摘要:
An arc-scanned sector cathode ray tube display system achieves constant writing speed by developing trigonometric X and Y deflection signals with amplitude linearly decreasing and scan rate linearly increasing as arcs are drawn from periphery toward apex of the display sector. Video/deflection synchronism is achieved by development of a video clock pulse train comprised of selected pulses from a clock source by means of which displayed video bits are shifted from rho-theta formated storage on a time/position basis such that video and beam position are synchronized to within one displayed picture element throughout the sector display.
摘要:
A system and technique is disclosed which enables a reduction in memory for the display of superimposed data (alpha-numerics, symbols and graphics) in an all-raster scanned display. A video signal containing information to be displayed on a video monitor by raster scanning techniques is multiplexed with the output of a storage device containing information representing data for controlling the intensity of specific points on the monitor during the raster scan. The intensity is controlled by the signals from memory to produce data on the video monitor as an overlay to the normal video display produced by the video signal. In one embodiment, the storage device is formed by two separate memory areas having a size substantially less than the total number of lines forming one raster field of the video display. The first memory area is multiplexed with the video signal while the second memory area is being filled and the second memory area is multiplexed with the video signal while the first memory area is being filled. This process is repeated a predetermined number of times for each field scan of the video display.
摘要:
A multi-color display system employing a raster-scanned cathode ray tube having a single gun, single beam and without shadow mask. Vertical color stripe phosphor triads are carried on the face of the tube. During a predetermined one or ones of non-viewed raster lines, beam impingement on successive red stripes is optically detected and this sample pulse train is compared with a system clock defined reference pulse train which corresponds to red video on-times of the system. Center-line defining ones of the sample and reference pulses are phase compared to calculate a raster offset error for offset correction of the horizontal deflection signal for the ensuing raster frame, while pulse-pairs of respective ones of sample and reference pulses are examined for time-occurrence discrepancy and errors for successive pulse pairs are stored in corresponding digitally-defined horizontal sweep addresses for the pulse-pair for subsequently addressed readout of storage for horizontal sweep correction at each successive pulse pair address during ensuing lines of the raster frame. Digital correction means are utilized to correct both the horizontal and vertical beam deflection signals for tube geometry defined linearity errors on a continuous basis throughout each raster frame, while indexing for assurance of proper picture color content is accomplished on a sample basis prior to the viewable portion of each raster frame and determined horizontal deflection corrections imposed throughout that frame.
摘要:
A liquid crystal display having an non-uniform heat producing element disposed therein which produces more heat around the periphery of the display by providing a transparent heating element on the display surface and a plurality of shorting bars which provide for a lower impedance path around the display periphery, and therefore a higher current and higher heat generation in the resistive film disposed immediately about the shorting bars.
摘要:
A system for generating respective X and Y beam deflection command signals as respective running binary counts in X and Y deflection counters utilizing digital computations based on the straight line expressions Y=X tan .alpha., where .alpha. is the line slope. Relative clock rates are defined by the tan .alpha. relationship therebetween, and, by defining a line as lying in one of eight 45.degree. octants, and a circle as successive points of tangency of a plurality of lines tangent to the circle comprising circumferential segments in eight contiguous ones of the octants, the system effects generation of respective X and Y counts to trace a line of selected length and slope as well as a circle of selected radius utilizing but a single table of tangents for angles between 0.degree. and 45.degree. as the required data storage.
摘要:
An active matrix thin film transistor liquid crystal display having two thin film transistors for use in driving each of the liquid crystal pixels making up the matrix of the display. The first thin film transistor associated with each pixel is used in driving the pixel to capture data off of data lines in response to gate drive signals. The second thin film transistor associated with each pixel is used in compensating for the parasitic capacitances associated with the first thin film transistor and is driven by special compensating pulses.
摘要:
Attainment of exacting dynamic convergence or beam registration is realized in a multi-gun, multi-colored cathode ray tube display system which maintains beam superposition across the display area of the cathode ray tube regardless of scanning direction or scanning rate. The system is particularly effective in maintaining exacting convergence in random scanned displays wherein scanning direction and scanning rates vary considerably. Inherent lag differences in convergence force fields as compared to deflection force fields is compensated and corrected by the summation of each of the horizontal and vertical scan signals with a signal representing the sign and magnitude of the rate of change thereof and with this summation being applied to convergence signal development circuitry rather than the scan signal per se being applied as in conventional known convergence systems.
摘要:
A digital oscillator with output frequency accurately changeable from one period to the next. A plurality of retriggerable monostable multivibrators having discretely different design pulse widths are OR'd to an output monostable multivibrator having the narrowest design pulse width. The plurality of monostable multivibrators are triggered in common by the OR'd outputs thereof such that the longest pulse width one thereof defines the period of the output monostable multivibrator. Logic enabling means permit selection of multivibrator outputs to be OR'd.
摘要:
Method and apparatus for manipulating the gray scale voltage levels in liquid crystal displays, in order to provide for enhanced image quality, over temperature extremes by monitoring the actual transmittance through the liquid crystal over time and comparing the information with earlier information.
摘要:
A flat panel matrix display pixel structure emulates raster scan cathode ray tube shadow mask resolution. A display generator connected to anti-aliasing and/or dot flair circuitry activates the display. A selected pixel is fully activated and surrouding pixels are activated at a lower luminance level. As a function of the pitch of a shadow mask cathode ray tube the pixel density and the horizontal and vertical pixel spacing are derived for a monochrome matrix display, and the pixel density and the horizontal and vertical triad spacing are derived for a color matrix display panel.