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US 3,942,619 AGranted
Printer employing stylus correlation and motor damping means
AssigneeScope Incorporated
InventorsLarry A. Nordstrom, Daniel J. Szechy
Life of this patent
Estimating the term…
Abstract
Printing apparatus including a multi-phase stepping motor having a shaft rotated thereby, and detecting means opto-electronically coupled to the shaft. A printing stylus is mechanically coupled with the shaft such that the shaft drives the stylus along a path. A control circuit coupled with the opto-electronic detecting means correlates signals to the stylus with the position of the shaft.
Claims21
Apparatus comprising:
- a multiphase stepping motor having at least two phases and adapted to step one phase for each position along a path;
- a shaft rotated by said motor;
- means mechanically driven by said shaft along a path;
- circuit means coupled with said mechanically driven means for providing signals thereto during movement along said path;
- means coupled with said shaft and said circuit means for correlating each signal from said circuit means with a predetermined position of said shaft, said correlating means including a disc fixed on said shaft and having a plurality of striations thereon for each phase of said stepping motor;
- means for energizing a first phase of said motor during energization of a second phase of said motor, in order to brake said shaft;
- and
- means for energizing said first phase only at a predetermined position of said shaft during energization of said second phase, said predetermined position energizing means including a control circuit coupled to an output of said correlating means for counting each striation of said disc and for energizing said first phase after counting a predetermined number of striations during energization of said second phase.
5 more elements
Printing apparatus comprising:
- a multiphase stepping motor having at least two phases and adapted to step one phase for each position along a path;
- a shaft rotated by said motor;
- detecting means electromagnetically coupled to said shaft, said detecting means including a disc having a plurality of striations thereon for each phase of said stepping motor;
- a movable printing stylus;
- means mechanically coupling said stylus to said shaft such that said shaft drives said stylus along a path;
- character generating means coupled with said stylus and adapted to provide character signals thereto during movement of said stylus along said path;
- a control circuit coupled with said electromagnetic detecting means and said character generating means for correlating signals to said stylus with the position of said shaft;
- means for braking said shaft;
- and
- means for energizing said braking means as a function of the position of said shaft, said energizing means including means with said control circuit for counting a predetermined number of striations on said disc during energization of one phase of said motor, and for providing a signal responsive thereto for energizing said braking means for a duration sufficient to prevent oscillatory motion of said shaft.
7 more elements
Printing apparatus comprising:
- a multiphase stepping motor;
- a shaft rotated by said motor;
- a disc fixed on said shaft and having a plurality of radial striations thereon for each phase of said stepping motor;
- electromagnetic detecting means for providing signals representative of successive striations;
- means for receiving said signals from said detecting means and counting successive striations;
- and
- means for energizing a first phase of said motor coincident with the count of a predetermined striation detected by said counting means during energization of a second phase of said motor, in order to prevent oscillatory motion of said shaft.
4 more elements
Printing apparatus comprising:
- a multiphase stepping motor;
- a shaft rotated by said motor;
- detecting means electromagnetically coupled to said shaft;
- a movable printing stylus;
- means mechanically coupling said stylus to said shaft such that said shaft drives said stylus along a path;
- character generating means coupled with said stylus and adapted to provide character signals thereto during movement of said stylus along said path;
- a control circuit coupled with said electromagnetic detecting means and said character generating means for correlating signals to said stylus with the position of said shaft;
- driving circuit means electrically coupled between said stepping motor and said control circuit for providing a sequence of phasing signals to said motor for sequentially energizing said phases of said stepping motor;
- and
- means for sequentially reducing the period of said energization signals with increases in the rotational speed of said motor.
7 more elements
Dependencies are inferred from the claim text.