JPS6135601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic stylus pressure device for a sound player having a playback selection circuit, and in particular, to a device for starting a motor by turning on a specific start switch, thereby starting a rotating record. The provided swing contact connects to a fixed contact placed in a fixed positional relationship with the assumed pick-up lowering position before entering the playback start point of a specific recording groove along the rotational direction of the record. By doing so, the electromagnetic actuator is activated at the timing of connection between the specific start switch and the corresponding fixed contact, this movable piece applies stylus pressure to the pickup, the transistor circuit is used to hold the electromagnetic actuator, and the magnet is toned. The arm brings the record close to a magnetic sensing reed switch installed near the end of playback, closes the reed switch, sets the electromagnetic actuator to inactive, and completes one playback, and connects the electromagnetic actuator and this switch. A pick-up inhibitor transistor and a capacitor are separated from the holding transistor circuit so that the pick-up is electrically inactive at the moment when the electromagnetic actuator is activated, so that the collision sound of the playback needle is not amplified.

In general, recording and reproducing devices, especially simple phonographs of the multi-recording type, are widely used because they allow the enjoyment of reproducing various recorded contents.

However, regardless of the method in which recording contents are randomly selected, in the case of a method in which specific recording contents are consciously selected, a stopper corresponding to the number of record grooves is guided out outside the casing of the device and operated. It has a possible structure. The patent teaching this type of structure known to this inventor was published in Japanese Patent Publication No. 51
-This is Publication No. 19763.

This teaches that the mechanism for selecting recording content may employ a completely mechanical configuration.

According to the inventor's knowledge, the prior invention is very popular as a mechanical device for reproducing desired recorded content. Therefore,
This device that can selectively play back the desired recorded content is
In addition to dolls and toys, there has been a desire to apply this technology to general equipment. However, it has been found that there are limits to the application of this device to many types of equipment in its original form due to the relationship with the equipment to which it is applied.

Furthermore, in this type of simple gramophone, not only is a stylus pressure applied to the pickup by a stylus pressure spring, but the speaker is limited to a system that mechanically amplifies the reproduction vibration of the pickup. Such a simple gramophone can literally only be used for casual purposes, and it is difficult to improve the sound quality to a practical level. Therefore, it is desired that the stylus force be applied by an electromagnetic actuator and the speaker be provided with a function of amplifying the sound by electrical means.

Based on this viewpoint, the inventor first
Invented an electromagnetic stylus pressure device for a sound reproducer having a reproduction selection circuit (Japanese Patent Application No. 49404/1983). in this case,
Since the vibrations of the pickup are amplified by electrical means, the electromagnetic actuator reproduces and amplifies the sound of the pickup when it hits the record surface, causing unnecessary unpleasant noise to be heard by the listener. Become. The main object of the present invention is to suppress the amplification of the sound of the reproduction stylus hitting the record surface. Another object of the present invention is to provide a selective sound reproducing device without a stopper mechanism, and to expand the scope of its application.A further object of the present invention is to provide an inexpensive sound reproducing device with fewer failures. A further object of the present invention is to provide a selection-type sound reproducing device that allows easy selection operations, and a further object of the present invention is to provide a sound reproducing device for records with both a single recording groove and a plurality of recording grooves. It is another object of the present invention to provide an applicable switch structure, and also to use an electromagnetic stylus pressure method to enable the use of electric speakers, thereby improving the quality of reproduced sound. A further object of the present invention is to provide a mechanism that allows an electric selective reproduction device for sound to be compactly assembled.

That is, the present invention, as shown in the illustrated embodiment,
A record disc 2 rotatably supported on a chassis 1
, a motor M that drives this, a tone arm 3 which has an electric pick-up PU at its tip and is pivotally mounted so as to be biased in a direction away from the record surface and in a direction toward the playback start point, and a speaker 4. In the sound reproduction device including the electromagnetic actuator 5
is arranged so that the movable piece 5' can bias the tone arm 3 toward the record surface, so that the tone arm 3 enters the playback starting point of a specific recording groove G along the rotational direction of the record disc 2. A rotary switch RSW is made up of a fixed contact 6 arranged in a fixed positional relationship with the assumed pick-up lowering position in front of the switch, and a rotating contact 7 that rotates with the rotation of the record 2 and connects to the fixed contact 6. is provided between the record disc 2 and the part fixed to the chassis 1, and the power supply V is connected in series to the motor M and the motor circuit transistor _TR1 , and the power supply V is connected to the electromagnetic actuator 5 and the actuator transistor circuit 9.
Make a branch connection to the series connection of the start switch.
ST, the base of the motor circuit transistor TR ₁ and the non-actuated magnetically sensitive reed switch
MSW and the series circuit of the capacitor C ₁ are branch-connected, the rotary switch RSW's pivot contact 7 is connected to the base of the actuator transistor circuit 9, and the electromagnetic actuator 5 and the collector of the actuator transistor circuit 9 are connected to Connect the base of the self-holding transistor TR ₂ , the emitter of the self-holding transistor TR ₂ , the magnetic sensing reed switch MSW, the series circuit of the capacitor _C1 , the collector of the self-holding transistor TR ₂ , the turning of the rotary switch RSW. The base of an inhibitor transistor TR ₅ is connected between the contact 7 and the actuator transistor circuit 9, and the base of the inhibitor transistor TR ₅ is connected between the magnetic sensing reed switch MSW and the capacitor C ₁ .
a collector is connected between the rotary switch RSW and the actuator transistor circuit 9, a magnet 10 is provided on the tone arm 3, the magnetic sensing reed switch MSW is provided at the playback end point of the record 2, and Electromagnetic actuator 5 and actuator transistor circuit 9
pick-up inhibitor transistor between
Stylus pressure collision sound of an acoustic regenerator with a reproduction selection circuit, in which the base of TR ₆ and capacitor C ₂ are connected, and the collector of pick-up inhibitor transistor TR ₆ is connected between the connection circuit between pick-up PU and amplifier AMP. The present invention relates to an electromagnetic stylus pressure device having a suppression circuit.

In the present invention, one or more start switches are connected to the motor through the bases of the motor circuit transistors, which in turn are connected to corresponding fixed switches of the rotary switch. The pivot contacts of the rotary switch are connected to the base of an actuator transistor circuit, and the electromagnetic actuator is connected to the collector of this actuator transistor circuit and, together with the motor, to the power supply. From between the start switch and the motor circuit transistor, a magnetic sensing reed switch,
A series circuit of capacitors is branched, and the branch point and the magnetic sensing reed switch are connected to the emitter of a self-holding transistor, and the collector of this self-holding transistor is connected between the rotary switch's swivel contact and the actuator transistor circuit. The base of the self-holding transistor is connected to the electromagnetic actuator and the collector of the actuator transistor circuit by connecting it between the electromagnetic actuator and the actuator transistor circuit. The base of the inhibitor transistor is connected between the magnetic sensing reed switch and the capacitor, and the collector thereof is connected to the base of the actuator transistor circuit. The magnetically sensitive reed switch is provided at the end of the playback of the record, is turned off during playback, and is turned on when the magnet provided on the tone arm approaches the end of playback, that is, the magnetically sensitive reed switch.

A rotary switch has a fixed contact that is fixed to a wiring carrier such as a printed circuit board, and a rotating contact that rotates as the record rotates and connects to the fixed contact on the non-recording part of the top surface of the record. It is fixed at

The main parts of the circuit are carried on the printed circuit board and are compactly arranged. The printed circuit board is preferably installed above the record. The motor, electromagnetic actuator, tone arm, etc. are carried on the chassis. Note that a record disc is formed with one or more recording grooves with their playback starting points arranged at equal positions in the rotational direction of the record disc. The fixed contact of the rotary switch is arranged in a constant positional relationship with the pick-up lowering position, which is assumed to be just before entering the playback start point of a specific recording groove along the rotational direction of the record.

A capacitor and a pick-up inhibitor transistor are branch-connected between the electromagnetic actuator and the actuator transistor circuit, and the collector of the pick-up inhibitor transistor is in contact with the circuit between the pick-up and the amplifier.

Therefore, according to the present invention, when the start switch is pressed, the motor is activated and the record is rotated. As a result, when the swivel contact connects to the fixed contact corresponding to the pressed start switch, the actuator transistor circuit turns on at that timing, the electromagnetic actuator operates, and stylus pressure is applied to the tone arm's pick-up.
Then, at that timing, the pick-up descends so that the playback needle of the pick-up can anastomose with the intended recording groove, and collides with the surface of the record.

And the actuator transistor circuit is
Even if the rotating contact of the rotary switch separates from the fixed contact to which it is connected, it remains in the on state by the self-holding transistor. Then, when the pickup of the tone arm reaches the end of playback and approaches the magnetic reed switch, the magnet acts to turn on the magnetic reed switch. As a result, the inhibitor transistor turns on and prevents the base current from flowing into the actuator transistor circuit.

Therefore, the actuator transistor circuit is
off, the electromagnetic actuator is inactive,
Release the stylus pressure on the pick-up. Thus, the tone arm returns to the playback starting point by the return spring.
At this time, the magnetic sensing reed switch is turned off, but the inhibitor switch is turned off by the capacitor.
It maintains the on state and prevents the electromagnetic actuator from operating while the tone arm is returning.

When the actuator transistor circuit is off, the electromagnetic actuator is not operating. During this time, the capacitor branched between the electromagnetic actuator and the actuator transistor circuit is charged, and this current flows to the base of the pick-up inhibitor transistor. The current flows and the pick-up inhibitor transistor turns on. This makes the impedance at the input of the amplifier very low and the collision signal from the pickup is not amplified. However, the actuator transistor circuit turns on (this causes the electromagnetic actuator to operate, pushing the pickup against the record surface and colliding with it), and the capacitor branched between the electromagnetic actuator and the actuator transistor circuit is connected to the actuator transistor. It discharges toward the circuit, stops the base current of the pick-up inhibitor transistor, and turns off the pick-up inhibitor transistor. As a result, the suppression of the amplifier is released, and normal reproduction sound is amplified.

As described above, according to the present invention, a specific recording groove can be selected accurately using the electric contact, and is particularly suitable as a device for selectively playing back a record disc having a plurality of recording grooves, and the range of its application has been expanded. . Of course, the present invention can also be applied to playback of vinyl records having a single recording groove.

Further, since neither a needle pressure spring nor a sound transmission member is used, the present invention contributes to the miniaturization of the electric sound reproduction device.

Additionally, the sound from the pickup hitting the record surface at the start of playback is not amplified, and only the original recording is amplified, resulting in extremely good performance.

Embodiment FIG. 1 is a perspective view exposing the inside of this device.

A turntable 2' is rotatably pivoted to the chassis 1, and a tone arm 3 is mounted on a spring 12 so that its pickup PU can be hung above the turntable 2' and rotated. It is pivoted and biased upwardly and toward the outer circumference of the record 2, and further supports a flapper type solenoid as an electromagnetic actuator 5, a motor M, and a printed circuit board P.

The turntable 2' has a pulley groove 2'' (see FIG. 2) formed on its circumferential surface, and a belt 11 is stretched between it and the output shaft of the motor M. The movable piece 5 of the electromagnetic actuator 5 ′ extends from the playback start point at the outer periphery of the record 2 to the playback end point at the center.
It is integrated with a turntable 2' having a recording groove G formed on the upper surface of the turntable 2'. especially,
As clearly shown in FIG. 2, in this case, there are four recording grooves G, and their reproduction start point guide portions are arranged at equal intervals around the outer periphery of the record disc 2. As shown in Figure 1,
A magnet 10 is attached to the top of the tone arm 3. Tone arm 3 pick up
The PU is connected to an electric speaker 4 using an electric cartridge and an amplifier to be described later.

The printed circuit board P is arranged so as to extend above the record disc 2, and carries necessary electronic circuits. In particular, the magnetic sensing reed switch MSW
is placed over the playback end point of the recording groove G of the record disc 2, and at a position where the centers of the fixed contact 6 and the slip ring 7' forming the rotary switch RSW are aligned with the center of the record disc 2. do.

As shown in FIG. 2, a bifurcated pivot contact 7 is fixed at the center of the record disc 2, and the fixed contact 6 and the slip ring 7' formed on the lower surface of the printed circuit board P.
It is now connected to the

The rotary switch RSW has its fixed contact 6
There are four recording grooves G corresponding to the number of recording grooves G on the record disc 2, each with a pick-up lowering position assumed to be in front of the playback start point of a specific recording groove along the rotation direction of the record disc. They are arranged in a certain positional relationship.

And the start switch ST of the electronic circuit is
Four pieces are provided corresponding to the above-mentioned fixing, and are fixed at necessary locations outside the chassis 1. Similarly, the speaker 4 can also be fixed at a desired location outside the chassis 1. The electronic circuitry that operates such a device is
As shown in the figure.

In other words, the start switch ST is ST ₁ to _{ST 4.}
up to, each connected to one wire via diodes D ₁ to D ₄ and connected to the base of motor circuit transistor TR ₁ via resistor R ₁ . The collector of the motor circuit transistor is connected to the motor M, which is connected to the positive side of the power supply V.

The start switches _ST1 to _ST4 are branch-connected to the fixed contacts 6a to 6d of the rotary switch RSW before reaching the respective diodes _D1 to _D4 . Swivel contact 7 of rotary switch RSW
is connected to the base of the actuator transistor circuit ₉ via a resistor R2. This actuator transistor circuit 9 is a transistor
This is due to the Darlington connection between TR ₃ and TR ₄ .
The collector of the actuator transistor circuit 9 is connected to the electromagnetic actuator 5.
The electromagnetic actuator 5 has a diode _D5 for suppressing back electromotive force, and is connected to the positive side of the power supply V.

A series circuit consisting of a magnetic sensing reed switch _MSW , a resistor R ₃ and a capacitor C ₁ branches from before the resistor R 1 between the diode D and the motor circuit transistor TR ₁ .

A self-holding transistor TR ₂ is connected at its base between the electromagnetic actuator 5 and the actuator transistor circuit 9 via a resistor R ₄ .
The emitter of this self-holding transistor TR ₂ is located in front of the magnetic sensing reed switch MSW, and the collector is located in front of the rotary switch RSW's pivot contact 7 and the resistor in front of the actuator transistor circuit 9.
Connect between _R2 .

An inhibitor transistor is connected between the capacitor C ₁ and the resistor R ₃ in front of it through the resistor R ₅ .
Connect TR ₅ at its base. The collector of the inhibitor transistor TR ₅ is connected between the actuator transistor circuit 9 and the resistor R ₂ in front of it.

A resistor _R6 is branch-connected between the electromagnetic actuator 5 and the actuator transistor circuit,
_A resistor _R7 and the base of a pick-up inhibitor transistor _TR6 are connected in series to the resistor R6.

Also, capacitor C ₂ is branched out between resistors R ₆ and R ₇ .

The pickup PU is connected to a predetermined amplifier AMP via a variable resistor VR, and a speaker 4 is connected to the amplifier AMP. The collector of the pick-up inhibitor transistor _TR6 is connected between the circuit connecting the pick-up PU and the variable resistor VR.

Now, suppose that the first start switch ST ₁ is pressed. Then, the motor circuit transistor _TR1 is turned on, and the motor M rotates. At this time, the current is prevented from flowing around to the other start switches _ST2 to _ST4 by the diodes _D2 to _D4 .

As the record rotates, the rotating contact 7, which rotates along with it, connects to each of the fixed contacts 6a to 6d, but when it connects to the fixed contact 6a corresponding to the start switch _ST1 , the actuator transistor The circuit 9 is energized and turned on. At this moment, the electromagnetic actuator 5 operates, and the movable piece 5' (first
(see figure) pushes the tone arm 3 and descends to place the playback needle on the record 2. rotary switch
All of the fixed contacts 6 of the RSW, 6a to 6d, are
It is arranged so that it has a certain positional relationship with the pick-up lowering position that is assumed to be in front of the playback start point of a specific recording groove along the rotational direction of the record disc 2, so press the start switch ST ₁ ,
If the electromagnetic actuator 5 is activated and the pickup PU is lowered at the timing when the rotating contact 7 is connected to the corresponding fixed contact 6a, the playback needle will always enter a specific recording groove G due to the rotation of the record 2.

Even if the connecting contact 7 passes through the fixed contact 6a, the self-holding transistor TR ₂ will not operate the start switch ST ₁
is already turned on by the selection of and the connection of the rotary switch's rotating contact 7 and fixed contact 6a,
Through this, the actuator transistor circuit 9
is maintained, so the electromagnetic actuator 5 maintains its operating state.

If the electromagnetic actuator 5 still does not operate,
The actuator transistor circuit 9 is off, and in this state, the capacitor _C2 is charged through the resistor _R6 . Therefore, the base current of the pick-up inhibitor transistor _TR6 is supplied, and the pick-up inhibitor transistor _TR6 is in an on state. Therefore, the impedance on the input side of the amplifier AMP becomes extremely low, and even if a signal is generated at the pickup PU at this time, it will not be amplified.

Therefore, the actuator transistor circuit 9 turns on, and the electromagnetic actuator 5 operates.
When the pick-up inhibitor transistor _TR6 is on, even if the pick-up PU collides with the surface of the record 2 as described above, the collision sound is not amplified. However, when the actuator transistor circuit 9 is turned on, the charge amount of the capacitor _C2 is rapidly consumed through the resistors _R6 and _R7 , and the base current of the pick-up inhibitor transistor _TR6 is no longer supplied. ₆ off.

This increases the impedance on the input side of the amplifier AMP, making it possible to amplify the signal (playback vibration of the recording) from the pickup PU. In this way, when the playback progresses and the pick-up reaches the playback end point, the magnet 10 carried by the tone arm 3 activates the magnetic sensing reed switch MSW.
Turn on. As a result, the self-holding transistor TR ₂ is turned off, and the electromagnetic actuator 5 is also turned off.
becomes.

The tone arm 3 is then released and returns to the playback starting point, but at this time, the magnetic sensing reed switch MSW is turned off and the self-holding transistor is turned off.
TR ₂ turns on, but the current charged in the capacitor C ₁ turns on the inhibitor transistor TR ₅ , which turns on the actuator transistor circuit 9.
is kept off. In this way, one playback ends.

In this embodiment, the start switch itself does not have self-holding power, so it must be manually held during one regeneration, but a timer or other self-holding device may also be used. You can also do it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view exposing the internal structure of the apparatus according to the present invention, FIG. 2 is a perspective view of a record disc and a turntable, and FIG. 3 is an electronic circuit diagram. In the figure, 1 is the palm, 2 is the record, 3 is the tone arm, PU is the pickup, 4 is the speaker, 5
is an electromagnetic actuator, 5' is a movable piece of the electromagnetic actuator, 6 is a fixed contact, 7 is a rotating contact, 9 is a transistor circuit for actuator, 10 is a magnet, TR ₁ is a motor circuit transistor, TR ₂ is a self-holding transistor, TR ₃ , TR ₄ is the transistor that constitutes the actuator transistor circuit, TR ₅
is an inhibitor transistor, TR ₆ is a pick-up inhibitor transistor, C ₁ and C ₂ are capacitors, ST is a start switch, M is a motor, and MSW
is a magnetic sensing reed switch, V is a power supply, RSW is a rotary switch, and AMP is an amplifier.

Claims (1)

[Claims] 1 A record disc rotatably supported by a chassis, a motor for driving the record, an electric pick-up at the tip, and pivoted so as to be biased in the direction away from the record surface and in the direction of the playback start point. In a sound reproduction device including a tone arm and a speaker, an electromagnetic actuator is provided so that its movable piece is placed in a position where the tone arm can be biased toward the record surface, and the electromagnetic actuator is arranged in a position where the movable piece can bias the tone arm toward the record surface, and A fixed contact is placed so as to have a fixed positional relationship with the assumed pick-up lowering position before entering the playback start point of a specific recording groove along the direction, and a fixed contact that rotates with the rotation of the record and connects to the fixed contact. A rotary switch consisting of a rotating contact to be connected,
It is provided between the record disc and the part fixed to the chassis, and a power supply is connected in series to the motor and the motor circuit transistor, and further, the power supply is branch-connected to the series connection of the electromagnetic actuator and the transistor circuit for the actuator, and a start switch is connected. , a branch connection is made between the base of the motor circuit transistor, a magnetic sensing reed switch which is open when not activated, and a series circuit of a capacitor, and a pivot contact of the rotary switch is connected to the base of the actuator transistor circuit, and the electromagnetic actuator , the base of the self-holding transistor is connected to the collector of the actuator transistor circuit, the emitter of the self-holding transistor is connected to the magnetic sensing reed switch, and the series circuit of the capacitor is connected to the collector of the self-holding transistor, and the collector of the self-holding transistor is connected to the turning circuit of the rotary switch. A base of an inhibitor transistor is connected between the contact and the actuator transistor circuit, a base of an inhibitor transistor is connected between the magnetic sensing reed switch and the capacitor, and a collector of the inhibitor transistor is connected between the rotary switch and the actuator transistor circuit. a magnet is provided in the tone arm, the magnetic sensing reed switch is provided at the end point of the playback of the record, and further,
An acoustic device having a reproduction selection circuit, the base of a pick-up inhibitor transistor and a capacitor being connected between the electromagnetic actuator and the actuator transistor circuit, and the collector of the pick-up inhibitor transistor being connected between a connection circuit between the pick-up and an amplifier. An electromagnetic stylus pressure device with a needle collision noise suppression circuit for playback machines.