JPS62266721A - Permanent magnet erasing head - Google Patents

Abstract

PURPOSE:To transfer a magnetization pattern to a tape surface, to make the change of a reproduced magnetic field from N polarity to N polarity or from S polarity to.S polarity, and to reduce stop noises by arranging S and N poles alternately at a bar magnetization part and equalizing it to a barber's pole magnetization part in polarity and width. CONSTITUTION:The bar magnetization part 4 is arranged on the tape entrance side of a permanent magnet erasing head which erases the magnetic signal on a cassette tape, and the barber's pole magnetization part 5 is provided behind the magnetization part 4. Then, N poles 6 and S poles 7 are arranged alternately and horizontally at the magnetization part 4 and N poles 6 and S poles 7 are arranged at the pole magnetization part 5 to the same width successively to the n poles 6 and S poles 7 at the magnetization part 4. A magnet chip 9 is put in the resin case 8 of an erasing head with this magnetization pattern and adhered with an adhesive, and the insertion-side surface of a chip 9 is polished in an R shape to remove the adverse influence of the run of a tape, thereby reducing stop noises.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a radio cassette recorder having a recording/playback function, and a permanent magnet erasing nozzle used in the cassette recorder and tape deck.

2. Description of the Related Art Conventionally, this type of permanent magnet erase head has had a magnetization pattern as shown in FIG. That is, bar magnetization 1 of N pole or S pole is applied to 1M4 corresponding to the entrance a to the erasing head in the tape running direction, and then bar magnetization 2 of N pole and S pole is applied alternately to each other. 3 was applied. In other words, the pulse magnetization 1 applied to the tape population 0111 ensures the erase rate, which is the basic characteristic of the erase head, and then the barber's pole magnetization 2 applied to the tape population 7'7jl.
．． 3 had a magnetization pattern that improved the erasing characteristics such as S/N, distortion rate, strike, and noise.

The problem that Fan Ming tries to solve However, if the magnetization pattern of the permanent magnet erase head of 61. from the north pole to the south pole or from the south pole to the north pole over a short distance of the tape.
This results in a sudden change in the magnetic field, such as toward a pole. When this was played back, the sudden change in the magnetic field within a short distance of the tape produced stop noise containing high frequency components, which was very unpleasant to the ears.

The present invention provides an erasing head in which rapid changes in the magnetic field over a short distance of the tape are alleviated and stop noise is reduced.

Means for Solving the Problem In order to solve this problem, the present invention provides a permanent magnet erase head that is applied to the inlet side of the tape running direction to increase the erasing rate, which is one of the erasing characteristics of the erasing head, to a level higher than the standard. The bar magnetization that is maintained in the bar is configured such that N poles and S poles are alternately arranged.

Effect With the above configuration, the magnetized pattern is transferred to the tape surface, and the change in the magnetic field during reproduction becomes small because it changes from N1fj to N pole or from S pole to S pole. As a result, stop noise can be reduced.

EXAMPLE A permanent magnet erasing head according to an example of the present invention will be described below.

First, FIG. 1 shows the magnetization pattern of the permanent magnet erase head of the present invention. In FIG. 1, numeral 4 is a bar magnetized section provided on the inlet side of the erasing head in the tape running direction, and 5 is a barber's pole magnetized section at the rear of the bar magnetized section 4. The bar magnetized section 4 has a structure in which N poles 6 and S poles 7 are alternately arranged horizontally, and the barber's pole magnetized section 5 has N poles 6 and S poles 7 of the bar magnetized section 4 arranged horizontally.
It has a structure in which S poles are arranged in a continuous and diagonal direction with the same width.

Therefore, when the magnetized pattern of the erasing head is transferred to the tape and reproduced, the change in the magnetic field becomes small because it changes from north pole to north pole or from south pole to south pole.

A specific configuration of a permanent magnet erasing head using a magnet chip having such a magnetized pattern will be described.

As shown in Fig. 2, a magnetic chip 9 is inserted into a resin case 8 finished in the shape of a standard erasing head, and is adhered with thermosetting adhesive, and the erasing head is attached to the tape on the side where the magnetic chip 9 is inserted. The surface is polished in an R shape so that it does not adversely affect the tape and tape running when it comes into contact with it.

Furthermore, in order to make this function as an erasing head,
The magnet chip 9 is magnetized with the above-described magnetization pattern. Regarding the small window erasing head shown in FIG. 3, the ceramic dummy 10 and the magnetic chip 9
As in the case of the standard erasing head, it is bonded with a thermosetting adhesive and polished in an R shape. This is magnetized in the same way as for the standard erase head.

Effects of the Invention As described above, in the present invention, the bar magnetized portion has N poles and S poles arranged alternately, and has the same polarity and the same width as the bar pole magnetized portion, so that the magnetization pattern is formed on the tape surface. When the magnetic field is transferred to and reproduced, the change in the magnetic field changes from north pole to north pole and from south pole to south pole over a short distance. Therefore, the effect of reducing stop noise compared to the conventional case of changing to different signs can be obtained, and this is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the magnetization pattern of the permanent magnet erase head of the present invention, FIGS. 2 and 3 are perspective views of an embodiment of the permanent magnet erase head provided with the magnetization pattern of the present invention, and FIG. The figure shows conventional permanent magnet erasure. FIG. 419131. Bar magnetized part, 511016. Barber's pole magnetized part, 6...N pole, 7...S
very. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure Pregnancy Bar Old Sulfur No. 3 Figure 1 Tee [Di 1 side Figure 4 - Tee 7 Running and batting direction

Claims (3)

[Claims] (1) A permanent magnet erasing head that erases the magnetic signal of a cassette tape, with a single-pole magnetized part having a pattern in which N and S poles are alternately magnetized, and the polarity and width of the magnetic field are magnetized in an azimuthal pattern after that. A permanent magnet erase head that is the same as the magnetized part. (2) Mg in the case made of materials that are less likely to damage the tape, such as resin and ceramic.
A permanent magnet erase head according to claim 1, which is used as a standard type configured by inserting a chip. (3) M
2. A permanent magnet erasing head according to claim 1, which is used for a small window formed by bonding G-chips together.