Pen-recording apparatus capable of erasing written characters

A recording apparatus capable of writing characters on a recording medium with a writing instrument, and erasing written characters with an erasing instrument, comprising:

• a medium support member for supporting said recording medium;
• medium feeding means for feeding said recording medium supported by said medium support member, in a selected one of opposite directions along a line of feed;
• a carriage for supporting said writing and erasing instruments, said carriage being movable in a selected one of opposite directions perpendicular to said line of feed of said recording medium;
• carriage driving means for moving said carriage perpendicularly to said line of feed;
• instrument selecting means for selectively bringing said writing and erasing instruments into an operative position in which a writing end of said writing instrument or an erasing end of said erasing instrument is located opposite to a surface of said recording medium;
• instrument driving means for moving said writing and erasing instruments into said operative position, between an advanced position and a retracted position, for contact and release of said writing and erasing ends with or from said surface of said recording medium;
• a generator for producing character signals indicative of said characters, and an erasing signal commanding an erasing operation of said erasing instrument;
• a character pattern memory for storing sets of character pattern data representative of said characters;
• an erasing pattern memory for storing sets of erasing pattern data corresponding to said sets of character pattern data, for erasing said characters, each of said sets of erasing pattern data permitting each of components of an erasing path of said erasing instrument to be shifted from said character in a selected one of a first and a second direction which are normal to a first and a second reference line, respectively, which first and second reference lines intersect each other, said set of erasing pattern data causing said each component of said erasing path to be shifted in said first direction if a segment of said character corresponding to the component is positioned nearer to said first reference line than to said second reference line, or to be shifted in said second direction if said segment is positioned nearer to said second reference line than to said first reference line;
• and
• control means responsive to a character signal produced by said generator, for retrieving from said character pattern memory a corresponding one of said sets of character pattern data, and controlling the operations of said medium feeding means, said carriage driving means, and said instrument driving means, according to the retrieved set of character pattern data, so as to write on said recording medium with said writing instrument the character represented by said retrieved set of character pattern data,
• said control means being responsive to said erasing signal produced after said character has been written, to retrieve from said erasing pattern memory the set of erasing pattern data corresponding to said retrieved set of character pattern data, said control means controlling the operations of said medium feeding means, said carriage driving means, and said instrument driving means, according to the retrieved set of erasing pattern data, so as to trace said character along said erasing path with said erasing instrument.

A method of erasing a character which has been written on a recording medium with a writing instrument of a recording apparatus according to a set of character pattern data which is stored in a pattern memory and is representative of the character, said method comprising the steps of:

• retrieving from a pattern data memory said set of character pattern data;
• determining whether a segment of the written character corresponding to each of components of an erasing path of an erasing instrument is positioned nearer to a first reference line or to a second reference line, said first and second reference lines intersecting each other;
• modifying the retrieved set of character pattern data into a corresponding set of erasing pattern data such that said corresponding set of erasing pattern data causes said each component of said erasing path to be shifted from said written character in a first direction normal to said first reference line if said segment of said written character is positioned nearer to said first reference line than to said second reference line, or in a second direction normal to said second reference line if said segment is positioned nearer to said second reference line than to said first reference line;
• and
• controlling movements of said erasing instrument and said recording medium according to said corresponding set of erasing pattern data, to trace said written character along said erasing path.

A recording apparatus capable of writing characters on a recording medium with a writing instrument, and erasing written characters with an erasing instrument, comprising:

• a medium support member for supporting said recording medium;
• medium feeding means for feeding said recording medium supported by said medium support member, in a selected one of opposite directions along a line of feed;
• a carriage for supporting said writing and erasing instruments, said carriage being movable in a selected one of opposite directions perpendicular to said line of feed of said recording medium;
• carriage driving means for moving said carriage;
• instrument selecting means for selectively bringing said writing and erasing instruments into an operative position in which a writing end of said writing instrument or an erasing end of said erasing instrument is located opposite to a surface of said recording medium;
• instrument driving means for moving said writing and erasing instruments into said operative position, between an advanced position and a retracted position, for contact and release of said writing and erasing ends with or from said surface of said recording medium;
• a generator for producing character signals indicative of said characters, and an erasing signal commanding an erasing operation of said erasing instrument;
• a pattern memory for storing sets of character pattern data representative of said characters;
• first control means, responsive to a character signal produced by said generator, for retrieving from said pattern memory a corresponding one of said sets of character pattern data, and controlling the operations of said medium feeding means, said carriage driving means, and said instrument driving means, according to the retrieved set of character pattern data, so as to write on said recording medium with said writing instrument the character represented by said retrieved set of character pattern data;
• and
• second control means, responsive to said erasing signal produced after said character has been written, including (a) retrieving means for retrieving from said pattern memory the set of character pattern data representative of said character, (b) judging means for determining whether a segment of said character corresponding to each of components of an erasing path of said erasing instrument is positioned nearer to a Y axis parallel to said line of feed of said recording medium or nearer to an X axis parallel to a line of movement of said carriage, and (c) modifying means for modifying the retrieved set of character pattern data into a corresponding set of erasing pattern data such that said set of erasing pattern data causes said each component of said erasing path to be shifted in a first direction normal to said Y axis if said judging means has determined that said segment is positioned nearer to said Y axis than to said X axis, or in a second direction normal to said X axis if said judging means has determined that said segment is positioned nearer to said X axis than to said Y axis;
• said corresponding set of erasing pattern data comprising first erasing pattern data for shifting said each component of said erasing path by a predetermined distance to one side of the corresponding segment of said character, and second erasing pattern data for shifting said each component of said erasing path by said predetermined distance to the other side of said corresponding segment of said character, said second control means controlling the operations of said medium feeding means, said carriage driving means, and said instrument driving means, according to said first erasing pattern data and said second erasing pattern data, so as to trace said character two times along said erasing path with said erasing instrument.