Electro-optic readout of thermoplastic deformation patterns

Apparatus for increasing the intensity of a projected image of a periodic surface deformation pattern, comprising:

• means for projecting a beam of coherent light to said deformation pattern;
• imaging lens means for imaging a first order component of the diffraction pattern received from said deformation pattern onto an image receiving surface, said imaging lens means being optically positioned out of optical communication with the zero order component of said diffraction pattern;
• and
• optical filter means disposed to receive said zero order component and to transmit said zero order component to said image receiving surface whereat said zero order component mixes with said first order component to form an interference pattern comprised of image modulated sinusoidal interference fringes having an intensity that varies as a linear function of the amplitude of the deformation pattern.

A method of transmitting an image disposed as a regular periodic surface deformation pattern comprising the steps of:

• scanning successive portions of said deformation pattern with a coherent light beam;
• imaging at least a first order component of the diffraction pattern received from each scanned portion of said deformation pattern onto a photoconductive surface of a vidicon image transducer by focusing said at least first order component onto a focal plane and projecting said at least first order component from said focal plane to said photoconductive surface;
• focusing the zero order component of said diffraction pattern received from each scanned portion of said deformation pattern onto said focal plane at a point offset from the point at which said at least first order component is focused and projecting said zero order component from said offset point to said photoconductive surface whereat said at least first order component and said zero order component are mixed to form an interference pattern;
• flooding said photoconductive surface with relatively high intensity light intermittent each scan interval to erase residual signals of an immediately preceding scanned portion of said deformation pattern;
• demodulating the electrical representations generated by said vidicon image transducer in response to said mixed first order components and said zero order component, said electrical representations comprising an informational component related to each scanned portion of said deformation pattern modulated onto a carrier component related to the interference frequency, to thereby recover said informational component;
• and
• transmitting said informational component.

A method of electrically transmitting information contained in a regular periodic surface deformation pattern comprising the steps of:

• irradiating said regular periodic surface deformation pattern with a coherent light beam;
• imaging a first order component of the diffraction pattern received from the irradiated surface deformation pattern onto the surface of a photoelectric transducer;
• mixing said first order component with a further coherent light beam at said transducer surface to form an interference pattern thereat and to thereby generate an electrical representation thereof comprised of an electrical informational component related to said surface deformation pattern modulated onto an electrical carrier component related to the interference frequency;
• demodulating said electrical representation to recover said electrical informational component;
• and
• transmitting said electrical information component.

Apparatus for transmitting an image disposed as a regular periodic surface deformation pattern to a remote location, comprising:

• means for projecting a beam of coherent light to said deformation pattern;
• imaging means in optical communication with no less than a first order component of the diffraction pattern received from said deformation pattern for imaging said first order component onto the surface of a photoelectric transducer;
• a source of coherent light for transmitting a further beam of coherent light to said photoelectric transducer surface whereat said further beam of coherent light mixes with said first order component to form an interference pattern comprised of image modulated sinusoidal interference fringes;
• a photoelectric transducer having a surface upon which said interference pattern is formed for generating an electric signal representing said interference pattern, said signal comprised of an informational component related to said deformation pattern modulated onto a carrier component related to the spatial frequency of said interference fringes;
• demodulation means coupled to said photoelectric transducer for demodulating said electric signal to recover said informational component;
• and
• means for transmitting said recovered informational component to said remote location.