725 results about "Astigmatism" patented technology

The invention belongs to the technical field of optical detection, and particularly relates to a global power wave aberration prediction-based Ritchey-Common detection method and system, and the method comprises the steps: firstly building a three-dimensional optical model through the parameters of a standard spherical mirror, a to-be-detected plane mirror and an interferometer, and combining a preset Ritchey angle and an out-of-focus / astigmatism coefficient, injecting vibration and temperature noise by using Monte Carlo simulation to generate an enhanced training data space; secondly, constructing a phase error adjustment model based on an adversarial network, and decoupling a mapping relation between an adjustment error and wave aberration distortion through a multi-scale attention mechanism and a radial basis function network to realize adaptive correction of sub-aperture phase data; and finally, splicing sub-aperture phases by using a graph neural network and fusing multi-angle full-aperture measurement data to accurately reconstruct the surface shape of the plane mirror to be measured. According to the invention, through confrontation training and dynamic error compensation of physical constraints, the detection efficiency and reliability of the large-aperture optical element are significantly improved.

The embodiment of the invention provides a microscope objective and a microscope. The microscope objective comprises a first lens group, a second lens group and a third lens group which are sequentially arranged from an image space to an object space. The first lens group has negative refractive power and is at least used for correcting coma. The first lens group comprises a first cemented lens, and the first cemented lens comprises a first lens and a second lens which are cemented. The second lens group has positive focal power and is at least used for correcting astigmatism, field curvature and distortion. The second lens group comprises a second balsaming lens, a third balsaming lens and a fourth balsaming lens. The second bonding lens comprises a third lens and a fourth lens, the third bonding lens comprises a fifth lens and a sixth lens, and the fourth bonding lens comprises a seventh lens and an eighth lens. The third lens group has positive focal power and is at least used for correcting spherical aberration. And the third lens group comprises a ninth lens, a fifth bonding lens and a twelfth lens, and the fifth bonding lens comprises a tenth lens and an eleventh lens which are bonded.

The invention discloses a multi-point out-of-focus lens design optimization method for refractive error and a lens thereof, and relates to the technical field of optical design, and the method comprises the steps: carrying out the multi-refractive simulation optical test of the structure distribution characteristics of a to-be-optimized multi-point out-of-focus lens, obtaining the out-of-focus filling rate, aberration and astigmatism correction effect, then carrying out the partition aggregation, and obtaining the out-of-focus filling rate of the to-be-optimized multi-point out-of-focus lens. Obtaining a deviation area and a deviation characteristic of each diopter; constructing an optimization parameter library; performing compensation target analysis according to the deviation area and the deviation characteristic of each diopter to obtain an optical target parameter; and performing matching search in the optimization parameter library, determining a compensation parameter strategy, and performing structural design optimization on the structural distribution characteristics of the multi-point out-of-focus lens to be optimized. According to the invention, the technical problems of over-correction or insufficiency caused by defocus design unification in the prior art, serious stray light at the connection position of the edge of the multi-point micro lens and the circle of the lens and insufficient processing and assembling precision are solved, and the technical effect of improving the correction precision and visual stability of the lens is achieved.

The invention provides an optical lens. The optical lens comprises a lens barrel, first to seventh lenses, a third spacing element and a fourth spacing element, wherein the first to seventh lenses, the third spacing element and the fourth spacing element are arranged in the lens barrel; the center thickness CT4 of the fourth lens on an optical axis, the air spacing T34 of the third lens and the fourth lens on the optical axis, and the maximum thickness CP4 of the fourth spacing element meet the following conditions: 1.07 < = (CP4 + CT4) / T34 < = 1.5; the combined focal length f45 of the fourth lens and the fifth lens and the spacing distance EP34 between the third spacing element and the fourth spacing element meet the condition that f45 / EP34 is larger than or equal to 18.82 and smaller than or equal to 24.58. According to the invention, the problem of stray light caused by the optical lens in the prior art in order to meet the assembly stability is solved.

The invention provides a progressive addition lens design method based on free-form surface expression, is mainly used for vision correction of presbyopia groups, and belongs to the field of eye vision optical design. According to the design method, focal power matching and astigmatism minimization of the progressive multi-focus lens are achieved by optimizing the free-form surface, the design method constructs a nonlinear functional minimization problem by means of free-form surface expression, and meanwhile an optimized initial solution is obtained by solving a linear fourth-order partial differential equation related to a spherical base disturbance term; according to the method, astigmatism in an effective area of the lens can be minimized on the premise of realizing focal power matching as far as possible, high astigmatism areas on two sides of the progressive channel are transferred to an edge area of the lens, and various customization requirements including specific light adding degree, channel length, effective visual area range and the like can be met for a wearer.

The invention discloses a stray light gray value acquisition method, an automatic focusing processing method and an automatic focusing processing system, and relates to the field of automatic focusing. The method is applied to the microscopic automatic focusing device, and comprises the following steps: adjusting the distance between a microscope objective and a reflection point corresponding to light passing through the microscope objective, or the reflection angle of the light, so that the adjusted distance or reflection angle exceeds the focusing range of the microscope objective; or an extinction assembly is additionally arranged on the outer side of the microscope objective, so that the light penetrating through the microscope objective is eliminated; theoretical light spot areas formed by stray light on the surface of the first sensor at different axial height positions of the microscope objective are calculated; and gray values corresponding to theoretical light spot areas in the actual light spot images of the microscope objective at different axial height positions are extracted and used for correcting the light spot image of the object to be measured, so that the influence of stray light on a defocusing amount calculation result is reduced. Therefore, the influence of stray light reflected by the surface of the microscope objective on the defocusing amount calculation is reduced, and the accuracy of the defocusing amount calculation is improved.

The invention provides an optical imaging apparatus. The optical imaging device comprises a lens barrel, a lens group and a spacing element group, and the lens group and the spacing element group are arranged in the lens barrel. The eight lenses are sequentially a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with focal power from the object side to the image side. A seventh lens with positive focal power and an eighth lens with positive focal power; the spacing element group comprises a fourth spacing element, a fifth spacing element, a sixth spacing element and a seventh spacing element; the following conditions are satisfied: 1.4 lt; f8 / flt; 2.9, 2.9; the formula is as follows:-4.2 lt; d7m / (R15 + R16) lt; and-2.2. According to the invention, the problem of serious stray light at the tail end caused by the fact that the optical imaging device with eight lenses with relatively strong bending force of the eighth lens in the prior art meets the imaging effect is solved.

The invention relates to the technical field of optical detection, in particular to a bright and dark field detection device and method.First illumination light emitted by a bright field light source is modulated through an illumination modulation assembly, then the first illumination light and second illumination light emitted by a dark field light source are guided to irradiate the surface of a to-be-detected sample, and the first illumination light is reflected by the to-be-detected sample to form bright field signal light; the second illumination light is scattered by the sample to be detected to form dark field signal light, and the bright field signal light and the dark field signal light are transmitted along a common light path and are mutually separated in space; an objective lens matched with the illumination modulation assembly receives and microscopically amplifies the bright field signal light and the dark field signal light; the imaging assembly receives the bright-field signal light and the dark-field signal light and carries out bright-field imaging and dark-field imaging. Through a bright and dark field common-path sub-view-field design, simultaneous imaging detection of bright and dark fields is realized; in addition, by arranging the illumination modulation assembly, the reflection phenomenon of illumination light on the periphery of the exit pupil plane of the objective lens is inhibited, and interference of stray light on imaging is eliminated.

The invention discloses a method for generating high-quality Laguerre-Gaussian vortex light, which comprises the following steps: based on a V-shaped laser resonant cavity of a concave folded mirror, astigmatism is introduced by utilizing different convergence capacities of the concave folded mirror on a meridian plane and a sagittal plane of a light beam, so that the cylindrical symmetry of the resonant cavity is destroyed, and the high-quality Laguerre-Gaussian vortex light is generated; the influence of the cylindrical symmetry of the laser resonant cavity on the intrinsic mode of the cavity is eliminated, so that the intrinsic mode of the cavity is a Hermite-Gaussian mode, and the generation of an ellipse due-Gaussian mode is inhibited; an off-axis pumping method is adopted, and the laser resonant cavity generates high-order Hermite-Gaussian mode laser; the focusing lens focuses the generated high-order Hermite-Gaussian mode laser, so that the beam waist of the high-order Hermite-Gaussian mode laser is positioned in the center of the astigmatism mode converter; the astigmatism mode converter provides conditions for mode conversion by changing the Gouy phase of the laser mode, and high-quality Laguerre-Gaussian vortex light output is achieved.

An ophthalmic lens configured to correct and / or treat at least one condition of the eye (e.g., presbyopia, myopia, hyperopia, astigmatism, binocular vision disorders, night vision image quality, and / or visual fatigue syndrome) comprising: a base power profile; and at least one pulse selected to modify the base power profile.

The invention relates to the technical field of optical detection, in particular to an optical detection system and optical detection equipment. A first optical element for changing a bright field illumination light beam into first linearly polarized light is arranged in a light path of the bright field illumination light beam; a second optical element for changing the dark field illumination light beam into second linearly polarized light is arranged in a light path of the dark field illumination light beam, the polarization direction of the first linearly polarized light is different from that of the second linearly polarized light, and the first optical element is used for inhibiting the first stray light from being mixed into a transmission path of the first linearly polarized light; the first stray light comprises light which reaches the bright field illumination lens group after the second linearly polarized light is reflected and / or scattered; therefore, in the dark field detection process, the first stray light is prevented from being reflected by the bright field illumination lens group through the first optical element, the adverse effect of the first stray light on dark field imaging is reduced, the imaging quality and the imaging effect of dark field images are improved, and the detection efficiency and the detection accuracy are improved.

The invention provides a visual system. The visual system comprises a lens cone, a lens group and a spacing element group, the lens group and the spacing element group are arranged in the lens cone, and the lens group is composed of four lenses, a polaroid, a reflective polarizing element, a quarter-wave plate and a reflective element. The four lenses are sequentially a first lens with positive focal power, a second lens with negative focal power, a third lens with negative focal power and a fourth lens with positive focal power from the first side to the second side; f23 / d3s is more than or equal to-9.75 and less than or equal to-8.72; f / (CP1 + EP13) is more than 5.00 and less than 5.40. The problem that stray light is serious due to the fact that a four-piece type visual system in the prior art is provided with a bonding lens and a reflecting part to meet the requirement for structure compactness is solved.

The invention provides a structure and method for bonding plane mirrors and calibrating angles at the same time, and relates to the technical field of aviation, the structure comprises a frame, an infrared turn-back assembly, a flexible lens pressing ring, a mirror frame, a mirror and a pin gauge, the flexible lens pressing ring and the mirror frame are used for axially positioning the mirror, and the pin gauge is arranged in the radial direction of the mirror. When the glue is injected, the area and the thickness of the glue are accurately controlled, the tension generated on the mirror surface of the reflector after the glue is cured is uniformly distributed, the surface precision of the reflector is ensured, the arrangement of the cover plate can effectively prevent light leakage, stray light is prevented from influencing the imaging quality, and the technical problem that the surface precision is reduced when an existing reflector is installed is solved.

The invention provides an optical lens. The optical lens comprises a lens barrel, a lens group and at least one spacer, the lens group and the spacer are arranged in the lens barrel, the lens group is composed of five lenses, and the five lenses are a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence; the at least one spacer comprises a first spacer; the curvature radius R1 of the object side surface of the first lens and the outer diameter D1s of the object side surface of the first spacer meet the condition that R1 / D1s is greater than or equal to 0.37 and less than or equal to 1.26; the inner diameter d1s of the object-side surface of the first spacer, the center thickness CT1 of the first lens on the optical axis, and the radius of curvature R2 of the image-side surface of the first lens satisfy 3.80 < = d1s / (CT1 * R2) < = 7.82. The five-piece optical lens solves the problem that stray light at the front end is increased due to the fact that a five-piece optical lens in the prior art meets the bearing stability of the first lens.

The utility model discloses a large-magnification continuous zooming fog-penetrating lens, which comprises a front fixed lens group, a zooming lens group, a compensating lens group, a rear fixed lens group, a temperature focusing lens group and an optical filter switcher which are sequentially arranged along the light incidence direction, and is characterized in that the front fixed lens group comprises a first lens and a first gluing group; the zoom lens group comprises a fifth lens and a second gluing group, the compensation lens group comprises an eighth lens and a third gluing group, the rear fixed lens group comprises a fourth gluing group, a fifth gluing group and a fifteenth lens, and the temperature focusing lens group comprises a sixth gluing group. The optical filter switcher comprises an optical filter and an anti-reflection sheet and is used for switching the optical filter and the anti-reflection sheet in the direction perpendicular to the optical axis. By reasonably setting the parameters of each lens and the overall mechanical structure of the lens, electric four-variable functions of focal length, resolving power compensation, aperture and fog penetration are realized, the stability is good, the response speed is high, stray light ghosting can be reduced, chromatic aberration can be corrected, the imaging quality can be improved, the service life can be prolonged, and miniaturization and light weight are facilitated.

The invention discloses a method and a device for detecting errors of a rotary table and a rotary shaft of an overall measurement light path connected upper rotary shaft type laser tracker, and belongs to the technical field of laser tracking measurement. The device comprises a microscope, a fluorescent microsphere, a substrate and a six-dimensional precision calibration displacement table, the microscope is located above the fluorescent microsphere, and the six-dimensional precision calibration displacement table is located above the substrate. The fluorescent microspheres are fixed on the substrate, and the substrate is fixed on the six-dimensional precise calibration displacement table. By combining the fluorescence microscope with the astigmatism imaging function, the precise displacement table, space coordinate calculation and other operations, the determination of the axis space linear equation of the upper and lower rotary tables of the whole measurement light path connected upper rotary shaft type laser tracker and the detection of the shaft radial runout in a complete rotation period are realized under one coordinate system; a necessary technical foundation is laid for realizing error compensation of the rotary table and the rotary shaft of the rotary shaft type laser tracker connected with an overall measurement light path and improving the tracking precision and the stability of the laser tracker.

A method for performing an astigmatism power test using a computing having a screen for displaying images relating to the astigmatism power test. The method includes determining an angle of astigmatism, calibrating visual acuity of the user, determining amplitudes required for the astigmatism correction, and determining the needed refraction, as well as a corresponding computer system.

The invention discloses a small vision detection device for eye examination, and particularly relates to the technical field of vision detection devices.The small vision detection device comprises a device bottom plate, a vision detection mechanism is arranged at the top of the device bottom plate and comprises a first moving plate, and the first moving plate is arranged at the top of the device bottom plate; the top of the first moving plate is fixedly connected with a moving mounting plate, and a display screen is mounted on the front side of the moving mounting plate. By arranging the vision detection mechanism and the adjusting mechanism, the comprehensiveness of vision detection is improved, the vision definition is detected, the type and degree of refractive errors such as myopia, hyperopia and astigmatism can be accurately diagnosed through a diopter test, whether a vision problem exists or not is determined, and the vision detection accuracy is improved. Meanwhile, some eye diseases possibly influencing vision can be indirectly found through intraocular pressure testing, retina injury and vision loss caused by too high intraocular pressure can be prevented by monitoring changes of the intraocular pressure, the examination effect is good, and vision detection is more comprehensive.

The invention provides an optical lens. The optical lens comprises a lens barrel, and first to seventh lenses and a spacing element group which are arranged in the lens barrel. The spacing element group at least comprises a sixth spacing element, and the sixth spacing element is located between the sixth lens and the seventh lens and makes contact with the image side face part of the sixth lens; the curvature radius R12 of the image side surface of the sixth lens and the outer diameter D6s of the object side surface of the sixth spacing element meet the following condition:-2.0 < = D6s / R12 < =-1.56; the curvature radius R13 of the object side surface of the seventh lens and the outer diameter D6m of the image side surface of the sixth spacing element satisfy the following relation:-2.47 < = D6m / R13 < =-1.81. According to the invention, the problem of stray light caused by the optical lens in the prior art in order to meet the assembly stability is solved.

The invention provides a linear optical tweezer astigmatism field regulation and control method based on an optical transmission matrix. The design method comprises the following steps: establishing a 4 * 4 optical matrix for generating a linear optical tweezer astigmatism field and a transmission equation; analyzing the regulation and control rule of the parameters of the optical element on the astigmatism characteristics; collecting a fluorescence slice image of the initial astigmatic light field through an axial tomography scanning method; reconstructing the spatial distribution of the initial image light field; judging whether the light field accords with a preset astigmatism characteristic or not, if not, determining the astigmatism characteristic to be optimized, and adjusting element parameters according to a regulation and control rule; and acquiring the adjusted image of the astigmatism light field again, reconstructing the image, and continuously performing judgment iteration until the image accords with the preset astigmatism characteristic, thereby realizing regulation and control of the astigmatism light field. Matrix optics is used in optimization of a linear optical tweezer image dispersion light field optical system, the limitation of traditional trial and error design is avoided, the method can be applied to the fields of light control technology, light sheet fluorescence microscopic imaging and the like, and the performance of the optical system is improved.

A method for correcting nonuniformity of a near-eye display (NED) includes: obtaining a first plurality of images in response to a first test pattern being displayed by a display of the NED, each of the first plurality of images being obtained at a different location adjacent to an end of an optical path coupled to the display; extracting a distinguishing frequency component among the first plurality of images, the distinguishing frequency component being at least caused by stray light introduced by the optical path; and determining a correction scheme for correcting nonuniformity of the NED based on the distinguishing frequency component.

The utility model belongs to the technical field of medical instruments, and particularly relates to an artificial lens for people with color vision disorder. The surface of the intraocular lens is a spherical surface or at least one surface is an aspheric surface or at least one surface is a discontinuous surface, the intraocular lens is colored and at least uses one coloring dye, and the coloring range of the intraocular lens at least comprises part of an optical area. According to the intraocular lens, at least one inhibition band exists in the wavelength range of 380 nm to 780 nm of the spectrum transmittance of the intraocular lens, and the minimum value of the spectrum transmittance in the inhibition band is lower than the nearest peak value of the spectrum transmittance in the wavelength range of 380 nm to 780 nm, so that the situation that the surface roughness is too high due to film coating is avoided, cell deposition on the surface of a film layer is avoided, the color vision correction safety is improved, and the color vision correction efficiency is improved. The correction effect of color vision correction is guaranteed, the problem that the surface reflectivity is high due to the fact that the surface of the artificial lens is coated with a film is effectively solved, optical interference is prevented, the retina is prevented from receiving stray light, and the signal-to-noise ratio of a retina image is prevented from being reduced.

The invention discloses a receiving module, a radar, a terminal and a vehicle end, and relates to the technical field of laser radars. Wherein the receiving module comprises an optical element and a detector, and the receiving module is used for receiving a linear light beam extending along a first direction. The optical element is used for astigmatism of the first light beam in the second direction and / or field curvature of the first light beam. The detector receives the light beams passing through the optical element through the plurality of monitoring areas, and the detector is located at a target focal plane of the optical element. According to the invention, the dynamic range of imaging can be ensured through the diffusion of the first light beam in the second direction by astigmatism and the diffusion of the edge view field light beam by field curvature. According to the optical element provided by the invention, the detector is arranged at the target focal plane of the optical element, and the configuration of the pixels on the detector is combined, so that the receiving module has a high-resolution receiving capability, and therefore, the optical element provided by the invention does not need a complicated manufacturing process, is simple in structure and low in manufacturing cost, and can realize the low-cost design of a high-resolution laser radar.

To provide contact lenses to be put on eyes experiencing axial-length related disorders, such as myopia.SOLUTION: A contact lens for managing myopia comprises: an optical zone defined to have a center substantially at its optical axis to provide substantially toric or astigmatic cues for the eye; and a non-optical peripheral carrier zone about the optical zone configured to have a thickness profile that is substantially rotationally symmetric to further provide temporally and spatially varying stop signals to decelerate, ameliorate, control, inhibit or reduce the rate of myopia progression over time.SELECTED DRAWING: Figure 3

The invention relates to a coaxial four-mirror optical system, which comprises a primary mirror, a secondary mirror, a third mirror, a fourth mirror and an annular diaphragm, all the mirrors and the annular diaphragm are coaxially arranged, both the secondary mirror and the third mirror are provided with light through holes, light is reflected by the primary mirror and then is reflected by the secondary mirror, the third mirror and the fourth mirror in sequence, and the light is reflected by the annular diaphragm. And finally converging and imaging. In the design, through application of the annular diaphragm, edge aberration is reduced, and stray light suppression capability is remarkably enhanced at the same time. The coaxial four-mirror optical system has the advantages of being compact in structure, high in imaging quality, wide in applicability and the like, and is suitable for being applied to multiple fields of aerospace, biomedicine, industrial detection and the like.

The invention discloses a D-type microcapsule probe suitable for intravascular OCT (optical coherence tomography) imaging. The probe comprises a single-mode optical fiber, a gradient refractive index optical fiber, an inclined-plane coreless optical fiber, refractive index matching glue and a D-type glass cap tube, the graded-index optical fiber is welded at one end of the single-mode optical fiber to serve as a micro-collimation / focusing lens; the bevel coreless optical fiber is welded to the other end of the gradient refractive index optical fiber and serves as a total reflection bevel; the head end of the optical fiber is arranged in the D-shaped glass cap tube, and the optical fiber and the inner wall of the D-shaped glass cap tube are filled with the refractive index matching glue; the outer tube wall of the D-shaped glass cap tube is subjected to flat-angle polishing to form a flat-angle mirror surface, and the reflection inclined plane of the coreless optical fiber is orthographically projected on the flat-angle mirror surface. According to the invention, through matching correction of the D-shaped optical capsule, transverse and radial photoetching resolutions are completely consistent in mechanical OCT spiral scanning 3D imaging, and astigmatism influence on imaging caused by the optical fiber and the cylindrical surface effect of the O-shaped optical capsule can be completely eliminated.

The embodiment of the invention discloses a stray light testing method and device for a vehicle-mounted image acquisition module, equipment and a medium. Comprising the following steps: acquiring a pixel image, a first brightness image and a second brightness image corresponding to a preset light source; wherein the pixel image is acquired by a to-be-detected vehicle-mounted image acquisition module, and the to-be-detected vehicle-mounted image acquisition module comprises a first lens; the first brightness image is collected by a first brightness meter composed of a preset sensor and a second lens, and the second brightness image is collected by a second brightness meter composed of a preset sensor and a first lens; and determining the energy level of stray light in the to-be-detected vehicle-mounted image acquisition module based on the pixel image, the first brightness image and the second brightness image. According to the scheme, the energy level of the stray light is directly determined by adopting a method of matching the brightness meter with the vehicle-mounted image acquisition module to be detected instead of using a dimmer and approximately calculating the energy level by adopting a pixel value and the dimmer, and any intermediate conversion and attenuation process does not exist, so that the accuracy of the magnitude of the stray light energy is improved.

Described are toric contact lenses that contain high energy visible (HEV) light absorbing compounds and their use for improving various vision attributes in astigmatic contact lens wearers, such as brightness perception and visual range.

The invention discloses a stray light removing system of a diffractive optical element for beam splitting, which comprises a laser light source, the diffractive optical element for beam splitting, a first focusing element, a diaphragm, a second focusing element and a third focusing element which are sequentially arranged along the direction of a laser light path, and is characterized in that the diffractive optical element is used for splitting incident light into a plurality of sub-beams; a plurality of light through holes used for removing stray light are formed in the diaphragm corresponding to the plurality of sub light beams, the focal lengths of the first focusing element and the second focusing element are the same and are F, the distance between the diaphragm and the first focusing element and the distance between the diaphragm and the second focusing element are the same and are L, and L is equal to F. By forming a 4f filtering system, stray light of each sub light beam is effectively removed, and under the condition that the transmission characteristic of light is not changed, the whole structure is simple, operation is convenient, the yield of machined products is guaranteed, and cost is saved.

The invention relates to the field of semiconductor manufacturing and detection, in particular to an anastigmatism method of electron beam imaging equipment, a product and the equipment. The anastigmatism method comprises the following steps: searching a target astigmatism parameter of an anastigmatism device in the electron beam imaging equipment; gradually adjusting the current of the preset objective lens according to a set step length, and collecting a plurality of fine focusing images corresponding to different objective lens currents; calculating gradients of the plurality of fine focusing images in different coordinate axis directions; judging whether the target astigmatism parameter meets the astigmatism elimination requirement or not according to the gradient consistency; and if yes, determining the target objective current of the electron beam imaging equipment according to the gradient. According to the anastigmatism method, after the target astigmatism parameter of the anastigmatism device is determined, the judgment operation on the target astigmatism parameter is executed, the anastigmatism accuracy is improved, the problem that the measurement accuracy is low due to the fact that a wrong anastigmatism result is applied is avoided, and therefore the measurement accuracy of the electron beam imaging device is improved.