Abstract:
[Problem ] To provide a technique that reduces a drop of induced voltage in a non-contact tag.  
     [Solution ] An expendable container of the present invention comprises a memory circuit. The memory circuit has a memory, an antenna being capable of establishing non-contact communication with an external receiver transmitter, and a controller controlling the non-contact communication and an access to the memory. The memory circuit has a plurality of modes including ID information confirmation mode and low power consumption mode. The memory circuit is capable of shifting to the low power consumption mode in response to a completion of confirmation of the ID information of the expendable container.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a technique of non-contact communication between a device like a printing device and its expendable container.  
         [0003]     2. Description of the Related Art  
         [0004]     The application of non-contact tags to a data carrier has been proposed recently. Such a non-contact tag may be attached to, for example, an ink cartridge for inkjet printers. Some pieces of useful information, for example, the expiration date of ink, are stored in the non-contact tag. The printer main body acquires these pieces of information from an ink cartridge attached to the printer main body through electromagnetic-inducing communication. The electromagnetic-inducing communication may adopt the anti-collision function that allows for communication with multiple non-contact tags without collisions (interference).  
         [0005]     The anti-collision function causes each command sent from the printer main body to include corresponding one among respective ID informations separately held by the multiple non-contact tags. Only a non-contact tag with the corresponding ID information responds to the command. The anti-collision function is on the premise that the printer main body has the respective ID informations on the multiple non-contact tags. The mapping of the ID information to the attachment position of each ink cartridge is also required for adequate user of the ink cartridge in the printer.  
         [0006]     One proposed technique of the electromagnetic-inducing communication regulates the relative position of a non-contact tag attached to each ink cartridge to an antenna of the printer and the transmission output of the antenna, which cause sufficient electromagnetic induction only in a target non-contact tag, so as to acquire ID information of the ink cartridge with the target non-contact tag at each attachment position.  
         [0007]     There is, however, a manufacturing variation in resonance frequency among multiple different resonance circuits included in non-contact tags. It is accordingly possible that a non-contact tag having a resonance frequency extremely close to the frequency of the transmission output of the antenna is located adjacent to a non-contact tag having a resonance frequency relatively apart from the frequency of the transmission output of the antenna.  
         [0008]     In such cases, excess induced current flows in the antenna of the former non-contact tag and undesirably weakens the surrounding AC magnetic field. This may cause a potential problem that only an insufficient induced voltage is generated in the antenna of the non-contact tag adjoining to the former non-contact tag.  
         [0009]     The enhanced transmission output of the antenna in the printer, on the other hand, causes another problem that the antenna of the printer may establish an unexpected communication with another non-contact tag that is not adjacent to the former non-contact tag. These problems are not restricted to the ink cartridges but are commonly found in any expendable containers that utilize non-contact tags for storage of information on expendables.  
       SUMMARY OF THE INVENTION  
       [0010]     The object of the invention is thus to eliminate the drawbacks of the prior art and to provide a technique that reduces a drop of induced voltage in a non-contact tag.  
         [0011]     There is provided an expendable container storing an expendable. The expendable container comprises a memory circuit. The memory circuit has a memory, an antenna being capable of establishing non-contact communication with an external receiver transmitter, and a controller controlling the non-contact communication and an access to the memory. The memory circuit has a plurality of modes including ID information confirmation mode and low power consumption mode. The ID information confirmation mode is for the external receiver transmitter to communicate with the memory circuit in order to confirm ID information of the expendable container. The low power consumption mode is for the controller to lessen function. The memory circuit is capable of shifting to the low power consumption mode in response to a completion of confirmation of the ID information of the expendable container.  
         [0012]     The expendable container of the invention shifts to the low power consumption mode, in which the controller stops its function, in response to a completion of confirmation of ID information on the expendable container. This arrangement effectively reduces a drop of induced voltage in a non-contact tag attached to an adjoining expendable container.  
         [0013]     The technique of the invention is implemented by diversity of applications, for example, a device with an expendable container detachably attached thereto, an expendable container, a storage element or a memory circuit for an expendable container, a printing device (printer), a computer system including a device with an expendable container detachably attached thereto, methods of controlling the operations of such device, system, and storage element, computer programs to attain the functions of such device, system, and storage element, recording media with such computer programs recorded therein, and data signals that include such computer programs and are embodied in carrier waves. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a perspective view schematically showing the appearance of a color printer  10  in one embodiment of the invention.  
         [0015]      FIG. 2  is a perspective view showing the internal structure of the color printer  10 .  
         [0016]      FIG. 3 ( a ) shows the relative positions of non-contact tags to an antenna.  
         [0017]      FIG. 3 ( b ) shows the relative positions of non-contact tags to an antenna.  
         [0018]      FIG. 4 ( a ) shows the structure of the non-contact tag  311  and the receiver transmitter  30 .  
         [0019]      FIG. 4 ( b ) shows the structure of the non-contact tag  311  and the receiver transmitter  30 .  
         [0020]      FIG. 5 ( a ) shows the details of information stored in the memory  3117 .  
         [0021]      FIG. 5 ( b ) shows the details of information stored in the memory  3117 .  
         [0022]      FIG. 6  is a block diagram showing the internal structure of control circuit  50  of the color printer  10 .  
         [0023]      FIG. 7  is a flowchart showing a process of communication between each of the non-contact tags  311  through  316  attached to the respective ink units INC 1  through INC 6  and the receiver transmitter  30  of the color printer  10 .  
         [0024]      FIG. 8 ( a ) shows an operation sequence of the carriage  20  when the color printer  10  activates the receiver transmitter  30  to confirm the ID information stored in each of the non-contact tags  311  through  316 .  
         [0025]      FIG. 8 ( b ) shows an operation sequence of the carriage  20  when the color printer  10  activates the receiver transmitter  30  to confirm the ID information stored in each of the non-contact tags  311  through  316 .  
         [0026]      FIG. 8 ( c ) shows an operation sequence of the carriage  20  when the color printer  10  activates the receiver transmitter  30  to confirm the ID information stored in each of the non-contact tags  311  through  316 .  
         [0027]      FIG. 8 ( d ) shows an operation sequence of the carriage  20  when the color printer  10  activates the receiver transmitter  30  to confirm the ID information stored in each of the non-contact tags  311  through  316 .  
         [0028]      FIG. 8 ( e ) shows an operation sequence of the carriage  20  when the color printer  10  activates the receiver transmitter  30  to confirm the ID information stored in each of the non-contact tags  311  through  316 .  
         [0029]      FIG. 9  is a state transition chart showing operation modes of the non-contact tag  311 .  
         [0030]      FIG. 10  shows one modified configuration in which the induced current in antenna  311  is reduced by changing the resonance frequency of the oscillation circuit. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]     One mode of carrying out the invention is discussed below in the following sequence: 
        A. Structure of Color Printer     B. Communication between Color Printer and Non-Contact Tag     C. Modifications        
 
         [0035]     A. Structure of Color Printer  
         [0036]      FIG. 1  is a perspective view schematically showing the appearance of a color printer  10  in one embodiment of the invention. The color printer  10  is an inkjet printer that forms an image on a printing medium by ejection of four color inks, cyan (C), magenta (M), yellow (Y), and black (K), as well as two light colored inks, light cyan having a lower density than cyan ink and light magenta having a lower density than magenta ink.  
         [0037]      FIG. 2  is a perspective view showing the internal structure of the color printer  10 . One black ink unit INC 1  for keeping black ink therein and five color ink units INC 2  through INC 6  for respectively keeping five color inks therein are attached to a carriage  20 . The carriage  20  is designed to move parallel to a platen  25  by means of a carriage motor  23  and a drive belt  21 . The carriage motor  23  has a non-illustrated encoder and sets the carriage  20  at an arbitrary position by feedback control.  
         [0038]     FIGS.  3 ( a ) and  3 ( b ) show the relative positions of six non-contact tags  311  through  316  attached to the respective ink units INC 1  through INC 6  to an antenna  301  included in a receiver transmitter  30  of the printer  10 . As clearly understood of  FIG. 3 ( b ), the antenna  301  has a width to simultaneously face two of the non-contact tags  311  through  316 . The output of the receiver transmitter  30  is regulated to cause electromagnetic induction transmittable with only the two facing non-contact tags. In the illustrated example of  FIG. 3 ( b ), the output of the antenna  301  is regulated to be transmittable with only the non-contact tags  311  and  312 .  
         [0039]     FIGS.  4 ( a ) and  4 ( b ) show the structure of the non-contact tag  311  and the receiver transmitter  30 .  FIG. 4 ( a ) is a plan view showing the structure of the non-contact tag  311 . The non-contact tag  311  used in this embodiment is a proximity-type (coverage of 2 mm to 10 cm) non-contact tag in conformity with ISO/IEC14443. The non-contact tag  311  includes an IC chip  3111 , a resonant capacitor  3112  formed by etching a metal film, and an antenna  3113  as a plane coil, which are all mounted on a plastic film.  
         [0040]      FIG. 4 ( b ) is a block diagram showing the internal structure of the non-contact tag  311  and the receiver transmitter  30 . The IC chip  3111  of the non-contact tag  311  includes a rectifier circuit  3114 , a voltage regulator  3122 , a reset signal generator  3121 , an RF (radio frequency) unit  3115 , a controller  3116 , and a non-volatile memory  3117 . The receiver transmitter  30  includes the antenna  301  and an IF circuit  302 , which is linked to a peripheral equipment input-output unit (PIO)  54  included in a printer control circuit (discussed later).  
         [0041]     The rectifier circuit  3114  carries out full-wave rectification to convert AC power, which is excited in the antenna  3113  by an AC magnetic field generated by the receiver transmitter  30 , into DC power. The voltage regulator  3122  stabilizes the DC power generated by the rectifier circuit  3114  and supplies the stabilized DC power to the reset signal generator  3121 , the RF unit  3115 , and the controller  3116 . The reset signal generator  3121  outputs a reset signal to the controller  3116 , in response to the output voltage of the voltage regulator  3122 . The control circuit  3116  controls ‘stop’ and ‘operation’ in response to the input reset signal. The controller  3116  functions to control the RF unit  3115  and read and write data from and into the memory  3117 .  
         [0042]     The RF unit  3115  has the functions of: 
        (1) extracting a reference clock signal from the AC power excited in the antenna  3113  to utilize the extracted reference clock signal as the own operation reference, while supplying the extracted reference clock signal to the controller  3116 ; and     (2) demodulating signals received from the receiver transmitter  30  and modulating signals to be transmitted to the receiver transmitter  30 .        
 
         [0045]     FIGS.  5 ( a ) and  5 ( b ) show the details of information stored in the memory  3117 . The memory  3117  has a rewritable area RAA that allows the color printer  10  to read data therefrom and write data therein and a non-rewritable area ROA that allows the color printer  10  to read data therefrom but not to write data therein ( FIG. 5 ( a )).  
         [0046]     The rewritable area RAA is further divided into a user memory and a classification code storage area. The user memory is used for writing, for example, information on remaining quantity of ink in the ink unit INC 1 . The color printer  10  may read the ink remaining quantity information from this user memory and give an alarm to the user when the remaining quantity becomes to or below a preset level. The classification code storage area stores various codes for identifying the types of the ink units. The user may personally use these codes.  
         [0047]     The non-rewritable area ROA stores manufacturing information on the ink unit INC 1  with the non-contact tag  311  attached thereto. The manufacturing information includes unique ID information for identification of the ink unit INC 1  and information on the year, month, day, hour, minute, and second when and the place where the ink unit INC 1  was manufactured ( FIG. 5 ( b )).  
         [0048]      FIG. 6  is a block diagram showing the internal structure of control circuit  50  of the color printer  10 . The control circuit  50  includes a CPU  51 , an EEPROM  52 , a RAM  53 , a peripheral equipment input-output unit (PIO)  54 , a timer  55 , a drive buffer  56 , an oscillator  58 , and an output distributor  59 .  
         [0049]     The PIO  54  is connected with an operation panel  11 , a personal computer PC, the carriage motor  23 , and the receiver transmitter  30 . The drive buffer  56  functions to supply on-off signals for dot formation to print heads IH 1  through IH 6 . Driving waveforms from the oscillator  58  are supplied via the output distributor  59  to the respective print heads IH 1  through IH 6 .  
         [0050]     B. Communication Between Color Printer and Non-Contact Tag  
         [0051]      FIG. 7  is a flowchart showing a process of communication between each of the non-contact tags  311  through  316  attached to the respective ink units INC 1  through INC 6  and the receiver transmitter  30  of the color printer  10 .  
         [0052]     At step S 100 , the color printer  10  carries out an ID information confirmation process, which confirms whether ID information held in the color printer  10  is identical with ID information stored in each of the non-contact tags  311  through  316 . The ID information confirmation process is executed, for example, at each power-on time and in response to the user&#39;s replacement of any of the ink units INC 1  through INC 6  in the power-on state.  
         [0053]     FIGS.  8 ( a ) through  8 ( e ) shows an operation sequence of the carriage  20  when the color printer  10  activates the receiver transmitter  30  to confirm the ID information stored in each of the non-contact tags  311  through  316 .  FIG. 9  is a state transition chart showing operation modes of the non-contact tag  311 . The non-contact tag  311  has five modes, that is, a power-off mode Ml, a standby mode M 2 , an ID information acquisition mode M 3 , an active mode M 4 , and a disable mode M 5 . The other non-contact tags  312  through  316  also have these modes.  
         [0054]     In the non-access state of  FIG. 8 ( a ), the receiver transmitter  30  does not establish communication with any of the non-contact tags  311  through  316 . In this state, the carriage  20  is located apart to the right from a left non-printing area with the receiver transmitter  30 , and all the non-contact tags  311  through  316  are accordingly set in the power-off mode M 1 . The controller  3116  and the RF unit  3115  stop their functions in the power-off mode M 1 .  
         [0055]     In the state of  FIG. 8 ( b ), the carriage  20  stops at the position where the receiver transmitter  30  is communicable with only the non-contact tag  311 . At this position, the right end of the antenna  301  of the receiver transmitter  30  faces the approximate center of the non-contact tag  311 . The output of the receiver transmitter  30  is regulated to fail communication with the non-contact tag  312  for the ink unit INC 2  at this position. In this state, only the non-contact tag  311  shifts to the standby mode M 2 , while the other non-contact tags  312  through  316  are kept in the power-off mode M 1 .  
         [0056]     In the standby mode M 2 , the controller  3116  and the RF unit  3115  are in the power-off state. More specifically, the reset signal generator  3121  of the non-contact tag  312  ( FIG. 4 ( b )) outputs a power-on reset command to the controller  3116 , which accordingly starts its operation. The power-on reset command is output when the non-contact tag  311  approaches to the antenna  301  and the output voltage of the voltage regulator  3122  becomes sufficiently high for the operation of the non-contact tag  311 .  
         [0057]     At this position, the ID information of the non-contact tag  311  is confirmed. The confirmation of the ID information is performed according to the following procedure: 
        (1) The receiver transmitter  30  sends an active mode command including ID information read from the EEPROM  52 ;     (2) The non-contact tag  311  shifts to the active mode M 4  when the ID information included in the active mode command is identical with the own ID information in the non-contact tag  311 ;     (3) On completion of the shift to the active mode M 4 , the non-contact tag  311  sends a signal representing completion of the shift to the receiver transmitter  30 . The signal is sent, for example, by amplitude modulation in a varying magnetic field generated when the non-contact tag  311  varies the load of the antenna  3113 .        
 
         [0061]     In this manner, the color printer  10  receives the signal representing completion of the shift and confirms whether the ID information stored in the EEPROM  52  is identical with the ID information of the non-contact tag  311 .  
         [0062]     In the state of  FIG. 8 ( c ), the carriage  20  stops at the position where the receiver transmitter  30  is communicable with only the two non-contact tags  311  and  312 . In this state, the non-contact tag  311  is in the active mode M 4  and the non-contact tag  312  is in the standby mode M 2 , while the other non-contact tags  313  through  316  are in the power-off state M 1 . At this position, the ID information of the non-contact tag  312  is confirmed in the same manner as the confirmation of the ID information of the non-contact tag  311  discussed above. This series of processing is repeated to confirm the ID information on all the six non-contact tags  311  through  316 .  
         [0063]     After successful confirmation of the ID information on all the six non-contact tags  311  through  316 , the routine goes to step S 130  ( FIG. 7 ). The color printer  10  utilizes the anti-collision function to communicate with the six non-contact tags  311  through  316  at step S 130 . In the case of failed confirmation of the ID information on any one of the six non-contact tags  311  through  316 , on the other hand, the routine goes to step S 120 . No reception of the signal representing completion of the shift to the active mode M 4  means failed confirmation of the ID information.  
         [0064]     At step S 120 , the color printer  10  carries out an ID information acquisition process. The ID information acquisition process acquires the ID information from the six non-contact tags  311  through  316  and stores the acquired ID information into the EEPROM  52 . The ID information acquisition process is triggered by output of an ID information acquisition command from the receiver transmitter  30 .  
         [0065]     In response to output of the ID information acquisition command from the receiver transmitter  30 , any tag in the standby mode M 2  (see  FIG. 9 ) among the six non-contact tags  311  through  316  shifts to the ID information acquisition mode M 3 . For example, when the relative position of the carriage  20  to the receiver transmitter  30  is in the state of  FIG. 8 ( b ), only the non-contact tag  311  shifts from the standby mode M 2  to the ID information acquisition mode M 3 .  
         [0066]     The ID information may be acquired from the non-contact tag  311  according to the following procedure, where it is assumed that the ID information of the non-contact tag  311  is ‘100110’: 
        (1) The receiver transmitter  30  of the color printer  10  checks with the non-contact tag  311  whether the 0 th  bit and the 1 st  bit are ‘00’;     (2) The non-contact tag  311  does not respond to this check since the 0 th  bit and the 1 st  bit in its ID information are ‘10’. The color printer  10  thus confirms that the 0 th  bit and the 1 st  bit in the ID information of the non-contact tag  311  are not ‘00’;     (3) The receiver transmitter  30  checks with the non-contact tag  311  whether the 0 th  bit and the 1 st  bit are ‘01’;     (4) The non-contact tag  311  does not respond to this check since the 0 th  bit and the 1 st  bit in its ID information are ‘10’. The color printer  10  thus confirms that the 0 th  bit and the 1 st  bit in the ID information of the non-contact tag  311  are not ‘01’;     (5) The receiver transmitter  30  checks with the non-contact tag  311  whether the 0 th  bit and the 1 st  bit are ‘10’;     (6) The non-contact tag  311  gives a matching response since the 0 th  bit and the 1 st  bit in its ID information are ‘10’. The color printer  10  thus acquires the value ‘10’ of the 0 th  bit and the 1 st  bit in the ID information of the non-contact tag  311 ;     (7) The receiver transmitter  30  checks with the non-contact tag  311  whether the 2 nd  bit and the 3 rd  bit are ‘00’; and     (8) The color printer  10  acquires the value ‘01’ of the 2 nd  bit and the 3 rd  bit in the ID information of the non-contact tag  311  in the same manner as the processing with regard to the 0 th  bit and the 1 st  bit.        
 
         [0075]     This series of processing is repeated to acquire the value of all the bits in the ID information of the non-contact tag  311 .  
         [0076]     After acquisition of the value of all the bits in the ID information of the non-contact tag  311 , the receiver transmitter  30  outputs a disable command including the acquired ID information. The non-contact tag  311  having the identified ID information then shifts to the disable mode M 5 .  
         [0077]     The controller  3116  and the RF unit  3115  are at a stop in the disable mode M 5 , as in the power-off mode M 1 . The difference from the power-off mode M 1  is that the disable mode M 5  does not shift to the standby mode M 2  regardless of the output voltage of the voltage regulator  3122 . This is attained, for example, by setting the reset signal generator  3121  not to output the power-on reset command irrespective of the output voltage of the voltage regulator  3122  but to output a power-off command to the controller  3116 .  
         [0078]     The shift of the operation mode of the non-contact tag  311  having the identified ID information to the disable mode M 5  assures successful acquisition of the ID information from the subsequent non-contact tag  312  at the position of the carriage  20  shown in  FIG. 8 ( c ).  
         [0079]     In the following environments, the color printer  10  may fail in acquisition of the ID information from the subsequent non-contact tag  312 . This is ascribed to a variation of the transmission frequency of the receiver transmitter  30  and variations of the resonance frequencies of the non-contact tags  311  and  312 . 
        (1) The resonance frequency of the non-contact tag  311  is extremely close to the transmission frequency of the receiver transmitter  30 ; and     (2) The resonance frequency of the non-contact tag  312  is deviated from the transmission frequency of the receiver transmitter  30  in the range of a tolerance.        
 
         [0082]     Under such environments, a relatively strong electric current is flown to the antenna  3113  of the non-contact tag  311 . The magnetic field produced by the antenna  3113  weakens the magnetic field in the non-contact tag  312 . The non-contact tag  312  may accordingly have only an insufficient level of voltage and may not shift from the power-off mode M 1  to the standby mode M 2 .  
         [0083]     One possible countermeasure is to raise the transmission output of the receiver transmitter  30 . This, however, leads to a potential trouble, that is, an unexpected response of the non-contact tag  313 . The procedure of this embodiment shifts the operation mode of the adjoining non-contact tag  311  to the disable mode M 5  after acquisition of the ID information, in order to enhance the magnetic field in the non-contact tag  312  without raising the transmission output of the receiver transmitter  30 .  
         [0084]     In the disable mode M 5 , substantially no electric power is consumed in the non-contact tag  311 , and very little electric current is flown to the antenna  3113 . This naturally leads to generation of a very weak magnetic field by the antenna  3113  and thus does not significantly weaken the magnetic field in the adjoining non-contact tag  312 .  
         [0085]     At step S 130 , the color printer  10  carries out a reset process. The reset process stops transmission by the receiver transmitter  30  on completion of acquisition of the ID information on all the six non-contact tags  311  through  316 . The six non-contact tags  311  through  316  then shift from the disable mode M 5  to the power-off mode M 1 , and the routine returns to step S 100  ( FIG. 7 ).  
         [0086]     As discussed above, the procedure of this embodiment shifts the operation mode of a non-contact tag to the disable mode M 5  after acquisition of the ID information on the non-contact tag and thereby prevents the magnetic field produced by the non-contact tag from being significantly enhanced. This does not significantly weaken the electromagnetic induction in an adjoining non-contact tag and thus effectively restrains deterioration of the reliability in communication.  
         [0087]     C. Modifications  
         [0088]     The embodiment discussed above is to be considered in all aspects as illustrative and not restrictive. There may be many modifications, changes, and alterations without departing from the scope or spirit of the main characteristics of the present invention. Some examples of possible modification are given below.  
         [0089]     C-1. In the structure of the above embodiment, after acquisition of ID information on a cartridge from a non-contact tag attached to the cartridge, the non-contact tag is shifted to the disable mode. In the case where the color printer has already acquired the ID information of the cartridge, the non-contact tag may be shifted to the disable mode after confirmation of no change of the cartridge.  
         [0090]     The terminology ‘confirmation of ID information’ in the claims is used in the broadest sense and includes acquisition of ID information discussed in the above embodiment. The ‘ID information confirmation mode’ in the claims is equivalent to the ‘ID information acquisition mode’ in the embodiment.  
         [0091]     C-2. In the structure of the above embodiment, the non-contact tag shifts to the disable mode, in response to reception of the disable command sent from the receiver transmitter. In one modified structure, the expendable container may be designed to automatically shift to the disable mode on completion of transmission of all the ID information.  
         [0092]     C-3. In the above embodiment, in response to a shift of a non-contact tag to the disable mode, its controller and RF unit stop the respective functions. Another possible structure may decrease the frequency of an internal clock to lower the power consumption. The only requirement for the low power consumption mode of the invention is to lessen the functions of the controller and thereby lower the power consumption. The clock signal may be oscillated and generated inside the non-contact tag.  
         [0093]     C-4. In the structure of the above embodiment, the reset signal generator is set to output the power-off command to the controller, irrespective of the output voltage of the voltage regulator. In one modified structure, an oscillation circuit as shown in  FIG. 10  may be attached to the non-contact tag. A self-holding circuit La in the oscillation circuit switches off, in response to confirmation of the ID information. This decreases the flow of electric current through the antenna  3113  and ensures an automatic reset process, in response to the weakened magnetic field by a stop of the transmission output of the receiver transmitter  30  or by the relative motion of the receiver transmitter  30 . The structure of the invention is generically designed to stop the functions of the controller on completion of confirmation of ID information on the cartridge.  
         [0094]     C-5. In the structure of the above embodiment, the color printer establishes non-contact communication with each non-contact tag by taking advantage of the electromagnetic induction. Electromagnetic coupling may alternatively be used to establish non-contact communication. The target of the invention is thus any non-contact communication without any electrical connection.  
         [0095]     C-6. The above embodiment regards the printer with ink units detachably attached thereto. The technique of the invention is generically applicable to diverse devices with an expendable cartridge detachably attached thereto. It is not necessary that multiple expendable cartridges are simultaneously mountable on the device, but the only requirement is the device is capable of utilizing multiple expendable cartridges. In the structure of the above embodiment, the expendable cartridges are moved with the carriage (cartridge attachment module). In one modified design, the receiver transmitter may be moved, instead of the carriage.