Patent ID: 7079192
Filing Date: 2006-07-18
Classification: H04N,Y10S

Abstract:
1. A blackener for letter box lines associated with HDTV/conventional-analog hybrid television signals comprising: a radio-frequency tuner for tuning said HDTV/conventional-analog hybrid television signals; a vertical sync detector for detecting a specific vertical sync pulse sequence in said HDTV/conventional-analog hybrid television signals and outputting a signal after receipt of said specific vertical sync pulse sequence; a horizontal sync pulse counter receiving said signal from said vertical sync detector for counting horizontal sync pulses to determine and output a logic test signal that indicates whether said HDTV/conventional-analog hybrid television signals are in a letter box area or an image area; and a letter box logic test that receives said logic test signal for blocking said HDTV/conventional-analog hybrid television signals and sends a substitute black signal to an output when said horizontal sync pulses are in a said letter box area, and sends said HDTV/conventional-analog hybrid television signals directly to said output when said horizontal sync pulses are in said image area.