Abstract: A method for controlling operation of an electron emission source includes acquiring, while varying an emission current of an electron beam, a characteristic between a surface current of a target object at a position on the surface of the target object irradiated with the electron beam, and the emission current, calculating, based on the characteristic, first gradient values each obtained by dividing the surface current of the target object by the emission current, in a predetermined range of the emission current in the characteristic, calculating a second gradient value by dividing a surface current of the target object by an emission current in a state where the electron beam has been adjusted, and adjusting a cathode temperature to make the second gradient value in the state where the electron beam has been adjusted be in the range of the first gradient values in the predetermined range of the emission current.

Abstract: A power supply device disclosed in the present specification has an output portion which generates an output voltage from an input voltage by means of on-off control of an output transistor and feeds the output voltage to a load, an output feedback controller which drives the output portion by performing output feedback control, and a detector which detects, by means of an electromagnetic induction method, a ripple component in a monitoring target current resulting from the on-off control of the output transistor. The output feedback controller performs the output feedback control based on the result of detection by the detector.

Abstract: A remote, noncontact temperature determination method and apparatus is provided, which is operable to determine the temperature of a conducting member in operative thermal communication with an object of interest. The method comprises the steps of first inducing a closed vortex eddy current in a conducting member by subjecting the member to a magnetic field, such that the corresponding eddy current magnitude changes exponentially over time. A characteristic time constant of the exponential current magnitude changes is then determined, and this is used to calculate the temperature of the object. The apparatus includes a field transmitting coil coupled with a waveform generator for inducing the eddy current, and a field receiving coil assembly which detects the corresponding induced magnetic. Temperature determinations can be made which are substantially independent of the relative distance and/or angular orientation between the conducting member and the field receiving coil assembly.

Abstract: A video display includes a scanner operable at a first frequency and a higher second frequency. A switch mode power supply drives a transformer with three secondaries. First and second rectifiers & filters are associated with the first and second secondaries. A rectifier is coupled to the third secondary and by way of a switch to the first filter. Feedback from the first filter controls the SMPS. In a first operating mode, the scanner is operated at the first frequency, the switch is open, the scanner supply is a first voltage from the first filter, and ancillary equipment is supplied with a third voltage by the second filter. In a second operating mode, the scanner is operated at the second frequency, the switch is closed, the scanner supply is a second voltage, higher than the first, from the first filter, and ancillary equipment is supplied with the same third voltage.

Abstract: In a CRT display apparatus, a horizontal distortion correction apparatus is provided for correcting horizontal distortion of an image by applying a residual phase to control the phase of a horizontal deflection current. The horizontal distortion correction apparatus corrects horizontal distortion of an image caused by an assembly error of the CRT display apparatus for displaying an image by scanning a video signal, based on a horizontal synchronizing signal included in the video signal. The horizontal distortion correction apparatus includes a PLL supplying the horizontal deflection current to a video signal controller for displaying an image on the CRT. A distortion-correcting waveform generator is operated by the user, applying a wave signal having a desired waveform to the PLL to provide a residual phase for the horizontal deflection current to control the phase thereof. As a result, the image without horizontal distortion is displayed on the CRT display apparatus.

Abstract: A method and a apparatus are provided for operating an E-beam system including an E-beam source for generating an E-beam directed along a column axis and an electrode aligned with the column axis direct the E-beam towards means for measuring the E-beam. A signal proportional to leakage current emitted from the E-beam is generated. When the result of a comparison with a desired value is excessive, an excess leakage signal is generated. The excess leakage signal can be provided as an emergency output signal and/or produce an OFF signal for stopping production of the E-beam by turning OFF voltage/power sources for producing the E-beam in response to the excess leakage signal. Preferably, a filament is heated by an electric current and a cathode is bombarded with electrons from the filament to produce the E-beam. Then a filament control signal is employed for controlling the filament heating current.

Abstract: A vertical linearity correction circuit including diodes and resistors is provided in a vertical deflection circuit, and a vertical deflection voltage applied to a vertical deflection yoke is corrected so as to follow a change in input impedance of the vertical deflection yoke. As a result, the vertical deflection speed in the vicinity of the central part of the image plane of the color picture tube is prevented from decreasing.

Abstract: A CRT display apparatus is disclosed. The CRT display apparatus includes a CRT having an electron gun whose electrodes for controlling an electron beam are applied with voltages from their respective voltage sources specifically designed to supply an electrode current, and is capable of automatically ceasing a discharge that has occurred under fault conditions between any electrode within the electron gun and the cathode or an anode of the CRT.

Abstract: A vertical deflection amplifier drives a vertical deflection coil according to a ramp input signal and has a current sensing resistor providing a feedback signal. The vertical deflection coil is subject to crosstalk or excitation by a horizontal deflection coil. A compensation network is coupled between a source of the horizontal deflection signal and the current sense resistor, and has a network that produces a corrective current in the current sense resistor to substantially cancel horizontal rate crosstalk component from the feedback signal.

Abstract: A deflection circuit generates a deflection current (If) through a deflection coil (Lf). The deflection circuit includes a series resistor (Rs) arranged in series with the deflection coil (Lf) to supply a feedback voltage (Vf;Vr), and a drive circuit (1,5) which has an output coupled to the series arrangement of the deflection coil (Lf) and the series resistor (Rs). The drive circuit (1,5) has an input coupled to the series resistor (Rs) to receive a feedback voltage (Vs). The drive circuit (1,5) further is coupled to a conversion resistor (Rc) for receiving an input waveform (Vi). The drive circuit (1,5) is arranged in a feedback loop to obtain a deflection current (If) with a shape resembling the input waveform (Vi). The deflection circuit further includes a damping impedance (Rd) arranged in parallel with the deflection coil (Lf), and a current generating circuit (3) for generating a correction current (Ic) within the flyback period (Tf).

Abstract: A picture stabilizing circuit for a semiwide-screen television receiver capable of preventing vertical lines of the picture from being bent by detecting and compensating for a high-voltage variation caused by a picture brightness variation.

Abstract: A deflection waveform correction signal generator comprises a multiplying circuit for generating a pincushion correction signal. A horizontal frequency ramp is generated by a clipped retrace pulse. The ramp generator has an output coupled to an integrating circuit for generating a parabolic shaped signal. The ramp generator and ramp integrator are reset at a horizontal rate by reset pulses of differing duration. The different duration of reset pulses results in the parabolic signal having regions of non-parabolic shape. The parabolic shaped signal is coupled to an input of the multiplying circuit. A control circuit is coupled to the parabolic shaped signal for maintaining a peak amplitude thereof by controllable coupling to the ramp generator. A control loop is coupled to the integrator for controlling an integrator input bias current to generate the parabolic shaped signal at a predetermined time interval.

Abstract: In a D.C. coupled vertical deflection circuit, an input sawtooth signal is coupled to an inverting input of a vertical deflection amplifier via a first resistor network. A D.C. voltage is coupled to a second input of the amplifier via a second resistor network for preventing the D.C. signal component from affecting the deflection current. To provide temperature compensation, for every resistor included in the first resistor network, there is included a corresponding resistor of equal value in the second resistor network.

Abstract: In a television receiver, to prevent interference between the magnetic field used for degaussing and the magnetic field of the vertical yoke, a switch is used for delaying turning on the vertical deflection circuit during degaussing.

Abstract: A deflection waveform correction signal generator comprises a multiplying circuit for generating a pincushion correction signal. A horizontal frequency ramp is generated by a clipped retrace pulse. The ramp generator has an output coupled to an integrating circuit for generating a parabolic shaped signal. The ramp generator and ramp integrator are reset at a horizontal rate by reset pulses of differing duration. The different duration of reset pulses results in the parabolic signal having regions of non-parabolic shape. The parabolic shaped signal is coupled to an input of the multiplying circuit. A control circuit is coupled to the parabolic shaped signal for maintaining a peak amplitude thereof by controllable coupling to the ramp generator. A control loop is coupled to the integrator for controlling an integrator input bias current to generate the parabolic shaped signal at a predetermined time interval.

Abstract: A device for controlling the linearity of a horizontal deflection stage comprising a deflection yoke supplied with a yoke current controlled by a switch and series-connected to a capacitor for varying the yoke voltage according to the phase of the yoke current; the device comprising a circuit for detecting and generating a real signal proportional to the yoke current, a ramp generator for generating an ideal ramp signal having rising portions defining a given S-shaped wave:form, and an error amplifier for receiving the real and ideal ramp signals and generating an error signal for driving a power transistor having its emitter and collector terminals connected parallel to the capacitor for modifying the voltage in the capacitor so that the yoke current assumes the required waveform.

Abstract: A television receiver is controlled as to the degree of vertical zoom via a deflection current ramp that varies in slope and which may be delayed to achieve panning. Due to the increased slope when zoomed, the deflection current and the electron beam complete a trace in less time than the normal vertical interval. The deflection current is maintained at one extreme or the other outside the trace interval, and the beam is blanked. A retrace signal generator coupled in a feedback loop with the power supply for the deflection circuit determines the midpoint of the blanking period and generates a fast retrace at or near the midpoint. The feedback loop is arranged to minimize the DC average current in the deflection winding by having a current source responsive to the DC average current for charging a timing ramp that triggers retrace upon reaching a threshold. The slope of the timing ramp varies with DC loading, thus advancing or retarding retrace to center retrace in the blanking interval.

Abstract: A deflection apparatus comprises a deflection amplifier coupled to a deflection waveform modulation circuit such as a diode modulator. An East-West modulation signal is generated by a digital to analog convertor in accordance with a reference potential coupled thereto. The modulation signal has a DC component for width control, and is coupled to an input of a comparator. The reference potential is also coupled to an input of the comparator to establish a reference bias therefor. The comparator has an output coupled to the deflection waveform modulation circuit to provide the East-West modulation.

Abstract: A focus yoke used for an electromagnetically focused CRT display comprises: a cylindrical permanent magnet unit which is disposed around a neck portion of a CRT and is spaced from the circumference of the neck portion; a core unit which defines a toroidal space together with the cylindrical magnet unit for substantially surrounding the neck portion, the core unit forming a magnetic path to guide magnetic lines of force generated by the cylindrical magnet unit; a dynamic focus winding unit disposed in the toroidal space; and a winding unit disposed externally of said toroidal space for eliminating an undesired magnetic field of an inverse polarity generated due to the cylindrical magnet unit.

Abstract: A first voltage-to-current converter responsive to a picture height adjustment control signal generates a first current in a capacitor for producing a trace portion of a sawtooth signal in the capacitor having a rate of change that is adjustable in accordance with an adjustment of the control signal. A second voltage-to-current converter responsive to the control signal generates a second current in a resistor for producing a third signal that is adjustable in accordance with the control signal. The sawtooth and third signals are coupled via a differential amplifier to a vertical deflection winding to produce a vertical deflection current in accordance with a difference between the sawtooth and third signals such that picture height adjustment does not affect vertical centering.

Abstract: In a vertical sawtooth generator of a vertical deflection circuit, a first comparator generates an output signal when a retrace portion of a sawtooth signal is at a first magnitude to initiate a vertical trace portion of the sawtooth signal. An amplifier responsive to the sawtooth signal generates a feedback current at a time that occurs more than one-half of the length of vertical trace portion after vertical trace is initiated. The feedback current is coupled to a capacitor to develop a capacitor voltage. The capacitor voltage is applied via a voltage-to-current converter to an integrating capacitor to develop in the integrating capacitor the trace portion of the sawtooth signal.

Abstract: A vertical deflection ramp voltage is generated by the charge and discharge of a resistor capacitor combination. The voltage ramp is coupled to an amplifier which drives a current through a deflection coil producing a magnetic deflection field. The ramp voltage produced by the resistor capacitor combination has an inherent exponential shape which is linearized to prevent vertical linearity errors in the deflected electron beam. Linearization is achieved by multiple feedback paths which couple the amplifier output voltage and a voltage sample of the deflection coil current to the ramp forming resistor. These feedback signals are of a polarity such to establish a constant voltage across the resistor which consequently produces a constant current flow through the resistor. Hence with constant current flow in the resistor, a linear voltage ramp is produced across the capacitor and exponential deflection cramping is avoided.

Abstract: A video output circuit for driving a CRT of a grid-cathode differential drive type is disclosed, in which a collector potential of an output transistor in a horizontal blanking interval is detected by a diode arrangement; the potential thus detected is smoothed by a smoothing filtering arrangement output current of the output transistor is controlled by an output obtained by the smoothing filtering arrangement; and negative feedback control is effected so that the collector potential of the output transistor is made constant. In this way, a bias adjusting power supply, which was required heretofore, is made unnecessary.

Abstract: A saw-tooth wave signal is supplied to the non-inverting input terminal of a first power amplifier constituting a first negative feedback amplifier. The output terminal of the first power amplifier is connected to one terminal of a deflection coil. A signal output from the other terminal of the deflection coil is supplied to the inverting input terminal of the first power amplifier. The other terminal of the deflection coil is connected, through a resistor, to the output terminal of a second power amplifier constituting a second negative feedback amplifier. The output terminal of the second power amplifier is connected to the inverting input terminal of the second power amplifier. The DC voltage appearing at the output terminal of the second power amplifier in the non-signal state is set to be equal to that of the first negative feedback amplifier.

Abstract: An arrangement that compensates for a tendency in a raster width of a display screen of a video display or television to increase when a variation in a beam current occurs, decreases an amplitude of a deflection current to decrease in a nonlinear manner as a function of an increase in the beam current. At a low beam current, a given increase in the beam current produces a decrease in the amplitude of the deflection current that is substantially greater than caused by the same increase at a high beam current.

Abstract: A vertical deflection circuit for a CRT display device comprises a first negative feedback circuit for detecting a vertical deflection current flowing through a vertical deflection coil feeding it back to a ramp wave generator to thereby stabilize a vertical size of the display image on the CRT screen, second negative feedback circuit connected between the deflection coil to an input of the output circuit for detecting a mean vertical deflection current which is fedback to an output circuit to thereby stabilize a vertical position of the display image on the CRT screen and a controlling circuit for controlling feedback amount of the first and second negative feedback circuits to thereby regulate a vertical size and a vertical position of the display image on the CRT screen variably.

Abstract: For a multi-scan display having a single S-capacitor incorporated, a S-distortion correcting circuit capable of correcting S distortion at any horizontal scanning frequency. The S-distortion correcting circuit comprises a first circuitry for cancelling out horizontal S-distortion making appearance in dependence on geometrical relation between scanning locus of an electron beam and the plane of screen of a picture tube, a second circuitry for cancelling out horizontal S-distortion generated in a horizontal scanning circuit in inverse proportion to the second power of the horizontal scanning frequency and an auxiliary deflection coil. The outputs of the first and second circuitries are added together. A current supplied to the auxiliary deflection coil is so controlled that a signal representing the result of the addition substantially coincides with a feedback signal from the auxiliary deflection coil.

Abstract: When a diode modulator is used in a television receiver for correcting pin-cushion distortion, circuitry is included in a diode modulator driver circuit, having an operational amplifier for summing various input voltages, for providing additional correction for distortions in the corners of the raster display. This additional circuitry removes any DC component in the output signal of the driver circuit, passes only that portion of the output signal exceeding a predetermined threshold level, and negatively feeds back this signal as an input to the operational amplifier.

Abstract: A base drive compensation circuit for a power amplifier samples a fixed saturation voltage level on the output of a power transistor and couples the sampled output to an inverting input of an error amplifier having a sawtooth signal on its non-inverting input. The output of the error amplifier is a negative going signal whose duty cycle is established by the voltage level on the inverting input. The negative going signal is coupled to a switching power supply that develops a voltage which controls the base drive current to the power transistor.

Abstract: A timebase circuit for use in the vertical timebase of a television receiver in which a linearity control current fed to the ramp capacitor is derived by multiplying a current proportional to the difference between the instantaneous and average ramp voltages by a reference current which may be adjusted to control linearity.

Abstract: A method and apparatus for the fast retrace of the electron beam in a cathode ray tube are disclosed. A deflection signal is presented to a cathode ray tube deflection system upon the detection of the end of the retrace period of the deflection signal so that a cathode ray tube electron beam can scan across the screen of the cathode ray tube. Upon detecting the beginning of the retrace period of the deflection signal, a forcing signal is presented to the cathode ray tube deflection system. The presenting of the forcing signal to the deflection system quickly reverses the direction of the current flow through the deflection system and allows for the electron beam to slew to its initial position and settle before the end of the normal retrace period.

Abstract: A vertical deflection circuit of the negative feedback type wherein a feedback signal, being generated at a terminal of a deflection current detector resistance connected in series with a vertical deflection yoke, is connected to negative feedback amplifier which guides the output of a sawtooth wave generating circuit through a third order distortion wave generating circuit. The third order distortion wave generating circuit imparts third order distortion of positive polarity to said feedback signals, so that third order distortion of negative polarity is imparted to the current of said deflection yoke, and whereby the third order distortion is compensated and extinguished on the CRT display.

Abstract: A field deflection circuit for use in a picture display device, comprising an amplifier to whose output the series network of a field deflection coil, a separated capacitor and a negative feedback resistor is disclosed. A circuit is provided in parallel with the separating capacitor for fixing the d.c. component of the voltage across the capacitor at a more less constant value. Frequency-dependent negative feedback networks may therefore be omitted.

Abstract: A top/bottom pincushion correction transformer injects a horizontal rate correction signal in series with a vertical yoke that is driven from a vertical amplifier that has a non-inverting and an inverting terminal. A feedback arrangement includes a voltage sensing resistor for supplying a voltage indicative of the current flow in the yoke to the non-inverting terminal of the amplifier. The primary winding of a pincushion transformer is connected in series with a current limiting resistor and their junction is connected by a bridging resistor to the voltage sensing resistor. The voltage developed across the voltage developing resistor is of opposite polarity to the voltage developed across the current limiting resistor for offsetting the same.

Abstract: A deflection amplifier for a CRT display device which generates a sweep ramp by means of a low distortion complimentary push-pull amplifier. The amplifier generates a compliance voltage which is fed back to an initial push-pull differential amplifier input stage and which is also used to generate a current through a deflection yoke coil. A sense resistor in series with the deflection yoke coil operates with a differential amplifier to direct a negative feedback signal to the input for the complimentary push-pull amplifier.

Abstract: A cathode ray beam deflection system operable in slew and random stroke and periodic raster display modes provides automatic power supply voltage switching to maintain linear operation and high efficiency. Control of automatic switching is obtained by continuously monitoring yoke voltage, yoke current, and deflection voltage, a power supply voltage being switched to a voltage of higher magnitude to provide a higher deflection rate when the yoke voltage exceeds a predetermined level at a predetermined current polarity and returned to a power supply voltage of lower magnitude when the higher deflection rate is no longer required.

Abstract: A vertical deflection amplifier of a video display apparatus includes first and second transistor amplifier output stages arranged in a totem-pole, push-pull configuration. A vertical deflection winding is coupled to the output stages at a deflection amplifier output terminal. An S-capacitor is coupled to the deflection winding at a second terminal remote from the output terminal. A source of deflection rate signals is coupled to the deflection amplifier for generating a deflection current in the deflection winding. A base current generating circuit is coupled to one of the transistor amplifier output stages for providing base current thereto. The S-capacitor voltage is applied to the base current generating circuit for enabling conduction of base current in the one amplifier output stage. When the video display apparatus is first turned on, the initially discharged S-capacitor is slowly charged from a DC voltage supply to delay generation of vertical deflection past completion of picture tube degaussing.

Abstract: Control circuit for use with an image pickup tube permits highlights of an image to be scanned appropriately by a scanning electron beam by increasing the beam current fed to the cathode of the image pickup tube and prevents unwanted oscillations typically found when such beam currents are increased. The control circuit first determines whether the output from the image pickup tube exceeds a predetermined level and produces a control signal to be added to the normal beam current and also uses this control signal to control a vertical deflection circuit to shift the scanning electron beam upwardly toward a region on the photoelectric transducer of the image pickup tube that has already been scanned, thereby providing negative feedback and preventing unacceptable oscillations in the output signal.

Abstract: In a video display apparatus having a service mode of operation, a vertical deflection circuit includes a vertical deflection winding coupled to a DC blocking capacitor. An output stage includes first and second output amplifiers coupled to the vertical deflection winding in a push-pull arrangement at an output terminal. A vertical sawtooth voltage generator is coupled to a driver stage via an error amplifier that provides both AC and DC negative feedback for driving the output stage at a vertical rate in a sawtooth manner to generate a sawtooth deflection current in the deflection winding and for establishing a DC operating voltage level at the output terminal that charges the DC blocking capacitor. A service mode switching circuit is coupled to the driver stage for asserting the service mode of operation by maintaining the first output amplifier in cutoff and the second output amplifier in conduction to discharge the DC blocking capacitor and disable the generation of the sawtooth deflection current.

Abstract: A picture pick-up or display device, respectively for recording a scene or displaying a scene image, respectively with the aid of a line raster formed by a plurality of horizontal lines which are consecutively scanned in opposite directions. The device comprises a line deflection circuit in which the line deflection coil forms part of a resonant circuit whose tuning frequency is substantially equal to half the line frequency, as a result of which the power dissipation is kept low. By means of a control circuit it is ensured that corresponding points of scanned lines are accurately in line in the vertical direction, the control circuit being arranged for causing a zero-crossing of the line deflection current and a signal which is characteristic of half the video information of a line substantially to coincide. The control circuit comprises an analogue delay element for setting the time position of this signal.

Abstract: A vertical compensation circuit for a digital TV receiver having a vertical drive signal that is insensitive to changes in CRT beam current includes a variable gain amplifier and means for sensing changes in B+ operating potential that track changes in CRT high voltage which is related to CRT beam current. The voltage sensing means detects a change in B+ operating potential and applies a voltage indicative of that change to a feedback circuit for changing the feedback level on a variable gain amplifier to which the vertical drive signal is applied.

Abstract: A first regulating amplifier (7) provides a linearly increasing current to the horizontal deflection coil during the forward trace sweep and the amplifier is disconnected from the deflection coil and its parallel capacitor (2) during the retrace period to provide flyback by free reaction of the oscillating circuit. In order to shorten the retrace period an auxiliary coil (17) is energized with a regulated current during the forward trace sweep with the help of a second regulating amplifier (8) gated on during a preliminary portion of the line interval and a controllable voltage source (14) set thereby. During a first portion of the retrace interval currents flowing respectively in the auxiliary coil and in the horizontal deflection coil are stored in the capacitor (2), which discharges during the remainder of the retrace period only through the deflection coil.

Abstract: A circuit for generating a sawtooth current (I) in a coil (25), the coil (25) being driven during the trace periods of the sawtooth from an amplifier circuit (4, 6, 7, 9, 15) by a current, and during the shortest possible retrace periods, the amplifier circuit being blocked, the coil (25) being included in a resonant circuit (25, 20, 21, 18, 7) which further comprises a capacitor (20), a first (21) and a second diode (18) and a transistor (7). In order to prevent disturbing ringing phenomena from occurring when a retrace period of the shortest possible duration is required, the junction of the capacitor (20), the first (21) and the second diode (18) and the transistor (7) is fed-back via a resistor (23) to a signal input of an amplifier (4) comprised in the amplifier circuit (4, 6, 7, 9, 15), this signal input further being coupled to a terminal (1) for the supply of a sawtooth voltage.

Abstract: A vertical frequency deflection signal generator includes a comparator whose output is coupled to a capacitor the voltage across which constitutes the vertical deflection voltage. The capacitor is charged from a voltage source in the vertical trace interval and discharged when the comparator output switches to ground potential, i.e. when the voltage at the inverting input of the comparator is greater than the voltage at the direct input. To synchronize such a vertical deflection signal generator to vertical synchronization pulses derived from an incoming television signal, the vertical synchronization signals are applied to the base of a transistor whose emitter-collector circuit is connected to the comparator output through a resistor. Each received vertical synchronization signal therefore causes a slight decrease in the output voltage of the comparator and, because of a feedback resistor, a corresponding decrease at the direct input of the comparator.

Abstract: A cathode ray tube display system for displaying data and/or pictorial images in an undistorted manner over the entire display screen. Programmable video polarity circuits add versatility to the system, enabling the cathode ray tube to be driven by any one of a variety of different drive circuits and effectively eliminating any skewing or delay experienced by the control signals as a result of the particular drive circuitry employed.Versatile deflection of the cathode ray tube electron beam at low power levels is achieved through the use of deflection circuitry employing a feedback circuit for achieving linearity and a totem pole circuit employing a coupling diode for achieving rapid, automatic flyback during the retrace portion of the deflection cycle.Automatic sizing of the display generated by the cathode ray tube (CRT) is obtained regardless of changes in the operating frequency of the horizontal and vertical sync signals employed to control the cathode ray tube.

Abstract: A circuit for increasing the stability of a sawtooth signal in regard to thermal drift comprises a conventional generator whose output is controlled by a loop circuit constituted by a switch controlled in opposition with respect to a switch connected in shunt on an integration capacitor, a low-pass filter having a cut-off frequency determined to select substantially the d.c. component and an operational amplifier network for determining the gain of the loop circuit which consequently produces a voltage corresponding to the mean value of the signal. The direct-current voltages and the passive components are so determined that the mean value of the sawtooth signal preferably corresponds to the reference zero potential.

Abstract: A circuit within a cathode-ray tube electromagnetic deflection system for correcting side pincushion distortion and regulating picture width independent of changes in the video line rate. The circuit employs a predistorted AC reference signal and a second DC reference signal in a closed-loop manner to cause a deflection current to describe precisely an ideal waveform defining simultaneously both pincushion correction and picture width regulation.

Abstract: An efficient cathode ray deflection amplifier is provided having a selectable scan rate capability, providing sweep rate linearity through the use of a feed back arrangement that also cooperates in a self-adaptive manner with respect to commanding changes in the raster scan rate or display size.

Abstract: An automatic Y-axis offset system for a cathode ray tube, which performs automatic positioning of a trace to a predetermined position on the cathode ray tube face such that the trace becomes visible, by applying a Y-axis offset voltage to the input signal voltage. The automatic positioning is performed when commanded by an operator through switch actuation. The offset voltage is produced by a feedback circuit which includes an amplifier receiving the input signal, a comparator for comparing an output voltage from the amplifier with a predetermined level, a counter which is enabled to count a clock signal so long as the level of output signal from the amplifier is different from the predetermined level, and a digital-to-analog converter which converts the count in the counter to an analog signal constituting the Y-axis offset voltage.

Abstract: A horizontal scan linearization circuit generates a linear ramp voltage during the active picture scan interval, which is compared to the non-linear ramp current of a cathode ray tube yoke circuit. The difference signal is fed back to the yoke circuit via a damper diode and is selectively added to the non-linear yoke current to correct the non-linearity.