Abstract:
A circuit within a video monitor for making corrections during horizontal scan includes a data storage device containing information relating to a selected display parameter, an integrator receptive of the stored information and adapted to produce an integrated signal therefrom, and an amplifier receptive of the integrated signal for supplying signals to the video monitor based on the integrated signal. The information supplied from the data storage device to the integrator is encoded in a pulse density modulated wave form via a tri-state gate and a one-shot timer. The information stored in the data storage device is stored in bytes, each byte containing a "sign bit" and a plurality of data bits.
Abstract:
An automatic precision video monitor alignment and calibration system is described which functions to precisely align all of the adjustable display characteristics of a video monitor to a high degree of precision. This alignment system can function in an automated calibration mode wherein it is independent of human input and automatically performs a series of alignment/calibration operations to precisely adjust all of the display characteristics of the video monitor in a fraction of the time required by a person to manually align the video monitor. The alignment system includes a digital control circuit located within the video monitor to precisely set and maintain each of the monitor display characteristics. The values maintained by this control circuit can be input by a person, or set automatically by a computer controlled display alignment system. The system of the present invention uses a single camera and a color analyzer to make all the measurements necessary to automatically align and calibrate a video monitor. The measurements are then used to make the adjustments, via the digital control circuit, necessary for alignment and/or calibration. A calibration computer coupled with a video coprocessor subsystem accomplish all adjustments to the monitor automatically, without the need for human intervention.
Abstract:
A method and apparatus used to step and correct the position of raster lines in a sinusoidal or zig-zag deflection system. By combining the magnetic flux generated with a rotation “twister” coil and a vertical deflection coil, scan lines can be uniformly spaced and separated nearly to their ends. Accordingly, the magnetic flux generated with the twister coil is adjusted going in the left to right direction then reversed in polarity and readjusted while returning from right to left. It is this controlled twister flux that combines with the linear vertical deflection flux to straighten and then step each scan line to produce an aligned raster.
Abstract:
An apparatus and method are disclosed for generating timing pulses to control various functions in a video monitor including the switching of video amplifiers in cathode ray tube (CRT) devices, the control of the phase and frequency of phase locked loops, etc. Unlike previous methods, where switching is timed and controlled by monitoring the retrace voltage level, the system of the present invention monitors the change in direction of current in the retrace tuning capacitor. Monitoring the retrace capacitor current, provides an extremely accurate method for timing in horizontal deflection circuits. The apparatus of the present the invention comprises a small bead inductor placed in the current path of a horizontal retrace capacitor within the horizontal deflection circuit of the cathode ray tube device. Measuring the voltage across the bead inductor allows a very precise monitoring of the current through the retrace tuning capacitor. By designing the size of the bead inductor as disclosed, precise electrical pulses can be generated and detected during the retrace time of the CRT electron beam. These precise pulses are then used to generate accurate control signals for use within the CRT device. The invention also discloses an apparatus and method that minimizes left side ringing distortion in cathode ray tube video displays. Left side ringing is reduced due to the addition of the bead inductor to the horizontal deflection circuit, which lowers the stray resonant frequency within the horizontal deflection circuit.
Abstract:
A circuit within a video monitor for making corrections during horizontal scan includes a data storage device containing information relating to a selected display parameter, an integrator receptive of the stored information and adapted to produce an integrated signal therefrom, and an amplifier receptive of the integrated signal for supplying signals to the video monitor based on the integrated signal. The information supplied from the data storage device to the integrator is encoded in a pulse density modulated wave form via a tri-state gate and a one-shot timer. The information stored in the data storage device is stored in bytes, each byte containing a "sign bit" and a plurality of data bits.
Abstract:
A new fiber optic connector housing and a new fiber optic receptacle, both of which conform to a new standard proposed by the X3T9.3 committee of the American National Standards Institute, are disclosed. In addition, four accessory devices for electro-optic modules, each of which includes one or more essentially conventional plug frames which fit into either one or more conventional, individual fiber optic connector housings or the new fiber optic connector housing, are disclosed.
Abstract:
A method and apparatus used to step and correct the position of raster lines in a sinusoidal or zig-zag deflection system. By combining the magnetic flux generated with a rotation “twister” coil and a vertical deflection coil, scan lines can be uniformly spaced and separated nearly to their ends. Accordingly, the magnetic flux generated with the twister coil is adjusted going in the left to right direction then reversed in polarity and readjusted while returning from right to left. It is this controlled twister flux that combines with the linear vertical deflection flux to straighten and then step each scan line to produce an aligned raster.
Abstract:
A system for generating correction factor data that is representative of the distortion characteristics of a cathode ray tube. The correction factor data is stored with a cathode ray tube to allow later alignment of a video signal, or can be provided on a storage medium or on a network. Distortion data, and resultant correction factor data is generated for a series of discrete physical locations on the cathode ray tube screen. In this manner, the entire screen surface can be utilized to align a video image. Maximum correctable distortion data is also generated in accordance with the present invention to provide exit criteria for cathode ray tube manufacturers. The exit criteria is based upon maximum correction factor data that can be generated to correct distortions. A characterization module is provided that can be coupled to cathode ray tube coils that stores the correction factor data or an identification number for the cathode ray tube that can be used to retrieve the correction factor data from any desired source such as CD ROMS, a LAN, a database coupled to a WAN, or the Internet, etc. Interpolation techniques can be used to generate correction factor data for any desired number of interpolation points based upon correction factor data provided for a lesser number of characterization locations.
Abstract:
A system for synchronous alignment of cathode ray tube (CRT) rasters by application of time variable rotation driver signals to the CRT rotation coil during trace of the raster. The system may be implemented by either digital or analog means of measuring and storing cathode ray tube raster distortion data as rotational correction factor data. The rotational correction factor data is used by device circuitry to generate and apply the required time variable rotation driver signals, to the CRT rotation coil, to effect the desired CRT raster alignment.
Abstract:
A voltage regulator for flyback-type high voltage supplies having a supplementary energy storage transformer with its secondary interconnected in series with the primary of the conventional flyback transformer, a control circuit for sensing (a) the generation of the conventional flyback pulse, (b) a reference voltage, and (c) a feedback voltage signal appearing at the output of the conventional flyback transformer and a switch for selectively applying energy to the primary of the supplemental energy storage transformer. The aforesaid switch being activated whenever the feedback voltage is less than the reference voltage and said switch being activated earlier in time as the aforesaid difference becomes greater. Just after the occurrence of the flyback pulse, the switch is opened to permit energy in the energy storage transformer to be placed on the primary of the flyback transformer so that it is added with the flyback pulse to maintain the resultant voltage at the output of the secondary conventional flyback transformer at a regulated value.