Abstract:
An electronic apparatus includes a card slot into which a card-shaped expansion device is inserted. A connector connects with the expansion device inserted in the card slot. A slide mechanism slides the connector in the card slot in an insertion direction and a pull direction of the expansion device, holds the connector in a first position in which the expansion device projects from the card slot, and holds the connector in a second position in which the expansion device projects less from the card slot than in the first position. A control circuit is provided to control the expansion device connected to the connector in accordance with a position into which the connector is slid.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2002-253067, filed Aug. 30, 2002.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an electronic apparatus having a card slot into which a card-shaped expansion device is inserted, and a control method of the expansion device.  
           [0004]    2. Description of the Related Art  
           [0005]    In an electronic apparatus having a card slot into which a card-shaped expansion device (hereinafter referred to as the expansion card) is inserted, various techniques have been developed for wireless network connection by use of the expansion card (e.g., refer to Japanese Patent Application KOKAI Publication No. 2002-91709).  
           [0006]    The expansion card having this kind of wireless functionality generally has such a card shape that a portion of the card projects from the card slot when the expansion card is inserted into the card slot, and a wireless antenna is built in the projecting portion. Such a configuration realizes the efficient wireless function by which emission characteristics of the wireless antenna can be fully achieved.  
           [0007]    In this structure, however, the expansion card having the built-in wireless antenna is always used in a state where the portion projects from the card slot. Therefore, in a notebook-type personal computer, PDA, or the like that is especially easy to carry, the projecting portion of the expansion card is easily subjected to an external force such as impact or pressure, which can easily lead to not only damage in the expansion card, but also damage in a main unit of the apparatus.  
         BRIEF SUMMARY OF THE INVENTION  
         [0008]    According to an aspect of the present invention, an electronic apparatus capable of realizing a wireless function by use of an expansion card and a control method of the expansion device are provided that can maintain a stable wireless communication operation without causing, for example, damage in the card or damage in a main unit of the apparatus.  
           [0009]    Specifically, according to one aspect of the present invention, the expansion card can be continuously used in each of card slot positions of a state where a portion of the expansion card projects from a card slot and a state where the expansion card is entirely inserted in the card slot, and an operation of a specific circuit in the expansion card can variably be controlled in accordance with the position in which the expansion card is used. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0010]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.  
         [0011]    [0011]FIG. 1 is a block diagram showing a configuration of essential parts of an electronic apparatus in a first embodiment of the present invention;  
         [0012]    [0012]FIG. 2 is a perspective view showing an external configuration of the electronic apparatus according to the first embodiment;  
         [0013]    [0013]FIG. 3A and FIG. 3B are diagrams showing a configuration of a slide mechanism and an insertion state of an expansion card according to the first embodiment;  
         [0014]    [0014]FIG. 4A and FIG. 4B are diagrams describing the operation of the first embodiment;  
         [0015]    [0015]FIG. 5A to FIG. 5C are diagrams describing the operation of the first embodiment; and  
         [0016]    [0016]FIG. 6A to FIG. 6D are diagrams describing an operation of a second embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0017]    Embodiments of the present invention will be described below in reference to the drawings.  
         [0018]    [0018]FIG. 1 is a block diagram showing a configuration of essential parts of an electronic apparatus according to a first embodiment of the present invention.  
         [0019]    A main unit of the electronic apparatus comprises a connector  100  for card connection (hereinafter, referred to as a “connector  100 ”) which performs a connection with an expansion card (e.g., a secure digital card, or “SD-Card”)  20  inserted in a card slot  30 , and a slide mechanism which slidably holds the connector  100  in the card slot  30  and holds it at a first position (P 1 ) and a second position (P 0 ), respectively. A configuration of the slide mechanism will be described later in reference to FIG. 3A and FIG. 3B. In the first embodiment, the first position (P 1 ) will be referred to as a position P 1 , and the second position (P 0 ) will be referred to as a position P 0 .  
         [0020]    Furthermore, the main unit of the apparatus comprises a detector  101  which detects the position (P 1 , or P 0 ) of the connector  100  in the card slot  30 , a controller  102  which controls transmission power of a power amplifier  202  in a wireless unit  201  built in the expansion card  20  on the basis of a detection signal (position detection signal) from the detector  101 , a ROM  103  which stores control information used by the controller  102 , and the like. In the first embodiment, a set value of the transmission power corresponding to the position of the connector  100  is stored in the ROM  103 .  
         [0021]    Furthermore, the expansion card (SD-Card)  20 , which is inserted in the card slot  30  and configures an expansion device, is inserted into the card slot  30 . The expansion card  20  has such a size and a shape that the rear end portion thereof projects from an opening of the card slot  30  to a predetermined extent when the connector  100  is held at the position P 1 . A wireless antenna module (ANT)  203 , which transmits a power-amplified wireless signal of the power amplifier  202  provided in the wireless unit  201 , is built in the rear end portion of the expansion card  20 .  
         [0022]    [0022]FIG. 2 is a perspective view showing an external configuration of the electronic apparatus according to the first embodiment, and shows a portable type personal computer as an example. In the configuration shown in FIG. 2, the main unit of the apparatus (main unit of the personal computer)  10  has a base case  11  and a display unit case  12 . The base case  11  comprises a keyboard  15 , a power source switch  16 , a circuit board (not shown) on which a CPU is mounted, and the like. The display unit case  12  is rotatably held by the base case  11  via hinge portions  14   a ,  14   b.    
         [0023]    The display unit case  12  comprises an LCD panel  13  and the card slot  30  to insert the expansion card  20  shown in FIG. 1. In the embodiment shown in FIG. 2, the display unit case  12  comprises the card slot  30  to insert the expansion card  20  shown in FIG. 1 at its free end backside portion. FIG. 2 shows an insertion state of the inserted expansion card  20  when the connector  100  is held at the position P 1  shown in FIG. 1.  
         [0024]    [0024]FIG. 3A and FIG. 3B are diagrams showing a configuration of a slide mechanism which slidably holds the connector  100  in the card slot  30  and holds it at the position P 1  and position P 0 , respectively, and showing an insertion state of the inserted expansion card  20  at the respective positions P 1 , P 0  in the first embodiment. FIG. 3A is a diagram showing an inserted state of the expansion card  20  when the connector  100  is held at the position P 1 . FIG. 3B is a diagram showing an inserted state of the expansion card  20  when the connector  100  is held at the position P 0 .  
         [0025]    In the embodiment shown in FIG. 3A and FIG. 3B, the slide mechanism of the connector  100  is configured by a push-push type switch which comprises an eject button  32  and a returning spring  303  to switch the position in two steps.  
         [0026]    In the slide mechanism of the connector  100  using the push-push type switch, the connector  100  in the card slot  30  is switched to the position P 1  and position P 0  alternately every time the expansion card  20  inserted in the card slot  30  is pressed in an insertion direction.  
         [0027]    [0027]FIG. 4A to FIG. 5C are diagrams each describing the operation in the first embodiment.  
         [0028]    [0028]FIG. 4A is a diagram showing an insertion state of the expansion card  20  when the connector  100  is held at the position P 1 . FIG. 4B is a diagram showing an insertion state of the card slot  30  when the connector  100  is held at the position P 0 . The expansion card  20  at the position P 0  projects outwardly from the opening of the card slot  30  less than the expansion card at position P 1 . According to one embodiment of the present invention, the expansion card  20  projects outwardly by about 5 mm from the opening of the card slot  30 . The expansion card  20  in position P 0  may project outwardly from the opening of the card slot  30 , be flush with the opening of the card slot  30 , or even be inward of the opening of the card slot  30  while still maintaining an active transmission state.  
         [0029]    [0029]FIG. 5A is a diagram showing an insertion state of the expansion card  20  when the connector  100  is held at the position P 1 . FIG. 5B is a diagram showing an insertion state of the card slot  30  when the connector  100  is held at the position P 0 . FIG. 5C is a graph showing a variable state of a transmission output from the wireless unit  201  in the state of FIG. 5A where the connector  100  is held at the position P 1  and in the state of FIG. 5B where it is held at the position P 0 . Similarly to FIG. 4B above, the expansion card  20  at the position P 0  of FIG. 5B projects outwardly from the opening of the card slot  30  less than the expansion card at position P 1  of FIG. 5A. According to one embodiment of the present invention, the expansion card  20  projects outwardly by about 5 mm from the opening of the card slot  30 . The expansion card  20  in position P 0  may project outwardly from the opening of the card slot  30 , be flush with the opening of the card slot  30 , or even be inward of the opening of the card slot  30  while still maintaining an active transmission state. A transmission output (PB) when the connector  100  is held at the position P 0  is increased as compared with a transmission output (PA) when it is held at the position P 1 . This increase compensates for attenuation of a transmission electric wave emitted from the wireless antenna module (ANT)  203  to the external of the apparatus when the wireless antenna module (ANT)  203  is housed in the card slot  30 .  
         [0030]    Here, the operation in the first embodiment of the present invention will be described in reference to FIG. 1 to FIG. 5C.  
         [0031]    When the expansion card  20  is inserted into the card slot  30  provided at the free end backside portion of the display unit case  12  shown in FIG. 2, the connector  100  is held at the position P 1  at a first insertion step by the function of the slide mechanism shown in FIG. 3A and FIG. 3B. FIG. 2 to FIG. 5A show insertion states of the expansion card  20 . In this case, the wireless antenna module (ANT)  203  built in the rear end portion in an insertion direction of the expansion card  20  projects from the card slot  30 . As a result, the transmission electric wave emitted from the wireless antenna module (ANT)  203  to the external of the apparatus is in a state hardly influenced by a shielding function of the apparatus case.  
         [0032]    The position P 1  of the connector  100  in the card slot  30  is detected by the detector  101  and then the controller  102  is informed thereof.  
         [0033]    On receipt of a position detection signal from the detector  101 , the controller  102  controls the transmission power of the power amplifier  202  provided in the wireless unit  201  of the expansion card  20  in accordance with the position indicated by the detection signal. In other words, on receipt of a position detection signal from the detector  101  indicating that the connector  100  is at the position P 1 , the controller  102  refers to information indicating the set value of the transmission power for each position (P 1 , P 0 ) stored in the ROM  103 , and variably controls the transmission power of the power amplifier  202 . Here, since the position detection signal indicating that the connector  100  is at the position P 1  is received, the transmission output (transmission power) of the power amplifier  202  is controlled to be on the low transmission output level (PA) shown in FIG. 5C.  
         [0034]    If the expansion card  20  is further pressed along an insertion direction in a state where the expansion card  20  is inserted in the card slot  30 , the connector  100  is held at the position P 0  at a next insertion step by the function of the slide mechanism shown in FIG. 3A and FIG. 3B. FIG. 3A to FIG. 5B show insertion states of the expansion card  20 . In this case, the wireless antenna module (ANT)  203  built in the rear end portion in an insertion direction of the expansion card  20  is housed in the card slot  30 , which provides a state where the transmission electric wave emitted from the wireless antenna module (ANT)  203  to the external of the apparatus is attenuated by a shielding function of the apparatus case.  
         [0035]    The position P 0  of the connector  100  in the card slot  30  is detected by the detector  101  and then the controller  102  is informed thereof.  
         [0036]    On receipt of a position detection signal from the detector  101  indicating that the connector  100  is at the position P 0 , the controller  102  refers to the information indicating the set value of the transmission power for each position (P 1 , P 0 ) stored in the ROM  103 , and variably controls the transmission power of the power amplifier  202 . Here, since the position detection signal indicating that the connector  100  is at the position P 0  is received, the transmission output (transmission power) of the power amplifier  202  is controlled to be on the high transmission output level (PB) shown in FIG. 5C.  
         [0037]    As described above, as a function for control of the transmission power is provided to variably control the transmission power in accordance with the inserted position of the card, a stable communication operation can be maintained both in a state where the antenna portion of the expansion card  20  projects from the card slot  30  and in a state where the expansion card  20  is entirely inserted in the card slot  30 .  
         [0038]    A second embodiment of the present invention will be described in reference to FIG. 6A to FIG. 6D. The transmission power is controlled in accordance with the two positions of the connector  100  in the first embodiment, whereas the transmission power can be controlled in accordance with three positions (P 1 , P 0 , Pn) of the connector  100  in the second embodiment. In this case, instead of the push-push type switch to switch the position in two steps in the first embodiment, a push-push type switch to sequentially switch the position in three steps is used to configure the slide mechanism of the connector  100 .  
         [0039]    The second embodiment is particularly different from the first embodiment in that if the expansion card  20  is further pressed in an insertion direction in a state where the connector  100  in a card slot  30  for card connection is at the position P 0  shown in FIG. 6B (e.g., a state where the rear end in an insertion direction of the expansion card  20  projects from the card slot  30  by 5 mm), the connector  100  is held at the position Pn shown in FIG. 6C. In this case, the expansion card  20  is entirely housed in the card slot  30 .  
         [0040]    On receipt of a position detection signal from the detector  101  indicating that the connector  100  is at the position Pn, the controller  102  controls to shut off the transmission output (transmission power) of the power amplifier  202  as shown in FIG. 6C.  
         [0041]    Furthermore, in this case, the controller  102  cuts off unnecessary power supplies of the wireless unit  201  at the same time in predetermined order of control, and instead of this, activates a wired LAN, for example, thereby also enabling switching control from a wireless network to a wired network.  
         [0042]    The transmission power in the expansion card is variably controlled in accordance with the stepwise insertion positions into the card slot in the configuration taken as an example in the above embodiments, which is not limited to this. For example, in an expansion card equipped with a Bluetooth wireless function, wireless LAN card or the like, not only the transmission power but also an amplification degree of a received signal (high frequency signal) may be controlled together. Alternatively, the present invention may be applied to a memory card using an SD card, smart media or the like, or may be applied to stepwise use limitation by a multifunction card or the like, or to stepwise switch of a function, for example.  
         [0043]    According to the embodiments of the present invention, in an electronic apparatus capable of realizing wireless functionality by use of, for example, the expansion card, a stable wireless communication operation can be maintained without causing, for example, damage in the card or damage in the main unit of the apparatus.  
         [0044]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general invention concept as defined by the appended claims and their equivalents.