A screen memory is a memory fallacy and defense mechanism used to disguise the psychological disturbance from an event as resulting from another (typically less traumatic) event or memory. It is a blend of repression and transference.
An example would be an adult experiencing severe depression and anxiety. Although they experienced an abusive and traumatic childhood that is most likely the root of these psychological disturbances the client uses a screen memory and blames their issues on a minor traffic accident they experienced. By doing this they are repressing or minimizing the effects their early trauma had on their psyche and instead is blaming a less traumatic event instead.