Piezoelectric driving type variable-diaphragm dimming apparatus and method

Abstract

The invention discloses a piezoelectric driving type variable-diaphragm dimming apparatus and method. The apparatus is composed of a variable diaphragm unit, a piezoelectric actuator and a pedestal. The piezoelectric actuator consists of four cantilever beams and eight piezoelectric ceramics; the four cantilever beams employ square ring beam structures formed by end-to-end connection of metallic elastic base bodies; driving feet in an interference fit relationship with the outer wall of a moving ring of the variable diaphragm unit are arranged at the midpoints of the inner wall of the four cantilever beams; and the eight piezoelectric ceramics are arranged on the outer wall of the two sides of the midpoints of the four cantilever beams correspondingly. When the apparatus works, excitation signals with a phase difference of 90 degrees are applied to the two piezoelectric ceramics on each beam, elliptic motion is caused at the driving feet, the moving ring is driven to make rotation, and thus a diaphragm piece is driven by the moving ring to rotate, so that expansion or contraction of the aperture of a through hole is realized. According to the invention, with piezoelectric driving, the piezoelectric driving type variable-diaphragm dimming apparatus has advantages of flat and compact structure, small size, light weight, high adjustment precision, fast speed, and high reliability; the performances of the optical instrument are improved; and the production cost is lowered.

Description

technical field [0001] The invention relates to the field of optical instruments, in particular to a piezoelectric-driven iris diaphragm dimming device and method. Background technique [0002] In order to control the light energy accepted by the target surface of the photodetector and ensure proper imaging illumination, light adjustment must be carried out in the optical instrument. The iris dimming is a commonly used dimming method, which is realized by the iris dimming device. The iris dimmer generally consists of an iris and a driving part. The variable diaphragm mainly includes the diaphragm plate, the diaphragm moving circle and the diaphragm fixed circle. The relative rotation of the moving and fixed circles of the diaphragm can drive the rotation of the diaphragm, and then change the size of the light aperture surrounded by the diaphragm. The driving part drives the diaphragm moving coil to rotate according to the illuminance requirement of the light or the power ...

AI Technical Summary

Problems solved by technology

Most of the existing variable diaphragm dimming devices are designed and processed by themselves or remanufactured with standard diaphragms. The driving part mostly adopts electromagnetic motor and worm gear transmission or gear transmission. Usually, the structure is relatively complicated, and the transmission accuracy is low and the friction is large. , short service life, high processing cost, long cycle and low reliability

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