JPS5837632B2 - Tape position display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for displaying the amount of tape used or remaining amount of tape in a tape recorder, video tape recorder, 8 mm movie projector, etc. that uses a running medium such as a magnetic tape.

Conventionally, to display the tape position, a reed relay or the like is placed close to a circular magnet that rotates integrally with the feed reel stand, and the on/off operation of the reed relay is detected and converted to voltage, and a voltage comparison circuit is used. In most cases, display devices such as level meters were driven through the

This method not only requires a very complicated circuit configuration, but also
In order to reduce the cost, a level meter or the like must be used, and it is difficult to distinguish the tape position indication from a slightly distant position.

It is also desirable that the tape position display be visible from a distance, especially one or two minutes before the end of the tape, but using the level meter etc. mentioned above cannot meet the above requirements. There was a drawback.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks, to provide an inexpensive tape position display device that allows the tape position to be clearly confirmed even from a distance, and that can also be used as a tape run display.

In the present invention, in relation to the feeding reel stand, changes in the rotation angle of the reel stand or a rotating disk that rotates in relation to the reel stand, which is raised over a certain period of time from the start to the end of tape winding, are controlled by a switch mechanism. The change in rotation angle is determined and converted into voltage by a resistor installed in the switch mechanism, and the number of lights on a display mechanism such as a plurality of LEDs is determined according to this voltage change, thereby intermittent tape position. This allows the tape position to be clearly confirmed even from a distance, and the intermittent display of a plurality of display mechanisms such as LEDs also doubles as a tape travel indicator.

A case where the present invention is applied to a cassette tape recorder will be described below.

FIG. 1 is a plan view showing the main tape drive section of a cassette tape recorder.

The magnetic tape 5 wound on the feed reel 4 is fed at a constant speed by a capstan 8 and a pinch roller 7, and is then transferred to the take-up reel 3.
It is wound up.

Reference numeral 6 indicates a guide roller located within the cassette, and reference numeral 9 indicates a head.

Although not shown, the take-up reel 3 receives rotational force from the take-up reel stand 1 and winds up the magnetic tape 5.

As is conventionally known, the number of rotations of the feed reel 40 gradually increases from the beginning to the end of tape winding, and the number of rotations of the feed reel stand 2 that follows this also gradually increases.

FIG. 2 is a diagram showing changes in the rotational speed N of the feed reel stand 2 with respect to the elapsed time T from the start of tape winding.

Elapsed time T. ,T1,T2......T
The number of revolutions N of the feed reel stand 20 for 8 is N.

, N1......j N. Third
The figure is a diagram showing the rotation angle θ (degrees) at which the feed reel stand 2 rotates per unit time (second) along the elapsed time T axis.

, T1, T2 5・・・・・・・・・・・・, T5
Rotation angle θ with respect to.

, θ1, ......, θ, correspond to each other, and the relationship between the rotation angle θ and the rotation speed N is as follows.

At this time, since θ<3600, it is necessary to throw N<1.

4 and 5 show a first embodiment and a second embodiment of a switch mechanism and a disk that rotates integrally or passively with the feed reel stand, and FIG. 6 shows an example of an electric circuit of the present invention. An example block diagram is shown.

In FIG. 6, 15 is a plurality of display elements L1 such as LEDs.
, L2 y......, L5, and the control circuit 14 is operated by the voltage applied from the terminal b of the wire switch 11, and by the output of the control circuit 14, The number of lights on the 1,000-stage display 15 is controlled.

Note that the control circuit 14 includes an IC called a meter IC, for example.
By using , it is possible to easily achieve this purpose.

Next, the circular substrate 10 shown in FIG. 4 will be explained.

In the figure, P, j P2 ,...
・, P5 is a time-divided pattern group, P7 is a pattern for starting the time-controlled switching circuit 13, P6
is the power introduction pattern.

And pattern P,,P2,...
Contact b of the wire switch 11 is connected to pattern P5, and pattern P7
Contact point C corresponds to pattern P6, and contact point a corresponds to pattern P6.

Also, patterns P1, P2,...
Resistors R1J, R2F, R5 are arranged between P and pattern P6, respectively, and when a current i is passed between terminals a and b of the wire switch 11, V1=iR, V2=iR, respectively
A voltage of 2, . . . , V, = iR, is generated between terminals a and b.

Further, when a constant potential pulse is generated between the terminals a and C by the action of the time-controlled switching circuit 13 and the transistor Q, the time-controlled switching circuit 13 starts operating and the transistor Q is turned off, and during this time the terminal a ,b voltages V1, V2,...
..., v5 are applied to the control circuit 14 while changing sequentially.

Then, after a certain period of time controlled by the switching circuit 13 has elapsed, the transistor Q is turned on and the terminals a and b are turned on.
The voltage generated during this period is no longer applied to the control circuit 14, and the display 15 is turned off.

Note that the off-state time of the transistor Q is set so as to be always shorter than the time for the circular substrate 10 to rotate once.

If we tabulate the voltage generated at terminal b as described above, the number of lights on the display means 150, and the elapsed time from the start of tape winding, we get the following, and as time passes, the number of lights on the 1,000-stage display 15 gradually increases. I'm going to go.

As a result, the usage time of the tape, or in other words, the remaining amount of tape can be displayed in stages.

The time control switching circuit 13 is started by a short circuit between terminals a and c, and the time at which the transistor Q is turned off for a certain period of time is set at the time when the feed reel stand 2 rotates fastest, that is, at the end of tape winding. Rotation speed N
5, and the time t during which the transistor Q is off must be .

During the time t determined by this, the circular substrate 10 reaches θ.

, θ1, . . . . . . By rotating by θ5, the number of lights on the display means 150 changes from 1 to 5.

As another embodiment, as shown in FIG. 5, a magnet 17 is embedded in a disc 16 associated with the feed reel stand 2, and a switch is turned on and off by magnetic force along the outer periphery of the disc 16. S1, S2, ・・・・・・・・・・・・
S5 may also be provided.

In this case, the switches S1 and S1 are connected between terminals a and b, respectively.
S2・・・・・・・・・・・・S, and registers R1, R2,・・・・・・・・・・・・R5 are arranged in series,
A switch S7 corresponding to the above pattern P7 is placed between the terminals a and C, and when this is turned on by the magnet 17, the time control switching circuit 13 starts operating, and similarly to the above, between the terminals a and b, ■2・・・・・・・・・
..., ■5 voltage is generated.

In this method, the operation can be performed without contacting the feed reel stand 2, so that not only durability but also no sliding noise between the wire switch 11 and the board can be produced, and extremely good performance can be exhibited.

In the present invention, the display means 15 has been described as having five display elements, but if there is only one display element near the end of the tape, it is possible to detect the end of the tape by turning it on a certain period of time before the end of the tape. Furthermore, the effect of the present invention may be further enhanced by increasing the number of display elements.

By changing the color tone of the display element that lights up 3 minutes or 5 minutes before the end of the tape from that of other elements, it is also possible to predict the end of the tape more clearly.

Furthermore, as is clear from the explanation up to now, since there is no lighting holding circuit for the display element, the display means repeats blinking each time the feed reel base rotates once, and this means that the tape run indicates whether or not the tape is running. It can also be used as a display, and is extremely valuable.

Furthermore, in the above two embodiments, the rotation angle detection device was placed on the feed reel stand side, but by appropriately changing the length of the patterns P1 to P5 or the positions of the switches 81 to S5, The rotation angle may also be detected.

As explained in detail above, according to the present invention, by employing light emitting elements such as LEDs as display means, it is possible to easily determine the remaining amount of tape or the amount used by the number of light emitting elements lit even from a slightly distant position. Moreover, since the display means disappears once every time the feed reel stand or the rotary body driven by it rotates once, the display means can constantly repeat blinking and serve as a tape run.

In addition, by linking the feed reel stand or the rotating body that follows it to the switch mechanism, dividing it into angles according to the tape usage time or remaining amount time, and arranging a register in series with each switch, the rotating body Since the control circuit is driven by converting the rotation angle in stages, an inexpensive tape position display device can be provided and is extremely practical.

[Brief explanation of drawings]

Fig. 1 shows a schematic plan view of the tape drive system, Fig. 2 shows the relationship between the rotational speed of the feeding reel stand and the elapsed tape running time, and Fig. 3 shows the relationship between the feeding reel stand and the elapsed tape running time. It is a relationship diagram of the rotation angle of a stand. FIG. 4 shows a first embodiment of the rotation angle detection device of the present invention, and FIG. 5 shows a second embodiment. FIG. 6 is a circuit diagram of one embodiment of the control circuit of the present invention. 2... Feeding reel stand, 5... Band-shaped information recording medium, 10... Circular substrate, 11...
・Wire switch, 13...Time control switching circuit, 14・゜゜・゛control circuit, 15...
・Display means, 16... Disk, 17...
Macnet, P1-P7... pattern, R1
~R,...Register, S1-S7...
...Switch, L1-L5...Display element.

Claims (1)

[Claims] 1. In a reel-to-reel type information medium traveling device that winds an information medium from one feed reel to another take-up reel, the conversion means generates a voltage according to the rotation angle of the one reel, and a plurality of light emitting devices are provided. a display means comprising a display element, a first control means to which an output voltage of the conversion means is applied and controls the number of light emitting elements lit according to the magnitude of the voltage; and a first control means that operates in response to rotation of the reel. and a second control means for intermittently controlling the lighting time of at least one of the light emitting elements turned on by the first control means.