Abstract:
A cartridge has an angled face formed at a rear end side of a case accommodating a recording medium. An operation portion for switching between two modes is provided on the angled surface. The two modes are a mode which enables recording of the recording medium and a mode which disables recording. The angled face comprises an opening. A write-protect portion, which switches the cartridge between the two modes, is provided with the operation portion, which is for switching between the modes, and is disposed near the opening. The operation portion is operated by an operating movement. Resultantly, in a writing-disabled state, an opening/closing plate of the write-protect portion is positioned at the opening, and in a recording-enabled state, the opening/closing plate is moved away from the opening. Thus, a user can judge from the rear end side which of the two modes the cartridge is in.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a cartridge which accommodates a recording medium, and more specifically relates to a recording medium cartridge which is provided with a write-protect portion which switches a state of the cartridge between a mode which enables recording to the accommodated recording medium and a mode which disables recording.  
           [0003]    2. Description of the Related Art  
           [0004]    Cartridges which accommodate a recording medium in a case are widely used. Such cartridges are often accommodated in a library or the like. Because of requirements for taking a cartridge out from the library or the like, an angled surface is often formed by cutting away an edge portion at a case back face side (case rear side) of the cartridge. (For example, the angled surface may have a form corresponding to cutting away an edge portion at which a back face and a lower face of a lower case would otherwise have intersected.)  
           [0005]    In such a case, the area of a “label area” at the back face side of the case, which is a portion of an outer side of a case rear wall, and which is continuous with the angled surface and orthogonal to an upper face and a lower face of the case, is reduced. Accordingly, if a write-protect portion, which prevents accidental erasure of data recorded on the recording medium, is provided at the back face side of the case, an opening which structures the write-protect portion must be formed in the rear wall of the case, and the label area becomes even smaller. Accordingly, there are also cartridges in which the write-protect portion is provided not at the back face side of the case but at a front face side or a side face side thereof.  
           [0006]    However, in a state in which a cartridge is accommodated in a library, a user can only observe the back face side of the cartridge. Therefore, there has been a problem in that users cannot determine by visual inspection whether a cartridge accommodated in a library is in a recording-enabled state or in a recording-disabled state.  
         SUMMARY OF THE INVENTION  
         [0007]    In consideration of the circumstances described above, an object of the present invention is to provide a cartridge with which a user can determine whether the cartridge is in a recording-enabled state or a recording-disabled state by observing a back face side of the cartridge, without a label area being reduced, even when an angled surface is formed at the cartridge back face side.  
           [0008]    A first aspect of the present invention is a cartridge for accommodating a recording medium, the cartridge being loadable in a predetermined direction at a drive device, and being selectively switchable between at least two modes, one of the modes allowing writing of information to the recording medium, and another of the modes prohibiting writing of information to the recording medium, the cartridge comprising: a case for accommodating the recording medium and including an outer wall face at a rear end of the case relative to the predetermined direction of loading and an angled face adjacent to the outer wall face, the angled face including an opening; and a switching member for switching between the modes, the switching member including an operation portion for the switching, the operation portion being exposed through the opening.  
           [0009]    The case further includes an upper outer face and a lower outer face, and the angled face is formed at a boundary region between the rear end outer wall face and one of the upper outer face and the lower outer face. The switching member is provided so as to be slideable along the angled face, and switches between the modes by being slid.  
           [0010]    Hereinafter, references to a rear end side or back end side in the present specification mean a side facing in a direction opposite to a direction of loading when the cartridge is inserted at a drive device at which the cartridge is loadable or at an accommodation shelf in a library or the like, that is, a rear end side of the cartridge.  
           [0011]    According to the first aspect of the present invention, even though the angled surface is formed at the rear end side of the case, because the opening is formed in the angled surface, a user can visually inspect the back face side and judge whether the cartridge is in a recording-enabled state or a recording-disabled state, even though the label area of the outer side of the case rear wall, which label area is orthogonal to the case upper face and lower face and is continuous with the angled surface, is not reduced in size. Therefore, even if the cartridge is in a state of accommodation in a library, the user can easily determine whether the cartridge is in the recording-enabled state or the recording-disabled state by observing the back face side of the cartridge.  
           [0012]    Further, because the operation portion is exposed through the opening, the operation portion can be easily switched between the recording-enabled state and the recording-disabled state by application of a movement force to the operation portion.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a top perspective view of a cartridge relating to a first embodiment.  
         [0014]    [0014]FIG. 2 is a back perspective view of the cartridge relating to the first embodiment, and shows a recording-disabled state.  
         [0015]    [0015]FIG. 3 is a partially enlarged view of the cartridge relating to the first embodiment.  
         [0016]    [0016]FIG. 4 is a perspective view showing a lower case of the cartridge relating to the first embodiment.  
         [0017]    [0017]FIG. 5 is a plan view of the lower case of the cartridge relating to the first embodiment, which view shows a state in which an erroneous erasure prevention plug is slidingly moveably attached at the lower case of the cartridge.  
         [0018]    [0018]FIG. 6 is a side sectional view, cut along the line indicated by arrows  6 - 6  in FIG. 5, showing the cartridge relating to the first embodiment.  
         [0019]    [0019]FIG. 7 is a perspective view of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0020]    [0020]FIG. 8 is a back perspective view, seen from diagonally downward, of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0021]    [0021]FIG. 9 is a front view of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0022]    [0022]FIG. 10 is a plan view of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0023]    [0023]FIG. 11 is a bottom view, seen from below, of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0024]    [0024]FIG. 12 is a side sectional view, cut along the line indicated by arrows  12 - 12  in FIG. 11, showing the erroneous erasure prevention plug.  
         [0025]    [0025]FIG. 13 is a side view of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0026]    [0026]FIG. 14 is a side view of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0027]    [0027]FIG. 15 is a back view of the erroneous erasure prevention plug provided at the cartridge relating to the first embodiment.  
         [0028]    [0028]FIG. 16 is a perspective view showing a variant example of the lower case of the cartridge relating to the first embodiment.  
         [0029]    [0029]FIG. 17 is a plan view of a lower case of a cartridge relating to a second embodiment, which view shows a state in which an erroneous erasure prevention plug is slidingly moveably attached.  
         [0030]    [0030]FIG. 18 is a side sectional view, cut along the line indicated by arrows  18 - 18  in FIG. 17, showing the cartridge relating to the second embodiment. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]    Hereafter, a magnetic tape cartridge accommodating a recording medium, which is a magnetic tape wound onto a single reel, is embodied, and embodiments of the present invention are described.  
         [0032]    First Embodiment  
         [0033]    Firstly, a first embodiment will be described. A direction of loading a magnetic tape cartridge into a drive device (the direction of an arrow P) is taken to be a forward direction, and front, back, left, right, up and down are taken with reference to a case of looking in the direction of the arrow P.  
         [0034]    As shown in FIG. 1, a case  12  of a magnetic tape cartridge  10  (hereinafter, referred to simply as “the cartridge  10 ”) is assembled to be a rectangular box-shaped case by matching up peripheral wall portions of an upper case  14  and a lower case  16 , which are made of synthetic resin, to one another. A single reel (not shown), at which a magnetic tape is wound, is rotatably accommodated in the case  12 . This reel is urged downward by a spring (not shown) provided between the upper case  14  and the reel. Thus, the reel is vertically displaceable.  
         [0035]    As shown in FIGS. 2 and 3, an angled wall  20  is formed at the lower case  16 . The angled wall  20  is provided with an angled surface  20 S which has a form corresponding to cutting away an edge portion at which a back face and a lower face of the lower case  16  would otherwise have intersected. An acute angle θ between the angled wall  20  and a lower wall  16 U which structures the lower case  16  may be, for example, 30° (see FIG. 6).  
         [0036]    A write-protect portion  30 , which prevents mistaken erasure of data recorded on the magnetic tape, is provided at a rear portion of the cartridge  10 .  
         [0037]    The write-protect portion  30  includes an erroneous erasure prevention plug  32  (see FIGS. 5 and 6) and a support portion  34  (see FIGS.  4  to  6 ). The plug  32  switches, by slidingly moving, between a state in which recording onto the magnetic tape is enabled and a state in which recording is disabled. The support portion  34  is provided at the lower case  16  and supports the plug  32  such that the plug  32  is slidingly moveable in a left-right direction (a direction H which intersects the direction P) along a rear wall  16 B of the lower case  16 . The write-protect portion  30  also includes a restricting portion  36  inside the upper case  14  (see FIG. 6). The restricting portion  36  prevents the plug  32  from moving upward and separating from the support portion  34 .  
         [0038]    As shown in FIGS.  2  to  15 , an opening/closing plate portion  38 , an upper structure  39  (restricted portion), and a lower structure  40  (supported portion) are provided at the plug  32  (see FIG. 7). The opening/closing plate portion  38  is positioned inside the angled wall  20  and is a part which implements opening and closing of an aperture  22 , which is formed in the angled wall  20 . The upper structure  39  is disposed at an upper side of the opening/closing plate portion  38 , and is a part whose upward movement is restricted by the restricting portion  36 . The lower structure  40  extends forward (in the direction P) from the opening/closing plate portion  38 , and is a part which is supported by and slides along an inner wall face of the lower wall  16 U.  
         [0039]    A rib-like part  46  (finger-engaging portion), for engaging with and being moved by fingers, is formed at an outer side of the opening/closing plate portion  38 , and is exposed through the aperture  22 .  
         [0040]    A retention plate portion  42  is provided at the opening/closing plate portion  38 . The retention plate portion  42  extends in the left-right direction, and is a part for maintaining the recording-enabled state or recording-disabled state of the write-protect portion  30 . The retention plate portion  42  includes an engaging rib  44  at an outer face side thereof. A standing plate  35  is standingly provided at the support portion  34 . The engaging rib  44  enters into and comes out of engaging grooves  35 D in the standing plate  35  (see FIG. 4). Consequently, when at least a certain movement force is applied to the finger-engaging portion  46  and the plug  32  is slidingly moved, the engaging rib  44  enters one of the engaging grooves  35 D in accordance with a recording-enabled position or a recording-disabled position and generates a “click” sound. Thus, the plug  32  is lightly held in place.  
         [0041]    The upper structure  39  includes a sliding plate portion  39 M, a right reinforcing plate portion  39 R, a central reinforcing plate portion  39 C, and a left reinforcing plate portion  39 L. The sliding plate portion  39 M is slidingly moveable along the rear wall  16 B of the lower case  16 . The right reinforcing plate portion  39 R and central reinforcing plate portion  39 C are continuous with an inner side of the sliding plate portion  39 M and an inner side of the opening/closing plate portion  38 . The left reinforcing plate portion  39 L is continuous with an inner side of the restricted portion. The upper structure  39  also includes an upper reinforcing plate portion  39 U, which is continuous with upper ends of the right reinforcing plate portion  39 R, the central reinforcing plate portion  39 C and the left reinforcing plate portion  39 L, and is continuous with the inner side of the sliding plate portion  39 M. Because of this structure, structural strength of the upper structure  39  and the opening/closing plate portion  38  is raised.  
         [0042]    The lower structure  40  is provided with a edge plate portion  48  and a leg portion  50 . The edge plate portion  48  is continuous with the opening/closing plate portion  38 . The leg portion  50  extends forward from the edge plate portion  48 . A short cylindrical distinguishing portion  52  (a detectable portion) is formed at a lower face side of a distal end portion of the leg portion  50 . The distinguishing portion  52  is exposed through a later-described exposure hole  56 , and can be detected from outside the cartridge  10 .  
         [0043]    As shown in FIGS.  2  to  6 , the aperture  22  formed in the angled wall  20  of the lower case  16  opens in a square shape and exposes the finger-engaging portion  46 . The exposure hole  56  is formed in a long, narrow shape in the lower wall  16 U of the lower case  16 , along a direction parallel to the angled wall  20 .  
         [0044]    When the plug  32  is positioned at the recording-disabled position (a position for when writing is prohibited), the aperture  22  enters a state of being closed by the plug  32  (see FIGS. 2 and 3).  
         [0045]    If the cartridge  10  is loaded into a drive device when the plug  32  is positioned at the recording-disabled position, the drive device detects the position of the distinguishing portion  52  through the exposure hole  56  and determines that the cartridge  10  is in the recording-disabled state.  
         [0046]    When the finger-engaging portion  46  is engaged by a finger, and the plug  32  is slidingly moved and positioned at the recording-enabled position (a position for when writing is allowed), the aperture  22  enters a state of not being closed by the opening/closing plate portion  38  of the plug  32  (refer to the finger-engaging portion  46  as shown by the broken line in FIG. 3).  
         [0047]    If the cartridge  10  is loaded into a drive device when the plug  32  is positioned at the recording-enabled position, the drive device detects the position of the distinguishing portion  52  through the exposure hole  56  and determines that the cartridge  10  is in the recording-enabled state.  
         [0048]    The plug  32  is colored with a color that can be easily distinguished from a color of the case  12 , so that a user can easily distinguish the different positions of the plug  32 , and thus distinguish the recording-enabled state from the recording-disabled state, by visual observation of the rear side of the cartridge. For example, the case  12  may be colored black and the plug  32  colored red. In such a case, the red member is hardly exposed at all in the recording-enabled state, but the red member covers the aperture  22  in the recording-disabled state.  
         [0049]    As described above, in the first embodiment, even though the angled wall  20  forming the angled surface  20 S is provided at the back wall side (rear side) of the lower case  16 , because the aperture  22  which exposes the opening/closing plate portion  38  of the plug  32  is formed in the angled wall  20 , the write-protect portion  30  can be provided at the rear portion of the cartridge  10 . Therefore, even when the cartridge  10  is in an accommodated state in a library, a user can easily judge whether the cartridge  10  is in the recording-enabled state or the recording-disabled state by observing the back face side of the cartridge  10 . Further, as shown in FIGS. 2 and 3, the aperture  22  is formed in the angled wall  20 , and is not formed in a rear wall  14 B of the upper case  14  or the rear wall  16 B of the lower case  16 . Therefore, a label area  58  can be formed over the whole of the rear wall outer side of the case  12 , and the label area  58  is not constricted.  
         [0050]    Moreover, because the exposure hole  56  which exposes the distinguishing portion  52  of the leg portion  50  is formed in the lower face side of the lower case  16 , when the cartridge  10  is assembled, the plug  32  can be brought down toward the support portion  34  from one direction (that is, from above the lower case  16 ), with the distinguishing portion  52  of the leg portion  50  being exposed through the exposure hole  56  and the finger-engaging portion  46  being exposed through the aperture  22 . Thus, the plug  32  can be easily assembled to the lower case  16 .  
         [0051]    As shown in FIG. 16, a structure is also possible in which an angled wall  60  is formed along the whole length of the back face side of the lower case, and two engaging grooves  65 D, for engaging with the engaging rib  44 , are directly provided to the inner side of the angled wall  60 .  
         [0052]    Second Embodiment  
         [0053]    Next, a second embodiment will be described. Structural elements which are the same in the second embodiment as in the first embodiment are given the same reference numerals, and explanations thereof are omitted.  
         [0054]    As shown in FIGS. 17 and 18, in a cartridge  70  relating to the second embodiment, a leg portion  80  of an erroneous erasure prevention plug  72 , which switches between the recording-enabled state and the recording-disabled state, is shorter than in the first embodiment. In addition, an exposure hole  86  which exposes a detectable portion  82 , which is formed at a lower face side of the leg portion  80 , is provided closer to a lower end of the angled wall  20  than in the first embodiment.  
         [0055]    Consequently, the erroneous erasure prevention plug  72  can be made smaller, and the leg portion  80  can be made less susceptible to breakage.  
         [0056]    The present invention has been explained by description of the above embodiments. However, these embodiments are merely examples, and various alterations can be implemented within a scope not departing from the spirit of the present invention. Obviously, the scope of any rights to the present invention is not to be limited to the embodiments described above.  
         [0057]    Because the present invention has the structure described above, a recording medium cartridge can be realized with which, even though an angled surface is formed at a back face side of a case, a user can observe the back face side and judge whether the cartridge is in a recording-allowed state or a recording-prohibited state, without a label area having been reduced.