PURPOSE: To speed up the processing of time adjustment in a production by reading out only the previously set up in plural time deciding windows out of the image pickup data for a time display surface stored in a picture memory and deciding the coincidence of hands on the basis of the read out data.

CONSTITUTION: A picture signal on a time piece display surface which is picked up by a camera 10 is written in the picture memory 16 through an A/D converter 12. At the reading of data from the memory 16, a reading circuit 18 reads out the data of square time decision window parts set up in every one minute and inputs the read-out data to a coincidence detecting circuit 22 through a buffer 21. The circuit 22 compares the data in the time decision windows successively with window data in a master data memory 24. A decision circuit 26 counts up an inconsistency signal from the circuit 22 to decide the time on the basis of the counted value and outputs the time information to an external apparatus 28.