BACKGROUND

Field

The present disclosure relates to a printing apparatus and a conveyance control method thereof. In particular, the present disclosure relates to, for example, a printing apparatus that includes a full-line inkjet printhead and a conveyance control method of this apparatus.

Description of the Related Art

Conventionally, there is a printing apparatus that uses a rolled sheet as a print medium, uses a cutter to cut a printed portion when printing is completed, and discharges the cut printed portion outside the apparatus. In such a printing apparatus, in order not to stop the next printing operation, a rolled sheet is looped (slacked) on a conveyance path of the rolled sheet before the rolled sheet is cut, the conveyance of the rolled sheet which is closer to the downstream side than the looped portion is stopped when the rolled sheet is to be cut, and the rolled sheet is cut by using the time in which the loop is consumed.

In order to implement a more accurate rolled sheet conveyance, for example, Japanese Patent Laid-Open No. 2009-220498 includes the following control arrangement. That is, a unit for correcting the number of rotation pulses applied to a conveyance motor for driving a conveyance roller and a unit for controlling a loop amount are included, control is performed by reducing the loop amount if a sheet length designated by a print job is a predetermined length or more, and control is performed without reducing the loop amount if the sheet length is less than the predetermined length. By such control, tension acts on the rolled sheet while the loop amount has been reduced, and the skewing and the meandering of the rolled sheet on the conveyance roller can be suppressed.

In addition, a rotation pulse correction value of the conveyance motor that conveys the conveyance roller is switched in accordance with whether the designated sheet length is equal to or more than a predetermined value (whether loop amount reduction control is present). As result, a conveyance shift between an actual sheet conveyance amount and the number of pulses caused by a difference in the tension applied to the sheet due to the magnitude of the loop amount can be corrected. Subsequently, in a case in which the loop amount has been reduced, the rolled sheet will be cut after a sufficient loop has been formed by increasing the loop amount when the remaining sheet length to the completion of a page undergoing printing has become equal to or less than a predetermined length.

In this arrangement, since a uniform rotation pulse correction value will be used for the conveyance moor during a print job, the conveyance of the rolled sheet in the entire single print job can be implemented highly accurately.

However, in the above-described conventional example, if control is performed to reduce the loop amount, the tension acting on the rolled sheet will rapidly change at the point of time at which the loop amount is changed midstream, and the conveyance amount of the rolled sheet will rapidly change before and after the change in the loop amount. Such a rapid change in the conveyance amount can make the printed image nonuniform and degrade the image quality.

SUMMARY

The disclosure provides information regarding a printing apparatus that can implement highly accurate conveyance of a print medium and print a high quality image, and a conveyance control method of this apparatus.

According to an aspect of the present disclosure, a printing apparatus to convey a print medium that is continuous and to use a printhead to perform printing on the conveyed print medium, includes a feeding unit configured to feed the print medium, a conveyance unit configured to nip the print medium conveyed from the feeding unit by a first roller and a second roller which is arranged closer to a downstream side than the first roller with respect to a conveyance direction of the print medium, and to convey the nipped print medium, a cutting unit configured to cut the print medium, wherein the cutting unit is arranged closer to an upstream side than the first roller with respect to the conveyance direction of the print medium, and a control unit configured to control the conveyance of the print medium and an operation of the cutting unit, wherein the control unit: (1) performs control to make a command speed of the first roller lower than a command speed of the second roller until printing by the printhead reaches near a trailing edge of a printing length after the printhead has started the printing on the print medium conveyed by the conveyance unit, (2) performs control to make the command speed of the first roller higher than the command speed of the second roller when the printing by the printhead has reached near the trailing edge of the printing length, and (3) subsequently performs control to control the cutting unit configured to cut the print medium.

Further features of the present disclosure will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

