Abstract: A camera module includes a lens, an image sensor, a carrier carrying the image sensor, two spring supporting members, a frame, a base and a printed circuit board. The carrier has a comb-shaped first electrode having a number of first teeth. The carrier is suspended in the frame by the two spring supporting members, and is movable in a direction perpendicular to a surface of the image sensor. The base has a comb-shaped second electrode having a number of second teeth. The first teeth and second teeth are arranged in a staggered fashion. The printed circuit board provides a potential difference between the first and second electrodes, whereby an electrostatic force is generated between the first and second teeth to drive the first teeth to move towards the second teeth.

Abstract: A system is provided where the system comprises a plurality of optical sources, each optical source configured to generate an optical beam and direct the optical beam from each of the plurality of optical sources towards a target; a beam discriminator module configured to monitor a parameter for each optical beam generated from each of the optical source; and a position sensor configured to receive a feedback from the beam discriminator module based on the monitored parameter; wherein based on the feedback, the position sensor determines if any optical beam at the target is off-target.

Abstract: The present disclosure includes systems and techniques relating to focusing in automated microscope systems. In general, in one implementation, the technique includes obtaining an image of at least a portion of a scan region, analyzing the image to find an area in the image representing a sample, determining a nature of the sample at a selected focus point location in the area in the image, selecting an automated focusing process for use at the selected focus point location based on the determined nature of the sample at the selected focus point location, and focusing the selected automated focusing process. The selecting can include selecting different automated focusing processes for different focus point locations based on different tissue characteristics at the locations.

Abstract: There is provided an apparatus that includes a receiving unit configured to receive instructions for focus adjustment; an image-pickup unit configured to perform image-pickup of an object image input through a focus lens; a setting unit configured to set a focus detecting area to be used at a time of detection of a focus state of the focus lens; a light control unit configured to control an amount of light incident on the image-pickup unit; and a focus adjusting unit configured to detect a focus signal representing the focus state in the focus detecting area to move the focus lens based on the focus signal and a position of the focus lens corresponding to the focus signal.

Abstract: A solid-state imaging device comprises a plurality of pixels disposed in a two-dimensional pattern and each equipped with a photoelectric conversion unit that generates and accumulates a signal charge corresponding to a subject image formed with light entering from an optical system and a readout control unit that executes control under which signals are read out from the plurality of pixels. The plurality of pixels include a plurality of imaging pixels that output imaging signals for forming image signals that represents the subject image and a plurality of focus detection pixels that output focus detection signals for detecting a focusing condition of the optical system through a split-pupil phase difference method.

Abstract: An apparatus and a method are presented for detecting the focal position of an optical system (10) with a radiation source (12), a focusing imaging system (16), an at least partially reflective surface (18) on the focus (18a), a digital camera (24) for recording an image reflected by said surface (18), a computer (C) for evaluating the image recorded by the camera (24), and with an optical element (34; 36) in the beam path of the optical system (10) upstream of the focusing imaging system (16), which element influences said image depending on the focal position.

Abstract: Provided is a microscope equipped with an automatic focusing mechanism, comprising an illumination light source; an objective lens for focusing first light emitted from the illumination light source onto an object to be detected; an illumination light source for imaging the first light that is reflected by the object to be detected and passes through the objective lens; and a focal-point detector for detecting a positional shift of a microtiter plate from a focal position of the objective lens, wherein the focal-point detector includes a focal-point-detection light source for emitting focal-point-detection light serving as second light, a focal-point detection light acquisition unit on which the focal-point-detection light is focused, and a region setting unit which can set an in-focus assessable region of the focal-point-detection light acquired by the focal-point detection light acquisition unit to any position on the focal-point detection light acquisition unit.

Abstract: Focus adjustment for a projector which includes a projection lens having an adjustable focus position. An asymmetrically focused pattern is projected through the projection lens onto a projection screen, wherein the asymmetrically focused pattern is imaged by the projection lens onto the projection screen with a focus at one portion on the screen that differs with focus at another portion thereof. An image of the asymmetrically focused pattern is captured from the projection screen. A focus adjustment direction is calculated by using asymmetrical aspects of the captured image of the asymmetrically focused pattern. The focus position of the projection lens is driven in the calculated focus adjustment direction so as to move from an out-of-focus state of the projection lens toward an in-focus state.

Abstract: The invention pertains to methods, components, and operations of multi-focal intraocular lens systems, including range finding for driving same and for discriminating between multiple objects and varying brightness conditions. The invention also pertains to intraocular photosensors and range-finding methods to be used with intra-ocular lens systems, and components, that provide multi-focal IOL capabilities in dynamic visual environments.

Abstract: A digital camera includes: an image capture data creation unit; a CPU for directing the image capture data creation unit to perform image captures several times and acquire a plurality of image capture data; and an image processing device that determines whether or not a common specific image region exists in a plurality of image capture data acquired by the CPU and, in the case where it is determined that a specific image region exists, performs a pixel additive synthesis for image data of the specific image region and creates image data.

Abstract: Disclosed in a focus detecting apparatus comprising: a micro lens array arranged with a plurality of micro lenses, a photo detector that has a plurality of detecting elements provided in correspondence with the micro lenses and receives light flux from an optical system via the micro lenses; and a focus detector that selects a pair of groups of detecting elements from the plurality of detecting elements based on an F-value of the optical system and a brightness of the light flux from the optical system and detects a focus adjustment status of the optical system based on a pair of light receiving signals obtained in the groups of detecting elements.

Abstract: A machine vision inspection system acquires a plurality of images of a workpiece region of interest at various focus heights, and determines a Z-height (e.g., the best focus height) for the region of interest based on a focus peak determining data set for the region of interest. The focus peak determining data set is derived from the plurality of images. The machine vision inspection system also determines Z-height quality meta-data based on data derived from the plurality of images (e.g., based on the focus peak determining data set), and associates the Z-height quality meta-data with the corresponding Z-heights. The Z-height quality meta-data are usable to establish weighting factors that are used in association with the corresponding best focus Z-heights in subsequent operations that fit a workpiece surface representation to a plurality of the best focus Z-heights.

Abstract: An apparatus carried by an unmanned vehicle to provide passive sensing and facilitate avoiding airborne aerial obstacles is provided. The apparatus can include at least one, but typically multiple optical systems installed, for example, in the nose of the aerial vehicle to passively sense and determine a range, direction, and velocity of the airborne obstacles to allow the aerial vehicle to avoid the airborne obstacles. The typical optical system includes at least one focal plane array or other imaging device configured to receive a wide field of view and at least one focal plane array or other imaging device configured to receive a steerable narrow field of view within the wide field of view to allow concentrated determination of the range, direction, and/or velocity of obstacles detected by the wide field of view imaging devices.

Abstract: An optical disc device comprising: first and second laser diodes to radiate first and second laser beams with different first and second wavelengths, respectively; a first objective lens to irradiate the first laser beam to reflection area to read out image recording control data for controlling record of image recorded in the reflection area on label side of optical disc; a second objective lens to irradiate the second laser beam to image recording area to record image in the image recording area on the label side after reading out the data; a lens holder that the lenses are fixed thereon to be arranged side by side in radial direction, to be displaced in direction toward signal side and the radial direction; and a control unit to obtain distance between the lenses in the radial direction to calibrate recording position of image signal recorded in the image recording area.

Abstract: A circuit for calibrating a focus position of an optical module includes a calibration signal generating unit and a focus position adjusting unit. The calibration signal generating unit is utilized for generating a calibration signal according to a first focus signal and a second focus signal at the same time, where the first focus signal and second focus signal correspond to a first focus position and a second focus position, respectively, and the first focus position is different from the second focus position. The focus position adjusting unit is coupled to the calibration signal generating unit and is utilized for adjusting the focus position of the optical module to a specific focus position according to the calibration signal.

Abstract: A combination of a laser transmitter and a laser receiver and a method determine the elevation of the receiver with respect to the transmitter. The laser transmitter includes a a laser light source for providing a beam of laser light and an element for directing the beam. The beam diverges vertically and varies in intensity vertically. A laser receiver includes an array of laser beam detectors for detecting the beam and the variations in the beam intensity in a vertical direction. The vertical position of the laser receiver with respect to the laser transmitter can be determined in this manner. The beam varies in intensity vertically in a predetermined vertical pattern, and the laser receiver detects at least a portion of the pattern defined by the beam such that the portion of the beam detected by the laser receiver may be determined.

Abstract: A focus control method is provided that performs focus control by sensing a plurality of images of an object while moving a position of a focusing lens and determining in-focus positions in auto focusing areas located at a plurality of positions. The focus control method calculates an in-focus position of the focusing lens based on the focusing lens position at the time of reading an image signal of each of the auto focusing areas and a degree of focused state of each of the auto focusing area that is based on the image signal of each of the auto focusing areas.

Abstract: An auto focus adjustment apparatus includes: a correction unit which corrects a defocus amount detected by a defocus amount detection unit, correspondingly to a focus area selected from a plurality of focus areas; a storage unit which stores a correction value to be used by the correction unit at a time of correcting the defocus amount; and a correction value changing unit configured to change the correction value, wherein the correction value changing unit is arranged to be capable of changing the correction value for a plurality of selected focus areas and at a plurality of zoom positions.

Abstract: A laser energy microinscribing system, comprising a semiconductor excited Q-switched solid state laser energy source; a cut gemstone mounting system, allowing optical access to a mounted workpiece; an optical system for focusing laser energy from the laser energy source onto a cut gemstone; a displaceable stage for moving said gemstone mounting system with respect to said optical system so that said focused laser energy is presented to desired positions on said gemstone, having a control input; an imaging system for viewing the gemstone from a plurality of vantage points; and a rigid frame supporting said laser, said optical system and said stage in fixed relation, to resist differential movements of said laser, said optical system and said stage and increase immunity to vibrational misalignments. The laser energy source is preferably a semiconductor diode excited Q-switched Nd:YLF laser with a harmonic converter having an output of about 530 nm.

Abstract: An auto-focusing method of creating a focus value when a point light source image and an image having a low contrast are focused, a recording medium recording the method, and an auto-focusing apparatus for performing the method are provided. In an embodiment, point light source reference graphs and non-point light source graphs are previously stored in a database, a reference graph having the most similar pattern to a focus graph is created by comparing the focus graph of input images to the point light source and non-point light source reference graphs, and a focus value is created when an image is focused using a different method according to the type of corresponding reference graph.

Abstract: Predetermined voltage is applied to a liquid crystal lens by a liquid crystal lens driver. Image signals are generated based on an optical image passed through the liquid crystal lens during transient response operation caused by application of the predetermined voltage, and plural focus signals are extracted by sampling the image signals at predetermined cycles. Levels of the extracted autofocus signals are compared to determine the maximum value of the autofocus signal. Thus, with the liquid crystal lens, by making use of the transient response operation of the liquid crystal lens, a focus point can be detected in sufficient speed.

Abstract: A liquid lens driver 10 has DC-DC converter 12, oscillator 14, pulse width modulator 16, and control logic circuit 18. The output buffer circuit 30 divides converter output voltage Vs of a prescribed amplitude (voltage level), input as the power source voltage, into bipolar, that is, positive/negative, output voltages Out-A, Out-B for output, and, corresponding to the H/L level of PWM signal CPWM, it turns ON/OFF the two output voltages Out-A, Out-B. In this way, from liquid lens driver 10, pulse width modulation (PWM) output voltages Out-A, Out-B are applied as driving voltage VL on electrodes 104, 108 of liquid lens 100.

Abstract: The method of determining a focus measure from an image includes detecting one or more edges in the image by processing the image with one or more first order edge detection kernels adapted to reject edge phasing effects. A first measure of the strength of each of the edges, and the contrast of each of the edges may be determined. The method may include normalizing the first measure of the strength of each of the edges by the contrast of each of the edges to obtain a second measure of the strength of each of the edges, and resealing the second measure of the strength of each of the edges. The method may also include selecting one or more of the edges from the image in accordance with the second measure of their strengths, and calculating the focus measure from the second measure of the strengths of the selected edges.

Abstract: An autofocus apparatus and a method achieve a higher level of speed and robustness, and are particularly suited for fluorescence microscopy of biological samples, automated microscopy and scanning microscopy. A high speed is achieved via a light pattern in the sample, detected spatially resolved by a detector generating at least two signals corresponding to a reflex pattern of the light pattern. The two signals are subtracted generating a positioning signal and the focus of the objective in the sample is adjusted depending on the positioning signal.

Abstract: A light detection device includes a lens array of a plurality of lenses arranged in the form of a honeycomb; and a photoelectric device array of a plurality of photoelectric devices for each of the plurality of lenses. The plurality of photoelectric devices is arranged under each of the plurality of lenses. Also disclosed are a focus detection device provided with the light detection device, and an imaging apparatus provided with the focus detection device as well as a method of producing such a light detection device and a method of detecting a focus.

Abstract: Disclosed is a projection type image display apparatus including a projection section to output a projection light in which an image is attached through a projector lens and a photographing section to photograph a projected image projected by the projection section through a photographing lens, and the projected image which is projected on a screen by the projection section is obtained by the photographing section and a focus of the projected image is adjusted based on a photographing result of the image obtained by the photographing section, and the projector lens and the photographing lens are movable in a direction to change the focus of the projected image or a focus of the photographed image by a same drive section.

Abstract: An exemplary MLA unit for use in a projection device is disclosed. The projection device includes an LCD panel. The LCD panel includes a number of pixels each having an opening. The MLA unit includes a first MLA, and a second MLA. The first MLA includes a number of first micro lenses each configured for focusing incident light into the opening of a respective pixel of the LCD panel. The second MLA includes a number of second micro lenses each aligned with a respective first micro lens of the first MLA so as to form a micro lens system. The second MLA is movable so as to change the effective focal length of the lens systems.

Abstract: This is an optical apparatus provided with an objective with a correction collar for correcting aberration due to an error in the optical thickness of a piece of cover glass comprising a focusing mechanism for changing a distance between the objective and the sample, an optical thickness detecting unit for detecting the optical thickness of the cover glass, an operating unit for calculating the amount of aberration correction, based on the optical thickness of the cover glass detected by the optical thickness detecting unit, a driver unit for driving a correction collar, based on the amount of aberration correction calculated by the operating unit and an imaging sensor for forming the image of the sample that passes through the objective.

Abstract: A method for focusing discrete points on an under-measured object is provided. The method includes: (a) receiving an image of the object, selecting measurement points on the image, and obtaining X, Y coordinate values of the measurement points; (b) searching a solid point on the under-measured object according to the X, Y coordinate value of one of the measurement points, wherein the solid point corresponds to the measuring point; (c) emitting a laser light to the solid point for computing a vertical distance “h” between the laser aid and the solid point; (d) computing a Z coordinate value of the measurement point according to the “h”; repeating step (b) to step (d) until all the Z coordinate values of the measurement points have been computed; and (e) focusing the solid points according to the X, Y and Z coordinate values of the measurement points. A related system is also provided.

Abstract: An imaging system is presented for use in multi-range imaging of an object scene by incoherent light. The imaging system comprises aligned a phase mask section, a single focus lens section, and a pixel detector array (PDA). The phase mask section has a generally non-diffractive, narrowly bounded, phase variation corresponding to a profile of a through-object Modulated Transfer Function (MTF) of the imaging system, where the profile has, at an at least one non-zero spatial frequency, at least two regions of growth leading to the MTF higher than 10%.

Abstract: The present invention further improves operability related to setting the position and size of a focus detection region. An image capturing apparatus of the invention is provided with an image sensor that photo-electrically converts an object image formed by an optical lens, a focus detection unit that detects the focus state of the object image using an image signal from a focus detection region that is a region that is a portion within a frame of the image sensor, a setting unit that sets one focus detection mode from among a plurality of focus detection modes in which the size and position of the focus detection region within the frame differ, and a storage unit that stores a focus detection region size and position for each of the plurality of focus detection modes.

Abstract: A method and apparatus for recalibrating a liquid lens. In one embodiment, a lens holder is provided to adjust the focal length of the lens as a function of temperature. In another embodiment, a recalibration circuit including a second lens of similar characteristics to the imaging lens is used to determine an appropriate focus. In other embodiments, an open loop calibration process is used.

Abstract: The present invention discloses methods and systems for improved focusing of imaging systems for the acquisition of high-quality focused tissue image data. A light emitter (L) aims a focusing light beam (FLB) towards an object of interest (O) so that the focusing light beam (FLB) is at an angle relative to the optical axis (OA) of the imager (I). If the object of interest (O) is out of focus, the focusing light spot (FLS) will appear above or below the focal point in the image (I). The pixel difference between the center of the focusing light spot (FLS) and the focal point indicates the range adjustment value. The range between the imager (I) and the object of interest (O) can then be adjusted according to the range adjustment value using a lookup table or calculations.

Abstract: An image pickup apparatus, a control method and a program are provided. The image pickup apparatus includes an imaging module which takes an image; a display module which displays the image taken by the imaging module; a touch panel configured integrally with the display module and manipulatable by a user; a focus frame control module which controls a focus frame in accordance with a manipulation of the touch panel by the user, the focus frame being set at a given position on the image displayed on the display module and being used for focus control; and a focus control module which controls focus based on an image inside the focus frame on the image displayed on the display module.

Abstract: The present invention is to provide a laser irradiation method for performing homogeneous laser irradiation to the irradiation object even when the thickness of the irradiation object is not even. In the case of irradiating the irradiation object having uneven thickness, the laser irradiation is performed while keeping the distance between the irradiation object and the lens for condensing the laser beam on the surface of the irradiation object constant by using an autofocusing mechanism. In particular, when the irradiation object is irradiated with the laser beam by moving the irradiation object relative to the laser beam in the first direction and the second direction of the beam spot formed on the irradiation surface, the distance between the irradiation object and the lens is controlled by the autofocusing mechanism before the irradiation object is moved in the first and second directions.

Abstract: A system and method of autofocusing an optical system uses transforms of images or portions of images formed by the optical system. A detector is used to capture images at different positions relative to the optical system. Transforms and blur spread parameters are calculated for the images for use in determining a position to which the detector should be moved to autofocus the system.

Abstract: A method of capturing a focused image of a continuously moving slide/objective arrangement is provided. A frame grabber device is triggered to capture an image of the slide through an objective at a first focus level as the slide continuously moves laterally relative to the objective. Alternatingly with triggering the frame grabber device, the objective is triggered to move to a second focus level after capture of the image of the slide. The objective moves in discrete steps, oscillating between minimum and maximum focus levels. The frame grabber device is triggered at a frequency as the slide continuously moves laterally relative to the objective so multiple images at different focus levels overlap, whereby a slide portion is common to each. The image having the maximum contrast value within overlapping images represents an optimum focus level for the slide portion, and thus the focused image. Associated apparatuses and methods are also provided.

Abstract: A focus detection device includes a micro lens array having a plurality of micro lenses, a light receiving element array having a plurality of light receiving elements for each micro lens and that receives light rays from a plurality of partial areas in which pupils of an imaging optical system are different from each other, in a plurality of light receiving elements respectively through each micro lens and a focus detection calculation circuit. The device generates at least three signal strings respectively corresponding to images of light rays which have been transmitted through at least three of the partial areas, based on signals output from the plurality of light receiving elements of the light receiving element array. The device obtains, from the at least three signal strings, shift amounts of two signal strings corresponding to two partial areas, and detects a focus adjustment state of an imaging optical system based on the obtained plurality of shifts amounts.

Abstract: A wavelength detecting apparatus capable of detecting the main wavelength of the light coming into an image capture apparatus and a focus detecting apparatus using the same are disclosed. The wavelength detecting apparatus may include a spectral unit which separates the incoming light according to the respective wavelengths, and may focus the separated light onto a sensor. The main wavelength can be determined based on the wavelength distribution sensed by the sensor. The determined wavelength can be used to further determine amount of adjustment to be made to the defocus amount to compensate for the chromatic aberration associated with the wavelength of the light illuminating the source.

Abstract: A crystallization method and system are provided which improve a crystallization process by deciding a best-fit focal plane for a laser beam using a test mask and then applying the decided best-fit focal plane to the crystallization process. The crystallization method includes loading a test mask on a mask stage; deciding a best-fit focal plane by performing a crystallization test using the test mask, checking the test result and deciding conditions of a best-fit focal plane from the test result; moving the mask stage to a position corresponding to the best-fit focal plane; loading a mask for crystallization process onto the moved mask stage; and performing the crystallization process using the mask for crystallization process.

Abstract: This invention has as its object to reduce the number of pixels to be read from an image sensor in accordance with a required image size and to shorten the time required to capture an image upon capturing a still image in an image capturing apparatus. To this end, this apparatus has an image sensor which comprises a plurality of photoelectric conversion pixels arranged in a two-dimensional matrix in the vertical and horizontal directions, and a common output unit which is commonly provided to the plurality of photoelectric conversion pixels to sequentially output signals from the plurality of photoelectric conversion pixels; and a read drive unit which can switch a first read mode for dividing signals of photoelectric conversion pixels from the image sensor into m fields (m is a natural number not less than 3) by interlaced scan, and reading signals for the m fields, and a second read mode for reading signals for n fields (n is a natural number that meets 2?n<m) of the m fields from the image sensor.

Abstract: The invention relates to a focus detection optical system used with the so-called autofocus (AF) system mounted on single-lens reflex cameras (SLRs) or the like, and an imaging apparatus incorporating it. The focus detection optical system comprises at least n focus detection areas that are adjacent to or intersect each other on a predetermined imaging plane, where n?2. A re-imaging lens group comprises n+1 re-imaging lenses, A (n?1)th re-imaging lens and an nth re-imaging lens are a pair of re-imaging lenses that correspond to a (n?1)th focus detection area and are adjacent to each other. An nth re-imaging lens and a (n+1)th re-imaging lens are a pair of re-imaging lenses that correspond to the nth focus detection area and are adjacent to each other. The (n?1)th re-imaging lens and (n+1)th re-imaging lens are located at different positions.

Abstract: An extended range focus sensor is provided. In various embodiments, the focus sensor may include a relay lens assembly to image a plane between an objective lens and the relay lens arrangement to a plane near an entrance pupil of a focus detector arrangement of the focus sensor. In some embodiments, the objective lens pupil is imaged onto the focus detector entrance pupil. In some embodiments, an illumination beam passes through the relay lens arrangement and is magnified on its way to be output by the objective lens, and the reflected focus detection beam passes back through the objective lens and the relay lens arrangement and is reduced prior to being input to the focus detector arrangement. In some embodiments, the focus detector arrangement may comprising a broad range focus detector combined with a high resolution Shack-Hartmann focus detector, and in others a single extended range Shack-Hartmann focus detector is used.

Abstract: A spatial information detection system, which is capable of, even when detecting spatial information from a common target space by use of a plurality of detection devices, achieving accurate detection without causing interference between the detection devices. Each of the detection devices has a light emitting source for projecting light intensity-modulated with a modulation period into the target space, a photodetector for receiving light from the target space, and an evaluation portion for detecting the spatial information of the target space from a change between the light projected from the light emitting source and the light received by the photodetector. The system includes a timing control portion for controlling the timings of projecting the lights from the light emitting sources such that a light projection period of the light emitting source of one of the detection devices does not overlap with the light projection period of the light emitting source of another detection device.

Abstract: A method of focus and a focusing apparatus and a detecting module are provided. The detecting module includes an ellipse curved-surface reflection device and a light detector. The ellipse curved-surface reflection device has a beam gate, a first focus and a second focus. A light beam is focused by a light focusing device, and is projected on a surface of an object to be detected through the beam gate. The ellipse curved-surface reflection device reflects the light beams reflected or scattered by the object. The light detector is disposed on the second focus for receiving the light beam reflected by the ellipse curved-surface reflection device to generate a detecting result, by which a distance between the light focusing device and the surface of the object to be detected is adjusted, so that the light beam is correctly focused on the surface of the object.

Abstract: A video projector (1) comprises a projection lens (18) which projects an image on a screen (S), a zoom ring (19) which varies a magnification ratio of the projection lens (18), a drive wheel (32) which is partially protruded from a bottom face of a housing (2), and a plurality of gears (310, 311, 312) that constitutes a power transmission mechanism (31) between the drive wheel (32) and the zoom ring (19). When the video projector (1) is moved in an anteroposterior direction to the screen with rotating the drive wheel (32), the zoom ring (19) is turned in conjunction with the rotation of the drive wheel (32) through the power transmission mechanism (31). Since the magnification ratio of the projection lens (18) is varied with the turning of the zoom ring (19), the size of the image projected on the screen is varied without a direct operation of the zoom ring (19) by a user.

Abstract: The invention is directed at a method and apparatus for auto-focusing an infinity corrected microscope. Light beams are directed and then converged towards a specimen of interest and at least one image is formed from the reflected light. The image, or images, are then reviewed and calibration measurements are retrieved from the image. These calibration measurement are then used to determine focusing measurements which are used to auto-focus the microscope.

Abstract: In a method and system for focusing a camera focus can be repeatedly alternated between an original focus position and a plurality of other focus positions. An image can be displayed when the focus position is the original focus position. The image can be suppressed at other focus positions when the images are out of focus. The image can be displayed at one of the other focus position when the image is in focus. In this manner, the display of annoying and distracting unfocused images is mitigated.

Abstract: A method and apparatus for assessing a height of a specimen includes an electron beam unit having an electron beam source, lenses, a table for setting a specimen and controllable in a height direction, and a detector, and a height detection system for detecting height of the specimen set on the table while the specimen is irradiated by an electron beam. The height detection system further includes an illumination system, a collection system, first and second detectors, a device configured to receive output signals from the first and second detectors while the specimen is irradiated by the electron beam and to generate a comparison signal from the output signals, wherein the comparison signal is responsive to the height of the specimen.

Abstract: A lens-controlling device controls a first lens unit which moves for zooming and a second lens unit which moves for correcting the displacement of an image plane caused by zooming and for focusing. The lens-controlling device includes a memory which stores data for obtaining target-position information representing a target position to which the second lens unit is to be moved, the target position corresponding to a position to which the first lens unit is moved from a current position and a controller which generates the target-position information on the basis of the data and controls the movement of the second lens unit on the basis of position information of the first lens unit and the target-position information.