| 摘要 |
An electromechanically-switched glasses system for flicker-free sequential video television at a field frequency of 50-120 Hz. The system is based not on mask/unmask switching (which is too slow when synchronous with the field frequency) but on the number of light pulses received by the eye in the time interval of one frame, however long that may be, at a frequency no higher than 10 ms. The system comprises a Fresnel, microprism or optical fibre mask which lets the light beam through without a picture and without cancelling out the three-dimensional effect, either with continuous pulses during the unmasked time interval, or with sequential pulses lasting no longer than 10 ms during the masked time interval, regardless of the mechanical mask/unmask switching frequency which at all times remains synchronous with the field frequency. Visual perception is equivalent to the 100/120 Hz during the time interval, of whatever length, of one frame switching at 50-92 Hz. |
