JPH0429136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for determining the hub diameter of a magnetic recording tape for determining two types of hub diameters of a VHS magnetic recording tape.

[Description of prior art]

In a VHS type magnetic recording/playback device, the remaining amount of magnetic recording tape is detected by calculation from the number of rotations of a take-up reel and a supply reel.

National Technical Report VoL.28No.3 (1982
There is something described on pages 526 to 531 (Published June 2016). This device first determines whether the hub diameter is 16 mm or 23 mm, which is the standard hub diameter for VHS magnetic recording tape, from the rotational speed of the take-up reel and supply reel, and then It is calculated by calculating the amount.

However, in recent years, T-160 magnetic recording tapes with longer recording times than conventional tapes have come on the market, and some tapes have appeared whose hub diameters cannot be determined from the rotation speeds of the supply reel and take-up reel. . For this reason,
In particular, in order to support the use of T-160 magnetic recording tape, the magnetic recording and reproducing device must be equipped with a manual switch that instructs the use of T-160.
160 magnetic recording tape was troublesome to use and was prone to operational errors.

[Summary of the invention]

The present invention was made for the purpose of improving the above-mentioned drawbacks of the conventional technology, and includes a light projector and a light receiver that have a reflection point on the top surface of a hub of a magnetic recording tape, and the reflection point is set on the hub. Magnetic recording capable of determining whether the hub diameter is a thick hub or a thin hub by detecting the presence or absence of reflected light from the top surface of the hub with the light receiver at a distance of 16 mm or more and 32 mm or less from the center of rotation. This provides a method for determining the hub diameter of a tape.

[Explanation of Examples]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Figure 1 is a plan view of the magnetic recording tape, and Figure 2 is the X-X of the magnetic recording tape in Figure 1.
A line sectional view, FIG. 3 is a schematic structural diagram of a main part showing an embodiment of an apparatus using the magnetic recording tape hub diameter determination method of the present invention, and FIG. 4 is a diagram of the magnetic recording tape of the present invention shown in FIG. FIG. 2 is a block diagram of a tape remaining amount detecting device which inputs a hub diameter signal obtained by a device using a recording tape hub diameter determination method.

The VHS type magnetic recording tape 1 shown in FIGS. 1 and 2 has two reels 3 and 4, a take-up reel and a supply reel, rotatably disposed in a case 2. A tape 7 is wound around the hubs 5 and 6 of the case 2, and transparent windows 8 and 9 are provided in a part of the case 2 so that the hubs 5 and 6 and the tape 7 wound thereon can be seen. ing.

The standard values for the hubs 5 and 6 in such a VHS type magnetic recording tape 1 are two types: radius 16 mm and radius 32 mm. In order to determine the diameters of the hubs 5 and 6, as shown in FIG. Reflection point P on the upper surface of the hub 5, 6 facing the transparent windows 8, 9 of
A light projector 10 and a light receiver 11 are provided. This reflection point P is provided at a distance of 16 mm or more and 32 mm or less from the center of rotation of the hubs 5 and 6. This is because the diameter a of the thin hub shown by the solid line in FIG. It is. The hubs 5 and 6 are generally made of white synthetic resin, and the tape 7 is black or brown.
The intensity of the reflected light can be sufficient for discrimination.

Here, the signal of the hub diameter detected by the presence or absence of reflected light to the light receiver 11 is transmitted to the tape remaining amount detection device 12, which includes a microcomputer, etc., as shown in FIG.
given to. This remaining amount detection device 12 includes devices 13 and 1 for detecting the number of rotations of the two reels 3 and 4.
A signal is also given from 4, making it possible to detect the remaining amount of tape even for T-160 magnetic recording tape without requiring any manual switch operation.

Note that the light receiver 11 may be any photo sensor such as a photo transistor or a photo interrupter. Further, the projector 10 and the light receiver 11 may be arranged in one hub or in two hubs. If a light emitter 10 and a light receiver 11 are respectively disposed on two hubs, the reflection point P of at least one of the light emitters 10 is the wound end face of the tape 7 in the case of a thin hub magnetic recording tape 1. , it becomes possible to reliably detect that the hub is thin.

〔Effect of the invention〕

As explained above, according to the present invention, the light emitter and light receiver are arranged so that the upper surface of the hub is a reflection point, and this reflection point is 16 mm or less and 32 mm or more from the center of rotation of the hub, so the presence or absence of reflected light can be determined. The hub diameter can be determined by detecting it with a light receiver, and if this hub diameter signal is given to the tape remaining amount detection device, it can be used for T-160 magnetic recording tape as well as with conventional devices of this type. It has excellent effects such as not requiring manual operation, and also eliminating the need for the remaining amount detection device to calculate the hub diameter from the reel rotation speed, allowing the remaining amount detection device to have a simple structure. play.

[Brief explanation of drawings]

FIG. 1 is a plan view of the magnetic recording tape, FIG. 2 is a sectional view taken along the line X-X of the magnetic recording tape in FIG.
FIG. 3 is a schematic structural diagram of main parts showing an embodiment of an apparatus using the method for determining the hub diameter of a magnetic recording tape of the present invention, and FIG. 4 is a hub diagram of the magnetic recording tape of the present invention shown in FIG. FIG. 2 is a block diagram of a tape remaining amount detecting device which inputs a hub diameter signal obtained by a device using a diameter determining method. In the figure, 1...magnetic recording tape, 2...case, 3, 4...reel, 5, 6...hub, 7...
...Tape, 8,9...Transparent window, 10...Floodlight,
11...A light receiver.

Claims (1)

[Claims] 1. In the magnetic recording tape storage section of the magnetic recording or playback device, a light projector and a light receiver are installed, facing a transparent window provided in the case of the stored magnetic recording tape, and whose reflection point is the top surface of the hub of the magnetic recording tape. and the reflection point is 16mm from the center of rotation of the hub.
A method for determining the hub diameter of a magnetic recording tape, wherein the hub diameter is determined by detecting the presence or absence of reflected light from the upper surface of the hub using the light receiver, with the diameter being 32 mm or less.