Abstract:
A sliding mechanism includes: a slidable intermediate member having first and second guide holes; a first shaft that is slidably inserted into the first guide hole, the first shaft having first and second end portions; a first spring member that is interposed between the first end portion of the first shaft and the slidable intermediate member to urge the slidable intermediate member toward the second end portion of the first shaft; a second shaft that is slidably inserted into the second guide hole, the second shaft having third and fourth end portions, the third end portion being disposed at a position opposite to the first end portion; and a second spring member that is interposed between the third end portion of the second shaft and the slidable intermediate member to urge the slidable intermediate member toward the fourth end portion of the second shaft.

Description:
RELATED APPLICATION(S) 
       [0001]    The present disclosure relates to the subject matters contained in Japanese Patent Application No. 2007-317508 filed on Dec. 7, 2007, which are incorporated herein by reference in its entirety. 
       FIELD 
       [0002]    The present invention relates to a sliding mechanism and a portable electronic device having the sliding mechanism that is reduced in size, the sliding mechanism being provided with a connection cable arranged to connect first and second case  40  of the portable electronic device while allowing the first and second case  40  to slide with each other. 
       BACKGROUND 
       [0003]    A cellular phone having a sliding mechanism that is reduced in size is disclosed in JP-A-2006-333079. The sliding mechanism disclosed in JP-A-2006-333079 is configured that an actuator slides over a shaft. The sliding mechanism has a cylindrical spring is provided on the shaft and imparts resilient force to sliding action of the actuator. The shaft of the sliding mechanism is mounted to a frame of an upper case of the cellular phone, and the actuator of the sliding mechanism is attached to a lower case, whereby the upper case and the lower case slide with each other. The frame needs to have a space to allow the spring and the actuator to slide. 
         [0004]    Another example of such sliding mechanism for a portable equipment is disclosed in JP-A-2006-245347. The sliding mechanism disclosed in JP-A-2006-245347 has a configuration similar to that disclosed in JP-A-2006-333079. 
         [0005]    An example of a cellular phone having a sliding mechanism provided with a flexible substrate as a connection cable between upper and lower cases is disclosed in JP-A-2006-128808. In the sliding mechanism disclosed in JP-A-2006-128808, a bent portion of the flexible substrate moves within the case in conjunction with the sliding action. 
         [0006]    An example of a cellular phone having a sliding mechanism provided with a lead wire as a connection cable between upper and lower cases is disclosed in JP-A-2005-167309. In the configuration disclosed in JP-A-2005-167309, the connection cable located between upper and lower cases is a wire having a sheath made of resin and 30 lead wires being bundled together. A coil spring is used for a spring for urging purpose that slides the upper and lower cases. The connection cable is disposed in a space within the coil spring and bents in accordance with expansion and contraction of the coil spring to be extended and shortened. 
         [0007]    In the sliding mechanism disclosed in JP-A-2006-333079, a slidable distance becomes essentially equal to the length of the shaft. Therefore, in order to acquire a desired slide distance, the length of the shaft needs to be increased, and a frame to which the shaft is to be attached also becomes longer. Hence, there is a problem of a structural limitation being imposed on the upper case on which the frame is mounted. The configuration disclosed in JP-A-2006-245347 also has a similar problem. 
         [0008]    The flexible substrate disclosed in JP-A-2006-128808 is generally formed to be wide, and a bent portion of the substrate is movable in the case. Hence, the movable space needs to be ensured in the case, and there is a problem of difficulty being encountered in designing the case to be small in size. The flexible substrate needs to be movable by an amount corresponding to the slide distance of the case, and a certain degree of high rigidity is required. A lead wire having low rigidity, or the like, has a problem in allowing the lead wire to be extended and shortened in the case by bending the lead wire. 
         [0009]    The configurations disclosed in JP-A-2006-128808 and in JP-A-2005-167306 have a problem of difficulty being encountered in smoothly inserting or withdrawing the connection cable in or from a narrow space in the coil spring that expands or contracts in accordance with the slide distance of the case without being stuck therein. 
       SUMMARY 
       [0010]    According to a first aspect of the invention, there is provided a sliding mechanism for a portable electronic device having a first case and a second case that faces the first case, the sliding mechanism including: a slidable intermediate member having first and second guide holes that are provided to be in parallel with each other; a first shaft that is slidably inserted into the first guide hole, the first shaft having first and second end portions that are to be attached to the first case; a first spring member that is interposed between the first end portion of the first shaft and the slidable intermediate member to urge the slidable intermediate member toward the second end portion of the first shaft; a second shaft that is slidably inserted into the second guide hole, the second shaft having third and fourth end portions that are to be attached to the second case, the third end portion being disposed at a position opposite to a position where the first end portion is disposed; and a second spring member that is interposed between the third end portion of the second shaft and the slidable intermediate member to urge the slidable intermediate member toward the fourth end portion of the second shaft. 
         [0011]    According to a second aspect of the invention, there is provided a portable electronic device including: a first case; a second case that faces the first case; and a sliding mechanism including: a slidable intermediate member having first and second guide holes that are provided to be in parallel with each other; a first shaft that is slidably inserted into the first guide hole, the first shaft having first and second end portions that are attached to the first case; a first spring member that is interposed between the first end portion of the first shaft and the slidable intermediate member to urge the slidable intermediate member toward the second end portion of the first shaft; a second shaft that is slidably inserted into the second guide hole, the second shaft having third and fourth end portions that are attached to the second case, the third end portion being disposed at a position opposite to a position where the first end portion is disposed; and a second spring member that is interposed between the third end portion of the second shaft and the slidable intermediate member to urge the slidable intermediate member toward the fourth end portion of the second shaft. 
         [0012]    According to a third aspect of the invention, there is provided a portable electronic device including: a first case; a second case that faces the first case; a first sliding mechanism; and a second sliding mechanism, wherein the first sliding mechanism includes: a first slidable intermediate member having first and second guide holes that are provided to be in parallel with each other; a first shaft that is slidably inserted into the first guide hole, the first shaft having first and second end portions that are attached to the first case; a first spring member that is interposed between the first end portion of the first shaft and the first slidable intermediate member to urge the first slidable intermediate member toward the second end portion of the first shaft; a second shaft that is slidably inserted into the second guide hole, the second shaft having third and fourth end portions that are attached to the second case, the third end portion being disposed at a position opposite to a position where the first end portion is disposed; and a second spring member that is interposed between the third end portion of the second shaft and the first slidable intermediate member to urge the first slidable intermediate member toward the fourth end portion of the second shaft, and wherein the second sliding mechanism includes: a second slidable intermediate member having third and fourth guide holes that are provided to be in parallel with each other; a third shaft that is slidably inserted into the third guide hole, the third shaft having fifth and sixth end portions that are attached to the first case; and a fourth shaft that is slidably inserted into the fourth guide hole, the fourth shaft having seventh and eighth end portions that are attached to the second case, the seventh end portion being disposed at a position opposite to a position where the fifth end portion is disposed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In the accompanying drawings: 
           [0014]      FIG. 1  is an external perspective view of a portable electronic device and a sliding mechanism according to the present invention; 
           [0015]      FIG. 2  is a perspective drawing to show a front view, a side view, and a bottom view of the portable electronic device according to a first embodiment of the present invention; 
           [0016]      FIG. 3  is perspective drawing to show side views for describing an intermediate state of the portable electronic device according to the first embodiment; 
           [0017]      FIG. 4  is a perspective drawing to show a front view, a side view, and a bottom view of a portable electronic device according to a second embodiment; and 
           [0018]      FIG. 5  is a perspective drawing to show a side view for describing an intermediate state of the portable electronic device according to the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0019]    Embodiments of the present invention will be described with reference to the drawings. 
         [0020]      FIG. 1  is an external perspective view of a portable electronic device and a sliding mechanism according to embodiments of the present invention, showing a state where first case  20  and the second case  40  are slidably opened. An upper part of  FIG. 1  shows an external perspective view of a portable electronic device  100 ; and a lower part of  FIG. 1  shows an external perspective view of a sliding mechanism  50 . The sliding mechanism  50  is incorporated into a space in the portable electronic device  100  indicated by a dotted arrow. The portable electronic device  100  and the sliding mechanism respectively shown in the upper part and lower part of  FIG. 1  differ from each other in terms of a scale. 
         [0021]    The sliding mechanism  50  includes a first shaft  1 , a first end cap (first end portion)  2 , a first spring  3 , a second end cap (second end portion)  4 , a second shaft  5 , a third end cap (third end portion)  6 , a second spring  7 , a fourth end cap (forth end portion)  8 , a slidable intermediate member  9 . The slidable intermediate member  9  is formed with a first guide hole  10  and a second guide hole  11 , which are arranged to be in parallel with each other. 
         [0022]    The first shaft  1  is inserted into the first spring  3  and the first guide hole  10 , and both ends of the first shaft  1  are fixed by the first end cap  2  and the second end cap  4 , respectively. The second shaft  5  is inserted into the second spring  7  and the second guide hole  11 , and both ends of the second shaft are fixed by the third end cap  6  and the fourth end cap  8 . The first shaft  1  and the second shaft  5  are equal in length. 
         [0023]    The first spring  3  and the second spring  7  are coil springs that generate urging force in a direction of extension. Therefore, in the sliding mechanism  50 , the first shaft  1  and the second shaft  5  slide with each other through the intervention of the slidable intermediate member  9  in a direction where the first end cap  2  and the third end cap  6  separate from each other. The first spring  4  and the second spring  5  are identical with each other in terms of a shape and strength. 
         [0024]    The first end cap  2  and the second end cap  4  of the sliding mechanism  50  are attached to the first case  20  of the portable electronic device  100 . The third end cap  6  and the fourth end cap  8  are fixedly attached to the second case  40 . Therefore, the sliding mechanism  50  imparts urging force by means of which the first case  20  and the second case  40  of the portable electronic device  100  slide each other. 
         [0025]    A shock-absorbing member for absorbing an impact resulting from sliding action induced by urging force is provided between the slidable intermediate member  9  and the second end cap  4  so as to fit around the first shaft  1  and between the slidable intermediate member  9  and the fourth end cap  8  so as to fit around the second shaft  5 . The shock-absorbing member is not shown in the drawings. 
         [0026]    The portable electronic device  100  has a structure in which the first case  20  enwraps the second case  40 . A guide projection  25  of the first case  20  and a guide groove  43  of the second case  40  are provided in a sliding direction from a bottom surface of the portable electronic device. The guide projection  25  and the guide groove  43  engage with each other to allow the first case  20  and the second case  40  to slide. 
         [0027]    A speaker  21 , a display section  22 , and a multifunction key  23  are provided on a front face of the first case  20 . A lock key  24  is provided on side faces of the first case  20 . A microphone  41 , and a ten-key  42  are provided on a front face of the second case  40 . 
         [0028]    When the user slides the second case  40  toward the first case  20  against urging force of the sliding mechanism  50  and presses the second case  40  to the end, the first case  20  and the second case  40  are locked together in a closed state by means of an internal lock mechanism (not shown). When the user pressed the lock key  24  while holding the first case  20  in the hand, the lock mechanism is released, whereupon the second case  40  projects by means of the urging force of the sliding mechanism  50 , to thus become an opened state shown in  FIG. 1 . 
       First Embodiment 
       [0029]    A detailed structure of the portable electronic device  100  will now be described. A first embodiment is an example where single set of the sliding mechanism  50  is provided. 
         [0030]      FIG. 2  is a perspective view of a front view, a side view, and a bottom view of the portable electronic device of the first embodiment of the present invention in an opened state. The drawing shows that the portable electronic device is opened and remains stable by means of urging force of the sliding mechanism  50 . The topmost section of  FIG. 2  shows a front view. In order to make explanations easy to comprehend, sections associated with the sliding mechanism  50  and the cable  70  are shown in a perspective manner. The right part in the middle section of  FIG. 2  shows a side view, and the right part of the middle section of  FIG. 2  shows a bottom view. Since difficulty is encountered in providing an explanation when the sliding mechanism  50  and the cable  70  overlap each other when viewed from the side. Hence, sections associated with the sliding mechanism  50  are provided in a perspective manner. The left part of the bottom section of  FIG. 2  shows a side view, and right part of the bottom section of  FIG. 2  shows a bottom view. Sections associated with the cable  70  are shown in a perspective manner. 
         [0031]    Members to be provided on the first case  20 , except the sliding mechanism  50  and the cable  70 , are denoted by the numbers of twenties and thirties. Members to be provided on the second case  40  are denoted by the numbers of forties. 
         [0032]    In addition to the members shown in  FIG. 1 , the first case  20  has a first circuit board  26 , a connector  27 , a first window  28 , a second window  29 , and first attachment parts  30 . In addition to including the members shown in  FIG. 1 , the second case  40  has a second circuit board  44 , a connector  45 , a third window  46 , a fourth window  47 , and second attachment parts  48 . 
         [0033]    The first end cap  2  and the second end cap  4  of the first shaft  1  of the sliding mechanism  50  are attached to the (two) first attachment parts  30  of the first case  20 . The (two) first attachment parts  30  are structured such that the first end cap  2  and the second end cap  4  are fitted into the respective first attachment parts. 
         [0034]    The third end cap  6  and the fourth end cap  8  of the second shaft  5  of the sliding mechanism  50  are attached to the (two) second attachment parts  48  of the second case  40 . The (two) second attachment parts  48  are structured such that the third end cap  6  and the fourth end cap  8  are fitted into the respective second attachment parts. 
         [0035]    The second window  29  and the fourth window  47  are spaces for the slidable intermediate member  9  that runs through the first case  20  and the second case  40 . A distance for movement of the slidable intermediate member  9  that moves in association with sliding action is assured in a sliding direction. 
         [0036]    As a result, the sliding mechanism  50  imparts urging force to the first case  20  and the second case  40 , whereupon the first case  20  and the second case  40  can freely perform sliding motion. 
         [0037]    The cable  70  includes several tens of fine coaxial wires being bound with one another. The cable  70  is used for connection of an electrical signal between the first case  20  and the second case  40  that perform sliding motions. The cable  70  has a characteristic having superior noise resistance and flexibility. The respective ends of the cable  70  are connected to the connector  27  and the connector  45 . 
         [0038]    The speaker  21 , the connector  27 , and a camera imaging unit (not shown) are mounted on the first circuit board  26 . The first circuit board  26  is provided with connectors (not shown) connected to the display section  22  and the multifunction key  23  ( FIG. 1 ). The microphone  41 , the ten-key  42 , the connector  45 , and a controller (not shown), such as a CPU, are mounted on the second circuit board  44 . 
         [0039]    The first window  28  and the third window  46  are spaces for the cable  70  that runs through the first case  20  and the second case  40 . A distance for movement of the cable  70  that moves in association with sliding action is assured in a sliding direction. 
         [0040]      FIG. 3  is a perspective side view of the portable electronic device of the first embodiment in an intermediate state of the slide action. The upper section of  FIG. 3  shows a stable state where the cases of the portable electronic device are opened after having slid by the urging force of the sliding mechanism  50 . The upper section of  FIG. 3  separately shows a perspective view of an associated section of the sliding mechanism  50  and a perspective view of an associated section of the cable  70 , as such shown in  FIG. 2 . The middle section of  FIG. 3  shows a state between an opened state and a closed state, and the slide section does not automatically stay in this state. The bottom section of  FIG. 3  shows a stable state where the sliding mechanism is locked by a lock mechanism (not shown) after having slid and become closed. 
         [0041]    In the opened state shown in the upper section of  FIG. 3 , the first case  20  and the second case  40  remain stable after slid in an opening direction by the urging force exerted in the direction of extension of the first spring  3  and the second spring  7 . In this state, the user slides the second case  40  toward the first case  20  against the urging force of the sliding mechanism  50  and presses the second case  40  into the first case  20 . When the second case  40  is pushed into the end after having passed through an intermediate state shown in the middle section of  FIG. 3 , the first case  20  and the second case  40  transition into a closed state as shown in the bottom section of  FIG. 3 . In this state, the first case  20  and the second case  40  are directly locked together by means of an internal lock mechanism (not shown) and become stable in a closed state. 
         [0042]    In a closed state shown in the bottom section of  FIG. 3 , when the user pressed the lock key  24  while holding the first case  20  in the hand, the lock mechanism is released, whereupon the second case  40  projects by the urging force of the sliding mechanism  50  exerted in the extending direction. After having passed through the intermediate state shown in  FIG. 3B , the second case  40  becomes stable in the opened state shown in the upper section of  FIG. 3 . 
         [0043]    Operation of the slidable intermediate member  9  will now be described. Since the first spring  3  and the second spring  7  are identical with each other in terms of strength and shape, the slidable intermediate member  9  slides so as to stop at an essentially-intermediate position between the first end cap  2  and the third end cap  6  in any of the states shown in  FIG. 3 . 
         [0044]    A distance over which the second case  40  slides with respect to the first case  20  is indicated by L in the drawing. In contrast, a distance over which the slidable intermediate member  9  slides in the first case  20  with respect to the first case  20  is indicated by L/2 in the drawing. Although unillustrated as a distance, the distance over which the slidable intermediate member  9  slides in the second case  40  with respect to the second case  40  is also indicated by the same reference numeral L/2. 
         [0045]    Specifically, in contrast with the slide distance L between the first case  20  and the second case  40 , ensuring the slide distance L/2 of the slidable intermediate member  9  in each of the first case  20  and the second case  40  is the minimum requirement. Specifically, the essential requirement is that each of the first case  20  and the second case  40  should share one-half the slide distance. 
         [0046]    Motion of the cable  70  will be described. The connector  45  moves over the distance L with respect to the connector  27  at one end of the cable  70 . However, the cable  70  assumes a U-turn shape, and hence the movable distance of the U-turn portion requires only one-half of the distance L; namely, L/2. The minimum requirement for the cable  70  is to have a length in the sliding direction over which the cable  70  can move as illustrated and over which the first window  28  and the third window  46  can respond to movement of the U-turn portion of the cable  70 . 
         [0047]    According to the first embodiment, two short shafts, such as the first shaft  1  and the second shaft  5 , are provided when compared with a conventional case of one shaft. The respective shafts are attached in a dispersed manner to the first case  20  and the second case  40 , whereby even the short shafts can provide a comparatively-long slide distance. 
         [0048]    The slide distance of the slidable intermediate member  9  in the respective cases is also dispersed between the cases. The distances of the windows  29  and  47  achieved in the sliding direction for ensuring the movable area can also be shortened and dispersed between the respective cases. Structural constraints on the respective cases and constraints on the cable wire between the cases can also be dispersed. Since the distances of the windows achieved in the sliding direction can be shortened, exposure of the window to the outside can be prevented. 
         [0049]    The first spring  3  and the second spring  7  are springs that generate urging force in the direction of extension. However, they may also be embodied as springs that generate urging force in the direction of contraction; the first spring  3  may be provided between the second end cap  4  of the first shaft  1  and the slidable intermediate member  9 ; and both ends of the first spring  3  may be fixed to them. The second spring  7  may also be provided between the fourth end cap  8  of the second shaft  5  and the slidable intermediate member  9 , and both ends of the second spring  7  may be fixed to them. Alternatively, a spring generating urging force in the direction of extension and a spring generating urging force in the direction of contraction may also be combined together. 
       Second Embodiment 
       [0050]      FIG. 4  is a perspective drawing showing a front view, a side view, and a bottom view of the portable electronic device according to the second embodiment of the present invention in an opened state. A difference between the first and second embodiments lies in that two sets of sliding mechanisms; namely, the first sliding mechanism  50  and a second sliding mechanism  51 , are provided and that the second sliding mechanism  51  is provided integrally with the cable  70 . The upper section in  FIG. 4  shows a front view of the portable electronic device. In order to make explanations easy to comprehend, sections associated with the first sliding mechanism  50 , the second sliding mechanism  51 , and the cable  70  are shown in a perspective manner in  FIG. 4 . 
         [0051]    The left part of the bottom section in  FIG. 4  shows a side view, and the right part of the bottom section in  FIG. 4  shows a bottom view, thereby showing sections associated with the second sliding mechanism  51  and the cable  70  in a perspective manner. In the side view, the fourth shaft  5   a  and the second circuit board  44  overlap each other. In order to make explanations easy to comprehend, the second circuit board  44  is drawn as being shifted intentionally. The side view of the first sliding mechanism  50  is identical with that of the first embodiment, and illustration of the side view is omitted. Elements which are the same as those of the first embodiment are assigned the same reference numerals, and their explanations are omitted. Differences between the embodiments will be described hereunder. 
         [0052]    The portable electronic device according to the second embodiment is provided with the second sliding mechanism  51  in addition to the configuration of the first embodiment. The second sliding mechanism  51  is identical in structure with the first sliding mechanism  50 , and both end caps of the third shaft  1   a  are fixedly fitted into (two) third attachment parts  30   a  of the first case  20 . Both ends of the fourth shaft  5   a  are fixedly fitted into (two) fourth attachment parts  48   a  of the second case  40 . 
         [0053]    A hole  12  into which an intermediate portion of the cable  70  is passed and fixed is formed in a slidable intermediate member  9   a . The intermediate portion of the cable  70  moves along with movement of the slidable intermediate member  9   a . The connector  45  connected to one end of the cable  70  is placed at a position differing from that in the first embodiment. The cable  70  is arranged to be in the shape of an S. 
         [0054]    The first window  28  and the third window  46  are spaces for the slidable intermediate member  9   a  that runs through the first case  20  and the second case  40 . A distance for movement of the slidable intermediate member  9   a  that moves in association with sliding action is assured in a sliding direction. Further, the windows  28  and  46  double also as spaces for the cable  70  that run through the first case  20  and the second case  40 . A distance for movement of the cable  70  that moves in association with sliding action is assured in the sliding direction. 
         [0055]    Since two sets of sliding mechanisms are provided, the strength required to each of the springs is only one-half of that required in the first embodiment, and hence the springs can be reduced in size. 
         [0056]    An intermediate state of the portable electronic device will now be described. 
         [0057]      FIG. 5  is a perspective drawing showing the side view for explaining an intermediate state of the portable electronic device according to the second embodiment. The first sliding mechanism  50  is identical with its counterpart of the first embodiment and hence omitted from the illustrative descriptions. The upper section in  FIG. 5  is identical with the left part of the bottom section in  FIG. 4 , showing a stable state where cases of the portable electronic device are slid and opened by means of the urging force of the first sliding mechanism  50  and the second slid mechanism  51 . The middle section in  FIG. 5  shows an intermediate state achieved between an opened state and a closed state, and the cases do not automatically stay in this state. The bottom section in  FIG. 5  shows a stable state where the sliding mechanisms are locked by a lock mechanism after having slid and become closed (not shown). 
         [0058]    Operation of the second sliding mechanism  51  is identical with that of the side mechanism  50  of the first embodiment, and its explanation is omitted. 
         [0059]    Movement of the cable  70  will be described. The hole (a stationary point provided at substantially intermediate position on the cable  70 ) of the slidable intermediate member  9   a  moves over a distance L/2 with respect to the connector  27  provided at one end of the cable  70 . Therefore, a distance over which a U-turn portion of the cable  70  on the side of the first case  20  moves is only one-half of L/4. Likewise, a distance over which a U-turn portion of the cable  70  on the side of the second case  40  moves is only L/4. Namely, the minimum requirement for the cable  70  is to have a length in the sliding direction over which the cable  70  can move as illustrated and over which the first window  28  and the third window  46  can respond to movement of the U-turn portion of the cable  70 . 
         [0060]    Although the cable  70  is provided integrally on the second sliding mechanism  51 , the cable  70  may also be provided integrally on the first sliding mechanism  50 . 
         [0061]    According to the second embodiment, there is obtained the same advantage as that obtained by the first embodiment, and the moving distance of the cable  70  can be shortened. A cable having rigidity that is comparatively lower than that of a flexible cable can also be used as the cable, as in the case of a fine coaxial wire. 
         [0062]    As another embodiment, the first sliding mechanism  50  may be omitted from the configuration of the second embodiment, to thus realize only an integrated structure having the second sliding mechanism  51  and the cable  70 . As a result, the number of windows can be reduced. 
         [0063]    Alternatively, the spring of the second sliding mechanism  51  may also be deleted from the structure of the second embodiment, to thus cause the second sliding mechanism  51  to serve as a guide mechanism not generating urging force. In that case, the slidable intermediate member  9   a  is not forced to the intermediate position on the second sliding mechanism  51  by the spring. Hence, the integrated structure consisting of the cable  70  is abandoned, and a custom-designed window may also be provided as in the first embodiment. 
         [0064]    It is to be understood that the invention is not limited to the specific embodiment described above and that the present invention can be embodied with the components modified without departing from the spirit and scope of the present invention. The present invention can be embodied in various forms according to appropriate combinations of the components disclosed in the embodiments described above. For example, some components may be deleted from all components shown in the embodiments. Further, the components in different embodiments may be used appropriately in combination.