Abstract: A reverse current protection circuit includes a MOSFET and an on/off controller. When the on/off controller applies an on-state control voltage to a gate of the MOSFET, a main power supply input through a main power supply line is output to a common connection node via the MOSFET; and when an off-state control voltage is applied to the gate of the MOSFET, the electrical connection between the main power supply line and the common connection node is interrupted to prevent a reverse current. A diode is connected to enable a forward current flowing from a sub power supply line to the common connection node and the reverse current is prevented. The voltage drop of the main power supply, when the on-off controller applies the on-state control to the gate of the MOSFET, is lower than the voltage drop of the sub power supply through the diode.

Abstract: A reverse current protection circuit includes a MOSFET and an on/off controller. When the on/off controller applies an on-state control voltage to a gate of the MOSFET, a main power supply input through a main power supply line is output to a common connection node via the MOSFET; and when an off-state control voltage is applied to the gate of the MOSFET, the electrical connection between the main power supply line and the common connection node is interrupted to prevent a reverse current. A diode is connected to enable a forward current flowing from a sub power supply line to the common connection node and the reverse current is prevented. The voltage drop of the main power supply, when the on-off controller applies the on-state control to the gate of the MOSFET, is lower than the voltage drop of the sub power supply through the diode.

Abstract: A video signal transmission system which includes a video transmission apparatus and a main-display apparatus and in which a sub-display apparatus is connectable between the video transmission apparatus and the main-display apparatus is provided. The video transmission apparatus transmits a video signal in which video data of a main-screen and video data of sub-screen is stored collectively. The main display apparatus separate the video data of the main-screen from the received video signal and displays the main-screen. When the sub-display apparatus is connected between the video transmission apparatus and the main-display apparatus, the sub-display apparatus separates the video data of the sub-screen from the video signal received from the video transmission apparatus for another sub-display apparatus on a signal source side and displays the sub-screen and transmits the video signal to the main-display apparatus or another sub-display apparatus on a main-display apparatus side.

Abstract: A transmission device includes a transmitter and a receiver and transmits an image signal of an image of a periphery of a movable object from an imaging device to a display device near a driver of the movable object. The transmitter transmits an image signal to the receiver through a first transmission path and a second transmission path. The transmitter adds error detection information to each unit data item of a screen of the display device to generate an image signal. The receiver detects an error in the first transmission path using the error detection information. When continuously detecting an error in multiple transmitted unit data items, the receiver determines that malfunction occurs in a transmission state of the first transmission path and selects an image signal transmitted through the second transmission path instead of an image signal transmitted through the first transmission path.

Abstract: A transmission device includes a transmitter and a receiver and transmits an image signal of an image of a periphery of a movable object from an imaging device to a display device near a driver of the movable object. The transmitter transmits an image signal to the receiver through a first transmission path and a second transmission path. The transmitter adds error detection information to each unit data item of a screen of the display device to generate an image signal. The receiver detects an error in the first transmission path using the error detection information. When continuously detecting an error in multiple transmitted unit data items, the receiver determines that malfunction occurs in a transmission state of the first transmission path and selects an image signal transmitted through the second transmission path instead of an image signal transmitted through the first transmission path.