초록 ▼

A device for detecting the focused state of an objective lens comprises a re-imaging lens unit arranged to distribute light from a primary image formed by the objective lens to form secondary images which have their relative positions varying with the focused state of the objective lens, the re-imag

A device for detecting the focused state of an objective lens comprises a re-imaging lens unit arranged to distribute light from a primary image formed by the objective lens to form secondary images which have their relative positions varying with the focused state of the objective lens, the re-imaging lens unit including a plurality of re-imaging lenses having a plurality of lens surfaces; and sensing means arranged to sense the light distributions made for the secondary images and to produce signals to be used in computing information on the focused state of the objective lens according to the relative positional relation between light distributions for the secondary images, the sensing means having a plurality of photosensors. In detecting the focused state of the objective lens, the optical axis of at least one of the lens surfaces of each of the re-imaging lenses is decentered relative to other lens surfaces in parallel with the direction in which the photosensors are arrayed.

대표청구항 ▼

A device for detecting the focused state of an objective lens, comprising: a re-imaging lens unit arranged to distribute light from a primary image formed by said objective lens to form secondary images which have their relative positions varying with the focused state of said objective lens, said r

A device for detecting the focused state of an objective lens, comprising: a re-imaging lens unit arranged to distribute light from a primary image formed by said objective lens to form secondary images which have their relative positions varying with the focused state of said objective lens, said re-imaging lens unit including a plurality of re-imaging lenses having a plurality of lens surfaces; and sensing means arranged to sense the light distributions in relation to the secondary images and to produce signals to be used in computing information on the focused state of said objective lens according to the relative positional relation between said light distributions in relation to said secondary images, said sensing means having a plurality of photosensors, and wherein, an optical axis of at least one of the lens surfaces of each of said re-imaging lenses deviates from that of another lens surface in the direction in which said photosensors are arrayed, wherein said deviations are symmetrical about an axis of the re-imaging lens unit.