34results about How to "Improve autofocus accuracy" patented technology

In a camera system according to the present invention, a lens controller obtains an exposure synchronizing signal that is generated by a camera controller from a camera body, causes a configuration formed of a first encoder, a second encoder and a counter to detect the position of a focus lens according to the obtained exposure synchronizing signal, and notifies the camera body of the detected position of the focus lens. The camera controller associates the position of the focus lens or the mechanism member obtained from the lens controller with an AF evaluation value based on the exposure synchronizing signal, and controls an autofocus operation of the camera system based on the position and AF evaluation value that are associated with each other. With this configuration, it is possible to improve the accuracy of an autofocus operation with a contrast system.

The invention relates to a self-focusing preprocessing method based on a short-time fractional order Fourier domain filter, which belongs to the field of synthetic aperture radar (SAR) signal processing. The method comprises the following steps of: (1) extracting a phase error signal of a single special showing point; (2) judging whether the phases of the phase error signal mainly are quadratic phase or not; (3) filtering noise in a transform domain: if the phases mainly are quadratic phases, using short-time fractional order Fourier domain filter; otherwise, using short-time Fourier domain filter; and (4) inversely transforming result time frequency to a time domain, estimating and compensating the phase error and realizing self-focusing preprocessing. The method effectively solves the problems of estimation and compensation of the phase error in a low-signal-to-noise ratio environment, especially the estimation and compensation of the quadratic phase error, and can obtain the main part of a phase error course and greatly improve the imaging quality after removing the phase error course from an original signal, thereby improving the signal-to-noise ratio of a special showing point signal.

In a camera system including an interchangeable lens and a camera body, a body controller performs control a drive signal transmission unit to drive a focus lens in a predetermined direction, and transmit a timing signal to the interchangeable lens. The lens controller performs control to detect a position of the focus lens in synchronization with the timing signal received from the camera body and store the detected position in a storage unit.

A CPU performs a control for photographing a main subject in absence of auxiliary light, whereby an image signal is outputted from an analogue signal processing section. Next, the CPU performs a control for photographing the main subject in presence of the auxiliary light, whereby an image signal is outputted from the analogue signal processing section. An AF area extracting section extracts image signals in an AF area from the image signals. A differential signal calculating section outputs a differential signal between the extracted image signal, and a distance measuring section compares magnitudes of that differential signal and a reference value in a distance data base to calculate distance information based on the comparison result. An AF control section executes AF control of mountain climbing system with the use of the distance information.

The invention belongs to the field of radar signal processing, and particularly relates to an SA-ISAR (Sparse Aperture-Inverse Synthetic Aperture Radar) self focusing method based on structure sparsity and entropy joint constraints. The method comprises the following steps of Step 1, performing echo modeling on radar echo subjected to envelope alignment; Step 2, applying layered structured sparseprior to an ISAR image; Step 3, updating the ISAR image and an upper layer variable by a relax variational bayes method; Step 4, updating a phase error through a minimum entropy method based on fixedpoints; and Step 5, judging whether a termination condition is reached or not, stopping iterative loop if the termination condition is reached, returning to the Step 3 if the termination condition isnot reached, and outputting an image subjected to self focusing after the termination condition is reached. The SA-ISAR self focusing method has the advantages that the self focusing precision of theISAR images at the sparse aperture can be improved, so that the formed ISAR images are clearer; the calculation complexity is lower; the iterative convergence speed is faster; and the sparse apertureresistance capability is high.

The present invention provides an auto-focusing method and apparatus for a projection apparatus and the projection apparatus, wherein a current acceleration value is detected by an acceleration sensorarranged in the projection apparatus; A main processor receives and determines whether that current acceleration value has changed; If yes, the image acquisition unit acquirs the second geometric parameter of the current identification image; ing an absolute difference between the first geometric parameter and the second geometric parameter can be determined according to the first geometric parameter determined based on the original identification image; whether the absolute difference value is greater than or equal to the adjusted geometric threshold value is judged; If yes, the electric motor is controlled to move to drive the optical machine, the image acquisition unit acquires the current image, the main processor receives the current image and determines the definition value of the current image, and when the definition value of the current image is greater than or equal to the definition threshold value, the electric motor is controlled to stop the movement;otherwise, the acceleration sensor continues to detect the current acceleration value. According to the invention, the accuracy of auto-focusing of the projection device is improved and the viewing experience of the useris enhanced.

An electronic apparatus that achieves a function of a compound eye camera using a plurality of photographing modules and that improves AF accuracy even if environmental conditions vary or even if a state is changed by impact from outside. The electronic apparatus includes two photographing modules. A first obtaining unit performs contrast AF by one of the two photographing modules to obtain a first focus detection result. A second obtaining unit calculates an object distance from parallax information between the two photographing modules to obtain a second focus detection result. A correction unit corrects a calculation result of the object distance obtained by the second obtaining unit in a case where a state of at least one of the two photographing modules and a body of the electronic apparatus varies and where a difference between the first and second focus detection results is more than a threshold.

An image capture device and a calibration method of phase detection autofocus thereof are provided. A contrast-based autofocus procedure is executed to move a lens to multiple lens positions, and a statistical distribution of focus values is obtained based on the contrast-based autofocus procedure. Whether the phase linear relationship for a phase detection autofocus procedure is calibrated is determined according to the statistical distribution of the focus values. If yes, then a first phase difference detected when the lens is located at one of the lens positions is obtained, and a second phase difference detected when the lens is located at another one of the lens positions is obtained. The phase linear relationship of the phase detection autofocus procedure is calibrated according to the one of the lens positions, the first phase difference, the other one of the lens positions, and the second phase difference.

The invention discloses a COB camera module and a packaging method thereof. The voice coil motor comprises a circuit board, a chip attached to the circuit board, a light filtering assembly attached tothe chip, a motor and a lens locked inside the motor, the motor is glued to the light filtering assembly, the locking height of the lens on the motor is h1, and the distance between the voice coil motor and the light filtering assembly is h2. The camera module is packaged by adopting two specific sizes of h1 and h2, and is matched with compensation type optical axis correction, so that the automatic focusing accuracy of the camera module and the optical axis overlap ratio between modules can be improved to the greatest extent. The automatic focusing accuracy of the COB camera module is improved by adopting two specific sizes of h1 and h2; defective products are accurately discriminated through compensation type optical axis correction, and meanwhile, the fault tolerance of optical axis correction is improved, so that the yield is improved; grading of the COB camera module can be completed in the packaging process through primary optical axis correction and compensation type secondarycorrection of the camera active focusing equipment.

The invention discloses a miniature camera applying a stepping ultrasonic motor and a control method for the miniature camera. The miniature camera applying the stepping ultrasonic motor comprises a motor base, a stator, a rotor, a lens mount and a pre-pressing device, wherein the stator, the rotor and the lens mount are arranged on the motor base in sequence, and the pre-pressing device is used for applying pre-pressure to the lens mount; the stator comprises an elastomer and a piezoelectric ceramic piece, wherein the piezoelectric ceramic piece is arranged on the lower surface of the elastomer and is used for exciting standing-wave vibration; at least two electrodes are arranged on the lower surface of the piezoelectric ceramic piece; at least one contact tooth is arranged on the rotor,and the rotor makes contact with the upper surface of the elastomer through the contact teeth. According to the miniature camera and the control method thereof, the electrodes are controlled to be electrified in different ways, the principle that nodes after standing wave superposition are located between two nodes before standing wave superposition is adopted, and therefore the automatic focusingprecision of the miniature camera applying the stepping ultrasonic motor is improved.

A focal point detector includes: a condenser lens for transmitting a light image from an optical system; and a distance measurement sensor group for receiving a luminous flux which has passed through the condenser lens. The sensor group includes a first distance measurement sensor pair for receiving divided beams of the luminous flux for a first focus detection region which is located off the center of a shooting region. The first distance measurement sensor pair includes first and second distance measurement sensors. The first focus detection region extends in a first direction in the shooting region from a position where the first focus detection region is spaced from the center in the first direction and also in a second direction. The first and second distance measurement sensors are spaced from each other and arranged at different angles in the direction associated with the first direction on the sensor arrangement surface.