Method of sensing connection of USB device in power save mode and image forming apparatus for performing the same
AssigneeSamsung Electronics Co., Ltd.
InventorsByung-sun Min, Si-nae Choi
Life of this patent
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Abstract
An image forming apparatus includes a main controller, a universal serial bus (USB) interface to which an external USB device is connected, a voltage bus (VBUS) power supply to supply power to the USB interface through the VBUS line, a voltage change detector to output a wake-up signal to the main controller if a voltage change occurs on the VBUS line, a USB host controller to perform data communication with the USB device connected through the USB interface, and an image forming job performing unit to perform an image forming job according to control by the main controller.
Claims21
An image forming apparatus comprising:
- a main controller;
- a universal serial bus (USB) interface;
- a voltage bus (VBUS) power supply to supply power to the USB interface through a VBUS line;
- a voltage change detector to output a wake-up signal to the main controller if a voltage change occurs on the VBUS line;
- a USB host controller to perform data communication with a USB device connected through the USB interface;
- and
- an image forming job performing unit to perform an image forming job according to control by the main controller,
- wherein the main controller turns off the USB host controller when the image forming apparatus enters a power save mode, and the main controller turns on the USB host controller when the wake-up signal is output by the voltage change detector.
A method of sensing connection of a universal serial bus (USB) device when an image forming apparatus is in a power save mode, the method comprising:
- turning off a USB host controller of the image forming apparatus when the image forming apparatus enters the power save mode;
- outputting a wake-up signal to a main controller of the image forming apparatus when a USB device is connected to a USB port of the image forming apparatus and a voltage change occurs on a voltage bus (VBUS) line that supplies power to the USB port;
- receiving the wake-up signal by the main controller;
- and
- turning on the USB host controller by the main controller.
An image forming apparatus comprising:
- a main controller;
- an external device interface;
- a power supply to supply power to the external device interface through a power supply line;
- a voltage change detector to output a wake-up signal to the main controller if a voltage change occurs on the power supply line;
- wherein the main controller turns off one or more components of the image forming apparatus when the image forming apparatus enters a power save mode, and the main controller turns on one or more components of the image forming apparatus when the wake-up signal is output by the voltage change detector.
Dependencies are inferred from the claim text.