US 4,680,720 AGranted

Dot interpolation control system

AssigneeKabushiki Kaisha Toshiba

InventorsJiro Yoshii, Akira Komatsu, Hiroshi Ishii

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Abstract

A dot interpolation control system according to the invention includes a dot pattern memory storing character pattern data having a predetermined dot matrix format. Dot data of four adjacent dots is obtained from the dot pattern memory. X and Y off-set values of a position in an area surrounded by the four dots are stored using one of the dot data of four adjacent dots as a reference point. Dot interpolated value data in the area surrounded by the four dots is stored in an interpolating table ROM in accordance with all combination of ON- and OFF-states of the dot data of four adjacent dots. The dot data of four adjacent dots and the X and Y off-set values are supplied to the interpolating table ROM. A dot interpolated value at a coordinate point indicated by the off-set values is generated in correspondence with ON- and OFF-states of the four adjacent dots.

Claims16

Dependent claims

A dot interpolation control system comprising:

a dot pattern memory for storing character pattern data formed in a predetermined dot matrix format;
recognizing means for recognizing ON- and OFF-states of dot data of four adjacent dots of a desired position from said dot pattern memory;
memory means for storing data representing a position of a region surrounded by said four adjacent dots in terms of an X-direction offset and a Y-direction offset, with one of said four adjacent dots being a reference dot;
dot interpolation value generating means for, when said recognizing means recognizes, based on said X- and Y-direction offsets, that only one of said four adjacent dots is at an ON-state, outputting that content of either a first interpolation table or a second interpolation table which is specified by coordinates represented by said offsets, in accordance with dot data of those two of dots lying on a diagonal line, passing said ON-state dot but not passing any of the remaining three dots, which are adjacent to said On-state dot;
for, when two of said four adjacent dots are at an ON-state, outputting that content of either a third interpolation table or a fourth interpolation table which is specified by coordinates represented by said offsets, depending on whether or not said two dots lie on a diagonal line;
and for, when three of said four adjacent dots are at an ON-state, outputting that content of either said first interpolation table or said second interpolation table which is specified by coordinates represented by said offsets, in accordance with dot data of those two of dots lying on a diagonal line, passing the remaining OFF-state dot but not passing any of said three ON-state dots, which are adjacent to said OFF-state dot;
threshold value memory means for storing a threshold value;
and
comparator means for comparing a dot interpolation value from said dot interpolation value generating means with said threshold value from said threshold value memory means, and for producing a signal indicative of said ON-state dot, when said interpolation value exceeds said threshold value.

6 more elements

A dot interpolation control system for performing a dot interpolation on a character pattern formed in a specific dot matrix format, at least along an X-direction or a Y-direction, said system comprising:

first memory means for storing an X-direction initial value, obtained when the dot interpolation is performed;
second memory means for storing X-direction dot pitch data;
X-direction dot interpolation position generating means for adding contents of said first and second memory means to generate data of an X-direction component of a dot interpolation position, which consists of an integer portion and a decimal portion;
third memory means for storing a Y-direction initial value, obtained when the dot interpolation is performed;
fourth memory means for storing a Y-direction dot pitch data;
Y-direction dot interpolation position generating means for adding contents of said third and fourth memory means to generate data of a Y-direction component of the dot interpolation position, which consists of an integer portion and a decimal portion;
dot data selecting means for selecting dot data of four dots in one grid, which includes the dot interpolation position, selected in accordance with said integer portions of said X-direction and Y-direction components respectively generated by said X-direction dot interpolation position generating means and said Y-direction dot interpolation position generating means;
dot pattern recognizing means for recognizing a pattern of said dot data selected by said dot data selecting means and generating an interpolation value selection signal for selectively changing an interpolation value of a new dot surrounded by said four dots of one grid;
fifth memory means for storing a threshold value;
an interpolation table ROM for receiving said decimal portions of said X-direction and Y-direction components respectively generated by said X-direction dot interpolation position generating means and said Y-direction dot interpolation position generating means, said dot data of said four dots from said dot data selecting means, and said interpolation value selection signal from said dot pattern recognizing means, and for generating an interpolation value of a new dot in a region surrounded by said for dots in one grid in accordance with said dot data of said four dots and said interpolation value selection signal;
and
comparator means for comapring said interpolation value from said interpolation table ROM with said threshold value stored in said fifth memory means, and for producing a signal indicative of an ON-state dot when said interpolation value exceeds said threshold value.

9 more elements

Dependencies are inferred from the claim text.