Optical display apparatus

Claim 1

OPTICAL INFORMATION DISPLAY APPARATUS COMPRISING: FIRST MEANS FOR PRODUCING A PRIMARY LIGHT BEAM OF A MAIN OPTICAL PATH ALONG AN AXIS; SECOND MEANS DISPOSED WITHIN SAID MAIN OPTICAL PATH FOR SUPPLYING PRIMARY INFORMATION TO SAID PRIMARY LIGHT BEAM AND FOR PRODUCING IN A FIRST IMAGE PLANE AN OPTICAL IMAGE REPRESENTATIVE OF SAID PRIMARY INFORMATION; A NORMALLY TRANSPARENT FILM DISPOSED AT SAID FIRST IMAGE PLANE COMPRISED OF A MATERIAL WHICH IS RENDERED OPAQUE IN RESPONSE TO LIGHT OF A FIRST WAVELENGTH BAND; THIRD MEANS FOR PRODUCING IN AN AUXILIARY OPTICAL PATH A SUBSTANTIALLY COLLIMATED LIGHT BEAM INCLUDING LIGHT OF SAID FIRST WAVELENGTH BAND AND DIRECTING SAID BEAM TOWARDS SAID FIRST IMAGE PLANE AT AN ANGLE TO THE AXIS OF THE MAIN OPTICAL PATH; A WRITING LENS FOR FOCUSING AT LEAST A PORTION OF LIGHT IN SAID COLLIMATED BEAM ONTO SAID FIRST IMAGE PLANE; MEANS FOR MOVING SAID WRITING LENS IN A PLANE DISPOSED SUBSTANTIALLY PARALLEL TO SAID FIRST IMAGE PLANE TO PRODUCE AT SAID FIRST IMAGE PLANE A MOVING LIGHT SPOT OF UNIFORM AREA AND INTENSITY TO ENABLE THE LIGHT OF SAID FIRST WAVELENGTH BAND TO WRITE A TRACE ON SAID FILM, AND A FOURTH MEANS FOR PROJECTING THE INFORMATION PROVIDED AT SAID FIRST IMAGE PLANE ONTO A SECOND IMAGE PLANE.