Magnetic recording and reproducing apparatus

In the helical scan type magnetic recording and reproducing apparatus having the tape loading mechanism for training the magnetic tape against the wall of the tape guide drum including the magnetic head over the predetermined angle, an idler is arranged to selectively engage the supply reel pedestal and the takeup reel pedestal and is provided with a driving torque transmitting means for transmitting driving torque from a drive source to this idler wherein the aforesaid driving torque transmitting means is arranged to be switchable between a 1st mode where the driving torque of the drive source is directly transmitted to the idler and a 2nd mode where the driving torque of the drive source is transmitted through a slip torque transmission portion to the idler, and this switching is effected in relation to operation of the aforesaid tape loading mechanism.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to helical scan type magnetic recording and 
reproducing apparatus having the so-called high speed search function, and 
more particularly to improvements of its reel pedestal drive mechanism. 
2. Description of the Prior Art 
In the magnetic recording and reproducing apparatus having the fast speed 
search function, that is, such mode that while, in the tape loading 
condition, the tape is running at a fast speed, reproduced images are 
obtained (hereinafter called "search mode"), to cope with the problem of 
regulating tape movement such that the tape may be wound at the increased 
speed, the required torque transferring system for the supply and takeup 
reel pedestals becomes very complex. For this reason, the conventional 
type of such systems has utilized either a separate motor for each reel 
pedestal with the electrical control of rotation of this motor, or a 
complicated mechanical clutch in order to accomplish the desired driving 
of the reel pedestal in each mode. The use of such system therefore, 
results in complex apparatus, constituting one of the necks in minimizing 
the bulk and size and weight thereof. Also the actuation control portion 
is, because of its requiring besides the actuating members for the 
ordinary fast feed and fast rewind, the provision of two actuating members 
adapted only to the search mode for the forward and reversed feeds 
respectively as in the separate form, increased in the complexity by that 
provision, and this calls for an increase in the space which the actuation 
control portion occupies. These problems becomes serious particularly when 
the compactness, light weight and good manageability are extremely 
important as in the portable type magnetic recording and reproducing 
apparatus. 
In general, the search mode operates in such a manner that whilst the tape 
is being loaded, the capstan is driven to rotate as far higher a speed 
than when in the ordinary recording or reproducing mode, causing the tape 
to run in the forward or reversed direction at the increased speed. In 
this case, the one of the reels which takes up the tape (namely, the 
takeup reel when the tape runs in the forward direction, or the supply 
reel when the tape movement is reversed) must be driven through a 
slip-coupling means of prescribed appropriate transfer torque, while the 
number of revolutions is adjusted to slightly faster a value than the tape 
speed required when in the search mode. When in the ordinary rewind or 
fast feed mode, on the other hand, the supply reel or take up reel is 
connected directly to the output of the motor. Since, in this case, the 
winding torque increases and further the tape runs at the high speed, it 
is undesirable to permit the tape to remain in contact with the tape guide 
drum and other members such as the stationary head during that operation. 
SUMMARY OF THE INVENTION 
With the foregoing in mind, it is an object of the present invention to 
provide a magnetic recording and reproducing apparatus capable of search 
mode which is very simple in structure as compared with the conventional 
one. 
Another object of the invention is to provide a magnetic recording and 
reproducing apparatus with the actuating member for the fast feed and fast 
rewind of the tape within the cassette being rendered possible to also 
serve as an actuating member for the search mode. 
Still another object of the invention is to provide a magnetic recording 
and reproducing apparatus of simplified construction while still 
permitting an optimum winding torque to be obtained for a corresponding 
one of the various modes. 
One of the features of the present invention is that the torque 
transferring means for transferring torque to the supply or takeup reel 
when in the fast rewind or fast wind mode is caused to change its 
operative position in response to loading of the tape so that with the 
tape loaded, when the actuating member for the fast rewind and fast wind 
mode is operated, the tape movement is regulated to suit the search mode. 
That is, the present invention concerns with the helical scan type magnetic 
recording and reproducing apparatus having the tape loading mechanism for 
bringing the magnetic tape into contact around the tape guide drum over 
the predetermined angular distance in which drum is included the magnetic 
head and is to provide a magnetic recording and reproducing apparatus 
characterized in that an idler is provided as arranged to selectively 
engage the supply reel pedestal and takeup reel pedestal, and this idler 
is provided with driving torque transmitting means arranged to be 
switchable between a 1st operative position where driving torque of a 
drive source is transmitted directly to the idler, and a 2nd one where 
driving torque of the drive source is transmitted through a slip-coupling 
means to the idler, and that this switching is performed in relation to 
the operation of the aforesaid tape loading mechanism. 
Such features enable a tape reel drive system for the search mode with the 
tape loaded and for the fast wind and fast rewind modes with the tape 
retracted within the cassette (unloaded) to be constructed in an extremely 
simple form and to operate with a high reliability, and a single actuating 
member to suffice for selection of these modes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will next be described in connection with an 
embodiment thereof by reference to the drawings. 
FIGS. 1 and 2 illustrate a magnetic recording and reproducing apparatus 
employing one form of the invention with FIG. 1 in an operative position 
before the tape loading and FIG. 2 in an operative position after the 
completion of the tape loading. The tape loading method employed in this 
apparatus is substantially the so-called "M loading method." In FIG. 1, a 
tape cassette 2 is put in the illustrated position as guided by a cassette 
attachment device (not shown), where supply and takeup reels (not shown) 
are fitted onto rotary spindles of turn tables 12 and 13 respectively. 
Though not shown in the drawings, a front panel of this cassette (2) 
casing is provided with an apertured portion through the wall thereof to 
expose a magnetic tape, and a bottom panel of the aforesaid casing is 
provided with cutout portions formed therein through which tape pull means 
such as those denoted by 3 and 4 freely move. Such construction of tape 
cassette 2 is known in the art, and no more detailed explanation is given 
here. 
When the aforesaid cassette 2 has taken the prescribed position illustrated 
in FIG. 1, the tape pull members 3 and 4, a pinch roller 5 and a tape pull 
pin 35a are inserted into and seated in an inside space of the tape behind 
the aforesaid aperture portion of cassette casing 2. The aforesaid tape 
pull member 4 and pinch roller 5 are rotatably mounted on a loading ring 
7, and the aforesaid tape pull member 3 also rotatably on another loading 
ring 8. Again, the tape pull pin 35a is carried on a tape pull arm 35. The 
aforesaid loading rings 7 and 8 are positioned in superimposed relation 
around a tape guide drum 36, and are driven by a loading motor 9 to turn 
in mutually opposed directions. That is, the aforesaid loading rings 7 and 
8 have geared portions formed in the peripheries thereof, which mesh with 
pinions 10 and 11 respectively. These pinions 10 and 11 are also engaged 
with each other, and the pinion 11 is connected to the output shaft of the 
motor 9. Therefore, the loading rings 7 and 8 are caused to rotate always 
in opposite directions to each other as the motor 9 rotates in either 
direction. When loading the tape, the aforesaid loading ring 7 is rotated 
in a direction indicated by arrow B, and the other loading ring 8 in a 
direction indicated by arrow C. Such movement of the loading rings 7 and 8 
causes the aforesaid tape pull members 4 and 3 to move in their 
predetermined paths defined by guide means (not shown), whereby the tape 
39 is pulled out of the interior of the cassette 2 and then brought into 
training engagement against the wall of the tape guide drum 36 over a 
predetermined angular distance of about 180.degree.. It is noted that the 
interior of the aforesaid tape guide drum 36 incorporates a rotary head 
(not shown). This rotary head functions to record video signals on the 
tape contacting with the guide drum 36 and also to reproduce the video 
signals recorded on the tape. 
The aforesaid pinch roller 5 is rotatably mounted on the free end of a 
lever 5a which is pivotally mounted at a pin 5b on the loading ring 7 and, 
as the aforesaid rotative movement of loading ring 7 in B direction goes 
on, the pinch roller 5 is moved in a prescribed path defined by a guide 
means (not shown), while bringing the tape 39 into contact with a sound 
and control head 37 illustrated in FIG. 2, finally reaching a position 
near a capstan 6. Then, the completion of loading is detected to actuate a 
pinch roller solenoid 38, thereby the pinch roller 5 is pressed against 
the capstan 6 with the tape 39 sandwiched therebetween. It is noted that 
responsive to actuation of the aforesaid pinch roller solenoid 38, an 
idler 28 which is driven to rotate by an endless belt trained over an 
output shaft 19 of a motor 18 is brought into driving connection with the 
takeup reel turn table 13 so that motion of the motor 18 is transmitted to 
the takeup reel turn table 13, thus driving the takeup reel turn table 13 
to rotate. It is also noted that the output shaft 19 of this motor 18 is 
drivingly connected through an endless belt (not shown) to a fly wheel 6a 
of the capstan 6, thus driving the capstan to rotate. 
The aforesaid tape pull arm 35 is pivotally mounted at a pin 35b on a base 
plate 1, and, as the aforesaid loading ring 8 rotates, moves to a tape 
guiding position illustrated in FIG. 2 where the tape 39 is pressed 
against an overall width eraser head 40 and where in cooperation with a 
back tension control mechanism (not shown), it exerts a braking action on 
the supply reel turn table 22 to impart into the tape 39 a predetermined a 
back tension. 
It is noted that formed on the aforesaid loading ring 7 are also actuating 
projections 7a and 7b. These projections 7a and 7b actuate a loading 
completion detecting switch 100 and an unloading completion detecting 
switch 101 respectively, and are arranged in such positions that when the 
loading ring 7 has turned to the terminal end of loading movement, or to 
the position illustrated in FIG. 2, or when to the opposite terminal end 
of movement, or to the position illustrated in FIG. 1, the aforesaid 
switch 100 or 101 is pushed by the projection 7a or 7b to the closed 
position respectively. 
In the aforesaid apparatus, driving of the reel table 12 or 13 when in the 
fast feeding mode is carried out by an idler 14 normally arranged at an 
almost center of the distance between the supply and takeup reels 12 and 
13 rotatably fitted on spindles 12a and 13a planted on the base plate 1 
after it is pressed against the takeup side reel table 12 or 13. The 
aforesaid idler 14 of which the details are shown in FIGS. 3 and 4 is 
fixedly mounted on the upper end of an idler shaft 20 which is rotatably 
supported by an idler table 15. Affixed to this idler shaft 20 is an 
intermediate ring 26, the inner side of the lower surface of which a slip 
member 25 is adhered to, and its outer side of which is provided with an 
engagement projected portion 26a. And below the intermediate ring 26 of 
the aforesaid idler shaft 20 is a drive pulley 24 rotatable relative to 
the shaft 20 and slidingly movable in thrust directions. This drive pulley 
24 consists of an annular flanged portion 24a and a cylindrical boss 
portion 24b. Over the outer periphery of the annular flanged portion 24 is 
trained a drive belt (not shown) so that driving torque of the capstan 
motor 18 is transferred. Therefore, the outer peripheral edge of the 
flanged portion 24a has a recessed portion 24c in which the drive belt is 
snugly fitted. Also the aforesaid flanged portion 24 a has a pair of slots 
24d and 24d' formed in predetermined positions. A clutch disc 23 is 
rotatably and slidingly fitted on the outer diameter of the aforesaid boss 
portion 24b and is provided with a pair of extensions 23b and 23b' portion 
thereof which are freely fitted in the aforesaid slots 24d and 24d' formed 
in the flanged portion 24a of the aforesaid drive pulley 24. Again, this 
clutch disc 23 has an integral flange 23a on the outer periphery thereof, 
and this flange 23a is sandwiched by a forked portion of a clutch 
changeover plate 27 to be more fully described later. In the loaded 
position shown in FIG. 3, the clutch disc 23 is held by the clutch 
changeover plate 27 in the illustrated position. It is noted that fixed to 
the lower end of the aforesaid idler shaft 20 is a stopper sleeve 21, and 
a coil spring 22 inserted between this sleeve 21 and the lower end of the 
boss 24b of the aforesaid drive pulley 24 urges the aforesaid drive pulley 
24 in an upward direction as viewed in FIG. 3, that is, toward the 
intermediate ring 26. Therefore, the drive pulley 24 is normally pressed 
against the slip member 25 provided on the lower surface of the 
intermediate ring 26. When in the position illustrated in FIG. 3, 
therefore, rotation of the drive pulley by the capstan motor 18 is 
transmitted through the slip member 25 to the idler shaft 20, thereby the 
idler 14 is driven to rotate. 
The clutch changeover plate 27 functions to move the aforesaid clutch disc 
23 slidingly on the ilder shaft 20 in vertical directions, and, as 
illustrated in FIG. 5, is provided with a pair of mount arms 27a and 27a'. 
These mount arms 27a and 27a' have respective penetration holes formed 
therein and, as shown in FIG. 6, these penetration holes and ones in a 
pair of mount portions 1a and 1a' formed in predetermined positions of the 
base plate 1 by bending off are penetrated by a common mount pin 41 so 
that the plate 27 is pivotally mounted on the lower surface of the base 
plate 1. One end portion of this clutch changeover plate 27 is bent off in 
part to a letter-L shape and forms a forked portion 27d appearing to be of 
a letter-U shape as viewed sidewards. And this formed portion 27d receives 
the flange 23a of the aforesaid clutch disc 24 slidably. The opposite end 
portion of the clutch changeover plate 27 is stepped up by a portion 27e 
toward the base plate 1 to form an actuating area 27b which takes a 
position beneath the aforesaid loading ring 8. In one of the side portions 
of this actuating area 27b is formed a stopper portion 27c. It is noted 
that the clutch changeover plate 27 is urged by a spring (not shown) to 
turn in a counter clockwise direction as viewed in FIG. 3, and this 
rotation is limited by the aforesaid stopper portion 27c abutting on the 
base plate 1. Also formed in the lower portion of the aforesaid loading 
ring 8 at a position corresponding to the unloading completion is an 
actuating projection 8a as shown in FIG. 6. When the loading ring 8 is in 
the unloading position, this actuating projection 8a contacts with the 
actuating area 27b of the clutch changeover plate 27 and then pushes this, 
thereby the clutch changeover plate 27 is turned in a clockwise direction 
as viewed in FIG. 3 against the bias force of the spring. Such clockwise 
movement of this clutch changeover plate 27 causes the clutch disc 23 to 
move upwards by the forked portion 27d engaging the flange 23a so that the 
extensions 23b and 23b' freely fitted in the penetration holes 24d and 
24d' of the dirve pulley 24 engage with the engagement projections 26a 
formed in the intermediate ring 26, and the driving torque of the drive 
pulley 24 by the capstan motor 18 is directly transmitted to the 
intermediate ring 26. 
It is noted that the aforesaid idler table 15 is rotatably supported on a 
shaft 16 planted on the base plate 1 and is urged to the central position 
by a spring 17 affixed to a pin 42 planted on the base plate 1 and 
engaging a projected portion 15a formed in the idler table 15 in 
sandwiching manner, thus normally taking an almost central point in 
position of the two reel tables 12 and 13. It is noted that formed in the 
idler table 15 are a pair of armed portions 15b and 15c symmetric to each 
other with respect to the shaft 16, and these armed portions 15b and 15c 
are arranged in opposition to a fast feed control member 30 and a fast 
rewind control member 31 which are slidingly moved by pushing a fast feed 
button 30a and a fast rewind button 31a respectively. Therefore, 
responsive to pushing operation of the fast forward button 30a, the 
aforesaid armed portion 15b is acted on which in turn causes the idler 
table to turn in a clockwise direction until the idler 14 engages the 
takeup reel table 13. Likewise responsive to depressing of the fast rewind 
button 31a, the aforesaid armed portion 15b is acted on which in turn 
causes the idler table to turn in a counter-clockwise direction until the 
idler 14 engages the supply reel table 12. 
It is noted that in FIG. 1, 32 is a slide plate arranged upon actuation of 
the fast feed control member 30 and fast rewind control member 31 to move 
to the left as viewed in the figure. Such leftward movement of this slide 
plate 32 causes an actuating lever with its one end engaging therewith to 
turn in a clockwise direction, while the opposite end is displaced to move 
the aforesaid takeup idler 28 away from the takeup reel table 13. Also 
responsive to actuation of the aforesaid fast feed control member 30 and 
fast rewind control member 31, switches 103 and 104 illustrated in FIG. 7 
are turned on. 
FIG. 7 illustrates a drive circuit for the loading motor 9 and capstan 
motor 18 in a position where unloading is completed. In the drawing, 100 
is the above-described loading completion detecting switch; 101 is the 
aforesaid unloading completion detecting switch; 102 is a switch arranged 
to turn on when a play button 43 illustrated in FIG. 1 is depressed; 103 
is a switch arranged to turn on when the fast feed button 30a is 
depressed; and 104 is a switch arranged to turn on when the fast rewind 
button 31a is depressed. These switches 100 to 104 are formed to normally 
open microswitches, each of which is turned on (that is, conducting) when 
actuated, and off (that is, non-conducting) when de-actuated. And, the 
aforesaid switches 100 to 104 are connected at one terminals thereof to a 
positive voltage source V and at the other terminals to the circuit earth 
through respective resistors R0 to R4, and produce outputs P0 to P4 at 
those of the terminals which are connected to the resistors R0 to R4 
respectively. Therefore, these outputs P0 to P4 take high level when the 
corresponding switches 100 to 104 are actuated, or closed, and low level 
when de-actuated or opened. The aforesaid loading motor 9 and capstan 
motor 18 are direct current motors. Drive of the loading motor 9 is 
controlled by a circuit 44. This drive control circuit 44 has control 
terminals 44a and 44b. And, when a control signal supplied to the first 
control terminal 44a is of high level, and a control signal supplied to 
the second control terminal 44b is of low level, a drive current is 
allowed to flow through the loading motor 9 in a direction indicated by 
arrow E. When the control signal supplied to the control terminal 44a is 
of low level, and the control signal supplied to the control terminal 44b 
is of high level, a drive current is allowed to flow through the motor 9 
in a direction indicated by arrow F. In more detail, the aforesaid drive 
control circuit 44 is constructed, for example, as shown in the figure, 
with a pair of PNP transistors T1 and T2 with their emitters connected to 
each other, and pair of NPN transistors T3 and T4 with their emitters 
connected to each other, these pairs constituting a bridge circuit having 
a junction point S of the transistors T1 and T3 and a junction point T of 
the transistors T2 and T4 between which is connected the winding of the 
motor 9. Then, these transistors T1 to T4 are made switchable as are 
controlled by a pair of NPN transistors T5 and T6. That is, the base of 
the aforesaid transistor T5 is connected through a resistor to the 
aforesaid control terminal 44a so that when this transistor T5 is ON, the 
aforesaid transistors T2 and T3 are rendered conducting. Also the base of 
the transistor T6 is connected through a resistor to the aforesaid control 
terminal 44b so that when this transistor T6 is ON, the aforesaid 
transistors T1 and T4 are rendered conducting. Such motor drive circuit is 
known to those skill in the art, and no more explanation is given here. 
The aforesaid control terminal 44a is supplied through an inverter 45 with 
an output of NAND circuit 46 which is supplied with the outputs P1 and P2 
of the switches 101 and 102 through inverters 47 and 48 respectively. The 
control terminal 44b is supplied through an inverter 49 with an output of 
an NAND circuit 50 which is supplied with the output P2 of the switch 102 
and through an inverter 51 with the output P0 of the switch 100. 52 is a 
drive circuit for the capstan motor 18, comprising a speed control circuit 
521 and a drive control circuit 522. The speed control circuit 521 
functions dependently of the control signal to set the number of 
revolution of the capstan motor 18 to either a first value N1 for the 
capstan 6 running the tape 39 at the ordinary speed, or a second value N2 
for the capstan 6 running the tape 39 at the increased speed in the search 
mode. As the control signal is supplied the output P5 of an AND circuit 
53. And, this output P5 of AND curcuit 53 when of low level results in 
setting the number of revolutions of the capstan motor 18 to the 1st value 
N1, and when of high level, results in setting to the 2nd value N2. The 
drive control circuit 522 functions dependently of the supplied control 
signal to control the direction of rotation of the capstan motor in such a 
manner that the capstan 6 drives the tape to move either in the ordinary 
running direction (hereinafter called "forward direction"), or in the 
opposite direction thereto (hereinafter called "reversed direction"). As 
the control signal is supplied the output P6 of an amplifier 54. And, when 
the output P6 of the amplifier 54 is of low level, the capstan motor is 
driven to rotate in the forward direction, and when of high level, it is 
driven to rotate in the reversed direction. Such drive control circuit 522 
can readily be constructed as, for example, being similar to the aforesaid 
loading motor 9 drive control circuit 44 and comprising a bridge circuit 
of four transistors of which the switching is controlled depending upon 
the control signal. Here, therefore, its details are no more explained. 
Also the aforesaid speed control circuit 521 can readily be constructed 
as, for example, in such form that the intensity of current flowing 
through the capstan motor 18 is changed depending upon the control signal. 
Particularly where the aforesaid drive control circuit 522 is constructed 
with the use of the four-transistorized bridge circuit as has been 
mentioned above, the voltage of the electrical power source may be changed 
in magnitude depending upon the control signal P5. Therefore, its details 
are no more described here. 
It is noted that the aforesaid AND circuit 53 is supplied through an AND 
circuit 55 with the AND output of the outputs P0 and P2 of the switches 
100 and 102, and through an OR circuit 56 with the OR output of the 
outputs P3 and P4 of the switches 103 and 104, and the aforesaid amplifier 
54 is supplied with the output P4 of the switch 104. 
Also, in the figure, dashed line circuit blocks 57 and 58 represent a 
solenoid drive circuit and a clutch solenoid to be driven by this drive 
circuit respectively. These circuits 57 and 58 are added in an alternate 
embodiment where when to actuate the aforesaid clutch changeover plate 27, 
instead of using the actuating projection 8a formed in the lower surface 
of the loading ring 8, use is made of the clutch solenoid 58. Applied to 
the aforesaid solenoid drive circuit 57 as a control signal is the output 
P0 of the switch 100. And this drive circuit 57 operates in such a manner 
that when the output P0 of the switch 100 is of high level, the clutch 
solenoid 58 is driven. 
Also, in FIG. 7, though not particularly shown, there is an additional 
circuit responsive to depression of any one of the play button 43, fast 
forward button 30a and fast rewind button 31a for supplying drive voltage 
to the drive circuit 52 for the capstan motor 18, thereupon the capstan 
motor is driven to rotate with the selection of the speeds and directions 
depending upon the control signals P5 and P6. 
The operation of the apparatus of such construction is as follows: In case 
where the tape is unloaded as shown in FIG. 1, the aforesaid clutch 
changeover plate 27 is in the pushed position with its actuating area 27b 
engaging the actuating projection 8a formed in the bottom surface of the 
loading ring 8. Therefore, the clutch changeover plate 27 takes the 
clockmost position illustrated in FIG. 3 against the bias force of a 
spring (not shown). Therefore, the clutch disc 23 of which the flange 23a 
is clamped by the forked portion 27d of the clutch changeover plate 27 is 
held in the lifted position where the extensions 23b and 23b' of the 
clutch disc 23 pass through the respective freely fitted holes 24d and 
24d' to engage the lugs 26a of the intermediate ring 26. That is, in the 
tape-unloaded position, the driving torque of the motor 18 is connected 
directly to the idler 14 by means of the drive pulley, clutch disc 23 and 
intermediate ring 26. Therefore, with this drive system, when the fast 
forward or fast rewind button 30a or 31a is pushed to press the idler 14 
against the takeup reel tape 13 or supply reel table 12, the tape runs at 
the high speed within the cassette 2 under the direct driving action of 
the motor 18. 
When to switch the aforesaid apparatus to the reproducing mode, the 
operator needs to push the PLAY button 43. That is, when the PLAY button 
43 is pushed, this PLAY button 43 is locked in the pushed position by a 
lock mechanism (not shown), and the switch 102 is held in ON position, 
thereby its output P2 is changed from low to high level. Since, at this 
time, the loading completion detecting switch 100 is OFF with its output 
P0 of low level, the inputs of the NAND circuit 50 are all of high level, 
causing the output of the NAND circuit 50 to change to low level. As a 
result, a signal of high level is applied to the control terminal 44b of 
the drive control circuit 44 for the loading motor 9. In this case, the 
other control terminal 44a is supplied with a signal of low level, since 
the output P2 of the switch 102 is of high level and therefore one of the 
inputs of the NAND circuit 46 is of low level which causes production of 
an output of high level. Therefore, the motor 9 is energized by current 
flowing in F direction from the drive control circuit 44 and starts to 
rotate. As a result, the aforesaid loading ring 7 is driven through the 
gear 11 to turn in B direction in FIG. 1, while the aforesaid loading ring 
8 is driven through the gears 10 and 11 to turn in O direction in FIG. 1. 
As the rings 7 and 8 turns in the opposite directions to each other, the 
tape pull out means 4 and 3 while exerting pull on the tape 39 are moved 
in the predetermined paths, thus starting to train the tape over the wall 
of the tape guide drum 36. At the same time, the aforesaid unloading 
completion detecting switch 101 is released from depression by the 
actuating projection 7b formed on the loading ring 7, thereby its output 
P1 is changed from high to low level. Then, when the aforesaid loading 
rings 7 and 8 have turned the predetermined angular distance to complete 
the loading of the tape 39, the actuating projection 7a on the loading 
ring 7 closes the aforesaid loading completion detecting switch 100, 
thereby its output P0 is changed from low to high level. Therefore, one of 
the inputs of the NAND circuit 50 becomes low level, so that the output of 
the NAND circuit 50 changes from low to high level. As a result, a signal 
of low level is applied to the control terminal 44b of the drive control 
circuit 44. Since, at this time, the output P2 of the switch 102 is of 
high level, as has been mentioned above, the signal of low level appears 
on the control terminal 44a. Therefore, the drive control circuit 44 stops 
the loading motor 9 from further rotation. As a result, rotation of the 
loading rings 7 and 8 stops. As the aforesaid loading of the tape 39 is 
completed, the pinch roller 5 is brought into pressing contact against the 
capstan by means (not shown) and the tape 39 starts to run at the ordinary 
speed in the reproducing mode. In synchronism with the reach of the pinch 
roller 5 to the capstan 6, the takeup idler 28 is caused by a drive 
mechanism (not shown) to contact with the takeup reel table 13. Then, the 
takeup reel table 13 is driven to rotate with its reel starting to wind 
the tape 39. It is in this state that the electrical signals recorded on 
the tape 39 are read out by the rotary head (not shown) arranged in the 
interior of the tape guide drum 36 and an electronic circuit for 
reproduction (not shown), then undergo a predetermined signal processing 
and then is applied to a display device (not shown) where the recorded 
images are reproduced. That is, the apparatus takes the reproducing 
position. In this position, the actuating area 27b of the clutch 
changeover plate 27 is taken out of engagement with the actuating 
projection 8a formed in the lower surface of the loading ring 8, and the 
clutch changeover plate 27 is held in the position illustrated in FIG. 3 
under the action of a bias spring (not shown). As a result, the clutch 
disc 23 is held in the position where its extensions 23b and 23b' do not 
engage the projections 26a formed in the intermediate ring 26. For this 
reason, the driving torque of the motor 18 is transmitted through the 
drive pulley 24, slip member 25 and intermediate ring 26 to the idler 14. 
Whilst the aforesaid reproducing is under progression, when the fast 
forward button 30a or the fast rewind button 31a is depressed, the idler 
14 engages either the takeup reel table 13, or the supply reel table 12, 
and at the same time the slide plate 32 is moved to the left as viewed in 
FIG. 1, causing the actuating lever 33 to turn in the clockwise direciton 
which in turn causes the takeup idler 28 to move away from the takeup reel 
table 13. Along therewith, the switch 103 or switch 104 is turned on to 
produce the output P3 or P4 of high level. Responsive to this, the OR 
circuit 56 changes its output from low to high level. Since, at this time 
the aforesaid switches 100 and 102 have their outputs P0 and P2 both of 
high level, the inputs of the AND circuit 53 are all of high level, and 
the output P5 of the AND circuit 53 becomes high level. As a result, the 
control signal of high level is applied to the speed control circuit 521, 
thereby the capstan motor 18 is speeded up to the 2nd number of 
revolutions N2 for the capstan 6 running the tape 39 at the speed for the 
search mode. In this case, the direction of rotation of the captstan motor 
18 as the fast rewind button 31a is pushed to turn on the switch 104, is 
reversed by the drive control circuit 522. Otherwise, it is driven in the 
forward direction. Thereupon, the tape 39 is impelled by the pinch roller 
5 and capstan 6 to run at the increased speed above the ordinary 
reproducing tape speed in the forward or reversed direction. At this time, 
as has been described above, the one of the reel tables which takes up the 
tape, namely when in the fast forward, the takeup reel table 13, or when 
in the fast rewind, the supply reel table 12 engages the idler 14, and is 
driven to rotate by the idler 14. In this connection, it should be pointed 
out that the idler 14 because of its being rendered to cooperate with the 
slip member 25 in the transfer of the driving torque of the capstan motor 
18 therethrough enables that reel to wind the tape which is being fed at 
far faster a speed than the ordinary reproducing speed smoothly thanks to 
the properly adjusted torque. 
When to stop the apparatus from the aforesaid reproducing, the STOP button 
57 is depressed. Such depression of the STOP button 57 causes release of 
the PLAY button 43 from the locking connection by a lock release mechanism 
(not shown), thereby the switch 102 is turned off to change its output P2 
from high to low level. As a result, the control signal appearing at the 
control terminal 44a of the drive control circuit 44 for the loading motor 
9 changes from low to high level. Since, at this time, the output P2 of 
the aforesaid switch 102 is of low level, the control signal appearing at 
the control terminal 44b is of low level. As a result, the drive control 
circuit 44 gives off current flowing through the motor 9 in the direction 
indicated by arrow E. In this case, the direction of current flow to the 
motor 9 is opposite to that when in the loading time, that is, the F 
direction, so that the motor 9 is driven in the reversed direction to that 
when in loading time. Therefore, the loading rings 7 and 8 starts to turn 
in the reversed directions to those when in the loading time. Also in 
synchronism with the start of the movement of the loading rings 7 and 8, a 
control means (not shown) moves the pinch roller 5 away from the capstan 
6. In connection with this movement of the pinch roller 5, the takeup 
idler 28 is also moved away from the takeup reel table 13. At the same 
time, the loading completion detecting switch 100 is freed from the 
pressure of the actuating projection 7a of the loading ring 7, and is 
turned off, thereby its output P0 is changed from high to low level. 
As the loading rings 7 and 8 are turning in the unloading direction, the 
tape pull out means 4 and 3 moves in the reversed directions to those when 
in the loading time, permitting the tape 39 to be retracted into the 
interior of the cassette 2. In this case, the supply reel table 12 winds 
up the slack loop of the tape 39 as motion of the loading ring 8 is 
transmitted thereto through an intermediary (not shown). Then when the 
loading ring 7 reaches the unload completion position, the unload 
completion detecting switch 101 is actuated by the projection 7b so that 
its output P1 changes from low to high level. As a result, one of the 
inputs of the NAND circuit 46 becomes low level, then the output of the 
NAND circuit 46 changes from low to high level, and then the control 
signal at the control terminal 44a of the drive control circuit 44 becomes 
low level. Since, at this time, the control signal supplied to the other 
control terminal 44b is of low level, the aforesaid drive control circuit 
44 stops the motor 9 from rotating. That is, rotative movement of the 
loading rings 7 and 8 is stopped, and the unloading completion position 
illustrated in FIG. 1 is regained. In this position, as has been described 
above, the clutch changeover plate 27 is pushed again at the area 27b by 
the actuating projection 8a of the loading ring 8. It is noted that the 
tapered surface of the stopper portion 27c formed in the side wall of the 
actuating area 27b serves to guide the aforesaid actuating projection 8a 
onto the actuating area 27b smoothly. 
As in the above, in the above described embodiment of the apparatus, the 
driving torque transferring mechanism for the idler 14 is constructed so 
that responsive to movement of the loading rings 7 and 8, the 1st 
operative position where the driving torque of the motor 18 is transferred 
directly to the idler 14 is changed over to the 2nd operative position 
where the driving torque of the motor 18 is transferred through the slip 
member 25 to the idler 14. This gives rise to an advantage that the 
driving of the reel table when in the ordinary fast forward, or fast 
rewind time, and the driving of the takeup side reel table when in the 
search mode can be selectively performed by the use of the same idler 14. 
Therefore, the reel table drive mechanism in the search mode-equipped 
magnetic recording and reproducing apparatus is made extremely simplified, 
and the operating member for the fast forward and fast rewind of the tape 
within the cassette can be made to also serve as an operating member for 
the search mode, thus giving an additional advantage that the structure of 
the control panel is also simplified. 
It is noted that in the above-described embodiment of the apparatus the 
switching of the driving torque transfer mechanism is controlled by the 
use of the clutch disc 23 in combination with the clutch changeover plate 
27 which the latter is arranged to be displaced in response to the 
movement of the loading ring 8. However, the present invention is not 
confined thereto. For example, as indicated by a dashed line block in FIG. 
3, use may be made of a clutch solenoid as an actuator for the clutch 
changeover plate 27, and the operation of the clutch solenoid 58 is 
controlled in accordance with the output of the loading completion 
detecting switch 100. What is essential is in that the driving torque 
transfer mechanism of the invention is made switchable between the 1st and 
2nd positions depending upon the loading state of the tape in order to 
insure that when in the search mode, either one of the reel tables 12 and 
13 is driven with a proper winding torque by the idler 14. It is therefore 
to be understood that the foregoing description of the accompanying 
drawings are intended to be illustrative of the invention, and are not 
intended to be limiting since the practical structure may be modified in 
various ways. 
Also, though the above embodiment of the apparatus has been described in 
connection with the cooperation of the idler 14 with the capstan motor 18 
through the driving torque transfer mechanism in such a manner that only 
when in the search mode, the motor 18 is caused to rotate in the increased 
speed, it is preferred that as the idler 14 is made to be driven by the 
capstan motor 18, not only when in the search mode, but also when in the 
ordinary fast forward and fast rewind modes, the motor 18 is further 
speeded up. It is noted that the driving of the idler 14 may be carried 
out by a separate motor from the capstan motor 18. 
As has been explained in greater detail, according to the present 
invention, it is made possible to realize a magnetic recording and 
reproducing apparatus capable of the search mode of which the structure is 
very simple as compared with the conventional one. Further, there is no 
need to increase the number of manual operating members than the ordinary 
fast forward and fast rewind control members, since one of them can be 
used as the control member for the search mode. Therefore, the bulk and 
size and weight of the magnetic recording and reproducing apparatus 
capable of the search mode can be minimized as compared with the 
conventional one, and the control panel also can be simplified as compared 
with the conventional one.