US2728024A - Cathode-ray tubes of the lenticular grill variety - Google Patents

Cathode-ray tubes of the lenticular grill variety Download PDF

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US2728024A
US2728024A US277182A US27718252A US2728024A US 2728024 A US2728024 A US 2728024A US 277182 A US277182 A US 277182A US 27718252 A US27718252 A US 27718252A US 2728024 A US2728024 A US 2728024A
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Prior art keywords
grill
screen
electrode
target
field
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US277182A
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Edward G Ramberg
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RCA Corp
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RCA Corp
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Priority to NLAANVRAGE7710667,A priority Critical patent/NL176924B/xx
Priority to US25091D priority patent/USRE25091E/en
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Priority to US277182A priority patent/US2728024A/en
Priority to FR1076290D priority patent/FR1076290A/fr
Priority to GB6330/53A priority patent/GB726569A/en
Priority to DER11207A priority patent/DE1022258B/de
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/20—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours
    • H01J31/201—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours using a colour-selection electrode
    • H01J31/203—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours using a colour-selection electrode with more than one electron beam
    • H01J31/205—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours using a colour-selection electrode with more than one electron beam with three electron beams in delta configuration
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching
    • H01J29/803—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching for post-acceleration or post-deflection, e.g. for colour switching
    • H01J29/806—Electron lens mosaics, e.g. fly's eye lenses, colour selection lenses
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/16—Picture reproducers using cathode ray tubes

Definitions

  • a color-kinescope containing a bi-part screen assembly which comprises (i) a transparent viewing screen having a target surface made up of a multiplicity of groups of parallelly arranged strips or lines of diiferent (e. g. red, blue and green) coloremissive areas and (ii) a grill formed of a large number of spaced apart wires mounted adjacent to the target side of said screen.
  • the beam electrons travel in substantially straight paths through the space between the grill and the screen. These straight beam-paths terminate, ideally, on respectively different ones of the (red, blue and green) line-like screen areas.
  • the proper geometrical location of the grill wires provides a Crookes-shadow which masks those line-like screen areas which at any given instant are to remain unilluminated.
  • Crookes-shadow tubes One very real limitation upon the efiicient use of the above described Crookes-shadow tubes is that only a small percentage of the beam electrons ever reach the viewing screen; the larger percentage being dissipated (in the form of heat) upon impact with the imperforate parts of the grill or mask.
  • This limitation was recognized by Dr. Flechsig and his patents mention that it can be minimized (a) by making the mask wires of such fine gauge that the Crookes-shadow is no longer a factor in the operation of the tube and (b) by substituting for the Crookes-shadow efiect a beam-focusing cylindrical-lens effect which he achieved by operating the viewing screen at a relatively high potential with respect to the fine wire grill.
  • Color-kinescopes which incorporate electron pervious focusing electrodes in the vicinity of the screen or target, and which are hereinafter referred to as being of the lenticular grill variety, are far more efiicient than those operating on the Crookes-shadow principle.
  • the color images produced by lenticular grill tubes are frequently marred by color dilution, halo effects, low contrast, and other image defects commonly associated with cathode-ray tubes of the post-accelerated variety.
  • a post-accelerated cathode-ray tube is here defined as one wherein the electron beam or beams are subjected to an auxiliary accelerating force immediately prior to their arrival at the screen.
  • the principal object of the present invention is to achieve, in a cathode-ray tube, the efficient utilization of the scanning beam, or beams, without loss of contrast and, in the case of a color-tube, Without color dilution resulting (a) from the return of high velocity back scattered electrons to the fluorescent screen as well as from (b) the acceleration of low velocity secondary electrons from other elements in the tube.
  • a cathode-ray tube of a target assembly comprising (1) an electrically conductive line-like or dotlike screen and (2) two or more field electrodes or lens elements each containing a multiplicity of apertures, with the apertures of at least one of said field electrodes arranged in a pattern which is geometrically related, in a manner later specified, to the line-like or dot-like raysensitive areas on the screen.
  • the voltage applied to whichever one of the field electrodes that lies next adjacent to the target surface of the image screen is made substantially equal to or greater than the voltage applied to said target surface.
  • the target assembly may be said to comprise an electron-lens system consisting of one set or array of converging lenses and one array of diverging lenses.
  • the electric field of the diverging lens-array tends to defocus the beam and hence to distort its pattern of impact upon the mosaic surface of the target electrode.
  • the unique structure of the lens elements and their novel orientation with respect to the screen operate to confine the boundaries of the distorted beam to the particular areas of the screen which have been selected for illumination.
  • Pig. 1 is a partly broken-away view in perspectivev of a three-gun color kinescope of the linerscr'een variety containing a tri-part target assembly with'i'ts several elements constructed and arranged in accordance with the principles of the invention
  • Figs. 1a, 1b, 1c and 1d are a series of potential or voltage plot-s which will be referred to in explaining.
  • Fig. 2 is a partly diagrammatic side elevation of the gun and target assemblies of the tube of' Fig. 1 but showing a linear (instead of triangular) arrangement of the three guns; the drawing being marked with lines indicative of the paths of the three beams, with symbols indicative of the spacing and voltages" applied to the separate elements of said assembly, and also with lines indicative of the converging eifect' of the focusing, grill upon the beam electrons;
  • Fig. 3 is a diagrammatic view similar to Fig. 2 but with the tube turned 90 to show the defocusing or divergent effect of the auxiliary grill upon the beam electrons;
  • Fig. 4' is a diagrammatic view similar to Fig. 2 (but showing a single beam), the drawing being marked with lines indicative of a preferred relative voltage distribution among the three electrodes of the screen assembly in the tubes of Figs. 1 and 2; I
  • Fig. 5 is a diagrammatic view similar to Fig. 4 but showing a difierent relative arrangement of the two grill elements of the target assembly, and a di iierent' relative voltage distribution;
  • Fig. 6 is adiagrammatic view showin'g'th'e grill assembly of Fig. 5 with still another relative voltage distribution among the three elements of the screen or target assembly;
  • Fig. 7 is a diagrammatic view showing" the invention as applied to a cathode-ray tube, of the switching-at-thescren variety disclosed in Schroeder U. S. P. 2,446,791; therelative arrangement of the color areas on the screen being essentially similar to that shown in said parent;
  • Fig. 8 is a view from the rear of the bi-pa'rt focusing and; switching grill of the tube of Fig. 7
  • Fig. 9 isan electrical diagram of certain operating" voltages applied to the tube elements ofFig'. 7;.
  • Fig. 10 is a view" in perspective of a targetassembly including two apertu-re'd grills of a: construction suitable for use in connection with a target of the, clot screen variety;
  • Fig.- 11 is alongitudinal sectional view" of the invention as applied to a color camera or pickup. tube;
  • Fi'gill is a fragmentary sectional view of the photo'- emissive screen or target. electrode of the, pickup tube of Fig. 11;
  • Fig- 13 is a view similar to Fig. 1 2 but showing photoconductive (instead of photo-emissive) screen and";
  • Fig. 1'4 is a partl ydiagrammatic side elevation of. a. stereoscopic black-and-whi't'e kine'scope' embodying the in: vention.
  • the color-kinesc'ope shown in Fig. 1 comprises; an evacuated envelope 1 havinga mainchamber 3 in the form ofa trust-um which termatihat'esat its large end in a window's through which the obverse faceoffthe'vieviing" screen 7 of a: tri-part target-assembly 1, 9; 11 may be" 4, viewed.
  • the viewing screen 7, here illustrated, is of the line-screen variety described in the French and German Flechsig patents, previously mentioned. It is provided on its rear or target surface with a multiplicity (say, 1500 or more) of parallelly disposed phosphor lines R (red), 13 (blue), G (green) of diiierent-color-emissive characteristics, arranged in a repetitive pattern in groups of three.
  • These parallel lines R, B and G are here shown as extending horizontally across the screen, they may however extend vertically, or at. an angle with respect to said directions.
  • An electron-transparent light-reflecting film 13 constituted, for example, of evaporated aluminum, renders the entire target surface of the screen conductive.
  • the other elements of the screen or targetassembly comprisev two wire-grills 9 and 11 mounted in spaced "apart parallel planes in front of the conductive target surface of the screen 7. The spacing, orientation and functions of these grills 9 and 11 are described in detail later on in this specification.
  • the beam source. of electrons, and the beam-focusing and deflecting means employed for scanning the target assembly '7, 9 11 may comprise any of the several single or multiple gun-systems suitable for use in connection with color-television tubes.
  • the tube is of the three-gun variety
  • the three electron guns 15 17 and 1 9 are individual to the three screenv colors.
  • the beams approach the target assembly along converging. paths and eventually impingeupon separate ones of the color phosphor lines R, B and (3, respectively.
  • suitable auxiliary deflecting means may be: employed for directing. the beam.
  • the guns are oh duplicate constructionand comprisean indirectly' heated cathode; 21, a control grid 23, a short cup-like; screenrgrid electrode 25,v a first accelerating electrodev 27' and a. second accelerating. electrodeconsi-sting essentially. of. a tubular portion 29" commonto the three guns.
  • a conductive coating31 on the inn'e'r surface of the main chamber '3 and neck 33 of the envelope 11 comprises a third accelerating electrode;
  • the three beams are simultaneously scanned over the target assembly by scanning fieldsproduced by two pairs of deflecting coilscontained in a; ycke' structure 35.
  • Thusea-ch beam is directed: to the subelemental screen areas of the color to which that beam is allotted.
  • the advantwges ofthepresent invention flow from the addition of a suitably oriented and suitably energized auxiliary grill,- to' the lenticular-grill tubes of the Flechsig patents.
  • awdliary-grill 11 may be mounted either adjacent to the gun. side (ii the focusing grill 9 (as in Figs. 1 4 7, l0 and 1'-1)' or intermediate the focusing grill 9 and the screen 'or target electrode '7 (as in Figs; 5 and 6).
  • the wires of the focusing g'rill i wherever situated, extend substantially parallel to the line-like areas R'-, B- and G on the screen and the s ace (d; Fig. 2 between adjacent ones at said wires is pref- ,beam electrons to diverge.
  • auxiliary grill 11 erably aligned with the central line (e. g. the blue line B) of each group (R, B and G) of lines.
  • the wires of the auxiliary grill 11, on the other hand, extend substantially at right angles with respect to the screenlines R, B and G. Irrespective of the relative position of the two grills 9 and 1.1, it is desirable to make the field strength zero on the gun side of the target structure, since this prevents distortion of the scanning pattern by any irregularities of the electrodes in this region. As shown in Fig. 1, a zero field on the gun side of the target assembly can be achieved simply by connecting the first field-electrode (in this case, the auxiliary grill 11) to the conductive coating 31 on the inner surface of the envelope 1.
  • the voltage applied to the conductive target surface 13 (Fig. 1) of the screen 7 is of the order of, say 12,000 volts.
  • the primary electrons of which the beam is comprised back-scatter upon incidence on the screen i. e. release both high and low velocity secondary electrons from the conductive target surface 13 of the screen.
  • the back-scattered and other spurious electrons, upon losing their initial rearward velocity are drawn toward the screen in arcuate paths that terminate at points spaced from the screen area upon which the beam itself impinged, thus giving rise to color dilution and other image defects.
  • the preferred practice is to make the voltage applied to whichever one of the grills that lies next adjacent to the screen or target either substantially equal to or greater than the voltage of the screen or target electrode 7. (Here all voltages are assumed to be measured with respect to the voltage of the cathodes as zero.) As a consequence of such a voltage distribution there is no field in front of the fluorescent screen capable of attracting back-scattered electrons toward the screen, nor is there any field capable of accelerating low-velocity secondary electrons emitted by the grill wires to such a velocity that they will create annoyingly distributing luminous effects on said screen.
  • the lens action at a field electrode depends upon the sign of the change in field which takes place at that electrode. If the field in front of such an electrode (i. e. on its gun side) has a greater tendency to accelerate the beam than has the field on its opposite side (i. e. in the direction of the target) then the field change is positive and causes the If, on the other hand, there is a negative change in field the beam electrons will converge adjacent to that electrode.
  • an auxiliary grill makes it possible to obtain the desired negative field change, and consequentconverging lens action, at the focusing grill Without the presence of fields within the target structure which will result in the arrival of spurious electrons at the target screen. Furthermore, the apertures in this auxiliary grill need not be geometrically aligned with 6 those of the focusing grill, as they must be in the plural grill lens tubes of Epstein U. S. Patent 2,315,367.
  • the lens action at the apertures of the auxiliary grill 11 must be diverging because 1) in order to perform its focusing function the field change at the focusing grill 9 must be of negative sign, (2) in order to avoid harmful effects from the back-scattered and secondaryelectrons the potential of the target must be substantially the same as or lower than the grill electrode 9 or 11 which lies adjacent to the screen. All of this will the more readily be apparent upon inspection of the potential plots shown in the drawings.
  • Figs. 1a to 1d an angle that opens upwardly corresponds to a negative field change and converging lens action.
  • An angle that opens downwardly corresponds to a positive field change and diverging lens action.
  • the focusing grill 9 lies between the auxiliary grill 11 and the target 7 (as it does, for example in Figs. 1 to 4, inclusive) the actual potential variation must lie belowa line joining 11 and 7.
  • This line 11'7 slopes downwardly whether the potential of the target 7 is equal to the potential of either the focusing or the auxiliary grills (as in Fig. 1a), or Whether the potential of the target 7 is lower than the potentials of both of said grill electrodes 9 and 11 (as in Fig. 1b).
  • auxiliary grill 11 lies between the focusing grill 9 and the target or screen 7 (as it does, for example in Figs. 5 and 6) the actual potential variation at the auxiliary grill 11 must necessarily lie above the line (97) joining the focusing grill 9 and the target 7 (to make the angle at 9 open upwardly). The angle at 11 is then seen to open downwardly, corresponding to a diverging lens action.
  • the focusing electrode 9 at 12,000 volts and the auxiliary grill 11 at 15,000 volts
  • focusing can be achieved by the focusing grill 9 because the field change at the focusing grill 9 is negative.
  • voltages of 20,000, 15,000 and 10,000 were assumed for auxiliary grill 11, focusing grill 9 and screen 7, respectviely, and if the spacing between the grills is less than that between the focusing grill 9 and the target 7, as in examples hereinafter given in this application, convergence will be achieved because of the negative field change at the focusing grill 9.
  • the field change at the auxiliary grill 11 is seen to be positive and hence the lens action at this grill is divergent.
  • the divergent action at the auxiliary grill 11 is, however, in the direction along the phosphor lines R, B and G on the target and hence does not result in color dilution because the wires of the auxiliary grill are approximately perpendicular to the wires of the focusing grill (and approximately so to the phosphor lines). It does, however, render the scanning beam astigmatic, so that if it focuses sharply in a direction perpendicular to the phosphor lines it does not do so in a direction at right angles thereto.
  • This effect can be minimized (as explained in connection with Formula No. 3) by employing a sufiiciently small grill wire spacing in the auxiliary grill. If this spacing, d Fig. 3) is comparable with the separation of the scanning lines, moir effects may be produced, which however canbe minimized by scanning the screen at 45 to the phosphor lines.
  • the resultant lens field adjacent to each pair of wires in said focusing grill is that of a cylindrical lens whose generatrices are substantially parallel to the color lines (R, B and G) on the line-screen or target 7.
  • the lens action of said grill 9 is such as to converge the beam electrons toward the long central axis of each of said lines, the lens action at the auxiliary grill 11 being divergent.
  • Figs. 4 and 5 illustrate two realizations of the invention which have the advantage of requiring only one v0ltage in addition to those employed in a tri-color kinescope of the kind (e. g. Crookes shadow) which operate without focusing at the screen.
  • a tri-color kinescope of the kind e. g. Crookes shadow
  • Fig. 4 (as in Fig. 1) the focusing grill 9 is next adjacent to the fluorescent screen 7 and the auxiliary grill 11 is nearer the gun, i. e. adjacent to the gun side of the focusing grill.
  • auxiliary grill 11 is next adjacent to the fluorescent screen '7 and the focusing grill 9 is adjacent to the gun side of the auxiliary grill 11.
  • the electrons scattered back at the target are directed away from the screen 7 where they may be collected by the conductive coating 33 (Fig. l) on the inner surface of the main chamber 3.
  • the behavior of the electrons in passing through the grill assembly can be inferred from the lens action of a slit lens, which is well known to deflect an electron incident on it at a distance h from its center (in the plane of the slit) by an angle:
  • E2 and E1 are the electric fields prevailing on the side of incidence and on the side of departure, respectively, and V is. the accelerating voltage of the electron as it passes through the center of the slit, and second from the known parabolic shape of the paths of electrons moving in'uniform electric fields. It may be stated that the formula for the lens action is satisfied very accurately as long as the angles of convergence and divergence are small, a condition generally satisfied in the instant cases.
  • the angle a will be called the convergence angle.
  • a For a given placement of the guns -i. .e. a given value of yc-the distances'a and a must be chosen so that, for a value of a which causes the beams to converge on identical points on the focusing grill, each beam strikes only the appropriate phosphor lines.
  • the condition that the three beams reach the same point on the focusing grill (more accurately, the same line parallel to the phosphor lines) is given by:
  • the value of a must be such that a ray with the initial tilt or strikes the screen with a displacement equal to the separation of centers of two adjoining (e. blue and red) phosphor lines. Since this separation is Mod/3 where Mn is the magnification with which a scanning beam projects the focusing-grill pattern on the phosphor screen, or and "11" must satisfy the relation:
  • magnification Mo of the focusing grill pattern projected by a ray proceeding from the center of deflection on the screen is:
  • V 2a a 1 a Relation between phosphor line pattern and focusinggrill pattern If we consider a ray leaving the center of deflection at an angle 6 to the tube axis, aimed so as to pass through centers of slit lenses in both grills, the radial coordinate T3 of the point of incidence on the phosphor screen is related to the radial coordinate r of the point of incidence on the focusing grill by:
  • the master for preparing the phosphor screen could be prepared by electronic projection, as indicated in a copending application of Harold B. Law, Serial No. 277,133 filed concurrently herewith.
  • the deflection angle which may be employed except such as may be imposed by difliculties in the design of the yoke and eventually excessive astigmatism in the lens elements of the grill.
  • the eflect of the auxiliary grill in broadening the lines into which an initially parallel electron beam is concentrated on the screen can be shown to be extremely small for reasonable values of the pitch of the auxiliary grill (e. g. 0.020 inch) and of the deflection half-angle (e. g. 30); it exists only in oblique directions of deflection, particularly the corners of'the picture.
  • Thezmagnification near the center of the picture is given, by:
  • the phosphor linepattern may readily be replaced by a pattern. focllslng. EH1 15 dj to the et. he condition consisting ofequidistant straight lines. 5 becomes? I a (we-texts? W) In a thlrd y shown In f the dlspesltleflt of If. the auxiliary grill is adjacent to the targetthe condition focusing grill 9 and auxiliary grill 11 is. as in System11 5 b (Fig. 5') but, now,..the.auxiliary grill 11 and the phosphor screen 7' are cormecteclv together, and placed at the, higher.
  • the system has the advanoff, spurious electrons, including electrons scattered with tage of making the screen voltage equal to the maximumt high velocityat the grill Wires; voltage in the tube and slightly reducing the deflecting v 'Thedellble-gfillgfQellSing- System of the P e invenpgwer requirei tion': can be employed to advantage.
  • the deflecting voltage V may be either in the form of a step voltage 51 (Fig. 9) to give the proper sequence of reproduced colors (e. g. BGRBGRBGR) or more conveniently, in the form of a sinusoidal variation 53 (Fig. 9) with. rrns amplitude:
  • V l e rms A blanking signal 55 (Fig. 9) with three times the color change frequency must be applied to the grid (or cathode) of the gun of the tube to assure that the beam 57 (Fig. 7) is biased off except when the deflecting voltage on the bi-part grill 46-47 is such as to center the electron current on a set of the phosphor lines.
  • the essential features of the tubes thus far described is the employment of (i) two field electrode grills 9 and 11 made up of wires or other elements having parallel-slit openings between them so that the two sets of wires or slits are at right angles to each other, in combination with (ii) a line screen 7 wherein the lines extend in rows parallel to the wires or slits in one or another of said grills.
  • the target assemblies of these tubes when operated in the manner described in connection with Figs.
  • 1 to 9, inclusive may be said to comprise an electron-optical system made up of (i) at least one converging lens and (ii) at least one diverging lens and including (iii) means (i. e. the specified orientation of the wires of each grill with respect to the lines on the screen or target) for so orienting the defocusing action of the diverging lens that it is in a direction along the phosphor lines so that it does not produce any color dilution.
  • means i. e. the specified orientation of the wires of each grill with respect to the lines on the screen or target
  • the virtual absence of color-dilution (which might bepresent as an incident to the necessary presence of a divergent lens in the system) can also be achieved irre spective of the orientation of the auxiliary grill by making said grill of very fine, very closely spaced, wires.
  • grill wires of a diameter of 0.002 of an inch and spaced apart approximately .004 of an inch would prove entirely satisfactory. It was found that the diverging effect of the auxiliary grill 11 was minimized when a wire mesh (11', Fig. 10) consisting of both warp and weft strands with 200 openings per linear inch was substituted for the parallel wire structure of the auxiliary grill 11 shown in Figs. 1 to 8.
  • auxiliary grill formed of such fine, closely spaced, wires is that it may be inserted in the target assembly without any regard to the relative orientation with respect to the wires of the focusing grill. This, obviously, simplifies the manufacture of the screen-assembly. It need scarcely be pointed out, however, that a grill or mesh of such fine construction will absorb more beam current than one of more open-work construction. This disadvantage, however, is offset to a large degree by the fact that the openings in the other or focusing grill (9, Figs. l-6; 9', Fig. 10) can be several times larger than they are in a tube operating on the Crookes-shadow principle.
  • a screen-assembly which includes a screen electrode '7' having a target surface made up of a multiplicity of groups of red (R), blue (B) and green (G) phosphor dots which, in the instant case, are arranged in a repetitive hexagonal pattern similar to one shown in the copending application of Alfred C. Schroeder, Serial No. 730,637, filed February 24, 1947, now U. S. Patent 2,595,548, issued May 6, 1952.
  • the other two elements of the screen or target assembly comprise (1) a focusing grill in the form of a thin metal plate 9 containing a multiplicity of hexagonally arranged apertures corresponding in number to the number of groups (of three) color-phosphor dots on the screen electrode 7' and (2) an auxiliary grill in the form of a fine wire mesh 11' mounted adjacent to the gun or target side of the apertured focusing grill or plate 9.
  • the relative potential distribution among these three electrodes of thescreen-assembly may be made the same as described in connection with the line-screen tubes of Figs. 1-8.
  • the resultant lens field adjacent to the apertures in said focusing grill is that of an axially symmetrical or spherical lens (instead of a cylindrical lens) whose center of symmetry is such that the red, blue and green beams passing through the lens (and originating at the three centers of symmetry, see Fig. 10) converge toward the centers of the dots R, B and G, respectively.
  • the lens action of the focusing grill 9 is such as to converge the beam electrons from any one gun toward the centers of the dots of the color allotted to that gun.
  • the close spacing of the wires of the auxiliary grill 11' renders the diverging effect of this lenticular electrode so small that the beam electrons do not spread beyond the periphery of the dot upon which said beam impinges.
  • the focusing grill 9 is mounted next adjacent to the dot-screen 7' the beam electrons will be confined to the separate areas or dots R. B and G when the following relation exists between a (the spacing between the screen 7 and the focusing grill 9'), a (the spacing between the focusing grill 9 and the auxiliary grill 11), V (the voltage applied to the screen 7'), V (the voltage applied to the focusing grill 9') and V (the voltage applied to the auxiliary grill 11'):
  • Electrode such as Nesa glass,- and aset of parallel filter strips R, G and B which trans- H In'either event its photosensitive target surface (61a, Fig. 12; 61b, Fig. 13) is backed by atransparent I mitt red, greenv and blue light, respectively.
  • grill. 65 (Fig. 11.) is placed a distance ainfront of the photosensitivesurface of the screen 61. It consists of thin wires parallel to and aligned with the filter strips, with,thr.ee.strips.per wire spacing.
  • the auxiliary grill 67 is placed.at.a distance a in front. ofv the focusing grill 65-,-
  • sampler in a dot-sequential.transmitter using a; simultaneous camera if the rateof .changing the beam incidenceis varied-at the sampling frequency; if. varied: at field frequencyit corresponds to:the output of a field-sequential color camera.
  • Ifithegathode-of the gun 71. of the tube is grounded, a voltage v is applied. torthe, focusing (color-selecting) grill; 65and;a.v0.ltage V" tothe auxiliarygrill' 67, the prefer-red relationship, between the voltages and the spacings a, a-
  • the screen ismade up of a clearlyormly metallized phosphor layer 81- on a thin transpar: ent' support 83 whichbearsequally spaced filter strips 85 and' 87 of" polarizing material, successive strips operating topolar'ize incident light in mutually perpendicular directions.
  • These polarizing strips 85"and-87- are disposed parallel to the wires of-the focusing grill 89, and the wires of the auxiliary grill'91 extend at right angles-to said strips.
  • the spacing of'the polarizing strips is made equal to one-half the spacing of wires ofthe focusing grill times" the magnification (Mu) -of the grill patterngon' the screen. (The position of the two grills-g 89 and 911' maybe reversed, if desired.)
  • the tube contains two guns, 93 and? 95, which are so disposed that the beam electrons from one gun fall eX-. clusively on the filter strips 85 of one polarity and the beam electrons from the other gun upon the filter strips 87 ofthe other. polarity.
  • Thescreen is viewed" by the observer through spectacles whose lenses 9']. and 99 are polarizedtin opposite directions corresponding to the directionsof polarization of the-filter strips 85 and 87, respectively. In this manner each eye sees the picture repro Jerusalem through one of the two sets of filter strips only. Sinceit is assumed that the-signals applied to the grids of the guns 93 and are supplied by'the two images formed in. a stereoscopic. television camera (not shown) the composite image perceived by; the observer: is a three-dimem. sionalreplica of the ;s c ene:be ing televised.
  • cathode-raytubest constructedin accordance: with the principles of the inventionett'ectan eflicient utilization ofi their. scanning beam. or beams without loss of contrast and, in the case of color-tubes, without,color-dilutionv resulting- (a-)' from the: return oft high velocity backscattered'electrons to the color-screen as well asfrom (b) the acceleration of low velocity secondary electrons from other elementsinthe tube.
  • said target-electrode is of the line-screen variety
  • said lenticular field-electrodes are of the cylindrical-lens variety and, jointly with said target electrode, comprise the means for subjecting said beam to said electric-field
  • said electron-optical means comprises an arrangement of said field electrodes wherein the generatrices of the cylindrical-lens elements of one electrode are substantially parallel to the lines on said line-screen and the generatrices of the lens elements of another of said electrodes are in a direction substantially at right angles thereto.
  • said target electrode is of the dot-screen variety
  • said lenticular field-electrodes are mounted in spaced apart relationship, successively, in the path of said beam, wherein atleast one of said field-electrodes is of the spherical-lens variety
  • said field-electrodes jointly with said target electrode comprise the means for subjecting said beam to said electric field
  • said electron-optical means comprises another of said lenticular field electrodes, said last mentioned electrode comprising a foraminous structure wherein the apertures are so closely spaced that the distorting effect of said structure upon said beam isnegligible as compared to the diameter of the individual dots upon said dot-screen.
  • a cathode-ray device comprising a source of beam electrons and a target assembly including first and second field-electrodes and a target electrode of the line-screen variety mounted in spacedapart relation in the order named within an evacuated envelope, said field electrodes containing line-like apertures with the apertures in said first field-electrode extending in a direction substantially at right angles to the lines on said line-screen and the apertures in said second fieldelectrode extending in a direction substantially parallel to said screen-lines, of means for applying an operating potential to said first field-electrode and a discrete common operating potential to said second field-electrode and to said target electrode all in accordance, substantially, with the formula:
  • VI 2 v the operating potential applied to said first field! electrode
  • V the common operating potential applied to said sec- .ond field-electrode and to said target electrode
  • a cathode-ray device comprising a source of beam electrons and a target assembly including first and second field-electrodes and a target electrode of the line-screen variety mounted in spacedapart relation in the order named within an evacuated envelope, said field-electrodes containing line-like apertures with the apertures in said first field-electrode extending in a direction substantially parallel to the lines on said line-screen and the apertures in said second field-electrode extending in a direction substantially at right-angles to said screen-lines, of means for applying an operating potential to said second field-electrode and a discrete common operating potential to said first fieldelectrode and to said target electrode all in accordance, substantially, with the formula:
  • V the operating potential applied to said secondfieldelectrode
  • V the common operating potential applied to said first field-electrode and to said target electrode
  • a the spacing between said second field-electrode and said target electrode.
  • a cathode-ray device comprising a source of beam electrons and a target assembly including first and second field-electrodes and a target electrode of the line-screen" variety mounted in spacedapart relation in the order named within an evacuated envelope, said field electrodes containing line-like apertures with the apertures in said first field-electrode extending in a direction substantially parallel to the lines on said line-screen and the apertures in said second fieldelectrode extending in a direction substantially at rightangles to said screen-lines, of means for applying an operating potential to said first field-electrode and a discrete common operating potential to said second fieldelectrode and to said target electrode all in accordance, substantially, with the formula:
  • V the common operating potential applied to said target electrode and to said second field-electrode
  • V the operating potential applied to said first fieldelectrode
  • a' the spacing between said first and second fieldelectrodes.
  • a cathode-ray device comprising a source of beam electrons, a first field-electrode containing a multiplicity of parallel line-like apertures, a second field-electrode containing a multiplicity of linelike apertures extending at right angles to the apertures on said first field-electrode, and a target electrode, all mounted in spaced-apart relation in the order named within an evacuated envelope, of means including a source of voltage for energizing said device in accordance, substantially, with the formula:
  • V' the voltage applied 'to "said first field-electrode
  • a cathode-ray device comprising a source of beam electrons, a firstfield-electrode containing a multiplicity ofparallel line-like apertures, a second field-electrode containing a multiplicity of linelike apertures extending substantially at rightangles to the apertures in said first-field-electrode and a target electrode, all mounted in spaced-apart relation in the order named within an evacuated envelope, ofmeans including a source of voltagefor-energizing said device in accordance, substantially, with the formula:
  • V the voltage applied to said target electrode
  • V!- the voltage applied to said second'field-electrode
  • said beam when subjected to-a scanning movement, will trace upon said target electrode a series of narrow lines parallel to the apertures of, said first fieldelectrode.
  • a cathode-ray device comprising a source of beam electrons, first and second. apertured field-electrodes and a target electrode mounted in spaced-apart relation in the order named inanevacuated envelope, the apertures in said second field-electrode comprising a repetitive pattern of circular holes, and said first fieldrelectrode containing apertures whose smallest diameter is less than the diameter of the circular holes in said second field-electrode, of means including a source of voltage for energizing said device in accordance, substantially, with the formula:
  • trodes q the spacing betweensaid second field selectrode-and said target electrode
  • Vt the voltage applied to said target electrode
  • V the common. operating potential applied to said 'target electrode and to said second field-electrode.
  • V- ,,the"operating potentialrapplied to said first field-electrode ae -thelspacing:betwcen said target electrode and said:sec-
  • line-like ray sensitive areas comprise a multiplicity of groups of phosphor colored areas of different color-response characteristics.
  • one of said sets of parallel wires consists of two groups disposed in a common plane with the wires of one group arranged between the wires of the other group and electrically insulated therefrom.
  • lenticular field-electrodes each containing a plurality of elongated apertures through which said electrons pass in their transit from said source to said line-like screen areas, the elongated apertures in at least one of said lenticular field electrodes extending in parallel relationship with respect to said line-like screen areas and the elongated apertures in another of said field electrodes extending at an angle of substantially 90 with respect to said line-like screen areas.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
  • Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
US277182A 1952-03-18 1952-03-18 Cathode-ray tubes of the lenticular grill variety Expired - Lifetime US2728024A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
NLAANVRAGE7710667,A NL176924B (nl) 1952-03-18 Houder gevuld met een deeltjesvormig wasmiddel.
US25091D USRE25091E (en) 1952-03-18 Cathode-ray tubes of the lenticular grill variety
US277182A US2728024A (en) 1952-03-18 1952-03-18 Cathode-ray tubes of the lenticular grill variety
FR1076290D FR1076290A (fr) 1952-03-18 1953-03-04 Tubes à rayon cathodique, du genre à réseau lenticulaire
GB6330/53A GB726569A (en) 1952-03-18 1953-03-06 Cathode-ray tube of the lenticular grill variety
DER11207A DE1022258B (de) 1952-03-18 1953-03-16 Kathodenstrahlroehre

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US277182A US2728024A (en) 1952-03-18 1952-03-18 Cathode-ray tubes of the lenticular grill variety

Publications (1)

Publication Number Publication Date
US2728024A true US2728024A (en) 1955-12-20

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US25091D Expired USRE25091E (en) 1952-03-18 Cathode-ray tubes of the lenticular grill variety
US277182A Expired - Lifetime US2728024A (en) 1952-03-18 1952-03-18 Cathode-ray tubes of the lenticular grill variety

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US25091D Expired USRE25091E (en) 1952-03-18 Cathode-ray tubes of the lenticular grill variety

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US (2) US2728024A (fr)
DE (1) DE1022258B (fr)
FR (1) FR1076290A (fr)
GB (1) GB726569A (fr)
NL (1) NL176924B (fr)

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US2793319A (en) * 1955-07-26 1957-05-21 Chromatic Television Lab Inc Electron lens structure for television tubes
US2837689A (en) * 1954-12-02 1958-06-03 Csf Post acceleration grid devices
US2861210A (en) * 1954-05-27 1958-11-18 Zenith Radio Corp Image reproducing system
US2863091A (en) * 1956-03-07 1958-12-02 Rca Corp Flat tri-color kinescopes
US2864032A (en) * 1954-07-30 1958-12-09 Zenith Radio Corp Method and apparatus for color television
US2879446A (en) * 1956-02-08 1959-03-24 Kaiser Ind Corp Electronic device
US2888603A (en) * 1954-12-29 1959-05-26 Gen Electric Color television tube and method for color television
US2890379A (en) * 1956-09-18 1959-06-09 Chromatic Television Lab Inc Distortion correction in cathode-ray tubes
US2947898A (en) * 1956-03-16 1960-08-02 Gen Electric Color picture tube screen
US2951178A (en) * 1955-01-07 1960-08-30 Philco Corp Multi-beam cathode-ray tube transducer
US2961314A (en) * 1955-06-24 1960-11-22 Zenith Radio Corp Method of manufacturing color image reproducer
US3016474A (en) * 1954-05-11 1962-01-09 Raytheon Co Cathode ray tubes
US3028521A (en) * 1956-12-21 1962-04-03 Zenith Radio Corp Image-reproducting device
US3032608A (en) * 1956-11-15 1962-05-01 Gen Electric Color tube potential switching between color and monochrome reproduction
US3102212A (en) * 1959-04-24 1963-08-27 Motorola Inc Cathode ray tube with low velocity deflection and post deflection beam acceleration
US3185879A (en) * 1960-03-17 1965-05-25 Rca Corp Cathode ray tube having deflection enhancement means
US3502942A (en) * 1968-10-24 1970-03-24 Zenith Radio Corp Post-deflection-focus cathode-ray tube
US3619688A (en) * 1969-03-28 1971-11-09 Griffiths Electronics Inc Electron gun with connector of alternate electrodes shielding intermediate electrode
US4059781A (en) * 1974-07-17 1977-11-22 U.S. Philips Corporation Shadow mask each aperture of which is defined by a quadrupolar lens
US4128790A (en) * 1975-12-23 1978-12-05 U.S. Philips Corporation Cathode ray tube for displaying colored pictures
US4514658A (en) * 1983-03-31 1985-04-30 Rca Corporation Mesh lens focus mask for a cathode-ray tube
US5085606A (en) * 1989-04-12 1992-02-04 Zenith Electronics Corporation Method of manufacture for post-mask deflection type tension mask color cathode ray tube

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Publication number Priority date Publication date Assignee Title
US2971117A (en) * 1956-03-01 1961-02-07 Rca Corp Color-kinescopes, etc.
US3340421A (en) * 1963-07-31 1967-09-05 Sony Corp Cathode ray tube having metallic layer of non-uniform thickness
US4316126A (en) 1979-11-23 1982-02-16 Rca Corporation Color television picture tube with color-selection structure and method of operation thereof
US5111106A (en) * 1989-04-12 1992-05-05 Zenith Electronics Corporation Post-mask-deflection type tension mask color cathode ray tube
DE10117343B4 (de) * 2001-04-06 2007-09-13 Siemens Ag Fernantriebseinrichtung

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US2580250A (en) * 1950-07-29 1951-12-25 Gen Electric Cathode-ray type of electron discharge device
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US2595548A (en) * 1947-02-24 1952-05-06 Rca Corp Picture reproducing apparatus
US2602145A (en) * 1950-08-25 1952-07-01 Rca Corp Control grille assembly for colorkinescopes, etc.
US2606303A (en) * 1951-02-17 1952-08-05 Bramley Jenny Color television tube and process
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US2692532A (en) * 1951-04-04 1954-10-26 Chromatic Television Lab Inc Cathode ray focusing apparatus

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US1810018A (en) * 1924-05-28 1931-06-16 Westinghouse Electric & Mfg Co Cathode ray oscillograph
FR866065A (fr) * 1938-07-11 1941-06-16 Fernseh Ag Procédé de télévision en couleurs
US2315367A (en) * 1940-07-31 1943-03-30 Rca Corp Cathode-ray tube
US2532511A (en) * 1946-11-16 1950-12-05 Okolicsanyi Ferene Television
US2595548A (en) * 1947-02-24 1952-05-06 Rca Corp Picture reproducing apparatus
US2660684A (en) * 1948-02-06 1953-11-24 Int Standard Electric Corp Electronic color television
US2581487A (en) * 1950-03-01 1952-01-08 Rca Corp Color television reproduction tube
US2580250A (en) * 1950-07-29 1951-12-25 Gen Electric Cathode-ray type of electron discharge device
US2602145A (en) * 1950-08-25 1952-07-01 Rca Corp Control grille assembly for colorkinescopes, etc.
US2606303A (en) * 1951-02-17 1952-08-05 Bramley Jenny Color television tube and process
US2692532A (en) * 1951-04-04 1954-10-26 Chromatic Television Lab Inc Cathode ray focusing apparatus
US2669675A (en) * 1952-01-08 1954-02-16 Chromatic Television Lab Inc Display surface for color television tubes

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3016474A (en) * 1954-05-11 1962-01-09 Raytheon Co Cathode ray tubes
US2861210A (en) * 1954-05-27 1958-11-18 Zenith Radio Corp Image reproducing system
US2864032A (en) * 1954-07-30 1958-12-09 Zenith Radio Corp Method and apparatus for color television
US2837689A (en) * 1954-12-02 1958-06-03 Csf Post acceleration grid devices
US2888603A (en) * 1954-12-29 1959-05-26 Gen Electric Color television tube and method for color television
US2951178A (en) * 1955-01-07 1960-08-30 Philco Corp Multi-beam cathode-ray tube transducer
US2961314A (en) * 1955-06-24 1960-11-22 Zenith Radio Corp Method of manufacturing color image reproducer
US2793319A (en) * 1955-07-26 1957-05-21 Chromatic Television Lab Inc Electron lens structure for television tubes
US2879446A (en) * 1956-02-08 1959-03-24 Kaiser Ind Corp Electronic device
US2863091A (en) * 1956-03-07 1958-12-02 Rca Corp Flat tri-color kinescopes
US2947898A (en) * 1956-03-16 1960-08-02 Gen Electric Color picture tube screen
US2890379A (en) * 1956-09-18 1959-06-09 Chromatic Television Lab Inc Distortion correction in cathode-ray tubes
US3032608A (en) * 1956-11-15 1962-05-01 Gen Electric Color tube potential switching between color and monochrome reproduction
US3028521A (en) * 1956-12-21 1962-04-03 Zenith Radio Corp Image-reproducting device
US3102212A (en) * 1959-04-24 1963-08-27 Motorola Inc Cathode ray tube with low velocity deflection and post deflection beam acceleration
US3185879A (en) * 1960-03-17 1965-05-25 Rca Corp Cathode ray tube having deflection enhancement means
US3502942A (en) * 1968-10-24 1970-03-24 Zenith Radio Corp Post-deflection-focus cathode-ray tube
US3619688A (en) * 1969-03-28 1971-11-09 Griffiths Electronics Inc Electron gun with connector of alternate electrodes shielding intermediate electrode
US4059781A (en) * 1974-07-17 1977-11-22 U.S. Philips Corporation Shadow mask each aperture of which is defined by a quadrupolar lens
US4128790A (en) * 1975-12-23 1978-12-05 U.S. Philips Corporation Cathode ray tube for displaying colored pictures
US4514658A (en) * 1983-03-31 1985-04-30 Rca Corporation Mesh lens focus mask for a cathode-ray tube
US5085606A (en) * 1989-04-12 1992-02-04 Zenith Electronics Corporation Method of manufacture for post-mask deflection type tension mask color cathode ray tube

Also Published As

Publication number Publication date
USRE25091E (en) 1961-11-28
GB726569A (en) 1955-03-23
NL176924B (nl)
DE1022258B (de) 1958-01-09
FR1076290A (fr) 1954-10-25

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