A sheet printer includes a sheet conveyor assembly including a first conveyor with a first holding device configured for exerting a holding force on a sheet proportional to a coverage of the sheet on the first conveyor and a second conveyor upstream of the first conveyor including a second holding device configured for holding and releasing the sheet, a print head assembly positioned over the first conveyor, a detector assembly for sensing the transport of the first conveyor, a controller storing on its memory a sheet media catalogue and configured to control a release timing of the second holding device for releasing the sheet partially engaged by the first conveyor based on a media type parameter selected from the media catalogue and to control the print head assembly to commence printing the sheet based on transport information from the detector assembly.

A cassette comprises a sheet housing portion that has an opening in an upper face and houses sheets, a cassette cover that can be attached and detached and covers at least a portion of the opening, a first protruding portion that is provided in one edge portion of the cassette cover and protrudes toward a bottom face of the sheet housing portion, and a second protruding portion that is provided in the other edge portion of the cassette cover and opposes the first protruding portion, wherein the sheet housing portion includes a projection-shaped portion that protrudes toward the first protruding portion and a position regulating portion that has a gap into which the second protruding portion enters, and the first protruding portion is provided with a receiving portion into which the projection-shaped portion enters.

A sheet conveyance apparatus includes a sheet supporting tray to support a sheet, a sheet conveyance unit to convey the sheet supported on the sheet supporting tray, a first detection sensor to detect the supported sheet at a first detection position, and a second detection sensor to detect the supported sheet at a second detection position farther from a center of the sheet supporting tray in a sheet width direction than the first detection position. In addition, a control unit controls the sheet conveyance unit in a first mode in a case where the first and second detection sensors detect the sheet, and controls the sheet conveyance unit in a second mode in which a sheet conveyance speed is slower than that of the first mode in a case where the first detection sensor detects the sheet and the second detection sensor detects no sheet.

A sheet conveyance apparatus includes a sheet supporting tray to support a sheet, a sheet conveyance unit to convey the sheet supported on the sheet supporting tray, a first detection sensor to detect the supported sheet at a first detection position, and a second detection sensor to detect the supported sheet at a second detection position farther from a center of the sheet supporting tray in a sheet width direction than the first detection position. In addition, a control unit controls the sheet conveyance unit in a first mode in a case where the first and second detection sensors detect the sheet, and controls the sheet conveyance unit in a second mode in which a sheet conveyance speed is slower than that of the first mode in a case where the first detection sensor detects the sheet and the second detection sensor detects no sheet.

In a sheet conveyance apparatus a control unit controls lifting and lowering of a sheet supporting portion by a lifting unit and executes a mixed feeding in one of a plurality of modes including a first mode and a second mode. The mixed feeding is an operation in which a plurality of sheets having different lengths in a width direction orthogonal to a feed direction of a sheet feeding unit are fed by the feeding unit, wherein in the first mode, the control unit causes the lifting unit to move the supporting portion from the second position to the first position based on an instruction to start sheet feeding, and in the second mode, the control unit causes the lifting unit to move the supporting portion from the second position to the first position based on a detection of a sheet by the detection unit.

A sheet supporting apparatus includes a positioning device to position a regulating portion to a sheet support. The positioning device includes a first group of teeth provided on the sheet support, a second group of teeth disposed at a position different from the first group of teeth provided on the sheet support, a third group of teeth provided on a regulator and capable of transiting to a first state of engaging with the first group of teeth and to a second state of engaging with less area of the first group of teeth than that in the first state, and a fourth group of teeth provided on the regulator and capable of transiting to a third state of engaging with the second group of teeth and to a fourth state of engaging with less area of the second group of teeth than that in the third state.

A sheet supporting apparatus includes a positioning device to position a regulating portion to a sheet support. The positioning device includes a first group of teeth provided on the sheet support, a second group of teeth disposed at a position different from the first group of teeth provided on the sheet support, a third group of teeth provided on a regulator and capable of transiting to a first state of engaging with the first group of teeth and to a second state of engaging with less area of the first group of teeth than that in the first state, and a fourth group of teeth provided on the regulator and capable of transiting to a third state of engaging with the second group of teeth and to a fourth state of engaging with less area of the second group of teeth than that in the third state.

A sheet feeding apparatus includes a tray that stores a recording medium in a closed state in which the tray is placed in an apparatus body, the tray being capable of being pulled out from the apparatus body in a predetermined pulling direction; a transport unit that is provided on the apparatus body and that transports the recording medium in a direction crossing the pulling direction when the tray is in the closed state; a first contact portion provided on the tray and having a contact surface spaced from the transport unit when viewed in the pulling direction, the first contact portion being located upstream of the transport unit in the pulling direction and the contact surface being in contact with an upstream end portion of the recording medium stored in the tray in the pulling direction when the tray is in the closed state; a second contact portion disposed at a position that is upstream of the transport unit in the pulling direction and at which the second contact portion overlaps the transport unit when viewed in the pulling direction, the second contact portion having a contact surface that is in contact with the end portion when the tray is in the closed state; a first overlapping portion provided on the first contact portion and disposed downstream of the second contact portion in the pulling direction, the first overlapping portion overlapping the second contact portion when viewed in the pulling direction; and an urging portion that urges the second contact portion downstream in the pulling direction so that the second contact portion abuts against the first overlapping portion when the tray is in the closed state.

An automatic detection method for a paper size is disclosed. a plurality of mark points is set on a paperweight along a paperweight direction that is different from a feeding direction. The disclosure senses a plurality of row images combining into a scan image during a paper passing between the paperweight and an image sensor, determines an edge length of the paper based on a range of the mark points covered by the paper, and determines a paper size based on the edge length. The disclosure can effectively detect the paper size without any additional sensors.

An automatic detection method for a paper size is disclosed. a plurality of mark points is set on a paperweight along a paperweight direction that is different from a feeding direction. The disclosure senses a plurality of row images combining into a scan image during a paper passing between the paperweight and an image sensor, determines an edge length of the paper based on a range of the mark points covered by the paper, and determines a paper size based on the edge length. The disclosure can effectively detect the paper size without any additional sensors.