JPS57138262A - Conversion system for main scanning line density - Google Patents

Abstract

PURPOSE:To achieve line density conversion with fidelity by obtaining the vinary numeral of analog data by performing the main scanning line density conversion in the state of the analog data. CONSTITUTION:Optical information from an original has M lines/mm. line density and is inputted to an image sensor 11. The sensor 11 inputs a 1/TMHz clock signal to output an image signal 12 from the 1st bit successively as shown in Fig. (a). This image signal 12 is sampled and held, as shown in Fig. (b), successively by a sample holding circuit 13. When recording line density is N lines/mm., an integrator 15 inputs a 1/TNHz reset signal, so it integrates an image signal 14 at a TN-second period to generate an image signal 16 whose line density is converted as shown in Fig. (c). A sample holding circuit 17 samples and holds the peak value of this image signal 16 as shown in Fig. (d). This held image signal is supplied to an AGC circuit 19 for level adjustment (e) and binary-coded by a binary coding circuit 21 to generate a ditital image signal 22 shown in Fig. (f).