Patent ID: 7988296
Filing Date: 2011-08-02
Classification: G02B

Abstract:
1. A stereoscopic attachment for a projection lens for providing left and right eye images as a pair of pseudo-stereoscopic images from a single two-dimensional image or series of two-dimensional moving images, the apparatus comprising: optical means arranged to provide said left and right images as a pair of substantially identical images with matching geometry and luminosity such that said left and right eye images are simultaneously projected by a single film or digital projector; said optical means including a first optical element comprising a semi-reflective plane mirror being located along the optical axis of the projection lens of said film or digital projector and arranged to reflect the two-dimensional image being projected by said projection lens at an angle of 90 degrees at approximately 50% of the luminous value and transmit said two-dimensional image being projected by said projection lens along said optical axis of the projection lens at approximately 50% of the luminous value; said optical means including a second optical element comprising a plane mirror being positioned parallel to the first optical element and arranged to receive the two-dimensional image being projected by said projection lens and reflected by said first optical element, and reflect said two-dimensional image being projected by said projection lens to a viewing screen at a variable angle of approximately 90 degrees; said optical means including a third optical element comprising a plane mirror being located along said optical axis of the projection lens and arranged to receive said two-dimensional image being projected by said projection lens and transmitted by the first optical element, and reflect said two-dimensional image at an angle of 90 degrees in the opposite direction to said two-dimensional image being projected by said projection lens and reflected by said first optical element; said optical means including a fourth optical element comprising a plane mirror being positioned parallel to the third optical element and arranged to receive the two-dimensional image being projected by said projection lens and reflected by said third element and reflect said two-dimensional image being projected by said projection lens to the viewing screen at a variable angle of approximately 90 degrees; said optical means further comprising a linear or circular polarizing filter being located along the optical axis of said two-dimensional image being projected by said projection lens and reflected by the first optical element and a second linear or circular polarizing filter arranged to have the opposite polarity to said first linear or circular polarizing filter and being located along the optical axis of said two-dimensional image being projected by said projection lens and transmitted by the first optical element; the apparatus also includes convergence adjustment means comprising a mechanism for varying the angle of convergence of the optical axis of said two-dimensional image being projected by said projection lens and reflected by the first optical element and the optical axis of said two-dimensional image being projected by said projection lens and transmitted by the first optical element; said mechanism for varying the angle of convergence includes a means for rotating said second optical element comprising a plane mirror in the horizontal plane arranged to have the center of rotation on the optical axis of the two-dimensional image being projected by said projection lens and reflected by said first optical element; said mechanism for varying the angle of convergence includes a means for rotating said fourth optical element comprising a plane mirror in the horizontal plane arranged to have the center of rotation on the optical axis of the two-dimensional image being projected by said projection lens and transmitted by said first optical element; said mechanism for varying the angle of convergence includes a means for adjusting said angle of convergence manually; said convergence adjustment means includes a mechanism for adjusting said angle of convergence remotely by means of a servo motor and encoder unit; said convergence adjustment means also includes a mechanism for adjusting said angle of convergence by computerized control of said servo motor and encoder unit to provide recording and playback of said angle of convergence in synchronization with the projected image.