USB interface flash memory card reader with a built-in flash memory

A USB interface flash memory card reader with built-in flash memory, comprising

• a casing, being composed of an upper cover and a lower cover joining to each other, and providing an inner space;
• a printed circuit board, being disposed in the casing, providing a micro controller for decoding orders of a main unit such as data read, data write, and data delete;
• a USB terminal, being disposed outside the casing, and connecting with the printed circuit board by way of a wire;
• a socket, being disposed outside the casing, connecting with the printed circuit board by way of a circuit, and having a slot being detachably inserted by a flash memory;
• a flash memory, being disposed on the printed circuit board;
• a semiconductor switch, being disposed on the printed circuit board, being able to shift to a state of “ON” or “OFF” based on different trigger voltage positions so as to result in the built in flash memory connecting with or disconnecting from the micro controller;
• and
• an application circuit for memory shift, triggering the semiconductor switch in accordance with the flash memory card inserting into or taking out from the socket to shift to the built-in flash memory or to the flash memory card automatically.