Abstract: A frame conversion device for switching between a plurality of image signals that are not synchronous and outputting each image signal continuously and synchronously. In addition, a desired signal is extracted from the continuous image signals and then output in parallel with the continuous image signals. The frame conversion device utilizes a frame conversion unit for recording an image signal optionally selected from a plurality of input image signals. A frame unit is utilized for reproducing a recorded signal outputted from the frame conversion unit independent of the operation of the frame conversion unit. The frame conversion unit includes an identification signal assigning part which assigns an identification signal to a non-image region of an image signal selected from a plurality of input signals. Frame-converting storage parts store the selected image signal. A signal output part selectively reads the image signal stored in each frame-converting storage device.