are shown with the polarizing 
direction oriented normal to the diagram, and element 54 is shown with the 
polarizing direction oriented in the plane of the diagram. In the 
intermediate areas 56 and 57, the dipoles are at random, that is, not 
oriented; therefore these areas substantially absorb all light, and 
provide a black absorbing surround or mask. A thin transparent conductor 
51 is coated over the polarizing layer 50 as a sink for the electrons from 
the electron beam. The color phosphors 58, 59 and 60, blue, green and red 
respectively, are deposited in proximity to the polarizing layer 50; thus 
providing the polarizing and color pattern shown in a plan view in FIG. 3. 
The construction shown in FIGS. 3 and 4 will of course be understood to be 
a preferred embodiment of this invention, but other structures may be 
employed in lieu thereof, as for example, a polarized lens structure 
superimposed over the face of the color CRT..sup.6 
The structure shown in FIG. 4 is on the internal face of the CRT, within 
which a high vacuum must be maintained. It is customary to hard-seal the 
faceplate to the tube body at a temperature T.sub.1 sufficient to fuse a 
glass or metal seal to provide a permanent joint to maintain the high 
vacuum without leakage over a long period of time. The joint is fused 
while all elements are heated to the temperature T.sub.1, below the 
deformation temperature T.sub.2 of the faceplate. Conventional organic 
polyiodide polarizers so widely used for other purposes cannot withstand 
temperatures in excess of about 100.degree. C., which is usually much less 
than T.sub.1. Consequently, the polarizers of this invention are dipoles 
in a glass layer. Glass dipole polarizers have been previously 
described..sup.7 They comprise submicron metal dipole particles which act 
as antennae resonating to visible light; that is, the dipoles have a 
length of about .lambda./2n and a width of about .lambda./20n, where 
.lambda. is the wavelength of the light, and n is the index of the 
refraction of the glass, usually about 1.5. These submicron dipoles, 
preferable of an inert metal, for example chromium needles, are suspended 
in a fusible glass layer 50, which has a melting point T.sub.3 which is 
greater than the sealing temperature T.sub.1 of the faceplate to the tube, 
but less than the deformation temperature T.sub.2 of the faceplate 48. 
FIG. 5 shows a method of orienting the polarizing elements at each pixel. 
Only one polarizing element 54 is shown undergoing orientation, although 
it will be understood that a whole row or column can be simultaneously 
oriented. 
In FIG. 5, the step of preparing the polarizing layer 50 and orienting the 
polarizing areas 53, 54 and 55 is shown together with the disoriented 
areas 56 and 57. In preparing the polarizing layer 50, a liquid suspension 
of dipole particles in a fluid such as water and/or alcohol is prepared, 
in which also is included a submicron suspension of fusible glass frit. 
Alternatively, a solution of an inorganic glass such as aluminum 
phosphate.sup.8 glass is prepared, and the dipoles are suspended in this 
solution. This suspension is coated on the surface 49; for example, by 
spin-coating. The solvent is driven off at a moderate temperature T.sub.4, 
the temperature is then increased to produce a uniform thin layer of glass 
containing a suspension of a random orientation of dipole particles. The 
layer is a strong absorber of radiation and appears jet black. The 
substrate and the coating is heated to a temperature T.sub.5 which is just 
under the melting temperature T.sub.3 of the coating 50. To orient the 
dipoles in the area 54, for example, a laser beam 61 is imaged onto the 
area 54, increasing its temperature to T.sub.3 causing only area 54 to 
become liquid in the precise pattern required, usually a circular area of 
diameter d; for example, d=400 m.mu.. The greatest temperature T.sub.3 is 
of course, less than the support face glass deformation temperature 
T.sub.2. In this condition, the dipoles may be oriented within the fluid 
by momentarily applying an electric field parallel to the surface 49. 
Typically the electric field intensity required for orientation of the 
dipoles is 5 to 50 volts per micrometer. Since the breakdown of electric 
field intensity in air at 1 Atm. is 3 V/m.mu. m the increased electric 
field intensity can be supported without spark breakdown by increasing the 
pressure of an inert gas (nitrogen) to 2 to 20 atmospheres. The electric 
field employed is preferably a square wave at a frequency of 1-10 Khz. The 
electric field is momentarily applied in the plane of the diagram, as 
shown at 54, between the electrodes 63 and 64 for a time just sufficient 
to orient the dipoles, for example, about 10 ms. By repositioning the 
electrodes about the axis ZZ' through a 90.degree. rotation, the dipoles 
are oriented normal to the plane of the diagram at areas 53 and 55. A 
stepping motion may be employed in the XY plane to move the electrodes 63 
and 64 and the laser spot 61 from place to place during the orientation 
procedure. When the laser beam is turned off while the orientation field 
is applied, the temperature of the surface area 52 quickly decreases and 
the oriented dipoles are frozen into position. In the next step, the 
conducting transparent layer 51 is applied, then the color phosphors 58, 
59 and 60 are applied to the surface of the layer 51, and the tube is 
completed in the well known manner. 
The above describes a complete 2D/3D compatible Color Video Camera, 
transmission means, control circuits and a 2D/3D compatible polarizing 
color CRT TV; which may be abbreviated: (2D/3D-CPC-CRT-TV), which provides 
intermixed stereo images on its face. A 3D image is seen by wearing the 
polarizing viewers 43 containing the orthogonally polarized lenses 44 and 
45. In the event that only a flat 2D picture is transmitted, the polarized 
viewers are not worn. Since the polarizing elements are neutral in color, 
a flat 2D color image will appear in the usual manner. 
Various modifications may be made of this invention without departing from 
the scope thereof. For example, a conventional 3D TV color camera may be 
employed with a single gun, and the right and left images scanned 
successively, instead of simultaneously; subsequently one image may be 
delayed so alternate pixels may be addressed with corresponding points on 
both right and left images; a longer acting phosphor may be used to hold 
the image between scans. 
The means for the successive selection of adjacent pixels of the right and 
left images may be accomplished in any suitable manner, for example, (1) 
right and left adjacent images are focussed onto each of the color tubes 
simultaneously and scanned with two electron guns. (2) In another 
embodiment, the ray bundles from the right and left vantage points are 
first polarized orthogonally; then mixed and imaged onto a special 
polarizing screen in which successive pixels are polarized orthogonally; 
and this then images on each of the color tubes which have a single gun. 
(3) Electro-optic shutters 40,41 over the right and left lenses 
open/close, and then close/open for intervals equally the pixel length, 
controlled via leads 42,42', respectively. 
High intensity color 3D CRT of the type herein described, may also be 
employed in a 3D TV projection system. The system described herein may be 
simplified to a single tube video camera, and corresponding black and 
white polarized CRT. The various embodiments which have been disclosed 
herein and not illustrated will be understood by those skilled in the art. 
REFERENCES 
1. U.S. Pat. No. 3,848,964 issued Nov. 19, 1974 Col. 10, Alvin M. Marks 
2. U.S. Pat. No. 4,134,644 issued Jan. 16, 1979 3D Color Pictures with 
Multichrome Filters. Alvin M. Marks and Mortimer Marks. 
3. U.S. Pat. No. 4,178,090 issued Dec. 11, 1979 3 Dimensional Camera 
Device, Alvin M. Marks and Mortimer Marks. 
4. U.S. Pat. No. 4,175,829 issued Nov. 27, 1979 3 Dimensional Camera 
Devices, Alvin M. Marks and Mortimer Marks. 
5. U.S. Pat. No. 3,990,087 issued Nov. 2, 1976 3 Dimensional Camera, Alvin 
M. Marks and Mortimer Marks. 
6. I bid 2. FIGS. 6 and 7, Cols. 7 and 8. 
7. U.S. Pat. No. 3,813,265 issued May 28, 1974, Electrooptical Dipolar 
Material, Alvin M. Marks. 
8. New Inorganic Materials, J. D. Birchall and Anthony Kelly, Scientific 
American, May 1983 p. 104-114 particularly p. 114 re: Glassy Aluminum 
Phosphate Al PO.sub.4, and bibliography p. 170.