Resources Contact Us Home
Automatic letterbox detection

Image Number 12 for United States Patent #5486871.

A video control system, comprises a deflection system having a dimensionally adjustable raster, a circuit for detecting a letterbox video signal source and a circuit for dimensionally controlling the raster of the deflection system responsive to the detecting circuit. The detecting circuit and the control circuit are operable automatically. The detection circuit can comprise a circuit for measuring video luma levels of the video signal source in at least two regions of each video field and a circuit for comparing the luma levels from each of the regions to respective threshold levels. In an alternative, the detection circuit comprises a circuit for comparing respective minimum and maximum luminance values for a plurality of successive video lines, a circuit for storing minimum and maximum luminance values for the plurality of video lines, a circuit for generating gradients indicative of the stored values and a circuit for comparing the gradients to threshold values.

  Recently Added Patents
Dehydratable hygiene articles
Method and system for detecting center pivot collision
Apparatus for transmitting and receiving data in a wireless communication system and method thereof
Network decoys
Switchgear operating apparatus and three-phase switchgear
Watch dial
Rain barrel
  Randomly Featured Patents
Use of substances with oxytocin activity against climacteric disorders
Test of electronic devices at package level using test boards without sockets
Device and method for controlling output power of mobile communication terminal
Method and apparatus for preventing overheating of a thermal head
Self-lubricating thrust rivet and its method of manufacture
Method for making quinoline carboxylic acids or naphthyridine carboxylic acids in free base form
Method and apparatus for changing a configuration of a computing system
Fixture component for liquid crystal display, liquid crystal display assembly and LCD fixture structure for liquid crystal display
Separation of t-Amyl alcohol from isobutanol by extractive distillation