A image forming apparatus includes a power control unit, an operation mode control unit, and a first timer. The power control unit performs control so as to switch between a normal power state for supplying the operation power supply voltage to the image forming unit, a first power saving state for not supplying the operation power supply voltage to the image forming unit, and a second power saving state having less power consumption than the first power saving state. The operation mode control unit performs control so as to switch a normal mode corresponding to a normal power state, a first power saving mode corresponding to a first power saving state, and a second power saving mode corresponding to a second power saving state.

An image forming apparatus includes a plurality of devices configured to perform different job processing, a control unit configured to control job processing performed by each device, a reception unit configured to receive an instruction for causing the control unit to shift to a state where the job processing is capable of being performed, and a power control unit configured to, when the control unit is shifted to a stand-by state in response to receiving the instruction, supply a power to a device specified based on a job processing function corresponding to an initial screen to be displayed.

An office machine with intelligent sleep and wake function and a control method thereof are introduced. The office machine comprises a storage module, image module, processing module, and power supply module. The processing module is connected to the storage module, image module, and power supply module. The storage module stores user data and first feature data. The processing module obtains a user image from the image module to generate second feature data and then process the first and second feature data to generate comparison result information. After determining user confirmation information according to the comparison result information, the processing module sends a first control signal to the power module, such that the office machine wakes up automatically from sleep. The office machine wakes up automatically when a user approaches the office machine, so as to save time and improve work efficiency and ease of use.

An image communication apparatus has, as operation states, a first power state and a second power state with lower power consumption than the first power state. The apparatus comprises a ringing unit that rings according to an predetermined incoming signal from an external; a setting unit that sets whether the ringing unit rings according to the predetermined incoming signal or not; and a control unit that shifts the operation state from the first power state to the second power state based on at least the setting set by the setting unit.

A communication apparatus includes a communication unit, having operation modes including a first operation mode in which data communication is enabled and a second operation mode in which power consumption is lower than that in the first operation mode, configured to perform data communication with an opposed device, and a control unit configured to control switching between the operation modes of the communication unit, wherein the control unit controls a speed of communication, at a transition of the communication unit from the first operation mode to the second operation mode, between the communication unit and the opposed device to a predetermined communication speed or lower, then causes the communication unit to transition from the first operation mode to the second operation mode, and then stops clock supply to the communication unit.

An information processing apparatus, including an interface and a controller configured to: receive, from an external device, first change acceptable or non-acceptable information indicating whether changing of an amount of electric power to be supplied to the external device is allowable; supply, after the receiving the first change acceptable or non-acceptable information, the electric power to the external device; receive, during executing the supplying the electric power, second change acceptable or non-acceptable information indicating whether the changing of the power amount is allowable; determine, during executing the supplying the electric power, whether limiting of the power amount is necessary; and limit, based on the second change acceptable or non-acceptable information, the power amount when the controller determines to limit the power amount in the determining whether limiting of the power amount is necessary and the receiving the second change acceptable or non-acceptable information is executed.

In order to turn on power of an information processing apparatus at an appropriate timing. For this purpose, the information processing apparatus includes a manually power-on function of turning on the power in a case where a mechanical power supply switch is turned on and an automatically power-on function of turning on the power in a case where predetermined information is detected. In a case where the information processing apparatus is in a particular mode, the automatically power-on function is disabled.

An image processing apparatus includes a first processor and a second processor. The first processor has a power saving function. The second processor is configured to consume less power than the first processor during operation. When the first processor stopped by the power saving function is activated in response to reception of a network packet, the first processor determines an operating frequency of the first processor in accordance with a type of the network packet.

A printing apparatus connectable to an external power supply having outputtable voltage information, including: a printing head performing printing by electric power supplied from the external power supply; a resistor having an electric resistivity based on the printing head; a detector detecting a substantial voltage; and a controller configured to: obtain the voltage information from the external power supply; decide a tentative voltage; request the external power supply to output the tentative voltage; energize the resistor with the tentative voltage; decide the substantial voltage if a voltage corresponding to each of the obtained voltage information is supplied based on a result of the detector during the energizing of the resistor; decide an electric power supply voltage based on the substantial voltage; and request the external power supply to output the electric power supply voltage.

According to aspects of the present disclosures, a printing device has a print head, a battery, a USB PD controller. The printing device is connected to an external power source in accordance with a connection compliant with a USB standard. The external power source has a plurality of electrical power profiles. The printing device uses one of the external power source and the battery as an electrical power supplying source of the print head. The printing device a power source voltage value with a rated voltage value of the print head, when the power source voltage value is larger than the rated voltage value, determine the battery as the electrical power supplying source, and, when the power source voltage value is equal to or less than the rated voltage value, determining the external power source as the electrical power supplying source.