Patent ID: 7116377

Claim:
A cable television video terminal for selectively combining graphics with video signals, the video terminal comprising: (a) a tuner for outputting a video signal; (b) a digital channel demodulator configured to output a first digital signal in response to receiving the video signal from the tuner; (c) an analog channel demodulator configured to output a first analog signal in response to receiving the video signal from the tuner; (d) a video output; (e) a processor; (f) a video graphics subsystem comprising: (i) an analog to digital converter configured to output a second digital signal in response to receiving the first analog signal from the analog channel demodulator; (ii) an on-screen display (OSD) insertion unit configured to output a composite digital signal generated by combining OSD graphics with a selected one of the first and second digital signals; (iii) a first switch, controlled by the processor, for feeding the first digital signal to the OSD insertion unit during selected time intervals when the tuner is tuned to a digital channel, and for feeding the second digital signal to the OSD insertion unit during selected time intervals when the tuner is tuned to an analog channel; and (iv) a digital to analog converter coupled to the OSD insertion unit and configured to output a second analog signal in response to receiving the composite digital signal; and (g) a second switch, controlled by the processor, for selectively coupling the video output to the digital to analog converter when the processor determines that OSD graphics are available to be combined with one of the first and second digital signals, and for selectively coupling the video output to the analog to digital converter when the processor determines that there are no OSD graphics available to be combined with the second digital signal.