摘要:
Apparatus and method are provided for using a multi-element field emission cathode in a color cathode ray tube. The field emission cathode may have from four to ten field emission arrays linearly arranged. The arrays are preferably formed from carbon-based material. An electron gun assembly focuses electron beams from each array on to a phosphor stripe or dot on the screen of the cathode ray tube. Deflection apparatus moves the beam from each field emission array according to clock signals. Clock signals also turn on or turn off voltage to contacts controlling electron current from the array. Values of voltage applied, determined by a video signal, determine the intensity of electron current from each array, which controls the intensity of the light emitted by each color stripe or dot of phosphor on the phosphor screen.
摘要:
A color picture tube includes a screen and an improved inline gun for generating and directing three inline electron beams along separate paths toward the screen. The gun includes a plurality of cathodes and at least six electrodes longitudinally spaced from the cathodes. The improvement comprises the first, second and fourth electrodes from the cathodes being of materials having lower coefficients of thermal expansion than the coefficients of thermal expansion of the materials of the other electrodes.
摘要:
Electronic high-speed frame pick-up cameras for instantaneously or successively picking up an image of an object being observed while the structure and birghtness thereof are being changed at high speed. Each camera of this type consists of a first electron lens to reforming the photoelectronic image formed on the photoelectric layer, deflection means arranged so that the re-formed image of the photoelectronic image is located at the deflection center thereof, a singularity or plurality of second electron lenses arranged so that the electron beam deflected by the deflection means can be received thereby, a singularity or plurality of phosphor layers arranged to receive the electron beam sent from the second electron lens(es), a lens drive circuit to supply power to the first and second electron lenses, and a deflection means drive circuit to supply power to the deflection means. The exposure time and/or time interval between exposures in each camera of the present invention are of the order of 10 ns or less so as to pick up a frame or a plurality of frames for the image of the object being observed.
摘要:
A color television receiver is disclosed, which includes a circuit for detecting a color saturation level of a color from red, green and blue primary color signals or from color difference signals and a color temperature control circuit for increasing at least a blue color component on a screen of a color cathode ray tube in accordance with an increase of the color saturation level, the color temperature control circuit being controlled by the output of the color saturation level detecting circuit.
摘要:
An enchanced luminance field sequential color image display system having an image source for providing a sequence of monochrome images. The monochromatic light images are formed of first, second and third different spectral colors. A liquid crystal switching system having crossed color selective polarizers is used to transmit the second and third colors with a first direction of polarization and to transmit the first and third colors with an orthogonal direction of polarization. A liquid crystal retarder is used to rotate the direction of polarization of light incident from the crossed polarizers by ninety degrees when the retarder is in its OFF state and to transmit the light substantially unchanged when the retarder is in its ON state. The light is then coupled to an analyzing system which in one embodiment is a neutral polarizer that transmits either the second and third colors or the first and third colors, depending on the state of the liquid crystal retarder. In a second embodiment, the analyzing system is one or more color selective (pleochroic) polarizers that transmits both polarizations of the third color, while transmitting only one polarization of the first color or one polarization of the second color depending on the state of the retarder. By transmitting two of the three spectral colors in each of both directions of polarization through the retarder, a significant increase in display luminance is obtained.
摘要:
A brightness control circuit in a video signal processing system includes an amplifier and an adjustable brightness control coupled to the amplifier input, which also receives keying pulses via a resistor-capacitor input circuit. Output pulses from the amplifier exhibit a brightness determinative amplitude related to the setting of the brightness control. To maintain a substantially constant waveshape for the output pulses as the brightness control is adjusted, a shaping capacitor is coupled between the input and output of the amplifier.
摘要:
A color television receiver with luminance and chrominance signal channels includes an automatic kinescope beam current limiter, an automatic white level drive control network, and an automatic black level bias control network. A switching network is timed to operate such that a control signal developed by the beam current limiter is coupled to the luminance and chrominance channels during normal picture intervals, decoupled from at least the luminance channel during white level drive control intervals, and coupled to at least the chrominance channel during black level bias control intervals.
摘要:
An apparatus for color and brightness correction for a multi-gun color CRT display, providing compensation for variation in phosphor efficiency with cathode energization and for color tracking between guns. The brightness correction circuit is required to respond only to essentially DC changes, while a color selection circuit responds at a video rate. In a preferred digital embodiment, brightness and color tracking correction factors are stored in memory dedicated to a particular CRT, and addressed in response to input from a reference brightness level selected by an operator. A color selection decoder having stored in a second memory relative brightness characteristics of each color phosphor as a function of the hue commanded converts an input binary command to an analog output, which is combined with the brightness and color tracking correction factor to determine the resulting cathode energization for each color gun. In an analog embodiment, brightness and tracking corrections are performed by a logarithmic amplifier which applies an appropriate multiplier factor to the reference brightness level. Color selection is provided by a variable gain amplifier having gain control bias varied by a digital color decoder in proportion to the desired relative brightness levels. A hybrid system is also described combining digital memory storage for brightness and tracking correction and an analog variable gain amplifier for relative brightness compensation, using the circuits described above.
摘要:
An automatic kinescope bias (AKB) control system for a television receiver operates in response to an enabling timing signal for maintaining a desired level of kinescope blanking current. The timing signal is applied to a control input of the AKB system via a timing signal coupling path. The timing signal input to the AKB system is inhibited for a given time interval after the receiver is initially energized, to delay AKB action until the kinescope has reached a desired operating temperature. The timing signal is inhibited by means of a control network coupled to the timing signal path. The given time interval is determined by a time constant circuit which is associated with the control network and which is substantially insensitive to the amplitude, and duty cycle of the timing signal.
摘要:
Apparatus is disclosed in a video signal processing system for automatically monitoring and controlling the blanking (black) current level of an image reproducing kinescope. A kinescope cathode output signal proportional to the level of cathode black level current conduction is induced during periodic monitoring intervals during which image signals are absent. The cathode signal is induced in response to a grid drive pulse applied during the monitoring intervals. The induced cathode signal is processed by a digital signal processing network to produce incremental bias control voltage steps for modifying the cathode bias, if necessary, in a direction to produce a desired cathode black current level. In addition, there is disclosed a special form of grid drive pulse which serves to prevent system "hunting" in the vicinity of the correct cathode bias.