US2358902A

US2358902A - Cathode-ray translating device

Info

Publication number: US2358902A
Application number: US479153A
Authority: US
Inventors: Ziebolz Herbert
Original assignee: ELECTRONBEAM Ltd
Current assignee: ELECTRONBEAM Ltd
Priority date: 1943-03-13
Filing date: 1943-03-13
Publication date: 1944-09-26
Anticipated expiration: 1961-09-26

Description

Sept. 26, 19. H. ZIEBOLZ CATHODE-RAY TRANSLATING DEVICE Filed March 13, 1943 2 Sheets-Sheet l l l l l l l l l l l l l l l l l lgl l l BY W @JM ATTORNEY INVZJNTOR. :HEZRBERT ZIEBOLZ,

CATHODE-RAY 1 Herbert Ziebolz, Chicago, 111., assignor, by mesne assignments, to Elect:- Ill., a partnership Illinois onbeam,

s erms. nnvrca Ltd., Chicago,

Application March 13, 1943,Serial No. 479,153

12 Claims.

The invention relates to an electronic translating device of the cathode-ray tube type for relaying, amplifying, converting, transforming or otherwise translating electrical signals or signals of any nature which may be converted by known means into electric signals. The invention is useful in translating signals representing physical, chemical or other conditions, such as chemical reactions, heat, sound, light, mechanical motion or displacement which may be converted into electric signals by such means as thermocouples, microphones, light sensitive cells, or other devices.

The present invention is related to the invention disclosed in the specification of my copending application Serial No. 417,871, filed November 4, 1941, issued as Patent 2,314,302, March 16, 1943, and the arrangements described in the present application are modifications of the invention disclosed in the said specification.

In the apparatus described in my earlier application, the electron stream or beam of a cathode-ray tube is deflected by suitable deflecting means to vary the number of electrons intercepted by electron receiving means or an anode, the deflecting means being energized in accordance with signals to be translated. A second deflecting means is provided to act upon the electron stream in opposition to the first deflecting means, and the second deflecting means is energized in accordance with variations in the number of electrons acting upon the electron receiving means or anode, the arrangement bein such that the stream is deflected to estab lish a state of equilibrium between the two deflecting means.

The apparatus according to the present invention operates by varying the focusing of the electron beam and includes a cathode-ray or vacuum type tube in which an electron stream or beam is produced, means for focusing the beam upon an electron intercepting means, means for varying the focusing of the beam in accordance with signals to be translated, and a counter-focusing means energized from the output (electron intercepting means) and acting upon the electron beam in opposition to the first focusing means, thereby producing variation in the number of electrons intercepted by the electron receiving means, the arrangement being such that the beam is focused to establish a stateof equilibrium between the opposed focusing efiects.

The translating functions are performed with.

a minimum of distortion due to any change in the characteristics or the means or of the electronic device, and without reflecting any variation from the controlled means back into the signal source. e

The invention provides for amplifying or repeating signals so that the output signals have a linear relation to the inputsignals. Also, an electronic device of this character can be employed as a direct current amplifier.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawings, wherein:

Figure 1 is a circuit diagram showing one form of translating device according to the invention;

Figures 1a, 1b and 1c are detail views in side and front elevation of the cathode beam interceptor discs under different conditions of operation; 1

Figures 2, 3, 4 and 5 are circuit diagrams similar to Figure 1 of further translating devices embodyin the present invention.

In the arrangement shown in Figure 1, there is diagrammatically represented a cathode-ray tube consisting of an insulating envelope 20. The internal construction of the cathode-ray tube may be of any suitableand well known type, but for the purpose of illustration,. the tube has a source of electrons represented by a heater or filament 2| for heating an electron emitting cathode 22. The electrons emitted by cathode 22 are accelerated and focused into an electron beam of suitable shape and are directed along the axis of the tube by means of a system of accelerating andconcentrating electrodes comprising a grid or control electrode 20a, a first anode 23 and a second anode 23a mounted in the. tube. The elements are maintained at proper potentials with respect to the cathode 22 by means of a suitable source of potential, represented by the battery 24 and potentiometer 24a. The electron beam established within the tube isindicated by dotted lines 25.

Suitable electron receiving means, represented by the

discs

26 and 21 of different diameter are axially spaced from each other within the tube to receive electrons from the beam 25. The

discs

26 and 21 are connected to

suitable coupling resistances

28 and 29 and are shown as being connected to receive a positive potential from the battery 24 relatively to the cathode 22. Moreover, it is not essential that

resistances

28 and 29 be connected to the battery 26, but'they may be connected to ground. A load or output circuit or any other device 3| utilizing load current or potential is connected directly across the leads to

discs

26 and 21. Two pairs of deflection plates IIIII and NH, the pair I36 acting at right angles to the pair III, are also mounted in the cathode ray tube and" are connected .to the battery or other source of potential through suitable adjusting resistances, as shown, for the purpose of centering the beam on

discs

26 and 21 or for setting the beam to any other desired initial position.

The electron beam 26 may be initially concentrated or focused on the

discs

26 and 21 to give an equal electron interception on each disc, as indicated in Figure 1b. This may be accomplished by adjusting the potentials applied to

anodes

23 and 23a from potentiometer 24a until there is no difference of potential between

plates

26 and 21. The beam is variably contracted or expanded to different cross-sectional areas by superimposing on anode 23 a variable potential derived from a suitable source of signal or input current 33, whereby the beam is contracted or expanded depending upon 'the increase or decrease of the input current or potential drop across the input resistor 33a.

Variation in cross-sectional area of the beam 25 in accordance with signals from the source 33 causes corresponding variations in the relative number of electrons focused and impinging upon

plates

26 and 21, as will be readily understood from Figures 1a, 1b, 10, thereby causing discs 26 and .21 to vary in potential in response to the signals from source 33. The difference in potential between the plates supplies the load or. output circuit 3I with current or voltage which varies in accordance with the signals supplied from source 33.

A counter-focusing magnetic field is established axially of the beam 23 by means of a magnetic coil 34 which is shown as being energized by current derived from the potential variations existing between

discs

26 and 21. The coil 34 is so connected to the output circuit that its field tends to focus the beam 25, or to vary its. crosssectional area, in an opposite direction from the action of anode 23. The field of coil 34 produces a concentrating action for either direction of current through the coil, so it is desirable to provide for an initial or biasing current in the coil which is varied above and below'its normal value in accordance with the input signals. The normal biasing current for coil 34 may be derived from battery 24 by connecting coil 34 to the output circuit by means of variable contacts on

resistors

28 and 23 as shown in Figure 1, or it may be supplied from a separate source as in Figures 2 to 4.

The operation of the arrangement shown in Figure 1 is believed to be clear from the foregoing description. It is assumed that the field established by the plates IIIII, IIII centers the beam on

plates

26 and 21 and that the initial focus of the beam provides equal distribution between the disc 26 and the disc 21 as shown in Figure lb whereby with zero input, no potential diflerence is established between discs 26 end. However, a normal biasing current flows in coil 34, exerting a certain concentrating action on the beam.

A signal or input voltage increases or decreases the voltage applied to anode 23, thereby varying the cross-sectional area of the beam at

plates

26 and 21. An increase in signal strength relatively to the initial or datum setting produces concentration of the beam, which condition is shown mass,

'in Figure 1a, in which all the electrons impinge on the smaller disc 26. A decrease in signal strength will cause dispersal or increase in crosssectional area of the beam whereby more electrons will impinge on the disc 21 than on the disc 26, a condition shown in Figure 1c. The resulting potential diflerence between

electrodes

26 and 21 changes the currents flowing in

resistors

26 and 26 and thereby changes the current in coil 34 in a direction such as to establish a counter-focusing action which tends to focus the beam in the opposite direction, that is it tends to restore the initial distribution of the. electrons between the

discs

26, 21. In case a steady signal voltage is supplied to anode 23, the beam 26 will assume a position in which the focusing and counterfocusing actions are in a state of equilibrium and, under this condition, the potential difi'erence existing between

discs

26 and 21 will be directly proportional to the applied signal.

Preferably, the amount of counterfocusing requircd to produce the maximum difference in potential is produced by a relatively small unbalance between the actions of the anode 23 and of I the coil 34. For example, the amount of unbalance may be only 1%.

For the reasons explained in the specification of my prior patent application No. 417,811 which reasons apply equally to the present instances, .there will be a substantially linear relationship between the input signal voltage and the voltage produced across the load, and this relation is not substantially affected by changes in the operating characteristics of the cathode-ray tube.

The arrangement shown in Figure 2 is generally similar to that of Figure 1 and operates on the same principle of variable focusing of the beam on a pair of axially aligned discs of different diameters. In this modification, however, the

40 input is not connected to anode 23 but the

anodes

23, 23a are directly connected to points of suitable potential on potentiometer 24a, the potentials being adjusted to values which will give the condition of Figure 1b for zero or datum strength of input signal. The input device 33 is connected to the focusing coil 34 whereby an input signal will focus the beam in the direction of Figure la or that of Figure 1c according to whether it is an increase or a decrease relatively to the zero or datum for which the tube is initially adjusted. Thenormal biasing current for coil 34 is supplied from a suitable source represented by battery 36 and potentiometer 35a. The potential diiference across

discs

26, 21 is fed back through anamplifier I63 to the focusing coil 34 in such a manner as to oppose the action of the input signal therein. The amplification is applied to a potentiometer I04 so connected that the variable part of the amplified voltage is in opposition to the input voltage. The load circuit is con nected to the output of amplifier I 03. V

The initial focus of the beam in Figures 1 and 2 may be controlled or set by adjusting the value of the biasing current in coil 34, as well as by adjusting the potentials applied to

anodes

23 and 23a.

Figure 3 illustrates a third modification. In this arrangement a single accelerating anode 23 is employed which may or may not be used for controlling the initial focus of the'beam. The initial focus of the beam may be controlled by the adjustable biasing current supplied to coil 34 from source 36. A second magnetizing coil 32 arranged" concentric with the tube and substantially coextensive with coil 34 is energized by the signaleffect of thegrid 20 upon the amount of electrons.

ling current from the source 33 and serves to vary the focusing field acting on'the beam. As in Figure 2, a counterbalancing voltage is supplied to the circuit of magnetizing coil 34 from potentiometer I04 connected across the output circuit.

The operation of Figure 3 is believed to be clear. The incoming signal disturbs the balance between the electrons received by the two

electrodes

26 and 21 and produces a potential variation across the output circuit which is impressed back upon the circuit to coil 34 in a direction tending torestore the condition of the focusing field acting on the beam. The normal biasing current supplied to coil 36 from source 35 should be sumciently large so that the incoming signal does not reverse the focusing field acting on the electron beam.

It may be noted that Figure 3 discloses an alternative arrangement of the

electrodes

26 and 27 in that electrode 26 is formed as an apertured plate positioned in front of electrode 21. This arrangement is equivalent to the arrangements shown in Figures land 2 and the two arrangements may be used interchangeably. An amplifier like that shown in Figure 2 may be used in Figure 3if desired.

In all of the modifications shown in Figures 1 to 3, it will be understood that when an input signal is applied to the system, the focusing of the electron beam is influenced, resulting, according to the sign of the signal relatively to an initial or zero value, in a more concentrated spot of electron interception (Figure 1a) or in a larger spot (Figure 10). In either case, one or the

other disc

26, 21 receives more electrons than the other whereby a potential difference is set up between the discs. This potential difference, or a part of it, is applied to a feedback circuit which influences the focusing of the beam in a direction opposite to the influence of the signal.

In the modification shown in Figure 4 the electrode arrangement is the same as that shown in Figures 1 and 2 except that only one accelerating anode is employed, and the input signal is applied to vary the potential on control grid 20a. The initial focus of the beam is controlled by adjusting the normal biasing current supplied to coil 35 from source 35. The circuit of coil 3% also includes a variable portion of coupling resistance 28, and the arrangement is such that the potential drop across the included portion of resistance 28 opposes the potential supplied from source 35. It will be understood, however, that coil 34 may be energized by connections like those shown in Figure 3. The load circuit may be connected directly across electrodes 26 and 2'! as shown at 31, or one terminal of the circuit may be connected directly to one of the electrode leads and the other terminal connected to a variable tap on pctentiometer 24a to counterbalance the normal potential drop across resistance 29, as shown at 3 la. It will be understood that the load circuit connection 3m. in Figure 4 may be used in any of the other figures.

In the operation of Figure 4, the normal biasing current in coil 34 is adjusted to establish a predetermined relation between the electrons received by

plates

26 and 21. The incoming signal does not ilect the focus of the bgam but varies the intensity of the beam andifauses corresponding variations in the potential drop across coupling resistances28 and 29. The change in potential drop across resistance 28 is in a direction to vary the biasing current in coil as and thereby vary the focus of the beam in a manner to counteract the received by plate 26. In other words, if the incoming signal increases the intensity of the beam, the potential drop across resistance 28 increases, thereby resulting in less current through coil 34 which causes the beam to spread and reduces the number of electrons received by electrode 26. By energizing coil 34 from the potential drop across a variable portion of resistance 29, the biasing source 35-3511 may be omitted.

Figure 5 illustrates an arrangement reversed from that of Figure 1, that is, the input signal is connected to energize coil 34, while the counterfocusing eifect supplied from the output circuit is applied to the anode 23. In this arrangement, a suitable separator circuit C is interposed be= tween the circuit of anode 23 and the potentiometer I06 connected to the output circuit. This separator circuit is provided to prevent shortcircuiting of part of the anode battery, and it may be formed of any suitable D. C. amplifier circuit of well known construction. It could be formed of another electron beam tube circuit having a coil input. I

If no source of biasing current is connected in series with coil 34 in Figure 5, both positive and negative pulses of the signal source 33 will exert a concentrating action on the electron beam, since a signal of either polarity has a converging effect on the beam. Accordingly, the potential variations produced in the output circuit will all be of one polarity, and the resulting output current will correspond to a pulsating direct current having a principal alternating component of a frequency equal to double the frequency of the input signal. Part of the output taken from potentiometer "It is supplied through separator circuit C to vary the potential of anode 23 which exerts a diverging influence on the beam. Since the polarity supplied to anode 23 from the output circuit is always the same, the feedback action on anode 23 will always be divergent, and tends to counteract the converging effect of the input coil 34. The

circuit arrangement of Figure 5 may be employed as a full wave rectifier where the input signal is an alternating current. Also, by providing a suitable smoothing filter in the output circuit, the circuit of Figure 5 may be used to derive a direct current from an alternating current signal, the direct current being proportional to the amplitude of the alternating current signal. It is also obvious that the circuit of Figure 5 may be used as a frequency doubler, since the output circuit includes a strong double frequency component.

The focusing coil or coils 32, 34 in the several arrangements are shown as extending over a substantial length of the cathode ray tube, but short coils may be used if desired. Purely electrostatic focusing means may be used for the initial focusing of the beam, and for the counterfocusing. In Figure 3, the initial biasing current may be supplied to coil 32 instead of to coil 38, if

desired.

The

discs

26, 21 may be of any desired shape and means may be provided to avoid undesired influence of secondary electrons.

It will be obvious to those skilled in the art that the input signal may be derived from any condition or conditions which can be translated into electromagnetic or electrostatic fields which control the focus of the electron beam. Likewise, the input signal may be set or adjusted or it may be varied and the output signal, which may be of a diiferent magnitude or character, can be maintained proportional to the input signal.

Obviously, the present invention is not restricted to the particular embodiments thereof herein shown and described.

What I claim is:

1. Electronic translating apparatus compris-' counter-focusing means arranged to vary the cross-sectional area of the cathode beam in op-" position to said focusing means, and means for energizing said counter-focusing means in accordance with variations in electrons received by said electron receiving means.

2. Electronic translating apparatus comprising a cathode-ray tube, means'for focusing the electron beam thereof, a pair of overlapping concentric discs of different sizes arranged in the path of said beam for intercepting different concentric portions thereof, input means arranged to vary the focusing of the cathode beam from a datum differential of electron interception between said discs, counter-focusing means arranged .to vary the focusing of the cathode beam assaooa meanaand means responsive to variations in the electrons received by said electron receiving means for varying the eifect of the other of said focusing means inopposition to the variation produced by said input means.

7. Electronic translating apparatus comprising a cathode-ray tube, an anode of fixed potential focusing the electron beam thereof to a predetermined cross-sectional area, electron receiving means positioned to receive a variable portion of the electrons of said beam dependent on variations in the focus thereof, a magneto-static coil arranged to produce a field of force extending in the path of the electron beam to vary the focusing thereof, input means arranged to var theaction of said magneto-static coil in one direction, and output means influenced by said electron receiving means and arranged to vary the focusing of the electron beam by said coil in the opposite direction.

8. Electronic translating apparatus according to claim 7 including amplifyin means between the electron receiving means and the magnetostatic coil.

9. Electronic translating apparatus comprising a cathode-ray tube, an anodeof fixed potential for focusing the electron beam thereof to a prein opposition to said focusing means, and means for' energizing said counter-focusing means in accordance with the difference in electron interception of said discs.

3. Electronic translating apparatus comprising a cathode-ray tube, input means including an anode system arranged to vary the focusing of the, cathode beam from a datum cross-sectional area, electron receiving means positioned to receive a variable portion of the electrons of said beam dependent on variations in focus thereof, counter-focusing means including a magnetostatic coil developing a field with its lines extending in the path of the electron beam and arranged to vary the focusing of the cathode beam in opposition to said focusing means, and means for energizing said magneto-static coil in accordance with the electrons received by said electron receiving means.

determined cross-sectional area, electron receiving means positioned to receive a variable portion of the electrons of said beam dependent on variations of the focus thereof, a magneto-static coil arranged to develop a field of force with its lines extending along the path of the electron beam of said tube to vary the focusing thereof,

' input means arranged to vary the field of said magneto-static coil, a second magneto-static coil arranged to produce a similar field of force, and means for energizing said second coil in accordance withvariations in electrons received by said receiving means and ina direction to establish a field in opposition to the field of said first coil.

4. Electronic translating apparatus comprising a cathode-ray tube, an electrode for receiving at least a portion of the electrons of the cathode beam. means controlled by input signals for varying the number of electrons received by said electrode, focusing means acting on the cathodev beam for varying the concentration of the beam on said electrode, and means responsive to the variation in electrons received by said electrode for energizing said focusing means to vary the concentration of said beam in a direction tending to opp se the action of the input means in vary-; ing the number of electrons received by saidelectrode.

5. Electronic translating apparatus according to claim 4 wherein said focusing means comprises a coil for establishing a magnetic field extending along the path of said beam, and including means for supplying a normal-biasing current to said coil.

6. Electronic translating apparatus. comprising a cathode-ray tube, focusing means tending to spread the beam of said tube,v second focusing means tending to concentrate said beam, elec-' tron receiving means positioned-to receive a variable portion of the electrons of said beam dependent on variations in focus thereof, input means for varying the effect of one of said focusing 10. Electronic translating apparatus according to claim 1 and including beam deflecting means operable in, two different planes for adjusting the initial beam position of said beam.

11.. Electronic translating apparatus comprising a cathode ray tube including means for producing, an electron beam, an anode for controlling the focus of said electron beam. electron receiving means positioned to receive a variable portion of the electrons of said beam dependent on variations in the focus thereof, input means including a magnetic coil arranged to produce a variable magnetic field along the path of said electron beam to vary the focusing thereof, an

'- output circuit controlled by said electron receiving means, and a connection from said output circuit to said focusing anode to va th f cusing of theelectron beam in oppositi on t: the action of said magnetic coil.

l2. Electronic' translating apparatus comprisinga cathode-ray tube having the electron beam thereof focused to a predetermined cross-sectional area, electron receiving means positioned to receive a variable portion of the electrons of said beam dependent on variations in the cross-sectional .area thereof, means for producing a magnetic field extending in'the path of theelectron beam to vary the 'focusinglthereof, input means arranged to vary the intensity of said field in one direction, and output means influenced by said electron receiving means and arranged to vary the" intensity of said field in the opposite. ett

'1' ZIEBOLZ.

CERTI FIGATE OF CORRECTION.

Patent No. 2,558,902. September 26, 191 1;.

HERBERT ZIEB OLZ It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 14., first column, lines 10 and 11, for "cross-sectional area" read --foeusing--; line 11, for "focusing" read --cross-sectiona1 area-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of-December, A. D. 19%.

Leslie Frazer (Seal) Acting Commissioner of Patents.

Patent No. 2, 59,902.

HERBERT ZIEBOLZ.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page )4, first column, lines 10 and 11, for "cross-sectional area read --focusing--; line 11, for "focusing" read cross-sectional area--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of-Decemb'er, A. D. 19%.

Leslie Frazer (Seal) 7 Acting Commissioner of Patents.