Abstract:
A setting parameter modifying apparatus, the apparatus including a developing cartridge, containing consumables having certain characteristics, detachably installed in a main body of an image forming apparatus, containing a constituent element to operate on the consumables; and a setting parameter modifying element, installed on the developing cartridge, to modify setting parameters of the constituent element of the image forming apparatus such that the constituent element operates on the consumables according to the characteristics thereof.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of Korean Application No. 2005-19093, filed Mar. 8, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     An aspect of the present invention relates to an electro-photographic image forming apparatus. More specifically, the invention relates to a setting parameter modifying apparatus and an image forming apparatus comprising a setting parameter modifying apparatus in which setting parameters of various constituent elements of the image forming apparatus are modified using a developing cartridge that is mounted on the image forming apparatus in a replaceable manner with a certain lifespan.  
         [0004]     2. Description of the Related Art  
         [0005]     Generally, an electro-photographic image forming apparatuses, such as laser beam printers, digital photocopiers, digital facsimile machines, multi-operational devices, and the like, form electrostatic latent images by exposing image data that is obtained from documents to a photosensitive drum charged with a certain electrical potential, and spread developer on a certain portion of the photosensitive drum where electrostatic latent images are formed so as to form visible images. Then, the visible images are transferred onto printing media by a transferring device, and fixed to the media by an application of heat and pressure. As a result, desired images are printed.  
         [0006]     In such an electro-photographic image forming apparatus, there are some constituent elements having limited lifespans (hereafter, referred to as consumables), such as a developer containers, which contain developer, photosensitive drums, and developing rollers to supply developer to the photosensitive drums. Recently, for user convenience when replacing consumables, the developer containers, photosensitive drums, and developing rollers have been integrated in one body in the form of a cartridge.  
         [0007]      FIG. 1  is a configuration showing a major portion of an electro-photographic image forming apparatus applying an example of a developing cartridge. With reference to  FIG. 1 , the printing process of a conventional image forming apparatus will be explained.  
         [0008]     When laser beams are scanned from a laser scanning unit (LSU)  120  on the photosensitive drum  112 , the surface of which is charged with a certain electrical potential by a charging device  111 , an electrostatic latent image is formed on a certain area of the surface of the photosensitive drum  112 . A developing roller  113  spreads developer on a certain area of the photosensitive drum  112  where the electrostatic latent image is formed, and a visible image is formed as a result. The visible image formed on the photosensitive drum  112  is transferred onto a printing medium P that is supplied by a transferring device  114 . Reference numeral “ 115 ” denotes an agitator to agitate developer, and reference numeral “ 116 ” denotes a supply roller to supply developer to the developing roller  113 . Reference numeral “ 117 ” denotes a cleaning blade to remove the developer that is not transferred onto the printing medium and that remains on the photosensitive drum  112 , and reference numeral “ 118 ” denotes waste developer removed by the cleaning blade  117 . The visible image transferred onto the printing medium P is fixed by a fixing unit  130  that comprises a heating roller  132  containing a heating source inside and a pressing roller  134 .  
         [0009]     On the other hand, the LSU  120  includes a laser diode  121  as a light source, a rotary polygon mirror  122 , and a driving motor  123  for driving the rotary polygon mirror  122 . As shown in  FIG. 1 , each constituent element of the developing cartridge  100  is installed inside a resin housing  110 .  
         [0010]     When the developer of such an integrated developing cartridge  100  is used up, a user separates the cartridge from the image forming apparatus and mounts a newly purchased developing cartridge on the image forming apparatus. However, diverse models of developing cartridges are manufactured by different companies. Thus, when a new developing cartridge is to be replaced, models of the consumables inside the old developing cartridge may be different from those of a new developing cartridge at the point of replacement.  
         [0011]     If the internal parts of the old and new developing cartridges are different at the point of replacement, the setting parameters of the image forming apparatus that are optimally adapted to the previous parts may not be suitable for the parts of the new developing cartridge, thereby degrading printing quality. Accordingly, in order to obtain optimal printing quality, the setting parameters need to be modified so as to be suitable for the new parts.  
         [0012]     A developing cartridge may be classified into a model having a Customer Replacement Unit Memory (CRUM) and a model not having a CRUM. Generally, a CRUM stores unique information of a product such as lifespan of developer and photosensitive drum, a serial number given in the manufacturing process of the product, and the like. However, in the case of a developing cartridge that does not have a CRUM, no particular methods exist under which the specifications of a product may be modified so as to be suitable for the replaced parts if the characteristics are different when comparing the internal consumables of the developing cartridge with those of the initial models. With these devices, once the software and hardware configurations of an image forming apparatus are determined, the configurations cannot be easily modified after being manufactured, except in those cases where new parts have sufficiently similar specifications or characteristics as the replaced parts. In any other cases, such that consumables of a new and an old developing cartridge do not have similar specification or characteristics, optimal printing quality cannot be obtained.  
         [0013]     In contrast, in the case of a developing cartridge that has a CRUM, if the characteristics are different when comparing the internal consumables of a new developing cartridge with those of initial models, the information on the parts is stored in the CRUM in order to modify the specifications so as to be suitable for the changed parts, so that the software of an image forming apparatus may be modified when a developing cartridge is mounted on the image forming apparatus. However, in a case where a CRUM in the form of a semiconductor chip is attached to a developing cartridge, material costs increase. In addition, additional circuits are installed in order to modify the software of the image forming apparatus, thereby ultimately increasing production costs.  
       SUMMARY OF THE INVENTION  
       [0014]     An aspect of the present invention solves the above and/or other drawbacks in the art. Another aspect of the invention is to provide a setting parameter modifying apparatus and an image forming apparatus comprising the same, in which, even though the parts of a new cartridge have different specifications from those of the internal consumables of an old developing cartridge, the parts may be used in the existing image forming apparatus when developing cartridges are replaced.  
         [0015]     According to one aspect of the invention for achieving the aspects, there is provided a setting parameter modifying apparatus, the apparatus comprising a developing cartridge, containing consumables having certain characteristics, detachably installed in a main body of an image forming apparatus, containing a constituent element to operate on the consumables; and a setting parameter modifying element, installed on the developing cartridge, to modify setting parameters of the constituent element of the image forming apparatus such that the constituent element operates on the consumables according to the characteristics thereof.  
         [0016]     In an aspect of the invention, the setting parameter modifying element comprises a resistor element.  
         [0017]     According to one aspect of the invention, the consumables of the developing cartridge include a developer, and the setting parameter is the optical output power of a laser diode that scans laser beams on the photosensitive drum. The resistor element modifies the optical output power of the laser diode.  
         [0018]     In addition, the setting parameter modifying apparatus comprises a controller that includes a laser diode power supply to supply power to the laser diode and is connected to the setting parameter modifying element so as to exchange signals when the developing cartridge is mounted on the image forming apparatus main body. The resistor element may be installed between the laser diode power supply and the laser diode.  
         [0019]     According to another embodiment of the invention, the consumables of the developing cartridge include a photosensitive drum, and the setting parameter is the fixing temperature of a fixing unit that fixes developer onto a printing medium. The resistor element modifies the fixing temperature. In addition, the setting parameter modifying apparatus comprises a controller that includes a lamp power controller to supply power to the fixing unit and is connected to the setting parameter modifying element so as to exchange signals when the developing cartridge is mounted on the image forming apparatus main body.  
         [0020]     In addition, the fixing unit includes a heating roller provided with a lamp as a heat source and a temperature detecting device to detect the temperature around the heating roller, and the resistor element may be installed between the controller and the temperature detecting device.  
         [0021]     The above and/or other aspects are also accomplished by an image forming apparatus having the following configurations. The image forming apparatus comprises a developing cartridge, a laser scanning unit, a fixing unit, a setting parameter modifying element, and a controller.  
         [0022]     The developing cartridge includes a photosensitive drum, a developing roller, and developer that have certain lifespans, forms a visual image by spreading developer onto an electrostatic latent image formed on the photosensitive drum, and is installed at an image forming apparatus main body in a detachable manner. The laser scanning unit includes a laser diode as a light source, and forms an electrostatic latent image by scanning laser beams emitted from the laser diode onto the photosensitive drum. The fixing unit fixes an image on a printing medium by applying high temperature heat and pressure after the visual image formed by the developing cartridge is transferred onto the printing medium. The setting parameter modifying element is installed at one side of the developing cartridge, and modifies the setting parameters of the laser scanning unit or the fixing unit in a case where either one of the photosensitive drum or developer of a new developing cartridge to be replaced is different from those of an old developing cartridge. The setting parameter modifying element may be a resistor element. The controller is connected to the setting parameter modifying element so as to exchange signals when the developing cartridge is mounted on the main body.  
         [0023]     Additional and/or other aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
         [0025]      FIG. 1  is a configuration showing a major portion of a conventional electro-photographic image forming apparatus;  
         [0026]      FIG. 2  is a cross-sectional view of a developing cartridge provided with a setting parameter modifying element according to one embodiment of the invention;  
         [0027]      FIG. 3  is an elevation view of a setting parameter modifying element according to one embodiment of the invention;  
         [0028]      FIG. 4  is an elevation view of a setting parameter modifying element according to another embodiment of the invention;  
         [0029]      FIG. 5  is a block diagram showing a configuration of a setting parameter modifying according to one embodiment of the invention; and  
         [0030]      FIG. 6  is a block diagram showing a configuration of a setting parameter modifying apparatus according to another embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0031]     Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
         [0032]     Referring to  FIGS. 2 and 5 , a setting parameter modifying apparatus comprises a developing cartridge  100 , a setting parameter modifying element  140  installed at one side of the developing cartridge  100 , and a controller  150  (see  FIG. 5 ). The developing cartridge  100  is detachably installed in an image forming apparatus main body (not shown), and developer D, a charging roller  111 , a photosensitive drum  112 , a developing roller  113 , a supply roller  116 , and a cleaning blade  117  are installed in the resin housing  110 . Because the developing cartridge  100  has the same configuration as the developing cartridge disclosed in  FIG. 1 , a description thereof will be omitted for the sake of brevity.  
         [0033]     The setting parameter modifying element  140  is installed at one side of the outer surface of the housing  110  of the developing cartridge  100 . As shown in  FIG. 2 , the setting parameter modifying element  140  is installed on a front surface of the developing cartridge  100 . However, this arrangement is not limiting and the setting parameter modifying element  140  may be installed at other positions of the developing cartridge  100 . That is, a setting parameter modifying element  140  can be installed at the side, top, bottom, or rear surfaces.  
         [0034]     Referring to  FIG. 3 , a setting parameter modifying element  140  includes a circuit board  141  and a series of resistor elements  143  installed between two contact points  142  of the circuit board  141 . Here, it is understood that the resistor elements  143  may be replaced by other electrical elements to achieve a similar effect and that the discussion of the use of the resistor elements  143  is not intended to limit the present invention. The resistor elements  143  are applied when the consumables inside a developing cartridge  100  to be replaced have different specifications from those of the developing cartridge  100  (hereinafter referred to as a modified product) to which the setting parameter modifying element  140  is attached. The resistor elements  143  may be connected in series or in parallel and the number of elements is not limited to the three shown in  FIG. 3 .  
         [0035]     When the developing cartridge  100 , having the setting parameter modifying element  140  attached thereto, is mounted on the image forming apparatus main body (not shown), the setting parameter modifying element  140  of the invention to which the resistor elements  143  are applied is connected to a contacting point terminal (not shown) of the controller  150  that is implemented in a board to modify setting parameters such as the optical output power of the laser diode  162  (see  FIG. 5 ) and the fixing temperature of the heating roller  172  (see  FIG. 6 ) so as to be suitable for the new parts.  
         [0036]     Where consumables, which are inside a developing cartridge  100  to replace another developing cartridge that is already in use, have the same specifications as those of the other developing cartridge (i.e., the developing cartridge  100  is not a modified product), a setting parameter modifying element  140 ′ disclosed in  FIG. 4  is applied. As shown in  FIG. 4 , the setting parameter modifying element  140 ′ includes a circuit board  141  and a conductive wire  144  installed between two contact points  142  of the circuit board  141 . Again, it is understood that the conductive wire  144  may be replaced by another electrical element to achieve a similar effect and that the discussion of the use of the conductive wire  144  is not intended to limit the present invention.  
         [0037]     When the developing cartridge  100  is mounted on the image forming apparatus, the controller  150 ,  150 ′ (referring to  FIGS. 5 and 6 ) is connected to the setting parameter modifying element  140 ,  140 ′, respectively, in a manner that allows for signal communication between the controller  150  and the setting parameter modifying element  140  or the controller  150 ′ and the setting parameter modifying element  140 ′. This will be explained in detail below.  
         [0038]     Hereafter, a setting parameter modifying apparatus according to one embodiment of the invention will be explained. Referring to  FIG. 5 , a setting parameter modifying apparatus according to the embodiment comprises a controller  150 , a laser beam scanning unit  160 , and a setting parameter modifying element  140 . The controller  150  analyzes printing data received from a computer through an interface  152 , and controls each constituent element of the image forming apparatus so as to perform general printing operations such as paper feeding, charging, exposing, transferring, and fixing. The controller  150  includes a laser diode power supply  154 . The controller  150  supplies power to a laser diode  162  in a default value through the laser diode power supply  154 .  
         [0039]     The laser beam scanning unit (LSU)  160  forms a latent image, i.e., an electrostatic latent image, by scanning laser beams (light) onto the photosensitive drum  112  (see  FIG. 2 ) of the developing cartridge  100  according to electrical signals from the controller  150 , and includes a laser diode  162 , a rotary polygon mirror  164 , and a driving motor  166 . A general semiconductor laser is used as a laser diode  162  that emits laser beams of a certain optical output power (approximately 1-5 mW) in a 787 nm wavelength (red color). Generally, the optical output power arriving at the photosensitive drum  112  is approximately 0.5˜0.8 mW considering the efficiencies of the lenses and reflecting mirrors. The rotary polygon mirror  164  is rotated at a certain speed by the driving motor  166 , and reflects the laser beams emitted from the laser diode  162  to the photosensitive drum  112 . A synchronization signal (beam detection) signifying the start of beam scanning is generated according to the rotation of the rotary polygon mirror  164 . Thus, the controller  150  may transmit video signals synchronized in substantially every horizontal line to the laser diode  162 .  
         [0040]     The optical output power of the laser diode  162  to form electrostatic latent images on the photosensitive drum  112  may vary according to the type of photosensitive drum  112  that is used, and the optical output power is determined by the default power source of the laser diode power supply  154 . That is, the optical output power of the laser diode  112  varies according to the sensitivity of the photosensitive drum  112 , and the sensitivity of the photosensitive drum  112  relates to the rotation speed of the photosensitive drum. The higher the sensitivity of the photosensitive drum  112 , the less optical output power of laser diode  162  is needed in order to form electrostatic latent images. However, if the sensitivity of the photosensitive drum  112  is low, electrostatic latent images may be formed when the photosensitive drum is scanned by a higher optical output power of the laser diode  162 . Therefore, in order to reduce the waiting time after sending a print command and to reduce power consumption, photosensitive drums  112  with high sensitivities have been recently developed.  
         [0041]     The setting parameter modifying element  140  is installed between the laser diode power supply  154  of the controller  150  and the laser diode  162  of the LSU  160  when the developing cartridge  100  is mounted on the image forming apparatus main body (not shown).  
         [0042]     Operations of the setting parameter modifying apparatus will be explained below.  
         [0043]     First, where a modified product in which the photosensitive drum of a developing cartridge  100  to which the setting parameter modifying element  140  is attached has a higher sensitivity than that of the photosensitive drum in the developing cartridge to be replaced or substituted for, the resistor elements  143  shown in  FIG. 3  are applied as a setting parameter modifying element  140 . The laser diode power supply  154  supplies a similar amount of voltage as was supplied previously. However, lesser amounts of current are supplied to the laser diode  162  than before due to the resistor elements  143 . Accordingly, the optical output power of the laser diode  162  is lower than before the changing of the developing cartridge  100 . Therefore, laser beams having less optical output power than before are scanned onto the highly sensitive photosensitive drum  112  of a new developing cartridge  100 , and electrostatic latent images having a similar density as before are formed on the photosensitive drum  112 .  
         [0044]     On the other hand, values determined by experiment are applied to the resistance values of the resistor elements  143 . That is, the optimal output power of a laser beam to form an electrostatic latent image on a new photosensitive drum  112  is calculated, and the resistance values of the resistor elements  143  are adjusted so as to output the calculated optical output power.  
         [0045]     However, where the photosensitive drum  112  of the developing cartridge  100  has the same specifications as those of the photosensitive drum in the developing cartridge to be replaced or substituted for (i.e., a case where a modified product is not being used), the wire  144  in  FIG. 4  is applied as a setting parameter modifying element  140 . In this case, the wire  144  only performs a switching operation that electrically connects the laser diode power supply  154  and the laser diode  162 . Therefore, laser beams having the same optical output power as before are scanned onto the photosensitive drum  112 .  
         [0046]     As shown in  FIG. 6 , a setting parameter modifying apparatus according to another embodiment of the invention comprises a controller  150 ′, a fixing unit  170 , and a setting parameter modifying element  140 .  
         [0047]     Here, the fixing unit  170  dissolves the developer that is transferred onto a printing medium by applying high temperature heat (approximately 150° C.-200° C.), and fixes the developer onto the printing medium by an application of pressure. The fixing unit  170  includes a heating roller  172  that contains a lamp  173  as a heat source to generate high temperatures both inside and outside of the heating roller  172 , a pressing roller  174  that is installed to face the heating roller  172  to be positioned to press the printing medium at a uniform pressure along a longitudinal length of the pressing roller  174 , and a temperature detecting device  176 .  
         [0048]     The temperature detecting device  176  detects the temperature around the surface of the heating roller  172 . Generally, a heat-detecting sensor such as a thermistor is used as the temperature detecting device  176 . However, it is understood that this embodiment is not limited to the use of thermistors and that other devices may be used to detect temperature around the surface of the heating roller. The temperature detecting device  176  exchanges information with an analog digital converter (ADC) of the controller  150 . On the other hand, the temperature detecting device  176  has a characteristic in that the measured temperature varies according to the resistance values around the heating roller  172  that is to be measured. As such, the higher the resistance value is around the roller, the lower the measured temperature becomes.  
         [0049]     The temperature of the heating roller  172  that is applied to dissolve the developer attached to a printing medium differs according to the type of developer used. That is, the fixing temperature of the developer differs according to the developer type. Where the fixing temperature of developer is high, the lamp  173  of the heating roller  172  is required to consume more electrical power. Therefore, developer that may be fixed at lower temperatures has been recently developed.  
         [0050]     The controller  150 ′ according to the embodiment includes a lamp power controller  156  and an ADC  158 . The lamp power controller  156  supplies power to control the heating temperature of the lamp  173 , which, as noted above, is a heat source of the fixing unit  170 . The ADC  158  exchanges signals with the temperature detecting device  176  of the fixing unit  170 , and converts the analog values of the temperature data transmitted by the temperature detecting device  176  into digital values so that the controller  150 ′ may recognize them.  
         [0051]     The setting parameter modifying element  140  is installed between the ADC  158  of the controller  150  and the temperature detecting device  176  of the fixing unit  170  when the developing cartridge  100  is mounted on the image forming apparatus main body (not shown).  
         [0052]     Hereinafter, operations of the setting parameter modifying apparatus according to another embodiment of the invention will be explained.  
         [0053]     First, where a developing cartridge  100 , to which the setting parameter modifying element  140  is attached, is a modified product that has developer whose fixing temperature is lower than that of the existing developer, the resistor elements  143  in  FIG. 3  are applied as a setting parameter modifying element  140 . The resistance value of the environment neighboring the heating roller  172  increases due to the resistor elements  143 . Therefore, the temperature measured by the temperature detecting device  176  decreases.  
         [0054]     Accordingly, the temperature detecting device  176  transmits temperature data that is lower than the temperature data transmitted before the developing cartridge  100  was replaced. More particularly, the controller  150  obtains temperature data through the ADC  158 , and controls the heating temperature of the lamp  173  through the lamp power controller  156 . Therefore, the heating temperature of the heating roller  172  measured after the developing cartridge has been replaced becomes lower than the heating temperature of the heating roller  172  before the replacement. Accordingly, the developer of the new developing cartridge  100  is fixed at a temperature lower than before.  
         [0055]     Values determined by experiment are applied to the resistance values of the resistor elements  143 . That is, the optimal fixing temperature at which new developer may be fixed onto a printing medium is calculated, and the resistance values of the resistor elements  143  are adjusted to output the calculated fixing temperature.  
         [0056]     However, in a case where the developer of a developing cartridge  100  to be replaced or substituted for has the same specifications as those of the developer of the developing cartridge  100  (i.e., where a modified product is not being used), the wire  144  in  FIG. 4  is applied as a setting parameter modifying element  140 . In this case, the wire  144  only performs a switching operation that electrically connects the ADC  158  and the temperature detecting device  176 . Therefore, the heating roller  172  heats the developer at the same temperature as before.  
         [0057]     As is described above, according to a setting parameter modifying apparatus and an image forming apparatus comprising the same according to the invention, only hardware constituent elements such as a setting parameter modifying element are installed in a developing cartridge, so that, when replacing a developing cartridge that is used up, the developing cartridge may be used even though the internal parts are different from the parts being replaced.  
         [0058]     Therefore, a developing cartridge having a photosensitive drum and developer that are improved in their performance may be applied to an existing image forming apparatus without being provided with a CRUM. As a result manufacturing costs may be reduced.  
         [0059]     Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.