JPH0437283Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an erasing head that is attached to a cassette type tape mechanism and is capable of erasing information recorded on a tape and also detecting the tape end of the tape.

Generally, the tape end of a cassette tape is detected by detecting a change in tape tension, that is, when the tape tension increases, using a detection member.
One uses a mechanical mechanism that stops the operation of the tape, and the other uses a transparent tape end provided at the tip of a magnetic coating that irradiates light and reflects the irradiated light with a reflective plate, etc. There is also a reflected light method that uses an optical circuit that receives the reflected light with a light receiving element and uses the optical signal to stop the operation of the tape.

However, in the case of a mechanical mechanism that detects the tape end based on the tension of the tape tension,
If the tape tension changes for some reason while the tape is in operation, it may be activated, and since the tape end is reliably detected and the tape does not stop, it is true tape end detection. Instead, the problem is that it becomes uncertain. In addition, in the case of the reflected light type, it is necessary to install a light receiving element in the cassette case to receive the light transmitted from the light emitting element and the reflector through the end of the tape and reflected, so space must be secured. , there is a cost problem.

The present invention was devised in consideration of the above-mentioned problems, and aims to provide an erasing head that can reliably detect the tape end, requires almost no space, and minimizes cost increases. This is the purpose.

The structure of the present invention is such that a center core is inserted into a core mounting hole of a bobbin around which a coil is wound, and a hollow through hole is formed between the inner peripheral surface of the core mounting hole and the surface of the center core, and the center core is mounted. death,
A light guide fiber cable is inserted into the hollow through hole, the insertion end of the light guide fiber cable faces the tape sliding surface, and the other end of the light guide fiber cable extends outside the head main body. shall be.

With this configuration, the light guiding fiber cable is held between the inner circumferential surface of the core mounting hole forming the hollow through hole and the surface of the center core, and the light transmitted through the tape passing through the head body is guided. It can be transmitted to the outside of the head body via an optical fiber cable.

An embodiment of the erasing head of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a center core, 2, 2 are side cores, 3 is a card board, and 4 is a bobbin around which a coil is wound.

The bobbin 4 has a coil insertion hole 5, and the center core 1 is inserted into the core insertion hole 5 of the bobbin 4.
The upper surface of the center core 1 and the upper inner peripheral surface 4a of the bobbin 4
A light guide fiber cable 6 is inserted through the hollow through hole 5a formed by the two. Here, an optical fiber cable is used as the light guide fiber cable 6, and one end of this optical fiber cable 6 serves as a light receiving part for the light transmitted through the tape. In the figure, numerals 7 and 7 are terminals to which the ends of the windings wound around the bobbin 4 are wound and connected, and 8 is a gap portion.

The thus formed semi-finished product A' is coated with resin, etc. with a protective glass 9 having light transmittance attached to one end of the optical fiber cable 6 on the receiving side, as shown in FIGS. 4 to 6. The tape 10 is molded so that the tape sliding surface 11 becomes a curved part, and the other end of the optical fiber cable 6 is extended outside the rear end of the head body, and is then polished. is to be completed.

The erasing head according to the present invention constructed as described above operates as follows.

First, when the tape end 10a of the tape 10 reaches the center of the tape sliding surface 11 of the erasing head A, the tape 10
Erase head A via fiber optic cable 6
The light guide cable 1 is arranged facing the tip of the
The light emitted from the light emitting section 12a of No. 2 passes through the tape end section 10a and is received by the optical fiber cable 6, and the optical signal is sent to a mechanism that stops the operation of the tape 10 (not shown) connected to the other end of the optical fiber cable 6. This will cause the tape 10 to stop running.

FIG. 3 shows a second embodiment of the head of the present invention. Note that the same members as those described in the first embodiment are designated by the same reference numerals, and their explanations will be omitted.

In this example, an optical fiber cable 13 having a light emitting part, which is a light guiding fiber cable, is inserted into the hollow through hole 5a together with the aforementioned optical fiber cable 6, and the semi-finished erase head is inserted into the hollow through hole 5a.
In this case, a reflector plate (not shown) is provided at a position facing the ends of both cables 6 and 12 with the tape 10 in between, so that the light emitted from the optical fiber cable 13 is The optical fiber cable 6 transmits the light through the tape end portion 10a, and the transmitted light is received by the optical fiber cable 6 via the tape end portion 10a again, and has the same functions and effects as the first embodiment.

As is clear from the configuration described above, since the light guiding fiber cable is arranged in parallel with the center core in the core mounting hole in the erasing head, no new installation space is required in the erasing head, and the core mounting hole is It is easy to hold because it is guided by the inner peripheral surface and the surface of the center core. In addition, the light-guiding fiber cable extending from the rear end of the head body allows the light-receiving element to be installed anywhere, making it more compact, and the empty space in the mechanical mechanism can be used to install the light-receiving element. . Further, since the light receiving element is not limited by the size of the erasing head and a highly sensitive one can be attached, the end of the tape can be detected reliably and costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a first embodiment of the erasing head of the invention, Fig. 2 is a perspective view of a semi-finished product of the erasing head of the invention, and Fig. 3 shows a second embodiment of the erasing head of the invention. FIGS. 4 to 6 are a front view, a top view, and a top view of the erasing head of the present invention, respectively.
FIG. 4... Bobbin, 5... Core insertion hole, 6, 13...
...Light guiding fiber cable.

Claims (1)

[Scope of utility model registration request] A center core is inserted into a core mounting hole of a bobbin around which a coil is wound, a hollow through hole is formed between the inner peripheral surface of the core mounting hole and a surface of the center core, and the center core is mounted into the hollow through hole. An erasing head characterized in that a light guide fiber cable is inserted through the head, the insertion end of the light guide fiber cable faces a tape sliding surface, and the other end of the light guide fiber cable extends outside the head main body.