Apparatus for generating halftone dots from dot envelope parameters

Claim 2

Apparatus for generating a halftone dot pattern comprising: means for providing dot parameters representing intersect values of a number of lines drawn from boundary points on the envelope of a dot to a reference axis of the dot; means for receiving position signals corresponding to the printing coordinates of a marking engine; and logic means for comparing the receiving position signals with the provided dot parameters to determine if a printing is to be performed by a marking engine at the printing coordinates and for providing an output signal for enabling the marking engine.

Claim 3

The apparatus according to claim 1 wherein said means for providing dot parameters provides groups of dot parameters, with each group representing a dot of different size.

Claim 4

The apparatus according to claim 2 wherein said means for providing dot parameters provides groups of dot parameters, with each group representing a dot of different type.

Claim 5

The apparatus according to claim 3 wherein said logic means includes; means for utilizing the dot parameters representing only a symmetrical segment of the envelope of a dot to provide said output signal to enable the marking engine.

Claim 6

Apparatus for generating a halftone dot pattern utilizing dots defined by envelope parameters comprising: addressable memory means for storing a plurality of dot descriptors each at its own address with each descriptor formed from a set of dot parameters and each set of parameters including intercept values representing corresponding halftone dot sizes wherein dot size corresponds to a density value and wherein said intercept values represent the intercept of tangent lines with a reference axis and the outer boundary of the dot; means for receiving signals representing the printing position of a dot onto a receiving medium and for selecting fonts and for providing a partial address to said addressable memory means in response to said received signals; means for providing a contone value to said addressable memory means to provide the remaining portion of the address to select a corresponding set of dot parameters; and engine means coupled to said addressable memory means for receiving the set of dot parameters and the signals representing a dot's printing position for providing output values to a printing engine for causing the printing of a halftone dot at the indicated position with the dot's size and shape being represented by the set of dot parameters.

Claim 7

Apparatus for generating a halftone dot pattern utilizing dots defined by envelope parameters comprising: addressable memory means for storing a plurality of dot descriptors each at its own address with each descriptor formed from a set of dot parameters and each set of parameters including intercept values representing corresponding halftone dot sizes wherein dot size corresponds to a density value and wherein said intercept values represent the intercept of tangent lines with a reference axis and the outer boundary of the dot; means for receiving signals representing the printing position of a dot onto a receiving medium and for selecting fonts and for providing a partial address to said addressable memory means in response to said received signals; means for providing a contone value to said addressable memory means to provide the remaining portion of the address to select a corresponding set of dot parameters; and engine means coupled to said addressable memory means for receiving the set of dot parameters and the signals representing a dot's printing position for providing output values to a printing engine for causing the printing of a halftone dot at the indicated position with the dot's size and shape being represented by the set of dot parameters.

Claim 8

The apparatus according to claim 5 wherein the dot parameters represent at least one segment of symmetry of the envelope of the dots and said engine means further comprises: means for reconstructing said dots from said dot parameters by flipping the at least one segment of symmetry to complete the entire dot envelope.

Claim 9

The apparatus according to claim 6 and further comprising: means for providing flip coordinates to said engine means comprised of: first and a second multiplexers receiving as selectable inputs bits representing the x and negated x coordinate and the y and the negated y coordinate, respectively of the dot that is to be printed, said multiplexers having a selection input for receiving a selection bit that selects which bits will be passed to said engine means to represent actual x and actual y coordinates.

Claim 10

The apparatus according to claim 6 wherein said engine means is further comprised of: means for receiving the signals representing a dots printing position and for folding, the position to be within the segment of symmetry represented by said dot parameters and for providing signals representing the folded position; flipping means for flipping the position represented by the provided signals wherein a dot parameter indicates that the size of the dot exceeds a predetermined size; testing means for receiving and testing the provided signals from said flipping means with the received dot parameters to provide an output print value for all coordinate positions within the envelope of a selected dot.