Single motor dynamic ribbon feedback system for a printer

• US 10,035,367 B1
• Filed: 06/21/2017
• Issued: 07/31/2018
• Est. Priority Date: 06/21/2017
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Datamax-O'Neil Corporation (Honeywell International Inc.)
• Inventors: Yap, Yaw Horng, Wong, Chin Young, Chua, Ching Hong
• Primary Examiner(s): Nguyen, Lamson
• Application Number:
  US15/629,050
• Time in Patent Office: 405 Days
• CPC Class Codes: B41J 17/08 Feed independent of the record-paper feed
• CPC Class Codes: B41J 2/325 by selective transfer of ink from ink carrier, e.g. from ink ribbon or sheet
• CPC Class Codes: B41J 33/22 by gears or pulleys
• CPC Class Codes: B41J 33/24 with drive applied directly to ribbon
• CPC Class Codes: B41J 33/34 driven by motors independently of the machine as a whole

Abstract

A printer with a single motor system to match torques between ribbon supply and ribbon take-up is provided. The printer comprises a ribbon supply spindle, a take-up ribbon spindle, sensors to output ribbon width and diameter at ribbon supply, and a sensor which outputs ribbon diameter at ribbon take-up. The printer is provided with a drive system providing rotation to the ribbon supply via tension on the ribbon loaded on the ribbon supply spindle and taken-up on the take-up ribbon spindle. Firmware, communicatively linked to the sensors and the drive system, is configured to calculate ribbon tension at the ribbon supply spindle, to calculate the torque required on the ribbon on the ribbon take-up spindle to match the ribbon tension at the take-up spindle to the ribbon tension at the ribbon supply spindle, and to adjust the drive system to match these torques.

Claims

1. A printer for printing media comprising:

a rotatable ribbon supply spindle;

a rotatable take-up ribbon spindle;

at least one sensor that outputs ribbon width and diameter of a ribbon loaded on the rotatable ribbon supply spindle;

a sensor which outputs ribbon diameter on the ribbon loaded on the rotatable take-up ribbon spindle;

a drive system configured to rotate the rotatable take-up ribbon spindle, the drive system further providing rotation to the rotatable ribbon supply via tension on the ribbon loaded on the rotatable ribbon supply spindle and taken-up on the rotatable take-up ribbon spindle;

firmware, the firmware being communicatively linked to the at least one sensor for determining ribbon width and diameter of the ribbon loaded on the rotatable ribbon supply spindle, to the sensor for determining ribbon diameter on the ribbon loaded on the rotatable take-up ribbon spindle, and to the drive system;

the firmware being configured to calculate ribbon tension at the ribbon supply spindle from the output of the at least one sensor on the rotatable ribbon supply spindle;

the firmware being further configured to calculate the torque on the ribbon on the rotatable ribbon take-up spindle required to match the ribbon tension at the take-up spindle to the ribbon tension at the rotatable ribbon supply spindle based upon the calculated total tension at the rotatable ribbon supply spindle and the output from the sensor on the ribbon take-up spindle; and

the firmware being configured to adjust the drive system so that the torque at the rotatable take-up spindle is the calculated torque required to match the ribbon tension at the rotatable ribbon take-up spindle to the ribbon tension at the rotatable ribbon supply spindle.

2. The printer of claim 1, wherein the at least one sensor that outputs ribbon width and diameter of a ribbon loaded on the rotatable ribbon supply spindle is comprised of an encoder sensor that outputs the diameter of the ribbon loaded on the rotatable ribbon supply spindle, the encoder sensor being disposed on a base of the rotatable ribbon supply spindle;

and a second sensor that outputs the width of the ribbon loaded on the rotatable ribbon supply spindle, the second sensor being disposed on the rotatable ribbon supply spindle.

3. The printer of claim 1, wherein the ribbon width is proportional to the torque at the rotatable ribbon supply spindle.

4. The printer of claim 2, wherein the encoder sensor rotates with the rotatable supply spindle;

the encoder sensor rotation rate being proportional to the radius of the ribbon loaded on the rotatable ribbon supply spindle; and

the encoder sensor on the ribbon supply spindle being configured to determine the rotation rate based upon a number of encoder interrupts for a given period.

5. The printer of claim 1, wherein the sensor which outputs ribbon diameter on the ribbon loaded on the rotatable take-up ribbon spindle is an encoder sensor that rotates with the rotatable ribbon take-up spindle;

the encoder sensor at the rotatable ribbon take-up spindle has a rotation rate proportional to the ribbon radius at the rotatable ribbon take-up spindle;

the encoder sensor at the rotatable ribbon take-up spindle being configured determine the rotation rate based upon a number of encoder interrupts for a given period.

6. The printer of claim 1, wherein the firmware calculation for ribbon tension at the rotatable ribbon supply spindle is SRT/SRR, where SRT is the torque at the supply ribbon spindle, and SRR is the supply ribbon radius.

7. The printer of claim 6, wherein the firmware calculation of torque on the ribbon on the rotatable ribbon take-up spindle required to match the ribbon tension at the take-up spindle to the ribbon tension at the rotatable ribbon supply spindle is (SRT/SRR)*TRR, where TRR is the radius of the ribbon at the rotatable ribbon take-up spindle.

8. The printer of claim 1, wherein the drive system is an electronic motor;

and wherein the firmware is configured to adjust current to the motor so that the torque at the rotatable take-up spindle is the calculated torque required to match the ribbon tension at the rotatable ribbon take-up spindle to the ribbon tension at the rotatable ribbon supply spindle.

9. The printer of claim 1, further comprising spring wraps on the rotatable ribbon supply spindle, the spring wraps providing torque to the ribbon on the rotatable ribbon supply spindle.

10. The printer of claim 1, wherein the firmware is configured to periodically adjust the drive system based upon periodic calculations of the torque on the ribbon on the rotatable ribbon take-up spindle required to match the ribbon tension at the take-up spindle to the ribbon tension at the rotatable ribbon supply spindle based upon the calculated total tension at the rotatable ribbon supply spindle and the output from the sensor on the ribbon take-up spindle.

11. A printer comprising:

a rotatable ribbon supply spindle;

an encoder sensor for determining the diameter of a ribbon loaded on the ribbon supply spindle;

a sensor for determining width of the ribbon loaded on the ribbon supply spindle;

a rotatable ribbon take-up spindle for taking up the ribbon;

an encoder sensor on the ribbon take-up spindle for determining the diameter of the ribbon on the take-up spindle;

a drive system configured to rotate the ribbon take-up spindle, the drive system being powered by an electric power supply, the drive system further providing rotation to the rotatable ribbon supply spindle via tension on a ribbon loaded on the rotatable ribbon supply spindle and taken-upon the rotatable take-up ribbon spindle;

firmware, the firmware being communicatively linked to receive sensor outputs from the encoder sensor on the ribbon supply spindle, the sensor for determining ribbon width, and the encoder sensor on the ribbon take-up spindle;

the firmware being configured to determine torque in the ribbon at the supply spindle based upon the output from the sensor for determining width of the ribbon on the ribbon supply spindle;

the firmware being configured to calculate the total tension in the ribbon supply based upon the torque determined at in the ribbon at the supply spindle and based upon the output from the encoder sensor on the ribbon supply spindle, the firmware calculation being SRT/SRR, where SRT is Supply Ribbon Torque and SRR is Supply Ribbon Radius;

the firmware being further configured to calculate the torque in the rotatable ribbon take-up spindle required to match the ribbon tension in the take-up spindle to the ribbon tension in the supply spindle based upon the calculated total tension in the ribbon supply and the output from the encoder sensor on the ribbon take-up spindle, the firmware calculation being (SRT/SRR)*TRR, where TRR is the radius of the ribbon at the take-up spindle;

the firmware being communicatively linked to the electric power supply and configured to control current supplied to the drive system, the current being proportional to a rate of rotation of the drive system and the take-up spindle; and

the firmware being configured to adjust the current supplied to the drive system so that the torque at the take-up spindle is the calculated torque required to match the ribbon tension in the take-up spindle to the ribbon tension in the supply spindle.

12. The printer of claim 11, further comprising spring wraps on the rotatable ribbon supply spindle, the spring wraps securing the ribbon on the rotatable ribbon supply spindle.

13. The printer of claim 12, wherein the ribbon width is proportional to the torque at the rotatable ribbon supply spindle.

14. The printer of claim 11, wherein the rotatable ribbon supply spindle is comprised of:

multiple segments, the first segment of the multiple segments being adjacent to a base, each subsequent segment of the multiple segments being adjacent to the previous segment of the multiple segments;

the sensor for determining ribbon width is comprised of;

a commutator, the commutator being disposed circumferentially on the first segment of the spindle;

at least two brushes, the brushes being connected to a voltage source, disposed generally on either side of the commutator, and in electrical contact with the commutator, wherein the voltage source, the brushes, and the commutator form a closed electrical circuit;

a c-shaped conductive spring disposed on each of the multiple segments;

wherein the c-shaped conductive spring has two ends and a center portion;

wherein the c-shaped conductive springs are in an uncompressed state in the absence of a printer ribbon over the one or more c-shaped conductive springs;

wherein the c-shaped conductive springs are in a compressed state in the presence of a printer ribbon positioned over the one or more c-shaped conductive springs;

wherein the c-shaped conductive spring on each segment of the multiple segments has a length such that when the c-shaped conductive spring is in the compressed state, the two ends of the c-shaped conductive spring make electrical contact with the commutator or the c-shaped conductive spring of a previous segment completing an additional electrical circuit in parallel with the closed electrical circuit;

a resistor, the resister is disposed proximate to the center portions of each of the c-shaped conductive springs and in electrical contact with the center portion of the c-shaped conductive springs; and

a resistance meter, the resistance meter connected to the closed electrical circuit, such that the reading on the meter indicates how many additional parallel circuits are completed, the number of additional parallel circuits completed indicating the approximate ribbon width.

15. The printer of claim 14, wherein the encoder sensor on the rotatable ribbon supply spindle is disposed on the base of the rotatable ribbon supply spindle and rotates with the rotatable ribbon supply spindle, the encoder sensor rotation rate being proportional to the ribbon radius;

and the encoder sensor on the ribbon supply spindle being configured to determine the rotation rate based upon a number of encoder interrupts for a given period.

16. The printer of claim 11, wherein the encoder sensor on the ribbon take-up spindle has a rotation rate proportional to the ribbon radius;

and the encoder sensor on the ribbon take-up spindle being configured to determine the rotation rate based upon a number of encoder interrupts for a given period.

17. A method of controlling ribbon tension on a printer, the printer having a rotatable ribbon supply spindle, a rotatable ribbon take-up spindle, and a motor driving the ribbon take-up spindle, comprising the steps of:

i. sensing the diameter of the ribbon on the ribbon supply spindle;

ii. sensing the ribbon width on the ribbon supply spindle;

iii. calculating tension on the ribbon at the ribbon supply spindle, the tension based upon the first and second sensing steps;

iv. sensing the ribbon diameter of the ribbon at ribbon take-up spindle;

v. calculating the torque required to match tensions between the ribbon supply and the ribbon take-up based upon the first calculating step and the third sensing step; and

vi. adjusting the motor driving the ribbon take-up spindle to supply the required torque found in the second calculating step.

18. The method of 17, wherein the first calculating step is accomplished with firmware, wherein the first calculating step is comprised of the steps of:

receiving information about the diameter of the ribbon on the ribbon supply spindle from the first sensing step;

receiving information about the width of the ribbon on the ribbon supply spindle from the second sensing step;

converting the information about the width of the ribbon into a torque; and

dividing the torque by the ribbon radius derived from the information about diameter or the ribbon to obtain a supply ribbon tension.

19. The method of claim 18, wherein the second calculating step is accomplished with the firmware, wherein the second calculating step is comprised of the steps of:

receiving information about the diameter of the ribbon on the take-up spindle from the third sensing step; and

multiplying the ribbon radius on the take-up spindle by the supply ribbon tension.

20. The method of claim 19, wherein the adjusting step is accomplished with the firmware, the firmware being configured to control current supplied to the motor.