Duplex printer using a ribbon shifting mechanism
AssigneeInternational Business Machines Corporation
InventorRichard Hunter Harris
Life of this patent
Estimating the term…
Abstract
A duplex printer for printing on opposite sides of a document includes a ribbon shifting mechanism for moving a printing ribbon between a first position, in which the ribbon extends between a print head and the document for printing on a front side of the document, and a second position, in which the ribbon extends between the document and a platen for printing on a reverse side of the document. In one version of the printer, the ribbon is shifted as a carriage used to move the print head within a printing range, within which printing occurs, is moved outside this printing range into a ribbon shifting range.
Claims21
A duplex printer, for printing on opposite sides of a document, comprising:
- an impact print head;
- a platen disposed in a spaced-apart relationship with said impact print head, absorbing impact forces from said impact print head;
- a ribbon disposed between said impact print head and said platen, wherein said ribbon is impregnated with an ink which is partially transferred from said ribbon to an adjacent surface in response to an impact force from said impact print head;
- document feed rolls, moving said document between said impact print head and said platen in a document feed direction and opposite said document feed direction:
- ribbon shifting means holding said ribbon, wherein said ribbon shifting means is movable between a disengaged position and an engaged position wherein said ribbon shifting means in said disengaged position holds said ribbon in a forward position, between said impact print head and said document as said document is moved between said impact print head and said platen and wherein said ribbon shifting means in said engaged position holds said ribbon in a rearward position between said platen and said document as said document is moved between said impact print head and said platen.
A method for printing on first and second opposite sides of a document, comprising steps of:
- (a) moving said document in a first direction between an impact print head and a platen, with a printing ribbon extending adjacent said first side of said document;
- (b) forming a printing pattern with said impact print head by selectively moving portions of said impact print head toward said platen, with ink being transferred from said printing ribbon to said first side of said document;
- (c) moving said document in said first direction into a first ribbon shifting document position allowing movement of said printing ribbon between a position adjacent said impact print head and a position adjacent said platen;
- (d) shifting said printing ribbon in a second direction between said position adjacent said impact print head and said position adjacent said platen;
- (e) moving said document opposite said first direction between said impact print head and said platen, with said printing ribbon extending adjacent said second side of said document;
- and
- (f) forming a printing pattern with said impact print head by selectively moving portions of said impact print head toward said platen, with ink being transferred from said printing ribbon to said second side of said document.
Dependencies are inferred from the claim text.