Abstract: The disclosure relates to a scantling unit (20) comprising an interlocking assembly (45). The interlocking assembly (45) comprises; an interlock arm (40) pivotably connected to a scanner base of the scanning unit (20) and movable between a locked position and an unlocked position; and a biasing mechanism, for biasing the interlock arm toward the locked position, A combo gear (31) of the scanning unit (20) is locked by the interlocking assembly (45), thereby being prevented from, rotating, before a scan bar driver gear (26) of the scanning unit (20) engages with the combo gear (31) of the scanning unit (20).

Abstract: An LED assembly adapted to mount in a bayonet type socket of the type having a slotted casing comprising the negative terminal and a central pin comprising the positive terminal in which a plurality of LED's are mounted on a circuit board and the LED assembly has an electrically conductive screw comprising the positive connection for engaging the central pin of the socket and an electrically conductive tube with a pin member extending outwardly therefrom for insertion in the slots of the casing of the socket for comprising the negative connection.

Abstract: Disclosed are a method and an apparatus for preventing appearance of a zigzag flush of light in a cathode-ray tube at the time of turning it off. A train of power-off control pulses are produced in synchronization with the vertical sweeping signal; a spot-killer control signal starts in synchronization with a selected power-off pulse to make the whole screen of the cathode-ray tube bright; and the power supply turns off in synchronization with another selected power-off control pulse, so that the power-off is caused at the termination of the vertical sweeping. Thus, the remaining static electricity is discharged at the lowermost of the screen of the cathode-ray tube. To assure that the residual static electricity is discharged completely, the length of time “t1” (continuing for a selected integer as long as the pulse-to-pulse duration) is determined to meet the size of the cathode-ray tube.

Abstract: A cut-off adjusting apparatus in which a signal source for detecting cathode current is not required, the cost can be reduced, the cathode current can be detected with high precision, and the correction corresponding to time-variation can be performed with high precision. Includes a controller in which when an enforced adjusting mode is set, during a vertical period a control signal is output to a video amplifier to output such a signal that no video signal is contained in the output and the pedestal level is the black level irrespective of the input video signal, and wherein an averaged cathode current at this time is detected.

Abstract: The invention relates to a display device comprising a cathode ray tube including an electron source and an electron beam guidance cavity having an entrance aperture and an exit aperture for concentrating electrons emitted from the cathode in an electron beam. Furthermore, the cathode ray tube comprises a first electrode which is connectable to a first power supply for applying, in operation, an electric field with a first field strength E1 between the cathode and the exit aperture. &dgr;1 and E1 have values, which allow electron transport through the electron beam guidance cavity. Furthermore, a modulating means positioned between the cathode and the exit aperture is present for modulating a beam current to the display screen. According to the invention, the display device is provided with switching means for preventing the electron beam from passing through the exit aperture in a blanking period and for passing the electron beam through the exit aperture in a display period.

Abstract: A Braun tube discharge apparatus that includes a so-called spot killer function. In the apparatus, an operational amplifier included in a vertical IC receives a vertical ramp signal from a one-chip IC at the non-inversion input terminal. The operational amplifier also receives a part of the output as a negative feedback to the inversion input terminal, and performs differential amplification of it and transmits the results to a vertical deflection coil. At the time a spot killer circuit discharges a remaining electrical charge held by a Braun tube when the power is turned off, a switching transistor is rendered conductive by using a spot killer pulse signal that instructs the activation of the spot killer circuit. When the negative feedback input side of the operational amplifier drops to the ground level, the center DC value of the vertical output signal is increased, and the amplitude is increased.

Abstract: Supplementary grid blanking and spot burn protection are provided in a receiver/monitor (10) by a grid bias control circuit (50) including a blanking signal generator (60) that produces a blanking output signal (S1) devoid of any picture representative component whenever a vertical blanking signal (VB) or a horizontal blanking signal (HB) is present. A capacitor (C1) strips DC from the blanking signal and the resultant signal (S2) is applied to a modulation input (84) of a grid bias generator to produce an output grid bias reference voltage (Vr) modulated by the AC component of the blanking signal. The reference voltage (Vr) is coupled via a spot burn protection circuit (100) and a grid coupling circuit (120) to the control grids of three projection kinescopes (16, 18, 20).

Abstract: An apparatus for automatically stabilizing the black level of a displayed picture when (1) an automatic black level stabilizing function is OFF, (2) black level error occurs between at an ON state and at an OFF state and (3) black level variation and picture disturbance occurs during activation and deactivation of the automatic black level stabilizer. Black level variations when the automatic black level stabilizer are OFF is controlled by processing a cathode current in a negative feedback loop and controlling a CRT grid voltage, storing a divided grid voltage during a converging period and processing the grid voltage in another negative feedback loop in order to adjust the grid voltage to an ON state value.

Abstract: A spot is prevented from occurring on the center portion of a cathode ray tube when electric power is turned off by using a voltage charged in a capacitor which are used for outputting a vertical blanking signal in a vertical blanking signal generating circuit of an image display device for displaying an image in use of the cathode ray tube. The present invention is provided with a discharge cut-off element between a negative electric power source and the capacitor for outputting a vertical blanking signal and a discharging element for discharging a charged voltage of the capacitor to the ground. The present invention prevents a charged voltage ofthe capacitor from being discharged until thermoelectrons are not emitted from the cathode so as to supply a negative charged voltage to the first grid of the cathode ray tube continuously, so that a spot is prevented from occurring.

Abstract: A method is provided for reducing a residual spot on a cathode ray tube when a power supply is turned off. The method is executed by applying a holding voltage being no less than the value of the voltage enabling to enhance the back raster luminance and a cut-off voltage, or a voltage of a lower value, to a second grid electrode while the anode voltage is lowered to a predetermined voltage value when the main power supply is turned off.

Abstract: The most popular method for reducing stray emission effects in a cathode ray tube is to install a bleeder resistor at the flyback transformer of the tube. Such a bleeder resistor is, however, quite expensive. Therefore, the stray emission reduction circuit according to the invention differentiates the H pulse when the TV set is switched from "on" to "standby" which results in a higher duty cycle of the control transistor, implying a lower duty cycle of the horizontal output transistor HOT. This results in a lower voltage at the tuning capacitor and hence lowers the flyback peak voltage at the anode. This results in a drop of the EHT voltage.

Abstract: A device having a display device employing a cathode-ray tube and an electron beam includes an on-screen display memory for storing data used to display white on an entire screen of the cathode-ray tube, a circuit for supplying signals used to display white on the entire screen of the said display device employing the electron beam based on the data stored in the on-screen display memory, and a controller for outputting a signal indicative of a command for displaying white on the entire screen from the on-screen display memory in accordance with a de-energizing operation. The signals used to display white on an entire screen of the cathode-ray tube are output to the display device employing the electron beam after the device having the display device is de-energized. Displayed contents are erased by removing a residual high voltage in the display device employing the electron beam.

Abstract: A device and method for protecting a CRT screen. The device includes first and second amplifying circuits for amplifying a video signal input thereto and outputting an amplified signal; a buffer circuit for buffering the amplified signal and generating an output signal for a screen; a Vcc voltage sensing circuit for detecting a drop in a Vcc voltage during a power cut-off stage; and a transistor being turned on based on the detection and being connected at the input stage of the buffer circuit for eliminating AC and DC components of the amplified signal outputted from the second amplifying circuit so as to eliminate formation of a spot on the screen during the power cut-off stage.

Abstract: Method of discharging a picture display tube (3) in a picture display device, and picture display device provided with a picture display tube discharge circuit, in which the picture display tube (3) is discharged by switching off a generation (20; 23) of an anode voltage (Va) of the picture display tube (3) and by controlling (4) a defined electron current in the picture display tube (3). Prior to generating (4) the defined electron current, the deflection (2) of the electron beam is displaced to beyond a visible part of a display screen (32) of the picture display tube (3). In this way, the picture display tube (3) is discharged without this being accompanied with bright light phenomena visible on the display screen (32). The anode voltage (Va) decreases to a safe value and there is no cold emission and no phosphor burn-in on the display screen (32).

Abstract: A stray emission prevention circuit for a system having a cathode ray tube including a charging and discharging section for applying a system power supply voltage upon power-on of the system to charge with a constant voltage and for discharging the charged voltage upon power-off of the system, and a switching section for forming an open circuit between a high voltage unit of the cathode ray tube and a ground upon the power-on of the system and forming a closed circuit therebetween upon the power-off of the system to discharge the residual high voltage in the cathode ray tube, the circuit being provided on a circuit board of the system.

Abstract: A horizontal oscillator, responsive to an on/off control signal, generates an output signal that is coupled via a driver stage to a control terminal of a horizontal deflection output transistor. During a transition interval that follows a standby mode of operation, the duty cycle of the oscillator output signal is reduced relative to when a run mode of operation occurs to provide soft-start operation.

Abstract: A limiter device essentially includes a comparator connected to a capacitor charged by a current proportional to the beam current and short-circuited by pulses during one line just after the frame return pulses. This comparator receives a threshold voltage and its output is connected to a capacitor connected to another reference voltage, and this comparator is validated by the frame return pulses.

Abstract: A deflection generator of a television receiver includes a trace switch that during normal mode of operation is switched at a deflection rate to generate scanning current in a deflection winding. The deflection generator includes a retrace capacitance for forming a retrace resonant circuit with the deflection winding to produce a retrace pulse voltage. A load circuit is coupled to the deflection generator and is energized by the retrace pulse voltage during normal operation. A remote control circuit develops a remote ON-OFF command signal. A standby circuit is series coupled with the deflection generator and is responsive to a remote ON-OFF command signal for producing a substantially short circuited trace switch upon receipt of the OFF-state of the command signal. The retrace pulse voltage collapses and places the load circuit in a standby mode of operation.

Abstract: To prevent display screen burn-in of a picture having, for example, bright lines or other picture components remaining stationary for a long period of time, a video circuit is examined to detect how long the information has not been changed. If a predetermined time limit is exceeded, the picture brightness is limited to a sufficiently low average value or, if so desired, to zero brightness, by means of one or more protection switches.

Abstract: In a raster display device, such as a cathode-ray tube, in which the display is computed on-the-fly, such as in the raster vector generator type, when the computation of a line, or group of lines, exceeds a given period, the raster scan is halted until the computation is complete. The line at which the scan is halted is retraced at reduced brightness, and without modulation by video information overflow, is detected by coincidence of a computation signal and line sync.

Abstract: A system for compensating for mislanding of electron beams on the screen of a color cathode ray tube resulting from thermal expansion of a beam selecting structure in the tube which comprises electromagnetic devices provided on the tube for producing respective magnetic fields by means of a current supplied thereto so as to change the paths of the electron beams passing through the beam selecting structure, and a circuit for supplying to the electro-magnetic devices a first correcting current varying substantially in response to changes in the temperature of the beam selecting structure and a second correcting current varying in accordance with a predetermined change in value during the initial period of the operating condition of the tube.

Abstract: A cathode ray tube device includes a cathode ray tube of which cathode is heated in a waiting state as well as a normal operating state to emit an electron beam. The emitted electron beam in the waiting state is prevented from impinging the fluorescent surface of the tube by supplying a predetermined voltage or current independent of a signal for the normal operation to the grid of an electron gun assembly or a deflecting device.