Abstract:
A rearview mirror is located between a driver&#39;s seat and a front passenger&#39;s seat. The rearview mirror includes a housing, a reflector, and an interface. The housing includes a front surface facing the driver&#39;s seat, a rear surface at the opposite side of the front surface, and a slot at a part closer to the driver&#39;s seat than the passenger&#39;s seat. A recording medium is attached to and removed from the interface by moving the recording medium along a predetermined moving axis. The interface performs at least one of reading of data from the medium and writing of data to the medium. The predetermined moving axis is inclined relative to the width direction of the housing such that the predetermined moving axis approaches the center in the width direction of the housing from the front surface toward the rear surface.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a rearview mirror provided in the passenger compartment of a vehicle.  
           [0002]    In recent years, with the development of intelligent transport systems (ITS), incorporation of an information network into vehicles is now under progress. Together with this trend, vehicles are equipped with a human machine interface (HMI) associated with a variety of information systems. The HMI is located at a location at which a driver can easily operate it, such as near the driver&#39;s seat. For example, in an electronic toll collection system (ETC), a car-equipped ETC is provided near the driver&#39;s seat as an HMI.  
           [0003]    Generally, a variety of operation devices, a display, and the like are provided near the driver&#39;s seat, so that it is sometimes difficult to ensure a space for installing a car-equipped ETC To address this problem, conventionally, there has been proposed to arrange the car-equipped ETC within a rearview mirror which is provided with multiple functions. In the following, a conventional rearview mirror  51  will be described with reference to FIGS.  9  to  11 .  
           [0004]    As shown in FIG. 9, the rearview mirror  51  is located between a driver&#39;s seat  54  and a passenger&#39;s seat  55  in a front section of a passenger compartment  53  of a vehicle  52  As shown in FIGS. 10 and 11, the rearview mirror  51  includes a housing  56  and a reflector  57 . The reflector  57  is fixed in the passenger compartment  53  to orient substantially toward the back of the vehicle. A slot  58 , through which an IC card  159  can be inserted as a recording medium, is formed on a side facing the driver&#39;s seat of the housing  56  (on the right side in FIGS. 10 and 11).  
           [0005]    As shown in FIG. 11, the housing  56  contains an interface unit  59  and a data processing unit  60  which make up a car-equipped ETC. The interface unit  59  is provided with a card holder  59   a  which is in communication with the slot  58 . The card holder  59   a  is formed such that the IC card  159  can be inserted into or removed from the card holder  59   a  in a direction substantially parallel with the mirror surface of the reflector  57 .  
           [0006]    For ensuring a backward field of view from the driver&#39;s seat, the mirror surface of the rearview mirror  51  must be inclined toward the driver&#39;s seat. Specifically, as shown in FIG. 9, the rearview mirror  51  is used with its mirror surface inclined toward the driver&#39;s seat by up to 30 degrees. However, the rearview mirror  51  is set such that the IC card  159  is inserted in a direction substantially parallel with the mirror surface of the rearview mirror  51 . For this reason, for inserting the IC card  159 , the driver is obliged to insert the IC card  159  backward from a direction in which the vehicle  52  is running, as indicated by an arrow F 1  in FIG. 9. In other words, the driver must insert the IC card  159  in front from a position far from the driver&#39;s scat. Therefore, a windshield is likely to interfere with the driver&#39;s hand or the like when the driver inserts or remove the IC card  159 , making it difficult to perform operations involved in the insertion and removal of the IC card  159   
         SUMMARY OF THE INVENTION  
         [0007]    It is an object of the present invention to provide a rearview mirror which permits the driver to readily insert or remove a thin recording medium.  
           [0008]    In order to attain the above object, the present invention provides a rearview mirror located between a driver&#39;s seat and a front passenger&#39;s seat in a front section of the passenger compartment of a vehicle. The rearview mirror includes a housing, a reflector and an interface. The housing includes e front surface facing the driver&#39;s seat, a rear surface at the opposite side of the front surface, and a slot at a part closer to the driver&#39;s seat than the passenger&#39;s seat. The slot receives a recording medium that stores predetermined data. The reflector is attached to the front surface of the housing. The interface is located in the housing. The recording medium is attached to and removed from the interface by moving the recording medium along a predetermined moving axis. The interface performs at least one of reading of data from the recording medium and writing of data to the recording medium. The predetermined moving axis is inclined relative to the front surface of the housing such that the predetermined moving axis approaches the center of the housing.  
           [0009]    Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with be accompanying drawings, illustrating by way of example the principles of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:  
         [0011]    [0011]FIG. 1 is a top plan view showing a passenger compartment of a vehicle which is equipped with a rearview mirror in one embodiment which embodies the present invention;  
         [0012]    [0012]FIG. 2 is a perspective view showing the rearview mirror of FIG. 1;  
         [0013]    [0013]FIG. 3 is a partially cutaway plan view of the rearview mirror of FIG. 1;  
         [0014]    [0014]FIG. 4 is a block diagram schematically showing the internal configuration of a data processing unit built in the rearview mirror of FIG. 1;  
         [0015]    [0015]FIG. 5 is a perspective view showing a rearview mirror in another embodiment of the present invention;  
         [0016]    [0016]FIG. 6( a ) is a front view showing the rearview mirror in the other embodiment of the present invention when a slide cover is closed;  
         [0017]    [0017]FIG. 6( b ) is a front view showing the rearview mirror of FIG. 6( a ) when the slide cover is opened;  
         [0018]    [0018]FIG. 7 is a perspective view showing a rearview mirror in a further embodiment of the present invention;  
         [0019]    [0019]FIG. 8 is a partially cutaway plan view of the rearview mirror in the further embodiment of the present invention;  
         [0020]    [0020]FIG. 9 is a plan view showing a passenger compartment of a vehicle equipped with a conventional rearview mirror;  
         [0021]    [0021]FIG. 10 is a perspective view showing the rearview mirror of FIG. 9; and  
         [0022]    [0022]FIG. 11 is a partially cutaway plan view of the rearview mirror of FIG. 9. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    In the following, a first embodiment which embodies the present invention will be described in detail with reference to FIGS.  1  to  4 .  
         [0024]    As shown in FIG. 1, a rearview mirror  11  is located between a driver&#39;s seat  3  and a passenger&#39;s  4  in a front section of a passenger compartment  2  of a vehicle  1 . As shown in FIGS. 2 and 3, the rearview mirror  11  includes a housing  12 , a reflector  13 , and a fixture  14 . An opening  12   b  is formed on a front surface  12   a  of the housing  12 , and the reflector  13  is fixed in the opening  12   b . The fixture  14  is joined on the top surface of the housing  12 . The fixture  14  includes a supporting shaft  14   a  which is in contact with the housing  12  through a spherical surface. Thus, the housing  12  is three dimensionally pivotally movable about the supporting shaft  14   a  in three axial directions.  
         [0025]    As shown in FIG. 3, the supporting shaft  14   a  is joined to the housing  12  at a location deviated by a distance C to the right in FIG. 3 with respect to a center line C of the housing  12 . In other words, the supporting shaft  14   a  is joined to the housing  12  at a location spaced by the distance C from the center line O of the housing  12 . The distance C is set such that the supporting shaft  14   a  is joined to the housing  12  at a location which matches the center of gravity of the rearview mirror  11 . As shown in FIG. 1, the rearview mirror  11  is fixed to the vehicle  1  such that the reflector  13  is oriented approximately to the rear of the vehicle.  
         [0026]    As shown in FIGS. 2 and 3, a slot  15  is formed beside the reflector  13  (on the right side in FIGS. 2 and 3) on the front surface  12   a  of the housing  12 . Thus, the driver, opposite to the reflector  13 , can view the slot  15 . In this embodiment, the slot  15  extends vertically in the shape of an arc which is curved toward the mirror surface  13 .  
         [0027]    As shown in FIG. 3, the housing  12  contains a reflectivity varying device  16 , and an interface unit  17  and a data processing unit  18  which make up a car-equipped ETC.  
         [0028]    The reflector  13 , which has a double-structure, includes a first mirror  13   a  and a second mirror  13   b . Electro-optical element, such as an electro-chromic element, and a liquid crystal element (neither shown) are interposed between the first mirror  13   a  and second mirror  13   b . The reflectivity varying device  16  is located near the rear surface of the reflector  13  for controlling the electro-optical element to vary the reflectivity of the reflector  13  for preventing the glare.  
         [0029]    The interface unit  17  is formed with a mount portion. In this embodiments the mount portion is a card holder  17   a , into which an IC card  20  can be inserted as a recording medium, When the IC card  20  is inserted into the card holder  17   a , the interface unit  17  reads data recorded on the IC card  20  or writes data into the IC card  20 .  
         [0030]    The interface unit  17  is located within the housing  12  such that the card holder  17   a  is in communication with the slot  15 . As the IC card  20  in inserted into the slot  15 , the IC card  20  is mounted in the interface unit  17 . As shown in FIG. 1, when the IC card  20  is completely inserted into the interface unit  17 , a proximal end portion  20   a  of the IC card  20  slightly protrudes from the housing  12 . This protruding proximal end portion  20   a  serves as a portion to be caught by the driver when he removes the IC card  20 .  
         [0031]    As shown in FIG. 3, the interface unit  17  is located within the housing  12  such that the card holder  17   a  is at a predetermined angle θ to the mirror surface of the reflector  13 . In other words, the interface unit  17  is located within the housing  12  such that the IC card  20  is inserted into the card holder  17   a  in a direction which is inclined by the predetermined angle θ to a direction parallel with the mirror surface of the reflector  13 . More specifically, the interface unit  17  is inclined relative to the mirror surface of the reflector  13  such that the card holder  17   a  approaches the center the housing  12  from the front surface  12   a  toward the rear surface  12   c . The predetermined angle θ is set to an angle equivalent to a maximum inclination angle (angle θ 1  shown in FIG. 1) to direction h of the vehicle  1  shown in FIG. 1, when the driver inclines the mirror surface of the reflector  13  toward the driver for ensuring a backward field of view of the vehicle  1 , or to an angle slightly larger than the inclination angle θ 1 . With such setting, the IC card  20  is inserted into the interface  17  in a direction identical to the direction h of the vehicle. The inventors have confirmed that the inclination angle θ 1  of the mirror surface is about 29 degrees at maximum. In this embodiment, the predetermined angle θ is set to about 30 degrees.  
         [0032]    The data processing unit  18  is located at a location in the housing  12  at which the data processing unit  18  does not interfere with the reflectivity varying device  16  and interface unit  17 . As shown in FIG. 4, the data processing unit  18  mutually communicates with road-side antennas  21  installed at a toll gate of a toll road. More specifically, the road-side antennas  21  are installed near the entrance and exit of the toll gate, respectively. The data processing unit  18  includes an antenna  22 , a transceiver  23 , a controller  24 , and an SAM unit  25 .  
         [0033]    When a vehicle equipped with a car-equipped ETC enters a toll road, a radio wave which carries encrypted predetermined data is output from the road-side antenna  21  installed near the entrance of a toll gate. As the transceiver  23  of the data processing unit  1   a  receives the radio wave through the antenna  22 , the data processing unit  18  demodulates the radio wave to a pulse signal to generate a received signal which is output to the controller  24 . The controller  24  instructs the SAM unit  25  to decrypt the received signal, and outputs the decrypted data to the interface unit  17 . Subsequently, the interface unit  17  writes the decrypted data into the IC card  20 . The predetermined data includes data related to the location and time at which the vehicle entered the toll road, and the type of vehicle (light car, ordinary car, truck, bus, and the like).  
         [0034]    On the other hand, when the vehicle exits the toll road, a radio wave including a response request signal is output from a road-side antenna  21  installed near an exit. Upon receipt of this response request signal, the controller  24  reads data related to the location from which the vehicle entered the toll road, and the type of vehicle, written into the IC card  20 , through the interface unit  17 , and encrypts the data using the SAM unit  25 . The controller  24  forces the transceiver  23  to modulate the encrypted data to a radio wave at a predetermined frequency, and outputs the radio wave from the antenna  22 . In summary, the controller  24  reads data related to the location from which the vehicle entered the toll roads and the type of vehicle from the IC card  20 , encrypts the data, and transmits the encrypted data to the road-side antenna  21 . The road-side antenna  21  outputs data indicative of the fee calculated from the encrypted data, the used date and time, and the like to the data processing unit  18 . The controller  24  writes the data into the IC card  20 .  
         [0035]    An operation unit  26  and a display  27  are electrically connected to the controller  24 . As shown in FIG. 2, the operation unit  26  and display  27  are located below the reflector  13  on the front surface  12   a  of the housing  12  Therefore, the operation unit  26  and display  27  can be operated and viewed by a passenger. In this embodiment, the operation unit  26  is made up of three push button switches, while the display  27  is made up of an LCD. As a passenger operates the operation unit  26 , the display  27  displays information on a toll gate, information on a fare to the destination, and the like, in response to the operation.  
         [0036]    The foregoing embodiment provides the following advantages.  
         [0037]    (1) The interface unit  17  is located within the housing  12  such that the IC card  20  is inserted into the card holder  17   a  in a direction inclined by the predetermined angle θ to a direction parallel with the mirror surface of the reflector  13 . Therefore, even when the rearview mirror  11  is inclined such that the mirror surface is oriented to the driver&#39;s scat, the IC card  20  in not inserted from a position far from the driver&#39;s seat. Therefore, when the IC card  20  is inserted into the interface unit  17 , the windshield is less likely to interfere with the IC card  20 , the driver&#39;s hand, and the like, thereby permitting the driver to readily insert and remove the IC card  20  into and from the interface unit  17 .  
         [0038]    Particularly, in the foregoing embodiment, the predetermined angle θ is set to 30 degrees. It is therefore possible to securely prevent the direction in which the IC card  20  is inserted into the interface unit  17  from being inclined in a direction from the front to the rear of the vehicle.  
         [0039]    (2) The slot  15  is formed on the front surface  12   a  of the housing  12 . This permits the driver to view the slot  15  when he directly faces the reflector  13 . Therefore, even when the rearview mirror  11  is inclined such that the mirror surface of the reflector  13  is oriented to the driver&#39;s seat, the driver can view the slot  15 . This permits the driver to readily insert the IC card  20  into the slot  15  and readily view whether or not the IC card  20  is inserted.  
         [0040]    (3) The slot  15  is formed beside the reflector  13  on the front surface  12   a  of the housing  12  close to the driver&#39;s seat. In other words, the slot  15  is provided near the driver&#39;s seat in a vehicle with a right-hand steering wheel. Thus, the IC card  20  is inserted into the slot  15  near the driver&#39;s seat. This permits the driver to readily insert and remove the IC card, and prevents another passenger (a passenger seated on the passenger&#39;s seat, or a passenger seated on a back seat) from inserting and removing the IC card  20 .  
         [0041]    (4) The supporting shaft  14   a  is joined to the housing  12  at a location spaced by the distance C from the center line O in the housing  12 . Thus, the supporting shaft  14   a  supports the rearview mirror  11  at the center of gravity. It is therefore possible to prevent a biased stress from being applied to the joint of the supporting shaft  14   a  and the housing  12  to prevent a degraded strength of the joint.  
         [0042]    It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.  
         [0043]    As a rearview mirror  111  shown in FIG. 5, a slot  115  is formed over a front surface  112   a  and a lower surface  112   d  of a housing  112 . In this way, the IC card  20  can be inserted into an interface unit  117  from the front surface  112   a  of the housing  112  as well as from the lower surface  112   d  of the housing  112 . In other words, the IC card  20  can be inserted into the interface unit  117  from multiple directions. Thus, the driver can insert and remove the IC card according to his preference, thereby improving the efficiency in inserting and removing the IC card  20 .  
         [0044]    As a rearview mirror  211  shown in FIGS.  6 ( a ) and  6 ( b ), a slide cover  31  slidable in a direction F indicated by an arrow in the figures is formed at a location at which a slot  215  is formed on a front surface  212   a  of a housing  212 . A finger resting protrusion  31   a  is formed on the surface of the slide cover  31 . The slide cover  31  is slidable in a direction parallel with the reflector  13 . As the slide cover  31  is slid, the slot  215  is selectively exposed and covered. The slot  215  has an arcuate section which is curved in a direction away from the reflector  13 . A recess  32  is formed at a substantially central location of the slot  215  on the front surface  212   a  of the housing  212 . When the IC card  20  is inserted into the interface unit  17 , the proximal end portion  20   a  of the IC card  20  protrudes from the recess  32 . This protruding proximal end portion  20   a  serves as a portion to be caught by the driver when he removes the IC card  20 . According to the rearview mirror  211 , the IC card  20  can be covered by the slide cover  31 , thereby preventing unfailingly the IC card  20  from being stolen.  
         [0045]    As a rearview mirror  311  shown in FIGS. 7 and 8, a slot  315  and an interface unit  317  may be provided on both sides of the reflector  13 . One slot is located at a part of the housing closer to the driver&#39;s seat than the front passenger&#39;s seat, and the other slot is located at a part of the housing closer to the front passenger&#39;s seat than the driver&#39;s seat. In this case, a housing  312  is substantially symmetric about the center line O so that the supporting shaft  14   a  is joined to the housing  312  on the center line O. The first slot and the second slot are substantially symmetric with respect to a plane passing thorough the center line O, and a first interface and a second interface are substantially symmetric with respect to the same plane. In this way, a passenger seated on the passenger&#39;s seat can also insert and remove the IC card  20  with ease. In addition, the rearview mirror  311  can be used both for a vehicle with a right-hand steering wheel and a vehicle with a left-hand steering wheel.  
         [0046]    The slot  15  and interface unit  17  shown in FIG. 2 may be formed on the left side of the reflector  13 . Wilt this arrangement made, the rearview mirror  11  can be applied to a vehicle with a left-hand steering wheel.  
         [0047]    The slot  15  may be formed on a bottom surface  12   d  or a side surface  12   e  of the housing  12  shown in FIG. 2, not limited to the front surface  12   a  of the housing  12 . However, it is more desirable to form the slot  15  at a location at which the driver can view the slot  15  when he directly faces the reflector  13 .  
         [0048]    The recording medium is not limited to the IC card  20 , but any thin recording medium can be applied, such as card-type recording media, e.g. a magnetic card, discoidal recording media, e.g. a floppy disk, a CD-ROM, and a mini-disk, plate-type recording media, e.g. a memory stick, and the like.  
         [0049]    The data processing unit  18  need not be contained in the housing  12 ,  112 ,  212 ,  312 .  
         [0050]    The operation unit  26 ,  126 ,  226  and display  27 ,  127 ,  227  need not be contained in the corresponding housing  12 ,  112 ,  212 ,  312 .  
         [0051]    The rearview mirror  11  need not be provided with a glare preventing function.  
         [0052]    The rearview mirrors  11 ,  111 ,  211 ,  311  according to the present invention are not limited to be used for the receipt of a fare for a toll road, but may be applied, for example, to the receipt of a fee at a drive-through of a fast-food restaurant, and the receipt of a fee at a parking area and a gas station. In addition, the rearview mirrors  11 ,  111 ,  211 ,  311  according to the present invention are not limited to be used for the receipt of fee or fare, but may be used for opening and closing gates provided at the entrance and exit of a parking area of a company, a shutter of a garage, and the like.  
         [0053]    Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.