WO1999020044A1

WO1999020044A1 - Multiple head signal distribution method and apparatus

Info

Publication number: WO1999020044A1
Application number: PCT/US1998/012070
Authority: WO
Inventors: George S. Fan
Original assignee: Fan George S
Priority date: 1997-10-10
Filing date: 1998-06-09
Publication date: 1999-04-22
Also published as: AU7835098A

Abstract

The invention is a multiple head signal distribution system, for recording and reading a program signal feed (35) onto a disk (33), comprising a multiple head disk unit (30), a main switch (42) having a plurality of channel inputs (44), and a decoder (14). The multiple head disk unit (30) has a record head (31) for writing the program signal feed (35) to the disk (33), and a plurality of read heads (32) disposed along radial read head paths for reading the disk (33). The read heads each produce a read head outputs (34) which are assigned to discrete channel inputs (44) on the main switch (42). A subscriber selects a program at the decoder (14). A read head (32) is assigned to the subscriber, the read head (32) producing a subscriber signal that is transmitted to the decoder (14) for viewing by the subscriber.

Description

MULTIPLE HEAD SIGNAL DISTRIBUTION METHOD AND APPARATUS

BACKGROUND OF THE INVENTION

The invention relates to a multiple head signal distribution system. More particularly, the invention relates to a system in which an information bearing disk is recorded, and then is read with a plurality of staggered heads, for reading the same information at delayed intervals. Typically such system is described in applicant copending application entitled: MULTIPLE HEAD SIGNAL DISTRIBUTION SYSTEM, Agents Doc. No.FANG33A, filed in the U.S. PTO on or about Feb. 03, 1995.

The demand for information services, especially movie and audio programs has increased dramatically. In the last few decades, the American public has outgrown the few viewing options offered by broadcast TV. They have demanded the ability to choose from a large variety of programming options.

Further, the viewing consumer wants to watch the program of their choice, and they want to watch it at a convenient time. Often, it is not possible to arrange one's life around the scheduled program start times. What is desired is the ability to watch the program at the desired start time.

The popularity of videocassette rentals has stemmed from the ability to choose from a large variety of movies, and then watch them when desired. However, renting videocassettes has its shortcomings. One must travel to the video store not only to select a program to watch, but also to return the videocassette the next day.

Pay-per-view programs have gained in popularity in part because of their convenience. However, they have three main shortcomings: selection, inconvenient start times, and inability to "stop" the program when the viewer is interrupted. From the random accessibility of videocassettes, viewers have grown accustomed to watching a program when they wish, and to having the ability to pause or rewind the program when they are interrupted during its play. Pay-per-view programs do not give the viewers this convenience. One must begin watching the pay-per-view at the scheduled time, and must either stay glued to the television set, or risk missing a portion of the show.

Others have proposed systems for delivering video programs to a viewer. U.S. Patent Nos. 4,567,512 and 4,590,516 to Abraham both disclose a recorded program communication system.

U.S. Patent No. 4,890,320 to Monslow et al discloses a television broadcast system for selective transmission of view- chosen programs at viewer-requested times. However, this system does not allow multiple viewers to view the same program with differing start times.

U.S. Patent No. 5,133,079 to Ballantyne et al discloses a method and apparatus for distribution of movies in which the video signal is compressed for transmission to a subscriber. U.S. Patent No. 5,172,413 to Bradley et al discloses a video delivery system and method in which multiple versions of the same program are transmitted, each time delayed by five minutes. However, this system requires a separate video play unit and separate copy of the program for each time delayed version of the program transmitted to the subscribers.

While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a videodisc based system which provides multiple time delayed signals to multiple viewers. It is another object of the invention to provide a videodisc system that allows a viewer to select a desired program, as well as a convenient start time.

It is further object of the invention to provide a videodisc system that allows a viewer to conveniently access a particular program at a particular start time from a remote controller, wherein the selected program is then fed to a television at the viewer's location.

It is a still further object of the invention to produce a videodisc system in which the disk is recorded with a single record head, and is read by a plurality of reading heads spaced at fixed angles, the relative radial position of the reading heads being continuously variable.

To the accomplishment of the above and related objects the invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like elements are depicted by like reference numerals. The drawings are briefly described as follows.

FIG 1 is a diagrammatic perspective view illustrating the instant invention in use.

FIG 2 is a block diagram illustrating the flow logic of the instant invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG 1 illustrates a television 10, attached to an interface box 12 with a decoder 14. Television programs arrive at the interface box 12, and are decoded by the decoder 14 for viewing on the television 10.

A subscriber 16 selects desired television programs with a remote controller 18.

FIG 2 illustrates a multiple start movie-on-demand system 20. A multiple-head disk unit 30 has a plurality of read heads 32, and a record head 31. The record head 31 is capable of recording a disk 33 with a program signal feed 35. The disk 33 is a videodisc, or other magnetic or optical media having a flat surface, having high storage resolution, and capable of storing large quantities of data arranged in circular paths on the surface of the disk 33.

The read heads are capable of reading the same disk 33, each producing a read head output 34. The read heads 32 are also capable of reading the disk 33 while data is being recorded onto the disk 33. The read head outputs 34 are fed into a disk controller 36. The read heads 32 are positioned along radial read paths 38 with respect to the disk 33. The position of each read head 32 along its radial read path 38 is controlled by the disk controller 36.

The read head outputs 34 are combined in the disk controller 36 into a disk controller output 40.

A main switch 42 has a plurality of channel inputs 44. Discrete read head outputs 34 present in the disk controller output 40 are individually fed into several of the channel inputs 44. A control channel is connected between the decoder 14 and the multiple head disk unit 30 for allowing the subscriber to control the operation of the multiple head disk unit 30 from the decoder 14.

To select a particular program, the subscriber presses appropriate buttons 50 on the remote controller 18. The remote controller transmits an infrared signal 52 that is received by an infrared receiver 54 on the decoder 14. The decoder sends a particular program request along a control channel 56, which propagates through the interface box 12 , through the main switch 42, and to the disk controller 36. In accordance with the selection, the disk controller 36 will assign one the read heads 32, e.g. a first read head, to the subscriber. If there are read heads 32 that are currently not in use at the multiple head disk unit 30, the first read head 32 will be under the control of the subscriber. Thus, if the subscriber desires to watch the selected program from the beginning, the assigned read head 32 will move along its read head path 38 to a point on the disk 33 where the record head 31 began recording. Advantageously, the read heads 32 can be engaged while the record head is still recording the program signal feed to the disk. The read head output 34 produces a subscriber signal from the first read head 32, which is fed into one of the channel inputs 44. All channel inputs 44 are combined using an encoding technique well known to those skilled in the art, such as time or frequency division multiplexing, and are transmitted to the subscriber with a multiplexed local cable 60, which reaches the decoder 14 through the interface box 12. The multiplexed local cable 60 is decoded by the decoder 14 to extract the subscriber signal, which is viewed on the television 10. After the subscriber has been viewing the subscriber signal, he might wish to pause, rewind, fast forward, or stop viewing said signal. The subscriber presses buttons 50 on the remote control 18 that correspond to pause, rewind, fast forward, or stop commands. The decoder 14 receives these commands and transmits the command to the multiple head unit

30. The multiple head unit 30 alters the movement of the read head 32 assigned to the subscriber according to the command selected. Advantageously, the read head 32 can retrace data previously read to effect a "rewind" function; the read head 32 can skip data to effect a "fast forward" function; the read head 32 can momentarily freeze along its radial path 38 until signaled to continue, to effect a "pause" function; or the read head 32 can stop its movement until reassigned to another subscriber, to effect a "stop" function.

In accordance with the foregoing system, a second subscriber and indeed multiple subscribers can be accommodated. A second decoder is associated with the second subscriber and is present at the location of the second subscriber. When the second subscriber requests the program, a second read head 32 is assigned to the second subscriber, and produces a second subscriber signal. The second subscriber signal is fed into a discrete channel input 44 in the main switch 42, and is encoded alongside the subscriber signal from the first read head 32. The second subscriber signal is extracted by the second decoder from the local multiplexed cable, and is viewed by the second subscriber on a second subscriber television. Furthermore, at least one multiple head disk unit 30 is to be used according to the present invention. However, several multiple head disk units 30 can be employed, each linked to some of the channel inputs 44 on the main switch 42. In this way, several programs can be selectively viewed by subscribers in real time, or at time-delayed intervals.

In conclusion, herein is presented a system for allowing multiple subscribers to view a selected program, or selected programs, the viewing beginning at different start times.

Claims

CLAIMSWhat is claimed is:

1. A signal distribution method, for recording and reading a program signal feed to a disk, having at least one multiple head disk unit having a record head and a plurality of read heads each having a read head output and a radial read path, the read heads including a first read head and a second read head, a main switch having a plurality of channel inputs, a decoder, a multiplexed local cable connecting the decoder and the main switch, and a television connected to the decoder, comprising the steps of: a) recording the program signal feed to the disk with the record head; b) selecting a program at the decoder that corresponds to the program signal feed; c) transmitting a selected program request from the decoder to the multiple head disk unit on a control channel ; d) assigning a first read head to read the disk for the subscriber; e) reading the disk with the first read head to produce a subscriber signal while the step of recording is still being performed; f) transmitting the subscriber signal to the decoder; and g) viewing the subscriber signal on the television.

2. The method as recited in claim 1, wherein the step of transmitting the subscriber signal further comprises: a) feeding the subscriber signal into one of the channel inputs; b) encoding the subscriber signal into a multiplexed local cable; and c) extracting the subscriber signal from the multiplexed local cable at the decoder.

3. The method as recited in claim 2, further comprising the step of: a) selecting at the decoder a command selected from pausing, rewinding, fast forwarding, and stopping the subscriber signal; b) transmitting the command to the multiple head disk unit; c) altering the movement of the first read head along its radial path according to the command.

4. The method as recited in claim 3 , further comprising the step of: a) selecting by a second subscriber the program that corresponds to the program signal feed; b) assigning the second read head to read the disk for the second subscriber; c) reading the disk with the second read head to produce a second subscriber signal while the step of reading the disk with the first read head is still being performed ; and d) transmitting the second subscriber signal to the second subscriber for viewing.

5. A multiple disk signal distribution system, for recording and reading a disk to provide a subscriber signal to a subscriber from a program signal feed, comprising: a) at least one multiple head disk unit, having: i) a disk, ii) a record head for writing the program signal feed to the disk, and iii) a plurality of read heads that read the disk including a first read head, each read head having a radial read head path and having a read head output, the read heads including a first read head which produces a subscriber signal; b) a main switch, having a plurality of channel inputs, the read head outputs assigned to discrete channel inputs, the subscriber signal assigned to one of the channel inputs, the main switch having a local multiplexed cable, the main switch encoding the channel inputs into the local multiplexed cable; c) a decoder associated with the subscriber that is connected to the local multiplexed cable, the decoder extracting the subscriber signal from the local multiplexed cable; and d) a television for viewing the subscriber signal, the television being where the subscriber is located.

6. The apparatus as recited in claim 5, wherein a second subscriber views the program signal feed, further comprising: a) a second decoder associated with the second subscriber; and b) the read heads including a second read head assigned to the second subscriber, the second read head producing a second subscriber signal that is fed into a discrete channel input, the second decoder extracting the second subscriber signal for viewing by the second subscriber.

7. The apparatus as recited in claim 6, further comprising a control channel, attached between the decoder and the multiple head disk unit, for allowing the decoder to control the operation of the multiple head disk unit.