Internal test method and apparatus for facsimile transceiver

Abstract

Disclosed is a circuit for and method of testing a facsimile transceiver to determine whether it is operating properly. The method employed utilizes a document having a test pattern on a first portion thereof which is placed adjacent the read head of the transceiver. The reading means of the transceiver is energized and the test pattern is scanned. The output of the reading means, when the transceiver is being diagnosed, is directed to a digital memory and stored. Subsequently, the output of this memory is connected to the transmitter section and from there to the receiver section of the transceiver which is then energized to display the contents of the memory on a second portion of the document. In the preferred embodiment of the invention, the test pattern is located on a portion of a document which does not encompass the entire circumference of a rotating drum. The reading means of the transmitter section of the transceiver is energized during a portion of each drum revolution corresponding to the passage of the test pattern adjacent the read head and the modulation/demodulator and writing means are energized during a different portion of the same drum revolution.