Thermal transfer printer

Patent metadata

Field	Value
Publication number	US-11007792-B2
Application number	US-201816470468-A
Country	US
Kind code	B2
Filing date	Sep 13, 2018
Priority date	Sep 13, 2018
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

An object is to provide a thermal transfer printer having an inexpensive configuration and capable of making a tension given to an ink ribbon as constant as possible, even when a secular change and an environmental change occur in a DC motor used as a supply motor and a winding motor. A supply motor control unit controls a supply motor of an ink ribbon supply unit. A winding motor control unit controls a winding motor of an ink ribbon winding unit. A remaining amount detection unit detects a remaining amount of an ink ribbon. A variable calculation unit acquires parameters for an armature current, an applied voltage, and a rotational speed of each of the supply motor and the winding motor, and calculates variables to be used for controlling the supply motor and the winding motor on the basis of the acquired parameters.

First claim

The invention claimed is:

1. A thermal transfer printer that performs printing on a sheet by using an ink ribbon, the thermal transfer printer comprising:
a thermal transfer unit having a thermal head to press and heat the sheet and the ink ribbon;
an ink ribbon supply unit having a supply bobbin to supply the ink ribbon to the thermal transfer unit, and a supply motor to rotate the supply bobbin;
a supply motor control unit to control the supply motor of the ink ribbon supply unit;
an ink ribbon winding unit having a winding bobbin to wind the ink ribbon, and a winding motor to rotate the winding bobbin;
a winding motor control unit to control the winding motor of the ink ribbon winding unit;
a remaining amount detection unit to detect a remaining amount of the ink ribbon; and
a variable calculation unit to acquire parameters for an armature current, an applied voltage, and a rotational speed of each of the supply motor and the winding motor while voltages are applied to the supply motor and the winding motor respectively from the supply motor control unit and the winding motor control unit, and to calculate variables to be used for controlling the supply motor and the winding motor based on the acquired parameters,
wherein the calculated variable used for controlling the supply motor and the winding motor aid the thermal transfer printer to achieve a tension in the ink ribbon that is approximately constant in the presence of a secular change and an environmental change in the supply motor and the winding motor, and
the supply motor and the winding motor are DC motors.

2. The thermal transfer printer according to claim 1 , wherein the variable calculated by the variable calculation unit includes a torque constant and armature resistance.

3. The thermal transfer printer according to claim 2 , wherein
the supply motor control unit
applies, at a time of thermal transfer, to the supply motor, a voltage calculated based on the torque constant, the armature resistance, a remaining amount of the ink ribbon, and a target value of a tension given to the ink ribbon, and
the winding motor control unit
applies, at a time of thermal transfer, to the winding motor, a voltage calculated based on the torque constant, the armature resistance, a remaining amount of the ink ribbon, and a target value of a tension given to the ink ribbon.

4. The thermal transfer printer according to claim 3 , wherein
the supply motor control unit
changes the calculated voltage based on the rotational speed of the supply motor acquired at a time of thermal transfer, to apply the changed voltage to the supply motor, and
the winding motor control unit
changes the calculated voltage based on the rotational speed of the winding motor detected at a time of thermal transfer, to apply the changed voltage to the winding motor.

5. The thermal transfer printer according to claim 2 , wherein
the supply motor control unit
uses, as a target current, at a time of thermal transfer, a current calculated based on the torque constant, the armature resistance, a remaining amount of the ink ribbon, and a target value of a tension given to the ink ribbon, to perform current control of the supply motor, and
the winding motor control unit
uses, as a target current, at a time of thermal transfer, a current calculated based on the torque constant, the armature resistance, a remaining amount of the ink ribbon, and a target value of a tension given to the ink ribbon, to perform current control of the winding motor.

6. The thermal transfer printer according to claim 5 , wherein
the supply motor control unit
changes the calculated target current based on the rotational speed of the supply motor acquired at a time of thermal transfer, to perform current control of the supply motor, and
the winding motor control unit
changes the calculated target current based on the rotational speed of the winding motor acquired at a time of thermal transfer, to perform current control of the winding motor.

7. The thermal transfer printer according to claim 2 , further comprising:
a sheet conveyance unit having a conveyance roller to convey the sheet, and a conveyance motor to rotate the conveyance roller; and
a conveyance motor control unit to control the conveyance motor of the sheet conveyance unit, wherein
the supply motor control unit
sets a voltage to be applied to the supply motor at a time of acquisition of parameters for an armature current, an applied voltage, and a rotational speed of the supply motor to cause an ink ribbon supply speed to be greater than a sheet conveyance speed by the conveyance motor.

8. The thermal transfer winter according to claim 2 , further comprising:
a sheet conveyance unit having a conveyance roller to convey the sheet, and a conveyance motor to rotate the conveyance roller; and
a conveyance motor control unit to control the conveyance motor of the sheet conveyance unit, wherein
the winding motor control unit
sets a voltage to be applied to the winding motor at a time of acquisition of parameters for an armature current, an applied voltage, and a rotational speed of the winding motor to cause an ink ribbon winding speed to be smaller than a sheet conveyance speed by the conveyance motor.

9. A thermal transfer printer that performs printing on a sheet by using an ink ribbon, the thermal transfer printer comprising:
a thermal transfer unit having a thermal head to press and heat the sheet and the ink ribbon;
an ink ribbon supply unit having a supply bobbin to supply the ink ribbon to the thermal transfer unit, and a supply motor to rotate the supply bobbin;
a supply motor control unit to control the supply motor of the ink ribbon supply unit;
an ink ribbon winding unit having a winding bobbin to wind the ink ribbon, and a winding motor to rotate the winding bobbin;
a winding motor control unit to control the winding motor of the ink ribbon winding unit;
a remaining amount detection unit to detect a remaining amount of the ink ribbon; and
a variable calculation unit to acquire parameters for an armature current, an applied voltage, and a rotational speed of each of the supply motor and the winding motor while voltages are applied to the supply motor and the winding motor respectively from the supply motor control unit and the winding motor control unit, and to calculate variables to be used for controlling the supply motor and the winding motor based on the acquired parameters,
wherein the supply motor and the winding motor are DC motors,
the variable calculated by the variable calculation unit includes a torque constant and armature resistance,
the supply motor control unit
applies, at a time of thermal transfer, to the supply motor, a voltage calculated based on the torque constant, the armature resistance, a remaining amount of the ink ribbon, and a target value of a tension given to the ink ribbon, and
the winding motor control unit
applies, at a time of thermal transfer, to the winding motor, a voltage calculated based on the torque constant, the armature resistance, a remaining amount of the ink ribbon, and a target value of a tension given to the ink ribbon.

10. A thermal transfer printer that performs printing on a sheet by using an ink ribbon, the thermal transfer printer comprising:
a thermal transfer unit having a thermal head to press and heat the sheet and the ink ribbon;
an ink ribbon supply unit having a supply bobbin to supply the ink ribbon to the thermal transfer unit, and a supply motor to rotate the supply bobbin;
a supply motor control unit to control the supply motor of the ink ribbon supply unit;
an ink ribbon winding unit having a winding bobbin to wind the ink ribbon,

Assignees

• Mitsubishi Electric Corp

Inventors

• Kanatake Yusuke
• Sakuwa Makoto
• Oda Kosuke

Classifications

• B41J2/3558

  Voltage control or determination · CPC title

• B41J2/325 Primary

  by selective transfer of ink from ink carrier, e.g. from ink ribbon or sheet · CPC title

• B41J33/24

  with drive applied directly to ribbon · CPC title

• B41J33/36

  with means for adjusting feeding rate · CPC title

• B41J33/14

  Ribbon-feed devices or mechanisms · CPC title