Apparatus and method using a memory for processing television picture signals and other information.

摘要

A problem arises when simultaneous attempts are made to write and read from the same location in a random access memory. The invention deals with this problem by delaying the writing operations automatically by a varying amount to prevent attempts at simultaneous writing and reading: and preferably to position each write operation approximately mid-way between two read operations.

The invention is particularly applicable to a television synchroniser. In a television synchroniser video information is digitised and then fed into a memory by write clock signals derived from the video information, e.g. from its line synchronising pulses. It is fed out of the memory by read clock signals derived from some other source.

The invention is also applicable to standards conversion systems, noise reduction systems and picture size reduction and expansion systems.