METHOD AND DEVICE FOR IMAGE PROJECTION WITH A HIGH LEVEL OF SAFETY Russian patent published in 2017 - IPC G03B21/00 

FIELD: physics.

SUBSTANCE: method of projecting an image using a projection device comprising a MEMS mirror oscillating with respect to one or more swing axes for scanning light from one or more lasers on a display screen to project the pixels forming the image onto a display screen, the method comprising the steps of (a) selection of the class of lasers for the projection device; (b) calculating the relationship between the maximum allowable radiation level and the distance for the selected laser class and for a given number of black pixels in the image; (c) repeating step (b) multiple times, each time for another predetermined number of black pixels in the image, to obtain a plurality of relationships between the maximum allowable emission level and the distance for the selected laser class, where each ratio corresponds to its own, different from the other predetermined number of black pixels in the image; (d) determining the distance between the display screen and the projection device; (e) selecting the desired maximum allowable emission level for the image that the projection device should project onto the display screen; (g) selecting, from a plurality of relationships between the maximum allowable radiation level and the distance, a ratio containing the maximum allowable radiation level equal to the desired maximum allowable emission level selected in step (e) for the distance determined in step (d), and; (g) identifying a predetermined number of black pixels in the image for the selected ratio; (h) modifying the stream of pixels constituting the image to be projected by the projection device, so as to obtain a pixel stream containing a predetermined number of black pixels identified in step (g). In addition, an appropriate projection device has been proposed.

EFFECT: increased security level.

15 cl, 8 dwg