When an image read start command is received from a PC, an image reading unit
first sequentially reads an image of an original. An output signal of the image
reading unit is processed by an analog signal processing circuit, an A/D converter,
and an image processing circuit and is supplied to a transfer control circuit.
When an instruction from the PC indicates a direct transfer mode, the transfer
control circuit outputs the image data from the image processing circuit as it
is to an interface. When the instruction from the PC indicates a temporary storage
mode, the transfer control unit temporarily stores the image data into a storage
medium of an auxiliary storage device. When there is a reading request from the
PC, the transfer control circuit reads out the image data which is stored into
the auxiliary storage device and transfers it to the PC through the interface.
