Facsimile machine having line density switching function

Claim 1

A facsimile machine or receiving image data in any of a plurality of line densities, the image data being transmitted from a transmitting facsimile machine which sends the image data in a selected one of the plurality of line densities, the facsimile machine having a memory reception mode in which the image data is received from the transmitting facsimile machine during an automatic reception and is stored, comprising: control means for sending an initial capability notification to the transmitting facsimile machine in a pre-procedure during the automatic reception, said control means receiving an initial specification of line density from the transmitting facsimile machine so that the receiving facsimile machine receives the image data at the specified line density; memory means for storing the received image data; detecting means coupled to said memory means for detecting a remaining memory region which is usable within said memory means during data transmission; and line density switching means for providing an instruction to said control means for switching of the line density during data transmission if the remaining memory region detected by said detecting means is less than or equal to a predetermined region; said control means automatically transmitting a second capability notification to the transmitting facsimile machine in response to said instruction from said line density switching means so as to receive the image data from the transmitting facsimile machine with a line density which is lower than the specified line density when the automatic reception was started.