Color thermal printer and color thermal printing method
AssigneeFuji Photo Film Co., Ltd.
InventorShusuke Mogi
Life of this patent
Estimating the term…
Abstract
The printer has a conveyor roller pair and three thermal heads to record yellow, magenta and cyan images onto a recording sheet. The conveyor roller pair receives forward tension Ff from the forward tension roller pairs located near the thermal heads to pull the recording sheet with tension. A backward tension roller pair is provided to generate backward tension Fb to cancel forward tension Ff so that the recording sheet is conveyed at a stable conveyance speed. The coefficient of friction between the thermal head and the recording sheet is varied depending on the temperature, humidity and so force. Backward tension Fb is equal to Ef·α in consideration of the correction value α to correct variation in the coefficient of friction.
Claims15
A color thermal printer having a conveyor roller pair and plural thermal heads that are arranged in the downstream side of said conveyor roller pair, said thermal heads recording a color image onto a recording sheet while said recording sheet is conveyed forward, said printer comprising:
- plural forward tension roller pairs each of which is provided in the downstream side of said thermal head, said front tension roller pair nipping and applying forward tension to said recording sheet to convey said recording sheet downstream;
- and
- a backward tension roller pair provided in the upstream side of said conveyor roller pair, said backward tension roller pair applying backward tension to decrease said forward tension.
A color thermal printer having a conveyor roller pair and plural thermal heads that are arranged in the downstream side of said conveyor roller pair, said thermal heads recording a color image onto a recording sheet while said recording sheet is conveyed forward, said printer comprising:
- plural platen rollers each of which is provided in the position to face said thermal head, said recording sheet being nipped between said platen roller and said thermal head, said platen roller applying forward tension to said recording sheet to convey said recording sheet downstream;
- and
- a backward tension roller pair provided in the upstream side of said conveyor roller pair, said backward tension roller pair applying backward tension to decrease said forward tension.
A thermal printing method for recording a color image by plural thermal heads that are arranged in the downstream side of a conveyor roller pair to convey said recording sheet forward, said method comprising steps of:
- applying forward tension to said recording sheet near said thermal head to convey said recording sheet downstream;
- and
- applying backward tension to said recording sheet in the upstream side of said conveyor roller pair to decrease said forward tension.
Dependencies are inferred from the claim text.