Abstract:
A portable terminal device ( 100 ) comprising a microcomputer ( 2 ) and a memory card ( 5 ) is mounted on a vehicle for collecting operation information of the vehicle. The microcomputer ( 2 ) has a flash read only memory ( 23 ) storing a firmware of the terminal device ( 100 ), and a memory card slot ( 6 ). The memory card ( 5 ) comprises a firmware layer ( 5   a ) storing a second firmware and a data storage layer ( 5   c ) for recording the operating information. The microcomputer ( 2 ) replaces the firmware in the flash read only memory ( 23 ) with the second firmware, thereby rendering the firmware replacement easy.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a portable terminal device for communicating with a vehicle mounted equipment.  
       BACKGROUND OF THE INVENTION  
       [0002]     JP H10-55464-A issued in 1998 by the Japan Patent Office discloses a vehicle information collection device comprising a microcomputer for recording data output from a vehicle mounted equipment and representing an operating condition of a vehicle in an external recording medium.  
         [0003]     “Automotive Handbook 4th Edition by BOSCH (ISBN 0-8376-0333-1)” discloses in pages 800-802, a serial bus system called “Controller Area Network (CAN)”. CAN enables exchange of various signals between a vehicle mounted equipment and, for example, a terminal device temporarily disposed in a vehicle cabin. Herein, the vehicle mounted equipment includes a microcomputer for controlling vehicle running and the portable terminal device includes the above described vehicle information collection device.  
       SUMMARY OF THE INVENTION  
       [0004]     In the device disclosed in JP H10-55464-A, in order to change the type of recorded data or recording conditions of the terminal device it is necessary to rewrite a firmware or a program stored in the microcomputer of the terminal device. When those items are written in a read only memory (ROM) of the microcomputer, it is necessary to replace the ROM. When these items are written in an erasable programmable read only memory (EPROM), it is necessary to connect the device to an EPROM rewriting device to rewrite the content of the EPROM. That is, even if the device is formed in the form of a portable terminal device, each time the information collection conditions are changed, either the replacement of the ROM or rewriting of the EPROM contents by the EPROM rewriting device is required. Therefore, it is difficult to fully utilize the function of the CAN that has a high versatility in view of signal transmitting.  
         [0005]     It is therefore an object of this invention to provide a portable terminal device having improved applicability to different conditions of use.  
         [0006]     In order to achieve the above object, this invention provides a portable terminal device for communicating with a vehicle mounted equipment, comprising a microcomputer and a memory card. The microcomputer comprises a connector for exchanging signals with the vehicle mounted equipment, an erasable programmable only memory which stores firmware of the microcomputer, and a memory card slot in which the memory card is fitted so as to communicate with the microcomputer. The memory card comprises a firmware layer which stores a second firmware and a data storage layer which stores the signals output from the microcomputer through the memory card slot. The microcomputer is programmed to replace the firmware stored in the erasable programmable read only memory with the second firmware stored in the firmware layer of the memory card in response to an input of a predetermined command.  
         [0007]     The details as well as other features and advantages of this invention are set forth in the remainder of the specification and are shown in the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a diagram showing a connection between a vehicle mounted computer and a portable terminal device disposed in a drink holder in a vehicle cabin, according to this invention.  
         [0009]      FIGS. 2A and 2B  are perspective views of the portable terminal≈.  
         [0010]      FIG. 3  is a perspective view of main body of the portable terminal device.  
         [0011]      FIG. 4  is a plan view of the portable terminal device as viewed from above.  
         [0012]      FIG. 5  is a plan view of the portable terminal device as viewed from below.  
         [0013]      FIG. 6  is a cross-sectional view of the portable terminal device taken along the line VI-VI of  FIG. 4 .  
         [0014]      FIG. 7  is a cross-sectional view of the portable terminal device taken along the line VII-VII of  FIG. 4 .  
         [0015]      FIG. 8  is a schematic diagram of the portable terminal device and a memory card according to this invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     Referring to  FIG. 1  of the drawings, a portable terminal device  100  according to this invention is connected with a computer  200  mounted on a vehicle for controlling, for example, vehicle drive device. The vehicle is provided with a serial bus system called “Controller Area Network (CAN) that transmits various kind of signals between the vehicle mounted computer  200  and the portable terminal device  100 . The portable terminal device  100  is formed in a cylindrical shape and is disposed in a drink holder  300  in a cabin compartment of the vehicle.  
         [0017]     Referring to  FIGS. 2A and 2B , the terminal device  100  comprises a cylindrical case  1  and a main body  2  disposed inside the cylindrical case  1 . The main body is constituted by a microcomputer. A ring cap  3  is attached to an upper end  1   a  of the cylindrical case  1 , and a bottom lid  4  is attached to a lower end  1   b  of the cylindrical case  1 .  
         [0018]     An outer diameter of the cylindrical case  1  is about 67 mm, which is substantially the same as the outer diameter of normal 350-milliliter beverage cans so as to be suitable for fitting in the drink holder in the cabin compartment. The cylindrical case  1  is made of an aluminum thin plate. Therefore, the cylindrical case  1  is light, and is held easily.  
         [0019]     The ring cap  3  is made of rubber, and is attached to an outer circumference of an upper end  1   a  of the cylindrical case  1 .  
         [0020]     The bottom lid  4  is made of a resin, and closes the lower end  1   b  of the cylindrical case  1 .  
         [0021]     Referring to  FIG. 8 , the microcomputer constituting the main body  2  comprises a micro processing unit (MPU)  22 , an external random access memory (external RAM)  27 , an erasable programmable read only memory (EPROM)  28 , an input/output interface (I/O interface)  25 , and a power source unit  126 . The MPU  22  comprises a central processing unit (CPU)  21 , a flash read only memory (flash ROM)  23 , and a random access memory (RAM)  24 . Those components  21 - 25 ,  27 , 28  and  126  are separately provided on a main board  2   a  and a sub-board  2   b  which are shown in  FIG. 3 .  
         [0022]     Referring to  FIG. 3 , the main board  2   a  and the sub-board  2   b  are provided in parallel with each other, and vertically upright on a circular lower panel  15 . The vertical length of the main board  2   a  is longer than the vertical length of the sub-board  2   b.  The vertical length of the main board  2   a  and the vertical length of the sub-board  2   b  depend on the layout of electronic components of the main body  2 . As the main board  2   a  and the sub-board  2   b  get shorter, the position of the center of gravity of the terminal device  100  becomes lower. The terminal device  100  having the center of gravity at the low position is preferable in view of stability when it is placed in the drink holder. An upper panel  11  is fixed to an upper end of the main board  2   a  and an upper end of the sub-board  2   b.  The main board  2   a  and the sub-board  2   b  are interconnected by a connector board  2   c  to form an electric circuit and a signal circuit.  
         [0023]     The upper panel  11  comprises an upper semicircular surface  11   a  fixed to the main board  2   a,  and a lower semicircular surface  11   b  fixed to the sub-board  2   b.  The upper end of the main board  2   a  is higher than the upper end of the sub-board  2   b,  so there is a step between the upper semicircular surface  11   a  and the lower semicircular surface  11   b.  Then, the upper semicircular surface  11   a  and the lower semicircular surface  11   b  are connected by a vertical coupling surface  11   c.    
         [0024]     Referring to  FIG. 4 , LEDs  9  indicating the operating condition of the terminal device  100  are arranged on the upper semicircular surface  11   a  of the upper panel  11 . The number of LEDs  9  is three, and the LEDs  9  have different colors. The LEDs  9  reports the operating condition to a driver or a user of the terminal device  100 . Preferably, the relationship between lighting patterns of the LEDs  9  and the operating condition of the terminal device  100  is marked on the outer circumferential surface of the upper semicircular surface  11   a  or the cylindrical case  1 .  
         [0025]     A push switch  10  is provided on the upper semicircular surface  11   a.  The push switch  10  is operated by the driver or the user of the device. When the push switch  10  is turned on, the microcomputer starts recording signal information inputted from the CAN of the vehicle in a memory card  5  which is described later. The push switch  10  is also used for rewriting data in the EPROM  23 .  
         [0026]     The terminal device  100  has a connector  8   a  on the lower semicircular surface  11   b  of the upper panel  11  for connection to a CAN cable.  
         [0027]     Further, the terminal device  100  has a terminal  8   b  on the lower semicircular surface  11   b  for obtaining electricity from a cigar lighter socket of the vehicle.  
         [0028]     The length of the cylindrical case  1  is determined such that the LEDs  9 , the push switch  10 , and a connector  7  of the CAN cable connected to the connector  8   a  do not protrude above the cylindrical case  1 .  
         [0029]     Referring to  FIG. 5 , the main body  2  comprises a memory card slot  6  for inserting the memory card  5  between the main board  2   a  and the sub-board  2   b.  The memory card slot  6  has a connector for connection to the memory card  5 .  
         [0030]     Referring to  FIGS. 6 and 7 , the upper panel  11  and the lower panel  15  are fixed to the cylindrical case  1 , respectively.  
         [0031]     A female screw  1   c  is formed in an internal circumferential surface at the lower end of the cylindrical case  1 . The bottom lid  4  has a male screw  4   a  screwed into the female screw  1   c.  The male screw  4   a  has a chamfered tip end.  
         [0032]     Rubber material is attached to a surface  4   b  of the bottom lid  4 , which contacts the memory card  5 . After the memory card  5  is inserted into the memory card slot  6 , the bottom lid  4  is screwed into the cylindrical case  1 . The bottom lid  4  screwed into the cylindrical case  1  keeps the memory card  5  inside the memory card slot  6  by the elastic force of the rubber member. Therefore, it is possible to prevent disconnection of the memory card  5  from the connector in the memory card slot  6  due to vibrations while the vehicle is running. The memory card slot  6  is hermetically closed by the bottom lid  4  to prevent the entry of dust into the memory card slot  6 .  
         [0033]     Next, referring to  FIG. 8 , the structure of the memory card  5  will be described.  
         [0034]     The memory card  5  is a portable recording medium used as an external recording medium for the microcomputer. The memory card  5  includes, but not limited to, a CompactFlash®, a MemoryStick® or a SmartMedia®.  
         [0035]     The memory card  5  comprises a firmware layer  5   a  storing a firmware of the microcomputer of the main body  2  a recording condition setting layer  5   b  storing a recording condition setting file in order to select signals for recording from among input signals to the connector  8   a,  and a data storage layer  5   c  storing data.  
         [0036]     In normal condition, when the push switch  10  is turned on, the microcomputer of the main body  2  selectively records signals inputted to the connector  8   a  as data in the memory card  5  in the slot  6  in accordance with the instructions from the firmware stored in the flash ROM  23  and the recording condition setting file stored in the external RAM  27 . In accordance with the firmware stored in the ROM  22 , the CPU  21  controls the flash ROM  23 , RAM  24 , I/O interface  25  and the memory slot  26  in order to accomplish the above operation. Further, when the push switch  10  is turned off, the microcomputer stops recording of the data.  
         [0037]     Recording of the data can be started when an ignition switch of the vehicle is turned on, or an accessory switch is turned on, or a specific trigger signal is inputted from the CAN without the ON/OFF operation of the push switch  10 . When recording of the data is carried out in response to the specific trigger signal inputted from the CAN, using a loop memory, it is possible to record data of a certain period before and after the start of data recording.  
         [0038]     The operation of the terminal device  100  is stopped by turning off a switch used for starting up the terminal device  100 . If the operation of the terminal device  100  is start up by the trigger signal from the CAN, operation of the terminal device  100  is also stopped by a stop signal from the CAN. It is needless to say that the stop operation of the terminal device  100  does not affect the data recorded in the memory card  5 .  
         [0039]     The microcomputer of the main body  2  has a counter function, and is capable of recording in the memory card  5  the lapsed time since the start-up of the operation.  
         [0040]     The firmware stored in the memory card  5  and the recording condition setting file are used as follows.  
         [0041]     When the type of the vehicle or target information to be collected changes, it is necessary to rewrite the firmware stored in the flash ROM  23  and the recording condition setting file stored in the external RAM  27 . With respect to the recording condition setting file stored in the external RAM  27 , it is always erased when the terminal device  100  is switched off and, when the terminal device  100  is switched on, the recording condition setting file in the recording condition setting layer  5   b  of the memory card  5  is newly loaded into the external RAM  27 . So the recording condition setting file is automatically renewed every time when the terminal device  100  is switched on.  
         [0042]     Unlike the recording condition setting file, renewal of the firmware in the flash ROM  23  requires a specific operation. In order to rewrite the firmware stored in the flash ROM  23 , a memory card  5  storing the applicable firmware in its firmware layer  5   a  is inserted into the slot  6  of the terminal device  100  while the push switch  10  is pushed. When this operation is carried out, the terminal device  100  replaces the firmware in the flash ROM  23  with the firmware stored in the firmware layer  5   a  of the memory card  5 .  
         [0043]     The above firmware rewriting operation is achieved by defining the process in a specific block in the flash ROM  23  that is first referred when the terminal device  100  is switched on. It should be noted that this specific block is different from the block for storing the firmware. The firmware newly installed in the flash ROM  23  is not erased until another rewriting operation is performed.  
         [0044]     When the terminal device  100  is restarted after rewriting the firmware, the terminal device  100  records the designated information in the data storage layer  5   c  of the memory card  5  according to the instructions by the new firmware stored in the flash ROM  23 . It should be noted that, even if the terminal device  100  is repeatedly turned on and off, unlike the recording condition setting file in the external RAM  27 , the firmware in the flash ROM  23  is not rewritten without the above described specific operation of the push switch  10 .  
         [0045]     As described above, the information inputted from the CAN is recorded always depending on the firmware in the flash ROM  23 . The firmware in the memory card  5  is not used except the case in which the above described operation of the push switch  10  is performed.  
         [0046]     In the normal information recording operation, the terminal device  100  simply writes information in the memory card  5 , and does not read data from the memory card  5 . Therefore, the memory card  5  is not accessed excessively.  
         [0047]     As described above, in the terminal device  100  according to this invention, when the firmware needs to be changed, simply by inserting a suitable memory card  5  to the slot  6  while the push button  10  is pushed, it is possible to rewrite the firmware. Therefore, it is possible to rewrite the firmware easily while the terminal device  100  is mounted in the vehicle without replacing the flash ROM  23  of the microcomputer or connecting the terminal device  100  to a special firmware rewriting device.  
         [0048]     The contents of Tokugan 2003-387743, with a filing date of Nov. 18, 2003 in Japan, are hereby incorporated by reference.  
         [0049]     Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, within the scope of the claims.  
         [0050]     For example, any other types of erasable programmable read only memories (EPROM) or rewritable non-volatile memories can be used instead of the flash ROM  23  in the terminal device  100 .  
         [0051]     In the above embodiment, the recording condition setting file is loaded from the memory card  5  into the external RAM  27  every time when the terminal device  100  is switched on. However, it is also possible to configure the terminal device  100  to be able to rewrite the recording condition setting file stored in the external RAM  27  by a specific command that may be inputted by a specific operation of the push switch  10 .  
         [0052]     Further, it is also possible to store the recording condition setting file into the flash ROM  23  together with the firmware and to provide a special command to rewrite the recording condition setting file in the flash ROM  23 .  
         [0053]     While the embodiment of this invention has been described in conjunction with the terminal device  100  for recording the input signals from the CAN, this invention is applicable to any portable terminal device that communicates with a vehicle mounted equipment via any kind of signal circuit.  
         [0054]     The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows: