332results about How to "Improve focus accuracy" patented technology

The invention discloses an automatic focusing microscope based on an eccentric beam method and a focusing method thereof. The hardware comprises an eccentric beam defocus amount detection module, a microscopic imaging module, a piezo lens drive, an XY stage and a computer processing system. The defocus amount detection module transmits a semicircular laser beam to irradiate the surface of a sample and acquire a semicircular spot image formed by sample reflection. The computer processing system uses self-adaptive median filtering, Canny edge detection based on OSTU, the least square fitting and other algorithms to process the grayscaled spot image to acquire spot radius. According to a radius-defocus amount linear relationship model, the sample defocus amount in a field of vision can be calculated. The piezo lens drive drives a lens to compensate the defocus amount. After focusing, the microscopic imaging module acquires a clear sample image. The automatic focusing microscope based on the eccentric beam method and the focusing method thereof, which are provided by the invention, have the advantages of fast focusing speed, high focusing accuracy and large linear range, and can meet the requirement of fast and precise focusing of the microscope under a high power lens.

The present invention relates to a laser differential confocal tomography focusing method and device, and relates to the technical field of optical imaging and detection. The method uses a rear pupilto block half of a measurement beam, uses a spectroscopic differential confocal detection system to detect the unblocked measurement beam, and uses an absolute zero point of a differential confocal response curve to achieve high precision tomographic focusing. The method organically combines a laser differential confocal technique and a ray tracing technique to establish a ray tracing and compensation model to eliminate influence among each fixed focal surface parameters, and achieves fast trigger of focus through data near a linearly fitting absolute zero point. The method can obtain the differential confocal response curve by using only one detector, and realizes the tomographic focusing through the absolute zero point of the differential confocal response curve, greatly simplifies system structure, in the same time, avoids error introduced by adjustment inaccuracy, and greatly improves precision of focusing. The method will provide a new technical approach to the field of confocal imaging/detection.

The invention relates to a method for fixing a focus and measuring a curvature radius by confocal interference, and belongs to the technical field of optical precision measurement. The method comprises the following steps of: introducing interfering reference light based on a confocal light path; precisely positioning an apex of the surface of a tested spherical element and a location of the centre of a sphere by using the maximum value of a confocal interference response curve to obtain the curvature radius of the surface of the tested spherical element; and maximumly sharpening a main lobe of the confocal response curve. By the invention, the traditional confocal interference microscopy imaging technique is first applied to improvement on the fixed-focus precision of an optical measuring system, so that the optical measuring system has a higher axial resolution and a simple structure, and the research and development costs of the system device are reduced.

The invention discloses an auto focusing method comprising following steps: driving the lens to move in the whole range can be reached with a predetermined step width, obtaining an image at the initial position of the lens and at the position of each step of the lens; comparing each obtained image, memorizing corresponding lens position, and calculating the fractal dimension value of each pixel in a certain area therein; calculating the image evaluation value by using the fractal dimension value, thereby obtaining an image evaluating sequence; finding out the maximum value, and the values corresponding to the front and post n (n is a positive integer) steps in the sequence, making a parabolic curve according to the 2n+1 evaluating values and the corresponding lens position values; and calculating the corresponding lens position of the parabola vertex which is the lens focusing position. The invented auto focusing method can analyze image detail information well with good adaptability, focusing accuracy is increased, focusing position can be found out quickly, and the invented method can be used broadly in diversified cameras.

A stereoscopic imaging apparatus which uses contrast AF to obviate disadvantages of phase-difference AF, shorten processing time of contrast AF, and improve focusing accuracy. A phase-difference CCD in which object images having passed through different regions in a predetermined direction of a single photographing optical system are pupil-split and imaged subjects the object images having passed through the respective regions to photoelectric conversion to obtain a main pixel image and a sub-pixel image which have a mutual phase difference. Contrast AF is performed using only one of the main pixel image and the sub-pixel image. Which one of the main pixel image and the sub-pixel image will be used for the contrast AF is determined depending on whether the position of an AF area in the angle of view belongs to a main pixel AF area or a sub-pixel AF area.

The invention belongs to the technical field of display panel defect detection, and discloses a fast auto-focusing method based on a display panel. The method includes the following steps: a focusingscreen image of a display panel is collected, focusing is carried out by dichotomy in the full focal range, the clear focusing range of the image is determined by long-step focusing, and the clear focusing position is determined in the focusing range by short-step focusing; an image corresponding to the clear focusing position is collected at the clear focusing position, and the focusing clarity is judged; if the focusing clarity satisfies a preset threshold requirement, the image is output; and otherwise, an image is collected and the focusing clarity is judged again after auto-focusing fine-tuning until the focusing clarity satisfies the preset threshold requirement, and the image is output. According to the auto-focusing method provided by the invention, the clear focusing position is calculated through coarse focusing, and fine-tuning is carried out according to the clarity of the image at the focusing position. Therefore, the focusing accuracy is improved, error focusing is prevented, the accuracy of defect detection is improved, and the detection time is shortened.

The application relates to a microscope focusing method and apparatus, a computer apparatus, and a storage medium. The method includes: collecting a coarse focusing image of a microscope; evaluating the image sharpness of the coarse focusing image; determining a coarse focusing position and a focusing adjustment direction according to the image sharpness; acquiring a fine focusing image, being animage shot by the microscope based on the coarse focusing position, of the microscope; and according to the fine focusing image, determining an optimal focusing position. According to the embodiment of the application, the optimal focusing position can be searched directly in the search range determined according to the coarse focusing position; repeated multi-focusing is avoided; the focusing time is saved; and the focusing efficiency is improved.

The invention relates to an actuator including a base, a fixing frame, a movable frame and a drive unit. The fixing frame is fixedly arranged on the base. The movable frame is accommodated in the fixing frame and loaded on the base. The movable frame includes an abutting face which faces the base. The drive unit includes an SMA wire, a controller, a position sensor and a guide rod. The SMA wire includes a bending part arranged between two ends, wherein the bending part contacts the abutting face. The guide rod passes through the movable frame and is fixed on the base. The controller is used for applying current to heat the SMA wire and change the length of the SMA wire so as to drive the movable frame to move along the guide rod. The position sensor is used for sensing the position of the movable frame and transmitting the sensing result to the controller. The controller is also used for adjusting the size of the current according to the sensing result.

The accuracy of focus adjustment operation is enhanced further. When focus adjustment operation is performed, a first measured distance acquired by utilization of TTL-AF and a second measured value acquired by utilization of a distance between the eyes have been computed in advance. The degree of reliability of the first measured distance is compared the degree of reliability of the second measured distance in accordance with a result of a determination as to whether or not a face is detected (S10), a result of a determination as to whether or not an ambient brightness value Br is equal to or less than a reference value (S12), a result of a determination as to whether or not a focal length “f” is equal to or less than a reference value (S16), and a result of a determination as to whether or not a second measured distance De is less than a first measured distance Dt (S18). Focus adjustment operation is performed in accordance with a measured distance determined to be more reliable.

The invention discloses a lens driving device and a camera shooting module. A first driving module is connected with a first bracket and a second bracket, and a gap is formed between the first bracketand the second bracket; a driving line is connected with a third bracket and the second bracket; and an elastic part is arranged between the third bracket and the second bracket. By applying a driving signal to the first driving module and/or the driving line, the first driving module is controlled and/or the driving line is controlled to stretch for driving the first bracket and the second bracket to relatively move along an optical axis and/or controlling a distance between the third bracket and the second bracket. Therefore, accurate and coarse adjustment of displacement between the brackets can be achieved; the adjustment precision of the displacement between the brackets is improved; and the focusing precision of an optical lens group is improved.

The invention discloses an image collecting system and an image collecting method. The system comprises a fixation point detection device and an image collecting device, wherein the fixation point detection device is used for detecting the position, relative to a user, of a user current fixation point, and the image collecting device is used for conducting focusing and image collecting according to the position, relative to the user, of the fixation point. The fixation point detection device comprises an eye fundus image collecting module, an adjustable lens module and an image processing module, the eye fundus image collecting module is used for collecting an image of the eye fundus of the user, the adjustable lens module is used for adjusting imaging parameters of a light path between the eye fundus image collecting module and the eyes so as to enable the eye fundus image collecting module to obtain the clearest image, and the image processing module is used for calculating the position, relative to the user, of the user current fixation point according to the imaging parameters of the light path between the eye fundus image collecting module and the eyes and the optical axis direction of the eyes when the clearest image is obtained. According to the mage collecting system and the image collecting method, the focusing accuracy and the focusing speed of the image collecting device can be improved.

An imaging apparatus includes: an imaging optical system including a focus lens; an imaging element generates an image indicating an object image; a lens drive device which moves the focus lens along an optical axis direction of the imaging optical system; an evaluation value calculation device which calculates an evaluation value of a contrast for each of a plurality of evaluation value calculation areas while moving the focus lens; a point light source presence/absence determination device which determines a presence or absence of a point light source in a specific region of the image; an area selection device which selects a focusing determination area based on the presence or absence of the point light source; and a focusing control device which determines the focusing position of the focus lens based on the evaluation value in the focusing determination area and moves the focus lens to the focusing position.

The invention relates to an auto-focus device for a visible light lens. The auto-focus device comprises an FPGA (field programmable gate array) controller, a video input circuit, a power management module, a motor driving circuit and a serial port communication circuit, wherein the FPGA controller drives a focus motor to move to the best focus position through the motor driving circuit. A focus method includes the steps: a) determining the farthest clear position and setting the position of the motor as A; b) determining the nearest clear position and setting the position of the motor as B; c) determining the whole focus course between the two points A and B; d) judging whether trigger signals are generated or not; e) moving to the nearest local end point; f) seeking a primary focus clear point; g) seeking a secondary focus clear point; h) seeking a tertiary focus clear point. According to the auto-focus device and the method, the focus mode of the maximum stroke of a focus motor in the past is avoided, focus speed is high, the focus motor successively approximates the focus position by gradually decreasing the speed and the step length of the focus motor, so that the final focus position is more accurate, and images are clearer.

The invention relates to a laser optical tweezer microscope. The microscope comprises: a lens cone, an image sensor, a microscopic objective lens, an objective table which can move up and down, a carrying substrate, a support and a digital optical phase conjugate apparatus which is used to generate laser optical tweezer and focus the optical tweezer on an object. The lens cone is fixed on the support. The objective table which can move up and down is connected with the support through a rack. The carrying substrate is placed on the objective table which can move up and down. The microscopic objective lens, which is used to carry out amplification imaging to the object placed on the carrying substrate, is installed on a bottom of the lens cone. The image sensor, which is used to record and amplify the microscopic image, is arranged in the lens cone and is located above the microscopic objective lens. By using the microscope of the invention, focusing accuracy and positioning accuracy of the optical tweezer can be increased. A precision machinery motor is not needed to increase a moving speed of the optical tweezer. An optical tweezer number can be increased. Any one optical tweezer can be independently operated. Through cooperation of a plurality of the optical tweezers, a high-precision complex microscopic operation can be realized.

The invention relates to the field of image processing and food monitoring, and particularly discloses a method and a device for improving the automatic focusing accuracy and speed of a camera. The method for improving the automatic focusing accuracy and speed of the camera is characterized by sequentially comprising the steps of video image collection, image format conversion, focusing template setting, night vision low-illumination scene definition evaluation value calculation, daytime scene definition evaluation value calculation, peak searching and motor-driven lens focus finding. The threshold value of the change of the definition evaluation value in the hill climbing algorithm is adaptively adjusted according to the brightness contrast, the gradient contrast and the ISO value, the change trend of the current evaluation value can be effectively judged, the peak value can be found more quickly, and the automatic focusing speed and accuracy of night vision and low-illumination scenes are improved.

An image processing device and method in which only an image or part(s) of an image in adequate focus may be printed through an image forming apparatus such as a printer, are provided. The image processing device includes a focus determiner for determining whether a focus accuracy of an image displayed on a display unit is greater than a predetermined focus accuracy, and a focus processor for processing the image to be printed only if it is determined that the focus accuracy of the image is greater than the predetermined focus accuracy.

The invention relates to a laser differential confocal curvature radius measuring method and a laser differential confocal curvature radius measuring device, which belong to the technical field of optical precision measurement. The laser differential confocal curvature radius measuring method utilizes a post-positioned pupil to block half of a measuring beam, uses a light splitting pupil differential confocal detection system for detecting a measuring beam to obtain a differential confocal response curve, and utilizes an absolute zero point of the differential confocal response curve to perform precise focus fixation on a surface vertex position and a sphere center position of a spherical element separately, so as to obtain a curvature radius of the element. According to the laser differential confocal curvature radius measuring method and the laser differential confocal curvature radius measuring device, the post-positioned light splitting pupil laser differential confocal technologyis applied to the high-precision detection of the curvature radius of the spherical element for the first time, the differential confocal focus fixation and curvature radius measurement is realized byusing only one path of detector, the system structure is simple, the assembly and debugging difficulty is reduced, the possible decrease of focus fixation precision caused by replacement of a measured lens is avoided, further the measurement precision is improved; and data near a zero point of the differential confocal response curve is subjected to linear fitting, so as to achieve fast triggering of the focus fixation and measurement, thus the measurement speed and precision as well as the scattering resistance are greatly improved.

The invention relates to an automatic focusing method, a device and a system; the method comprises the following steps: obtaining an object imaging pre-estimated focusing area from out-of-focus imagesobtained by a camera under a preset object distance; calculating a coarse positioning gray value for each pixel point in the out-of-focus image, and obtaining a coarse positioning focusing evaluationfunction value corresponding to each out-of-focus image; respectively calculating a precise searching gray value of each pixel point in the out-of-focus image, thus obtaining a precise searching focusing evaluation function value corresponding to each out-of-focus image; obtaining an initial focusing direction according to each coarse positioning focusing evaluation function value; driving the camera to make global searches according to each precise searching focusing evaluation function value when the camera reaches the pre-estimated focusing area according to the initial focusing direction,thus obtaining the best focusing point for finishing the automatic focusing. The automatic focusing method, device and system are high in focusing precision, and fast in speed.