Method and device for detecting light irradiation state

Abstract

Abstract PURPOSE:To find accurate illuminance distribution or exposure distribution by outputting photoelectric conversion signals successively by connecting one terminal of each optical fiber to a common photoelectric element while positioning the other terminal in unit areas arrayed in the length direction of a light-irradiated area. CONSTITUTION:One-side terminals of optical fiber (five fibers in the figure) F1- F5 are connected to a common photoelectric element P through a common filter, and its output is connected to an amplifier or integrating amplifier 14. The other-side terminals of the fibers F1-F5 are led from the circumferential wall of a hollow disk carrier 11 to an internal space and positioned in unit areas S1-S5 obtained by dividing a beltlike effective light-irradiated area L formed on the exposed surface 12 of the carrier 11. A control slit plate 21 having a control slit opening overlapping with a slit 5 is provided so that it can be displaced freely in the length direction of the slit 5. Unit opening areas T1-T5 which correspond to the unit areas S1-S5 are selected, one by one, successively and light is permitted to pass through only the selected area. Consequently, the illuminance or exposure distribution of the beltlike light-irradiated area is measured in a simple way with high reliability.

Inventors

• 👤 Manabu Goto

Bibliographic Details