Ribbon feed control apparatus and method

• US 4,878,773 A
• Filed: 06/08/1988
• Issued: 11/07/1989
• Est. Priority Date: 06/08/1988
• Status: Expired due to Fees

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Mazumder, Ali T.
• Primary Examiner(s): WIECKING, DAVID
• Application Number:
  US07/203,962
• Time in Patent Office: 517 Days
• Field of Search: 400/223, 400/225, 400/231, 400/232, 400/234, 400/236, 400/236.2, 400/247, 400/703, 400/711, 242/75.4, 242/75.43, 242/75.44, 242/75.5, 242/75.51, 242/89, 242/190, 242/201, 242/202, 242/203, 242/204, 360/72.3, 360/74.3, 360/93, 360/95, 360/96.1
• US Class Current: 400/234
• CPC Class Codes: B41J 33/12 Ribbons carried by coaxially-mounted spools
• CPC Class Codes: B41J 33/34 driven by motors independently of the machine as a whole

Abstract

Ribbon feed control apparatus includes a rotatable supply roll on which a supply of ribbon to be dispensed is placed, a rotatable take-up roll on which the ribbon is collected after being used in printing, a mechanism for driving the take-up roll in one direction for pulling the ribbon from the supply roll, a device for determining the amount of ribbon required for a printing operation, a device for measuring the amount of ribbon used in such an operation, a device for comparing the amount of ribbon required with that actually used, and for terminating operation of the take-up roll driving mechanism when the amount required and the amount used are equal, tension sensing mechanism for determining when the ribbon becomes slack while it is being driven between the supply roll and the take-up roll, driving mechanism controlled by the tension sensing mechanism for driving the supply roll in a direction opposite to the direction in which the take-up roll is driven in order to take up the slack in the ribbon, and delay mechanism operable to keep the supply roll drive mechanism from operating until after the take-up roll driving mechanism has completed its operation.

Claims

1. Ribbon feed control apparatus comprising:

apparatus support means;

ribbon supply means on which a supply of ribbon may be placed, said ribbon supply means being rotatably mounted on said apparatus support means;

ribbon take-up means rotatably mounted on said apparatus support means;

first drive means for driving said ribbon take-up means in a first direction of rotation;

ribbon advance timer means for controlling operation of said first drive means;

second drive means for driving said ribbon supply means in a second direction of rotation;

ribbon tension means for controlling operation of said second drive means;

guide means for guiding said ribbon in a path from said ribbon supply means to said ribbon take-up means;

control means for providing information as to the distance which said ribbon is to be advanced during a given operation;

measuring means for measuring the distance which said ribbon is actually advanced during a given operation;

comparison means coupled to said control means, said measuring means and said ribbon advance timer means for providing a halt signal to said ribbon advance timer means when ribbon distance information provided by said control means and by said measuring means are equal;

adjustable delay means comprising coupled resistor means, including a potentiometer, and capacitor means for determining time duration, said adjustable delay means being controlled by said ribbon advance timer means for controlling initiation of operation of said ribon tension means after a predetermined time period greater than zero following termination of operation of said first drive means; and

ribbon tension sensing means coupled to said ribbon tension means for causing operation of said ribbon tension means when said ribbon in said path between said ribbon supply means and said ribbon take-up means is slack, whereby said ribbon tension means is operable to operate said second drive means to drive said ribbon supply means in said second direction of rotation to take-up said slack after expiration of said predetermined time period greater than zero.