Wave-form observation apparatus

A wave-form observation apparatus comprising:

• A/D converting means (10) for converting an analog input picture signal (1) including at least a wave-form with its intensity information to be observed to digital data to obtain picture data with its intensity data (2);
• storing and subtracting means (12, 13) for storing intense picture data with its intensity data (6) to obtain stored picture data with its intensity data (7) and subtracting a predetermined subtractive value from the intensity data of the stored picture data (7) to obtain subtracted picture data with its intensity data (3), wherein a memory operation is executable to store data of at least a wave-form being displayed by setting the predetermined subtractive value to zero for displaying;
• comparing means (11) for comparing the intensity data of the picture data (2) and the subtracted picture data (3) to obtain a compared result (4) for selecting a stronger intensity data than another;
• composing and displaying means (17, 18, 14) for composing and displaying wave-forms included in the picture data (2) and the subtracted picture data (3) every display timing (8), wherein an afterglow operation is executable to display at least a wave-form with afterglow determined by the predetermined subtractive value;
• selecting means (S1, S2, 15) for selecting the compared result (4) as a selection signal (5) to select data as at intense picture data (6) which selected data has a stronger intensity than another between the picture data (3) in the afterglow operation, or, to select the subtracted picture data (3) as the intense picture data (6) and to select the subtractive data (3) as an intense picture data (6) during a cycle of the display timing (8) operation by an instruction (16) to store, wherein said selecting means (S1, S2, S15) comprises
• a first selecting means (S1) for selecting the compared result (4) as the selection signal (5) in the afterglow operation,
• a second selecting means (S2) for selecting a data as an intense picture data (6) which selected data has a stronger intensity than another between the picture data (2) and the subtractive picture data (3).