Nova Patents
EP1501684B1

A thermal printer

Abstract

This record has no abstract on file.

EP1501684B1, drawing sheet 1
Sheet 1 of 35

Term

Term ended

Expired 23 April 2023, 3.4 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

15 claims: 6 independent, 9 dependent

  1. 1
    A thermal printer (10) for producing a printing (26, 26a, 26b, 26', 26'b, 26'c, 26") on the surface of a foil (16, 16', 16") in an ink transfer operation, comprising:means (18, 30) for supplying said foil to said thermal printer, a thermal transfer ribbon (130, 130', 130") including an ink which is transferable in said ink transfer operation at specific locations of said thermal transfer ribbon by heating said specific locations to an elevated temperature causing said ink to be fluid, means (96 v , 98 v ) for arranging said thermal transfer ribbon in facial contact with said surface of said foil, energizable printing means (100) for heating said specific locations of said thermal transfer ribbon to said elevated temperature on said ink transfer operation, means (14) for energizing said energizable printing means, means (170) including an actuator for moving said energizable printing means and said foil together so as to sandwich said thermal transfer ribbon there-between in a constrained state and for moving said energizable printing means and said foil apart, means (30, 190) for moving said foil and said energizable printing means relative to one another at a specific speed while pressing said energizable printing means and said foil together and while energizing said energizable printing means, and means (128, 140) including a roller driven by a motor for moving said thermal transfer ribbon relative to said energizable printing means for causing said ink of said thermal transfer ribbon to be transferred at said specific locations to said foil at specific areas thereof constituting said printing, said printer being characterized in that : said thermal transfer ribbon is delivered from a supply reel (124 v ) to a first spring biased tensioning pin (125 v ), is moved past said energizable printing means to a second spring biased tensioning pin (133 v ) and is received by a take-up reel (132 v ), said first and second tensioning pins serving the purpose of allowing said thermal transfer ribbon to be accelerated or decelerated without simultaneously accelerating or decelerating, respectively, said delivery and take-up reels.
  2. 4
    A thermal printer according to claims 1 to 3, said first and second spring biased tensioning pins (125 v , 133 v ) being angularly rotatable, encoders being provided to monitor the angular rotation of said tensioning pins (125 v , 133 v ).
  3. 5
    A thermal printer according to any one of claims 1 to 4 further comprising a control means (22) for controlling said means for supplying said foil to said thermal printer, said means for arranging said thermal transfer ribbon in facial contact with said surface of said foil, said energizable printing means, said means for energizing said energizable printing means, said means for pressing said energizable printing means and said foil together, said means for moving said foil and said energizable printing means relative to one another, and said means for moving said thermal transfer ribbon relative to said energizable printing means.
  4. 6
    A thermal printer according to any one of claims 1 to 5 wherein said energizable printing means (100 v ) comprises a printing head including individual energizable printing elements.
  5. 7
    A thermal printer according to any one of claims 1 to 6, wherein said energizable printing means (100 v ) is stationary, said means (30) for moving said foil and said energizable printing means relative to one another causes said foil to move relative to said energizable printing means in a continuous motion, and said means (128) for moving said thermal transfer ribbon relative to said energizable printing means moves said thermal transfer ribbon relative to said energizable printing means at a reduced speed as compared to the speed of said foil relative to said energizable printing means;consequently moving said thermal transfer ribbon relative to said foil to cause ink from said thermal transfer ribbon to be transferred at said specific locations to said foil at specific areas thereof constituting said printing so as to smear said ink of said thermal transfer ribbon at said specific locations onto said foil through said motion of said thermal transfer ribbon relative to said foil while said energizable printing means are heated during said ink transfer operation, and keeping said thermal transfer ribbon stationary relative to said energizable printing means while said energizable printing means are not heated.
  6. 8
    A thermal printer according to any one of claims 1 to 6, wherein said energizable printing means (100 v ) is stationary, said means for moving said foil and said energizable printing means relative to one another causing said foil to move relative to said energizable printing means in a continuous motion, and said means for moving said thermal transfer ribbon relative to said energizable printing means operating at a reduced speed as compared to the speed of said foil relative to said energizable printing means, consequently moving said thermal transfer ribbon relative to said foil to cause ink from said thermal transfer ribbon to be transferred at said specific locations to said foil at specific areas thereof constituting said printing so as to smear said ink of said thermal transfer ribbon at said specific locations onto said foil through said motion of said thermal transfer ribbon relative to said foil while said energizable printing means are heated during said ink transfer operation, and moving said thermal transfer ribbon relative to said energizable printing means in a reverse direction relative to said energizable printing means while said energizable printing means are not heated so as to utilize an unused part of said thermal transfer ribbon in a subsequent ink transfer operation.
  7. 9
    A thermal printer according to any one of claims 1 to 6, wherein said means for moving said foil and said energizable printing means (100 v ) relative to one another is operated to cause said foil to move intermittently, to maintain said foil stationary during said ink transfer operation, and to cause said energizable printing means to move relative to said stationary foil, said means for moving said thermal transfer ribbon relative to said energizable printing means moving said thermal transfer ribbon relative to said energizable printing means at a reduced speed as compared to the speed of said foil relative to said energizable printing means, consequently moving said thermal transfer ribbon relative to said foil to cause ink from said thermal transfer ribbon to be transferred at said specific locations to said foil at specific areas thereof constituting said printing so as to smear said ink of said thermal transfer ribbon at said specific locations onto said foil through said motion of said thermal transfer ribbon relative to said foil while said energizable printing means are heated during said ink transfer operation, and moving said thermal transfer ribbon in a reverse direction relative to said energizable printing means while said energizable printing means are not heated so as to utilize an unused part of said thermal transfer ribbon in a subsequent ink transfer operation.
  8. 10
    A thermal printer according to any of the preceding claims said energizable printing means (100 v ) being controlled so as to perform said ink transfer operation utilizing a part of said thermal transfer ribbon not previously used in a preceding ink transfer operation.
  9. 12
    A thermal printer according to any one of the preceding claims, said specific speed being of the order of 50-1,000 mm/sec, such as of the order of 100-500 mm/sec, preferably of the order of 200-500 mm/sec, while said reduced speed constitutes 20-98%, such as 20-50% or 50-98% of said specific speed or alternatively constitutes 20-30%, 30-40%, 40-50%, 50-60%, 60-70%, 70-80%, 80-90% or 90-98% of said specific speed.
  10. 13
    A thermal printer according to any one of the preceding claims, said energizable printing elements of said printing head (100 v ) being arranged at a mutual spacing of the order of 0.05 mm-1 mm, such as of the order of 0.1 mm-0.5 mm, preferably substantially 0.1 mm.
  11. 14
    A thermal printer as claimed in any one of the preceding claims wherein said supply reel and said take-up reel comprise hollow plastics or cardboard cores or bobbins received on respective reel cores (124 v , 132 v ), each of said reel cores having a cylindrical or conical shaft (326) defining an outer surface in which outer surface a pair of planar and non-radially extending support surfaces (338) are provided for supporting in a respective support surface a rotatably and tiltably journalled circular plate (348) extending beyond said outer surface of said cylindrical or conical shaft.