1 янв 1945 г. - OVERHEAD PROJECTROR
Описание:
Roger Appledorn was responsible for the technology that was used for the first overhead projector. n 1945, the U.S. Army used overhead projectors for training just as World War II was ending. Then in the late 1950s and early 1960s, overhead projectors began to be used in schools and businesses.Добавлено на ленту времени:
Дата:
1 янв 1945 г.
Сейчас
~ 80 г назад