In response to a requirement of transferring a file from a personal computer PC to a projector 10 that is output by dragging and dropping a corresponding file icon onto a projector icon, a CPU 50 requires setting of a password. The CPU 50 maps the preset password to a file and transfers the file with the password to an external storage device of the projector 10. The projector 10 requires input of a password, which is expected to be assigned to the file, and allows reproduction of the file when the input password is coincident with the preset password.