Keystone aberration correction in overhead projectors.
Keystone distortion that occurs in overhead projectors when the projecting lens head is tilted upward to a high screen is commonly observed. Here we suggest a modification of the typical overhead projector to eliminate this distortion of the image.
Durán-Ramírez
Victor M
VM
Centro de Investigaciones en Optica, A.C., Apartido Postal 1-948, 37000 Leon, Gto., Mexico. vicdur@cio.mx
Malacara-Doblado
Daniel
D