Abstract: In a waveform generator, a repetitive non-linear waveform is generated by varying the number supplied to a pulse reduction circuit during the repetition period. Consequently, the pulse reduction circuit supplies a number of desired output pulses, which number varies in time corresponding to the varying number. For example, when a lower number is inputted to the pulse reduction circuit during a sub-period of the repetition period, a corresponding lower number of output pulses will be generated. Consequently, a lower number of increment values will be summed or integrated during this sub-period and the waveform changes less steeply.

Abstract: A color display device comprises an electron gun, a display screen and a color selection electrode as well as a deflection means. The distance between the electron beams is dynamically varied, i.e. the distance between the electron beams in the deflection plane decreases as the beams are deflected in at least one direction. The decrease of the distance enables the distance between the color selection electrode and the display screen to be increased in that direction. As a result, the curvature of the color selection electrode is increased, which has a position effect on the strength, doming and microphonics of the color selection electrode. The distance is dynamically varied by first and second means, the first means being arranged in or near the pre-focusing parts of the electron gun. Said first means comprise magnetic means outside the neck of the CRT for generating dynamically varying magnetic fields, and magnetic field conducting means to conduct the fields to a position near the electron beams.

Abstract: Color television apparatus and color monitors are provided with a device, in particular with an electron lens system, to vary the mutual spacing of the electron beams generated in an electron beam generating system. By reducing the mutual spacing between the generated electron beams, in accordance with the deflection of the electron beams, the spacing of the shadow mask to the viewing screen can be increased at an increasing distance to the center of the screen, and thereby a less expensive shadow mask design can be used without having to take the former disadvantages of a flat screen into account.

Abstract: A horizontal deflection circuit of a video display includes a first retrace capacitance and a second retrace capacitance. A deflection winding is coupled to the first and second retrace capacitances to form a resonant circuit, during retrace. A first switching transistor is coupled to the first retrace capacitance for generating a resonant, first retrace pulse voltage in the resonant circuit. In a first embodiment of the invention, a second switching transistor is responsive to the first retrace pulse voltage and coupled to the second retrace capacitance for controlling the second switching transistor in accordance with the first retrace pulse voltage. A second retrace pulse voltage is generated in the second retrace capacitance in a manner to provide for capacitance transformation.

Abstract: A laser CRT includes a cathode, a modulator having an orifice for forming an electron beam from the electrons emitted by the cathode, and a beam directing unit directing the electron beam formed by the orifice of the modulator to the laser screen of the laser CRT. To reduce the diameter of the electron beam and to thereby improve the resolution of the laser CRT, the laser CRT includes at least one other modulator having an orifice for forming another electron beam from the electrons emitted by the cathode, the beam directing unit being adapted for directing the other electron beam formed by the at least one other modulator to the laser screen.

Abstract: A shadowmaskless tracking cathode ray tube control circuit is described, comprising a control loop, which is coupled to a deflection unit of a shadowmaskless tracking cathode ray tube. The shadowmaskless tracking cathode ray tube control circuit further comprises a loop gain control means for compensating the loop gain of the control loop in dependence on the inverse value of the beam current in the shadowmaskless tracking cathode ray tube. The effect is that a constant loop gain is created, which is independent of the beam current.

Abstract: A circuit for stabilizing a screen voltage of the video display apparatus is capable of supplying a uniform screen voltage to the video display apparatus even though a voltage level of an output voltage from a flyback transformer is changed. A horizontal output section generates a horizontal output voltage in response to a horizontal driving signal. A flyback transformer supplies a first power source to a primary winding according to the horizontal output voltage, induces a voltage in a secondary winding thereof based on a turns-ratio, and induces a voltage in a tertiary winding thereof according to the voltage induced in the secondary winding.

Abstract: A primary winding of a transformer is serially connected to a horizontal deflection coil. An amplitude regulating circuit outputs a first correction voltage in response to a voltage generated on a secondary winding of the transformer. A phase regulating circuit regulates the phase of the first correction voltage output from the amplitude regulating circuit and outputs a second correction voltage. An addition circuit adds the second correction voltage to a sawtooth wave voltage generated by a sawtooth wave voltage generation circuit. A correction current output from an amplifier in response to the second correction voltage output from the phase regulating circuit cancels a current component generated on a vertical deflection coil by a horizontal deflection current.

Abstract: A secondary winding of a horizontal flyback transformer of a horizontal deflection circuit develops a horizontal retrace pulse voltage. A secondary winding of a second transformer is coupled in series with a vertical deflection coil of a vertical deflection circuit. An R-C filter is coupled between the secondary winding of the flyback transformer and a primary winding of the second transformer. Horizontal parallelogram errors are corrected by a horizontal rate current injected in a current path of the vertical deflection coils. The R-C filter prevents the vertical deflection current from being parasiticaly coupled to the horizontal deflection circuit.

Abstract: A deflection-distortion correcting circuit for correcting deflection-distortion of an image on a screen by modulating a source voltage for horizontal deflection is disclosed. The deflection-distortion correcting circuit includes a first correcting data generating unit for generating a first correcting data for an image display period, a second correcting data generating unit for generating a second correcting data for a vertical blanking period, deflection-distortion correcting signal generating unit for generating a correcting signal for the image display period and the vertical blanking period in accordance with the first and second correcting data, and a horizontal-deflection circuit which modulates a source voltage for horizontal deflection with the correcting signal.

Abstract: A deflection apparatus capable of generating a stable deflection pulse in a deflection output circuit even when turning on the power source or changing over the frequency of horizontal synchronizing signal is disclosed. A pulse width modulation (PWM) controlled power supply circuit generates a supply voltage for obtaining a desired horizontal amplitude depending on the frequency of horizontal synchronizing signal. The PWM voltage controller discriminates the frequency of horizontal synchronizing signal, and controls the output voltage of the PWM controlled power supply circuit. An oscillation frequency switching controller discriminates the frequency of horizontal synchronizing signal, and outputs a frequency changeover signal to an oscillator so as to be an optimum oscillation frequency depending on the output voltage of the PWM controlled power supply circuit.

Abstract: A tracking index cathode ray tube circuit includes a tracking circuit connected to a shadowmaskless tracking cathode ray tube for deriving a tracking signal therefrom. The tracking circuit comprises a modulator demodulator circuit. The tracking signal from the CRT tube is thus modulated, AC coupled to a low voltage and demodulated to obtain a baseband tracking signal for use as a control signal for the electron beam spots on the screen of the CRT tube.

Abstract: In a waveform generator according to the first aspect of the invention, a repetitive non-linear waveform is generated by varying the number supplied to the pulse reduction circuit during the repetition period. Consequently, the pulse reduction circuit supplies a number of desired output pulses, which number varies in time corresponding to the varying number. For example, when a lower number is inputted to the pulse reduction circuit during a sub-period of the repetition period, a corresponding lower number of output pulses will be generated. Consequently, a lower number of increment values will be summed or integrated during this sub-period and the waveform changes less steeply.

Abstract: A signal is sent to a deflection circuit and a video signal processing circuit. On receiving the signal, the deflection circuit outputs a vertical deflection signal and a horizontal deflection signal. The vertical deflection signal is sent directly to a deflection yoke while the horizontal deflection signal is sent via an S-shaped wave modulation circuit to the deflection yoke. On the other hand, the video signal processing circuit receives the signal and outputs a video signal via an amplitude modulation circuit and a frequency modulation circuit to a cathode of an electron gun. The S-shaped wave modulation circuit performs modulation on the horizontal deflection signal to change scanning speed. The amplitude modulation circuit and the frequency modulation circuit perform, on the video signal, amplitude modulation and frequency modulation which are appropriate for this speed.

Abstract: In a horizontal deflection circuit, a waveform response of a horizontal output pulse must be adequately taken into account before and after a switching of the horizontal output pulse so that the waveform does not lack in shape and does not lose continuity at the switching. A switching apparatus for a horizontal driving apparatus includes (a) a horizontal driving pulse generator which generates a horizontal driving pulse from a horizontal synchronization signal, (b) an alternative signal generator which outputs an alternative signal different from the horizontal driving pulse, (c) a horizontal output control device which determines a timing to switch between the horizontal driving pulse and the alternative signal, and (d) a switching device which switches an output pulse with a control signal which is output from the horizontal output control device.

Abstract: An inline type color cathode-ray tube deflection yoke applies a deflecting magnetic field to electron beams from a neck portion of a valve accommodating three electron guns toward the funnel portion of the valve. The deflection yoke is provided with a vertical deflection coil, auxiliary coils serially connected to the vertical deflection coil, and a U-shaped magnetic member around each of both leg portions of which the auxiliary coils are wound. The U-shaped magnetic member is arranged so that the leg portions face the neck portion.

Abstract: A focusing circuit (1) for generating a focus control signal for a cathode ray tube (3) has a modulation input (4) for influencing the focus control signal, which focus control signal contains a measure for an envelope of excursions of horizontal scan lines across the cathode ray tube. The focusing circuit (1) comprises a load control circuit (5) for influencing the focus control signal, and having a control input (6) coupled to the modulation input (4) for influencing the focus control signal by load control variation in dependence on a desired focus control signal modulation. The load control circuit (5) may comprise a current source and/or a voltage source and/or controllable impedance that have a control input for coupling to a modulation output of a synchronization processor (7).

Abstract: A current variable inductor having closed loop characteristics and a horizontal linearity compensation circuit. The current variable inductor having the closed loop characteristics is constructed with the legs of the first E-shaped core and the legs of the second E-shaped core extend toward each other, an I-shaped core is arranged between the first E-shaped core and the second E-shaped core such that the I-shaped core is in contact with the first E-shaped core, and the I-shaped core is spaced apart from the second E-shaped core. A primary coil is wound around a center leg of the first E-shaped core and a secondary coil is wound around a center leg of the second E-shaped core. A magnetic flux generated from the primary coil is cut due to the magnetic resistance characteristics of the I-shaped core to vary the inductance of the secondary coil, to thereby form enclosed loops of magnetic flux inside the first and second E-shaped cores, respectively.

Abstract: Disclosed is a color CRT (Cathode Ray Tube) integrated with deflection circuit. The color CRT includes a sync signal separation and deflection circuit board attached on at least a portion of the color CRT. The sync signal separation and deflection circuit board includes a sync signal separation circuit for separating sync signal from video signal to regenerate video signal into the same contents, a horizontal deflection circuit for impressing horizontal deflection current onto a horizontal deflection coil and a vertical deflection circuit for impressing vertical deflection current onto a vertical deflection coil. The color CRT, which has the sync signal separation and deflection circuit attached on at least a portion of the color CRT, allows a one-to-one matching of the deflection circuit and a deflection yoke by removing the causes of DY fluctuation due to the change of set condition.

Abstract: As described above, according to the present invention, there is provided a color CRT display having a one-beam electron gun for reproducing colors by sequentially switching respective chrominance signals, R, G, and B, supplied to the one-beam electron gun. The color CRT display is characterized in that a color image displayed on a CRT screen is picked up by a CCD image pickup device and the image pickup signal is stored in an image pickup signal memory, the image pickup signal is compared with an original video signal stored in a video signal memory in terms of components of chromaticity using an arithmetic operator, and the frequency and phase of the image pickup signal of a VCO, which are required for determining the switching timing of chrominance signals in a multiplexer, are adjusted so that the difference between the image pickup signal and the original video signal in terms of components of chromaticity is minimized.

Abstract: To facilitate the adjustment of the S correction in apparatus comprising cathode-ray tubes (televisions, monitors), the process consists in displaying visual marks on the screen, at the location of the picture points which remain stationary as the amplitude of the S correction which is applied to the sawtooth current flowing through the deflection coils of the cathode-ray tube is varied.

Abstract: In a cathode-ray tube including a modulator, the modulator has different settings in the intermediate portion and in the peripheral portions of the picture so that the change of inductance along the horizontal axis on the phosphor screen or the change of inductance along the vertical axis on the phosphor screen compensates the difference of distortion between the intermediate portion and the peripheral portions of the picture.

Abstract: A deflection-distortion correcting circuit for correcting deflection-distortion of an image on a screen by modulating a source voltage for horizontal deflection is disclosed. The deflection-distortion correcting circuit includes a first correcting data generating unit for generating a first correcting data for an image display period, a second correcting data generating unit for generating a second correcting data for a vertical blanking period, deflection-distortion correcting signal generating unit for generating a correcting signal for the image display period and the vertical blanking period in accordance with the first and second correcting data, and a horizontal-deflection circuit which modulates a source voltage for horizontal deflection with the correcting signal.

Abstract: A series arrangement of an isolating diode and an East-West switching transistor is coupled between a flyback transformer primary winding and a horizontal deflection output transistor circuit to control retrace energy to obtain an East-West modulation of the deflection current amplitude. A first inductor, a tapped inductor and an S-shaping capacitor are coupled via a switch to form a resonant circuit, during the first half of trace. The tapped inductor includes a portion forming a current path for a deflection current. The tapped inductor develops a voltage that controls the switch. The first inductor, the tapped inductor and the S-shaping capacitor are coupled via the switch to form the trace resonant circuit, during the first half of trace. The trace resonant circuit provides inside pincushion raster distortion correction.

Abstract: In a television receiver comprising a horizontal deflection circuit (2) associated with a flyback transformer (9), the horizontal deflection circuit comprises a switch (6) which is controlled by a control signal (Hdrive) generated by a deflection control circuit (1). The deflection control circuit generates a phase difference signal (Vcomp) which is a function of the phase difference of a horizontal synchronisation pulse and a flyback pulse and generates the control signal (Hdrive) as a continuous function of the phase difference signal (Vcomp). The deflection circuit is further arranged to generate at least one discrete phase jump of the control signal (Hdrive) when the phase difference signal (Vcomp) lies outside of a range of preset values (Vlow, Vhigh).

Abstract: A horizontal position adjusting circuit for a raster includes a reference voltage outputting unit for outputting a reference voltage to enable a raster to be centered on a fluorescent screen; a reference voltage adjusting unit for varying an output voltage of the reference voltage outputting unit in accordance with an operating mode for displaying an image signal; and a deflection voltage outputting unit for generating a deflection voltage in accordance with the output signal of the reference voltage outputting unit, and for applying it to a horizontal deflection coil. In accordance with the present invention, the position of the raster formed on the fluorescent screen of the cathode-ray tube is automatically adjusted according to the operating mode so that positioning of the image screen on the fluorescent screen is simply adjusted to be at the center of the fluorescent screen, resulting in improved reliability of the display device.

Abstract: A display apparatus of multi-mode cathode ray tube is disclosed which is capable of enlarging a horizontal screen size by adjusting a size of the horizontal screen by employing a step-up type without occurrence of additional power consumption or a double trigger phenomenon.

Abstract: A system for automatically aligning video images on display devices such as cathode ray tube (CRT) monitors that use the processor and memory of a host computer to implement the alignment process. The system uses a host computer processor and previously generated correction factor data, representative of specific display distortion characteristics, to produce driver signals necessary to affect the alignment of video images on a CRT screen. The previously stored correction factor data may be retrieved from a characterization module within the display device or from any other convenient storage location. The correction factor data is processed by the host computer to produce correction control data which is transmitted, over a bi-directional serial connector, or a video connector, to the display device where the data is read by correction and driver circuitry.

Abstract: An electronic circuit for switching an inductive load (10) by means of a bipolar transistor (1) whereby a switching signal is supplied to the base (5) of a switching transistor (1) via an LRC circuit (6, 7, 9). During switching off the LRC circuit (6, 7, 9) causes a peak voltage at the base (5) of the switching transistor (1). The value of the peak voltage is a maximum when the power dissipation of the switching transistor (1) is a minimum. A regulator circuit (12-17) regulates a current source (18) in a primary winding of a switched transformer (22) in such a way that the peak voltage (Vp) is maximized.

Abstract: An electron beam tends to slope downwardly as it is deflected horizontally to form a raster in a video display apparatus. The sloping of the beam can cause geometric errors in the raster, for example orthogonality and parallelogram errors. A raster correction circuit substantially offsets the downward slope of the electron beam by modulating a vertical deflection current with an induced horizontal-rate raster correction current, thereby substantially eliminating orthogonality and parallelogram errors in the raster. A raster correction transformer utilizes a raster centering inductor for a primary winding, and a horizontal-rate centering current is magnetically coupled into the vertical deflection coils to modulate the vertical deflection current.

Abstract: A wide band horizontal size regulation circuit of a display, is selectively switched according to input frequency, to control the amount of current transmitted to a current sensing port of a PWM IC. This circuit includes a microcomputer for generating a signal for regulating the horizontal size of a picture, a PWM-IC for generating a PWM signal for controlling the amount of current which flows through a horizontal deflection coil according to the control signal of the microcomputer, a current sensor for feeding back a current corresponding to a picture state to the PWM-IC in order to maintain a specific horizontal size, and a current controller which is selectively switched according to the control signal of the microcomputer, to control the amount of current fed back to the current sensor of the PWM-IC.

Abstract: A power source to drive a deflecting output unit is fixed, thereby simplifying so that it is possible to cope with two or more different horizontal frequencies. A resonance capacitor 4a and an auxiliary resonance capacitor 4b are serially connected and a variable capacitive switching element 7 to short-circuit the capacitor 4b is connected. When a tracing period changes from Tt to Tt′ (Tt<Tt′) in correspondence to a change from a first horizontal frequency on the high side to a second horizontal frequency on the low side, by turning on the variable capacitive switching element 7, the capacitor 4b is short-circuited and a capacitance is increased from C1•C1′/(C1+C1′) to C1, thereby enabling (Tr′=Tr•Tt′/Tt) to be satisfied. Even when a fixed power source is used, a voltage of a retrace pulse does not change and a fluctuation of another voltage such as an anode voltage or the like which is formed from the retrace pulse can be prevented.

Abstract: A deflection circuit includes a deflection correction circuit (Vs) with a controllable active voltage source (Vs) arranged in a loop formed by a deflection coil (Ld), an S-capacitor (Cs), and a flyback capacitor (Cf). The voltage source (Vs) receives a further power supply voltage (Vb2) and a modulating signal (M) to supply a modulating voltage (Vm) varying in response to the modulating signal (M). The active voltage source (Vs) includes a switching element (S2) which is switched on and off with a frequency which is substantially higher than the deflection frequency to to enable waveforms of the modulating voltage (Vm) with a frequency content which is substantially higher than the deflection frequency such that any desired waveform can be generated within the deflection period (Td).

Abstract: In a horizontal deflection circuit output stage of a video display monitor capable of operating at multi-scan rates, a given S-capacitor, selected from a bank of S-capacitors, provide S-correction at a corresponding range of frequencies. A resistor-capacitor-diode clamp selected from a bank of clamps is coupled to the selected S-capacitor for reducing ringing by causing critical damping. The in-circuit selected resistor-capacitor-diode clamp is selectable, in accordance with the selected horizontal deflection frequency.

Abstract: A field emission display and display driving method, wherein the display includes a plurality of cathode lines arranged in a first direction in parallel; a plurality of gate lines arranged in a second direction in parallel, perpendicular to the first direction and isolated from the cathode lines; a field emission device at a cross point of one of the cathode lines and one of the gate lines, including an anode, an emitter connected to the one of the cathode lines, and a gate connected to the one of the gate lines; a scanning circuit configured to apply a scanning signal to one of the gate lines; and a modulating circuit configured to form a modulated signal synchronized with the scanning signal from an image signal having intensity information.

Abstract: A method for controlling the power consumption in a tilt correcting coil is disclosed. The power consumption is corrected in the tilt correcting coil for correcting the tilt of the images of the cathode ray tube. If a microcomputer judges that the mode is the on-state mode, then the microcomputer outputs a tilt correcting PWM signal in accordance with the user's inputting. Then the output tilt correcting PWM signal is converted into a dc voltage, and the level is adjusted. Then the signal is supplied to the tilt correcting coil, so that the tilt of the image on the screen would be corrected. In the cases of the standby mode, the suspend mode and/or the power-off mode, the microcomputer outputs a signal which has a function of minimizing the power consumption of the tilt correcting coil. Therefore, the tilt of the image of the screen is corrected in the normal manner.

Abstract: The present invention is a method and apparatus for selecting a capacitor value corresponding to a horizontal frequency in a video monitor. The technique determines the horizontal frequency and creates a limit on a default capacitor value which is obtained from the determined horizontal frequency. An updated value is compared with the limit to generate a comparison result. The capacitor value between the default capacitor value and the updated value is selected based on the comparison result.

Abstract: The present invention relates to a method for correction of the horizontal scanning current of a cathode-ray tube based on a modulation of this scanning current by a substantially parabolic signal at the image frame frequency, obtained by a squaring of a current ramp, including inflecting the ends of this current ramp before its squaring.

Abstract: A horizontal deflection circuit is provided in which a large retrace pulse voltage applied to a horizontal deflection yoke can be taken to reduce the deflection current and which is capable of easily performing horizontal image size adjustment and distortion adjustment. A parallel connection of a switching element, a damper diode, and a resonance capacitor is connected in series to a parallel connection of another switching element, another damper diode, and another resonance capacitor, and power is supplied from the connection point via a fly-back transformer. The comparison value of the retrace pulse voltages applied across both ends of the switching elements is fed back through a switching element control circuit to the switching element so that the deflection current of the horizontal deflection yoke is controlled.

Abstract: A compensating circuit is for compensating distortion of a picture which is displayed on a display unit having a yoke. The compensating circuit controls a yoke current to compensate a picture distortion. The compensating circuit comprises a first generating section for generating a digital deflecting compensation signal in accordance with deflecting compensation data representative of compensation value of the picture. A second generating section generating a variable voltage (+B voltage) in accordance with a PWM pulse signal to control the yoke current on the basis of the variable voltage. A peak holding circuit holds a peak voltage of a flyback pulse based on the variable voltage to produce a peak voltage signal representative of the peak voltage. An A/D converter circuit converts the peak voltage signal into a digital peak signal. A PWM section produces the above-mentioned PWN pulse signal in accordance with the digital deflecting compensation signal and the digital peak signal.

Abstract: A horizontal deflection circuit for a monitor is disclosed.

Abstract: An electron beam tends to slope downwardly as it is deflected horizontally to form a raster in a video display apparatus. The sloping of the beam can cause geometric errors in the raster, for example orthogonality and parallelogram errors. A raster correction circuit substantially offsets the downward slope of the electron beam by modulating a vertical deflection current with an induced horizontal-rate raster correction current, thereby substantially eliminating orthogonality and parallelogram errors in the raster. In respective embodiments of an inventive arrangement taught herein, the horizontal-rate raster correction current is induced in the vertical deflection coils by magnetically coupling a filament pulse waveform, a horizontal deflection voltage waveform, or a horizontal deflection current into the vertical deflection coils.

Abstract: A raster distortion correction and deflection circuit arrangement includes a deflection coil adapted to be mounted on a cathode ray tube, a horizontal deflection coil driving circuit for passing a current of saw-tooth waveform of a horizontal deflection period through a horizontal deflection coil constituting the deflection coil, a flyback transformer the primary winding of which is connected between a power supply and an output terminal of the horizontal deflection coil driving circuit, an S-correction capacitor connected in series with the horizontal deflection coil, and an anode voltage detection circuit for detecting variations in an anode voltage of the cathode ray tube which is a secondary winding output of the flyback transformer. A raster distortion correction current based on an output voltage of the anode voltage detection circuit is injected into a connection point of the horizontal deflection coil and the S-correction capacitor.

Abstract: A diode modulator circuit which is adapted to supply an acceptable S-correction of the S-linearity error of the line scanning of a picture tube (CRT) at substantially different line scan widths. A known diode modulator has two loops. The first loop includes a series arrangement of a line deflection coil (LD) and an S-capacitor (CS), which series arrangement is arranged in parallel with a first flyback capacitor (CF1) and a first diode (D1). The second loop includes a modulator coil (LB) arranged in parallel with a second flyback capacitor (CF2) and a second diode (D2). The two loops are arranged in series. An inner-pincushion capacitor (CSM) is arranged in a common path in which the line deflection current (Id) and a modulator current (Ib) flowing through the modulator coil (LB) flow in opposite directions. The amount of S-correction depends on the values of the S-correction capacitor (SC) and the inner-pincushion capacitor (CSM). The S-capacitor (CS) has been omitted in the subject diode modulator.

Abstract: A horizontal deflection circuit including a horizontal deflection output circuit and a horizontal sawtooth wave current generation circuit. The horizontal output deflection circuit has a horizontal deflection coil and an S-shape capacitor connected in series with the horizontal deflector coil for supplying a horizontal deflection current to the horizontal deflector coil and the S-shape capacitor in accordance with a horizontal drive pulse.

Abstract: A parabolic signal generator (100) for use in a cathode ray tube (CRT) display circuit, comprising: programmable delay means (110) for receiving a CRT horizontal flyback signal and for producing a trigger signal which is delayed relative to the horizontal flyback signal by a programmable predetermined time; ramp generating means (130, 140) coupled to receive the trigger signal from the programmable delay means for producing a symmetric ramp signal in response to the trigger signal; and parabola generating means (150) coupled to receive the ramp signal from the ramp generating means for producing the parabolic signal. Since the trigger signal delay is programmable, it can be adjusted to match the delay of a range of external components. Since the ramp signal is symmetric it does not require the use of complex blanking circuitry to suppress spuriae.

Abstract: A wide-band horizontal linearity correction circuit includes: a primary line coil connected between a horizontal deflection yoke and an S-correction capacitor, the primary coil being wound around a first a core having a hysteresis characteristic; a secondary line coil wound around a second core adjacent the first core; a pair of permanent magnets of opposite polarities, disposed on either end of the first core; a microprocessor for supplying an analog linearity correction control signal in response to the variation of the frequency of a horizontal drive pulse signal; and a coil driver for driving the secondary line coil in response to the correction control signal supplied by the microcomputer. Accordingly, horizontal linearity can be corrected over an entire frequency band.

Abstract: The focus coil 14 adjusts the focal point of electron beam which forms raster. The electromagnetic focus apparatus controls the ON/OFF-combinations of the respective switches 42 to 45 in synchronization with the horizontal synchronization signal S1. By this ON/OFF-controlling, the current waveform is formed, which is supplied into the focus coil 14. The microcomputer 55 adjusts the timing of the ON/OFF-controlling of the respective switches 42 to 45 in compliance with the horizontal amplitude value of the electron beam.

Abstract: An upper and lower distortion correcting circuit by modes in a display device which displays a video signal as a visible image, includes: a parabolic generator for receiving a vertical pulse to generate a parabolic wave in accordance with the received vertical pulse; a multivibrator for s receiving a horizontal pulse outputted from a microcomputer and for triggering the horizontal pulse in accordance with a horizontal balance signal outputted from a digital to analog converter to adjust and output a triggered horizontal pulse having a controlled duty cycle; a multiplier for multiplying the horizontal pulse outputted from the multivibrator and the parabolic wave outputted from the parabolic generator to thereby output a correction current; a buffer for stabilizing and outputting a gain of the correction current outputted from the multiplier; an amplifying portion for receiving and amplifying the gain of the correction current outputted from the buffer; and a modulation portion for receiving the correction curr

Abstract: A circuit for compensating for a vertical distortion of images by modes includes: a compensation position regulator for regulating a pulse width of a horizontal output signal by varying an integration value of an output pulse width of a horizontal output circuit, for adjusting an output position of the horizontal output signal; a compensation size regulator for selectively amplifying the horizontal output signal voltage whose output position has been regulated by the compensation position regulator, for adjusting the voltage amplitude of the horizontal output signal; and a modulation circuit including a primary circuit for receiving the horizontal output signal whose output position and size are regulated by the compensation position regulator and the compensation size regulator, and a secondary circuit for receiving a vertical output signal having a period variable by modes through one terminal thereof, the modulation circuit modulating the vertical output signal selected by modes with the horizontal output