Method and system of controlling the mode of access to signals, in particular picture signals

Claim 3

Apparatus as defined in claim 1, wherein said control means (UC) comprises programmable time-delay means (UC 4 ) for addressing and cyclically (T1+T3) connecting the first input (E 1 ) to the output (S) of said switching means (40) for a first predetermined period of time (T1), and for connecting the second input (E 3 or E 4 ) to the output (S) of the switching means (40) for a second predetermined period of time (T3).

Claim 4

Apparatus as defined in claim 1, and further including means (Mt n ) associated with said each grid output (ST n ) for combining the wanted signal (IMAGE) supplied by said each grid output with a further signal (TITRE) to yield a resultant signal (IT); and further wherein the switching means (40) associated with said each grid output further comprises a third input (E 2 ) receiving the resultant signal (IT) to be connected selectively to the output (S) of the switching means under the control of the control means (UC).

Claim 5

Apparatus as defined in claim 3, wherein said combining means includes one of the group consisting of a picture embedding means, a picture titling means (MT n ), and a picture superposition means.

Claim 6

Apparatus as defined in claim 3, wherein said wanted signals are picture signals (IMAGE); and further wherein said combining means comprises: (a) means (21) for extracting frame and line synchronization signals (TSYNC, LSYNC) from the wanted picture signal (IMAGE) supplied by said each output (ST n ); and (b) picture embedding means (22) for embedding an additional picture (DATA) in the picture represented by said delivered picture signal (IMAGE) in synchronism with said frame and line synchronization signals (TSYNC, LSYNC).

Claim 7

Apparatus as defined in claim 16, and further including: (d) validation means (30a, 30b) for validating each of input address words (CO,C1)transmitted by said control means (UC) to select one of the inputs (E 1 to E 4 ) of said switching means: (e) storage means (37a, 37b) for storing said each of input address words (CO, C1 ) in a stored switching control word (CMAn) selecting one of the inputs of said switching means in response to an output address validation signal, (AD n ) transmitted by said control means (UC) and relating to said each output (ST n ); and (f) means (36, 37c) for taking one of the values (("0","0"), ("1", "0"), ("0","1") or ("1","1")) of the stored switching control word (CMAn); (g) said control means (UC) comprising means for comparing said taken value with the input address word (CO,C1), so that if said compared value and s aid word are different, said control means deactivates said validation means (30 a , 30 b ) and applies in said storage means a predetermined input address word ("0","0"; 37a, 37b) which is adapted to select said first input (E 1 ) of said switching means (40) to transmit said wanted signal (IMAGE) to said output (S) of the switching means (40).

Claim 8

Apparatus as defined in claim 6, wherein said validation means (30a,30b) includes AND gates having first inputs respectively receiving bits of the input address word (C0,C1), and second inputs connected to a terminal (+Vcc) at a high state ("1"), said terminal being grounded by means of a switch (31) to deactivate said validation means (30a,30b); and further wherein said storage means comprises flip-flop means (37a,37b) having data inputs (D) respectively connected to outputs of said AND gates, and clock inputs receiving said output address validation signal (AD n ).

Claim 9

Apparatus as defined in claim 1, and further wherein said switching grid is integrated into a switching node in the form a local area network (RL) to which is connected a plurality of stations (POL, POD) for transmitting first messages (MESSAGE) each including a crosspoint address word (m,n) detected by a grid control unit (UCG) to establish a corresponding crosspoint: and further wherein said stations (POL, POD) transmit second messages each including a control word for mode of access to the wanted signal outputting from the output (ST n ) of the glid (GC) connected to said crosspoint (E m ,ST n ) when said crosspoint is established, said control word for the access mode being received by a coupling means (CO) to the local area network (RL) to be transmitted to said control means (UC) with the address (n) of said output (ST n ) connected to said crosspoint (E m ,ST n ).

Claim 10

Apparatus as defined in claim 8, wherein each of said second messages further includes a user identification word which is received by a centralized supervisory means (OS) connected to said local area network (RL) to increment a respective charge meter in said central supervisory means (OS), addressed by said user identification word, at an incrementing frequency dependent on said control word for the access mode in each of said second messages.

Claim 11

Apparatus as defined in claim 1, wherein the wanted signals are picture signals and the control means (53,54,55) comprises synchronization extractor means (53) connected to said each grid output for detecting and extracting a syvnchronization signal in one of said picture signals in order to connect said first and second inputs (e1, e2) selectively to said output of the switching means (51) alternately, conditioned by detection and non-detection of said synchronization signal in the picture signal or conditioned by the presence or absence of the picture signal.