US3178606A - Single electron gun time sharing oscilloscope - Google Patents

Description

April 13, 1965 F. L. KATZMAN N 'SINGLE ELECTRON GUN TIME SHARING OSCILLOSCOPE Filed Sept. 9, 1960 2 Sheets-Sheet l F fg.

FRED L. KATZMANN ATTORNEYS United States Patent O 3,173,606 SlNGlLE ELECTRON GUN Thi/1E SHARENG @SCHLLSCGPE Fred L. Katzmann, Cedar lGrove, NJ., assigner to Fairchild Camera and instrument Corporation, Syosset,

NJY., a corporation oi Delaware Filed Sept. 9, 1960, Ser. No. 55,014 16 Claims. (Cl. S15- 22) The present invention relates to time sharing oscilloscopes in which a cathode ray tube having a single electron gun is employed. A variety of waves are displayed on the face of the tube by means of switching from one wave to another and from one sweep speed to another. Thus, the single electron beam is used to display different waves successively.

An objection to time sharing Oscilloscopes used heretofore is that in many instances the trace of one wave was intense whereas that of the other was dim due to the fact that the electron beam slowly crossed the tube in one case, and rapidly crossed the tube in the other. In my invention this disadvantage is eliminated since when switching from one signal source to the other I provide means for simultaneously switching from one bias level to another so that the bias of the grid or cathode of the cathode ray tube is varied in accordance with the desired setting thereby making it possible to adjust the tube trace intensities to be equal, or to have other desired relationship. My invention although described in copending application entitled Direct Read-Out System for Oscilloscopes (in the name of Bernard L. 1i-legernan, Serial No. 34,124, filed une 6, 1960, and assigned to the assignee of this application), as applicable to varying the intensity of index and readout dots relative to a display is likewise applicable to those situations in which it is desired that two completely unrelated electrical waveforms be displayed on the face of a single tube; to those situations where it is desirable to display a single waveform on dilerent time bases; or to the display of diiierent waveforms on the same time base.

It is an object of this invention to produce two related or unrelated electrical waveform displays in time shared, alternate sequence on a single gun oscilloscope, said displays being o varying amplitude and on diierent time bases, the intensity of said displays being adjustable in any desired manner.

1t is another object of my invention to present a display wave to be measured alternately with a second display wave, which may tor example be a rectangular' wave to produce readout dots, the rst and second display waves being presented at adjustable relative intensities, adjustment being effected by prior adjustment of the bias level applied to the control unit of the cathode ray tube according to the alternate presentations of the two display waves (or display wave and readout dots). It is understood of course that the waves are visible simultaneously on the cathode ray tube screen.

It is another object of the invention to blank the second or dot producing display wave, i.e., reduce its intensity' to zero during the vertical and overshoot portions thereof in order to eliminate tails on the dots.

lt is still another object of the invention to provide a single gun oscilloscope in which the intensities of related displays may be adjusted. Thus, if an electrical waveform is to be displayed on a given time base, and a portion of that waveform is to be shown on an expanded scale in the second ot two presentations, this may be done and the portion selected produced with increased (or decreased) intensity in the rst presentation. The portion to be enlarged can be picked out readily from the first small scale presentation, and it will be known that this particular portion is the portion enlarged on the large scale presentation.

Other objects and features of the invention will be clear when the following description is considered in connection with the annexed drawings in which,

FIGURE 1 is a block diagram of a single gun oscilloscope having two switches for alternately displaying two displays on the same tube, while at the same time having those two displays in a correct intensity relationship due to the provision of a third switch which switches the bias level of the cathode ray tube to produce the correct intensities; and

FiGURE 2 is a detailed schematic circuit of the means for adjusting the relative intensities of alternately displayed patterns, and the means for switching to produce these relative intensities alternately.

Referring now to FIGURE 1, 101 and 102 are independent and unrelated display waves. Waves 101 and 102 are applied respectively to two push-pull D.C. ampliers 103, 104l through input pairs of push- pull terminals 109, 110. Display waves 101, 102 are amplified by arnpliers 103, 104 and are applied to pairs of output conductors 133, 143 and 1334, 144 respectively. Synchronizing signals 147 and 14S having periods designated T, t respectively, are derived from waves 101, 102 by well known differentiating circuits in amplifiers 103, 104 and are applied to input conductors 153, 154 of synchronizing amplifiers 105, 106 respectively.

Output conductors 145, 146 of ampliiers 105, 1116 are connected to conventional triggered sweep generators 107, 103 to generate sweep waves 119, 120 with periods T, t respectively. Output conductors 135', 13e are connected to a switch the arm 12S of which is usually placed in contact with the conductor 135, 136 associated with the display wave 101, 102 having the longest period T in order to synchronize a master clock square wave multivibrator 111.

The master clock 111 comprises a multivibrator which generates a pair of out-o-phase square switching waves 112, 113, having a period 2T and applies these to conductors 131, 132 respectively to connect the switching Waves to the three switches 114, 115, 116.

Switch 114 is the vertical or Y-axis switch which is supplied with two pairs oi push-pull input signals from outputs 133, 143 and 134-, 144 of push-pull display wave amplifiers in channels A and B respectively.

Thus, displays 101, 102 are caused to appear alternately and repetitively at push- pull output conductors 151, 152 by the coaction of switch waves 112 and 113, which are applied to grids 183 and 184 also, where they cause anodes 13S and 1% of triodes 131 and 182 to alternate oppositely in potential level. The input conductors 191 and 192 to push-pull amplifier 123 are connected to anodes 18S and 156 and thus receive biases determined by the adjustment of potentiometer 137 which controls the anode currents through resistors 187 and 18S when grid 183 or 184 is made positive. rThis action occurs at the rate of 1/2T times per second. This alternating bias is for the purpose of trace separation between the displays from channels A and B, which displays also occur alternately and repetitively at l/zT times per second.

Thus, when signals over channel B are being transmitted to the vertical (Y-axis) push-pull DC. amplifier 123 to produce deflection waves 102 at vertical plates 121, 122, plate 121 is biased positively with respect to plate 122 and when signals over channel A are being transmitted plate 122 is biased positively with respect to 121. As a result, the displays 101 and 102 are shifted on tube face 100 relative to each other. The amount of shift depends on the adjustment of 137.

Each of sweep generators 107, 108 has at least three jr t aisance outputs. These are respectively: linear time base sweep waves H9, 5.3.5' on conductors 39, *130; positive going brightness waves 1.6i, 362 on conductors i559, 25d; and negative going blanking waves M7, M3 on conductors iii, iii. rThe sweep waves H?, are applied to the c (X-axis) switch i5, and the brightness waves tel, to2 and blanking waves M7, 11% are applied to the i (Z-axis) switch le.

Coaction between the various waves generated in channels A and B, and the master clock switch wave outputs M2, M3 at the three switches iid, M5, tio, pro duces alternate and repetitive displays of waves Milt, En?. on tube face we. Two successive displays occur with a periodicity 2T, each display occupying a portion of time interval T. Each display is brightened during the trace time of its respective sweep wave, and blanked during the retrace and dead time of that sweep wave. The displays may be superposed or separated verticaliy by adjustment 37; or, horizontally, by the customary sync phase control led of sweep generator 98, in the usual manner for triggered sweep generators; or both.

Referring now to FGURE 2, an arrangement is shown illustrating another use of my invention. Display wave 299 of period T has a section S which it is desired to examine in detail while (at the same time) examining 29d. Wave 2d@ is applied to both pairs of terminals liti?, M0. Switch arm 65 disconnects sweep generator i523 from normal sync output idd (sec also PEG. l) and connects it to output le@ of sweep generator 167 in order to synchronize te@ with the 1M sweep instead of with the display wave 209. This is in preparation for a delayed sweep observation.

This type of operation wherein a delayed portion of `a sweep is used to initiate a second, or delayed, sweep is well known in the art, one method of such initiation being described in US. Patent No. 2,825,848, in the name of R. F. Casey.

A delaying sweep switch 173 is provided on sweep generator 167. This switch when operated causes sweep wave 2319 to act as a celaying sweep in the manner described in detail in the above-mentioned Casey patent. in brief a synchronizing signal is erived from a portion S of wave 2129 and applied through potentiometer 69, conductor 164, and switch arm 16S to sweep generator 10S.

As in the Casey patent adjustment 'of potentiometer 169 determines the starting point 292 at which sweep generator 10S is triggered and adjustment of 2ti3 determines the termination of sweep wave 22d generated by sweep generator MBS at a time such as 264. The duration S of sweep wave 22@ thus is made to correspond to a desired portion S of sweep wave 21W.

In order to produce the two separate but related displays 200, 2M on tube face the, where display 291 is an expanded view of the brightened portion S ot display 26o, the display wave 2%@ is ampiied in amplitiers 15G, 104 and applied over output conductor pairs 133, 143 and 134, 144 to the input of the V switch it@ as described above for FIGURE 1. At the same time the delaying sweep 29 and the delayed sweep 220 are applied to the input of the H switch 215.

The V switch and the H switch are controlled by switch waves 212, M3 to cause the display wave to be displayed on two time bases, namely the regular sweep 219 and the delayed sweep 229.

At the time when the positive going portion 221,4 of switch wave 212 is applied to the V switch and the H switch and to the anode of diode 221 to make cathode follower tube 2&5 conductive in the I (intensity) switch structure 11.6, the negative portion 2F11 of switch wave 213 is applied to the anode of diode 222. Thus, no positive potential is applied to grid 2% of cathode follower 2% at this time. The cathode follower remains in a cut-off condition due to positive bias developed on cathode resistor 23@ by the positive wave peal; 2id on gri 267'. Thus, all potentials from diodes 224, 226, 228 are ineffective to produce outputs at 239 for transmission on conductor 179 for application to cathode ray tube T25 (FIGURE l) and these potentials cannot modulate the cathode ray tube beam 271 during the first half cycle time T orf switch wave 212.

During this same time, however, a positive bias from potentiometer 229 is applied to the anode of diode 227 and is applied to grid 297 and by cathode follower action of tube 295 controls the intensity level of beam 3.7i. This type of intensity gate is described in a copending application by Fred L. Katzmann, Serial No. 800,337, now Patent No. 2,997,620, assigned to the same assignee.

Switch 73 also causes a brightening wave 174, of duration S, in synchronism with T but shorter than T', to be applied to the anode of diode 223 via output conductor 159. Positive portions of brightening Wave 174 are applied to grid 2ti7 and appear on conductor 17d-and grid 28 to increase the beam Itl and intensify the portion S of display 2G@ on tube face We. A blanking wave 175, of dure.- tion B, corresponding to the retrace and dead-time of sweep wave 219 may be applied to the cathode of diode 22S, if desired, to cut-oft beam 171 during the retrace and dead time of sweep wave 2l?.

Nlien the positive going portion 215 of switch wave 2i3 is applied to the anode of diode 222, tube 286 becomes conductive and 2555 becomes non-conductive. Thus, the brightening, blanlting and bias potentials associated with amep 22h are applied to control the intensity of beam i, when sweep 220 is switched to the H deflection plates i231, 124 in piace of sweep 29 by the heretofore described action of the H switch M5. During the second half period 2liot the wave ZLZ, the intensity signals applied to grid 267 are made ineffective by cut-01T laction on cathode follower 265.

it will be clear to those skilled in the art that dot producing waves and their associated brightening, blanking and bias potential may be applied to the H, V and I switches, as described in Patent No. 2,997,620 referred to above, or any other waves related or unrelated to display waves i d or 206i as described herein may, by means or a multi-contact switch, be selected and applied to the H, V and switches, to produce a variety of displays.

F or example, when a display wave 200 is to be measured quantitatively by means of read-out dots on an oscilloscope equipped with a direct read-out system switch, the display wave 2d@ is displayed with the dots 270, 271 instead of with the expanded section 29T.. To accomplish this, the switch arms 243, 244, 247, 248, 249 of the system switch are manualiy and simultaneously placed in positions indicated as 26? in FGURE 2.

When the switch arm are in this position a vertical readout wave V and its base level are applied to the V-switch arms 243, 24d respectively, and a horizontal read-out wave H with its base level is applied to H-switch arm 247. These waves are generated in generator 241 which may be of the type shown at 49d in copending application Serial No. 34,124.

A free running unsymrnetrical multivibrator 24) which produces an output pulse 259, at a mean frequency of '7de cycles for example as shown at 403 in the above copending application, synchronizes generator 241 at 383 cycles. The pulse width of waves 250 is made adequate to include the rapidly moving portions 257 of the readout waves. Waves 25? are applied to switch arm 248 and provide beam blanliing during the rapidly moving tails between the dots.

`While I have described preferred embodiments of my invention it will be understood that many modifications and variations are possible. I wish therefore to be limited not by the foregoing description but solely by the claim granted to me.

What is claimed is:

1. in a display device having elements to produce a atrasos single light spot, in combination, means for applying rst and second deliecting fields of different frequencies to deilect said spot in a lirst direction, means for applying a field to deflect said spot in a second direction, rst switch means for alternately applying said irst and second fields, thereby to develop two independent traces in time sharing sequence; second switch means to adjust the intensity of the spot to either of two selected constant levels throughout a trace interval; and means for actuating said two switch means in synchronism, whereby the intensity of said spot throughout one `trace may be adjusted independently of the intensity of the spot throughout the other trace.

2. ln a cathode ray oscilloscope having a single cathode ray tube with at least one electron beam, in combination, two beam dellecting means for producing a two dimensional display, means to alternately apply two deilection waves of diierent frequencies to one of said beam deflecting means, means 'to alternately apply two corresponding derlection waves of different frequencies to the other of said beam deflecting means, means to derive beam intensifying waves synchronous with the i'irst and second of said deflection waves, means to apply said derived waves to intensify the electron beam, and switch means to simultaneously effect said alternate application of deection waves to said one and said other detlecting means and the alternate application of said derived waves to intensify said beam.

3. ln a cathode ray oscilloscope having at least one electron beam with a control electr-ode therefor and first and second beam deection means for developing elds substantially at right angles to one another, in combination, means for applying lirst and second waveforms to be displayed alternately to the irst deflection means for alternately producing two rst fields, two corresponding sweep generators for applying sweep waves to the second deflection means for alternately producing two second fields, means `to derive corresponding beam intensity controlling waves synchronous with said irst land second waveforms, means to apply said intensity controlling waves to the control electrode to intensify the beam, and switch means to switch said corresponding display waveforms, sweep waves and intensity controlling waves simultaneously to said iirst and second deflection means and the control electrode, respectively.

4. In a cathode ray oscilloscope having a cathode ray tube including a fluorescent screen, at least one electron beam source and means for deilecting the beam in two directions; in combination, means for applying an electrical waveform to be analyzed to one of said deflection means and a second electrical waveform to the other of said means simultaneously to form a pattern on said screen; means to bias the beam at two intensity levels; means for generating two dot producing signals, means t-o apply said signals simultaneously to said deilecting means alternately with said pattern, means to modify said two dot producing signals individually to position the generated dots at selected points on said screen with respect to said waveform display Vand means to indicate the amount of modilication of said dot producing signals to thereby indicate on one of two indicating means one coordinate dimension from one of said dots to the other and on the other of said two indicating means the other coordinate dimension from said one ot said dots to the other thereof, and means to apply one of said intensity levels to bias said beam when said dots are displayed, and the other of said levels to bias said beam when said pattern is displayed.

5. In a cathode ray oscilloscope having a cathode ray tube including a lluorescent screen, a single electron beam source and t-he means for dellecting the beam in two directions; in combination; means for applying an electrical waveform to be analyzed to one of said deflection means and a second electrical waveform to the other of said deflection means simultaneously to form a pattern on said screen; means for generating two dot producing signals;

means to apply said signals to said deection means; means to adjust the intensity of the electron beam to at least a. `rst and a second level, switching means for applying said dot producing signals alternately with the pattern producing signals to said vdeilection means and means for simul- Itaneously adjusting said intensity at said first level when said dots are produced and at said second level when said pattern is produced; means to modify said two dot producing signals individually to position the generated dots at selected points on said screen ywith respect to said wave- -form display; means to indicate the amount of modication of said dot producing signals individually .to thereby indicate on one of two indicating means one coordinate distance `from one of said dots to the other and on the other of said two indicating means the other coordinate distance from one of said dots to the other thereof; and means to position said waveform display together with said dots with respect to the tube screen.

6. In a cathode ray oscilloscope having a cathode ray tube including a fluorescent screen, a single electron beam source and t-he means for dellecting the beam in two directions; in combination; means for applying an electrical waveform to be analyzed to one of said deflection means and a second electrical waveform to the other of said deflection means simultaneously to form a pattern on said screen; means for generating two dot producing signals; means to apply said signals to said dellection means; means to adjust the intensity of the electron beam to at least a lfirst and a second level, switching means for applying said dot producing signals alternately with the pattern producing signals to said deilection means and means for simultaneously adjusting said intensity at said iirst level when said dots are produced and at said second level when said pattern is produced; means to modify said two dot producing signals individually to position the generated dots at selected points on said screen with respect to said waveform display; and means to indicate the amount of modification of said dot producing signals individually t0 thereby indicate on one of two indicating means one coordinate distance r-om one of said dots to the other and on t-he other ot said two indicating means the other coordinate distance from one of said dots to the other thereof.

7. In a cathode ray oscilloscope having a cathode ray tube including a lluorescent screen, at least one electron beam source and means for deflecting the electron beam in two directions; in combination; means for simultaneously applying an electrical waveform to be analyzed to one deiiection means and a second electrical waveform to the other deection means to form a pattern on said screen; means to apply at least two intensity levels to the electron beam; means to apply one of said intensity levels to said electron beam when said pattern is formed on said screen; means to produce a pair of phase related rectangular electrical waves of the same frequency; means to adjust the base level and amplitude of said waves individually; means `for simultaneously applying one of said adjusted rectangular waves to one deflection means and the second of said rectangular wav-es to the other dellection means to thereby produce two dots on said screen; the position of one of said dots depending upon the base levels of said waves and the position of the second of said dots depending upon the base levels and amplitudes of said waves; means to apply ano-ther of said intensity levels to said beam simultaneously with the application or" said rectangular waves; and means to indicate the settings of said adjustment means to thereby directly indicate the position of said other dot with respect to said one dot.

8. In a cathode ray oscilloscope Ihaving at least one electron beam and a lluorescent screen; in combination, first means to deflect the beam, second means to deflect the beam at right angles to said first means, means to control fthe beam intensity; means to generate a plurality of display producing waves for application to said lirst means; means for producing a plurality of sweep waves for application to said second means; means to derive a plurality of beam intensity controlling waves from said display prosnr/aces ducing waves for application to said intensity control means; display switch means -to select a pair from among the plurality of display producing waves, a pair from among the plurality of sweep waves and a pair from among the plurality of beam intensity controlling waves; and electronic switch means iorsirnultaneously applying one of each of said selected pairs of waves to said first means, said second means, and said beam intensity control means, to alternately produce selected time sharing pairs o-f displays at selected intensity levels.

9. in a cathode ray Ioscilloscope lhaving at least one electron beam and a iluorescent screen; in combination, irst means to deilect the beam, second means to deilect the beam at right angles to` said first means, means to control the beam intensity; means to generate a plurality of display producing `Waves for application to said iirst means; means for producing a corresponding plurality of sweep waves` in Vsynchronism with each of said plurality of display producing waves respectively for application to said second means; means to derive a plurality of lbeam intensity controlling waves from said display producing waves for application to` said intensity control means; display switch means to select a pair from among the plurality of display producing waves, a pair from among the plurality of sweep waves and a pair from among the plurality of beam intensity controlling waves; and electronic switch means for simultaneously applying one or" each of said sclected pairs of waves to said first means, said second means, and said beam intensity control means, to alternately produce selected time sharing pairs of displays at selected intensity levels.

l). in a cathode ray oscilloscope having at least one electron beam and a fluorescent screen; in combination; first means to deflect the beam; second means to deilect the beam at right tangles to said first means; means to control the beam intensity; means to apply a display waveform to said first means; means for producing a sweep wave of desired duration and applying said sweep wave to said second means at a predetermined time relative to said display Waveform; means to produce a delayed sweep wave iof a predetermined amplitude, said delayed sweep wave being initiated subsequently to said predetermined time and being of a duration shorter than said duration of said iirst sweep wave; means for apply= ing said delayed sweep wave to said second means; means for deriving an intensity wave simultaneous in time with said delayed sweep wave; means for generating iirst and second blanking waves in synchronism with said rst sweep wave and said delayed sweep wave respectively; means for applying said intensity and blanking waves to said intensity control means; and electronic switch means for simultaneously applying said display waveform, said tirst sweep wave, said intensity Wave and said first blanking wave to said yhrst means, said second means, and said beam intensity control means, respectively, and for alternately applying said display waveform, said delayed sweep wave, and said second blanking wave to said rst means, said second means, and said intensity control means respectively to thereby malte visible simultaneously ra display waveform with a portion intensied and the same display waveform with said intensilied portion ex* panded.

ll. In a cathode ray oscilloscope having at least one electron beam and a fluorescent screen; in combination, rst means to deflect the beam; second means to difterently deflect the beam; means to intensify the beam; means to amplify display waves including a display Waveform, a related portion of that waveform, an unrelated waveform, and a dot-producing square wave, and for applying said display waves to said irst means; means to generate a sweep wave synchronous with each of said display waves; means for deriving lanlcing waves from each said display wave at a Selected amplitude; means for applying said blanking waves to said beam intensity ing means; display switch means to select a pair from among said display waves, a corresponding pair from among said sweep waves, and at least one from among said blanking waves; and electronic switch means actuated synchronously vwith one of said pair of display waves for simultaneously applying one of each of said selected pairs of waves to said first means and said second means, and for applying at least said one of said blanking Waves to said beam intensifying means alternately, to thereby produce alternately a selected pair of patterns with portions at selected intensity levels.

12. In a cathode ray oscilloscope having at lcast one electron beam and a iiuclrescent screen; in combination, iirst means to deflect the beam; second means to deflect the beam at right angles to seid first mcans; means to control the beam intensity; means to amplify a plurality of display waveforms for application to said first means; means to apply a predetermined DC. component to each said amplified waveform; means for producing a corre spending plurality of sweep waves each in synchronism with said display `lviaveforms for application to said second means; means to derive a plurality of beam intensity controlling waves from said display waveforms for application to said intensity control means; display switch means to select a pair from among the plurality of ampled display waveforms having D.C. components, to select a corresponding pair from among the plurality of sweep waves and to select a pair from among the plurality of beam intensity controlling waves; and electronic switch means for simultaneously applying one of each of said selected pairs of waves to said first means, said second means, and said beam intensity control means alternately, to thereby alternately produce selected time sharing pairs of separated displays at selected intensity levels on the iiuorescent screen.

13. In a cathode ray oscilloscope having at least one electron beam and a tiuorescent screen; in Combination, lirst means to deilect the beam; second means to deflect the beam at right angles to said tirst means; means to control the beam intensity; means to amplify a display waveform; means for producing a sweep wave of desired duration and applying said sweep wave to said second means at a predetermined time relative to said display waveform; means to produce .a delayed sweep wave of a predetermined amplitude, said delayed sweep wave being initiated subsequently to said predetermined time and being of a duration shorter than said duration of said rst sweep wave; means for applying said delayed sweep wave to said second means; means for deriving an intensity wave simultaneous in time with said delayed sweep wave; means for generating first and second blanking waves in synchronism with said tirst sweep wave and said delayed sweep wave respectively; means for applying both said intensity and blanking waves to said intensity control means; means to generate a square wave with a positive portion having the same duration as said sweep wave and a negative portion having said duration; means to mix said display waveform and said square wave to produce mixed waves for application to said iirst beam deiiection means; means for applying said mixed waves to said first deecting means; and electronic switch means actuated by said square Wave for simultaneously applying said mixed waves, said first sweep wave, both said intensity wave and iirst blanking wave to said iirst means, said second means, and said beam intensity control means, respectively, and for alternately applying said mixed waves; said delayed sweep wave, and said second blanking wave to said first means, said second means, and said intensity control means respectively to thereby make visible simultaneously a display waveform with a portion intensiiied and the same display waveform with said intensiiied portion expanded and separated from said display waveform.

i4. ln a cathode ray oscilloscope having at least one electron beam and a fluorescent screen; in combination; a iirst means to deiiect the beam and a second means to `deflect the beam; means to intensify the beam; means to amplify a display waveform with a first period and a display waveform with a second period; means to generate rectangular waves with a period twice that of said first period; means for mixing said display waveforms and said rectangular waves to produce first and second mixed waves for application to said first means; means to generate sweep waves synchronized with said first and second periods for application to said second means; means to derive iirst intensity controlling waves from said first period display waveforms and second intensity controlling waves from said second period display waveforms for application to said intensifying means; first, second, and third electronic switch means operated in synchronism by said rectangular waves for applying simultaneously said first mixed waves, said sweep waves of said first period, and said first intensity controlling waves to said first detiecting means, said second deflecting means, and said intensifying means, respectively, and alternately applying said second mixed waves, said sweep waves of said second period, and said second intensity controlling waves to said first deecting means, said second defiecting means and said intensifying means, respectively, whereby alternate and unrelated two dimensional display patterns are produced on the fluorescent screen in time shared sequence, said display patterns being spaced apart in one dimension.

15. In a cathode ray oscilloscope having a cathode ray tube including a fluorescent screen, at least one electron beam source and means for deflecting the electron beam in two directions; in combination; means for simultaneously applying an electrical waveform -to be analyzed to one deflection means and a second electrical waveform t-o the other deflection means to form a pattern on said screen; means to apply at least two intensity levels to the electron beam; means to apply one of said intensity levels to said electron beam when said pattern is formed on said screen; means to produce a pair of phase related rectangular electrical waves of the same frequency which rests alternately at a base level and at an amplitude level and which has rapidly moving portions between said levels; means for simultaneously applying one of said rectangular waves to one deflection means andthe second of said rectangular waves to the other deflection means to thereby produce two dots on said screen; the position of one of said dots depending upon the base levels of said waves and the position of the second of said dots depending upon the base levels and amplitude levels of said waves; means to derive a blanking wave corresponding in time with said rapidly moving portions of said rectangular waves; and means to apply another of said intensity levels and said blanking wave to said beam simultaneously with the application of said rectangular waves to thereby make said beam trace invisible between said dots.

16. In a cathode ray oscilloscope having a cathode ray tube including a fluorescent screen, at least one electron beam source and means for deliecting the electron beam in two directions; in combination; means for simultaneously applying an electrical waveform to be analyzed to one deflection means and a second electrical waveform to the other deflection means to form a pattern on said screen; means to apply at least two intensity levels to the electron beam; means to apply one of said intensity levels to said electron beam when said pattern is formed on said screen; means to produce a pair of phase related rectanguiar electrical waves of the same frequency which rests alternately at a base level and at an amplitude level and which has rapidly moving portions between said levels; means to adjust the base levels and amplitude levels of said waves individually; means for simultaneously applying one of said adjusted rectangular waves to one deflection means and the second of said adjusted rectangular waves to the other defiection means to thereby produce two dots on said screen; the position of one of said dots depending upon the base levels of said waves and the position of the second of said dots depending upon the base levels and amplitude levels of said waves; means to derive a blanking wave corresponding in time with said rapidly moving portions of said rectangular waves; means to apply another of said intensity levels and said blanking wave to said beam simultaneously with the application of said rectangular waves to thereby make said beam trace invisible between said dots; and means to indicate the settings of said adjustment means to thereby directly indicate the position of said other dot with respect to said one dot.

References Cited by the Examiner UNITED STATES PATENTS 2,313,967 3/43 Read 314-22 2,407,898 9/ 46 Norgaard 315-22 2,418,133 4/47 Miller etal 315-22 2,483,140 9/49 Higham 315-22 2,492,700 1 2/ 49 Jeanne 315-22 2,547,289 4/51 Smart 315-22 2,620,455 12/52 Fockler 315-22 2,625,667 1/53 Chance 315-22 2,739,264 3/ 56 Shreve et al. 315-22 2,830,227 4/ 5 8 Hasbrook 315-22 2,858,475 10/58 Blake 315-26 2,860,284 11/58 McKim 315-22 OTHER REFERENCES Heins van der Ven: Testing Amplifier Output Valves by Means of the Cathode Ray Tube, Philips Technical Review, vol. 5, No. 3, March 1940, pp. 61-64.

DAVID G. REDINBAUGH, Primary Examiner.

RALPH G. NILSON, ROY LAKE, Examiners.

Claims (1)

1. IN A DISPLAY DEVICE HAVING ELEMENTS TO PRODUCE A SINGLE LIGHT SPOT, IN COMBINATION, MEANS FOR APPLYING FIRST AND SECOND DEFLECTING FIELDS OF DIFFERENT FREQUENCIES TO DEFLECT SAID SPOT IN A FIRST DIRECTION, MEANS FOR APPLYING A FIELD TO DEFLECT SAID SPOT IN A SECOND DIRECTION, FIRST SWITCH MEANS FOR ALTERNATELY APPLYING SAID FIRST AND SECOND FIELDS, THEREBY TO DEVELOP TWO INDEPENDENT TRACES IN TIME SHARING SEQUENCE; SECOND SWITCHES MEANS TO ADJUST THE INTENSITY OF THE SPOT TO EITHER OF TWO SELECTED CONSTANT LEVELS THROUGHOUT A TRACE INTERVALS; AND MEANS FOR ACTUATING SAID TWO SWITHCH MEANS IN SYNCHRONISM, WHEREBY THE INTENSITY OF SAID SPOT THROUGHOUT ONE TRACE MAY BE ADJUSTED INDEPEND-

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