JPS6032270B2 - Braking device for tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tape recorder in which a pair of reel shafts are respectively driven by a pair of reel motors that are directly connected to the reel shafts, and when a stop command is issued, the above-mentioned This invention relates to a braking device that brakes a reel shaft.

In a tape recorder, when using a dedicated motor for rotating the reel shaft, that is, a reel motor,
It is easy to wind the tape at high speed, and pure electrical operation is relatively simple.

However, since the tape is wound at a high speed, various problems may occur when stopping the winding. That is,
It is difficult to quickly bring the running tape to a standstill without damaging it, and there is a risk that the tape may become loose, run too much, or even run in reverse. The present invention is intended to solve these problems using relatively simple means.

Next, an embodiment in which the present invention is applied to a reel motor control device in a tape recorder will be described with reference to the drawings. In the block diagram of the control circuit shown in FIG. The play switch element 7 to be applied is a flip-flop 1.
1, and is connected to the set terminal S of flip-flop 1.
The output Q of 1 is coupled to the input terminal 1 of the NOR gate 39.

The fast-forward switch element 9, which provides a pulse for fast-forward operation, is connected to the set terminal S of the flip-flop 12, and the output Q of the flip-flop 12 is supplied to the input terminal 2 of the NOR gate 39 and the set terminal S of the flip-flop 26, respectively. ing. A rewind switch element 10 that provides a rewind operation pulse is connected to a set terminal S of a flip-flop 13, and an output Q of the flip-flop 13 is supplied to an input terminal 3 of a NOR gate 39 and a set terminal S of a flip-flop 27, respectively. It has become. Note that the output side of the NOR gate 39 is a flip-flop 19.
and 21 set terminals S, respectively. An AND gate 30 is connected to the reset terminal R of the flip-flop 11.
The output side of the AND gate 31 is connected to the reset terminal R of the flip-flop 12, and the output side of the AND gate 32 is connected to the reset terminal R of the flip-flop 13.

One input terminal of each of these AND gates 30, 31, 32 is connected in common, and this common connection point 55 is connected to the IJ set terminal R of each of the flip-flops 19, 21 and a stop switch element that provides a stop pulse. 8 are connected to each other. The output side of the AND gate 33 is connected to the other input terminal of the AND gate 30, and the output Q of the flip-flop 12 is supplied to one input terminal of the AND gate 33, similarly to the other input terminal of the AND gate 32. It has become so. Similarly to the other input terminal of the AND gate 31, the output Q of the flip-flop 13 is supplied to the other input terminal of the AND gate 33. Frequency generators 14 and 15 are attached to the combined reel motor 40 and take-up reel motor 41 shown in FIG. 2, respectively, and the frequency signals of these frequency generators 14 and 15 are supplied to waveform shaping circuits 16 and 17, respectively. It has become so.

The outputs of these waveform shaping circuits 16 and 17 are connected to the trigger terminals of retrigger type monostable multipipetrators 18 and 20, respectively. A signal is generated when the period of the input frequency becomes longer than the reference time by comparing the time with each other. The outputs Q of the retriggerable monostable multipipulators 18 and 20, respectively, are connected to the OR gates 34 and 36.
V is supplied to the other input terminal of each of the two input terminals. The other input terminals of the OR gates 34 and 36 are connected to positive trigger type monostable multipipulators 22 and 2, respectively, which have the outputs Q of the flip-flops 19 and 21 as trigger inputs.
The respective outputs Q of 3 are supplied to the OR gate 34.
and 36 are connected to the IJ set terminals R of edge-triggered flip-flops 24 and 25, respectively. The outputs Q of the flip-flops 19 and 21 are supplied to the set terminals S of the flip-flops 24 and 25, and to one input terminal of each of the OR gates 35 and 37.
The flip-flop 2 is connected to the other input terminal of 37 and 37, respectively.
4 and 25 outputs Q are supplied respectively.

The output side of OR gate 35 is connected to one input terminal of OR gate 38, and the output side of OR gate 37 is connected to OR gate 38.
The output side of the OR gate 38 is connected to the set terminals R of the flip-flops 26 and 27, respectively. In FIG. 2 showing the relationship between the control circuit and the reel motors 40 and 41, drive amplifiers 42 and 43 having signal terminals 1 to 6 are connected to the supply reel motor 40 and the take-up reel motor 41, respectively. are driven to their respective operating states by drive amplifiers 42 and 43. At each signal terminal 1 to 6 of drive amplifiers 42 and 43,
1 is a play signal terminal, 2 is a fast forward signal terminal, 3 is a rewind signal terminal, 4 and 5 are electromagnetic brake signal terminals, and 6 is an on/off signal terminal, and each signal terminal has a 1 or 0 signal. is supplied to control each operation. Mechanical brakes 44 and 45 include plunger mechanisms 48 and 49 that apply braking force to brake drums 46 and 47, respectively, which are fixed to rotating shafts 56 and 57 of supply and take-up motors 40 and 41, respectively, and these plungers. They each consist of energizing means for turning on and off energization to the mechanism. Furthermore, frequency generators 14 and 15 are attached to the motors 40 and 41, respectively, to generate frequency signals proportional to their rotational speeds. The respective outputs of the control circuit shown in FIG. 1 are connected to the respective signal terminals shown in FIG. 2. That is, the play signal terminal 1 of each of the drive amplifiers 42 and 43 receives the output Q of the flip-flop 11, and the fast-forward signal terminal 2
The output Q of the flip-flop 12 is connected to the rewind signal terminal 3, the output Q of the flip-flop 26 is connected to the electromagnetic brake signal terminal 4, and the output Q of the flip-flop 26 is connected to the electromagnetic brake signal terminal 5. The output Q of the flip-flop 27 is supplied to the on/off signal terminal 6 and the mechanical brake signal terminals 6 of the mechanical brakes 44 and 45, respectively. Figures 1 and 2 configured as described above
In the reel motor control device shown in the figure, when the play switch element 7 is short-circuited, a negative start pulse is applied to the set terminal S of the flip-flop 11 and this flip-flop 11 is triggered, so that the flip-flop 11 is set and thus Its output Q is inverted from 0 to 1.

When the output of flip-flop 11 is inverted from 0 to 1,
Its output triggers flip-flops 19 and 21, respectively, via NOR gate 39 as a negative trigger pulse.
Therefore, since the flip-flops 19 and 21 are set, their outputs Q are inverted from 0 to 1 and sent to the OR gate 3.
5 and 37, respectively. Level 1 of these
The signals are sent to the on/off signal terminals 6 of the drive amplifiers 42 and 43 and the mechanical brake 44 via the OR gates 35 and 37, respectively, and the OR gate 38, respectively.
and 45, respectively. The drive amplifiers 42 and 43 are each turned on, and the mechanical brakes 44 and 45 are also turned on, respectively, so that the brake drums 46 and 47 are unlocked, respectively. On the other hand, the output Q of flip-flop 11
Since the level 1 signal of is supplied to the play signal terminal 1 of each drive amplifier 42, 43, the drive amplifier 42,
43 are in a play operation state.

Therefore, the supply and take-up roll motors 40 and 41 perform a play operation, so that the take-up roll motor 41
1 is the direction in which the tape 62 is wound (i.e., counterclockwise in FIG. 2)
The supply reel motor 40 applies a relatively small rotational driving force in the direction in which the reel 60 winds the tape 62 (that is, clockwise in FIG. 2). Given. This latter driving force is for applying back tension to the tape. Therefore, the tape is pulled from both sides, but in this case the winding force by the winding reel 61 is greater than the winding force by the companion groove reel 60. Therefore, in the fast forward operation state, the tape 62 is wound onto the take-up reel 61 due to the difference in these winding forces, but in the play operation state, the tape is wound by the capstan and the pinch roller (none of which are shown). It is transported at a constant speed and wound onto a winding reel. When the V supply and winding motors 40 and 41 are driven and rotated,
Since the frequency generators 14 and 15 generate frequency signals proportional to the rotational speed of the respective motors, these frequency signals are waveform-shaped by waveform shaping circuits 16 and 17, so that pulses are generated in proportion to the frequency change. A retrigger type monostable multipipulator 18 as a positive pulse train with varying intervals;
20 respectively.

The retrigger type monostable multipipetrators 18 and 20 are monostable multipipetrators that are continuously triggered and maintain a monostable state if a trigger pulse is applied again within the metastable period determined by the time constant. The quasi-stable period (hereinafter referred to as a set value) 0 is set longer than the pulse interval of the pulse train in a predetermined running state. Therefore, while the tape is running in a predetermined running state, the retrigger type monostable multipipetrators 18 and 20 are successively triggered while the level of these outputs Q is 1, so that these outputs Q maintains its level at 1. In this state, short-circuit the switch element 8 to flip the negative trigger pulse.

When applied to the reset terminals R of flip-flops 19 and 21, flip-flops 19 and 21 are reset, so their outputs Q are inverted from 1 to 0, respectively. When the outputs Q of the flip-flops 19 and 21 are inverted from 1 to 0 in this way, the flip-flops 24 and 25 are set, so the outputs Q of the flip-flops 24 and 25 are inverted from 0 to 1. , for this reason orgate 38
The output side of continues to hold the level at 1. On the other hand, since the stop pulse is applied to the reset terminal R of the flip-flop 11 via the AND gate 30, the flip-flop 11 is reset. Therefore, the output Q of the flip-flop 11 is inverted from 1 to 0, so that the drive amplifiers 42 and 43 are switched from the play operation state to the play release state. As a result, the rotational speed of the motor decreases and the pulse interval of the pulse train becomes longer than the set value, so the output Q of each of the retrigger type multipipulators 18 and 20 remains at 1 even with the set value determined by these time constants. to 0,
For this purpose, these outputs trigger edge-triggered flip-flops 24 and 25, respectively, via OR gates 34 and 36, respectively. Therefore, edge trigger type flip-flop 2
4 and 25 are inverted from 1 to 0, and the level on the output side of the OR gate 38 becomes 0, so the drive amplifier 42
, 43 are turned off, and the mechanical brake 44 is turned off.
, 45 are turned off and apply braking force to the brake drums 46, 47, thereby stopping the rotation of the motors 40, 41, respectively. 3A to 3G are waveform diagrams of each part shown in FIG. 1 for explaining the operation from the play start state to the stop state (in other words, the normal play state). 3A shows the start pulse, FIG. 3B shows the stop pulse, FIG. 3C shows the outputs Q of the flip-flops 19 and 21, and FIG. 3D shows the outputs of the retrigger type monostable multivibrators 18 and 20. 3E shows the outputs Q of the retrigger type monostable multipipulators 18 and 20, FIG. 3F shows the outputs Q of the flip-flops 24 and 25, and FIG. 3G shows the output side of the OR gate 38. Each signal waveform is shown.

In the positive trigger type monostable multipipetrators 22 and 23, when a stop pulse is applied immediately after the start pulse is applied, the level on the output side of the OR gate 38 does not become 0, and the rotation of the motor does not stop because of this. is prevented.

That is, when the stop pulse is applied immediately after the start pulse is applied, the outputs of the frequency generators 14 and 15 do not yet have a value sufficient for the waveform shaping circuits 16 and 17 to form a pulse train, and therefore The retrigger type monostable multipipelators 18 and 20 are not yet supplied with a pulse train. Therefore, since the trigger pulses applied via the OR gates 34 and 36, respectively, have not yet been applied to the flip-flops 24 and 25, these flip-flops are in the set state, and therefore their outputs Q are in the set state immediately after the application of the stop pulse. The mustard bell 1 is held, so the motors 40, 41 will not stop rotating as they are. Positive trigger type monostable multipipulator 22
, 23 are for preventing the motors 40, 41 from stopping even if a stop pulse is applied in this way. When the stop pulse is applied, the output Q of each of the flip-flops 19, 21 becomes 0. to 1. For this purpose, a positive trigger type monostable multipipulator 22,
23 are triggered, so their outputs Q are inverted from 0 to 1, but these plus-trigger type monostable multipipulators 22 and 23 are inverted from 1 to 0 again after a certain period of time determined by their time constants. This inversion of output Q from 1 to 0 triggers flip-flops 24 and 25, respectively, via OR gates 34 and 36, respectively. Therefore, the flip-flops 24 and 25 are reset and their respective outputs Q are inverted from 1 to 0, so that the motors 40 and 41 are stopped, respectively. Note that the time from when the stop pulse is applied until the motor stops rotating is determined by the time constant of the positive trigger type monostable multipipulators 22 and 23, so if this time constant is made very small, for example, several milliseconds, , can be ignored compared to the time from the start to the stop of play. 4A to 4G are waveform diagrams of various parts for explaining the operation of the above-mentioned positive trigger type monostable multipipelators 22 and 23, in which FIG. 4A shows the start pulse, and FIG. 4B shows the waveform diagram of each part. 4C shows the output Q of the flip-flops 19 and 21,
4D shows the outputs Q of the retrigger type monostable multivibrators 8 and 20, FIG. 4E shows the outputs Q of the plus trigger type monostable multivibrators 22 and 23, and FIG. 4F shows the outputs Q of the flip-flops 24 and 25. The output Q of
Furthermore, FIG. 4G shows the output side of the OR gate 38 in the respective signal waveforms.

Next, by shorting the fast-forward switch element 9 and applying a negative trigger pulse to the set input terminal S of the flip-flop 12, this flip-flop is triggered and set, so that its output Q is inverted from 0 to 1.

When the output Q of the flip-flop 12 is inverted from 0 to 1 in this way, the NOR gate 39, the flip-flop 19,
21, drive amplifiers 42, 4 via OR gates 35, 37 and OR gate 38 in the same way as in the play start.
3 are turned on, and the mechanical brake 4 is turned on.
4 and 45 are in the on state, so the brake drum 46
, 47 are unlocked. On the other hand, since the output Q level 1 signal of the flip-flop 12 is supplied to the fast-forward signal terminal 2 of the drive amplifiers 42 and 43, the drive amplifier 4
2 and 43 are in a fast forward operation state.

Therefore, the joint and take-up motors 40 and 41 are each driven in a fast forward operation, so that the tape runs in a fast forward condition. When the stop switch element 8 is short-circuited and a stop pulse is applied while the tape is running in a fast-forward state, the flip-flops 19 and 21 are reset, respectively, as in the case from the play state to the stop state described above, and therefore the edge trigger is activated. Type flip-flops 24 and 25 are set, respectively.

The above stop pulse is also applied to the flip-flop 12 via the AND gate 31, so this flip-flop is reset and its output Q is inverted from 1 to 0, thereby changing the fast-forward operating state of the drive amplifiers 42 and 43. Both are turned off. On the other hand, when the output Q of the flip-flop 12 is inverted from 1 to 0, the flip-flop 26 is set, so the output Q of the flip-flop 26 is inverted from 0 to 1.

Therefore, since electromagnetic brake signals are applied to the electromagnetic brake signal terminals 4 of the drive amplifiers 42 and 43, the winding motor 41 is given a rotational driving force in the direction opposite to the rotational direction in the fast forward running state. At the same time, the supply reel motor 40 is given a rotational driving force in the same direction as in the fast-forward state (ie, in the direction in which the supply reel winds the tape) and greater than in the fast-forward state. Therefore, the tape winding force by the take-up reel 61 decreases rapidly, and the tape winding force by the supply reel 60 increases rapidly, so that the fast-forwarding speed of the tape decreases rapidly.
In other words, the connecting groove and winding motors 40 and 41
As the rotational speed of the retrigger type monostable multipipetrators 18 and 20 decreases, the pulse interval of the input pulse train of the retrigger type monostable multipipetrators 18 and 20 becomes longer than the set value. Each output Q is inverted from 1 to 0. When the output Q is inverted from 1 to 0 in this way, the flip-flops 24 and 2 to which these outputs Q are applied via the OR gates 34 and 36,
5 are each in a reset state. Therefore flip flop 2
Since each output Q of 4 and 25 is inverted from 1 to 0,
The output side of the OR gate 38 is inverted from 1 to 01. The output side of the OR gate 38 is inverted from 1 to 0. When the output of OR gate 38 inverts from 1 to 0, flip-flop 26 is reset, so that its output Q inverts from 1 to 0. Therefore, the electromagnetic brake signal terminals 4 of each of the drive amplifiers 42 and 43 are turned off, so that the electromagnetic brakes are respectively released. Further, due to the above-mentioned reversal of the flip-flop 26, the drive amplifiers 42 and 43 are turned off, so the mechanical brakes 44 and 45 are turned off, and braking forces are applied to the brake drums 46 and 47, respectively. The rotations of 41 are respectively stopped. 5A to 5G are waveform diagrams of each part to explain the operation from the start of fast forwarding to the stop state, in which FIG. 5A shows the fast forwarding start pulse, and FIG. 5B shows the stop pulse. 5C shows the output Q of the flip-flop 12, FIG. 5D shows the input pulse trains of the retrigger type monostable multipipe layers 18 and 20, and FIG. 5F shows the output Q of the flip-flop 26, and FIG. 5G shows the output side of the OR gate 38 in their respective signal waveforms.

Furthermore, when the rewinding switch element 10 is short-circuited to enter the rewinding operation state, the flip-flop 13 is set.
Its output Q is inverted from 0 to 1.

The above-mentioned inversion of the output Q of the flip-flop 13 from 0 to 1 is performed via the /agate 39, the flip-flops 19 and 21, the OR gates 35 and 37, and the OR gate 38, respectively, to drive the drive amplifiers 42 and 43, respectively, in the same manner as at the start of play. At the same time, the mechanical brake 44 is turned on.
, 45 are turned on to unlock the brake drums 46 and 47, respectively. On the other hand, since the level 1 signal of the output Q of the flip-flop 13 is combined at the rewinding signal terminal 3 of the drive amplifiers 42 and 43, the drive amplifiers 42 and
43 are in a rewinding operation state.

The feed and take-up motors 40 and 41 are therefore driven in a rewind operation, so that the tape runs in a rewind condition. When the stop switch element 8 is short-circuited and a stop pulse is applied while the tape is running in the rewound state, the flip-flops 19 and 21 are reset, respectively, in the same way as from the start of play to the stop state as described above.
Edge trigger type flip-flops 24 and 25 are set, respectively.

Furthermore, the flip-flop 13 is reset by the stop pulse applied via the AND gate 32, and its output Q is inverted from 1 to 0.
3 rewinding operations are turned off. On the other hand, when the output Q of the flip-flop 13 is inverted from 1 to 0, the flip-flop 27 is set, so the output Q of the flip-flop 27 is inverted from 0 to 1. For this reason, the electromagnetic brake signal terminals 5 of the drive amplifiers 42 and 43 are turned on, so that the supply reel motor 40 is given a rotational driving force in the direction opposite to the direction of rotation in the rewinding state. At the same time, the take-up roll motor 41 is given a rotational driving force in the same direction as in the rewind state (ie, the direction in which the take-up roll winds the tape) and larger than that in the rewind state.
Therefore, the tape winding force by the supply reel 60 rapidly decreases, and the tape winding force by the take-up reel 61 rapidly increases, so that the tape rewinding speed rapidly decreases. In other words, since the rotational speed of the supply and take-up motors 40, 41 decreases, the pulse interval of the input pulse train of each of the retrigger type monostable multipipetators 18, 20 becomes longer than the set value, and therefore The output Q of each of the retrigger type monostable multivibrators 18 and 20 is inverted from 1 to 0. The flip-flops 24 and 25 to which the output Q is applied via the OR gates 34 and 36 are reset by this inversion of the world power Q from 1 to 0. Therefore, since the outputs Q of the flip-flops 24 and 25 are inverted from 1 to 0, respectively, the output side of the OR gate 38 is inverted from 1 to 0. When the output of OR gate 38 is inverted from 1 to 0, flip-flop 27 is reset and its output Q is inverted from 1 to 0. Therefore, the electromagnetic brake signal terminals 5 of the drive amplifiers 42, 43 are turned off, the electromagnetic brakes are released, and the drive amplifiers 42, 43 are controlled to be in the OFF state, respectively. At the same time, the mechanical brakes 44 and 45 are turned off, so the brake drums 46 and 47 are locked, respectively, and therefore the motors 40 and 45 are locked.
41 stops rotating. Signal waveforms at various parts from the start of rewinding to the stop state are the same as those shown in FIGS. 5A to 5G from the start of fast forwarding to the stop state. In the above embodiment, the electromagnetic brake is released and the mechanical brake is applied when the rotational speed of the reel shaft decreases to a certain degree. However, in some cases, it is possible to stop the rotation of the reel shaft using only the electromagnetic brake without using the mechanical brake. In this case, the mechanical brake can be applied as necessary after the reel shaft has stopped. You can also do this. Furthermore, although the electromagnetic brake is applied to both the reel shaft on the tape feeding side and the reel axis on the tape winding side, it may be applied only on the tape feeding side depending on the case. As described above, according to the present invention, it is possible to apply braking by purely electrical means, and it is possible to quickly bring a running tape to a standstill without damaging it.

Furthermore, since at least the reel shaft on the tape feeding side is braked by an electromagnetic brake, there is no risk of the tape becoming loose, running too much, or even running in reverse.
Further, when a pulse train with an appropriate pulse interval is obtained from the pulse generating means, the electromagnetic brake is configured to operate until the pulse interval reaches a predetermined value or more by the first monostable circuit, and The second
The monostable circuit was configured so that the electromagnetic brake would work for a certain period of time determined by its time constant. Therefore, not only when the stop button is pressed while the tape is running normally during play, fast forward, or rewind, but also in special situations such as when the stop button is pressed immediately after play, fast forward, or rewind. It is possible to stop travel very effectively.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a reel motor control device in a tape recorder, in which FIG. 1 is a block diagram of the control circuit, and FIG. 2 is a diagram showing the relationship between the control circuit and the reel motor. Figure 3 is a waveform diagram of each part shown in Figure 1 in the normal play operation state, Figure 4 is a waveform diagram of each part shown in Figure 1 when switching to the stop state immediately after the start of play, and Figure 5 is a waveform diagram of each part shown in Figure 1. FIG. 2 is a waveform diagram of each part shown in FIG. 1 in a fast forward operation state. In addition, 14 is a frequency generator (pulse generating means), 15 is a frequency generator (pulse generating means), 18 is a retrigger type monostable multipipulator (first monostable circuit), and 20 is a retrigger type monostable multipipulator. Pipelator (first monostable circuit), 22 is a positive trigger type monostable multipipelator (
23 is a plus-trigger type monostable multipipe layer (second monostable circuit), 24 is an edge-triggered flip-flop (bistable circuit), 25 is an edge-triggered flip-flop (bistable 40 is a reel motor, 41 is a take-up reel motor, 42 is a drive amplifier, 43 is a drive amplifier, 44 is a mechanical brake, and 45 is a mechanical brake. Fig. 2 Fig. 4N Fig. 4B Fig. 4C Fig. 40 Fig. 4E Fig. 4F Fig. 43 Fig. 1 Fig. 3A Fig. 3B Fig. 3C Fig. 30 Fig. 38 Fig. 3F Fig. 33 Fig. 5A Figure 58 Figure 5C Figure 5D Figure 58 Figure 5F Figure 53

Claims (1)

[Claims] 1 A pair of reel motors that are each directly connected to a pair of reel shafts of a tape recorder, a motor drive circuit that drives these pair of reel motors independently from each other, and a pulse interval that corresponds to the rotational speed of the reel shafts. pulse generating means for generating a pulse train having a pulse interval; when the pulse interval is less than or equal to a predetermined value, the pulse interval is maintained in a first state, and when the pulse interval is equal to or greater than the predetermined value, it is inverted to a second state and outputs a first control signal; When a stop command is issued from a predetermined running state of the tape recorder in which the tape runs from one reel shaft to the other reel shaft, the first monostable circuit is set to the first state. a second monostable control signal that generates a second control signal, and after a certain period of time determined by a predetermined time constant has elapsed from the time of the stop command, reverses to a second state and stops generating the second control signal; The circuit is set to a first state when the stop command is issued, and is set to a second state when the second control signal is not obtained and the first control signal is obtained. and a bistable circuit that inverts the direction of the tape in the predetermined running state while the bistable circuit is held in the first state when the stop command is issued. When an electromagnetic brake drive signal that provides a driving force in the opposite direction is supplied to the motor drive circuit, at least one of the reel shafts is braked by the electromagnetic brake, and the bistable circuit is reversed to the second state, A braking device for a tape recorder, characterized in that the supply of the electromagnetic brake drive signal is stopped.