Scan converting apparatus for transferring subtitles on a screen

A scan converting apparatus comprising:

• a video signal input terminal,
• an A/D converter connected to said video signal input terminal and which converts a video signal which is an input analogue signal including an original field to a digital signal,
• a movement detector connected to the output of said A/D converter and detects moving parts in the video signal,
• a brightness/chrominance signal separator connected to the output of said A/D converter and the output of said movement detector and separates a brightness signal from the video signal,
• an odd/even field discriminator which receives an input horizontal pulse and an input vertical pulse and determines a phase relationship between said input horizontal pulse and said input vertical pulse to discriminate whether said original field is an odd field or an even field,
• a subtitle signal processor connected to an output of said odd/even field discriminator and the brightness signal output of said brightness/chrominance signal separator and extracts and generates a subtitle signal according to a discrimination result of said odd/even field discriminator,
• a scanning line converter connected to said brightness signal output of said brightness/chrominance signal separator and converts scanning lines,
• a first synthesizer connected to a subtitle signal output of said subtitle signal processor, a subtitle control signal output of said subtitle signal processor, and a video output of said scanning line converter and synthesizes said subtitle signal from a subtitle signal output from said subtitle signal processor and a video output from said scanning line converter according to a subtitle control signal output generated by said subtitle signal processor to generate a further digital signal,
• a D/A converter connected to an output of said first synthesizer and converts said further digital signal to a further analogue signal, and
• a video signal output terminal which receives said further analogue signal from said D/A converter.

A scan converting apparatus comprising:

• a video signal input terminal,
• an A/D converter connected to said video signal input terminal and which converts a video signal which is an input analogue signal to a digital signal,
• a clamp level detector connected to an output of said A/D converter,
• a brightness/chrominance signal separator connected to the output of said A/D converter and separates a brightness signal from the video signal and which generates a chrominance signal,
• a first synthesizer connected to a chrominance signal output of said brightness/chrominance signal separator, an output of said clamp level detector, and a subtitle mask control signal input terminal and masks a subtitle area signal of the chrominance signal from said brightness/chrominance signal separator with a clamp level according to a subtitle mask control signal from said subtitle mask control signal input terminal,
• a scanning line converter connected to an output of said first synthesizer and converts scanning lines,
• a second synthesizer, connected to an output of said scanning line converter and which receives an input chrominance signal level which changes color of subtitle letters and a subtitle control signal input, synthesizes the chrominance signal from said scanning line converter and said input chrominance signal level according to said subtitle control signal to generate a further digital signal,
• a D/A converter connected to an output of said second synthesizer and converts said further digital signal to a further analogue signal, and
• a video signal output terminal which receives said further analogue signal from said D/A converter.