An image forming apparatus (1) includes photosensitive drums (41y, 41c, 41m, and 41k), static eliminators (45y, 45c, 45m, and 45k), transfer rollers (54y, 54c, 54m, and 54k), a power source (55a) for transfer, and load resistors (47y, 47c, 47m, and 47k). The static eliminators (45y, 45c, and 45m) perform static elimination on adjacently upstream or downstream photosensitive drums (41y, 41c, 41m, and 41k) in a movement direction of a transfer target. The transfer rollers (54y, 54c, 54m, and 54k) are disposed opposite to the respective photosensitive drums (41y, 41c, 41m, and 41k). The power source (55a) for transfer applies potential to the transfer rollers (54y, 54c, 54m, and 54k). The load resistors (57y, 57c, 57m, and 57k) are respectively connected in parallel to one another and in series between the power source (55a) for transfer and the respective transfer rollers (54y, 54c, 54m, and 54k).

There is provided an image forming apparatus including: an intermediate transfer belt; a photosensitive drum; a primary transfer member; a secondary transfer member; a first backup member; a first power supply electrically connected to the primary transfer member and to the secondary transfer member; and a first resistor electrically connected to the first power supply and to the primary transfer member. A first current route, in which the first resistor, the primary transfer member, and the photosensitive drum are connected in series in that order, is connected to the first power supply and to a basis potential. A second current route, in which the secondary transfer member and the first backup member are connected in series, is connected to the first power supply and to the basis potential. The first current route is connected in parallel to the second current route.

A state change of a status occurred during a communication interrupted state is stored as a state change status. Thus, a video controller 102 can recognize the change of the status during a period when communication between the video controller 102 and an engine control unit 103 is interrupted, based on the state change status.

A power controlling device includes a detecting unit that detects a person in a detection area, a first imaging unit that takes an image of the person in a detecting range in an operating state, a second imaging unit that takes an image of a face of the person for use in user authentication in an operating state, and a power controller that supplies power to and brings the first imaging unit into the operating state if the person is detected, supplies power to and brings a processing unit that performs a process into an operating state if the approach of the person is determined on the basis of the taken image of the person, and supplies power to an brings the second imaging unit into the operating state during a period from the detection of the person to the shift of the processing unit to the operating state.

An image forming apparatus includes a detection unit that detects a user of the image forming apparatus, a power supply control unit that, when a person approaching the image forming apparatus is detected by the detection unit when the image forming apparatus is in a power saving state where power supply to a function unit included in the image forming apparatus is stopped, activates the function unit while maintaining the display unit in a non-display state, and a display control unit that, when the user of the image forming apparatus instructs the display unit to present display after power is supplied to the function unit by the power supply control unit, changes the display unit to a display state.

A power control device includes non-volatile memory, a controller, and a logic circuit. The non-volatile memory includes a function of externally outputting a logical state of a bit stored in a specific area as a state hold signal that indicates an ON/OFF state of a device function unit before a power cutoff. The controller controls the ON/OFF state of the device function unit and also writes the ON/OFF state of the device function unit to the specific area of the non-volatile memory. The logic circuit controls power supply to the controller on the basis of a logic level of the state hold signal from the non-volatile memory.

An electronic device includes: an operation section, a reception section, a human body detection sensor, and a mode switching section. The mode switching section switches the electronic device between a normal operation mode permitting a normal operation and a sleep mode in a power saving state based on presence or absence of a detection signal from the human body detection sensor. Then the mode switching section stops in a case where a state in which the reception section receives an operation made by use of the operation section continues for a predefined period of time the switching between the normal operation mode and the sleep mode based on the presence or absence of the detection signal.

An image forming apparatus includes: a communication unit that receives first mode electric power to perform communication; an image forming unit that receives first mode electric power the to form an image on a medium; a fixing unit that generates heat by receiving first mode electric power corresponding, and performs a fixing process of fixing the image to the medium; a predicting unit that predicts a processing time required for a process of forming the image; and a supply controller that controls supply of electric power according to a first mode or a second mode in which power consumption is smaller than that of the first mode. The supply controller starts the supply of first mode electric power to the fixing unit at a timing based on the predicted processing time when the image forming apparatus transitions from the second mode to the first mode.

An image forming apparatus and an image forming method are provided. The image forming apparatus includes a printing engine to form an image, a step motor to drive the printing engine, a driving circuit to provide a constant current to the step motor and sense a voltage corresponding to a magnitude of the constant current provided to the step motor, and a processor to calculate a temperature of the step motor based on the voltage sensed by the driving circuit during an excitation period of the step motor and control an operation of the image forming apparatus based on the calculated temperature.

The printing apparatus according to the present invention includes: a printing unit configured to form an image on a printing medium by using a color material and to output the printing medium on which the image is formed; a printing control unit configured to control the printing unit and to store data relating to the printing unit; a power control unit configured to control supply of power to the printing unit and the printing control unit; and a main control unit connected with the printing control unit so as to be capable of communication, and in accordance with a predetermined request, the power control unit performs control so as to suspend supply of power to the printing unit, the main control unit starts acquisition of the data stored by the printing control unit, and the power control unit performs control so as to suspend supply of power to the printing control unit after the main control unit completes acquisition of the data.