Puncher and method of controlling the puncher

A card puncher comprising:

• a reversible motor;
• a conveyer belt driven by the motor for conveying a card to its target punching position;
• a mechanism for punching the card;
• an encoder rotated synchronously with the motor for outputting pulses proportional in number to the quantity of conveyance of the card;
• a sensor for sensing the passage of a leading or trailing end of the card through a predetermined position on the conveyer belt;
• a memory for storing data on a standard value indicative of the quantity of conveyance of the card from the predetermined position to the punching position where the card is punched, and data on a target position indicative of a quantity of conveyance of the card toward the punching position;
• a punching position counter for receiving the data on the target position from the memory when the leading or trailing end of the card is sensed by the sensor and sequentially updating the data on the target position with output pulses from the encoder;
• first control means for stopping the motor when the data on the target position in the punching position counter arrives at a predetermined value;
• a coast counter for measuring a quantity of coast of the card, after the motor is stopped, in accordance with output pulses from the encoder;
• and
• second control means for comparing the data on the standard value with the sum of the data on the target position and the data on the quantity of coast measured by the coast counter, directing the punching mechanism to punch the card if the error between the data on the standard value and the sum is within an allowable limit, correcting the data on the target position stored in the memory by a quantity corresponding to the error if the error is out of the allowable limit, driving the motor to return the card to the starting position of the punching operation, and causing the punching mechanism to retry the punching operation using the corrected data on the target position.

A method of controlling a card puncher comprising the steps of:

• driving a card conveying means until a quantity of card conveyance arrives at a predetermined target quantity of conveyance corresponding to a position where a card is punched;
• measuring a quantity of coast of the card after the drive of the card conveying means is terminated;
• and
• punching the card if the sum of the target quantity of conveyance and the measured quantity of coast of the card is within a predetermined allowable limit.