JPH04222955A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a tape from being abraded due to contact with a rotary drum at a window part of the drum by forming a specifically sized taper part in the vicinity of the window part of the rotary drum. CONSTITUTION:A rear surface of the rotary drum 1 in the forward direction of a magnetic head 3 in the vicinity of the window part is formed with a taper part 7 having d1 in depth and ll1 in length, while a front surface in the forward direction is formed with a taper part 8 having d2 in depth and l2 in length, where the depths d1 and d2 fall within 5mum-50mum, and the lengths l1 and l2 within 0.3mm-2mm. Thus, by eliminating them in the vicinity of the window part to a min. respectively, a contact part with the rotary drum 1 can be eliminated without exerting influence upon the magnetic tape 4 in its deformation, thus preventing the tape 4 from flawing and the occurrence of magnetic powder.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording/reproducing device in which a rotating drum has a tapered portion.

0002

2. Description of the Related Art A conventional helical scan type magnetic recording and reproducing apparatus will be described below.

As shown in FIG. 6, the guide drum 5 is composed of an upper cylindrical rotating drum 1 and a lower cylindrical fixed drum 2 which is rotatably supported at a predetermined distance from the rotating drum 1. The magnetic tape 4 is wound around a guide drum 5 and runs, and a magnetic head 3 attached to a window 6 at the bottom of the rotating drum 1 scans the surface of the magnetic tape at high speed in the direction shown by the white arrow. The signal is recorded or played back while the

[0004] The operation of the magnetic recording/reproducing apparatus constructed as follows will be described below.

As shown in FIGS. 7 to 9, a laminar flow of air (air film) is formed between the outer peripheral surface of the guide drum 5 and the magnetic tape 4 due to the high speed rotation of the rotating drum 1. 1 and the magnetic tape 4 are prevented from coming into contact with each other. However, in the window 6 where the magnetic head 3 is attached to record signals, the protrusion of the magnetic head 3 and the window 6 disturb the air flow (a so-called turbulent state), resulting in a stable laminar flow. is not formed, and the magnetic tape 4 has a depression of several tens of micrometers in the front I part, the rear H part, and the upper J part of the magnetic head 3.

[0006]

However, in the conventional structure described above, the magnetic tape comes into contact with the rotating drum rotating at high speed at the front part of the magnetic head, the rear part of the magnetic head, and the upper part of the magnetic head, and is scraped off. However, there were problems in that a large amount of magnetic powder was generated, which caused scratches on the magnetic tape and clogging of the magnetic head. The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a magnetic recording and reproducing device that prevents contact between the window of a rotating drum and a magnetic tape, thereby eliminating tape scratches and generation of tape magnetic powder. do.

[0007]

[Means for Solving the Problems] In order to achieve this object, the magnetic recording generating device of the present invention includes a guide drum consisting of a fixed drum, a rotating drum that is rotatably supported by the fixed drum, and a guide drum that rotates while being rotatably supported by the fixed drum. A magnetic recording generating device comprising a magnetic head protruding from a window of a drum, wherein a magnetic recording head having a depth of 5 μm to 50 μm in the radial direction and a length in the circumferential direction near the window of the rotating drum is provided. It has a configuration including a guide drum on which a tape portion of 0.3 mm to 2 mm is formed.

[0008]

[Operation] This structure eliminates contact between the rotating drum and the magnetic tape in the vicinity of the window portion of the rotating drum.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 5 showing an embodiment of the present invention, parts that are the same as those in the conventional example are given the same numbers and their explanations will be omitted. As shown in FIG. 1, the surface of the rotating drum 1 at the rear in the direction of movement of the magnetic head 3 (left side in the figure) has a depth d1 and a length l.
The tapered part 7 of 1 is attached and is located at the front in the direction of travel (on the right side in the figure)
A tapered portion 8 having a depth d2 and a length l2 is formed on the surface of the rotating drum 1. As shown in FIG. 2, a tape portion 9 having a depth d3 and a length l3 is attached to the surface of the rotating drum 1 above the magnetic head 3. A shaded area E in FIG. 3 indicates a region of a tapered portion attached to the window portion of the rotating drum 1. As shown in FIG. However, 5μm≦d1, d2, d
3≦50μm0.3mm≦s1, s2, s3≦2mm
The magnetic tape 4 has a thickness of several micrometers to several tens of micrometers in the depth direction of the window at the front and rear of the magnetic head 3 attached to the rotating drum 1 in the traveling direction.
m feel depressed. However, according to actual measurements, the area where the magnetic tape 4 comes into contact with the rotating drum 1 is limited to the window edge of the rotating drum 1. The contact portion with the rotating drum 1 can be eliminated without affecting the deformation of the drum. As shown in FIG. 4, the depth d, which is the lower limit of the above, is 5
In the tapered portions 10 and 14, where the length l is 0.3 mm or less in μm, the surface of the rotating drum 1 is reduced by the amount of depression at the front part A and the rear part B of the magnetic head 3 of the magnetic tape 4. is small and the magnetic tape 4 makes contact. In addition, as shown in FIG. 5, the upper limit of the depth d is 50 μm and the length l is 2 mm.
The above-described tapered portions 12 and 13 affect the drop in the magnetic tape 4 at the C section in front and the D section at the rear of the magnetic head 3, thereby further increasing the contact between the magnetic tape 4 and the rotating drum 1.

As described above, according to this embodiment, by providing a tape section of a predetermined size near the window of the rotating drum, contact between the magnetic tape and the rotating drum can be eliminated without changing the deformation of the magnetic tape. This eliminates scratches on the magnetic tape and generation of magnetic powder, allowing good recording and playback, and providing good images stably for a long time.

0012

As described above, the guide drum of the present invention has a tape having a depth of 5 μm to 50 μm in the radial direction and a length of 0.3 μm to 2 mm in the circumferential direction near the window of the rotating drum. This is an excellent magnetic recording and reproducing device that prevents the window of the rotating drum from coming into contact with the magnetic tape, and eliminates scratches on the magnetic tape and the generation of magnetic powder. This is something that can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS [FIG. 1] A schematic cross-sectional view taken along the line XX in FIG. [FIG. 3] A schematic front view showing the concept of the structure of the window portion of the guide drum of the magnetic recording/reproducing device according to an embodiment of the present invention [FIG. 4] A schematic diagram of the magnetic recording/reproducing device according to the embodiment of the present invention [Figure 5] A schematic cross-sectional view showing the concept of the tapered part as the lower limit dimension of the rotating drum.[Figure 5] A schematic cross-sectional diagram showing the concept of the tapered part as the upper limit dimension of the rotating drum.[Figure 6] Window of the guide drum of a conventional magnetic recording and reproducing device. [Fig. 7] A schematic front view showing the concept of the structure of the window part of the guide drum. [Fig. 8] A schematic cross-sectional view taken along line GG in Fig. 7. [Fig. 9] F-- Schematic cross-sectional view of F [Explanation of symbols] 1 Rotating drum 3 Magnetic heads 7, 8 Tapered part

Claims (1)

[Claims] 1. A magnetic recording and reproducing device comprising a fixed drum, a guide drum consisting of a rotating drum rotatably supported by the fixed drum, and a magnetic head protruding from a window of the rotating drum. , a magnetic recording and reproducing device comprising a guide drum having a tapered portion having a depth of 5 μm to 50 μm in the radial direction and a length of 0.3 mm to 2 mm in the circumferential direction near the window portion of the rotating drum. .