Abstract: The present invention relates to a plasma display apparatus and driving method thereof, wherein rising and/or falling times of data pulses applied to address electrodes in an address period are controlled to reduce noise generation. Thus, address discharge is stabilized, discharge efficiency of plasma display panel is enhanced, and electrical damage to data drive ICs is prevented. The plasma display apparatus includes a plasma display panel including a plurality of address electrodes, a data driving unit including a plurality of data drive ICs that has a plurality of channels, wherein the data drive ICs are electrically connected to the address electrodes through the channels and drive the address electrodes, and a data pulse controller that controls the voltage-rising time and/or the voltage-falling time of the data pulses applied to the plurality of the address electrodes in an address period to be a sufficient duration, e.g. 100 ns or longer, by controlling the data driving unit.

Abstract: A method and an apparatus of re-adjusting convergence of a projection TV are disclosed. The apparatus includes a display device on which an image is projected and at least one light-sensing element (101) being provided around the display device. The light-sensing element (101) is composed of first and second sub-sensors (101a, 101b) that generate separate output signal projected alignment pattern moves over the sub-sensors (101a, 101b). The apparatus further includes a microprocessor calculating a convergence re-adjustment vector by obtaining a location of the light-sensing element (101), from which a previous convergence correction was made. The location of the light-sensing element (101) is obtained by analyzing the output signals. By using the apparatus and method of present invention, the misconvergence of the projection TV can be corrected very quickly and precisely.

Abstract: The present invention relates to a plasma display apparatus and driving method thereof, wherein application time points of data pulses applied to address electrode groups, where each group includes one or two address electrodes, are controlled. This results in a reduction of noise generation. The benefits of reducing noise include enhancing the driving efficiency of the plasma display panel and preventing electrical damage to driving circuits. The plasma display apparatus includes a plasma display panel including a plurality of address electrodes, a data driving unit that drives the plurality of the address electrodes, and a data pulse controller that controls the data driving unit to make application time points of the data pulses, which are applied to neighboring address electrode groups, to be different from each other.

Abstract: The present invention relates to a plasma display apparatus and driving method thereof, wherein rising and/or falling times of data pulses applied to address electrodes in an address period are controlled to reduce noise generation. Thus, address discharge is stabilized, discharge efficiency of plasma display panel is enhanced, and electrical damage to data drive ICs is prevented. The plasma display apparatus includes a plasma display panel including a plurality of address electrodes, a data driving unit including a plurality of data drive ICs that has a plurality of channels, wherein the data drive ICs are electrically connected to the address electrodes through the channels and drive the address electrodes, and a data pulse controller that controls the voltage-rising time and/or the voltage-falling time of the data pulses applied to the plurality of the address electrodes in an address period to be a sufficient duration, e.g. 100 ns or longer, by controlling the data driving unit.

Abstract: A method and an apparatus of re-adjusting convergence of a projection TV are disclosed. The apparatus includes a display device on which an image is projected and at least one light-sensing element (101) being provided around the display device. The light-sensing element (101) is composed of first and second sub-sensors (101a, 101b) that generate separate output signals as a projected alignment pattern moves over the sub-sensors (101a, 101b). The apparatus further includes a microprocessor calculating a convergence re-adjustment vector by obtaining a location of the light-sensing element (101), from which a previous convergence correction was made. The location of the light-sensing element (101) is obtained by analyzing the output signals. By using the apparatus and method of present invention, the misconvergence of the projection TV can be corrected very quickly and precisely.

Abstract: The present invention relates to a power supply having a plurality of converters which is capable of easily setting a load share of each converter and simplifying the construction of the circuit, thereby reducing the cost. A DC source circuit having such a power supply includes a plurality of converters (each having a transformer, switches for interrupting a DC input and supplying the same to a first side of the transformer and a rectifier circuit for rectifying a voltage outputted from a second side of the transformer), an output circuit which cascade-connects each output voltage of the plurality of converters and thereby obtains a composite output voltage Vout, and a common control circuit for feedback-controlling the plurality of switches as a function of the composite output voltage, e.g., according to the difference between the composite output voltage and the reference voltage. A load of each converter is shared according to each set output voltage.

Abstract: A beam index type color television receiver having a beam index type color cathode ray tube which includes a screen having a plurality of groups of color phosphor elements and index phosphor elements, an index signal sensing device for detecting index signals from the index phosphor elements and generating index pulses, a frequency multiplier for providing a timing signal with a frequency that is a multiple of the frequency of the index pulses, a gate signal generator supplied with the timing signal from the frequency multiplier and generating a plurality of gate signals, a gate circuit for sequentially selecting, response to the gate signals three primary color signals desired from an input video signal and supplying the selected primary color signals to the cathode ray tube, and a velocity modulating device for modulating the beam scanning velocity of the cathode ray tube.

Abstract: A side pincushion correcting circuit is provided in a color television receiver of the type including a cathode ray tube having an index stripe disposed on a screen scanned by a cathode beam and a detector for detecting the scanning of the index stripe by the cathode beam and producing a pulse signal as a result of such detecting.

Abstract: In a beam index color television receiver of the type having a cathode ray tube provided with beam-excitable color elements disposed on an image area of a display screen of the cathode ray tube and index elements disposed on the image area and a contiguous run-in area of the display screen, both of the color elements and index elements being scanned by the electron beam as the beam scans the display screen, apparatus for controlling the electron beam includes an index signal generator for generating a periodic index signal as the index elements are scanned by the beam, a phase-locked loop for producing an output signal having a frequency related to the index signal, color gates which sequentially gate respective color control signals individually to modulate the electron beam as the beam scans the color elements, a gating signal circuit which generates sequential gating signals at a frequency synchronized with the frequency of the output signal from the phase-locked loop and which supplies the gating signals

Abstract: A horizontal scanning rate correction apparatus for a cathode-ray tube, particularly of the beam index color cathode-ray tube type, includes a memory for storing correction values representing deviations of the horizontal scanning rate of the electron beam from a desired scanning rate at each of a plurality of horizontal sampling positions along each of a plurality of predetermined horizontal sampling lines which are substantially fewer in number than the horizontal lines along which scanning occurs. During display of a video signal, a selected one of the stored correction values is read out of the memory for each scanning position of the beam along a scanned one of the horizontal lines, with each read correction value, and a corresponding sampling line correction signal produced therefrom, representing the deviation at a corresponding horizontal sampling position on one of the sampling lines.

Abstract: Horizontal scanning rate correction apparatus is provided for beam index color cathode-ray tubes of the type having a screen, an electron gun for projecting an electron beam upon the screen, a plurality of index elements positioned to be struck by the electron beam as it scans across the screen, a deflection device for causing the electron beam to repeatedly scan across the screen in a vertical succession of horizontal lines, and an index signal processing circuit for producing an index signal having a frequency determined by the frequency of the incidence of the electron beam upon the index elements as it scans horizontal lines and for controlling color switching circuitry which determines which of a plurality of color signals modulates the intensity of the electron beam.

Abstract: In a beam index color television receiver of the type having a cathode ray tube which is provided with beam-excitable color elements and index elements disposed on a display screen of the cathode ray tube and which are scanned by an electron beam; color switching is controlled by an index signal generator, comprised of a photo-detector and band-pass filter, for generating a periodic index signal as the index elements are scanned by the beam, color gates which sequentially gate respective color control signals individually to modulate the electron beam as the beam scans the color elements, a gating signal circuit including a phase-locked loop which generates sequential gating signals at a frequency synchronized with the frequency of the periodic index signal and a gate pulse generator which supplies the gating signals in sequence to the color gates to control the latter so as to gate the respective color control signals, and a phase-controlling circuit for imparting a phase shift to the gating signals supplied

Abstract: In a beam index color television receiver of the type having a cathode ray tube which is provided with beam-excitable color elements disposed on a display screen of the cathode ray tube and index elements which are scanned by an electron beam as the beam scans the display screen, an apparatus for controlling the beam includes an index signal generator for generating a periodic index signal as the index elements are scanned by the beam, color gates which sequentially gate respective color control signals individually to modulate the electron beam as the beam scans the color elements, a gating signal circuit which generates sequential gating signals at a frequency synchronized with the frequency of the periodic index signal and which supplies the gating signals in sequence to the color gates to control the latter so as to gate the respective color control signals, and a phase-controlling circuit for controlling the phase of the gate pulse signals in response to the highest-level one of the color control signals

Abstract: An index signal amplifier arrangement is disclosed for use in a beam index color television receiver of a type which includes a picture reproducer having index stripes disposed to be scanned by an electron beam and a photodetector for detecting when respective index stripes are scanned by the beam to produce an index signal. A local oscillator generates a local oscillating signal which is mixed with the index signal produced by the photodetector. The mixed signal is amplified by a band-pass amplifier, the latter preferably being formed of a band-pass filter having a predetermined, limited pass-band characteristic substantially centered on the expected frequency of the mixed signal, and a limiter amplifier coupled to the band-pass filter for removing amplitude modulations from the filtered mixed signal.

Abstract: In a color television system having a video tape recorder and a color television receiver which includes an automatic control circuit for automatically controlling color level and hue with a reference signal contained in a predetermined horizontal scanning line section of a video signal, and which is so designed that a broadcasting signal and a reproduced signal of the video tape recorder are selectively received by the color television receiver, the automatic control circuit rendered inoperative in response to a change-over operation by which the color television system is changed over to apply the reproduced signal of the video tape recorder to the color television receiver.

Abstract: Hue and color saturation are controlled in response to a received VIR signal, the latter having a chrominance reference portion and a luminance reference portion. The level of a preselected one or more demodulated color signals which are produced by the color demodulator in color video signal receiving apparatus is detected during the time that the VIR signal is received. The level-detected demodulated color signal is used to produce a control signal for controlling the hue or color saturation. A storage circuit, such as a capacitor, is provided to store the control signal throughout the duration which separates successive VIR signals. A VIR detector is provided for detecting the presence of a VIR signal in the received video signal; and when the absence of a VIR signal from the received video signal is detected, the control signal storage circuit is preset to a predetermined value.

Abstract: In a color video display device, such as a television receiver or a monitor associated with a color video tape recording and reproducing apparatus, and which is responsive to a composite color video signal including a luminance component and a chrominance component containing a chrominance signal, a burst signal and a chrominance reference portion of a vertical interval reference (VIR) signal; a hue-correction circuit is provided for dynamic correction of chrominance phase errors.

Abstract: Color control apparatus for use in color video receiving apparatus of the type capable of receiving a color video signal which includes a VIR signal, the latter having at least a chrominance reference signal therein. A chrominance channel is provided for processing the chrominance component included in the color video signal. An extracting circuit connected to the chrominance channel separates burst and chrominance reference signals from the received color video signal. A predetermined parameter in the separated burst signal is detected, and a corresponding parameter in the chrominance reference signal is detected. A common amplifier is responsive to the detected parameters for producing an amplified control signal which, in turn, is supplied to an adjustable circuit so as to adjust a color characteristic of the processed chrominance component in accordance with the amplified control signal.

Abstract: A hue correction circuit for use in video display apparatus which is responsive to a composite color video signal including luminance, chrominance, burst and VIR signals. A controllable local oscillator circuit generates a reference oscillating signal of controllable phase for use in demodulating the chrominance signal. A first phase control circuit is responsive to the burst signal for deriving a first phase control signal as a function of the phase error between the burst signal and the reference oscillating signal, this first phase control signal being applied to the local oscillator circuit to vary the phase thereof for minimizing the phase error. A gain controlled amplifier is connected to receive the luminance signal and has a controllable gain for deriving a second phase control signal as a function of the luminance signal, this second phase control signal being applied to the local oscillator circuit to vary the phase thereof.

Abstract: A color correction circuit responsive to a VIR signal that includes a clamping circuit to clamp a color demodulated signal to a predetermined voltage level during the chrominance reference portion of the VIR signal. A sample-and-hold circuit samples the luminance reference portion of the VIR signal immediately succeeding the clamped portion and holds the sampled value, and a comparator compares the sampled signal with the predetermined clamping voltage to generate an error-correction voltage that can be applied to a gain-control amplifier in the chrominance channel to correct saturation and to a phase-control circuit to adjust the hue by shifting the phase of the locally generated subcarrier.