US 4,384,286 A · High speed graphics

Abstract

A display processor for displaying complex curves includes an initiating processor, responsive to indicia selection signals for producing signals representing at least one coordinate on said indicia, and recursive processor means responsive to said initiating processor for generating a sequence of signals, each signal in the sequence representing different coordinates of said indicia, and for also generating a corresponding sequence of signals representing rate of change of at least one parameter of said coordinates, a comparator responsive to the output of said recursive processor and to instantaneous sweep position for, at times, illuminating the display field when the instantaneous sweep position matches one of the sequence of indicia coordinates. The recursive nature of the processor limits the memory required during the course of the processing, and since the recursive processor performs only the functions of shifting and adding, the processing time expended is materially reduced over that previously required.

Claims11

Dependent claims

In a display device for displaying selected indicia on a field swept in a predetermined pattern apparatus for determining coordinates of an ellipse or degenerate forms thereof including:

a processor for generating a sequence of digital signals, each representing a coordinate of said selected indicia in response to indicia selection signals, said processor comprising:
initiating processor means responsive to said indicia selection signals for producing at least one signal representing a first coordinate and a further signal representing a rate of change of at least one component of said first coordinate,
recursive processor means consisting essentially only of adders and shifters with an output of said recursive processor means coupled to an input and responsive to said at least one signal and to said further signal for producing a sequence of digital signals, each representing different coordinates of said selected indicia, each said different coordinates spaced from adjacent coordinates by a predetermined distance, and
comparator means responsive to said signal sequences from said recursive processor means, and to signals indicative of instantaneous sweep position for illuminating said display field when said sweep is in a position corresponding to a coordinate of said indicia.

1 more element

A display apparatus for displaying information bearing signals having a predetermined relationship with fixed indicia comprising

means for generating signals indicative of said indicia,
processor means responsive to said indicia indicating signals for producing in response to a gating signal a sequence of digital signals each representing different coordinates of said fixed indicia,
a clock,
two dimensional sweep means responsive to said clock for generating sweep signals for sweeping a display field in two dimensions,
first gating means for gating said information bearing signals,
visible signal generating means responsive to said sweep means and to said first gating means for generating visible signals corresponding to information bearing signals passed by said first gating means,
first comparator means for comparing one of said indicia defining signals with a signal representing one coordinate of said instantaneous sweep position and for generating an output signal,
second gating means responsive to said first comparator means for producing said gating signal for gating said processor means in response to an output signal from said first comparator means representing equal comparison,
second comparator means responsive to an output of said processor means and to a signal representative of instantaneous sweep position in another coordinate for producing an output signal when said instantaneous sweep position signal bears a predetermined relation to an output of said processor means,
means coupling said output signal of said second comparator means to said first gating means,
wherein said processor means includes:
initiating processor means responsive to said indicia indicating signals for producing intermediate signals, and
recursive processor means responsive to said intermediate signals for generating said sequence of digital signals,
whereby said processor means develops a sequence of digital signals describing said fixed indicia, and said second comparator means is conditioned to control said first gating means to pass only those information bearing signals which are represented by visible signals lying on a selected side of said fixed indicia.

11 more elements

Dependencies are inferred from the claim text.

High speed graphics

Life of this patent

High speed graphics

Life of this patent

Abstract

Claims11