35results about How to "Improve autofocus accuracy" patented technology

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.

The invention belongs to the field of radar signal processing, and specifically relates to a SA-ISAR self-focusing method based on joint constraints of structure sparsity and entropy, comprising the following steps: S1: performing echo modeling on radar echoes after envelope alignment; S2: Apply a hierarchical structured sparse prior to the ISAR image; S3: update the ISAR image and high-level variables through a relaxed variational Bayesian method; S4: update the phase error through a fixed point-based minimum entropy method; S5: Judging whether the termination condition is reached, if the termination condition is reached, the iterative cycle is stopped, otherwise, return to S3, and the self-focused image is output until the termination condition is reached. The present invention can improve the self-focusing precision of the ISAR image under the sparse aperture, so that the formed ISAR image is clearer; the present invention has low computational complexity, fast iterative convergence speed, and strong ability to resist the sparse aperture.

The driving module controls the supply of current to a shape memory alloy member by setting a command value for an electrical resistance of the shape memory alloy member so that the lens frame is moved intermittently to thereby controlling the driving of driving means. The driving module includes control means which includes resistance detection means, command value generation means, and current supplying means. The command value generation means changes the command value gradually by a predetermined variation width R so that the electrical resistance of the shape memory alloy member increases or decreases gradually by a predetermined width when the lens frame is moved intermittently. Moreover, the command value generation means performs a correction calculation which uses the ratio of an actual reference value R 0 of the electrical resistance of the shape memory alloy member to an ideal reference value R stan of the electrical resistance of the shape memory alloy member as a correction ratio to calculate a correction variation width by multiplying the correction ratio by an ideal variation width R step of the command value R t ( n ) to thereby change the command value R t ( n ) gradually using the correction variation width as the variation width R.