Patent ID: 7605941

Claim:
A drawing apparatus in which drawing data, which is required to perform a drawing operation on drawing blocks on a surface that can be drawn at one time by drawing heads moving relatively to said drawn surface, is sequentially generated based on design data and temporarily stored in a memory and, then, sequentially supplied to drawing engines, comprising: computing means for computing drawing start instruction data to start the relative movement and the drawing operation of said drawing heads after a delay from the start of generation of said drawing data so that at least said drawing data is stored in said memory, wherein said computing means includes measuring means for measuring and estimating time points to start the generation of each of said drawing data and time points to complete the supply of said drawing data to said drawing engines by performing a series of computation processes from generating said drawing data based on said design data to supplying it to said drawing engines, first creating means for creating data generation profiles that show on a graph a relationship between said estimated time points to start the generation and to complete the supply for each of said drawing data and positions of said drawing blocks corresponding to said drawing data on said drawn surface, second creating means for creating, on said graph, a drawing speed line that shows change over time of coordinates of said drawing heads with respect to said drawn surface by using a moving speed of said drawing heads relative to said drawn surface, and defining means for comparing said data generation profiles with said drawing speed line, calculating a starting point of said drawing speed line that allows each point on said data generation profiles to precede in time each point on said drawing speed line at all coordinate positions of said drawing heads and, then, defining this starting point as a time point to start the relative movement and the drawing operation of said drawing heads.