Abstract:
A disk drive that includes a noise reduction unit, and a method of reducing noise by using the disk drive. The disk drive includes a main chassis; a tray operatively coupled to the main chassis such that the tray is slidable relative to the main chassis, the tray including a disk accommodation portion configured to accommodate a storage medium such that the storage medium is rotatable relative to the disk accommodation portion; and a noise reduction unit configured to reduce a pressure concentration on an end portion of the storage medium as the storage medium rotates to reduce noise.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2010-0104247, filed on Oct. 25, 2010, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The following description relates to disk drives, and additionally, to disk drives configured to reduce noise of a specific frequency band generated when a disk rotates, and methods of reducing noise by using the disk drives. 
         [0004]    2. Description of the Related Art 
         [0005]    The term disk drive may refer to an device using an pickup to read or write data to a storage medium. For example, the term disk drive may include an optical device that uses an optical pickup to read or write data to a storage medium. Examples of storage mediums are a compact disk having read only memory (CD-ROM), a rewritable compact disk (CD-RW), a digital versatile disk (DVD) and a rewritable digital versatile disk (DVD-RW). 
         [0006]    Often, a tray type disk drive, into which a storage medium may be inserted, is used to read or write data to the storage medium. A tray type disk drive that includes a support unit which supports a storage medium is installed in a housing, and the support unit may be ejected from the housing in order to facilitate the insertion and removal of the storage medium. 
         [0000]    Tray type disk drives are often installed into personal computers. However, because of the interest in integrating personal computer products with television monitors and liquid crystal displays, such personal computer products have undergone rapid development. Data may be read or written to a storage medium through use of a slim type disk drive. A slim type disk drive is often incorporated into a portable computer such as a notebook computer. A slim type disk drive is a disk drive into which a storage medium may be directly inserted. A slim type disk drive has a narrow space for accommodating a storage medium. If the disk rotates at high speed, the narrow space causes a flow of turbulent air, separation of air flows, and a pressure change at an air flow boundary layer on a surface of a disk, thereby generating noise 
         [0007]    Because noise is caused by a pressure change due to an air flow that occurs if a disk rotates, noise reduction methods have been developed. Such noise reduction methods use a change in an air flow in a limited space inside a disk drive. 
         [0008]    In an example of a noise reduction method, air flow is changed by selectively changing the shapes and sizes of components installed in a disk drive. For example, an air flow is changed by changing the diameter of an external circumference of a disk accommodation unit of a tray. As another example, an air flow is changed by changing a size of a pickup base. As a further example, an air flow in a disk drive is changed by using a bead shaped cover. 
         [0009]    However, because tray type slim disk drives are designed to reduce thickness and weight, and to have a stable structure, the inner size of the disk drive is likewise reduced and limited. As a result, a bead shaped cover generates touch noise by reducing a gap between an upper surface of a disk and a cover, and disk scratch generated when a tray is open and closed. Because of such touch noise, the use of bead shaped cover is not feasible. In addition, if a cover has a bead shape, manufacturing costs may be increased for maintenance of planarization of the cover due to problems with manufacture of the cover. 
       SUMMARY 
       [0010]    In one general aspect, there is provided a disk drive. The disk drive includes a main chassis, a tray operatively coupled to the main chassis such that the tray is slidable relative to the main chassis, the tray comprising a disk accommodation portion configured to accommodate a storage medium such that the storage medium is rotatable relative to the disk accommodation portion, and a noise reduction unit configured to reduce a pressure concentration on an end portion of the storage medium as the storage medium rotates to reduce noise. 
         [0011]    The disk drive may include a noise reduction unit that includes a plurality of air flow holes formed in at least one portion of an outer circumference portion of the disk accommodation portion. 
         [0012]    The disk drive may include a noise reduction unit that includes a plurality of air flow holes are formed through the disk accommodation portion. 
         [0013]    The disk drive may include a noise reduction unit that includes a plurality of air flow holes each having a circular shape, and are spaced apart from each other by a predetermined interval. 
         [0014]    The disk drive may include a noise reduction unit that includes a plurality of air flow holes each having a square shape, and are spaced apart from each other by a predetermined interval. 
         [0015]    The disk drive may include a noise reduction unit that includes a plurality of air flow holes each having a rectangular shape, and are spaced apart from each other by a predetermined interval, and the plurality of air flow holes may be disposed such that long sides of rectangular shapes are positioned in parallel to each other. 
         [0016]    The disk drive may include a noise reduction unit that includes a plurality of air flow holes each have a rectangular shape, and are spaced apart from each other by a predetermined interval, and the plurality of air flow holes may be disposed so that short sides of rectangular shapes are positioned in parallel to each other. 
         [0017]    The disk drive may include a noise reduction unit that is disposed inside a disk scratch prevention portion formed along the outer circumference portion of the disk accommodation portion. 
         [0018]    The disk drive may include a noise reduction unit that is disposed on a side of the tray that faces the main chassis when the tray is inserted into the main chassis. 
         [0019]    The disk drive may include a driver integrated circuit (IC) such that if the tray is inserted into the main chassis, the driver IC is disposed below the noise reduction unit. 
         [0020]    The disk drive may include a spindle motor for rotating the disk and slidably installed on the tray; and an optical pickup base comprising an optical pickup unit for storing information in or reading information from the disk while linearly reciprocating along a radial direction of the disk. 
         [0021]    The disk drive may include a noise reduction unit such that the noise reduction unit reduces noise generated within at least one frequency band. 
         [0022]    The disk drive may be included in an electronic device. 
         [0023]    The electronic device may be one of one of a portable game console, a portable/personal multimedia player (PMP), a portable lap-top PC, a desktop PC, a high definition television (HDTV), and an optical disc player. 
         [0024]    In another aspect, there is provided a disk drive. The disk drive includes a tray slidably installed so as to selectively slide into and out of a cavity formed by combining a main chassis and a cover, the tray comprising a disk accommodation portion configured to accommodate a storage medium, and a reduction noise unit comprising a plurality of air flow holes formed through the disk accommodation portion, wherein air flows below the tray through the plurality of air flow holes when a storage medium in the disk drive rotates. 
         [0025]    The disk drive may include a plurality of air flow holes that are formed inside a disk scratch prevention portion along an outer circumference portion of the disk accommodation portion. 
         [0026]    The disk drive may include a plurality of air flow holes each have a circular shape, and are spaced apart from each other by a predetermined interval. 
         [0027]    The disk drive may include a plurality of air flow holes each have a square shape, and are spaced apart from each other by a predetermined interval. 
         [0028]    The disk drive may include a plurality of air flow holes that each have a rectangular shape, and that are spaced apart from each other by a predetermined interval. The plurality of air flow holes may be disposed such that sides having the same length of rectangular shapes are positioned in parallel to each other. 
         [0029]    The disk drive may include a noise reduction unit that is disposed on the disk accommodation unit and a driving drive IC that is disposed below the noise reduction unit if the tray is inserted into a space formed between the tray and the cover. 
         [0030]    The disk drive may be included in an electronic device. 
         [0031]    The electronic device may be one of one of a portable game console, a portable/personal multimedia player (PMP), a portable lap-top PC, a desktop PC, a high definition television (HDTV), and an optical disc player. 
         [0032]    In another aspect, there is provided a method of reducing noise of a disk drive. The method includes reducing a pressure concentration on an end portion of a disk by forming a plurality of air flow holes through a disk accommodation portion of a tray, through which air flows below the tray when a storage medium in the disk drive rotates. 
         [0033]    The disk drive may include a plurality of air flow holes that are formed inside a disk scratch prevention portion along an outer circumference portion of the disk accommodation portion. 
         [0034]    The disk drive may include a plurality of air flow holes that each have a circular shape, and that are spaced apart from each other by a predetermined interval. 
         [0035]    The disk drive may include a plurality of air flow holes that each have a square shape, and that are spaced apart from each other by a predetermined interval. 
         [0036]    The disk drive may include a plurality of air flow holes that each have a rectangular shape, and that are spaced apart from each other by a predetermined interval. The plurality of air flow holes may be disposed such that sides having the same length of rectangular shapes are positioned in parallel to each other. 
         [0037]    The disk drive may include a driver integrated circuit (IC) such that if the tray is inserted into the main chassis, the driver IC is disposed below the noise reduction unit. 
         [0038]    The method may reduce noise generated within at least one frequency band. 
         [0039]    Other features and aspects may be apparent from the following detailed description, the drawings, and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]      FIG. 1  is a diagram illustrating an example of a disk drive that includes a noise reduction unit. 
           [0041]      FIG. 2  is a diagram illustrating an example of a tray of a disk drive inserted into a main chassis of the disk drive. 
           [0042]      FIG. 3  is a diagram that illustrates an example of a tray of a disk drive inserted into a main chassis of the disk drive. 
           [0043]      FIG. 4  is a diagram illustrating an example of a disk drive that includes a noise reduction unit. 
           [0044]      FIG. 5  is a diagram illustrating an example of a disk drive that includes a noise reduction unit. 
           [0045]      FIG. 6  is a diagram illustrating an example of a disk drive that includes a noise reduction unit. 
           [0046]      FIG. 7  is a diagram that illustrates a pressure distribution in a conventional disk drive as a storage medium (e.g., a disk) in the disk drive rotates. 
           [0047]      FIG. 8  is a diagram that illustrates a pressure distribution in an example of a disk drive that includes a noise reduction unit and that reduces noise as a storage medium (e.g., a disk) in the disk drive rotates. 
           [0048]      FIG. 9  is a graph that illustrates a comparison of noise levels between a conventional disk drive and a disk drive that a noise reduction unit. 
       
    
    
       [0049]    Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience. 
       DETAILED DESCRIPTION 
       [0050]    The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness. 
         [0051]      FIG. 1  is a diagram that illustrates an example of a disk drive  100  that includes a noise reduction unit  140 .  FIG. 2  is a diagram illustrating an example of a case by which a tray  120  of the disk drive  100  may be inserted into a main chassis  110  of the disk drive  100 .  FIG. 3  is a diagram illustrating an example of a case by which a tray  120  may inserted into the main chassis  110 . 
         [0052]    Referring to  FIGS. 1 through 3 , the disk drive  100  includes the main chassis  110 , a tray  120 , and a cover  130  configured to cover an upper portion of the main chassis  110  so as to define an inner space between the cover  130  and the main chassis  110 . For example, the tray  120  may be slidably installed on the main chassis  110 . The tray may be configured such that a user may insert or eject the tray  120  from the main chassis  110 . The tray includes a disk accommodation unit  121  that is configured to accommodate a storage medium. For example, the storage medium may be a disk D. 
         [0053]    As an example, guide rails  111  and  112  may be formed on two sides of the main chassis  110 . The guide rails  111  and  112  may be formed on opposing sides of the main chassis  110 . The tray  120  is operatively coupled to the main chassis  110  so as to facilitate sliding of the tray between an inserted and an ejected position. For example, the tray  120  may be slidably coupled to the guide rails  111  and  112  in such a way that the tray  120  is able to be inserted into and ejected from the main chassis  110 . 
         [0054]    A disk scratch prevention unit  122  is formed on an edge portion of the disk accommodation portion  121  in order to support a non-information region D 1  formed along an edge portion (an outer circumference portion) of the storage medium so as to prevent an information region D 2  of the storage medium from being scratched. For example, the disk scratch prevention unit may be formed on an outer circumference portion of the disk accommodation portion  121 . As an example, the storage medium may be a disk D. Disk D is a disk such as a CD-ROM, CD-RW, DVD, DVD-RW, BLU-RAY disc (BD), or the like. The non-information storage region D 1  is formed along an outer circumference portion of the disk D. The information storage region D 
         [0055]    As an example, the tray  120  may be detachable from the main chassis  110 . The tray  120  includes a spindle motor  124  that is configured to rotate the storage medium (e.g., disk D) if the storage medium (e.g., disk D) is accommodated in the disk accommodation unit  121 . The tray  120  also includes a pickup base  123  having a pickup unit  125  (e.g., an optical pickup unit) that is configured to record information to or read information from the storage medium (e.g., disk D). The pickup unit  125  moves relative to the storage medium. As the pickup unit  125  moves, the pickup unit  125  records and reads information from the storage medium. For example, if the storage medium is a disk D, the pickup unit  125  linearly reciprocates along a radial direction of the disk D. 
         [0056]    The disk drive  100  includes the noise reduction unit  140  that is configured to inhibit or otherwise prevent a pressure concentration on the edge portion of the storage medium. For example, if the storage medium is a disk D, the noise reduction unit  140  inhibits or prevents a pressure concentration on the outer circumference portion of the disk D. The noise reduction unit  140  reduces noise of a specific frequency band during rotation of the disk D. 
         [0057]    For example, the noise reduction unit  140  may include a plurality of air flow holes  141  that are formed through the disk accommodation portion  121 . The plurality of air flow holes  141  may be formed along and inside the disk scratch prevention portion  122  formed on the disk accommodation portion  121 . 
         [0058]    The noise reduction unit  140  may be formed on both (i) a side of the tray  120  that is furthest inserted into the disk drive  100  if the tray  120  is in an inserted position, and (ii) a space formed at a portion exposed outside the main chassis  110 . As an example, the noise reduction unit  140  may be formed on only the side of the tray  120  corresponding to that side of the tray  120  which is furthest inserted into the disk drive  100  if the tray  120  is in an inserted position. The noise reduction unit  140  may be solely formed on such a side of the tray  120  because a pressure generated as the storage medium (e.g., disk D) rotates is concentrated on such a side of the tray  120 . 
         [0059]    The air flow holes  141  may each have a circular shape, and may be spaced apart from each other by a predetermined interval. The main chassis  110  may include an integrated circuit (IC) operatively coupled thereto such that if the tray  120  is completely inserted into the main chassis  110 , the driver integrated circuit (IC)  113  is disposed below the air flow holes  141  (refer to  FIGS. 2 and 3 ). The arrangement of the air flow holes  141  is not limited to the arrangements illustrated in  FIGS. 2 and 3 . For example, the air flow holes  141  may not be spaced apart from each other by a predetermined interval, and may be spaced apart from each other by different intervals. As another example, the air flow holes  141  may each have a square shape. 
         [0060]    As the storage medium (e.g., disk D) is rotated by the spindle motor  124 , air around the storage medium (e.g., disk D) flows through the air flow holes  141  towards the driver IC  113  below the tray  120 . Thus, heat generated by the driver IC  113  may be transferred away from the driver IC  113  by air flowing through the air flow holes  141 . 
         [0061]      FIG. 4  is a diagram illustrating an example of a disk drive that includes a noise reduction unit  FIG. 5  is a diagram illustrating an example of a disk drive that includes a noise reduction unit.  FIG. 6  is a diagram illustrating another example of a disk drive that includes a noise reduction unit. 
         [0062]    Referring to  FIG. 4 , a disk accommodation portion  221  has a plurality of air flow holes  241  formed therein. The plurality of air flow holes  241  are spaced apart from each other by a predetermined interval along an edge portion (e.g., an outer circumference portion) of the disk accommodation portion  221 . Each of the plurality of air flow holes  241  has a square shape. 
         [0063]    Referring to  FIG. 5 , a disk accommodation portion  321  has a plurality of air flow holes  341  formed therein. The plurality of air flow holes  341  are spaced apart from each other by a predetermined interval along an edge portion (e.g., an outer circumference portion) of a disk accommodation portion  321 . Each of the plurality of air flow holes  341  has a rectangular shape. The plurality of air flow holes  341  are disposed in the disk accommodation portion  321  such that the long sides of the rectangular-shaped air flow holes  341  are positioned substantially parallel to each other. 
         [0064]    Referring to  FIG. 6 , a disk accommodation portion  421  has a plurality of air flow holes  441  formed therein. The plurality of air flow holes  441  are spaced apart from each other by a predetermined interval along an edge portion (e.g., an outer circumference portion) of the disk accommodation portion  421 . Each of the plurality of air flow holes  441  has a rectangular shape. The plurality of air flow holes  441  are disposed in the disk accommodation portion  421  such that the air the short sides of the rectangular-shaped air flow holes  441  are positioned relatively parallel to each other. 
         [0065]    The arrangements of the air flow holes  241 ,  341 , and  441  are not limited to as shown in  FIGS. 4 through 6 . For example, the air flow holes  241 ,  341 , and  441  may be spaced apart from each other so as not to be disposed at predetermined intervals. In other words, the distance between respective air flow holes  241 ,  341 , and  441  may be different or varying. 
         [0066]    The shapes of the air flow holes  241 ,  341 , and  441  are not limited to a circular shape, a square shape, and a rectangular shape, as described above. For example, the air flow holes  241 ,  341  and  441  may each have any shape and function. The air flow holes  241 ,  341 , and  441  enable or facilitate air to flow below a tray and through the disk accommodation portions  221 ,  321 , and  421  as a storage medium (e.g., a disk) rotates. 
         [0067]      FIG. 7  illustrates a pressure distribution in a conventional disk drive as a storage medium (e.g., a disk) in the disk drive rotates.  FIG. 8  illustrates a pressure distribution in a disk drive that includes a noise reduction unit as a storage medium (e.g., a disk) in the disk drive rotates. 
         [0068]    Referring to  FIGS. 7 and 8 , as a disk drive (e.g., a slim type disk drive) rotates a storage medium at a high speed, a complex air flow is formed. Specifically, air flows in a spiral shape on a surface of a storage medium (e.g., a disk) due to the Coriolis effect and a viscous flow in a boundary layer. Air flows outwards from a central axis, towards an edge portion of a disk accommodation portion, and then back to the central axis in order to compensate for a reduced air layer near the disk axis of the storage medium (e.g., disk). Referring to  FIG. 7 , in a conventional disk drive, as a disk therein rotates, there is a pressure concentration on an end portion of the disk and thus noise is generated. 
         [0069]    Referring to  FIG. 8 , in a disk drive that includes a noise reduction unit as described above. For example, as described above with regard to FIG.  1 ., as a storage medium (e.g., a disk), which is disposed in a disk drive, rotates, a pressure concentration on an end portion of the storage medium is less than that of the case of the conventional disk drive. As the disk rotates, air flows below a tray through a plurality of air flow holes. Such air flow thereby inhibits or prevents air from being concentrated on the end portion of the storage medium (e.g., the disk). In other words, air on the end portion of the storage medium (e.g., the disk) flows below the tray through the air flow holes to inhibit or prevent air from being concentrated on the end portion of the storage medium (e.g., the disk). 
         [0070]      FIG. 9  is a graph that illustrates comparison of noise levels between a conventional disk drive and a disk drive that includes a noise reduction unit. The graph illustrates the noise level generated as a function of frequency. 
         [0071]    As illustrated in  FIG. 9 , a dotted line corresponds to the noise level generated as a conventional disk drive as a function of a frequency band. A solid line corresponds to the noise level generated as a function of the frequency band as a disk drive, that includes a noise reduction unit, rotates. 
         [0072]    Although the noise level of the disk drive according to an aspect is higher than that of a conventional disk drive in some frequency bands, the noise level of the disk drive according to an aspect is lower than that of the conventional disk drives in most frequency bands. 
         [0073]    In some examples a disk drive includes a noise reduction unit that minimizes noise generated as a disk rotates in a tray-type slim disk drive and that facilitates a smooth air flow to a driver integrated circuit (IC) to obtain heat dissipation effects. 
         [0074]    The disk drive may be included in an electronic device. As a non-exhaustive illustration only, an electronic device described herein may refer to mobile devices such as a digital camera, a portable game console, a portable/personal multimedia player (PMP), a portable lap-top PC, and devices such as a desktop PC, a high definition television (HDTV), an optical disc player, a setup box, and the like capable of wireless communication or network communication consistent with that disclosed herein. 
         [0075]    A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.