Patent ID: 6037961
Filing Date: 2000-03-14
Classification: B41J

Abstract:
A thermal printing method in which thermosensitive recording material is conveyed relative to a thermal head, and has a recording surface contacted on said thermal head, and said thermal head applies heat energy to said recording material to record an image on said recording material, said thermal printing method comprising the steps of:providing a platen roller confronting said thermal head;providing a preheating device; andpreheating said recording material with said preheating device shortly before recording of said recording material with said thermal head by applying a preheating energy lower than enough to color said recording material, but high enough to heightening temperature of said recording material upon relative movement of said recording material to said thermal head, whereby said heat energy to be applied by said thermal head is reduced according to said preheating energy,wherein said preheating step causes said recording surface to have surface temperature Ts upon relative movement of said recording material to said thermal head, said surface temperature Ts meeting:Ts.gtoreq.50.degree. C.;t1-t2.ltoreq.Ts; andTr.gtoreq.Ts;where t1 is a temperature of said recording surface for coloring said recording material at maximum density thereof without said preheating step;t2 is a temperature of said recording surface at which said recording surface is thermally damaged; andTr is room temperature.