An automatic focus system for an optical microscope that facilitates faster focusing by using at least two offset focusing cameras. Each offset focusing camera can be positioned on a different side of an image forming conjugate plane so that their sharpness curves intersect at the image forming conjugate plane. Focus of a specimen can be adjusted by using sharpness values determined from images taken by the offset focusing cameras.

An imaging apparatus includes an imaging element that captures an image for detecting a phase difference in a predetermined direction on an image surface in order to detect a focal state of an image formed by an image formation lens, an imaging element driving unit configured to be able to drive the imaging element in a parallel movement direction and a rotation direction within a plane perpendicular to an optical axis of the image formation lens, and a focus detection unit configured to detect a focus by rotating the imaging element using the imaging element driving unit in accordance with a result of an image captured by the imaging element.

A method and system for autofocusing an objective lens in a microscope system are disclosed. A decentered aperture is disposed in an optical path between an objective lens and an image plane of an image capturing device and a plurality of reference images are captured. Each reference image is captured when the objective lens is positioned at a corresponding z-position of a plurality of z-positions along an axis of travel of the objective lens and the optical path is at least partially occluded by the decentered aperture. At least one reference image of the plurality of the reference images is associated with a best focus position. The plurality of reference images are analyzed to develop a plurality of pattern locations, wherein each pattern location represents a position of a pattern formed on the image plane when a corresponding reference image was captured. The objective lens is positioned in accordance with the best focus position and the plurality of pattern locations.

A system for optimizing optics is provided. The system is configured to calibrate a position of a reference arm of an interferometric imaging system such that an image of a sample is visible when the sample is positioned at a working distance of an objective lens to provide an initial calibrated position. An image is obtained using the initial calibrated position. Image quality of the obtained image is assessed to determine if the obtained image is a valid image. A path length of the reference arm is adjusted if it is determined that the obtained image is not a valid image. A difference between the calibrated position of the reference arm and the adjusted position of the reference arm is calculated. System elements are adjusted based on the calculated difference such that the ample is visible when the sample is positioned at the working distance at the adjusted position.

High-speed and high-accuracy focus adjustment is achieved. A microscope system (1) includes: an irradiation unit (18) that emits line illumination parallel to a first direction; a stage (26) that supports a specimen and is movable in a second direction perpendicular to the first direction; a phase difference acquisition unit (60I) that acquires phase difference information regarding an image of light emitted from the specimen by being irradiated with the line illumination; an objective lens (22) that focuses the line illumination on the specimen; a derivation unit (60E) that derives relative position information between the objective lens and the specimen based on the phase difference information; and a movement control unit (60F) that causes at least one of the objective lens and the stage to move in a third direction vertical to each of the first direction and the second direction based on the relative position information.

The invention relates to a device for measuring a mask for microlithography, the device including an imaging device and an autofocusing device. The imaging device comprises an imaging optical unit with a focal plane for imaging the mask, an object stage for mounting the mask, and a movement module for producing a relative movement between object stage and imaging optical unit. The autofocusing device is configured to generate a focusing image by way of the imaging of a focusing structure in a focusing image plane intersecting the focal plane, in which the focusing structure is embodied as a gap. Furthermore, the invention relates to an autofocusing method for a device for measuring a mask for microlithography.

A height measurement device includes: a lens system; a lens controller to output a drive signal to the lens system; a continuous illuminator to continuously illuminate a workpiece; an image detector to detect an image of the workpiece; an image calculation unit to calculate an EDOF image on a basis of a detected image; a focal depth adjustment unit to cause an extended focal depth of the EDOF image to be increased or decreased by increasing or decreasing an amplitude of the drive signal; a focus determination unit to determine a focus state of a portion of interest of the workpiece included in the EDOF image; and a height measurement unit to measure an upper limit or a lower limit of the extended focal depth, the upper limit or the lower limit being based on a timing at which the focus state of the portion of interest has changed.

An image pick up apparatus includes an image sensor configured to pick up an image while changing an in-focus position during pickup of the image, at least one memory configured to store instructions, and at least one processor coupled to the at least one memory and configured to execute the instructions to perform a correction of a difference in exposure resulting from a change in the in-focus position while one image is picked up.

An image pick up apparatus includes an image sensor configured to pick up an image while changing an in-focus position during pickup of the image, at least one memory configured to store instructions, and at least one processor coupled to the at least one memory and configured to execute the instructions to perform a correction of a difference in exposure resulting from a change in the in-focus position while one image is picked up.

In an example embodiment, method, apparatus and computer program product for improving image and video captures using depth maps of viewfinder depth map, are provided. The method includes facilitating receipt of a viewfinder depth map of a scene, the viewfinder depth map comprising depth information of a plurality of objects in the scene. One or more objects are selected from the plurality of objects based on depth information of the one or more objects in the viewfinder depth map. Two or more images of the scene are facilitated to be captured by at least adjusting focus of a camera corresponding to the depth information of the one or more objects that are selected. In an example, a method also includes facilitating capture of an image of the scene by at least adjusting focus of a camera corresponding to the depth information of the two or more objects that are selected.