In recording data with a transfer type heat-sensitive printer, an ink donor sheet on which thermally sublimable or thermally meltable solid ink has been coated is laid over a recording sheet (which is an ordinary sheet). When the donor sheet and recording sheet are arranged in this manner the thermal pulses are applied thereto from the side of the ink donor sheet. This causes the sublimated or molten ink to be transferred onto the recording sheet.
FIG. 1 shows a conventional transfer type heat-sensitive printer having conveying systems which supply an ink donor sheet and a recording sheet separately to the recording section. The printer has a supply donor roll 2 for supplying the ink donor sheet 1 and a take-up donor roll 3 for winding the ink donor sheet 1. The ink donor sheet 1 from the supply donor roll 2, being guided by an idler shaft 4, passes between a back roll 5 and a thermal head 6. The sheet 1 further passes between the back roll 5 and a drive roll 7 and between the drive roll 7 and a pinch roll 8. The sheet 1 thus run, being guided by another idler shaft 9, is wound on the take-up donor roll 3.
On the other hand, the recording sheet 11 which has been cut to a predetermined size is fed with predetermined timing by a pair of feed rollers 12 and 13. The recording sheet 11 is combined with the ink donor sheet 1 upstream of the recording section A which is made up of the back roll 5 and the thermal head 6. The recording sheet 11 thus combined passes over the heat generating elements of the thermal head 6, while being held between the ink donor sheet 1 and the back roll 5. In this operation, thermal transfer recording is carried out. Hereafter, the recording sheet 11 passes between the back roll 5 and the drive roll 7. During this operation, the recording sheet 11 is run in the common tangential direction of the rolls 5 and 7 by its own elastic strength, to separate from the ink donor sheet 1. Then, the recording sheet 1, being guided by a guide plate 14 disposed above the drive roll 7, is delivered to a discharging roll 15 which is located near a recording sheet discharging outlet (not shown). After being caught by the discharging roll 15, the recording sheet 11 is delevered to a discharging tray (not shown).
The conveying systems for the ink donor sheet 1 and the recording sheet 11 have two drive sources, respectively. The first drive source 16 drives the feed roll 12, to feed the recording sheet 11 simultaneously when the recording operation starts. On the other hand, when the top end of the recording sheet 11 comes near the recording section A, the second drive source 17 turns the take-up donor roll 3 and the drive roll 7 in the directions of the arrows through belts. The rotation of the drive roll 7 is transmitted to the back roll 5 which is in contact with the drive roll 7, and the rotation of the back roll 5 is transmitted to the discharging roll 15 through a belt. Thus, the ink donor sheet 1, and the recording sheet which has reached the recording section A are conveyed and discharged. When the recording sheet has been discharged, the second dirve source 17 is stopped.
As is apparent from the above description, in the conventional transfer type heat-sensitive printer, is is necessary to operate the second drive source until the recording sheet is completely delivered to the discharging tray by the discharging roll 15. Accordingly, for a while after the rear edge of the recording sheet has passed through the back roll 5 and the drive roll 7, the ink donor sheet 11 is run; that is, the ink donor sheet is uselessly consumed.
USPTO Backgrounds
USPTO Backgrounds