PURPOSE: To measure the light emission position with simple arrangement and also enabling multi-point measurement by measuring the output value of a photoelectric transducing element installed ahead the light emitting part of a color CRT, and determining the change in the light emitting position.
CONSTITUTION: A photoelectric transducing element 4 equipped at its light receiving surface with a filter 3 is installed ahead the light emitting surface of a color CRT 1. This photoelectric transducing element 4 is connected with a processing device 5 for performing measurement of the output and subsequent processings. From this processing device 5 a control signal 5a to move the light emission position is given to a driver circuit 2. According to the position of light emitting point the output of the photoelectric transducing element 4 varies. Therefore, the relation between the output and the amount of displacement is calibrated in advance, and the amount of displacement is directly read from the output. The light emission position 6 is axially aligned with the photoelectric transducing element 4 so that the green output maximizes. Then the other two colors, red and blue, are switched and emitted one after another, and at the same time, the light emitting point is moved. The amount of movement at this time serves determination of misconvergence.
MIZUNO KAZUHIKO
ATOBE TAKASHI
TSUKII NORIO
