JPS633388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically controlled tape recorder, and more particularly to improvements in its control circuit.

Conventionally, a so-called electronic control (or IC logic control) tape recorder configured as shown in FIG. 1 has been known. In other words, this is a two-motor drive mechanism for small (micro) cassette tapes, and during playback, the drive mechanism moves from capstan motor CM to flywheel 1.
Power is transmitted to run the tape (not shown) at a constant speed along the route 1→capstan 12→idler→13→take-up reel 14.

In this regeneration mode, the brake plate 15 is attached to both the take-up reel 14 and the supply reel 16 for the purpose of obtaining an appropriate back tension, obtaining a braking effect at the time of stopping, and preventing undesired slack from occurring. (a position moved downward from the illustrated state).

On the other hand, during fast forwarding or rewinding, the reel motor
Power is transmitted to make the tape run at high speed in the forward or reverse direction along the path RM→pulley 17→gear A→gear B→gear C or D→take-up reel 14 or supply reel 16.

In this case, gear B is rotatable in the clockwise or counterclockwise direction with the rotation center of gear A as a fulcrum, as if planetary motion, and the rotation center itself is rotatable in the direction of drive by reel motor RM. When is in the direction of arrow FF, it rotates clockwise and meshes with gear C coaxial with take-up reel 14. Further, when the drive direction by the tape motor RM is in the direction of the arrow REW, the supply reel 16 is rotated counterclockwise and engaged with the gear D coaxial with the supply reel 16.

By the way, during such fast forwarding or rewinding, it is convenient to lighten the load on the reel 14 or 16 and drive it as fast as possible. , 16 (the state shown in the figure).

Therefore, if we consider the state immediately after switching from the rewinding state to the playback state, a force will be applied to gear B to rotate it counterclockwise due to the inertia force of reel motor RM. If this is not done, the gears B and D will be rotated in the direction of biting into each other and will mesh with each other, and as a result, the rewind reel 16 will stop at the meshing position. There is a problem in that the take-up reel 14 cannot be driven and, as a result, a regenerated state cannot be obtained.

For this reason, the brake plate 15 that is engaged with the reel stands 14 and 16 during playback is provided with position regulating protrusions 151 and 152 that prevent the gear B from rotating in any direction. This prevents the above-mentioned problems from occurring.

Figure 2 shows the control circuit of the tape recorder (excluding the playback system) as described above.
During fast forwarding or rewinding, a high-level signal is applied to terminals T ₁ and T ₂ from an operation unit (not shown), causing diodes D ₁ and D ₂ and transistor Q ₀
The above-mentioned brake solenoid 18 is operated through the OR circuit OR, and the above-mentioned reel motor RM is driven in the forward or reverse direction through the motor drive circuit MD ₁₁ formed of transistors _Q1 to _Q4 . There is.

During regeneration, a play solenoid (not shown) is activated so that the above-mentioned idler 13 is connected to the capstan 1.
2 and the take-up reel 14, and a head and a pinch roller (not shown) are at a predetermined driving position.

By the way, the brake solenoid 18 used in the conventional tape recorder as described above becomes an obstacle when trying to miniaturize the device, simplify the circuit, and reduce current consumption and change in operation, so it is better to omit it if possible. It's advantageous.

However, omitting the brake solenoid 18 in this way does not change the brake plate 1.
5 is omitted, the rotation of gear B during playback, which was previously restricted by the position regulating projections 151 and 152, is no longer restricted. In other words, even if an attempt is made to immediately switch from the rewinding state to the reproducing state as described above, it becomes impossible to do so, which again becomes a problem.

However, it is not preferable to adopt a complicated configuration to solve this problem, since the benefits obtained by omitting the brake solenoid will be canceled out.

Therefore, this invention was made in view of the above points, and is useful when the brake solenoid is omitted to reduce the size of the device, simplify the circuit, and reduce current consumption and change in operation. It is an object of the present invention to provide an extremely good electronically controlled tape recorder which is capable of solving undesirable problems that occur when switching from rewinding to playback even with a simple configuration.

That is, the electronically controlled tape recorder according to the present invention operates the reel motor for a short fixed period of time in response to a playback command signal obtained from the operation unit to drive the play solenoid etc. during playback, for example, in the fast forward direction, which is the opposite direction to rewinding. By configuring it to be driven, we have designed a circuit solution that can prevent the aforementioned undesirable problem caused by omitting the brake solenoid when switching from rewinding to playback. The feature is that the configuration can be simplified.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

That is, in the drive mechanism shown in Fig. 3, the CM
is a capstan motor and is connected to a flywheel 23 via a belt 22. An idler 26, which is removably connected to both a capstan 24 and a take-up reel 25, which are coaxial with the flywheel 23, is connected to other heads and pinch rollers by a play solenoid driven by a regeneration operation switch (not shown). controlled.

Also, RM is a reel motor, and belt 2
8 to a pulley 29. Here, the gear B meshed with the gear A coaxial with the pulley 29 moves clockwise or counterclockwise depending on the rotation direction of the reel motor RM, with the rotation center of the gear A serving as a fulcrum. The center of rotation itself is rotatable. As a result, the pulley 29 is connected to the take-up reel 25 and the supply reel 30.
It is possible to selectively engage and disengage from both.

In such a configuration, during regeneration, the power is transmitted from the capstan motor CM driven by a regeneration operation switch (not shown) to the idler 26 via the flywheel 22.
→ Tape in the path of take-up reel 25 (not shown)
Power is transmitted such that the vehicle travels at a constant speed in the forward direction.

In addition, during fast forwarding or rewinding, gears A→
Power is transmitted to make the tape run at high speed in the forward or reverse direction along a path of gear B→gear C or D→take-up reel 25 or supply reel 30.

This drive mechanism is similar to the conventional drive mechanism shown in FIG. 1, except that the brake solenoid and brake plate are omitted.

Figure 4 shows a control circuit for driving the drive mechanism as described above (however, only the high-speed system is shown here, omitting the constant-speed system).
Terminal _T21 , to which a high-level signal is supplied via an IC-based operation control circuit (the same applies hereinafter) when a rewind operation switch (not shown) is operated, is a resistor.
Connected to the base of transistor Q ₂₁ via R ₂₁ . Also, a terminal to which a high-level signal is supplied when a fast-forward operation switch (not shown) is operated.
T ₂₂ is connected to ground through a diode D ₂₁ of the polarity shown and a resistor R ₂₂ in series. The midpoint between the diode D ₂₁ and the resistor R ₂₂ is connected to the base of the transistor Q ₂₂ via the resistor R ₂₃ .

Further, a terminal _T23 to which a high level signal is supplied when a regeneration operation switch (not shown) is operated is connected to a play solenoid (not shown) and is grounded via a capacitor _C21 and a resistor _R24 in series. The midpoint of the connection between capacitor C ₂₁ and resistor R ₂₄ is connected via resistor R ₂₅ to the other end of a two-input AND circuit A ₂₁ whose one end is connected to power supply Vcc. Further, the output terminal of this AND circuit A ₂₁ is connected to the connection midpoint between the diode D ₂₁ and the resistor R ₂₃ via a diode D ₂₂ of the illustrated polarity.

Here, the diodes D ₂₁ , D ₂₂ and the resistor R ₂₃ constitute a so-called OR circuit OR ₂₁ . In this case, the capacitor C ₂₁ , resistors R ₂₄ , R ₂₅ , and AND circuit A ₂₁ generate a play signal during playback as shown in Figure 5a, with a pulse width of several 100 msec as shown in Figure 5b. Waveform shaping circuit WO ₂₁ which is supplied as _{a signal to one diode D 22 of} OR circuit OR 21
It consists of

The transistors Q ₂₁ and Q ₂₂ constitute a motor drive circuit MD ₂₁ , and their respective emitters are both grounded, the reel motor RM is connected between their collectors, and their collectors are connected to the transistor Q ₂₃ . or Q ₂₄ each commonly connected to the power supply Vcc through its emitter passage. Here, the bases and collectors of the transistors Q ₂₃ and Q ₂₄ are connected across each other via a resistor R ₂₆ or R ₂₇ .

In the control circuit configured as above, during rewinding when a high level signal is supplied to the terminal T ₂₁ , the transistors Q ₂₁ and Q ₂₄ of the motor drive circuit MD ₂₁ are turned on and the transistors Q ₂₂ and Q _{23 are} turned on. By turning off, power supply Vcc→transistor
A current path is formed in the direction of the arrow shown by the broken line Q ₂₄ → reel motor CM → transistor Q ₂₁ ,
Drive the reel motor RM in the direction of the arrow REW in Figure 3.

Also, during fast forwarding when a high level signal is supplied to the terminal T ₂₂ , a current path is ultimately formed in the direction shown by the solid line in the figure in the opposite relationship to the above, and the reel motor RM is driven to the direction shown by the arrow in FIG. Drive it in the FF direction.

During rewinding or fast forwarding, the drive mechanism drives the tape in the reverse or forward direction by transmitting power through the path described above.

Next, a case will be described in which a playback operation switch (not shown) is operated to enter the playback state immediately after such rewinding or fast forwarding. In this state, a high level signal is supplied only to the terminal _T23 .

By the way, in this state, the reel motor RM is still
Since there is an inertial force acting on the gear B, as mentioned above, if the gear B and D becomes engaged and the regeneration state becomes impossible.

However, in this invention, the high level signal from the regeneration operation switch supplied to terminal _T23 not only drives a play solenoid (not shown), but also drives a waveform shaping circuit provided in the control circuit.
As mentioned above in WO ₂₁ , a signal having a pulse width of several 100 msec is obtained. In other words, since this signal is logically ORed with the signal from terminal T ₂₂ during fast forwarding using the OR circuit OR ₂₁ , the reel motor RM will move several 100 msec in this case.
The film is driven in the fast-forward direction, which is opposite to the rewinding direction on which the inertial force acts for a period of time.

Figure 6 shows a part of the drive mechanism driven by such a control circuit, and as shown in figure a, immediately after switching from the rewinding state to the playback state, the reel motor RM Gear B is still in mesh with gear D due to the inertia force acting thereon. However, if the reel motor RM is driven in the fast forward direction for a certain period in this state, the gear B
is rotated in the direction in which it is disengaged from the gear D, so that the supply reel 30 becomes rotatable and a reproducing state in which the tape is immediately run at a constant speed in the forward direction can be obtained. become.

Furthermore, when the fast-forwarding state is immediately switched to the reproducing state, as shown in Fig. 6b, gear B and gear C rotate in a direction in which they run away from each other, so gear B is removed from gear C. Therefore, the reproducing state can be obtained immediately without any problems.

The above explanation has been made with the assumption that it is applied to micro cassette tape, but it can of course be applied to ordinary compact cassette tape, which has the opposite tape running direction, as well as other applications. It goes without saying that various modifications and applications can be made without departing from the gist of the invention.

Therefore, as detailed above, according to the present invention, the brake solenoid is omitted in a two-motor type electronically controlled tape recorder that is equipped with separate reel motors and capstan motors, thereby making the device more compact and the circuit simpler. In order to achieve simplification and lower current consumption and lower operational changes, the reel motor can be configured to drive in the forward or reverse direction for a certain period of time based on the regeneration command signal obtained from the operation section. Therefore, it is possible to provide an extremely good electronically controlled tape recorder in which the undesirable problem caused by omitting the brake solenoid can be solved with a simple circuit configuration.

[Brief explanation of the drawing]

1 and 2 are diagrams showing a drive mechanism of a conventional electronically controlled tape recorder and its control circuit, and FIGS. 3 and 4 are diagrams showing a drive mechanism of an electronically controlled tape recorder according to an embodiment of the present invention. A diagram showing its control circuit, Figure 5,
FIG. 6 is a waveform diagram for explaining the operation of the embodiment and a diagram showing the operating state of the drive mechanism section. CM... Capstan motor, 22... Belt, 23... Flywheel, 24... Capstan, 25... Take-up reel, 26... Idler,
RM...Reel motor, 28...Belt, 29...
...Pulley, A to D...Gear, 30...Supply reel, _T21 to _T23 ...Terminal, _C21 ...Capacitor,
_R21 to _R27 ...Resistance, _D21 , _D22 ...Diode,
Q ₂₁ to Q ₂₄ ...transistor, OR ₂₁ ...OR circuit,
A ₂₁ ...AND circuit, Vcc...power supply, MD ₂₁ ...motor drive circuit, WO ₂₁ ...waveform shaping circuit.

Claims (1)

[Claims] 1. A supply reel and a take-up reel on which the tape is loaded so that it can be fed out or taken up; a capstan motor that transmits a driving force to the take-up reel to make the tape travel at a constant speed during a playback operation; Transmitting an idle force for selectively engaging the take-up reel or the supply reel during a fast-forward or rewind operation to a high-speed rotation transmission body located between the supply reel and the take-up reel, and
In a two-motor electronically controlled tape recorder comprising a reel motor that transmits a driving force for causing the tape to run at high speed in a forward or reverse direction, at least the rewinding operation causes the tape to run at high speed in a reverse direction. When the tape is switched to a constant speed running state by the playback operation, the reel motor is operated for a predetermined period of time in the opposite direction to the previous rewinding direction by the inertial driving force based on the playback command signal by the playback operation. An electronically controlled tape recorder comprising a circuit that generates a signal for driving in the fast forward direction.