A method for heat treatment of mixed media sheets in an image reproduction apparatus having an image forming station, a heat treatment station, a conveying path for conveying the sheets one by one through the image forming station and the heat treatment station, and a duplex loop for looping sheets back from the heat treatment station to the image forming station includes pre-heating a sheet before an image is formed thereon in the image forming station. The pre-heating includes the sub-steps of passing the sheet through the image forming station while the image forming station is idle, passing the sheet through the heat treatment station for pre-heating, and looping the sheet back to the image forming station.

An image forming device includes a transfer unit that transfers a toner image onto a recording medium that has first and second surfaces and is conveyed in a conveyance direction; a main heating unit arranged downstream of the transfer unit in the conveyance direction, and which contacts and heats the recording medium and fixes the toner image onto the recording medium; a reversing unit that reverses front and back of the recording medium having a first toner image fixed onto the first surface; and a preheating unit arranged between the transfer and main heating units in the conveyance direction and that heats the recording medium having a second toner image transferred onto the second surface. The preheating unit heats the recording medium so that a temperature of the first surface is lower than a softening point of a toner before the recording medium is heated by the main heating unit.

An image forming apparatus includes a receiving portion to receive an image forming job signal for forming an image on a recording material, an image forming portion to form the image based on the received image forming job signal, and an image heating portion to heat the image, formed on the recording material by the image forming portion, in a nip where the recording material is nipped and fed. An inputting portion inputs a waiting time, and a controller performs an operation in an image forming mode so an image forming operation is not performed until a lapse of the input waiting time from the reception of the image forming job signal, and then the image forming operation is started based on the lapse of the waiting time in a stand-by state in which the image forming apparatus waits for reception of the image forming job signal.

An image forming device includes a transfer unit that transfers a toner image onto a recording medium that has first and second surfaces and is conveyed in a conveyance direction; a main heating unit arranged downstream of the transfer unit in the conveyance direction, and which contacts and heats the recording medium and fixes the toner image onto the recording medium; a reversing unit that reverses front and back of the recording medium having a first toner image fixed onto the first surface; and a preheating unit arranged between the transfer and main heating units in the conveyance direction and that heats the recording medium having a second toner image transferred onto the second surface. The preheating unit heats the recording medium so that a temperature of the first surface is lower than a softening point of a toner before the recording medium is heated by the main heating unit.

An image forming apparatus includes an image forming unit, a storage portion to which a heating unit configured to heat the sheet stored in the storage portion is detachably attached, a conveyance unit, a detection unit configured to detect attachment of the heating unit to the storage portion, and a control unit configured to control the conveyance unit such that a standby time by which conveyance of the sheet fed from the storage portion is stopped is shorter when the detection unit detects the heating unit than when the detection unit does not detect the heating unit.

An image forming apparatus includes an image forming unit, a storage portion to which a heating unit configured to heat the sheet stored in the storage portion is detachably attached, a conveyance unit, a detection unit configured to detect attachment of the heating unit to the storage portion, and a control unit configured to control the conveyance unit such that a standby time by which conveyance of the sheet fed from the storage portion is stopped is shorter when the detection unit detects the heating unit than when the detection unit does not detect the heating unit.

An image forming apparatus includes a receiving portion, an image forming portion, an image heating portion and a controller for controlling an image forming operation so that the image forming operation is started after a lapse of a time from reception of the signal of the image forming job received by the image forming apparatus in a stand-by state in which the image forming apparatus waits for the reception of the signal of the image forming job.

A method of operating an electrophotographic printer (100) to control the optical density of a printed image is described. The method comprises providing a printing substance on a transfer member (104); emitting a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and transferring, from the transfer member to a substrate (108), the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.

A method of operating an electrophotographic printer (100) to control the optical density of a printed image is described. The method comprises providing a printing substance on a transfer member (104); emitting a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and transfer-ring, from the transfer member to a substrate (108), the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.

A method of operating an electrophotographic printer (100) to control the optical density of a printed image is described. The method comprises providing a printing substance on a transfer member (104); emitting a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and transferring, from the transfer member to a substrate (108), the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.