Patent Publication Number: US-2007099575-A1

Title: Transceiver and adjusting system for transceiver

Description:
CROSS REFERENCE TO RELATED APPLICATION  
      This application is based on and incorporates herein by reference Japanese Patent Application No. 2005-315212 filed on Oct. 28, 2005.  
     FIELD OF THE INVENTION  
      The present invention relates to a transceiver and an adjusting system for the transceiver.  
     BACKGROUND OF THE INVENTION  
      A packaged transceiver is produced by accommodating a circuit board having circuit devices mounted thereon in a case or molding the circuit board with mold resin. When the electrical characteristic of such a transceiver is to be adjusted, a probe pin or the like is brought into contact with the circuit board and a set value is written into a memory of the circuit device or the like before packaging.  
      However, when the circuit board having the circuit devices mounted thereon is molded, capacitance components are formed between the circuit devices and between each circuit device and the circuit board by the mold resin. If the capacitance components are formed by the mold resin, the electrical characteristic of the transceiver may be varied. Furthermore, when the circuit board having the circuit devices mounted thereon is accommodated in a case, the electrical characteristic of the transceiver may be varied in accordance with the case.  
      As described above, the electrical characteristic may be varied before and after packaging, and thus a transceiver having a desired electrical characteristic cannot be achieved.  
      Furthermore, when the adjusting is executed by bringing the probe pin or the like into contact with the circuit board to write a set value into the circuit device or the like, mechanical control for bringing the probe pin into contact with the circuit board is required. In addition, it needs time to bring the probe pin into contact with a test point and to separate the probe pin from the test point. As a result, the adjusting time is increased and the manufacturing cost is increased.  
     SUMMARY OF THE INVENTION  
      The present invention therefore has an object to provide a transceiver that can shorten an adjusting time and has a proper electrical characteristic, and an adjusting system for the transceiver that can adjust the electrical characteristic of the transceiver to a proper electrical characteristic.  
      According to one aspect of the present invention, a transceiver comprises a transmitter for transmitting a radio wave wirelessly, a receiver for receiving a radio wave wirelessly transmitted from a measuring device, and a rewritable memory for storing a set value to control an electrical characteristic of at least one of the transmitter and the receiver. The transceiver further comprises a controller for controlling the electrical characteristic of the at least one of the transmitter and the receiver based on the set value, and rewriting the set value stored in the memory to an adjusting set value received by the receiver when the radio wave containing the set value is received by the receiver.  
      According to another aspect of the present invention, a measuring device is provided in combination with the transceiver. The measuring device comprises a device-side transmitter for transmitting the radio wave wirelessly to the transceiver, a device-side receiver for receiving the radio wave wirelessly from the transceiver, and a device-side controller for setting the adjusting set value to control an electrical characteristic of the transceiver based on the radio wave transmitted from the transceiver and transmitting the radio wave containing the adjusting set value from the device-side transmitter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:  
       FIG. 1  is a schematic block diagram showing an adjusting system according to a first embodiment of the present invention;  
       FIG. 2  is a schematic view showing a portable device in the first embodiment of the present invention;  
       FIG. 3  is a flowchart showing the processing operation of a measuring device in the first embodiment of the present invention;  
       FIG. 4  is a flowchart showing the processing operation of the portable device in the first embodiment of the present invention;  
       FIG. 5  is a table showing an example of an adjusting map in the first embodiment of the present invention; and  
       FIG. 6  is a diagram showing an adjusting system according to a second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     First Embodiment  
      Referring to  FIG. 1 , an adjusting system includes a portable device (transceiver)  10  and a measuring device (tester)  20 , which are wirelessly connected to each other. The portable device  10  is a transmitter/receiver, which may be used in a smart entry system for remotely locking/unlocking doors of a vehicle in a non-contact way, etc.  
      The portable device  10  is equipped with a transceiver-side controller  11 , a transceiver-side EEPROM (electrically erasable programmable memory)  12 , a transceiver-side transmitter  13 , a transceiver-side receiver  14 , etc. The controller  11  is a microcomputer having a CPU, etc., and controls the transmitter  13 , the receiver  14 , etc. based on a set value stored in the EEPROM  12 .  
      The EEPROM  12  is a rewritable storage device. In EEPROM  12  are stored a set value for controlling the transmission power, the transmission frequency, etc. when a radio wave is transmitted from the transmitter  13 .  
      When the adjusting system is used in the smart entry system, the controller  11  determines reception or non-reception of a request signal based on the reception signal of the receiver  14 , generates a response signal containing ID code, etc. in response to the request signal, transmits the response signal from the transmitter  13 , etc. In EEPROM  12  are also stored an ID code specific to the portable device  10 , etc. when the portable device  10  is used in the smart entry system.  
      The transmitter  13  is equipped with an RF circuit for transmitting RF radio wave, etc., superposes a signal output from the controller  11  on a modulated RF radio wave, and then transmits the signal from the antenna wirelessly. When the radio wave is transmitted from the transmitter  13  wirelessly, the controller  11  controls the electrical characteristic (transmission power, transmission frequency) based on the set value stored in EEPROM  12 .  
      The receiver  14  demodulates a radio wave which is transmitted from the external location wirelessly and received by the antenna, and then outputs the demodulated signal to the controller  11 .  
      As shown in  FIG. 2 , the portable device  10  is equipped with a circuit board  15 , circuit devices  16  and an antenna (not shown), and is molded with mold resin  17  while the circuit devices  16 , the antenna, etc. are mounted on the board  15  in an electronic product state.  
      The measuring device  20  is equipped with a tester-side controller  21 , a tester-side memory (memory)  22 , a tester-side transmitter  23 , a tester-side receiver  24 , a tester-side measuring circuit  25 , etc. The controller  21  is a microcomputer having a CPU, etc., and controls the transmitter  23 , the receiver  24 , the measuring circuit  25 , etc.  
      The memory  22  may be a hard disk, ROM or the like, and an adjusting set value is stored in the memory  22 . The adjusting set value is used to control the electrical characteristic of the transmitter  13  in the portable device  10 . Those are stored in association with the measuring result (measurement values) of the measuring circuit  25  as shown in an adjusting data in mapped form of  FIG. 5 .  
      The transmitter  23  has an LF circuit, etc., and it superposes a signal output from the controller  21  on the modulated LF radio wave and transmits the signal from the antenna wirelessly. The signal output from the controller  21  contains a signal indicating the adjusting set value, a transmission request signal (measuring command) for requesting wireless transmission of a radio wave from the portable device  10  to start the measurement, etc.  
      The receiver  24  demodulates the radio wave which are wirelessly transmitted from the portable device  10  and received by the antenna, and then outputs the demodulated signal to the controller  21 .  
      The measuring circuit  25  measures the electrical characteristic (transmission power, transmission frequency) of the transmitter  13  based on the radio wave which is transmitted wirelessly from the portable device  10 .  
      The operating switch  26  is operable by an operator of the measuring device  20 , and outputs an operation signal indicating that it is operated by the operator.  
      The adjusting system is further constructed or programmed to operate as shown in  FIGS. 3 and 4 . When the operation switch  26  of the measuring device  20  is operated, the operation signal indicating the start of the measurement is output. When a measurement command is received from the measuring device  20 , the portable device  10  starts the processing shown in  FIG. 4 .  
      Specifically, at step S 10 , the controller  21  superposes the measuring command requesting the wireless transmission of radio waves from the portable device  10  on the modulated LF radio wave and then wirelessly transmits the signal from the antenna by the transmitter  23 .  
      When the portable device  10  receives the measuring command transmitted from the measuring device  20  by the receiver  14 , controller  11  activate the RF circuit of the transmitter  13  at step S 20  to prepare for the wireless transmission of the RF radio wave. At step S 21 , the controller  11  controls the transmission power and the transmission frequency based on the set value stored in EEPROM  12  and wirelessly transmits the RF radio wave from the transmitter  13 .  
      At step S 11 , in response to the measuring command transmitted at step S 10 , the measuring device  20  determines whether the RF radio wave is transmitted from the portable device  10 , that is, the RF radio wave is received by the receiver  24 . If it is determined that the RF radio wave is received, the processing proceeds to step S 12 . On the other hand, if it is determined that no RF radio wave is received, the determination at step S 11  is repeated. At step S 11 , the processing is finished when no RF radio wave cannot be received although reception of the RF radio wave is confirmed at a predetermined number of times.  
      At step S 12 , the controller  21  measures the electric characteristic (e.g., transmission power and transmission frequency) of the transmitter  13  by using the RF radio wave received through the measuring circuit  25 . At step S 13 , the controller  21  determines whether the measurement result at step S 12  is normal or not, that is, whether it is within a standard range. This determination may be carried out by storing a predetermined reference value in the memory  22  or the like in advance and comparing the measurement result of the measuring circuit  25  with the stored reference value. If it is determined that the measurement result is within the standard range, the processing is finished. If it is determined that the measurement result is not within the standard range, the processing proceeds to step S 14 .  
      It is also possible to shift the processing to step S 14  irrespective of the measurement result when the electrical characteristic is measured at step S 12 . In this case, by shifting the processing to step S 14  to set the adjusting set value only when it is determined that the electrical characteristic of the transmitter  13  is not normal, the radio waves can be transmitted only as occasion demands.  
      At step S 14 , when the measurement result of the measuring circuit  25  is not normal, the controller  21  checks the adjusting data shown in  FIG. 5  so that the transmission power and the transmission frequency of the transmitter  13  in the portable device  10  are set to normal values.  
      At step S 15 , the controller  21  determines the adjusting set value corresponding to the measurement result, that is, the measurement value of the measuring circuit  25  by using the adjusting data.  
      At step S 16 , the controller  21  superposes a rewriting command and the adjusting set value on the modulated LF radio wave and wirelessly transmits the signal from the antenna by the transmitter  23  in order to write the adjusting set value determined at step S 15  into EEPROM  12 .  
      At step S 22 , the controller  11  checks the reception of the rewriting command and the adjusting set value through the receiver  14 . Then, at step S 23 , the controller  11  determines whether the rewriting command and the adjusting set value is received or not. If it is determined that they are received, the processing proceeds to step S 24 . If it is determined that they are not received, the processing is finished.  
      At step S 24 , the controller  11  rewrites the set value presently stored in EEPROM  12  with the received adjusting set value according to the received rewriting command. That is, the present adjusting values are replaced with new adjusting set value.  
      As described above, when the set value for controlling the electrical characteristic of the transmitter  13  into EEPROM  12 , and the radio wave containing the adjusting set value is wirelessly received through the receiver  14 , the set value stored in EEPROM  12  are rewritten to the adjusting set value received through the receiver  14 , whereby the electrical characteristic can be adjusted even after the portable device  10  is packaged in a case or by mold resin. Accordingly, the portable device  10  can be provided with a proper electrical characteristic without paying attention to the variation amount caused by the mold resin, the case, etc.  
      Furthermore, the set value stored in EEPROM  12  can be rewritten in the stage that the portable device  10  is under product state. Therefore, no defective occurs in the manufacturing process of the portable device  10 .  
      Still furthermore, with respect to the adjusting set value, the measuring device  20  measures the electrical characteristic of the transmitter  13  based on the radio wave transmitted from the portable device  10 . The adjusting set value is set by using the measurement result to rewrite the set value stored in EEPROM  12 , so that the electrical characteristic of the portable device  10  can be more properly adjusted.  
      It has been general that when a set value are written, a probe pin is brought into contact with a test pointer provided on the board under the state that circuit devices and an antenna are mounted (circuit state) in consideration of the influence of the mold resin or the case. However, according to this embodiment, the adjusting set value can be written into EEPROM  12  of the portable device  10  wirelessly. Thus it is unnecessary to provide a test pointer in the portable device  10 , and restriction on the artwork can be reduced. Furthermore, the adjusting set value can be written into EEPROM  12  of the portable device  10  wirelessly, so that it is unnecessary to bring the probe pin into contact with the test pointer and thus the adjusting time can be shortened.  
      When a power source such as a cell or the like for driving the controller  11 , etc. is mounted in the portable device  10 , the electrical characteristic of the transmitter  13  may be varied by the power source. However, according to this embodiment, the adjusting set value can be written into EEPROM  12  of the portable device  10  wirelessly. Thus, the set value stored in EEPROM  12  can be rewritten in the stage where the portable device  10  is under product state. Accordingly, the portable device  10  can be provided with a proper electrical characteristic without paying attention to the variation amount caused by the power source.  
     Second Embodiment  
      In this embodiment, the portable device  10  is equipped with a measuring circuit  15  for measuring the electrical characteristic (reception sensitivity, reception frequency) of the receiver  14  based on the radio wave wirelessly transmitted from the measuring device  20 .  
      When the operation switch  26  is operated and the operation signal indicating the start of the measurement is output, the controller  21  superposes on the modulated LF radio wave the measuring command requesting wireless transmission of the radio wave from the portable device  10  to start the measurement, and wirelessly transmits the signal from the antenna by the transmitter  23 .  
      When wirelessly receiving the LF radio wave containing the measuring command in the receiver  14 , the controller  11  measures the electrical characteristic (reception sensitivity, the reception frequency) of the receiver  14  by using the received LF radio wave in the measuring circuit  15 .  
      Then, the controller  11  controls the transmission power and the transmission frequency based on the set value stored in EEPROM  12 . It superposes the signal indicating the measurement result measured in the measuring circuit  15  on the modulated RF radio wave and wirelessly transmits the signal thus achieved from the transmitter  13 .  
      The measuring device  20  which wirelessly receives the RF radio wave containing the measurement result measured in the measuring circuit  15  executes a determination as to whether the measurement result is normal or not, check of the adjusting map, determination of the adjusting set value, transmission of the rewriting command and the adjusting set value, etc. in the similar manner as steps S 13  to S 16  of the first embodiment.  
      When the rewriting command and the adjusting set value is received by the receiver  14 , the controller  11  rewrites the present a set value stored in EEPROM  12  with the received adjusting set value according to the received rewriting command.  
      As described above, the radio wave containing the measurement result measured based on LF radio wave received by the receiver  14  is transmitted to the measuring device  20 , and the radio waves containing the adjusting set value based on the measurement result concerned is received from the measuring device  20 , whereby the electrical characteristic of the receiver  14  can be adjusted.  
      In the above embodiments, the radio wave output from the transmitter  13  is set as the RF radio wave, and the radio wave output from the transmitter  23  is set as the LF radio wave. However, the present invention is not limited to this, and the object of the present invention can be attained insofar as radio waves are wirelessly transmitted.  
      In the above embodiments, the memory  22  for storing the measurement result of the measuring circuit  25  and/or the measurement result of the measuring circuit  15  and the adjusting set value in association with each other is provided to set the adjusting set value. However, the present invention is not limited to these embodiments. However, the adjusting set value can be easily set if the adjusting set value is set by using the memory  22 .