GB2062934A - Tape recorder - Google Patents

Abstract

The required operational state of a tape recorder, which may be an automatic reversing cassette tape recorder, is selected by manual keys 53 (Figure 8) and established under control of an electronic control unit 54 by motor 50 driven cam means 44 which moves the various mechanical parts to the appropriate position. Cam 44 has cam surfaces to operate forward and reverse pinch rollers 8, 9, reel brakes 45b and a plate 47 carrying heads 5, 6, 7. A CPU in control 54 has inputs from manual keys 53, record/reproduce dectector 56a, reel rotation detector 56b, and a cam detector 56c and gives outputs to a driver 55 controlling the direction of cam motor 50 and the direction and speed of reel motor 26. Motor 26 drives an idler gear 31 on a lever 29 which via friction means is caused to swing and engage gear 31 with the appropriate reel shaft 3 or 4 in accordance with the direction of rotation of motor 26. Cam 44 can establish fast forward and reverse, forward and reverse record/reproduce, and pause in the forward and reverse state, and detector 56c comprises a cam position indicating switch 52 (Figure 7). A cam rotation direction memory switch 154 (Figures 12, 13) may also be provided to ensure proper recording operation even if a timer is used to restart the recorder after autoreversing has been effected in the previous recording operation. If the CPU senses overrun of cam 44 past the desired position, it effects a cam reversal sequence until the correct position is achieved. An alternative embodiment (Figures 18-21) in which the reel brakes 234 are mounted on the movable head plate 203, has a first cam wheel 236 to move head plate 203 and forward pinch roller 215, and a second cam wheel 235 to move reverse pinch roller 216. This recorder can be simply changed from an auto reversing two recording/reproducing direction type to a unidirectional recording/reproducing type by omitting cam wheel 235, pinch roller 216 and associated components. <IMAGE>

Description

SPECIFICATION Cassette tape recorder The present invention relates to a cassette tape recorder and, more particularly to a cassette tape recorder having an automatic tape feed reversing mechanism controlled by an electronic control unit incorporated in the tape recorder.

One prior art automatic reversing mechanism of a cassette tape recorder comprises two mechanisms, one for the selected operation of play, pause, quick feeding of the tape or stop in the forward feeding of the tape, which has no relation to the reverse operation, and the other for those in the reverse feeding of the tape. Thus, the construction is rendered complicated and the cost is accordingly high.

In another prior art automatic reversible tape recorder using a reversible driving motor driven through an electronic control unit for selectively setting the tape recorder in the desired operation, false functions may arise if no ascertaining means is provided for ascertaining whether or not the selected mechanism for the desired operation is properly set in operation.

Also in the prior art automatic reversible tape recorders of the types described above, false function may arise, if the recording operation of the tape recorder is stopped after the feeding of the tape in one direction has been automatically reversed at the tape end and if the tape recorder is again started for recording operation after it has been stopped, because the tape recorder is operated in the originally set direction of feeding of the tape notwithstanding the automatic reversing of the feeding of the tape at its end. Therefore, latch relay means was required heretofore for positively preventing the above described false function by giving to the control unit memory a signal of the direction of feeding of the tape before the tape is stopped, thereby rendering the cost to be high because of the complicated construction of such latch relay means.

In the course of development of tape recorders, a large number of types of tape recorders have appeared in the market for satisfying different purposes ranging from a simple unidirectionally operable tape to a very complicated multi-purpose tape. This makes the production of the tape recorders very complicated and the investment very expensive, requiring an increase in the number of production lines and parts of different designs and storage of large numbers of various parts.

In view of the above, it is an object of the present invention to provide a novel and useful cassette tape recorder of the automatic reversing type which avoids the above described disadvantages of the prior art tape recorders and which is simple in construction, inexpensive in manufacture and accurate in operation.

The present invention resides in a tape recorder having at least one electrical motor and operating mechanisms adapted to be driven thereby for the performance of various different operations and having an electrical control unit for the manual selection of any one of said operations and cam means driven by said one motor or one of said motors and having cam surfaces operatively engaging respective ones of said operation mechanisms, said control unit being adapted to control said motor or motors and to position said cam means in accordance with the selected operation, whereby the selected operation is performed by the respective operating mechanism under the control of said control unit.

A preferred embodiment avoids false functions which might occur in the recording operation using a timer mechanism due to the automatic reversing of the feeding direction of the tape at its end prior to the restarting of recording operation after the tape recorder has been stopped by the timer.

The general design of the tape recorder can be common to a simple compact unidirectionally operable tape recorder, whereby either of the automatic reversible type or the unidirectionally operable type can be constructed by merely additionally assembling or omitting assembly of parts exclusively necessary for the reversing operation of the tape recorder, thus enabling the production lines to be reduced and the investment to be largely reduced for producing various types of tape recorders.

Thus, a characteristic feature of the present invention is the provision of a tape recorder characterized by cam means adapted to be driven to any of the predetermined positions by a reversible motor controlled by an electronic control unit which is incorporated in the tape recorder and which can be manually set at will by the operator to any of the various operating positions of the tape recorder, the cam means having a plurality of cam surfaces, each operatively engaging with the respective operating mechanism of the tape recorder for various operations thereof, thereby permitting the tape recorder to be set automatically in the desired operation in either the forward or the reverse direction of feeding of the tape by virtue of automatic positioning of the cam means by the motor at the position as determined by the control unit.

In another embodiment of the present invention, the cam means is divided into two units, one of which has cam surfaces for operating mechanisms required exclusively for the reversing of feeding of the tape while the other unit has those for the operating mechanisms required for all the remaining operations of the tape recorder, thereby permitting assembly of either an automatic reversing tape recorder or a unidirectionally operable tape recorder generally common in design to each other by merely additionally assembling or omitting assembly of parts exclusively required for the reverse operation of the tape recorder, thus making it possible to largely lower the total investment for the production of a plurality of types of tape recorders by reducing the production lines and parts of different design and storage of various parts.

The present invention will be further described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view showing the construction of a cassette tape recorder in accordance with one embodiment of the present invention; Figure 2 is a plan view showing the construction of the tape recorder of Figure 1 located beneath the mechanism shown in Figure 1; Figures2A and 2B are plan views showing the configuration of the forward feed and the reverse feed pinch roller actuating lever incorporated in the mechanism shown in Figure 2, respectively; Figure 3 is an elevational view partly in crosssection showing the mechanism for selectively driving the reel mounting shafts; Figure 4 is an elevational view showing the cam member for actuating various operating mechanisms of the tape recorder;; Figure 5 is an elevational view showing the mechanism for driving the cam member; Figure 6 is a plan view showing in detail the cam member of Figure 4; Figure 6A is a plan view showing a cam surface formed in the cam member of Figure 6 for actuating the forward feed pinch roller through the forward feed pinch roller actuating lever shown in Figure 2A; Figure 7 is a plan view showing the cam position detecting switch co-operating with the cam member shown in Figure 6; Figure 8 is a block diagram showing the electronic control unit for controlling the various operating mechanisms in the tape recorder; Figure 9 is a table showing the relationship between the actuation of the various operating mechanism;; Figure 10 is a diagram showing the relationship between the rotational position of the cam member and the lift of the respective cam surfaces; Figure 11 is a plan view showing the modification of the cam position detecting switch shown in Figure 7, wherein a tape feed direction memory switch is incorporated; Figure 12 is a bottom view showing the tape feed direction memory switch incorporated in the cam position detecting switch of Figure 11; Figure 13 is an elevational view partly in crosssection showing the cam member and the cam position detecting switch as well as the tape feed direction memory switch shown in Figures 11 and 12;; Figure 14 is a block diagram showing the electric circuit including the electronic control unit, the cam position detecting switch, the tape feed direction memory switch, and the drive circuit for driving the cam member driving motor; Figure 15 is a diagram showing the timed sequential relationship between the wave forms of the pulses To, T1, T2 delivered by the electronic control ; unit for indicating the reverse operation position, stop position and the forward operation position of the tape recorder, respectively; Figure 16 is a diagram showing the repeated occurrence of the pulses T2 as controlled by the cam position detecting switch of Figure 14 set in the forward feed position; Figures 17A and 17B are diagrams showing the flow chart of the operation of the electronic control unit of Figure 14; Figure 18 is a plan view similarto Figure 1 but showing a modified tape recorder in accordance with another embodiment of the present invention; Figure 19 is a plan view similar to Figure 2 but showing the mechanism located beneath the mechanism shown in Figure 18; Figure 20 is a plan view showing the mechanism located beneath the mechanism shown in Figure 19; and Figure21 is a plan view showing the belt drive mechanism for driving the capstan fly wheels of the tape recorder shown in Figure 18, the belt drive mechanism being located beneath the mechanism shown in Figure 20.

With reference to Figure 1, an automatic tape feed reversing cassette tape recorder in accordance with the present invention comprises forward feed capstan 1, reverse feed capstan 2, tape supply reel shaft 3 (in forward feed operation), tape take-up reel shaft 4 (in forward operation), recording/reproducing head 5, forward feed eraser head 6, reverse feed eraser head 7, forward feed pinch rollers 8 cooperating with the capstan 1 and reverse feed pinch roller 9 co-operating with the capstan 2.

As shown in Figure 2, a flywheel 10 is integrally secured to the capstan 1 and a flywheel 11 is integrally secured to the capstan 2, and a belt 14 tensioned around a driving pulley 13 of a tape drove motor 12 adapted to rotate in the clockwise direction is stretched around the upper half of the periphery of the flywheel 10 and the lower half of the periphery of the flywheel 11 and extends over the upper portion of the periphery of the flywheel 11 to and around a guide pulley 15 and is returned to the pulley 13, so that the flywheel 10 is driven in the counterclockwise direction together with the forward feed capstan 1 while the flywheel 11 is driven in the clockwise direction together with the reverse feed capstan 2.

The supply reel shaft 3 mounts thereon integrally a gear 16 and a friction wheel 18. In like manner, the take-up reel shaft 4 mounts thereon integrally a gear 17 of the same size as the gear 16 and a friction wheel 19 of the same size as the wheel 18. As shown in Figure 3, a friction wheel 21 having a sleeve portion 21 a is secured to a shaft 20 rotatably supported by the frame of the tape recorder, and a pulley 22 is rotatably supported and axially shiftable on the sleeve portion 21a with the inner sleeve portion 22a of the pulley 22 fitting on the sleeve portion 21 a. An annular friction pad 23 is interposed between the lower surface of the friction wheel 21 and the upper surface of the pulley 22, while a compression coil spring 24 is located around the sleeve portion 22a between the pulley 22 and the bottom plate of the tape recorder, so that the pulley 22 is urged against the friction wheel 21 by the action of the spring 24 with the friction pad 23 interposed therebetween thereby permitting the friction wheel 21 to be frictionally driven together with the shaft 20 in either of the opposite two rotational directions through the friction pad 23 by the pulley 22, which is in turn driven by a pulley 27 of a reversible reel drive motor 26 through a belt 25 stretched therebetween.

A gear 28 is secured to the upper end of the shaft 20 and a switching lever 29 is swingably supported on the shaft 20 immediately below the gear 28. A gear 31 adapted to engage with the gear 28 is rotatably mounted on a shaft 30 which is secured to the free end of the lever 29. An annular friction pad 32 is interposed between the gear 31 and the free end of the lever 29, and a dish-shaped compression spring 33 is located on the shaft 30 between the upper surface of the gear and a collar secured to the top of the shaft 30, so that the gear 31 is frictionally engaged with the lever 29 through the friction pad 32 by the action of the spring 33.

Therefore, when the shaft 20 is rotated by the motor 26 in either of the opposite two directions, the lever 29 is swung in the same direction by virtue of the frictional engagement of the gear 31 and the lever 29 and the engagement of the gear 31 with the gear 28 secured to the shaft 20, while the gear 31 per se is rotated in the opposite direction by the rotation of the gear 28.

As shown in Figure 2, the gear 31 is located between the gear 16 of the supply reel supporting shaft 3 and the gear 17 of the take-up reel supporting shaft 4 and is spaced an appropriate distance from each of the gears 16, 17 in the inoperative position of the tape recorder.

Thus, when the lever 29 is swung in either of the opposite two directions, depending upon the direc 'tion of rotation of the motor 26 (counterclockwise rotation of the motor 26 for the forward feed clockwise rotation of the motor 26 for the reverse Steed), the gear 31 on the lever 29 will engage with either the gear 17 of the take-up reel shaft 4 or the gear 16 of the supply reel shaft 3 so as to frictionally rotate the reel shaft 4 or 3 by virtue of the frictional force of the friction pad 23 (Figure 3) so as to take up the tape.

As shown in Figure 2, the pinch roller 8 or 9 co-operating with the capstan 1 or 2 is rotatably supported by pinch roller supporting lever 36 or 37 which is in turn rotatably supported by shaft 34 or 35 secured to the frame of the tape recorder, the levers 36,37 being in symmetry with each other as shown in Figure 2. Each of the arms 36a, 37a extending downwardly from the respective levers 36, 37 has a hole at the lower end thereof through which one end of the tension spring 38 or 39 is supported while the other end of each spring 38, 39 is supported by the bent lug 40c or 41 c of each pinch roller actuating tappet 40,41 horizontally shiftably supported in the frame by slot-pin guide means 40d, 41 d, 42 as shown in Figures 2, 2A and 2B.The tappets 40, 41 are shown separately in Figures 2A, 2B in which the opposite two ends of each tappet 40, 41 are designated by numerals 40a, 40b; 41 a, 41 b.

Each of the springs 38,39 is arranged to swing the respective pinch roller supporting lever 36, 37 so as to urge the pinch roller 8 or 9 against the respective capstan 1 or 2. However, the bent lug 36b or 37b formed in the lower end of the arms 36a, 37a of each lever 36,37 is adapted to be abutted by the end 40a or41a of the tappet 40 or 41, as shown also in Figure 4 so that the lever 36,37 is prevented from being swung and the pinch roller 8 or 9 is held in spaced apart from the respective capstan 1,2.

Atension spring 43 is supported at its one end by a bent lug 40e of the tappet 40 and at its other end by a bent lug 41e of the tappet 41 to urge the tappet 40 to the right so that the right hand end 40a thereof urges the lever 36 in the counterclockwise direction to maintain the pinch roller 8 spaced apart from the capstan 1, while the tappet 41 is urged to the left so that the left hand end 41 a thereof urges the lever 37 in the clockwise direction, thereby maintaining the pinch roller 9 spaced apart from the capstan 2.

In this position neither of the springs 38,39 need be tensioned.

The operation of the pinch roller actuating tappets 40,41 for bringing either of the pinch rollers 8,9 into the operative position will be described later in connection with a cam member 44.

Referring further to Figure 2, a collar 20a for the shaft 20 slidably guides the elongated hole 45a formed in a T-shaped brake tappet 45. A friction brake shoe 45b is supported on the free end of each arm of the tappet 45 and the brake shoes 45b are urged respectively to abut against the friction wheels 19 and 18 of the reel shafts 4, 3, so as to brake the same, by means of a spring 46 wound around the collar 20a and having the opposite two ends engaging with the respective arms of the tappet 45 so as to urge the tappet 45 downwardly.

The operation of the tappet 45 for releasing the brake shoes 45b will be described later in connection with the cam member 44.

The recording/reproducing head 5 and the eraser heads 6,7 are mounted on a head supporting base plate 47 as shown in Figure 1 which is slidably supported by guide means (not shown in Figure 1) between the forward operative position of the heads 5, 6, 7 and the rearward inoperative position thereof (upwardly and downwardly in Figure 1) and a spring 48 is tensioned between the frame of the tape recorder and the base plate 47 so that the base plate 47 is urged to the operative position.

The operation of the base plate 47 for bringing the head 5,6,7 into the inoperative position will be described below with reference to the cam member 44.

The above described operations of the head supporting base plate 47, the pinch roller actuating levers 40,41 and the brake lever 45 are carried out by one and the same cam member 44.

As shown in Figure 6, the cam member 44 is formed integrally with cam surfaces 44a, 44b, 44c, 44d and gear teeth 44e. The cam surface 44a engages with a pin 49 secured to the headsupporting base plate 47, and the cam surface 44b (see Figure 6A) engages with the cam engaging arm 40f of the pinch roller actuating tappet 40 (see Figure 2A). The cam surface 44c engages with the cam engaging arm 41f of the pinch roller actuating tappet 41 (see Figure 2B), while the cam surface 44d engages with the lower cam engaging end 45c of the brake tappet 45.

The gear teeth 44e are driven from a reversible motor 50 in either the clockwise (forward feed of the tape) or counterclockwise (reverse feed of the tape) direction through a gear train 50', as also shown in Figure 5, so that all the cam surfaces 44a to 44d are rotated integrally therewith.

The cam surface 44a engaging with the pin 49 is of a downwardly raised shape in the inoperative position as shown in Figure 6 so that, when the cam member 44 is rotated in the clockwise (or counterclockwise) direction to bring the tape recorder into the forward (or reverse) quick feed position (at the angle of 45 , for example), the pause position in forward feed (at the angle of 90% for example) or the recording/reproducing position in forward feed (at the angle of 1500, for example), the base plate 47 is moved forwardly by a predetermined amount for the respective operation of the tape recorder.In the quick feed position, the heads 5,6,7 are kept spaced apart from the tape and the brake shoes 45b are kept apart from the friction wheels 17, while the reel driving motor 26 is supplied at a high voltage so as to rotate the selected reel at a high speed by virtue of the actuation of the electronic control unit as set manually for the forward (or reverse) quick feed of the tape. In the pause position, the head base plate 47 is moved further forwardly, the selected pinch roller being moved close to the capstan with a slight clearance held therebetween as described later, and the brake shoes 45b being kept in contact with the friction wheels 17, 18 as described later.

In the recording/reproducing position, the head base plate 47 is moved to the foremost position with the selected pinch roller in contact with the capstan (being driven by the motor 12) as described later and the brake shoes 45b moved apart from the friction wheels 17, 18 as described later, while the selected one(s) of the heads 5,6,7 are actuated by the control unit as set manually and the reel driving motor 26 is driven in the selected direction by a low voltage for the normal tape take up operation.

The cam surface 44b engaging with the upwardly extending arm 40f of the pinch roller actuating tappet 40 has in the inoperative position thereof a raised portion at the right hand side decreasing the height in the clockwise direction as shown in Figure 6A.

As the cam member 44 is rotated in the clockwise direction for forward feed of the tape, the arm 40f and, hence, the tappet 40 are urged to the left together with the end 40a and the bent lug 40c by the engagement of the cam surface 44b with the arm 40f, thereby permitting the pinch roller supporting lever 36 to be swung in the clockwise direction to move the pinch roller 8 towards the capstan 1 by the action of the spring 38 which is now being tensioned by the leftward movement of the bent lug 40c. Thus, when the cam member 44 is rotated in the clockwise direction by 450 in the clockwise direction to the quick feed position, the end 40a comes to the position where the pinch roller 8 moves towards the capstan 1 but is held apart from the capstan 1 to allow free movement of the tape therebetween by the accelerated driving of the reel driving motor 26.

In the pause position where the cam member 44 is rotated by 90 , the pinch roller 8 is moved close to the capstan 1 with only a slight clearance held therebetween so that the immediate recording/ reproducing operation is allowed as is well known in the art. When the cam member 44 is rotated in the clockwise direction by 1500 to the forward recording/ reproducing position, the pinch roller supporting lever 36 comes to the position at which the pinch roller 8 is urged against the capstan 1 by the action of the spring 38 so that the tape sandwiched therebetween is fed at a constant speed given by the flywheel 10 of the capstan 1 for the recording/ reproducing operation while the selected one(s) of the heads 5,6,7 for the forward feed of the tape are actuated by the control unit of the tape recorder.

In like manner, the arm 41f of the pinch roller actuating tappet 41 (symmetrical with the lever 40 in left-right relation as shown in Figure 2B) engages with the cam surface 44c (symmetrical with the cam surface 44b (Figure 6A) in left-right relation) so that, when the cam member 44 is rotated in the counterclockwise direction for the reverse feed of the tape by 450, 900 and 1500, respectively, then the pinch roller 9 moves to the reverse quick feed position, pause position and the reverse feed recording/reproducing position, respectively, in the similar manner as in the case of the pinch roller 8.

As described earlier, the springs 38,39 are normally held in relaxed or non-tensioned state except when either one of them is brought to the operative position by the actuation of the tappet 40 or 41, thereby reducing the energy required for the actuation of the springs and ensuring the smooth operation, while the life of the spring is prolonged. # - The cam surface 44d has a recessed portion 44fizz the top thereof in the inoperative position of the tape recorder as shown in Figure 6, so that, in the in operative position, the lower engaging end 45c of the brake tappet 45 is held apart from the recessed portion 44f of the cam surface 44d and the brake shoes 45b are urged against the friction wheels 17, 18 by the action of the spring 46, thereby applying braking force to the wheels 17, 18 and hence to the reel shafts 3,4.When the cam member 44 is rotated in either the clockwise or the counterclockwise direction for the forward or the reverse feed of the tape, the cam surface 44d urges the end 45c of the tappet 45 upwardly thereby moving the brake shoes 45b away from the friction wheels 17, 18 to allow free rotation of the reel shafts 3,4. In Figure 3 the actual position of the tappet 45 is shown by the chain line, while the tappet 45 and the brake shoe 45b are shown by the solid line in a virtual position forthe clear showing of the relationship to the friction wheel 18.

As described above, all the desired operations of the tape recorder of the present invention can be carried out by only one and the same cam member 44 thereby rendering the mechanism compact and simple.

The cam member 44 is driven to any of the desired rotational positions by the demand from the electronic control unit 54 as shown in Figure 8.

To this end, a cam position detecting switch 52 as shown in Figure 7 is provided so as to feed back the detected cam position signal to the control unit 54 in order to ascertain that the cam member 44 is accurately positioned in the position for the desired operation of the tape recorder.

The switch 52 comprises a movable contact 51 having a pair of sliding tongues 21 a, 51 b which is secured to the lower surface of the cam member 44 as shown in Figure 4 and a printed circuit secured to the frame of the tape recorder co-operating with the movable contact 51.

As shown in Figure 7, the printed circuit includes a common stationary contact 52a connected to a terminal 52'a and electrically contacting at all times with the sliding tongue 51a, a stationary inoperative position contact 52b connected to a terminal 52'b, a stationary forward quick feed position contact 52c, a stationary forward feed pause position contact 52d and a stationary forward feed recording/reproducing position contact 52e, the contacts 52c, 52d, and 52e being connected commonly to a terminal 52'c, a stationary reverse quick feed position contact 52f, a stationary reverse feed pause contact 52g and a stationary reverse feed producing/reproducing position contact 52h, the contacts 52f, 52g and 52h being connected commonly to a terminal 52'f, all the stationary contacts 52c to 52h selectively contacting with the sliding tongue 51 b as the cam member 44 is rotated from the inoperative position at which the tongue 51 b contacts with the contact 52b as shown in Figure 7, in the clockwise or counterclockwise direction by about half a revolution or about 1500 for the forward feed or the reverse feed of the tape.

Each of the position contacts 52b to 52h, when selectively contacting with the sliding tongue 51 b, transmits the respective operation position signal to the control unit 54 as described later in detail.

Referring # Refereing now to Figure 8 showing the electronic control circuit 54, the output of the manual keys 53 for setting the desired operation of the tape recorder is applied to the matrix 54a of the unit 54, and the output of the matrix 54a is applied to the central processing unit (CPU) 54b so that the result of the operation of CPU 54b is applied to the driver circuit 55 so as to rotate the motors 26, 50 for the desired operation, while the tape drive motor 12 is controlled by the constant speed control device 57.The operations of the respective motors 12,26, 50 are detected by a recording/reproducing detector 56a, a reel shaft rotation detector 56b and a cam position detection 56c of the detecting station 56, the detector 56c including the cam position detecting switch 52 as will be described in detail later.

The detecting signals from the detectors 56a, 56b, 56c are fed back to the matrix 54a of the control unit 54 thereby ascertaining whether or not the operation of each motor 12, 26, 50 is properly carried out. Thus, the proper operation of the tape recorder is ensured bythecontrol unit 54.

Figure 9, which is in two parts 9A, 9B as illustrated, shows the manner of operation of each of the various operating mechanisms of the tape recorder as the cam member is rotated for the desired operation.

Figure 10 is a diagram in which the operating position of the brake cam 44d, the head base plate cam 44a, the pinch roller cam 44b, 44c and the cam position switch 52 as set according to the rotation angle of the cam member 44 are shown. The signals delivered by the cam position switch 52 will be described later.

Figure 11 shows a position detecting switch 52' similar to the switch 52 in which, however, a cam rotation direction memory switch 154-as shown in Figures 12 and 13 is incorporated in order to make it possible to operate the automatic reverse feed tape recorder using a timer as previously described.

The switch 52' comprises, as shown in Figure 13, a printed circuit supporting plate 153 having stationary contacts 52a to 52h similar to those in the switch 52 on the upper surface thereof, while a stationary contact 154a connected to a terminal 154' and a stationary contact 154b connected to a terminal 154'b of the switch 154 are provided on the lower surface of the plate 153 exposed downwardly through an opening formed in the frame of the tape recorder.

The stationary contacts 52a to 52h co-operate with the movable contact 51 in like manner as the switch 52 so as to transmit the selected cam position signal to the control unit 54 as described in detail later.

The stationary contact 154a of relatively short arcuate length and the stationary contact 154b having a longer arcuate length are diametrically oppositely positioned along a circle on the lower surface of the plate 153 as shown in Figure 12 showing the bottom view of the switch 154.

A movable contact 157 having a sliding tongue 157a co-operating with the contact 154a and a sliding tongue 157b co-operating with the contact 154b is rotatably secured to the lower end of a stationary shaft rotatably supporting the cam member 44 and extending downwardly therefrom through a central opening formed in the plate 153 and the opening in the frame by a screw 156 with a friction washer 155 interposed between the screw 156 and the movable contact 157 can be frictionally rotated.

The movable contact 157 is formed with an upwardly extending bent lug 157e (Figures 11 to 13) which passes upwardly through a window 153a formed in the plate 153 and into a recessed portion 158a (Figure 13)formed in the bottom surface of the cam member 44. The inner periphery of the recessed portion 158a is formed with a pair of shoulders 158c and 158d defined by an inwardly raised portion 158b in the inner periphery of the recessed portion 158a.

The shoulders 1 58c and 158d co-operate with the lug 157c and are so positioned that, when the cam member 44 is rotated from the inoperative position of the tape recorder for the forward tape feed operation, i.e., in the counterclockwise direction in Figure 12 (clockwise direction in Figure 11) by about 1500 to the forward recording/reproducing position as shown by the solid line in Figure 12 wherein the sliding torque 157a disengages from the contact 154a whereas the tongue 157b is left contacting with the contact 154b, thereby cutting off the electrical connection between the terminals 154'a and 1 54'b to indicate that the cam member 44 is in the forward tape feed direction. In like manner, when the cam member is rotated from the inoperative position for the reverse tape feed operation, e.g., in the clockwise direction in Figure 12 (counterclockwise direction in Figure 11) by about 1500 to the reverse recording/ reproducing position, the lug 1 57c is moved to the left in Figure 12 to the position indicated by the chain line by the shoulder 158d which has moved in the clockwise direction to abut and urge the lug 1 57c from the right hand side thereof, thereby making electrical contact between the contact 154a and the tongue 157 while the tongue 157b remains contacting with the contact 154b, so that the electrical connection between the terminals 154'a and 154'b is established to indicate that the cam member 44 is in the reverse tape feed direction.

The signal established between the terminals 1 54'a and 154'b is applied to the control unit 54 and memorized therein so that the proper recording operation of the tape recorder is ensured even though the timer is used so as to start the recording operation again from the stopped position of the tape recorder after the automatic feed reversing operation has been effected in the previous recording operation.

Alternatively, the movable contact 157 may be frictionally rotatably supported by the cam member 44 and a pair of stops (not shown) is provided so as to appropriately limit the range of movement of the lug 157c, i.e., the movable contact 157 during the clockwise or counterclockwise rotation of the cam member 44.

Figure 14 shows the electric circuit whereby the position of the cam member 44 is accurately controlled by the cam position signal from the switch 52 and the tape feed direction memory signal from the switch 154 both of which are fed back to the control unit 54 as shown. For simplifying the showing in Figure 14, control circuits for controlling the motors 12 and 26 are omitted from Figure 14.

In Figure 14, the output of the manual operation demand keys 53 is connected to the input IN of the control unit 54 while the OUT of the control unit 54 is connected to the driving circuit 55 for driving the cam driving motor 50 so that the cam member 44 driven by the motor 50 through the reduction gear train 50' is positioned in the desired operational position as set by the manual keys 53.

The movable contacts 51 and 157 respectively of the cam position switch 52' and the tape feed direction memory switch 154 are rotated to the positions as determined by the keys 53.

The terminals 52'b, 52'c, 52'f, 1 54'a, 1 54'b and 52'a are connected to the control unit 54 so as to feed back the cam position signal and the tape feed direction memory signal to the control unit 54 for ascertaining the actual position of the cam member 44 to avoid the false function of the tape recorder.

In detail, a series of pulses To (see Figure 15) is applied from the control unit 54 commonly to the reverse quick feed position contact 52f, the reverse pause position contact 52g and the reverse recording/reproducing position contact 52h through terminal 52'f, and a series of pulses T1 (Figure 15) is applied from the control unit 54 to the stop or inoperative position contact 52b through the terminal 52'b, while a series of pulses T2 is applied from the control unit 54 commonly to the forward quick feed position contact 52c, the forward pause position contact 52d and the forward recordingireproducing position contact 52e through the terminal 52'c.

The forward feed direction signal or the reverse feed direction signal is transmitted to the control unit 54 through the terminals 154'a and 154'b as previously described.

As shown in Figure 15, occurrence of the pulses To T1 and T2 is sequentially shifted from one to another.

Thus, when the cam member 44 is in the stop position with the movable contact 51 connecting the terminal 52'b to the terminal 52'a, the stop position pulses T1 applied to the terminal 52'b are fed back to the control unit 54 through the movable contact 51 and the terminal 52'a to indicate that the cam member 44 is in its stop position.

When the cam member 44 is rotated in the clockwise direction for the forward feed of the tape and the movable contact 51 connects the stationary contact 52a to one of the stationary contacts 52c, 52d or 52e which are commonly connected to the terminal 52'c, then the pulses T2 applied to the terminal S2'c from the control unit 54 are fed back to the control unit 54 through the terminal 52'a thereby indicating that the cam member 44 is in the forward feed position and is set in the forward quick feed position, the forward pause position or the forward recording/reproducing position.

In order to positively discriminate in which of the forward quick feeding position, the forward pause position and the forward recording/reproducing - - position the cam member 44 is positioned, means ~ are provided as follows.

Assuming that the cam member 44 is rotating in the clockwise direction for the forward tape feed, for example, then a group of pulses T2 as indicated by PULSES 1 in Figure 16 is fed back to the control unit 54 during the time the sliding tongue 51b rides on the forward quick feed position contact 52c. The feed back of the pulses T2 is intercepted when the tongue 51b moves off the contact 52c as the cam member 44 further rotates until the tongue 51b reaches the forward pause position contact 52d and a second group of pulses T2 as indicated as pulses 2 in Figure 16 will be again fed back to the control unit 54 insofar as the tongue 51 b rides on the contact 52d.In like manner, the feed back of the pulses T2 is again intercepted when the tongue 51b moves off the contact 52d until the tongue Sib reaches the forward recording/reproducing position contact 52e. Then, a third group of pulses T2 (pulses 3 in Figure 16) will be fed back again to the control unit 54 insofar as the tongue 51b rides on the contact 52e.

Therefore, the number of occurrence of the feed back of the pulse group T2 can indicate in which of the quick feed position, the pause position and the recording/reproducing position the cam member is actually positioned, one occurrence of a pulse group indicating the quick feed position, two occurrences of pulse groups indicating the pause position while three occurrences of pulse groups indicates the recording/reproducing position.

Just the same as above applies to the reverse feed operation when the cam member 44 is rotated in the counterclockwise direction.

The common connection of the contacts 52c, 52d and 52e and the contacts S2f, 52g and 52h greatly simplifies the circuit for detecting the position of the cam member 44.

As described above, the position of the cam member 44 is ascertained by the control unit 54 by virtue of the signals fed back from the switches 52' and 154.

Generally speaking, since a motor has a relatively large inertia so that the motor will continue running even though the input voltage is cut off at the desired position of the cam member 44, the cam member 44 might overrun past the desired position so that false function of the tape recorder would result.

Such a false function must be avoided without fail by providing compensation means for the above described overrun of the motor.

Such compensation means is provided in the control unit 54 by advantageously utilizing the signals from the cam position switch 52' and the tape feed direction memory switch 154.

The principle of the compensation for the position of the cam member 44 is as follows: (1) Ascertain the desired operating position as set by the keys 53 and memorize the direction of rotation of the motor 50 prior to cutting off the input voltage to the motor 50.

(2) Ascertain whether or not the cam position switch 52 is properly set at the desired operating position (whether or not the sliding tongues of the switch 52 ride on the desired contacts) when the motor 52 is stopped.

(3) If it is detected that the sliding tongues of the switch 52 overrun past the desired contacts, then rotate the motor 50 in the direction opposite to that as memorized in item (1) above until the sliding tongues ride on the desired contacts and repeat the procedure (1).

(4) Repeat the procedures (1), (2), (3) until it is ascertained that the sliding tongues properly ride on the desired contacts.

As described above, the overrunning of the motor 50 is positively compensated for so that proper operation of the tape recorder is ensured.

With the above described cam position control device, the cam member 44 is first moved to the in-operative position corresponding to the single contact 52b of the switch 52 and then move to the desired operating position, the contact 52b constituting the reference point, thereby avoiding the false function which might be caused due to the noise and the like.

Figures 1 7A, 1 7B show the sequentially operated logic of the above described cam position control device incorporated in the control unit 54, Figure 17B being the continuation of Figure 17A.

As shown, the motor 50 is rotated in either of the opposite two directions or stopped in accordance with the results logically obtained by the comparison of the actual position of the cam member 44 with the desired cam position as set by the manual keys 53.

Figures 18 to 21 show another embodiment of the tape recorder of the present invention which can be constructed selectively as an automatic tape feed reversible tape recorder or an unidirectionally operable single type tape recorder of the generally common design.

In Figure 18, the tape recorder shown comprises in the well known manner a head base plate 203 slidably supported on a base plate 201 having guide slots 202 for guiding the same. A recording/reproducing head 205, a forward feed eraser head 206 and a reverse feed eraser head 207 are mounted on the head base plate 203. The tape recorder includes a forward feed capstan 213, a reverse feed capstan 214, a forward feed pinch roller 215 rotatably supported bya pinch roller supporting lever 219 pivoted by a shaft 217, a reverse feed pinch roller 26 rotatably supported by a pinch roller supporting lever 220 pivoted by a shaft 218, a supply reel supporting shaft 230, and a take-up reel supporting shaft 232.

Referring to Figure 19 showing the mechanism located beneath that shown in Figure 18, a pinion 238a of a reversible motor 238 is operatively connected to a gear 235a, integrated with a cam wheel 235 which is rotatably supported on the capstan 214, through gear train 240. The gear 235a is operatively connected to a gear 236a, integral with a cam wheel 236 which is rotatably supported on the capstan 213, through an idler gear 237 supported by a shaft 227.

The gears 235 and 236 are of the same size so that they are rotated by the same angle and the same angular phase with each other by the interposition of the idler gear 237.

In order to move the head base plate 203 between the operative and the inoperative positions, a pin 241 (Figure 19) is secured to the lower surface of the head base plate 203 and a cam surface 236b is formed on or secured integrally to the cam wheel 236 which slidably abuts against the upper portion of the periphery of the pin 241 so as to arrest the upward movement of the head base plate 203 by the action of a spring 204 (Figure 18).The cam surface 236b has an oval shape with a raised portion formed in the lower side thereof so that, in the inoperative position of the cam surface 236b as shown in Figure 19, the head base plate 203 is held in the inoperative position, but, when the cam surface 236b is rotated in either the counterclockwise (forward tape feed) direction or the clockwise (reverse tape feed) direction, the pin 241 is allowed to move upwardly so that the head base plate 203 can be moved to the operative position, i.e. the forward (or reverse) quick feed, the pause, orthe recording/reproducing position according to the rotation angle of the cam surface 236b in like manner as in the case of the cam surface 44a of the cam member 44.

In order to actuate the forward feed pinch roller 215, a cam surface 236c similar to the cam surface 44b of the cam member 44 (but inverted in the left-right direction due to the rotation of the cam wheel 236 opposite to that of the cam member 44 for giving the same operative position of the tape recorder) is formed on or secured integrally to the cam wheel 236. The cam surface 236c co-operates with the upper end 221 b of a forward feed pinch roller actuating lever 221 pivoted at its intermediate portion by the shaft 217 (also shown in Figure 18).

The lower end of the lever 221 is provided with a pin 221a and is urged to the right by a spring 223 having its opposite ends supported by the frame and the lower end of the lever 221 so as to urge the upper end 221 b of the lever 221 in the counterclockwise direction against the cam surface 236c.

As shown in Figure 18, the pin 221a projects upwardly through an opening 201 a formed in the base plate 201 and co-operates with the bent lug 219a of the lever 219 and the opposite two ends of a spring 223 wound around the pin 217 abut respec tivelyagainstthe pin 221a and the lug 219a so as to resiliently urge the pin 221a and the lug 219a against each other.Therefore, as the cam surface 236c rotates in the counterclockwise direction for the forward tape feed operation, the lever 221 is swung in the clockwise direction to resiliently urge the pinch roller supporting lever 219 in the same direction by the interposition of the spring 223 so that the pinch roller 215 is moved to its respective operative positions according to the rotational angle of the cam surface 23sic in the similar manner as in the case of the cam surface 44b of the cam member 44.

In a similar manner, a cam surface 235b for actuating the reverse feed pinch roller 216 is fixedly secured to the cam wheel 235 and co-operates with a reverse feed pinch roller actuating lever 222 pivoted by the shaft 218 and urged by a spring 224 in the clockwise direction. The cam surface 235b is symmetrical in left-right direction with the cam surface 236c and the shape and arrangement of the lever 222 are symmetrical with the lever 221 in the left-right direction, so that a pin 222a secured to the lower end of the lever 222 co-operates with the reverse feed pinch roller supporting lever 220, thereby permitting the pinch roller 216 to be resiliently moved to its respective operative positions by a spring 224 according to the clockwise rotational angle of the cam surface 235b.

In order to frictionally drive either the take-up reel shaft 232 or the supply reel shaft 230 in the forward feed or in the reverse feed operation of the tape recorder, a swingable reel shaft actuating lever 228 (Figure 19) is swingably and radially shiftably supported at its lower end on a sleeve 227a of the shaft 227 with an elongated opening 228a of the lever 228 slidably engaging with the opening 228a. The lever 228 extends upwardly between the reel shafts 230 and 232. A spring 228c is supported on a radially inwardly extending lug 228b formed in the opening 228a with its respective ends abutting against the sleeve 227a and the end of the opening 228a remote from the sleeve 227a, so that the lever 228 is resiliently urged radially outwardly from the sleeve 227a.

The reel shafts 230 and 232 have integrally mounted thereon friction wheels 231 and 233, respectively, which are adapted to be selectively actuated frictionally by a friction wheel 226 secured to the shaft 235a of a reversible motor 225 driven in either the counterclockwise or the clockwise direction according to the desired forward or reverse tape feed operation. To this end, an idler friction wheel 229 is rotatably but frictionally supported on the upper end of the lever 228 between the friction wheels 231,233 and is resiliently abutted against the friction wheel 226 by the action of the spring 228c.

Thus, when the motor 225 is rotated in the counterclockwise direction for the forward feed operation, the idler friction wheel 229 is urged to the right by virtue of the frictional supporting of the wheel 229 by the lever 228 thereby permitting the idler friction wheel 229 to engage with both the friction wheels 226 and 233 so that the reel Ishaft 232 is frictionally driven in the counterclockwise direction by the motor 225. In like manner, the reel shaft 230 is frictionally driven in the clockwise direction by the motor 225 through the idler friction wheel 229 in the reverse feed operation by virtue of the selective engagement of the idler friction wheel 229 with both the friction wheels 226 and 231.

In the tape recorder shown in Figure 18, the brake shoes 234 are formed of a sufficiently elastically deformable material, such as soft rubber, and are directly secured to the head base plate 203. The actuation of the shoes 234 is similar to that of the shoes 45b attached to the brake shoe supporting tappet 45 shown in Figure 2, but the arrangement of the shoes 234 shown in Figure 18 greatly simplifies the construction and reduces the number of the parts required while the quick response to the movement of the head base plate is ensured in comparison with the shoes mounted on the separate brake shoes supporting lever.

Referring now to Figure 20 showing the arrange- ment of the cam position detecting switch 241 anti, the tape feed direction memory switch 243 of the tape recorder shown in Figure 18, the switch 241 comprises a stationary inoperative or stop position contact 241 a, a stationary forward quick feed position contact 241 b, a stationary forward pause position contact 241 c, a stationary forward recording/ reproducing position contact 241 d, a stationary reverse quick feed position contact 241 e, a stationary reverse pause position contact 241f, a stationary reverse recording/reproducing position contact 2419, a stationary common contact 241h, a terminal 241 'a connected to the contact 241 a, a terminal 241 'b commonly connected to the contacts 241 b, 241c and 241d, a terminal 241 'e commonly con nected to the contacts 241e, 241f and 2419, and a terminal 241 'h connected to the contact 241 h, and a movable contact 241k having a sliding tongue 241i contacting at all times with the contact 241 h and a sliding tongue 241j selectively contacting with one of the contacts 241 a to 2419. The stationary contacts 241 a to 241 h are formed on a printed circuit plate 242 secured to the frame of the tape recorder while the - movable contact 241k is secured to the cam wheel 236 for rotation therewith. Since it is clear that the switch is similar in construction and function in connection with the control unit 54 to the cam position detecting switch 52' shown in Figure 11, further description is omitted here.

The switch 243 comprises an arcuate stationary contact 243d connected to a terminal 243'd and having a relatively long arcuate length, an arcuate stationary contact 243e connected to a terminal 243'e and having a relatively short arcuate length b positioned on the same circle as that on which the contact 243d is positioned, and a movable contact 243a having a sliding tongue 243b contacting at all times with the contact 243d and a sliding tongue 243c.

In a similar manner to the case of the movable contact 157 shown in Figure 12, the movable contact 243a is moved to a predetermined counterclockwise rotated position as the cam wheel 235 is rotated from the stop position in the forward feed direction by means of a projection 243f which is adapted to abut against a pin (not shown) secured to the cam wheel 235, while it is moved to a predetermined clockwise rotated position as the cam wheel 235 is rotated from the stop position in the reverse feed direction.

The sliding tongue 243c is so positioned that, when the movable contact 243 is moved to the above described forward feed position, the sliding tongue 243c comes to the position where it contacts with the contact 243e, thereby isolating the electrical connection between the terminals 243'd and 243'e to indicate that the cam wheel 235 and, hence, the cam wheel 236 are in the forward feed position, whereas, when the movable contact 243a is moved to the reverse feed position, the sliding tongue 243c comes to the position where it contacts with the contact 243d with which the tongue 243b also contacts, thereby connecting the terminal 243'd to the terminal 243e to indicate that the cam wheel 235 as well as the cam wheel 236 is in the reverse feed position.

The function of the switch 243 is similar to the switch 154 shown in Figure 12.

The operation of the tape recorder shown in Figures 18 to 21 is similar to that previously described.

However, since the cam surface 235b for the reverse feed operation and the tape feed direction memory switch 243 are installed on the cam wheel 235 separately from the cam surface 236b for both the forward and reverse feed operation, the cam surface 236c for the forward tape feed operation and the cam position detecting switch 241 for both the forward and reverse feed operation, all of which are installed on the cam wheel 236, the tape recorder of Figure 18 constituted as a full automatic tape feed reversing tape recorder can be rendered to be a unidirectionally operable simple tape recorder by merely omitting the assembling of the reverse feed pinch roller system 216, 218, 220, 222, 224, the reverse feed eraser 207, the tape feed direction memory switch 243, the reverse feed capstan system 214,212 and stretching the belt 210 driven by pulley 209 of the motor 208 around only the forward feed flywheel 211.

This greatly simplifies the production lines for production of a plurality of types of the tape recorders by rendering the general design common to the above described two types and lowers the overall investment cost.

Further, since the cams and the switches are divided into two groups, they can be made compact and this affords greater freedom in design.

Claims (14)

1. Atape recorder having at least one electrical motor and operating mechanisms adapted to be driven thereby for the performance various of different operations and having an electrical control unit for the manual selection of any one of said operations and cam means driven by said one motor or one said motor and having cam surfaces operatively engaging respective ones of said operating mechanisms, said control unit being adapted to control said motor or motors and to position said cam means in accordance with the selected operation, whereby the selected operation is performed by the respective operating mechanism under the control of said control unit.

2. A tape recorder according to claim 1, wherein said cam surfaces on said cam means comprise a first cam surface operatively coupled with a head base plate having mounted thereon a recording/ reproducing head, a forward feed eraser head and a reverse feed eraser head, a second cam surface operatively coupled with a forward feed pinch roller and a third cam surface operatively coupled with a reverse feed pinch roller, and in which said cam means is provided with a cam position detecting switch for generating and feeding back to said control unit position detecting signals comprising a stop position signal, a forward quick feed position signal, a forward feed pause position signal, a forward feed recording/reproducing position signal, a quick reverse quick feed position signal, a reverse feed pause position signal and a reverse feed recording/reproducing position signal in accordance with the position at which said cam means is actually positioned, thereby monitoring the proper operation of the tape recorder as set by said control unit in either of the forward and reverse tape feed operations.

3. Atape recorder according to claim 2, in which said cam means comprises a single body having thereon said first, second and third cam surfaces, and in which a movable contact of said cam position detecting switch are integrally provided on said body.

4. A tape recorder according to claim 3, in which a fourth cam surface is provided on said single body and is operatively coupled with a braking member having brake shoes for braking reel supporting shafts of said tape recorder.

5. Atape recorder according to claim3, in which reel supporting shaft brake shoes are mounted on said head base plate.

6. Atape recorder according to claim 2, wherein said cam means comprises a first cam wheel and a second cam wheel of the same size and simultaneously rotated by the same amount and in the same angular phase as said first cam wheel, said first and second cam surfaces and a movable contact of said cam position detecting switch being in said first cam wheel, said second cam wheel having thereon said third cam surface, thereby permitting the tape recorder to be constructed as an unidirectionally operable single type tape recorder of a generally common design by omitting said third cam surface and the mechanism relating to operation in the reverse feed direction.

7. Atape recorder according to claim 3,4 or 5 further comprising a tape feed direction memory switch having a movable contact actuated by said single body so as to generate and feed back to said control unit a forward tape feed direction memory signal or a reverse tape feed direction memory signal according to the position of said cam means, thereby permitting the proper recording operation when the automatic reversing of the tape feed direction has been effected by said control unit.

8. Atape recorder according to claim 6, in which a fourth cam surface is provided on said shaft cam wheel and is operatively coupled with a braking member having brake shoes for braking reel supporting shafts of said tape recorder.

9. A tape recorder according to claim 6, in which reel supporting shaft brake shoes are mounted on said head base plate.

10. A tape recorder according to claim 6, 8 or 9 further comprising a tape feed direction memory switch having a movable contact actuated by said second cam wheel so as to generate and feed back to said control until a forward tape feed direction memory signal and a reverse tape feed direction memory signal according to the position of said second cam wheel, thereby permitting the proper recording operation when the automatic reversing of the tape feed direction has been effected by said control unit.

11. Atape recorder according to claim 7 or 10, in which said electronic control unit includes a cam means position compensating logic circuit capable of rotating said cam means in the opposite direction upon detection of overrunning of said cam means past the desired position as set by said control unit by virtue of the signals from said cam position detecting switch and said tape feed direction memory switch until said cam means is positioned properly in the desired position.

12. Atape recorder constructed and adapted to operate substantially as herein described with referpence to and as illustrated in Figures 1 to 10 of the accompanying drawings.

13. Atape recorder constructed and adapted to operate substantially as herein described with referenceto and as illustrated in Figures 11 to 17B of the accompanying drawings.

14. A tape recorder constructed and adapted to operate substantially as herein described with referenceto Figures 18to 21 ofthe accompanying drawings.