Abstract:
A toner cartridge for use with an image forming apparatus includes a memory storing identification data of the toner cartridge and parameter information including image formation process parameters dependent on toner characteristic or ambient conditions. A transceiver unit communicates with the image forming apparatus to send the process parameter information stored in the memory to the image forming apparatus when the identification data is authentic.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/729,679, filed on Jun. 3, 2015, which is a continuation of U.S. patent application Ser. No. 14/320,260, filed on Jun. 30, 2014, which issued as U.S. Pat. No. 9,081,326 on Jul. 14, 2015, which is a continuation of U.S. patent application Ser. No. 14/016,508, filed on Sep. 3, 2013, which issued as U.S. Pat. No. 8,805,211 on Aug. 12, 2014, which is a division of U.S. patent application Ser. No. 13/683,705, filed on Nov. 21, 2012, which issued as U.S. Pat. No. 8,554,091 on Oct. 8, 2013, which is a continuation of U.S. patent application Ser. No. 13/310,631, filed on Dec. 2, 2011, which issued as U.S. Pat. No. 8,331,807 on Dec. 11, 2012, which is a continuation of U.S. patent application Ser. No. 12/257,268, filed on Oct. 23, 2008, which claims the benefit of U.S. Provisional Application No. 61/086,767, filed on Aug. 6, 2008; U.S. Provisional Application No. 61/076,988, filed on Jun. 30, 2008; and U.S. Provisional Application No. 60/983,518, filed on Oct. 29, 2007; the entire contents of each of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to an image control technique depending on toner filled in a toner cartridge. 
       BACKGROUND 
       [0003]    In the past, as described in Japanese Unexamined Patent Application Publication No. H6-149051, a method of correcting image formation conditions in consideration of characteristic data of toner stored in advance in an IC chip disposed in a toner cartridge is known. 
         [0004]    In order to improve the color reproducibility of a color image, an image forming apparatus forms a specific solid image on a photoconductive member and reads the toner concentration thereof by use of a sensor. When the toner concentration is low or the toner concentration is high, the non-uniformity of amounts of attached color toner is adjusted by adjusting development contrast to be the proper toner concentration. Since the amounts of attached color toner can be obtained uniformly by adjusting the development contrast, it is possible to stabilize the color reproducibility of the color image in comparison with the non-adjustment of the development contrast. 
         [0005]    However, in the configuration described in the above-mentioned patent publication, the variation in physical property of the toner due to environments is not considered and thus it cannot be said that the image formation condition is properly corrected. 
         [0006]    When the amounts of attached toner become uniform but the toner cartridge is replaced with a toner cartridge filled with toner different color tones, the amounts of attached toner can be made to be uniform, but the color reproducibility of a color image varies from that before replacing the toner. 
         [0007]    Accordingly, the invention provides an image forming apparatus that can properly make image control depending on a toner cartridge. 
       SUMMARY 
       [0008]    According to an aspect of the invention, there is provided an image forming apparatus mounted with a toner cartridge having a memory unit, including: a toner cartridge which stores a plurality of control data depending on toner in the memory unit; an acquisition unit which selects one of the plurality of control data in the memory unit and acquires image formation-related information; and a setting unit which sets image formation parameters on the basis of the image formation-related information. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a diagram schematically illustrating an appearance of an image forming apparatus which is mounted with a toner cartridge according to a first embodiment; 
           [0010]      FIG. 2  is a diagram schematically illustrating an inner structure of the image forming apparatus according to the first embodiment as viewed from the front side; 
           [0011]      FIG. 3  is a block diagram illustrating operations of the image forming apparatus and the toner cartridge according to the first embodiment; 
           [0012]      FIG. 4  is a flowchart illustrating an information writing process at the time of setting an image formation parameter in the image forming apparatus according to the first embodiment; 
           [0013]      FIG. 5  is a diagram illustrating a control table used for the setting of the image forming apparatus according to the first embodiment; 
           [0014]      FIG. 6  is a diagram illustrating the image formation parameters in the image forming apparatus according to the first embodiment; 
           [0015]      FIG. 7  is a diagram illustrating the comparison result of a case where the image formation parameters are set and a case where the image formation parameters are not set in the image forming apparatus according to the first embodiment; 
           [0016]      FIG. 8  is a flowchart illustrating a process of setting the image formation parameter using color information in an image forming apparatus according to a second embodiment; 
           [0017]      FIG. 9  is a diagram illustrating an image sensor disposed in the image forming apparatus according to the second embodiment; and 
           [0018]      FIG. 10  is a block diagram illustrating operations of an image forming apparatus and a toner cartridge according to a third embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Embodiments will be described below with reference to the accompanying drawings. 
         [0020]      FIG. 1  is a perspective view illustrating an appearance of an image forming apparatus  101  according to an embodiment. The image forming apparatus  101  is a four-tandem type color copier. The image forming apparatus  101  includes an image forming unit  1  outputting image information as an output image called a hard copy or a printout, a sheet feeding unit  3  feeding various sizes of sheets (output mediums) used for the image output to the image forming unit  1 , and a scanner  5  scanning the image information, which is formed as an image by the image forming unit  1 , as image data from an object (hereinafter, referred to as document) holding the image information. When the document has a sheet shape, an auto document feeder  7  discharging a document, which the image information is read by the scanner  5  from, from a reading position to a discharge position and guiding a next document to the reading position is disposed above the image forming unit  1 . A command input unit commanding the image forming unit  1  to start forming an image or commanding the scanner  5  to start reading the image information of the document, that is, a display unit  9  which is a control panel, is disposed in the image forming apparatus  101 . 
         [0021]      FIG. 2  is a diagram schematically illustrating an inner structure of the image forming unit  1  as viewed from the front side. Toner cartridges  40   a ,  40   b ,  40   c , and  40   d  are disposed in the upper portion of the image forming unit  1 . The toner cartridges  40   a ,  40   b ,  40   c , and  40   d  can be mounted on and demounted from a cartridge holding mechanism  60  disposed in the front side of the image forming unit  1 . The toner cartridges  40   a ,  40   b ,  40   c , and  40   d  supply toner of yellow, magenta, cyan, and black. 
         [0022]    The image forming unit  1  includes first to fourth photoconductive drums  11   a  to  11   d  holding latent images, developing devices  13   a  to  13   d  developing the latent images formed on the photoconductive drums  11   a  to  11   d , a transfer belt  15  holding the developer images developed on the photoconductive drums  11   a  to  11   d  in a stacked state, cleaners  16   a  to  16   d  removing the toner remaining on the photoconductive drums  11   a  to  11   d  from the photoconductive drums  11   a  to  11   d , respectively, and chargers  17   a  to  17   d  charging the photoconductive drums  11   a  to  11   d.    
         [0023]    The image forming unit  1  includes a transfer device  18  transferring the developer images stacked on the transfer belt  15  to a sheet-like output medium such as a normal sheet not subjected to any particular process or an OHP sheet which is a transparent resin sheet, a fixing device  19  fixing the developer images transferred to the output medium onto the output medium, and an exposure device  21  forming the latent images on the photoconductive drums  11   a  to  11   d.    
         [0024]    The first to fourth photoconductive drums  11   a  to  11   d  hold electrostatic latent images (latent images) of colors to be visualized (developed) by the developing devices  13   a  to  13   d  containing color toner of Y (yellow), M (magenta), C (Cyan), and Bk (black), and the arrangement order thereof is defined as a predetermined order depending on the image forming process or the toner (developer) characteristic. The transfer belt  15  holds the color developer images formed by the first to fourth photoconductive drums  11   a  to  11   d  and the corresponding developing devices  13   a  to  13   d  in the order of forming the developer images. 
         [0025]    The sheet feeding unit  3  feeds the output medium to the transfer device  18  at a predetermined time when the transfer device  18  transfers the developer images. 
         [0026]    Cassettes set in plural cassettes slots  31  receive various sizes of output mediums. A pickup roller  33  picks up the output medium with the image forming operation. The size of the output medium corresponds to the size of the developer images formed by the image forming unit  1 . A separation mechanism  35  prevents two or more output mediums from being picked up from the cassettes by the pickup roller  33 . Plural transport rollers  37  transport the output medium, which is restricted to one sheet by the separation mechanism  35 , to an aligning roller  39 . The aligning roller  39  sends the output medium to a transfer position where the transfer device  18  and the transfer belt  15  come in contact with each other, at the timing when the transfer device  18  transfers the developer images from the transfer belt  15 . The numbers of the cassette slots  31 , the pickup rollers  33 , and the separation mechanisms  35  may be two or more as needed, and the cassettes can be mounted on different slots. 
         [0027]    The output image of which the image information is fixed onto the output medium by the fixing device  19  is discharged to a sheet discharge tray  51  disposed aside the scanner  5  and above the image forming unit  1 . The image forming apparatus  101  includes a side sheet discharge tray  59  on a side surface of the image forming unit  1 . The output medium discharged from the fixing device  19  is guided to the side sheet discharge tray  59  through a relay transport unit  71  connected to a switching unit  55 . 
         [0028]      FIG. 3  is a block diagram illustrating operations of the toner cartridge  40   a  and the image forming apparatus  101 . The toner cartridge  40   a  is described but the same is true of the toner cartridges  40   b ,  40   c , and  40   d.    
         [0029]    First, an example of a procedure of setting an image formation parameter for controlling process conditions when the toner cartridge  40   a  is mounted on the image forming apparatus  101 . 
         [0030]    Here, the process condition control means the operation control of various devices necessary for actually performing a printing operation and the like. Specifically, one thereof is the control of a bias voltage value applied to the charger  17   a  for charging the photoconductive drum. The process condition control may be the operation control of the developing device  13   a , the cleaner  16   a , and the fixing device  19 , as well as the charger  17   a . The image formation parameter means set values for the operations of the photoconductive drum  11   a , the developing device  13   a , the cleaner  16   a , the charger  17   a , and the fixing device  19  performing the printing operation. 
         [0031]    The toner cartridge  40   a  includes a memory  403 . The memory  403  stores inquiry data and plural control tables to be described later. The memory  403  employs, for example, a general-purpose IC chip. 
         [0032]    The control tables include plural tables storing charging voltage values of the charger  17   a  for the printing operation and the like depending on the physical properties of the toner contained in the cartridge. Instead of the charging voltage values of the charger  17   a , set values such as a developing bias value of the developing device  13   a , a toner concentration (or the intensity of laser beam), a peeling output voltage value of the cleaner  16   a , a controlled voltage value of the fixing device  19 , and a value relating to the operation of the photoconductive drum  11   a  may be defined. The physical properties of the toner include an amount of charged electricity of the toner, a resistance value, a manufacturing lot, and a particle diameter, and plural control tables depending on the characteristics are prepared in this embodiment. 
         [0033]    The image forming apparatus  101  includes a CPU  110 , a memory  111 , a temperature and humidity sensor  112 , a transceiver unit  114 , and the display unit  9 . 
         [0034]    The CPU  110  controls the units of the image forming apparatus  101 . The memory  111  stores a variety of information. The temperature and humidity sensor  112  is disposed at a predetermined position in the image forming apparatus  101  and serves to measure the temperature and humidity of the image forming apparatus  101 . 
         [0035]    The transceiver unit  114  reads and rewrites information recorded in the memory  403  of the toner cartridge  40   a . The transceiver unit  114  may communicate with the memory  403  by wired or wireless. The display unit  9  displays a variety of information in response to the request of the CPU  110 . A toner concentration sensor  115  is disposed in the vicinity of the developing devices  13   a  to  13   d . The toner concentration sensor  115  senses the toner concentration of the toner contained in the developing device  13   a . The same is true of the developing devices  13   b  to  13   d.    
         [0036]      FIG. 4  is a flowchart illustrating a process of writing information to the memory  111  and the memory  403  at the time of setting the image formation parameters according to the first embodiment. 
         [0037]    First, when the CPU  110  recognizes that the image forming apparatus  101  is turned on or a front cover  1   a  is opened or closed (Act  100 ), the CPU performs the following processes. The CPU  110  compares inquiry data A 1  stored in a predetermined area of the memory  111  of the image forming apparatus  101  with inquiry data B 1  stored in a predetermined area of the memory  403  of the toner cartridge (Act  101 ). The image forming apparatus stores the same code A 1  as the inquiry code B 1  previously acquired from the toner cartridge  40   a.    
         [0038]    When the inquiry data A 1  is not matched with the inquiry data B 1  (No in Act  101 ), the CPU  110  does not change the image formation parameter described in this embodiment, but performs a normal printing operation (Act  102 ). That is, only when the image forming apparatus  101  can recognize the inserted toner cartridge  40   a , the CPU performs the process condition control of changing the image formation parameter. 
         [0039]    When the inquiry data A 1  is matched with the inquiry data B 1  (Yes in Act  101 ), the CPU  110  selects and reads one of the image-formation control tables stored in the memory  403 . Then, the CPU  110  writes the selected control table to the memory  111  (Act  103 ). 
         [0040]    Here, the CPU  110  selects the control table as follows. It is assumed herein that plural control tables are prepared depending on the resistance value of the toner. 
         [0041]    As shown in  FIG. 5 , three patterns of the toner resistance values less than 8.0, 8.0 or more and less than 14.0, and 14.0 or more are prepared in the control tables. The CPU  110  selects one control table from the tables. The selection method is not limited. The table read by a service man&#39;s selection may be changed at that time, or a table may be determined by default and may be then changed by the setting. 
         [0042]    As shown in  FIG. 6 , in the control tables, bias voltages C 1 , C 2 , C 3 , . . . , or D 1 , D 2 , D 3 , . . . , or E 1 , E 2 , E 3 , . . . of the charger are set depending on the temperature range or the humidity range, which are controlled depending on the environment (temperature or humidity) or the life time. In the control tables, the bias voltages F 1 , F 2 , F 3 , . . . of the charger may be set depending on the number of printed sheets. The environment or the life may be combined to prepare a set of tables for any toner resistance value. Three tables shown in  FIG. 5  are set correspondingly to the toner resistance values such that the bias voltages C 1 , C 2 , and C 3  of the charger in each table are changed depending on the humidity ranges. 
         [0043]    Then, the CPU  110  sets the image formation parameters from the selected control table by the use of the values calculated from the temperature and humidity sensor  112  or a printed sheet counter  116  disposed at predetermined positions in the image forming apparatus  101 . That is, the CPU  110  extracts the operation setting values defined using the environment temperature or the relative humidity or the number of printed sheets as variables from the control table and sets the extracted setting values as the image formation parameters. The CPU  110  does the optimal process condition control (image control) using the set image formation parameters (Act  104 ). Then, the CPU  110  performs a printing operation of 1 job under the optimal process condition control (Act  105 ). 
         [0044]    In the above-mentioned embodiment, the CPU  110  reads control data from the selected table on the basis of the value detected by the temperature and humidity sensor  112  disposed in the image forming apparatus  101 , writes the read control data to the memory, and changes the image formation parameters on the basis of the control data, thereby performing the optimal process condition control. In addition to the values of temperature and humidity, the image formation parameters may be changed to perform the optimal process condition control with reference to the control table based on the counted number of printed sheets in the image forming apparatus  101  or the counted use time of expendable supplies such as the developer in the photoconductive drum  11   a  and the developing device  13   a . The controlled voltage value of the fixing device  19  may be optimized to perform the process condition control on the basis of the counted value of the fixing device  19 . 
         [0045]      FIG. 7  is a diagram illustrating the comparison result of the process condition control when plural control tables are stored in the memory  403  of the toner cartridge  40   a  with the process condition control when a predetermined control table is stored in the memory  111  of the image forming apparatus  101 . 
         [0046]    By using the plural control tables recorded in the memory  403  of the toner cartridge  40   a , it is possible to more properly perform a printing operation in view of the image concentration and the foggy rate. 
         [0047]    As described above, since the toner cartridge  40   a  records the control tables suitable for the toner cartridge  40   a  in the memory  403 , the image forming apparatus  101  can make the optimal process condition control corresponding to the toner cartridge  40   a  with reference to the control tables in the memory  403 . Accordingly, the toner cartridge  40   a  can be used for a long time. 
         [0048]    Although the toner cartridge  40   a  is exemplified in the above-mentioned embodiment, the above-mentioned embodiment can be applied to expendable supplies such as the photoconductive drum  11   a , the fixing device  19 , the cleaner  16   a , and the developing device  13   a  containing the developer. The embodiment can be applied to a printer as well as the image forming apparatus  101 . 
         [0049]    The change of image formation parameters according to a second embodiment based on the color information recorded in the memory  403  when the toner cartridge  40   a  is mounted on the image forming apparatus  101  will be described now with reference to the flowchart shown in  FIG. 8 . 
         [0050]    Inquiry data are stored in the memory  403  of the toner cartridge  40   a  similarly to the first embodiment. Color information is also stored in the memory. The color information is information obtained by measuring color coordinates (L*, a*, b*) of the toner filled in the toner cartridge  40   a  by the use of the X-Lite. 
         [0051]    When the CPU  110  detects that the toner filled in the toner cartridge  40   a  is exhausted, the CPU displays “please replace the toner cartridge  40   a ” on the display unit  9  (Act  200 ). A user demounts the used toner cartridge  40   a  from the image forming apparatus  101  and mounts a new toner cartridge  40   a  on the image forming apparatus  101  (Act  201 ). When the new toner cartridge  40   a  is mounted on the image forming apparatus  101 , the CPU  110  inquires the information in the memory  111  of the image forming apparatus  101  and the information in the memory  403  of the toner cartridge  40   a  (ACT  202 ). 
         [0052]    When the memory  403  is not disposed in the toner cartridge  40   a  or when the inquiry data cannot be read (No in Act  202 ), the CPU  110  does not change the image formation parameters based on the color information, but supplies the toner to the developing device  13   a  and displays the mark of “under toner supply” on the display unit  9  (Act  203 ). Only when the inquiry is confirmed, the change of the image formation parameters based on the color information is valid. 
         [0053]    When the inquiry is confirmed, the CPU  110  reads the color information stored in the memory  403  (Act  204 ) and changed the image formation parameters (Act  205 ). The image formation parameters before change are stored in the memory  111  of the image forming apparatus  101 . When the CPU  110  recognizes that an image sensor  22   a  is disposed in the image forming apparatus  101  after changing the image formation parameters based on the color information as shown in  FIG. 9  (Yes in Act  207 ), the developing device  13   a  supplies the toner (Act  209 ). The image sensor  22   a  is located in the lower surface side of the transfer belt  15  and serves to sense the toner concentration of the electrostatic latent image on the photoconductive drum  11   a . The image sensor is also disposed in the developing devices  13   b ,  13   c , and  13   d.    
         [0054]    When the developing device  13   a  finishes the supply of toner, the CPU  110  actuates the image sensor  22   a  to acquire the toner concentration. Then, the CPU  110  adjusts the development contrast in the developing device  13   a  on the basis of the acquired toner concentration (Act  209 ). 
         [0055]    When the adjustment of the development contrast is finished, the CPU  110  displays the mark of “printable” on the display unit  9  (Act  210 ). 
         [0056]    As shown in  FIG. 10 , when the image sensor  22   a  is not disposed in the image forming apparatus  101  (No in Act  207 ), the CPU  110  changes the image formation parameters on the basis of the color information and then the developing device  13  starts the supply of toner (Act  207 ). 
         [0057]    With the above-mentioned configuration, even when the toner cartridge  40   a  is replaced, the image forming apparatus  101  reads the color information of the toner filled in the toner cartridge  40   a  and changes the image formation parameters on the basis of the color information, thereby accomplishes the stable color reproducibility. Of course, similarly to the first embodiment, the color information may be previously stored in plural control tables depending on the physical properties of the toner and may be selected from the control tables. 
         [0058]    A third embodiment will be described with reference to the block diagram illustrating the operations of the toner cartridge  40   a  and the image forming apparatus  101  shown in  FIG. 10 . 
         [0059]    The memory  403  of the toner cartridge  40   a  stores material characteristic information and variable resistance element characteristic information. 
         [0060]    The material characteristic information is information indicating variations in toner characteristics (such as the amount of charged electricity, the fluidity of the toner, and the toner resistance value) depending on the environment (the absolute humidity in the image forming apparatus  101 ). The variable resistance element characteristic information is information for correlating the toner resistance values with the absolute humidity of 20% to 85% or characteristic curve information for converting the toner resistance value into the absolute humidity. 
         [0061]    First, when the toner cartridge  40   a  is mounted on the image forming apparatus  101 , the CPU  110  acquires inquiry data from the memory  403  of the toner cartridge  40   a . The CPU  110  compares the acquired inquiry data with the inquiry data stored in the apparatus body and determines whether a desired toner cartridge  40   a  is mounted thereon. 
         [0062]    When the CPU  110  does not determine that the desired toner cartridge  40   a  is mounted thereon, the material characteristic of the toner filled in the toner cartridge  40   a  is not clear and thus the setting of the image formation parameters described below is not performed. The CPU  110  controls the display unit  9  to display the mark of “not mounted with the toner cartridge  40   a.”   
         [0063]    The CPU  110  determines that the desired toner cartridge  40   a  is mounted thereon on the basis of the inquiry data, the CPU  110  acquires the material characteristic information and the variable resistance element characteristic information from the memory  403  of the toner cartridge  40   a . Here, a toner resistance measuring unit  113  includes a variable resistance element  1131  of which the resistance value varies depending on the environment conditions such as temperature and humidity, a resistance element  1132  which is connected in series to the variable resistance element  1131  and of which the resistance value does not vary depending on the environments, a power source  1133  applying a voltage of 5 V or 12 V across the resistance element  1132  and the variable resistance element  1131 , and an OP amplifier  1134  reading the voltage value across the variable resistance element  1131 . The CPU  110  can calculate the toner resistance value, which is the resistance value of the variable resistance element  1131 , varying from the voltage value across the variable resistance element  1131 , which is read by the OP amplifier  1134 . The toner resistance measuring unit  113  measures the voltage value of the variable resistance element read by the OP amplifier  1134  to measure the toner resistance value which is the value of the variable resistance element. The CPU  110  acquires the environment conditions by comparing the toner resistance value measured by the toner resistance measuring unit  113  with the variable resistance element characteristic information acquired from the memory  403  of the toner cartridge  40   a.    
         [0064]    Here, the variable resistance element may be disposed on the toner resistance measuring unit  113  of the image forming apparatus  101  or may be disposed in the toner cartridge  40   a.    
         [0065]    The CPU  110  acquires the image formation parameters stored in the memory  111 . The CPU  110  changes the image formation parameters defined depending on the environment conditions and the material characteristics to the optimal values corresponding to the environment conditions and the material characteristic information acquired from the memory  403  of the toner cartridge  40   a . The image formation parameters are parameter data in which the control voltages for the developing device  13   a , the cleaner  16   a , the charger  17   a , and the fixing device  19  in the printing operation and the physical property values of the amount of charged electricity, the developing bias, the toner concentration (or the intensity of laser beams), the particle diameter distribution, and the heat characteristic on the photoconductive drum  11   a  are set for each material characteristic of the toner varying depending on the environment conditions. The CPU  110  sets the optimal image formation parameters depending on the material characteristics and the environment conditions for the units and performs the printing operation. 
         [0066]    With the above-mentioned configuration, the image forming apparatus  101  according to this embodiment can set the image formation parameters for printing operation corresponding to the toner-specific characteristics of the toner filled in the toner cartridge  40   a  without causing the increase in size of the apparatus and the setting delay. That is, the toner filled in the toner cartridges  40   a  having the same product quality can be different in quality. Accordingly, even when a toner cartridge  40   a  filled with the cheap toner having low quality is mounted on the image forming apparatus  101 , the image forming apparatus  101  can perform the optimal printing operation depending on the toner-specific material characteristics and the environment conditions.