JPS6220890Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an erasing head in a cassette tape recorder. It is suitable as a head. Conventionally, the magnetic tape pressed against the capstan by the pinch roller is 2
Since the playback head runs stably in the section where it is pressed by the pinch rollers, insert the playback head into the cassette through the above-mentioned central window in the section, and insert the recording head into the cassette through the small windows on both sides of the central window. Insertion is being done. The erasing head, which is inserted into the windows at both ends along with the pinch roller, comes into contact with the magnetic tape outside the above-mentioned section. Here, the fact that the erasing head is inserted together with the pinch roller does not mean that the insertion operations are performed together; rather, the magnetic tape is run at a constant speed with the pinch roller and erasing head inserted into the same window, and the tape is erased. This means that an action can be taken. A tape guide is often provided as the erasing head to regulate the position of the magnetic tape in the width direction. Also, such erasing heads usually form a double gap.

By the way, if the gap material forming the double gap is shorter than the core width at the magnetic tape abutting surface of the erasing head, unerased portions will remain, so generally a long material is used. If the gap material is thus long, the above-described tape guide will come into contact with the gap material, and the position of the tape guide will be different from the intended magnetic tape regulation position.

The present invention eliminates the above-mentioned drawbacks,
The tape guide is provided with a recessed portion that avoids contact with the gap material, and a retracted portion that partially avoids contact with the edge of the magnetic tape is provided continuous to the retracted portion, and the retracted portion prevents contact with the edge of the magnetic tape. It is possible to prevent defective erasing caused by the adhesion of dust near the gap of the erasing head and curling of the tape due to the adhesion of dust.

The figure shows an embodiment of the present invention, in which a case 1 made of plastic is provided with an opening extending from the left side to the left half of the front, and a core block with a coil 2 wound thereon is inserted through the opening. Further, the concave grooves of the tape guide pieces 3 and 4 made of plastic or the like slide along the convex grooves provided in the case 1 and are fitted, and the guide pieces come into contact with the case 1. The contact portion between the case 1 and the core block and the contact portion between the core block and the tape guide pieces 3 and 4 are adhered to each other, so that the core block and the tape guide pieces 3 and 4 are integrally fixed to the case 1. There is. The core block includes a core 5 made of ferrite that forms a magnetic path for erasing magnetic flux that erases the lower half of the running magnetic tape, a non-magnetic ferrite 6 with which the upper half of the magnetic tape comes into contact, and a gap of the core 5. A gap material 7 made of magnetic ferrite is fitted and fixed in a groove provided in the coil 2 through a non-magnetic material.
is wound around the core 5, and the core 5 and the ferrite 6 are fixed by adhesive.

Ideally, the gap material 7 described above should have a length equivalent to half the width of the magnetic tape on the magnetic tape abutting surface of the core 5, but as mentioned above, if the gap material 7 is short, the unerased portion may be Because it occurs,
I have no choice but to leave it somewhat long. Gap material 7
If it is long, the gap material 7 will come into contact with the tape guide piece 4, and the gap between the tape guide pieces 3 and 4 will widen, making it impossible to regulate the position of the tape in the width direction.

In the embodiment described above, a groove 8 is provided in the tape guide piece 4 to serve as a recess for the gap material 7, and the groove partially avoids contact with the edge of the magnetic tape. Incidentally, the same effect can be obtained even if the recessed portion is formed by a notch instead of the groove 8 described above.

Reference numeral 9 in the figure indicates a hole for screwing.

As described above, the present invention provides an erasing head with a tape guide, which is inserted together with a pinch roller into the three large windows provided in the cassette, excluding the central window, and is made up of tape guide pieces 3 and 4. The head has a gap material 7 forming a double gap, and when the gap material 7 is longer than the width of the core 5 on the magnetic tape contacting surface of the erasing head, the gap material 7 regulates the position of the magnetic tape in the width direction. The tape guide is provided with a recess part such as a groove 8 to avoid contact with the tape guide, and the tape guide has a recess part continuous with the recess part to partially avoid contact with the edge of the magnetic tape. In addition to establishing a section,
Since the erasing head is inclined in the tape running direction, it can be fully inserted into the window together with the pinch roller.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view, FIG. 2 is a cross-sectional plan view, and FIG. 3 is a longitudinal cross-sectional side view of the main part. 4: tape guide piece, 5: core, 7: gap material, 8: groove.

Claims (1)

[Claims for Utility Model Registration] 1. An erasing head with a tape guide that is inserted together with a pinch roller into three large windows provided in a cassette except for the central window, the erasing head having a double gap. evacuation to avoid contact with the tape guide that regulates the position of the magnetic tape in the width direction when the gap material is longer than the core width on the magnetic tape contacting surface of the erasing head; a part is provided on the tape guide, and the tape guide is provided with a retracting part continuous to the retracting part to partially avoid contact with the edge of the magnetic tape, and the erasing head is moved in the tape running direction. An erasing head in a cassette tape recorder characterized by being tilted. 2. The erasing head in a cassette tape recorder as set forth in claim 1 of the utility model registration claim, wherein the retracting portion is a groove provided in a tape guide. 3. The erasing head in a cassette tape recorder as set forth in claim 1 of the utility model registration claim, wherein the retracting portion is a notch provided in the tape guide.