GII/GIII transmission system

Abstract

A document is moved across a scanner unit and successive PEL lines are scanned. Reflected light from the document with the high PEL density produces binary signal 1 or 0 in accordance with the amount of the reflected light received by the scanner. The PEL data of binary 1 or 0 of one PEL line are serially supplied to a serial parallel conversion circuit, which converts the input serial data to a parallel data and supplies the parallel data to a two PEL line buffer. The two PEL line buffer stores PEL data of the succeeding two PEL lines. Sample windows are set up and the size of the sample windows is selected as equal to the PEL size. The sample windows enclose four bits which are used to access a conversion table. The four bits in the sample window produce sixteen combinations of the white or black PELs. The conversion table stores sixteen data or entries which represent degree of amplitude modulation for the carrier signal of the transmission mode. A modulator within the system modulates the amplitude of the carrier signal of the transmission mode using AM-PM-VSB, in accordance with the bit combination sampled by the sample window, such as by the distribution status or the position of black or white high density PELs enclosed by the sample window.

Dependencies are inferred from the claim text.