Thermal ink-transfer printer capable of preventing off-registration of colors at color printing
First Claim
1. A thermal ink-transfer printer for printing a color image on a printing paper wound along an outer surface of a platen roller by pressing a thermal head against the paper and an ink film interposed therebetween and by melting an ink on the ink film caused by the thermal head, said paper being moved by rotation of the platen roller, said printer comprising:
- driving means for causing controlled rotation of the platen roller;
clamp means provided rotatably at both ends of said platen roller for clamping and holding an end of the paper fed to the outer surface of said platen roller, said clamp means being rotatable independently from the platen roller and comprising supporting rings rotatably provided at both ends of a shaft of said platen roller for supporting a holding member parallel to said platen roller along a longitudinal direction, and clamp levers mounted respectively on inner surfaces of both said supporting rings for clamping corners of said end of the paper in conjunction with said holding member;
clutch means for coupling and decoupling said clamp means to and from said platen roller so that said clamp means rotate together with said platen roller when coupled thereto by said clutch means, said clutch means comprising clutch levers arranged respectively at inner surfaces of said supporting rings and arranged to engage with said clamp levers for causing said clamp levers to separate from said holding member, and clutch rings mounted on both ends of the shaft of the platen roller between the platen and inner sides of the clamp and clutch levers for rotation with said platen, each of said clutch rings having a recess with which a projection provided on each of said clutch levers engages;
a pinch roller for pressing the paper against said platen roller, when the paper is clamped by said clamp means and is moved by said platen roller in a printing mode;
encoder means mounted on said platen roller for generating a control signal for controlling a print starting time for each color; and
control means for controlling said clutch means to couple said platen roller to said clamp means so that said platen roller and said clamp means holding the end of the paper rotate together for a predetermined angular range thereof and to decouple said platen roller from said clamp means to allow said platen roller to rotate beyond said predetermined angular range independent from the clamp means so that the paper continues to move for full printing range thereof in the printing mode, for controlling operations of said pinch roller and said driving means and for controlling said print starting timing for each color on the basis of said control signal from said encoder means.
1 Assignment
0 Petitions
Accused Products
Abstract
A thermal ink-transfer printer for printing a color image on a paper wound along a platen roller in the manner where a thermal head is pressed against the paper and an ink film interposed therebetween so that ink on the ink film is melted by the thermal head. The printer comprises clamp mechanisms having supporting rings and clamp levers for holding an end of the paper against a holding member, clutch mechanisms having clutch rings and clutch levers for fixing the clamp mechanisms and platen roller in a start positioning mode and a printing mode, and a controlling element for coupling the clutch mechanisms with the platen roller in a paper feeding mode and a paper ejecting mode. As the clamp mechanisms hold the supplied end of the paper and the platen roller and the clamp mechanisms have their rotation individually controlled, it is possible to prevent color off-registration in color printing.
37 Citations
7 Claims
-
1. A thermal ink-transfer printer for printing a color image on a printing paper wound along an outer surface of a platen roller by pressing a thermal head against the paper and an ink film interposed therebetween and by melting an ink on the ink film caused by the thermal head, said paper being moved by rotation of the platen roller, said printer comprising:
-
driving means for causing controlled rotation of the platen roller; clamp means provided rotatably at both ends of said platen roller for clamping and holding an end of the paper fed to the outer surface of said platen roller, said clamp means being rotatable independently from the platen roller and comprising supporting rings rotatably provided at both ends of a shaft of said platen roller for supporting a holding member parallel to said platen roller along a longitudinal direction, and clamp levers mounted respectively on inner surfaces of both said supporting rings for clamping corners of said end of the paper in conjunction with said holding member; clutch means for coupling and decoupling said clamp means to and from said platen roller so that said clamp means rotate together with said platen roller when coupled thereto by said clutch means, said clutch means comprising clutch levers arranged respectively at inner surfaces of said supporting rings and arranged to engage with said clamp levers for causing said clamp levers to separate from said holding member, and clutch rings mounted on both ends of the shaft of the platen roller between the platen and inner sides of the clamp and clutch levers for rotation with said platen, each of said clutch rings having a recess with which a projection provided on each of said clutch levers engages; a pinch roller for pressing the paper against said platen roller, when the paper is clamped by said clamp means and is moved by said platen roller in a printing mode; encoder means mounted on said platen roller for generating a control signal for controlling a print starting time for each color; and control means for controlling said clutch means to couple said platen roller to said clamp means so that said platen roller and said clamp means holding the end of the paper rotate together for a predetermined angular range thereof and to decouple said platen roller from said clamp means to allow said platen roller to rotate beyond said predetermined angular range independent from the clamp means so that the paper continues to move for full printing range thereof in the printing mode, for controlling operations of said pinch roller and said driving means and for controlling said print starting timing for each color on the basis of said control signal from said encoder means. - View Dependent Claims (2)
-
-
3. A thermal ink-transfer printer for printing a color image on a printing paper wound along an outer surface of a platen roller having a shaft by pressing a thermal head against the paper and an ink film interposed therebetween and by melting an ink on the ink film by the thermal head, said paper being moved by rotation of the platen roller, comprising:
-
driving means for causing controlled rotation of the platen roller; clamp means provided rotatably at both ends of the platen roller for clamping and holding an end of the paper fed to the outer surface of the platen roller, and comprising supporting rings rotatably provided at both ends of the shaft of the platen roller for supporting a holding member parallel to the platen roller along a longitudinal direction, and clamp levers respectively mounted on inner surfaces of both of said supporting rings for clamping corners of an end of the paper in conjunction with the holding member, said clamp means being rotatable independently from said platen roller; clutch means for coupling and decoupling said clamp means to and from said platen roller so that said clamp means rotate together with said platen roller when coupled thereto by said clutch means, and comprising clutch levers respectively arranged at inner surfaces of said supporting rings and arranged to engage with said clamp levers for causing said clamp levers to separate from said holding member, and clutch rings mounted to both ends of the platen roller shaft and between the platen and inner sides of the clamp and clutch levers for rotation with said platen, each of said clutch rings having a recess with which a projection provided on each of said clutch levers engages; a pinch roller for pressing the paper against said platen roller, when the paper is clamped by said clamp means and is moved by said platen roller in a printing mode; and means for controlling said clutch means to couple said platen roller to said clamp means so that said platen roller and said clamp means holding the end of the paper rotate together for a predetermined angular range thereof, and to decouple said platen roller from said clamp means to allow said platen roller to rotate beyond said predetermined angular range independent from the clamp means so that the paper continues to move for full printing range thereof in the printing mode and for controlling operation of said pinch roller and said driving means. - View Dependent Claims (4)
-
-
5. A thermal ink-transfer printer for printing a color image on a printing paper wound along an outer surface of a platen roller having a shaft by pressing a thermal head against the paper and an ink film interposed therebetween and by melting an ink on the ink film by the thermal head, said paper being moved by rotation of the platen roller, comprising:
-
driving means for causing controlled rotation of the platen roller; clamp means provided rotatably at both ends of the platen roller for clamping and holding an end of the paper fed to the outer surface of the platen roller; clutch means for coupling and decoupling said clamp means to and from said platen roller so that said clamp means rotate together with said platen roller when coupled thereto by said clutch means; a pinch roller for pressing the paper against said platen roller when the paper is clamped by said clamp means and is moved by said platen roller in a printing mode; means for controlling said clutch means to couple said platen roller to said clamp means so that said platen roller and said clamp means holding the end of the paper rotate together for a predetermined angular range thereof, and to decouple said platen roller from said clamp means to allow said platen roller to rotate beyond said predetermined angular range independent from the clamp means so that the paper continues to move for full printing range thereof in the printing mode, and for controlling operation of said pinch roller and said driving means; and wherein said clamp means comprises supporting rings rotatably supported on both ends of the shaft of said platen roller, said supporting rings further supporting a clamp lever of said clamp means and said clutch means, said supporting rings respectively further supporting a corner of a holding member, said holding member comprising a long plate having an L-shaped cross-section, and having a recess on an outer surface thereof with which fastening pins provided on a clutch lever of said clutch means respectively engage, said clamp lever of said clamp means clamping and holding a corner of the end of said paper between said clamp lever and said holding member. - View Dependent Claims (6)
-
-
7. A thermal ink-transfer printer for printing a color image on a printing paper wound along an outer surface of a platen roller by pressing a thermal head against the paper and an ink film interposed therebetween and by melting an ink on the ink film caused by the thermal head, said paper being moved by rotation of the platen roller, said printer comprising:
-
driving means for causing controlled rotation of the platen roller; clamp means provided rotatably at both ends of said platen roller for clamping and holding an end of the paper fed to the outer surface of said platen roller, said clamp means being rotatable independently from the platen roller and comprising supporting rings rotatably supported on both ends of a shaft of said platen roller and further supporting on the inner sides thereof respectively a clamp lever of said clamp means and a clutch lever of said clutch means, said supporting rings further supporting a holding member at respective corners of the holding member, the holding member comprising an elongated plate having an L-shaped cross-section, and each supporting ring having a recess on an outer surface thereof with which fastening pins provided on each clutch lever of said clutch means respectively engage, each clamp lever of said clamping means clamping and holding a corner of the end of said paper between said clamp lever and said holding member; clutch means for coupling and decoupling said clamp means to and from said platen roller so that said clamp means rotate together with said platen roller when coupled thereto by said clutch means; a pinch roller for pressing the paper against said platen roller, when the paper is clamped by said clamp means and is moved by said platen roller in a printing mode; encoder means mounted on said platen roller for generating a control signal for controlling a print starting time for each color; and control means for controlling said clutch means to couple said platen roller to said clamp means so that said platen roller and said clamp means holding the end of the paper rotate together for a predetermined angular range thereof and to decouple said platen roller from said clamp means to allow said platen roller to rotate beyond said predetermined angular range independent from the clamp means so that the paper continues to move for full printing range thereof in the printing mode, for controlling operations of said pinch roller and said driving means and for controlling said print starting timing for each color on the basis of said control signal from said encoder means.
-
Specification