Abstract:
The invention relates to a back cover for an electronic device and a method for retaining and locking a detachable electronic unit in an internal compartment of an electronic device. The invention relates to a electronic device comprising an internal compartment for retaining a detachable unit; a back cover for closing said internal compartment and covering the unit; and electronic contacts for establishing an electrical connection with said unit. Said back cover comprises a guiding means for pushing and holding said unit against said contacts and for securing said electrical connection. Said guiding means and said contacts are dimensioned to press the unit between said guiding means and said contacts with a force adequate for securing said electrical connection while said back cover is closed.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The invention relates to means for securing an electronic unit, e.g. a battery pack or a memory card, into operating position and enabling easy insertion and detachment of the unit.  
           [0002]    Internal batteries in are traditionally used in portable communication units, such as Nokia™ mobile phones 3210 and 8850 or Motorola™ mobile phones cd920 and L7089. The Nokia™ 3210 mobile phone has holding means located mainly on the battery and protruding parts that project into slots in the battery compartment. One of these protruding parts can be depressed to release the battery from the battery compartment.  
           [0003]    The Nokia™ 8850, Motorola™ cd920 and L7089 mobile phones all have batteries that are squeezed into the battery compartment and pressed in a holding position in the battery compartment by resilient battery contacts. The battery contacts are depressed, establishing a pressure on the battery when the battery is placed into the battery compartment. The Motorola™ cd920 mobile phone has two slots at one end of the battery and another slot at the other end of the battery, wherein protruding parts from the battery compartment project outwards. The Motorola™ L7089 mobile phone has two protruding parts at each end of the battery, said protruding parts projecting into slots in the battery compartment. The Nokia™ 8850 mobile phone has two slots at one end of the battery, wherein the protruding parts projects from the battery compartment.  
           [0004]    Prior art battery locks are arranged to lock the battery pack in place in the battery compartment for avoiding dropping or unintentional releasing of the battery while the back cover is not in position. The battery lock may be arranged to hold the battery in the compartment loosely without pressing the battery against the battery contacts.  
           [0005]    Alternatively, pressing may be effected by resilient contacts and/or spring elements between which the battery is held.  
         SUMMARY OF THE INVENTION  
         [0006]    An object of the present invention is to provide an electronic device as set forth in the preamble of claim 1. According to the claimed invention this objective is obtained by an electronic device characterized in what is presented in the characterizing part of claim 1.  
           [0007]    Another object of the present invention is to provide a back cover for an electronic device as set forth in the preamble of claim 8. According to the claimed invention this objective is obtained by a back cover characterized in what is presented in the characterizing part of claim 8.  
           [0008]    Yet another objective of the claimed invention is to provide a method for holding and locking a detachable electronic unit as set forth in the preamble of claim 11. According to the claimed invention this objective is obtained by a method characterized in what is presented in the characterizing part of claim 11.  
           [0009]    With the invention, considerable advantages are achieved, particularly during manual insertion, and detachment of the battery. The need for tight fastening and accurate positioning by the user is eliminated, wherein the guide means, e.g. a protruding wedge means, is dimensioned to guide and squeeze the unit into the correct place. The wedge means are situated in the separate back cover of the electrical device, e.g. a communication unit, and arranged to press the battery or the memory card in a reliable manner against the electronic contacts of the compartment when closing the cover. Pressing force is not needed upon opening the back cover, wherein the loose detachable unit is easy to remove. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    In the following, the present invention will be described in more detail with reference to the appended drawings, in which  
         [0011]    [0011]FIG. 1 shows, in a perspective view, a prior art communication unit, seen from above,  
         [0012]    [0012]FIG. 2 shows, in a perspective view, the communication unit according to FIG. 1, seen from below,  
         [0013]    [0013]FIG. 3 schematically shows the essential parts of a telephone for communication with a cellular network,  
         [0014]    [0014]FIG. 4 shows a communication unit where a removable back cover has been removed, with an internal battery in operative position,  
         [0015]    [0015]FIG. 5 shows a communication unit where a removable cover has been removed, without an internal battery located in operative position,  
         [0016]    [0016]FIG. 6 shows a prior art internal battery, in a perspective view seen from above,  
         [0017]    [0017]FIG. 7 shows, in a perspective view, the internal battery according to FIG. 6, seen from below and,  
         [0018]    [0018]FIG. 8 shows the internal battery and a section of the removable back cover according to the present invention at the point A-A of FIG. 2 of a corresponding communication unit which is arranged according to the present invention,  
         [0019]    [0019]FIG. 9 shows an embodiment of the battery pack according to the present invention in a perspective view seen from above,  
         [0020]    [0020]FIG. 10 shows another embodiment of the battery pack according to the present invention in a perspective view seen from above. 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0021]    According to a first aspect, the communication unit according to the present invention will be described with reference to an electronic device, especially a hand portable phone, preferably a cellular/mobile phone. A prior art phone is shown in FIGS. 1 and 2, where a cellular/mobile phone is shown in a perspective view. As the figures illustrate, the phone is provided with a front cover  2  having a window frame  3  encircling the protection window of a display assembly  1 . The cellular/mobile phone comprises a user interface having an on/off button  4  (shown in FIG. 4), a keypad  7 , a battery  14  (shown in FIG. 4), an internal antenna  24  (shown in FIG. 4), a display/LCD  1 , an earpiece  21  and a microphone  22  (not shown). In FIG. 2, the phone is shown from another perspective, the wherein back cover  13  can be seen. FIG. 2 also shows a release device  23  for releasing the back cover  13  from the rest of the phone, and a horseshoe-shaped edge  12 .  
         [0022]    The keypad  7  has a first group of keys  8  as alphanumeric keys, by means of which the user can for example enter a telephone number, write a text message (SMS), and write a name (associated with the phone number). Each of the twelve alphanumeric keys  8  is provided with a figure “0-9” or a sign “#” or “*”, respectively. In alpha mode, each key is associated with a number of letters and special signs used in text editing.  
         [0023]    The keypad  7  additionally comprises a menu selection key  9 , an up/down key  10 , and a cancel key  11 . The functionality of the menu selection key or NaviKey™  9  depends on the state of the phone. The cancel key  11  is used to delete an input, or cancel the last selection and jump to another menu level.  
         [0024]    [0024]FIG. 3 schematically shows the most important parts of the phone/terminal. The microphone  22  records the user&#39;s speech, and the analogue signals formed thereby are A/D converted in an A/D converter (not shown) before the speech is encoded in an audio part  20 . The encoded speech signal is transferred to the controller  18  (physical layer processor), which for example supports the GSM terminal software. The controller  18  also forms the interface to the peripheral units of the apparatus, including RAM and ROM memories  17   a  and  17   b,  a SIM card  16 , the display  1  and the keypad  7  (shown in FIG. 1) as well as data, power supply, etc. The controller  18  communicates with the transmitter/receiver circuit  19 . The audio part  20  speech-decodes the signal, which is transferred from the controller  18  to the earpiece  21  via a D/A converter (not shown). The controller  18  is connected to the user interface. Thus, the controller  18  monitors the activity in the phone and controls the display  1  in response thereto.  
         [0025]    The phone is adapted for use in connection with the GSM network, but, of course, the invention may also be applied in connection with other telephone networks, such as cellular networks, various cordless telephone systems, or in dual band phones accessing sets of these systems/networks. The invention may also be applied in connection with other electronic devices having internal compartments for detachable electronic units and back covers and using battery packs or extension cards or both. An embodiment of the present invention will be described with reference to the appended FIGS.  4  to  10 .  
         [0026]    [0026]FIG. 4 shows the back side of the communication unit when the removable back cover  13  (shown in FIGS. 1 and 2) is removed and the battery  14  is visible. The figure also shows a SIM card reader  32  that is only accessible when the battery  14  is removed. FIG. 5 shows the back side of the communication unit when the battery  14  removed and the compartment  33  for the battery  14  is visible showing resilient electronic contacts  5  for the battery  14 . An internal compartment for an extension card or a memory card is arranged in a similar manner. The battery compartment  33  forms an integral part of the electronic device. The battery compartment  33  is also provided at one end with protrusions  34  projecting into corresponding recesses  35  (shown in FIG. 4) on the battery  14 , to hold the battery  14  in the operating position in the battery compartment  33 . The protrusions  34  are arranged to prevent the rectangular battery  14  from moving up in a transversal direction in relation to a pressing direction of the battery  14 , which pressing is intended to secure a good electrical contact between the battery contacts  5  and the battery  14 . The up direction refers here to the direction substantially perpendicular to the bottom  33   a  of the compartment  33 . The battery  14  is provided with metallic contact pads  15  for interaction with the corresponding resilient battery contacts  5 . In a preferred embodiment of the invention, the pressing direction and the bottom  33   a  are parallel with each other. The cover  13  is removed by sliding it to the direction of the button  4  over the antenna  24  (the pressing direction) and then lifting the cover  13  up. Latches and grooves on the sides of the device lock the cover  13  in place. In a preferred embodiment of the communication unit according to the present invention, the cover  13  is opened by sliding it to the opposite direction. Thus, the pressing direction and the sliding movement for closing the cover  13  are directed to the same direction. Latches and grooves for locking the cover  13  are arranged accordingly in a way known as such to a one skilled in the art. The other end of the battery compartment  33  comprises a battery lock  30 . The battery lock  30  is provided with taps  36  that project into another set of corresponding recesses  37  on the battery  14  for holding the battery  14  in the operating position in the battery compartment  33 . The taps  36  snap into place upon insertion of the battery  14 .  
         [0027]    [0027]FIG. 5 illustrates the back side of the communication unit when the battery  14  is removed from the battery compartment  33  and in FIGS.  6  to  7  the battery pack  14  is shown separately.  
         [0028]    The battery  14  is removed from the battery compartment  33  by opening the battery lock  30 . By opening, the taps  36  are removed out of the recesses  37  and the battery  14  is released and free to be removed by hand.  
         [0029]    In FIGS. 6 and 7, the battery  14  is shown when it is removed from the battery compartment  33 . The battery  14  is, as mentioned earlier, provided with recesses, or slots  35 ,  37  that interact with protrusions, and taps  34 ,  36  to hold the battery  14  in the battery compartment  33 . Said slots and protrusions in combination prevent the battery  14  from detaching from the battery compartment  33  by any other way than by releasing the battery lock  30 . The battery  14  is usually flat and rectangular, having typically three contact pads  15  for electrical contact with the corresponding battery contacts  5 , which electrical contact is secured with their mutual pressing force. The contact pads  15  are arranged at one end of the battery  14  and on a side wall  28  arranged to be substantially perpendicular in relation to the pressing direction described earlier. The lower side  25  of the battery  14  is placed at the bottom  33   a  of the battery compartment  33 . The contacts  5  are situated on a side wall  33   b  of the battery compartment  33  to interact with the contacts  5 . The protrusions  34  are situated on the same wall  33   b  and the taps  36  are situated on the opposite wall  33   c.    
         [0030]    [0030]FIG. 8 schematically shows the most important parts of a preferred embodiment of the protruding wedge means, said parts being essential to the understanding of the present invention. The wedge means  27 , the back cover  13  and the battery  14  are shown in positions similar to a situation when the battery  14  is held in the battery compartment  33  with the cover  13  in place. The cover  13  and the upper side  26  and the lower side  25  of the battery  14  are substantially parallel with each other.  
         [0031]    The protruding wedge means  27  are arranged to extend from the inner side  13   a  of the cover  13 . The inner side  13   a  faces the battery compartment  33 . The protruding wedge means  27  comprise at least one wedge  27  extending in a transversal direction from the inner side  13   a  into the compartment  33 . The angle of the wedge  27  is about 10 degrees from perpendicular on a side intended to be facing the battery  14 , separate from the cover  13 , and intended to press the battery  14  in the pressing direction towards the contacts  5 . The wedge  27  is angled for effecting a clamping feature while closing the cover  13  for squeezing the battery  14  against the contacts  5 . The angled wedge  27  presses simultaneously the battery  14  slightly against the bottom  33   a.  The loose battery  13  is slidingly driven at the bottom  33   a  towards the contacts  5 . The wedge  27  presses the edge of a side wall of the battery  14 .  
         [0032]    In FIG. 9, on the upper side  26  of the battery  14  may alternatively be arranged one or more notches or recesses  38  into which the wedge  27  intrudes. Advantageously, in the pressing direction, the notch  38  is slightly broader than the wedge  27 . The wedge  27  presses a side wall of the recess  38  for effecting the pressing force. Advantageously, the side wall is parallel to the side wall  28 . While the cover  13  is removably or permanently hinged, the arched closing movement of the cover  13  drives the battery  14  against the contacts  5  even if the wedge  27  is not angled, i.e. the angle is zero degrees. Instead, a side wall of the battery  14  may be angled. The end of a pin-like wedge touches the angled side wall and guides the battery  14  when the cover  13  is lowered. The end of the cover  13  is hingedly attached to the device and the contacts  5  are situated inside the curvature of the arched movement.  
         [0033]    In FIG. 10, in another embodiment of the invention the upper side  26  of the battery  14  is provided with one or more elevated forms  31 . A sliding cover is provided with ribs, protrusions or pins which hit a side of the elevated form and press the battery  14  against the contacts  5  while closing the cover. The cover slides over the battery  14  towards the contacts  5 .  
         [0034]    To align the contacts  5  better with the pads  15  the lateral movevent of the battery  14  may be restricted, for example, by ribs or protruding parts on both sides or on one side of the compartment  33 . The ribs and the protruding parts press against the side walls of the battery  14 . The ribs or the protruding parts may be arranged to hold the battery in place when the cover  13  is not in place. Thus, the protrusions and taps  34 ,  36  may be replaced by the ribs or the protruding parts. The pressing force of the ribs is arranged to keep the battery in place in different postures of the device. The ribs or the protruding parts may also be arranged for avoiding dropping the battery wherein the battery  14  is pressed pass the ribs into the compartment  33 . A tight fitting keeps the battery  14  in place.  
         [0035]    The wedge  27  and the battery contacts  5  are dimensioned to press the battery  14  between said wedge  27  and battery contacts  5  with a force adequate for securing the electrical connection during the use of the device. In the presented embodiment, the wedge  27  interacts with the side of the battery  14  opposite to the pads  15  (a side wall  29 ). The width of the wedge  27  may be varied, and two or more wedges can be arranged in a similar alignment in relation to the battery  14 . The height of the wedge  27  is dimensioned to fit into the compartment  33  or, more preferably, into a recess formed in a side wall  29  of the compartment  33 . The cover  13 , a removable or a hinged cover, attached to the device may move pivotally in relation to the battery  14 , slidingly towards the contacts  5 , and/or in a lowering fashion onto the compartment  33 , while locking into place. In different embodiments of the cover, the wedge  27  is always positioned and dimensioned to be moved with the cover  13  at some stage to a location at the battery  14  for effecting described securing feature. The wedge means  27  form an integral part of the back cover  13  and, being of plastic material, provide resilient clamping feature.  
         [0036]    Electronic devices are often provided with extension card interfaces or card slots for adding a memory storage to the device. Standards define the specifications of these memory cards, such as MultiMediaCard (size 32 mm×24 mm×1,4 mm), Miniature Card (size 38 m×33 mm ×3,5 mm), SmartMedia Card™ (size 45 mm×37 mm×0,76 mm) and CompactFlash™ card (sixe 42,8 mm×36,4×3,3 mm). The memory cards are provided with pin connectors for electrical coupling and they may have contact pads similar to the pads  15  of the battery  14 . The cards are pressed and held against a corresponding connector (the male or the female part of the connector) for securing electrical connection. The movement of the card and the pressing direction are similar to the battery described earlier.  
         [0037]    The lateral movement of the card should often be restricted for aligning the connectors and the pins more precisely. The cover  13  may be provided with other wedges, pins (the cover moving pivotally), bevelled forms (the cover moving slidingly) or other members of the guide means on the underside of the cover  13  for the tranversal alignment of the battery or the card. While closing the cover  13 , the loose electronic unit is guided between two opposite members or between a member and a side wall of the compartment. Said side wall is situated adjacent to the contacts  5 . The method is especially applicable to a unit with contact pads (e.g. the pads  15 ) which allow tranversal movement while in contact with the contacts of the device (e.g. the contacts  5 ).  
         [0038]    The invention is not limited to the above-described examples or to the drawings showing examples of one embodiment, but can be varied within the scope of the appended claims.