JPS5810234Y2 - Tape remaining amount display device - Google Patents

Description

[Detailed description of the invention] This invention relates to a tape remaining amount display device for a tape recorder.A tape recorder uses a magnetically coated tape that is held between a cap stand and a pinch roller and run at a constant speed. This is used to record or playback.

In this case, what is important when recording or playing back using a tape recorder is to constantly know the remaining amount of tape.

This is especially important when recording, and if, for example, recorded music is recorded for a longer time than the remaining time of the tape, there will be a shortage of tape and the latter half of the recorded material will not be able to be recorded.

Attempts to solve this problem include devices that display the remaining amount of tape by using a counter that is linked to the running of the tape, and a generator that is linked to the tape supply reel, and the output of this generator is Proposed methods include displaying the tape on a meter, or sounding a buzzer or using a light-emitting element such as a light-emitting diode to warn when the tape approaches its end.

However, the above-mentioned tape remaining amount display device usually only has one function, either to display the remaining amount of the tape one after another or to indicate that the end of the tape is near. It is not possible to accurately display the vicinity of the end of the tape, and those that display the end of the tape do not require a sufficient amount of remaining tape to be pressed in the middle, so it is not sufficient as a tape remaining amount display device, and improvements are desired.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tape remaining amount display device having two functions: continuously displaying the remaining amount of tape and indicating that the tape is nearing its end.

The remaining tape amount display device according to the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the tape remaining amount display device according to the present invention, in which 1 and 2 are a supply reel and a take-up reel around which a magnetic tape 3 is wound, and 4 is a supply reel 1 and a take-up reel. A tape guide for guiding the magnetic tape between the take-up reels 2, 5
, 6 is an erasing head and a recording head provided in contact with the magnetic tape 3 between the tape guides 4 and 4, and 7 is a button between the recording head 1 and the tape guide 4, which rotates the magnetic tape 3 at a constant speed during play operation. These pinch rollers press the magnetic tape 3 against the cap stun 8 which runs at a constant speed, and constitute the tape running system of the tape recorder.

A rotation detector 9 rotates in conjunction with the supply reel 1 and thereby outputs an output, for example a generator, and the output of the generator 9 as the rotation detector is converted into a full wave by four diodes 10a to 10d. Rectifying diode bridge, 1
1 is a capacitor that normalizes the output of the diode bridge 10; 12 is a resistor connected between the output terminals of the diode bridge 10 via the meter movable section 13; and 14 is a lamp that displays the pointer button and scale of the meter movable section 13. These constitute a meter 15 that displays the remaining amount of tape.

16 is a resistor that supplies the power supply Vcc to the lamp 14;
17 is a relay having normal off contacts S], S2, 18 and 19 are resistors that divide the output of the generator 9, and 20
uses the voltage dividing point potential by resistor 18.19 as the base input,
A transistor 21 that drives the relay 17 with its on-current is connected to a power source VC through a contact S1 of the relay 17.
This oscillation circuit is constituted by an ordinary non-stable multivibrator which performs oscillation by the transistors 22 and 23 supplied with signal c, and supplies the oscillation output to the lamp 14 via the contact S2 of the relay 17.

When the tape running system of the tape recorder is set, for example, to recording by pressing the button on the tape remaining amount display device configured as described above, the magnetic tape 3 wound around the supply reel 1 is fed out at a constant speed and taken up. 2.

In this case, the rotation speed of the tape supply roll 1 is slow when the tape starts being fed, and becomes faster as it approaches the end of the tape supply.

Therefore, the relationship between the rectified output voltage (■) of the generator 9 and the tape supply time t is as shown in FIG. indicate.

On the other hand, since the lamp 14 is supplied with current from the power supply Vcc via the resistor 16, the lamp 14 continues to light up and continues to illuminate the meter pear portion 13 in the meter 15.

Next, the magnetic tape 3 on the supply reel 1 side is gradually wound onto the winding reel 2 until it reaches the vicinity of the terminal end shown at time tl in FIG. When the voltage is reached, the voltage dividing point by the resistors 18 and 19 turns on the transistor 20.

When the transistor 20 is turned on, the relay 17 is energized and its contacts Sl and S2 are closed.

When the contact S1 is closed, the power supply VCC is switched to the oscillation circuit 2.
1, thereby causing the oscillation circuit 21 to perform normal astable multivibrator operation using transistors 22, 23, etc.

When the button for this oscillation operation is activated and the transistor 22 is turned on, both ends of the lamp 14 are short-circuited by the series connection of the contact S2 and the transistor 22, so that the light is turned off while the transistor 220 is on.

Therefore, while the oscillation circuit 21 is in operation, the lamp 14 blinks at the oscillation cycle of the oscillation circuit 21, thereby indicating that the supply of the magnetic tape is nearing its end.

Therefore, in the magnetic tape remaining amount display device configured as described above, changes in the remaining tape amount are known from the indicated value of the meter movable part 13, and the lighting lamp provided in the meter 15 is turned on. Depending on the state, it is possible to accurately determine whether the magnetic tape is near the end.

In the above-described embodiment, an astable multivibrator was used as the oscillation circuit, but it goes without saying that other oscillation circuits may also be used.

In the above description, a case has been described in which the point at which the oscillation circuit is driven is set near the end of the tape to display the vicinity of the end of the tape, but this value can be set freely.

As explained above, the tape remaining amount display device according to the present invention operates the oscillation circuit when the output of the rotation detector rotating in conjunction with the supply reel reaches a predetermined value, and uses this oscillation output to indicate the amount of remaining magnetic tape. Since it is configured to blink the illumination lamp installed in the display meter, it is an excellent device that allows you to easily set the remaining amount of tape without installing a special display. have an effect.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the tape remaining amount display device according to the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the output of the generator shown in FIG. 1 and the magnetic tape supply time. 1... Supply reel, 2... Take-up reel, 9... Generator, 10... Diode bridge, 11... Capacitor, 13...
...Meter moving part, 14...Lamp, 15...
...Meter, 17...Relay, 20゜22
, 23...transistor, 21...
Oscillation circuit, 12.16, 18.19...Resistance.

Claims (1)

[Scope of utility model registration request] a rotation detector that rotates in conjunction with the rotation of the supply reel stand;
a meter that displays the output voltage of the rotation detector; an illumination lamp provided in the meter; and a blinking control of the lamp that is activated when the output voltage of the rotation detector rises above a set value. This is a tape remaining amount display device equipped with an oscillation circuit.