Real-time autofocus. In an embodiment, a scanning apparatus includes an imaging sensor, a focusing sensor, an objective lens, and processor(s) configured to analyze image data captured by the imaging and focusing sensors, and move the objective lens. Real-time autofocus during scanning of a sample is achieved by determining a true-Z value for the objective lens for a point on a sample and for each of a plurality of regions on the sample. The true-Z values and/or surfaces calculated therefrom are used to determine a predicted-Z value for an unscanned region of the sample. The objective lens is adjusted to the predicted-Z value at the beginning of the unscanned region. After scanning the region, a true-Z value is determined for the region and compared to the predicted-Z value. A rescan of the region is initiated if the comparison exceeds a predetermined threshold.

A microscope system comprises: a light source; an objective lens; a stage; a two-dimensional image sensor that captures an image of a specimen placed on the stage; a focusing device that changes distance between the objective lens and the stage; and a control circuit, wherein the control circuit executes, during a movement period in which the stage moves in a direction orthogonal to an optical axis of the objective lens, focus control for controlling the focusing device based on focus evaluation information detected during the movement period, and exposure control for controlling an exposure period of the two-dimensional image sensor, and executes light emission control that causes the light source to emit light with different light emission intensities during the exposure period and during a focus evaluation period in which the focus evaluation information is detected.

Keeping the excitation light sheet in focus is critical in selective plane illumination microscopy (SPIM) to ensure its 3D imaging ability. Unfortunately, an effective method that can be used in SPIM on general biological specimens to find the axial position of the excitation light sheet and keep it in focus is barely available. Here, we present a method to solve the problem. We investigate its mechanism and demonstrate its performance on a lattice light sheet microscope.

Continuous-scanning image acquisition in an automated microscopy system uses an image reflected off of an object that supports a specimen being imaged to automatically focus the microscopy system.

The invention relates to an autofocusing method for an imaging device (for semiconductor lithography) comprising an imaging optical unit, an object to be measured and an autofocusing device having a reflective illumination, comprising the following method steps: a) defining at least three basis measurement points M(x.sub.j, y.sub.j) on a surface of the object, b) determining the deviation A.sub.z(M)j of a nominal position of the surface of the object from the focal plane of the autofocusing device at the defined basis measurement points M(x.sub.j, y.sub.j), c) storing the deviations A.sub.z(M)j from at least three basis measurement points M(x.sub.j, y.sub.j), d) using the stored deviation A.sub.z(M)j for determining a deviation A.sub.z(P)k at an arbitrary point P(x.sub.k, Y.sub.k) of the surface, and e) using the deviation A.sub.z(P)k for focusing onto the point P(x.sub.k, Y.sub.k).

An apparatus for baseline estimation in input signal data is configured to retrieve input signal data (I(x.sub.i)) and to subtract baseline estimation data (ƒ(x.sub.i)) from the input signal data (I(x.sub.i)) to compute output signal data. The apparatus is further configured to compute the baseline estimation data (ƒ(x.sub.i)) from a convolution using a discrete Green's function (G(x.sub.i)).

A device may use a camera to capture an image of an end face of an optical fiber in a field of view of the camera. The device may monitor a focus metric associated with the image while the image is manually focused using an opto-mechanical assembly. The device may automatically initiate a test to inspect the image of the end face of the optical fiber for compliance with a set of criteria related to cleanliness and damage based on the focus metric satisfying a condition. The device may output a result from the test indicating whether the end face of the optical fiber satisfies the set of criteria related to cleanliness and damage.

In the image capturing apparatus, the optical path difference producing member is disposed on the second optical path. Thereby, it is possible to suppress the amount of light when an optical image which is focused at the front of an optical image made incident into the first imaging device (front focus) and an optical image which is focused at the rear thereof (rear focus) are respectively imaged at the second imaging device and also to secure the amount of light on image pickup by the first imaging device. Further, in the image capturing apparatus, a position of the first imaging region and a position of the second imaging region on the imaging area are reversed with respect to the axis P in association with reversal of a scanning direction of the sample. Therefore, despite the scanning direction of the sample, it is possible to obtain a deviation direction of the focus position under the same conditions.

A focus position maintaining apparatus and a microscope are provided. The focus position maintaining apparatus can three-dimensionally correct a shift of a specimen in real time to maintain the focal point of an objective lens in a desired position in the specimen, and the microscope includes the focus position maintaining apparatus. The focus position maintaining apparatus includes a microlens array having a plurality of unit lenses and disposed in a position where the microlens array receives light from a specimen via an objective lens, a focus imaging device disposed in a position where the focus imaging device receives light from the unit lenses of the microlens array, and a control unit that outputs a signal for controlling operation of a focus actuator based on image formation positions of a plurality of images of the specimen detected by the focus imaging device via the microlens array.

A method is used for optical scanning of at least one object region placed on a transparent specimen holder. The method is as follows: for each sample lateral position of plural predefined sample lateral positions performing a focus determination by: performing laser reflection and using a first camera taking plural first images to determine a reference distance between the specimen holder and an objective lens; performing transmission flash illumination and using a second camera taking plural second images to define a focus distance taking into account the reference distance; after completing the focus determination, determining a focus distance topology across the object region based on the focus distances determined for ail sample lateral positions; and laterally moving the specimen holder and acquiring third images while focusing according to the focus distance topology.