Patent Publication Number: US-2007108093-A1

Title: Case module having auto-folder function and control method thereof

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invnetion  
      The present invention is related to a case module, more specifically to a case module for an auto-folder function controlling automatic opening and closing of the cover of the case with a receptacle.  
      A variety of uses are possible for a portable case with receptacle space. Representative among these are cosmetics cases. It is common that women carry cosmetics, such as mascara, eye shadow, and lipstick, in a case. Also, women often carry a compact, in which compressed powder is filled. These cosmetics cases accompanied inconvenience of having to open the cover with one hand, and at time with two hands.  
      2. Description of Related Art  
       FIG. 1  is an exploded perspective view of a cosmetics case, having an automatic ejection function, in accordance with the prior art.  
      The cosmetics case includes a housing  10  containing a receptacle  40  for storing various types of coloring cosmetics defined by a plurality of partitions  41 , a drawer  30  for accommodating a cosmetic set  35 , and a receiving room  13  for storing the drawer  30 . A cover  50  is mounted to the rear wall through a pair of pivot pins such that the cover  50  can be opened and closed. An entrance  11  is disposed at a right wall  10   d  of the receiving romm of the housing. A pair of walls  12  guide an elastic spring  12   a,  which is mounted against a left wall  10   c.  A groove  13   a  is disposed on the bottom and extends from the middle portion of a front wall  10   a.  A key plate is seated in the groove  13   a.  An opening spring part  16  is disposed on a rear wall  10   b.  A locking holder seat  14  is disposed at the center of the front wall  10   a  with a pair of biased elements  14   a.  A locking holder  20  includes a locking hook  21  disposed on the top thereof, a pair of elastic wedges  23  extending from both ends thereof, and a key plate  22  having a key projection  22   a.    
      When the user pushes the locking holder, the drawer is released, and the cover is opened simultaneously, allowing the user to take out the cosmetic set  35  from the drawer  30  and storing the cosmetic set  35  in the drawer  30 .  
      Referring to  FIG. 1 , the elasticity of the elastic spring releases the drawer  30 . Howerver, the user still has been experiencing inconvenience of having to manually open the cover  50  of the cosmetics case.  
      Recently, the popularity of automated products is booming throughout the world. Automation is attempted in small, portable products as well as in large products, such as the robots in manufacturing facilities.  
      Take the mobile phone, which almost everyone has these days, for example. It comes in a variey of styles, from the flip style to the folder style to the slide style. Some of the folder style phones, in particular, are produced with an automated funciton, called the “auto-folder.” That is, when the user needs to open the folder to use various functions of a folder-style mobile phone, pressing a predesignated button opens, and closes in effect, the folder such that the inconvenience of manually having to open the folder is eliminated.  
      Therefore, it is logical to introduce the auto-folder function to a portable case, such as the cosmetics case.  
     SUMMARY OF THE INVENTION  
      Therefore, the present invention aims to provide a case module and a controlling method thereof to eliminate the inconvenience of having to open and close the cover by using a driving circuit to control the forward and reverse rotations of a DC motor and to have the cover open and close in accordance with the rotation of the DC motor.  
      Moreover, the present invention aims to provide a case module and a controlling method thereof that do not require a microcomputer, as mobile phones do, by controlling the rotation direction of a DC motor through the use of a simple circuit to have the cover open and close.  
      Other objects of the present invention shall be easily understood through the description below.  
      In order to achieve the above objects, an aspect of the present invention features a case module. The case module can comprise a case, a buffer, and a driving unit. The case comprises a motor, which enables a cover to rotate. The cover opens when a forward rotation switch is turned on, and the cover closes when a reverse rotation switch is turned on. The buffer generates a forward rotation signal or a reverse rotation signal, corresponding to the turn-on state of the forward rotation switch or the reverse rotation switch, respectively. The driving unit rotates the motor, using a signal from the buffer as an input.  
      Preferably, the case comprises a housing, which has a receptacle isolated from the outside by the cover, and hinges, which connects the cover to the housing such that the cover rotates about the hinges. The motor is disposed inside the hinges such that the motor rotates the cover.  
      Here, the reverse rotation switch can be turned on when the cover opens and turned off when the cover covers the housing. The buffer can generate the forward rotation signal when both the forward rotation switch and the reverse rotation switch are turned on.  
      Moreover, the case module can further comprise a cover open state sensing unit, which generates an open signal by sensing the opening of the cover to a predetermined angle. The buffer generates a stop signal, which stops the rotation of the motor in accordance with the open signal.  
      Here, the cover open state sensing unit can comprise a voltage source, which provides an open voltage, a sensor PCB (printed circuit board), which generates the open signal by sensing the open voltage at a predetermined location, and a conductive arm, which rotates by the rotation of the motor and connects the voltage source and the sensor PCB at the predetermined location.  
      The driving unit can comprise a first driving unit, which rotates the motor in the forward direction in accordance with the forward rotation signal from the buffer, and a second driving unit, which rotates the motor in the reverse direction in accordance with the reverse rotation signal from the buffer.  
      The driving unit can be an H-bridge circuit to rotate the motor in the forward direction or the reverse direction in accordance with the forward rotation signal or the reverse rotation signal, respectively.  
      Moreover, the case module can further comprise a magnet, which forms a certain intensity of magnetic field by being disposed in either the cover or the housing, and a hall sensor, which senses the magnetic field by being disposed in the other of the cover or the housing where the magnet is disposed. The location of the hall sensor corresponds to the location of the magnet. The hall sensor generates a signal as the magnet nears the hall sensor and delivers the signal, which stops the reverse rotation of the motor, to the buffer.  
      The case module can further comprise a drawer, which is housed in the housing and has a small storage space, and a main switch, which structurally opens the storage. The drawer turns off the forward rotation switch when the drawer is housed in the housing and turns on the forward rotation switch when the drawer is released from the housing.  
      In order to achieve the above objects, another aspect of the present invention features a method for controlling the cover rotaton of a case module. The case module comprises a motor, a forward rotation switch, and a reverse rotation switch. The motor rotates a cover, and the switches open or close the cover. The method can comprise the steps of (a) generating a forward rotation signal when the forward rotation switch is turned on, (b) rotating the motor in the forward direction in accordance with the forward rotation signal, (c) the cover being opened in accordance with the forward rotation of the motor, (d) sensing the opening of the cover to a predetermined angle, and (e) generating a stop signal, which stops the forward rotation of the motor.  
      Preferably, the case module can further comprise a cover open state sensing unit, which generates an open signal by sensing the opening of the cover to the predetermined angle. The step (d) can generate a stop signal, which stops the rotaion of the motor in accordance with the open signal.  
      Here, the cover open state sensing unit can comprise a voltage source, which provides an open voltage, a sensor PCB (printed circuit board), which generates the open signal by sensing the open voltage at a predetermined location, and a conductive arm, which rotates by the rotation of the motor and connects the voltage source and the sensor PCB at the predetermined location.  
      Preferably, the step (c) can turn on the reverse rotation switch when the cover opens.  
      Here, the method can further comprise the steps of (f) generating a reverse rotation signal, which rotates the motor in the reverse direction, when the forward rotation switch is turned off, (g) rotating the motor in the reverse direction in accordance with the reverse rotation signal, (h) the cover covering the housing in accordance with the reverse rotation of the motor, and (i) generating the stop signal, which stops the reverse rotation of the motor.  
      The case module can further comprise a magnet, which is disposed in either the cover or the housing and forms a certain intensity of magnetic field, and a hall sensor, which is disposed in the other of the cover or the housing where the magnet is disposed and senses the magnetic field. The location of the hall sensor corresponds to the location of the magnet. The step (f) generates the stop signal as the magnet nears the hall sensor.  
      The case module can further comprise a drawer, which is housed in the housing and has a small storage space, and a main switch, which structurally opens the storage. The drawer turns off the forward rotation switch when the drawer is housed in the housing and turns on the forward rotation switch when the drawer is released from the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:  
       FIG. 1  shows an exploded perspective view of a cosmetics case, having an automatic ejection function, in accordance with the prior art;  
       FIG. 2  illustrates a case in accordance with a preferred embodiment of the present invention;  
       FIG. 3  shows perspective views of a case with the cover opened and closed, in accordance with another preferred embodiment of the present invention;  
       FIG. 4  shows an exploded perspective view of the case without the upper housing;  
       FIG. 5  shows an enlarged view of a section of  FIG. 4 ;  
       FIG. 6  shows a schematic of a case cover rotation control circuit in accordance with a preferred embodiment of the present invention;  
       FIG. 7  illustrates a method of the sensor PCB (printed circuit board) inside the motor for sensing the complete opening of the cover;  
       FIG. 8  shows a case cover rotation control circuit using an H-bridge circuit in accordance with another preferred embodiment of the present invention; and  
       FIGS. 9-10  show flowcharts of a method for controlling the case cover rotation in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Hereinafter, preferred embodiments of a case module and its controlling method thereof in accordance with the present invention will be described with reference to the accompanying drawings. In describing the present invention, if it is determined that detailed description of a certain pertinent technology, known to those of ordinary skill in the art, can make the essence of the present invention obscure, the detailed description of the pertinent technology will not be provided. The ordinal numbers (e.g. the first, the second, etc.) used in the description are only for the purpose of distinguishing similar elements in the order of appearance in the description.  
      The case module of the present invention comprises a case and a case cover rotation control circuit. The case will be described in detail through  FIGS. 2-5 , and the case cover rotation control circuit and its operation will be described in detail through FIGS.  6 - 8 .  
       FIG. 2  is an illustration of the case in accordance with a preferred embodiment of the present invention.  
      Referring to  FIG. 2 , the case comprises a cover  210 , a housing  220 , a forward rotation switch  230 , a reverse rotation switch  240 , hinges  211   a,    211   b,  and a motor  200 .  
      The housing  220  includes a receptacle  221 , which is isolated from the outside by the cover  210 .  
      The forward rotation switch  230  is disposed on the outside of the housing  220 . Turning on the forward rotation switch  230  generates a forward rotation signal, which rotates the motor  200  forward, and delivers the signal to the motor  200  through a connection terminal  201 . Turning off the forward roation switch  230  stops the generation of the forward rotation signal.  
      The reverse rotation switch  240  is disposed on the upper part of where the cover  210  and the housing  220  make contact when the cover  210  covers the housing  220 . A push pin  241 , which turns off the reverse rotation switch  240 , is disposed at a location on the surface of the cover  210  corresponding to the location of the reverse rotation switch  240 . When the cover  210  opens, the cover  210  loses contact with the housing  220 , and subsequently the push pin  241  loses contact with the reverse rotation switch  240 , thereby turning on the reverse rotation switch  240 . Then, a reverse rotation signal, which rotates the motor  200  in the reverse direction, is generated and delivered to the motor  200  through the connection terminal  201 .  
      Here, the push pin  241  can turn off the reverse rotation switch  240  by mechanically pressing the reverse rotation switch  240 . It is also possible to mount a hall sensor on the reverse rotation switch  240  and a magnet on the push pin  241 . The magnet creates a certain intensity of magnetic field, and the hall sensor senses the magnetic field. In other words, when the magnet and the hall sensor become narrower than a predetermined distance, the intensity of the magnetic field increases, and the output of the hall sensor becomes high; when the magnet and the hall sensor become wider than a predetermined distance, the intensity of the magnetic field decreases, and the output of the hall sensor becomes low. Using this, the reverse rotation of the motor can be stopped by making the reverse rotation switch turn off if the output of the hall sensor becomes high.  
      In the present invention, while the cover  210  is opening because the forward rotation swtich  230  is turned on, the reverse rotation switch  240  is turned on also. However, it is preferable that the reverse rotation signal is not generated while the forward rotation signal is generated.  
      The cover  210  and the housing  220  are connected through the hinges  211   a,    211   b.  The hinges  211   a,    211   b  allow the cover  210  to rotate about the hinges  211   a,    211   b.    
      The motor  200  is disposed inside the hinges  211   a,    211   b.  The motor  200  is a DC motor, which is capable of rotating forward and backward or stopping, in accordance with the applied driving signal. The embodiment can further comprise a gear to reduce the speed of the rotation of the motor  200  by a predetermined proportion, making the cover  210  rotate in the A direction only within 360 degrees.  
       FIG. 3  shows perspective views of a case with the cover opened and closed, in accordance with another preferred embodiment of the present invention.  FIG. 4  is an exploded perspective view of the case without the upper housing.  FIG. 5  is an enlarged view of a section of  FIG. 4 .  
      The case illustrated in  FIGS. 3-5  shows an example of a cosmetics case having a first receptacle  322 , for storing cosmetics such as coloring cosmetics or compressed powder, and a drawer  350 , which includes a second receptacle  352  for storing a cosmetic set for use of the above cosmetics. Of course, the present invention is not limited to cosmetic cases and can be applied to any case that requires two receptacles.  
      The case comprises a cover  310 , a upper housing  320   a,  a lower housing  320   b,  a drawer  350 , hinges  311   a,    311   b,  and a reverse rotation switch  340 .  
      The upper housing  320   a  includes the first receptacle  322  and is in direct contact with the cover  310 . The reverse rotation switch  340  and a push pin  341  can be disposed on the upper housing  320   a  and the cover  310 , respectively.  
      The lower housing  320   b  supports the upper housing  320   a,  and houses the drawer  350 , which includes the second receptacle  352 , between the upper housing  320   a  and the lower housing  320   b.  A guide rail  356  is disposed on the bottom surface of the lower housing  320   b  such that the drawer  350  can be slid out in the C direction, as illustrated in  FIG. 3 .  
      The drawer  350  included the second receptacle  352  and can be drawn out in the C direction through a groove disposed on one side that is open when the upper housing  320   a  and the lower housing  320   b  are coupled. The drawer is drawn out in a sliding method in order to protect the contents in the second receptacle  352  from a sudden projection. For this, the drawer  350  has a transfer roller  354  (refer to  FIG. 4 ) engaged with the guide rail  356  disposed on the bottom surface of the lower housing  320   b.    
      The drawer  350  has a fixed groove (not illustrated), to which a fixed hook  332  is engaged, such that the drawer  350  is not drawn out unless it is necessary. However, if a main switch  330 , which is integrated in the fixed hook  332 , is pressed to the inside of the lower housing  320   b,  the fixed hook  332  departs from the fixed groove of the drawer  350 , thereby projecting the drawer  350  to the outside. The drawing of the drawer  350  can be driven by either the gravity or the elasticity of a spring.  
      When the drawer  350  is fixed by the fixed hook  332  and thus not drawn out, the drawer keeps the forward rotation switch  331  pressed. The pressing operation turns off the forward rotation switch  331 , and therefore the forward rotation signal is not generated. However, if the drawer  350  is drawn out to the outside by pressing the main switch  330 , the pressure on the forward rotation switch applied by the drawer becomes released, and the forward rotation switch  331  is turned on. This subsequently generates a forward rotation signal and rotates the motor  300  disposed inside the hinges  311   a,    311   b  in the forward direction along with the projection of the drawer  350 .  
      The main switch  330  is connected to a fixed block  334 , disposed on the lower housing  320   b,  through a spring  333  such that it returns to the original position when the external pressure is removed. Thus, the fixed hook  332 , integrated in the main switch  330 , also returns to the original position, and fixes the drawer  350  by engaging the fixed hook  332  in the fixed groove of the drawer  350  when the drawer  350  is later inserted.  
      The forward rotation switch  331  is disposed inside the lower housing  320   b,  and is turned off when it is pressed by the drawer  350 . When the drawer  350  is ejected, the pressure is removed, and subsequently the forward rotation switch  331  is turned on. Turning on the forward rotation switch  331  generates a forward rotation signal, which rotates the motor  300  in the forward direction, and delivers the signal to the motor  300  through a connection terminal. When the forward rotation switch  331  is turned off, the generation of the forward rotation signal is stopped.  
      The reverse rotation switch  340  is disposed at a location on the upper housing  320   a  where the cover  310  and the upper housing  320   a  make contact when the cover  310  covers the upper housing  320   a.  The push pin  341 , which turns off the reverse rotation switch  340 , is disposed on the surface of the cover  310  corresponding to the location of the reverse rotation switch  340 . When the cover  310  opens, the reverse rotation switch  340  loses contact with the upper housing  320   a,  and subsequently the push pin  341  loses contact with the reverse rotation switch  340 , thereby turning on the reverser rotation switch  340 . Then, a reverse rotation signal, which turns the motor  300  in the reverse direction, is generated and delivered to the motor  300  through the connection terminal.  
      Here, the push pin  341  can turn off the reverse rotation switch  340  by mechanically pressing the reverse rotation switch  340 . It is also possible to mount a hall sensor on the reverse rotation switch  340  and a magnet on the push pin  341 . The magnet creates a certain intensity of magnetic field, and the hall sensor senses the magnetic field. In other words, when the magnet and the hall sensor become narrower than a predetermined distance, the intensity of the magnetic field increases, and the output of the hall sensor becomes high; when the magnet and the hall sensor become wider than a predetermined distance, the intensity of the magnetic field decreases, and the output of the hall sensor becomes low. Using this, the reverse rotation of the motor  300  can be stopped by making the reverse rotation switch  340  turn off if the output of the hall sensor becomes high.  
      In the present invention, while the cover  310  is opening because the forward rotation swtich  331  is turned on, the reverse rotation switch  340  is turned on also. However, it is preferable that the reverse rotation signal is not generated while the forward rotation signal is generated.  
      The cover  310  and upper housing  320   a  or the upper housing  320   a  and lower housing  320   b  are combined through the hinges  311   a,    311   b  such that the cover  310  can be rotated in the B direction (as shown in  FIG. 3 ( a )).  
      The motor  300  is disposed inside the hinges  311   a,    311   b.  The motor  300  is a DC motor, which is capable of rotating forward and backward or stopping, in accordance with the applied driving signal. The embodiment can further comprise a gear to reduce the speed of the rotation of the motor  300  by a predetermined proportion, making the cover  310  rotate in the B direction only within 360 degrees.  
      Hereinafter, a case cover rotation control circuit for driving the motor  200 ,  300  by the forward rotation switch  230 ,  331  and the reverse rotation switch  240 ,  340  will be described.  
       FIG. 6  is a schematic of a case cover rotation control circuit in accordance with a preferred embodiment of the present invention.  FIG. 7  is a diagram showing a method of the sensor PCB inside the motor for sensing the complete opening of the cover.  
      Referring to  FIG. 6 , the circuit comprises a motor  300 , a sensor PCB  610  inside the motor  300 , an open signal generating unit  620 , a forward rotation switch  230 ,  331 , a reverse rotation switch  240 ,  340 , driving units  650   a,    650   b,  and a buffer  660 .  
      The buffer  660  generates a forward rotation signal or a reverse rotation signal, depending on the turn on/off of the forward rotation switch  230 ,  331  and reverse rotation switch  240 ,  340 .  
      The driving units  650   a,    650   b  are connected to the buffer to receive the forward rotation signal or the reverse rotation signal, and rotate the motor in the forward direction or reverse direction accordingly.  
      The operating principle of the case cover control circuit is as follows:  
      The operation mode of the forward rotation switch  331  and the reverse rotation switch  340  is shown in Table 1, and the operation mode of the buffer  660  is shown in Table 2, indicating the signal at the sensor PCB  610  inside the motor  300 .  
                           TABLE 1                                   Forward rotation   Reverse rotation           switch   switch                                                        Switch is pressed   OPEN   OPEN           Switch is not pressed   SHORT   SHORT                      
 
      Here, OPEN means turning on the switch, and SHORT means turning off the switch.  
                       TABLE 2                       INPUT(A)   OUTPUT(Y)   CONTROL(C)                  X   OPEN   H       L   L   L       H   H   L                  
 
      Here, H refers to “high”, L refers to “low”, and X refers to “irrelevant.” The output for the input is provided from the buffer  660  when the control signal is L.  
                           TABLE 3                                      Case remains closed   L           Case opens   L           Case is completely opened   H           Case closes   L           Case is completely closed   L                      
 
      Here, the motor  300  operates in accordance with the input signal (i.e. forward rotation signal) from Y 0  and Y 1  (forward operation) or the input signal (i.e. reverse rotation signal) from Y 2  and Y 3  (reverse operation) of the buffer  660 . It is not possible to operate in the forward direction and in the reverse direction simultaneously through the signal operation of the buffer  660 , but it is possible to operate neither in the forward direction nor in the reverse direction simultaneously.  
      Hereinafter, the operating principle of the case with a dual receptacle structure, shown in  FIG. 3 , will be described.  
      When the cover  310  remains closed, the drawer  350  is inserted between the upper housing  320   a  and the lower housing  320   b.  At this time, structurally, the drawer  350  is made to press the forward rotation switch  331 , which becomes an OPEN state. Since the forward rotation switch  331  is in an OPEN state, an H signal is inputted to the C 0  pin of the buffer  660 , making the buffer not operate. Thereby, the buffer  660  does not generate a forward rotation signal, and the motor  300  does not rotate in the forward direction. Besides, since the cover  310  is closed, and the push pin  341  is pressing the reverse rotation switch  340 , the reverse rotation switch  340  is in an OPEN state, thereby not generating a reverse rotation signal and not rotating the motor  300  in the reverse direction. Therefore, when the cover  310  is closed, the motor  300  is in a stopped state, without any operation.  
      When the cover  310  opens, the operation is as follows:  
      In order to open the cover  310 , the main switch  330  must be pressed. When the main switch  330  is pressed, the drawer  350 , which has been structurally fixed by the fixed hook  332 , is ejected from the case along the guide rail  356 . As the drawer  350  is ejected front the case, the forward rotation switch  331 , which has been pressed, becomes open, and the circuit becomes SHORT. By this, an L signal is inputted to the C 0  pin and C 1  pin of the buffer  660 , and a forward rotation signal is applied to the first driving unit  650   a,  rotating the motor  300  in the forward direction. That is, as the forward rotation switch  331  becomes short, the motor  300  operates, and the cover  310  gets to open. When the cover  310  gets to open, the reverse rotation switch  340 , which has been pressed, is no longer pressed, becoming short. However, since an H signal is inputted to the C 2  and C 3  pins of the buffer  660 , a reverse rotation signal is not applied to the second driving unit  650   b,  not rotating the motor  300  in the reverse direction.  
      When the cover  310  is completely opened, the operation is as follows:  
      Referring to  FIG. 7 , the open state of the cover can be detected because of the cover open state sensing unit inside the motor  300 . The cover open state sensing unit comprises a sensor PCB  610 , in which a part is grounded, an open voltage source  720 , having an open voltage (3V in the present embodiment), and a conductive arm  710 . The sensor PCB  610  sends out an H signal (OPEN signal) when an open voltage is applied to a certain location, and sends out an L signal otherwise. The conductive arm  710 , made of a conductive material, is disposed on the axle of the motor  300 , rotating according to the rotation of the motor  300 . Preferably, it can be a brush inside the motor  300 . In case the cover  310  is open by the angle that the user desires, the conductive arm  710  connects a certain location of the sensor PCB  610  and the open voltage source  720 , applying the open voltage to the certain location of the sensor PCB  610 . When the sensor PCB  610  sends out an H signal, which is a stop signal of the motor  300 , the motor  300  stops its forward rotation and comes to a halt.  
      When the cover  310  closes, the operation is as follows:  
      In order to close the cover  310 , the drawer  350  is inserted into the case. When the drawer  350  is inserted all the way in the case, the drawer  350  presses the forward rotation switch  331 . This makes the forward rotation switch  331  become an OPEN state. At this time, since the reverse switch  340  is in a SHORT state, an L signal is inputted to the C 2  and C 3  pins of the buffer  660 , generating a reverse rotation signal, which is then applied to the second driving unit  650   b.  The second driving unit  650   b  rotates the motor  300  in the reverse direction according to the applied reverse rotation signal.  
      When the cover  310  is completely closed, the operation is as follows:  
      As the cover  310  is completely closed, the push pin  341  of the cover  341  presses the reverse rotation switch  340 , making the reverse rotation switch  340  become an OPEN state. Since both the forward rotation switch  331  and the reverse rotation switch  340  are in an OPEN state, an H signal is applied to the control pins (C 0 , C 1 , C 2 , and C 3  pins) of the buffer  660 , immobilizing the buffer  660 . By this, the input signal to the motor  300  is cut off, and the motor  300  stops its reverse rotation and comes to a halt.  
      As illustrated in  FIG. 7 , the first driving unit  650   a  and the second driving unit  650   b  can be separately disposed to apply a forward rotation signal or a reverse rotation signal in order to rotate the motor in the forward or reverse direction. However, it is also possible to use an H-bridge circuit.  
       FIG. 8  is a case cover rotation control circuit using an H-bridge circuit in accordance with another preferred embodiment of the present invention.  
      Referring to  FIG. 8 , each transistor (TR 1 , TR 2 , TR 3 , TR 4 ) connected to the motor works as a kind of switch. Referring to the truth table of  FIG. 8 , when an H signal is applied to A and D, and an L signal to the rest, TR 1  and TR 4  become conductive, making the motor rotate in the forward direction. When an H signal is applied to B and C, and an L signal to the rest, TR 2  and TR 3  become conductive, making the motor rotate in the reverse direction. When an H signal is applied to A and B or to C and D, the motor stops. Here, each transistor can be a field effect transistor.  
      Although the operation of the case cover rotation control circuit of the case with a dual receptacle structure, shown in  FIG. 3 , has been described, it should be evident that the same description can be applied to the case shown in  FIG. 2 .  
       FIGS. 9-10  are flowcharts of a method for controlling the case cover rotation in accordance with a preferred embodiment of the present invention.  
      Referring to  FIG. 9 , the forward rotation switch  331  is structurally pressed, in step S 905 , to become an OPEN state, which is a turn-on state. In step S 910 , the buffer  660  generates a forward rotation signal and delivers to the first driving unit  650   a.  In step S 915 , the first driving unit  650   a  rotates the motor  300  in the forward direction in accordance with the inputted forward rotation signal. In step S 920 , the cover  310 , which is connected to the axle of the motor, opens in accordance with the forward rotation of the motor  300 .  
      In S 925 , an open signal about whether the cover open state sensing unit has detected the opening of the cover  310  to a certain angle is generated, through which it is determined whether the buffer  660  has generated a stop signal. If a stop signal is not sensed, steps S 915 -S 925  are repeated. If a stop signal is sensed, the motor  300 , which is rotating in the forward direction, is stopped in step S 930 .  
      Referring to  FIG. 10 , as the cover  310  opens in step S 920  of the above steps, the reverse rotation switch  340  opens and becomes a SHORT state, and this causes the reverse rotation switch  340  to turn on, in step S 1005 . In step S 1010 , inserting the drawer  350  presses the forward rotation switch  331 , and this causes the forward rotation switch  331  to turn off. In step S 1015 , the buffer  660  generates a reverse rotation signal because the forward rotation switch  331  is turned off and the reverse rotation switch  340  is turned on.  
      In step S 1020 , the second driving unit  650   b  senses the reverse rotation signal from the buffer  660  and rotates the motor  300  in the reverse direction. In step S 1025 , the cover  310  rotates and closes in accordance with the reverse rotation of the motor  300 .  
      In step S 1030 , when the cover  310  is completely closed on the upper housing  320   a,  the pushi pin  341  presses the reverse rotation switch  340 , turning off the reverse rotation switch  340 . Therefore, it is determined whether the cover  310  is completely closed by checking the turn-off state of the reverse rotation switch  340 .  
      If it is determined that the reverse rotation switch  340  is not turned off, the motor  300  continues its reverse rotation because it means that the cover  300  is still not completely closed. However, if it is determined that the reverse rotation switch  340  is turned off, the reverse rotation of the motor  300  is stopped because it means that the cover  300  is completely closed.  
      As described above, the case module and the controlling method thereof in accordance with the present invention control the forward rotation and the reverse rotation of the DC motor and have the cover open and close according to the rotation of the DC motor by use of the driving circuit such that the inconvenience of having to manually open and close the cover is eliminated.  
      Since a simple circuit is used to control the rotational direction of the DC motor, thereby opening and closing the cover, it is possible to apply the present invention to a product such as a cosmetics case, which, unlike mobile telephones, does not use a microcomputer.  
      Although the preferred embodiments of the present invention have been described, anyone of ordinary skill in the art to which the invention pertains should be able to understand that a very large number of permutations are possible within the spirit and scope of the present invention.