When a disconnection detecting circuit detects failure, a controller of a temperature controller manipulates a duty ratio to distribute the duty ratio to normal heating rollers. Since the amount of heat decreased by failure of a heating roller can be compensated for by the other heating rollers, no defective drying will occur. It is not necessary to stop a printing process immediately when the disconnection detecting circuit detects failure, but a maintenance operation can be carried out after fully securing a preparation time for maintenance. The quick maintenance can be performed to restrain downtime of the printing apparatus.

An ink jet recording method includes a treatment liquid attachment step, in which a treatment liquid is attached to a recording medium, and an ink attachment step, in which a water-based ink composition is attached to the recording medium. An ink jet recording apparatus includes a recording medium support and a heating mechanism that heats the recording medium support. The ink attachment step is carried out with the recording medium supported and heated by the recording medium support. In the ink attachment step, the recording medium is heated so that a surface thereof reaches a maximum temperature of 28.0° C. or more and 45.0° C. or less. The ratio between absorbances A and B (A/B) is 0.5 or more and 0.95 or less, where absorbance A is that of a 0.1% by mass mixture of the water-based ink composition in the treatment liquid, and absorbance B is that of a 0.1% by mass mixture of the water-based ink composition in purified water. The recording medium support has a flat support surface for supporting the recording medium.

A heating device heats a sheet to which a liquid discharge unit discharges a liquid. The heating device includes a first heater to heat the sheet that has passed through the liquid discharge unit, a vacuum conveyor to convey the sheet that has passed through the first heater while sucking the sheet, a second heater to heat the sheet being conveyed by the vacuum conveyor, and circuitry that cause the first heater to heat the sheet when sheet data regarding the sheet satisfies a predetermined condition.

A drying device includes a heater, a supporter, a controller, and a temperature detector. The heater heats a medium. The supporter is disposed opposite the heater to support the medium. The controller turns on the heater while the medium is conveyed, and turns off the heater when the medium is stopped. The temperature detector detects a temperature of the supporter. The controller is connected to the temperature detector to turn off the heater when the temperature detected with the temperature detector is a predetermined temperature or higher.

A heating device includes a holder, a receiver, a heating unit, a vertical mover, and circuitry. The holder holds a heating target object. The receiver removably holds the holder. The heating unit heats the heating target object. The vertical mover moves at least one of the receiver and the heating unit vertically relative to each other, between a non-contact heating position and a contact heating position. The circuitry causes the vertical mover to move the at least one of the receiver and the heating unit to the non-contact position, causes the heating unit to heat the heating target object in a non-contact state, causes the vertical mover to move the at least one of the receiver and the heating unit to the contact heating position, and causes the heating unit to heat the heating target object in a contact state.

A heating device includes a conveyor configured to convey a sheet, the sheet having a first surface on which a liquid is applied and a second surface contacting the conveyor, a first heater facing the first surface opposite to the second surface of the sheet, the first heater configured to heat the sheet, and a second heater configured to heat the conveyor.

A medium drying device includes a transport roller pair as a transport unit that transports a medium and a heat roller pair as one heating unit that heats the medium transported by the transport roller pair and is provided in a transport direction of the medium, in which the medium is configured to be transported to a heating area by the heat roller pair a plurality of times.

A recording system includes a recording device including a recording unit configured to perform recording, and a drying device including a drying mechanism. The recording device includes a support surface configured to support the recording medium and provided downstream of the recording unit in the conveyance direction, the device is configured to be mounted on the recording device at a position where the support surface and the drying mechanism face each other, one of the recording device and the drying device includes a setting member configured to set a spacing between the support surface and the drying mechanism to a predetermined spacing when the drying device is mounted on the recording device, the drying mechanism functions when the spacing is set to the predetermined spacing by the setting member, and a function of the drying mechanism stops when the setting by the setting member is released.

An image forming apparatus conveys a recording medium along a predetermined conveyance path and ejects ink onto a front surface of the recording medium to form an image when the recording medium passes through a predetermined drawing position, and includes: a first heater that is provided in the conveyance path on an upstream side of the drawing position and that heats the recording medium; and a control part that controls the first heater, wherein the first heater includes a front surface heater that heats a front surface side of the recording medium and a back surface heater that heats a back surface side of the recording medium, and the control part individually controls a temperature of the front surface heater and a temperature of the back surface heater when the recording medium has a multilayer structure.

Provided is an inkjet printing device including an ink storage unit configured to store an ink, an ejection head configured to eject the ink to form a print layer, and a heating unit configured to heat a material to be printed, wherein the ink is an aqueous clear ink including a resin and water, the inkjet printing device has a low gloss printing mode that is a printing mode for imparting low gloss, and a high gloss printing mode that is a printing mode for imparting high gloss, and the heating unit is configured to heat to satisfy the following formula T.sub.matte>T.sub.gloss, where T.sub.matte (degrees Celsius) is a temperature of a low gloss printing region of the material to be printed where the low gloss printing region is printed with the low gloss printing mode when the aqueous clear ink is deposited on the material to be printed, and T.sub.gloss (degrees Celsius) is a temperature of a high gloss printing region of the material to be printed where the high gloss printing region is printed with the high gloss printing mode when the aqueous clear ink is deposited on the material to be printed.