Patent Publication Number: US-6984012-B2

Title: Cartridge and recording apparatus

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a cartridge that has a chamber for holding a recording material used for recording therein. More specifically the invention pertains to a cartridge with a built-in non-volatile memory and a technique of transmitting information to and from such a cartridge. 
   2. Description of the Related Art 
   Recording apparatus that eject inks on printing paper to record images, such as ink jet printers, and recording apparatus that utilize toners for recording have widely been used. A cartridge attached to such a recording apparatus has a chamber for holding a recording material like ink or toner therein. Management of the residual quantity of the recording material is an important technique in the recording apparatus. The recording apparatus counts the consumption of the recording material according to the software program. Data on the residual quantity of the recording material computed from the observed count are stored in a memory of the recording apparatus for the management purpose. The same data may also be stored in a built-in memory of the cartridge. 
   A non-volatile memory is applicable for the built-in memory of the cartridge. The non-volatile memory enables data, such as the residual quantity of ink, to be kept even after detachment of the cartridge from the recording apparatus. Application of such a memory ensures consistent management of the residual quantity of ink and other data even when the replaced cartridge is attached again to the recording apparatus. 
   An important issue of such cartridges with the built-in memory is to ensure a sufficiently high reliability in the storage content of the memory. There are two primary causes of lowering the reliability in the storage content of the memory. One cause is an accidental cutoff of the power supply to the recording apparatus in the course of updating data into the cartridge or a careless detachment of the cartridge in the course of updating data. In such cases, it is practically impossible to verify the updated storage content in the memory of the cartridge. The other cause is a failed electrical connection. The cartridge is basically designed to be freely attachable to and detachable from the recording apparatus so that no fixed signal line is usable for connection with the memory in the cartridge. This may cause a loose contact or another failure in electrical connection. 
   One possible measure carries out the memory updating operation a plurality of times. Another possible measure provides duplicate memories and writes identical data into the duplicate memories. In the case of a loose connection of a signal line, however, these measures do not heighten the reliability. When an electrically erasable semiconductor memory (EEPROM) is applied for the built-in memory of the cartridge, the data rewriting procedure first erases the existing data in the memory and then writes new data into the memory. This requires two normal accesses for erasing and writing data and thus demands a high reliability. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is thus to remove the drawbacks of the prior art techniques and to ensure a sufficiently high reliability in the operation of updating data in a cartridge equipped with a memory. 
   In order to attain at least part of the above and the other related objects, the present invention is directed to a cartridge that holds a recording material used for recording therein and is mounted on a recording apparatus. The cartridge includes: a memory that stores information regarding the cartridge in a non-volatile manner; an instruction reception module that receives an external instruction including at least a specified address of the memory with regard to a series of processing that involves rewriting a storage content of the memory; a processing execution module that executes the series of processing that involves rewriting the storage content at the specified address of the memory; and an output module that outputs specific data corresponding to the specified address after execution of the series of processing. 
   The cartridge has the memory that stores the cartridge-related information in a non-volatile manner and receives an external instruction including at least a specified address of the memory with regard to a series of processing that involves rewriting the storage content of the memory. The cartridge executes the series of processing that involves rewriting the storage content at the specified address of the memory in response to the given external instruction, and outputs specific data corresponding to the specified address. The specific data corresponding to the specified address may be identical with the specified address or data representing multiple upper bits or multiple lower bits of the specified address. The specific data may otherwise be a checksum of the specified address, a cyclic redundancy code (CRC), or a hamming code. The recording apparatus, which has given the external instruction with regard to the series of processing that involves rewriting the storage content of the memory, reads the output data and verifies whether the series of processing has been executed successfully at the specified address. 
   The series of processing that involves rewriting the storage content of the memory may be an operation of writing data into the memory or an operation of erasing data from the memory. In some memories, the data erasing operation is required prior to the data writing operation. In such cases, the series of processing includes the data erasing operation and the subsequent data writing operation. 
   When the series of processing that involves rewriting the storage content of the memory is the data erasing operation, it is preferable that the externally specified address with regard to the data erasing operation has a redundancy of at least 2. The data erasing operation eliminates the storage content of the memory, so that the high redundancy of the specified address, for example, duplication of the address, is desirable. For example, the redundancy of at least 2 possessed by the specified address is attained by a signal corresponding to the specified address and a signal generated by changing bits of the specified address according to a preset rule. Here the preset rule may be at least one of a reciprocal operation, a complementary operation, and a bit rotation. 
   The data output by the output module in response to the externally specified address may be any data corresponding to the specified address; for example, data identical with the specified address, data representing a predetermined part of the specified address, or a code induced from the specified address like a parity code, a hamming code, or a CRC. These codes desirably reduce the number of bits included in the output data, compared with the number of bits constituting the specified address. 
   The output module may output the specific data together with a signal representing completion of the series of processing, after conclusion of the series of processing that involves rewriting the storage content of the memory. The specific data may otherwise be output separately from the signal representing completion of the series of processing. The simultaneous output desirably shortens the total processing time, whereas the separate output desirably enhances the degree of freedom in data structure. 
   The data rewritten in the memory may be data regarding a residual quantity or a consumption of the recording material held in the cartridge, data relating to a state of the processing, data regarding occurrence of any abnormality, data regarding the frequency of detachment of the cartridge or accumulation of the use time of the cartridge, or data regarding the working environment, for example, the temperature and the humidity. 
   The recording material held in the cartridge may be a preset color ink used for a printer or another recording apparatus or a toner for a photocopier, a facsimile, or a laser printer. The recording material may be any material that allows for recording in any manner, for example, a material for a semiconductor or a solution of a catalyst. 
   The memory may be a general parallel access-type memory, but a serial access-type memory is also applicable to reduce the number of signal lines required for signal transmission. The memory desirably has non-volatility or is backed up by a battery. Preferable examples are an electrically erasable programmable memory (EEPROM) and a dielectric memory. 
   Data may be transmitted to and from the cartridge by wire communication or by wireless communication. The technique of partial wire communication and partial wireless communication is also applicable. In the case of wireless communication, the cartridge further includes a wireless communication module that transmits data to and from an outside by wireless communication. At least one of the instruction with regard to the series of processing that involves rewriting the storage content of the memory, the specified address, and the specific data corresponding to the specified address is transmitted via the wireless communication module. The wireless communication does not require any additional electrical connection means like a connector or a terminal and thus facilitates attachment and detachment of the cartridge. 
   In one preferable embodiment, the wireless communication module has a loop antenna that is used to establish the communication, and a power supply module that utilizes an electromotive force induced in the antenna to supply electric power to the cartridge. This structure does not require any additional power source, for example, a battery, in the cartridge for wireless communication. The cartridge may otherwise include a primary battery, or a secondary battery or a capacitor in addition to or in place of the primary battery. 
   The present invention is also directed to a recording apparatus, on which a cartridge having a chamber for holding a recording material used for recording therein is mounted. The cartridge includes: a memory that stores information regarding the cartridge in a non-volatile manner; an instruction reception module that receives an external instruction including at least a specified address of the memory with regard to a series of processing that involves rewriting a storage content of the memory; a processing execution module that executes the series of processing that involves rewriting the storage content at the specified address of the memory; and an output module that outputs specific data corresponding to the specified address after execution of the series of processing. 
   The recording apparatus includes: an address specification module that specifies the address at which the storage content of the memory is to be rewritten; an input module that inputs the specific data corresponding to the specified address output from the output module of the cartridge; and a verification module that compares the input specific data with the address specified by the address specification module and, when the input specific data is identical with the specified address, verifies that the series of processing that involves rewriting the storage content of the memory has been implemented normally. 
   The recording apparatus of the invention gives an instruction including a specified address with regard to a series of processing that involves rewriting the storage content of the memory included in the cartridge. The cartridge executes the series of processing that involves rewriting the storage content at the specified address of the memory in response to the given instruction, and outputs at least the specific data corresponding to the specified address to the recording apparatus. The recording apparatus reads the output specific data and compares the specific data with the specified address. When the specific data is identical with the specified address, the recording apparatus verifies that the series of processing that involves rewriting the storage content at the specified address of the memory has been implemented normally. This arrangement verifies whether data has been rewritten successfully at a right address and thus enhances the reliability in the storage content of the memory in the cartridge. 
   In one preferable arrangement of the invention, the recording apparatus compares the specific data with the address specified by the address specification module and, when the specific data is different from the specified address, causes the processing execution module of the cartridge to execute the series of processing that involves rewriting the storage content of the memory all over again and thereby correct a mistake. This further enhances the reliability in the storage content of the memory. Another preferable arrangement gives a notification representing the discrepancy, when the specific data is different from the specified address. This arrangement informs the user of the occurrence of some error and thereby enhances the reliability of the recording apparatus and the cartridge. In one preferable embodiment, the address specification module of the recording apparatus specifies the address by a signal representing the address at which the storage content of the memory is to be rewritten and a signal generated by changing bits of the address according to a preset rule. Here the preset rule may be at least one of a reciprocal operation, a complementary operation, and a bit rotation. 
   The technique of the present invention is not restricted to the cartridge or the recording apparatus of various arrangements discussed above, but is also applicable to an information transmitting method. 
   The present invention is thus directed to a method of transmitting information to and from a cartridge, which has a chamber for holding a recording material used for recording therein. The information transmitting method includes the steps of: giving an external instruction including at least a specified address with regard to a series of processing that involves rewriting a storage content of a memory from an outside of the cartridge, the memory being provided in the cartridge to store information regarding the cartridge in a non-volatile manner; causing the cartridge to execute the series of processing that involves rewriting the storage content at the specified address of the memory and outputting specific data corresponding to the specified address to the outside of the cartridge; and comparing the output specific data with the specified address and verifying whether the series of processing that involves rewriting the storage content of the memory has been implemented normally. 
   These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  schematically illustrates the structure of an ink cartridge and a printer, to which the ink cartridge is attached, in one mode of the invention; 
       FIG. 2  is a flowchart showing a series of processing executed by a memory controller of the ink cartridge, in combination with a series of processing executed by a control unit of the printer; 
       FIG. 3  schematically illustrates the structure of an ink jet printer in one embodiment of the invention; 
       FIG. 4  shows the electric construction of a control circuit included in the printer of the embodiment; 
       FIGS. 5A and 5B  show the appearance of a detection memory module in the embodiment; 
       FIG. 6  is an end view showing attachment of the detection memory module to an ink cartridge in the embodiment; 
       FIG. 7  is a block diagram showing the internal structure of the detection memory module; 
       FIGS. 8A and 8B  show the positional relation between a receiver transmitter unit and ink cartridges mounted on a carriage of the printer; 
       FIGS. 9A and 9B  show information stored in an EEPROM as an internal memory of the detection memory module; 
       FIG. 10  is a flowchart showing a series of processing executed by the control circuit of the printer in cooperation with the detection memory module attached to each ink cartridge; 
       FIG. 11  is a timing chart in a data rewriting operation in the EEPROM; and 
       FIG. 12  is a flowchart showing a verification routine executed by the control circuit of the printer in the data rewriting operation in the EEPROM. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  schematically illustrates the structure of an ink cartridge  10  and a printer  20  as a recording apparatus, to which the ink cartridge  10  is attached, in one mode of the invention. The printer  20  makes ink ejected from a print head  25  and thereby prints an image on printing paper T, which is transported by means of a platen  24 . The printer  20  includes a control unit  22 , although the internal structure of the printer  20  is not described nor illustrated specifically. The control unit  22  computes an ink consumption used for printing and other required data and transmits the computed data to the ink cartridge  10  via a receiver transmitter unit  30 . Data are transmitted between the printer  20  and the ink cartridge  10  by wireless, although wire communication may be adopted alternatively. The electromagnetic induction technique is applied for wireless communication in this mode of the invention, though another technique is also applicable. 
   The ink cartridge  10  includes a communication controller  12  that controls communication, a memory controller  15  that controls reading and writing data from and into a memory  14 , a sensor  17  of a piezoelectric element, and a sensor controller  19  that actuates and controls the sensor  17  to detect a residual level of ink. The memory controller  15  transmits data to and from the memory  14 , in response to instructions output from the printer  20  and received by the communication controller  12 . The data transmission includes three primary processes, that is, a process of reading data from a specified address in the memory  14 , a process of erasing data from the specified address in the memory  14 , and a process of writing data at the specified address in the memory  14 . The sensor controller  19  actuates the sensor  17  and detects the residual level of ink by taking advantage of a variation in resonance frequency of a resonance chamber  18  provided in an ink chamber  16 . 
     FIG. 2  is a flowchart showing a series of processing executed by the memory controller  15 , in combination with a series of processing executed by the control unit  22  of the printer  20 . The memory controller  15  is actualized, for example, by a circuit structure including a gate array. For convenience of the explanation, however, the respective operations performed in the memory controller  15  are described according to the flowchart. The control unit  22  of the printer  20  gives an instruction for rewriting the storage contents at a specific address in the memory  14  (step S 5 ). More specifically, the control unit  22  gives either an instruction for erasing data from the specified address in the memory  14  or an instruction for rewriting data at the specified address in the memory  14 . The memory controller  15  of the ink cartridge  10  receives the given instruction including the specification of the required processing and the specified address as the object to be processed (step S 10 ). 
   The memory controller  15  then instructs the specified address in the memory  14  to rewrite its storage contents (step S 13 ). The concrete procedure of this step outputs a 1-byte operand and a 1-byte address to the memory  14 . The 1-byte operand represents the specification of the required processing, for example, an erasing operation, a reading operation, or a writing operation. The address is specified by the 1-byte data in this description, but the data size may be varied according to the length of the address in the case of the memory  14  having a sufficiently large storage capacity. For the enhanced reliability, even if the capacity of 1 byte is enough for the data size of the address, the capacity of 2 bytes may be assigned to the address specification. For example, an identical address is output consecutively as the 2-byte data after the 1-byte operand representing either a rewriting or erasing operation. In another example, 1-byte complement address data may follow the 1-byte address specification data. The order of the latter 2-byte data may be inverted. Namely the instruction may include the 1-byte operand representing either a rewriting operation or an erasing operation, the 1-byte complement address data, and the 1-byte address data in this order. The 1-byte data added to the address may be obtained by a preset arithmetic operation, for example, a reciprocal operation, a complementary operation, or a bit rotation, of the bit sequence representing the address. The additional 1-byte data is not restricted to the arithmetic operation of the address, but may be a checksum of the address, a hamming code, an error correcting code, or any other suitable data. 
   The memory  14  receives the operand and the address output from the memory controller  14 , rewrites or erases data at the specified address in response to the given instruction, and sends back a signal representing a concluded access to the memory controller  15  within a preset time. The memory controller  15  is accordingly informed of the result of the data rewriting or erasing operation at the specified address in the memory  14 . The memory controller  15  then outputs an acknowledgement ACK and the 1-byte address as the object of the data rewriting operation via the communication controller  12  (step S 15 ). 
   The control unit  22  of the printer  20  receives the acknowledgement ACK and the address as the object of the data rewriting operation (step S 20 ) and compares the received address with the address specified previously by the control unit  22  (step S 30 ). When the address received from the ink cartridge  10  is identical with the address specified previously by the control unit  22 , the control unit  22  determines that data has been rewritten normally (step S 40 ). When the received address is not identical with the specified address, on the other hand, the control unit  22  determines that there has been some error in the process of rewriting data at the specified address in the memory  14  of the ink cartridge  10  (step S 50 ). 
   As described above, the technique of the invention applied to the ink cartridge  10  enables the storage contents to be rewritten at an externally specified address in the memory  14  and allows the specified address as the object of rewriting to be checked after the data rewriting operation. Even if the specified address in the memory  14  is changed by noise or another reason, this arrangement effectively informs the control unit  22  of the printer  20  of an erroneous data rewriting operation at a wrong address. 
   This technique of the invention is applicable to various printers. The following describes application of the invention to an ink jet printer  200  as one embodiment.  FIG. 3  schematically illustrates the structure, especially the operation-related structure, of the ink jet printer  200 .  FIG. 4  shows the electric construction of a control circuit  222  of the printer  200 . As shown in  FIG. 3 , the printer  200  makes ink droplets ejected from print heads  211  through  216  onto printing paper T, which is fed from a paper feed unit  203  and is transported by means of a platen  225 , so as to form an image on the printing paper T. The platen  225  is actuated and rotated by the driving force transmitted from a paper feed motor  240  via a gear train  241 . The rotational angle of the platen  225  is measured by an encoder  242 . The print heads  211  through  216  are mounted on a carriage  210 , which moves back and forth along the width of the printing paper T. The carriage  210  is linked with a conveyor belt  221 , which is actuated by a stepping motor  223 . The conveyor belt  221  is an endless belt and is spanned between the stepping motor  223  and a pulley  229  arranged on the opposite side. With rotations of the stepping motor  223 , the conveyor belt  221  moves to reciprocate the carriage  210  along a conveyor guide  224 . 
   Ink cartridges  111  through  116  of six different color inks are attached to the carriage  210 . The six color ink cartridges  111  through  116  basically have an identical structure and respectively store inks of different compositions, that is, inks of different colors, in their internal ink chambers. More specifically, the ink cartridges  111  through  116  respectively store black ink (K), cyan ink (C), magenta ink (M), yellow ink (Y), light cyan ink (LC), and light magenta ink (LM). The light cyan ink (LC) and the light magenta ink (LM) are regulated to have ¼ of the dye densities of the cyan ink (C) and the magenta ink (M). Detection memory modules  121  through  126  (discussed later) are attached to these ink cartridges  111  through  116 , respectively. The detection memory modules  121  through  126  transmit data to and from the control circuit  222  of the printer  200  by wireless communication. In the structure of this embodiment, the detection memory modules  121  through  126  are attached to the respective side planes of the ink cartridges  111  through  116 . 
   The printer  200  has a receiver transmitter unit  230  to establish wireless communication with and data transmission to and from these detection memory modules  121  through  126 . The receiver transmitter unit  230 , as well as the paper feed motor  240 , the stepping motor  223 , the encoder  242 , and the other electronic parts, are connected to the control circuit  222 . Diverse switches  247  and LEDs  248  on an operation panel  245  located on the front face of the printer  200  are also connected with the control circuit  222 . 
   As shown in  FIG. 4 , the control circuit  222  includes a CPU  251  that controls the constituents of the whole printer  200 , a ROM  252  that stores control programs therein, a RAM  253  that is used to temporarily register data, a PIO  254  that functions as an interface with external devices, a timer  255  that manages the time, and a drive buffer  256  that stores data for driving the print heads  211  through  216 . These circuit elements are mutually connected via a bus  257 . The control circuit  222  also includes an oscillator  258  and an output divider  259 , in addition to these circuit elements. The output divider  259  distributes a pulse signal output from the oscillator  258  into common terminals of the six print heads  211  through  216 . Each of the print heads  211  through  216  receives dot on-off data (ink ejection non-ejection data) from the drive buffer  256  and makes the ink ejected from corresponding nozzles according to the dot on-off data received from the drive buffer  256  in response to driving pulses output from the output divider  259 . 
   A computer PC that outputs object image data to be printed to the printer  200 , as well as the stepping motor  223 , the paper feed motor  240 , the encoder  242 , the receiver transmitter unit  230 , and the operation panel  245  are connected to the PIO  254  of the control circuit  222 . The computer PC specifies an object image to be printed, makes the specified object image subjected to required series of processing, such as rasterizing, color conversion, and halftoning, and outputs resulting processed data to the printer  200 . The printer  200  detects the moving position of the carriage  210  according to the driving quantity of the stepping motor  223 , while checking the paper feed position based on the data from the encoder  242 . The printer  200  expands the processed data output from the computer PC into dot on-off data representing ink ejection or non-ejection from nozzles of the print heads  211  through  216  and actuates the drive buffer  256  and the output divider  259 . 
   The control circuit  222  transmits data by wireless to and from the detection memory modules  121  through  126  attached to the ink cartridges  111  through  116  via the receiver transmitter unit  230  connecting with the PIO  254 . The receiver transmitter unit  230  accordingly has an RF conversion element  231  that converts signals from the PIO  254  into alternating current (AC) signals of a fixed frequency, and a loop antenna  233  that receives the AC signals from the RF conversion element  231 . When the loop antenna  233  receives the AC signal, the electromagnetic induction excites an electric signal in another antenna located close to the loop antenna  233 . The distance of wireless communication is restricted in the printer  200 , so that electromagnetic induction-based wireless communication technique is adopted in the structure of this embodiment. 
   The following describes the structure of the detection memory module  121  attached to the ink cartridge  111 .  FIGS. 5A and 5B  are a front view and a side view showing the detection memory module  121 . The detection memory modules  121  through  126  mounted on the respective ink cartridges  111  through  116  have an identical structure, except ID numbers stored therein. The discussion accordingly regards the detection memory module  121  as an example. As illustrated, the detection memory module  121  has an antenna  133  formed as a metal thin film pattern on a thin film substrate  131 , an exclusive IC chip  135  having diverse functions built therein as discussed later, a sensor module  137  that detects the presence or the absence of ink, and a wiring pattern  139  that mutually connects these constituents. 
     FIG. 6  is an end view showing attachment of the detection memory module  121  to the ink cartridge  111 . The detection memory module  121  is fixed to the side face of the ink cartridge  111  by means of an adhesive layer  141  of, for example, an adhesive or a double-faced tape. The sensor module  137  disposed on the rear face of the substrate  131  is fit in an opening  143  formed in the side plane of the ink cartridge  111 . A resonance chamber  151  is formed inside the sensor module  137 , and a piezoelectric element  153  functioning as a sensor is bonded to the side wall of the resonance chamber  151 . 
     FIG. 7  is a block diagram showing the internal structure of the detection memory module  121 . The detection memory module  121  has an RF circuit  161 , a power supply unit  162 , a data analyzer  163 , an EEPROM controller  165 , an EEPROM  166 , a detection controller  168  that transmits data to and from the sensor module  137  equipped with the piezoelectric element  153  to detect the residual quantity of ink, and an output unit  178 , which are all built in the exclusive IC chip  135 . 
   The RF circuit  161  demodulates an AC signal generated in the antenna  133  by the electromagnetic induction, extracts an electric power component and a signal component from the demodulated AC signal, and outputs the electric power component to the power supply unit  162  while outputting the signal component to the data analyzer  163 . The RF circuit  161  also functions to receive a signal from the output unit  178  (described later), modulates the received signal to an AC signal, and transmits the modulated AC signal to the receiver transmitter unit  230  of the printer  200  via the antenna  133 . The power supply unit  162  receives the electric power component from the RF circuit  161 , stabilizes the received electric power component, and outputs the stabilized electric power component as power sources of the exclusive IC chip  135  and the sensor module  137 . No independent power source, such as dry cells, is thus required for each of the ink cartridges  111  through  116 . When the signal-induced power supply time from the receiver transmitter unit  230  is restricted, the detection memory module  121  may additionally have a charge accumulator element, such as a capacitor, that effectively accumulates the stabilized power source generated by the power supply unit  162 . The charge accumulator element may be disposed before the power supply unit  162 . 
   The data analyzer  163  analyzes the signal component received from the RF circuit  161  and extracts a command and data from the analyzed signal component. The data analyzer  163  specifies either data transmission to and from the EEPROM  166  or data transmission to and from the sensor module  137 , based on the result of the data analysis. The data analyzer  163  also carries out identification of the object ink cartridge of the data transmission to and from either the EEPROM  166  or the sensor module  137 . The details of the identification process will be discussed later, but basically the identification process identifies the ink cartridge, based on information representing the location of each ink cartridge mounted on the carriage  210  relative to the receiver transmitter unit  230  as shown in  FIGS. 8A and 8B  and the ID stored in each ink cartridge.  FIG. 8A  is a perspective view showing the positional relation between the ink cartridges  111  through  116  with the detection memory modules  121  through  126  attached thereto and the receiver transmitter unit  230 .  FIG. 8B  shows the relative widths of the ink cartridges  111  through  116  and the receiver transmitter unit  230 . 
   For identification of the object ink cartridge, the control circuit  222  shifts the carriage  210  to approach to the receiver transmitter unit  230 . The location of the carriage  210  facing the receiver transmitter unit  230  is outside a printable range. As shown in  FIGS. 8A and 8B , the detection memory modules  121  through  126  are attached to the side faces of the respective ink cartridges  111  through  116 . The shift of the carriage  210  causes two detection memory modules at the maximum to enter a transmittable range of the receiver transmitter unit  230 . In this state, the data analyzer  163  receives a request from the control circuit  222  via the receiver transmitter unit  230  and performs identification of the object ink cartridge and subsequent data transmission to and from the EEPROM  166  or the sensor module  137 . The details of the processing will be discussed later with reference to the flowchart. 
   When data transmission to and from the EEPROM  166  is performed after identification of the object ink cartridge, the data analyzer  163  transfers a specified address for a reading, writing, or erasing operation and specification of the processing, that is, selection of the reading operation, the writing operation, or the erasing operation, as well as data in the case of the data writing operation, to the EEPROM controller  165 . The EEPROM controller  165  receives the specified address, the specification of the processing, and the data to be written and outputs the specified address and the specification of the processing to the EEPROM  166 , so as to read the existing data from the specified address of the EEPROM  166 , write the received data at the specified address of the EEPROM  166 , or erase the existing data from the specified address of the EEPROM  166 . 
   The internal data structure of the EEPROM  166  is shown in  FIGS. 9A and 9B . The memory space of the EEPROM  166  is roughly divided into two sections as shown in  FIG. 9A . The former section of the memory space is a readable and writable area RAA including a classification code area and a user memory area, which data like the residual quantity of ink are read from and written in. The latter section of the memory space is a read only area ROA which ID information for identifying the ink cartridge is written in. 
   The ID information is written into the read only area ROA prior attachment of each of the detection memory modules  121  through  126  including the EEPROM  166  to the corresponding ink cartridge  111  through  116 , for example, in the manufacturing process of the detection memory module or in the manufacturing process of the ink cartridge. The printer  200  is allowed to write data into the readable writable area RAA and read and erase the existing data stored in the readable writable area RAA. The printer  200  is, however, not allowed to write data into the read only area ROA, while being allowed to read data from the read only area ROA. 
   The user memory area of the readable writable area RAA is used to write information regarding the residual quantity of ink in the corresponding ink cartridge  111  through  116 . The printer  200  reads the information on the residual quantity of ink and may give an alarm to the user when the residual quantity of ink is below a preset level. The classification code area stores various codes for distinction of the corresponding ink cartridge. The user may use these codes according to the requirements. 
   The ID information stored in the read only area ROA includes production information on the corresponding ink cartridge, to which the detection memory module is attached. A typical example of the ID information regards the year, the month, the date, the hour, the minute, the second, and the place of production of the corresponding ink cartridge  111  through  116  as shown in  FIG. 9B . Each piece of the ID information requires a memory area of 4 to 8 bits, so that the ID information totally occupies a memory area of 40 to 70 bits. On each power supply of the printer  200 , the control circuit  222  of the printer  200  may read the ID information including the production information of the ink cartridges  111  through  116  from the detection memory modules  121  through  126  and give an alarm to the user when any of the ink cartridges has been expired or will be expired soon. 
   Adequate pieces of information other than the information discussed above may also be stored in the EEPROM  166  of the detection memory module  121 . The whole area of the EEPROM  166  may be constructed as a readable and writable area. In this case, an electrically readable and writable memory, such as a NAND flash ROM, may be applied for the EEPROM  166  to store the ID information like the production information of the ink cartridge. In the structure of this embodiment, a serial-type memory is applied for the EEPROM  166 . 
   When data transmission to and from the sensor module  137  is performed after identification of the object ink cartridge, on the other hand, the data analyzer  163  receives a detection condition from the control circuit  222  and transfers the received detection condition to the detection controller  168 . The detection controller  18  receives the transferred detection condition, actuates the sensor module  137  according to the detection condition, and determines whether the level of the ink reaches the position of the sensor module  137 , based on the variation in resonance frequency of the piezoelectric element  153 . The result of the detection is sent back from the sensor module  137  to the detection controller  168 . The output unit  178  receives the detection result from the detection controller  168  and outputs the detection result to the control circuit  222  of the printer  200  via the RF circuit  161 . 
   The following describes the identification of the object ink cartridge and the subsequent access, which are executed by the control circuit  222  of the printer  200  in cooperation with the data analyzer  163  of the corresponding detection memory module.  FIG. 10  is a flowchart showing a series of processing executed by the control circuit  222  of the printer  200  in cooperation with the detection memory module attached to each ink cartridge through communication via the receiver transmitter unit  230 . The control circuit  222  of the printer  200  and the data analyzer  163  of each detection memory module establish communication via the receiver transmitter unit  230  and carry out an ID information reading process (first process), a memory access process to read information other than the ID information and write information on the residual quantity of ink (second process), and a sensor access process to transmit data to and from the sensor module  137  (third process). 
   On each power supply to the printer  200 , at the time of replacement of any of the ink cartridges  111  through  116  in the power ON condition, or after elapse of a preset time since previous execution of communication, the printer  200  reads the production information of the ink cartridge and writes and reads the residual quantity of ink into and from a predetermined area in the EEPROM  166 . Unlike the general printing process, this series of processing require communication with each of the detection memory modules  121  through  126  via the receiver transmitter unit  230 . 
   In order to establish communication with the detection memory modules  121  through  126 , the carriage  210  with the ink cartridges  111  through  116  mounted thereon is apart from its standard printable area or a right-side non-printable area and is shifted to a left-side non-printable area where the receiver transmitter unit  230  is present. As the carriage  210  moves to the left-side non-printable area, the detection memory module approaching the receiver transmitter unit  230  receives an AC signal from the loop antenna  233  of the receiver transmitter unit  230  via the antenna  133 . The power supply unit  162  extracts an electric power component from the received AC signal, stabilizes the electric power component, and supplies the stabilized electric power to the respective controllers and circuit elements to activate the controllers and the circuit elements. 
   When the processing routine starts with communication established between the receiver transmitter unit  230  and each of the detection memory modules  121  through  126 , the control circuit  222  of the printer  200  first determines whether there is a power ON request (step S 100 ). This step determines whether the power has just been supplied to the ink jet printer  200  to start its operations. When there is a power ON request (in the case of an affirmative answer at step S 100 ), the first process starts to read the ID information from the respective detection memory modules  121  through  126  (step S 104 ). 
   When there is no power ON request (in the case of a negative answer at step S 100 ), on the other hand, the control circuit  222  determines that the printer  200  is carrying out the general printing process and subsequently determines whether there is a replacement request of the ink cartridges  111  through  116  (step S 102 ). The replacement request of the ink cartridges  111  through  116  is output, for example, when the user presses an ink cartridge replacement button  247  on the operation panel  245  in the power ON state of the printer  200 . In response to a press of the ink cartridge replacement button  247 , the printer  200  stops the general printing process to allow for replacement of any of the ink cartridges  111  through  116 . The replacement request is output after actual replacement of any of the ink cartridges  111  through  116 . 
   When there is a replacement request of the ink cartridges  111  through  116  (in the case of an affirmative answer at step S 102 ), the first process starts to read the ID information from the detection memory module attached to a replaced ink cartridge (step S 104 ). When there is no replacement request of the ink cartridges  111  through  116  (in the case of a negative answer at step S 102 ), on the other hand, the control circuit  222  determines that the ID information has already been read normally from the respective detection memory modules  121  through  126 , for example, at the time of power supply and then specifies the object of access (step S 150 ). There are two options, that is, the EEPROM  166  and the sensor module  137 , as the object of access in each of the ink cartridges ill through  116  of the embodiment. When the object of access is the EEPROM  166  (in the case of selection of memory at step S 150 ), the second process starts to gain access to one of the detection memory modules  121  through  126  (step S 200 ). When the object of access is the sensor module  137  (in the case of selection of sensor at step S 150 ), on the other hand, the third process starts to read the detection result from the sensor module  137 . 
   The details of the first through the third processes are discussed. The first process is executed when the control circuit  222  detects the power ON request of the printer  200  or the replacement request of the ink cartridges  111  through  116  as mentioned above. The first process starts reading the ID information from the respective detection memory modules  121  through  126  (step S 104 ) and carries out anti-collision processing (step S 106 ). The anti-collision processing is required to prevent interferences when the control circuit  222  reads the ID information from the respective detection memory modules  121  through  126  for the first time. In the case of any failure or trouble in the middle of the anti-collision processing, the anti-collision processing is carried out all over again. In the structure of the embodiment utilizing wireless communication, the receiver transmitter unit  230  is always communicable with multiple detection memory modules (for example, two detection memory modules). At the start of communication, the control circuit  222  has not gained yet the ID information of the respective detection memory modules  121  through  126  attached to the ink cartridges  111  through  116  mounted on the carriage  210 . The anti-collision processing is thus required to prevent interferences at this moment. The anti-collision processing is a known technique and is thus not described here in detail. The receiver transmitter unit  230  outputs a specific piece of ID information. Only a detection memory module having ID information identical with the specific piece of ID information responds to the receiver transmitter unit  230 , while the other detection memory modules fall into a sleep mode. The control circuit  222  of the printer  200  establishes communication with the detection memory module of the ink cartridge, which is located in the communicable range and has the identical ID information. 
   On conclusion of the anti-collision processing, the control circuit  222  causes the data analyzer  163  to read the ID information from the respective detection memory modules  121  through  126  (step S 108 ). After reading the ID information, the program may exit from this communication processing routine or may subsequently read all the data stored in the EEPROM  166  as described below. 
   In order to ensure the reliability of data stored in the detection memory modules  121  through  126  attached to the ink cartridges  111  through  116 , the control circuit  222  reads all the data stored in the EEPROMs 166 of the respective detection memory modules  121  through  126  and stores the read-out data into the RAM  253 . At the time of power supply to the printer  200 , the control circuit  222  establishes communication with the respective detection memory modules  121  through  126  of the ink cartridges  111  through  116  attached to the printer  200 , reads data from the EEPROMs 166 of the detection memory modules  121  through  126 , and stores the read-out data into a specific area of the RAM  253 . The actual flow of this procedure is similar to the second process discussed below with only difference is that this procedure sequentially reads data from all the addresses in the EEPROM  166  without any verification, which is executed in the second process. The read-out data are continuously kept in the RAM  253  and are used to correct the data registered in the ink cartridge  111  when the data in the ink cartridge  111  has poor reliability, for example, when some error arises in the ink cartridge  111  in the course of communication. Whenever rewriting the data stored in the EEPROM  166  of any of the detection memory modules  121  through  126 , the control circuit  222  of the printer  200  updates data at a corresponding address in the RAM  253 . This arrangement enables the data stored in the RAM  253  to be updated at required timings and thereby have high reliability. 
   According to the second process, the control circuit  222  initiates a memory access (step S 200 ) and outputs an active mode command AMC to each of the detection memory modules  121  through  126  (step S 202 ). The active mode command AMC is output together with the ID information regarding each of the detection memory modules  121  through  126 . The data analyzer  163  included in each of the detection memory modules  121  through  126  compares the received ID information with the ID information stored in the detection memory module and transmits a response signal ACK showing ready for an access to the control circuit  222  only when the received ID information is identical with the stored ID information. 
   The control circuit  222  gains an actual memory access to the detection memory module, which has just transmitted the response signal ACK responding to the output active mode command AMC (step S 204 ). The memory access is implemented to write data at a specified address in the EEPROM  166 , to erase the existing data from the specified address in the EEPROM  166 , or to read the existing data from the specified address in the EEPROM  166 . In any case, the EEPROM controller  165  receives the specified address and the specification of the required processing, that is, the writing operation, the erasing operation, or the reading operation from the control circuit  222  and accesses the specified address in the EEPROM  166  to carry out the required operation. 
   The writing operation and the erasing operation are discussed in detail.  FIG. 11  is a timing chart showing the writing operation and the erasing operation. The control circuit  222  outputs a 1-byte operand code OP and 2-byte address codes AD 1  and AD 2 , which represent the specified address as the object of the writing operation or the erasing operation. The address codes AD 1  and AD 2  are complementary to each other, so that the address is actually specified by the 1-byte code AD 1 . 
   The EEPROM controller  165  receives the address codes AD 1  and AD 2  and verifies the received address codes AD 1  and AD 2 . When the address codes AD 1  and AD 2  are not complementary to each other, the EEPROM controller  165  determines an erroneous specification of the address, prohibits the memory access, and outputs an error signal as shown in  FIG. 11 . When the address codes AD 1  and AD 2  are complementary to each other, on the other hand, the EEPROM controller  165  allows the writing operation or the erasing operation to be performed at the specified address AD 1  in the EEPROM  166 . On completion of the access to the EEPROM  166 , the EEPROM controller  165  transmits a response signal ACK representing completion of the access and an address-mapping signal ADC mapped to the accessed address to the control circuit  222  via the data analyzer  163 . The address-mapping signal ADC mapped to the accessed address may be identical with the specified address code AD 1  or may be any of its complement, 1-bit or several-bit shifting or rotating address signals, and other processed address signals or any of error detecting and correcting codes including a checksum, a CRC, and a hamming code. The EEPROM controller  165  has access to the specified address in the EEPROM  166  in this manner at step S 204 . 
   When the EEPROM controller  165  completes the memory access and transmits the response signal ACK representing completion of the access and the address-mapping signal ADC, the control circuit  222  executes verification according to the received address-mapping signal ADC (step S 210 ). The details of the verification are discussed with reference to the flowchart of  FIG. 12 . The control circuit  222  first reads the transmitted address-mapping signal ADC (step S 211 ) and determines whether the address-mapping signal ADC is a correct signal mapped to the specified address AD 1  for access (step S 212 ). When the address-mapping signal ADC is correctly mapped to the specified address AD 1 , the control circuit  222  determines that the data writing operation or the data erasing operation at the specified address AD 1  has been performed successfully and carries on the subsequent processing (step S 214 ). 
   When the address-mapping signal ADC is not correctly mapped to the specified address AD 1 , on the other hand, there is a possibility that the data writing operation or the data erasing operation has been performed mistakenly at a wrong address specified by the address-mapping signal ADC. The control circuit  222  reads address data corresponding to the address-mapping signal ADC (step S 216 ) and verifies whether the read-out address data is identical with the address data stored in the RAM  253  (step S 218 ). As described previously, the control circuit  222  reads all the data from the detection memory modules  121  through  126  of the ink cartridges  111  through  116  and stores the read-out data in the RAM  253  at the time of power supply to the printer  200  and occasionally updates the data stored in the RAM  253 . The verification process thus reads the address data specified by the address-mapping signal ADC from the detection memory module of the ink cartridge and compares the read-out address data with the address data stored in the RAM  253  for the purpose of verification. 
   When the read-out address data is not identical with the stored address data, the control circuit  222  determines that the address data specified by the address-mapping signal ADC has been rewritten wrong, and writes the correct address data stored in the RAM  253  over the wrong address data specified by the address-mapping signal ADC (step S 220 ). When the read-out address data is identical with the stored address data, on the other hand, the control circuit  222  determines that the address data specified by the address-mapping signal ADC has been written correctly, and proceeds to step S 222 . 
   After verification of the address data specified by the address-mapping signal ADC, the control circuit  222  reads the address data corresponding to the address AD 1  from the detection memory module (step S 222 ) and verifies whether the read-out address data is identical with the address data stored in the RAM  253  (step S 224 ). Namely the verification process reads the address data specified in advance as the address AD 1  from the detection memory module of the ink cartridge and compares the read-out address data with the address data stored in the RAM  253  for the purpose of verification. 
   When the read-out address data is not identical with the stored address data, the control circuit  222  determines that the address data specified in advance by the address AD 1  has been rewritten wrong, and writes the correct address data stored in the RAM  253  over the wrong address data specified by the address AD 1  (step S 226 ). When the read-out address data is identical with the stored address data, on the other hand, the control circuit  222  determines that the address data specified by the address AD 1  has been written correctly, and exits from this verification routine. 
   The third process is described with referring back to the flowchart of  FIG. 10 . The control circuit  222  initiates a sensor access to the sensor module  137  (step S 300 ), and outputs an active mode command AMC (step S 302 ) in the same manner as the memory access. Among the detection memory modules  121  through  126  of the ink cartridges  111  through  116  that have received the active mode command AMC, the detection memory module of the ink cartridge having the ID information identical with the ID information received with the active mode command AMC sends back a response signal ACK showing ready for an access to accept the subsequent processing. 
   When any of the detection memory modules  121  through  126  is activated in response to the active mode command AMC, the control circuit  222  transmits specification of detection conditions to the activated detection memory module (step S 304 ). In this embodiment, the detection measures the resonance frequency of the piezoelectric element  153 , and the detection conditions specify a start pulse of the detection of the resonance frequency of the piezoelectric element  153  (for example, the first pulse from the start of the vibration) and the number of pulses corresponding to a detection time (for example,  4  pulses). When the activated detection memory module receives the specification of detection conditions and sends back a response signal ACK, the control circuit  222  subsequently outputs a detection instruction (step S 306 ). The detection instruction may be included in the specification of detection conditions. 
   In response to the detection instruction, the data analyzer  163  of the detection memory module  121  analyzes the detection instruction and instructs the detection controller  168  to carry out the detection. The detection controller  168  charges and discharges the piezoelectric element  153  according to the specified detection conditions to excite a forcible vibration of the piezoelectric element  153 . The interval of charging and discharging the piezoelectric element  153  is set to make the frequency of the forcible vibration excited in the piezoelectric element  153  approach to the resonance frequency of the resonance chamber  151  in the sensor module  137 . 
   The charge and discharge of the piezoelectric element  153  by the detection controller  168  causes the piezoelectric element  153  to vibrate at the resonance frequency of the resonance chamber  151  and generates a vibrations-induced voltage between electrodes of the piezoelectric element  153 . The frequency of the vibration is basically equal to the resonance frequency determined in conformity with a property of the resonance chamber  151 . The property of the resonance chamber  151  here represents an ink level in the resonance chamber  151 . In the structure of this embodiment, when the resonance chamber  151  is filled with ink, the resonance frequency is approximately 90 KHz. When the ink in the resonance chamber  151  is consumed for printing to substantially empty, on the other hand, the resonance frequency is approximately 110 KHz. The resonance frequency naturally varies according to the size of the resonance chamber  151  and the properties (for example, water repellency) of the inner wall of the resonance chamber  151 . The resonance frequency is thus measured for each type of the ink cartridge. 
   The piezoelectric element  153  vibrates at the resonance frequency of the resonance chamber  151 , due to the forcible vibration excited by the voltage application. The detection controller  168  activates a built-in circuit to detect the vibration and outputs the detection result to the control circuit  222  of the printer  200  via the output unit  178 . The control circuit  222  receives the detection result and specifies the presence or the absence of ink in each of the ink cartridges  111  through  116 . The detection controller  168  may output some of the detection conditions specified by the control circuit  222 , in addition to the frequency of the vibration of the piezoelectric element  153 . The output detection condition may be identical with any of the specified detection conditions or another condition induced from the specified detection conditions. The output detection condition may be data representing a termination pulse of the detection of the resonance frequency (for example, the fifth pulse from the start of the vibration). 
   The control circuit  222  receives the resonance frequency as the detection result (step S 308 ) and the output detection condition and specifies the residual quantity of ink. The residual quantity of ink is specified, based on the determination of the presence or the absence of ink in the resonance chamber  151 . The control circuit  222  of the printer  200  counts the number of ink droplets ejected from each of the print heads  211  through  216  according to the software program and manages the ink consumption. The current quantity of ink in each of the ink cartridges  111  through  116  is accurately managed, based on the calculated ink consumption and the information on the presence or the absence of ink in the resonance chamber  151  received from each of the detection memory modules  121  through  126  of the ink cartridges  111  through  116 . 
   The quantity of ink ejected at once from each of the print heads  211  through  216  varies with a variation in nozzle diameter, a variation in viscosity of ink, and a variation in ink temperature in use. The calculated residual quantity of ink based on the count of ink droplets is thus deviated from the actual residual quantity. Each of the memory detection modules  121  through  126  is designed to empty the ink in the resonance chamber  151 , when approximately half the ink is consumed in each of the ink cartridges  111  through  116 . The procedure detects the time when the specified ink level in each of the detection memory modules  121  through  126  has been changed from the ink presence to the ink absence and corrects the count of ink consumption at the detected time, so as to accurately manage the ink consumption. The correction may simply reset the ink consumption to ½, based on the detection result from each of the detection memory modules  121  through  126 . The correction may otherwise adjust the count of ink droplets. Such correction enables an ink end of each ink cartridge (that is, a timing when ink in the ink cartridge is completely emptied out) to be accurately estimated. This arrangement desirably prevents a certain quantity of unused ink from still remaining in the ink cartridge, which has been specified as the ink end and replaced with a new ink cartridge, thus saving the valuable resource. This arrangement also prevents the ink in the ink cartridge from being emptied out prior to detection of the ink end and thus protects the print heads  211  through  216  from damages due to inkless hitting. 
   As described above, the control circuit  222  readily verifies whether the data rewriting operation (either the data erasing operation or the data writing operation) has been implemented correctly to rewrite data at the specified address in the EEPROM  166  in any of the detection memory modules  121  through  126  attached to the ink cartridges  111  through  116 . Even if data has been rewritten mistakenly at a wrong address, the arrangement of the embodiment allows the control circuit  222  to be readily informed of the wrong address. The same data are stored in both the EEPROM  166  and the RAM  253 . In the case of any failure of the data rewriting operation in any of the ink cartridges  111  through  116 , correct data are read from the RAM  253  and are written over the failed data. 
   The control circuit  222  establishes communication with each of the detection memory modules  121  through  126  attached to the ink cartridges  111  through  116  via the receiver transmitter unit  230  in the first through the third processes and in the process of rewriting data in the EEPROM  166 . The control circuit  222  sequentially communicates with each of the detection memory modules  121  through  126  from the left-end detection memory module  121  to the right-end detection memory module  126 . The carriage  210  successively moves by the width of one ink cartridge and establishes communication with the detection memory module of each ink cartridge at the stop position. In the structure of the embodiment, the receiver transmitter unit  230  has a width substantially corresponding to the width of two ink cartridges. The carriage  210  may thus move three times by the width of two ink cartridges and establish communication with two detection memory modules of two ink cartridges at each stop position. This arrangement desirably reduces the number of the shifting and positioning actions of the carriage  210 . In this modified arrangement, the control circuit  222  executes the anti-collision processing to effectively prevent the communication with the two ink cartridges from being interfered with each other. 
   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. For example, the arrangement of the detection memory module discussed in the above embodiment is applicable to a toner cartridge, as well as to the ink cartridge of the ink jet printer. The detection memory module may be located on the bottom face or the top face of the ink cartridge, in place of the side face. The location of the detection memory module on the top face of the ink cartridge desirably heightens the degree of freedom in layout of the receiver transmitter unit  230  and simplifies the whole structure. 
   In the structure of the embodiment, the EEPROM is used as the internal memory of the ink cartridge. An SRAM or a DRAM backed up by a battery may replace the EEPROM. The internal memory of the ink cartridge may be any of other non-volatile memories, dielectric memories, and magnetic memories. 
   The scope and spirit of the present invention are indicated by the appended claims, rather than by the foregoing description.