The present invention is directed to a deviation detecting device that detects a deviation angle of a rotary unit of a laser light projector relative to a projector body. When the versatile paper feeding device is used to print images on paper of various sizes, the paper can be properly positioned and straightly fed without skewing. In the device, the memory interface controller inserts a waiting state into the CPU when address of the information or the program to be fetched by the CPU is not located within a predetermined address range until the information or the program is completely fetched.