Method for operating a media feed motor of a printer

A method for operating a media feed motor of a printer to perform a media feed move of a predetermined distance comprising the steps of:

• a) choosing a position-error scale factor for a media feed move that is within a range of distances;
• b) calculating a media-feed-motor drive signal which includes a position error contribution substantially equal to the product of the position-error scale factor and the difference between a desired final media position at the end of a media feed move and the actual media position;
• and
• c) modifying the position error contribution in step b) to reduce its effect when the predetermined distance is greater than the maximum distance within the range but not when the predetermined distance is less than the maximum distance within the range,
• wherein step c) modifies the position error contribution by setting a limit on the position error contribution at the start of a media feed move and by thereafter causing the position error contribution versus actual media position to decay throughout the media feed move.

A method for operating a media feed motor of a printer to perform a media feed move of a predetermined distance comprising the steps of:

• a) choosing a position-error scale factor for a media feed move that is within a range of distances;
• b) calculating a media-feed-motor drive signal which includes a position error contribution substantially equal to the product of the position-error scale factor and the difference between a desired final media position at the end of a media feed move and the actual media position;
• and
• c) modifying the position error contribution in step b) to reduce its effect when the predetermined distance is greater than the maximum distance within the range but not when the predetermined distance is less than the maximum distance within the range,
• wherein the media-feed-motor-drive signal includes a desired media feed velocity contribution,
• wherein a chart of the desired media feed velocity versus actual media position includes an acceleration portion, a substantially steady-state portion, and a deceleration portion, and
• wherein step c) modifies the position error contribution by setting a limit on the position error contribution at the start of a media feed move, by thereafter causing the position error contribution versus actual media position to decay for actual media positions corresponding to the acceleration and deceleration portions of the chart, and by using a substantially constant value for the position error contribution versus actual media position for actual media positions corresponding to the steady-state portion of the chart.

A method for operating a media feed motor of a printer to perform a media feed move of a predetermined distance comprising the steps of:

• a) choosing a position-error scale factor for a media feed move that is within a range of distances;
• b) calculating a media-feed-motor drive signal which includes a position error contribution substantially equal to the product of the position-error scale factor and the difference between a desired final media position at the end of a media feed move and the actual media position;
• and
• c) modifying the position error contribution in step b) to reduce its effect when the predetermined distance is greater than the maximum distance within the range but not when the predetermined distance is less than the maximum distance within the range,
• wherein step c) modifies the position error contribution by setting a limit on the position error contribution at the start of a media feed move and by replacing the value of the desired final media position in the product of step b) with a replacement value less than the desired final media position.

A method for operating a media feed motor of a printer to perform a media feed move of a predetermined distance comprising the steps of:

• a) choosing a position-error scale factor for a media feed move that is within a range of distances;
• b) calculating a media-feed-motor drive signal which includes a position error contribution substantially equal to the product of the position-error scale factor and the difference between a desired final media position at the end of a media feed move and the actual media position;
• and
• c) modifying the position error contribution in step b) to reduce its effect when the predetermined distance is greater than the maximum distance within the range but not when the predetermined distance is less than the maximum distance within the range,
• wherein step c) modifies the position error contribution by setting a limit on the position error contribution at the start of the media feed move, by thereafter maintaining the limit until the actual media position reaches a predetermined media position, and by causing the position error contribution versus actual media position to decay when the actual media position exceeds the predetermined media position.

A method for operating a media feed motor of a printer to perform a media feed move of a predetermined distance comprising the steps of:

• a) choosing a position-error scale factor for a media feed move that is within a range of distances;
• b) calculating a media-feed-motor drive signal which includes a position error contribution substantially equal to the product of the position-error scale factor and the difference between a desired final media position at the end of a media feed move and the actual media position;
• and
• c) modifying the position error contribution in step b) to reduce its effect when the predetermined distance is greater than the maximum distance within the range but not when the predetermined distance is less than the maximum distance within the range,
• wherein step c) modifies the position error contribution by setting a limit on the position error contribution at the start of the media feed move, by thereafter maintaining the limit until the actual media position reaches a predetermined media position, and by causing the position error contribution versus actual media position to decay when the actual media position exceeds the predetermined media position, and
• wherein the predetermined media position is equal substantially to the media position corresponding to when the unlimited position error contribution first becomes less than the limit.

A method for operating a media feed motor of a printer to perform a media feed move of a predetermined distance comprising the steps of:

• a) choosing a position-error scale factor for a media feed move that is within a range of distances;
• b) calculating a media-feed-motor drive signal which includes a position error contribution substantially equal to the product of the position-error scale factor and the difference between a desired final media position at the end of a media feed move and the actual media position;
• and
• c) modifying the position error contribution in step b) to reduce its effect when the predetermined distance is greater than the maximum distance within the range but not when the predetermined distance is less than the maximum distance within the range,
• wherein step c) modifies the position error contribution by setting a limit on the position error contribution at the start of the media feed move, by thereafter maintaining the limit until the actual media position reaches a predetermined media position, and by causing the position error contribution versus actual media position to decay when the actual media position exceeds the predetermined media position,
• wherein the media-feed-motor-drive signal includes a desired media feed velocity contribution,
• wherein a chart of the desired media feed velocity versus actual media position includes an acceleration portion, a substantially steady-state portion, and a deceleration portion, and
• wherein the predetermined media position is the media position which corresponds to the start of the deceleration portion of the chart.