Abstract:
In the magnetic recording and reproducing apparatus disclosed, a loading arrangement displaces magnetic tape between a position where the tape&#39;s running path from a tape supply member to a take up member relative to a recording and reproducing arrangement makes it possible to record and reproduce and a position where such recording and reproduction is disabled. A transfer friction arrangement between a tape drive and the supply member or the take up member changes its frictional operation depending upon the tape running path controlled by the loading arrangement. According to a specific embodiment disclosed, the drive is shiftable between a direct direct mode when the tape is disabled from recording or playback and a slip torque transmission mode when the recording-playback is enabled.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a recording and reproducing apparatus with a high speed search function, and more particularly to improvements in its reel pedestal drive mechanism. 
     2. Description of the Prior Art 
     In magnetic recording and reproducing apparatuses with fast speed search functions, wherein tape engaging a recording-playback head is driven at high speed to reproduce images in a so-called &#34;search&#34;, it is necessary to cope with the problem of regulating tape movement so that the tape may be wound at the high speed. The required torque transfer system for the tape supply and tape take up reel pedestals thus becomes very complex. For this reason, conventional types of such systems have utilized either separate electrically controlled motors for each reel pedestal, or complicated mechanical clutch mechanisms in order to accomplish the desired reel pedestal drive in each mode. The use of such systems therefore results in complex apparatuses which constitute one of the bottlenecks in attempts to minimize the bulk and size and weight of the system. Aside from requiring the actuating member for the ordinary fast feed and rewind, the actuation control portion also must have two actuating members adapted to operate only in the search mode for the forward and reverse feeds respectively. This increases the complexity of the actuation control portion and also calls for an increase in the space which the actuation control portion occupies. These problems become particularly serious when compactness, light weight, and good manageability are extremely important as in portable magnetic recording and reproducing apparatuses. 
     Generally, in the search mode, the recorder operates by rotating the capstan at a far higher speed then in the ordinary recording or reproducing mode. This causes the tape to run in the forward or reverse direction at this increased speed. The reel which takes up the tape, namely the take up 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 of a prescribed appropriate transfer torque. The number of revolutions is adjusted to be slightly faster than the tape speed required in the search mode. On the other hand, in the ordinary rewind or fast feed mode, the supply reel or take up reel is coupled directly to the output of the motor. Since, in this case, the winding torque increases and the tape runs at a 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 a helical scan type magnetic recording and reproducing apparatus having the tape loading mechanism for bringing magnetic tape into contact around a tape guide drum over the predetermined angular distance in which drum is included a magnetic head and is to provide a magnetic recording and reproducing apparatus characterized in that an idler is provided to selectively engage a 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. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 and 2 are plan views of an embodiment of a magnetic recording and reproducing apparatus according to the present invention in the loaded and unloaded positions respectively. 
     FIG. 3 is a fragmentary sectional view taken along line A--A&#39; of FIG. 2. 
     FIG. 4 is an exploded perspective view of the driving torque transferring mechanism. 
     FIG. 5 is a perspective view of the clutch changeover plate. 
     FIG. 6 is a side elevational view looking from a direction indicated by arrow D in FIG. 3. 
     FIG. 7 is a schematic diagram of the drive circuit of the loading motor and capstan motor. 
    
    
     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 showing an operative position before the tape loading and FIG. 2 an operative position after the completion of the tape loading. The tape loading method employed in this apparatus is substantially the so-called &#34;M loading method.&#34; In FIG. 1, a tape cassette 2 is guided into the illustrated position by a cassette attachment device (not shown). In that position, 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 the casing of the cassette 2 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 members 3 and 4 freely move. Such construction of tape cassette 2 is known in the art, and no further 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 inside the tape behind the aforesaid apertured 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 rotatably mounted on another loading ring 8. A tape pull pin 35a is carried on a tape pull arm 35. The 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 also engaged each other, and the pinion 11 is connected to the output shaft of the motor 9. Therefore, the loading rings 7 and 8 are always rotated in opposite directions as the motor 9 rotates in either direction. When loading the tape, the 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 tape pull members 4 and 3 to move in their predetermined paths defined by guide means (not shown) so that the tape 39 is pulled out of the interior of the cassette 2 and then brought into training engagement against the wall of a tape guide drum 36 over a predetermined angular distance of about 180°. The aforesaid tape guide drum 36 incorporates a rotary head (not shown). This rotary head functions to record video signals on the tape contacting 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. 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 it brings the tape 39 into contact with a sound and control head 37 illustrated in FIG. 2, and finally reaches 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. Actuation of the pinch roller solenoid 38 brings an idler 28 which is rotated by an endless belt trained over an output shaft 19 of a motor 18 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. This rotates the takeup reel turn table 13. 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 rotationally. 
     The aforesaid tape pull arm 35 is pivotally mounted at a pin 35b on a base plate 1, and, as the 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 12 to impart into the tape 39 a predetermined a back tension. 
     It is noted that the loading ring 7 also carries 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, i.e., to the position illustrated in FIG. 2, or when to the opposite terminal end of movement, i.e., to the position illustrated in FIG. 1, the aforesaid switches 100 or 101 are pushed by the projection 7a or 7b to their respective closed positions. 
     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 almost half the distance between the supply and takeup reel tables 12 and 13, which are rotatably fitted on spindles 12a and 13a mounted on the base plate 1, after the idler 14 is pressed against the takeup side reel table 12 or 13. 
     The idler 14 whose 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 to, the inner side of the lower surface of which a slip member 25 adheres, and its outer side of which is provided with an engagement projection portion 26a. 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 is composed 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) which transfers the driving torque of the capstan motor 18. Therefore, the outer peripheral edge of the flanged portion 24a has a recessed portion 24c in which the drive belt fits snugly. Also the aforesaid flanged portion 24a has a pair of slots 24d and 24d&#39;  formed in predetermined positions. A clutch disc 23 rotatably and slidingly fits on the outer diameter of the aforesaid boss portion 24b and is provided with a pair of extensions 23b and 23b&#39; which freely fit in the slots 24d and 24d&#39; formed in the flanged portion 24a of the drive pulley 24. 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. In the loaded position shown in FIG. 3, the clutch disc 23 is held by the clutch changeover plate 27 in the illustrated position. Fixed to the lower end of the aforesaid idler shaft 20 is a stopper sleeve 21. 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 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. This rotates the idler 14. 
     The clutch changeover plate 27 functions to slide the aforesaid clutch disc 23 on the idler shaft 20 in vertical directions, and, as illustrated in FIG. 5, is provided with a pair of mount arms 27a and 27a&#39;. These mount arms 27a and 27a&#39; have respective penetration holes formed therein and, as shown in FIG. 6, these penetration holes and those in a pair of mount portions 1a and 1a&#39; bent down in predetermined positions of the base plate 1 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. This formed portion 27d slidably receives the flange 23a of the aforesaid clutch disc 24. 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. One of the side portions of this actuating area 27b projects into a stopper portion 27c. The clutch changeover plate 27 is urged by a spring (not shown) 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. 
     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 and pushes the actuating area 27b of the clutch changeover plate 27. This turns the clutch changeover plate 27 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 virtue of the forked portion 27d engaging the flange 23a. As a result the extensions 23b and 23b&#39; freely fitted in the penetration holes 24d and 24d&#39; of the dirve pulley 24 engage the engagement projections 26a formed in the intermediate ring 26, and the driving torque of the drive pulley 24 from the capstan motor 18 is directly transmitted to the intermediate ring 26. 
     The idler table 15 is rotatably supported on a shaft 16 mounted on the base plate 1 and is urged to the central position between the two reel tables 12 and 13 by a spring 17 affixed to a pin 42 mounted on the base plate 1 and sandwiching a projecting portion 15a formed in the idler table 15 in sandwiching manner, table 15 includes 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 slidably moved by pushing a fast feed button 30a and a fast rewind button 31a respectively. Therefore, a pushing operation of the fast forward button 30a, acts on the aforesaid armed portion 15b which in turn causes the idler table to turn in a clockwise direction until the idler 14 engages the takeup reel table 13. Likewise, depressing the fast rewind button 31a, acts on the aforesaid armed portion 15b 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, a slide plate 32, upon actuation of the fast feed control member 30 and fast rewind control member 31 moves to the left as viewed in the figure. Such leftward movement of this slide plate 32 cases an actuating lever 33 with its one end engaged 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 actuation of the aforesaid fast feed control member 30 and fast rewind control member 31 turns on switches 103 and 104 illustrated in FIG. 7. 
     FIG. 7 illustrates a drive circuit for the loading motor 9 and capstan motor 18 in a position where unloading is completed. The drawing includes the loading completion detecting switch 100; the aforesaid unloading completion detecting switch; 101; a switch 102 arranged to turn on when a play button 43 illustrated in FIG. 1 is depressed; a switch 103 arranged to turn on when the fast feed button 30a is depressed; and a switch 104 arranged to turn on when the fast rewind button 31a is depressed. These switches 100 to 104 are formed as 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 to one terminal thereof to a positive voltage source V and at the other terminals to the circuit earth or ground 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 assume high level when the corresponding switches 100 to 104 are actuated, or closed, and low levels when de-actuated or opened. 
     The 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 a 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 switched by a pair of NPN transistors T5 and T6. That is, the base of the 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 conductive. 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 conductive. Such motor drive circuit is known to those skilled in the art, and no further explanation is given here. 
     The aforesaid control terminal 44a is supplied through the inverter 45 with an output of a 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. A drive circuit 52 for the capstan motor 18 includes 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. The control signal is supplied by the output P5 of an AND circuit 53. The output P5 of AND circuit 53, when low, sets the number of revolutions of the capstan motor 18 to the first value N1, and when high, sets it to the second 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 &#34;forward direction&#34;), or in the opposite direction thereto (hereinafter called &#34;reversed direction&#34;). A control signal therefor is supplied by the output P6 of an amplifier 54. And, when the output P6 of the amplifier 54 is of low level, the capstan motor is rotated in the forward direction, and when of high level, it is driven in the reverse 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. Therefore, its details are not further 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 not further described. 
     The 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. 
     According to an embodiment of the invention, a solenoid drive circuit 57 drives a clutch solenoid 58. 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 such that when the output P0 of the switch 100 is high, the clutch solenoid 58 is driven. 
     According to another embodiment of the invention, the circuits 57 and 58 are omitted and the actuating projection 8a formed on the lower surface of the loading ring 8 actuates the clutch changeover plate 27. 
     Also, in FIG. 7, though not particularly shown, an additional circuit responsive to depression of any one of the play button 43, fast forward button 30a and fast rewind button 31a supplies drive voltage to the drive circuit 52 for the capstan motor 18. The capstan motor is then driven 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: 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 assumes the most clockwise position illustrated in FIG. 3 against the bias force of a spring (not shown). Therefore, the clutch disc 23 whose flange 23a is clamped by the forked portion 27d of the clutch changeover plate 27 is held in the raised position where the extensions 23b and 23b&#39; of the clutch disc 23 pass through the respective freely fitted holes 24d and 24d&#39; 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 foward or fast rewind button 30a or 31a is pushed to press the idler 14 against the tapeup 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. 
     To switch the aforesaid apparatus to the reproducing mode, the operator needs to push the PLAY button 43. When the PLAY button 43 is pushed it is locked in the pushed position by a lock mechanism (not shown), and the switch 102 is held ON so its output P2 is changed from low to high. Since, at this time, the loading completion detecting switch 100 is OFF with its output P0 low, the inputs of the NAND circuit 50 are all high, causing the output of the NAND circuit 50 to change to low. 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 low which causes 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 the direction B in FIG. 1, while the aforesaid loading ring 8 is driven through the gears 10 and 11 to turn in the direction C in FIG. 1. As the rings 7 and 8 turns in the opposite directions to each other, the tape pull out members 4 and 3 while exerting pull on the tape 39 are moved in the predetermined paths and start 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 its depressed state by the actuating projection 7b formed on the loading ring 7 so its output P1 is changed from high to low level. Then, when the 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 loading completion detecting switch 100 so 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 the takeup reel table 13. Then, the takeup reel table 13 is rotated and its reel starts 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 assumes 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&#39; 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. 
     During reproduction, 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 direction 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. 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 second 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 capstan 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 rotated by the idler 14. In this connection, it should be pointed out that the idler 14 because of its cooperation with the slip member 25 in the transfer of the drive torque of the capstan motor 18 therethrough enables the reel to wind the tape which is being fed smoothly at far faster a speed than the ordinary reproducing speed thanks to the properly adjusted torque. 
     To stop the apparatus from 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) so 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. 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 produces a current flow 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 during loading, that is, the F direction, so that the motor 9 is driven in the direction opposite to that when loading. Therefore, the loading rings 7 and 8 start to turn in directions opposite to those during loading. Also in synchronism with the start of 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 members 4 and 3 move in directions opposite to those at the time of loading, thereby 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. As a result, one of the inputs of the NAND circuit 46 becomes low, then the output of the NAND circuit 46 changes from low to high, and then the control signal at the control terminal 44a of the drive control circuit 44 becomes low. 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 this embodiment of the apparatus, the driving torque transfer mechanism for the idler 14 is constructed so that responsive to movement of the loading rings 7 and 8, the first operative position where the driving torque of the motor 18 is transferred directly to the idler 14 is changed over to the second 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 extremely simplified, and the operating member for the fast forward and fast rewind of the tape within the cassette also can be made to 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 first and second 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 in the search mode is the motor 18 caused to rotate in the increased speed, it is preferred that as the idler 14 be made to be driven by the capstan motor 18, not only in the search mode, but also in the ordinary fast forward and fast rewind modes, the motor 18 is further speeded up. According to an embodiment, the driving of the idler 14 is carried out by a motor separate from the capstan motor 18. 
     As has been explained in greater detail, according to the present invention, it is possible to realize a magnetic recording and reproducing apparatus capable of a search mode with a structure that 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.