Video display device and system
View Patent ↗In a video display device and system, a timing control section performs timing control for right- and left-eye video signals and to each have a blanking period whose length (Duty) is longer than that of a first-time blanking period Tb1 at least once in second-time and later blanking periods, e.g., performs timing control for a second-time blanking period Tb2 to be longer in Duty than the first-time blanking period Tb1. With such timing control, for stereoscopic display video viewing using open-state shutter glasses in the second-time blanking period Tb2 with a sequential write mode, there are advantages that the shutter glasses can remain longer in the open state while the response characteristics of the liquid crystal material being enhanced. As such, with the resulting video display device and system, the occurrence of crosstalk can be favorably prevented at the same time as reducing any reduction in display brightness.
1. A video display device, comprising:
a video processing section that performs output control over a plurality of video streams each including a plurality of unit video pieces in time sequence for output of the unit video pieces each for a plurality of times in a row, and for time-division switching of the video streams for output;
a timing control section configured to receive the unit video pieces from the video processing section, perform timing control over each of the unit video pieces to make variable at least either a starting time or a duration of each blanking period located between output periods of the unit video pieces coming from the video processing section, and transmit the unit video pieces on which timing control has been performed;
a display section that performs video display based on each of the unit video pieces after the timing control, wherein
the timing control section performs the timing control over each of the video streams to have, in a blanking period following immediately after a second-time or later output of the unit video pieces, at least one second blanking period that is longer in duration (Duty) than a first blanking period following immediately after a first-time output of the unit video pieces,
wherein for each output of a unit video piece a plurality of times in a row, the first blanking period occurs between consecutive outputs of the unit video piece and the second blanking period occurs after the final output of the unit video piece and before the first output of a next unit video piece;
a shutter control section that performs control over shutter glasses in terms of open-close operation to open and close in synchronization with a display switching among the plurality of video streams in the display section,
wherein the timing control section performs the timing control over the shutter control section to make the shutter glasses to go into an open state in the second blanking period in each of the video streams such that the duration of each open state is longer than the duration of each first blanking period; and
a temperature detection section, coupled to the timing control section, for detecting temperature in the operation environment,
wherein the timing control section performs the timing control to change the Duty of the second blanking period in accordance with a temperature change observed in an operation environment, and
wherein the timing control section reduces further the Duty of the second blanking period in response to a temperature reduction in the operation environment, and increases further the Duty of the second blanking period in response to a temperature increase therein.
2. The video display device according to claim 1 , wherein
the timing control section performs the timing control over each of the video streams to start earlier the second-time or later output of the unit video pieces than in a case of outputting the unit video pieces all at an equally-controlled timing for an equally-controlled duration.
3. The video display device according to claim 1 , wherein
the timing control section performs the timing control over each of the video streams to be shorter in length for a period for the first-time output of the unit video pieces than for periods for the second-time or later output thereof.
4. The video display device according to claim 1 , wherein
the timing control section performs the timing control over each of the video streams to be shorter in length in the same proportion for the periods of the first-time and later output of the unit video pieces than in a case of outputting the unit video pieces all at an equally-controlled timing for an equally-controlled duration.
5. The video display device according to claim 1 , wherein
the timing control section performs the timing control to change the Duty of the second blanking period depending on contents of each of the unit video pieces.
6. The video display device according to claim 1 , wherein
the timing control section performs the timing control for, in each of the video streams, a unit frame period being a combination of periods for the first-time and later output of the unit video pieces and the blanking period following immediately after each of the output periods to continuously have a length same as in a case of outputting the unit video pieces all at an equally-controlled timing for an equally-controlled duration.
7. The video display device according to claim 1 , wherein
the display section performs the video display by writing a video signal corresponding to each of the unit video pieces at the same as scanning a display screen line-sequentially, and
the timing control section performs the timing control over a write frequency for the line-sequential scanning to be higher during three-dimensional (stereoscopic) video display in the display section than during two-dimensional video display therein.
8. The video display device according to claim 1 , wherein
the plurality of video streams include a left-eye video stream and a right-eye video stream producing parallax.
9. The video display device according to claim 1 , wherein
the display section is a liquid crystal display section configured using a liquid crystal element.
10. The video display device according to claim 3 , wherein
the display section performs the video display by writing a video signal corresponding to each of the unit video pieces at the same as scanning a display screen line-sequentially, and
the timing control section performs the timing control over a write frequency for the line-sequential scanning to be higher during the first-time output of the unit video pieces than during the second-time or later output thereof.
11. The video display device according to claim 3 , wherein
the display section performs the video display by writing a video signal corresponding to each of the unit video pieces at the same as scanning a display screen line-sequentially, and
the timing control section performs the timing control over the number of simultaneous-selection horizontal lines for use during the line-sequential scanning to be larger for the first-time output of the unit video pieces than for the second-time or later output thereof.
12. The video display device according to claim 4 , wherein
the display section performs the video display by writing a video signal corresponding to each of the unit video pieces at the same as scanning a display screen line-sequentially, and
the timing control section performs the timing control over
the number of simultaneous-selection horizontal lines for use during the line-sequential scanning to be larger for the first-time output of the unit video pieces than for the second-time or later output thereof, and
over the number of the simultaneous-selection horizontal lines to be scanned during the second-time or later output of the unit video pieces to be decimated based on the number of the horizontal lines in the entire display screen.
13. A video display system, comprising:
a video display device that performs video display by time-division switching of a plurality of video streams each including a plurality of unit video pieces in time sequence; and
shutter glasses that perform an open/close operation in synchronization with the switching of the video streams in the video display device, wherein
the video display device includes
a video processing section that performs output control over the plurality of video streams for output of the unit video pieces each for a plurality of times in a row, and for enabling the time-division switching of the video streams for output,
a timing control section configured to receive the unit video pieces from the video processing section, perform timing control over the unit video pieces to make variable at least either a starting time or a duration of each blanking period located between output periods of the unit video pieces coming from the video processing section, and transmit the unit video pieces on which timing control has been performed,
a display section that performs video display based on each of the unit video pieces after the timing control, and
the timing control section performs the timing control over each of the video streams to have, in a blanking period following immediately after a second-time or later output of the unit video pieces, at least one second blanking period that is longer in Duty than a first blanking period following immediately after a first-time output of the unit video pieces,
wherein for each output of a unit video piece a plurality of times in a row, the first blanking period occurs between consecutive outputs of the unit video piece and the second blanking period occurs after the final output of the unit video piece and before the first output of a next unit video piece,
a shutter control section that performs control over shutter glasses in terms of open-close operation to open and close in synchronization with a display switching among the plurality of video streams in the display section,
wherein the timing control section performs the timing control over the shutter control section to make the shutter glasses to go into an open state in the second blanking period in each of the video streams such that the duration of each open state is longer than the duration of each first blanking period, and
a temperature detection section, coupled to the timing control section, for detecting temperature in the operation environment,
wherein the timing control section performs the timing control to change the Duty of the second blanking period in accordance with a temperature change observed in an operation environment, and
wherein the timing control section reduces further the Duty of the second blanking period in response to a temperature reduction in the operation environment, and increases further the Duty of the second blanking period in response to a temperature increase therein.