| 摘要 |
PURPOSE:To reduce production of a speckle by projecting and displaying a diffraction image so as to allow the diffraction image of a luminance signal for plural picture elements to be still on a screen. CONSTITUTION:A luminance signal for plural picture elements from a picture signal source 5 is written in an AOM 4 as a diffraction grating for an ultrasonic wave and passes through a cylindrical lens 6 and a lens 7 of the Schlieren optical system and the diffraction image is projected and displayed onto a screen 18. Then a polygon mirror 13 is used to allow the diffraction image to be still on the screen 18. When a TeO2 crystal is employed for the AOM 4, the effective aperture of the crystal is 12mm or over and the diffraction grating having brightness information by 100 picture elements is always formed in the AOM 4 and the image is latched therein while being propagated for 3musec. |
