Abstract:
A disc-visible type disk drive apparatus is disclosed. The disk drive apparatus includes: a main body casing having a first slot provided at a first side surface to load a disc; a protection cover having a first cover provided on the first side surface of the main body casing, wherein the first cover covers a portion of the disc exposed outside the main body casing through the first slot and forms a passage through which the disc passes during loading and unloading; a disc detecting sensor disposed in the first cover which detects the disc; and a disc loading unit disposed in the main body casing and having a loading roller which is driven so as to load the disc if the disc is detected by the disc detecting sensor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from of Korean Patent Application No. 10-2012-0003622, filed Jan. 11, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    Apparatuses and methods consistent with the present inventive concept relate to a disc-visible type disc drive apparatus, which when mounting a disc, such as CD, DVD and BD, in a main body casing, exposes a portion of the disc outside the main body casing. More particularly, exemplary embodiments relate to a disc-visible type disc drive apparatus capable of preventing foreign substances, such as dust or the like, from getting into the main body casing through an estrangement space between the disc drive apparatus and other equipment combined therewith and/or front and rear portions of the disc exposed outside the main body casing in use. 
         [0004]    2. Background Art 
         [0005]    A disc drive apparatus, as an apparatus for recording information on a disc, such as a compact disc (CD), Digital Versatile Disc (DVD) and Blu-ray Disc (BD), or reproducing information recorded on the disc, often uses a slot-in type disc drive apparatus into which the disc is inserted through a slot. 
         [0006]    The slot-in type disc drive apparatus can reduce a thickness as slim as possible because the disc is inserted through the slot therein. However, the slot-in type disc drive apparatus is configured so that the disc is not exposed to the outside when it is inserted and chucked therein. Thus, there was a limit in that it is always designed to have a width in the disc inserting direction, that is, the forward-backward direction, which is larger than a diameter of recordable or reproducible biggest disc. 
         [0007]    To address such a problem, in recent times, there has been proposed a disc-visible type disc drive apparatus in which a main body casing is configured, so that when the disc is inserted therein, front and rear portions of the disc are exposed as much as a given width to the outside, thereby allowing the apparatus to reduce the width in forward-backward direction. 
         [0008]    According to such a disc-visible type disc drive apparatus, however, since the front and rear portions of the disc are exposed outside of the main body casing through front and rear slots of the main body casing, foreign substances, such as dust or the like, may enter into the apparatus through an estrangement space between the disc drive apparatus and other equipment combined therewith and/or the front and the rear portions of the disc exposed outside the main body casing, via the front and the rear slots of the main body casing. If the foreign substances enter into the apparatus as described above, they may cause an optical system in the apparatus to reproduce or record information incorrectly or cause a drive part in the apparatus, such as a gear train or the like, to malfunction. 
         [0009]    In addition, according to the disc-visible type disc drive apparatus, a loading roller for loading the disc into the main body casing is located in a position where it blocks the front slot at an initial state where there is no disc in the main body casing. Also, as the width in a forward-backward direction is reduced, a space for installing a sensing unit including sensing arms, disc detecting sensors and the like to detect the disc is not available at an entrance of the front slot of the main body casing. As a result, the sensing unit is not disposed in front of the loading roller, but in the rear thereof. Accordingly, to automatically load the disc when inserting the disc into the main body casing at the initial state where there is no disc in the main body casing, a user has to forcibly push the disc against the loading roller blocking the front slot, so that the disc can push the loading roller down, move into the front slot and then operate the sensing unit. Thus, there was a problem in that since the user has to forcibly push the disc until a driving motor is driven to rotate the loading roller by the operation of the sensing unit, she or he should feel a labored disc inserting sensation. 
       SUMMARY 
       [0010]    Exemplary embodiments may overcome the above disadvantages and other disadvantages not described above. Also, the exemplary embodiments are not required to overcome the disadvantages described above, and an exemplary embodiment may not overcome any of the problems described above. 
         [0011]    According to an aspect of an exemplary embodiment, there is provided a disc-visible type disk drive apparatus including: a main body casing having a first slot provided at a first side surface to load a disc; a protection cover having a first cover provided on the first side surface of the main body casing, wherein the first cover covers a portion of the disc exposed outside the main body casing through the first slot and forms a passage through which the disc passes during loading and unloading; a disc detecting sensor disposed in the first cover which detects the disc; and a disc loading unit disposed in the main body casing and having a loading roller which is driven so as to load the disc if the disc is detected by the disc detecting sensor. 
         [0012]    The main body casing may further include a second slot, which is provided at a second side surface disposed opposite to the first side surface and which may pass through the disc, and the protection cover may further include a second cover, which is provided on the second side surface of the main body casing and may cover a portion of the disc exposed outside the main body casing. 
         [0013]    The first and the second covers may each have an arc-like shape. 
         [0014]    The second cover may close the portion of the disc exposed outside the main body casing through the second slot, so as to not to let the portion of the disc be exposed outside of the main body casing. 
         [0015]    The loading roller may be disposed to pivot between a first position blocking the first slot and a second position opening the first slot, wherein the disc loading unit may further include: a loading roller lifting part which lifts and lowers the loading roller between the first position and the second position; and a drive part to drive the loading roller and the loading roller lifting part according to an operation of the disc detection sensor and a drive command which is input. 
         [0016]    The loading roller lifting part may move the loading roller: to the first position if the disc is in an ejecting position, to the second position if in a chucking position, and to a third position not coming in contact with the disc if the disc is removed outside the main body casing. 
         [0017]    The third position may include one of the second position and an intermediate position where, if the disc is inserted into the main body casing, the loading roller is positioned in a state just before coming in contact with the disc, which is being inserted. 
         [0018]    The third position may include one of the second position and the intermediate position. 
         [0019]    The loading roller lifting part may include: a loading roller support which supports the loading roller to be pivotable between the first position and the second position; a lifting protrusion on the loading roller support; a slider having a lifting cam groove accommodates and guides the lifting protrusion to lift or lower the lifting protrusion as the slider is being moved right and left; and a slider moving portion which moves the slider right and left. 
         [0020]    The lifting cam groove may guide the lifting and lowering of the lifting protrusion, so that the loading roller support has the loading roller be pivotable to one of the first position, the second position and the third position. 
         [0021]    The slider moving portion may include: a moving protrusion projected from the slider; and a moving guide groove, which is provided in a cam gear of a chucking unit driven by the drive part, and which moves the moving protrusion right and left according to a rotation of the cam gear. 
         [0022]    The disc detection sensor may include one of an optical sensor and a micro switch. 
         [0023]    The disc loading unit further may include: a sensing arm part disposed in the main body casing and having first and second sensing arms, each of which has a hanging protrusion projected into a disc moving path to be moved by the disc; and at least one sensing switch, which is disposed in the main body casing and which is operated by one of the first and second sensing arms and sensing the disc. 
         [0024]    According to another aspect of an exemplary embodiment, there is provided a disc drive apparatus, including: a main body casing having a slot to load a disc; a sensing unit disposed in the main body casing to sense the disc; and a loading roller disposed in the main body casing to be pivotable between a first position blocking the slot and a second position opening the slot, the loading roller being maintained in a third position not coming in contact with a disc if there is no disc in the main body casing, wherein the loading roller is operated to load the disc into the main body casing and to pivot from the third position to the first position if the disc is detected by the sensing unit. 
         [0025]    The apparatus may further include: a loading roller lifting part to lift and lower the loading roller between the first position and the second position according to an operation of the sensing unit and an outer ejecting command. 
         [0026]    The third position may include one of the second position and an intermediate position where, if the disc is inserted into the main body casing, the loading roller is positioned in a state just before coming in contact with the disc, which is being inserted. 
         [0027]    The loading roller lifting part may include: a loading roller support to support the loading roller to be pivotable between the first position and the second position; a lifting protrusion provided on the loading roller support; a slider having a lifting cam groove to accommodate and guide the lifting protrusion to lift or lower the lifting protrusion as the slider is being moved right and left; and a slider moving portion to move the slider right and left. 
         [0028]    The lifting cam groove may be provided to guide the lifting and lowering of the lifting protrusion, so that the loading roller support has the loading roller be pivotable to one of the first position, the second position and the third position. 
         [0029]    The apparatus may further include: a drive part to drive the loading roller and the loading roller lifting part, wherein the slider moving portion may include: a moving protrusion projected from the slider; and a moving guide groove formed in a cam gear of a chucking unit driven by the drive part, to move the moving protrusion right and left according to a rotation of the cam gear. 
         [0030]    The sensing unit may include: a sensing arm part disposed in the main body casing and having first and second sensing arms, each of which has a hanging protrusion projected into a disc moving path to be moved by the disc; and at least one sensing switch, which is disposed in the main body casing to be operated by one of the first and second sensing arms, and which senses the disc. 
         [0031]    The at least one sensing switch may include first and second switches, which are operated by first and second operating portions, respectively, wherein the first and second switches are provided on an outer side of a lower portion of the first sensing arm. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    The above and/or other aspects will become more apparent by describing certain exemplary embodiments with reference to the accompanying drawings, in which: 
           [0033]      FIG. 1  is a perspective view showing a disc drive apparatus according to a first exemplary embodiment; 
           [0034]      FIG. 2  is a side elevation of the disc drive apparatus shown in  FIG. 1 ; 
           [0035]      FIG. 3  is a top plan view of a rectangular member of a main body casing of the disc drive apparatus shown along line III-III of  FIG. 1 ; 
           [0036]      FIG. 4  is a top plan view of a plate member of the main body casing of the disc drive apparatus shown along line IV-IV of  FIG. 1 ; 
           [0037]      FIG. 5  is a perspective view of a loading roller lifting part of the disc drive apparatus shown in  FIG. 1 ; 
           [0038]      FIGS. 6A to 6C  are views showing an operation of the loading roller lifting part shown along line VI-VI of  FIG. 3   
           [0039]      FIGS. 7A to 7C  are views showing the operation of the loading roller lifting part shown along line VII-VII of  FIG. 3   
           [0040]      FIG. 8  is a flow chart showing an operation of the disc drive apparatus according to the first exemplary embodiment when it is in a turned-on state; 
           [0041]      FIG. 9  is a flow chart showing an operation of the disc drive apparatus according to the first exemplary embodiment when is in a turned-off state; 
           [0042]      FIG. 10  is a perspective view showing a disc drive apparatus according to a second exemplary embodiment; 
           [0043]      FIG. 11  is a side elevation of the disc drive apparatus shown in  FIG. 10 ; 
           [0044]      FIG. 12  is a top plan view of a rectangular member of a main body casing of the disc drive apparatus shown along line III-III of  FIG. 10 ; 
           [0045]      FIG. 13  is a top plan view of a plate member of the main body casing of the disc drive apparatus shown along line IV-IV of  FIG. 10 ; 
           [0046]      FIG. 14  is a flow chart showing an operation of the disc drive apparatus according to the second exemplary embodiment; 
           [0047]      FIG. 15  is a perspective view showing a disc drive apparatus according to a third exemplary embodiment; and 
           [0048]      FIG. 16  is a top plan view of a plate member of a main body casing of the disc drive apparatus shown along line IV-IV of  FIG. 15 . 
       
    
    
       [0049]    Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0050]    Hereinafter, a disc drive apparatus according to exemplary embodiments will be described in greater detail below with reference to the accompanying drawings. In the following description, same drawing reference numerals are used for the same elements or equivalents even in different drawings. 
       First Embodiment 
       [0051]    First, referring to  FIG. 1 , there is illustrated a disc drive apparatus  100  according to a first exemplary embodiment in a perspective view. 
         [0052]    As shown in  FIG. 1 , the disc drive apparatus  100 , as a disc-visible type disc drive apparatus capable of being combined and used with other image and/or audio equipment, such as TV or the like, includes a main body casing  110 , a disc loading unit  130 , as shown in  FIG. 3 , and protection cover  150 . 
         [0053]    The main body casing  110  is formed in an approximately rectangular shape. For this, the main body casing  110  is made up of a rectangular member  111  having one side opened and a cover member  112  to cover the opened one side of the rectangular member  111 . 
         [0054]    As shown in  FIG. 2 , a first slot  114  through which a disc D (see also  FIGS. 6A to 7C ) is inserted is formed at a first side surface, for example, an upper surface of the main body casing  110  between the rectangular member  111  and cover member  112 . In addition, a second slot  115  through which when the disc D is in a chucking position, a front portion (in inserting direction) thereof is projected outside the main body casing  110  is formed at a second side surface, for example, a lower surface of the main body casing  110  between the rectangular member  111  and cover member  112 . The first and the second slots  114  and  115  are connected in a disc inserting direction through an inner space between the rectangular member  111  and cover member  112  of the main body casing  110 . 
         [0055]    On both side surfaces of the rectangular member  111  are provided mounting brackets  116  for mounting the disc drive apparatus  100  on the other image and/or audio equipment. 
         [0056]    As shown in  FIG. 3 , in the main body casing  110  are disposed an optical system  103  having an optical pickup device for recording or reproducing information on or from the disc D, such as CD, DVD, and BD, a disc loading unit  130  for loading the disc D to be described later, and a chucking unit  105  for chucking the loaded disc. 
         [0057]    Such a main body casing  110  has a width or depth in disc inserting direction less than a standard disc having a predetermined size, for example, a diameter of 12 cm, so that when the standard disc is inserted through the first slot  114  and positioned in a chucking position, front and rear portions (in inserting direction) thereof are projected outside the main body casing  110  through the first and the second slots  114  and  115 , respectively. 
         [0058]    The protection cover  150  is provided on the first and second side surfaces, that is, the upper and the lower surfaces of the main body casing  110 . The protection cover  150  prevents foreign substances, such as dust or the like, from getting into the main body casing  110  through an estrangement space between the disc drive apparatus  100  and the other image and/or audio equipment combined therewith and/or the front and the rear portions of the standard disc projected outside the main body casing  110  through the first and the second slots  114  and  115 . Also, the protection cover  150  absorbs or shuts off noises generated in the main body casing  110  to minimize leakage thereof outside the main body casing  110 . For this, the protection cover  150  includes a first cover  151  and a second cover  155 . 
         [0059]    The first cover  151  is disposed on the upper surface of the main body casing  110 . The first cover  151  is made up of approximately parallel two members in a form of an arc, i.e., in an arc-like shape, so that when the disc D is in the chucking position, they cover the rear portion thereof projected outside the main body casing  110  through the first slot  114 . The two members in the form of the arc are disposed on the rectangular member  111  and cover member  112 , respectively. Accordingly, in the first cover  151  there is formed a cover slot  152 , which connects between the first slot  114  and the outside to form a passage through which the disc D passes. 
         [0060]    The second cover  155  is disposed on the lower surface of the main body casing  110 . The second cover  155  made up of a c-shaped member in a form of an arc, i.e., in an arc-like shape, so that when the disc D is in the chucking position, it wraps and closes the front portion of the disc D projected outside the main body casing  110  through the second slot  115 . Accordingly, in the second cover  152  is formed a closing-up slot  156 , one side of which communicates with the second slot  115  to pass the disc D therethrough and the other side of which closes the front portion of the disc not to let it be exposed to the outside. 
         [0061]    With such configurations of the first and the second cover  151  and the  155 , the disc drive apparatus  100  can maximally prevent the foreign substances, such as dust or the like, from getting into the main body casing  100  through the estrangement space between the disc drive apparatus and the other image and/or audio equipment combined therewith and/or the front and the rear portions of the standard disc exposed outside the main body casing  110  in use as in the related art disc-visible type disc drive apparatus, and also absorb or shut off the noises generated in the main body casing  110  to minimize the leakage thereof outside the main body casing  110 . 
         [0062]    Referring to  FIGS. 3 to 5 , the disc loading unit  130 , which is for moving the disc D to the chucking position in the main body casing  110  when the disc D is inserted into the main body casing  110 , includes a disc detecting sensor  132 , a loading roller  133 , and a loading roller lifting part  145 . 
         [0063]    As shown in  FIGS. 1 and 4 , the disc detecting sensor  131  is disposed in the first cover  151 . The disc detecting sensor  131  may be made up of an optical sensor, such as a reflection or transmission type photo sensor with a light emitting part and a light receiving part. At an initial operation stage of the disc drive apparatus  100 , when the disc D is inserted through the cover slot  152  of the first cover  151 , such a disc detecting sensor  131  detects the disc D and outputs a detecting signal, that is, an ‘OFF’ signal of the optical sensor, to a control unit (not shown). The control unit controls a driving motor  141  of a drive part  140  to drive in a normal or reverse direction according to the ‘OFF’ signal from the disc detecting sensor  131 . 
         [0064]    As shown in  FIG. 3 , the drive part  140  includes a driving motor  141  as described above and a gear train  143  including pulley and gears connected with the driving motor  141 . 
         [0065]    The loading roller  133  is formed of an elastic material, such as rubber or urethane, and is disposed adjacent and parallel to the first slot  114  in the rectangular member  111  of the main body casing  110 . The loading roller  133  at a right end thereof (see  FIG. 3 ) is inserted and rotatably supported in an elongated recess formed at a body  135   c  of a loading roller support  135 . Also, the loading roller  133  is connected with the gear train  143  of the drive part  140  through a driving gear  133   a  formed on a left end thereof (see  FIG. 3 ). 
         [0066]    The loading roller support  135  is formed of a c-shaped body  135   c,  and is pivotably supported to the rectangular member  111  by axes  135   a  and  135   b  formed on left and right ends thereof, as shown in  FIG. 3 , respectively. In addition, as shown in FIGS,  6 A to  6 C, the loading roller support  135  is elastically urged in a direction of bringing the loading roller  133  in contact with the disc D by torsion springs  134  at the axes  135   a  and  135   b  of the right and left ends thereof. 
         [0067]    Also, as shown in FIGS,  6 A to  6 C, the loading roller support  135  may be lifted or lowered to a first position, a second position and a third position by the loading roller lifting part  145 , which is operated by a driving force of the driving motor  141  of the drive part  140 . The first position is a position where the loading roller  133  blocks up the first slot  114 , for example, a lifted position (that is, a position where when the disc D is inserted through the first slot  114 , the loading roller  133  comes in press contact with the disc D), as shown in  FIG. 6B . The second position is a position where the loading roller  133  completely opens the first slot  114 , for example, a lowered position (that is, a position where when the disc D is inserted through the first slot  114 , the loading roller  133  completely stays away from the disc D, as shown in  FIG. 6C . The third position is a position where the loading roller  133  is not to come in contact with the disc D, for example, an intermediate position between the lifted position and the lowered position (that is, a position where when the disc D is inserted through the first slot  114 , the loading roller  133  is positioned in a state just before coming in contact with the disc D, which is spaced by a thickness of the disc D, for example, approximately 0.5 mm, apart from the disc D), as shown in  FIG. 6A . Here, although the third position is explained and illustrated as the position where the loading roller  133  is positioned in the state just before coming in contact with the disc D, it may be any of positions between the lowered position and the intermediate position, including the lowered position and the intermediate position according to designs if the loading roller  133  does not come in contact with the disc D. 
         [0068]    As shown in  FIG. 5 , the loading roller lifting part  145  includes a lifting protrusion  146 , a slider  147  having a lifting cam groove  148  formed therein, and a slider moving portion  149  for moving the slider  147  right and left (i.e., either right or left at any given time). 
         [0069]    The lifting protrusion  146  is formed, so that it is projected outward below the recess of the body  135   c  of the loading roller support  135  in which the loading roller  133  is inserted. The lifting cam groove  148  is formed corresponding to the lifting protrusion  146  in a vertically bent portion  147   a  of the slider  147 , and accommodates and guides the lifting protrusion  146  to lift or lower as the slider  147  is moved right and left, that is, in directions of arrow A and B, as shown in  FIG. 7B , by the slider moving portion  149 . 
         [0070]    To be specific, when the slider  147  is in a position of solid line a in  FIG. 3 , the lifting protrusion  146  is located in a position shown in  FIG. 7A  in the lifting cam groove  148 . At this time, the loading roller support  135  is positioned in an intermediate position shown in  FIG. 6A  by the lifting protrusion  146 . In this state, when the slider  147  moves in the direction of arrow A to a position of alternated long and short dashed line b in  FIG. 3 , the lifting protrusion  146  is positioned in a position shown in  FIG. 7B  in the lifting cam groove  148 . At this tine, the loading roller support  135  is positioned in a lifted position shown in  FIG. 6B  by the lifting protrusion  146 . Also, when the slider  147  further moves in the direction of arrow A to a position of alternated long and two short dashed line c in  FIG. 3 , the lifting protrusion  146  is located in a position shown in  FIG. 7C  in the lifting cam groove  148 . At this time, the loading roller support  135  is positioned in a lowered position shown in  FIG. 6C  by the lifting protrusion  146 . To the contrary, when the slider  147  moves in the direction of arrow B from the position of alternated long and two short dashed line c to the position of alternated long and short dashed line b in  FIG. 3 , the lifting protrusion  146  and the loading roller support  135  are positioned in corresponding positions as explained above, respectively. 
         [0071]    The slider moving portion  149  is made up of a moving protrusion  149   a,  and a moving guide groove  149   b.  The moving protrusion  149   a  is formed on and vertically projected from an inner end of a horizontal portion  147   b  of the slider  147 . The moving guide groove  149   b  is formed on a bottom surface of a cam gear  106  of a chucking unit  105 , and accommodates and guides the moving protrusion  149   a  to move the moving protrusion  149   a  and the slider  147  right and left according to a rotation of clockwise or counterclockwise direction of the cam gear  106 . 
         [0072]    At this time, the moving guide groove  149   b  may be formed in such a shape that the slider  147  is positioned corresponding to the rotated position of the cam gear  107 . For example, the shape of the moving guide groove  149   b  may be formed, so that the slider  147  is operated as follows: If the diving motor  141  is driven in a normal or reverse direction according to an ‘OFF’ signal of the disc detecting sensor  131  and thus the cam gear  106  is rotated form an initial position to a chucking position for chucking the disc D, the slider  147  is moved to the position of alternated long and two short dashed line c from the position of solid line a via the position of alternated long and short dashed line b in  FIG. 3 , so that the loading roller support  135  is positioned in the lowered position. If the diving motor  141  is driven in a normal or reverse direction according to a disc ejecting command by a disc ejecting button operation of a user or the like and thus the cam gear  106  is rotated form the chucking position to an ejecting position, the slider  147  is moved to the position of alternated long and short dashed line b from the position of alternated long and two short dashed line c in  FIG. 3 , so that the loading roller support  135  is positioned in the lifted position. At this time, If the ejected disc D is removed to the outside by the user to allow the diving motor  141  to be more driven in the normal or reverse direction, the slider  147  is moved in the position of solid line a in  FIG. 3 , so that the loading roller support  135  is positioned in the intermediate position. 
         [0073]    The cam gear  106  is connected with the gear train  143  through a worm  107  and a worm gear  108 , so that it is driven by the driving force of the driving motor  141 . Since construction and operation of the cam gear  106  are the same as those of the cam gear known in the art except that it has the moving guide groove  149   b  formed at the bottom surface thereof, more detailed explanation thereon will be omitted. 
         [0074]    On the other hand, to reduce power consumption of the disc drive apparatus  100  or the other image and/or audio equipment combined therewith, the power disc drive apparatus  100  may be designed, so that if the disc drive apparatus  100  or/and the other image and/or audio equipment is turned off, a power supply to the disc detection sensor  132  disposed in the first cover  151  is also shut off. In this case, because the disc detection sensor  132  does not operate even though the disc D is inserted through the first cover  151 , the disc drive apparatus  100  does not embody a function of automatically moving or conveying the disc D to the chucking position. 
         [0075]    Accordingly, when the disc D is inserted through the first slot  114  in a state where the disc drive apparatus  100  or the other image and/or audio equipment combined therewith are turned off, to physically detect the disc D thus to automatically convey it to the chucking position and at the same time, detect a size of the disc D thus to control the driving of the driving motor  141 , the disc loading unit  130  may further include a sensing arm part  170  and at least one sensing switch  180 , which form a sensing unit for sensing the disc D, as shown in  FIG. 4 . 
         [0076]    The sensing arm part  170  is disposed at the cover member  112  of the main body casing  110 , and includes first and second sensing arms  171  and  173  and a link member  174 . 
         [0077]    The first and the second sensing arms  171  and  173  at lower portions thereof are rotatably fixed on first and second rotation axes  171   a  and  173   a  disposed at the cover member  112 , respectively. In addition, the first and the second sensing arms  171  and  173  at upper ends thereof have hanging protrusions  171   b  and  173   b  projected into a disc moving path, respectively. When the disc D is inserted through the first slot  114 , the hanging protrusions  171   b  and  173   b  are pushed by the disc D to rotate the first and the second sensing arms  171  and  173  in a direction moving away from each other about the first and the second rotation axes  171   a  and  173   a.    
         [0078]    The link member  174  at both ends thereof has first and second partial teeth  174   a  and  174   b  formed to be engaged with first and second corresponding partial teeth  171   c  and  173   c  formed at lower portions of the first and the second sensing arms  171  and  173 , and at a center thereof, has a guide protrusion  174   c  formed to be inserted into a guide hole  112   a  of the cover member  112  and to be guided up and down. 
         [0079]    The link member  174  is elastically urged to be pulled down by an elastic force applied thereto by first and second compression springs  175  and  176 , and thus the first and the second sensing arms  171  and  173  are elastically pressed to rotate in a direction toward to each other. 
         [0080]    The sensing switch  180  include first and second switches  181  and  183 , which are operated by first and second operating portions  171   d  and  171   e  formed on an outer side of the lower portion of the first sensing arm  171 . 
         [0081]    The first switch  181  is disposed in a position where it can be operated by the first operating portion  171   d  of the first sensing arm  171 , which is rotated by a disc D having a first size, for example, a diameter of 6 cm, when it is inserted through the first slot  114 . Also, the second switch  183  is disposed in a position where it can be operated by the second operating portion  171   e  of the first sensing arm  171 , which is rotated by a disc D having a second size, for example, a diameter of 12 cm, when it is inserted through the first slot  114 . Such first and second switches  181  and  183  may be made up of micro switches. 
         [0082]    Accordingly, if only the first switch  181  is operated, the control unit determines that the disc D having the diameter of 6 cm is inserted, and controls a driving time of the driving motor  141  or the like corresponding thereto. Also, if both the first switch  181  and the second switch  183  are operated, the control unit determines that the disc D having the diameter of 12 cm is inserted, and controls a driving time of the driving motor  141  or the like corresponding thereto. 
         [0083]    A driving process of the disc drive apparatus  100  according to the first exemplary embodiment as constructed as described above will now be described with reference to  FIGS. 8 and 9 . 
         [0084]    First, assuming that the disc drive apparatus  100  is in a turned-on state, a disc D is inserted into the main body casing  110  through the cover slot  152  of the first cover  151  by a user, as shown in  FIG. 8  (S 1 ). 
         [0085]    The optical sensor of the disc detecting sensor  131  detects the inserted disc D, and outputs an ‘OFF’ signal to the control unit (S 2 ). 
         [0086]    The control unit controls to drive the driving motor  141 , for example, in a normal direction, according the ‘OFF’ signal from the disc detecting sensor  131 . As the driving motor  141  is driven, the loading roller  133  is rotated, for example, in a counterclockwise direction, by a driving force of the driving motor  141 , which is transmitted to the driving gear  133   a  through the gear train  143 . 
         [0087]    At the same time, the cam gear  106  is rotated, for example, in a counterclockwise direction, by the driving force of the driving motor  141 , which is transmitted through the gear train  143  and the worm  107  and the worm gear  108 . As a result, the slider  147  is moved in a direction arrow A from a position of solid line a in  FIG. 3 , as shown in  FIG. 7A , to a position of alternated long and short dashed line b in  FIG. 3 , as shown in  FIG. 7B , and thereby the loading roller support  135  is moved from an intermediate position, as shown in  FIG. 6A , where the loading roller  141  does not come in contact with the disc D to a lifted position, as shown in  FIG. 6B , where the loading roller  141  comes in press contact with the disc D (S 3 ). Accordingly, the loading roller  133  conveys the disc D to a chucking position while rotating in contact therewith. 
         [0088]    At this time, as the disc D is inserted, the first sensing arm  171  of the sensing arm part  170  is pushed by the disc D to operate the first and/or the second switch  181  and  183 , and the control unit determines a size of the disc D whether the first and/or the second switch  181  and  183  is operated and controls a driving time of the driving motor  141  for conveying the disc D to the chucking position or the like according to the determined result, thereby to convey the disc D to the chucking position. 
         [0089]    As the driving motor  141  continues to rotate, the loading roller  141  conveys the disc D to the chucking position. At the same time, the chucking unit  105  chucks the disc D in the method known in the art by using the cam gear  106 . Also, the slider  147  is moved to a position of alternated long and two short dashed line c in  FIG. 3 , as shown in  FIG. 7C , and the loading roller support  135  is moved to a lowered position shown in  FIG. 6C  by the lifting protrusion  146  (S 4 ). 
         [0090]    In this state, a reproducing or recoding button, which is not shown, is pushed by the user to reproduce information recorded on the disc D or record information on the disc D. 
         [0091]    After that, to eject the disc D, if an ejecting button, which is not shown, is pushed by the user, the control unit controls the driving motor  141  to drive in a reverse direction. As the driving motor  141  is driven in the reverse direction, the chucking unit  105  releases the disc D from the chucking state through the cam gear  106  and at the same time, the slider  147  and the loading roller support  135  are operated in a manner opposite to that in the loading, so that they are moved to the position of alternated long and short dashed line b in  FIG. 3  ( FIG. 7B ) and the lifted position shown in  FIG. 6B , respectively (S 5 ). At this time, a portion of the disc D is projected outside the first cover  151  and the loading roller  133  is maintained in a state where it is in contact with the disc D in a given pressure by the torsion spring  134 . 
         [0092]    In this state, if the disc D is removed to the outside with the projected portion thereof grasped by the user, the optical sensor of the disc detecting sensor  131  and the micro switches of the first and the second switches  181  and  183  of the sensing switch  180  output an ‘ON’ signal and ‘OFF’ signals to the control unit, respectively. According to the signals from the disc detecting sensor  131  and the sensing switch  180 , the control unit controls the driving motor  141 , so that the driving motor  141  is more driven in the reverse direction. According to this, the slider  147  and the loading roller support  135  are moved to the position of solid line a in  FIG. 3  (FIG,  7 A) and the intermediate position shown in  FIG. 6A , respectively. As result, the loading roller  133  is maintained in a position where when the disc D is inserted through the first slot  114 , it is in a state just before coming in contact with the disc D, which is spaced by a thickness of the disc D, for example, approximately 0.5 mm, apart from the disc D. Accordingly, even though at an initial insertion stage where a next disc D is inserted, a front portion of the next disc D enters the first slot  114  through the first cover  151  before the disc detecting sensor  131  operates, it can be smoothly inserted into the first slot  114 . This, a disc inserting sensation or feeling of user is improved. 
         [0093]    Next, assuming that in a disc drive apparatus  100  designed, so that to reduce power consumption, if the disc drive apparatus  100  or/and the other image and/or audio equipment is turned off, the power supply to the disc detection sensor  132  is also shut off, the disc drive apparatus  100  is in a turned-OFF state, a disc D is inserted into the main body casing  110  through the cover slot  152  of the first cover  151  and the first slot  114  of the main body casing  110  by the user, as shown in  FIG. 9  (S 1 ′). 
         [0094]    At this time, since the loading roller  133  is maintained in the intermediate position, as shown in  FIGS. 6A and 7A , that is, the position where it does not come in contact with the disc D while being spaced by the thickness of the disc D, for example, approximately 0.5 mm, apart from the disc D, the disc D can be smoothly inserted into the main body casing  110  by the user. 
         [0095]    After that, when the first sensing arm  171  operates the sensing switch  180  as the first and the second sensing arms  171  and  173  are pushed by the disc D to rotate about the first and the second rotation axes  171   a  and  173   a,  the micro switches of the first and the second switches  181  and  183  of the sensing switch  180  outputs ‘ON’ signals to the control unit (S 2 ′). 
         [0096]    According the ‘ON’ signals from the sensing switch  180 , the control unit controls the driving motor  141  to drive, for example, in a normal direction. Subsequent operations are the same as the operation steps S 3 ˜S 6  in case that the disc drive apparatus  100  is in the turned-on state, as explained above. 
         [0097]    As explained above, although the disc drive apparatus  100  according to the first exemplary embodiment is explained and illustrated as having the disc detecting sensor  131  made up of the optical sensor, the present inventive concept is not limited thereto. For instance, the disc detecting sensor  131  may be a micro switch, which is physically operated by the disc D, like the sensing switch  180 . At this time, even though the disc drive apparatus  100  is designed, so that to reduce power consumption, if the disc drive apparatus  100  or/and the other image and/or audio equipment is turned off, the power supply to the disc detection sensor  132  is also shut off, the disc detecting sensor  131  can normally operate during the insertion of the disc D. Accordingly, in this case, regardless of whether the disc drive apparatus  100  is in the turned-on/off state, the disc detecting sensor  131  is operated in the same manner as the operation steps S 1 ˜S 6  in case that the disc drive apparatus  100  is in the turned-on state, as explained above. 
         [0098]    As apparent from the foregoing, the disc drive apparatus  100  according to the first exemplary embodiment is configured to have the first and the second cover  151  and  155  disposed at the upper and lower surfaces of the main body casing  110  to cover and close up the rear and front portions of the disc D projected outside the main body casing  110  through the first and the second slots  114  and  115 , respectively, when the disc D is in the chucking position. Accordingly, the disc drive apparatus  100  can maximally prevent the foreign substances, such as dust or the like, from getting into the main body casing  100  through the estrangement space between the disc drive apparatus and the other image and/or audio equipment combined therewith and/or the front and the rear portions of the disc exposed outside the main body casing  110  in use as in the related art disc-visible type disc drive apparatus, and also absorb or shut off the noises generated in the main body casing  110 , thereby minimizing the leakage thereof outside the main body casing  110 . 
         [0099]    Further, the disc drive apparatus  100  according to the first exemplary embodiment is configured to have the disc detecting sensor  131  capable of detecting the insertion of the disc D into the first cover  151  located in front of the loading roller  133 . Accordingly, the disc drive apparatus  100  can be operated, so that the disc detecting sensor  131  detects the disc D thus to operate the loading roller  133  as soon as the disc D is inserted. Thus, a loading speed of the disc D can be improved. 
         [0100]    Also, the disc drive apparatus  100  according to the first exemplary embodiment is configured to have the loading roller lifting part  145  capable of moving the loading roller support  135  supporting the loading roller  133  to the intermediate position ( FIG. 6A ), when the disc D, a portion of which is projected outside the first cover  151  during the disc ejecting, is removed to the outside from the first cover  151  by the user. Accordingly, when the disc D is inserted into the main body casing  110  at the initial operation state where there is no disc therein, the disc drive apparatus  100  can smoothly insert the disc D into the main body casing  110  even though the disc D enters the main body casing  110  before the disc detecting sensor  131  operates. Also, even though the disc drive apparatus  100  is designed, so that if the disc drive apparatus  100  or/and the other image and/or audio equipment is turned off, the power supply to the disc detection sensor  132  is also shut off, when the disc D is inserted into the main body casing  110 , it can arrive at the first and the second sensing arms  171  and  173  without coming in contact with the loading roller  133 , to operate the disc detecting sensor  131  for detecting the insertion thereof and thereby operating the driving motor  141  through the first sensing arm  171 . Accordingly, a disc inserting sensation of the user can be improved 
       Second Embodiment 
       [0101]    Referring to  FIGS. 10 to 13 , there is illustrated a disc drive apparatus  100 ′ according to a second exemplary embodiment. 
         [0102]    Such a disc drive apparatus  100 ′ of the second exemplary embodiment has the same construction as that of the disc drive apparatus  100  of the first exemplary embodiment, except that it is not provided with the protection cover  150  and the disc detection sensor  131  disposed in the protection cover  150 , as compared with the disc drive apparatus  100  of the first exemplary embodiment. 
         [0103]    In other words, the disc drive apparatus  100 ′ of the second exemplary embodiment includes a main body casing  110  and a disc loading unit  130 , and the disc loading unit  130  includes a loading roller  133 , a loading roller lifting part  145 , a sensing arm part  170 , and a sensing switch  180  including first and second switch  181  and  183 . Here, constructions of respective components of the main body casing  110  and the disc loading unit  130  are the same as those of the disc drive apparatus  100  of the first exemplary embodiment. Accordingly, detailed explanations on the respective components of the main body casing  110  and the disc loading unit  130  will be omitted. 
         [0104]    A driving process of the disc drive apparatus  100 ′ according to the second exemplary embodiment as constructed as described above will now be described with reference to  FIG. 14 . 
         [0105]    First, a disc D is inserted into the main body casing  110  through the first slot  114  of the main body casing  110  by the user (S 1 ″). 
         [0106]    At this time, since the loading roller  133  is maintained in the intermediate position, as shown in  FIGS. 6A and 7A , that is, the position where it does not come in contact with the disc D while being spaced by the thickness of the disc D, for example, approximately 0.5 mm, apart from the disc D, the disc D can be smoothly inserted into the main body casing  110  by the user. 
         [0107]    After that, when a first sensing arm  171  operates the first and the second switch  181  and  183  of the sensing switch  180  as the first and a second sensing arms  171  and  173  are pushed by the disc D to rotate about first and second rotation axes  171   a  and  173   a,  the micro switches of the first and the second switches  181  and  183  of the sensing switch  180  outputs ‘ON’ signals to the control unit (S 2 ″). 
         [0108]    According the ‘ON’ signals from the sensing switch  180 , the control unit controls a driving motor  141  to drive, for example, in a normal direction. Subsequent operations are the same as the operation steps S 3 ˜S 6  in case that the disc drive apparatus  100  of the first exemplary embodiment is in the turned-on state, as explained above. 
         [0109]    According to such a disc drive apparatus  100 ′ of the second exemplary embodiment, since the loading roller  133  is located in the intermediate position, as shown in  FIGS. 6A and 7A , in a state where the disc D is removed outside of the main body casing  110 , the disc D can be smoothly inserted into the main body casing  110 , such as when a user wants to reproduce information recorded on the disc D or record information on the disc D, it is inserted through the first slot  114  of the main body casing  110 . Accordingly, the user can feel a smooth disc inserting sensation in an initial operation stage until the loading roller  133  operates, as compared with the related art disc-visible disc drive apparatus. 
       Third Embodiment 
       [0110]    Referring to  FIGS. 15 and 16 , there is illustrated a disc drive apparatus  100 ″ according to a third exemplary embodiment. 
         [0111]    Such a disc drive apparatus  100 ″ of the third exemplary embodiment has the same construction as that of the disc drive apparatus  100  of the first exemplary embodiment, except that as shown in  FIG. 16 , it is not provided with the sensing arm part  170  disposed in the main body casing  110  and the sensing switch  180  including the first and the second switches  181  and  183  and the disc detecting sensor  131  is made up of a micro switch, which is physically operated by the disc D, as compared with the disc drive apparatus  100  of the first exemplary embodiment. 
         [0112]    In other words, the disc drive apparatus  100 ″ of the third exemplary embodiment includes a main body casing  110 , a disc loading unit  130  and a protection cover  150 , and the disc loading unit  130  includes a loading roller  133  and a loading roller lifting part  145 , as shown in  FIGS. 1 to 4 ,  15  and  16 . Here, constructions of respective components of the main body casing  110 , the disc loading unit  130  and the protection cover  150  are the same as those of the disc drive apparatus  100  of the first exemplary embodiment. Accordingly, detailed explanations on the respective components of the main body casing  110 , the disc loading unit  130  and the protection cover  150  will be omitted. 
         [0113]    According to the disc drive apparatus  100 ″ of the third exemplary embodiment as constructed above, since the disc detecting sensor  131  for detecting an insertion of the disc D is made up of the a micro switch, which is physically operated by the disc D, the disc detecting sensor  131  can operate to sense the insertion of the disc D, regardless of whether the disc drive apparatus  100 ″ is in the turned-on/off state. Accordingly, a driving process of the disc drive apparatus  100 ″ of the third exemplary embodiment may be carried out in the same way as the operation steps S 1 ˜S 6  in case that the disc drive apparatus  100  of the first exemplary embodiment is in the turned-on state, as explained above. 
         [0114]    However, in this case, since there is no sensing arm part  170  and no sensing switch  180  ( 181 ,  183 ) installed in the main body casing  110 , the disc drive apparatus  100 ″ does not perform operations, which determine a size of the disc D according whether the sensing switch  180  ( 181 ,  183 ) is operated and which control a driving time of the driving motor  141  or the like according to the determined result. Accordingly, the disc drive apparatus  100 ″ of the third exemplary embodiment is adapted to record information on a disc D of any given size or reproduce information record on the disc D of any given size. 
         [0115]    Although the present inventive concept has been illustrated and explained by the exemplary embodiments, it is not limited to the foregoing exemplary embodiments. The present teaching can be readily applied to other types of apparatuses and many alternatives, modifications, and variations will be apparent to those skilled in the art. Thus, the scope is not to be construed as being limited to the description of the exemplary embodiments, and is to be construed by the attached claims and equivalents.