Abstract:
An electronic apparatus has a main unit, a display unit rotatably attached to the main unit, an input device detachably connected to the main unit and a retaining mechanism retaining the input device between the display unit and the main unit.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to an electronic apparatus and input device, and more particularly, to an electronic apparatus and input device in which the input device is detachably connected to the main unit of the electronic device. 
   2. Description of the Related Art 
   In recent years the personal computer has come into widespread use, with space-efficient personal computers designed with office environment and home use needs in mind being sought amid increasing demand for enhanced performance and enhanced expansion capabilities. 
   In response to these needs there has appeared a more compact desktop-type personal computer, in which the main unit and the liquid crystal display panel are integrated so as to form a single unit. 
   For the above-described personal computer, it is preferable that the keyboard used be a compact one so as to be easily moved when not in use. If the keyboard is left on top of the desk when not in use, then the usable work area of the desk is reduced proportionally, and the space-saving advantage of a compact main unit is thereby lost. 
   As a result, when the personal computer is not in use the keyboard is stored out of the way by mounting it on the main unit. 
     FIG. 1  shows an example of a conventional personal computer (Japanese Laid-Open Patent App. No. 9-6505 to be described later), having a structure such that the keyboard  2  can be slung on the front of the main unit  1  and shown with the keyboard  2  attached to the main unit  1 . 
   In the case of the above-described personal computer, legs  3  rotatable to the front and rear as indicated by the arrow in  FIG. 1  are provided on a back surface  2   a  of the keyboard at both the left and right sides near the edge. Additionally, a groove portion  4  is formed on the legs  3 . At the same time, supporting members  6  extend from both edges of a front surface  5   a  of a display unit  5  of the personal computer main unit  1 . 
   When the keyboard  2  is not in use, after an operating power source not shown in the drawing is shut down the legs  3  are extended, the groove portion  4  of the legs  3  engages the supporting member  6  of the display unit  5  and the keyboard is slung. It should be noted that the legs  3  are stored in slot portions  7  formed on the back surface  2   a  of the keyboard  2  when the keyboard  2  is not in use. 
   However, according to the above-described keyboard storage structure, a width between the inside edge surfaces  3   a  of the legs  3  of the keyboard  2  must be identical to a width between the supporting members  6  of the display unit  5 . As a result, an inconvenience arises in that the keyboard  2  is naturally wider than this width  3   a  between the legs  3  thereof. 
   According to the keyboard storage structure of Japanese Laid-Open Patent App. No. 9-6505 which remedied this disadvantage, legs  3  that open laterally outward are provided on both left and right side edges of the keyboard  2  as shown in  FIG. 2 , such that in an open state groove or engaging portions  4  formed on the legs  3  engage supporting members (engaging portions)  6  formed on both side edges of the display unit  5  of the main unit  1 . 
   It should be noted that identical parts of the prior art examples shown in  FIGS. 1 ,  2  and elsewhere hereinafter, as the case may be, are given identical reference numbers. 
   Additionally, according to the keyboard storage structure of Japanese Laid-Open Patent App. No. 4-123218, a groove portion, that is, an engaging hole  4 A, is provided on a front edge portion and a hook  7 A is provided on a rear edge portion as shown in  FIG. 3 . At the same time, a support stand  8  that is pulled out for storage is provided on a lower part of a front surface of the personal computer main unit  1 , with a groove portion  4 B formed on the support stand  8 . When storing the keyboard  2  the support stand  8  is pulled out, the hook  7 A of the keyboard  2  engages the groove portion  4 B and a detachable keyboard attachment accessory  9  that fits onto an upper part of the front surface of the display unit  5  is attached so that a hook  7 B of the above-described keyboard attachment accessory  9  engages the groove portion  4 A. 
   However, the above-described conventional keyboard storage structure suffers from the disadvantage that the keyboard easily comes loose from the personal computer main unit whenever any type of shock is applied. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is a general object of the present invention to provide an improved and useful electronic apparatus and input device in which the disadvantage described above is eliminated, and more specifically, to provide an improved and useful electronic apparatus and input device in which the input device is securely stored in the main unit of the electronic apparatus when the input device is not in use, so that desktop space may be utilized more efficiently. 
   Another and further object of the present invention is to provide an improved and useful electronic apparatus that controls a desired operation of the electronic apparatus by the storage of the input device in or the removal of the input device from the electronic apparatus. 
   Still another and further object of the present invention is to provide an electronic apparatus having a superior aesthetic appearance in a state in which the input device is stored in the electronic apparatus. 
   The above-described objects of the present invention are achieved by an electronic apparatus detachably connected to an input device, comprising: 
   a main unit; 
   a display unit rotatably attached to the main unit; and 
   a retaining mechanism retaining the input device between the display unit and the main unit. 
   Additionally, the above-described objects of the present invention are also achieved by the electronic apparatus as described above, wherein the retaining mechanism comprises at least one supporting member. 
   According to the invention described above, the input device is restrained by the back surface of the display unit and stored between the display unit and the main unit in order to utilize the desktop space more efficiently when the input device is not in use. Accordingly, the input device does not come loose from the main unit even when some shock force is applied thereto and the input device can be securely stored between the main unit and the display unit. Additionally, the electronic apparatus can be given a superior functional appearance in a state in which the input device is stored because the supporting member is provided on a lower back surface of the display unit and does not intrude upon the field of vision. 
   Additionally, the above-described objects of the present invention are also achieved by the electronic apparatus as described above, wherein the supporting member is mounted so as to be storable in the main unit when the input device is not being stored. 
   According to the invention described above, the supporting member does not become an obstruction and thereby damage either the main unit or the display device. Moreover, the aesthetic appearance of the electronic apparatus as a whole is further improved because the main unit supporting member does not intrude upon the user&#39;s vision. 
   It should be noted that that either a hinge mechanism or a slide mechanism can be used with the above-described supporting member. 
   Additionally, the above-described objects of the present invention are also achieved by the electronic apparatus as described above, wherein the supporting mechanism comprises an engaging member engaging the main unit and the input device. 
   According to the invention described above, the input device can be more securely and more strongly stored between the display unit and the main unit. 
   It should be noted that the above-described engaging member can be composed of either a hook or a recessed portion engaging a projection or a hook. 
   Additionally, the above-described objects of the present invention are also achieved by the electronic apparatus as descried above, wherein the engaging member is mounted so as to be storable in the main unit when the input device is not being stored. 
   According to the invention described above, the engaging member does not become an obstruction and thereby damage either the main unit or the display device. Moreover, the aesthetic appearance of the electronic apparatus as a whole is further improved because the main unit engaging member does not intrude upon the user&#39;s vision. 
   It should be noted that the above-described engaging member and the above-described supporting member may be used in combination, such that the input device can be more strongly and more securely stored between the main unit and the display unit. 
   Additionally, the above-described objects of the present invention are also achieved by the electronic apparatus as described above, further comprising: 
   at least one detector detecting each of a storage and a removal operation of the input device; and 
   control means controlling a predetermined operation of the electronic apparatus according to a signal of the detector. 
   According to the invention described above, the user of the electronic apparatus can freely select a variety of desired operations to be controlled by the signal of the detector. 
   For example, in the case of a configuration set to control a suspend mode, that is, an energy-saving standby mode, the apparatus can be put into the standby mode according to the detector signal triggered when the input device is stored and the apparatus can be released from the standby mode according to the detector signal triggered when the input device is removed for use. As a result, it is no longer necessary to shut off the power when the input device is stored and to turn on the power when the input device is removed. Rather, the apparatus can be switched directly to the standby mode by storing the input device and can be put directly into an operating mode by removing the input device. 
   Additionally, according to the conventional input device storage structure the input device is attached to and stored on the front surface of the display unit, in which case the display unit cannot be used. By contrast, according to the present invention it is possible to store the input device and thereby obtain additional desktop space, in which state an additional auxiliary input device separate from the original input device can be used to operate the electronic apparatus. 
   Additionally, the burning of an image onto the display screen can be avoided, for example, if the electronic apparatus is configured so that a screen saver is activated by the detector signal triggered when the input device is stored. Similarly, a web browser can be activated by a detector signal triggered when the input device is stored, thereby making it possible to access the internet without the need to use the input device and thus freeing additional desktop space for use which would otherwise be occupied by the input device. 
   Additionally, for example, it is possible to configure the electronic apparatus so that an e-mail program, a word processing program, a spreadsheet program or some other desired application is immediately activated by the detector signal triggered by the removal of the input device when the electronic apparatus is being readied for use. 
   Additionally, the above-described objects of the present invention are also achieved by an input device detachably connected to an electronic apparatus, the electronic apparatus comprising a main unit and a display unit rotatably attached to the main unit, the input device comprising: 
   at least one engaging member engaging the main unit so that the input device is retained between the display unit and the main unit. 
   According to the invention described above, the input device can be applied with optimum efficiency to the electronic apparatus of the present invention. 
   Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a conventional personal computer; 
       FIG. 2  is a perspective view of a conventional personal computer; 
       FIG. 3  is a side view of another conventional personal computer; 
       FIGS. 4A and 4B  are front and side views, respectively, of the personal computer according to a first embodiment of the present invention for the purpose of explaining a storage state of a keyboard; 
       FIGS. 5A and 5B  are front and side views, respectively, of the personal computer according to a first embodiment of the present invention for the purpose of explaining a usage state of a keyboard; 
       FIGS. 6A and 6B  are enlarged views of a personal computer main unit for the purpose of explaining an operation of a supporting member according to a first embodiment of the present invention; 
       FIGS. 7A and 7B  show a tilt mechanism according to a first embodiment of the present invention; 
       FIGS. 8A and 8B  are partial side views of a personal computer showing a storage state of a keyboard and a usage state of a keyboard, respectively, for the purpose of explaining a first variation of a personal computer according to a first embodiment of the present invention; 
       FIG. 9  is a side view of a personal computer according to a second embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 10  is a side view of a personal computer according to a second embodiment of the present invention, for the purpose of explaining a usage state of a keyboard; 
       FIG. 11  is a side view of a personal computer according to a third embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 12  is a side view of a personal computer according to a third embodiment of the present invention, for the purpose of explaining a usage state of a keyboard; 
       FIG. 13  is a side view of a personal computer according to a fourth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 14  is a side view of a personal computer according to a fourth embodiment of the present invention, for the purpose of explaining a usage state of a keyboard; 
       FIG. 15  is a perspective view of a personal computer according to a fifth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 16  is a perspective view of a personal computer with the keyboard removed according to a fifth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 17  is a perspective view of a personal computer according to a sixth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 18  is a perspective view of a personal computer with the keyboard removed according to a sixth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 19  is a side view of a personal computer according to a seventh embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; 
       FIG. 20  is a side view of a personal computer according to a seventh embodiment of the present invention, for the purpose of explaining a storage state of a keyboard; and 
       FIG. 21  is a schematic diagram illustrating the personal computer operation control mechanism triggered by the storage and removal of the keyboard. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A description will now be given of embodiments of the present invention with reference to the accompanying drawings, specifically in the first instance  FIGS. 4A ,  4 B,  5 A,  5 B,  6 A,  6 B,  7 A and  7 B. 
     FIGS. 4A ,  4 B,  5 A,  5 B,  6 A,  6 B,  7 A and  7 B are diagrams for describing a desktop personal computer, hereinafter referred to as a personal computer, according to a first embodiment of the present invention.  FIGS. 4A and 4B  are front and side views, respectively, of a personal computer according to a first embodiment of the present invention for the purpose of explaining a storage state of a keyboard.  FIGS. 5A and 5B  are front and side views, respectively, of the personal computer according to a first embodiment of the present invention for the purpose of explaining a usage state of a keyboard.  FIGS. 6A and 6B  are enlarged views of a personal computer main unit for the purpose of explaining an operation of a supporting member according to a first embodiment of the present invention.  FIGS. 7A and 7B  show a tilt mechanism according to a first embodiment of the present invention. 
   The personal computer  10  comprises a keyboard  16  and a main unit  14  on a front surface  14   a  of which a liquid crystal display panel  12  is provided. The liquid crystal display panel  12 , hereinafter referred to as a display unit, has a top part that engages a top part of the main unit  14  via a tilt mechanism  18 , such that the display unit  12  is rotatably mounted about the tilt mechanism  18 . For ease of explanation the tilt mechanism  18  will be described later. At least one supporting member  20  is storably provided on the front surface  14   a  of the main unit  14 . For ease of explanation the supporting member  20 , too, will be described later. The keyboard  16  is connected to the main unit  14  by a connection cable not shown in the drawing. Additionally, an auxiliary input device such as a mouse not shown in the drawing may also be connected to the main unit  14  by a separate connection cable. 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIGS. 4A and 4B  which show a storage state of the keyboard  16 . First, the display unit  12  is rotated so as to be lifted in an upper left direction as seen from the diagram so as to form a space between a back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 , the keyboard  16  is positioned in this space and a bottom portion of the keyboard  16  is supported by the supporting member  20  projecting from the front surface  14   a  of the main unit  14 . Next, the display unit  12  is rotated once again, this time in reverse and pressed slightly against the keyboard  16  so as to sandwich the keyboard  16  between the display unit  12  and the main unit  14 . As a result, desktop space not shown in the diagram in front of the front surface  14   a  of the main unit  14  that would normally be occupied by the keyboard  16  is now freed for other use. Additionally, unlike with the conventional arrangement, the front surface  12   a  of the display unit  12  remains unobstructed because the keyboard  16  is stored between the display unit  12  and the main unit  14 . Accordingly, the display unit  12  can still be used even when the keyboard  16  is stored out of the way. 
   When using the keyboard  16 , as shown in  FIGS. 5A and 5B  the display unit  12  is rotated upward and outward so as to separate the display unit  12  from the keyboard  16 , after which the keyboard  16  is removed from the main unit  14  and positioned in front of the front surface  14   a  of the main unit  14  in such a way that the keyboard  16  is easy to use for the user. At the same time, the supporting member  20  is folded upward and out of the way so as to no longer project from the front surface  14   a  of the main unit  14 . In the configuration shown in  FIGS. 5A and 5B , the display unit  12  is rotated downward so as to be substantially vertical, with the back surface  12   b  of the display unit  12  left in a state of contact with the front surface  14   a  of the main unit  14 . 
   It should be noted that the display unit  12  is not limited to the above-described position but may be rotated upward to any position that is comfortable for a user seated at the keyboard  16 . 
   A more detailed description will now be given of the supporting member  20  supporting the bottom portion of the keyboard  16 . 
   The supporting member  20  shown in  FIGS. 6A and 6B  comprises a projecting portion  20   a  and further a hook-shaped engaging portion  20   b  located at the tip of the projecting portion  20   a . A hinge  22  is mounted on the front surface  14   a  of the main unit  14 , with a recessed portion  24  formed on an upper portion of the hinge  22 . A rear edge of the supporting member  20  engages the hinge  22 . 
   In the keyboard  16  storage state shown in  FIG. 6A , the keyboard  16  is supported by the projecting portion  20   a  of the supporting member  20  projecting from the front surface  14   a  of the main unit  14  when the supporting member  20  is swung open horizontally about the hinge  22 . Further, a bottom edge of a back surface of the keyboard  16 , that is, the surface opposite the surface on which the keys of the keyboard  16  are disposed, is securely engaged by the engaging portion  20   b.    
   In the keyboard  16  usage state shown in  FIG. 6B , the supporting member  20  is swung shut and stored in the recessed portion  24 . As a result, the supporting member  20  does not remain as an obstruction on the front surface  14   a  of the main unit  14  and thus does not pose any danger of damaging either the main unit  14  or the display unit  12 . Additionally, the back surface  12   b  of the display unit  12  can be directly contacted against the front surface  14   a  of the main unit  14 . 
   It should be noted that the operations of storing and removing the supporting member  20  can be performed with ease because the supporting member  20  is mounted on the front surface  14   a  of the main unit  14 . 
   A description will now be given of the tilt mechanism  18  that integrates the display unit  12  with the personal computer main unit  14 , with reference to  FIGS. 7A and 7B . It should be noted that the tilt mechanism  18  also makes it possible to rotate the display unit  12  so as to change the degree of inclination or tilt of the display unit  12  to a desired angle. 
   As an initial matter, it should be noted that the tilt mechanism  18  comprises a tilt member  26  and a tilt member mounting member  28 . 
   The tilt member  26  comprises a shaft  26   a , a plurality of bearing members  26   b ,  26   c  and  26   d  supporting the shaft  26   a  and a plurality of leaf springs  26   e . The tilt member  26  is mounted on the tilt member mounting member  28  by installing the shaft  26   a  on the plurality of bearing members  26   b ,  26   c  and  26   d , passing a tip of the shaft  26   a  through a recessed portion  30  formed in the tilt mechanism mounting member  28 , connecting the tip of the shaft  26   a  to the plurality of leaf springs  26   e  and securing the leaf springs  26   e  to a mounting position. A top surface of the member  26   b  that forms part of the tilt member  26  that in turn forms part of the tilt mechanism  18  is mounted on the back surface  12   b  of the display panel  12 . At the same time, a bottom surface of the tilt member mounting member  28  is mounted on the front surface  14   a  of the main unit  14 . 
   According to the above-described structure, the display unit  12  rotates about the tilt mechanism  18  in the directions indicated by the arrow shown in  FIG. 7B , such that by manually tilting the display unit  12  to a desired position the frictional effect of the leaf springs  26   e  maintains the display unit  12  at that desired angle of inclination. Accordingly, in a state in which the keyboard  16  is positioned between the display unit  12  and the main unit  14 , the back surface  12   b  of the display unit  12  presses against the keyboard  16  so as to securely retain the keyboard  16  between the display unit  12  and the main unit  14 . 
   According to the personal computer according to the first embodiment of the present invention as described above, when the keyboard  16  is not in use the keyboard  16  can be securely stored between the display unit  12  and the main unit  14  in such a way that the keyboard does not come loose from the personal computer  10  by the force of some shock applied against the personal computer  10 . As a result, more efficient use can be made of the desktop space that the keyboard  16  would otherwise occupy, and at the same time the aesthetic appearance of the personal computer  10  as a whole is improved because the keyboard  16  is not mounted on the front surface  12   a  of the display unit  12  when the keyboard  16  is stored. 
   A description will now be given of a variation of the personal computer according to the first embodiment of the present invention, with reference to  FIGS. 8A and 8B . 
   According to this variation, the hinge mechanism of the supporting member  20  of the above-described first embodiment is replaced by a slide mechanism. It should be noted that, in principle, parts of this variation as well as all subsequent embodiments described hereinafter that are identical to corresponding parts of the first embodiment as described above are given identical reference numerals. 
   As shown in  FIG. 8A , a supporting member  32  comprises a projection  32   a , on a front edge portion of which a hook-shaped engaging member  32   b  is formed. Additionally, engaging portions  32   c  extend from both side surfaces near a back edge portion of the supporting member  32 . At the same time, a recessed portion  34  is formed on the front surface  14   a  of the main unit  14 , on both sides of which are formed rail-shaped grooves  34   a  that engage the engaging portions  32   c . In a state in which the supporting member  32  is inserted in the recessed portion  34  and the engaging portions  32   c  engage the rail-shaped grooves  34   a , an opening part of the recessed portion  34  retains room to penetratingly insert the projection  32   a  of the supporting member  32  so as to accommodate the engaging member  32   b . It should be noted that the engaging portions  32   c  are provided in order to keep the supporting member  32  from falling out when removed, that is, pulled out, to support the display unit  12 . 
   A description will now be given of the operation of the supporting member  32  when the keyboard  16  is stored, with reference to the keyboard storage state shown in  FIG. 8A . The supporting member  32 , of which there is at least one, is retracted from the recessed portion  34  by the slide mechanism, the bottom of the keyboard  16  is supported by the projection  32   a  and the bottom edge of the back surface  16   b  of the keyboard  16  is securely engaged by the engaging portion  32   b.    
   Additionally, the supporting member  32  is completely contained within the recessed portion  34  when the keyboard  16  is in use and thus is not an obstruction. Accordingly, there is no danger that either the main unit  14  or the display unit  12  will be damaged, and moreover the aesthetic appearance of the personal computer  10  is improved because the supporting member does not intrude upon the user&#39;s field of vision. 
   Next, a description will be given of a personal computer according to a second embodiment of the present invention, with reference to  FIG. 9  and  FIG. 10 .  FIG. 9  is a side view of the personal computer according to the second embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 10  is a side view of the personal computer according to the second embodiment of the present invention, for the purpose of explaining a usage state of the keyboard. 
   In the second embodiment of the present invention, at least one supporting member  36  comprising a projection  36   a  and a hook-shaped engaging portion  36   b  is provided on a bottom edge of the back surface  12   b  of the display unit  12  so as to be swung into and storable within a recessed portion  38  formed in the back surface  12   b  of the display unit  12  via a hinge mechanism. 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIG. 9  which shows a storage state of the keyboard  16 . First, the display unit is rotated upward and outward to form a space between the back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 . The keyboard  16  is then positioned within the space so formed, with a bottom portion of the keyboard  16  supported by the supporting member  36  provided on the display unit  12 . The display unit  12  is then rotated so as to press slightly against the keyboard  16 , thereby sandwiching and storing the keyboard  16  between the display unit  12  and the main unit  14 . 
     FIG. 10  shows a state in which the keyboard  16  is removed for use, with the supporting member  36  stored within the hole  38  of the display unit  12 . 
   Accordingly, the same effects and advantages as those obtained with the personal computer according to the first embodiment of the present invention can be obtained with the personal computer according to the above-described second embodiment of the present invention. In particular, the aesthetic appearance of the personal computer  10  is further improved insofar as the supporting member  36  is provided on the back surface  12   b  of the display unit  12  and thus does not intrude upon the user&#39;s field of vision. 
   Next, a description will be given of a personal computer according to a third embodiment of the present invention, with reference to  FIGS. 11 and 12 .  FIG. 11  is a side view of the personal computer according to the third embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 12  is a side view of the personal computer according to the third embodiment of the present invention, for the purpose of explaining a usage state of the keyboard. 
   In the third embodiment of the present invention, the supporting members  20  and  36  of the above-described first and second embodiments, respectively, are replaced by engaging members by which the keyboard  16  is slung from the front surface  14   a  of the main unit  14 . 
   Hooks  40  are provided as engaging members on a top edge of the back surface  16   b  of the keyboard  16 , with recessed portions  42  as engaging members formed in the front surface  14   a  of the main unit  14 . 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIG. 11  which shows a storage state of the keyboard  16 . First, the display unit is rotated upward and outward to form a space between the back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 . The keyboard  16  is then positioned within the space so formed, with the hooks  40  of the keyboard  16  engaging the recessed portions  42  of the main unit  14  so that the keyboard  16  is slung on the main unit  14 . The display unit  12  is then rotated so as to press slightly against the keyboard  16 , thereby sandwiching and storing the keyboard  16  between the display unit  12  and the main unit  14 . 
   Referring to  FIG. 12 , it can be appreciated that when the keyboard  16  is removed for use, the hooks  40  of the keyboard  16  function as projections that raise a top edge of the keyboard  16  slightly so as to facilitate use of the keyboard  16  by the user. 
   Accordingly, the same effects and advantages as those obtained with the personal computer according to the first embodiment of the present invention can be obtained with the personal computer according to the above-described third embodiment of the present invention. 
   Next, a description will be given of a personal computer according to a fourth embodiment of the present invention, with reference to  FIGS. 13 and 14 .  FIG. 13  is a side view of the personal computer according to the fourth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 14  is a-side view of the personal computer according to the fourth embodiment of the present invention, for the purpose of explaining a usage state of the keyboard. 
   Unlike in the third embodiment of the present invention as described above, in the fourth embodiment of the present invention the recessed portions that form one half of the engaging members are formed on the display unit  12  instead of the main unit  14 . 
   In other words, hooks  44  are provided as engaging members on the top edge of the back surface  16   b  of the keyboard  16 . At the same time, recessed portions  46  are formed in a center part of the back surface  12   b  of the display unit  12 . 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIG. 13  which shows a storage state of the keyboard  16 . First, the display unit is rotated upward and outward to form a space between the back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 . The keyboard  16  is then positioned within the space so formed, with the hooks  44  of the keyboard  16  engaging the recessed portions  46  of the main unit  14  so that the keyboard  16  is slung on the display unit  12 . The display unit  12  is then rotated so as to press slightly against the keyboard  16 , thereby sandwiching and storing the keyboard  16  between the display unit  12  and the main unit  14 . 
   Referring to  FIG. 14 , it can be appreciated that when the keyboard  16  is removed for use, the hooks  44  of the keyboard  16  function as projections that raise a top edge of the keyboard  16  slightly so as to facilitate use of the keyboard  16  by the user. 
   Accordingly, the same effects and advantages as those obtained with the personal computer according to the first embodiment of the present invention can be obtained with the personal computer according to the above-described fourth embodiment of the present invention. 
   Next, a description will be given of a personal computer according to a fifth embodiment of the present invention, with reference to  FIGS. 15 and 16 .  FIG. 15  is a perspective view of a personal computer according to a fifth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 16  is a perspective view of a personal computer with the keyboard removed according to a fifth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard. 
   Unlike in the third and fourth embodiments of the present invention as described above, in the fifth embodiment of the present invention the hooks that function as engaging members are provided on the main unit while the recessed portions that function as engaging members are formed on the keyboard. 
   In other words, a first set of rotatable hooks  48  rotated by a hinge mechanism is provided on the front surface  14   a  of the main unit  14  together with recessed portions  52  for storing the hooks  48 . At the same time, recessed portions  50  having an L-shaped cross-section are formed on a back surface  16   b  of the keyboard  16 . 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIG. 16  which shows a storage state of the keyboard  16 . First, the display unit is rotated upward and outward to form a space between the back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 . The keyboard  16  is then positioned within the space so formed, with the hooks  48  of the main unit  14  engaging the recessed portions  50  of the keyboard  16  and the keyboard  16  slung on the main unit  14 . The display unit  12  is then rotated so as to press slightly against the keyboard  16 , thereby sandwiching and storing the keyboard  16  between the display unit  12  and the main unit  14 . 
   As shown in  FIG. 16 , when the keyboard  16  is in a stored state the hooks  48  of the main unit  14  are opened so as to extend from the front surface  14   a  of the main unit  14 , with the hooks  48  stored in the recessed portions  52  of the main unit  14  when the keyboard  16  is in a usage state not shown in the diagram. 
   Accordingly, the same effects and advantages as those obtained with the personal computer according to the first embodiment of the present invention can be obtained with the personal computer according to the above-described fifth embodiment of the present invention. 
   Next, a description will be given of a personal computer according to a sixth embodiment of the present invention, with reference to  FIGS. 17 and 18 .  FIG. 17  is a perspective view of a personal computer according to a sixth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 18  is a perspective view of a personal computer with the keyboard removed according to a sixth embodiment of the present invention, for the purpose of explaining a storage state of a keyboard. 
   Unlike in the fifth embodiment of the present invention as described above, in the sixth embodiment of the present invention the hooks that function as engaging members are provided on the keyboard while the recessed portions that function as engaging members are formed on the main unit. 
   In other words, rotatable hooks  54  rotated by a hinge mechanism are provided on the back surface  16   b  of the keyboard  16  together with recessed portions  56  for storing the hooks  54 . At the same time, recessed portions  58  having an L-shaped cross-section are formed on a front surface  14   a  of the main unit  14 . 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIG. 17  which shows a storage state of the keyboard  16 . First, the display unit is rotated upward and outward to form a space between the back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 . The keyboard  16  is then positioned within the space so formed, with the hooks  54  of the keyboard  16  engaging the recessed portions  58  of the main unit  14  so that the keyboard  16  slung on the main unit  14 . The display unit  12  is then rotated so as to press slightly against the keyboard  16 , thereby sandwiching and storing the keyboard  16  between the display unit  12  and the main unit  14 . 
   As shown in  FIG. 18 , when the keyboard  16  is in a stored state the hooks  54  of the keyboard  16  are opened so as to extend from the back surface  16   b  of the keyboard  16 , with the hooks  54  stored in the recessed portions  56  of the keyboard  16  when the keyboard  16  is in a usage state not shown in the diagram. 
   Accordingly, the same effects and advantages as those obtained with the personal computer according to the fifth embodiment of the present invention can be obtained with the personal computer according to the above-described sixth embodiment of the present invention. 
   Next, a description will be given of a personal computer according to a seventh embodiment of the present invention, with reference to  FIGS. 19 ,  20  and  21 .  FIG. 19  is a side view of a personal computer according to a seventh embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 20  is a side view of a personal computer according to a seventh embodiment of the present invention, for the purpose of explaining a storage state of a keyboard.  FIG. 21  is a schematic diagram illustrating the personal computer operation control mechanism triggered by the storage and removal of the keyboard. 
   The basic structure of the apparatus according to the seventh embodiment of the present invention is identical to that of the first embodiment of the present invention as described above. However, in the seventh embodiment of the present invention at least one detector is provided on the main unit for detecting both storage and removal of the keyboard, together with a control means for the operating system to control a desired operation of the personal computer according to signals from the detector. 
   In other words, at least one supporting member  64  comprising a storable projection  60  and a hook-shaped engaging portion  62  extends from the front surface  14   a  of the main unit  14 , with a switch  66  provided on the projection  60 . 
   A description will now be given of a sequence for storing the keyboard  16 , with reference to  FIG. 19  which shows a storage state of the keyboard  16 . First, the display unit is rotated upward and outward to form a space between the back surface  12   b  of the display unit  12  and the front surface  14   a  of the main unit  14 . The keyboard  16  is then positioned within the space so formed, and the bottom of the keyboard  16  contacts the supporting member  64  extending from the front surface  14   a  of the main unit  14  and is supported thereby, comprising a STEP  100  as shown in  FIG. 21 . At this time the switch  66  is depressed and turns ON, comprising a STEP  110 , the operating system is activated in a STEP  120 , an operation selected at random by the user such as, for example, an energy-saving standby mode, is enabled in a STEP  130 , thereby permitting energy savings without shutting off the power to the personal computer. The display unit  12  is then rotated so as to press slightly against the keyboard  16 , thereby sandwiching and storing the keyboard  16  between the display unit  12  and the main unit  14 . In such a state, a mouse or other auxiliary input device, for example, is directly enabled, permitting input operation in a state in which additional desktop space that would otherwise have been occupied by the keyboard  16  is freed for other use. 
   When the keyboard  16  is to be used, the removal of the keyboard  16  from the supporting member  64  in a STEP  140  as shown in  FIG. 21  turns the switch  66  OFF in a STEP  150  so that a standby mode, for example, is released in a STEP  160  and input from the keyboard  16  is directly enabled. In a usage state of the keyboard  16  the supporting member  64  is stored in the recessed portion  68  formed in the front surface  14   a  of the main unit  14 . 
   It should be noted that the user can specify a variety of operations other than the standby mode described above as the desired operation of the personal computer  10  triggered by the actions of storing and removing the input device. The operation of storing the keyboard  16  shown in  FIG. 21  as STEP  100  can, for example, activate a screen saver in a STEP  170 , for example, or activate an internet browser in a STEP  180 , as desired. Additionally, the action of removing the keyboard  16  shown as STEP  140  in  FIG. 21  can activate a e-mail program in a STEP  190 , for example, or a word processing or spreadsheet program in a STEP  200 , as desired. 
   Accordingly, the same effects and advantages as those obtained with the personal computer according to the first embodiment of the present invention can be obtained with the personal computer according to the above-described seventh embodiment of the present invention, and more particularly, a desired operation of the personal computer can be controlled by the actions of storing and removing the input device. 
   The above description is provided in order to enable any person skilled in the art to make and use the invention and sets forth the best mode contemplated by the inventors of carrying out their invention. 
   The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention. 
   The present application is based on Japanese Priority Application No. 11-191023, filed on Jul. 5, 1999, the entire contents of which are hereby incorporated by reference.