US2220688A - Arrangement for receiving television images - Google Patents

Arrangement for receiving television images Download PDF

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Publication number
US2220688A
US2220688A US145020A US14502037A US2220688A US 2220688 A US2220688 A US 2220688A US 145020 A US145020 A US 145020A US 14502037 A US14502037 A US 14502037A US 2220688 A US2220688 A US 2220688A
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US
United States
Prior art keywords
image
cathode
anode
grid
electron
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US145020A
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English (en)
Inventor
Schroter Fritz
Knoll Max
Kluge Werner
Etzold Hellmuth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefunken AG
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Telefunken AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefunken AG filed Critical Telefunken AG
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Publication of US2220688A publication Critical patent/US2220688A/en
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Classifications

    • 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
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen

Definitions

  • cathode ray 1 system having fluorescent" screen and control grid 40 cathode ray systems may also be provided only for the image elements of the one image coordinate, while the other image coordinate is established by means of a suitable photo-optical arrangement for instance by means of an oscillating mirror or mirror wheel.
  • a suitable photo-optical arrangement for instance by means of an oscillating mirror or mirror wheel.
  • the cathode ray systems can be produced in the I sense of the invention principally by means of any switch connecting the individual control grids in ary electron emission current and secondary emission surface of Fig. 3a.
  • a cathode ray switch shall be utilized to this end, whose contacts are formed by the control grids of the cathode ray systems, and by con- 5 trolling the current in the switching ray, the control grid potentialsshall be determined by the balance between switch ray current'and secondof' the switch contacts '(control grids).
  • Fig. 1 is a schematic diagram showing'the method of operation of a cathode ray secondary emitter.
  • Fig. 2 shows the characteristic curves of the 1 1 device shown in Fig. 1.
  • Fig. 3a shows an image reproducer in which the emission from a thermionic surface is con trolled by a secondary emission surface.
  • Fig. 3b is a partial front View of the thermionic I Figs. 4 to 9 are views of other modifications of the invention.
  • I II is a control cylinder
  • item I2 is an anode
  • I3 is an absorption plate to which is imparted ahigh secondary emission capacity forinstance by means of a cesium layer.
  • a plate voltage source I 4 is 85 inserted and between the plate l3 and the anode l2, a direct voltage sourceU is placed.
  • the control cylinder Ii there'is at first assumed a certain constant potential determining the ray current leaving the cathode Ill and which is assumed to pass in its entirety the anode Ill.
  • the current which can'be measured in the line-between'the plate l3 and the voltage source U varies-in this arrangement in accordance with the value of the voltage U such as indicated in Figure 2.
  • the positive. abscissa axis corresponds with the polarity of thevolt'age source U as indicated in Figure 1.
  • the ordinate axis indicates the current that can-be measured with the measuring instrument M. If the voltage U has the sign'reversed asfregards that in- .dicated in; Figure 1, 'a current flows onlyin the circuit designated"by"A;"'-and the measuring in----- strument M indicates the-same deviation in as a, measuring instrument mi in the lead-in to the and if it has the sign indicated in Figure 1, in
  • the instrument M points to zero.
  • the entire curve I is then determined by a constant primary current im, and constant secondary emission factor (measure of the number of secondary electrons produced by a primary electron) which is greater than 1.
  • the curve 2 is obtained having the values irz, isz, inz.
  • the secondary emission factor for the curve 2 is the same as for the curve I.
  • a glass vessel I5 contains a cathode ray switch consisting of the cathode IS, a control cylinder IT, a first anode l8, a second anode l9 and switch contacts to 22. Furthermore, there is accommodated within the glass vessel I5, cathode ray systems having fluorescent screen comprising the cathodes 23, 24 and a common anode 25 shaped as agrid embedded in the fluorescent substance 26.
  • the contacts 20 to 22 of the cathode ray switch form at the same time the control grids for the individual cathode ray systems.
  • the cathodes 23, 24 are connected to each other either in series (as shown in Figure 3a) or in parallel, and are passed by a heating current.
  • the number of cathodes and control grids in the tube I5 may correspond to the number of image elements. As viewed from the side of the fluorescent screen the cathodes and control grids are situated for instance in the manner shown in Figure 317. Between the first anode I8 and the cathodeIIi a plate voltage source 21 is inserted, and a further plate voltage source 28 is placed between the second anode I9 and the first anode I8. Furthermore, a common plate voltage source 29 is inserted between the cathodes 23, 24 and the anode 25 common to all cathode ray systems. Regarding the .value and polarity of the voltage source between the second anode I9 and the cathodes 23, 24 it is referred to a later chapter.
  • the arrangement according to Figure 3a operates such that the voltage between the control cylinder I1 and cathode I6 of the cathode ray switch will be the more reduced the greater the brightness of the image point being transmitted at the moment. If in the usual manner dark image points are transmitted by a small amplitude of the carrier wave, and bright points by a large amplitude, it is therefore necessary to provide a corresponding phase reversal before the image signals are passed to the control cylinder I'I.v
  • the cathoderay in the course of a deviation across the switch contacts or control grids 20 to 22 corresponding to an image line, thus varies its intensity inversely proportional to the brightness distribution along this image line. As explained on hand of the Figure 2, the individual contact elements and control grids therefore, assume potentials (namely the balance potentials) which are the more negative relative to the second anode IS' acting as secondary emission anode,
  • the control grid therefore, has a relatively high negative potential, so that from the cathode 23 no current or only a very small current passes to the respective place of the fluorescent screen 26.
  • the television image will be reconstructed point by point, with the brightness corresponding with the carrier amplitudes transmitted into distance.
  • the voltage source 30 is to be chosen with the polarity indicated in Figure 3a (corresponding with the value c in Figure 2), or whether it be chosen with another value, and eventually with the reversed polarity depends on the construction of the individual cathode ray systems and in particular on the through grip of the anodes 29.
  • the mode of construction represented in Figure 5 differs from that according to Figure 3a substantially in that the individual cathodes are reproduced on the fluorescent screen 26 by means of an electron-optical reproducing device for instance a concentration coil 3
  • a grid 32 ormed of metal has an insulating cover-gfor instance of enamel whose bottomsurface contains a large numberflo'ff individual metal particles capable, of
  • This arrangement consists of a cathode 33, a
  • first anode'3l, and a second anode 35 both of cylindrical shape.
  • the voltage between the anode 35relative to the'cathode' 33 is supplied by the direct voltage source and is higher than the voltage of anode 34 originating with the direct voltage source 31.
  • the grid 32 is connected to the cathode 33. The electrons penetrating the,
  • anode 35 at a high velocity are decelerated shortly before reaching the mesh-shaped electrode 32 forming at this place a space charge cloud acting of the metal particles 20'to 22 acting as control grid, which potential is adjusted to by the switchlng ray, determines the electron quantity passing through each individual gridopening.
  • the arrangement according to Figure 7 may 7 also be such that above the grid 32 a further grid electrode is provided having the same potential as the anode 35 in which case the retarding field for the production of the spacecharge cloud acts 7 between the mesh-shaped electrode 32 and the grid situated above said electrode.
  • the switch ray tube and the tube for producing the diffused cathode ray beam may be interchanged also if only a single grid electrode 32 is i provided, and likewise where a second grid electrode placed parallel to the first one, is provided.
  • the arrangement for the last mentioned case is 1 shown in Fig. 8 in which the second grid electrode is designated by 38.
  • the retarding of the difluse cathode ray beam originating with the cathode 32 takes place between the grid electrodes 32 and 38.
  • the control grid elements is produced
  • the anode 25 has a through grip through the meshes of the grid 32 thus being capable of withdrawing electrons from this space charge cloud, whereby the potential f sources comprises a electrode 32.
  • InFlgJQ a mode of construction is 'shown'inwhich'the arrangementfor producing the dif- 1 fuse cathode-raybeam, the switch ray tube and the, arrangement for the electron-optical repro duction' on the fluorescent screen are all situated; the control grid elements.
  • a tt'elevision reproducing device comprising while the secondimage coordinate isproduce d" means for developing an electron beam forma tion, meansfor deflecting said beam in at least I one co-ordinate, means'for modulating said beam in accordance with received television signals, means adapted to give off lightunder the impact of electrons thereon, a plurality of electron emis-'- sionw sourceseachfor reproducing one element,
  • each individualgrid element is'. interposed between the plurality of electron emission means and the meansvresponsiveto electron im f pact, and is also positioned between the deflected cathode ray beam and the plurality of electron emission sources.
  • the method of reproducing an optical image which comprises providing a plurality of individual foci .of electron emission each adapted to reproduce one incremental element of the image to be reproduced and continuously producing electrons, and controlling the emission from each of said foci sequentially in accordance with the equilibrium potential produced during the control of each of said individual foci by the action of a modulated electron emission.
  • An apparatus for reproducing signals representative of optical images comprising means for developing a cathode ray beam, means for modulating said beam in accordance with the values of the image to be reproduced, means for producing a plurality of individual virtual cathodes each adapted to produce an electronemission for reproducing one element 0! the optical image to be reproduced along at least one coordinate thereof, means responsive to electron bombardment for reproducing light, said latter means beingadapted to be impinged upon by the electrons from said virtual cathodes, a pmrality of individual grid elements' positioned adjacent said virtual cathodes and adapted to control the impingement of electrons from said virtual cathode onto said reproducing means, and means for directing the modulated cathode ray beam sequentially onto said grid elements.

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  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
US145020A 1936-05-27 1937-05-27 Arrangement for receiving television images Expired - Lifetime US2220688A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2220688X 1936-05-27

Publications (1)

Publication Number Publication Date
US2220688A true US2220688A (en) 1940-11-05

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ID=7990826

Family Applications (1)

Application Number Title Priority Date Filing Date
US145020A Expired - Lifetime US2220688A (en) 1936-05-27 1937-05-27 Arrangement for receiving television images

Country Status (3)

Country Link
US (1) US2220688A (fr)
FR (1) FR822063A (fr)
NL (1) NL53370B (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2449339A (en) * 1945-11-13 1948-09-14 Rca Corp Cathode-ray tube
US2481458A (en) * 1943-10-12 1949-09-06 Bell Telephone Labor Inc Cathode-ray device
US2500929A (en) * 1946-07-12 1950-03-21 Chilowsky Constantin Means for reproducing television images
US3930120A (en) * 1974-01-07 1975-12-30 Hughes Aircraft Co Multi-beam cathode ray tube having equalized line brightness

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2481458A (en) * 1943-10-12 1949-09-06 Bell Telephone Labor Inc Cathode-ray device
US2449339A (en) * 1945-11-13 1948-09-14 Rca Corp Cathode-ray tube
US2500929A (en) * 1946-07-12 1950-03-21 Chilowsky Constantin Means for reproducing television images
US3930120A (en) * 1974-01-07 1975-12-30 Hughes Aircraft Co Multi-beam cathode ray tube having equalized line brightness

Also Published As

Publication number Publication date
NL53370B (fr)
FR822063A (fr) 1937-12-20

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