Abstract: A temperature detection device includes first and second temperature detection units configured to detect first and second temperatures, respectively, of a first roller at first and second positions in an axis direction, heated by a central heating unit and an end part heating unit; third and fourth temperature detection units configured to detect third and fourth temperatures, respectively, of a second roller which can be in pressure-contact with the first roller, at the first and second positions; and a control unit configured to control the heating units. The control unit determines a state of at least one of the first, second, third and fourth temperature detection units based on a comparison between first and third rise rates of the first and third temperatures, respectively, or on a comparison between second and fourth rise rates of the second and fourth temperatures, respectively.

Abstract: A heating device includes: a heater; and a power distribution controller. The heater heats a predetermined heating target. The power distribution controller controls supply of AC power to the heater. The power distribution controller performs power distribution to the heater in units of AC half wave, and controls the power supply to the heater in accordance with power distribution control patterns respectively corresponding to a first time period as a power distribution start period, a third time period as a power distribution stop period, and a second time period between the first time period and the third time period.

Abstract: A temperature detection device includes first and second temperature detection units configured to detect first and second temperatures, respectively, of a first roller at first and second positions in an axis direction, heated by a central heating unit and an end part heating unit; third and fourth temperature detection units configured to detect third and fourth temperatures, respectively, of a second roller which can be in pressure-contact with the first roller, at the first and second positions; and a control unit configured to control the heating units. The control unit determines a state of at least one of the first, second, third and fourth temperature detection units based on a comparison between first and third rise rates of the first and third temperatures, respectively, or on a comparison between second and fourth rise rates of the second and fourth temperatures, respectively.

Abstract: A heating device includes: a heater; and a power distribution controller. The heater heats a predetermined heating target. The power distribution controller controls supply of AC power to the heater. The power distribution controller performs power distribution to the heater in units of AC half wave, and controls the power supply to the heater in accordance with power distribution control patterns respectively corresponding to a first time period as a power distribution start period, a third time period as a power distribution stop period, and a second time period between the first time period and the third time period.

Abstract: An image forming system includes an image forming apparatus that that forms an image on a paper sheet and a sheet finishing device that performs finishing on a paper sheet discharged from the image forming apparatus. The sheet finishing device is disposed beneath the image forming apparatus.

Abstract: A group commodity purchasing system for performing a purchasing operation by causing a commodity list to be downloaded and displayed onto a user terminal, the system includes a database of the server contains a commodity master in which at least a commodity code and a price are associated with each other, and a group commodity table for registering a group of commodities selected arbitrarily by a specific user as a group commodity. The server reads a group commodity code from the group commodity table and registering the group commodity code as one of the commodity codes on the commodity master. The group commodity code registered on the commodity master is indicated within the commodity list.