Thermal printer

• US 5,674,013 A
• Filed: 04/19/1995
• Issued: 10/07/1997
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Koike, Hisayuki, Takami, Toru
• Primary Examiner(s): Wedking, David A.
• Application Number:
  US08/424,198
• Time in Patent Office: 902 Days
• Field of Search: 400/120.16, 400/120.17, 400/120 HE, 347/197, 347/198
• US Class Current: 400/120.16
• CPC Class Codes: B41J 25/304 Bodily-movable mechanisms for print heads or carriages movable towards or from paper surface
• CPC Class Codes: B41J 25/316 with tilting motion mechanisms relative to paper surface

Abstract

A thermal printer having a head carriage that includes: a head support member to which the thermal head is attached; a holding member for holding the head support member; and a connecting mechanism for connecting the head support member to the holding member so as to be rockable in forward and backward as well as leftward and rightward directions. The connecting mechanism includes: a shaft member fixed to the holding member; and an insertion hole for allowing the shaft member to be inserted thereinto, the insertion hole being formed in the head support member. The width of the insertion hole in the printing direction is substantially the same as the width of the shaft member, and the width of the insertion hole in a direction of the platen, the direction being orthogonal to the printing direction, is larger than the width of the shaft member as a whole but narrowed at a position in an axial direction thereof. The head support member is rotatable in the direction of the platen.

Claims

1. A thermal printer comprising:

a thermal head having heating elements formed thereon;

a head carriage carrying the thermal head;

a first moving mechanism for moving the head carriage in a printing direction; and

a printing paper forwarding mechanism;

the thermal head being brought in contact with the printing paper forwarded on the platen by the printing paper forwarding mechanism;

wherein

the head carriage includes;

a head support member to which the thermal head is attached;

a holding member for holding the head support member; and

a connecting mechanism for connecting the head support member to the holding member so as to be rockable in forward and backward as well as leftward and rightward directions;

the connecting mechanism includes;

a shaft member fixed to the holding member; and

an insertion hole for allowing the shaft member to be inserted thereinto, the insertion hole being formed in the head support member;

a width of the insertion hole in the printing direction is substantially the same as a width of the shaft member;

a width of the insertion hole in a direction of the platen, the direction being orthogonal to the printing direction, is larger than the width of the shaft member as a whole but narrowed at an intermediate position in an axial direction thereof; and

the head support member is rotatable in the direction of the platen.

2. A thermal printer according to claim 1, further comprising a second moving mechanism for moving at least one of the platen and the head relative to each other so that the head comes in pressure contact with the platen when printing, and the head moves away from the platen when forwarding the printing paper, wherein

a pressure contact surface of the thermal head is arranged with respect to the shaft member with a predetermined inclination with the thermal head being in pressure contact with the platen by the second moving mechanism.

3. A thermal printer according to claim 2, wherein the pressure contact surface of the thermal head is arranged with respect to the shaft member with such an inclination as to cause the thermal head and the shaft member to be spaced further apart in a downward direction, when the thermal head is in pressure contact with the platen.

4. A thermal printer according to claim 1, wherein said connecting mechanism includes a spring member for energizing said head support member in an axial direction of said shaft member.

5. A thermal printer according to claim 1, wherein the connecting mechanism has a regulating member for regulating a quantity of rock of the head support member about an axis of the shaft member, the regulating member being located either in the head support member or in the holding member.

6. A thermal printer according to claim 2, wherein the second moving mechanism is a platen moving mechanism for moving the platen with respect to the thermal head carried on the head carriage.

7. A thermal printer according to claim 6, wherein the thermal head is driven so that a reciprocating printing can be made;

and the platen moving mechanism is designed to evacuate the platen from the thermal head when the head carriage has reached one of both end positions in a direction of movement thereof.

8. In a thermal printer having a thermal head having heating elements formed thereon, a head carriage carrying the thermal head, a first moving mechanism for moving the head carriage in a printing direction, and a printing paper forwarding mechanism, and being designed to print data by causing the thermal head to come in contact with a printing paper forwarded on a platen by the printing paper forwarding mechanism, the improvement wherein:

the head carriage includes;

a head support member to which the thermal head is attached;

a holding member for holding the head support member; and

a connecting mechanism for connecting the head support member to the holding member so as to be rockable in forward and backward as well as leftward and rightward directions;

the connecting mechanism includes;

a shaft member fixed to the holding member; and

an insertion hole for allowing the shaft member to be inserted thereinto, the insertion hole being formed in the head support member;

a width of the insertion hole in the printing direction is substantially the same as a width of the shaft member;

a width of the insertion hole in a direction of the platen, the direction being orthogonal to the printing direction, is larger than the width of the shaft member as a whole but narrowed at an intermediate position in an axial direction thereof; and

the head support member is rotatable in the direction of the platen.

9. A thermal printer comprising:

a platen for supporting a printing paper, the platen having a contacting plane surface which has a rectangular shape;

a head carriage which is movable along a longitudinal direction of the contacting plane surface of the platen;

a thermal head having a plurality of heating elements provided on a surface which is brought into contact with the printing paper supported on the platen, said heating elements being arranged in a direction perpendicular to a movable direction of the head carriage; and

means for supporting the thermal head, said means for supporting the thermal head being rockably supported in a direction of the longitudinal direction of the contacting plane surface and a direction perpendicular thereto, and being inhibited from moving in the movable direction of the head carriage.