JP5337514B2 - Image forming apparatus - Google Patents

Description

  An image forming apparatus using toner such as a multifunction machine or a printer has a large number of parts combined. Among the members of the image forming apparatus, there are some members in which a plurality of parts are unitized, such as a developing device and a photosensitive drum, and the entire unit can be replaced (exchange unit). By unitizing a plurality of parts in advance, they can be handled as a single part, and there are advantages such as the life management of the parts and easy replacement at the end of life or failure. In this replacement unit, from the standpoint of maintaining and improving image quality and managing the life of the replacement unit, the replacement unit such as a developing device is equipped with a memory for storing appropriate usage conditions and the history of the number of printed sheets in a nonvolatile manner. There is a case. An example of an image forming apparatus equipped with such an exchange unit is described in Patent Document 1.

Specifically, Patent Document 1 includes a main body including a first nonvolatile memory that holds information, and an apparatus unit that is replaceably installed in the main body and includes a second nonvolatile memory. An image forming apparatus is described in which at least one of a first nonvolatile memory and a second nonvolatile memory has a write prohibited area for prohibiting rewriting of information with respect to existing information and a writable area capable of writing information. Yes. With this configuration, the degree of freedom of writing information is weighted and hierarchized, organized, and information manipulation by a third party unrelated to the manager managing quality is prevented (Patent Literature) 1: Claim 1, paragraph [0035] etc.).
JP-A-2005-070254

  Here, while the basic structure is common (for example, the same developing device and photosensitive drum are used), the image forming apparatuses may be developed in series such as having different functions. In this case, the replacement unit may be incorporated into a plurality of models. However, at the time of shipment, it is unclear which model is used for the replacement unit that is sold separately and distributed to the market for replacement by the user or service person when the service life is reached. For this reason, it is necessary to store data for all compatible models in the memory of the exchange unit sold separately in order to ensure compatibility.

  On the other hand, since it is clear that the replacement unit is built in at the time of factory shipment, the content stored in the memory mounted on the replacement unit is strictly limited to one model. Therefore, in an exchange unit sold separately, there is a case where it is desired to make the capacity of the mounted memory larger than the exchange unit incorporated at the time of factory shipment.

  Also, at the beginning of the design, consideration will be given to not having to change the memory capacity of the replacement unit built into the product and the replacement unit sold separately. In some cases, the data to be stored increases. In this case as well, it becomes necessary to increase the capacity of the memory mounted in the optional replacement unit.

  However, if the capacity of the memory varies depending on the exchange unit, the communication format may differ depending on the capacity of the memory mounted on the exchange unit, such as a different address designation format. If it does so, the memory mounted in an exchange unit cannot be accessed, but there exists a problem that an access error may generate | occur | produce. In general, when the access error state continues, the control unit on the main body side may determine that the error is not eliminated and stop the operation of the image forming apparatus. Incidentally, looking at Patent Document 1, there is no description regarding the above-mentioned problem caused by the difference in the capacity of the memory mounted by the replacement unit, and the invention described in Patent Document 1 does not solve the above problem. Can not.

  In view of the above problems, the present invention enables communication with a memory even when a replacement unit such as a developing device is replaced, even if there is a change in the capacity of the memory mounted on the replacement unit. The problem is to operate the system without problems.

In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention includes a replaceable exchange unit attached to the apparatus body, a memory mounted in the exchange unit and storing data in a nonvolatile manner, and an apparatus body. A backup memory that stores data indicating a communication format that can communicate with the memory; and a control unit that is provided in the apparatus main body and communicates with the memory, wherein the control unit communicates with the memory. If data indicating the communication format that can be stored is stored in the backup memory, communication is performed in the stored communication format, and if an access error occurs in the memory, the communication format is changed to one or a plurality of different communication formats. switch to communicate with the memory, the change the number of bytes in the address portion that specifies an address in said memory The Rukoto switches the communication format, if there is no access error in switched communication format, and stores the data indicating the communication format can communicate with the memory in the backup memory.

According to this configuration, the capacity of the memory mounted on the replacement unit is changed by unit replacement, and even if an access error occurs because the communication format is different, the control unit performs communication with the memory by switching the communication format. The control unit of the apparatus main body can communicate with the memory. Accordingly, since the memories have different capacities, the image forming apparatus does not stop when the access error state continues. In addition, since the control unit determines the communication format with the memory of the exchange unit by referring to the backup memory, once the communication is possible, the control unit does not need to switch the communication format and confirm whether communication is possible. Therefore, the time required for accessing the memory of the replacement unit, such as when the main power is turned on, can be shortened, and the warm-up process until the image forming apparatus can be used can be shortened. Also, the number of bits for designating the address of the data in the memory may differ depending on the capacity of the memory of the exchange unit. According to this configuration, even if the number of bits for designating the address is different, the control unit Can communicate with memory.

Further, the invention provides the invention of claim 1 according to claim 2, wherein the control unit 1 or the switch to a plurality of different communication formats if an access error even if the communication with the memory persists, again, all Retry to try communication with the communication format of.

  According to this configuration, an access error in communication with the memory may occur due to factors such as noise. However, since the control unit performs a retry process to check whether communication with the memory is possible, the control unit The reliability of communication between the memory and the memory can be improved.

According to a third aspect of the present invention, in the first or second aspect of the present invention, there is provided a display unit for displaying the status of the apparatus, and the control unit switches the memory to one or a plurality of different communication formats. If an access error continues even if communication is performed, the display unit displays that the memory is abnormal.

  According to this configuration, after clarifying that an access error has occurred due to a factor other than the capacity of the memory of the replacement unit, it is possible to notify and recognize the occurrence of an abnormality such as a failure to the user or the like. Therefore, the user can easily find out the cause of the access error and can easily eliminate the access error.

  According to the present invention, when a replacement unit such as a developing device is replaced, even if there is a change in which the capacity of the memory mounted in the replacement unit sold separately increases or decreases compared to before the replacement, the control unit Communication between memory and memory is done without problems. Accordingly, compatibility in replacing the unit is improved, and the image forming apparatus is not stopped due to an access error to the memory on which the replacement unit is mounted due to the unit replacement.

1 is a schematic cross-sectional view illustrating a schematic configuration of a multifunction machine according to an embodiment. FIG. 3 is an enlarged cross-sectional view of one image forming unit according to the embodiment. 1 is a block diagram illustrating an example of a hardware configuration of a multifunction machine according to an embodiment. It is a block diagram for demonstrating the outline | summary of communication with the control part which concerns on embodiment, and each memory. It is explanatory drawing which shows an example of the communication format between the control part which concerns on embodiment, and each memory. It is a flowchart which shows an example of the communication control between the control part which concerns on embodiment, and each memory.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. An electrophotographic tandem color multifunction peripheral 1 (corresponding to an image forming apparatus) will be described as an example. However, each element such as the configuration and arrangement described in the present embodiment is merely an illustrative example without limiting the scope of the invention.

(Schematic configuration of image forming apparatus)
First, an outline of the multifunction machine 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a multifunction machine 1 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of one image forming unit 5 according to the embodiment of the present invention.

  As shown in FIG. 1, the MFP 1 according to the present embodiment is provided with a document conveying device 2 and an image reading unit 3 (scanner) from the top, and an operation panel 1a (shown by a broken line in FIG. 1). Equivalent to the part). In the main body, a paper feed unit 4a, a conveyance path 4b, an image forming unit 5, an intermediate transfer unit 6, a fixing unit 7 and the like are provided.

  The document transport device 2 automatically and continuously scans the document loaded on the document loading tray 21 one by one by rotating the plurality of rollers during document copying. It is conveyed toward the contact glass for reading 31). The image reading unit 3 reads a document and generates image data of the document. On the upper surface of the image reading unit 3, a feed reading contact glass 31 and a placement reading contact glass 32 are provided. In the image reading unit 3, an exposure lamp, a mirror, a lens, an image sensor (for example, a CCD), and the like are provided. An optical system member (not shown) is provided.

  Then, the image reading unit 3 uses these optical system members to irradiate light on a document transported by the document transport device 2 or a document placed on a contact glass, and receives the reflected light of the document. A / D conversion is performed on the output value of each pixel to generate image data. The multifunction device 1 can perform printing based on the image data obtained by reading (copy function). The document conveying device 2 is provided with a fulcrum on the back side of the paper surface of FIG. 1 and can be lifted. After the document is placed on the placement reading contact glass 32, the document conveying device 2 can hold the document. Further, the operation panel 1a includes a liquid crystal display unit and various keys, and accepts display of the state of the multi-function device 1 (for example, error occurrence and mode) and various inputs from the user.

  Further, the paper feed unit 4a accommodates various sizes of sheets (sheets) such as copy paper and label paper toward the intermediate transfer unit 6 and the like, and is rotated by a driving mechanism (not shown) such as a motor. The paper roller 41 sends out to the conveyance path 4b. The conveyance path 4 b conveys the sheet in the multifunction machine 1 and guides the sheet supplied from the sheet feeding unit 4 a to the discharge tray 42 through the intermediate transfer unit 6 and the fixing unit 7. The conveyance path 4b is provided with a conveyance roller pair 43, a guide 44, and a registration roller pair 45 that waits for the conveyed sheet in front of the intermediate transfer unit 6 and sends it in time.

  Further, as shown in FIG. 1, the multifunction machine 1 includes an image forming unit 5 for four colors as a part for forming a toner image based on image data of an image to be formed. Specifically, the multifunction device 1 includes, from the left side in FIG. 1, an image forming unit 5k that forms a black image, an image forming unit 5y that forms a yellow image, and an image forming unit 5c that forms a cyan image. , An image forming unit 5m for forming a magenta image, one exposure device 52, and the like.

  Here, the image forming units 5k to 5m will be described in detail with reference to FIG. Each of the image forming units 5k to 5m has basically the same configuration except for the color of the toner image to be formed, and can be described in the same manner. Therefore, only one image forming unit 5 is shown in FIG. 2, and in the following description, the symbols k, y, c, and m, which are color identification codes of the image forming units 5, are not particularly described. Omitted.

  First, each photosensitive drum 51 (corresponding to an exchange unit) carries a toner image on its peripheral surface, and has, for example, a photosensitive layer such as amorphous silicon on the outer peripheral surface of an aluminum drum, and a driving device (not shown). ) Is driven to rotate counterclockwise at a predetermined process speed.

  Each photosensitive drum 51 includes a cylindrical member constituting the peripheral surface of the photosensitive drum 51, a cap fitted to both ends of the cylindrical member, a drum shaft inserted through the cap or the cylindrical member, a ground plate, and a drum shaft support. A shaft member (not shown), a substrate on which a non-volatile memory M1 (for example, EEPROM, details will be described later), and the like are combined and unitized. Here, the photosensitive layer of the photoconductive drum 51 is worn, and when the end of the life is approached, adverse effects such as deterioration in image quality appear. For this reason, the photosensitive drum 51 can be replaced in units when the lifetime is reached.

  An exposure device 52 below each image forming unit 5 converts an input color-separated image signal into an optical signal by a laser output unit (not shown), and laser light (converted optical signal). 4) can be output for four colors, and the charged photosensitive drum 51 is scanned and exposed to form an electrostatic latent image. Each charging device 53 includes a charging roller 53a, and each charging roller 53a contacts each photoconductor drum 51 and rotates together. The charging device 53 applies a voltage to the charging roller 53a, and as a result, the photosensitive drum 51 is charged with a constant potential. The charging device 53 may be one using a corona discharge type or a brush.

  Each developing device 54 has a developing roller 54a and stores a developer (not shown) containing toner (the developing device 54 of the image forming unit 5k is black, the developing device 54 of the image forming unit 5y is yellow, and image forming). The developing device 54 of the unit 5c stores cyan, and the developing device 54 of the image forming unit 5m stores magenta developer). Each developing roller 54 a faces the photosensitive drum 51 and is provided with a predetermined gap (for example, 1 mm or less). The developing roller 54 a carries toner and supplies toner to the photosensitive drum 51 during image formation. Further, the developing device 54 circulates and agitates the developer in the developing device 54 in order to charge the toner to the developing roller 54a and to mix the new developer with the old developer for charging the toner. It has a conveying member 54c and the like.

  As described above, each developing device 54 includes various rotating bodies such as the developing roller 54a, the supply roller 54b, and the conveying member 54c, support shaft members of various rotating bodies, gears, and a non-volatile memory M2 (for example, EEPROM, for details). A board on which (described later) is mounted is gathered and unitized. Then, the developing device 54 also deteriorates with time, and when the end of the life of the developing device 54 is approaching, adverse effects such as deterioration in image quality appear. For this reason, the developing device 54 can be replaced in units when the lifetime is reached.

  Explaining the development process, the charged photosensitive drum 51 is exposed by laser light from the exposure device 52 in accordance with image data, and an electrostatic latent image is formed. Then, the charged toner flies by a developing bias applied to the developing roller 54a by a developing bias applying unit 55 (see FIG. 3), which will be described later, and adheres to the surface of the photosensitive drum 51 according to the magnitude of the potential provided by the exposure. The electrostatic latent image is developed as a toner image.

  Each cleaning device 56 cleans the photosensitive drum 51 and includes, for example, a cylindrical cleaning member 57 having elasticity, and the cleaning member 57 rubs each photosensitive drum 51 to transfer residual toner on the drum surface. Remove and recover. Further, a resin-made flat blade 58 that is brought into contact with the photosensitive drum 51 may be additionally provided.

  Returning to FIG. 1, the intermediate transfer unit 6 receives the primary transfer of the toner image from the photosensitive drum 51, performs the secondary transfer on the sheet, and attaches each primary drum provided to one of the photosensitive drums 51. It includes a transfer roller 61 (a total of four rollers 61k to 61m), an intermediate transfer belt 62, a driving roller 63, driven rollers 64 to 66, a secondary transfer roller 67, a belt cleaning device 68, and the like. Each primary transfer roller 61 is in contact with the intermediate transfer belt 62 so as to sandwich each of the photosensitive drums 51 and the endless intermediate transfer belt 62, and applies a transfer bias voltage for applying a transfer voltage in which alternating current and direct current are superimposed. The toner image is transferred to the intermediate transfer belt 62 by being connected to a portion (not shown).

  The intermediate transfer belt 62 is stretched around a primary transfer roller 61, a driving roller 63, and driven rollers 64 to 66, and is rotated by a driving roller 63 connected to a driving mechanism (not shown) such as a motor. Circulate clockwise. The driving roller 63 sandwiches the secondary transfer roller 67 and the intermediate transfer belt 62. The transfer of the toner image onto the paper will be described. In the transfer of the toner image (black, yellow, cyan, and magenta) formed by each image forming unit 5, a transfer bias is applied to each primary transfer roller 61, and the timing The images are sequentially transferred to the intermediate transfer belt 62 while being superimposed without deviation. The superimposed toner images are transferred onto a sheet by a secondary transfer roller 67 to which a predetermined voltage is applied. The residual toner on the intermediate transfer belt 62 after the secondary transfer is removed and collected by the belt cleaning device 68.

  The fixing unit 7 is disposed on the downstream side in the sheet conveyance direction, and fixes the toner image secondarily transferred to the sheet by heating and pressing. The fixing unit 7 is mainly composed of a fixing roller 71 having a built-in heat source and a pressure roller 72 pressed against the fixing roller 71 to form a nip. Then, the paper on which the toner image is transferred passes through the nip and is heated and pressurized, and as a result, the toner image is fixed on the paper. The fixed sheet is discharged to the discharge tray 42 and the image forming process is completed.

(Hardware configuration of MFP 1)
Next, a hardware configuration of the multifunction machine 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram illustrating an example of a hardware configuration of the multifunction machine 1 according to the embodiment of the present invention.

  As shown in FIG. 3, the multifunction machine 1 according to the present embodiment includes a control unit 8 on an internal control board. The control unit 8 is a part that controls each unit of the multifunction machine 1. Further, regarding the present invention, the control unit 8 is provided in the apparatus main body, communicates with a memory mounted on the exchange unit, receives data read from the memory, and transmits data to be written to the memory. In addition to the CPU 81, the control unit 8 can include storage devices such as a program ROM 82, a backup memory 83, a RAM 84, and an HDD 85 (Hard disk drive).

  First, the CPU 81 is a central processing unit, expands a program or data stored in the program ROM 82 or the like in the RAM 84 or the like, and controls or calculates each part of the multifunction machine 1 based on the expanded control program or data. For example, a flash ROM can be used as the program ROM 82, and the program ROM 82 stores programs and data related to the multifunction machine 1 such as a startup program when the power is turned on.

  Further, for example, an EEPROM (Electrically Erasable Programmable ROM) can be used as the backup memory 83. Data relating to the system of the multifunction device 1, data relating to control of the multifunction device 1, setting data of the multifunction device 1 by the user, and the like. Can be stored in a nonvolatile manner. Further, regarding the present invention, the backup memory 83 stores data indicating a communication format in which communication can be performed in communication between the control unit 8 and the memory mounted on the exchange unit (details will be described later). The RAM 84 is a storage device as a work space in which various programs and data such as a control program, control data, and image data are developed to be referred to by the CPU 81. The HDD 85 is, for example, a large-capacity nonvolatile storage device that stores image data, and may store setting data and the like by the user.

  The control unit 8 is connected to, for example, the main body driving unit 91, the sensor input unit 92, the document conveying device 2, the image reading unit 3, the paper feeding unit 4a, the FAX controller 93, the printer controller 94, the I / F unit 95, and the like. Then, control is performed so that the multifunction device 1 operates appropriately.

  The main body drive unit 91 is connected to, for example, a main motor 91a, a fixing motor 91b, a conveyance motor 91c, and the like, and is arranged inside the multifunction device 1 based on instructions from the control unit 8, such as the photosensitive drum 51 and the developing roller 54a. It controls ON / OFF of each motor drive and rotation speed. The main motor 91a is connected to the rotating shafts of various rotating bodies such as the photosensitive drum 51 and the developing roller 54a via gears, clutches, and the like, for example, and is a motor for rotating various rotating bodies in the image forming unit 5 and the like. It is. The fixing motor 91 b is a motor for rotating a rotating body in the fixing unit 7 such as a heating roller and a pressure roller 72. Further, the transport motor 91c is a motor for rotating a sheet transporting rotating body such as a paper feed roller 41 or a transport roller pair 43 provided along the transport path 4b, and is driven by the transport motor 91c. The paper is transported at

  The sensor input unit 92 is connected to various sensors (for example, a paper conveyance sensor S1 and a temperature sensor S2) disposed inside and outside the multifunction machine 1 and operates various sensors in response to instructions from the control unit 8. The output results of various sensors are transmitted to the control unit 8. A plurality of sheet conveyance sensors S1 are provided in the apparatus, for example, near the upstream side of the registration roller pair 45 in the sheet conveyance direction, near the entrance or exit of the fixing unit 7, and at the sheet discharge port. For example, an optical sensor can be used as the sheet conveyance sensor S1, and the arrival and passage of the sheet can be known by the sheet conveyance sensor S1, thereby detecting a jam of the sheet. . For example, a thermistor is used as the temperature sensor S2, and one or a plurality of temperature sensors S2 are provided in the multifunction machine 1 such as the fixing unit 7. This temperature sensor S2 makes it possible to keep the temperature of the fixing unit 7 constant.

  Next, the FAX controller 93 is for performing transmission / reception of FAX, and is configured as, for example, one board (board) and connected to the modem 93a (the modem 93a may be included in the board). . As a result, the FAX function is realized, and as shown in FIG. 3, FAX communication is performed between the other FAX apparatus 200 and the multifunction peripheral 1 through a public line or the like.

  The printer controller 94 is a part that takes charge of control of printing (image formation) in the multifunction machine 1 and can be configured by a substrate on which a processor, a microcomputer, a semiconductor memory, an ASIC (not shown), and the like are mounted. In addition, the printer controller 94 can be provided with an image processing unit 94a that performs various image processing such as enlargement, reduction, and density change on the image data during printing. For example, the printer controller 94 transmits image data to be printed to the exposure device 52 and controls the operations of the image forming unit 5 and the exposure device 52.

  The image forming unit 5 is provided with the photosensitive drum 51, the developing device 54, and the like as described above (in FIG. 3, only a part of the image forming unit 5 is illustrated). A developing bias applying unit 55 that applies a developing bias in which a DC voltage of about several tens to several hundreds V and an alternating voltage of Vpp of several hundreds to several kV are superimposed on the developing roller 54a of the developing device 54 is Provided for each forming unit 5.

  The I / F unit 95 (interface unit) includes various connectors and sockets, and the multifunction device 1 is communicably connected to, for example, a terminal 100 (for example, a PC) via the network. Further, the I / F unit 95 may include a connector for directly connecting the terminal 100 and the multifunction device 1 with a cable. Thereby, the multifunction device 1 can receive image data and the like from the terminal 100 and perform printing (printer function). Further, the image data read by the image reading unit 3 can be transmitted to the terminal 100 (scanner function).

  As described above, the photosensitive drum 51 is unitized and has a nonvolatile memory M1 (for example, EEPROM) as shown in FIG. Since the memory M1 of each photoconductive drum 51 performs printing with high image quality, it can store voltage control data related to the voltage for charging the photoconductive drum 51 during printing. Further, since it is necessary for managing the life, it is possible to store the cumulative number of printed sheets from the start of use to the present after being attached to the multifunction device 1.

  As described above, the developing device 54 is also unitized. As shown in FIG. 3, the developing device 54 also has a nonvolatile memory M2 (for example, an EEPROM). The memory M2 of the developing device 54 can store voltage control data that defines a developing bias applied to the developing roller 54a during printing so that printing can be performed with high image quality. In addition, it is possible to store the cumulative number of printed sheets from the start of use to the present after being attached to the multifunction device 1 necessary for life management.

  Note that the memory M1 of the photosensitive drum 51 and the memory M2 of the developing device 54 are the same type of non-volatile storage device such as an EEPROM, and the present invention covers both the memory M1 and the memory M2. Therefore, for simplification of description, in the following description, the symbols “1” and “2” are omitted and simply referred to as the memory M unless otherwise specified.

  As described above, the multifunction peripheral 1 according to the present embodiment includes a replaceable exchange unit attached to the apparatus main body, such as the developing device 54 and the photosensitive drum 51, and a memory that is mounted on the replaceable unit and stores data in a nonvolatile manner. M. Then, the control unit 8 communicates with each memory M to acquire data on the voltage applied to each photosensitive drum 51 and each developing roller 54a and information on the total number of printed sheets from the start of use for each replacement unit. To do. Further, the control unit 8 adds the number of printed pages to the data of the cumulative number of printed sheets acquired from the memory M, and transmits the data indicating the updated cumulative number of printed sheets to each memory M. Remember me.

(Communication between the control unit 8 and each memory M)
Next, an outline of communication between the control unit 8 and each memory M will be described with reference to FIG. FIG. 4 is a block diagram for explaining an outline of communication between the control unit 8 and each memory M according to the embodiment of the present invention. Here, in this description, an example in which the memory M and the CPU 81 of the control unit 8 communicate with each other will be described. However, a communication control chip (controller) is provided between the CPU 81 and the memory M so that the processing load on the CPU 81 is reduced. You may make it reduce. 4 shows the distinction between the memory M1 and the memory M2, and k, y, c, and m, which are color identification codes of the image forming units 5, are attached to the respective photoconductors of the image forming units. Each memory M is connected to the drum 51 and each developing device 53 so as to be communicable with the control unit 8.

  In this example, the communication between the CPU 81 and each memory M is basically performed by two signal lines. In FIG. 4, a signal line extending to the left side of the CPU 81 is a clock signal line CL for transmitting a clock signal from the CPU 81 to each memory M. In other words, the CPU 81 supplies a clock signal to each memory M.

  On the other hand, in FIG. 4, a signal line extending to the right side of the CPU 81 is a data signal line DA for performing communication between each memory M and the CPU 81. Data exchange between the CPU 81 and each memory M is performed by serial bidirectional communication using the data signal line DA using a clock signal. As described above, in the multi-function device 1 of the present embodiment, the plurality of memories M are bus-connected. Each memory M is assigned a unique address, and the CPU 81 transmits the unique address to the data signal line DA to designate the memory M to be communicated. The designated memory M communicates with the control unit 8.

(Different capacity of each memory M and specific communication method between the control unit 8 and each memory M)
Next, a specific communication method between the control unit 8 and each memory M according to the embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 5 is an explanatory diagram showing an example of a communication format between the control unit 8 and each memory M according to the embodiment of the present invention.

  First, as described above, the memory M is mounted on a unit (hereinafter referred to as a “replacement unit”) that is replaced when the service life is reached, such as the photosensitive drum 51 and the developing device 54. Then, the memory M can store the total number of printed sheets that have been installed in the multifunction device 1 from the viewpoint of life and quality control, such as knowing that the life has been reached. Further, voltage control data indicating an appropriate voltage to be applied to the replacement unit can be stored. In addition, compatible model data indicating a compatible model of the replacement unit may be stored, and the control unit 8 may confirm whether the replacement unit is appropriate. Also, when a failure occurs before the end of its service life, data related to origin such as the factory and serial number where the replacement unit was manufactured or recycled should be stored in the memory M from the viewpoint of confirming the history of the replacement unit. You can also.

  Here, conventionally, the capacity of the memory M mounted in the replacement unit is unified regardless of the photosensitive drum 51, the developing device 54, and the like. That is, the memory M mounted on the photosensitive drum 51, the developing device 54, etc. is the same type. This unification makes it possible to share devices used for manufacturing replacement units, and there are merits in various points such as manufacturing cost and manufacturing part management. Therefore, only one type of communication format (communication method) between the control unit 8 and each memory M needs to be prepared.

  In addition, since each replacement unit to be mounted on the image forming apparatus such as the multifunction machine 1 is specified and is clearly identified at the time of manufacture, the memory M mounted on each replacement unit has one model. Just store the data.

  On the other hand, image forming apparatuses such as the multifunction machine 1 may be developed in series with some differences in functions and configurations while sharing the basic configurations such as the photosensitive drum 51 and the developing device 54. is there. For example, in order to meet the demands of users who want a high-performance and high-performance image forming device even though the price is high, it is necessary to prepare a high-end model that pursues functions and performance. It is also necessary to prepare a low-end model in order to meet the desires of users who think that cheaper is better even if they are not abundant. In some cases, improvements may be made to some of the previous models, and improved models reflecting the addition of functions and user requests may be sold later. In some cases, the multifunction peripheral 1 may be sold as a printer by omitting the document feeder 2 and the image reading unit 3. As described above, due to various circumstances, the image forming apparatus may be serialized by preparing a plurality of models sharing parts.

  In each model developed in series, for example, a difference may be provided in image forming conditions such as a voltage value applied to the developing roller 54a while using the photosensitive drum 51 and the developing device 54 of the same type. Accordingly, the voltage control data stored in the memory M differs depending on the model. The replacement unit itself can be used with each model developed in the series, but it is unclear which model will eventually be installed in the replacement unit that is sold separately and distributed to the market due to replacement at the end of its life. Therefore, it is necessary to store data for all models that can be mounted, such as voltage control data for each model, in the memory M mounted on the replacement unit.

  In this case, it may be necessary to increase the capacity of the memory M of the replacement unit that is sold separately than the memory M of the replacement unit that is mounted when the image forming apparatus is produced. Further, there may be more models developed in series than originally planned, and the amount of data for storing data for all compatible models may expand in the memory M of the replacement unit sold separately.

  If the capacities of the memory M of the exchange unit are made different, two or more types of communication formats may be required in communication between the control unit 8 and each memory M. However, conventionally, since only one type of communication format is usually prepared, an access error occurs in communication between the control unit 8 and the memory M. In other words, the control unit 8 cannot recognize the memory M of the replacement unit such as the newly installed photosensitive drum 51 or the developing device 54.

  Therefore, in the MFP 1 according to the present embodiment, when an access error occurs in the communication between the control unit 8 and each memory M, the control unit 8 switches the communication format to perform communication with each memory M, and the access error There is a feature in the point of canceling. A communication format between the control unit 8 and each memory M and switching of the communication format will be described with reference to FIG. It is assumed that each memory M of the present embodiment has an address attached to data in units of 8 bits (1 byte).

  First, the “START” and “STOP” bits in FIG. 5 (shown by shading in FIG. 5) indicate that when the clock signal supplied by the CPU 81 is High, the CPU 81 sets the state of the data signal line DA to “High → Low” or It is a bit for notifying the start and end of communication from the CPU 81 to each memory M by setting “Low → High” or the like. Each memory M knows the start and end of communication from these bits. The “ACK” bit is a bit transmitted by the data receiving device (that is, the CPU 81 or the memory M) as to whether or not the data has been normally received. (ACK) to the side. On the other hand, if it is High, it indicates to the transmitting side that there was an abnormality in reception (NOACK).

  Next, a basic communication format between the control unit 8 and each memory M of the MFP 1 according to the present embodiment will be described. In the communication format of the present embodiment, data is roughly classified into three types: a control part A, an address part AD, and a data part D. The control unit A, address unit AD, and data unit D are basically configured in units of 8 bits (byte units) in this embodiment.

  The control unit A is basically a part transmitted by the CPU 81 (each memory M is a receiving side). For example, the memory M with which the CPU 81 communicates is determined by High and Low of each bit of A6 to A0 shown in FIG. specify. In other words, the CPU 81 transmits the control unit A to all the memories M to be communicated, and causes the memory M to recognize that it is a communication object. The R / W shown in FIG. 5 is a bit for the CPU 81 to instruct whether to perform reading (READ) or writing (WRITE) to the designated memory M. For example, when R / W is High, it means reading, and when Low, it means writing data into the memory M.

  The address part AD is also a part that is basically transmitted by the CPU 81, and is a part that specifies which data in each memory M is to be read and written. The data part D indicates data with High and Low of each bit of D7 to D0, and the R / W bit changes whether the memory M transmits data or the CPU 81 transmits data. When the R / W bit is R (read), the memory M specified by the control unit A transmits the data of the address specified by the address unit AD as the data unit D toward the data signal line DA, and the CPU 81 Receive. On the other hand, when the R / W bit is W (write), the CPU 81 transmits data to the data signal line DA as the data portion D and is received by the memory M designated by the control portion A, and then designated by the address portion AD. Data is written (updated) to the specified address. Thus, in the communication between the control unit 8 and each memory M of this embodiment, the control unit 8 (CPU 81) takes the initiative.

Here, each memory M of the present embodiment stores data in units of 1 byte, and the address portion AD of the communication format shown in FIG. 5A is 8 bits. Therefore, the communication format shown in FIG. The address of data in each memory M having a capacity of the memory M of less than 256 bytes (2 ⁸ ) can be designated. However, when the capacity of the memory M of the newly installed exchange unit is increased to 256 bytes or more, the communication format shown in FIG. 5A does not have enough bits for the address part AD for data designation. .

  Therefore, the control unit 8 of the present embodiment has caused an access error, for example, there is no response from the memory M even if communication is performed in the communication format shown in FIG. 5A (the address unit AD is 8 bits). In this case, in order to cope with the increase in the capacity of the memory M of the exchange unit, as shown in FIG. 5B, 1 byte of the address part AD is added to switch the communication format. For example, in the example shown in FIG. 5B, the data in each memory M can be specified if the memory M has a capacity of 256 bytes or more and less than 64 kbytes.

  If an access error occurs even in the communication format shown in FIG. 5B, an address part AD is further added in bytes as shown in FIG. 5C, and the control unit 8 switches the communication format. Also good. In the example of the communication format in FIG. 5C, data in each memory M can be designated for the memory M having a capacity of 64k or more. Note that ADx in FIG. 5C indicates the most significant bit in the designation of data in each memory M. Here, x = 8n−1 (where n = 3, 4, 5,... Integer). In the case of FIG. 5C, ACK is inserted for each byte in the address part AD.

  To summarize the switching of the communication format, the control unit 8 (CPU 81) performs communication with each memory M in the communication format shown in FIG. 5A, for example, and if an access error occurs, FIG. Switch to the communication format shown in (2) and try again. If an access error still occurs, the communication format shown in FIG. As described above, the control unit 8 switches the communication format by changing the number of bits of the address unit AD for designating the address in the memory M.

(Communication control between the control unit 8 and each memory M)
Next, an example of communication control between the control unit 8 and each memory M according to the embodiment of the present invention will be described. FIG. 6 is a flowchart showing an example of communication control between the control unit 8 and each memory M according to the embodiment of the present invention.

  First, the start of FIG. 6 is a time when the control unit 8 communicates with each memory M. For example, the case where the control unit 8 confirms the connected exchange unit when the main power of the multifunction device 1 is turned on is applicable.

  Next, referring to the backup memory 83, the control unit 8 confirms whether the communication format of the memory M to be communicated is stored (step # 1). Details of the backup of the communication format will be described later (see step # 8). Next, if the communication format is stored (Yes in step # 1), communication is performed in the stored communication format (step # 2). On the other hand, if the communication format is not stored (No in step # 1), communication is performed using the communication format of the memory M having the smallest capacity (step # 3). That is, as shown in FIG. 5A, communication is performed using a 1-byte address part AD.

  Next, the control unit 8 confirms whether an access error has occurred (step # 4). If there is no access error (No in step # 4), the memory M is set to perform communication in the same communication format until the power is turned off (step # 5). On the other hand, if there is an access error (Yes in step # 4), the controller 8 increases the address part AD by 1 byte, switches the communication format, and communicates with the memory M (step # 6).

  Next, the control unit 8 confirms whether an access error has occurred (step # 7). If there is no access error (No in step # 7), it is determined that the capacity of the memory M mounted in the replacement unit has changed due to replacement of the photosensitive drum 51 and the developing device 54, and the control unit 8 performs communication. With respect to the memory M that has been subjected to the above, data indicating a communicable communication format is stored and updated in the backup memory 83 (step # 8). That is, the control unit 8 stores in the backup memory 83 data indicating the communication format that has been able to communicate with the memory M, and determines the communication format with the memory M with reference to the backup memory 83 (step # 2). ). As a result, after the main power is turned on next time, the control unit 8 can immediately communicate in a communicable communication format without switching the communication format, and the processing time is shortened. Thereafter, the process proceeds to step # 5.

  On the other hand, if there is an access error (Yes in step # 7), the control unit 8 confirms whether the address part AD has reached a predetermined number of bytes (step # 9). This is a process for stopping the increase in bytes of the address part AD within a certain range. The predetermined number of bytes is, for example, 2 bytes or more if the minimum number of bytes of the address part AD is 1 byte in the communication format, and may be 3 bytes or 4 bytes. As described above, the predetermined number of bytes can be arbitrarily determined, and can be determined in consideration of the amount of data stored in the memory M. That is, when an access error to the memory M occurs, the control unit 8 performs communication with the memory M by switching to one or a plurality of different communication formats.

  If the predetermined number of bytes has not been reached (No in step # 9), the process returns to step # 6. That is, the number of bytes in the address part AD is increased until no access error occurs. On the other hand, if the predetermined number of bytes has been reached (Yes in step # 9), it is confirmed whether reaching the predetermined number of bytes has been repeated n times (step # 10). If it has not been repeated n times (No in step # 10), the process returns to step # 3, and retry is executed for all communication formats. In other words, if the access error is not resolved even after switching to one or a plurality of different communication formats and performing communication with the memory M, the control unit 8 performs a retry to try communication with all communication formats again.

  Here, n times of repetition is the number of retries. Since an access error can be caused not only by a communication format mismatch but also by other factors such as noise, it is clarified whether the access error is caused by a communication format mismatch or not by n retries. . The number of retries may be, for example, about 5 to 10 times (that is, n = 5 to 10).

  On the other hand, if it has been repeated n times (Yes in step # 10), the access error will not be resolved even if the retries are performed a plurality of times, and the communication port abnormality or signal line abnormality of the control unit 8 or the memory M will not occur. It can be judged that the probability is high. Therefore, the control unit 8 displays on the operation panel 1a or the like that there is an abnormality in the memory M of the replacement unit (step # 11). That is, if the access error continues even if the control unit 8 switches to one or a plurality of different communication formats and communicates with the memory M, the control unit 8 displays on the display unit such as the operation panel 1a that the memory M is abnormal. . At this time, the operation of the multifunction device 1 may be stopped and a new job input may not be accepted. Thereby, it is clarified that the cause of the access error is not the difference in the communication format due to the change in the capacity of the memory M.

  As described above, according to the configuration of the present embodiment, an access error occurs because the capacity of the memory M mounted in the replacement unit (for example, the developing device 54 and the photosensitive drum 51) is changed due to the unit replacement, and the communication format is different. Even if this occurs, the control unit 8 switches the communication format and communicates with the memory M, so that the control unit 8 of the apparatus main body can communicate with the memory M. Accordingly, since the memories M have different capacities, the image forming apparatus (for example, the multifunction device 1) is not stopped due to the continued access error state.

  Further, the control unit 8 determines the communication format with the memory M of the exchange unit with reference to the backup memory 83. Therefore, once communication is possible, the control unit 8 switches the communication format and confirms whether communication is possible. There is no need. Therefore, the time required for accessing the memory M of the replacement unit, such as when the main power is turned on, can be shortened, and the warm-up process until the image forming apparatus can be used can be shortened.

  An access error in communication with the memory M may occur due to factors such as noise. Since the control unit 8 performs a retry process to check whether communication with the memory M is possible, the control unit 8 And reliability in communication with the memory M can be improved. In addition, after clarifying that an access error has occurred due to a factor other than the capacity of the memory M of the replacement unit, it is possible to notify the user or the like of the occurrence of an abnormality such as a failure. Therefore, the user can easily find out the cause of the access error and can easily eliminate the access error. Also, the number of bits for addressing data in the memory M may differ depending on the capacity of the memory M of the exchange unit. According to this configuration, even when the number of bits for addressing is different, the control is performed. The unit 8 can communicate with the memory M.

  Here, another embodiment will be described. In the above-described embodiment, the photosensitive drum 51 and the developing device 54 are exemplified as the replacement unit. However, other replaceable wear such as a toner container (developer container) that supplies toner to the developing device 54 is used. The present invention can be applied if the memory M is mounted on the product or component.

  In the above embodiment, an example in which the communication format is changed by changing the number of bytes of the address part AD is shown. However, when the order of the control part A, the address part AD, the data part D, etc. is different, For example, the control unit 8 may be able to switch to a greatly different communication format.

  The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used in an image forming apparatus including a replaceable unit (exchange unit) such as the photosensitive drum 51 and the developing roller 54a.

1 MFP (image forming device)
1a Operation panel (display unit)
8 Control unit 83 Backup memory 51 Photosensitive drum (one of the exchange units)
54 Developer (one of the replacement units)
M (M1, M2) memory

Claims (3)

An exchange unit that is attached to the main unit and can be exchanged;
A memory mounted in the exchange unit and storing data in a nonvolatile manner;
A backup memory for storing data indicating a communication format capable of communicating with the memory in the apparatus body;
A control unit provided in the apparatus main body and communicating with the memory;
The control unit communicates with the stored communication format if data indicating the communication format that can communicate with the memory is stored in the backup memory, and an access error to the memory occurs. Switch to one or a plurality of different communication formats to communicate with the memory, change the number of bytes in the address portion for specifying the address in the memory, switch the communication format,
Without access error in switched communication format, images forming device you characterized by storing data indicating the communication format can communicate with the memory in the backup memory. If the access error is not resolved even after switching to one or a plurality of different communication formats and performing communication with the memory, the control unit again performs a retry to try communication in all communication formats. Item 2. The image forming apparatus according to Item 1 . Having a display for displaying the status of the device;
The control unit causes the display unit to display that the memory is abnormal when an access error continues even after switching to one or a plurality of different communication formats and performing communication with the memory. Item 3. The image forming apparatus according to Item 1 or 2 .

Images