Apparatus for imprinting an unmarked foil

• US 6,564,710 B1
• Filed: 10/29/1999
• Issued: 05/20/2003
• Est. Priority Date: 10/31/1998
• Status: Expired due to Term

• Current Assignee: Heidelberger Druckmaschinen Ag
• Original Assignee: CSAT Gesellschaft Fur Computer Systeme und Automations-Technik Mit Beschrankter Haftung
• Inventors: Mathea, Hans
• Primary Examiner(s): Nguyen, Anthony H.
• Application Number:
  US09/431,572
• Time in Patent Office: 1,299 Days
• Field of Search: 101/227, 101/226, 101/228, 101/219, 101/242, 101/232, 101/234, 101/216, 101/212
• US Class Current: 101/227
• CPC Class Codes: B41J 11/42 Controlling printing material conveyance for accurate alignment of the printing material with the printhead; Print registering
• CPC Class Codes: B41J 15/16 Means for tensioning or winding the web

Abstract

In an apparatus for imprinting an unmarked foil with images which are to be arranged within sections of the foil of a predetermined length L, including a printing device, a foil section transport device for moving the foil stepwise in sections of the length L, a cutting device for cutting the foil into the sections and a foil buffer arrangement accommodating a varying length of the foil between the printing device and the transport device, a foil motion sensor is arranged at the exit of the buffer arrangement for sensing the foil movement out of the buffer arrangement and controlling accordingly the speed of the printing device and a foil length sensor is arranged in the buffer arrangement and providing a print initiation signal when the foil length between the end of the foil in the cutting device and the printing device is a predetermined multiple of the foil section length L.

Claims

1. An apparatus for imprinting an unmarked foil with images which are arranged within sections of the foil of a predetermined length, comprising a printing device through which said foil moves continuously and in which images are imprinted centered on said foil sections, a transport device receiving said foil for transporting said foil in steps of said predetermined length, a cutting device arranged adjacent said transport device for cutting said foil into said sections of said predetermined length, a control unit, a buffer arrangement having an entrance and an exit and being disposed between said printing device and said transport device and including a first foil motion sensor at the exit of said buffer arrangement and a foil length sensor providing a signal to said control unit when the length of the foil between its end in the cutting device and the printing device is a predetermined multiple of said predetermined length, said first foil motion sensor at the exit of said buffer arrangement generating a varying foil motion signal which depends on the discontinuous motion of said transport device which signal is averaged in said control unit to represent the average speed with which said foil leaves said buffer arrangement, and the averaged signal is applied to said printing device so as to operate said printing device at the same average speed at which the foil leaves the buffer arrangement.

2. An apparatus according to claim 1, wherein said buffer arrangement includes a compensation roller around which said foil extends so as to form a loop and which is movably supported such that its position depends on the length of the foil between the end of the foil at said cutting device and said printing device, said foil length sensor being positioned so as to sense the location of said compensation roller.

3. An apparatus according to claim 2, wherein said buffer arrangement includes an offset roller around which said foil extends and whose position is adjustable for controlling length of said foil between said cutting device and said printing device.

4. An apparatus according to claim 2, wherein said foil length sensor is a compensating roller position sensor and said compensating roller position sensor is arranged so as to provide a signal when the length of said foil between said cutting device and said printing device is a predetermined multiple of said predetermined length of a section of said foil on which an image is to be imprinted.

5. An apparatus according to claim 1, wherein a second foil motion sensor is arranged at the entrance to said buffer arrangement for providing a signal to said control unit indicative of the speed and foil length leaving said printing device and entering said buffer arrangement, said control unit comparing the signals from said first and second foil motion sensors for controlling the speed of said printing device.

6. An apparatus according to claim 5, wherein said control unit determines the difference between said first and second foil motion sensor signals for correcting initiation of the operation of said printing device.