SYSTEM AND METHOD FOR VIBRATING SCREENS TO REDUCE SPECKLE Russian patent published in 2018 - IPC G03B21/56 

FIELD: images forming devices.

SUBSTANCE: invention relates to a projection screens provided with means for reducing speckles. Method for reducing speckle on a projection screen comprises vibrating a projection screen within a predetermined frequency spectrum having power which is broadly dispersed, mitigating speckle on the projection screen to an acceptable level. Vibrating elements are located behind masking to reduce acoustic transmission from the vibrating elements. Transducer is made in the form of a coil and functions in the frequency range of 30–500 Hz. Acceptable speckle level is less than about 15 % contrast at approximately 15 feet from the projection screen. Projection screen further comprises a substrate having a modulus of elasticity of 0.4 GPa. Device can detect primary transducer failure by measuring the projection screen vibrations and driving the redundant transducers only when a failure of at least one primary transducer is detected. Screen masking contains noise absorbing material.

EFFECT: reducing speckles of the image, increasing reliability of functioning, reducing the discomfort caused by undesirable noise of the device.

26 cl, 8 dwg