JP3496995B2 - Magnetic disk cartridge - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk cartridge, and more particularly to an improved method of welding a liner in a magnetic disk cartridge having a magnetic disk rotatably contained in a cassette shell.

[0002]

2. Description of the Related Art A magnetic disk cartridge is a thin cassette shell in which a magnetic disk for magnetically recording analog or digital signals is rotatably incorporated. The cassette shell has a substantially square upper surface slightly larger than the magnetic disk. , A flat prism having a bottom surface having an opening for exposing a center core supporting the center of the magnetic disk and narrow side surfaces extending between the top surface and the peripheral edge of the bottom surface. The magnetic disk cartridge is provided with a magnetic head insertion slot into / from which magnetic heads for magnetic recording / reproduction come in and out on both sides of the magnetic disk from the outside or come close to each other. An open / close shutter is provided to prevent dust and the like from entering at the time.

Further, a liner such as a non-woven fabric is attached to the inner surface of the cassette shell facing the magnetic disk so that the surface of the magnetic disk is not scratched when the magnetic disk rotates and dust and the like adhered to the surface. I try to wipe it off.

In the conventional magnetic cartridge, there is a sufficient gap in the thickness direction of the magnetic disk in the cassette shell,
This liner is pushed up from the inner surface of the cassette shell by a weak leaf spring-like thing called a lifter and urged against the magnetic disk to maintain sufficient contact with the magnetic disk door. In many cases, the entire surface is not attached to the inner surface of the shell, for example, only the peripheral portion is attached by ultrasonic welding or the like.

A magnetic cartridge (slightly larger than 3.5 inches) having a recording capacity as much as 50 times that of a magnetic cartridge (3.5 inch floppy disk) which has been popular in the past by a new high density recording system. Is being developed. In such a magnetic cartridge, the magnetic disk is rotated at a speed much higher than that of the conventional one, and at the time of recording / reproducing, extremely high positional accuracy of the magnetic disk is required for the magnetic head.

In order to meet such a demand for high-speed rotation and high accuracy, it is preferable that a large gap exists in the cassette shell as in the conventional magnetic cartridge because vibration is generated and it is difficult to secure positional accuracy. Instead, the inner surface of the cassette shell to which the liner is attached and the magnetic disk must be entirely in contact with each other with high accuracy.

[0007]

Therefore, in view of this point, the present invention provides a magnetic cartridge in which the inner surface of the cassette shell to which the liner is attached and the magnetic disk can be evenly and accurately contacted with each other. The purpose is.

[0008]

A magnetic disk cartridge according to the present invention is a magnetic disk cartridge in which a liner is attached to the inner surface of a cassette shell in which a magnetic disk is rotatably contained so as to face the magnetic disk.
An energy director is formed on the inner surface of the cassette shell to concentrate the energy of ultrasonic vibrations on the welded portion, and the entire surface of the liner is attached to the inner surface of the cassette shell by ultrasonic welding through the energy director. br /> of Ri, thereby, the cassette shell that was stuck to liner
Make sure that the inner surface and the magnetic disk contact uniformly and with high precision.
It is characterized by becoming .

It should be noted that since a protrusion or a protrusion called a welding rib is used for ultrasonic welding, depending on the welding pattern, the inner surface of the cassette shell to which the liner is attached and the magnetic disk can be evenly and accurately contacted. Therefore, the welding pattern for ultrasonically welding the liner to the inner surface of the cassette shell is, for example, a radial pattern radially spreading from the point facing the center of the magnetic disk, or a spiral pattern from that point. The present invention is characterized in that the spiral pattern spreads or a combination thereof. (Concentric is not preferable because the contact pressure changes depending on the track of the magnetic disk)

[0010]

In the magnetic disk cartridge according to the present invention, the entire surface of the liner is adhered to the inner surface of the cassette shell by ultrasonic welding. Therefore, the inner surface of the cassette shell to which the liner is adhered and the magnetic disk are entirely covered. It is possible to make uniform contact with high accuracy over the entire length.

Further, the welding pattern for ultrasonically welding the liner to the inner surface of the cassette shell is a radial pattern radially spreading from a point facing the center of the magnetic disk or a spiral pattern spreading spirally from that point. By setting the above, it is possible to realize uniform uniformity in recording and reproduction.

[0012]

Embodiments of the magnetic disk cartridge according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of a magnetic disk cartridge according to the present invention. The cassette shell is composed of a pair of cassette shell halves formed by dividing the cassette shell into two parts, and one of the cassette shell halves has a circular hole 2b exposing a center core for fixedly supporting the center of the magnetic disk. . The figure shows the cassette half 2 on the side having the circular hole 2b.

In this embodiment, a donut-shaped liner 4 having a circular hole 4a slightly larger than the circular hole 2b is formed in the center of the inner surface 2a of the cassette shell half 2 and has a donut shape which is substantially the same as a magnetic disk (not shown). Are ultrasonically welded by the radial welding pattern 5. The interval (angle) between the radial lines of the radial welding pattern is preferably as small as possible in order to evenly weld the entire liner, but there is a limit because the interval is narrower in the part near the center, so practically there is a limit. The interval is appropriately set so that there is no problem.

Of the pair of cassette shell halves, the liner 4 welded to the one of the cassette shell halves which does not have the circular hole 2b exposing the center core has a circular hole at the portion facing the other end of the center core. It is preferable not to interfere with the center core. In this embodiment, the magnetic head insertion port 6 into / out of which the magnetic head comes in contact with or comes close to both sides of the magnetic disk for magnetic recording / reproduction is formed by cutting out a part of the peripheral wall of the cassette shell 2. No opening for inserting a magnetic head is formed on the inner surface (top surface or bottom surface) of the cassette shell. For this reason, the liner 4 has a perfect donut shape, and does not have a shape in which a part is notched in the radial direction as seen in a conventional magnetic disk.

FIG. 2 shows a second embodiment of the magnetic disk cartridge according to the present invention. In this embodiment, the circular hole 2 is formed on the inner surface 2a of the cassette shell half 2.
A donut-shaped liner 4 having a circular hole 4a, which is slightly larger than b, in the center and which is substantially the same shape as a magnetic disk (not shown).
Are ultrasonically welded by the spiral radial welding pattern 7. The spiral interval of the spiral welding pattern 7 is
It is desirable to be as small as possible in order to uniformly weld the entire liner, but the interval is appropriately set so that there is no practical problem.

The spiral welding pattern 7 according to the second embodiment may be employed in combination with the radial welding pattern according to the first embodiment. (Because the example of the combination is clear, the figure is omitted. In the fourth example shown in FIG. 4, an example of the same combination pattern is shown for the cassette shell halves having different forms.) In the example, the magnetic head insertion opening 6 has a shape in which a part of the peripheral wall of the cassette shell 2 is cut out, and an opening for inserting the magnetic head is not formed on the inner surface of the cassette shell. The present invention can also be applied to a cassette shell half in which an opening for inserting a magnetic head that extends in the radial direction of the magnetic disk is provided on the inner surface of the. Such an example is shown below in FIGS. 3 and 4.

FIG. 3 shows a third embodiment of the magnetic disk cartridge according to the present invention. Each of the pair of cassette shell halves 12 has a circular hole 12b for exposing a center core for fixedly supporting the center of the magnetic disk and an opening 12c for inserting a magnetic head. A doughnut-shaped liner 14 having a circular hole 14a slightly larger than the circular hole 12b at the center and having a portion substantially the same size as a magnetic disk (not shown) cut out in accordance with the opening 2c for inserting the magnetic head. Are ultrasonically welded by the radial welding pattern 15.

Incidentally, only the radial welding pattern 15 is cut out in accordance with the opening 2c for inserting the magnetic head.
Since the peripheral edge of 14b is not sufficiently welded and the peripheral edge is easily peeled off, it is desirable to additionally apply the weld 15a to the peripheral edge of the notched portion 14b.

Also in the cassette shell half in which the inner surface 12a of the cassette shell 12 is provided with the opening 12c for inserting the magnetic head as in each of the above embodiments, the spiral welding pattern is formed as in the second embodiment. Can be applied. It is also possible to apply a pattern in which the spiral welding pattern is combined with the radial welding pattern. The latter example is shown in FIG.

FIG. 4 shows a fourth embodiment of the present invention, in which a cassette shell half 12 similar to that of the third embodiment,
A liner 18 is ultrasonically welded by a pattern 16 which is a combination of a spiral welding pattern and a radial welding pattern.

In the ultrasonic welding, an ED (energies) for concentrating the ultrasonic vibration energy at the welded portion is used.
gy director) is used, but if ED21 is provided on the ultrasonic transducer 20 (horn) side as shown in FIG. 5, a recess 8 is formed in the liner 4 during welding. Since this impairs the flatness of the liner 4, an ED is provided on the cassette shell half 2 side as shown by reference numeral 9 in FIG. It is good to ensure flatness.

[Brief description of drawings]

FIG. 1 is a plan view showing a welding pattern of ultrasonic welding when a liner is attached to a cassette shell according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a welding pattern of ultrasonic welding when a liner is attached to a cassette shell according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a welding pattern of ultrasonic welding when a liner is attached to a cassette shell according to a third embodiment of the present invention.

FIG. 4 is a plan view showing a welding pattern of ultrasonic welding when a liner is attached to a cassette shell according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing an unfavorable example of the relationship between the ED and the ultrasonic transducer during ultrasonic welding.

FIG. 6 is a diagram showing a preferred example of a relationship between an ED and an ultrasonic transducer during ultrasonic welding.

[Explanation of symbols]

2,12 cassette shell 2a, 12a Inside of cassette shell 2b, 12b A circular hole exposing the center core 4,14,18 liner 4a, 14a Circular hole for exposing the center core of the liner 5 Radial welding pattern 6 Magnetic head insertion slot 7 Spiral welding pattern 12c Magnetic head insertion opening 16 Combined radial and spiral welding patterns 20, 22 Ultrasonic transducer (horn)

Continuation of front page (56) Reference JP-A-3-37879 (JP, A) JP-A-61-115286 (JP, A) JP-A-6-286376 (JP, A) JP-A-6-87164 (JP , A) JP 1-256085 (JP, A) JP 60-40582 (JP, A) Actual development S54-147216 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G11B 23/03 603

Claims (3)

(57) [Claims] 1. A magnetic disk cartridge in which a liner is attached to an inner surface of a cassette shell that rotatably houses a magnetic disk, the inner surface facing the magnetic disk, wherein the energy of ultrasonic vibration is welded to the inner surface of the cassette shell. An energy director for concentrating on a location is formed, the entire surface of the liner is affixed to the inner surface of the cassette shell by ultrasonic welding via the energy director, and the liner is ultrasonically welded to the inner surface of the cassette shell. welding pattern for the liner are a radial pattern spread radially from the point facing the center of the magnetic disk opposite, the cassette shell inner surface and magnetic di was stuck to the liner
A magnetic disk cartridge characterized by making uniform and highly accurate contact with the disk. 2. A magnetic disk cartridge in which a liner is attached to an inner surface of a cassette shell that rotatably houses a magnetic disk, the inner surface facing the magnetic disk, wherein ultrasonic vibration energy is deposited on the inner surface of the cassette shell. An energy director for concentrating on a location is formed, the entire surface of the liner is affixed to the inner surface of the cassette shell by ultrasonic welding via the energy director, and the liner is ultrasonically welded to the inner surface of the cassette shell. The welding pattern for this purpose is a spiral pattern that spreads spirally from the point where the liner faces the center of the facing magnetic disk, and the inner surface of the cassette shell to which the liner is attached and the magnetic disk
A magnetic disk cartridge characterized by making uniform and highly accurate contact with the disk. 3. A magnetic disk cartridge in which a liner is attached to an inner surface of a cassette shell that rotatably houses a magnetic disk, the inner surface facing the magnetic disk, wherein ultrasonic vibration energy is deposited on the inner surface of the cassette shell. An energy director for concentrating on a location is formed, the entire surface of the liner is affixed to the inner surface of the cassette shell by ultrasonic welding via the energy director, and the liner is ultrasonically welded to the inner surface of the cassette shell. The welding pattern for, the liner is a pattern that is a combination of a radial pattern that spreads radially from a point facing the center of the magnetic disk facing the liner, and a spiral pattern that spreads spirally from that point , and La
With the inner surface of the cassette shell to which the inner is attached and the magnetic disk
Magnetic disk cartridge characterized that you contact uniformly high precision.