JPS5873044A - Display device for tape recorder - Google Patents

Abstract

PURPOSE:To make matching of the interval easy at after recording, by changing the number of revolutions of a capstan rotated at the specified number of revolutions with the interval pitch, and displaying the amount of change in the unit of cent. CONSTITUTION:The mode is selected into the pitch changeover mode at a changeover switch 22, an up button 19a and a down button 19b are depressed and a voltage controlled oscillation circuit 36 is oscillated via a control section 35 and a voltage control circuit 40. The control section 35 makes count up to a set value equivalent to a preset value and sets the output to a progran counter 37. This value and the difference of a reference counter circuit 32 are compared 33 to drive 26 a capstan and the result is displayed 20 via a latch circuit 27 through operation. The preset value as above mentioned is determined as an interval is 200 cents and the frequency-dividing ratio is determined for 100, 50, 25, 12.5, 6.25, and 3.125 at each decrement of 1/2 interval. Thus, the mixing operation at the after recording can be made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device for a tape recorder, and more particularly to a display device for a tape recorder that is capable of varying the rotational speed of a capstan in pitch pitches and displaying the amount of change in cents. It is something.

Conventionally, in tape recorders, as shown in Fig. 1, a magnetic tape (2) wound around a supply reel (1) is rotated at a constant speed through a guide roller (3a) and a head group (4). A pinch roller (6) is used to press the magnetic tape (2) onto a capstan (5) that is attached to the magnetic tape, and a guide roller (3b) is provided to run the magnetic tape (2) at a constant speed and wind it onto a take-up reel (7). In the capstan/device for running at a constant speed, in recent high-performance machines, the rotating shaft of the motor (8) itself is the capstan (5), as shown in Figure 2, and the rotating speed is As shown in the figure, a control circuit is provided to control the rotation speed to obtain constant rotation. To explain these control methods according to Fig. 2, a signal from a pulse wheel (9) that is attached to the motor (8) and records magnetic pulses is detected as the rotational speed of the motor (8) by a detection head Ql. , it is subjected to frequency-voltage conversion through a detection circuit αυ and a converter for converting it into an amplifier, and the output voltage is
Compare it with the reference power source from the reference voltage source α9 using the comparator I,
The output of the difference signal is supplied to the capstan motor (8) through the drive amplifier circuit (44J).

Furthermore, the phase of the signal of the oscillation circuit Qe having a crystal oscillator (X) and the signal of the detection circuit 01) is compared by a phase comparator αη, and the difference is converted into a voltage. A so-called phase control method with high rotational accuracy has become mainstream, in which the voltage of the reference voltage source a4 is changed by the same amount. Furthermore, in a commercial tape recorder, the frequency of an oscillation circuit αe having a crystal oscillator (X) is divided by a program counter Q barrel. At this point, the division ratio can be arbitrarily selected using the operation button Ql, and the rotational speed of the capstan can be arbitrarily selected under phase control. A number related to the number of revolutions is then displayed on the display screen.

However, the division ratio in the program counter mentioned above is
Since it is a percentage or % unit, capstan (5)
The rotation speed can also be varied step by step in percentage units. This is very inconvenient when actually matching the accompaniment and singing in a studio, etc., because the pitch is expressed in pitch units. In other words, at Studio Go, if a singer sings in time with the performance of musical instruments recorded in advance on a tape recorder, depending on the range of the singer's range, it may not be possible to sing in tune with the performance of the recorded instruments. .

In that case, the tape speed of the tape recorder is changed to match the sound, but in such cases, conventional speed variable devices
It is often difficult to know how much the speed should be changed. This is because when a singer is singing, the director instructs them to raise or lower the speed by a semitone, but the tape recorder operator responds to these instructions by converting how many percentage points the speed should be raised or lowered than the specified speed. Operate the rotation speed control device of the capstan (5). The problem in this case is that, for example, if you want to raise the pitch by a semitone, or 100 cents, if you use % as the standard, +5.9% will be 99.24 cents, and 6.0% will be 100.88 cents, which is the exact 100 cents. The speed cannot be finely adjusted. As described above, conventional methods have the disadvantage that operations, conversions, etc. are extremely complicated.

The present invention provides a display device for a tape recorder that eliminates the above-mentioned drawbacks, and is characterized by the following:
The capstan variable step is the percentage of rotation speed (
5) to control the step in pitch units without changing the pitch value (%), and to display the cent, which is the changed pitch value, digitally. The point is that the 5 frequency division ratio can be varied in pitch units of cents.

Hereinafter, the display device for a tape recorder with variable rotational speed control according to the present invention will be described in detail with reference to FIG. FIG. 1 shows a display (to) and an operation button α of a pitch varying means having a means for pitchwise varying the rotational speed of a capstan (5) of a rotary drive device of the present invention. In the example of the present invention, when there is a difference of one pitch from the reference rotational speed of the capstan (5), it is displayed as 200 cents on the display (to),
Below, a semitone is 100 cents, a quarter tone is 50 cents, and a pitch is 25 cents.

1/16th interval is 12.5 cents, /3 consonant interval is 6.25
cent.

The 1/64 pitch is 3.125 cents. Also, 3.12
The minimum unit is 5 cents, and the stealth ratio is determined to control the pitch. The pitch becomes higher by operating the up button (19m) of the operation button a,
By operating the down button (19b), the pitch becomes lower.

Next, based on the general operating procedure and explained with reference to Fig. 1, the speed changeover switch υ is now 39 cm.
/see. The selector switch (2) of the capstan drive means is normally fixed (FIX).
When the recording/reproducing operation is performed on the side and the need for pitch control as described above arises, the switch 4 is switched to the pitch (PITCH) side. At that time, although the explanation will be omitted, the display (2), which was used as a timer, will display the pitch control reel mentioned above, and will display oooo. For example, if you want to raise the pitch, press the operation button α's up button (19
If you keep pressing m), at the predetermined time interval, the minimum unit of 3.125 pitch mentioned above is 3.125 (0,18%).
, 6.25 (0,36%) , 9.375 (0,l
$4%).

12.5 (0.72%), 20G (12,
25%), the display on the display (2) changes up to the l pitch.

Then, the rotational speed of the capstan is increased to reach the indicated rotational speed, and when the indicated rotational speed is reached,
The indicator lamp (c) lights up. Also, if you want to lower the pitch, operate the operation button (19 down button (19b),
-3,125 (-0,18%L -6,25
(-0,36%), ・・・・・・・・・-200(-1
0.91%). The configuration for operating in this way is as shown in Figure 3 (5), when the changeover switch of the capstan drive circuit (c) is switched to the fixed (FIX) side. , the program counter circuit (b) is set to a value equal to the reference counter circuit @ by the pitch control fixed switching circuit (incorporated), and the outputs of these two counter circuits (2) and C371 are given to the comparison circuit (c). The capstan drive circuit (c) is controlled by the comparison output.

The outputs of the program counter circuit C17) and the reference counter circuit 0 are also given to the arithmetic circuit (to), and the value obtained by subtracting the output of the reference counter C3 from the output of the program counter circuit 0η (for example, the output of the reference counter circuit 0 If the count number at the edge is 5000, the value calculated by 3.125/9) is input from the calculation circuit (to) to the latch circuit. That is, when the changeover switch (2) is switched to the fixed side, @θ'' is output.

On the other hand, when the selector switch @ is switched to the pitch control side, the predetermined value (3.125
, 6.25 , 9.375 , 12.5...2
00, etc.) is set in the program counter circuit 07) by the control unit (c). Furthermore, if you want to change the value, operate the up button (19M) or down button (19b) of operation button 0, and the signal from the crest operation button O1 is input to the control S (c). Control part (g)
The voltage controlled oscillation circuit (to) is caused to oscillate by the control signal. The signal from the operation button α
41) to the voltage control circuit (g). The voltage controlled oscillator (7) is connected to a capacitor (
C1), oscillates at a frequency proportional to the voltage determined by the time constant of the resistor (R2), and the oscillation output is input to the control unit 0!5). The control section (to) has predetermined values (3.125°6.25, 9.375, 12
．． 5...200, etc.), and when they become equal, the output is set to the 0 output of the program counter circuit. At this time, press the up or down button (19m) or (19b) of operation button 01.
If continues to be operated, the above-mentioned operation is repeated and the process continues until the next set value is reached. At this time, it is normal to display and operate, and at that time,
When the display changeover switch (To) is set to the pitch control side, the latch circuit (B) will display the data (2) of the calculation circuit (2).
27a) is output to the display.

Due to this operation, the capstan drive circuit (
c), the rotation speed is varied by the musical pitch, and at the same time, the musical pitch is displayed.

Since the present invention is configured as described above, the rotational speed control device is operated so as to be several pitches lower or higher than normal according to instructions from the director, etc., and even though it is rotating, it can be directly viewed. It has the characteristic that it can be said.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the running system of a conventional tape recorder.
FIG. 2 is a system diagram of FIG. 1, and FIG. 3 is a system diagram of a display device for a tape recorder according to the present invention. In the figure, C9 is the operation button, (t9a) is the up button, (
19b) is the down button, the wire is the display, (2) is the changeover switch, (c) is the capstan drive circuit, @ is the latch circuit,
04 is a reference counter circuit, (2) is a comparison circuit, (B) is a pitch control fixed switching circuit, (G) is a control unit, (
07) is a voltage controlled oscillation circuit, 07) is a program counter circuit, 07) is an arithmetic circuit, and 07) is a voltage control circuit. Figure 1

Claims (1)

[Claims] A tape recorder display comprising a capstan device rotating at a specified rotational speed, wherein the rotational speed is varied by a musical pitch, and the amount of change is displayed in cents relative to the specified rotational speed. Device.