Abstract: A chromatic confocal scanning apparatus comprises a light source for producing light rays comprising a plurality of wavelengths, a first screen having an open elongated slit which allows a strip of light rays produced from the light source to pass through the slit and a cylindrical objective lens both to converge the light rays onto an object surface that is to be measured, and to image light rays reflected from the object surface. An intermediate cylindrical lens set converges a strip of light rays imaged from the cylindrical objective lens to pass through an open elongated slit comprised in a second screen, and a color sensor receives light rays which have passed through the slit of the second screen for determining a plurality of wavelengths of the said strip of light rays, to thereby construct a height profile of at least a portion of the object surface.

Abstract: An apparatus for measuring a height of an object plane or multiple points on an object is disclosed. The apparatus comprises an imaging system having a focal plane passing through a focal point of the imaging system, wherein the focal plane of the imaging system is tilted at an oblique angle with respect to the object plane such that only a small portion of the object is in focus. Alternatively, the focal plane is tilted at an oblique angle with respect to a scanning direction of the imaging system during relative movement between the imaging system and the object.

Abstract: An apparatus for measuring a height of an object plane or multiple points on an object is disclosed. The apparatus comprises an imaging system having a focal plane passing through a focal point of the imaging system, wherein the focal plane of the imaging system is tilted at an oblique angle with respect to the object plane such that only a small portion of the object is in focus. Alternatively, the focal plane is tilted at an oblique angle with respect to a scanning direction of the imaging system during relative movement between the imaging system and the object.

Abstract: A method for inspecting a substrate having intrinsic heterogeneous patterns for the presence of cracks comprises the steps of providing an optical device and front-side lighting on a first side of the substrate and providing near-infrared lighting on a second side of the substrate opposite to the first side. The near-infrared lighting is operable to penetrate the substrate so as to be detectable by the optical device through the substrate. One or more images are obtained by illuminating the substrate with the front-side lighting and/or the near-infrared lighting from the second side. The one or more images are thereafter processed to distinguish between the heterogeneous patterns on the substrate and any cracks present on the substrate.