PURPOSE: To maintain good contrast and to perform measurement with desired quality by determining the quantity of light corresponding to a single particle level with the time until the count value of an assigned address attains a preset value.
CONSTITUTION: The image of an object 1 to be photographed is formed by an optical system on the photoelectric surface of an image tube 3. The output thereof is processed in an arithmetic circuit 4 for an incident position which calculates a position signal and incident quantity. A corresponding address is assigned by the output signal thereof and the content of the counter is called in an incrementor 7. A "1" is added to the content to restore the original address of a memory 6 only when the content of the counter is discriminated as an object to be measured by a pulse height discriminator 5. The content called from the memory 6 is converted to the data with time by a count time converter 9 and the original address is restored if said content attains the preset value. The content of the memory 6 is then successively read out and is displayed on a monitor 10. A hard copy of the content of the memory 6 is obtd. with an output device 11.
INUZUKA EIJI
TSUCHIYA YUTAKA
Next Patent: DETECTOR FOR THICKNESS OF COATED FILM AND SURFACE DEFECT