摘要 |
A crypto display apparatus contains a first and second spatial optical pattern generation device (120, 122, 14). The first device generates an encrypted optical image pattern. The second device (14) generates an optical key pattern. The first and second devices (120, 122, 14) are spatially arrangement relative to one another so that an output image is formed by optical interaction of the optical encrypted image pattern and the optical key pattern. A key information computation circuit (140), in the second device computes information that controls the optical key pattern. The key information computation circuit (140) is an asynchronous circuit. Preferably, the second device contains a synchronously operated display screen (142) and an asynchronous-synchronous interface between the computation circuit (140) and the display screen (142). |