JPS588067B2 - Remaining amount display device for tape-shaped material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention displays the remaining amount of tape on a reel on the sending side (or supply side) in a device that runs a tape at a constant speed, such as a tape recorder. It is related to the device.

In recent years, constant-speed running devices such as cassette-type tape recorders, in which the tape is stored in a case, have become popular, but with this structure, it is difficult to see how much tape remains on the reel from the outside. , which is extremely inconvenient to use.

For example, if you are recording with a tape recorder, you may be concerned about whether the program source you are recording will be able to be recorded on the remaining tape.

Although it is effective to provide a tape-like remaining amount display device to eliminate such concerns, the display generally requires high accuracy and has the disadvantage of increasing cost.

Also, due to uneven tape winding, etc., errors in displaying the remaining amount may occur.

The present invention takes such points into consideration and uses a reel tension control mechanism to display the remaining amount of the tape-like body.

If a reel tension control mechanism is used as in the present invention, there will be fewer additional parts, and the cost will therefore be lower.

In addition, since tension control is performed, uneven winding is extremely reduced, making it possible to display the remaining amount with high accuracy.

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a block diagram for explaining the basic configuration of the present invention.

To explain this, the detection reel 1 is a delivery reel or a take-up reel.

The winding diameter detecting section 2 detects the winding diameter of the detection reel 1 and supplies the detection signal to the torque generating section 3 and the display section 4.

The torque generating section 3 applies torque to the detection reel 1 according to the signal from the winding diameter detecting section 2 .

Further, the display section 4 displays the remaining amount of the tape-like body according to the signal from the winding diameter detection section 2.

As is clear from the above explanation, the detection reel 1, the winding diameter detection section 2, and the torque generation section 3 constitute a tension control mechanism, and the only block added to display the remaining amount is the display section 4. It is.

Therefore, it is possible to obtain a tape-shaped body remaining amount display device that is low in cost and highly accurate.

Next, it will be explained that the configuration shown in FIG. 1 makes it possible to display the remaining amount of the tape-shaped body and to control the tension of the reel.

The remaining amount of the tape-shaped body that is run by a suitable constant-speed running device (not shown) is related to the winding diameter of the detection reel 1.

Therefore, if the winding diameter of the detection reel 1 is detected by the winding diameter detecting section 2, it is possible to display the remaining amount of the tape-like body on the display section 4.

Furthermore, if the torque generating section 3 generates a torque proportional to the winding diameter of the detection reel 1, the tension of the tape-shaped body on the detection reel 1 side can be kept constant.

FIG. 2 shows a block diagram of an embodiment of the present invention 6 To explain this, an electronic commutator type motor is installed to rotate coaxially (integrally) or in conjunction with the delivery reel shaft 5. Using the position signal 6, the rotational speed of the delivery reel shaft 5 is detected by the speed detection section 7, and a periodic signal having a period inversely proportional to the rotational speed is obtained.

The period-to-voltage conversion section 8 obtains a voltage at a level corresponding to the period of the periodic signal from the speed detection section 7, and supplies the voltage to the display section 9 and the motor drive section 10.

The display section 9 displays the remaining amount of the tape-shaped body according to the voltage of the period-to-voltage conversion section 8.

In addition, the motor drive section 10 causes the period-to-voltage conversion section 8
The motor 6 generates a torque corresponding to the voltage of , and tension control of the reel on the sending side is performed.

Next, it will be explained that the configuration shown in FIG. 2 makes it possible to detect the winding diameter of the delivery reel.

Generally, since the running speed of a tape-shaped body that is run in a constant-speed running device such as a capstan or a pinch roller is constant, the reel rotates in inverse proportion to the winding diameter of the tape-shaped body.

Therefore, by using a speed-to-voltage converter having a function of obtaining a voltage corresponding to the rotational speed of the reel, it is possible to obtain a voltage corresponding to the winding diameter of the reel.

The speed detection section 7 and the period-to-voltage conversion section 8 in FIG. 2 constitute the speed-to-voltage conversion section.

To explain further, the speed-to-voltage conversion section corresponds to the winding diameter detecting section in FIG. 1, and has the function of detecting the winding diameter.

If the diameter of the reel is detected using a speed-to-voltage converter that obtains a voltage according to the rotational speed of the reel, as in this embodiment, the tape-like object can be placed inside the case, such as in a cassette-type tape recorder. Even in a retracted structure, the winding diameter can be easily detected.

Furthermore, as in this embodiment, if a periodic signal having a period inversely proportional to the rotation speed is used as the reel rotation speed detection means, highly accurate rotation can be achieved even when the reel rotation speed is slow, such as in a cassette tape recorder. Speed detection becomes possible.

Furthermore, if a delivery reel is used as the detection reel as in this embodiment, the zero value of the remaining amount of tape corresponds to the reel hub, so the zero value of the remaining amount will be determined regardless of the total amount of tape. This makes it easier to display.

Furthermore, as in this embodiment, if a motor that rotates coaxially or in conjunction with the detection reel is used as the torque generating section, and a motor drive section that drives the motor, it is possible to perform tension control with good controllability. As a result, uneven winding of the tape-like body can be reduced, and a highly accurate remaining amount display device can therefore be obtained.

In particular, when a motor that rotates coaxially with the detection reel is used, the effect is significantly greater because there is no sliding mechanism between the motor and the detection reel.

Furthermore, if an electronic commutator type motor is used as the motor, the rotational speed of the detection reel can be detected using the position signal used to control its rotation, which simplifies the configuration of the speed detection section and This is extremely effective in achieving low cost.

Next, an example of the circuit of the period-to-voltage conversion section 8 and the display section 9 used in the embodiment shown in FIG. 2 will be described with reference to FIG. 3.

Transistors Q1 and Q2, resistors R1 to R4, and capacitor C1 constitute a sample pulse generator A, and transistors Q3 to Q5, resistors R5 to RIO, and capacitors C2 and C3 constitute a sawtooth voltage generator B. There is.

Transistors Q6 to Q8, resistors R11 and R12, and capacitor C4 constitute a sample and hold section C, and transistors Q9, diode d, resistors R13 to R18,
Capacitor C5 and meter M constitute display section D.

The sample pulse generating section A, the sawtooth voltage generating section B,
and the sample and hold section C constitute the period-to-voltage conversion section 8 in FIG.

The operation of the circuit shown in FIG. 3 will now be described with reference to the operational waveform diagram shown in FIG. 4.

If the pulse-like periodic signal A obtained from the speed detection section 7 in FIG. 2 is applied to the input terminal a in FIG. A sample pulse port is obtained at the collector of the beam transistor Q2.

The sawtooth wave voltage generator B includes a capacitor C3, a transistor Q3, a Q resistor R, ~R7, and a capacitor C2.
a discharge section J consisting of a transistor q and a resistor R8~
and a constant current section K consisting of RIO.

In the discharge section J, the capacitor C2 is charged and discharged according to the sample pulse 8, and a clear pulse 8 is obtained at the collector of the transistor Q3.

The capacitor C3 is charged with a substantially constant current by the constant current section K, and is discharged in response to the clear pulse of the discharge section J, so that a sawtooth wave voltage 2 is obtained across the capacitor C3.

Therefore, the peak value of the sawtooth wave voltage 2 becomes a value proportional to the period of the periodic signal A.

In the sample and hold section C, the transistor Q6 is gated by the sample pulse port, and the peak value of the sawtooth wave voltage 2 is sampled to the capacitor C4 and held until the next sampling point.

Therefore, a hold voltage is obtained at the emitter of transistor Q7.

This hold voltage E is supplied from the display section D and the output terminal b to the motor drive section 10 shown in FIG.

FIG. 5 shows the relationship between the hold voltage E and the winding diameter of the delivery reel.

In FIG. 5, r1 is the minimum winding diameter, and r2 is the maximum winding diameter.

(2) and (2) are hold voltages corresponding to r1 and r2, respectively.

The hold voltage E and the winding diameter are in a proportional relationship. In the display section D, a current flows through the meter M in accordance with the value of the hold voltage E, and the remaining amount of the tape-shaped body is displayed in analog form.

Resistors R17 and R18 divide the power supply voltage E to obtain a reference voltage Es so that the meter M points to zero at the hold voltage 1 when the minimum winding diameter r1 is set.

The diode d prevents the meter M from swinging in the opposite direction, and also compensates for temperature changes in the base-emitter voltage of the transistor Q7 of the sample-and-hold section C.

A capacitor C5 connected in parallel with the meter M absorbs the ripple contained in the hold voltage H, and the capacitor C5
This was added to make the instructions more stable.

An emitter follower circuit L consisting of a transistor Q9 and resistors R14 and R15 is added to limit the voltage applied to the meter M so that the meter M does not swing out.

Therefore, if the remaining amount of tape-like material is to be displayed from the maximum value to the minimum value, the emitter follower circuit L is not necessary.

The operation of the circuit shown in FIG. 3 will be briefly explained as follows.

A periodic signal A corresponding to the rotational speed of the delivery reel is input to the sample pulse generator A to obtain a sample pulse.

In the sawtooth voltage generator B, a sawtooth voltage C is obtained having a peak value corresponding to the period of the periodic signal A.

In the sample and hold section C, the peak value of the sawtooth wave voltage C is sampled by the sample pulse port and held until the next sampling point.

The hold voltage E is supplied to the display section D and the motor drive section 10 shown in FIG.

As in this embodiment, if a sample pulse generator, a sawtooth voltage generator, and a sample hold section are used as a period-one voltage conversion section, an accurate and stable period-one voltage conversion section can be constructed. Moreover, since there is very little variation in the hold voltage during the hold period, the swing of the meter M is stable.

Furthermore, if a capacitor, a constant current section, and a discharge section are used as the sawtooth wave voltage generating section as in this embodiment, it is possible to obtain a hold voltage H proportional to the winding diameter of the detection reel, as shown in FIG. This improves the linearity of the tension control of the detection reel and reduces uneven winding of the tape-like body, making it possible to display the remaining amount with high accuracy.

Moreover, if the hold voltage corresponds to the period of the periodic signal, any sawtooth wave voltage can be generated, but as in this embodiment, a sawtooth wave voltage having a peak value according to the period can be generated. For example, the sample pulse generator and the sawtooth voltage generator can be connected in cascade, and the sample pulse and the sawtooth voltage can be obtained with a simple configuration.

Further, as in this embodiment, if a meter is used as the display section and a diode is connected in series with the meter, it is possible to prevent the meter from swinging in the opposite direction.

In addition, as mentioned above, a meter is used as a display section,
Moreover, by connecting an emitter follower circuit to the meter so as not to apply a voltage higher than a certain voltage, it is possible to prevent the meter from running out, and it is possible to enlarge the display of the remaining amount.

Furthermore, it is of course possible to input the hold voltage obtained in the sample and hold section as a display section to a nonlinear amplifier to enlarge and display a portion with a small remaining amount.

Furthermore, it goes without saying that the display section may have a function of displaying an acoustic warning by means of a lamp or a buzzer when the remaining amount is below a certain value.

FIG. 6 shows another embodiment of the invention.

To explain this, the winding diameters of the sending reel 11 and the take-up reel 12 are detected by the winding diameter detecting parts 13 and 14, respectively, and the detection signals are transmitted to the torque generating parts 15 and 1, respectively.
6, and tension control is applied to each reel.

Further, the detection signals from the winding diameter detection sections 13 and 14 are supplied to a winding diameter difference calculation section 17 to obtain a signal corresponding to the difference in winding diameter between the delivery reel 11 and the take-up reel 12.

The display operation section 18 displays the remaining amount according to the signal from the winding diameter difference calculation section 17.

The winding diameter difference calculation section 17 and the display operation section 18 constitute a display section 19.

If a tension control mechanism is provided on the delivery reel and the take-up reel as in this embodiment, the uneven winding of the tape-like body can be greatly reduced, and the error in displaying the remaining amount can be further reduced.

As described above, the tape-shaped body remaining amount display device of the present invention is inexpensive and can display the remaining amount with high accuracy.

Therefore, the present invention is applicable not only to tape recorders but also to any constant-speed running device for tape-like bodies having one or both of a delivery reel and a take-up reel, and its range of use is extremely wide.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining the basic configuration of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is a diagram showing an example of a specific circuit used in the embodiment, and FIG. 4 is a signal waveform diagram of each part in FIG. 3, FIG. 5 is a diagram showing the relationship between the winding diameter of the delivery reel and the hold voltage in the sixth embodiment, and FIG. 6 is another embodiment of the present invention. FIG. 1... Detection reel, 2... Winding diameter detection section, 3... Torque generation section, 4... Display section, 5... Delivery reel, 6... Electronic commutator type motor, 7... Speed detection section , 8...Period-voltage conversion unit, 9...Display unit, 10...Motor drive unit,
A...Sample pulse generation section, B...Sawtooth wave voltage generation section, C...Sample hold section, D...Display section, J...
Discharging section, K... Constant current section, M... Meter, 11... Delivery reel, 12... Winding reel, 13.14... Winding diameter detection section, 15, 16... Torque generation section, 17... ... Winding diameter difference calculation section, 18 ... Display operation section, 19 ... Display section.

Claims (1)

[Claims] 1. A torque generating section using an electronic commutator type motor that uses a sending reel or a take-up reel as a detection reel and drives the detection reel to rotate coaxially, and is used for controlling the rotation of the electronic commutator type motor. a speed detection unit that uses a position signal to obtain a periodic signal that is inversely proportional to the rotational speed of the detection reel; and a voltage that is proportional or approximately proportional to the winding diameter of the detection reel based on the period of the periodic signal of the speed detection unit. a period-to-voltage conversion section to obtain a period-to-voltage conversion section; and a display section for displaying a display according to an output of the period-to-voltage conversion section, the electronic commutator type motor outputs a torque according to an output of the period-to-voltage conversion section. The remaining amount of the tape-like body generated is controlled so that the tension of the tape-like body on the detection reel side is kept constant, and the remaining running amount of the tape-like body is displayed on the display unit. Quantity display device.