USRE25833E - Color television image reproduction - Google Patents

Description

I SUBSTITUTE FOR MISSING COPY JJw-C'J RE 25 v 833 Aug. 10, 1965 H. C- GOODRICH COLOR TELEVISION IMAGE REPRODUCTION Orig. 2 3M3 Original Filed March 21 1951 I NVENTOR md'ltk O RNEY ERR ll beam as it scans the screen United States Patent poration of Delaware 0r nal No. 2,634,326 dated Apr. 7, 1953, Ser. No. 2 6,766, Mar.2l, 19 Applicationforrelssue-Iam28, 1955, Ser. No. 484,862

17 Claims. (Cl. 178-54) Nlatter enclosed in heavy brackets appears in the original patent but forms no part of this reissue s ification; matter printed in italics indicates the additions made by reissue.

This invention relates to television image reproducing systems and particularly, but not necessarily exclusively, to apparatus for controlling an electron beam so as to excite the luminescent screen of a ltinescope in a manner to reproduce television images substantially in their natural co ors.

The invention is related in general to systems of the type employing a multicolor kinescope such as that disclosed in US. Patent 2,310,863, granted February 2, 1943 to H. W. Leverenz and entitled Luminescent Screen." The screen of such a tube consists of discrete phosphor strips of a subelemental width and capable respectively of emitting diil'erently colored light when excited by an electron beam. The phosphor strips extend generally in a horizontal direction and the electron beam is deflected over the screen generally in a conventional manner. difl'erent phosphor strips of each of the groups are selectively excited to successive groups of strips horizontally. In order to [successively] successfully operate a tube of the [connection] character described, it is necessary that the vertical deflection of the beam be effected with a high degree of linearity.

Accordingly, it is an object of the present invention to provide an improved color television reproducing system in which an electron beam is maintained in substantially exact registration with a line phosphor screen.

Another object of the invention is to provide an electron beam controlling system in which signals generated in response to the beam deflection over a line phosphor screen are employed to maintain a desired registration of the beam with the screen.

In accordance with the invention, the image reproducing kinescope is provided with a line phosphor screen, the elements of which are capable of producing light of different colors when excited by an electron beam. The screen is also provided with signal generating facilities responsive to excitation by the beam and indicative of the registration of the beam with the screen. One of the features of the invention is in vertically deflecting the horizontally so as to successively and repeatedly traverse each of the phosphor strips comprising the group being scanned. The auxiliary vertical deflection of the beam may be efiected according to any predetermined pattern such as represented by a sine wave or a sawtooth wave, for example.

According to the invention, the signals generated by the excitation of the screen by the electron beam are combined with a wave corresponding to the auxiliary deflection of the beam to produce signals that may be used to control the vertical deflection wave generator, by means of which the beam is influenced to scan a conventional raster, so as to etfect the desired registration of the beam with the screen.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation as well as additional objects and advantages thereof will best be understood from the following description taken in connection with the accompanying drawing.

The single figure of the accompanying drawing is a combination block diagram and schematic circuit diagram of an illustrative form of a television reproducing system embodying the present invention.

Reference now will be made to the drawing for a more detatiled description of this embodiment of the invention. The system includes a composite television signal receiver 1 which may be entirely conventional. It will be understood that this apparatus may include one or more stages of radio frequency signal amplification, a first detector or frequency converter, one or more stages of intermediate frequency signal amplification and a second or signal detector. Accordingly, it will be understood that there is derived from the output circuits of the receiver demodulated video and synchronizing signal intelligence.

The video signals derived from the receiver 1 may be in any one of a number of different forms depending operation to be employed in operating the image reproducing kinescope. This feature of the part of the present invention and, accordingly, there is not shown in detail the specific means used for deriving the video signals in any particular form. It will be assumed, however, that the present invention is embodied in a color television system operating according to the dot or elemental multiplex principle. Such a system is described in greater detail in an article titled A sixmegacycle compatible high-definition color television system" published by RCA Laboratories Division in the RCA Review, December l949-vol. X, No. 4, p. 504. A representative system of this character also is described in a copending US. application of John Evans, Serial No. 111,384 filed August 20, 1949 and titled Color Television," now Patent No. 2,810,781,.irsued October 22, 1957. In accordance with a system of the type described in the publication and in the Evans application referred to, the video signals are in the form of time-spaced pulses representative respectively of the difierent color components of successive elemental area of the image to be reproduced. Accordingly, it will be understood that the pulses indicated at 2 represent for example the blue, green and red color components of successive elemental areas of the image to be reproduced. These impulses are amplified in a video signal channel 3 and thence they are impressed upon the intensity control electrode system of an electron gun 4 forming part of a multicolor kinescope 5.

The kinescope also is provided with a luminescent screen 6 formed of a multiplicity of horizontal phosphor strips such as the red, green and blue light-producing strips 7, 8 and 9, respectively. In accordance with the present invention, the screen 6 also includes a plurality of conducting strips such as 10 which may be imbedded between, but electrically insulated from, predetermined ones of the phosphor strips. These conducting strips serve as beam position-indicating strips or, more simply stated, indexing stripes. In the present case, it is assumed that the conductors 10 are placed between the red and green phosphor strips of each of the multiplicity of phosphor strip groups. The conductors 10 are electrically connected together to form a grid which is connected to an external circuit to be described more in detail subsequently.

A second anode in the form of a metallic wall coating 11 is another conventional kinescope electrode which, as customary, is connected to a source of relatively high positive potential. The kinescope 4 also is provided with a conventional deflection yoke 12 which may be energized in the usual manner to deflect the electron beam both horizontally and vertically in accordance with a predetermined pattern to scan a raster at the screen 6. Additionally, the kinescope is provided with an auxiliary deflection system which, in the present instance, is illustrated as a pair of plates 13. These electrodes are energized in a manner to be described to cause the electron beam to be deflected vertically with a relatively high frequency while it is being deflected horizontally to scan successive lines of the desired raster.

The synchronizing signal intelligence derived from the composite television signal receiver 1 is segregated from the video signals by means of a synchronizing signal separator 14 coupled to the output of the receiver. This apparatus also may be entirely conventional. Accordingly, it will be understood that there is derived from the synchronizing signal separator both the horizontal and vertical synchronizing pulses. The horizontal synchronizing pulses are impressed upon a conventional horizontal deflection wave generator 15. The output of this generator is connected to the deflection yoke 12 as indicated to energize it by a substantially sawtooth wave at line fre quency in the usual manner.

Suitable color synchronizing pulses are impressed upon a color deflection wave generator 16 so as to synchronize its operation. This generator also may be of the type capable of producing a substantially sawtooth wave at the color repetition frequency and at a fixed phase relationship to the color component of the video signal. In the assumed case of a system operating in accordance with the dot multiplex principle, the frequency of the wave produced by the generator 16 will be of the order of 3.6 mc. per second. The output circuit of this generator in which the sawtooth wave is produced is coupled to the auxiliary deflection plates 13. In this manner the electron beam is given an auxiliary sawtooth deflection of relatively small amplitude so that, as it is being deflected by the yoke 12 to scan successive horizontal lines in the usual manner, it traces a substantially sawtooth path as indicated at 17. It is seen that the trace 17 extends only over one group of phosphor strips.

Further details of the synchronization of the color deflection wave generator 16 may be found in two publicaions by Radio Corporation of America titled Synchronization for Color Dot Interlace in the RCA Color Television System, October 1949 and Recent Developments in Color Synchronization in the RCA Color Television System, February 1950. These color synchronizing systems from the subject matter of copending US. patent applications of Randall C. Ballard, Serial No. 117,528 filed September 24, 1949 and titled Systems of Color Television," now Patent No. 2,678,348, issued May 1], 1954 and of Alda V. Bedford, Serial No. 143,800, filed February ll, 1950 and titled Synchronizing Apparatus," now Patent No. 2,728,812, issued December 27, 1955.

There also is derived from the color deflection wave generator 16 is a series of pulses such as indicated at 18. These pulses occur at the color repetition rate and are of a fixed predetermined amplitude. Preferably this amplitude should be greater than the greatest possible amplitude of the video signal pulses 2. The pulses 18 are impressed upon the video signal channel 3 for mixing with the video signal pulses 2 in such a manner that they may be employed as position reference signals. The phase of the pulses 18 should be adjusted relative to the video signal pulses 2 so that, when mixed together, there is produced in the output circuit video channel 3 strain of pulses such as indicated at 19. It is seen that the position reference pulses 18 are mixed with the video signal pulses in such a way that they occur successively between the green and red representative video signal pulses. By means of the position reference pulses, the intensity of the electron beam is controlled independently of the video signal for a purpose to be described in conjunction with the utilization of the signals produced by the conductor grid of the kinescope screen.

The vertical synchronizing signals derived from the synchronizing signal separator 14 are impressed by a coupling including a capacitor 21 and a resistor 22 upon a vertical deflection wave generator 23 for the purpose of synchronizing it. This generator also may be entirely conventional. The essential components of it are illustrated in detail in order to illustrate the manner in which the present invention functions in conjunction with it. The vertical deflection wave generator includes a combincd oscillator and discharge tube 24 and an output tube 25. Both of these tubes have been illustrated as triodcs for the purpose of simplicity. It will be understood that other types of tubes may be used alternatively without departing from the present invention. In order that the tube 24 may function as a blocking type oscillator, feedback may be provided by inductively coupled anode and grid coils 26 and 27, respectively. The output circuit of the tube 24 also includes a capacitor 28 and resistors 29 and 3|] connected in series therewith between the anode circuit of the tube 24 and ground. The anode circuit of this tube also is connected through a resistor 31 to a source of energy of positive polarity.

The tube 24 normally is non-conducting so that the capacitor 28 charges at a relatively slow rate through resistors 29, 30 and 31. When the tube 24 is rendered conducting under the control of one of the vertical synchronizing signals impressed upon the grid, the condenser 28 is discharged at a relatively rapid rate through the tube 24. Accordingly, at the high potential terminal of the capacitor 28, there is developed a substantially sawtooth wave as a result of the described operation.

The high potential terminal of the capacitor 28 is coupled by a capacitor 32 and a leak resistor 33 to the control grid of the output tube 25. The anode of this tube is connected through the primary winding 34 of an output transformer 35 to an energy source of positive polarity. The secondary winding 36 of this transformer is connected for the deflection yoke 12 so as to provide it with a substantial sawtooth wave at the field deflection frequency.

The vertical deflection generator in actual practice may include other features such as potentiometers for controlling linearity and the vertical height of the raster scanned. However, since none of these features have any connection with the present invention they have not been specifically illustrated.

The vertical sawtooth deflection wave derived from the generator 23 is made subiect to control in amplitude by means of apparatus in accordance with a feature of the present invention. The grid formed by the conductors 10 of the screen 6 is connected to an output resistor 37 externally of the kinescope 5. The output resistor also is connected, as indicated, to the source of potential for the second anode 11 in order to minimize the potential difference between the grid conductors and the phosphor screen. The output resistor 37 also is bypassed to ground by a capacitor 38. The grid-connected terminal of the resistor 37, in the present form of the invention, is coupled by a capacitor 39 to an input resistor 41 for an amplitude limiter 42. The limiter may be conventional in form comprising, for example, an electron amplifier tube biased so as to be driven to saturation by the signals developed in the resistor 41.

The output circuit of the limiter 42 is connected to a resistor 43 forming part of a signal combining circuit. Another resistor 44 connected in series with the resistor 43 forms another component of the signal combining circuit and has its terminals connected to the sawtooth wave output terminals of the color deflection wave generator 16. The two resistors 43 and 44 are further connected to a series arrangement of a diode 45, a diode load circuit, including a resistor 46 and a shunting capacitor 47,

and a source of biasing voltage represented by the battery 48.

The sawtooth wave 49 developed by the generator 16 at the color repetition frequency'isimpressed upon the deflection plates 13 to cause the beam to be deflected vertically along the trace 17 in the maner described. In addition, the sawtooth wave 49 also is impressed upon the signal combining resistor 44. [Position] Beam position indicating signals such as represented at 50 are derived, in negative polarity, from the grid of conductors in response to each traversal of the electron beam over one of the conductors during the relatively slow portions of the sawtooth trace 17. Thae pulses, after being reversed in polarity and limited in amplitude to a predetermined common level by the limiter 42, are developed across the signal combining resistor 43 in such a way that they are impressed upon the diode 45 in conjunction with the sawtooth wave 49.

There is impressed upon the diode 45, therefore, a composite wave having substantially the form shown at 51. It is seen that the composite wave consists of successive cycles of a substantially sawtooth wave 52. Superimproved on each one of these sawtooth waves is a pulse such as 53 corresponding to one of the pulses 50. It is seen that, depending upon the time of occurrence of the pulses 50 relative to the sawtooth wave 49, the superimposed pulses such as 53 have dilferent peak amplitudes relative to a point of reference. The peak amplitudes of the the pulses such as 53 is an indication of the registration of the electron beam with the luminescent screen 6.

For example, if it be assumed that the pulse 53 reprecauses the horizontal sweep of the beam to move upward relative to the group of phosphor strips efl'ects the traversal of one of the conductive strips 10 at a time earlier than normal. Accordingly, such a signal pulse derived from the grid of conductors 10 would be represented at 54 when superimposed upon the sawtooth wave 52. Since the pulse 54 occurs earlier than it should, it is placed upon a lower amplitude portion of the sawtooth wave and, therefore, has a smaller peak amplitude than a normal pulse 53, for example. Similarly, a downward deflection should. Such a pulse is represented at 55 with reference to the sawtooth wave 52. It is seen that its peak amplitude is greater than that of the normal pulse 53.

Diode 45 function as a peak rectifier, because the time constant of the diode load circuit, including resistor 46 and capacitor 47, is long compared with the period of the composite waveform 51 impressed upon the anode. Accordingly, there is developed in the diode load circuit a unidirectional voltage which is approximately equal to the peak voltage, such as represented by the pulses 53,

tube 58 is provided by bias source 48.

Space current for the tube 58 is derived by a connection of the anode to the resistor 31. It is seen that the voltage developed at the anode of the tube 58 is controlled by the magnitude of the space current conduction in this tube. This, in turn, is responsive to the registration signals such as represented by the pulses 53, 54 and 55 in the maner described. The voltage developed at the anode of the tube 58 is that which is impressed upon the capacitor 28 for charging it as described. A variation of the voltage correspondingly varies the charging rate of this capacitor whereby to control the vertical deflection of the electron beam in the manner desired.

Thus, a decrease in the anode voltage of the tube 58 in response to an increase in the current conduction therein efi'ects a decrease in the rate at which the capacitor 28 is charged. Accordingly, the sawtooth wave derived from the generator 23 will be altered suitably so that the electron beam will be deflected vertically at a slower rate. Similarly, an increase in the vertical deflection of the electron beam is effected by increasing the rate at which the capacitor 28 is charged by means of an increase in the anode voltage of the tube 58 in response to a decrease in the current conduction therein.

It may be found in some cases that it is unnecessary to provide the conductors 10 in such form that they extend horizontally throughout the entire screen 6. It is considered ll) be within the scope of the present invention to provide a structure in which the conductors 10 are of a somewhat shorter nature. It may be found t at it is not necessary to the conductors regions so that they may be traversed by the scanning beam slightly in advance of the scansion of the screen for image reproduction. In such a case, the beam may be modulated in a desired maner prior to the modulation thereof by the video signals representing the different color components of the image to be reproduced. The position of the scanning beam relative to any group of phosphor strips then would be indicated prior to the start of the scansion of this group of strips. In such a case, the vertical deflection wave generaator must be sufliciently stable in operation to maintain good linearity for the duration of each horizontal line scansion.

In cases where it is found to be unnecessary to extend the conductors 10 throughout the entire length of each group of phosphor strips, it will not be necessary to include the position reference pulses such as 18 with the video signal pulses as described in connection with the illustrative embodiment of the invention shown herein. Furthermore, it may be determined, in some cases where the conductors 10 do extend the entire width of the screen, that the special position reference pulses 18 are not needed for the successful operation of the system.

that they are separated slightly from one another. Such an arrangement will minimize an undesired mixing of the colors which might otherwise be produced.

Also, it will be apparent that the diode 45, in conjunction with its associated circuit components, functions essentially as a phase comparator in detecting any phase diflerences between the color deflection wave and the gridgenerated position indicating pulses. Accordingly, it will be understood that equivalent types of phase comparators may be used instead of that disclosed without departing from this invention.

that there is provided an improved color television image reproducing system. The color selection is achieved in a particularly advantageous manner by the comparatively simple expedient of giving the electron beam a small amplitude, auxiliary vertical deflection while it is being deflected conventionally both horizontally and vertically so that it successively and repeatedly traverses difl'erent phosphor strips of a group capable respectively of producing light of the different component image colors in response to and concurrently with the reception of video signals representative of these component image colors.

Furthermore the invention provides a relatively simple and efficient means for maintaining the necessary registration of the electron beam with successive groups of a multiplicity of groups of horizontal phosphor strips.

The nature of the present invention is substantially as described in the foregoing specification. Its scope is set forth in the following claims.

What is claimed is.

1. In a color television system, a multi-color kinescope having a luminescent screen including a multiplicity of groups of phosphor strips capable respectively of producing light of a plurality of component image colors in response to excitation by an electron beam, said screen also having conductors aligned respectively with said groups of phosphor strips and connected together electrically to form a grid, means for developing an electron beam and deflecting it to scan a raster at said screen, means including a periodic wave generator for effecting an auxiliary deflection of said beam in a predetermined cyclically recurring pattern in a direction transverse to the direction of said phosphor strips, whereby successively and repeatedly to traverse said phosphor strips, thereby producing difl'erently colored image-representative light and also to traverse said grid conductors, thereby developing position-indicating pulses, means for combining said position-indicating pulses with said periodic auxiliary deflection wave to develop a control signal representative of any misregistration of said beam with said screen, and means responsive to said control signal and coupled to said beam-deflecting means to correct the deflection of said beam in the direction transverse to the direction of said phosphor strips.

2. In a color television system, apparatus as defined in claim 1 wherein, said combining means includes a. circuit upon which are concurrently impressed said periodic auxiliary deflection wave and said position-indicating pulses whereby said pulses are superimposed upon said wave to form said developed control signal, and means for converting the peak amplitudes of said control signal into a unidirectional control voltage for impression upon said beam-deflecting means- 3. In a color television system, apparatus as defined in claim 2 wherein, said converting means includes a diode biased so as to be rendered conducting only in response to said peak amplitudes whereby to develop a series of time-spaced pulses, and a filter coupled to the output circuit of said diode to produce said unidirectional control voltage from said series of pulses.

4. In a color television system, apparatus as defined in claim 3 wherein, said beam-deflecting correcting means includes an electron tube responsive to said unidirectional control voltage to variably control the rate of said beam deflection in said transverse direction.

5. In an image reproducing system, a cathode ray tube having a luminescent screen, a plurality of spaced conducting strips extending horizontally across said screen and connected together to form a grid, means for developing an electron beam and deflecting it horizontally and vertically to scan a raster at said screen, means for efiecting an auxiliary sawtooth vertical deflection of said beam whereby to repeatedly traverse each of said strips and consequently develop pulses indicative of the linearity of said vertical beam deflection, means responsive to said developed pulses for generating control signals having amplitudes varying in accordance with the time in said auxiliary sawtooth beam deflection cycles at which said pulses are developed, and means responsive to said control signals to maintain the linearity of said vertical beam deflection sumciently accurate to cause said beam to scan said screen in substantially precise horizontal lines.

6. In a color television receiver, the combination ineluding: a multl-color klnescope having a luminescent screen including a multiplicity of groups of phosphor strips capable respectively of producing light of a plurality of component image colors in response to excitation by an electron beam, said screen also having beam posilion-indicating strips aligned respectively with said groups of phosphor strips and capable of developing beam posilion-indicating signals in response to excitation by an electron beam; means for developing an electron beam and deflecting it to scan a raster at said screen; means for efiectlng an auxiliary deflection of said beam in a predetermined cyclically recurring pauern in a direction transverse to the direction of said phosphor strips, whereby successively and repeatedly to impinge upon said phorphor strips, thereby producing difierently colored imagerepresentative light, and also to impinge upon said beam position-indicating strips, thereby developing beam posilion-indicating signals; and means responsive to said beam position-indicating signals to control the rate of said raster-scanning beam deflection in a direction transverse to said screen strips.

7. In a color television receiver, the combination including: a multl-color kinescope having a luminescent screen including a multiplicity of groups of phosphor strips capable respectively of producing light of a plurahry of component image colors in response to impingemen: by an electron beam, said screen also having beam position indicating strips aligned respectively with said groups of phosphor strips and capable of developing beam position-indicating signals in response to impingement by an electron beam; means for developing an electron beam and deflecting it to scan a meter at said screen; means for efiecting an auxiliary deflection of said beam in a predetermined cyclically recurring pattern in a direction transverse to the direction of said phosphor strips, whereby successively and repeatedly to impinge upon said phosphor strips, thereby producing diflerently colored imagerepresentatlve light, and also to impinge upon said beam position-indicating strips, thereby developing beam post'- Iion-indicating signals; means responsive to video signals representative of said component image colors to modulate the intensity of said electron beam substantially concurrently with the impingement of said beam upon said phosphor screen strips; means responsive to substantially uniform amplitude reference signals occurring at said auxiliary beam deflection rate to modulate the intensity of said beam substantially concurrently with the impingement of said beam upon said beam position-indicating screen strips; and means repsonsive to said beam position-indicating signals to control the rate of said raster-scanning beam deflection in a direction transverse to said screen strips.

8. In a color television receiver, the combination including: a multi-color lu'nescope having a luminescent screen including a multiplicity of groups of phosphor strips capable respectively of producing light of a pluraliry of component image colors in response to impingement by an electron beam, said screen also having beamporition-indicating strips aligned respectively with said groups of phosphor strips and capable of developing beam position-indicating signals in response to impingement by an electron beam; means for developing an electron beam and deflecting it to scan a raster at said screen,- means for efiecting an auxiliary deflection of said beam in a prederermined cyclically recurring pattern in a direction transverse to the direction of said phosphor strips, whereby successively and repeatedly to impinge upon said phosphor strips, thereby producing dlfierently colored imagerepresenmtlve light, and also to impinge upon said beam position-indicating strips, thereby developing beam posilion-indicating .n'gnolr; means responsive to video signals varying in amplitude in accordance with said component image colors to modulate correspondingly the intensity of said electrom beam substantially concurrently with the impingement of sold beam upon sold phosphor screen strips: means responsive to reference signals having a substantially uniform amplitude greater than the greatest amplitude of sold video signals and occurring at said auxillary beam deflection rate to modulate correspondingly the intensity of said beam substantially concurrently with the impingement of said beam upon said beam position-indicating screen strips; and means responsive to said beam position-indicating signals to control the rate of said raster-scanning beam deflection in a direction transverse to said screen strips.

9. In a cathode ray tube display system: means for producing a signal comprising successive portions representative of difierent intelligence components, portions representative of particular components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for reproducing the intelligence represented by said signal, said tube comprising a source of an electron beam, and a fluorescent screen comprising a plurality of substantially parallelly disposed phosphor strips; means [or deflecting said beam in a direction generally parallel to said phosphor strips and at a rate such as to cause said beam to traverse only a portion of the length of a given strip during one cycle of said signals; means for deflecting said beam in a direction generally transverse to said phosphor strips at a rate such as to cause said beam to traverse diflerent strips during successive scans in said direction generally parallel to said strips; means for producing recurring auxliliary deflection of said electron beam in said direction generally transverse to said phosphor strips at a rate substantially equal to the rate of recurrence of said portions of said signal and of an amplitude sufiicient to cause said beam to traverse substantially the width of a phosphor strip during each cycle of said deflection; means responsive to electron beam impingement on a predetermined region extending longitudinally of each said strip to produce a signal indicative of said impingement; and means for ultillzing said produced signal to control the instantaneous rate of deflection of said beam in said direction generally transverse to said phosphor strips. 10. In a cathode ray tube display system: means for producing a signal comprising successive portions representative of diflerent intelligence components, portions representative of particular components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for reproducing the intelligence represented by said signal, said tube comprising a source of an electron beam, a fluorescent screen comprising a plurality of substantially parallelly disposed phosphor strips and a plurality of indexing stripes, each associated with one of said phosphor strips and disposed substantially parallel thereto; means for deflecting said electron beam in a direction generally parallel to said phosphor strips and an rate such as to cause said beam to traverse only a portion of the length of a given strip during one cycle of said signal; means for deflecting said electron beam in a direction generally transverse to said phosphor strips at a rate such as to cause said beam to traverse different strips during successive scans in said direction generally parallel to said strips; means for producing recurrent auxiliary deflection of said electron beam in said direction generally transverse to said phosphor strips at a rate substantially equal to the rate of recurrence of said portions of said signal and of an amplitude suflicient to cause said beam to traverse substantially the width of a phosphor strip and to traverse the indexing stripe associated with a strip during each cycle of said deflection; means for deriving a signal in response to impingement of said electron beam on said indexing stripes; and means for utilizing said derived signal to control the instantaneous rate of deflection of said beam in said direction generally transverse to said phosphor strips.

II. In a cathode ray tube display system: means for producing a signal comprising successive portions repreresentative of diflerent intelligence components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for producing visible indications of the intelligence represented by said signal, said tube comprising a screen and means for projecting an electron beam toward said screen; means for deflecting said beam in first and second diflerent directions across said screen and at rates such as to trace successively a plurality of substantially parallel paths upon said screen; a plurality of phosphor strips, each disposed longitudinally of one of said beam paths upon said screen; a plurality of indexing stripes, each associated with one of said phosphor stripes and disposed substantially parallel thereto; means for producing cyclical deflection of said beam across said screen in said first direction at a rate substantially equal to said rate of recurrence of particular portions of said signal and of an amplitude suflicient to cause said beam to traverse the width of a phosphor strip and the indexing stripe associated with said strip during each cycle of said deflection; means for deriving a signal in response to impingement of said beam on said indexing stripes; and means for utilizing said derived signal to control the rate of beam deflection in said first direction.

12. In a cathode ray tube display system, means for producing a signal comprising successive portions representative of difierent intelligence components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for producing visible indications of the intelligence represented by said signal, said tube comprising a screen and means for projecting an electron beam toward said screen; means for deflecting said beam in first and second mutually perpendicular directions across said screen and at rates such as to trace successively a plurality of substantially parallel paths upon said screen; a plurality of phosphor strips, each disposed longitudinally of one of said beam paths upon said screen; a plurality of indexing stripes, each associated with one of said phosphor stripes and disposed substantially parallel thereto; means for producing cyclical deflection of said beam across said screen in said first direction at a rate substantially equal to said rate of recurrence of particular portions of said signal and of an amplitude suflicient to cause said beam to traverse the width of a phosphor strip and the indexing stripe associated with said strip during each cycle of said deflection; means for deriving a signal in response to impingement of said beam on said indexing stripes; and means for utilizing said derived signal to control the rate of beam deflection in said first directio 13. In a cathode ray tube display system: means for producing a signal having successive portions representative of difierent intelligence components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for producing visible indications of the intelligence represented by said signal, said tube comprising a screen, means for projecting an electron beam toward said screen, and means responsive to said signal to control the intensity of said beam, said screen having a plurality of substantially parallel phosphor strips and a plurality of indexing stripes, each associated with one of said strips and disposed substantially parallel thereto; means for producing successive deflections of said beam longitudinally of diflerent ones of said phosphor strips at such a rate as to cause said beam to traverse only a fraction of the length of a particular strip during one cycle of said signal; means for producing cyclically recurrent deflections of said beam transversely of said phosphor strips at a rate substantially equal to the said rate of recurrence of signal portions and of an amplitude suflicient to cause said beam to traverse the width of a phosphor strip and its associated indexing stripe during each cycle of said tranverse deflections; means for deriving a signal in response to impingement of said electron beam on said indexing stripes; and means for utilizing said derived signal to control the deflection of said beam transversely of said phosphor strips.

14. In a cathode ray tube display system: means for rate; a cathode ray tube for producing visible indications of the intelligence represented by said signal, said tube comprising a screen, means for projecting an electron beam toward said screen, and means responsive to said intelligence signal to control the intensity of said beam, said screen having a plurality of substantially parallel phosphor strips and a plurality of indexing stripes, each associated with one of said strips and disposed substantially parallel thereto; means for producing successive deflections of said beam longitudinally of diflerent ones of said phosphor strips at such a rate as to cause said beam to traverse only a fraction of the length of a particular strip during one cycle of said signal; means for producing cyclically recurrent deflections of said beam transversely of said phosphor strips at a rate substantially equal to the said rate of recurrence of signal portions and of an amplitude sufficient to cause said beam to traverse the width of a phosphor strip and its associated indexing stripe during each cycle of said transverse deflection; means for deriving a signal in response to impingement of said electron beam on said indexing stripes; means responsive to variations in the times of occurrence of the said derived signal to produce a control signal; and means for utilizing said control 'gnal to control the deflection of said beam transversely of said phosphor strips.

15. In a cathode ray tube display system: means for producing a first signal having successive portions representative of diflerent intelligence components occurring in a predetermined order and recurring at a predetermined rate; a source of a second signal whose phase and frequency are respectively indicative of the times of occurrence and the rate of recurrence of the said intelligence representative portions of said first signal; a cathode ray tube for producing visible indications of the intelligence represented by said first signal, said tube comprising a screen, means for projecting an electron beam toward said screen, and means responsive to said signal to control the intensity of said beam, said screen having a plurality of substantially parallel phosphor strips and a plurality of indexing stripes, each associated with one of said strips and disposed substantially parallel thereto; means for producing successive deflections of said beam longitudinally of diflerent ones of said phosphor strips at such a rate as to cause said beam to traverse only a fraction of the length of a particular strip during one cycle of said first signal; means for producing cyclically recurrent deflections of said beam transversely of said phosphor strips at a rate substantially equal to the said rate of recurrence of signal portions and of an amplitude suiflcient to cause said beam to traverse the width of a phosphor strip and its associated indexing stripe during each cycle of said transverse deflections; means for deriving a signal in response to impingement of said electron beam on said indexing stripes; means supplied with said second signal and with said derived signal and responsive to relative phase variations therebetween to produce a control signal proportional to said variations; and means for utilizing said control signal to control the deflection of said beam transversely of said phosphor strips.

16. In a cathode ray tube display system: means for producing a signal having successive portions representative of intelligence respecting difierent color components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for producing visible indications of said color components, said tube comprising a screen, means for protecting an electron beam toward said screen, and means responsive to said intelligence signal to control the intensity of said beam,

said screen including a plurality of substantially parallelly disposed groups of phosphor stripes, each of said groups including diflerent stripes responsive to electron beam impingement to produce light of said diflerent colors, difierent color stripes being disposed in the same order within each said group in which the said successive signal portions are representative of difierent color components, and a plurality of indexing stripes, each associated with one of said groups of phosphor stripes and disposed substantially parallel thereto; means for producing successive deflections of said beam longitudinally of diflerent ones of said phosphor stripe groups at such a rate as to cause said beam to traverse only a portion of the length of a particular group during one cycle of said signal; means for producing cyclically recurrent deflections of said beam transversely of said phosphor stripe groups at a rate substantially equal to the said rate of recurrence of signal portions and of an amplitude sufi'icient to cause said beam to traverse all the phosphor stripes of a group and the indexing stripe associated therewith during each cycle of said transverse deflections; means for deriving a signal in response to impingement of said electron beam upon said indexing stripes; and means for utilizing said derived signal to control the deflection of said beam transversely of said groups.

17. In a cathode ray tube display system: means for producing a signal having successive portions representative of red, green and blue color components occurring in a predetermined order and recurring at a predetermined rate; a cathode ray tube for producing visible indications of said intelligence, said tube comprising a screen, means for projecting an electron beam toward said screen and means responsive to said intelligence signal to modulate the intensity of said beam, said screen including a plurality of substantially parallelly disposed groups of phosphor stripes, each group comprising a red, a green and a blue light emissive stripe arranged in the some order as the said order of occurrence of color representative signal portions, and a plurality of indexing stripes, each associated with one of said groups of phosphor stripes and disposed substantially parallel thereto; means for producing successive deflections of said beam across said screen longitudinally of difierent ones of said phosphor stripe groups; means for producing cyclically recurrent deflections of said beam transversely of said groups at a rate substantially equal to the said rate of recurrence of signal portions, of amplitude such as to traverse a red, a green and blue light emissive phosphor stripe and an indexing stripe during each cycle of said lastnarned deflections, and in such sense as to traverse said stripes in the order in which the said signal portions are representative of difierent color components; means for deriving a signal in response to impingement of said electron beam on said indexing stripes; and means for utilizing said derived signal to control the deflection of said beam transversely of said phosphor stripes.

References Cited by the Examiner The following references, cited by the Examiner, are of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,415,059 1/47 Zworykin 178-54 2,490,812 12/49 Hufimann 178-54 2,530,431 11/50 Hufimann 178-54 2,545,325 3/51 Welmer 1785.4 2,671,129 3/54 Moore l78-5.4

DAVID G. REDmitAUGI-L Primary Examiner. NEWTON N. LOVEWELL, Examiner.

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