Abstract: An apparatus and method for automatically switching between USB host and device is provided. In a device with a USB interface, the present invention automatically switches between a USB host and USB device by detecting the handshake protocol of the D+ and D? pins of the USB interface. The apparatus for automatically switching between USB host and device includes ah host mode element, a device mode element, a random auto-switcher, and a detection element. The random auto-switcher switches the connection to the host mode element or the device mode element at random time. The detection element monitors the handshake protocol of the D+ and D? pins of USB interface and the external USB-interface device to determine whether the host mode or the device mode is in use. When the present invention detects the external USB-interfaced device is a host, the present invention switches to become a USB device.

Abstract: An apparatus and method for automatically switching between USB host and device is provided. In a device with a USB interface, the present invention automatically switches between a USB host and USB device by detecting the handshake protocol of the D+ and D? pins of the USB interface. The apparatus for automatically switching between USB host and device includes ah host mode element, a device mode element, a random auto-switcher, and a detection element. The random auto-switcher switches the connection to the host mode element or the device mode element at random time. The detection element monitors the handshake protocol of the D+ and D? pins of USB interface and the external USB-interface device to determine whether the host mode or the device mode is in use. When the present invention detects the external USB-interfaced device is a host, the present invention switches to become a USB device.

Abstract: An apparatus for automatically detecting and differentiating between a USB host and a USB device is provided. In a device with a USB interface, the present invention is coupled with the VBUS pin of the USB interface of the device. By monitoring the voltage change on the VBUS pin, the present invention determines whether the external device connected through the USB interface is a USB host or a USB device. The apparatus for automatically detecting and differentiating between a USB host and a USB device of the present invention includes a voltage detection circuit and a voltage detector. The voltage detection circuit is coupled with the voltage detector and the VBUS pin of the USB interface. The voltage detection circuit can be a voltage splitter. The voltage of voltage detection circuit can be changed according to the voltage signal inputted externally from the VBUS pin of the USB interface.

Abstract: Provided with a film cutter that has a guiding mechanism in accordance with the present invention includes a housing providing a pair of guiding rails thereon. The housing is adapted to be mounted on a box containing a film roll. The housing includes at least a receiving slot arranged adjacent to the guiding mils. At least a film positioning element is arranged in the receiving slot for providing a robust positioning of the film spans thereover and a cutter assembly moveably supported by the guiding rails for separating the film spans over the rails. When the film from the film roll is tightly stretched by the film-positioning elements thereby providing a clean cut when the cutter assembly slides over the stretched film.