Magnetic recording and reproducing apparatus

Abstract: A magnetic recording and reproducing apparatus (K1, K2) comprising: a magnetic recording and reproducing medium (1); a spindle motor (2) for effecting rotational drive of the magnetic recording and reproducing medium (1); a transducer (3) for recording and reproducing information on one face of the magnetic recording and reproducing medium (1); a displacement member (4) for displacing the transducer (3) to an arbitrary radial position on the face of the magnetic recording and reproducing medium (1); an electric circuit board (7) for processing the information and controlling the spindle motor (2) and the displacement member (4); and a casing (5) in which the magnetic recording and reproducing medium (1), the spindle motor (2), the transducer (3), the displacement member (4) and the electric circuit board (7) are mounted; the casing (5) having a bottom wall (5a) such that a boxlike space (20) is defined below the bottom wall (5a); the electric circuit board (7) being disposed in the boxlike space (20).

Description: The present invention relates to a magnetic recording and reproducing apparatus comprising: a magnetic recording and reproducing medium, a spindle motor for effecting rotational drive of said magnetic recording and reproducing medium, a transducer for recording and reproducing information on one face of said magnetic recording and reproducing medium, a displacement means for displacing said transducer to an arbitrary radial position on the face of said magnetic recording and reproducing medium, an electric circuit board for processing the information and controlling said spindle motor and said displacement means, and a casing in which said magnetic recording and reproducing medium, said spindle motor, said transducer, said displacement means are mounted, and which casing is closed by a first cover. Such devices are generally known, for instance from US-A-4,965,684. In recent years, storage capacity of magnetic recording and reproducing apparatuses used as external storages of portable computers has been improved remarkably. In response to trends towards more compact and lighter portable computers, lighter and more compact magnetic recording and reproducing apparatuses which can be detachably mounted on a computer body are in demand. As described in, for example, U.S. Patent No. 5,025,335, a magnetic recording and reproducing apparatus incorporated in a computer body of especially, a so-called notebook-sized computer is as thin as less than 20 mm. Conventionally, when a casing of the magnetic recording and reproducing apparatus is mounted on a computer body, a mounting portion of the computer body is so formed as to be elastic or shock-absorbing rubber is used on the casing in order to not only eliminate positional error between a mounting face of the computer body and a fixing portion of the magnetic recording and reproducing apparatus but minimize strain of the casing. Since disturbances such as vibrations, impacts, etc. are intercepted from the magnetic recording and reproducing apparatus to some extent by such procedures, quantity of the disturbances applied to the magnetic recording and reproducing apparatus is not so large. However, the magnetic recording and reproducing apparatus is secured in the computer body. Therefore, even if data have been recorded on the magnetic recording and reproducing apparatus up to its full storage capacity, a user cannot replace the magnetic recording and reproducing apparatus with a new one by himself. On the other hand, in response to popular use of portable computers, a need for compact, e.g., 2.5" fixed storages is growing. However, since storage capacity of such compact fixed storages is small, a demand has arisen that the compact fixed storages be used through their replacement. In case the fixed storage is detachably mounted on a computer body, magnitude of disturbances such as vibrations, impacts, etc. applied to the fixed storage during its nonoperative state is far larger than that of the fixed storage secured in the computer body. When an extremely large impact is applied to the fixed storage during its nonoperative state, a strain is produced in a casing of the fixed storage, thereby constituting an obstacle to high-density magnetic recording. Accordingly, an essential object of the present invention is to provide a magnetic recording and reproducing apparatus which not only prevents drop of strength of the apparatus as a whole when the apparatus is made more compact and thinner but can be handled easily by closing an electric circuit. In order to accomplish this object of the present invention, a magnetic recording and reproducing apparatus according to the type defined, is characterized in that the casing has a bottom wall such that a boxlike space is defined below the bottom wall; and the electric circuit board is disposed in the boxlike space which is closed by a second cover. By the above described arrangement of the apparatus according to the present invention, since the boxlike space is provided below the bottom wall of the casing, and the electric circuit board is disposed in the boxlike space, section modulus of the casing is increased so as to secure high strength of the apparatus, and the electric circuit board can be protected from damage by closing the electric circuit board by the cover. Preferrable embodiments are defined in dependent claims and comprise features like the casing including a pair of rails formed at opposite sides of the casing, respectively, and a connector which is provided at one end of the rails; the rails being provided at a lower end of the casing; the rails having a thickness of about 3.3 mm and a span of about 54 mm such that a groove having a depth of not less than 3 mm is defined above each of the rails. Therefore, by the above features, the apparatus can be mounted on and detached from the computer body by the operator himself. This object and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a magnetic recording and reproducing apparatus according to a first embodiment of the present invention; Fig. 2 is a sectional view taken along the line II-II in Fig. 1; Fig. 3 is a perspective view of a magnetic recording and reproducing apparatus according to a second embodiment of the present invention; and Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3. Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout several views of the accompanying drawings. Referring now to the drawings, there is shown in Figs. 1 and 2, a magnetic recording and reproducing apparatus K1 according to a first embodiment of the present invention. The apparatus K1 includes at least one magnetic recording and reproducing medium 1 having a diameter of about 48 mm, a spindle motor 2 for effecting rotational drive of the medium 1 and a transducer 3 which is provided on one of opposite faces of the medium 1. At least one medium 1 is mounted on the spindle motor 2. Thus, when one medium 1 is used, two transducers 3 should be provided, and when two media 1 are used, four transducers 3 should be provided. The apparatus K1 further includes a displacement means 4, a boxlike casing 5 and a first cover 6. The displacement means 4 is provided for displacing the transducer 3 to an arbitrary position on one face of the medium 1 so as to record and reproduce information on the medium 1. The spindle motor 2 and the displacement means 4 are mounted on a bottom wall 5a of the casing 5 so as to be closed by the first cover 6. Moreover, the apparatus K1 includes an electric circuit board 7 and a second cover 24. In the casing 5, a boxlike space 20 is defined below the bottom wall 5a. The electric circuit board 7 is fitted in the boxlike space 20 so as to be attached to the casing 5 by screws 8 and is closed by the second cover 24. The apparatus K1 is secured to a computer body 11 by using tapped holes 23 formed on a bottom face 22 of a side wall 21 of the casing 5. Operation of the apparatus K1 of the above described arrangement is described with reference to Figs. 1 and 2. The spindle motor 2 is usually rotated at a constant speed of about 3,600 r.p.m. so as to drive the medium 1 for its rotation. The transducer 3 is attached to a distal end of the displacement means 4 via a flexible support member 12 and is usually caused to hover above the face of the medium 1 through a gap of about 0.1 µm by air flow produced by rotation of the medium 1. Therefore, air in the casing 5 is required to be kept clean. To this end, the first cover 6 closes the casing 5 so as to prevent entry of outside minute dust into the casing 5. The transducer 3 is positioned at an arbitrary location of a data region of the medium 1 while hovering above the face of the medium 1 such that exchange of information is performed between the transducer 3 and the medium 1. In the first embodiment of the present invention, since section modulus about a neutral axis B (Fig. 2) of the casing 5 is increased by the side wall 21 defining the boxlike space 20 below the bottom wall 5a, mechanical strength of the casing 5 rises. Thus, when the electric circuit board 7 is attached to the casing 5 or the apparatus K1 is mounted on the computer body 11, strain of the casing 5 can be lessened. Furthermore, contact with the electric circuit board 7 from outside is prevented by the side wall 21 and the second cover 24. As described above, the boxlike space 20 is defined below the bottom wall 5a of the casing 5 and the electric circuit board 7 is mounted in the boxlike space 20 so as to be closed by the second cover 24 in the first embodiment of the present invention. Therefore, in accordance with the first embodiment of the present invention, drop of strength of the casing 5 due to reduction of thickness of the apparatus K1 can be avoided and the electric circuit board 7 can be protected from outside. In the first embodiment of the present invention, since the electric circuit board is mounted in the boxlike space defined below the bottom wall of the casing, high strength of the casing can be secured. Therefore, it is possible to reduce strain of the apparatus produced when the apparatus is mounted on a computer body. Furthermore, since the electric circuit board can be enclosed by the second cover, the electric circuit board can be protected from damage during transport or assembly of the apparatus. Referring further to Figs. 3 and 4, there is shown a magnetic recording and reproducing apparatus K2 according to a second embodiment of the present invention. In the casing 5, each of a pair of rails 25 is formed integrally at a lower end of each of opposite longitudinal side faces of the side wall 21 so as to project laterally outwardly from the side wall 21. A groove 26 is defined between the bottom wall 5a and each of the rails 25. The groove 26 has a width of about 1 to 2 mm and a depth of about 3 mm. The rails 25 have a lower end face 27 of the casing 5 and a height of about 3.3 mm from the lower end face 27. A connector 28 is provided at one end of the rails 25 so as to be flush with the rails 25. The rails 25 are longer than the first cover 6. At one end of the rails 25 adjacent to the connector 28, one of the rails 25 is formed with a cavity 31 having a proper length, while the other of the rails 25 is formed with a recess 32 having a proper length. When the second cover 24 has been attached to the casing 5, the second cover 24 is disposed slightly above the lower end face 27 of the rails 25 such that a recessed portion 33 is formed between the second cover 24 and the lower end face 27 of the rails 25. A pair of guides 29 each having a substantially U-shaped cross section are provided on a computer body 30 so as to receive the rails 25, respectively. As a result, when the apparatus K1 is mounted on and detached from the computer body 30 through engagement of the rails 25 with the guides 29 and disengagement of the rails 25 from the guides 29, the second cover 24 is held out of contact with the guides 29. Since other constructions of the apparatus K2 are similar to those of the apparatus K1, description thereof is abbreviated for the sake of brevity. The apparatus K2 of the above described arrangement is operated in the same manner as the apparatus K1. The apparatus K2 is characterized in that not only strength of the casing 5 is increased but the apparatus K2 can be mounted on and detached from the computer body 30 by the operator himself. When the apparatus K2 is mounted on and detached from the computer body 30, position of the apparatus K2 in directions of height and width of the casing 5 is regulated by engagement of the rails 25 with the guides 29. Meanwhile, in the apparatus K2, the rails 25 are provided along the lower end face 27 of the casing 5. However, in order to secure high strength of the casing 5, the rails 25 may not be necessarily required to be provided along the lower end face 27 of the casing 5. When the rails 25 have a thickness of 3.3 mm and a span S of about 54 mm and the groove 26 has a width of 1 to 2 mm and a depth of 3 mm or more, the apparatus K2 can be used, without the need for its modification, for a mechanism for detachably mounting an IC (integrated circuit) memory card. In this case, it is proper that diameter of the medium 1 is not more than 50 mm. In the second embodiment of the present invention, the electric circuit board is mounted in the boxlike space defined below the bottom wall of the casing and a pair of the rails are, respectively, provided at the opposite longitudinal side faces of the side wall of the casing such that the connector is provided at one end of the rails. Therefore, the apparatus can be mounted on and detached from the computer body by the operator himself. In addition, since high strength of the casing can also be secured, the apparatus can withstand external forces or impacts applied thereto when the operator is carrying the apparatus.

Claims: A magnetic recording and reproducing apparatus comprising: a magnetic recording and reproducing medium (1); a spindle motor (2) for effecting rotational drive of said magnetic recording and reproducing medium (1); a transducer (3) for recording and reproducing information on one face of said magnetic recording and reproducing medium (1); a displacement means (4) for displacing said transducer (3) to an arbitrary radial position on the face of said magnetic recording and reproducing medium (1); an electric circuit board (7) for processing the information and controlling said spindle motor (2) and said displacement means (4); and a casing (5) in which said magnetic recording and reproducing medium (1), said spindle motor (2), said transducer (3), said displacement means (4) are mounted, and which casing is closed by a first cover (6); characterized in that said casing (5) has a bottom wall (5a) such that a boxlike space (20) is defined below said bottom wall (5a); and said electric circuit board (7) is disposed in the boxlike space (20) which is closed by a second cover (24). A magnetic recording and reproducing apparatus as claimed in claim 1, characterized by said casing (5) including a pair of rails (25) formed at opposite sides of said casing (5), respectively; and a connector (28) which is provided at one end of said rails (25). A magnetic recording and reproducing apparatus as claimed in claim 1 or 2, wherein said magnetic recording and reproducing medium (1) has a diameter of not more than 50 mm. A magnetic recording and reproducing apparatus as claimed in claim 2 or 3, wherein said rails (25) are provided at a lower end of said casing (5); said rails (5) having a thickness of about 3.3 mm and a span (S) of about 54 mm such that a groove (26) having a depth of not less than 3 mm is defined above each of said rails (25). A magnetic recording and reproducing apparatus as claimed in any one of claims 2-4, wherein said rails (25) are integrally molded with said casing (5).

Inventors: KOHSO HIROSHI, KUWAMOTO MAKOTO, TANAKA MICHIRO, YAGI YUJI, KOHSO, HIROSHI, KUWAMOTO, MAKOTO, TANAKA, MICHIRO, YAGI, YUJI
Applicants: MATSUSHITA ELECTRIC IND CO LTD, MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Application year: 1992
Main classification: G11B25
IPC codes: G11B33, G11B25