JPH0581966B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic head useful for a helical scan type magnetic recording/reproducing device equipped with a plurality of video heads and having a recording/reproducing function as well as a special reproduction function such as still reproduction. It is related to the device.

Conventional configurations and their problems In recent years, magnetic recording and reproducing devices (VTRs) have been equipped with a conventional recording/reproducing unit, in order to provide special functions such as stay and slow search in addition to normal recording/reproducing functions. The trend is to increase the number of video heads in addition to paired video heads. A magnetic head device installed in a conventional VTR will be explained below.

FIGS. 1 to 4 show conventional examples, each showing a head arrangement and an enlarged portion of a head tape. In the figures, 1 is a head cylinder portion in which a magnetic tape 2 is wound at a predetermined angle.

3 and 4 are video heads that have different head gap inclinations and are divided into approximately 180° equal parts. 5 is also a video head, and because it is used for special playback such as stills, it has the same head gap inclination as video head 3 above. have. Reference numeral 6 designates a head window portion provided in the head cylinder portion 1. As shown in FIG. 4, the videos 3, 4, and 5 fixed at predetermined positions on the head base 7 fixed to the head cylinder part 1 face out through this window part 6, protrude by a predetermined amount, and come into contact with the magnetic tape 2. Perform recording or playback operations. Numerals 8 and 9 are cores constituting the video head 4, and 10 is a coil wound around the cores 8 and 9. Numerals 11 and 12 are also the cores of the video head 5. 14 is the core 8 and 9, or core 1.
This is a glass material that constitutes a head gap 15 provided between 1 and 12. These two heads 4,
5 are arranged and fixed in parallel so that the distance 1 between them does not change even if the sliding surfaces of the magnetic tape 2 of the video heads 4 and 5 wear out. Reference numeral 13 indicates a gap between the video heads 4 and 5.

Problems with the conventional head device constructed by fixing two video heads 4 and 5 to one head base 7 as described above will now be described.

As shown in FIG. 2, in the configuration of the conventional head device, when the head device rotates in the direction of the arrow, the contact between the magnetic tape 2 and the video heads 4 and 5 is as shown in FIG. The magnetic tape 2 falls into the gap 3 between the two, and the contact between the magnetic tape 2 and the edge of the video head 4 creates a region of standing waves m. Since this area extends to the vicinity of the gap 15 of the video head 4, a spacing loss occurs and signal transmission and reception is inhibited.
A good playback signal cannot be obtained. This is particularly noticeable at the beginning of contact between the magnetic tape 2 and the head unit.

As shown in FIG. 3, the above-mentioned gap 13 is used for winding the coil 10 around the video heads 4 and 5.
Although the coil 10 is controlled to have a thickness of about 300 μm, the coil 10 may be wound with a bulge due to variations in the coil tightening force. In this case, the swollen coil 10 comes out close to the magnetic tape sliding surface of the gap 13, so
The magnetic tape 2 and the coil 10 came into contact, sometimes causing the coil to break. As described above, the conventional device has many problems.

Purpose of the Invention The present invention solves the above-mentioned conventional problems by reducing the area width of standing waves generated in the gap between video heads, reducing spacing loss, and enabling good signal transmission and reception. It is an object of the present invention to provide a head device in which the coil is prevented from coming out near the sliding surface of the magnetic tape.

Structure of the Invention The present invention narrows the gap near the magnetic tape sliding surface of two video heads arranged in parallel to each other, prevents the magnetic tape from falling into the gap, and reduces the area width of the standing wave. , which reduces spacing loss.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a plan view of essential parts of a magnetic head device according to an embodiment of the present invention.

Items 1 to 15 in FIG. 5 are the same as items 1 to 15 of the conventional example shown in FIG. In the figure, reference numeral 16 denotes a core that constitutes the video head 4 together with the core 8. A partially convex protrusion 18 is formed on the core 16 near the magnetic tape sliding surface. 17 also connects video head 5 to core 1
This core 17 is also provided with a convex protrusion 19 at a position opposite to the core 16. Reference numeral 20 indicates a gap between the convex protrusions 18 and 19 of the cores 16 and 17, which is smaller than the gap 13 and is set to about 150 μm.

According to the head device of this embodiment configured as described above, the convex protrusions 18 and 19 provided on the cores 16 and 17 create a gap between the video heads 4 and 5 that is narrower than the gap 13. It is possible to set the number to 20. For that purpose, video head 4
Since the gap 20 between the magnetic tape and the magnetic tape 5 is small, the amount of the magnetic tape 2 that falls into the gap 20 is reduced, the area of the standing wave m is relatively reduced, the spacing loss of the video head 4 is reduced, and a good signal is obtained. It becomes possible to give and receive. Further, since the gap 20 is narrower than the gap 13, the coil 10 wound in the gap 13 does not protrude into the gap 20, and the coil does not break.

Effects of the Invention As described above, according to the present invention, it is possible to stably obtain a good reproduction signal, and it is also possible to greatly reduce the occurrence of coil breakage.

[Brief explanation of the drawing]

Figure 1 is a head layout diagram of a conventional VTR head unit, Figures 2 and 3 are enlarged views of the main parts of the same unit,
FIG. 4 is an explanatory diagram of the same device, and FIG. 5 is an enlarged view of the main parts of a magnetic head device for a VTR which is an embodiment of the present invention. 1...Cylinder part, 2...Magnetic tape, 3,
4, 5...Video head, 6...Head window, 7
... Head base, 8, 9, 11, 12 ... Core, 10 ... Coil, 13 ... Gap, 15 ... Head gap, 16, 17 ... Core, 18, 19
...Convex shaped protrusion, 20...Gap.

Claims (1)

[Claims] 1 first and second magnetic heads comprising an I-shaped first core and a C-shaped second core, each of which has a coil wound around each of the first and second cores;
The I-shaped first cores of the first and second magnetic heads are opposed to each other and arranged in parallel to each other so that the magnetic tape sliding surfaces of the second magnetic head are formed in substantially the same arc shape. A magnetic head device comprising a head base that includes a first magnetic head and a second magnetic head, wherein a gap between the first core near the magnetic tape sliding surface formed by the first and second magnetic heads is formed by the first and second magnetic heads. A magnetic head device characterized in that the coil winding portion of each first core has a projecting piece portion that is made narrower than the gap between the opposing cores.