Nke chart Projector bụ ngwaọrụ nwere AC nke ezubere iji wepụta onyonyo n'ihuenyo maka nyocha ọhụụ. Enwere ike ijikwa eserese na-ebu diski, efere ihe nkpuchi na tube index astigmatic site na knobs niile enyere n'ihu panel nke projector.