An image forming apparatus includes: a main apparatus body having an image forming unit and a discharge tray; and a controller. The main apparatus body includes a conveyance path along which a sheet passed through the image forming unit is conveyed; a discharge path branched from the conveyance path and connected to the discharge tray; and a reconveyance path having a first path different from the discharge path and a second path for conveying the sheet to the image forming unit. In a double-sided printing, if a first sheet has passed through the first path when a forward end of a second sheet arrives at a predetermined position in the conveyance path, the controller conveys the second sheet to the first path and then conveys the second sheet to the second path.

An image forming apparatus operable at a plurality of image forming speeds includes a pattern detection unit configured to detect a registration correction pattern at a first image forming speed, a writing start timing determination unit configured to determine writing start timing at which an electrostatic latent image is started to be written on a photosensitive member by a light beam emitted from a light source, and a storage unit configured to store in advance a correction amount for correcting the writing start timing. When the image forming apparatus operates at the first image forming speed set in advance, an image is formed at the writing start timing determined by the writing start timing determination unit. When the image forming apparatus operates at a second image forming speed, an image is formed at a writing start timing corrected based on the correction amount and a speed ratio.

In an image forming system, a hardware processor controls whether the first sheet is conveyed to an upstream side of the image former via a first conveying path which reverses sides of the first sheet or via a second conveying path which does not reverse the sides of the first sheet as well as the first conveying path, when images are formed on both sides of a plurality of the first sheets by the image former, in order to narrow a space between a plurality of the first sheets.

An image forming apparatus includes first and second conveyance and calculation units, a reverse unit, a control unit, an image forming unit, and a stack unit to stack sheets. A recording material is conveyed from the stack unit to the image forming unit. The recording material is conveyed reversely, and is conveyed to a double-sided conveyance path and to the image forming unit. Without causing a recording material to wait in the reverse unit, a first recording material is conveyed from the stack unit, then a second recording material is conveyed, and subsequently a third recording material is conveyed. A conveyance interval time and a maximum waiting time are calculated. When the conveyance interval time exceeds the maximum waiting time, the second recording material conveyance starts at timing based on a waiting time after conveyance of the first recording material, and the third recording material conveyance starts at a timing.

A sheet discharge port is provided with a guide piece extending obliquely downward in a discharge direction from an upper edge of the sheet discharge port to oppose an outlet port. The guide piece blocks flow of cooling air, which has been blown out from the outlet port, into the sheet discharge port and also abuts the sheet discharged from the sheet discharge port to guide the sheet obliquely downward in the discharge direction.

A control apparatus comprises: a grouping unit that divides a plurality of sheets each associated with image data included in a processing target job into groups each having a predetermined size; and a control unit that controls feeding of a sheet from a feeding unit onto a conveyance path and refeeding of a sheet which has been conveyed on the conveyance path onto the conveyance path, wherein the predetermined size is not less than a maximum sheet size used in the processing target job, a plurality of groups can be conveyed on the conveyance path, and the control unit controls feeding and refeeding for each group grouped in the grouping unit.

This image forming device includes an image former, a fuser, a sheet transport path that transports a paper sheet to the image former and the fuser, first and second discharge ports that are connected to the sheet transport path so as to enable a paper sheet on which a toner image has been fused to be discharged to the outside, and a controller. The sheet transport path includes first to third transport paths, and a first and second switcher. The controller, in the case of duplex printing, controls the first and second switchers such that a one end side of the paper sheet is transported to the second discharge port, and controls the second switcher such that, when the one end side is being discharged from the second discharge port, reverses the paper sheet and causes the another end side to be transported toward the image former.

A spectral colorimetric apparatus comprises a light source, a spectral element, a light receiving element, a substrate on which the light receiving element is mounted, a housing and a pressing portion. The housing has a first side wall on which the substrate is fixed and a second side wall on which the spectral element is fixed. The pressing portion pinches the spectral element together with the second side wall and presses the spectral element to the second side wall.

An image forming apparatus for forming an image on a sheet, includes an image forming unit configured to form the image on the sheet, a double-sided conveyance path through which the sheet with the image formed on a first surface passes before the image forming unit forms an image on a second surface opposite to the first surface, a guide member having a contact portion configured to contact one end of the sheet in the width direction of the sheet, the guide member being provided on the double-sided conveyance path, and a reversing roller pair forwardly and reversely rotatable, configured to convey the sheet to the double-sided conveyance path during a reverse rotation, the reversing roller pair having a drive shaft, and a first roller and a second roller coaxially disposed on the shaft, rotatable with the shaft, wherein the second roller is disposed at a position more away from the contact portion than the first roller in the axial direction of the shaft, the second roller having a larger outer diameter than the first roller.

A printing device includes a first ejector that ejects a recording medium to an exterior, a second ejector that enhances a rigidity of the recording medium more than by the first ejector, and ejects the recording medium to the exterior, and an ejector selector that selects either the first ejector or the second ejector.