Image forming apparatus

Abstract

To provide an image forming apparatus that can suppress an increase in the number of ports in the control unit and an increase in the number of substrate types. [Solution] The image forming apparatus comprises a plurality of drum units 11, a plurality of developing units 12, a control unit 61 that accesses non-volatile memory 51 provided in each of the plurality of drum units 11 and the plurality of developing units 12, and a switching unit 71 that switches the connected object connected to the control unit 61 via a first communication line L1 between a plurality of non-volatile memory 51 corresponding to the plurality of drum units 11 and a plurality of non-volatile memory 51 corresponding to the plurality of developing units 12.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] There has been known an image forming apparatus including a plurality of units such as a developing unit used for forming an image. There has also been known the image forming apparatus including a control unit capable of accessing a non-volatile storage section provided in each of the units (see, for example, Patent Document 1).

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] Incidentally, in the image forming apparatus, by connecting the control unit and the plurality of storage sections via a single communication line, an increase in the number of ports of the control unit can be suppressed as compared with a configuration in which the communication line is provided for each of the storage sections.

[0005] Here, in a configuration in which the control unit and the plurality of storage sections are connected via the single communication line, it is necessary to assign different addresses to each of the storage sections. Therefore, it is necessary to change the circuit configuration of the substrate for each substrate on which the storage section is mounted, which increases the number of types of substrates included in the image forming apparatus.

[0006] An object of the present invention is to provide an image forming apparatus capable of suppressing an increase in the number of ports of a control unit and also suppressing an increase in the number of types of substrates.

Means for Solving the Problem

[0007] An image forming apparatus according to one aspect of the present invention comprises a plurality of units, a control unit, and a switching unit. The plurality of units share the execution of part or all of the image forming process. The control unit accesses a non-volatile storage unit provided in each of the units. The switching unit switches the connected object, which is connected to the control unit via a single communication line, between the plurality of storage units corresponding to the plurality of units. [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress an increase in the number of ports in the control unit and an increase in the number of types of substrates. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view showing the configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view showing the configuration of the image forming section of an image forming apparatus according to an embodiment of the present invention. [Figure 3] Figure 3 shows the communication path between the control unit and a plurality of non-volatile memories in an image forming apparatus according to an embodiment of the present invention. [Figure 4] Figure 4 shows the correspondence between the switch switching signal and the connected object connected to the control unit, and the addresses assigned to each non-volatile memory in an image forming apparatus according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] The embodiments of the present invention will be described below with reference to the attached drawings. Note that the following embodiments are merely examples of the present invention and do not limit the technical scope of the present invention.

[0011] [Configuration of the image forming apparatus 100] First, with reference to Figure 1, the configuration of the image forming apparatus 100 according to an embodiment of the present invention will be described.

[0012] The image forming apparatus 100 is a multifunction device having multiple functions, including a scanning function for reading an image from a document, a printing function for forming an image based on the image data, as well as a fax function and a copying function. The present invention may also be applied to image forming apparatuses such as printers, fax machines, and copiers.

[0013] As shown in Figure 1, the image forming apparatus 100 comprises an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, and an operation display unit 5.

[0014] The ADF1 transports the document to be scanned by the scanning function. The ADF1 comprises a document setting section, multiple transport rollers, a document holder, and a paper output section.

[0015] The image reading unit 2 implements the scanning function. The image reading unit 2 comprises a document glass, a light source, multiple mirrors, an optical lens, and a CCD (Charge Coupled Device).

[0016] The image forming unit 3 implements the printing function. Specifically, the image forming unit 3 forms an image on the sheet supplied from the paper feeding unit 4 according to the electrophotographic method. The image forming unit 3 uses four toners, Y (yellow), M (magenta), C (cyan), and K (black), to form a color image.

[0017] The paper feeding unit 4 supplies sheets to the image forming unit 3. The paper feeding unit 4 includes a paper feed cassette, a manual feed tray, and a plurality of transport rollers.

[0018] The operation display unit 5 is the user interface of the image forming apparatus 100. The operation display unit 5 has a display unit such as a liquid crystal display that displays various information in response to control instructions from a main control unit (not shown), and an operation unit such as operation keys or a touch panel that inputs various information to the main control unit in response to user operations.

[0019] [Configuration of the image forming unit 3] Next, the configuration of the image forming section 3 will be described with reference to FIGS. 1 to 3. Here, FIG. 2 is a cross-sectional view showing the configuration of four drum units 11, four developing units 12, and a transfer unit 14. In FIG. 3, each of the drum units 11 and each of the developing units 12 are indicated by broken lines.

[0020] As shown in FIGS. 1 and 2, the image forming section 3 includes four drum units 11 (11Y, 11M, 11C, 11K) corresponding to four printing colors, four developing units 12 (12Y, 12M, 12C, 12K) corresponding to four printing colors, two optical scanning units 13 (13A, 13B), a transfer unit 14, a fixing unit 15, and a paper discharge tray 16. The image forming section 3 also includes a control section 61 shown in FIG. 3. In the image forming section 3, an electrophotographic image forming process (a charging step, an exposure step, a developing step, a transfer step, and a fixing step) is shared and performed by the four drum units 11, the four developing units 12, the two optical scanning units 13, the transfer unit 14, and the fixing unit 15. Note that the image forming process of the present invention may also include a charge elimination step of eliminating charge from the photosensitive drum 21, a first cleaning step of cleaning the photosensitive drum 21, a second cleaning step of cleaning the intermediate transfer belt 41, and the like.

[0021] Each of the drum units 11 performs the charging step in the electrophotographic image forming process.

[0022] As shown in FIG. 2, each of the drum units 11 includes a photosensitive drum 21, a charging roller 22, and a drum cleaning section 23.

[0023] An electrostatic latent image is formed on the surface of the photosensitive drum 21. The photosensitive drum 21 receives rotational driving force supplied from a motor (not shown) and rotates in a drum rotation direction D1 shown in FIG. 2. Thereby, the photosensitive drum 21 conveys the electrostatic latent image formed on the surface thereof. The charging roller 22 charges the surface of the photosensitive drum 21.

[0024] Each of the optical scanning units 13 performs the exposure step, which is part of the image formation process in the electrophotographic method.

[0025] Specifically, the optical scanning unit 13A emits light based on image data toward drum units 11Y and 11M. The optical scanning unit 13B also emits light based on image data toward drum units 11C and 11K. The light emitted from optical scanning units 13A and 13B irradiates four pre-charged photoreceptor drums 21. This forms an electrostatic latent image on each of the photoreceptor drums 21.

[0026] Each of the developing units 12 performs the developing step, which is part of the image formation process of the electrophotographic method.

[0027] Specifically, the developing unit 12Y uses yellow (Y) toner to develop the electrostatic latent image formed on the photoreceptor drum 21 of the drum unit 11Y. As a result, a yellow (Y) toner image is formed on the surface of the photoreceptor drum 21 of the drum unit 11Y.

[0028] Furthermore, the developing unit 12M develops the electrostatic latent image formed on the photoreceptor drum 21 of the drum unit 11M using magenta (M) toner. As a result, a magenta (M) toner image is formed on the surface of the photoreceptor drum 21 of the drum unit 11M.

[0029] Furthermore, the developing unit 12C uses cyan toner to develop the electrostatic latent image formed on the photoreceptor drum 21 of the drum unit 11C. As a result, a cyan toner image is formed on the surface of the photoreceptor drum 21 of the drum unit 11C.

[0030] Furthermore, the developing unit 12K uses K (black) toner to develop the electrostatic latent image formed on the photoreceptor drum 21 of the drum unit 11K. As a result, a K (black) toner image is formed on the surface of the photoreceptor drum 21 of the drum unit 11K.

[0031] Each developing unit 12 is supplied with toner from a toner container 31 (see Figure 1) that contains toner of the corresponding color.

[0032] The transfer unit 14 performs the transfer step, which is part of the image formation process of the electrophotographic method.

[0033] As shown in Figure 2, the transfer unit 14 includes an intermediate transfer belt 41, a drive roller 42, a tension roller 43, four primary transfer rollers 44 (44Y, 44M, 44C, 44K) corresponding to four printing colors, a secondary transfer roller 45, and a belt cleaning unit 46.

[0034] The intermediate transfer belt 41 is an endless belt member. The intermediate transfer belt 41 is stretched at a predetermined tension by the drive roller 42 and the tension roller 43. The intermediate transfer belt 41 rotates in the belt rotation direction D2 shown in Figure 2 as the drive roller 42 rotates in response to the rotational driving force supplied from a motor (not shown).

[0035] The primary transfer roller 44Y transfers the yellow (Y) toner image formed on the photoreceptor drum 21 of the drum unit 11Y to the intermediate transfer belt 41.

[0036] The primary transfer roller 44M transfers the magenta (M) toner image formed on the photoreceptor drum 21 of the drum unit 11M to the intermediate transfer belt 41.

[0037] The primary transfer roller 44C transfers the cyan toner image formed on the photoreceptor drum 21 of the drum unit 11C to the intermediate transfer belt 41.

[0038] The primary transfer roller 44K transfers the K (black) toner image formed on the photosensitive drum 21 of the drum unit 11K to the intermediate transfer belt 41.

[0039] The four primary transfer rollers 44 transfer four toner images onto the intermediate transfer belt 41 in a superimposed manner. As a result, a color toner image is formed on the intermediate transfer belt 41.

[0040] The secondary transfer roller 45 transfers the color toner image formed on the surface of the intermediate transfer belt 41 to the sheet supplied from the paper feeding unit 4.

[0041] Each drum cleaning unit 23 in the drum unit 11 cleans the surface of the photoreceptor drum 21 after the toner image has been transferred by the transfer unit 14.

[0042] The belt cleaning unit 46 cleans the surface of the intermediate transfer belt 41 after the toner image has been transferred by the secondary transfer roller 45.

[0043] The fixing unit 15 performs the fixing step of the electrophotographic image formation process. In other words, the fixing unit 15 fixes the toner image transferred to the sheet by the transfer unit 14 to the sheet.

[0044] The output tray 16 ejects a sheet on which the toner image has been fixed by the fuser unit 15.

[0045] In the image forming apparatus 100, each drum unit 11 is detachably attached to the housing of the image forming apparatus 100.

[0046] Furthermore, in the image forming apparatus 100, each drum unit 11 is provided with a substrate 52 (see Figure 3) on which a non-volatile memory 51 (see Figure 3) is mounted. The non-volatile memory 51 of the drum unit 11 has information related to the drum unit 11 pre-stored in it. In addition, information such as the operating time of the drum unit 11 is recorded in the non-volatile memory 51 of the drum unit 11. For example, the non-volatile memory 51 is an EEPROM (registered trademark). The non-volatile memory 51 is an example of a non-volatile storage unit of the present invention.

[0047] Furthermore, in the image forming apparatus 100, each of the developing units 12 is detachably attached to the housing of the image forming apparatus 100.

[0048] Furthermore, in the image forming apparatus 100, each developing unit 12 is provided with a substrate 52 (see Figure 3) on which a non-volatile memory 51 (see Figure 3) is mounted. The non-volatile memory 51 of the developing unit 12 has information related to the developing unit 12 pre-stored in it. In addition, information such as the operating time of the developing unit 12 is recorded in the non-volatile memory 51 of the developing unit 12.

[0049] The drum unit 11 and the developing unit 12 are examples of multiple units that share and perform a part of the image formation process in the present invention.

[0050] The control unit 61 controls each part of the image forming unit 3. The control unit 61 includes a CPU, ROM, and RAM. The CPU is a processor that performs various arithmetic operations. The ROM is a non-volatile memory device in which information such as control programs for causing the CPU to perform various operations is stored in advance. The RAM is a volatile or non-volatile memory device used as a temporary memory (work area) for the various operations performed by the CPU. The CPU controls each part of the image forming unit 3 by executing various control programs stored in advance in the ROM. The control unit 61 may also be composed of electronic circuits such as an integrated circuit (ASIC). Furthermore, the control unit 61 may also be the main control unit that comprehensively controls the image forming apparatus 100.

[0051] The control unit 61 accesses each of the non-volatile memories 51 of the drum unit 11. Specifically, the control unit 61 records the operating time of the drum unit 11 in the non-volatile memory 51 of the drum unit 11. The control unit 61 also reads the information stored in the non-volatile memory 51 of the drum unit 11. For example, the control unit 61 predicts the replacement timing of the drum unit 11 based on the information read from the non-volatile memory 51 of the drum unit 11.

[0052] Furthermore, the control unit 61 accesses each of the non-volatile memories 51 of the developing unit 12. Specifically, the control unit 61 records the operating time of the developing unit 12 in the non-volatile memory 51 of the developing unit 12. The control unit 61 also reads information stored in the non-volatile memory 51 of the developing unit 12. For example, the control unit 61 predicts the replacement timing of the developing unit 12 based on the information read from the non-volatile memory 51 of the developing unit 12.

[0053] The substrate 52 may also be provided in each of the optical scanning units 13, the transfer unit 14, or the fixing unit 15. In this case, the control unit 61 only needs to access the non-volatile memory 51 of each of the optical scanning units 13, the non-volatile memory 51 of the transfer unit 14, or the non-volatile memory 51 of the fixing unit 15.

[0054] By the way, in the image forming apparatus 100, by connecting the control unit 61 and a plurality of non-volatile memories 51 with a single communication line, it is possible to suppress an increase in the number of ports of the control unit 61 compared to a configuration in which a separate communication line is provided for each non-volatile memory 51.

[0055] In this configuration, where the control unit 61 and multiple non-volatile memories 51 are connected by a single communication line, it is necessary to assign a different address to each non-volatile memory 51. Therefore, the circuit configuration of each substrate 52 on which the non-volatile memory 51 is mounted must be changed, increasing the number of types of substrates 52 included in the image forming apparatus 100 (the number of substrates 52 with different circuit configurations).

[0056] In contrast, the image forming apparatus 100 according to an embodiment of the present invention can suppress an increase in the number of ports of the control unit 61 and an increase in the number of types of substrates 52, as will be explained below.

[0057] Specifically, as shown in Figure 3, the image forming unit 3 includes a switching unit 71.

[0058] Furthermore, as shown in Figure 3, the four non-volatile memories 51 corresponding to the four drum units 11 are connected to the switching unit 71 via the second communication line L2 (see Figure 3).

[0059] Furthermore, as shown in Figure 3, the four non-volatile memories 51 corresponding to the four developing units 12 are connected to the switching unit 71 via the third communication line L3 (see Figure 3).

[0060] Furthermore, as shown in Figure 3, the control unit 61 is connected to the switching unit 71 via the first communication line L1. The control unit 61 is also connected to the switching unit 71 via the switching signal line L4 (see Figure 3), which is used to input the switch switching signal to the switching unit 71. The switch switching signal is a 1-bit signal.

[0061] Each of the first communication line L1, the second communication line L2, and the third communication line L3 includes a data line and an address line.

[0062] The switching unit 71 switches the connected object, which is connected to the control unit 61 via a single first communication line L1 (see Figure 3), between four non-volatile memories 51 corresponding to four drum units 11 and four non-volatile memories 51 corresponding to four developing units 12.

[0063] Specifically, the switching unit 71 is a switch IC that can switch the connected object connected to the first communication line L1 between the second communication line L2 and the third communication line L3 in accordance with the switch switching signal input from the control unit 61.

[0064] For example, the switching unit 71 connects the first communication line L1 and the second communication line L2 when the switch switching signal input from the control unit 61 is "0". This enables communication between the control unit 61 and the four non-volatile memories 51 corresponding to the four drum units 11 (see Figure 4).

[0065] Furthermore, the switching unit 71 connects the first communication line L1 and the third communication line L3 when the switch switching signal input from the control unit 61 is "1". This enables communication between the control unit 61 and the four non-volatile memories 51 corresponding to the four developing units 12 (see Figure 4).

[0066] This makes it possible to reduce the number of addresses required to specify the access target by half compared to a configuration in which the control unit 61 and the eight non-volatile memories 51 (see Figure 3) are connected by a single first communication line L1. In other words, it is possible to assign the same address to the non-volatile memory 51 of any drum unit 11 and the non-volatile memory 51 of any development unit 12. Therefore, it is possible to provide a circuit board 52 with the same circuit configuration (a circuit board of the same type 52) in any drum unit 11 and any development unit 12.

[0067] For example, in the image forming apparatus 100, the same address is assigned to the two non-volatile memories 51 corresponding to the drum unit 11 and the developing unit 12, which share the same printing color (see Figure 4). This reduces the error of assembling different types of substrates 52 during the manufacturing of the drum unit 11 or the developing unit 12, compared to a configuration in which different addresses are assigned to the two non-volatile memories 51 corresponding to the drum unit 11 and the developing unit 12, which share the same printing color.

[0068] [Other embodiments] The unit of the present invention may also be a light scanning unit 13 that performs an exposure process, a transfer unit 14 that performs a transfer process, or a fixing unit 15 that performs a fixing process. In other words, the plurality of units of the present invention may consist of two or more of the drum unit 11, developing unit 12, light scanning unit 13, transfer unit 14, and fixing unit 15.

[0069] Furthermore, the present invention may be applied to a monochrome image forming apparatus that does not have a color image forming function.

[0070] Furthermore, the image forming process of the present invention is not limited to an electrophotographic image forming process, but may also be an inkjet or other image forming process.

[0071] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0072] <Note 1> An image forming apparatus comprising: a plurality of units that each perform part or all of the image forming process; a control unit that accesses a non-volatile memory unit provided in each of the units; and a switching unit that switches the connected object, which is connected to the control unit via a single communication line, between a plurality of memory units corresponding to the plurality of units.

[0073] <Note 2> The image forming apparatus according to Appendix 1, wherein the image forming step includes a charging step and a developing step, the plurality of units include a drum unit that performs the charging step and a developing unit that performs the developing step, and the switching unit switches the connected object between the storage unit of the drum unit and the storage unit of the developing unit.

[0074] <Note 3> The image forming apparatus according to Appendix 2, comprising a plurality of drum units corresponding to a plurality of printing colors, and a plurality of developing units corresponding to a plurality of printing colors, wherein the switching unit switches the connected object between a plurality of storage units corresponding to a plurality of drum units and a plurality of storage units corresponding to a plurality of developing units.

[0075] <Note 4> The image forming apparatus according to Appendix 3, wherein the two storage units corresponding to the drum unit and the developing unit that share the same printing color are assigned the same address. [Explanation of symbols]

[0076] 1 ADF 2 Image reading unit 3 Image forming unit 4 Paper feed section 5 Operation display section 11 Drum Units 12 developing units 13 Optical scanning unit 14 Transfer Unit 15 Fixing Unit 16 Paper output tray 51 Non-volatile memory 52 circuit boards 61 Control Unit 71 Switching section 100 Image forming apparatus

Claims

1. Multiple units that share the task of performing part or all of the image formation process, A control unit that accesses a non-volatile memory unit provided in each of the aforementioned units, A switching unit that switches the connected object connected to the control unit via a single communication line between multiple storage units corresponding to multiple units, An image forming apparatus equipped with the following features.

2. The image forming process includes a charging process and a developing process. The plurality of units include a drum unit that performs the charging process and a developing unit that performs the developing process, The switching unit switches the connected object between the storage unit of the drum unit and the storage unit of the developing unit. The image forming apparatus according to claim 1.

3. Multiple drum units corresponding to multiple printing colors, Multiple developing units corresponding to multiple print colors, Equipped with, The switching unit switches the connected object between a plurality of storage units corresponding to a plurality of drum units and a plurality of storage units corresponding to a plurality of developing units. The image forming apparatus according to claim 2.

4. The two storage units corresponding to the drum unit and the developing unit, which share the same print color, are assigned the same address. The image forming apparatus according to claim 3.

Images