US2227480A - Energy generator for cathode ray deflection means - Google Patents

Energy generator for cathode ray deflection means Download PDF

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Publication number
US2227480A
US2227480A US109623A US10962336A US2227480A US 2227480 A US2227480 A US 2227480A US 109623 A US109623 A US 109623A US 10962336 A US10962336 A US 10962336A US 2227480 A US2227480 A US 2227480A
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United States
Prior art keywords
tube
trapezoid
current
voltage
condenser
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Expired - Lifetime
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US109623A
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English (en)
Inventor
Andrieu Robert
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Telefunken AG
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Telefunken AG
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/22—Circuits for controlling dimensions, shape or centering of picture on screen
    • H04N3/23—Distortion correction, e.g. for pincushion distortion correction, S-correction
    • H04N3/237—Distortion correction, e.g. for pincushion distortion correction, S-correction using passive elements, e.g. diodes
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/22—Circuits for controlling dimensions, shape or centering of picture on screen
    • H04N3/23—Distortion correction, e.g. for pincushion distortion correction, S-correction
    • H04N3/233—Distortion correction, e.g. for pincushion distortion correction, S-correction using active elements

Definitions

  • the flat fluorescent screen of a Braun tube is inclined with respect to the tube axis, for purposes of convenience in projecting the image formed on the screen, for instance, or for direct viewing on an angle to the axis of the tube, it-is not possible for all lines to be formed of the same length by the same value of deflecting field.
  • the individual image lines must have the same length on the fluorescent screen and this result can be accomplished only if during the line deflection of the cathode ray care is taken that the cathode ray beam is subjected to a non-constant deviation.
  • the lines nearer to the deflecting devices of the Braun tube would be traced too short and the lines further removed would become too long.
  • the receiving image would have the form of a trapezoid. Therefore, it is necessary to vary from line to line the amplitude of the line deflection in order that a rectangular image surface is traced on the inclined fluorescent screen.
  • the deflection field which produces the deflection in the direction of the line must, therefore, have an intensity that is the higher the nearer the respective part of the fluorescent screen is situated'with respect to the deflection devices of the tube.
  • the cathode ray would describe a trapezoidal image field on a surface positioned at right angle to the axis of the Braun tube.
  • a trapezoidal deflection in the sense explained is also required, for cathode ray type image scanners in which the screen to be scanned is obliquely arranged with respect to the axis of the scanning ray tube.
  • 'A1so,'a trapezoidal ray deflection may also be useful in fields of application outside of the televisionfield.
  • the present invention has for its object to produce saw tooth current of a wave shape necessary for the trapezoidal deflection of a cathode ray beam where electromagneticcoils' are used.
  • this is' accomplished byv providing a potential always having the same sign and of the proper frequency for reconstructing an image linearly.
  • the saw tooth shaped wave is applied to the deflecting apparatus whichforms-a part of an oscillatory circuit which preferably consists of the inductance and distributed capacity of the deviation coil, or coils, whereby the said voltage is applied during the long flanks of the saw-tooth current curves and is interrupted for each short flank.
  • Figure 1 is an arrangement of the prior art.
  • Figure 3 is one embodiment of my invention.
  • Figure .4 is an explanatory curve.
  • Figure 5 is an explanatory trapezoid.
  • Figure 6 isan explanatory trapezoid.
  • Figure 7 is another embodiment of my invention.
  • Figure 8 is a set of explanatory curves.
  • Figure 9 is another embodiment of my invention.
  • Figure 10 is still another embodiment of my invention'.
  • Figure 11 is a set of explanatory curves.
  • Figure 12 is another modification of my invention.
  • Figure 13 is a set of explanatory curves.
  • Figure 14 is an embodiment.
  • Figure 15 is a set of explanatory curves.
  • Figure 16 is a modification of the circuit shown in Fig. 14.
  • Figures 17 and 18 are a set of explanatory curves.
  • Figure 19 is another embodiment of my invention.
  • l0 designates a multi-grid tube i. e. a tube having a very high inner resistance
  • I I is a cathode ray beam deflection coil
  • I2 is a detector
  • I3, I l designate direct voltage sources.
  • the tube In is conducting during'the duration of the line signals, and non-conducting during the line pause.
  • a negative impulse is applied to the control grid of the tube It, while within the duration of the line a positive (or less negative) grid potential I6 is supplied to said grid.
  • the deviation coil II is energized by a current having the value i1 while a current Io passes through the tube It, so that" the detector conducts a current in.
  • the coil II has the constant voltage l3 so that the current in this coil must increase by a tangent determined by the value of this voltage.
  • t2 coil current i2
  • the current passage through the tube III will be blocked and thus the current across the detector l2 will be interrupted simultaneously.
  • the deflection coil ll then performs a free half oscillation, within which the current i2 varies up to the value is.
  • the voltage taking a saw tooth shaped course with the desired cycle of the trapezoid is formed by the direct voltage source l3 and an alternating voltage source of saw tooth shape connected in series to said source 5 l3.
  • This alternating potential source may consist, for instance, of a transformer ll whose secondary winding is connected in series with the detector l2 and the direct voltage source l3, and whose primary winding is energized by a 70 current whose curve form is a parabola.
  • Such parabolic current may be produced forinstance by controlling two parallel connected thermionic tubes having a performance characteristic of different steepness, .with two saw tooth voltages in 75 phase opposition.
  • a trapezoid according to Fig. 5 will be traced i. e. the value of the line deflection increases within the duration of the trapezoid. If care is taken that the saw tooth voltage de- 5 scribes a course according to the curve Z, such as can be readily accomplished by a corresponding polarization of the secondary winding of the transformer ll, or through corresponding choice of the direction of its primary current, a trapel0 zoid according to Fig. 6 will be described 1. e. the length of the lines decreases during the tracing of the trapezoid.
  • the curves of Fig. 4 would, of course, be of frame frequency.
  • Adirect voltage source 20 is placed in series to the condenser resistance members I8, I 9 and the detector.
  • the voltage 20 is designated by UAC. R. represents the voltage drop at resistor I9 which would appear if the voltage shown at the control grid in Fig. 1 were continuously, acting upon the control grid of tube I0.
  • negative voltage impulses act upon the control grid of tube ID, a saw tooth shaped voltage always having the same sign will be produced between the points A andB.
  • the short negative impulses I5 may be neglected for the following considerations, and it be thus assumed that the tube In permits the passage of currentfor the entire duration of the trapezoid.
  • the voltage IR corresponds to the state of charge of the condenser at which the entire detector current passes across the resistor R, and the condenser charge has become a constant charge.
  • the condenser [8 will be discharged across the resistor IS, in accordance-with the exponential function which approaches the end state of the voltage "drop at resistor 19, i. e., the voltage UAG at the coil I.
  • This end state would however likewise be attained only after a mul- 5 tiple of trapezoid intervals.
  • the tube Ill is again pervious to current so that the charge of the condenser Hi again begins to increase, again approaching the end value IR.
  • a new trapezoid pause begins, within which there takes place again a partial discharge of the condenser l8.
  • a saw tooth shaped voltage UAB having always the same sign
  • the sawtooth formed voltage in series to the detector I2 is then produced through charging of the con 5 denser I8, within the duration of the trapezoid and of the trapezoid interval with currents having opposite direction.
  • the increase in the charge of the condenser i8 takes place in accord- 30 ance with an e-function i. e. in accordance with a curved course, and, furthermore, a very high voltage 20 is required depending on the coil used and on the line frequency.
  • the resistor l9 may be replaced by a multi-grid tube'such as a screen 40 grid tube for instance.
  • the correspondingcircult is shown in Fig. 9 in which the screen grid tube is designated by 2
  • the voltage 22; is lower than in the case of Fig. .7.
  • the functioning is similar to that described in connection with Figs.
  • the screen grid tube 2! is used.
  • a negative bias potential source 22 in the control grid circuit there is placed also the secondary winding of a no transformer 23.
  • the condenser 18 may have a voltage with the signs as shown in Fig. 10, and which is higher 65 than the voltage Trio of the direct voltage source 20.
  • the tube I0 is conducting, whereas the tube 2
  • increases the 70 voltage at the condenser up to the moment is i. e.
  • a certain disadvantage resides in that the condenser
  • the circuit arrangement distinguishes itself from that according to Fig. 9 in that the bias potential of the tube 2
  • the current passes during the trapezoidinterval onlypartially across the condenser l8 so that with the same voltage variation the latter may have a lower capacity at the duration of the trapezoid. Hence also during the trapezoid interval only a smaller charge is to be removed, and thus a smaller tube 2
  • the Voltage course is the same as in Fig. 11a, the current course is shown in Fig. 13. The current in flows continuously and also the charging :40 current in for the condenser. The difference is between in and ic passes across the tube 2
  • a controlled tube 24 is inserted which may for instance also be a screen grid tube which is blocked during the duration of the trapezoid.
  • carries always the same current during the duration of the trapezoid and .175
  • FIG. 15a shows the voltage course at the condenser E8, the point B being maintained always at negative potential with respect to point A.
  • the condenser 18 will be discharged with constant current across the tube 2
  • the current remains unchanged in the tube 2
  • a charging current for the condenser 18 then passes across this circuit so that the voltage thereat increases again.
  • the appertaining current course is shown in Fig. 15b.
  • the current in and also the current is pass during the duration of the trapezoid and the trapezoid interval.
  • the condenser current is has, during the duration of the trapezoid, a direction opposite to that of Figs. 10 and 12.
  • the charging current ia passing across the tube 28 during the trapezoid interval has the direction opposite to the current passing during the trapezoid interval in accordance with Figs. 11b and 13.
  • the shaded surfaces above and below the zero line are again equal to each other.
  • a trapezoid according to Fig. 6 can be produced with the circuit according to Fig. 13, while the circuits according to Figs. '7, 9 and 11 produce a trapezoid according to Fig. 5.
  • the condenser charge increases in fact during the duration of the trapezoid, while decreasing according to Fig. 14a within the duration of the trapezoid.
  • a controlled tube in the sense of tube 26 in Fig. 14 can be operated also in such manner that it is blocked during the trapezoid interval, while being maintained open during the duration of the trapezoid.
  • the respective circuit differs from that in Fig.
  • the condenser I8 will be charged during the duration of the trapezoid across the tube 20 which in this case is suitably a multi-grid tube, and the discharge takes place during the trapezoid interval across tube 2!.
  • This discharge current passes also across the tube 2! during the duration of the trapezoid, however, in View of the current passing across tube 2d, the condenser charge decreases only during the trapezoid interval.
  • the constant detector current i flows across tube 2
  • the condenser in be constant during the duration of the trapezoid. This requirement is not exactly fulfilled owing to the finite resistance of the tubes for the alternating plate currents, although the resistance is high.
  • a constancy of the condenser current i. e. an increase in the time constant of the voltage course at the condenser can be attained during the duration of the trapezoid in that one of the tubes which determine the time constant is controlled in phase opposition to its alternating plate potential.
  • the current ie in Fig. 15b increases in the case of a constant voltage, at the control grid of tube III as represented in Fig. 17 for instance in accordance with the line is, since the charge of the condenser I3 decreases during the duration of the trapezoid. This causes a decrease of the current. across tube 2
  • the condenser current thus has a course according to the line i0 during the duration of the trapezoid.
  • a condenser current that is constant as regards time, can only be produced if care is taken that the current passing across the detector takes its course in accordance with the line i0 in Fig. 18. In considering the decrease of is then to can carry out the desired constant course in the trapezoid interval.
  • the screen grid of tube I0 is connected across a coupling condenser 25 to the anode of a triode 26, in whose plate circuit a resistor 21 is inserted, and whose plate potential is likewise furnished by the plate voltage source M of the screen grid tube ID.
  • a sawtooth formed voltage having the frequency of the trapezoid and slow increase and rapid decrease is applied to the control grid of the triode 26 across a coupling condenser 28.
  • the control grid of the triode Z5 is hereby placed at the tap point of a potentiometer 29.
  • the alternating plate potential appearing at the anode of the triode 26 is in phase opposition to the alternating grid potential of this tube, and, therefore, the screen grid voltage Whose direct voltage part is controlled by suitable setting of the potentiometer 30, will be decreased in such manner during the course of each duration of the trapezoid that the current course 2'0" in Fig. 18 appears.
  • a sawtooth wave generator comprising means for storing electromagnetic energy, a discharge path for said energy, a source of constant bias voltage for said discharge path, and means connected in series in said discharge path for progressively supplementing said constant bias for a predetermined interval.
  • a sawtooth wave generator comprising a thermionic tube having anode, cathode and at least one control electrode, an inductive element joined electrically in the anode-cathode circuit of said tube, a discharge path for said inductive element, means for applying a constant biasing voltage in series in said discharge path, and
  • a sawtooth wave generator comprising a thermionic tube having anode, cathode and at least one control electrode, an inductive element connected in the anode-cathode circuit of said tube, a unidirectional conducting device connected to said inductive element in a series circuit which is connected in parallel with said inductive element and forming a discharge path therefor, a source of constant potential connected to said discharge path, and means for progressively varying the biasing voltage on said discharge path for a predetermined period of time.
  • a sawtooth wave generator comprising means for storing electromagnetic energy, a thermionic tube having at least an anode and a cathode, said means for storing said electromagnetic energy being connected in the anode-cathode circuit of said tube, a uni-directional conducting device, a time constant circuit, and a source of energizing potential, said means for storing electromagnetic energy, said uni-directional conductor, said time constant circuit and said source of energizing potential being connected serially, whereby the energy stored in said electromagnetic energy storage means is progressively supplemented for a predetermined interval.
  • a sawtooth wave generator comprising means for storing electromagnetic energy, a thermionic tube including an anode and a cathode, said electromagnetic energy storage means being connected in the anode-cathode circuit of said tube, a source of steady biasing potential connected in the anode-cathode circuit of said tube and serially with said electromagnetic energy storage means, a uni-directional conductor, an inductive element, said electromagnetic energy storage means, said uni-directional conductor and said inductive element being serially connected, and means coupled to said inductive element for impressing thereon a signal to progressively supplement the constant bias for a predetermined interval.
  • a sawtooth wave generator comprising means for storing electromagnetic energy, a first thermionic tube including an anode and a cathode, a source of constant energizing bias, said electromagnetic energy storage means and said source of constant bias being connected in the anode-cathode circuit of said thermionic tube, a uni-directional conductor, a condenser, a second thermionic tube having anode, cathode and at least one control electrode, said condenser being connected in the anode-cathode circuit of said second thermionic tube whereby said condenser is connected substantially in parallel with the spaced discharge path of said second thermionic tube, said electromagnetic energy storage means, said uni-directional conductor, and the parallel connection of the condenser and the second thermionic tube being connected serially, and means for impressing signals from an external source onto the control electrodecathode path of said second thermionic tube, whereby said constant bias is supplemented progressively for a predetermined
  • Apparatus in accordance with claim 9 wherein the means for impressing signals from an external source onto the control electrodecathode path of said second thermionic tube comprises a transformer having the secondary thereof connected in the control electrode-cathode path of said second thermionic tube and the primary thereof energized by the signals from the external source.
  • said uni-directional conductor comprises a diode.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Textile Engineering (AREA)
  • Details Of Television Scanning (AREA)
US109623A 1935-10-29 1936-11-07 Energy generator for cathode ray deflection means Expired - Lifetime US2227480A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DET45919D DE756012C (de) 1935-10-29 1935-10-29 Schaltungsanordnung zur Erzeugung von Zeilensaegezahnstromkurven fuer eine trapezfoermige Ablenkung

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US2227480A true US2227480A (en) 1941-01-07

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US109623A Expired - Lifetime US2227480A (en) 1935-10-29 1936-11-07 Energy generator for cathode ray deflection means

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US (1) US2227480A (enrdf_load_stackoverflow)
DE (3) DE756012C (enrdf_load_stackoverflow)
FR (1) FR837823A (enrdf_load_stackoverflow)
GB (2) GB483999A (enrdf_load_stackoverflow)
NL (1) NL49156C (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2512400A (en) * 1948-09-21 1950-06-20 Rca Corp Television horizontal deflection
US2543428A (en) * 1947-02-25 1951-02-27 Rca Corp Direct-current transfer system
US2571131A (en) * 1946-01-21 1951-10-16 Farnsworth Res Corp Sweep circuit
US3015741A (en) * 1959-06-22 1962-01-02 Gen Dynamics Corp Pulse shaping circuitry

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE21400E (en) * 1932-04-04 1940-03-19 blumlein
US2040813A (en) * 1932-09-30 1936-05-12 Rca Corp Television system
GB443952A (en) * 1934-07-04 1936-03-04 Michael Bowman Manifold Improvements in and relating to electrical circuits for the deflection of cathode ray beams

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2571131A (en) * 1946-01-21 1951-10-16 Farnsworth Res Corp Sweep circuit
US2543428A (en) * 1947-02-25 1951-02-27 Rca Corp Direct-current transfer system
US2512400A (en) * 1948-09-21 1950-06-20 Rca Corp Television horizontal deflection
US3015741A (en) * 1959-06-22 1962-01-02 Gen Dynamics Corp Pulse shaping circuitry

Also Published As

Publication number Publication date
FR837823A (fr) 1939-02-21
DE756012C (de) 1953-03-16
GB483999A (en) 1938-04-28
GB526032A (en) 1940-09-10
DE909105C (de) 1954-04-12
NL49156C (enrdf_load_stackoverflow) 1940-09-16
DE893347C (de) 1953-10-15

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