Tape loading device with selective tape loading characteristic for magnetic recording/reproducing apparatus

A tape loading device is for a cassette type magnetic recording/reproducing apparatus in which a tape is drawn out of a cassette for record or reproduction, and includes movable tape guides for defining a path for running of the tape, a pair of reel driving motors which independently drive two reels of the cassette to apply a back tension to the tape, and a control unit. The reel driving motors are activated to apply the same torque to both the reels, before the tape loading operation. In this state, a tape wind diameter ratio and/or an inertia ratio between the reels is computed based on the speeds and directions of rotations of the reels. The control unit selects a control pattern which would effectively suppress rotations of the reels due to inertia, out of a plurality of control patterns, in accordance with the computed value. In tape loading or unloading operation, the control unit controls operation of the movable tape guides and/or the reel driving motors in accordance with the selected pattern. Thus, any undesirable effect of inertia of the cassette reels is avoided, so that tape is loaded or unloaded in a short time without suffering from damage.

BACKGROUND OF THE INVENTION 
The present invention relates to a tape loading device for a magnetic 
recording/reproducing apparatus such as a VTR (video tape recorder) or a 
DAT (Digital Audio Tape Recorder) and, more particularly, to a tape 
loading device which is used for a magnetic recording/reproducing 
apparatus of a type wherein a tape is drawn or pulled out of a cassette 
and then loaded. 
A VTR device, as a typical example of the magnetic recording and 
reproducing apparatus of the type mentioned above, has a tape loading 
device in which tape guides each having flanges at both ends thereof, as 
well as inclined tape guides, are provided and the flanged and inclined 
tape guides define a path along which the tape runs. Some of these tape 
guides are installed on a movable bases to protrude therefrom. After a 
tape cassette has been loaded on a VTR, as the movable bases move along a 
guide plate disposed around a rotary head drum, the tape guides on the 
movable bases draw the tape out of the tape cassette and wind the same on 
the peripheral surface of the rotary head drum. This type of tape loading 
device is disclosed, for example, in Japanese Unexamined Patent 
Publication No. 2-282968. 
In recent years, in the field of magnetic recording and reproducing 
apparatus, there are increasing demands for higher performance such as a 
greater speed of tape loading and unloading, higher access speed and other 
factors, particularly for VTRs used in broadcasting and other business 
purposes. On the other hand, there is a trend toward reduction in the 
thickness and stiffness of magnetic tapes, in order to meet requirements 
for digital signal recording/reproduction and for longer playing time, 
increasing the risk for the tape to be damaged. This tendency noticeably 
affects high-speed tape loading operation. 
For instance, the known apparatuses encounter the following problems. When 
a high-speed tape loading is conducted, the tape is excessively drawn out 
due to inertia of reels of the cassette even after the mechanism such as 
tape guides is stopped upon completion of the operation. As a result, the 
tape is slackened on the peripheral surface of the rotary head drum or on 
the tape guides, or the tape comes off the drum, resulting in damaging of 
the tape. 
SUMMARY OF THE INVENTION 
The invention has an object of providing a tape loading device for a 
magnetic recording/reproducing apparatus, which is capable of performing 
high-speed tape loading and unloading without being accompanied by the 
troubles or problems as described hereinabove. 
Another object of the present invention is to provide a tape loading device 
which can properly handle even the magnetic tape of a small thickness, 
thus contributing to improvement in the performance of a magnetic 
recording and reproducing apparatus. 
Some of the present inventors have proposed, in U.S. patent application 
Ser. No. 07/683875, now U.S. Pat. No. 5,307,215 , a tape loading device in 
which reel motors and a loading motor are controlled to cause a stepped 
change in the tape tension in relation to the progress of the tape loading 
process or in accordance with the time elapsed. Further, proposed in U.S. 
patent application Ser. No. 07/893072 pending is a tape loading device in 
which reel motors or a loading motor is controlled in accordance with the 
phase of loading operation and the values of inertia of reels which are 
computed on the basis of the speeds and direction of rotation of the reels 
and the phase of the tape loading operation. 
The invention aims at further improving these proposed tape loading devices 
in order to achieve the above-described objects. More specifically, the 
improvement resides in that the tape loading and unloading operations are 
controlled under controlling conditions for effectively suppressing the 
rotations of both cassette reels due to inertia, which controlling 
conditions are selected in accordance with the tape winding ratio and/or 
the inertia ratio between cassette reels computed on the basis of the 
speeds and direction of rotation of these reels as measured while these 
reels are under the same level of torque. 
According to one aspect of the invention, a tape loading device comprises a 
tape guide mechanism for drawing a tape out of a tape cassette and 
defining a path for run of the tape, a driving source for driving two 
reels of the cassette, respectively, to apply a back tension to the tape, 
a detector/computer for detecting directions and speeds of rotations of 
the reels and computing at least one of a tape winding diameter ratio and 
an inertia ratio between the reels, and a controller for activating the 
tape guide mechanism and the reel driving source. 
With the above construction, when the loading or unloading operation of a 
tape, the tape winding diameter ratio or the inertia ratio between two 
cassette reels is computed by the detecting/computing unit and the result 
of the computation is sent to the control unit which sets, in accordance 
with the computation result, tape loading or unloading conditions which 
would effectively suppress rotations of the reels due to inertia. The 
control unit then controls the tape guiding mechanism and/or the reel 
drive power source under the set conditions. Consequently, any rotation of 
the reels is suppressed to thereby take the tape under protection, thus 
enabling quick loading or unloading of the tape. 
It is preferable to provide the tape loading device, in addition to the 
above construction, with a detector for detecting the phase of operation 
of the tape guide mechanism and transferring the same to the control unit. 
When such a detector is used, the operational position of the tape guide 
mechanism is momentarily detected so that the control unit controls the 
tape loading or unloading operation while monitoring the operational 
position information.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The invention will be described in more detail on the basis of preferred 
embodiments shown in the drawings. 
FIGS. 2, 3 and 4 are plan views schematically showing the mechanical part 
of the tape loading device according to the first embodiment of the 
invention. FIG. 2 shows the mechanical part in its state of being in the 
course of a tape loading operation, while FIGS. 3 and 4 illustrate the 
mechanical part in the state before the commencement of the tape loading 
operation and in a state after completion of the tape loading operation, 
respectively. Referring to these Figures, a VTR has a rotary head drum 2 
which is rotatably mounted on a chassis of the VTR and carries magnetic 
heads for recording and reproduction. A cassette 3 has cassette reels 4 
and 5 mounted therein and accommodates a tape 6 wound on and extended 
between these reels 4, 5. An opening 7 is formed in the front wall of the 
cassette 3. In the state before the tape loading operation, the tape 6 is 
stretched along the opening 7, as shown in FIG. 3. 
The arrangement is such that, when the cassette 3 is loaded on the VTR, 
various tape guide members are inserted into the opening 7. These tape 
guide members are a supply-side drawing guide 10, a tape guide 12 and an 
inclined tape guide 14 which are mounted on a supply side movable base 19, 
an inclined tape guide 15 and a tape guide 13 which are mounted on the 
movable base 21 of the take-up side, a pinch roller 16 and a take-up side 
drawing guide 11. The movable bases 19 and 21 are adapted to be driven by 
a later-mentioned loading motor 106 so as to move along guide grooves 24, 
25 which are provided in a guide plate 23. The guide plate 23 has a 
bifurcated shape surrounding the rotary head drum 2. One of two legs of 
the bifurcated guide plate 23 has the guide groove 24, while the guide 
groove 25 is formed in the other leg. When the tape loading operation is 
completed, holding members 26, 27 disposed on both sides of the rotary 
head drum 2 in the close proximity therewith, locate and hold the movable 
bases 19, 21, respectively, thus enabling the tape 6 to be wound around 
the rotary head drum 2. 
The drawing guide 10 of the tape supply side is driven by the loading motor 
106 similarly to the driving of the movable bases 19, 21. When the tape 
loading operation is completed, the guide 10 is located at the position 
illustrated in FIG. 4, thus forming a supply-side tape path along which 
the tape being supplied runs. More specifically, the tape 6, while being 
drawn or pulled by the supply side drawing guide 10, is wound around a 
supply side tape guide 30 and a tension pin 31 for detecting tape tension. 
The tape 6 further runs from the supply side drawing guide 10 in contact 
with an inclined tape guide 40, a tape guide 42 and then with a full-width 
eraser head 41 and is wound around the rotary head drum 2 through the tape 
guide 12 and inclined tape guide 14 on the movable base 19. 
Similarly, the take-up side drawing guide 11 is driven by the loading motor 
106 so as to be located at a position shown in FIG. 4, thus forming a 
take-up side tape path along which the tape being taken up runs. More 
specifically, the tape 6 runs from the rotary head drum 2 into contact 
with an A/C (Audio/Control) head 43 through the inclined tape guide 15 and 
the tape guide 13 on the take-up side movable base 21. The tape 6 then 
runs around a tape guide 44, an inclined tape guide 45 and a tape guide 
46, so as to return into the cassette through a capstan 47, a take-up side 
drawing guide 11 and the tape guide 38. 
As shown in FIG. 4, the tape running path obtained after the completion of 
the tape loading operation is formed three-dimensionally by means of four 
inclined tape guides 40, 14, 15 and 45 so as to enable the tape to 
properly slant and contact the rotary head drum 2. In this state, the 
capstan 47 cooperates with the pinch roller 16 to nip the tape 6, and is 
driven by the power of a capstan motor (not shown) so as to forward the 
tape 6. The tape loading device of this embodiment further has reel motors 
104, 105 (see FIG. 1) which respectively drive the reels 4, 5 in the 
cassette 3 under controlled driving conditions. 
Tape loading and unloading operations are performed by mechanisms which 
will be described hereinafter with reference to FIGS. 5 to 9. FIG. 5 
illustrates a driving mechanism for the supply side movable base, while 
FIG. 6 shows a driving mechanism for the take-up side movable base. As 
will be seen from FIG. 5, the output torque of the loading motor 106 is 
transmitted through a cam gear 50 to a supply side loading ring 51 to 
which is secured a slide plate 52. The slide plate 52 is coupled to the 
aforesaid supply side movable base 19 via a connecting plate 56. The slide 
plate 52 is normally urged in a predetermined direction by a spring which 
is not shown. Therefore, as the loading ring 51 continues to rotate a 
certain angle against the spring force even after the movable base 19 has 
been moved along the guide plate 23 and then located, the movable base 19 
is urged to and surely located at a predetermined position by the spring 
force. 
Referring now to FIG. 6, a slide plate 58 is attached to a take-up side 
loading ring 57 to which the torque of the loading motor 106 is 
transmitted via the cam gear 50 and a power transmission gear train 
including gears 59, 60 and 61. The slide plate 58 is connected to the 
take-up side movable base 21 through a connector plate 65. The slider 
plate 58 is normally urged in a predetermined direction by a spring which 
is not shown. Therefore, as the loading ring 57 continues to rotate a 
certain angle against the spring force even after the movable base 21 has 
been moved along the guide plate 23 and then located, the movable base 21 
is urged to and surely located at a predetermined position by the spring 
force. 
As will be seen from FIGS. 5 and 6, the supply side loading ring 51 and the 
take-up side loading ring 57 are arranged concentrically around the rotary 
head drum 2 and are respectively supported by support members 53, 54, 55 
and 62, 63, 64, but are disposed at different horizontal levels so as not 
to interfere with each other. Both the loading rings 51 and 57 are driven 
through the con, non cam gear 50 by the loading motor 106, so as to rotate 
about the supporting members 53, 54, 55 and 62, 63, 64, respectively. The 
take-up side loading ring 57, however, rotates in the direction opposite 
to the direction of rotation of the supply side loading ring 51, because 
the ring 57 is driven via the gear train 59, 60, 61. Numeral 103 
designates a potentiometer which detects the tape loading operation 
position (or tape unloading operation position). The potentiometer 103 has 
a rotor which rotates in synchronization with the cam gear 50. 
As shown in FIG. 5, sensors 101, 102 for sensing the tape loading 
completion position and the tape unloading completion position, 
respectively, are disposed beneath the supply side loading ring 51. These 
sensors 101 and 102 are adapted to sense completion of the tape loading 
operation and the tape unloading operation, respectively, as these sensors 
are interrupted by shutters 98 and 99 which are secured to the reverse 
side of the supply side loading ring 51. 
Shown in FIG. 7 is the state of the sensor 102 for detecting completion of 
the tape unloading operation when the tape unloading operation has been 
completed, wherein the sensor is interrupted by the shutter 99. 
FIGS. 8 and 9 show a driving mechanism for the supply side drawing guide 10 
and the take-up side drawing guide 11, in its states before the loading of 
the tape and after completion of the tape loading, respectively. The 
operations of the drawing guides 10 and 11 on the supply and take-up sides 
are as follows. When the loading motor 106 operates in the tape loading 
direction, the driving torque of the motor 106 is transmitted to the cam 
gear 50 so that the cam gear 50 rotates in the tape loading direction 
(counterclockwise as viewed in FIG. 8) about a support shaft 75. As a 
result, a trifurcated drive arm 79, which has a follower projection 77 
engaging with a cam groove 76 formed in the underside of the cam gear 50, 
is rotated clockwise as viewed in FIG. 8 about a support shaft 78 in 
accordance with the movement of the cam groove 76. Consequently, a sector 
gear 91, which engages with a sector gear portion formed on one end of a 
driving arm 79, is rotated counterclockwise as viewed in FIG. 8. The 
sector gear 91 is supported by a support shaft 17 which also supports the 
drawing arm 18 having at its one end the supply side drawing guide 10, so 
that the sector gear 91 and the drawing arm 18 rotates as a unit with each 
other. Therefore, the supply side drawing guide 10 on the drawing arm 18 
also is rotated in the same direction as the rotation of the sector gear 
91, thereby extracting the tape 6. 
A pin 80 is provided on the other end of the above-mentioned driving arm 
79. This pin 80 engages with a bifurcated groove 94 formed in one end of 
an L-shaped connecting arm 82 which rotates about a supporting shaft 81. 
The clockwise rotation of the driving arm 79 described above, as viewed in 
FIG. 8, causes the connecting arm 82 to rotate counterclockwise. A 
pin-slit engagement is made between a pin 83 provided on the other end of 
the connecting arm 82 and an elongated groove 87 formed in one end of the 
slider 84. The slider 84 has a pair of limiting grooves which extend in 
the same direction and which engage with fixed pins 85, 86, respectively. 
The slider 84, because of such engagements, is slidable in a horizontal 
direction as viewed in FIG. 8. More specifically, the slider 84 slides to 
the right as viewed in FIG. 8 in response to the above-mentioned 
counterclockwise rotation of the connecting arm 82. The drawing arm 28, 
which is rotatable on the support shaft 27, carries a pin 89 which engages 
with an elongated groove 88 formed in the other end of the slider 84. The 
rightward slide motion of the slider 84 causes a clockwise rotation of the 
drawing arm 28 as viewed in FIG. 8 so that the take-up side drawing guide 
11 on the drawing arm 28 is moved correspondingly so as to draw or pull 
the tape 6. 
In FIGS. 8 and 9, numerals 92 and 93 denote stoppers for regulating the 
positions of the supply side guide 10 and the take-up side guide 11 at the 
end of the tape loading operation, respectively. It will be clear that, in 
the described mechanism in FIGS. 8 and 9, the tape unloading operation is 
executed in a sequence reverse to that of the tape loading operation. 
As have described above, the tape loading and unloading operations are 
performed by the power which is derived from the sole driving source, 
i.e., the loading motor 106, via the cam gear 50. The rotational phase of 
the cam gear 50 and an output from the aforesaid potentiometer 103 exactly 
correspond to each other as the potentiometer (phase detector) is rotated 
synchronously with the cam gear 50. It is therefore possible to know the 
phase or the state of progress of the tape loading or unloading operation 
by sensing the output of the potentiometer 103. 
FIG. 1 shows a control system for controlling the operation of the 
above-described mechanism in the first embodiment. In FIG. 1, reference 
numeral 100 denotes a control circuit for controlling the operation of the 
whole tape loading device. The control circuit 100 receives various output 
signals such as those from the loading completion sensor 101, unloading 
completion sensor 102, the potentiometer 103, and FG output signals from 
frequency generators 108, 109 (see FIG. 1) which are provided on the 
supply side and take-up side reel driving motors 104, 105. The signals 
from the frequency generators 108, 109 are indicative of the directions 
and speeds of rotations of the respective reel driving motors. The control 
circuit 100 also receives the results of computation from a tape winding 
diameter computing circuit 110 which is provided to perform a 
predetermined computation based on the output data from the frequency 
generators 108 and 109. The output signal from the potentiometer 103 is 
reset to zero in response to a tape unloading completion signal from the 
sensor 102 at the beginning of the tape loading operation, and is 
progressively incremented in accordance with the progress of the tape 
loading operation. Conversely, when the tape unloading operation is 
executed, the output signal from the potentiometer 103 is reset to zero in 
response to a tape loading completion signal from the sensor 101, and is 
counted in the control circuit 100 so as to be incremented progressively 
in accordance with the progress of the tape loading operation. In FIG. 1, 
numeral 107 designates an input terminal through which, for instance, 
operation con, hands given by an operator are entered. 
The operation of the tape loading device according to the embodiment will 
be described with reference to FIGS. 10 and 11. The cassette 3 is inserted 
into and loaded on the VTR, so that the cassette reels 4 and 5 are 
respectively seated on reel bases which are driven by the aforesaid reel 
driving motors 104 and 105 in a manner known per se. After the loading of 
the cassette 3, a computation is performed in accordance with the 
following procedure to determine the ratio between the tape wind diameters 
on the supply reel 4 and the take-up reel 5, prior to the commencement of 
the tape loading operation. 
After the loading of the cassette, both the reel driving motors 104 and 105 
operate for a predetermined time to apply torques of the same level to 
both the reels 4 and 5 of the cassette 3. If the tape wind diameters on 
both reels are different, the tape will run towards the reel of the 
smaller tape wind diameter. In Step 120 of the flow shown in FIG. 10, the 
data of rotation speeds and rotation directions of the reel driving motors 
are picked up in the form of the output signals from the frequency 
generators 108 and 109, and the ratio between the tape wind diameters on 
both the reels 4, 5 is computed by the aforesaid tape wind diameter ratio 
computing circuit 110 in Step 121. It is also possible to compute the 
inertia ratio between both the reels on the basis of the result of the 
above-described computation. In this case, representing the computed tape 
winding diameter ratio by .alpha., the inertia ratio is calculated by the 
circuit 110 as being approximately .alpha..sup.4, since the inertia of 
each reel is substantially proportional to the fourth order of the reel 
radius including the tape on the reel. The result of computation is 
delivered to the control circuit 100. A plurality of tape loading 
operation pattern characteristics in relation to time, corresponding to 
values of the ratio determined as described, are beforehand stored in the 
control circuit 100. In Step 122, the control circuit 100 selects one out 
of these operation pattern characteristics in accordance with the result 
of the computation of the ratio. The operation pattern characteristics are 
determined such that the loading time is shortest when the tape winding 
diameter ratio is 1:1 as shown by a characteristic curve (a) in FIG. 11 
and is prolonged as the difference in the tape winding diameter becomes 
greater, as shown by characteristic curves (b) and (c) in the same Figure. 
The characteristics have been determined by using experiment models, for 
various values of the tape wind diameter ratio or inertia ratio, so as to 
most effectively eliminate the influence of the reel inertia, i.e., so as 
to suppress any excess rotation of the reels due to inertia, thus enabling 
quickest extraction of the tape. The most appropriate operation pattern 
characteristic is selected in accordance with the result of the 
computation. The control operation pattern characteristic for controlling 
the tape loading operation may be selected on the basis of the aforesaid 
inertia ratio, instead of relying upon the described tape winding diameter 
ratio, so that the tape drawing operation is performed in accordance with 
the selected control operation pattern characteristic. Which one of the 
tape wind diameter ratio and the inertia ratio is to be used is a matter 
of discretion. 
Thus, in the illustrated embodiment, it is possible to eliminate any 
slacking or tensioning of the tape due to influence of inertia, even when 
one reel has larger inertia, by suitably setting the acceleration or 
deceleration in the tape drawing motion in accordance with the inertia of 
that reel. After the selection of the optimum tape loading operation 
pattern according to the computed tape wind diameter ratio, the control 
circuit 100 operates to activate the loading motor 106 in accordance with 
the selected pattern, thereby starting the tape loading operation. The 
phase of the tape loading operation, i.e., the state of the proceeding of 
the operation in relation to time, is momentarily detected by the 
potentiometer 103. The control circuit 100, on the basis of the result of 
the detection, operates to control the power of the loading motor 106 in 
such a manner that the loading operation be conducted in accordance with 
the selected operation characteristic pattern. This control operation is 
executed in Step 123. The tape loading operation is ceased when a signal 
from the sensor 101 indicative of completion of the loading operation is 
received by the control circuit 100. 
The operation of the device of this embodiment when unloading the tape is 
substantially the same as that described hereinbefore. When the tape 
unloading operation is executed after a running of the tape, the tape wind 
diameter computing circuit 110 computes the values of the diameters of the 
tapes on both the reels or the values of inertia derived from the tape 
diameters, on the basis of the output signals from the frequency 
generators 108 and 109 during running of the tape. Then, the control 
circuit 100 selects the operation pattern optimum for the result of 
computation, and conducts the control for the tape unloading operation. In 
the case where an instruction is given for unloading the tape while the 
tape has not run, the operation pattern for tape unloading operation is 
selected on the basis of the values which were computed for the tape 
loading operation when the cassette was loaded on the VTR. 
With the arrangement of the tape loading device shown in FIG. 1, it is 
possible to compute, in the course of the tape loading operation, the 
values of actual tape wind diameters and inertia on respective cassette 
reels, in accordance with the data derived from the potentiometer 103 and 
the frequency generators associated with the respective reel driving 
motors 104, 105. It is therefore possible to compute the actual values 
during the tape loading operation and to use these values in the tape 
unloading operation as described above. The results of the computation 
performed during tape loading operation can be corrected or changed as 
necessary during the tape loading operation. 
The tape loading device according to the second embodiment of the invention 
will be now described with reference to FIGS. 12, 13 and 14. The second 
embodiment, as will be understood from the following description, can 
eliminate such phenomenon as any slack of the tape, without requiring any 
change in the tape loading time. 
FIG. 12 shows the control system employed in the tape loading device of the 
second embodiment. In this system, the control circuit 100 controls the 
driving torques of the reel driving motors 104, 105 during the tape 
loading operation. More specifically, referring to FIG. 13, the tape wind 
diameter ratio or the inertia ratio is computed on the basis of the 
outputs from the frequency generators as described before, in advance of 
the start of the tape loading operation. This operation is executed in 
Steps 120 and 121 of the flow shown in FIG. 13. Then, the control circuit 
100 operates to select torque control patterns for the respective reel 
motors in accordance with the computation result, in Step 124, and then 
vary the output torque values of the reel driving motors in accordance 
with the selected patterns in Step 125 during the tape loading operation. 
The control circuit 100 stores a plurality of torque control pattern 
characteristics in relation to the computed values of the ratio, for 
instance, as represented by the characteristic curves (a), (b), (c) and 
(d) in FIG. 14. These characteristics have been determined beforehand in a 
similar manner to the aforementioned operation pattern characteristics 
employed in the first embodiment. Thus, in the second embodiment, optimum 
torque control pattern characteristics are selected in accordance with the 
result of the computation performed on the basis of the outputs from the 
frequency generators, and the output torques of the reel driving motors 
are controlled in accordance with the selected torque control operation 
pattern. 
FIG. 14 shows the torque control characteristic patterns, with the axis of 
abscissa showing the operational phase of the loading mechanism and the 
axis of ordinate indicating the reel motor torque. The characteristic 
curve (a) in FIG. 14 applies to the case where the ratio between the 
diameters of the tape wound on the reels is 1:1. In this case, the torques 
produced by the reel motors are equal to each other. The torques to be 
generated by the reel motors are varied, for instance, as shown by the 
curve (b) and the curve (c) as the tape wind diameter ratio increases. 
Thus, undesirable state such as slacking of the tape is avoided during the 
tape loading operation, as the set torque levels for the respective reel 
driving motors are varied in accordance with the levels of the inertia. 
Also in the device of this embodiment, the operational phase of the tape 
loading mechanism is known through the output from the potentiometer 103, 
and the control circuit 100 controls the reel motors such that each of 
them produces a torque of a level corresponding to the operational phase 
of the tape loading mechanism. 
It will be understood that the tape unloading operation can be controlled 
substantially in the same manner as that described above. The selection of 
the torque control operation patterns may be done on the basis of computed 
inertia ratio so that the output torque levels of the respective reel 
driving motors are controlled in accordance with the thus selected 
patterns. Whether the tape wind diameter ratio or the inertia ratio is 
used as the basis for the selection of the control pattern is a 
discretionary matter. 
Further, according to the invention, it is possible to carry out the 
control in which the control of the operation of the loading motor as 
adopted in the first embodiment and the control of the reel driving motors 
as employed in the second embodiment are combined with each other such 
that the control of acceleration or deceleration in the tape drawing 
motion and the torques on the reels during the tape loading operation are 
suitably combined. Such a combination of two types of control makes it 
possible to reduce the time required for the tape loading as short as 
possible while keeping the tape tension at a sufficiently low level 
without being accompanied by slack or excessive tensioning of the tape. 
The invention as described can be applied to an apparatus such as a VTR 
which is designed to handle tape cassettes of different sizes. In such 
application, different groups of control patterns to be selected are 
prepared for respective types of cassettes, the type of a cassette loaded 
in the apparatus is discriminated, and an adequate operation control 
pattern is selected from the group of control patterns for the loaded 
cassette in the manner described hereinbefore. Thus, the advantages 
brought about by the described embodiments can be enjoyed even in such 
application. 
As has been described, according to the invention, the loading motor output 
and/or the reel driving motor torques are controlled during tape loading 
or unloading operation, in accordance with the result of computation of 
the ratio between two cassette reels in tenths of the tape wind diameter 
or reel inertia. It is therefore possible to minimize the risk of damaging 
the tape during loading and unloading, by eliminating undesirable effect 
of factors such as inertia of cassette reels.