DE3645247C2 - Interactive video-sound data display via TV cable - Google Patents

Abstract

A cable television network includes a device for delivering prerecorded video frames and sound, each frame including data and a vertical blanking interval. A central processor organises all the network functions. Telephone lines allow subscribers to call up data, held on controlled video disc players, to be sent on a set radio frequency to a node of the network where the data is held in a node memory for subsequent transfer to the subscribers' television set.The processor inserts graphic data onto the frame retrieved from disc and the node memory has a logical coding device ensuring the data are sent to the subscriber who requires them

Description

The invention relates to a node frame memory for Storage of a TV still in one Cable television system for selective distribution from in advance recorded television still images, each from consist of at least one video field consisting of a Number of scan lines that make up a vertical blanking interval and a number of scan lines that the Correspond to image information, is constructed.

In North America and elsewhere it is common for one large number of participating households a CATV (Cable television system) subscribed to over a coaxial cable a number of commercial and public To receive television signals. Every signal consists of TV picture and sound with a refresh rate of 30 (or 25) frames of video per second. Every signal will through the CATV system over the coaxial cable to TV receiver of the subscriber household by means of a discrete frequency band, which is called the "channel" is known. The participant tunes his television receiver on the desired channel and receives that composite television signal.

It is not uncommon for a cable television system to be more  has more than 50,000 participants. With such a large system is generally a central one There is a "cable hub" that acts as a control center to the record various signals that are either over "Broadcast" or received from satellites or locally are produced by the system operator or third parties. These signals are on a coaxial line cable given. Typically, therefore, a cable television system a number of antennas on the signals from several Record radio stations or from satellite stations can. Amplifiers and the like, which are in the central cable hub, amplify these signals and transmit each signal as a single frequency channel one or more line coaxial cables. Along the Line coaxial cable lies a number of nodes. In each A bridge amplifier amplifies the signals of the node Route coaxial cable and transmits the reinforced Signals on a secondary distribution cable. Any secondary Distribution cable has a number of "taps" and each Tap has a number of connection coaxial cables, one of which is led to a participant. in the generally supplies every secondary distribution cable approximately 200 participants and there are usually between 50 and 100 taps, so that each Tapping supplies two to four connections.

Other systems have already been developed to work in interactive way data about the participants of the Cable television system upon your request to transfer. To be feasible, such Systems

• (1) a large number of participants at the same time supply,  
• (2) high quality video images within a short Deliver response time,
• (3) work without new devices in the subscriber household require, and
• (4) within the limits of the number of TV channels work for a typical one Cable television system are available. Most Cable television systems have a maximum of approximately 15 "empty" channels.

So far, no interactive system has been able to do it all to meet the requirements listed above. Typically the number of participants was normal at the same time with a TV still image TV quality and resolution can be supplied on limited to a very small number. To be a simultaneous Sending video is a television channel for everyone Participants required; therefore at the same time only approximately 15 participants are served. By the number the simultaneous user was enlarged only transfer computer graphics, under the responsibility of Image quality and delivery speed. In addition are accompanying by the invention Tone frequency messages along with the video images supplied to give a complete presentation.

A system of the type described above is known from U.S. Patent 4,455,570 known. The one described in it Cable television system has a center, a main cable with a trunk cable amplifier, junction nodes along of the main cable and several branch cables. On everyone Branch cables are, among other things, connection points  provided that via connecting lines to the Lead participant households. Such a structure Cable television system has those described above Disadvantages with regard to the simultaneous Responsibility of participants.

The invention is based on this prior art based on the task of a node frame memory for a Cable television system of the type mentioned above to design that the transmitted television still images have the usual television picture quality and that of one large number of television cable participants per used TV channel can be transmitted without the Participants require additional equipment.

This task is solved by one Node frame memory for a cable television system with the Features of claim 1.

Advantageous configurations of the full frame memory result from the subclaims.

Before describing a preferred one Embodiment it is appropriate to some of the to explain the terms used.

(1) Cable television system (CATV)

A television set with a communal antenna like her is currently used in North America.

(2) participants

A user of the CATV or another  Television transmission system, which the television signals on Receives television receivers in his household.

(3) TV still picture

The combination of two overlaid video fields, where each field is formed by (1.) a number of Scan lines called vertical blanking gaps and (2.) a second larger number of scan lines, that contain the image information that was created on TV screen to be converted to a video picture. The TV stills are 30 in the CATV Frames / second (North American and Japanese Standard) or at 25 frames / second (European standard) transfer. The invention is standardized according to north american transmission rate of 30 Full frames / second described, but works in the same 25 frames / second mode.

(4) Vertical blanking

The first 21 lines of a video field that encoded Data for synchronizing the display of the video image contain. Multiple lines of vertical blanking are currently left blank and will be added to the Invention used for the insertion of address data.

(5) Line cable

The primary coaxial distribution cable, that of a CATV cable hub goes out.

(6) knot

Points along a section cable at which Bypass amplifiers amplify the television signal and it for transmission along secondary distribution coaxial cables split.

(7) Distribution cable

A secondary distribution coaxial cable that runs from one Knot leads away.

(8) Tapping

A point on a distribution cable in which the Split TV signal and along connecting cables to Participant household is sent.

(9) connection

A connection coaxial cable to the subscriber household.

(10) Node frame memory

A device located within a node of the Cable television system is arranged and the one TV still can save it at a rate of 30 frames / second again along the distribution cable transmits. The node frame memory can also the Tone frequency message associated with TV still received and synchronized with the associated TV still, both on the same TV channel, lengthways of the associated distribution cable.

(1) Multi-node frame store

A group of node frame stores, all at one Knots lie, and each of which is its individual Distribution cable supplied.

The transmission could, without being limited to this, the transmission and reception by means of an antenna on Distribution point and in the participant's household include, or a broadcast to a satellite and a retransmission to a satellite antenna in the Participant's household, or by using a Fiber optic cable instead of a coaxial cable.

The invention provides that a CATV has a number of TV programs on different TV channels in transmits in the usual way while one is not currently used channel is used to view video frames to transfer a remote node frame store. The associated audio frequency messages are the same Full node storage using one on the section cable available bandwidth transferred for a TV transmission is unsuitable. At the Node frame stores are the video and Tone frequency data combined for transmission over the same channel (which was used to view the Transfer video frames to the node frame memory), along the distribution cable to the subscriber. Of the participants selects the desired video and audio frequency representations from a data catalog that, for example, advertising and Product brochures, prices and a verbal message or "Kick Off" includes. The catalog could too contain stipulating or educational material. The Invention lies in the means by which the Video and audio frequency data to the participant via the CATV be transmitted at his request, and  nothing with the specific, transferred in this way To do video and audio frequency data.

According to the invention, the subscriber requests data by: a given phone number that dials him with a Control center connects. The data are from Control center over the route cables of the CATV in shape a video frame on a given channel transmitted, together with the associated audio frequency data, namely over sections of the CATV bandwidth. The video frame that has a duration of Has 1/30 second, has the only address of the Node frame store of the subscriber in one of the Scan lines of their vertical blanking interval inserted. It can have more than one scan line of vertical Blanking interval used for the insertion of such addresses are, however, the invention is described as only one scan line would be used. All of the requested individually addressed video frames transmitted over a television channel. Of the Node frame memory of the subscriber recognizes his individual address on the particular requested Video frame and only stores this frame in his Storage. The associated audio frequency is via a unused television bandwidth in the form of transmit amplitude-modulated radio frequency. The Available unused CATV bandwidth can be over 300 accommodate discrete audio frequency channels. Everyone Node frame memory is on a single one of the 300 tuned discrete audio frequency channels. The Control center ensures that the video frame on Node frame memory at the same time as the The associated audio frequency data arrives. The The video frame is then displayed by the  Node frame memory continuously as a video still image (30 × per second) retransmitted together with the associated audio frequency on the same television channel the distribution cable of this node to the subscriber. All TV receiver of the participants who participated in that Distribution cable connected and on the specified TV channel are tuned to receive the same Video still image and the associated audio frequency. Of the Node frame memory transfers the associated one Tone frequency announcement and transmits the video frame continuously until another individually addressed Full frame video was identified on the section cable. The the first video frame is then deleted and the second Full frame video is for transmission with its associated Audio frequency data saved.

The audio frequency data can from the control center after a transmitted by three alternative routes, the suitable alternative as a preferred embodiment for a given CATV facility is selected. According to the the first alternative, the audio frequency data via the Transfer the telephone system to the subscriber's telephone become. According to the second alternative, the Audio frequency data from the control center to the Node frame memory as amplitude modulated Tone frequency transmitted and in the third alternative as compressed audio frequency in electronic format Full frame. Both the second and the third alternative is the tone frequency in the Full frame node storage in a standardized television FM audio frequency signal converted by the participant on the specified channel of his TV can be.  

According to the preferred embodiment of the invention the participant becomes interactive, d. H. specified Request data. The invention draws two interaction paths into consideration. The first and preferred way of interaction lies in the use of the home phone of the Participant to call the control center. The second The way of interaction is the CATV; however one would Two-way cable usage required across the entire CATV and hardware would be needed in the subscriber household, a message about the CATV back to the Control center can get.

Operation of a cable television system with the node frame memory according to the invention takes place according to the following procedures for distributing in advance recorded TV still images with the following Steps:

• (a) insert a coded address into a predefined scanning line within the blanking interval the video fields of the television still image,
• (b) transmitting the television still image along the primary transmission path,
• (c) capturing the inserted address along the primary transmission path,
• (d) Save the TV still at the beginning of the secondary transmission path, whose address with the registered address matches, and
• (e) repeated transmission of the stored TV still along the secondary Transmission path.

The video frame memory has a device for Storage of a single video frame (consisting of two overlaid video fields) with a standardized television protocol is compatible. The Video frame is stored by the video frame memory a single address identified in a Scan line or multiple scan lines of vertical Blanking of this video frame is included. Of the The remaining part of the scan lines in the video frame contains the Data for generating the video frame. Of the Video frame memory removes the video frames that through the video frame store on the primary path step through and select only the frame that the contains the single address of this video frame memory, saves this video frame and transmits it repeatedly along a secondary path at least 25 × per second to produce a television still image. Of the Video frame memory contains:

• (1) a device for checking a primary route regarding a video frame in which a of the scan lines in its television blanking interval is individually addressed; and
• (2) a device for storing a Video frame and for the transmission of the repeated video frame, at least 25 × per second, on the secondary path;
• (3) a comparator for comparing the address checked by the device ( 1 ) and, if there is a match with a predetermined address, for activating the memory device ( 2 ) for the purpose of storing the video frame from the primary path.

According to a preferred embodiment, the Video frame memory a device for recording a Tone frequency notification from the primary path on Accompanying each video frame. The Audio frequency message is with the video frame on a TV channel combined and both are put on together transmitted to the subscriber via a secondary route. The Tone frequency message can either be as amplitude modulated analog radio frequency or as compressed audio frequency in electronic format Video frame are received.

The invention is then based on a Embodiment with reference to the accompanying Drawings explained in more detail. It shows

Fig. 1 is a schematic diagram of the elements of a cable television system;

Fig. 2 is a block diagram of a central control unit (CCU),

Fig. 3 is a block diagram of a television screen units (VDU),

Fig. 4 is a block diagram of a node according to the invention arranged on a node frame store,

Fig. 5A + B a block diagram of an alternate embodiment, transmit Tonfrequenzdaten along the primary path to the node frame store to,

Fig. 6A and B, an inventive command scheme of the central processing unit (CPU) n the central control unit (CCU), and

FIG. 7A + B, an inventive flow chart of a VDU controller in the television display unit (VDU).

Referring to Fig. 1, a CATV constructed according to the preferred embodiment is shown at ( 15 ) and consists of a CATV hub ( 20 ) from which three line cables ( 21 ) emanate as primary signal paths. A plurality of nodes ( 25 ) are arranged along the section cables ( 21 ). A bridging amplifier (not shown) is generally arranged at each node ( 25 ) in order to amplify the television signals and to transmit them to a subscriber household ( 40 ) along a secondary path, a distribution cable ( 31 ). At the node ( 25 '), a multiple node full frame memory ( 30 ) is arranged according to the invention, which has at least one distribution cable ( 31 ) as an output. Four potential connections ( 1 , 2 , 3 , 4 ) for distribution cables ( 31 ) are shown and only ( 2 ) is indicated as being used. Similarly, only a multiple node frame memory ( 30 ) is shown connected to the node ( 25 '). It is evident that corresponding multiple-node frame memories ( 30 ) are connected to every other node ( 25 ) along the section cable ( 21 ) according to the invention. Along each distribution cable ( 31 ) there is a connection ( 35 ) for a connection ( 36 ) in the form of a coaxial cable, which leads to the subscriber household ( 40 ) for the purpose of connecting a television receiver ( 45 ). A number of television reception antennas ( 27 ) are present on the CATV hub ( 20 ), only one of which is shown.

According to the invention, a central control unit (CCU) ( 28 ) is assigned to the CATV hub ( 20 ). According to a preferred embodiment, the CCU ( 28 ) is in the same physical location as the CATV hub ( 20 ), but this is not necessary as long as the output ( 29 ) from the CCU ( 28 ) is connected to the line cable ( 21 ) in the CATV hub ( 20 ). The CCU ( 28 ) expediently has a plurality of telephone lines ( 50 ) which end there and establish a connection to a telephone exchange ( 55 ). The subscriber has connected his subscriber telephone ( 48 ) to the telephone exchange ( 55 ) via a telephone line ( 49 ).

Those skilled in the art will recognize that the signals received by the majority of television recording antennas ( 27 ) are amplified in the CATV hub ( 20 ) and that they are emitted along the trunk cable ( 21 ) on discrete channels, each channel having a plurality of frequencies of given bandwidth contains, which is generally about 6 MHz wide in North America. It is not uncommon for the link cable ( 21 ) to carry about 20 to 70 different channels for common video and audio frequency subband data. The majority of the channels are amplified at the nodes ( 25 ) (the multiple node frame memory ( 30 ) is currently not considered) and the amplified channel frequencies are along the distribution cable ( 21 ) via a connection point ( 35 ) to the connecting line ( 36 ) and thus transmitted to the subscriber's television receiver ( 45 ).

According to one aspect of the invention, the subscriber connects to the CCU ( 28 ) directly through the telephone exchange ( 55 ) using his telephone ( 48 ) when making a normal telephone call. If a key telephone is used, the keyboard of the telephone ( 48 ) can be used to enter specific requirements directly into the CCU ( 28 ), as will become apparent.

In the CCU ( 28 ) according to the invention, the data coming from the telephone ( 48 ) cause video frames, which consist of two superimposed video fields and which are recorded in advance and stored in one of the number of video players, along the line cable ( 21 ) to the television receiver ( 45 ). of the participant. In this regard, since amplification takes place at the nodes ( 25 ), the full video image is first transmitted along the section cable ( 21 ) to that node ( 25 ') which is also connected to the subscriber household ( 40 ). In this node ( 25 ') a video frame is stored within the multi-node frame memory ( 30 ) in order to be continuously transmitted again 30 × per second along one of the four distribution cables ( 31 ) to the subscriber's television set ( 45 ), via the in Fig. 1 as number (2) designated distribution cable. The amount of time it takes to transfer the video frame from the CCU ( 28 ) to the multi-node frame store ( 30 ) for storage is a single frame interval (1/30 second). The multi-node frame memory ( 30 ) retransmits the stored video frame 30 × per second along the distribution cable ( 31 ) for continuous reception on the television ( 45 ) until the multi-node frame memory ( 30 ) is properly addressed by the CCU ( 28 ) a new one individually Video frame is obtained, the cycle is obviously repeated.

In summary, it is therefore clear that a different video frame can be transmitted along the section cable ( 21 ) every 1/30 seconds. This means that 30 different nodes can be supplied with a new video frame every second. Each of these nodes then continuously transfers the frame located in its multi-node frame memory to the subscriber. The subscriber therefore takes a television still image, while the CCU ( 28 ) continuously delivers new video frames to other node frame memories at every frame interval. In this application it is imperative to have a main synchronous generator which synchronizes the scan lines and thus the vertical blanking gaps in the CATV.

Referring now to Fig. 2, the CCU ( 28 ) has a central processing unit ( 60 ) whose inputs are connected to a plurality of telephone management units (TMU) ( 65 ), ten of which are shown and each TMU ( 65 ) is shown schematically with the end piece of 30 telephone lines ( 50 ). The telephone lines ( 50 ) naturally lead with their other end to the telephone exchange ( 55 ) according to FIG. 1. Each TMU ( 65 ) receives commands from a number of subscribers and transmits these commands to the central unit ( 60 ) in an ordered sequence.

the central unit ( 60 ) has a number of outputs, which are shown together at ( 66 ) and the number of which is schematically indicated at 30, each output being led directly to a video screen unit ( 70 ) (VDU). There are thus 30 VDUs ( 70 ), each of which has its output routed to a single input of a vertical blanking switch ( 80 ) which includes a distributor ( 85 ). A main synchronization pulse generator ( 69 ) is provided which supplies the main synchronization pulses along paths ( 69 ') to each of the video display units ( 70 ) and the distributor ( 85 ). In this way, each of the video frames supplied by the video display units ( 70 ) in each feed line ( 79 ') can effectively pass through the vertical blanking switch ( 80 ) and finally reach the section cable ( 21 ). The video frames exiting from the vertical blanking switch ( 80 ) arrive on line ( 80 ') to a video modulator ( 81 ) which up-mixes the video frame baseband to a preselected channel frequency f (v) and then to the line cable ( 21 ). In a similar way, the associated audio frequency data along the line ( 76 ') to a high-frequency up-mixer ( 85 a), the output of which leads to the line cable ( 21 ).

Referring now to Fig. 3, each video display unit ( 70 ) consists of a single video display controller (VDU controller) ( 71 ) which, in one unit, contains a programmable microprocessor, a single video player ( 73 ) and in parallel for this purpose a number of audio frequency frame memories ( 75 ), of which ten are preferably present and whose common input line is the output line of the video player ( 73 ). Digital audio frequency output values from the video player ( 73 ) are converted into an analog signal in the audio frequency frame memories ( 75 ). The output lines of each audio frame store ( 75 ) are routed to their own selectively tuned AM transmitter ( 76 ), the output sequence of which is determined by the VDU controller ( 71 ) and is determined as f (ax) within each video display unit ( 70 ) , where x is an integer ranging from 1 to 10. Output values from the transmitters ( 76 ) reach the common outgoing line ( 76 ') and, now with reference to FIG. 2, via a high-frequency up-mixer ( 85 a) to the section cable ( 21 ).

Parallel to the video player ( 73 ) is a graphic decoder ( 77 ) with an output ( 77 '). A video combiner ( 78 ) has as an input the output ( 73 ') of the video player ( 73 ), which is composite video, and the output ( 77 ') of the graphic decoder ( 77 ), which is RGB video. The output ( 78 ') of the video combiner ( 78 ), which is RGB video, represents the input for an RGB / composite video converter and a node address input device ( 79 ), which is the only output the line ( 79 ′) has. The line ( 79 ') is, as shown in Fig. 2, connected to a single input ( 79 ') (s) of the vertical blanking switch ( 80 ), where (s) has the value 1 to 30. Referring to FIGS. 2 to 3, the vertical blanking switch ( 80 ) has a distributor ( 85 ) and a single output line ( 80 ') to a video modulator ( 81 ) which preselects the video baseband on line ( 80 ') Channel frequency f (v) rises and outputs this to the output line ( 81 ') and then with reference to Fig. 1 to the section cable ( 21 ).

Referring to FIGS. 2 and 3, according to which a main synchronization pulse generator (69) (69 ') is connected to the manifold (85) and with each of the video display units (70) via a line (in particular, with each of the 30 video players (73 ), the graphic decoder ( 77 ), the video combiner ( 78 ) and the RGB / composite converter and the node address input device ( 79 )), and with the distributor ( 85 ) which is arranged within the vertical blanking switch ( 80 ).

Similarly, the distributor ( 85 ) is directly connected to each of the 30 VDU controllers ( 71 ) via the line ( 715 ) and exchanges data with it. Each VDU controller ( 71 ) also has an output line ( 714 ) directly to the RGB / composite converter and node address input device ( 79 ) which inserts a "single node address" into a given scan line within the vertical blanking interval of each video field of the video frame . As additional output lines, the VDU controller ( 71 ) has a line ( 711 ) to the video player ( 73 ), a line ( 712 ) to each of the audio frequency frame memories ( 75 ) and a line ( 713 ) to each of the tunable AM transmissions ( 76 ) .

Referring now briefly to Figures 1 and 4, there are a number of multiple node frame stores ( 30 ), each of which has one or more node frame stores ( 95 ), each associated with a single address. If there is a video frame on a given video player ( 73 ) and this previously recorded frame is to be transmitted to the television ( 45 ), the specific address of the node frame memory ( 95 ) within the multiple node frame memory ( 30 ) in the node ( 25 ') must be Fig. 1 can be used. Therefore, that specific address contained within the memory of the central processing unit ( 60 ) reaches the video screen unit ( 70 ) which contains the video player ( 73 ) with the specific video frame requested by the subscriber. It is assumed that this is, for example, the video player ( 73 ) in the video screen unit number (1) shown in FIG. 3. The address of the node frame memory is fed along the line ( 66 ) to the VDU controller ( 71 ) and passes via the VDU controller ( 71 ) along the line ( 714 ) to the RGB / composite converter and to the node address input device ( 79 ). At the same time, along the line ( 711 ) the video frame within the video player ( 73 ) is selected together with the associated audio frequency frame (s) and the video and audio frequency frames reach the video combiner ( 78 ) and one of the audio frequency frame memory ( 78 ') via the line ( 73 '). 75 (1) - 75 (10)). The VDU controller ( 71 ) selects that audio frequency frame memory that is free and then transmits an enable pulse along the line ( 712 ) to the associated audio frequency frame memory ( 75 ) for the purpose of storing only the associated audio frequency frame or the associated audio frequency frames. The audio frequency frame memory ( 75 ) converts the audio frequency frame or the audio frequency frames into analog audio frequency values and transfers them on command from the VDU controller ( 71 ) to the line ( 75 ') as an input to its own tunable AM transmitter ( 76 ). The VDU controller ( 71 ) specifies the AM transmitter frequency f (ax) corresponding to that of the AM receiver in the node frame memory ( 95 ) via the line ( 713 ). However, it is expedient to subject all transmitter outputs ( 76 ') to an upmix and this is done by a high-frequency upmixer ( 85 a).

A "graphic overlay" can also be present in the memory of the VDU controller ( 71 ), which is assigned to the specific selected video frame. This overlay, if present, is fed along the line ( 710 ) to the graphic decoder ( 77 ), which reconstitutes it as RGB video and transmits it as an output value along the line ( 77 ') to the video combiner ( 78 ). The graphic overlay is then applied to the video frame within the video combiner ( 78 ) and the combined RGB output is transmitted along the line ( 78 ') to the RGB / composite converter and to the node address input device ( 79 ). The video frame consists of two video fields, each field being composed of a first number of scan lines representing the vertical blanking interval and a second number of scan lines representing the video image data. One of the scan lines in the vertical blanking interval is pre-selected to transmit the node address, and the RGB / composite converter and node address input device ( 79 ) take the node address from the VDU controller ( 71 ) along the line ( 714 ) and route it it to the selected scan line of the vertical blanking interval of that video frame. The individually addressed RGB video frame is converted into composite video and then transmitted along the line ( 79 ') to a specific input of the vertical blanking switch ( 80 ). At the appropriate signal from the VDU controller ( 71 ) for the distributor ( 85 ), the vertical blanking switch opens for this specific input and the addressed video frame reaches the output ( 80 ') of the vertical blanking switch. The distributor ( 85 ) then passes the corresponding signal to the VDU controller ( 71 ), which indicates that the video frame has been transmitted along the line ( 80 ') to the section cable ( 21 ). This sequence can be repeated at every frame interval. Therefore, a different video frame with a different node address can be transmitted on the line ( 80 ') every 1/30 seconds. These signals represent all baseband frequencies and therefore pass through the video modulator ( 81 ) shown in FIG. 2, which raises the baseband to the predetermined frequency f (v) in the manner explained above. The distributor ( 85 ) does not allow audio frequency frames to pass through the vertical blanking switch ( 80 ).

It can thus be seen that the line ( 715 ) between the distributor ( 85 ) and the VDU controller ( 71 ) is bidirectional and likewise the lines ( 710 , 711 ), while the lines ( 712 , 713 ) need not be directional.

According to the invention, the video playback devices ( 73 ) have a response time of approximately 1 second. Therefore, in order to ensure that a single video frame is available every 1/30 second interval, at least 30 different video display units ( 70 ) are provided, each of which operates for 1 second. This corresponds to the North American and Japanese conditions, where there are 30 video frames per second. If the response time of the video players is slower, the number of video display units ( 70 ) must be increased so that the same
Video frame response frequency per second occurs, while similarly, with faster video player response times, fewer video display units ( 70 ) are required. The number of video display units ( 70 ) can also be increased to allow multiple access to the same data that is often requested or to provide a wider range of data in the database.

Referring now to Figs. 2 and 3, each of the VDU controllers ( 71 ) is connected to the central processing unit ( 60 ) which suitably initiates activation of the corresponding VDU controller ( 71 ) of each video display unit. The VDU controller ( 71 ) places the node frame memory address on the given video frame for passage through the vertical blanking switch ( 80 ). The distributor ( 85 ) then selects this video frame on command from the VDU controller ( 71 ) for transmission by the vertical blanking switch ( 80 ) to the section cable ( 21 ).

From the foregoing, it is clearly apparent that, in accordance with the preferred embodiment of the invention, there are at least 30 video display units ( 70 ), each with its associated VDU controller ( 71 ), video player ( 73 ), audio frequency frame memories ( 75 ), tunable AM transmitters ( 76 ), graphic decoders ( 77 ), video combiners ( 78 ) and RGB / composite converters and node address input device ( 79 ). The outputs from all RGB / composite converters and node address input devices ( 79 ) within the number of video display units ( 70 ) open together at their respective individual input channels of the vertical blanking switch ( 80 ). Each of the 30 VDU controllers ( 71 ) has its individual input line ( 66 ), which is addressed by the central unit ( 60 ).

From the above explanation it follows that the distributor ( 85 ) communicates with each VDU controller ( 71 ) in each VDU ( 70 ) and coordinates the passage of each video frame from the input channels ( 79 ') to the output channel ( 80 '). The distributor therefore receives a "march pulse" from the corresponding VDU controller ( 71 ) and delivers an "executed" pulse to the same VDU controller after the video frame has passed through the vertical blanking switch ( 80 ). The VDU controller ( 71 ) then issues the accompanying audio frequency message, which is associated with the video frame just output. The cycle is repeated every 1/30 second so that different video display units ( 70 ) are able to send their individually addressed video frames through the vertical blanking switch ( 80 ) and then deliver the audio frequency message associated with each video frame.

At each of the number of nodes ( 25 ) along the section cable ( 21 ) there is a multiple node frame memory ( 30 ), corresponding to FIGS. 1 and 4. The multiple node frame memory ( 30 ) consists of a single control module ( 90 ) and a node frame memory module ( 95 ) or more thereof, each of the node frame memory modules ( 95 ) (n) transferring its respective output to its own distribution cable ( 31 ) (n), where (n) is an integer, 1, 2, 3 or 4 or greater Number, corresponding to the number of distribution cables. It can therefore be seen that for each node ( 25 ) the minimum equipment for a multiple node frame memory ( 30 ) comprises a single control module ( 90 ) and a single node frame memory module ( 95 ).

Reference is now made to the control module ( 90 ) which contains a tuner ( 94 ) which is tuned to a specific preselected channel frequency f (v) which represents its input from the section cable ( 21 ). Parallel to the tuner ( 94 ) is a comb filter or a channel blocking element ( 93 ) which, as its output ( 93 '), allows all other channel frequencies of the section cable ( 21 ) to pass through, except f (v). The output ( 93 ') of the channel blocking element ( 93 ) is routed to the output lines of all node frame memory modules ( 95 ) within the frame memory ( 30 ), as will be described below.

The output of the tuner ( 94 ) determines the channel f (v). This output goes to a clock generator ( 92 ) which has two outputs for each of the node frame memory modules ( 95 ). The first output is a clock output along line ( 92 ') to each video frame store ( 210 ). The second output is for gate pulses for vertical synchronization along the line ( 92 '') to each of the vertical blanking gates assigned ( 220 ) (VBI gate). The clock pulse can be any suitable multiple of the horizontal synchronizing pulse in channel f (v).

Reference is now made to a single node frame memory module ( 95 ) that includes two conduction paths, an audio frequency conduction path and a video conduction path. The audio frequency line path is parallel to the tuner ( 94 ) and consists of an AM radio frequency receiver ( 110 ) with a fixed tuned frequency f (ax). The input of the receiver ( 110 ) is directly connected to the line cable ( 21 ), and the output of the receiver ( 110 ) is a rectified audio frequency which is fed along the line ( 100 ) to the input of the modulator ( 300 ), the output frequency of which reconstructs a Channel f (v) represents. This f (v) output is fed along the line ( 300 ') to a high-frequency combiner ( 400 ) which has a further input which is formed by the output of the channel blocking element ( 93 ). The line ( 93 ') therefore transmits to the combiner ( 400 ) all channels that were present on the section cable ( 21 ), with the exception of channel f (v). The video line ( 94 ') of the node frame memory module ( 95 ) contains a video frame memory ( 210 ), the output of which consists of stored video frames which pass along the line ( 210 ') to the modulator ( 300 ). The audio frequency and video inputs to the modulator are mixed, causing the audio frequency input to become an FM audio frequency subband of channel f (v), while the video input becomes the video subband of the same channel f (v); the modulator ( 300 ) supplies a channel f (v) to one of the inputs of the combiner ( 400 ). The output of the combiner ( 400 ) is the secondary path, namely the distribution cable ( 31 ), which carries the reconstructed channel f (v), and all the other channels of the section cable ( 21 ).

In order to achieve the above, the gate ( 220 ) (VBI gate) assigned to the vertical blanking gap is led with its output ( 220 ′) as one of the inputs to the video frame memory ( 210 ). All video frame memories ( 210 ) have as an additional input the output of the tuner ( 94 ) along the line ( 94 '). Each of the individual VBI gates ( 220 ) of each node frame memory module ( 95 ) (n) has a unique address, if the corresponding scan line in the vertical blanking interval contains this address, the VBI gate ( 220 (1)) as an example taken, causing its video frame store ( 210 (1)) to "store" that video frame located at the output of the tuner ( 94 ). The immediately next vertical blanking interval at the output of the tuner ( 94 ) contains an address that differs from the address for the VBI gate ( 220 (1)) and this video frame is therefore not accepted by the VBI gate ( 220 (1)) . The video frame, which is once stored in the video frame memory ( 210 (1)), is continuously fed 30 × per second on the video line ( 210 ′) to the modulator ( 300 ) and then, as described above, on the distribution cable ( 31 ( 1)) forwarded.

Each of the number of node frame memory modules ( 95 ) (n) has its AM receiver ( 110 ) permanently tuned to a single radio frequency f (ax) and has assigned a single address to the VBI gate ( 220 ). A suitable table of AM radio frequency receiver frequencies of the frame memory module ( 95 ) (n) and the address of each of the VBI gates ( 220 ) in each node frame memory module ( 95 ) (n) are in the CATV hub ( 20 ) within the central unit ( 60 ) stored in the central control unit ( 28 ).

In summary, it applies that if the subscriber makes a call on his telephone ( 48 ) to the central control unit ( 28 ), this call goes directly to the central unit ( 60 ) via one of the telephone management units ( 65 ) if he has a keypad telephone. If the subscriber does not have a button telephone, a converter can convert the pulses into touch characters, or another device could be used to record the necessary commands and to enter them in the central unit ( 60 ). The participant may wish to go through various goods offered by different sellers. The various catalogs of these sellers are entered as single frames in the video playback devices and, if desired, coupled with audio frequency frames. If the central unit ( 60 ) activates a video screen unit ( 70 ), the associated video player ( 73 ) is activated in order to extract the necessary video frames and the associated audio frequency frame or the associated audio frequency frames. As previously explained, the video frame reaches the vertical blanking switch ( 80 ). At the modulator ( 81 ), the full video image is pressed onto a preselected channel f (v), for example the channel ( 35 ), and finally passed on to the section cable ( 21 ). Thus, the output of all video display units ( 70 ) on a given channel is f (v). In this way, 30 different frames can be transmitted in the CATV by means of the video display units ( 70 ) every given second, if for example the North American and Japanese television transmission standards are used. The audio frequency frame associated with each video frame or the associated audio frequency frames are converted into amplitude-modulated audio frequencies and transmitted on the line cable ( 21 ) with a discrete frequency f (ax) which is not used in any other way for the video channels.

Referring to Fig. 5A, an alternative to transmitting the audio frequencies for the video player ( 73 ) is to transmit the audio frequency frame along line ( 73 ') as compressed audio in the electronic format of a video frame. According to Fig. 5B is located in the node frame store (95) a Tonfrequenzvollbildspeicher (75), which replaces the AM radio frequency receiver (110). This application avoided the need to provide transmitters ( 76 ) in the video display units ( 70 ) and a radio frequency receiver ( 110 ) in the node frame memory ( 95 ). Thus, the audio frequency frame from the video player ( 73 ) along the line ( 73 ') every 1/30 second to a frame switch ( 74 ), which allows the individual passage of video frames or audio frequency frames. The full screen switch ( 74 ) is controlled by the VDU controller ( 71 ) via the line ( 716 ). Since the audio frequency frames must now also be addressed with a single address in their vertical blanking interval, the node address input device ( 790 ), which was previously part of the RGB / composite converter and the node address input device ( 79 ), is now moved and behind the Full screen switch ( 74 ) arranged along the line ( 74 '). The node address input device ( 790 ) inserts the corresponding single address into both the video frames and the audio frames. Both the video frames and the audio frequency frames are then transmitted from the node address input device ( 790 ) along the line ( 790 ') to the single input of the vertical blanking switch ( 80 ) and pass from there via its output ( 80 ') via the video modulator and not shown along the section cable ( 21 ) to the multi-node frame store ( 30 ). The multiple node frame memory ( 30 ) has its control module ( 90 ) in accordance with FIG. 4, however the node frame memory module ( 95 ) is designed according to FIG. 5B and comprises the audio frequency frame memory ( 75 ), which as input the output of the tuner ( 94 ), and, in parallel, the VBI gate ( 220 ), which performs the same function for the audio frequency frame memory as the VBI gate ( 220 ) for the video frame memory. The output of the audio frequency frame memory ( 75 ) consists of analog audio frequency values and is guided along the line ( 75 ') to the modulator ( 300 ) and thus to the combiner ( 400 ) and, as before, combined with all channels and outputs in the distribution cable ( 31 ).

As an alternative, it is not necessary to use the tonfre quenz on the same line as the video frames to transmit, but it can be done through that Transfer the telephone system to the subscriber's telephone or any other transmission device.

As far as the invention is concerned in general, it is obvious to a person skilled in the art that the node frame storage module ( 95 ) can be arranged on the node ( 25 ), but it could just as well be done on the subscriber's television set ( 45 ).

Reference is made to FIG. 6A, in which the instruction scheme represents an operating cycle of the central unit ( 60 ) in the central control unit ( 28 ). The box ( 1 ) is an ON / OFF switching device. The box ( 2 ) receives the output of the telephone management units ( 65 ) as an input. If a telephone call is received from the subscriber, box ( 3 ) asks the subscriber to use a voice generated by a computer to enter the subscriber identification number by pressing the corresponding keys on his key telephone. Regarding the decision box ( 4 ), if the node frame memory ( 95 ) serving the subscriber concerned is occupied, the subscriber is placed in a callback queue ( 5 ) until the node frame memory is available. If the subscriber node frame memory is available, box ( 6 ), the subscriber interaction mode is initiated, as will subsequently be explained in connection with FIG. 6B. If the subscriber has finished his data request, box ( 7 ) provides a "thank you" full screen on the subscriber's screen and disconnects the call. Box ( 8 ) asks whether another subscriber has been put on the callback queue: If so, this subscriber is called and notified that the service is calling back and the sequence is initiated again in box ( 3 ). If no other subscriber is in the callback queue, box ( 9 ) provides a "system ready" message to the subscriber's node frame memory and goes back to box ( 2 ) to wait for a new incoming subscriber call.

Referring to Fig. 6B, this shows an operational cycle within box ( 6 ), namely the subscriber interaction mode. If the node frame memory ( 95 ) of the subscriber is available, the box ( 6-1 ) places the introductory frame identifier on the main index page. Box ( 6-2 ) selects the frame data for the next frame from the central unit memory (either main index page or a frame requested by the subscriber in box ( 6-7 )). Box ( 6-3 ) then transmits the full screen data of the VDU ( 70 ) and waits for a subscriber request. If there is a request, decision box ( 6-4 ) causes box ( 6-6 ) to record the original request for statistical purposes, then box ( 6-7 ) determines the identity of the next requested frame and begins the cycle again on the box ( 6-2 ). If there are no further requests there, box ( 6-4 ) instructs decision box ( 6-5 ) to wait a predetermined amount of time and then time out, and the cycle is started again at box ( 7 ) in Fig. 6A.

Referring to Fig. 7A, the command scheme represents an operational cycle of the VDU controller ( 71 ) in the video display unit ( 70 ). Box ( 1 ) is an "ON / OFF" switch. Box ( 2 ) receives commands from central processing unit ( 60 ) (box ( 6 ) in Fig. 6A) and upon receiving a command, decision box ( 3 ) sends that command to box ( 4 ). Box ( 4 ) selects an unused audio frame store ( 75 ) (n) within the video display unit ( 70 ) and tunes its transmitter ( 76 ) to the frequency assigned to the node frame store ( 95 ). Box ( 5 ) then queries the image plate on the video player ( 73 ) within the video display unit ( 70 ) for the audio frequency frame or the audio frequency frames that belong to the subscriber request and transmits the frame or the frames to the previously selected audio frequency frame memory ( 75 ) (n). The box ( 6 ) then queries the image plate for the video frame requested by the subscriber and also loads each associated graphic into the graphic decoder ( 77 ). The box ( 7 ) then transmits the video frame into the track cable as a "normal" priority. "Normal" priority is used when the frame requested by the participant is the first frame of a series of frames forming a presentation. "High" priority is used when the requested frame is the second, third, etc. frame within a presentation - the transmission of such frames has priority over frames with normal priority, so that the continuity of the presentation is kept in sync with the audio frequency message. (Box ( 7 ) is subsequently described in more detail in Fig. 7.) Once the video frame has been transmitted, box ( 8 ) transmits the audio frequency values to the section cable. Decision box ( 9 ) asks whether additional video frames should be transmitted as part of the presentation. If not, box ( 10 ) waits for the end of the audio frequency message or receipt of a termination message from the subscriber and box ( 13 ) sends an "end of presentation" message to central unit ( 60 ) and the cycle is repeated on box ( 2 ) initiated. If there are several video frames in the presentation in the decision box ( 9 ), the box ( 11 ) either waits for the beginning of the next video frame (frame change) or for receiving an abort command from the participant. If an abort command is received, the decision box ( 12 ) causes box ( 13 ) to send an "end of presentation" message to central unit ( 60 ) and begin the cycle again in box ( 2 ). If a frame change message is received, the decision box ( 12 ) causes the box ( 14 ) to search for the next video frame in the presentation and to load its graphic into the graphic decoder. Box ( 15 ) then transmits that "high" priority video frame to maintain the continuity of the presentation, and the cycle is initiated again at decision box ( 9 ) and continues until the presentation ends or is canceled.

Referring to FIG. 7B, boxes ( 7 , 15 ) of FIG. 7A belonging to the "transmit frame" series begin their internal operation at box (T-1) by adding the node's frame store address to the RGB / composite converter and the node address input device ( 79 ) is loaded. Box (T-2) starts the transmission request with the specified priority (box ( 7 ) = "normal", box ( 15 ) = "high"). Box (T-3) waits for a transfer confirmation response from the distributor ( 85 ) in the vertical blanking switch ( 80 ). If the confirmation in box (T-4) was received, the frame was sent and the cycle extended from box ( 7 ) to box ( 8 ) if normal priority was given, or from box ( 15 ) to box ( 9 ), if there is high priority.

Claims (5)

1. Node frame memory for storing a television still image in a cable television system for selectively distributing pre-recorded television still images, each consisting of at least one video field composed of a number of scan lines corresponding to a vertical blanking interval and a number of scan lines corresponding to the image information , With
a frame memory ( 210 ) for storing a television still image,
a processing unit ( 220 ) for detecting an inserted coded address of the television still images transmitted to the account frame memory and for activating the frame memory ( 210 ) for storing the television still image when the detected coded address and an address assigned to the node frame memory and
a device ( 300 ', 400 ) for modulating and transmitting the stored television still image via a distribution cable ( 31 ) assigned to the full-frame memory of the cable television system. 2. node frame memory according to claim 1, marked by a device for detecting an audio frequency, the with the television still image the node frame memory is transmitted, and for the transmission of the audio frequency via the one assigned to the full-screen account store Distribution cable. A node frame memory according to claim 1 or 2, characterized by a television tuner ( 94 ) for passing video images transmitted to the node frame memory in a predetermined range of channel frequencies, and a channel blocking member ( 93 ) which is parallel to the television tuner to close the channel lock on which the television still images are transmitted to the node frame memory while other channel frequencies are passed to the distribution cable. 4. node frame memory according to claim 1, 2 or 3, characterized by a high-frequency receiver ( 110 ) for receiving the television still images and video images transmitted to the node frame memory. 5. node frame memory according to claim 1, 2, 3 or 4, marked by an audio frequency memory for storing a Tone frequency that matches the TV still Node frame memory is transferred.