Receiving apparatus and receiving method

• US 5,708,475 A
• Filed: 05/15/1996
• Issued: 01/13/1998
• Est. Priority Date: 05/26/1995
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Morisawa, Akiko, Hayashi, Toshihide
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US08/657,623
• Time in Patent Office: 608 Days
• Field of Search: 348/468, 348/465, 348/722, 348/725, 348/726, 348/564, 348/565, 348/563, 348/553, 348/556
• US Class Current: 348/468
• CPC Class Codes: H04N 21/4263 involving specific tuning arrangements, e.g. two tuners
• CPC Class Codes: H04N 21/4305 Synchronising client clock from received content stream, e.g. locking decoder clock with encoder clock, extraction of the PCR packets arrangements for synchronising receiver with transmitter by comparing receiver clock with transmitter clock H04L7/0012; arrangements for synchronising receiver with transmitter wherein the receiver takes measures against momentary loss of synchronisation H04L7/0083
• CPC Class Codes: H04N 21/4312 involving specific graphical features, e.g. screen layout, special fonts or colors, blinking icons, highlights or animations
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/47 End-user applications
• CPC Class Codes: H04N 21/4884 for displaying subtitles
• CPC Class Codes: H04N 21/4888 for displaying teletext characters
• CPC Class Codes: H04N 7/035 Circuits for the digital non-picture data signal, e.g. for slicing of the data signal, for regeneration of the data-clock signal, for error detection or correction of the data signal
• CPC Class Codes: H04N 7/0882 for the transmission of character code signals, e.g. for teletext circuits for the digital non-picture data signal H04N7/035
• CPC Class Codes: H04N 7/0884 for the transmission of additional display-information, e.g. menu for programme or channel selection
• CPC Class Codes: H04N 7/0885 for the transmission of subtitles

Abstract

A receiving apparatus including first and second tuners for receiving telecast signals and demodulating the signals of predetermined channels; a decoder for extracting the character broadcast data from either of the demodulated signals and decoding the extracted data; a selector switch for selecting either of the signals obtained from the first and second tuners and supplying the selected signal to the decoder; a controller for controlling the selector switch during its selection of the output signal from the second tuner in such a manner as to force the switch to periodically select the demodulated signal outputted from the first tuner; and a detector for detecting whether the character broadcast data extracted by the decoder represent a caption or not when the switch has selected the output signal from the first tuner; wherein, if the result of the detection by the detector signifies that the character broadcast data represent a caption, the controller forces the switch to select the output signal from the first tuner. In this apparatus, when any caption broadcast is started by teletext, priority display of the caption can be realized without enlarging the apparatus structure or raising the production cost thereof.

Claims

1. An apparatus for receiving telecast signals where character broadcast data is superimposed as teletext data, said apparatus comprising:

first and second receiving means each for receiving said telecast signals, for demodulating said telecast signals of predetermined channels, and for outputting respective demodulated signals;

decoder means for extracting said character broadcast data from one of said demodulated signals outputted respectively from said first and second receiving means, decoding the extracted data, and outputting a decoded data;

output means for selectively delivering as an output one of the outputs of said first and second receiving means and said decoder means, or combining two of the outputs of said first and second receiving means and delivering a combined output as the output;

selector means for selecting one of said demodulated signals from said first and second receiving means and supplying a selected signal to said decoder means;

control means for controlling said selector means during its selection of said demodulated signal outputted from said second receiving means so as to force said selector means to periodically select said demodulated signal outputted from said first receiving means; and

detector means for detecting whether said character broadcast data extracted by said decoder means represents a caption when said selector means has selected said demodulated signal outputted from said first receiving means, wherein when said detector means detects a caption, said control means controls said selector means to select said demodulated signal outputted from said first receiving means.

2. The receiving apparatus according to claim 1, further comprising display means for displaying said output of said output means.

3. The receiving apparatus according to claim 1, wherein when said detector means detects a caption, said output means combines said demodulated signal output from said first receiving means and said decoded data output from said decoder means, and delivers said combined output as said output.

4. A receiving method carried out in a receiving apparatus including first and second receivers for receiving telecast signals where character broadcast data is superimposed as teletext data for demodulating said telecast signals of predetermined channels and for outputting respective demodulated signals, a decoder for extracting the character broadcast data from either of the demodulated signals outputted from said first and second receivers and decoding the extracted data, an output circuit for selectively delivering one of the outputs of said first and second receivers and said decoder or combining two of said outputs and delivering a combined output, and a selector for selecting either of the signals outputted from said first and second receivers and supplying the selected signal to said decoder, said receiving method comprising the steps of:

enabling said selector to periodically select said demodulated signal output from said first receiver when the demodulated signal outputted from said second receiver is selected by said selector;

detecting whether the character broadcast data extracted by said decoder represents a caption when the demodulated signal outputted from said first receiver is selected by said selector; and

controlling said selector to select the demodulated signal output from said first receiver when the result of such detection represents a caption.

5. The receiving method according to claim 4, further comprising the step of combining the output of said first receiver and said decoder and displaying the combined output.