Incremental printing of symbolic information – Thermal marking apparatus or processes – Density control
Reexamination Certificate
2006-11-21
2006-11-21
Feggins, K. (Department: 2861)
Incremental printing of symbolic information
Thermal marking apparatus or processes
Density control
Reexamination Certificate
active
07139010
ABSTRACT:
A thermal head printer with image-invariant printing speeds for printing a substantially light-insensitive thermographic material having a print density-driving power level characteristic, the thermal head printer comprising a transport means, one or more thermal heads each having an array of heating elements, a thermal print head drive system capable of supplying power to each of the printing elements, and a calibration means based on the print density-driving power level characteristic of the thermographic material; a process for calibrating a thermal head printer with image-invariant printing speeds, the thermal head printer comprising one or more thermal heads each having an array of heating elements connected to a power supply capable of supplying a given number of heating element driving power levels from 0 to a maximum driving power level number, corresponding to Pmax, to each heating element for printing a substantially light-insensitive thermographic material by image-wise heating the thermographic material with the heating elements, the process comprising the steps of: (i) putting the printer into a calibration mode; (ii) printing one or more step-wedges of print densities by heating the thermographic material with the heating elements at different DPLN'S; (iii) determining the optical density of each step of the step-wedge(s) of print densities with a densitometer thereby obtaining the dependence of the print density upon DPLN; (iv) deriving from the dependence, or all the dependences of the print density upon DPLN, a single smoothed dependence of the rate of change of print density, D, with DPLN, ΔD/ΔDPLN, as a function of DPLN for the thermographic material; (v) establishing a threshold rate of print density change per DPLN for the specific thermographic material being printed; and (vi) setting up the thermal head printer so that the threshold rate of print density increase per DPLN cannot be undercut; and a process for printing a substantially light-insensitive thermographic material with a thermal head printer comprising one or more thermal heads each having an array of heating elements connected to a power supply capable of supplying a given number of heating element driving power levels from 0 to a maximum driving power level number, corresponding to Pmax, the process comprising the steps of: calibrating the thermal head printer according to the above-described calibration process, transporting the substantially light-insensitive thermographic material past the thermal head, and image-wise heating of the substantially light-insensitive thermographic material by means of the heating elements.
REFERENCES:
patent: 4939581 (1990-07-01), Shalit
patent: 5469203 (1995-11-01), Hauschild
patent: 5528275 (1996-06-01), Shinya et al.
patent: 5711621 (1998-01-01), Austin
patent: 5796420 (1998-08-01), Kaerts et al.
patent: 6234695 (2001-05-01), Freedman et al.
patent: 6411318 (2002-06-01), Sawano et al.
patent: 6462766 (2002-10-01), Roeber et al.
patent: 6503006 (2003-01-01), Freedman et al.
patent: 2001/0004284 (2001-06-01), Fukuda et al.
patent: 2002/0136582 (2002-09-01), Verdyck
patent: 0 453 714 (1991-10-01), None
patent: 0 922 585 (1999-06-01), None
patent: 1 006 404 (2000-06-01), None
patent: 1 247 654 (2002-10-01), None
patent: 2002 036610 (2002-02-01), None
Search Report for EP 03 10 0622 (Aug. 6, 2003).
DeMeutter Stefaan
Kaerts Eric
AGFA Gevaert
Feggins K.
Leydig Voit & Mayer Ltd
LandOfFree
Thermal head printer and process for printing substantially... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermal head printer and process for printing substantially..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal head printer and process for printing substantially... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3706357