Method and apparatus for monitoring TV channel selecting status

• US 6,487,719 B1
• Filed: 03/22/1999
• Issued: 11/26/2002
• Est. Priority Date: 03/23/1998
• Status: Expired due to Fees

• Current Assignee: KK Video Research
• Original Assignee: KK Video Research
• Inventors: Itoh, Yosikazu, Tanaka, Hiroshi
• Primary Examiner(s): Miller, John
• Assistant Examiner(s): BELIVEAU, SCOTT E
• Application Number:
  US09/273,733
• Time in Patent Office: 1,345 Days
• Field of Search: 725/14, 725/17, 725/31, 348/194
• US Class Current: 725/17
• CPC Class Codes: H04H 60/31 Arrangements for monitoring the use made of the broadcast services
• CPC Class Codes: H04H 60/43 for identifying broadcast channels
• CPC Class Codes: H04H 60/59 of video recognising characters or patterns in general G06F18/00, G06V20/00

Abstract

A monitoring apparatus connected to a TV set selects, from a plurality of internal sources, such as VHF/UHF and BS tuners and built in said TV, and a plurality of external sources connected to the TV set from the outside thereof, such as a CATV tuner and a VCR, the source of video currently displayed on a cathode-ray tube of the TV set by comparing a sync signal of the video signal applied to the cathode-ray tuber and a sync signal of the video signal output from each source. Then the monitoring apparatus determines the currently selected channel by comparing a sync signal of the video signal output from the currently selected source and a sync signal of a video signal of each of broadcast channels generated by reference receivers in the monitoring apparatus independently of the TV set. When the channels cannot be narrowed down to one currently selected channel by the comparison of sync signals, the video signals output from the currently selected source are compared with the video signals of the broadcast channels generated by the receivers to determine one of the channels as being currently selected.

Claims

1. A method for monitoring the channel selecting status of a TV set which has a plurality of video/audio sources built-in and at least one video/audio input terminal for inputting video and audio signals from at least one external video/audio source, said TV set being capable of providing a display and an acoustic output of video and audio signals supplied from a user'"'"'s arbitrarily selected one of said video/audio sources, said method comprising the steps of:

(a) detecting vertical and horizontal sync signals of a video signal applied to a cathode-ray tube of said TV set;

(b) detecting video signals output from said plurality of video/audio sources built in said TV set;

(c) detecting a video signal output from said video/audio source connected to said video/audio input terminal of said TV set;

(d) sequentially selecting said video signals detected in said steps (b) and (c);

(e) separating vertical and horizontal sync signals from each of said video signals sequentially selected in said step (d);

(f) measuring the time difference between said vertical and horizontal sync signals detected in said step (a) and said vertical and horizontal sync signals selected in said step (e);

(g) correcting said time difference measured in said step (f) in accordance with a premeasured delay time inherent in each of said plurality of video/audio sources, and determining that one of said video/audio sources for which said corrected time difference is minimum is the video/audio source currently selected by said user;

(h) controlling a plurality of reference receivers to sequentially generate video signals of channels receivable from that one of said video/audio sources which was determined to be currently selected by said user in said step (g), said plurality of reference receivers being capable of generating video signals of each channel of each TV broadcast independently of said TV set;

(i) separating vertical and horizontal sync signals from each of said video signals generated in said step (h);

(j) measuring the time difference between vertical and horizontal sync signals of said video/audio sources determined to be currently selected by said user in said step (g) and said vertical and horizontal sync signals separated in said step (i); and

(k) correcting said time difference measured in said step (i) in accordance with a premeasured delay time inherent in each of said plurality of video/audio sources, and determining that a channel for which said corrected time difference is smaller than a predetermined threshold value is a candidate for a channel currently selected by said user.

2. The method of claim 1, which further comprises the steps of:

(l) when a plurality of channels are determined as candidates for said user'"'"'s currently selected channel in said step (k), controlling said plurality of reference receivers to sequentially generate video signals of the same channels as said candidate channels; and

(m) comparing, at a plurality of sample points common thereto, a video signal generated from that one of said video/audio sources determined to be currently selected by said user in said step (g) and video signals sequentially generated in said step (l), and detecting said user'"'"'s currently selected channel based on the degree of coincidence between said video signals.

3. The method of claim 2, which further comprises the step of:

(n) when said video/audio source connected to said video/audio input terminal of said TV set is a CATV tuner for CATV broadcast reception use, quasi-descrambling that one of video signals from a CATV receiver provided as said reference receiver which is of a pay channel scrambled by the suppression of sync signal.

4. The method of claim 3, wherein said step (n) comprises the steps of:

(n-1) generating vertical and horizontal blanking intervals from said vertical and horizontal sync signals detected in said step (a);

(n-2) extracting signals in said vertical and horizontal blanking intervals in said scrambled video signal;

(n-3) restoring said extracted signals to their original form before said video signal was scrambled; and

(n-4) replacing said signals in said vertical and horizontal blanking intervals in said scrambled video signal with said restored signals to form descrambled video signals.

5. The method of claim 2, which further comprises the step of:

(o) determining, based on said vertical and horizontal sync signals detected in said step (a), whether the scanning system of said video signal applied to said cathode-ray tube is an interlaced or non-interlaced scanning system, and in the latter case, determining that preset equipment of the non-interlaced scanning system is the currently user'"'"'s selected video/audio source.

6. An apparatus for monitoring the channel selecting status of a TV set which has a plurality of video/audio sources built-in and at least one video/audio input terminal for inputting video and audio signals from at least one external video/audio source, said TV set being capable of providing a display and an acoustic output of the video and audio signals supplied from a user'"'"'s arbitrarily selected one of said video/audio sources, said apparatus comprising:

sync signal detecting means for detecting vertical and horizontal sync signals of a video signal applied to a cathode-ray tube of said TV set;

internal video signal detecting means for detecting video signals output from said plurality of video/audio sources built in said TV set;

external video signal detecting means for detecting a video signal output from said video/audio source connected to said video/audio input terminal of said TV set;

an analog switch which is supplied with said video signals detected by said internal video signal detecting means and said video signal detected by said external video signal detecting means, and selectively outputs one of said video signals;

first sync separating means for separating vertical and horizontal sync signals from said video signal output from said analog switch;

time difference measuring means which is supplied with first and second vertical and horizontal sync signals, and measures the time differences between said first and second vertical sync signals and between said first and second horizontal sync signals;

control means which;

inputs said vertical and horizontal sync signals detected by said sync signal detecting means, as said first vertical and horizontal sync signals, to said time difference measuring means;

inputs said vertical and horizontal sync signals separated by said first sync separating means from said video signal of each of said video/audio sources selectively fed thereto from said analog switch, as said second vertical and horizontal sync signals, to said time difference measuring means;

measures, by said time difference measuring means, the time differences between said vertical and horizontal sync signals detected by said sync signal detecting means and said vertical and horizontal sync signals of said each video/audio source;

corrects said measured time differences in accordance with a premeasured delay time inherent in said each video/audio source; and

determines that one of said video/audio sources for which said corrected time difference is minimum is the video/audio source currently selected by said user;

a plurality of reference receivers for generating video signals of each channel of each TV broadcast independently of said TV set;

second sync separating means for separating vertical and horizontal sync signals from each of said video signals generated by said reference receivers; and

a selector for selectively outputting either said vertical and horizontal sync signals detected by said sync signal detecting means or said vertical and horizontal sync signals separated by said second sync separating means;

wherein said control means;

inputs a video signal of said that one of video/audio source determined as being currently selected by said user, to said first sync separating means via said analog switch inputs vertical and horizontal sync signals separated by said first sync separating means, as said first vertical and horizontal sync signals, to said time difference measuring means;

sequentially generates, by said reference receivers, video signals of respective channels receivable from that one of said video/audio sources determined as currently selected by said user, and applies said video signals to said second sync separating means one by one;

inputs vertical and horizontal sync signals separated by said second sync separating means, as said second vertical and horizontal sync signals, to said time difference measuring means;

measures, by said time difference measuring means, the time differences between vertical and horizontal sync signals output from that one of said video/audio sources determined as currently selected by said user and vertical and horizontal sync signals of each channel generated by said reference receivers;

corrects said measured time differences in accordance with a premeasured delay time inherent in said each of said plurality of video/audio sources; and

determines that a channel for which said corrected time difference is smaller than a predetermined threshold value is a candidate for a channel currently selected by said user.

7. The apparatus of claim 6, which further comprises:

a first A-D converter/frame memory for digitizing and storing said video signal output from said analog switch; and

a second A-D converter/frame memory for digitizing and storing said video signals output from said reference receivers;

wherein when a plurality of channels are determined as candidates for said user'"'"'s currently selected channel by the comparison of said sync signals, said control means;

controls said plurality of reference receivers to sequentially generate video signals of the same channels as said candidate channels, and inputs said video signals to said second A-D converter/frame memory;

stores in said first A-D converter/frame memory a video signal generated by that one of said video/audio sources determined as the source currently selected by said user;

compares those video signals at a plurality of sample points common thereto; and

detects said user'"'"'s currently selected channel based on the degree of coincidence between said video signals.

8. The apparatus of claim 7, which further comprises:

a CATV receiver as one of said reference receivers; and

a suppressed sync signal quasi-regenerator which quasi-descrambles that one of video signals from said CATV receiver which is of a pay channel scrambled by the suppression of sync signal.

9. The apparatus of claim 8, wherein said suppressed sync signal quasi-regenerator comprises:

interval generating means for generating vertical and horizontal blanking intervals from said vertical and horizontal sync signals detected by said sync signal detecting means

signal extracting means for extracting signals in said vertical and horizontal blanking intervals in said scrambled video signal generated by said CATV receiver;

sync signal restoring means for restoring said extracted signals to their original form before said video signal was scrambled; and

video signal generating means for replacing said signals in said vertical and horizontal blanking intervals in said scrambled video signal from said CATV receiver with said restored signals from said sync signal restoring means to form descrambled video signals.

10. The apparatus of claim 8, which further comprises:

a scanning system identifying circuit for determining, based on said vertical and horizontal sync signals detected by said sync signal detecting means, whether the scanning system of said video signal applied to said cathode-ray tube is an interlaced or non-interlaced scanning system, and

wherein when the scanning system of said video signal is the non-interlaced scanning system, said control means determines that preset equipment of the non-interlaced scanning system is the video/audio source currently selected by said user.