Bilateral anti-copying device for video systems

Claim 3

The method of claim 1, wherein there is a predetermined relationship between the lines of video information in which said leading and trailing code sequences are contained, wherein the method further comprises the step of identifying lines of video information in which said trailing code sequence must be contained, and wherein said step of monitoring the luminance portion of said incoming video information for said trailing code sequence is carried out during transmission of the luminance portion of said identified lines.

Claim 4

The method of claim 1, wherein the leading and trailing code sequences are digital signals.

Claim 5

The method of claim 1, wherein said predetermined relationship is that of inversion.

Claim 6

The method of Claim 1, wherein said inhibiting step is carried out only for a predetermined time.

Claim 7

method for processing a video signal to embed therein information which, when detected by a video recorder, will inhibit recordation of such video signal by such recorder, comprising the following steps: establishing first and second lines of video information which are spaced one field apart from each other; recording, in the luminance portion of said first line of video information, a leading code sequence; and recording, in the luminance portion of said second line of video information, a trailing code sequence which bears a predetermined relationship with said leading code sequence.

Claim 8

method for processing a video signal to embed therein information which, when detected by a video recorder, will inhibit recordation of such video signal by such recorder, comprising the following steps: establishing first and second lines of video information which are spaced one field apart from each other; recording, in the luminance portion of said first line of video information, a leading code sequence; and recording, in the luminance portion of said second line of video information, a trailing code sequence which bears a predetermined relationship with said leading code sequence.

Claim 9

The method of claim 6, wherein said establishing step comprises the following steps: defining an active region comprising a group or lines in a first field of video information; monitoring the luminance signal of lines in said active region for the existence of a luminance signal which meets predetermined criteria of luminance for a predetermined period of time; and upon detection of the existence of such a signal, establishing an immediately succeeding line of video information identified as said first line and a corresponding line of video information identified as said second line which is one field later than said first line.

Claim 10

The method of claim 7, wherein a first portion of said active region begins with line 35 and ends with line 81.

Claim 11

The method of claim 7, wherein a second portion of said active region begins with line 181 and ends with line 227.

Claim 12

The method of claim 6, wherein said recording steps are carried out asynchronously with respect to the video synchronization of the video signal.

Claim 13

The method of claim 6, wherein the leading and trailing code sequences are digital signals.

Claim 14

The method of claim 11, wherein the leading and trailing code sequences are inversions of each other.

Claim 15

A circuit for use with a video recorder to inhibit recording operation thereof when recording a video signal which contains corresponding leading and trailing code sequences which are one field apart from each other, comprising: means for monitoring the luminance portion of said video signal for digital code sequences; first means for storing a digital code sequence which is detected by said monitoring means; second means for storing another digital code sequence which is detected by said monitoring means; means for comparing said digital code sequences which have been stored in said first and second storing means; and means for inhibiting recording operation of the video tape recorder when said comparing means indicates that said digital code sequences have a predetermined relationship with each other.

Claim 16

A circuit for use with a video recorder to inhibit recording operation thereof when recording a video signal which contains corresponding leading and trailing code sequences which are one field apart from each other, comprising: means for monitoring the luminance portion of said video signal for digital code sequences; first means for storing a digital code sequence which is detected by said monitoring means; second means for storing another digital code sequence which is detected by said monitoring means; means for comparing said digital code sequences which have been stored in said first and second storing means; and means for inhibiting recording operation of the video tape recorder when said comparing means indicates that said digital code sequences have a predetermined relationship with each other.

Claim 17

The circuit of claim 13, further comprising means for DC-restoring said video signal, and wherein said monitoring means operates on said video signal after it has been DC-restored.

Claim 18

The circuit of claim 13, wherein said monitoring means includes a serial-to-parallel shift register.

Claim 19

The circuit of claim 13, wherein said inhibiting means operates to inhibit recording operation of the video recorder only for a predetermined time.

Claim 20

circuit for inserting leading and trailing digital code sequences into a video signal, said sequences being spaced one field apart from each other, comprising: means for DC-restoring said video signal; means for monitoring the luminance portion or said video signal after it has been DC-restored; means for determining when said luminance portion satisfies predetermined luminance criteria for a predetermined time; first means for inserting into said DC-restored video signal at the line immediately following a line in which said luminance portion satisfies said criteria for said time, a digital leading code sequence inserted at a level between a predetermined IRE level and the luminance level of said DC-restored video signal; means for identifying, in said DC-restored video signal, a line which is one field later than said line in which said digital leading code sequence has been inserted; and second means for inserting into said DC-restored video signal at said later line a digital trailing code sequence between said predetermined IRE level and the luminance level of said DC-restored video signal.

Claim 21

circuit for inserting leading and trailing digital code sequences into a video signal, said sequences being spaced one field apart from each other, comprising: means for DC-restoring said video signal; means for monitoring the luminance portion or said video signal after it has been DC-restored; means for determining when said luminance portion satisfies predetermined luminance criteria for a predetermined time; first means for inserting into said DC-restored video signal at the line immediately following a line in which said luminance portion satisfies said criteria for said time, a digital leading code sequence inserted at a level between a predetermined IRE level and the luminance level of said DC-restored video signal; means for identifying, in said DC-restored video signal, a line which is one field later than said line in which said digital leading code sequence has been inserted; and second means for inserting into said DC-restored video signal at said later line a digital trailing code sequence between said predetermined IRE level and the luminance level of said DC-restored video signal.

Claim 22

The circuit of claim 17, wherein said monitoring means monitors a version of said video signal from which all chroma information has been removed.

Claim 27

A method as in Claim 20 wherein the analog signal is the luminance portion of a video signal, said leading and trailing code sequences have a predetermined time relationship, the combined signal is recorded on a video recording medium, the leading and trailing code sequences are detected upon playback of the recorded video signal, and the information conveyed is information to prevent video information from being recorded by a video tape recorder.