GB2280983A - A video tape duplicator with endless loop master tape storage and loading - Google Patents

Abstract

A tension controlled endless tape loop apparatus for use with a high speed video tape duplicator 11 which includes a master tape storage bin 12 for accumulating and storing a length of master video tape in endless loop form for repeated duplication onto a copy tape supplied by the video tape duplicator. Tension controllers, such as vacuum columns 61, 62 provide the master tape at a pre-determined high constant tension to the video tape duplicator 11. Leader tape is spliced to the master tape and used to load the master tape into the master tape storage bin 12 and into the video duplicator 11. An ionizer (fig 8, 75) neutralizes static charges on the master tape and avoids the need to use cleaning tapes. The tension control vacuum columns avoid the need to use a drive tape to pull the master tape and copy tape through the transfer drum of the duplicator. <IMAGE>

Description

PRECISION TENSION CONTROLLED MOP LOOP TAPE APPARATUS FOR USE WTTH A HIGH SPEED VIDEO TAPE DUPLICATOR Technical Field and Background of the Invention This invention relates to a precision tension controlled loop tape apparatus for use with a high speed video tape duplicator. specifically, the loop tape apparatus is intended for use with a Sony high speed contact printing duplicator, sometimes referred to as a "Sprinter", The Sony Sprinter is a well-deaigned, well-known and widely used video duplicator. It can duplicate tapes at up to 150 times real-time, and provides an alternative to using hundreds of conventional video tape recorders to reproduce tape at real time. weever extensive field use has revealed a number of drawbacks inherent jn the way the master tape is handled on the Sony Sprinter. This has primarily to do with the way the vaster tape is used to effect the contact printing of the signals onto the copy tape.

High speed contact printing takes advantage of the fact that a copy can be made of a magnetic tape recording by pressing the recorded surface of the recording (the "master") into intimate contact with the unagnetized surface of a copy tape, applying an AC field of a given value to the mated tapes, decreasing the field gradually over many cycles to zero, and finally separating the copy from the master. The copy tape is agnetized in a mirror : tzge replica of the master The Sony Sprinter works according to this principle. Usually, a drive tape is used to propel the aster tape and the copy tape through the print drum of the duplicator, although the Sony HSP 800 uses no drive tape. Also, e Sony HSP 800 uses a horizontal loop tape bin to hold the master tape.

The master tape on the Sony Sprinter is wound from a supply reel to a take-up reel as a single copy is made . As noted above, this copy may be made at up to 150 times real time, or about 4.5 miser. However, after each pass of the master tape, it must be re-wound from the take-up reel to the supply reel. Then the contact printing process takes place again. Since no copying can occur during rewind, the effective copying rate is reduced from 150 times real tive to about 80 times real time.

Eitforts have been trade tc increase the efficiency ky placing multiple copies of the program to be copied onto a single master tape. For example, a 30 minute video at 2.02 s/min. will take up 60 meters of video tape. Since a master reel can hold up to 400 meters of tape six copies of the program can be placed end- to-end on the single master tape. This has the effect of reducing the rewind time substantially, since six copies can be made between re-winds.

However, there are disadvantages to this practice, as well.

First, the mister tape is much longer and re-winding the tape takes longer per occurrence, so that the saving in re-wind time is not proportional to the number of copies contained on a single master tape.

Second, master tape is expensive, in the range of $1*00/meter, so that mastering cost is substantially increased, Third, the mastering room is tied up six tines as long preparing a single waster tape.

Fourth, because the waster tape contains six copies, quality control cannot be reliably carried out by checking one copy of the program and assuming that all of the other copies are good Since at least one copy from each of the programs on the master must be checked for quality control1 the cost of quality control is substantially increased.

There are other problems with the use of a re-wind master tape regardless of how many programs are contained, on the master tape. Even though efforts are generally made to maintain a clean environment for the duplicating process, dust and other small debris particles invariably find their way onto the waster tape during multiple repetitions of winding and ra.winding the master tape. Zn addition, the copy tape also contains debris in the form of edge particles resulting from the slitting of the tape into video-tape widths from much wider widths. When wound onto a reel of tape (called a '1pancake11), these edge particles cling to or are trapped on the edge of the copy tape. During operation of the conventional Sony Sprinter, debris from the copy tape is pushed into the surface of the master tape during contact as duplication takes place This causes a dent or bubble in the master tape.

When the master tape is rewound between copying steps, the packer wheels on the Sprinter press the debris into the master tape.

These dents and bubbles cannot be pressed completely out by the air pressure which presses the master tape into contact with the copy tape The very slight gap between the copy tape and the master tape causes a drop-out in the copy tape, The number and severity of these drop-outs increase as the master is used, until quality of the copy tape reaches an unacceptable level and the master tape inust be replaced In fact, the master tape as used on a conventional Sprinter does not wear out, but degrades in quality to the point ere it must be replaéd.

Tape cleaning on the conventional Sony Sprinter is also deficient. conventionally, cleaning tapes are provided to engage the magnetic tape and theoretically to remove dust and debris from the master tape. The conventi=al Sany Sprinter provides a separate cleaning tape for each of the copy tape, master tape and drive tape. The cleaning tape is a "lint-free" nonwoven paper tape intended to remove dust from the surface of the tape to be cleaned without damaging the tape surface. However, it is known that any cleaning tape brought into contact with another surface will create some abrasion, no matter how slight. Furthermore, it has been determined that cleaning tapes can create a static electrical charge in the tape being cleaned which actually causes the justcleaned tape to attract nearby particles.

These drawbacks in an otherwise superbly-engineered duplicator have been eliminated by use of a separate apparatus which Connects to the Sprinter and replaces some of its functions.

Specifically, in the invention according to this application the drive tape has been elitinated, and the master tape is no longer wound onto itself for duplication and during re-wind between duplication steps. This prevents debris from being pressed into the surface of the tape.

A vertical loop tape bin in the form of a fftreeN has been substituted1 so that the tape removes through the duplicator in an endless process. The Sprinter is stopped only to changes copy tape pancakes. Tension is provided by a ser'ro-vaouuni col which provides gentle tension control, while the vacuum air at the same time removes dust from the tape surface and the surrounded area and delivers it to a filter for removal from the environment, Air guides have been provided on the loop tape bin so that the tape is not mechanically manipulated by.:koving parts any more than absolutely necessary. Rather, the air floats on a "bearing" of air. This air also aides in the removal of dust and debris from the master tape.

In addition, the use of cleaning tapes is eliminated and ionized air is blown onto the tape to neutralize static charges on the tape and release dust and debris held on the tape by static charges. The result is that the Sprinter according to the invention is able to duplicate video tapes at a faster net duplication ratio, while at the same time substantially increasing the useful life of the master tape and the quality of tapes duplicated on t Sunuttary of the Invention Therefore, it is an object of the invention to provide a precision tension controlled loop tape apparatus for use with a high speed video tape duplicator.

It is another object of the invention to provide a precision tension controlled laop tape apparatus which elillinates the use of a drive tape for driving the copy and master tapes during duplication on a high speed video tape duplicator.

It is another object of the invention to provide a precision tension controlled loop tape apparatus which el^inates the step of rewinding the master tape after each complete single pass of the master tape past the print drum of the high speed video tape duplicator.

Tt is another object of the invention to provide a precision tension control-led loop tape apparatus which provides servo-vacuum tension control of the master tape of a high speed video tape duplicator.

It is another object of the invention to provide a precision tension controlled loop tape pparatus which provides an vacuum tension-controlled endless loop tape bin for use with a high speed video tape duplicator.

It is another object of the invention to provide a precision tension controlled loop tape apparatus which provides a means for autoaticalIy loading the master tape of a high speed video tape duplicator onto a vertical endless loop tape bin without manual handling of the master tape.

It is another object of the invention to provide a precision tension controlled loop tape apparatus for a high speed video tape duplicator which cleans the master tape without the use of cleaning tapes.

It is another object of the invention to provide a precision tension' controlled loop tape apparatus for a high speed video tape duplicator which uses a cloud of ionized particles entrained in a moving air stream to netitralize static charges on the master tape and blow away dust and debris previously held on the tape by those static charges.

It is another object of the invention to provide a precision tension controlled loop tape apparatus for a high speed video tape duplicator which uses air guides to manipulate the tape through the loop tape bin so that mechanical manipulation of the tape is reduced.

These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a precision tension controlled loop tape apparatus for use with a high speed video tape duplicator which includes a master tape storage means for accumulating and storing a length of master video tape in endless loop form for repeated duplication onto a copy tape supplied by the video tape duplicator, duplicator tension weans for providing the master tape at a pre-determined high constant tension to the video tape duplicator and leader tape loading means for splicing a leader tape to the master tape and utilizing the leader tape to load the master tape to the master tape storage means and into the video duplicator.

According to one preferred embodiment of the invention, storage tension means are provided for delivering the master tape at a pre-detereined low constant tension to the waster tape storage means.

According to another preferred embodiment Cf the invention, wherein the video duplicator comprises an AC bias magnetic contact printing apparatus According to yet another preferred embodiment of the invention, the apparatus includes capstan means for supplying the master tape ta the video duplicator at a constant speed.

According to yet another preferred enbodinent of the invention, the duplicator storage means and the storage tension means each include respective vacuum columns supplied with negative air pressure for exerting a pre-determined hold-hacX tension on master tape in the respective vacuum column.

According to one preferred embodiment of the invention, wherein the leader tape loading means includes a master tape supply reel for supplying master tape, a master tape take-up reel supplying leader tape for splicing to the head end of the master tape and for re.ceiving master tape from the master supply reel, splicing means for splicing the leader tape to the head end of the master taper and rewind tension means for controlling the tension of the master tape as it is supplied and taken-up by the master tape supply reel and the master tape take-up reels.

Preferably, the rewind tension means comprises a vacuum column supplied with negative air pressure for exerting a pre determined hold-bact tension on master tape in the vacuum column.

Preferably, the storage means comprises an endless loop magnetic tape tree having pairs of tape bearings carried by opposing ends of a plurality of support beams.

According to one preferred embodiment of the invention, the tape bearings comprise wicro-gas-porous powdered petal bearing supports, and the storage means includes a pressurized air supply for supplying pressurized air to the powdered metal bearing supports to create a cushion of air on the outer surface of the powdered metal bearing defining a non-contact bearing support for the master tape as it passes though the storage means.

According to another preferred embodiment of the invention, ionizing means are provided for delivering a cloua of ionized air onto the master tape as it passes through the master tape storage means for simultaneously neutralizing static charges on the surface of the master tape and blowing contaminants attracted by the static charges away fot the surface of the taster tape.

According to yet another preferred embodiment of the invention, the duplicator tension means comprises a vacuum column positioned downstream in the master tape path of travel from the ionizing means. The vacuum column is supplied with negative air pressure for exerting a pre-determined hold-back tension on master tape in the vacuum column and For removing charge-neutralized contaminants on the master tape ater the master tape has passed through the cloud of ionized air from the ionizing means.

According to yet another preferred embodiment of the invention, the features of the loop-tape apparatus are combined with a high speed video tape duplicator.

Brief Description of the Drawings Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the invention proceeds when taken in conjunction with the following drawings, in which: Fire 1 is a prior art Sony "Sprinter" high speed video duplicator ; Figure 2 is a schematic flow diagram of a high speed lic2ticn process according to an embodiment of the invention; Figure 3 is a front elevation of a high speed video tape duplicator with a precision tension controlled loop tape apparatus according to an embodiment of the invention with the precision tension controlled loop tape apparatus in a first position master loading mode; Figure d is a front elevation of a high speed video tape duplicator with a precision tension controlled loop tape apparatus according to an embodiment of the invention with the precision tension controlled loop tape apparatus in a second position master loading mode; Figure 5 is a front elevation of a high speed video tape duplicator with a precision tension controlled loop tape apparatus according to an embodiment of the invention in the duplicating modes Figure 6 is a perspective view of the high speed video tape duplicator and precision tension controlled loop tape apparatus; Figure 7 is a schematic front elevation of the contact printing apparatus of the high speed video tape duplicator; Figure 8 is an enlarged fragmentary view of the precision tension controlled loop tape apparatus according to an embodiment of the invention showing operation of the ionizing apparatus; Figure 9 is a side elevation of an air bearing tape guide on the loop tape bin; and Figure 10 is a cross-section of the air bearing tape guide shown in Figure 9 Description of the Preferred Embodiment and Best Mode Prior At Sony High peed Duplicator Referring now specifically to the drawings, a prior art Sony "Sprinter" high speed video tape duplicator is shown in Figure 1. To avoid conflict with the description of elements with regard to the embodiments of the invention, description of the prior art duplicator is provided without reference nuerals, but instead with text labels.

The Sony high speed duplicator has a copy tape supply reel and a copy tape take-up reel. The blank copy tape from the copy tape supply reel is fed through a series of controllers and guides and to a print drum where recording by contact printing takes place. Recorded copy tape passes through another series of tension controllers and guides and is wound onto the copy tape take-up reel.

A master tape supply reel holds the mirror mother master tape and delivers the master tape to the print drwm where contact print duplication takes place, The recorded tape is then delivered to the master tape take-up reel. A drive tape supply and take-up reel deliver a drive tape to the print drum. The drive tape is driver, and drives the master tape and copy tape with it, thus keeping tension on the master and copy tapes law.

A significant feature of the prior art Sony Sprinter is the requirement that the mirror mother master tape be rewound after each pass of the mirror mother aster tape past the print drum, as described above. Likevise, the drive tape must be rewound. Also, cleaning takes place by the use of non-woven cleaning tape which is contained on cleaning tape supply and take-up rolls tor both the copy tape and mirror mother master tape. A more detailed description of the Sony "Sprinter" High Speed Duplicating Systam is described in a publication by Sony corporation, copyright 1984, entitled "Sony Sprinter Sigh Speed Duplicating System".

Description of Overall video Duplication Process Referring now specifically to the drawings, a loop tape duplicator LO according to the present invention is illustrated in Figure 2 and shown generally at reference numeral 10.

For convenience, the high speed video tape duplicator with a precision tension controlled loop tape apparatus 10 according to the present invention will be referred to below as "loop tape duplicator 1011, and it will be understood that reference to "loop tape duplicator ion refers to the combination of a modified Sony "Sprinter" high speed duplicator 11 and a loop tape storage apparatus 12, as described below.

As is shown in Figure 2, the loop tape duplicator 10 is an integral part of a duplication process which begins with a prerecorded one inch master tape 13 which is played back on a one inCh-type "C" format master video tape recorder (VTR) 14. The play-back signal is supplied to a mirror mother vTR 15 where the signal from VTR 14 is recorded on blank one-half inch "mirror mother" master tape 16. The recorded mirror mother master tape 17 which results when the blank mirror mother master tape 16 is magnetized with signals from the VTR 14 is called the "mirror mother" master tape because the track pattern is reproduced onto the tape 16 as a mirror image of the master tape 13 and of the final recordings which will be duplicated fron the mirror mother master tape 17. Aphis is a requIreent since during duplication the metal-coated side of the tape holding the video signal must be mated to the coated side of the copy tape.

These procedures are conventional and are used in the conventional operation of the Sony Sprinter.

To maintain its magnetism during many multiple duplication passes, the recorded mirror mother master tape 17 (referred to below as "master tape lvnl is a special high coercivity metal tape, such as Bony Y-1/2N-4X metal tape. The recorded master tape 17 is then loaded into a loop tape bin 12 and threaded onto the Sony ''Sprinter" high speed printer 11 with its coated surface in close contact with the coated surface of a blank copy tape 19 wound on a pancake. Copying takes place by contact printing at a print drum 20, as explained in further detail below with reference to Figure 6.

Recorded video tape 21 is wound onto a copy tape take-up pancake, When a complete pancake of recorded video tape 21 has been duplicated, it is removed and transferred to a video cassette loader 22 where lengths of the recorded video tape 21 are loaded into empty video cassettes 23, resulting in copied program video tape cassettes 24.

Detailed Description r'f w Mo5fi ed High Speed Duplicator Referring now to Figure 2, tfle high speed duplicator 11 is u modified Sony "sprinter" . The Sony Sprinter has been modified in a way which will permit operation in the conventional manner to be resumed when desired by the operator. In general, the requirement of a drive tape to drive the master tape and copy tape through the Sprinter has been eliminated altogether. As modified. the high speed duplicator 11 has a copy tape supply reel 30 and a copy tape take-up reel 31. The blank copy tape 19 is fed through a series or controllers and guides 32 and to a print drum 33 where the recording by contact printing takes place Recorded copy tape 21 passes through another series of tension controllers and guides 34 and is wound onto the copy tape take-up reel 21.

The high speed duplicator 11. retains the master tape supply and take-up reels 35 and 36, the drive tape supply and takeup reels 37 and 39 and the nain capstan/pinch roller 40 from the prior art Sony Sprinter, even tholth not used, so that, as noted above, the high speed duplicator 11 can be converted to conventional use if necessary.

Operation of + e high speed duplicator 11 is substantially enhanced by the use of a loop tape storage apparatus 12, which provides precise tension control during duplication, automated, touch-free master loading, and other advantages named below. Loop tape storage apparatus 12 is housed in a cabinet 50, which contains power supply equipment, controls, rotors and air handling equipment on the inside, and has mounted on the front panel, shown, the operating elements which cooperate with the high speed duplicator 11. These elements are a library supply reel Sl and library take-up reel 52. Reeis 51 and 52 are used to splice a length of leader tape to the master tape, and then use the leader tape to load the master tape for duplication.

The leader is easily loaded by hand since it does not matter whether it is touched. This avoids hand contact with the master tape, which will create drop-outs where the contact occurs. The leader tape reel is placed on master takeup reel 52 and rewound onto library master reel 51 through vacuum column 80. The leader is threaded by hand through a loop tape bin 55, which is formed as a tree", and which has t'io sets of outwardly extending arms 56a-d and 57a-d. These sets of arms 56a-d and 57a-d are mounted on supports 58 and 59, respectively, which are moveable relative to each other, 1. e., they spread apart or move towards each other to accomscdate a given length ot tape. Each of the arms 56a-d and 57 a-d have dividers 60 (see Figure 7) so that seven wraps of tape can be passed over each of the arms 56a-d and 57 a-d. Thus, the loop tape bin 55 can acconmodate seven times four, or 28 times the length between the two sets of arms.

Referring now to Figure 4, the 'tree", i.e., the supports 58 and 59 expand as needed to accommodate the length of the master tape.

The ''tree" supports Sa and 59, are moved towards each other as the threading operation begins. When supports 58 and 59, reach minium separation the leader tape is fed by hand through the loop tape duplicator 10, threaded through the loop tape bin, through a vacuum column 61, through the tape path of the high speed duplicator 11, past the pinch roller 40, through a vacuun.column 62 anaback across the splicing blocks of the splicer 54. The master tape to be duplicated is placed on reel 52 and rewound onto reel 51. The head end of the master tape is spliced on splicer 54 to the tail end of the leader tape, by a splicer apparatus 54 of known type, such as applicant's splicer disclosed in United States Patent Nos. 4,475,970, 4,47a,674, 4,5S1,190. An empty reel is placed on take-up reel 52. The leader tape is pulled by the capstan/pinch roller 40 though the loop tape duplicator 10. The leader tape is accumulated on the library master tape take-up reel 82. When the head end of the master tape has circuited the loop tape duplicator a0 and arrives back at the splicer 54, the take-up reel 52 stops rotating.

A vacuum holding block which, part of splicer 54, retain the head end of the master, The tree is expanded and the master supply reel continues to rotate until the tail end of the master tape from master supply reel 51 arrives at splice block 54.

The head end of the master tape is spliced to the tail end of the master tape, and duplication is readyto begin.

The properly-loaded master tape is shown in Figure 5, ready for duplication to begin. A pers fully described in applicant's United States Patent No.

4,656,530, particularly at Cot. 5, Line 62 through Col. 7, line 65, and at Figures 2-8. Tension in the range of 60-SO grams provides proper tension on the tape as it is pulled through the high speed duplicator 11.

Vacuum column 62 provides constant faed tension for taking away slack from tape exiting the capstan/pinch roller 40 and for providing very low tension, in the range of 20 grams, on the master tape as it passes into the loop tape storage apparatus 12. The capstan/pinch roller 40, which acts as a capstan drive, maintains a relatively constant speed during the duplication process, Contact Printing Referring now to Figure 7, the print drum 33 includes a rotating driven transfer drum 70 across which the taster tape and the copy tape pass at high speed The metal signalbearing surface of the master tape and the oxide-ccated side of the copy tape are mated to each other across the transfer drum 70. A transfer magnetic field head 71 applies an external high-frecuency transfer bias to the master and copy tapes. Zn this envirorjnent, CTL, audio and high-density video signals are transferred from the master tape ta the copy tape at high speed.

The magnetic field head 71 resides in an air chamber 72, which blows high-pressure air against the master tape, pressing it and the underlying copy tape against the transfer drum 70, and maintaining intimate contact between the master and copy tapes. Since the magnetic-signal retaining layers of the master tape and copy tape are face-to-face during signal transfer, the mirror image on the master tape is transferred in proper play-back orientation to the copy tape.

Waster Tare Cleaning Referring now to Figure 8, ionizing means 75 are provided for delivering a cloud of ionized air onto the master: tape ag it passes -through the loop tape duplicator 10, and simultaneously neutralizes static charges on the surface of the master tape and blows contaminants attracted by the static charges away from the surface of the master tape.

Tape material normally contains an equal number of positive and negative charges and is electrically balanced.

In such a state the tape is 1,neutral' and does not attract debris However, friction, such as generated by passage of the master tape over the various guides, rollers and the like, causes a static condition on the tape which causes it to actually attract debris in the surrounding air and on surfaces which the master tape contacts.

The conventional Sony Sprinter provides a separate cleaning tape for each of the copy tape, master tape and drive tape. The cleaning tape is a 'lltnt-fre" nonwoven paper tape intended to remove dust from the surface of the tape to be cleaned without dawaaxng the tape surface. However, it is known that any cleaning tape brought into contact with another surface will create some abrasion, no matter how slight. Furthermore, cleaning tapes can create a static electrical charge in the tape being cleaned which causes the qust-cleaned tape to attract neatly particles.

This problem is solved by providing ioniing neans 75 which includes an air blower 76 which delivers a stream of pressurized air to an ionizing bar 77, where the stream is ionized by an emitter point, or points. The blower operates on the "coanda" effect, using a small amount of highly compressed air to entrain a high some of surrounding air.

As is shown in Figure 5, ionizing means 75 is positioned on the loop tape storage apparatus 12 immediataly above the top support 58 and close to where the upper arms 56a-d and 57 a-d are positioned during the duplication process. See Figure 5.

The ion strean floats onto the master tape as it traverses tse loop tape storage apparatus 12, neutralizing the static charges on the master tape and releasing the attraction between the debris particles clinging to the master tape and the master tape itself. Note that there is no extraneous contact with the master tape. As is also shown in Fiqure 5, immediately after the master tape exits the arm 57 it passes into the vacuum column 61, where negative air pressure is applied to the surface of the master tape. See discussion above. Thus, any particles residing loosely on the surface of the tape are simply suctioned off the master tape by the pull of the air in the vacuum column 61. This results in a very clean master tape and avoids degradation of master tape quality 2LEa Bearing of Loop Tape storage Apparatus 12 Referring now to Figures 9 and 10, the arms 56a-d and 57 a-d support the master tape on n cushion of high-pressure air and serve as "air guides". This is achieved by forming the arms 56 a-d and 57 a-d of sintered metal having a nominal ore size of approximately 2-5 microns, meaning that 2-5 microns is the largest particle size which will pass through the pore.

tow pressure air is not used because of the tendency of low pressure, high volume air to cause tape fluttering, and because of high air consumption. Large holes are not used as air outlets because of irregular tape guiding and high air consumption. In effect, the arms 56 a-d and 57 a-d form a type of pneumatic sparger which provides a very uniform platoon for supporting the master tape, particularly since the vacuum column 62 affectively lowers the tape tension to a very low 20 grams without slackness or lateral tape wandering. Use of the arms 56a-d and 57a-d greatly reduces tape wear, prevents tape wandering and edge damage caused by the use of crown rollers. In additicn, the high pressure air against the master tape surface will loosen and/or blow away some of the particles which wre attracted to the tape surface by static electricity until neutralized by the ioniing means 75, described above.

An air storage means (not shown) supplies high pressure, low volume air (10 psi at 20 cfa) to the arms 56a-d and 57a-d through a manifold in the supports SS and 59. An oil-free vane ptnnp is used since oil (whether from fingerprints, pump oil or other environmental causes) will quickly render the master tape useless.

Easter Unloading When duplication is complete, the master tape is removed by splicing the head end of the master tape to a short length of-leader tape wound onto master supply reel 52. The tail end of the master tape is spliced to a long length of leader tape which has been wound onto master supply reel 51, The master tape is wound onto the library take- up reel 52 until the leader tape is reached.

A precision tension controlled loop tape apparatus for use with a high speed video tape duplicator is described above, Various details of the invention way be changed without departIng from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation--the invention being defined by the claims.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (14)

1. A precision tension controlled loop tape apparatus for use with a high speed video tape duplicator, comprising: (a) a master tape storage means for accumulating and storing a length of master video tape in endless loop form for repeated duplication onto a copy tape supplied by the video tape duplicator; (b) duplicator tension means for providing the master tape at a pre-determined high constant tension to the video tape duplicator; and (c) leader tape loading means for splicing a leader tape to the master tape and utilizing the leader tape to load the master tape into said master tape storage means and into said video duplicator.

2. An endless loop tape apparatus according to Claim 1, and including storage tension means for providing the master tape at a pre-determined low constant tension to the master tape storage means.

3. An endless loop tape apparatus according to Claim 1 or Claim 2, wherein said video duplicator comprises an AC bias magnetic contact printing apparatus.

4. An endless loop tape apparatus according to any one of the preceding Claims, and including capstan means for supplying the master tape to the video duplicator at a constant speed.

5. An endless loop tape apparatus according to Claim 2 or Claim 3, or Claim 4 when dependent on Claim 2, wherein said duplicator storage means and said storage tension means each comprise respective vacuum columns supplied with negative air pressure for exerting a pre-determined hold-back tension on master tape in the respective vacuum column.

6. An endless loop tape apparatus according to any one of the preceding Claims, wherein said leader tape loading means comprises (a) a master tape supply reel for supplying master tape; (b) a master tape take-up reel supplying leader tape for splicing to the head end of the master tape and for receiving master tape from the master supply reel; (c) splicing means for splicing the leader tape to the head end of the master tape; and (d) rewind tension means for controlling the tension of the master tape as it is supplied and taken-up by the master tape supply reel and the master tape take-up reels.

7. An endless loop tape apparatus according to Claim 6, wherein said rewind tension means comprises a vacuum column supplied with negative air pressure for exerting a pre-determined hold-back tension on master tape in the vacuum column.

8. An endless loop tape apparatus according to any one of Claims 1 to 4, wherein said storage means comprises an endless loop magnetic tape tree having pairs of tape bearings carried by opposing ends of a plurality of support beams.

9. An endless loop tape apparatus according to Claim 8, wherein said tape bearings comprise micro-gas-porous powdered metal bearing supports, and said storage means includes a pressurized air supply for supplying pressurized air to said powdered metal bearing supports to create a cushion of air on the outer surface of the powdered metal bearing defining a non-contact bearing support for the master tape as it passes through the storage means.

10. An endless loop tape apparatus according to any one of the preceding Claims, and including ionizing means for delivering a cloud of ionized air onto the master tape as it passes through the master tape storage means for simultaneously neutralizing static charges on the surface of the master tape and blowing contaminants attracted by the static charges away from the surface of the master tape.

11. An endless loop tape apparatus according to Claim 10, wherein said duplicator tension means comprises a vacuum column positioned downstream in the master tape path of travel from said ionizing means, said vacuum column being supplied with negative air pressure for exerting a predetermined hold-back tension on master tape in the vacuum column and for removing charge-neutralized contaminants on the master tape after the master tape has passed through the cloud of ionized air from the ionizing means.

12. An endless loop tape apparatus, constructed and arranged substantially as herein described, with reference to Figures 2 to 5, and 8 to 10 of the accompanying drawings.

13. In combination with the endless loop tape apparatus according to any one of Claims 1 to 12, a high speed video tape duplicator.

14. A high speed video duplicator, constructed and arranged substantially as herein described, with reference to Figures 2 to 6, and 8 to 10 of the accompanying drawings.