Abstract: Pixel data is selected from among first and second dynamic-image memories (DI1, DI2) and a static-memory (SI). In the invention, (a) first and second window area memories (WA1, WA2) for designating shapes and sizes of windows to which video dynamic-images are assigned respectively, (b) first and second dynamic-image area memories (DA1, DA2) for designating memory locations of data stored in both the dynamic-image memories, and (c) a priority control register for designating which video dynamic-image should be displayed in front when video dynamic-images overlap with each other are provided, whereby display for every pixel is executed according to a logical AND value of read-out data from WA1 and read-out data from DA1, a logical AND value of read-out data from WA2 and read-out data from DA2, and read-out data from the priority control register.

Abstract: The invention relates to an interference device having a light source, detectors, and at least two diffraction elements with identical or only slightly different diffraction structures, wherein the parameters of the diffraction structures of the diffraction elements vary continuously as a function of location.