Abstract: A display inspection system for inspecting a light beam emitted from a panel with pixels positioned at several focal planes is provided. The display inspection system includes a focus tunable lens adjustable in a focal distance for focusing at the panel, a first sensing unit for receiving the light beam, a reduced aberration optical system arranged between the focus tunable lens and the first sensing unit for focusing at the first sensing unit, and one or more optical elements placed within a back focal length of the reduced aberration optical system. The reduced aberration optical system comprises a first serial cascade lens group of a first aplanatic lens and a first doublet lens for correcting an optical aberration. The first aplanatic lens and the first doublet lens are co-configured that the back focal length is extended in a manner that the light beam is incident to the first sensing unit.

Abstract: The invention provides a chromatic confocal system for inspecting an object. The system comprises a first light modulator for providing a spatially modulated light beam arranged to project on one or more parts of the object to form a reflected light beam carrying image information of the one or more projected parts of the object; a second light modulator for spatially filtering the reflected light beam to form a light beam carrying filtered image information of the one or more projected parts of the object; wherein operation of the first light modulator and the second light modulator is synchronized such that the spatial filtering of the second light modulator varies in concert with variations in the spatial modulation of the first light modulator.