Patent ID: 8023052

Claim:
An optical polarization state modulator for time-multiplexed stereoscopic three-dimensional image viewing by an observer, the modulator receiving in alternating sequence light in an input polarization state and carrying first and second perspective view images of a scene in different ones of first and second subframes that include updated image portions, comprising: first and second liquid crystal devices combined in optical series so that polarized light propagating through them can undergo a change in polarization state in response to voltages applied to the first and second liquid crystal devices; the first and second liquid crystal devices having respective first and second sets of directors and constructed and oriented to cause, in response to removal of applied equal voltages, the directors in the first and second sets to cooperatively relax and thereby dynamically offset the polarization state changes so that multiple wavelengths of the incident light propagating through and exiting the combination of first and second liquid crystal devices are in the input polarization state; drive circuitry delivering first and second drive signals to the respective first and second liquid crystal devices, the first and second drive signals including lower magnitude levels that establish lower magnitude director field states for the first and second liquid crystal devices, and the first and second drive signals including pulses having lower-to-higher magnitude level powered transitions that establish higher magnitude director field states for the first and second liquid crystal devices; the first and second drive signals cooperating during one of the first and second subframes to cause, in the first and second liquid crystal devices, formation of the higher magnitude director field states from which the directors relax during the updated image portion of the one subframe such that the directors in the first and second sets offset the polarization state changes and thereby impart, to the image-carrying polarized light propagating through the combination of first and second liquid crystal devices, a first output polarization state that is the input polarization state; and the first and second drive signals cooperating during the other of the first and second subframes to cause, in different ones of the first and second liquid crystal devices, formation of the lower and higher magnitude director field states during the updated image portion of the other subframe such that the directors in the first and second sets do not offset the polarization state changes and thereby impart, to the image-carrying polarized light propagating through the combination of first and second liquid crystal devices, a second output polarization state that is different from the first output polarization state.