US PATENT SUBCLASS 348 / 752
.~.~.~ Using birefringent or polarizing medium (e.g., Kerr cell, Pockel's cell, etc.)

Current as of: June, 1999
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348 /   HD   TELEVISION

739  DF  VIDEO DISPLAY {13}
744  DF  .~ Projection device {7}
750  DF  .~.~ Plural parallel light modulators {5}
752.~.~.~ Using birefringent or polarizing medium (e.g., Kerr cell, Pockel's cell, etc.) {1}
753  DF  .~.~.~.~> Electron beam addressed

DEFINITION

Classification: 348/752

Using birefringent or polarizing medium (e.g., Kerr cell, Pockel's cell, etc.):

(under subclass 750) Subject matter wherein the modulators comprise a medium which, under the influence of a video signal, alters a polarization plane of the source illumination in order to impart image information.

(1) Note. Kerr and Pockel cells exhibit electro-optic effects of a particular material (e.g., nitrobenzene in Kerr and piezoelectric in Pockel) which are capable of advancing or retarding the phase of an induced ordinary light ray relative to an extraordinary light ray when an electric current is applied. The effect is quadratic nonlinear in the Kerr cell and linear in the Pockel cell. Because the two polarized components of an incident light beam have different phase velocities in the medium, these devices can rotate the plane of polarization.

SEE OR SEARCH THIS CLASS, SUBCLASS:

762, and 767, for projection type image reproducers having a single light modulator.

SEE OR SEARCH CLASS

359, Optics: Systems (Including Communication) and Elements,

245+, and 315+ for generic optical modulator using electro-optical techniques for light wave temporal or directional modulation.