JP3271219B2 - Tape player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a motor servo device .
Related to a tape player .

[0002]

2. Description of the Related Art For example, in a device such as a tape player , not only is the rotational speed of a motor for running a magnetic tape controlled to a rated rotational speed, but also, for example, when a user performs a tape speed variable operation, the motor is driven. Some are designed to be able to change the rotation speed.

As one example of a motor servo system used in such a device, a CR time constant corresponding to a user's volume operation (tape running speed operation) is generated and used as a servo reference signal, and the rotation speed of the motor means is controlled. There is a method of controlling

FIG. 12 shows an example of a servo circuit unit 100 for driving a three-phase brushless motor. The terminal E is a charging voltage source. Charging voltage E from the E terminal is charged to the resistor R _100, a capacitor C ₁₀₀ are connected in series through a variable resistor VR _100. Then, both-terminal voltage V _C of the capacitor C ₁₀₀ is input to the SAW terminal as servo reference value E _SV, the servo circuit unit 100 will drive the motor M based on the servo reference value E _SV. Here, the variable resistor VR ₁₀₀ are user performs speed setting operation, that is, the variable resistor VR ₁₀₀ in response to user interaction
CR time constant is adapted to change due to the capacitor C ₁₀₀ and.

The operation of the servo circuit section 100 will be described with reference to FIG. Although not shown in FIG. 12, a discharge transistor is connected to the SAW terminal in the servo circuit unit 100. As shown in FIG. 13, for example, the discharge transistor is turned off at the same time as the start of energization of the U phase, Therefore charging begins in the capacitor C _100. And the capacitor C
_When the voltage V _C across the terminal ₁₀₀ reaches a certain potential (V _COMP ), the discharging transistor functions to discharge the charge of the capacitor C ₁₀₀ . If again in energization of the U phase is initiated the charging of the capacitor C ₁₀₀ is started. (It is assumed that energization of the motor coil is performed in the order of U → V → W → U...)

With this operation, a sawtooth waveform as shown in FIG. 13B is supplied to the servo circuit section 100 as the servo reference signal _ESV . Here, the time T ₁ is determined by the CR charging time constant, and is expressed by the following (Equation 1).

(Equation 1)

On the other hand, the time T ₂ is half of the time T ₁ (T ₂ =
When T _1/2) to the frequency F ₁ (Hz sawtooth shaped waveform of FIG. 13 (b)), the

(Equation 2) Is represented by The servo circuit 100 will control the motor speed in accordance with the frequency F _1.

[0008]

Here, in FIG. 12, the variable resistor RV _{100 is set} to ₁₀₀ KΩ, and the resistor R _{100 is set} to 10
K.OMEGA., 0.1ĩF the capacitor C _100, the charging voltage E 1.5
V, the comparison reference voltage V _{COMP is set} to 0.6 V, and the variable resistor RV
The change in the frequencies F ₁ with respect to changes in the ₁₀₀ computes, further movement of 50% of the variable resistor RV ₁₀₀ (= the moving range of the volume operation midpoint) reference frequencies F ₁ (1
00%), the change rate of the motor rotation speed is obtained.
4 (a) is obtained.

FIG. 14B is a graph of the volume moving amount (operating amount) and the change rate of the motor rotation speed in FIG. 14A. As can be seen clearly from this FIG. 14 (b), the relative movement amount of the variable resistor RV _100, the change in motor speed is not uniform.

[0010] This is a variable resistor RV ₁₀₀ is in B characteristic volume whose resistance value varies linearly with respect to the mechanical movement of operating member such as a rotating knob or slide lever (rotation angle or slide amount) If there is, when the user operates, the motor rotation speed does not linearly change according to the operation amount. For example, in the case of FIG. 14B, the rotational speed changes rapidly when the mechanical operation amount is around 0 to 20%, while it does not change much when the operation amount is around 50 to 100%. For this reason, there arises a problem that the user feels a sense of discomfort in the relationship between the operation amount and the change in the number of revolutions in actual use, and it is difficult to adjust the rotation to a desired number of revolutions.

In order to solve the above problem in such a servo system, a variable resistor having a special characteristic as a relationship between a resistance value and an operation amount may be used. This leads to an increase in cost and is not a suitable solution.

[0012] The commonly used variable resistors include:
Generally, since the resistance value has a variation of about ± 30%, in the method of controlling the time constant by changing the resistance value as described above and performing the motor servo, it is necessary to accurately set the variation width of the motor rotation speed. Had to use a special high-precision volume.

[0013]

SUMMARY OF THE INVENTION In view of the above problems, the present invention makes it possible to obtain a good operational feeling by proportionally corresponding to a user operation and a change in motor speed without using a special variable resistor. It is an object of the present invention to provide such a tape player .

Therefore, a brushless motor and a variable resistor
Volume operation means for operating a volume controller;
CR that changes in proportion to the change of the variable resistor
CR time constant generated based on the charging voltage of the time constant circuit
A servo reference signal generating means for generating a servo reference signal based on the difference that is generated by the servo reference signal generating means
The reference resistor signal changes the variable resistor and
Servo means for controlling a change in the rotation speed of the siles motor to be proportional, and the brush controlled by the servo means
Tape driving means driven by a motor
You .

[0015]

[Function] In the CR time constant circuit, the resistance value is set to a fixed value,
By making the charging voltage change in proportion to the volume operation amount, the resistance value of the normal volume operation means (a volume whose resistance value changes linearly with respect to the mechanical movement amount of the operation element) The change may be proportional to the change in the number of revolutions of the motor means.

For example, in the above (Equation 1) for finding the charging period T ₁ for a time constant signal serving as a servo reference signal,
It is assumed that the value of R is fixed (100 KΩ) and the charging voltage E changes from 0.5 V to 2.5 V corresponding to the amount of movement of the variable resistor (volume). Also, C = 0.1 μF, comparison reference voltage V
_{Assuming that COMP} = 0.4 V, the charging voltage E is obtained from (Equation 1) and (Equation 2).
When the changes in the frequencies F ₁ calculates a relative change, further obtains the motor rotational speed change rate frequencies F ₁ as a reference (100%) when the charging voltage E = 1.5V, FIGS. 4 (a) FIG. 4B is a graph of the volume movement amount (operation amount) and the change rate of the motor rotation speed in FIG. 4A. That is, the motor rotation speed changes in proportion to the volume movement amount.

[0017]

EXAMPLES Hereinafter, the FIGS. 1-11, the tape of the present invention
The motor servo device mounted on the player will be described.

First, the configuration of the tape player will be described with reference to FIGS. FIG. 2 shows an example of the appearance of the tape player 1.
Is a cassette tape loading section, 3 is a flat microphone, 4 is a speaker, 5 is playback, recording, stop, fast forward,
Shows operation keys for performing tape operations such as rewinding. Reference numeral 6 denotes a volume control knob for controlling the volume of the reproduced sound output from the speaker 4.

Reference numeral 7 denotes a pitch conversion mode key, 8 denotes a speed adjustment knob serving as an operation of a variable resistor for varying the tape speed, and 9 denotes a variable resistor for manually adjusting the pitch conversion amount of reproduced sound. 2 shows a pitch adjustment knob serving as an operation element. In addition, 10 is an external microphone connection terminal,
Reference numeral 11 denotes a headphone output terminal.

In the tape player 1, the user can increase the tape traveling speed by rotating the speed adjustment knob 8 in the + direction during reproduction to reproduce the tape, and rotate the speed adjusting knob 8 in the-direction to decrease the tape traveling speed. Become.

The pitch conversion mode key 7 is 3
The slide is set to one of two positions, and the mode operation can be set to an off state, a manual state, or an automatic state. When in the manual state, the user can increase the pitch of the reproduced sound by turning the pitch adjustment knob 9 in the + direction, and can decrease the pitch of the reproduced sound by turning the pitch adjustment knob 9 in the-direction. It has been made.

Further, when in the auto mode,
Regardless of the tape speed at that time, the reproduced sound is output at the pitch at which the tape is running at the rated speed. In other words, when the speed adjusting knob 8 is turned to increase or decrease the tape running speed during playback, the frequency of the playback signal increases or decreases accordingly. The pitch is converted to the original frequency by the change in the frequency of the playback signal,
The reproduced sound is output in a normal state. For example, if the tape running speed is such that the pitch of the reproduced voice is increased by five sounds, pitch conversion processing for lowering the pitch by five sounds is performed. In this auto mode, the pitch adjustment knob 9 does not function.

When the pitch conversion mode key 7 is turned off, the above manual / auto pitch conversion processing is not performed at all.

FIG. 3 is a block diagram of a main part in the tape player 1. T indicates a magnetic tape wound around and housed on a pair of reels in a tape cassette. In the tape player 1 of this embodiment, a cassette tape is loaded in the cassette tape loading section 2 and recording or reproduction operation is performed. Then, the magnetic head 21 comes into contact with the magnetic tape T to record / reproduce the audio signal.

Reference numeral 22a denotes a capstan, 22b denotes a pinch roller, and the capstan 22a and the pinch roller 22b
Rotates while holding the magnetic tape T in contact with the magnetic tape T, so that the magnetic tape T is rotated at a predetermined speed in accordance with the rotation speed of the capstan 22a.
Is run.

The rotation of the capstan 22a is, for example, 3
This is performed by a motor 23 which is a phase brushless motor. The motor 23 receives three-phase drive signals (U, V, W) from the motor drive unit 24 under the control of the servo circuit 25.
Is supplied and rotated at a predetermined rotation speed. The servo circuit 25 controls the output of the motor drive unit 24 according to the servo reference signal _ESV .

The servo reference signal _ESV is controlled by the speed control knob 8
Is generated by the servo reference signal generator 26 in accordance with the operation of, that is, the rotation angle. That is, when the speed adjustment knob 8 is at the middle position of the rotation range (the position shown as “N” in FIG. 2), that is, the variable resistor whose resistance value is changed by the speed adjustment knob 8 is in the resistance variable range. When the resistance value is intermediate, the servo reference signal E _SV for obtaining the number of rotations of the motor 23 is output so that the tape traveling speed becomes the rated traveling speed, and the speed adjustment knob 8 is turned in the + direction. At that time, when the servo reference signal E _SV is controlled so that the rotation speed of the motor 23 increases according to the rotation angle, on the contrary, when the speed adjustment knob 8 is turned in the negative direction,
A servo reference signal E _SV is output which is controlled so that the rotation speed of the motor 23 becomes slower according to the rotation angle.

The servo reference signal _ESV will be described later.
The speed adjusting knob 8 is an output of a CR time constant circuit obtained by changing a charging voltage in accordance with a resistance value of a variable resistor serving as an operating element, and according to a frequency of the output (servo reference signal E _SV ). The servo circuit 25 performs a servo operation.

As an audio signal recording system, an audio signal input from the microphone 3 or an external microphone connection terminal 1
The audio signal from the external microphone connected to 0 is
The signal is selected by the switch 26, amplified by the amplifier 27, and supplied to the recording processing unit 28. The signal subjected to recording equalization, level adjustment processing, and the like by the recording processing unit 28 is supplied to the magnetic head 21 via the R terminal of the switch 29, and is recorded from the magnetic head 21 on the running magnetic tape T at the rated speed. Will go on.

At the time of reproduction, a signal read from the magnetic tape T by the magnetic head 21 is supplied to the reproduction processing unit 30 via the P terminal of the switch 29, and is subjected to processing such as reproduction equalization. The audio signal output from the reproduction processing unit 30 is converted into a digital signal by an A / D converter 31 and input to a pitch conversion unit 32 formed by, for example, a DSP (digital signal processor).

The pitch conversion section 32 outputs a pitch conversion control signal S
_The digital audio signal input according to the _PT is processed by raising or lowering the pitch and output. Pitch converter 3
2 is converted back to an analog signal by the D / A converter 33,
Volume control 3 that can be varied by volume control 6
After the level is adjusted by the speaker 4, the signal is amplified by a predetermined level in the speaker amplifier 35 and output as a sound from the speaker 4. Alternatively, it is supplied to the headphone output terminal 11,
It is output as sound from the connected headphones.

The pitch converter 32 temporarily writes the input digital audio signal into the RAM, and changes the method of reading from the RAM from the time of writing to realize pitch conversion (frequency conversion). This operation will be described briefly.

The sampling frequency of the A / D converter 31 is
If the frequency is 16 KHz, the pitch conversion unit 32
Data is written in the AM every 1/16000 second (62.5 μsec) in order.

At this time, 1/1600 is also read from the RAM.
If data is read out and output every 0 seconds in the order in which it was written, the same waveform as the input signal of the A / D converter 31 is reproduced as the output of the D / A converter 33, that is, pitch conversion. Will not be performed.

When performing pitch conversion, R
Change the AM reading method. First, FIG. 8 shows a case where the frequency is reduced by half (= the sound is lowered by one octave). Assuming that the input signal waveform of the A / D converter 31 is the waveform shown in the lower part of FIG. 8, the data sampled by the A / D converter 31 and input to the pitch converter 32 are D ₁ , D _2.
..... a D _n.

[0036] Now, the RAM of the pitch converting unit 32, and the data D _1, D ₂ ······ D _n is gradually written, the data D _1, D ₂ ······ D _n Is audio data for 30 ms.

Here, when reading data from the RAM, if data is read twice in order from the data D ₁ , the first 15 m
A waveform as shown in the upper part of FIG. 8 is generated by the data for seconds (D _{1 to} D _C ). That is, by supplying such read data to the D / A converter 33, an audio signal waveform whose frequency is reduced by half is generated, and pitch conversion is performed such that the pitch is lowered by one octave. In addition,
In this case, data (D _{C + 1 to} D _n ) for the latter 15 ms is unnecessary.

Next, FIG. 9 shows a case where the frequency is doubled (= the sound is raised by one octave). Assuming that the input signal waveform of the A / D converter 31 is the waveform shown in the lower part of FIG. 9, the data input to the pitch converter 32 and stored in the RAM is D
_1, the D ₂ ······ D _n.

In this case, the data stored in the RAM is read out every other data from the beginning. That is, D ₁ , D
_3, are sequentially read as D _5, D ₇ · · · · ·, Figure 9 upper waveform is generated (indicating the correspondence by the solid arrow).
However, since the data for 30 ms stored in the RAM is read out every other time, only a waveform for 15 ms can be generated. Therefore, after the last data D _n is read, D ₃ , D ₅ , D ₇ are read again from the beginning. will read in the order that · · · · · D _n (indicating the correspondence by dashed arrows). As a result, as shown in the upper part of FIG. 9, a waveform whose pitch (frequency) is doubled for 30 ms is generated.

Further, when the pitch is converted to an intermediate state of 1/2 to 2 times, the RAM reading method is changed according to the pitch conversion amount. For example, in FIG.
This shows a case where the pitch is converted by 30% (about -3.5 sounds).

In this case, the data D ₁ held in the RAM
For to D _n, so that read by doubling one data per 3 data. That is, the data is D ₁ , D
_2, D _3, D _3, are sequentially read as _{D 4, D 5, D 6} , D 6 ····. Then, when the data _DE is read, pitch conversion data corresponding to the time length (30 msec) of the input data is generated as shown in the upper part of FIG. 10, which is D / A converted to about -3.5. Only the sound is output as a sound signal whose pitch has been converted.

In the case of other pitch conversion amounts, the RAM reading method is set according to the conversion amount, and pitch conversion is performed.

A pitch conversion control signal S _PT for controlling the pitch conversion amount in the pitch conversion unit 32 is generated by pitch control signal generation units 36 and 37, selected by a switch 38 and supplied to the pitch conversion unit 32. The switch 38 is switched by the pitch mode key 7. When the slide position of the pitch mode key 7 is set to the manual mode position, the MN terminal is set to the auto mode position, and the AT terminal is set to the off mode position. And the OF terminal are connected.

When the switch 38 is connected to the OF terminal, the pitch conversion control signal S _PT is not supplied to the pitch conversion unit 32, and the pitch conversion is not performed. Switch 38
Is connected to the MN terminal, a pitch conversion control signal SPT of a predetermined potential is _supplied to the pitch control signal generator 36 according to the resistance value of the variable resistor using the pitch adjustment knob 9 as an operator.
And supplied to the pitch conversion section 32, the pitch conversion processing corresponding to the operation of the pitch adjustment knob 9 by the user is performed.

When the switch 38 is connected to the AT terminal, the pitch conversion processing is executed so that the reproduced sound is output at the pitch when the tape is running at the rated speed, regardless of the tape speed at that time. Therefore, a pitch conversion control signal S of a predetermined potential based on the tape running speed information
_PT is output from the pitch control signal generator 37 and supplied to the pitch converter 32. As a result, even when the tape is played back at a tape speed higher or lower than the rated speed, it is possible to obtain a reproduced sound that is easy to hear at the same pitch as normal.

FIG. 11 shows the pitch conversion amount corresponding to the pitch conversion control signal S _PT when the operating voltage V _DD = 3.5 V.
(A) and (b). In this example, 32 levels of voltages are set for the operating voltage V _DD , and the pitch control signal generator 37
(36) supplies the pitch conversion control signal S _PT to the pitch conversion unit 32. For example, pitch conversion control signal S _PT =
In the case of 2.19 to 2.08V, pitch conversion is not performed.
When the pitch conversion control signal S _PT = 3.5V, the pitch conversion is performed so that the pitch is increased by six sounds (one octave). Also,
When the pitch conversion control signal S _PT is between 0.88 and 0.77 V, the pitch conversion is performed so as to lower the pitch by six sounds (one octave).

Further, in the case of the auto mode, FIG.
As shown in (e), the pitch conversion is performed in response to a change in the motor rotation speed (tape running speed). However, the reproduced audio signal generated by the change in the motor rotation speed (tape running speed) is changed. The pitch conversion amount is shown in FIG.
This corresponds to (b).

FIG. 11 (c) shows the frequency change rate of the audio data at the pitch conversion amount of FIG. 11 (b) with respect to the audio data at the pitch conversion amount of zero. In order to return the resulting change in the pitch of the reproduced audio signal to the pitch of the reproduced audio signal at the rated traveling speed, the pitch conversion corresponding to the frequency change rate in FIG.

That is, in the case of the auto mode, the pitch control signal generator 37 generates the pitch conversion control signal S _{PT having} the voltage value of FIG. 11A in accordance with the motor rotation speed of FIG.
Is generated, the tape player 1 can obtain a sound output at a normal pitch regardless of the tape running speed.

In this case, the pitch control signal generator 37
Requires a signal linearly responding to a tape speed change, such as a voltage value changing in proportion to the tape speed change, as tape running speed information. In this embodiment, this signal is used as a servo reference signal generator 26. Is taken out of. This will be described later.

The tape player 1 configured as described above
The motor servo device mounted on the
By setting the resistance value in the R time constant circuit to a fixed value and changing its charging voltage in proportion to the operation amount of the speed adjustment knob 8, the resistance value of the variable resistor using the speed adjustment knob 8 as an operator is set. The change is proportional to the change in the number of revolutions of the motor 23, so that the user does not feel uncomfortable between the operation amount of the speed adjustment knob 8 and the actual tape speed change amount,
Operability has been improved.

For this reason, in the servo reference signal generator 26, the charging voltage is varied according to the speed adjusting knob 8, and this charging voltage is supplied to the CR time constant circuit. Then, and its CR time constant circuit connected to the servo circuit 25 as described FIG. 12, to generate a servo reference signal E _SV of sawtooth waveform as shown in FIG. 13 by the charging and discharging operations. Then, the servo circuit 25 outputs the servo reference signal E _SV
It will control the rotational speed of the motor 23 in accordance with the frequency F _1.

FIG. 1 shows a circuit diagram of the servo reference signal generator 26 in which the charging voltage to the CR time constant circuit is varied according to the speed adjusting knob 8.

In FIG. 1, RV ₄ is a speed control knob 8
Is a variable resistor serving as an operation element, and the resistance value is changed according to the turning operation of the speed adjustment knob 8. That is, the variable resistor R
Servo reference signal E _SV for speed control according to the resistance value of V ₄
Is generated and output from the servo reference signal generator 26 to the servo circuit 25.

40 is a regulator, 41 is an amplifier 41
A buffer having a and 41b, and an adder 42 having an amplifier 42a. The power supply voltage V _CC is supplied to the input terminal of the regulator 40, and the output terminal of the regulator 40 −
Voltages V ₁ between the ground terminal resistor R ₁₀ and capacitor C
Set by ₁ for fixed voltage output. There is also a adjustable fixed output voltage value by the variable resistor RV _2.

The output voltage V ₁ of the regulator 40 is divided by the variable resistor RV ₄ and is input to the amplifier 41 b of the buffer 41 via the resistor R ₁ . The buffer 41
The amplifiers 41a, the power supply voltage V _CC is supplied divided by the variable resistor RV _1. That, DC potential V _A, which is adjusted by the variable resistor RV ₄ as the output of the amplifier 41b can be obtained and a variable resistor as the output of the amplifier 41a RV ₁
In the regulated DC voltage V _B is obtained. Incidentally, so that any value can be obtained by the variable resistor RV ₂ is a value of the DC potential V _A.

The DC potentials V _A and V _B are supplied to the inverting input terminals of the addition amplifier 42a of the adder 42 via the resistors R ₃ and R ₄ . The non-inverting input terminal of the summing amplifier 42a, a voltage V _ref2 is supplied which is set by the resistor R _9, R _8.

As the output voltage _Vout of the addition amplifier 42a, an output expressed by the following (Equation 3) is obtained.

[Equation 3]

This output voltage V _out becomes a charging voltage E for the time constant circuit by the resistor R ₁₁ and the capacitor C ₃ , and both ends of the capacitor C ₃ where charging and discharging are performed as described with reference to FIGS. The voltage is supplied from the terminal 43 to the SAW terminal of the servo circuit 25.

[0060] Consider now assuming that the variable resistor RV ₃ absent connected in parallel to the center tap CT and the hot side of the variable resistor RV ₄ in FIG. The DC potential V _A, in proportion to the amount of movement of the variable resistor RV ₄ (rotational operation angle of the speed control knob 8), so that the appear potential of until 0V~ potential V _1.

From the above (Equation 3),

(Equation 4) Is derived, but (3 · V _ref2 −V
_B), since a constant not influenced by the DC potential V _A, by varying the DC potential V _A between 0V~ voltage V _1, the output voltage _{V out, (3 · V ref2} -V B ) To (3 · V _ref2 −V _B −V ₁ ).

Since the DC potential V _A is a voltage obtained by dividing the voltage V ₁ by the variable resistor RV ₄ as described above, when a B-characteristic volume is used as the variable resistor RV ₄ ,
The DC potential V _A voltage proportional to the moving amount of the variable resistor RV ₄ is obtained, that a voltage proportional to the amount of movement of the output voltage V _out (charging voltage E) to the variable resistor RV ₄ as results Become.

The charging voltage E is changed proportionally in accordance with the manipulated variable, and the voltage waveform across the capacitor C in the CR time constant circuit is used as the servo reference signal _ESV.
, The operation amount (the operation angle of the speed adjustment knob 8)
And that the rate of change in the number of revolutions of the motor 23 is proportional to
This is as described above with reference to FIGS.

That is, in the present embodiment, a linear characteristic as shown in FIG. 4B can be obtained as a characteristic of the rate of change in the number of revolutions of the motor 23 with respect to the knob operation, and the operability is easily perceived by the user intuitively. Can be obtained.

By the way, up to this point, the description has been made assuming that the variable resistor RV ₃ does not exist.
Function of V ₃ will be described.

When actually manufacturing the tape player 1 and the tape running speed can be adjusted by the user in this way, the speed adjusting knob 8 is usually set to the center position (the position "N" in FIG. 2). At some point, it is preferable to set the speed to the rated speed, and considering the actual usage, it is preferable to make the speed variable up to about twice in the direction of high speed, but it is preferable to make the speed variable to about twice in the direction of low speed Up to 70% when the rated speed is 100%, for example.
It is sufficient if the speed can be changed to about the same speed, and moreover, there are cases where it is more convenient to use.

That is, there is a case where it is desired to set the speed change amount when the speed adjustment knob 8 is turned to the + side to be larger than the speed change amount when the speed adjustment knob 8 is turned to the-side. . In this case, for example, the characteristic shown by the solid line in FIG.

In the case of the characteristic indicated by the solid line in FIG. 4C, a rated speed (rotational rate change rate is 100%) is obtained at the position of "N" where the volume movement amount is 50%, and the volume movement amount is 0%. The speed of about twice the rated speed can be obtained at the "+" position, while the speed of about 70% (30% deceleration) of the rated speed can be obtained at the "-" position with a volume movement of 100%. Characteristics.

Since the variable resistor RV ₃ does not exist as described above, the rate of change in the number of revolutions becomes 7 according to the operation of the variable resistor RV _4.
If the tape running speed is varied between about 0% and 200% and the tape running speed is adjusted in accordance with the operation, the characteristics shown by the one-dot chain line in FIG. In this case, when the speed adjustment knob 8 is at the position "N" where the volume movement amount is 50%, the tape running speed is higher than the rated speed.

In order to obtain the characteristics indicated by the solid line in FIG. 4C, it is necessary to increase the voltage _VA at the position "N". Thus connecting the variable resistor RV ₃ in parallel to the center tap CT and the hot side of the variable resistor RV _4. Then, the variable resistor RV ₄ as shown in FIG. 5 is divided into resistor RV _4-1 and RV _4-2 by the center tap CT (RV _4-1 = RV
_4-2 ) The voltage at the center tap CT is a variable resistor RV
₃ and the combined resistance of the resistor RV _4-2 and the resistor RV _4-1
Is a divided value.

Here, since RV _4-1 = RV _4-2 , the combined resistance of the variable resistor RV ₃ and the resistor RV _4-2 becomes smaller than the resistor RV _4-1. Therefore, the voltage at the center tap position can be increased. Of course the voltage variation amount at this time can be adjusted by the variable resistor RV _3. Since the center tap position corresponds to the position of "N" of the speed control knob 8, the characteristic shown by the solid line in FIG. 4C can be obtained.

Even if the variable resistor RV ₃ is added, the linearity of the DC potential _VA can be maintained with respect to the moving amount of the variable resistor RV ₄ (operation of the speed control knob 8). For example, if the variable resistor RV ₄ is operated to the ground side of the center tap CT is shown in Figure 6, DC potential V _A
The combined resistance and the resistance R of the variable resistor RV ₃ and the resistor RV _4-2 is
V _4-1a and the voltage _divided by the resistor RV _4-1b , that is, the DC potential _VA is equal to the resistance RV
_The voltage is in accordance with the movement amount of _4-1a .

The variable resistor RV ₄ has a center tap C
If it is operated in the voltages V ₁ side of the T is as shown in FIG. 7, DC potential V _A is the center tap CT position and the voltage V
_The voltage between ₁ is a voltage _divided by the resistor RV _4-2a and the resistor RV _4-2b , that is, the DC potential _VA is a voltage corresponding to the moving amount of the resistor RV _4-2a .

By the way, contrary to the above-described characteristics, the speed change amount when the speed adjustment knob 8 is turned to the + side is smaller than the speed change amount when the speed adjustment knob 8 is turned to the-side. when you want to set so that occurs, the variable resistor RV _3, it Haisure in parallel between the center tap CT and the ground of the variable resistor RV _4. Also, the variable resistor RV
_A fixed resistor may be provided instead of ₃ .

As described above, in this embodiment, the tape running speed changes in proportion to the operation of the speed adjusting knob 8, but when the pitch conversion mode is set to the auto mode, the speed is changed. Pitch converter 32 according to the amount of change
Thus, a predetermined amount of pitch conversion is performed, and even if the tape speed changes, a reproduced sound having the same pitch as at the rated speed can be obtained.

In order to perform this control, the pitch control signal generator 37 needs a signal linearly responding to a tape speed change, such as a voltage value changing in proportion to the tape speed change, as the tape running speed information. Become. Therefore, in this embodiment, this signal is extracted from the servo reference signal generator 26. The signal that responds linearly to a change in the tape speed in the servo reference signal generator 26 in FIG. 1 corresponds to the output voltage _Vout .

By taking _{out the} output voltage _Vout from the terminal 44, the pitch control signal generator 37 can obtain the current motor rotation speed (tape running speed) information.
Motor speed (FIG. 11E)
By generating the pitch control signal generator 37 having the voltage value of FIG. 11A according to the above, the pitch conversion process in the auto mode is executed. Thus, the output voltage V
By using _out , a rotation speed detection mechanism such as FG and a circuit unit are not required, and an increase in circuit scale and an increase in the number of parts can be prevented.

[0078] Incidentally, te a motor servo system of the present invention more
Although the description has been given of the case where the motor servo device is mounted on a tape player , it goes without saying that the motor servo device of the present invention can be applied to various other electronic devices such as a tape player such as a DAT and a disk player. Further, the actual circuit configuration and the like are not limited to those of the embodiment, but can be variously changed.

[0079]

As described above, the tape player equipped with the motor servo device of the present invention is a brushless motor.
When the volume operation means for operating the variable resistor, the
In proportion to the change of the variable resistor by the volume operation means
It is generated based on the charging voltage of the changing CR time constant circuit.
A servo reference signal generating means for generating a servo reference signal based on the calculated CR time constant; and a servo reference signal generating means.
The variable resistor is changed by the generated servo reference signal.
And the change in the number of revolutions of the brushless motor are proportional.
And servo means for controlled so, is controlled by the servo means
Tape drive driven by the brushless motor
Means without using a variable resistor having a special change characteristic of the resistance value as a volume operation means.
By using the variable resistor having the characteristic, the user's operation and the change in the motor speed can be made to correspond proportionally, so that a good operation feeling can be obtained, and there is an effect that practical discomfort can be eliminated.

Further, since the CR time constant is not directly controlled by changing the resistance value of the volume operation means, it is not always necessary to use a high precision volume as the volume operation means. In addition, the amount of user operation
Characteristics that are practically suitable for
Can be set to improve usability
There is also an effect that can be done.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a servo reference signal generator of a motor servo device according to an embodiment of the tape player of the present invention.

FIG. 2 is a tape on which the motor servo device of the embodiment is mounted.
It is an external view of a player .

FIG. 3 is a tape on which the motor servo device of the embodiment is mounted.
It is a block diagram of a player .

FIG. 4 is an explanatory diagram of characteristics of an operation amount and a rotation rate change rate obtained by the motor servo device of the embodiment.

FIG. 5 is an explanatory diagram in a case where a resistance means is connected in parallel between one end point of the volume operation means and a center tap in the motor servo device of the embodiment.

FIG. 6 is an explanatory diagram in the case where a resistance means is connected in parallel between one end point of the volume operation means and a center tap in the motor servo device of the embodiment.

FIG. 7 is an explanatory diagram in a case where a resistance means is connected in parallel between one end point of the volume operation means and a center tap in the motor servo device of the embodiment.

FIG. 8 shows a tape on which the motor servo device of the embodiment is mounted.
FIG. 9 is an explanatory diagram of a pitch conversion process in the player .

FIG. 9 shows a tape on which the motor servo device of the embodiment is mounted.
FIG. 9 is an explanatory diagram of a pitch conversion process in the player .

FIG. 10 shows a table on which the motor servo device of the embodiment is mounted.
It is explanatory drawing of the pitch conversion process in a player .

FIG. 11 shows a table on which the motor servo device of the embodiment is mounted.
It is explanatory drawing of the pitch conversion process in a player .

FIG. 12 is an explanatory diagram of a motor servo system based on a CR time constant change.

FIG. 13 is an explanatory diagram of a motor servo system based on a CR time constant change.

FIG. 14 is an explanatory diagram of characteristics of an operation amount and a rotation speed change rate obtained in a motor servo system based on a CR time constant change.

[Explanation of symbols]

1 Tape player 3 Microphone 4 Speaker 7 Pitch mode key 8 Speed adjustment knob 9 Pitch adjustment knob 21 Magnetic head 22a Capstan 23 Motor 24 Motor drive unit 25 Servo circuit 26 Servo reference signal generation unit 30 Reproduction processing unit 31 A / D converter 32 pitch conversion unit 33 D / A converters 36 and 37 the pitch control signal generating unit 38 switches 40 regulator 41 buffer 42 adder RV ₁ ~RV ₄ variable resistor R ₁ to R ₁₁ resistor C ₁ -C ₃ capacitor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 5/00 G05D 13/62 G05B 1/01

Claims (1)

(57) [Claims] 1. A brushless motor, volume operation means for operating a variable resistor, and proportional to a change in the variable resistor by said volume operation means.
Generated based on the charging voltage of the CR time constant circuit that changes
A servo reference signal generating means for generating a servo reference signal based on the CR time constant is, the servo reference signal to said generated in the servo reference signal generating means
Signal and the brushless mode
Servo means for controlling the change in the number of rotations of the motor to be proportional, and the brushless motor controlled by the servo means.
Tape drive comprising:
Yah.