Printing system and method for printing on both surfaces of web
AssigneeHitachi Printing Solutions, Ltd.
InventorSouichi Nakazawa
Life of this patent
Estimating the term…
Abstract
A second printing unit includes a mark detection means for detecting a positioning mark that a first printing unit has formed on a front surface of a web. A control means controls web-transport speed in the second printing unit so that a time difference between a generation timing of a CPF-N signal and a detection timing of the positioning mark becomes constant, and also stores the web-transport speed into a memory. During a subsequent printing operation, a web-transport speed is controlled to be the same as the web-transport speed stored in the memory for a period until a positioning mark is first detected after the printing is started.
Claims18
A printing system comprising:
- a first printing unit that prints images on a first surface of a web, the first printing unit including a mark forming unit that forms a positioning mark at a predetermined position of the web;
- and
- a second printing unit that prints images on a second surface of the web opposite from the first surface, wherein at least the second printing unit includes:
- a mark detection means for detecting the positioning mark formed by the mark forming unit and outputting a mark detection signal accordingly;
- a calculation means for calculating an appropriate transport speed of the web based on an output timing of the mark detection signal;
- a memory means for storing a first information on the transport speed of the web calculated by the calculation means;
- and
- a control means for controlling a transport speed of the web based on the first information stored in the memory means at least for a period until the mark detection means detects the positioning mark for a first time after a printing operation was started.
A printing system comprising:
- a first printing unit that prints images on a first surface of a web, the first printing unit including a mark forming unit that forms a positioning mark at a predetermined position of the web;
- and
- a second printing unit that prints images on a second surface of the web opposite from the first surface, the second printing unit including a transport means for transporting the web, wherein
- at least the second printing unit includes:
- a mark detection means for detecting the positioning mark formed by the mark forming unit and outputting a mark detection signal accordingly;
- and
- a control means for controlling a transport speed of the web based on an output timing of the mark detection signal, wherein
- the control unit includes:
- a microcomputer that designates a first value and a second value;
- a first signal process portion including a first counter that stops counting at the output timing of the mark detection signal;
- a second signal process portion including a second counter that is set to the first value designated by the microcomputer, the second counter outputting a pulse indicating a start timing of web transport;
- and
- a web transport control portion that controls the transport means to start transporting the web in response to the pulse from the second counter and that controls the web transport speed based on the second value, wherein
- the microcomputer designates the second value based on the count value of the first counter at the time of when the first counter stops counting.
A printing method for printing images on both first and second surfaces of a web, the printing method comprising the steps of:
- a) forming a positioning mark at a predetermined position in addition to an image on a first surface of the web using a first printing unit;
- b) controlling a transport speed of the web in a second printing unit based on a first information that has been stored in a memory means, at least for a period until the positioning mark is detected in the step c) for a first time after a printing operation was started, the first information being on a transport speed of the web calculated by a calculation means during a previous printing operation;
- c) detecting the positioning mark using a detection unit of the second printing unit, and generating a mark detection signal accordingly;
- d) calculating an appropriate transport speed of the web based on an output timing of the mark detection signal;
- and
- e) updating the first information stored in the memory means.
Dependencies are inferred from the claim text.