Similar change information takeout method, similar change information takeout apparatus, and teletext receiver

摘要

A similar change information takeout apparatus is intended to take out automatically unit containing similar change information when character row data divided in certain units are given in a multiplicity, and comprises an input unit in which character row data are entered sequentially in time series, a former data memory unit for storing character row data, a start/stop input unit for accepting an input for designating start or stop of output of similar change information from the user, a new data unit takeout process for taking out sequentially the units contained in new data, a unit comparison process for comparing the units taken out in the new data unit takeout process and the units contained in former data to see if different or same character by character contained in the units sequentially, a different character and type counting process for calculating the variety and number of different or same characters as a result of comparison in the unit comparison process, and a similarity judging process for judging similarity between units in certain condition on the basis of the result of calculation of the different character and type counting process.