3 4
tridge tape recorder system is to make the cartridges as preferably a control circuit which controls the speeds of
simple as possible; the cartridges of this system are both motors. The motor driving the tapeup roll capstan
expensive and complicated. Another cartridge-type carries a tachometer and is driven in accordance with a
tape transport, ostensibly based on the same drive con- speed signal; the motor driving the supply roll capstan is
cept, is shown in Hollingsworth, U.S. Pat. No. 5 controlled in such a manner as to provide constant tape
3,638,880 (FIGS. 6-8). Although the cartridge dis- tension. Both motors preferably carry tachometers, to
closed in the patent is simple, the system is incapable of permit identical operation of the transport in either
high performance. In fact, the system is little more than • direction of tape movement. Novel tape drive systems
a conventional system without a capstan. Its tape speed having particularly advantageous control circuits are
and tape tension therefore vary as the sizes of the tape 10 described hereilli but are the joint invention of Bansi K.
rolls change. Shroff, the inventor herein, and Stephen K. Shu, and
Still another attempt to produce a high performance are daimed jn di appiication Ser. No. 635,940,
cartridge drive system utilizes a cartridge containing filed concurrentl herewith.
tape rolls on fixed axes and an endless band which en- —. . . . r ,
K , ■ , ■ r, ■ i, i- -t-x , , ., The transport system or the invention handles tape gages the peripheries of both rolls of tape. The band or 15 L. . . . „ , . ■ •
f, B ■ j ■ ■_ * , . -t-l u J ■ gently, yet very precisely. Because the tape tension is
the tape is driven by an external capstan. The band is so ° . : ....... . .. ... c ,
, , . , , . .. . maintained electronically at an optimum, with far less
arranged around support posts that its differential . .. .
stretch causes the takeup reel to run faster than the var,atl°n ,n tension than with previously known sys
supply reel, and thereby tens.ons the tape. Such a sys- *em* ,the configuration of the tape roll is highly repro
tem is shown in Wolff, U.S. Pat. No. 3,861,619 (1975). 20 duclble and stable. .
These systems may utilize a simple transport having a The caPstan en8ag'ng the periphery of the takeup roll
single drive motor and no separate tensioning means. squeezes air from beneath the outer wrapping of tape
However, the systems have inherent limitations which and forms a u&ht< ... roll. Becuse the tape
restrict the degree of performance they can provide. ro]ls behave much as if they were solid discs, their ac
They are subject to objectionable flutter and tension 25 celeration and deceleration rates are limited only by
variations caused by non-uniformities in the stretch and their moments of inertia and the available power which
frictional characteristics of the tensioning band and by can be applied to them. Therefore, although the system
undesired frictional and rotational characteristics of the is not capable of the acceleration/deceleration rates of a
posts which support the tensioning band. Such systems state-of-the-art vacuum column system, it is limited only
also require rather complex cartridges, provide limited 30 by the size and acceleraton/deceleration speeds of its
tensioning forces, are capable of limited acceleration capstan motors.
rates and a limited range of speeds, have a limited life, The tape transport system of the present invention,
and are of limited adaptability to varied applications. because it requires no reel motors and no complex tape
SUMMARY OF THE INVENTION tenS'°n Se"sing deV'CeS' 'S extreme'y simPle and reliable'
SUMMAKY Uf int. lIMVfclNllUJN J5 R ^ ^ particu,arly wd] adapted for using tape car.
One of the objects of this invention is to provide an fridges without degradation of performance. The car
extremely simple tape recorder transport system which tridges need contain only tape wrapped on hubs rotat
meets or exceeds present standards for high perfor- able on fixed axes, fixed tape guide means and certain
mance recorders, such as standards for tape speed and standard auxiliary equipment such as an internal brake
speed accuracy, acceleration and deceleration rates, 40 to prevent tape from spilling when the cartridge is out
low skew, and uniform tensioning. of a transport, and file protect means to prevent acci
Another object is to provide such a high performance denta] recording over existing data on the tape. Carsystem utilizing tape cartridges which are simple and tridge systems in accordance with the present invention reliable, and which are interchangeable without degra- may provide performance levels that in most respects dation of performance. 45 equal 0f exceed those of present|y known high perfor
Other objects will become apparent in light of the mance reel.to.ree, systems. Tape rec0rder systems uti
following description and accompanying drawings. ,jzj an j ved> si ,e> cartridge design> which
In accordance with one aspect of this invention gen- jdeg a hj fa rf ()f tection> main.
erally stated, a tape transport system is provided of a ... ■ , , , ... ,.
. ... . , , , , , ,, , . ,„ tains tape tension even under adverse handling condi
type including a pair of coplanar hubs rotatable about 50 . , ... , , °, ...
J J 1r i »i_ r i- i-i . j- n Hons, and positions the tape extremely accurately with
fixed axes and a length of pliable tape carried in rolls on xi r . ,. . , . ,
. ,° . ..u r» respect to a magnetic recording head or transducer, are the hubs, a transducer cooperative with a span of tape , ., , , ■ , .... r„ between the rolls, and drive means for driving the tape described herein, but are the joint invention of Bans. K. across the transducer from one of the tape rolls to the fhro1ff' 'he lnventor herein Frank Dekker and John other, wherein the drive means include a pair of mov- 55 Nordrehaug, and are claimed m copending application able capstans biased into driving engagement with the Ser- Na 635>939' flled concurrently herewith, peripheries of the rolls, and control means for driving The TMproved and simplified transport and cartridge the capstan engaging the tapeup roll faster than the have otner novel and advantageous features, which are capstan engaging the supply roll. The difference in more eas,1y understood in light of the following despeed is chosen so as to generate a desired tension in the 60 scription of the preferred embodiments, span of tape intermediate the rolls. Preferably, the cap- Throughout this description and claims, the cartridge stans are mounted on the rotors of separate drive mo- a"d transport are described as being oriented in such a tors, and each drive motor/capstan assembly is way that the cartridge reels rotate in a horizontal plane mounted on a separate movable carriage. The capstans about vertical axis. It will be understood that this orienare preferably biased into engagement with the tape 65 tation is used merely for convenience in describing the rolls by a common spring which automatically equalizes invention. One of the advantages of the present system the forces exerted by the capstans on the tape rolls, is that it may be used in different orientations without regardless of their positions. The control means are affecting its performance.
